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Sample records for platelets enhance neutrophil

  1. Enhancement by platelets of oxygen radical responses of human neutrophils

    International Nuclear Information System (INIS)

    McCulloch, K.K.; Powell, J.; Johnson, K.J.; Ward, P.A.

    1986-01-01

    When human blood neutrophils were incubated with immune complexes (consisting of IgG antibody) in the presence of platelets, there was a 2 to 10 fold enhancement in the generation of O- 2 and H 2 O 2 . This enhancement phenomenon was proportional to the dose of immune complex added and the number of platelets present. The response was not agonist specific since similar enhancement also occurred with the following agonists: phorbol myristate acetate, opsonized zymosan particles and the chemotactic peptide N-formyl-met-leu-phe. The platelet related phenomenon of enhanced O- 2 generation could not be reproduced by the addition of serotonin, histamine or platelet-derived growth factor and was not affected by prior treatment of platelets with cyclooxygenase inhibitors (indomethacin, piroxicam) or lipoxygenase inhibitors (nafazatrom, BW755C or nordihydroguaiaretic acid). However, activation of platelets by thrombin caused release into the platelet supernatant fluid of a factor that, only in the presence of immune complexes, caused enhanced O- 2 responses to neutrophils. These data indicate that platelets potentiate oxygen radical responses of human neutrophils and suggest a mechanisms by which platelets may participate in tissue injury which is mediated by oxygen radical products from activated neutrophils

  2. Enhancement by platelets of oxygen radical responses of human neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, K.K.; Powell, J.; Johnson, K.J.; Ward, P.A.

    1986-03-01

    When human blood neutrophils were incubated with immune complexes (consisting of IgG antibody) in the presence of platelets, there was a 2 to 10 fold enhancement in the generation of O-/sub 2/ and H/sub 2/O/sub 2/. This enhancement phenomenon was proportional to the dose of immune complex added and the number of platelets present. The response was not agonist specific since similar enhancement also occurred with the following agonists: phorbol myristate acetate, opsonized zymosan particles and the chemotactic peptide N-formyl-met-leu-phe. The platelet related phenomenon of enhanced O-/sub 2/ generation could not be reproduced by the addition of serotonin, histamine or platelet-derived growth factor and was not affected by prior treatment of platelets with cyclooxygenase inhibitors (indomethacin, piroxicam) or lipoxygenase inhibitors (nafazatrom, BW755C or nordihydroguaiaretic acid). However, activation of platelets by thrombin caused release into the platelet supernatant fluid of a factor that, only in the presence of immune complexes, caused enhanced O-/sub 2/ responses to neutrophils. These data indicate that platelets potentiate oxygen radical responses of human neutrophils and suggest a mechanisms by which platelets may participate in tissue injury which is mediated by oxygen radical products from activated neutrophils.

  3. New strategy for sepsis: Targeting a key role of platelet-neutrophil interaction

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    Xu Wang

    2014-07-01

    Full Text Available Neutrophil and platelet are essential arms of the innate immune response. In sepsis, platelet abnormal activation as well as neutrophil paralysis are well recognized. For platelet, it is characterized by the contribution to disseminated intravascular coagulation (DIC and the enhanced inflammation response. In terms of neutrophil, its dysfunction is manifested by the impaired recruitment and migration to the infectious foci, abnormal sequestration in the remote organs, and the delayed clearance. More recently, it has been apparent that together platelet-neutrophil interaction can induce a faster and harder response during sepsis. This article focuses on the activation of platelet, dysfunction of neutrophil, and the interaction between them during sepsis and profiles some of the molecular mechanisms and outcomes in these cellular dialogues, providing a novel strategy for treatment of sepsis.

  4. Recruitment of classical monocytes can be inhibited by disturbing heteromers of neutrophil HNP1 and platelet CCL5

    NARCIS (Netherlands)

    Alard, Jean-Eric; Ortega-Gomez, Almudena; Wichapong, Kanin; Bongiovanni, Dario; Horckmans, Michael; Megens, Remco T. A.; Leoni, Giovanna; Ferraro, Bartolo; Rossaint, Jan; Paulin, Nicole; Ng, Judy; Ippel, Hans; Suylen, Dennis; Hinkel, Rabea; Blanchet, Xavier; Gaillard, Fanny; D'Amico, Michele; von Hundelshausen, Phillipp; Zarbock, Alexander; Scheiermann, Christoph; Hackeng, Tilman M.; Steffens, Sabine; Kupatt, Christian; Nicolaes, Gerry A. F.; Weber, Christian; Soehnlein, Oliver

    2015-01-01

    In acute and chronic inflammation, neutrophils and platelets, both of which promote monocyte recruitment, are often activated simultaneously. We investigated how secretory products of neutrophils and platelets synergize to enhance the recruitment of monocytes. We found that neutrophil-borne human

  5. Cathepsin G-dependent modulation of platelet thrombus formation in vivo by blood neutrophils.

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    Nauder Faraday

    Full Text Available Neutrophils are consistently associated with arterial thrombotic morbidity in human clinical studies but the causal basis for this association is unclear. We tested the hypothesis that neutrophils modulate platelet activation and thrombus formation in vivo in a cathepsin G-dependent manner. Neutrophils enhanced aggregation of human platelets in vitro in dose-dependent fashion and this effect was diminished by pharmacologic inhibition of cathepsin G activity and knockdown of cathepsin G expression. Tail bleeding time in the mouse was prolonged by a cathepsin G inhibitor and in cathepsin G knockout mice, and formation of neutrophil-platelet conjugates in blood that was shed from transected tails was reduced in the absence of cathepsin G. Bleeding time was highly correlated with blood neutrophil count in wildtype but not cathepsin G deficient mice. In the presence of elevated blood neutrophil counts, the anti-thrombotic effect of cathepsin G inhibition was greater than that of aspirin and additive to it when administered in combination. Both pharmacologic inhibition of cathepsin G and its congenital absence prolonged the time for platelet thrombus to form in ferric chloride-injured mouse mesenteric arterioles. In a vaso-occlusive model of ischemic stroke, inhibition of cathepsin G and its congenital absence improved cerebral blood flow, reduced histologic brain injury, and improved neurobehavioral outcome. These experiments demonstrate that neutrophil cathepsin G is a physiologic modulator of platelet thrombus formation in vivo and has potential as a target for novel anti-thrombotic therapies.

  6. Soluble CD40 ligand stimulates CD40-dependent activation of the β2 integrin Mac-1 and protein kinase C zeda (PKCζ in neutrophils: implications for neutrophil-platelet interactions and neutrophil oxidative burst.

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    Rong Jin

    Full Text Available Recent work has revealed an essential involvement of soluble CD40L (sCD40L in inflammation and vascular disease. Activated platelets are the major source of sCD40L, which has been implicated in platelet and leukocyte activation, although its exact functional impact on leukocyte-platelet interactions and the underlying mechanisms remain undefined. We aimed to determine the impact and the mechanisms of sCD40L on neutrophils. We studied neutrophil interactions with activated, surface-adherent platelets as a model for leukocyte recruitment to the sites of injury. Our data show that CD40L contributes to neutrophil firm adhesion to and transmigration across activated surface-adherent platelets, possibly through two potential mechanisms. One involves the direct interaction of ligand-receptor (CD40L-CD40, i.e., platelet surface CD40L interaction with neutrophil CD40; another involves an indirect mechanism, i.e. soluble CD40L stimulates activation of the leukocyte-specific β2 integrin Mac-1 in neutrophils and thereby further promotes neutrophil adhesion and migration. Activation of the integrin Mac-1 is known to be critical for mediating neutrophil adhesion and migration. sCD40L activated Mac-1 in neutrophils and enhanced neutrophil-platelet interactions in wild-type neutrophils, but failed to elicit such responses in CD40-deficient neutrophils. Furthermore, our data show that the protein kinase C zeta (PKCζ is critically required for sCD40L-induced Mac-1 activation and neutrophil adhesive function. sCD40L strongly stimulated the focal clustering of Mac-1 (CD11b and the colocalization of Mac-1 with PKCζ in wild-type neutrophils, but had minimal effect in CD40-deficient neutrophils. Blocking PKCζ completely inhibited sCD40L-induced neutrophil firm adhesion. Moreover, sCD40L strongly stimulates neutrophil oxidative burst via CD40-dependent activation of PI3K/NF-KB, but independent of Mac-1 and PKCζ. These findings may contribute to a better

  7. Complement Activation Induces Neutrophil Adhesion and Neutrophil-Platelet Aggregate Formation on Vascular Endothelial Cells

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    Magdalena Riedl

    2017-01-01

    Discussion: Therefore, our findings of (i neutrophils adhering to complement-activated endothelial cells, (ii the formation of neutrophil-platelet aggregates on endothelial cells, and (iii the ability of aHUS serum to induce similar effects identify a possible role for neutrophils in aHUS manifestation.

  8. The effect of smoking on neutrophil/lymphocyte and platelet/lymphocyte ratio and platelet ındices: a retrospective study.

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    Tulgar, Y K; Cakar, S; Tulgar, S; Dalkilic, O; Cakiroglu, B; Uyanik, B S

    2016-07-01

    Smoking commonly leads to death. Although the neutrophil/lymphocyte Ratio, platelet/lymphocyte ratio and platelet indices have been shown to be important for the diagnosis, prognosis and severity of some diseases, the smoking status of patients in these studies has not been well defined. In this study, we compared ratios derived from complete blood count and platelet indices to smoking status and length in smokers and non-smokers. The data of healthy males and females aged between 18-60 years who presented to our institute for a routine check-up were collected, and subjects were divided in two groups - smokers and non-smokers. The presence of medical history or laboratory results which could affect inflammatory response, formed our exclusion criteria. All complete blood count results were noted and persons' smoking habits were calculated as pack/years. White blood cell, neutrophil, basophil and eosinophil counts; mean corpuscular volume, red cell distribution width and neutrophil/lymphocyte ratio were significantly higher in smokers when compared to non-smokers (psmokers were grouped according to smoking habits; positive linear correlations were detected between pack/year and Neutrophil/lymphocyte ratio and also pack/year and plateletcrit in smokers (paffected and platelet distribution width is increased in smokers. If smokers are not excluded from studies evaluating neutrophil/lymphocyte ratio and platelet distribution width, the relationship between smoking status as well as pack/year must be determined and reported.

  9. Mechanisms and kinetics for platelet and neutrophil localization in immune complex nephritis

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    Johnson, R.J.; Alpers, C.E.; Pruchno, C.; Schulze, M.; Baker, P.J.; Pritzl, P.; Couser, W.G. (Univ. of Washington, Seattle (USA))

    1989-11-01

    We have previously reported that both neutrophils (PMNs) and platelets mediate proteinuria in a model of subendothelial immune complex (IC) nephritis (GN) in the rat. In order to understand the interaction of PMNs and platelets in this model, we quantitated the uptake of {sup 111}In-labelled platelets in glomeruli and correlated this with the number of PMNs observed histologically at 10 and 30 minutes, 1, 4 and 24 hours following induction of GN. Platelet accumulation was biphasic with a major peak at 10 minutes and a minor peak at four hours. Early platelet accumulation was complement dependent, and PMN-independent. PMN accumulation occurred after the initial platelet influx, peaking at one and four hours, was complement dependent, but was not affected by platelet depletion. Complement depletion significantly reduced proteinuria. This is the first documentation that platelet accumulation in glomeruli in IC GN is complement dependent. In addition, the enhancement of PMN-mediated injury by the platelet in this model does not involve effects of platelets on PMN localization, thus implying a functional interaction between these cells within the glomerulus.

  10. Sirt3 deficiency does not affect venous thrombosis or NETosis despite mild elevation of intracellular ROS in platelets and neutrophils in mice.

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    Hideki Hayashi

    Full Text Available Inflammation is a common denominator in chronic diseases of aging. Yet, how inflammation fuels these diseases remains unknown. Neutrophils are the primary leukocytes involved in the early phase of innate immunity and inflammation. As part of their anti-microbial defense, neutrophils form extracellular traps (NETs by releasing decondensed chromatin lined with cytotoxic proteins. NETs have been shown to induce tissue injury and thrombosis. Here, we demonstrated that Sirt3, a nicotinamide adenine dinucleotide (NAD+-dependent protein deacetylase, an enzyme linked to human longevity, was expressed in mouse neutrophils and platelets. Using Sirt3-/- mice as a model of accelerated aging, we investigated the effects of Sirt3 deficiency on NETosis and platelet function, aiming to detect enhancement of thrombosis. More mitochondrial reactive oxygen species (ROS were generated in neutrophils and platelets of Sirt3-/- mice compared to WT, when stimulated with a low concentration of phorbol 12-myristate 13-acetate (PMA and a high concentration of thrombin, respectively. There were no differences in in vitro NETosis, with or without stimulation. Platelet aggregation was mildly augmented in Sirt3-/- mice compared to WT mice, when stimulated with a low concentration of collagen. The effect of Sirt3 deficiency on platelet and neutrophil activation in vivo was examined by the venous thrombosis model of inferior vena cava stenosis. Elevation of plasma DNA concentration was observed after stenosis in both genotypes, but no difference was shown between the two genotypes. The systemic response to thrombosis was enhanced in Sirt3-/- mice with significantly elevated neutrophil count and reduced platelet count. However, no differences were observed in incidence of thrombus formation, thrombus weight and thrombin-antithrombin complex generation between WT and Sirt3-/- mice. We conclude that Sirt3 does not considerably impact NET formation, platelet function, or venous

  11. Mean platelet volume, neutrophil to lyphocyte ratio and platelet to lymphocyte ratio in psoriasis

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    Mehmet Ünal

    2015-06-01

    Full Text Available Background and Design: It has been demonstrated that ratio of neutrophil and platelet count systemic inflammation and is associated with prognosis of many cardiovascular diseases, malignates and chronic inflammatory diseases.As far as it is known, there are no studies investigating neutrophil/lymphocyeratio(NLR, platelet/lymphocyte ratio(PLR and mean platelet volume(MPV values together within the context of psoriasis, a chronic and systemic inflammatory disease. Materials and Methods: 320 patients followed up in our polyclinic with psoriasis vulgaris and 200 healthy persons were evaluated in the study. Results: Leukocyte, neutrophil, platelet, MPV, NLR and PLR values in patients with psoriasis were significantly higher, and lymphocyte count, on the other hand, was significantly lower than those of the control group. No significant difference was found between MPV, NLR and PLR values of patients with or without a family history, nail and joint involvement. Conclusions: These parameters may be made use of as cheap and easily applicable methods in predicting which psoriasis patients are under the risk of cardiovascular disease. PLR is a better inflammation marker than MPV and NLR in patients with psoriasis. We did not observe a significant relationship between MPV, NLR and PLR values and such disease characteristics as severity of disease, joint involvement, nail involvement and duration of disease in patients with psoriasis. So, we believe that there is little information on the extent to which MPV,NLR and PLR might be useful regarding these characteristics.

  12. Platelet serotonin promotes the recruitment of neutrophils to sites of acute inflammation in mice

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    Suidan, Georgette L.; Demers, Melanie; Herr, Nadine; Carbo, Carla; Brill, Alexander; Cifuni, Stephen M.; Mauler, Maximilian; Cicko, Sanja; Bader, Michael; Idzko, Marco; Bode, Christoph

    2013-01-01

    The majority of peripheral serotonin is stored in platelets, which secrete it on activation. Serotonin releases Weibel-Palade bodies (WPBs) and we asked whether absence of platelet serotonin affects neutrophil recruitment in inflammatory responses. Tryptophan hydroxylase (Tph)1–deficient mice, lacking non-neuronal serotonin, showed mild leukocytosis compared with wild-type (WT), primarily driven by an elevated neutrophil count. Despite this, 50% fewer leukocytes rolled on unstimulated mesenteric venous endothelium of Tph1−/− mice. The velocity of rolling leukocytes was higher in Tph1−/− mice, indicating fewer selectin-mediated interactions with endothelium. Stimulation of endothelium with histamine, a secretagogue of WPBs, or injection of serotonin normalized the rolling in Tph1−/− mice. Diminished rolling in Tph1−/− mice resulted in reduced firm adhesion of leukocytes after lipopolysaccharide treatment. Blocking platelet serotonin uptake with fluoxetine in WT mice reduced serum serotonin by > 80% and similarly reduced leukocyte rolling and adhesion. Four hours after inflammatory stimulation, neutrophil extravasation into lung, peritoneum, and skin wounds was reduced in Tph1−/− mice, whereas in vitro neutrophil chemotaxis was independent of serotonin. Survival of lipopolysaccharide-induced endotoxic shock was improved in Tph1−/− mice. In conclusion, platelet serotonin promotes the recruitment of neutrophils in acute inflammation, supporting an important role for platelet serotonin in innate immunity. PMID:23243271

  13. Incorporating Neutrophil-to-lymphocyte Ratio and Platelet-to-lymphocyte Ratio in Place of Neutrophil Count and Platelet Count Improves Prognostic Accuracy of the International Metastatic Renal Cell Carcinoma Database Consortium Model

    OpenAIRE

    Chrom, Pawel; Stec, Rafal; Bodnar, Lubomir; Szczylik, Cezary

    2017-01-01

    Purpose The study investigated whether a replacement of neutrophil count and platelet count by neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model would improve its prognostic accuracy. Materials and Methods This retrospective analysis included consecutive patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors. The IMDC and modified-IMDC m...

  14. Investigation of neutrophil-to-lymphocyte ratio and mean platelet volume in sudden hearing loss,

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    Rauf Oguzhan Kum

    2015-12-01

    Full Text Available ABSTRACT INTRODUCTION: Several theories attempt to explain the pathophysiology of sudden hearing loss. OBJECTIVE: The objective of this study was to investigate the possible role of inflammation and atherothrombosis in sudden hearing loss patients through the neutrophil-to-lymphocyte ratio and mean platelet volume. METHODS: Study design - retrospective cross-sectional historical cohort. This study was conducted on two groups: one with 59 individuals diagnosed with sudden hearing loss, and other with 59 healthy individuals with the same characteristics of gender and age distribution, neutrophil-to-lymphocyte ratio and mean platelet volume levels were measured in patients diagnosed with sudden hearing loss as well as in the control group, and it was verified whether these results interfered for a better or worse prognosis with treatment of sudden deafness. RESULTS: Neutrophil-to-lymphocyte ratio levels are much higher in patients diagnosed with sudden hearing loss compared to the control group. Similarly, mean levels of neutrophil-to-lymphocyte ratio are higher in non-recovered versus recovered patients (p = 0.001. However, we could not find a correlation with mean platelet volume levels (p > 0.05. CONCLUSION: Neutrophil-to-lymphocyte ratio is a quick and reliable indicator regarding diagnosis and prognosis of sudden hearing loss; on the other hand, mean platelet volume may be considered a less important indicator in this aspect.

  15. Preoperative neutrophil-lymphocyte and platelet-lymphocyte ratios as independent predictors of cervical stromal involvement in surgically treated endometrioid adenocarcinoma

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    Wang D

    2013-03-01

    Full Text Available Dan Wang, Jia-Xin Yang, Dong-Yan Cao, Xi-Run Wan, Feng-Zhi Feng, Hui-Fang Huang, Keng Shen, Yang Xiang Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, People's Republic of China Background: The purpose of this study was to evaluate the relationship between preoperative inflammatory markers (neutrophil-lymphocyte ratio and platelet-lymphocyte ratio and cervical stromal involvement in patients with endometrioid adenocarcinoma. Methods: We studied 318 patients with endometrioid adenocarcinoma who underwent comprehensive surgical staging. We used univariate and multivariate analyses of cervical stromal involvement and receiver-operating curves to calculate optimal cutoff values for neutrophil-lymphocyte and platelet-lymphocyte ratios to predict cervical stromal involvement. Results: The presence of cervical stromal involvement was associated with neutrophil-lymphocyte ratio and platelet-lymphocyte ratio (P = 0.009 and P = 0.031, respectively. Multivariate analysis showed that higher neutrophil-lymphocyte and platelet-lymphocyte ratios independently predicted cervical stromal involvement (odds ratio 3.10, 95% confidence interval 1.10–8.76, P = 0.032, and odds ratio 5.27, 95% confidence interval 1.94–14.35, P = 0.001, respectively. At a threshold of 2.01, the neutrophil-lymphocyte ratio was 71.0% sensitive and 63.8% specific for stromal involvement; at a 172.24 threshold, the platelet-lymphocyte ratio was 48.4% sensitive and 88.9% specific. Conclusion: Preoperative neutrophil-lymphocyte and platelet-lymphocyte ratios can help identify the risk of cervical stromal involvement in patients with endometrial cancer. Evaluating these ratios may help select patients who should be particularly watched and tested for cervical stromal involvement. Keywords: neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, endometrioid adenocarcinoma

  16. Platelet indices and neutrophil to lymphocyte ratio in adults with ...

    African Journals Online (AJOL)

    Background: A study was performed in adults with acute appendicitis and matched controls to assess the utility of the platelet indices and neutrophil to lymphocyte ratio, as a diagnostic adjunct. Methods: Data were retrospectively collected from a complete blood count test of 155 adult patients (72 men and 83 women) with ...

  17. Evaluation of blood neutrophil-lymphocyte ratio and platelet distribution width as inflammatory markers in patients with fibromyalgia.

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    Aktürk, Semra; Büyükavcı, Raikan

    2017-08-01

    Fibromyalgia syndrome (FMS) is characterized by chronic widespread pain and systemic symptoms. The aetiology and pathogenesis of fibromyalgia are not yet fully understood. Blood neutrophil/lymphocyte ratio (NLR) is a marker of systemic inflammatory response. Platelet distribution width (PDW) and mean platelet volume (MPV) are the determinants of platelet activation and studied as markers in inflammatory diseases. The aim of the present study was to evaluate levels of NLR,PDW and MPV in patients with fibromyalgia. A total of 197 FMS patients and 53 healthy controls are included in the study. Demographic characteristics, erythrocyte sedimentation rate, C-reactive protein, neutrophil, lymphocyte and platelet counts, platelet distribution width and mean platelet volume levels were recorded. In the patient group, the blood NLR and MPV were significantly higher and the PDW was significantly lower compared to the control group. In the roc curve analysis, blood PDW ≥had 90.4% sensitivity and 90% specificity in predicting fibromyalgia. The results of this study suggest NLR and PDW as promising inflammatory markers indicating fibromyalgia and may be beneficial in facilitating the diagnosis of FMS patients.

  18. The relation of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and mean platelet volume with the presence and severity of Behçet's syndrome

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    Sevil Alan

    2015-12-01

    Full Text Available Behçet's syndrome (BS is associated with chronic inflammation and endothelial dysfunction. Although there have been extensive investigations on neutrophil-to-lymphocyte ratio (NLR, platelet-to-lymphocyte ratio (PLR, and mean platelet volume (MPV in many diseases, their roles in BS is unclear. The purpose of the present study was to evaluate NLR, PLR, and MPV levels in BS patients and explore their clinical significance. The study included 254 patients with BS and 173 healthy individuals. Age, sex, age of onset, duration of disease, smoking, Behçet activity score, total white blood counts, neutrophil, platelet, and T lymphocyte counts of the patients were recorded. White blood cell (WBC, neutrophil, platelet, NLR, and PLR were significantly higher in patients with BS when compared with healthy controls (all p  0.05. In the BS group, PLR and MPV were significantly different among the three severity groups (p = 0.037 and p = 0.016, respectively. We showed that any laboratory markers were not associated with joint, eye, central nervous system, large vessel, or gastrointestinal involvement in BS. NLR was shown to be an independent factor for BS by multivariate analysis. We suggest that NLR can be considered to be a diagnostic criterion of BS given the support of the findings from larger prospective studies.

  19. Monocytes, neutrophils, and platelets cooperate to initiate and propagate venous thrombosis in mice in vivo

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    von Brühl, Marie-Luise; Stark, Konstantin; Steinhart, Alexander; Chandraratne, Sue; Konrad, Ildiko; Lorenz, Michael; Khandoga, Alexander; Tirniceriu, Anca; Coletti, Raffaele; Köllnberger, Maria; Byrne, Robert A.; Laitinen, Iina; Walch, Axel; Brill, Alexander; Pfeiler, Susanne; Manukyan, Davit; Braun, Siegmund; Lange, Philipp; Riegger, Julia; Ware, Jerry; Eckart, Annekathrin; Haidari, Selgai; Rudelius, Martina; Schulz, Christian; Echtler, Katrin; Brinkmann, Volker; Schwaiger, Markus; Preissner, Klaus T.; Wagner, Denisa D.; Mackman, Nigel; Engelmann, Bernd

    2012-01-01

    Deep vein thrombosis (DVT) is a major cause of cardiovascular death. The sequence of events that promote DVT remains obscure, largely as a result of the lack of an appropriate rodent model. We describe a novel mouse model of DVT which reproduces a frequent trigger and resembles the time course, histological features, and clinical presentation of DVT in humans. We demonstrate by intravital two-photon and epifluorescence microscopy that blood monocytes and neutrophils crawling along and adhering to the venous endothelium provide the initiating stimulus for DVT development. Using conditional mutants and bone marrow chimeras, we show that intravascular activation of the extrinsic pathway of coagulation via tissue factor (TF) derived from myeloid leukocytes causes the extensive intraluminal fibrin formation characteristic of DVT. We demonstrate that thrombus-resident neutrophils are indispensable for subsequent DVT propagation by binding factor XII (FXII) and by supporting its activation through the release of neutrophil extracellular traps (NETs). Correspondingly, neutropenia, genetic ablation of FXII, or disintegration of NETs each confers protection against DVT amplification. Platelets associate with innate immune cells via glycoprotein Ibα and contribute to DVT progression by promoting leukocyte recruitment and stimulating neutrophil-dependent coagulation. Hence, we identified a cross talk between monocytes, neutrophils, and platelets responsible for the initiation and amplification of DVT and for inducing its unique clinical features. PMID:22451716

  20. DioxolaneA3-phosphatidylethanolamines are generated by human platelets and stimulate neutrophil integrin expression

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    Maceler Aldrovandi

    2017-04-01

    Full Text Available Activated platelets generate an eicosanoid proposed to be 8-hydroxy-9,10-dioxolane A3 (DXA3. Herein, we demonstrate that significant amounts of DXA3 are rapidly attached to phosphatidylethanolamine (PE forming four esterified eicosanoids, 16:0p, 18:0p, 18:1p and 18:0a/DXA3-PEs that can activate neutrophil integrin expression. These lipids comprise the majority of DXA3 generated by platelets, are formed in ng amounts (24.3±6.1 ng/2×108 and remain membrane bound. Pharmacological studies revealed DXA3-PE formation involves cyclooxygenase-1 (COX, protease-activated receptors (PAR 1 and 4, cytosolic phospholipase A2 (cPLA2, phospholipase C and intracellular calcium. They are generated primarily via esterification of newly formed DXA3, but can also be formed in vitro via co-oxidation of PE during COX-1 co-oxidation of arachidonate. All four DXA3-PEs were detected in human clots. Purified platelet DXA3-PE activated neutrophil Mac-1 expression, independently of its hydrolysis to the free eicosanoid. This study demonstrates the structures and cellular synthetic pathway for a family of leukocyte-activating platelet phospholipids generated on acute activation, adding to the growing evidence that enzymatic PE oxidation is a physiological event in innate immune cells.

  1. Incorporating Neutrophil-to-lymphocyte Ratio and Platelet-to-lymphocyte Ratio in Place of Neutrophil Count and Platelet Count Improves Prognostic Accuracy of the International Metastatic Renal Cell Carcinoma Database Consortium Model.

    Science.gov (United States)

    Chrom, Pawel; Stec, Rafal; Bodnar, Lubomir; Szczylik, Cezary

    2018-01-01

    The study investigated whether a replacement of neutrophil count and platelet count by neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model would improve its prognostic accuracy. This retrospective analysis included consecutive patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors. The IMDC and modified-IMDC models were compared using: concordance index (CI), bias-corrected concordance index (BCCI), calibration plots, the Grønnesby and Borgan test, Bayesian Information Criterion (BIC), generalized R 2 , Integrated Discrimination Improvement (IDI), and continuous Net Reclassification Index (cNRI) for individual risk factors and the three risk groups. Three hundred and twenty-one patients were eligible for analyses. The modified-IMDC model with NLR value of 3.6 and PLR value of 157 was selected for comparison with the IMDC model. Both models were well calibrated. All other measures favoured the modified-IMDC model over the IMDC model (CI, 0.706 vs. 0.677; BCCI, 0.699 vs. 0.671; BIC, 2,176.2 vs. 2,190.7; generalized R 2 , 0.238 vs. 0.202; IDI, 0.044; cNRI, 0.279 for individual risk factors; and CI, 0.669 vs. 0.641; BCCI, 0.669 vs. 0.641; BIC, 2,183.2 vs. 2,198.1; generalized R 2 , 0.163 vs. 0.123; IDI, 0.045; cNRI, 0.165 for the three risk groups). Incorporation of NLR and PLR in place of neutrophil count and platelet count improved prognostic accuracy of the IMDC model. These findings require external validation before introducing into clinical practice.

  2. Platelet-collagen adhesion enhances platelet aggregation induced by binding of VWF to platelets

    International Nuclear Information System (INIS)

    Laduca, F.M.; Bell, W.R.; Bettigole, R.E.

    1987-01-01

    Ristocetin-induced platelet aggregation (RIPA) was evaluated in the presence of platelet-collagen adhesion. RIPA of normal donor platelet-rich plasma (PRP) demonstrated a primary wave of aggregation mediated by the binding of von Willebrand factor (VWF) to platelets and a secondary aggregation wave, due to a platelet-release reaction, initiated by VWF-platelet binding and inhibitable by acetylsalicylic acid (ASA). An enhanced RIPA was observed in PRP samples to which collagen had been previously added. These subthreshold concentrations of collagen, which by themselves were insufficient to induce aggregation, caused measurable platelet-collagen adhesion. Subthreshold collagen did not cause microplatelet aggregation, platelet release of [ 3 H]serotonin, or alter the dose-responsive binding of 125 I-labeled VWF to platelets, which occurred with increasing ristocetin concentrations. However, ASA inhibition of the platelet release reaction prevented collagen-enhanced RIPA. These results demonstrate that platelet-collagen adhesion altered the platelet-release reaction induced by the binding of VWF to platelets causing a platelet-release reaction at a level of VWF-platelet binding not normally initiating a secondary aggregation. These findings suggest that platelet-collagen adhesion enhances platelet function mediated by VWF

  3. Tumor-Associated Macrophages and Neutrophils in Tumor Microenvironment

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    Jaehong Kim

    2016-01-01

    Full Text Available Distinct tumor microenvironment forms in each progression step of cancer and has diverse capacities to induce both adverse and beneficial consequences for tumorigenesis. It is now known that immune cells can be activated to favor tumor growth and progression, most probably influenced by the tumor microenvironment. Tumor-associated macrophages and tumor-associated neutrophils can exert protumoral functions, enhancing tumor cell invasion and metastasis, angiogenesis, and extracellular matrix remodeling, while inhibiting the antitumoral immune surveillance. Considering that neutrophils in inflammatory environments recruit macrophages and that recruited macrophages affect neutrophil functions, there may be various degrees of interaction between tumor-associated macrophages and tumor-associated neutrophils. Platelets also play an important role in the recruitment and regulation of monocytic and granulocytic cells in the tumor tissues, suggesting that platelet function may be essential for generation of tumor-associated macrophages and tumor-associated neutrophils. In this review, we will explore the biology of tumor-associated macrophages and tumor-associated neutrophils and their possible interactions in the tumor microenvironment. Special attention will be given to the recruitment and activation of these tumor-associated cells and to the roles they play in maintenance of the tumor microenvironment and progression of tumors.

  4. Mean Platelet Volume and Neutrophil-to-Lymphocyte Ratio in Patients with Crimean–Congo Hemorrhagic Fever

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    Derya Koçer

    2015-01-01

    Full Text Available Objectives: Crimean–Congo hemorrhagic fever (CCHF is a tick-borne zoonotic infection caused by Crimean Congo hemorrhagic fever virus (CCHFV. The aim of the present study was to investigate the association between blood neutrophil-to-lymphocyte ratio (NLR and mean platelet volume (MPV which are simple markers of subclinical inflammation and CCHF. We also investigated the relationship of these markers with coagulation parameters.Methods: Thirty-one suspected CCHF patients, who submitted to Training and Research Hospital, Kayseri, Turkey between 2009 and 2013, were evaluated retrospectively. Among thirty-one patients, nineteen were laboratory confirmed CCHF patients diagnosed by RT-PCR or CCHFV-specific IgM positivity. Alanine aminotransferase (ALT, aspartate aminotransferase (AST, lactate dehydrogenase (LDH, creatinin phosphokinase (CK, coagulation parameters, white blood cell counts (WBCs, and platelet counts of patient group were compared with twenty-five healthy individuals.Results: MPV, AST, ALT, LDH, CK and coagulation parameters were significantly higher in patients with CCHF than the controls, whereas WBCs, neutrophil, lymphocyte, hemoglobin, platelet counts and NLR were significantly lower (p<0.05. We found no significant correlation between MPV, NLR and coagulation parameters.Conclusions: Our study demonstrates that MPV and NLR may be beneficial markers in the diagnosis of CCHF. But these parameters should not be considered stand-alone tests for this use owing to nonspecificity with other diseases.

  5. 2SNP heritability and effects of genetic variants for neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio

    NARCIS (Netherlands)

    Lin, Bochao Danae; Carnero-Montoro, Elena; Bell, Jordana T; Boomsma, Dorret I; de Geus, Eco J; Jansen, Rick; Kluft, Cornelis; Mangino, Massimo; Penninx, Brenda; Spector, Tim D; Willemsen, Gonneke; Hottenga, Jouke-Jan

    2017-01-01

    Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are important biomarkers for disease development and progression. To gain insight into the genetic causes of variance in NLR and PLR in the general population, we conducted genome-wide association (GWA) analyses and

  6. Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios: are they useful for predicting gestational diabetes mellitus during pregnancy?

    Directory of Open Access Journals (Sweden)

    Sargın MA

    2016-04-01

    Full Text Available Mehmet Akif Sargın, Murat Yassa, Bilge Dogan Taymur, Ayhan Celik, Emrah Ergun, Niyazi Tug Department of Obstetrics and Gynecology, Fatih Sultan Mehmet Research and Training Hospital, Istanbul, Turkey Objective: We aimed to investigate whether the neutrophil-to-lymphocyte ratio (NLR and platelet-to-lymphocyte ratio (PLR could be utilized to screen for gestational diabetes mellitus (GDM.Subjects and methods: NLR and PLR were assessed by retrospective analysis of 762 healthy and pregnant women with GDM. The patients were stratified into four groups, as follows: GDM (n=144, impaired glucose tolerance (n=76, only screen positive (n=238, and control (n=304.Results: The leukocyte, neutrophil, and lymphocyte counts were significantly higher in the study groups compared with the control group (P=0.001; P<0.01. There were no statistically significant differences between the groups with respect to the NLR and PLR (P>0.05.Conclusion: We do not recommend that blood NLR and PLR can be used to screen for GDM. However, increase in the leukocyte count is an important marker for GDM as it provides evidence of subclinical inflammation. Keywords: inflammation, lymphocytes, neutrophils, platelets, pregnancy

  7. The relative role of neutrophils and platelets in the local accumulation of circulating lymphocytes at sites of ionophore A23187 inoculation

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, J.M.; Simmons, R.L. (Univ. of Pittsburgh, PA (USA))

    1991-03-01

    The early cellular infiltrate at inflammatory sites consists predominantly of neutrophils and cells of the monocyte/macrophage lineage. The mechanism by which circulating, unsensitized lymphocytes accumulate at sites of inflammation is unknown. The pattern of accumulation of 111indium-labeled circulating thymocytes in response to local injections of the ionophore A23187 was studied and compared with the pattern of (125)iodinated albumin accumulation as a measure of vascular permeability. The kinetics of thymocyte accumulation differed from those of vascular permeability. Sublethal total-body irradiation (750 rads) markedly decreased thymocyte accumulation but had little effect on vascular permeability. Irradiation of the local site alone had no effect. T lymphocyte, T lymphoblast, and platelet accumulation generally followed the same pattern as thymocytes. Intravenous injection of neutrophils, but not platelets, partially restored lymphocyte accumulation in vivo in irradiated mice via a pathway involving the circulating neutrophil, and seemed to be independent of changes in vascular permeability.

  8. The Neutrophil-Platelet Score (NPS Predicts Survival in Primary Operable Colorectal Cancer and a Variety of Common Cancers.

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    David G Watt

    Full Text Available Recent in-vitro studies have suggested that a critical checkpoint early in the inflammatory process involves the interaction between neutrophils and platelets. This confirms the importance of the innate immune system in the elaboration of the systemic inflammatory response. The aim of the present study was to examine whether a combination of the neutrophil and platelet counts were predictive of survival in patients with cancer.Patients with histologically proven colorectal cancer who underwent potentially curative resection at a single centre between March 1999 and May 2013 (n = 796 and patients with cancer from the Glasgow Inflammation Outcome Study, who had a blood sample taken between January 2000 and December 2007 (n = 9649 were included in the analysis.In the colorectal cancer cohort, there were 173 cancer and 135 non-cancer deaths. In patients undergoing elective surgery, cancer-specific survival (CSS at 5 years ranged from 97% in patients with TNM I disease and NPS = 0 to 57% in patients with TNM III disease and NPS = 2 (p = 0.019 and in patients undergoing elective surgery for node-negative colon cancer from 98% (TNM I, NPS = 0 to 65% (TNM II, NPS = 2 (p = 0.004. In those with a variety of common cancers there were 5218 cancer and 929 non-cancer deaths. On multivariate analysis, adjusting for age and sex and stratified by tumour site, incremental increase in the NPS was significantly associated with poorer CSS (p<0.001.The neutrophil-platelet score predicted survival in a variety of common cancers and highlights the importance of the innate immune system in patients with cancer.

  9. The Relationship Between 14C Urea Breath Test Results and Neutrophil/Lymphocyte and Platelet/Lymphocyte Ratios

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    Ertan Şahin

    2018-04-01

    Full Text Available Aim: Neutrophil/lymphocyte ratio (NLR and platelet/lymphocyte ratio (PLR are used as inflammatory markers in several diseases. However, there are little data regarding the diagnostic ability of NLR and PLR in Helicobacter pylori. We aimed to assess the association between the 14C urea breath test (14C-UBT results and NLR and PLR in H. pylori diagnosis. Methods: Results of 89 patients were retrospectively analysed in this study. According to the 14C-UBT results, patients were divided into two groups: H. pylori (+ and H. pylori (- (control group. Haematological parameters, including hemoglobine, white blood cell (WBC count, neutrophil count, lymphocyte count, NLR, platelet count, and PLR were compared between the two groups. Results: The mean total WBC count, neutrophil count, NLR and PLR in H. pylori (+ patients were significantly higher than in the control group (p<0.001 for all these parameters. In the receiver operating characteristic curve analysis, the cut-off value for NLR and PLR for the presence of H. pylori was calculated as ≥2.39 [sensitivity: 67.3%, specificity: 79.4%, area under the curve (AUC: 0.747 (0.637-0.856, p<0.0001] and ≥133.3 [sensitivity: 61.8%, specificity: 55.9%, AUC: 0.572 (0.447-0.697, p<0.05], respectively. Conclusion: The present study shows that NLR and PLR are associated with H. pylori positivity based on 14C-UBT, and they can be used as an additional biomarker for supporting the 14C-UBT results.

  10. Inflammatory role and prognostic value of platelet chemokines in acute coronary syndrome

    NARCIS (Netherlands)

    Blanchet, X.; Cesarek, K.; Brandt, J.; Herwald, H.; Teupser, D.; Küchenhoff, H.; Karshovska, E.; Mause, S. F.; Siess, W.; Wasmuth, H.; Soehnlein, O.; Koenen, R. R.; Weber, C.; von Hundelshausen, P.

    2014-01-01

    Activated platelets and neutrophils exacerbate atherosclerosis. Platelets release the chemokines CXCL4, CXCL4L1 and CCL5, whereas myeloperoxidase (MPO) and azurocidin are neutrophil-derived. We investigated whether plasma levels of these platelet and neutrophil mediators are affected by the acute

  11. Protein kinase C promotes restoration of calcium homeostasis to platelet activating factor-stimulated human neutrophils by inhibition of phospholipase C

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    Anderson Ronald

    2009-10-01

    Full Text Available Abstract Background The role of protein kinase C (PKC in regulating the activity of phospholipase C (PLC in neutrophils activated with the chemoattractant, platelet-activating factor (PAF, 20 and 200 nM, was probed in the current study using the selective PKC inhibitors, GF10903X (0.5 - 1 μM and staurosporine (400 nM. Methods Alterations in cytosolic Ca2+, Ca2+ influx, inositol triphosphate (IP3, and leukotriene B4 production were measured using spectrofluorimetric, radiometric and competitive binding radioreceptor and immunoassay procedures, respectively. Results Activation of the cells with PAF was accompanied by an abrupt increase in cytosolic Ca2+ followed by a gradual decline towards basal levels. Pretreatment of neutrophils with the PKC inhibitors significantly increased IP3 production with associated enhanced Ca2+ release from storage vesicles, prolongation of the peak cytosolic Ca2+ transients, delayed clearance and exaggerated reuptake of the cation, and markedly increased synthesis of LTB4. The alterations in Ca2+ fluxes observed with the PKC inhibitors were significantly attenuated by U73122, a PLC inhibitor, as well as by cyclic AMP-mediated upregulation of the Ca2+-resequestering endomembrane ATPase. Taken together, these observations are compatible with a mechanism whereby PKC negatively modulates the activity of PLC, with consequent suppression of IP3 production and down-regulation of Ca2+ mediated pro-inflammatory responses of PAF-activated neutrophils. Conclusion Although generally considered to initiate and/or amplify intracellular signalling cascades which activate and sustain the pro-inflammatory activities of neutrophils and other cell types, the findings of the current study have identified a potentially important physiological, anti-inflammatory function for PKC, at least in neutrophils.

  12. Platelet activation and platelet-leukocyte interaction in dogs naturally infected with Babesia rossi

    DEFF Research Database (Denmark)

    Goddard, Amelia; Leisewitz, Andrew L; Kristensen, Annemarie Thuri

    2015-01-01

    EDTA as anticoagulant. Activated platelets and PLA formation were detected by measuring surface expression of P-selectin (CD62P) on platelets, monocytes and neutrophils. Of the Babesia-infected dogs, 29 survived and seven died. The percentage of CD62P-positive monocytes was significantly higher (P = 0.......036) in the Babesia-infected dogs (54%) than in healthy control dogs (35.3%). However, there were no significant differences between the Babesia-infected and control groups for CD62P-positive platelets (4.9% and 1.2%, respectively) and CD62P-positive neutrophils (28.3% and 17.9%, respectively). The percentage of CD62...... groups for the percentage of CD62P-positive platelets (survivors 4.8%; non-survivors 5.3%; controls 1.2%) or CD62P-positive neutrophils (survivors 31.6%; non-survivors 5.6%; controls 17.9%). In conclusion, Babesia-infected dogs, specifically dogs that survived, had a significantly increased percentage...

  13. Platelet modulation of human neutrophil functions

    Energy Technology Data Exchange (ETDEWEB)

    McGarrity, S.T.; Hyers, T.M.; Webster, R.O.

    1986-03-01

    The combined presence of platelets (PLTS) and neutrophils (PMN) at inflammatory sites has led to examination of the hypothesis that interaction of these cells modulates their responses to stimuli. Gel-filtered human PLTS (GFP) were found to inhibit N-formyl-met-leu-phe (FMLP) and phorbol myristate acetate (PMA) stimulated PMN O/sub 2//sup -/ generation in a concentration-dependent fashion. The heat-stable inhibitory activity was present in the supernatants of GFP after incubation with FMLP (10/sup -7/M), thrombin (0.5 U/ml) or ADP (20 ..mu..M), suggesting a role for PLT release products. PLT lysates added to PMN produced up to 80% inhibition of O/sub 2//sup -/ generation for PMA and 40% for FMLP. Like GFP, lysates failed to scavenge O/sub 2/..pi.. produced by xanthine oxidase-hypoxanthine. The inhibitory activity could not be ascribed to serotonin or adenosine. PLT lysates failed to compete with /sup 3/H-FMLP for binding to PMN. Sephadex G-200 fractionation of PLT lysates releaved two peaks of inhibitory activity with apparent Mr > 200,000 and < 14,000 Daltons. Pretreatment of PMN with PLT lysates also results in a concentration-dependent inhibition of degranulation provoked by FMLP (2 x 10/sup -7/M) or PMA (2 ng/ml) and PMN chemotaxis to FMLP (10/sup -8/M). These studies indicate that preformed PLT mediator(s) released in response to physiological stimuli may limit tissue damage by PMN at sites of inflammation.

  14. Inhibition of FMLP-stimulated neutrophil chemiluminescence by blood platelets increased in the presence of the serotonin-liberating drug chloroquine

    Czech Academy of Sciences Publication Activity Database

    Jančinová, V.; Drábiková, K.; Nosáľ, R.; Petríková, M.; Číž, Milan; Lojek, Antonín; Danihelová, E.

    2003-01-01

    Roč. 109, 5-6 (2003), s. 293-298 ISSN 0049-3848 R&D Projects: GA MŠk ME 198 Grant - others:VEGA MŠ SR(SK) 2/1012/21 Institutional research plan: CEZ:AV0Z5004920 Keywords : blood platelets * neutrophils * chloroquine Subject RIV: BO - Biophysics Impact factor: 1.710, year: 2003

  15. Platelets and infections—complex interactions with bacteria

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    Hind eHAMZEH-COGNASSE

    2015-02-01

    Full Text Available Platelets can be considered sentinels of vascular system due to their high number in the circulation and to the range of functional immunoreceptors they express. Platelets express a wide range of potential bacterial receptors, including complement receptors, FcγRII, Toll-Like Receptors but also integrins conventionally described in the hemostatic response, such as GPIIb-IIIa or GPIb. Bacteria bind these receptors either directly, or indirectly via fibrinogen, fibronectin, the first complement C1q, the von Willebrand Factor, etc. The fate of platelet bound bacteria is questioned. Several studies reported the ability of activated platelets to internalize bacteria such as Staphylococcus aureus or Porphyromonas gingivalis, though there is no clue on what happens thereafter. Are they sheltered from the immune system in the cytoplasm of platelets or are they lysed? Indeed, while the presence of phagolysosome has not been demonstrated in platelets, they contain antimicrobial peptides that were shown to be efficient on S. aureus. Besides, the fact that bacteria can bind to platelets via receptors involved in hemostasis suggests that they may induce aggregation; this has indeed been described for Streptococcus sanguinis, S. epidermidis or C. pneumoniae. On the other hand, platelets are able to display an inflammatory response to an infectious triggering. We, and others, have shown that platelet release soluble immunomodulatory factors upon stimulation by bacterial components. Moreover, interactions between bacteria and platelets are not limited to only these two partners. Indeed, platelets are also essential for the formation of Neutrophil Extracellular Traps by neutrophils, resulting in bacterial clearance by trapping bacteria and concentrating antibacterial factors but in enhancing thrombosis. In conclusion, the platelet-bacteria interplay is a complex game; its fine analysis is complicated by the fact that the inflammatory component adds to the

  16. D-lactic acid interferes with the effects of platelet activating factor on bovine neutrophils.

    Science.gov (United States)

    Alarcón, P; Conejeros, I; Carretta, M D; Concha, C; Jara, E; Tadich, N; Hidalgo, M A; Burgos, R A

    2011-11-15

    D-lactic acidosis occurs in ruminants, such as cattle, with acute ruminal acidosis caused by ingestion of excessive amounts of highly fermentable carbohydrates. Affected animals show clinical signs similar to those of septic shock, as well as acute laminitis and liver abscesses. It has been proposed that the inflammatory response and susceptibility to infection could both be caused by the inhibition of phagocytic mechanisms. To determine the effects of d-lactic acid on bovine neutrophil functions, we pretreated cells with different concentrations of D-lactic acid and measured intracellular pH using 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and calcium flux using FLUO-3 AM-loaded neutrophils. Reactive oxygen species (ROS) production was measured using a luminol chemiluminescence assay, and MMP-9/gelatinase-B granule release was measured by zymography. CD11b and CD62L/l-selectin expression, changes in cell shape, superoxide anion production, phagocytosis of Escherichia coli-Texas red bioparticles, and apoptosis were all measured using flow cytometry. Our results demonstrated that D-lactic acid reduced ROS production, CD11b upregulation and MMP-9 release in bovine neutrophils treated with 100 nM platelet-activating factor (PAF). D-lactic acid induced MMP-9 release and, at higher concentrations, upregulated CD11b expression, decrease L-selectin expression, and induces late apoptosis. We concluded that D-lactic acid can interfere with neutrophil functions induced by PAF, leading to reduced innate immune responses during bacterial infections. Moreover, the increase of MMP-9 release and CD11b expression induced by 10mM D-lactic acid could promote an nonspecific neutrophil-dependent inflammatory reaction in cattle with acute ruminal acidosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. A comparison of the neutrophil-lymphocyte, platelet-lymphocyte and monocyte-lymphocyte ratios in schizophrenia and bipolar disorder patients - a retrospective file review.

    Science.gov (United States)

    Özdin, Selçuk; Sarisoy, Gökhan; Böke, Ömer

    2017-10-01

    Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR) have recently been used as indicators of inflammation. Higher MLR and PLR values have been determined in the euthymic and manic periods in patients with bipolar disorder compared to a control group. High NLR values were determined in the only study investigating this ratio in schizophrenia patients. The purpose of this study was to compare NLR, PLR and MLR values and complete blood count elements in patients receiving treatment and hospitalized due to schizophrenic psychotic episode and bipolar disorder manic episode. All patients meeting the inclusion criteria among subjects receiving treatment and hospitalized due to schizophrenia-psychotic episode and bipolar affective disorder-manic episode at the Ondokuz Mayıs University Medical Faculty Psychiatry Department, Turkey, in 2012-2016 were included in our study. A total of 157 healthy donors were included as a control group. White blood cell (WBC), neutrophil, lymphocyte, platelet and monocyte numbers were noted retrospectively from complete blood counts at time of admission, and NLR, PLR and MLR were calculated from these. NLR, PLR and MLR values and platelet numbers in this study were higher and lymphocyte numbers were lower in bipolar disorder patients compared to the controls. Elevation in NLR, MLR and PLR values and neutrophil numbers and lower lymphocyte numbers were determined in schizophrenia patients compared to the controls. Higher NLR and MLR values were found in schizophrenia patients compared to bipolar disorder. Findings of our study supported the inflammation hypothesis for schizophrenia and bipolar disorder.

  18. Important role of platelets in modulating endotoxin-induced lung inflammation in CFTR-deficient mice.

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    Caiqi Zhao

    Full Text Available Mutation of CFTR (cystic fibrosis transmembrane conductance regulator leads to cystic fibrosis (CF. Patients with CF develop abnormalities of blood platelets and recurrent lung inflammation. However, whether CFTR-mutated platelets play a role in the development of lung inflammation is elusive. Therefore, we intratracheally challenged wildtype and F508del (a common type of CFTR mutation mice with LPS to observe changes of F508del platelets in the peripheral blood and indexes of lung inflammation (BAL neutrophils and protein levels. Furthermore, we investigated whether or not and how F508del platelets modulate the LPS-induced acute lung inflammation by targeting anti-platelet aggregation, depletion of neutrophils, reconstitution of bone marrow or neutrophils, blockade of P-selectin glycoprotein ligand-1 (PSGL-1, platelet activating factor (PAF, and correction of mutated CFTR trafficking. We found that LPS-challenged F508del mice developed severe thrombocytopenia and had higher levels of plasma TXB2 coincided with neutrophilic lung inflammation relative to wildtype control. Inhibition of F508del platelet aggregation or depletion of F508del neutrophils diminished the LPS-induced lung inflammation in the F508del mice. Moreover, wildtype mice reconstituted with either F508del bone marrow or neutrophils developed worse thrombocytopenia. Blocking PSGL-1, platelet activating factor (PAF, or rectifying trafficking of mutated CFTR in F508del mice diminished and alveolar neutrophil transmigration in the LPS-challenged F508del mice. These findings suggest that F508del platelets and their interaction with neutrophils are requisite for the development of LPS-induced lung inflammation and injury. As such, targeting platelets might be an emerging strategy for dampening recurrent lung inflammation in cystic fibrosis patients.

  19. Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers.

    Science.gov (United States)

    Concha, Claudia; Carretta, María Daniella; Alarcón, Pablo; Conejeros, Ivan; Gallardo, Diego; Hidalgo, Alejandra Isabel; Tadich, Nestor; Cáceres, Dante Daniel; Hidalgo, María Angélica; Burgos, Rafael Agustín

    2014-01-01

    Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response.

  20. Advanced platelet-rich fibrin: a new concept for cell-based tissue engineering by means of inflammatory cells.

    Science.gov (United States)

    Ghanaati, Shahram; Booms, Patrick; Orlowska, Anna; Kubesch, Alica; Lorenz, Jonas; Rutkowski, Jim; Landes, Constantin; Sader, Robert; Kirkpatrick, Cj; Choukroun, Joseph

    2014-12-01

    Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets were detected throughout the clot in both groups, although in the A-PRF group, more platelets were found in the distal part, away from the buffy coat (BC). T- and B-lymphocytes, stem cells, and monocytes were detected in the surroundings of the BC in both groups. Decreasing the rpm while increasing the centrifugation time in the A-PRF group gave an enhanced presence of neutrophilic granulocytes in the distal part of the clot. In the S-PRF group, neutrophils were found mostly at the red blood cell (RBC)-BC interface. Neutrophilic granulocytes contribute to monocyte differentiation into macrophages. Accordingly, a higher presence of these cells might be able to influence the differentiation of host macrophages and macrophages within the clot after implantation. Thus, A-PRF might influence bone and soft tissue regeneration, especially through the presence of monocytes/macrophages and their growth factors. The relevance and feasibility of this tissue-engineering concept have to be proven through in vivo studies.

  1. The Dynamics of Platelet Activation during the Progression of Streptococcal Sepsis.

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    Sinead M Hurley

    Full Text Available Platelets contribute to inflammation however, the role of platelet activation during the pathophysiological response to invasive bacterial infection and sepsis is not clear. Herein, we have investigated platelet activation in a mouse model of invasive Streptococcus pyogenes infection at 5, 12, and 18 hours post infection and correlated this to parameters of infection. The platelet population in ex-vivo blood samples showed no increased integrin activation or surface presentation of CD62P, however platelet-neutrophil complex formation and plasma levels of CD62P were increased during bacterial dissemination and the progression of sepsis, indicating that platelet activation had occurred in vivo. Platelet-neutrophil complex formation was the most discriminatory marker of platelet activation. Platelet-neutrophil complexes were increased above baseline levels during early sepsis but decreased to significantly lower levels than baseline during late sepsis. The removal of these complexes from the circulation coincided with a significant increase in organ damage and the accumulation of platelets in the liver sinusoids, suggesting that platelet activation in the circulation precedes accumulation of platelets in damaged organs. The results demonstrate that monitoring platelet activation using complementary methods may provide prognostic information during the pathogenesis of invasive S. pyogenes infection.

  2. Elevated Neutrophil Lymphocyte Ratio in Recurrent Optic Neuritis

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    Hande Guclu

    2015-01-01

    Full Text Available Purpose. To demonstrate the relation between optic neuritis (ON and systemic inflammation markers as neutrophil lymphocyte ratio (N/L ratio, platelet count, mean platelet volume (MPV, and red cell distribution width (RDW and furthermore to evaluate the utilization of these markers to predict the frequency of the ON episodes. Methods. Forty-two patients with acute ON and forty healthy subjects were enrolled into the study. The medical records were reviewed for age, sex, hemoglobin (Hb, Haematocrit (Htc, RDW, platelet count, MPV, white blood cell count (WBC, neutrophil and lymphocyte count, and neutrophil lymphocyte ratio (N/L ratio. Results. The mean N/L ratio, platelet counts, and RDW were significantly higher in ON group (p=0.000, p=0.048, and p=0.002. There was a significant relation between N/L ratio and number of episodes (r=0.492, p=0.001. There was a statistically significant difference for MPV between one episode group and recurrent ON group (p=0.035. Conclusions. Simple and inexpensive laboratory methods could help us show systemic inflammation and monitor ON patients. Higher N/L ratio can be a useful marker for predicting recurrent attacks.

  3. Hypoxia upregulates neutrophil degranulation and potential for tissue injury

    Science.gov (United States)

    Hoenderdos, Kim; Lodge, Katharine M; Hirst, Robert A; Chen, Cheng; Palazzo, Stefano G C; Emerenciana, Annette; Summers, Charlotte; Angyal, Adri; Porter, Linsey; Juss, Jatinder K; O'Callaghan, Christopher; Chilvers, Edwin R

    2016-01-01

    Background The inflamed bronchial mucosal surface is a profoundly hypoxic environment. Neutrophilic airway inflammation and neutrophil-derived proteases have been linked to disease progression in conditions such as COPD and cystic fibrosis, but the effects of hypoxia on potentially harmful neutrophil functional responses such as degranulation are unknown. Methods and results Following exposure to hypoxia (0.8% oxygen, 3 kPa for 4 h), neutrophils stimulated with inflammatory agonists (granulocyte-macrophage colony stimulating factor or platelet-activating factor and formylated peptide) displayed a markedly augmented (twofold to sixfold) release of azurophilic (neutrophil elastase, myeloperoxidase), specific (lactoferrin) and gelatinase (matrix metalloproteinase-9) granule contents. Neutrophil supernatants derived under hypoxic but not normoxic conditions induced extensive airway epithelial cell detachment and death, which was prevented by coincubation with the antiprotease α-1 antitrypsin; both normoxic and hypoxic supernatants impaired ciliary function. Surprisingly, the hypoxic upregulation of neutrophil degranulation was not dependent on hypoxia-inducible factor (HIF), nor was it fully reversed by inhibition of phospholipase C signalling. Hypoxia augmented the resting and cytokine-stimulated phosphorylation of AKT, and inhibition of phosphoinositide 3-kinase (PI3K)γ (but not other PI3K isoforms) prevented the hypoxic upregulation of neutrophil elastase release. Conclusion Hypoxia augments neutrophil degranulation and confers enhanced potential for damage to respiratory airway epithelial cells in a HIF-independent but PI3Kγ-dependent fashion. PMID:27581620

  4. Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers

    OpenAIRE

    Concha, Claudia; Carretta, María Daniella; Alarcón, Pablo; Conejeros, Ivan; Gallardo, Diego; Hidalgo, Alejandra Isabel; Tadich, Nestor; Cáceres, Dante Daniel; Hidalgo, María Angélica; Burgos, Rafael Agustín

    2014-01-01

    Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood ne...

  5. Diagnostic Accuracy of Preoperative Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Detecting Occult Papillary Thyroid Microcarcinomas in Benign Multinodular Goitres

    Directory of Open Access Journals (Sweden)

    Dimitrios K. Manatakis

    2018-01-01

    Full Text Available Objective. To investigate the diagnostic accuracy of neutrophil-to-lymphocyte (NLR and platelet-to-lymphocyte (PLR ratios in detecting occult papillary thyroid microcarcinomas in benign, multinodular goitres. Methods. 397 total thyroidectomy patients were identified from the institutional thyroid surgery database between 2007 and 2016 (94 males, 303 females, mean age 53 ± 14.5 years. NLR and PLR were calculated as the absolute neutrophil and absolute platelet counts divided by the absolute lymphocyte count, respectively, based on the preoperative complete blood cell count. Results. NLR was significantly higher in carcinomas and microcarcinomas compared to benign pathology (p=0.026, whereas a direct association could not be established for PLR. Both NLR and PLR scored low in all parameters of diagnostic accuracy, with overall accuracy ranging between 45 and 50%. Conclusions. As surrogate indices of the systemic inflammatory response, NLR and PLR are inexpensive and universally available from routine blood tests. Although we found higher NLR values in cases of malignancy, NLR and PLR cannot effectively predict the presence of occult papillary microcarcinomas in otherwise benign, multinodular goitres.

  6. Thrombopoietin contributes to enhanced platelet activation in cigarette smokers.

    Science.gov (United States)

    Lupia, Enrico; Bosco, Ornella; Goffi, Alberto; Poletto, Cesare; Locatelli, Stefania; Spatola, Tiziana; Cuccurullo, Alessandra; Montrucchio, Giuseppe

    2010-05-01

    Thrombopoietin (TPO) is a humoral growth factor that primes platelet activation in response to several agonists. We recently showed that TPO enhances platelet activation in unstable angina and sepsis. Aim of this study was to investigate the role of TPO in platelet function abnormalities described in cigarette smokers. In a case-control study we enrolled 20 healthy cigarette smokers and 20 nonsmokers, and measured TPO and C-reactive protein (CRP), as well as platelet-leukocyte binding and P-selectin expression. In vitro we evaluated the priming activity of smoker or control plasma on platelet activation, and the role of TPO in this effect. We then studied the effects of acute smoking and smoking cessation on TPO levels and platelet activation indices. Chronic cigarette smokers had higher circulating TPO levels than nonsmoking controls, as well as increased platelet-leukocyte binding, P-selectin expression, and CRP levels. Serum cotinine concentrations correlated with TPO concentrations, platelet-monocyte aggregates and P-selectin expression. In addition, TPO levels significantly correlated with ex vivo platelet-monocyte aggregation and P-selectin expression. In vitro, the plasma from cigarette smokers, but not from nonsmoking controls, primed platelet-monocyte binding, which was reduced when an inhibitor of TPO was used. We also found that acute smoking slightly increased TPO levels, but did not affect platelet-leukocyte binding, whereas smoking cessation induced a significant decrease in both circulating TPO and platelet-leukocyte aggregation. Elevated TPO contributes to enhance platelet activation and platelet-monocyte cross-talk in cigarette smokers. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  7. CD177 modulates human neutrophil migration through activation-mediated integrin and chemoreceptor regulation.

    Science.gov (United States)

    Bai, Ming; Grieshaber-Bouyer, Ricardo; Wang, Junxia; Schmider, Angela B; Wilson, Zachary S; Zeng, Liling; Halyabar, Olha; Godin, Matthew D; Nguyen, Hung N; Levescot, Anaïs; Cunin, Pierre; Lefort, Craig T; Soberman, Roy J; Nigrovic, Peter A

    2017-11-09

    CD177 is a glycosylphosphatidylinositol (GPI)-anchored protein expressed by a variable proportion of human neutrophils that mediates surface expression of the antineutrophil cytoplasmic antibody antigen proteinase 3. CD177 associates with β2 integrins and recognizes platelet endothelial cell adhesion molecule 1 (PECAM-1), suggesting a role in neutrophil migration. However, CD177 pos neutrophils exhibit no clear migratory advantage in vivo, despite interruption of in vitro transendothelial migration by CD177 ligation. We sought to understand this paradox. Using a PECAM-1-independent transwell system, we found that CD177 pos and CD177 neg neutrophils migrated comparably. CD177 ligation selectively impaired migration of CD177 pos neutrophils, an effect mediated through immobilization and cellular spreading on the transwell membrane. Correspondingly, CD177 ligation enhanced its interaction with β2 integrins, as revealed by fluorescence lifetime imaging microscopy, leading to integrin-mediated phosphorylation of Src and extracellular signal-regulated kinase (ERK). CD177-driven cell activation enhanced surface β2 integrin expression and affinity, impaired internalization of integrin attachments, and resulted in ERK-mediated attenuation of chemokine signaling. We conclude that CD177 signals in a β2 integrin-dependent manner to orchestrate a set of activation-mediated mechanisms that impair human neutrophil migration. © 2017 by The American Society of Hematology.

  8. Association of High Density Lipoprotein with Platelet to Lymphocyte and Neutrophil to Lymphocyte Ratios in Coronary Artery Disease Patients

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    Jayesh H. Prajapati

    2014-01-01

    Full Text Available Background. We aimed to evaluate a relationship between platelet-lymphocyte ratio (PLR and neutrophil-lymphocyte ratio (NLR with high density lipoprotein (HDL cholesterol levels in coronary artery disease (CAD patients. Methods. A total of 354 patients with angiographically confirmed coronary blockages were enrolled in the study. Hematological indices and lipid profiling data of all the patients were collected. Results. We have observed significant association between HDL and PLR (P=0.008 and NLR (P=0.009; however no significant relationship was obtained with HDL and isolated platelet (P=0.488, neutrophil (P=0.407, and lymphocyte (P=0.952 counts in CAD patients. The association was subjected to gender specific variation as in males PLR (P=0.024 and NLR (P=0.03 were highly elevated in low HDL patients, whereas in females the elevation could not reach the statistically significant level. The PLR (217.47 versus 190.3; P=0.01 and NLR (6.33 versus 5.10; P=0.01 were significantly higher among the patients with acute coronary syndrome. In young patients the PLR (P=0.007 and NLR (P=0.001 were inversely associated with HDL, whereas in older population only NLR (P=0.05 had showed a significant association. Conclusion. We conclude that PLR and NLR are significantly elevated in CAD patients having low HDL levels.

  9. Is combination of neutrophil to lymphocyte ratio and platelet lymphocyte ratio a useful predictor of postoperative survival in patients with esophageal squamous cell carcinoma?

    Directory of Open Access Journals (Sweden)

    Tanoglu A

    2014-03-01

    Full Text Available Alpaslan Tanoglu,1 Ergenekon Karagoz,2 Nurettin Yiyit,3 Ufuk Berber4 1Department of Gastroenterology, 2Department of Infectious Diseases and Clinical Microbiology, 3Department of Thoracic Surgery, 4Department of Pathology, GATA Haydarpasa Training Hospital, Uskudar, TurkeyWe read with interest the recent article entitled "Combination of neutrophil to lymphocyte ratio and platelet lymphocyte ratio is a useful predictor of postoperative survival in patients with esophageal squamous cell carcinoma" by Feng et al.1 In their study, authors aimed to investigate the usefulness of a novel inflammation-based prognostic system, using the combination of neutrophil lymphocyte ratio (NLR and platelet lymphocyte ratio (PLR, for predicting survival in patients with esophageal squamous cell carcinoma (ESCC. Finally, they concluded that combination of NLR and PLR is a useful predictor of postoperative survival in patients with ESCC and combination of these parameters is superior to NLR or PLR as a predictive factor in patients with ESCC. We would like to thank the authors for their contribution.View original paper by Feng and colleagues.

  10. Platelet activation and platelet-leukocyte interaction in β-thalassemia/hemoglobin E patients with marked nucleated erythrocytosis.

    Science.gov (United States)

    Keawvichit, Rassamon; Khowawisetsut, Ladawan; Chaichompoo, Porntip; Polsrila, Korakot; Sukklad, Suchana; Sukapirom, Kasama; Khuhapinant, Archrob; Fucharoen, Suthat; Pattanapanyasat, Kovit

    2012-11-01

    Patients with thalassemia, an inherited hemolytic anemia, have increased risk of hypercoagulable complications. A whole blood flow cytometric (FCM) method has been used for studies of platelet activation and platelet-leukocyte aggregation in these patients. However, this FCM method presents technical difficulties because of the high proportion of immature red blood cells (RBCs) in these patients. A protocol for the simultaneous measurement of platelet activation and their aggregation with leukocyte populations in whole blood using four-color FCM which excluded immature RBC was devised, and evaluated for the evaluation of platelet function in patients with β-thalassemia/hemoglobin E (HbE). Whole blood from these patients and from healthy volunteers was stained for platelet activation and platelet-leukocyte aggregates using anti-CD42a, anti-CD62P, anti-CD45 and glycophorin A (GPA) conjugated with different fluorochromes. Our FCM method is simple, effective and based on the assumption that GPA is present on all immature RBCs, but is not expressed on CD45⁺ leukocytes. Results from the studies showed that blood samples from these patients contained a high frequency of circulating activated platelets (CD42a⁺/CD62P⁺) when compared to samples from healthy individuals. The percentage of platelet-neutrophil, platelet-monocyte-but not platelet-lymphocyte-aggregates were also elevated in both thalassemia genotypes with marked increase in patients who had undergone splenectomy. These findings suggest that platelets adhere to neutrophils and monocytes are activated which support the clinical observation that splenectomized thalassemia patients have an increased risk of arterial or venous thrombotic manifestations.

  11. Emerging Evidence for Platelets as Immune and Inflammatory Effector Cells

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    Matthew Thomas Rondina

    2014-12-01

    Full Text Available While traditionally recognized for their roles in hemostatic pathways, emerging evidence demonstrates that platelets have previously unrecognized, dynamic roles that span the immune continuum. These newly-recognized platelet functions, including the secretion of immune mediators, interactions with endothelial cells, monocytes, and neutrophils, toll-like receptor (TLR mediated responses, and induction of neutrophil extracellular trap (NET formation, bridge thrombotic and inflammatory pathways and contribute to host defense mechanisms against invading pathogens. In this focused review, we highlight several of these emerging aspects of platelet biology and their implications in clinical infectious syndromes.

  12. Serial alterations in digital hemodynamics and endothelin-1 immunoreactivity, platelet-neutrophil aggregation, and concentrations of nitric oxide, insulin, and glucose in blood obtained from horses following carbohydrate overload.

    Science.gov (United States)

    Eades, Susan C; Stokes, Ashley M; Johnson, Philip J; LeBlanc, Casey J; Ganjam, Venkataseshu K; Buff, Preston R; Moore, Rustin M

    2007-01-01

    To quantify changes in endothelium-derived factors and relate those changes to various aspects of digital hemodynamics during the prodromal stages of carbohydrate overload (CHO)-induced laminitis in horses. 20 adult horses without abnormalities of the digit. Digital and jugular venous blood samples were collected at 1-hour intervals (for assessment of endothelin-1 [ET-1] immunoreactivity and measurement of glucose, insulin, and nitric oxide [NO] concentrations) or 4-hour intervals (CBC and platelet-neutrophil aggregate assessment) for 8 hours or 16 hours after induction of CHO-associated laminitis in horses treated with an ET-1 antagonist. Effects of treatment, collection site, and time and the random effects of horse on each variable were analyzed by use of a repeated-measures model. Where treatment and collection site had no significant effect, data were combined. Compared with baseline values, CHO resulted in changes in several variables, including a significant increase from baseline in digital blood ET-like immunoreactivity at 11 hours; digital blood ET-like immunoreactivity was significantly greater than that in jugular venous blood at 8, 9, 11, and 12 hours. Digital and jugular venous blood concentrations of glucose increased from baseline significantly at 3, 4, and 5 hours; insulin concentration increased significantly at 5 hours; and the number of platelet-neutrophil aggregates increased significantly at 12 hours. In horses, concurrent increases in venous blood ET-1 immunoreactivity, insulin and glucose concentrations, and platelet-neutrophil aggregates support a role of endothelial dysfunction in the pathogenesis of CHO-induced laminitis.

  13. Enhanced neutrophil chemotactic activity after bronchial challenge in subjects with grain dust-induced asthma.

    Science.gov (United States)

    Park, H S; Jung, K S

    1998-03-01

    There have been few reports suggesting involvement of neutrophils in induction of bronchoconstriction after inhalation of grain dust. To understand the role of neutrophils in pathogenesis of grain dust-induced asthma. We observed serum neutrophil chemotactic activity during grain dust-bronchoprovocation tests in six asthmatic subjects with positive bronchial challenges (group I). They were compared with those of six symptomatic subjects from the same workplace with negative bronchial challenges (group II). After grain dust inhalation, serum neutrophil chemotactic activity significantly increased at 30 minutes (P = .028), and then decreased to baseline level at 240 minutes (P = .028) in five subjects of group I having isolated early asthmatic responses. Enhanced neutrophil chemotactic activity was persistent for up to 240 minutes in one asthmatic subject having both early and late asthmatic responses. There was, however, no significant change in serum neutrophil chemotactic activity during bronchial challenges in subjects of group II. Pre-incubation of sera with anti-interleukin-8 (IL-8) antibody did not affect the neutrophil chemotactic activity results of group I subjects. These results suggest that enhanced neutrophil chemotactic activity distinct from IL-8 may contribute to significant bronchoconstriction induced by grain dust.

  14. The ratio Neutrophil/Lymphocyte and Platelet/Lymphocyte in patient with Rheumatoid Arthritis that are Treating with Anti-TNF

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    İsmail Boyraz

    2014-06-01

    Full Text Available OBJECTIVES: Rheumatoid arthritis (RA is a chronic inflammatory disorder with unknown etiology. RA is characterized by a variable course of remissions and relapses, and subclinical inflammation persists between the disease exacerbations. Anti-TNF therapies have become more often preferred in recent years in the treatment of RA. The aim of the present study was to determine the relationship between N/L and P/L ratios and subclinical inflammation in patients with RA who achieved remission with anti-TNF therapy. METHODS: The present study was a retrospective, controlled and multicenter study. The present study reviewed the medical records of the patients who were on follow-up in the outpatient clinics of the Department of Physical Therapy in Abant İzzet Baysal University and Harran University due to rheumatoid arthritis (RA and who achieved remission with anti-TNF therapy.A total of 80 patients in the inactive phase of RA and 45 healthy subjects in the control group were included in the study. Hemogram results of the people were examined retrospectively. RESULTS: There was significant difference between the patient and the control group in terms of platelet ratio and lymphocyte and neutrophil ratio. There was no significant difference between the group in terms of N/L and P/L ratios.CONCLUSIONS:  In the current study, we found significant differences between the patient and the control group in terms of neutrophil, lymphocyte, and platelet counts; however, there was no significant difference between the two groups in terms of N/L and P/L ratios. These findings suggest that therapies with anti-TNF agents in patients with RA achieved complete control of inflammation. 

  15. In vivo characterization of neutrophil extracellular traps in various organs of a murine sepsis model.

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    Koji Tanaka

    Full Text Available Neutrophil extracellular traps (NETs represent extracellular microbial trapping and killing. Recently, it has been implicated in thrombogenesis, autoimmune disease, and cancer progression. The aim of this study was to characterize NETs in various organs of a murine sepsis model in vivo and to investigate their associations with platelets, leukocytes, or vascular endothelium. NETs were classified as two distinct forms; cell-free NETs that were released away from neutrophils and anchored NETs that were anchored to neutrophils. Circulating cell-free NETs were characterized as fragmented or cotton-like structures, while anchored NETs were characterized as linear, reticular, membranous, or spot-like structures. In septic mice, both anchored and cell-free NETs were significantly increased in postcapillary venules of the cecum and hepatic sinusoids with increased leukocyte-endothelial interactions. NETs were also observed in both alveolar space and pulmonary capillaries of the lung. The interactions of NETs with platelet aggregates, leukocyte-platelet aggregates or vascular endothelium of arterioles and venules were observed in the microcirculation of septic mice. Microvessel occlusions which may be caused by platelet aggregates or leukocyte-platelet aggregates and heterogeneously decreased blood flow were also observed in septic mice. NETs appeared to be associated with the formation of platelet aggregates or leukocyte-platelet aggregates. These observational findings may suggest the adverse effect of intravascular NETs on the host during a sepsis.

  16. The combination of platelet count and neutrophil lymphocyte ratio is a predictive factor in patients with esophageal squamous cell carcinoma.

    Science.gov (United States)

    Feng, Ji-Feng; Huang, Ying; Chen, Qi-Xun

    2014-10-01

    The prognostic value of inflammation indexes in esophageal cancer was not established. In this study, therefore, both prognostic values of Glasgow prognostic score (GPS) and combination of platelet count and neutrophil lymphocyte ratio (COP-NLR) in patients with esophageal squamous cell carcinoma (ESCC) were investigated and compared. This retrospective study included 375 patients who underwent esophagectomy for ESCC. The cancer-specific survival (CSS) was calculated by the Kaplan-Meier method, and the difference was assessed by the log-rank test. The GPS was calculated as follows: patients with elevated C-reactive protein (> 10 mg/l) and hypoalbuminemia (l) were assigned to GPS2. Patients with one or no abnormal value were assigned to GPS1 or GPS0, respectively. The COP-NLR was calculated as follows: patients with elevated platelet count (> 300 × 10(9)/l) and neutrophil lymphocyte ratio (> 3) were assigned to COP-NLR2. Patients with one or no abnormal value were assigned to COP-NLR1 or COP-NLR0, respectively. The 5-year CSS in patients with GPS0, 1, and 2 was 50.0%, 27.0%, and 12.5%, respectively (P GPS (P = .003) and COP-NLR (P = .003) were significant predictors in such patients. In addition, our study demonstrated a similar hazard ratio (HR) between COP-NLR and GPS (HR = 1.394 vs HR = 1.367). COP-NLR is an independent predictive factor in patients with ESCC. We conclude that COP-NLR predicts survival in ESCC similar to GPS.

  17. An intense and short-lasting burst of neutrophil activation differentiates early acute myocardial infarction from systemic inflammatory syndromes.

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    Norma Maugeri

    Full Text Available BACKGROUND: Neutrophils are involved in thrombus formation. We investigated whether specific features of neutrophil activation characterize patients with acute coronary syndromes (ACS compared to stable angina and to systemic inflammatory diseases. METHODS AND FINDINGS: The myeloperoxidase (MPO content of circulating neutrophils was determined by flow cytometry in 330 subjects: 69 consecutive patients with acute coronary syndromes (ACS, 69 with chronic stable angina (CSA, 50 with inflammation due to either non-infectious (acute bone fracture, infectious (sepsis or autoimmune diseases (small and large vessel systemic vasculitis, rheumatoid arthritis. Four patients have also been studied before and after sterile acute injury of the myocardium (septal alcoholization. One hundred thirty-eight healthy donors were studied in parallel. Neutrophils with normal MPO content were 96% in controls, >92% in patients undergoing septal alcoholization, 91% in CSA patients, but only 35 and 30% in unstable angina and AMI (STEMI and NSTEMI patients, compared to 80%, 75% and 2% of patients with giant cell arteritis, acute bone fracture and severe sepsis. In addition, in 32/33 STEMI and 9/21 NSTEMI patients respectively, 20% and 12% of neutrophils had complete MPO depletion during the first 4 hours after the onset of symptoms, a feature not observed in any other group of patients. MPO depletion was associated with platelet activation, indicated by P-selectin expression, activation and transactivation of leukocyte β2-integrins and formation of platelet neutrophil and -monocyte aggregates. The injection of activated platelets in mice produced transient, P-selectin dependent, complete MPO depletion in about 50% of neutrophils. CONCLUSIONS: ACS are characterized by intense neutrophil activation, like other systemic inflammatory syndromes. In the very early phase of acute myocardial infarction only a subpopulation of neutrophils is massively activated, possibly via

  18. Concomitant nitrates enhance clopidogrel response during dual anti-platelet therapy.

    Science.gov (United States)

    Lee, Dong Hyun; Kim, Moo Hyun; Guo, Long Zhe; De Jin, Cai; Cho, Young Rak; Park, Kyungil; Park, Jong Sung; Park, Tae-Ho; Serebruany, Victor

    2016-01-15

    Despite advances in modern anti-platelet strategies, clopidogrel still remains the cornerstone of dual anti-platelet therapy (DAPT) in patients undergoing percutaneous coronary interventions (PCI). There is some inconclusive evidence that response after clopidogrel may be impacted by concomitant medications, potentially affecting clinical outcomes. Sustained released nitrates (SRN) are commonly used together with clopidogrel in post-PCI setting for mild vasodilatation and nitric oxide-induced platelet inhibition. We prospectively enrolled 458 patients (64.5 ± 9.6 years old, and 73.4% males) following PCI undergoing DAPT with clopidogrel and aspirin. Platelet reactivity was assessed by the VerifyNow™ P2Y12 assay at the maintenance outpatient setting. Concomitant SRN (n=266) significantly (p=0.008) enhanced platelet inhibition after DAPT (251.6 ± 80.9PRU) when compared (232.1 ± 73.5PRU) to the SRN-free (n=192) patients. Multivariate logistic regression analysis with the cut-off value of 253 PRU for defining heightened platelet reactivity confirmed independent correlation of more potent platelet inhibition during DAPT and use of SRN (Relative risk=1.675; Odds ratio [1.059-2.648]; p=0.027). In contrast, statins, calcium-channel blockers, beta blockers, angiotensin receptor blockers, ACE-inhibitors, diuretics, and anti-diabetic agents did not significantly impact platelet inhibition following DAPT. The synergic ability of SRN to enhance response during DAPT may have important clinical implications with regard to better cardiovascular protection, but extra bleeding risks, requiring further confirmation in a large randomized study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Platelet-derived microparticles regulates thrombin generation via phophatidylserine in abdominal sepsis.

    Science.gov (United States)

    Wang, Yongzhi; Zhang, Su; Luo, Lingtao; Norström, Eva; Braun, Oscar Ö; Mörgelin, Matthias; Thorlacius, Henrik

    2018-02-01

    Sepsis is associated with dysfunctional coagulation. Recent data suggest that platelets play a role in sepsis by promoting neutrophil accumulation. Herein, we show that cecal ligation and puncture (CLP) triggered systemic inflammation, which is characterized by formation of IL-6 and CXC chemokines as well as neutrophil accumulation in the lung. Platelet depletion decreased neutrophil accumulation, IL-6, and CXC chemokines formation in septic lungs. Depletion of platelets increased peak thrombin formation and total thrombin generation (TG) in plasma from septic animals. CLP elevated circulating levels of platelet-derived microparticles (PMPs). In vitro generated PMPs were a potent inducer of TG. Interestingly, in vitro wild-type recombinant annexin V abolished PMP-induced thrombin formation whereas a mutant annexin V protein, which does not bind to phosphatidylserine (PS), had no effect. Administration of wild-type, but not mutant annexin V, significantly inhibited thrombin formation in septic animals. Moreover, CLP-induced formation of thrombin-antithrombin complexes were reduced in platelet-depleted mice and in animals pretreated with annexin V. PMP-induced TG attenuated in FXII- and FVII-deficient plasma. These findings suggest that sepsis-induced TG is dependent on platelets. Moreover, PMPs formed in sepsis are a potent inducer of TG via PS exposure, and activation of both the intrinsic and extrinsic pathway of coagulation. In conclusion, these observations suggest that PMPs and PS play an important role in dysfunctional coagulation in abdominal sepsis. © 2017 Wiley Periodicals, Inc.

  20. Bio-inspired composites with functionally graded platelets exhibit enhanced stiffness.

    Science.gov (United States)

    Tapse, Sanjay; S, Anup

    2017-11-09

    Unidirectional composites inspired from biological materials such as nacre, are composed of stiff platelets arranged in a staggered manner within a soft matrix. Elaborate analyses have been conducted on the aforementioned composites and they are found to have excellent mechanical properties like stiffness, strength and fracture toughness. The superior properties exhibited by these composites have been proved to be the result of its unique structure. An emerging development in the field of composite structures is Functionally Graded Composites(FGC), whose properties vary spatially and possess enhanced thermo-mechanical properties. In this paper, the platelets are functionally graded with its Young's Modulus varying parabolically along the length. Two different models - namely, Tension Shear Chain Model and Minimisation of Complementary Energy Model have been employed to obtain the stiffness of the overall composite analytically. The effect of various parameters that define the composite model such as overlapping length between any two neighbouring platelets, different gradation parameters and platelet aspect ratio on the overall mechanical properties have been studied. Composites with functionally graded platelets are found to possess enhanced stiffness (upto 14% higher) for certain values of these parameters. The obtained solutions have been validated using Finite Element Analysis. Bio-inspired composites with functionally graded platelets can be engineered for structural applications, such as in automobile, aerospace and aircraft industry, where stiffness plays a crucial role. © 2017 IOP Publishing Ltd.

  1. Neutrophil: Lymphocyte Ratio and Mean Platelet Volume in Patients with Gout

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    Ayse Balkarli

    2016-09-01

    Full Text Available Aim: Gout is a clinical syndrome with increased uric acid concentration, which is caused by inflammatory response against monosodium urate (MSU crystals. In gout, neutrophils are involved in inflammatory response and neutrophil activation is dependent on local cytokine production. Mean platelet volume (MPV and neutrophillymphocyte ratio (NLR are considered as inflammatory markers in several diseases and it is reported that they may have prognostic significance. Inthe current literature, there is no study evaluating MPV and NLR in gout. In this retrospective study, we investigated the role of MPV and NLR in determining inflammation in gout disease. Material and Method: In this retrospective study, 106 patients with gout (91 men and 15 women meeting the inclusion criteria based on patient records and 148 age- and sex-matched healthy controls (128 men and 20 women were included. Laboratory data during attacks (group I and intercritical period (group II were collected for the patient group. Results: Mean age was 59.46±12.93 years in the patient group and 59.00±11.33 years in the control group. Age at first attack was 52.00±12.77 years and mean time interval between first 2 attacks was 6.00±5.52 months. There was tophus in 9 patients (8.5% and family history of gout in 17 patients (16.0%. Compared to groupII (intercritical period and the control, no significant difference in MPV levels was found in groupI (during attack. MPV was similar among the three groups. C-reactive protein (CRP and erythrocyte sedimentation rate (ESR were found to be significantly higher in group I compared to group II. There was significant difference in NLR among three groups. When classified according to the presence of tophus, it was seen that MPV and NLR were similar in both groups. Discussion: The finding of increased NLR during attacks and intercritical period show that patients with gout are subjected to chronic inflammation. Thus, NLR can be a simple, inexpensive

  2. Associations between lifestyles and neutrophil-lymphocyte and platelet-lymphocyte ratios in colorectal cancer.

    Science.gov (United States)

    Hong, Chuyuan; Wei, Yisheng; Jiang, Jianxin; Zhao, Chuxiong; Liang, Guojian; Wang, Guoqiang; Yang, Hui

    2014-06-01

    To explore the etiology of the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) abnormalities in colorectal cancer. In total, 230 patients with histopathologically confirmed colorectal cancer from August 2009 to August 2011 were recruited to our study. The associations between lifestyles (smoking, alcohol and pickled food consumption) and pretreatment NLR and PLR were estimated using the Kruskal-Wallis tests and linear regression model. The Kruskal-Wallis test showed a significant association between pickled food intake and pretreatment NLR but not PLR (P = 0.002, 0.057, respectively). Pairwise comparisons showed that, compared with those with a moderately frequent (2-3 times/week) and an infrequent (≤ once a week) intake of pickled food, high frequency (≥ four times/week) consumption of pickled food had a higher pretreatment NLR (P = 0.01, 0.007, respectively). Multivariate linear regression analysis showed pretreatment NLR increased significantly in high frequency (≥ four times/week) consumption of pickled food (P frequency intake of pickled food possibly contributes to higher NLR, which may reflect a systemic inflammatory response in colorectal cancer. © 2013 Wiley Publishing Asia Pty Ltd.

  3. Thrombopoietin contributes to enhanced platelet activation in patients with unstable angina.

    Science.gov (United States)

    Lupia, Enrico; Bosco, Ornella; Bergerone, Serena; Dondi, Anna Erna; Goffi, Alberto; Oliaro, Elena; Cordero, Marco; Del Sorbo, Lorenzo; Trevi, Giampaolo; Montrucchio, Giuseppe

    2006-12-05

    We sought to investigate the potential role of elevated levels of thrombopoietin (TPO) in platelet activation during unstable angina (UA). Thrombopoietin is a humoral growth factor that does not induce platelet aggregation per se, but primes platelet activation in response to several agonists. No data concerning its contribution to platelet function abnormalities described in patients with UA are available. We studied 15 patients with UA and, as controls, 15 patients with stable angina (SA) and 15 healthy subjects. We measured TPO and C-reactive protein (CRP), as well as monocyte-platelet binding and the platelet expression of P-selectin and of the TPO receptor, c-Mpl. The priming activity of patient or control plasma on platelet aggregation and monocyte-platelet binding and the role of TPO in this effect also were studied. Patients with UA showed higher circulating TPO levels, as well as increased monocyte-platelet binding, platelet P-selectin expression, and CRP levels, than those with SA and healthy control subjects. The UA patients also showed reduced platelet expression of the TPO receptor, c-Mpl. In vitro, the plasma from UA patients, but not from SA patients or healthy controls, primed platelet aggregation and monocyte-platelet binding, which were both reduced when an inhibitor of TPO was used. Thrombopoietin may enhance platelet activation in the early phases of UA, potentially participating in the pathogenesis of acute coronary syndromes.

  4. The importance of the mean platelet volume in the diagnosis of ...

    African Journals Online (AJOL)

    In terms of the focus of the study, hemoglobin, neutrophil count, mean cell volume (MCV), red cell distribution width (RDW), platelet, white blood cell (WBC), and lymphocyte counts were similar in both group (p > 0.05). ... Keywords: mean platelet volume, inflammation, palpitation, supraventricular tachycardia, diagnostic

  5. Enhanced {sup 18}F-FDG uptake in activated neutrophils is unaffected by respiratory burst inhibition with RGD

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    Paik, J. Y.; Lee, K. H.; Go, B. H.; Jeong, K. H.; Kim, H. K.; Choi, J. S.; Choi, Y.; Kim, P. T [Samsung Medical Center, Seoul (Korea, Republic of)

    2004-07-01

    Respiratory burst generation is an important response of activated neutrophils and is associated with enhanced glucose metabolism. Since such activation in dependent on adhesion through integrins, we investigated how integrin occupation with RGD influences respiratory burst response and {sup 18}F-FDG uptake in neutrophils. Human neutrophils separated from healthy volunteers were incubated in RPMI media. For RGD peptide inhibitory experiments, neutrophils were preincubated with 200 {mu} g/ml of cRGD peptides ad 37.deg. for 2 hr prior. Respiratory burst generation and uptake of {sup 18}F-FDG was then measured with or without PMA stimulation. Cellular total hexokinase levels were assayed with a colorimetric method. Treatment with RGD in the basal state resulted in a significant but relatively small increase in neutrophil superoxide release to 1.5{+-}0.25 fold o control levels (p<0.005). Whereas PMA stimulation caused a marked increase in superoxide generation, pretreatment with RGD caused a significant attenuation of this response to 35.6{+-}0.2% (p<0.005). PMA stimulation resulted in a significant increase in {sup 18}F-FDG uptake. However, unlike the attenution of superoxide generation, neutrophils pretreated with RGD before PMA stimulation showed an identical magnitude of enhanced {sup 18}F-FDG uptake (201.8{+-}20.5 of controls, p=0.0001). In addition, hexokinase levels were increased to comparable levels of approximately 1.5 fold for PMA stimulated neutrophils irrespective of RGD pretreatment. In conclusion, soluble RGD blocks stimulation of respiratory burst activation in neutrophils but does not inhibit stimulation of cellular glucose metabolism. This dissociation may contribute to maximally enhanced neutrophil FDG uptake in inflammatory lesions regardless of the occupancy of their integrin receptors.

  6. Prognostic roles of neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in ovarian cancer: a meta-analysis of retrospective studies.

    Science.gov (United States)

    Zhao, Zhe; Zhao, Xinrui; Lu, Jingjing; Xue, Jing; Liu, Peishu; Mao, Hongluan

    2018-04-01

    The systemic inflammatory response markers have been reported to be associated with the prognosis of various cancers. We conducted this meta-analysis of retrospective studies to evaluate and identify the prognostic impact of neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) on ovarian cancer. PubMed, EMBASE, and China National Knowledge Infrastructure databases were included to search for eligible studies. The following terms were used: "neutrophil to lymphocyte ratio", "NLR", "platelet to lymphocyte ratio", "PLR", "ovarian cancer", "ovary cancer", "ovarian carcinoma", "ovary carcinoma", "ovarian neoplasm", "ovary neoplasm", "ovarian tumor", and "ovary tumor". The random-effects model was chosen to estimate the pooled HR with 95% CI. Heterogeneity between studies was assessed by Higgins I 2 value. The stability and heterogeneity of studies were analyzed by sensitivity analysis. Publication bias was examined by Egger's test and Begg's test with the funnel plots. 13 studies consisting of 3467 patients were considered for meta-analysis. We found that the high NLR had a poor prognostic impact on OS and PFS in ovarian cancer, with a pooled HR 1.70, 95% CI 1.35-2.15 and HR 1.77, 95% CI 1.48-2.12, respectively. Similarly, the results showed the high PLR adversely affected OS and PFS in ovarian cancer, with a pooled HR 2.05, 95% CI 1.70-2.48 and HR 1.85, 95% CI 1.53-2.25, respectively. In conclusion, we found that both NLR and PLR had an unfavorable impact on PFS and OS of patients with ovarian cancer. Our meta-analysis supported that NLR/PLR could be effective prognostic predictors of ovarian cancer.

  7. Activation and regulation of arachidonic acid release in rabbit peritoneal neutrophils

    International Nuclear Information System (INIS)

    Tao, W.

    1988-01-01

    Arachidonic acid release in rabbit neutrophils can be enhanced by the addition of chemotactic fMet-Leu-Phe, platelet-activating factor, PAF, or the calcium ionophore A23187. Over 80% of the release [ 3 H]arachidonic acid comes from phosphatidylcholine and phosphatidylinositol. The release is dose-dependent and increases with increasing concentration of the stimulus. The A23187-induced release increases with increasing time of the stimulation. [ 3 H]arachidonic acid release, but not the rise in the concentration of intracellular calcium, is inhibited in pertussis toxin-treated neutrophils stimulated with PAF. The [ 3 H]arachidonic acid released by A23187 is potentiated while that release by fMET-Leu-Phe or PAF is inhibited in phorbol 12-myristate 13-acetate, PMA, treated rabbit neutrophils. The protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine, H-7, has no effect on the potentiation by PMA of the A23187-induced release, it prevents the inhibition by PMA of the release produced by PAF or fMet-Leu-Phe. In addition, PMA increases arachidonic acid release in H-7-treated cells stimulated with fMet-Leu-Phe. The diacylglycerol kinase inhibitor R59022 increases the level of diacylglycerol in neutrophils stimulated with fMet-Leu-Phe. Furthermore, R59022 potentiates [ 3 H] arachidonic acid release produced by fMet-Leu-Phe. This potentiation is not inhibited by H-7, in fact, it is increased in H-7-treated neutrophils

  8. Enrofloxacin enhances the formation of neutrophil extracellular traps in bovine granulocytes

    Science.gov (United States)

    Jerjomiceva, Natalja; Seri, Hisham; Völlger, Lena; Wang, Yanming; Zeitouni, Nathalie; Naim, Hassan Y.; von Köckritz-Blickwede, Maren

    2014-01-01

    Several antibiotics are known for their ability to accumulate in neutrophils and thereby modulate the antimicrobial functions of those cells. This manuscript demonstrates for the first time that an antibiotic, namely the fluoroquinolone enrofloxacin, enhances the formation of bovine neutrophil extracellular traps (NETs). When pharmacologically inactivating NADPH oxidase or peptidylarginine deiminase-4, enrofloxacin-induced NET-formation was distinctly reduced. Additionally, when treating the cells with cytochalasin D or nocodazole, the enrofloxacin-mediated NET-induction was abolished, indicating that besides oxidative burst and histone citrullination also the actin and microtubule polymerization are involved in this process. PMID:24642685

  9. Activated platelets enhance IL-10 secretion and reduce TNF-α secretion by monocytes

    DEFF Research Database (Denmark)

    Gudbrandsdottir, Sif; Hasselbalch, Hans C; Nielsen, Claus H

    2013-01-01

    ), Escherichia coli LPS, or intact Porphyromonas gingivalis. Addition of platelets activated by thrombin-receptor-activating peptide enhanced IL-10 production induced by LPS (p gingivalis (p ....05), and P. gingivalis (p gingivalis-stimulated cultures (p ... of activated platelets. Adherence of platelets increased TG- and TT-induced IL-10 secretion by monocytes (p gingivalis (p

  10. The use of autologous 111In-labelled platelets and scintigraphy to illustrate enhanced platelet activity during erection in the chacma baboon

    International Nuclear Information System (INIS)

    Dormehl, I.C.; Du Plessis, M.; Maree, M.; Bornman, M.S.; Du Plessis, D.J.

    1984-01-01

    The demonstration of thrombelastographic hypercoagulability in the penile blood during erection, and the accompanying deposition of fibrin onto the endothelial layer of the deep penile artery and trabecular surface inspired this investigation of the possible role that platelets might play in the process. The bloodpooling pattern in the penis during and after erection from electro-stimulation was studied in 9 male adult baboons (Papio ursinus) using in vivo sup(99m)Tc-labelled red blood cells and scintigraphy. Platelet activity was similarly investigated after administering autologous 111 In-labelled platelets to the baboons. The results indicate an enhanced platelet concentration with respect to blood-pooling during erection, and an entrapment of platelets after erection. (orig.) [de

  11. Elevated thrombopoietin in plasma of burned patients without and with sepsis enhances platelet activation.

    Science.gov (United States)

    Lupia, E; Bosco, O; Mariano, F; Dondi, A E; Goffi, A; Spatola, T; Cuccurullo, A; Tizzani, P; Brondino, G; Stella, M; Montrucchio, G

    2009-06-01

    Thrombopoietin (TPO) is a humoral growth factor that does not induce platelet aggregation per se, but enhances platelet activation in response to several agonists. Circulating levels of TPO are increased in patients with sepsis and are mainly related to sepsis severity. To investigate the potential contribution of elevated TPO levels in platelet activation during burn injury complicated or not by sepsis. We studied 22 burned patients, 10 without and 12 with sepsis, and 10 healthy subjects. We measured plasma levels of TPO, as well as leukocyte-platelet binding and P-selectin expression. The priming activity of plasma from burned patients or healthy subjects on platelet aggregation and leukocyte-platelet binding, and the role of TPO in these effects were also studied in vitro. Burned patients without and with sepsis showed higher circulating TPO levels and increased monocyte-platelet binding compared with healthy subjects. Moreover, TPO levels, monocyte-platelet binding and P-selectin expression were significantly higher in burned patients with sepsis than in burned patients without sepsis. In vitro, plasma from burned patients without and with sepsis, but not from healthy subjects, primed platelet aggregation, monocyte-platelet binding and platelet P-selectin expression. The effect of plasma from burned patients with sepsis was significantly higher than that of plasma from burned patients without sepsis. An inhibitor of TPO prevented the priming effect of plasma from burned patients. Increased TPO levels may enhance platelet activation during burn injury and sepsis, potentially participating in the pathogenesis of multi-organ failure in these diseases.

  12. Activated prostaglandin D2 receptors on macrophages enhance neutrophil recruitment into the lung

    Science.gov (United States)

    Jandl, Katharina; Stacher, Elvira; Bálint, Zoltán; Sturm, Eva Maria; Maric, Jovana; Peinhaupt, Miriam; Luschnig, Petra; Aringer, Ida; Fauland, Alexander; Konya, Viktoria; Dahlen, Sven-Erik; Wheelock, Craig E.; Kratky, Dagmar; Olschewski, Andrea; Marsche, Gunther; Schuligoi, Rufina; Heinemann, Akos

    2016-01-01

    Background Prostaglandin (PG) D2 is an early-phase mediator in inflammation, but its action and the roles of the 2 D-type prostanoid receptors (DPs) DP1 and DP2 (also called chemoattractant receptor–homologous molecule expressed on TH2 cells) in regulating macrophages have not been elucidated to date. Objective We investigated the role of PGD2 receptors on primary human macrophages, as well as primary murine lung macrophages, and their ability to influence neutrophil action in vitro and in vivo. Methods In vitro studies, including migration, Ca2+ flux, and cytokine secretion, were conducted with primary human monocyte-derived macrophages and neutrophils and freshly isolated murine alveolar and pulmonary interstitial macrophages. In vivo pulmonary inflammation was assessed in male BALB/c mice. Results Activation of DP1, DP2, or both receptors on human macrophages induced strong intracellular Ca2+ flux, cytokine release, and migration of macrophages. In a murine model of LPS-induced pulmonary inflammation, activation of each PGD2 receptor resulted in aggravated airway neutrophilia, tissue myeloperoxidase activity, cytokine contents, and decreased lung compliance. Selective depletion of alveolar macrophages abolished the PGD2-enhanced inflammatory response. Activation of PGD2 receptors on human macrophages enhanced the migratory capacity and prolonged the survival of neutrophils in vitro. In human lung tissue specimens both DP1 and DP2 receptors were located on alveolar macrophages along with hematopoietic PGD synthase, the rate-limiting enzyme of PGD2 synthesis. Conclusion For the first time, our results show that PGD2 markedly augments disease activity through its ability to enhance the proinflammatory actions of macrophages and subsequent neutrophil activation. PMID:26792210

  13. Prediction of Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma by Using Neutrophil to Lymphocyte Ratio and Platelet to Lymphocyte Ratio.

    Science.gov (United States)

    Ozgonul, Cem; Sertoglu, Erdim; Mumcuoglu, Tarkan; Ozge, Gokhan; Gokce, Gokcen

    2016-12-01

    To assess the levels of neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) in patients with pseudoexfoliation syndrome (PEX) and to compare the NLR and PLR results of patients with PEX, PEX glaucoma (PXG), and healthy controls. In total, 34 patients with PEX, 29 patients with PXG, and 42 healthy subjects were enrolled in this retrospective study. Complete ophthalmologic examination and complete blood count measurements were performed of all subjects. Complete blood counts were performed within 2 h of blood collection. There was a significant difference in NLR between PEX and control groups (p = 0.012) and PXG and control groups (p = 0.003). Also, a significant difference was found in PLR values between control and PXG groups (p = 0.024). Our study for the first time provides evidence that PLR and NLR may be useful for predicting the prognosis of PEX patients and progression to PXG.

  14. MAC-1 Glycoprotein Family mediates adherence of neutrophils to endothelial cells stimulated by leukotriene B/sub 4/ and platelet activating factor

    Energy Technology Data Exchange (ETDEWEB)

    Tonnesen, M.G.; Anderson, D.C.; Springer, T.A.; Knedler, A.; Avdi, N.; Henson, P.M.

    1986-03-01

    The process of neutrophil (N) adhesion to and migration through endothelium (EC), an early event in the induction of the acute inflammatory response, has been attributed to the generation of extravascular chemoattractant peptides and lipids. Although both leukotriene B/sub 4/ (LTB/sub 4/) and platelet activating factor (PAF) enhance N adherence to EC, the mechanisms involved in this interaction are still not completely understood. Since the MAC-1 Glycoprotein (GP) Family has recently been shown to be required for a variety of adherence-dependent functions of stimulated N, the authors questioned whether these adherence-associated GP might be involved in N adherence to EC stimulated by LTB/sub 4/ or PAF. Using a microtiter adherence assay with /sup 111/In labeled N, they assessed the ability of N from patients with MAC-1, LFA-1 Deficiency to adhere to monolayers of human omental microvascular or umbilical vein EC as well as to serum-coated plastic. Patient N exhibited markedly diminished adherence in response to LTB/sub 4/ or PAF compared to normal controls. LTB/sub 4/ and PAF enhanced expression of the MAC-1 GP Family on the surface of normal N as determined by flow cytofluorimetry using a monoclonal antibody (TS1/18) to the GP common beta subunit. In addition TS1/18 (20 ..mu..g/ml) completely inhibited N adherence stimulated by either LTB/sub 4/ (10/sup -8/M) or PAF(10/sup -11/M). Thus, the MAC-1 GP Family appears to be important in chemotactic factor regulation of N adherence to EC.

  15. Neutrophil extracellular traps are pathogenic in primary graft dysfunction after lung transplantation.

    Science.gov (United States)

    Sayah, David M; Mallavia, Beñat; Liu, Fengchun; Ortiz-Muñoz, Guadalupe; Caudrillier, Axelle; DerHovanessian, Ariss; Ross, David J; Lynch, Joseph P; Saggar, Rajan; Ardehali, Abbas; Ware, Lorraine B; Christie, Jason D; Belperio, John A; Looney, Mark R

    2015-02-15

    Primary graft dysfunction (PGD) causes early mortality after lung transplantation and may contribute to late graft failure. No effective treatments exist. The pathogenesis of PGD is unclear, although both neutrophils and activated platelets have been implicated. We hypothesized that neutrophil extracellular traps (NETs) contribute to lung injury in PGD in a platelet-dependent manner. To study NETs in experimental models of PGD and in lung transplant patients. Two experimental murine PGD models were studied: hilar clamp and orthotopic lung transplantation after prolonged cold ischemia (OLT-PCI). NETs were assessed by immunofluorescence microscopy and ELISA. Platelet activation was inhibited with aspirin, and NETs were disrupted with DNaseI. NETs were also measured in bronchoalveolar lavage fluid and plasma from lung transplant patients with and without PGD. NETs were increased after either hilar clamp or OLT-PCI compared with surgical control subjects. Activation and intrapulmonary accumulation of platelets were increased in OLT-PCI, and platelet inhibition reduced NETs and lung injury, and improved oxygenation. Disruption of NETs by intrabronchial administration of DNaseI also reduced lung injury and improved oxygenation. In bronchoalveolar lavage fluid from human lung transplant recipients, NETs were more abundant in patients with PGD. NETs accumulate in the lung in both experimental and clinical PGD. In experimental PGD, NET formation is platelet-dependent, and disruption of NETs with DNaseI reduces lung injury. These data are the first description of a pathogenic role for NETs in solid organ transplantation and suggest that NETs are a promising therapeutic target in PGD.

  16. Endothelial cell SHP-2 negatively regulates neutrophil adhesion and promotes transmigration by enhancing ICAM-1-VE-cadherin interaction.

    Science.gov (United States)

    Yan, Meiping; Zhang, Xinhua; Chen, Ao; Gu, Wei; Liu, Jie; Ren, Xiaojiao; Zhang, Jianping; Wu, Xiaoxiong; Place, Aaron T; Minshall, Richard D; Liu, Guoquan

    2017-11-01

    Intercellular adhesion molecule-1 (ICAM-1) mediates the firm adhesion of leukocytes to endothelial cells and initiates subsequent signaling that promotes their transendothelial migration (TEM). Vascular endothelial (VE)-cadherin plays a critical role in endothelial cell-cell adhesion, thereby controlling endothelial permeability and leukocyte transmigration. This study aimed to determine the molecular signaling events that originate from the ICAM-1-mediated firm adhesion of neutrophils that regulate VE-cadherin's role as a negative regulator of leukocyte transmigration. We observed that ICAM-1 interacts with Src homology domain 2-containing phosphatase-2 (SHP-2), and SHP-2 down-regulation via silencing of small interfering RNA in endothelial cells enhanced neutrophil adhesion to endothelial cells but inhibited neutrophil transmigration. We also found that VE-cadherin associated with the ICAM-1-SHP-2 complex. Moreover, whereas the activation of ICAM-1 leads to VE-cadherin dissociation from ICAM-1 and VE-cadherin association with actin, SHP-2 down-regulation prevented ICAM-1-VE-cadherin association and promoted VE-cadherin-actin association. Furthermore, SHP-2 down-regulation in vivo promoted LPS-induced neutrophil recruitment in mouse lung but delayed neutrophil extravasation. These results suggest that SHP-2- via association with ICAM-1-mediates ICAM-1-induced Src activation and modulates VE-cadherin switching association with ICAM-1 or actin, thereby negatively regulating neutrophil adhesion to endothelial cells and enhancing their TEM.-Yan, M., Zhang, X., Chen, A., Gu, W., Liu, J., Ren, X., Zhang, J., Wu, X., Place, A. T., Minshall, R. D., Liu, G. Endothelial cell SHP-2 negatively regulates neutrophil adhesion and promotes transmigration by enhancing ICAM-1-VE-cadherin interaction. © FASEB.

  17. Th-17 regulatory cytokines IL-21, IL-23, and IL-6 enhance neutrophil production of IL-17 cytokines during asthma.

    Science.gov (United States)

    Halwani, Rabih; Sultana, Asma; Vazquez-Tello, Alejandro; Jamhawi, Amer; Al-Masri, Abeer A; Al-Muhsen, Saleh

    2017-11-01

    In a subset of severe asthma patients, chronic airway inflammation is associated with infiltration of neutrophils, Th-17 cells and elevated expression of Th-17-derived cytokines (e.g., interleukin [IL]-17, IL-21, IL-22). Peripheral neutrophils from allergic asthmatics are known to express higher IL-17 cytokine levels than those from healthy subjects, but the regulatory mechanisms involved are not well understood. We hypothesize that Th-17 regulatory cytokines could modulate IL-17 expression in neutrophils. Peripheral blood neutrophils isolated from asthmatics were stimulated with IL-21, IL-23, and IL-6 cytokines and their ability to produce IL-17A and IL-17F was determined relative to healthy controls. Signal transducer and activator of transcription 3 (STAT3) phosphorylation levels were measured in stimulated neutrophil using flow cytometry. The requirement for STAT3 phosphorylation was determined by blocking its activation using a specific chemical inhibitor. Stimulating asthmatic neutrophils with IL-21, 23, and 6 enhanced the production of IL-17A and IL-17F at significantly higher levels comparatively to healthy controls. Stimulating neutrophils with IL-21, IL-23, and IL-6 cytokines enhanced STAT3 phosphorylation, in all cases. Interestingly, inhibiting STAT3 phosphorylation using a specific chemical inhibitor dramatically blocked the ability of neutrophils to produce IL-17, demonstrating that STAT3 activation is the major factor mediating IL-17 gene expression. These findings suggest that neutrophil infiltration in lungs of severe asthmatics may represent an important source of pro-inflammatory IL-17A and -F cytokines, a production enhanced by Th-17 regulatory cytokines, and thus providing a feedback mechanism that sustains inflammation. Our results suggest that STAT3 pathway could be a potential target for regulating neutrophilic inflammation during severe asthma.

  18. Reduced platelet-mediated and enhanced leukocyte-mediated fibrinolysis in experimentally induced diabetes in rats

    International Nuclear Information System (INIS)

    Winocour, P.D.; Colwell, J.A.

    1985-01-01

    Studies of fibrinolytic activity in diabetes mellitus have produced conflicting results. This may be a result of methodologic insensitivity or of variable contributions of the different blood components to whole blood fibrinolysis. To explore these two possibilities, the authors used a sensitive solid-phase radiometric assay to examine the fibrinolytic activity of whole blood, platelet-rich plasma, leukocytes, and platelet- and leukocyte-poor plasma prepared from control rats and rats with streptozocin-induced diabetes at various times after induction of diabetes. Fibrinolytic activity of whole blood from diabetic rats after 7 days was significantly reduced, and remained reduced after longer durations of diabetes up to 28 days. Platelet-rich plasma from diabetic rats had decreased fibrinolytic activity, which followed the same time course of changes as in whole blood. The platelet contribution to whole blood fibrinolysis was further reduced in vivo after 14 days of diabetes by a reduced whole blood platelet count. In contrast, fibrinolytic activity of leukocytes from diabetic rats became enhanced after 7 days of diabetes. After 49 days of diabetes, the whole blood leukocyte count was reduced, and in vivo would offset the enhanced activity. Plasma fibrinolytic activity was small compared with that of whole blood and was unaltered in diabetic rats. The authors conclude that altered platelet function contributes to decreased fibrinolytic activity of whole blood in diabetic rats, and that this may be partially offset by enhanced leukocyte-mediated fibrinolysis

  19. The emerging role of neutrophils in thrombosis – The journey of TF through NETs

    Directory of Open Access Journals (Sweden)

    Konstantinos eKambas

    2012-12-01

    Full Text Available The production of TF by neutrophils and their contribution in thrombosis was until recently a matter of scientific debate. Experimental data suggested the de novo TF production by neutrophils under inflammatory stimuli, while others proposed that these cells acquired microparticle-derived TF. Recent experimental evidence revealed the critical role of neutrophils in thrombotic events. Neutrophil derived TF has been implicated in this process in several human and animal models. Additionally, neutrophil extracellular trap (NET release has emerged as a major contributor in neutrophil-driven thrombogenicity in disease models including sepsis, deep venous thrombosis and malignancy. It is suggested that NETs provide the scaffold for fibrin deposition and platelet entrapment and subsequent activation. The recently reported autophagy-dependent extracellular delivery of TF in NETs further supports the involvement of neutrophils in thrombosis. Herein, we seek to review novel data regarding the role of neutrophils in thrombosis, emphasizing the implication of TF and NETs.

  20. Salivary Thromboxane A2-Binding Proteins from Triatomine Vectors of Chagas Disease Inhibit Platelet-Mediated Neutrophil Extracellular Traps (NETs Formation and Arterial Thrombosis.

    Directory of Open Access Journals (Sweden)

    Daniella M Mizurini

    Full Text Available The saliva of blood-feeding arthropods contains a notable diversity of molecules that target the hemostatic and immune systems of the host. Dipetalodipin and triplatin are triatomine salivary proteins that exhibit high affinity binding to prostanoids, such as TXA2, thus resulting in potent inhibitory effect on platelet aggregation in vitro. It was recently demonstrated that platelet-derived TXA2 mediates the formation of neutrophil extracellular traps (NETs, a newly recognized link between inflammation and thrombosis that promote thrombus growth and stability.This study evaluated the ability of dipetalodipin and triplatin to block NETs formation in vitro. We also investigated the in vivo antithrombotic activity of TXA2 binding proteins by employing two murine models of experimental thrombosis. Remarkably, we observed that both inhibitors abolished the platelet-mediated formation of NETs in vitro. Dipetalodipin and triplatin significantly increased carotid artery occlusion time in a FeCl3-induced injury model. Treatment with TXA2-binding proteins also protected mice from lethal pulmonary thromboembolism evoked by the intravenous injection of collagen and epinephrine. Effective antithrombotic doses of dipetalodipin and triplatin did not increase blood loss, which was estimated using the tail transection method.Salivary TXA2-binding proteins, dipetalodipin and triplatin, are capable to prevent platelet-mediated NETs formation in vitro. This ability may contribute to the antithrombotic effects in vivo. Notably, both molecules inhibit arterial thrombosis without promoting excessive bleeding. Our results provide new insight into the antihemostatic effects of TXA2-binding proteins and may have important significance in elucidating the mechanisms of saliva to avoid host's hemostatic responses and innate immune system.

  1. Antiphospholipid Antibodies Promote the Release of Neutrophil Extracellular Traps: A New Mechanism of Thrombosis in the Antiphospholipid Syndrome

    Science.gov (United States)

    Yalavarthi, Srilakshmi; Gould, Travis J.; Rao, Ashish N.; Mazza, Levi F.; Morris, Alexandra E.; Núñez-Álvarez, Carlos; Hernández-Ramírez, Diego; Bockenstedt, Paula L.; Liaw, Patricia C.; Cabral, Antonio R.; Knight, Jason S.

    2015-01-01

    Objective Antiphospholipid antibodies (aPL), especially those targeting beta-2-glycoprotein I (β2GPI), are well known to activate endothelial cells, monocytes, and platelets, with prothrombotic implications. In contrast, the interaction of aPL with neutrophils has not been extensively studied. Neutrophil extracellular traps (NETs) have recently been recognized as an important activator of the coagulation cascade, as well as an integral component of arterial and venous thrombi. Here, we hypothesized that aPL might activate neutrophils to release NETs, thereby predisposing to the arterial and venous thrombosis inherent to the antiphospholipid syndrome (APS). Methods Neutrophils, sera, and plasma were prepared and characterized from patients with primary APS (n=52), or from healthy volunteers. No patient carried a concomitant diagnosis of systemic lupus erythematosus. Results Sera and plasma from patients with primary APS have elevated levels of both cell-free DNA and NETs, as compared to healthy volunteers. Freshly-isolated APS neutrophils are predisposed to high levels of spontaneous NET release. Further, APS-patient sera, as well as IgG purified from APS patients, stimulate NET release from control neutrophils. Human aPL monoclonals, especially those targeting β2GPI, also enhance NET release. The induction of APS NETs can be abrogated with inhibitors of reactive oxygen species formation and toll-like receptor 4 signaling. Highlighting the potential clinical relevance of these findings, APS NETs promote thrombin generation. Conclusion Neutrophil NET release warrants further investigation as a novel therapeutic target in APS. PMID:26097119

  2. The Use of Platelet-Rich and Platelet-Poor Plasma to Enhance Differentiation of Skeletal Myoblasts: Implications for the Use of Autologous Blood Products for Muscle Regeneration.

    Science.gov (United States)

    Miroshnychenko, Olga; Chang, Wen-Teh; Dragoo, Jason L

    2017-03-01

    Platelet-rich plasma (PRP) has been used to augment tissue repair and regeneration after musculoskeletal injury. However, there is increasing clinical evidence that PRP does not show a consistent clinical effect. Purpose/Hypothesis: This study aimed to compare the effects of the following non-neutrophil-containing (leukocyte-poor) plasma fractions on human skeletal muscle myoblast (HSMM) differentiation: (1) PRP, (2) modified PRP (Mod-PRP), in which transforming growth factor β1 (TGF-β1) and myostatin (MSTN) were depleted, and (3) platelet-poor plasma (PPP). The hypothesis was that leukocyte-poor PRP would lead to myoblast proliferation (not differentiation), whereas certain modifications of PRP preparations would increase myoblast differentiation, which is necessary for skeletal muscle regeneration. Controlled laboratory study. Blood from 7 human donors was individually processed to simultaneously create leukocyte-poor fractions: PRP, Mod-PRP, PPP, and secondarily spun PRP and Mod-PRP (PRP ss and Mod-PRP ss , respectively). Mod-PRP was produced by removing TGF-β1 and MSTN from PRP using antibodies attached to sterile beads, while a second-stage centrifugal spin of PRP was performed to remove platelets. The biologics were individually added to cell culture groups. Analysis for induction into myoblast differentiation pathways included Western blot analysis, reverse-transcription polymerase chain reaction, and immunohistochemistry, as well as confocal microscopy to assess polynucleated myotubule formation. HSMMs cultured with PRP showed an increase in proliferation but no evidence of differentiation. Western blot analysis confirmed that MSTN and TGF-β1 could be decreased in Mod-PRP using antibody-coated beads, but this modification mildly improved myoblast differentiation. However, cell culture with PPP, PRP ss , and Mod-PRP ss led to a decreased proliferation rate but a significant induction of myoblast differentiation verified by increased multinucleated

  3. The hemostatic agent ethamsylate enhances P-selectin membrane expression in human platelets and cultured endothelial cells.

    Science.gov (United States)

    Alvarez-Guerra, Miriam; Hernandez, Maria Rosa; Escolar, Ginés; Chiavaroli, Carlo; Garay, Ricardo P; Hannaert, Patrick

    2002-09-15

    Ethamsylate possesses antihemorrhagic properties, but whether or not it directly activates blood platelets is unclear. Here we investigated the platelet activation potential of ethamsylate, by measuring membrane P-selectin expression with flow cytometry in human whole blood and also by immunofluorescence imaging of isolated human platelets. Moreover, we measured membrane P-selectin expression in the SV40-transformed aortic rat endothelial cell line (SVAREC) and 14C-ethamsylate membrane binding and/or uptake in platelets and endothelial cells. Whole blood flow cytometry showed a modest, but statistically significant increase by ethamsylate in the percentage of platelets expressing P-selectin (from 2% to 4-5%, p ethamsylate tested (1 microM), with maximal enhancement of P-selectin expression (75-90%) at 10 microM ethamsylate. Similar results were obtained in SVAREC endothelial cells. 14C-ethamsylate specifically bound to platelets and endothelial cell membranes, without significant uptake into the cell interior. In conclusion, ethamsylate enhances membrane P-selectin expression in human platelets and in cultured endothelial cells. Ethamsylate specifically binds to some protein receptor in platelet and endothelial cell membranes, receptor which can signal for membrane P-selectin expression. These results support the view that ethamsylate acts on the first step of hemostasis, by improving platelet adhesiveness and restoring capillary resistance. Copyright 2002 Elsevier Science Ltd.

  4. Plerixafor (a CXCR4 antagonist following myeloablative allogeneic hematopoietic stem cell transplantation enhances hematopoietic recovery

    Directory of Open Access Journals (Sweden)

    Michael M. B. Green

    2016-08-01

    Full Text Available Abstract Background The binding of CXCR4 with its ligand (stromal-derived factor-1 maintains hematopoietic stem/progenitor cells (HSPCs in a quiescent state. We hypothesized that blocking CXCR4/SDF-1 interaction after hematopoietic stem cell transplantation (HSCT promotes hematopoiesis by inducing HSC proliferation. Methods We conducted a phase I/II trial of plerixafor on hematopoietic cell recovery following myeloablative allogeneic HSCT. Patients with hematologic malignancies receiving myeloablative conditioning were enrolled. Plerixafor 240 μg/kg was administered subcutaneously every other day beginning day +2 until day +21 or until neutrophil recovery. The primary efficacy endpoints of the study were time to absolute neutrophil count >500/μl and platelet count >20,000/μl. The cumulative incidence of neutrophil and platelet engraftment of the study cohort was compared to that of a cohort of 95 allogeneic peripheral blood stem cell transplant recipients treated during the same period of time and who received similar conditioning and graft-versus-host disease prophylaxis. Results Thirty patients received plerixafor following peripheral blood stem cell (n = 28 (PBSC or bone marrow (n = 2 transplantation. Adverse events attributable to plerixafor were mild and indistinguishable from effects of conditioning. The kinetics of neutrophil and platelet engraftment, as demonstrated by cumulative incidence, from the 28 study subjects receiving PBSC showed faster neutrophil (p = 0.04 and platelet recovery >20 K (p = 0.04 compared to the controls. Conclusions Our study demonstrated that plerixafor can be given safely following myeloablative HSCT. It provides proof of principle that blocking CXCR4 after HSCT enhances hematopoietic recovery. Larger, confirmatory studies in other settings are warranted. Trial registration ClinicalTrials.gov NCT01280955

  5. Specific Inflammatory Stimuli Lead to Distinct Platelet Responses in Mice and Humans.

    Directory of Open Access Journals (Sweden)

    Lea M Beaulieu

    Full Text Available Diverse and multi-factorial processes contribute to the progression of cardiovascular disease. These processes affect cells involved in the development of this disease in varying ways, ultimately leading to atherothrombosis. The goal of our study was to compare the differential effects of specific stimuli--two bacterial infections and a Western diet--on platelet responses in ApoE-/- mice, specifically examining inflammatory function and gene expression. Results from murine studies were verified using platelets from participants of the Framingham Heart Study (FHS; n = 1819 participants.Blood and spleen samples were collected at weeks 1 and 9 from ApoE-/- mice infected with Porphyromonas gingivalis or Chlamydia pneumoniae and from mice fed a Western diet for 9 weeks. Transcripts based on data from a Western diet in ApoE-/- mice were measured in platelet samples from FHS using high throughput qRT-PCR.At week 1, both bacterial infections increased circulating platelet-neutrophil aggregates. At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only. Microarray analysis of platelet RNA from infected or Western diet-fed mice at week 1 and 9 showed differential profiles. Genes, such as Serpina1a, Ttr, Fgg, Rpl21, and Alb, were uniquely affected by infection and diet. Results were reinforced in platelets obtained from participants of the FHS.Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity.

  6. Neutrophil extracellular traps promote deep vein thrombosis in mice

    Science.gov (United States)

    Brill, A.; Fuchs, T.A.; Savchenko, A.S.; Thomas, G.M.; Martinod, K.; De Meyer, S.F.; Bhandari, A.A.; Wagner, D.D.

    2011-01-01

    Summary Background Upon activation, neutrophils can release nuclear material known as neutrophil extracellular traps (NETs), which were initially described as a part of antimicrobial defense. Extracellular chromatin was recently reported to be pro-thrombotic in vitro and to accumulate in plasma and thrombi of baboons with experimental deep vein thrombosis (DVT). Objective To explore the source and role of extracellular chromatin in DVT. Methods We used an established murine model of DVT induced by flow restriction (stenosis) in the inferior vena cava (IVC). Results We demonstrate that the levels of extracellular DNA increase in plasma after 6 h IVC stenosis, compared to sham-operated mice. Immunohistochemical staining revealed the presence of Gr-1-positive neutrophils in both red (RBC-rich) and white (platelet-rich) parts of thrombi. Citrullinated histone H3 (CitH3), an element of NETs’ structure, was present only in the red part of thrombi and was frequently associated with the Gr-1 antigen. Immunofluorescent staining of thrombi showed proximity of extracellular CitH3 and von Willebrand factor (VWF), a platelet adhesion molecule crucial for thrombus development in this model. Infusion of Deoxyribonuclease 1 (DNase 1) protected mice from DVT after 6 h and also 48 h IVC stenosis. Infusion of an unfractionated mixture of calf thymus histones increased plasma VWF and promoted DVT early after stenosis application. Conclusions Extracellular chromatin, likely originating from neutrophils, is a structural part of a venous thrombus and both the DNA scaffold and histones appear to contribute to the pathogenesis of DVT in mice. NETs may provide new targets for DVT drug development. PMID:22044575

  7. Disruption of a Regulatory Network Consisting of Neutrophils and Platelets Fosters Persisting Inflammation in Rheumatic Diseases.

    Science.gov (United States)

    Maugeri, Norma; Rovere-Querini, Patrizia; Manfredi, Angelo A

    2016-01-01

    A network of cellular interactions that involve blood leukocytes and platelets maintains vessel homeostasis. It plays a critical role in the response to invading microbes by recruiting intravascular immunity and through the generation of neutrophil extracellular traps (NETs) and immunothrombosis. Moreover, it enables immune cells to respond to remote chemoattractants by crossing the endothelial barrier and reaching sites of infection. Once the network operating under physiological conditions is disrupted, the reciprocal activation of cells in the blood and the vessel walls determines the vascular remodeling via inflammatory signals delivered to stem/progenitor cells. A deregulated leukocyte/mural cell interaction is an early critical event in the natural history of systemic inflammation. Despite intense efforts, the signals that initiate and sustain the immune-mediated vessel injury, or those that enforce the often-prolonged phases of clinical quiescence in patients with vasculitis, have only been partially elucidated. Here, we discuss recent evidence that implicates the prototypic damage-associated molecular pattern/alarmin, the high mobility group box 1 (HMGB1) protein in systemic vasculitis and in the vascular inflammation associated with systemic sclerosis. HMGB1 could represent a player in the pathogenesis of rheumatic diseases and an attractive target for molecular interventions.

  8. Assessment of canine autologous platelet-rich plasma produced with a commercial centrifugation and platelet recovery kit.

    Science.gov (United States)

    Frye, Chris W; Enders, Andrew; Brooks, Marjory B; Struble, Angela M; Wakshlag, Joseph J

    2016-01-01

    To characterize the cellular composition (platelets, erythrocytes, and leukocytes) and confirm reproducibility of platelet enrichment, as well as determine the platelet activation status in the final product of a commercial platelet-rich plasma kit using canine blood. Venous blood from 20 sedated client-owned dogs was used to prepare platelet-rich plasma (PRP) from a commercial kit. Complete blood counts were performed to determine erythrocyte, leukocyte, and platelet numbers in both whole blood (WB) and resultant PRP. The WB and PRP samples from jugular (fast collection) and cephalic (slow collection) venipuncture were also compared. P-selectin externalization was measured in WB and PRP samples from 15 of 20 dogs. This commercial kit produced an average percent recovery in platelets of 64.7 ± 17.4; erythrocytes of 3.7 ± 0.8, and leukocytes of 31.6 ± 10.0. Neutrophil, monocyte, and lymphocyte percent recovery was 19.6 ± 7.2, 44.89 ± 19.8, and 57.5 ± 10.6, respectively. The recovery of platelets from jugular venipuncture (59.7 ± 13.6%) was lower than from cephalic recovery (68.8 ± 19.1%). The mean percent P-Selectin externalization for WB, PRP, and PRP with thrombin was 25.5 ± 30.9, 4.5 ± 6.4, and 90.6 ± 4.4 respectively. Cellular reproducibility of this kit was confirmed and platelets were concentrated within autologous serum. Additionally, measurements of P-selectin externalization showed that platelets are inactive in PRP unless stimulated to degranulate.

  9. Nimesulide inhibits platelet-activating factor synthesis in activated human neutrophils

    NARCIS (Netherlands)

    Verhoeven, A. J.; Tool, A. T.; Kuijpers, T. W.; Roos, D.

    1993-01-01

    In an inflammatory locus, products of activated neutrophils may be toxic both to the micro-organisms to be eliminated and to the surrounding tissue. In several models of inflammation, nimesulide possesses marked anti-inflammatory properties. The present study was undertaken to further investigate

  10. Platelets are required for enhanced activation of the endothelium and fibrinogen in a mouse thrombosis model of APS.

    Science.gov (United States)

    Proulle, Valerie; Furie, Richard A; Merrill-Skoloff, Glenn; Furie, Barbara C; Furie, Bruce

    2014-07-24

    Antiphospholipid syndrome (APS) is defined by thrombosis, fetal loss, and the presence of antiphospholipid antibodies, including anti-β2-glycoprotein-1 autoantibodies (anti-β2GP1) that have a direct role in the pathogenesis of thrombosis in vivo. The cellular targets of the anti-β2GP1 autoantibody/β2GP1 complex in vivo were studied using a laser-induced thrombosis model of APS in a live mouse and human anti-β2GP1 autoantibodies affinity-purified from APS patients. Cell binding of fluorescently labeled β2GP1 and anti-β2GP1 autoantibodies revealed their colocalization on the platelet thrombus but not the endothelium. Anti-β2GP1 autoantibodies enhanced platelet activation, monitored by calcium mobilization, and endothelial activation, monitored by intercellular adhesion molecule-1 expression. When eptifibatide was infused to block platelet thrombus formation, enhanced fibrin generation and endothelial cell activation were eliminated. Thus, the anti-β2GP1 autoantibody/β2GP1 complex binds to the thrombus, enhancing platelet activation, and platelet secretion leads to enhanced endothelium activation and fibrin generation. These results lead to a paradigm shift away from the concept that binding of the anti-β2GP1 autoantibody/β2GP1 complex activates both endothelial cells and platelets toward one in which activation of platelets in response to anti-β2GP1 autoantibody/β2GP1 complex binding leads to subsequent enhanced endothelium activation and fibrin generation. © 2014 by The American Society of Hematology.

  11. Podoplanin enhances lung cancer cell growth in vivo by inducing platelet aggregation.

    Science.gov (United States)

    Miyata, Kenichi; Takemoto, Ai; Okumura, Sakae; Nishio, Makoto; Fujita, Naoya

    2017-06-22

    Podoplanin/Aggrus, known as a platelet aggregation-inducing factor, is frequently overexpressed in lung squamous cell carcinomas (LSCC) and glioblastomas among other tumours, and its expression has been reported to be correlated with poor prognosis. However, the contribution of podoplanin to malignant progression has been elusive. Here we demonstrate that in podoplanin-positive LSCC cells, their growth was abrogated by podoplanin knockout in vivo but not in vitro. Conversely, ectopic expression of podoplanin promoted cell growth in vivo and facilitated intratumoral platelet activation. Consistently, LSCC cells evoked podoplanin-mediated platelet aggregation (PMPA), and the releasates from platelets during PMPA promoted the growth of LSCC cells in vitro. Phospho-receptor-tyrosine-kinase array analysis revealed that epidermal growth factor receptor (EGFR) phosphorylation of LSCC cells was responsible for the growth promotion induced by platelet releasates. Treatment with an antiplatelet agent or podoplanin-neutralizing antibody depressed the growth of an LSCC tumour xenograft via suppression of EGFR phosphorylation. These results suggested that podoplanin in LSCC enhanced cell growth by inducing PMPA in vivo and contributed to malignant progression.

  12. Enhanced Store-Operated Calcium Entry in Platelets is Associated with Peripheral Artery Disease in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Weijie Xia

    2015-11-01

    Full Text Available Background/Aims: Platelet dysfunction plays an important role in thrombosis in diabetes with peripheral artery disease (PAD. Store-operated calcium entry (SOCE and stromal interaction molecule 1 (STIM1 regulate platelet activity by modulating calcium influx. We hypothesized that enhanced SOCE in platelets is associated with diabetes with PAD. Methods: We studied the activity of platelets from healthy participants and from type 2 diabetic patients. Platelet calcium influx and protein expression of STIM1 and sarcoendoplasmic reticulum Ca2+-ATPase 3 (SERCA3 were investigated. Results: Compared with platelets from diabetic patients without PAD, platelets from diabetic patients with PAD exhibited significantly increased SOCE . Menthol administration completely inhibited calcium influx in platelets from diabetic patients without PAD, but this effect was blunted in those from diabetic patients with PAD. Furthermore, the increase in SOCE was correlated with the ankle brachial index (ABI in diabetic patients. High glucose significantly up-regulated STIM1 and SERCA3 protein expression and induced the phosphorylation of phospholipase C (PLC in platelets from healthy participants. This effect was attenuated in the presence of menthol or U73122, an inhibitor of PLC. Similarly, significant increases in STIM1 and SERCA3 protein expression were found in platelets from diabetic patients compared to those from healthy participants. Conclusion: Platelets from diabetic patients with PAD exhibited enhanced Store-operated calcium influx, which was associated with elevated STIM1/SERCA3 expression via a PLC-dependent pathway and was inhibited by menthol.

  13. The importance of the mean platelet volume in the diagnosis of ...

    African Journals Online (AJOL)

    EB

    2013-09-03

    Sep 3, 2013 ... The importance of the mean platelet volume in the diagnosis of ... terms of the focus of the study, hemoglobin, neutrophil count, mean cell volume (MCV), red cell distribution .... hormone replacement therapy and some drugs,.

  14. Quantitative proteomics reveals differential biological processes in healthy neonatal cord neutrophils and adult neutrophils

    KAUST Repository

    Zhu, Jiang; Zhang, Huoming; Guo, Tiannan; Li, Wenying; Li, Huiyu; Zhu, Yi; Huang, Shiang

    2014-01-01

    Neonatal neutrophils are characterized by the immaturity of bactericidal mechanisms that contributes largely to neonatal mortality. However, underlying molecular mechanism associated with the immaturity remains incompletely understood. In this study, we performed comparative proteomic analysis on neonatal neutrophils derived from human cord blood and adult peripheral neutrophils. A total of 1332 proteins were identified and quantified, and 127 proteins were characterized as differentially expressed between adult and cord neutrophils. The differentially expressed proteins are mapped in KEGG pathways into five clusters and indicated impaired functions of neonatal neutrophils in proteasome, lysosome, phagosome, and leukocyte transendothelial migration. In particular, many proteins associated with NETosis, a critical mechanism for antimicrobial process and auto-clearance, were also found to be downregulated in cord neutrophils. This study represents a first comparative proteome profiling of neonatal and adult neutrophils, and provides a global view of differentially expressed proteome for enhancing our understanding of their various functional difference. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Quantitative proteomics reveals differential biological processes in healthy neonatal cord neutrophils and adult neutrophils

    KAUST Repository

    Zhu, Jiang

    2014-06-11

    Neonatal neutrophils are characterized by the immaturity of bactericidal mechanisms that contributes largely to neonatal mortality. However, underlying molecular mechanism associated with the immaturity remains incompletely understood. In this study, we performed comparative proteomic analysis on neonatal neutrophils derived from human cord blood and adult peripheral neutrophils. A total of 1332 proteins were identified and quantified, and 127 proteins were characterized as differentially expressed between adult and cord neutrophils. The differentially expressed proteins are mapped in KEGG pathways into five clusters and indicated impaired functions of neonatal neutrophils in proteasome, lysosome, phagosome, and leukocyte transendothelial migration. In particular, many proteins associated with NETosis, a critical mechanism for antimicrobial process and auto-clearance, were also found to be downregulated in cord neutrophils. This study represents a first comparative proteome profiling of neonatal and adult neutrophils, and provides a global view of differentially expressed proteome for enhancing our understanding of their various functional difference. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Disruption of a regulatory network consisting of neutrophils and platelets fosters persisting inflammation in rheumatic diseases

    Directory of Open Access Journals (Sweden)

    Norma eMaugeri

    2016-05-01

    Full Text Available A network of cellular interactions that involve blood leukocytes and platelets maintains vessel homeostasis. It plays a critical role in the response to invading microbes by recruiting intravascular immunity and through the generation of Neutrophil Extracellular Traps (NETs and immunothrombosis. Moreover it enables immune cells to respond to remote chemoattractants by crossing the endothelial barrier and reaching sites of infection. Once the network operating under physiological conditions is disrupted, the reciprocal activation of cells in the blood and the vessel walls determines the vascular remodelling via inflammatory signals delivered to stem/progenitor cells. A deregulated leukocyte/mural cell interaction is an early critical event in the natural history of systemic inflammation. Despite intense efforts, the signals that initiate and sustain the immune-mediated vessel injury, or those that enforce the often-prolonged phases of clinical quiescence in patients with vasculitis, have only been partially elucidated. Here we discuss recent evidence that implicates the prototypic Damage-Associated Molecular Pattern/ alarmin, the High Mobility Group Box 1 (HMGB1 protein in systemic vasculitis and in the vascular inflammation associated to systemic sclerosis. HMGB1 could represent a player in the pathogenesis of rheumatic diseases and an attractive target for molecular interventions.

  17. Prognostic Impact of Neutrophil/Lymphocyte Ratio, Platelet Count, CRP, and Albumin Levels in Metastatic Colorectal Cancer Patients Treated with FOLFIRI-Bevacizumab.

    Science.gov (United States)

    Artaç, Mehmet; Uysal, Mükremin; Karaağaç, Mustafa; Korkmaz, Levent; Er, Zehra; Güler, Tunç; Börüban, Melih Cem; Bozcuk, Hakan

    2017-06-01

    Metastatic colorectal cancer (mCRC) is a lethal disease and fluorouracil-leucovorin-irinotecan (FOLFIRI) plus bevacizumab (bev) is a standard approach. Hence, there is a strong need for identifying new prognostic factors to show the efficacy of FOLFIRI-bev. This is a retrospective study including patients (n = 90) with mCRC from two centers in Turkey. Neutrophil/lymphocyte (N/L) ratio, platelet count, albumin, and C-reactive protein (CRP) were recorded before FOLFIRI-bev therapy. The efficacy of these factors on progression-free survival (PFS) was analyzed with Kaplan Meier and Cox regression analysis. And the cutoff value of N/L ratio was analyzed with ROC analysis. The median age was 56 years (range 21-80). Forty-seven percent of patients with N/L ratio >2.5 showed progressive disease versus 43 % in patients with N/L ratio ratio >2.5 versus 13.5 months for the patients with N/L ratio analysis, high baseline neutrophil count, LDH, N/L ratio, and CRP were all significantly associated with poor prognosis. At multivariate Cox regression analysis, CRP was confirmed to be a better independent prognostic factor. CRP variable was divided into above the upper limit of normal (ULN) and normal value. The median PFSs of the patients with normal and above ULN were 11.3 versus 5.8 months, respectively (p = 0.022). CRP and N/L ratio are potential predictors for advanced mCRC treated with FOLFIRI-bev.

  18. Factor H C-Terminal Domains Are Critical for Regulation of Platelet/Granulocyte Aggregate Formation

    Directory of Open Access Journals (Sweden)

    Adam Z. Blatt

    2017-11-01

    Full Text Available Platelet/granulocyte aggregates (PGAs increase thromboinflammation in the vasculature, and PGA formation is tightly controlled by the complement alternative pathway (AP negative regulator, Factor H (FH. Mutations in FH are associated with the prothrombotic disease atypical hemolytic uremic syndrome (aHUS, yet it is unknown whether increased PGA formation contributes to the thrombosis seen in patients with aHUS. Here, flow cytometry assays were used to evaluate the effects of aHUS-related mutations on FH regulation of PGA formation and characterize the mechanism. Utilizing recombinant fragments of FH spanning the entire length of the protein, we mapped the regions of FH most critical for limiting AP activity on the surface of isolated human platelets and neutrophils, as well as the regions most critical for regulating PGA formation in human whole blood stimulated with thrombin receptor-activating peptide (TRAP. FH domains 19–20 were the most critical for limiting AP activity on platelets, neutrophils, and at the platelet/granulocyte interface. The role of FH in PGA formation was attributed to its ability to regulate AP-mediated C5a generation. AHUS-related mutations in domains 19–20 caused differential effects on control of PGA formation and AP activity on platelets and neutrophils. Our data indicate FH C-terminal domains are key for regulating PGA formation, thus increased FH protection may have a beneficial impact on diseases characterized by increased PGA formation, such as cardiovascular disease. Additionally, aHUS-related mutations in domains 19–20 have varying effects on control of TRAP-mediated PGA formation, suggesting that some, but not all, aHUS-related mutations may cause increased PGA formation that contributes to excessive thrombosis in patients with aHUS.

  19. The Combination of Platelet Count and Neutrophil Lymphocyte Ratio Is a Predictive Factor in Patients with Esophageal Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Ji-Feng Feng

    2014-10-01

    Full Text Available OBJECTIVE: The prognostic value of inflammation indexes in esophageal cancer was not established. In this study, therefore, both prognostic values of Glasgow prognostic score (GPS and combination of platelet count and neutrophil lymphocyte ratio (COP-NLR in patients with esophageal squamous cell carcinoma (ESCC were investigated and compared. METHODS: This retrospective study included 375 patients who underwent esophagectomy for ESCC. The cancer-specific survival (CSS was calculated by the Kaplan-Meier method, and the difference was assessed by the log-rank test. The GPS was calculated as follows: patients with elevated C-reactive protein (>10 mg/l and hypoalbuminemia (300 × 109/l and neutrophil lymphocyte ratio (>3 were assigned to COP-NLR2. Patients with one or no abnormal value were assigned to COP-NLR1 or COP-NLR0, respectively. RESULTS: The 5-year CSS in patients with GPS0, 1, and 2 was 50.0%, 27.0%, and 12.5%, respectively (P < .001. The 5-year CSS in patients with COP-NLR0, 1, and 2 was 51.8%, 27.0%, and 11.6%, respectively (P < .001. Multivariate analysis showed that both GPS (P = .003 and COP-NLR (P = .003 were significant predictors in such patients. In addition, our study demonstrated a similar hazard ratio (HR between COP-NLR and GPS (HR = 1.394 vs HR = 1.367. CONCLUSIONS: COP-NLR is an independent predictive factor in patients with ESCC. We conclude that COP-NLR predicts survival in ESCC similar to GPS.

  20. The Predictive Value of Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratio for the Effusion Viscosity in Otitis Media With Chronic Effusion.

    Science.gov (United States)

    Elbistanli, Mustafa Suphi; Koçak, Hasan Emre; Acipayam, Harun; Yiğider, Ayşe Pelin; Keskin, Mehmet; Kayhan, Fatma Tülin

    2017-05-01

    The objective of the authors' study was to investigate the predictive value of the neutrophil-lymphocyte rate (NLR) and platelet-lymphocyte rate (PLR) in otitis media with effusion and the correlation of the effusion type with these ratios. Retrospective case-control study. One hundred twenty-six pediatric patients diagnosed otitis media with chronic effusion and had ventilation tube inserted between October 2015 and July 2016 were included in the study group and 124 healthy children, who applied for the routine examination and had blood count analysis, were included in the control group. The patients in the study group were divided into 2 groups regarding the effusion viscosity, which was obtained from the patients' operation files. Seventy-one patients were included in the serous group and 55 patients in the mucous group. The NLR and PLR rates of the groups were compared and statistically evaluated. The average NLR and PLR rates were significantly higher in the study group than in the control group (P = 0.000, P = 0.004 respectively). Comparison of the serous and mucous groups with the control group revealed a significant difference between the control group and the serous group regarding the NLR and PLR (P = 0.000; P = 0.000 respectively), but not between the control group and mucous group (P = 0.694; P = 0.691 respectively). Neutrophil-lymphocyte rate and PLR had a predictive value for otitis media with effusion and additionally it was a laboratory indicator supporting the typing of the viscosity of the fluid accumulated in the middle ear.

  1. Biomaterial-induced alterations of neutrophil superoxide production.

    Science.gov (United States)

    Kaplan, S S; Basford, R E; Mora, E; Jeong, M H; Simmons, R L

    1992-08-01

    Because periprosthetic infection remains a vexing problem for patients receiving implanted devices, we evaluated the effect of several materials on neutrophil free radical production. Human peripheral blood neutrophils were incubated with several sterile, lipopolysaccharide (LPS)-free biomaterials used in surgically implantable prosthetic devices: polyurethane, woven dacron, and velcro. Free radical formation as the superoxide (O2-) anion was evaluated by cytochrome c reduction in neutrophils that were exposed to the materials and then removed and in neutrophils allowed to remain in association with the materials. Neutrophils exposed to polyurethane or woven dacron for 30 or 60 min and then removed consistently exhibited an enhanced release of O2- after simulation via receptor engagement with formyl methionyl-leucyl-phenylalanine. Enhanced reactivity to stimulation via protein kinase C with phorbol myristate acetate, however, was not consistently observed. The cells evaluated for O2- release during continuous association with the biomaterials showed enhanced metabolic activity during short periods of association (especially with polyurethane and woven dacron). Although O2- release by neutrophils in association with these materials decreased with longer periods of incubation, it was not obliterated. These studies, therefore, show that several commonly used biomaterials activate neutrophils soon after exposure and that this activated state diminishes with prolonged exposure but nevertheless remains measurable. The diminishing level of activity with prolonged exposure, however, suggests that ultimately a depletion of reactivity may occur and may result in increased susceptibility to periprosthetic infection.

  2. Fish-Free Diet in Patients with Phenylketonuria Is Not Associated with Early Atherosclerotic Changes and Enhanced Platelet Activation.

    Directory of Open Access Journals (Sweden)

    Patrik Htun

    Full Text Available Since patients with phenylketonuria (PKU have to follow a lifelong restriction of natural protein to lower phenylalanine-intake, they never eat fish. This diet may lead to a chronic deficit of omega-3 and omega-6 fatty acids with the risk of early atherosclerotic changes. The aim of the study was to analyse the fatty acid profile of PKU patients and to correlate the results with surrogate markers of early atherosclerotic changes [enhanced carotid intima media thickness (CIMT and ß-stiffness index] and platelet activation.In 43 PKU patients and in 58 healthy controls we prospectively examined the fatty acid profile, CIMT, ß-stiffness index and platelet activation (flow cytometric determination of markers of platelet activation. CIMT was measured bilaterally by ultrasound. CIMTmean was defined as the mean value of the sum of CIMTleft and CIMTright.Despite of lower HDL-cholesterol and higher triglyceride concentrations in the PKU group, there was no significant difference in the omega-6 or omega-3 fatty acid profile, CIMT, ß-stiffness index between both groups. Platelet activation was not enhanced in the PKU group.Fish-free diet does not induce early atherosclerotic changes or enhanced platelet activation in PKU patients.

  3. Fish-Free Diet in Patients with Phenylketonuria Is Not Associated with Early Atherosclerotic Changes and Enhanced Platelet Activation.

    Science.gov (United States)

    Htun, Patrik; Nee, Jens; Ploeckinger, Ursula; Eder, Klaus; Geisler, Tobias; Gawaz, Meinrad; Bocksch, Wolfgang; Fateh-Moghadam, Suzanne

    2015-01-01

    Since patients with phenylketonuria (PKU) have to follow a lifelong restriction of natural protein to lower phenylalanine-intake, they never eat fish. This diet may lead to a chronic deficit of omega-3 and omega-6 fatty acids with the risk of early atherosclerotic changes. The aim of the study was to analyse the fatty acid profile of PKU patients and to correlate the results with surrogate markers of early atherosclerotic changes [enhanced carotid intima media thickness (CIMT) and ß-stiffness index] and platelet activation. In 43 PKU patients and in 58 healthy controls we prospectively examined the fatty acid profile, CIMT, ß-stiffness index and platelet activation (flow cytometric determination of markers of platelet activation). CIMT was measured bilaterally by ultrasound. CIMTmean was defined as the mean value of the sum of CIMTleft and CIMTright. Despite of lower HDL-cholesterol and higher triglyceride concentrations in the PKU group, there was no significant difference in the omega-6 or omega-3 fatty acid profile, CIMT, ß-stiffness index between both groups. Platelet activation was not enhanced in the PKU group. Fish-free diet does not induce early atherosclerotic changes or enhanced platelet activation in PKU patients.

  4. Neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in mood disorders: A meta-analysis.

    Science.gov (United States)

    Mazza, Mario Gennaro; Lucchi, Sara; Tringali, Agnese Grazia Maria; Rossetti, Aurora; Botti, Eugenia Rossana; Clerici, Massimo

    2018-06-08

    The immune and inflammatory system is involved in the etiology of mood disorders. Neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and monocyte/lymphocyte ratio (MLR) are inexpensive and reproducible biomarkers of inflammation. This is the first meta-analysis exploring the role of NLR and PLR in mood disorder. We identified 11 studies according to our inclusion criteria from the main Electronic Databases. Meta-analyses were carried out generating pooled standardized mean differences (SMDs) between index and healthy controls (HC). Heterogeneity was estimated. Relevant sensitivity and meta-regression analyses were conducted. Subjects with bipolar disorder (BD) had higher NLR and PLR as compared with HC (respectively SMD = 0.672; p analysis evidenced an influence of bipolar phase on the overall estimate whit studies including subjects in manic and any bipolar phase showing a significantly higher NLR and PLR as compared with HC whereas the effect was not significant among studies including only euthymic bipolar subjects. Meta-regression showed that age and sex influenced the relationship between BD and NLR but not the relationship between BD and PLR. Meta-analysis was not carried out for MLR because our search identified only one study when comparing BD to HC, and only one study when comparing MDD to HC. Subjects with major depressive disorder (MDD) had higher NLR as compared with HC (SMD = 0.670; p = 0.028; I 2  = 89.931%). Heterogeneity-based sensitivity analyses and meta-regression confirmed these findings. Our meta-analysis supports the hypothesis that an inflammatory activation occurs in mood disorders and NLR and PLR may be useful to detect this activation. More researches including comparison of NLR, PLR and MLR between different bipolar phases and between BD and MDD are needed. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Platelet-derived-growth-factor-induced signalling in human platelets: phosphoinositide-3-kinase-dependent inhibition of platelet activation.

    Science.gov (United States)

    Selheim, F; Fukami, M H; Holmsen, H; Vassbotn, F S

    2000-09-01

    Human platelets release platelet-derived growth factor (PDGF) from alpha-granules during platelet activation. We have previously shown that platelets have PDGF alpha-receptors, a transmembrane tyrosine kinase that takes part in negative feedback regulation during platelet activation. Here we have described a study of PDGF-induced tyrosine phosphorylation of platelet substrates and phosphoinositide 3-kinase (PI-3K) activity in collagen-stimulated platelets. By immunoblotting with phosphotyrosine antibodies of collagen-activated platelets we found that PDGF increased the phosphorylation of several platelet substrates, e.g. pp140, pp120 and pp85. PDGF inhibited collagen-induced platelet activation in the presence of inhibitors of autocrine stimulation, thus blocking the pure collagen-induced signal transduction. PDGF enhanced the collagen-induced formation of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3) as measured by HPLC. Wortmannin and LY294002, two unrelated inhibitors of PI-3K, were used to investigate the role of PI-3K in PDGF-induced platelet signalling. Incubation of platelets with wortmannin and LY294002 blocked the formation of three phosphorylated inositides as well as the inhibitory effect of PDGF on collagen-induced platelet activation. We conclude that the inhibitory effect of PDGF on platelet activation is PI-3K dependent. This is the first demonstration of a negative regulatory function of 3-phosphorylated inositides in platelets.

  6. Clinical Significance of Preoperative Neutrophil Lymphocyte Ratio versus Platelet Lymphocyte Ratio in Patients with Small Cell Carcinoma of the Esophagus

    Directory of Open Access Journals (Sweden)

    Ji-Feng Feng

    2013-01-01

    Full Text Available Recent studies have shown that the presence of systemic inflammation correlates with poor survival in various of cancers. The aim of this study was to determine the prognostic values of neutrophil lymphocyte ratio (NLR and platelet lymphocyte ratio (PLR in patients with small cell carcinoma of the esophagus (SCCE. Preoperative NLR and PLR were evaluated in 43 patients with SCCE from January 2001 to December 2010. The prognostic significance of both markers was then determined by both uni- and multivariate analytical methods. Receiver operating characteristic (ROC curves were also plotted to verify the accuracy of NLR and PLR for survival prediction. Patients with PLR ≥150 had significantly poorer (relapse-free survival RFS and (overall survival OS compared to patients with PLR <150. However, RFS or OS did not differ according to NLR categories (<3.5 and ≥3.5. The areas under the curve (AUC indicated that PLR was superior to NLR as a predictive factor. The results of the present study conclude that PLR is superior to NLR as a predictive factor in patients with SCCE.

  7. LDL oxidation by platelets propagates platelet activation via an oxidative stress-mediated mechanism.

    Science.gov (United States)

    Carnevale, Roberto; Bartimoccia, Simona; Nocella, Cristina; Di Santo, Serena; Loffredo, Lorenzo; Illuminati, Giulio; Lombardi, Elisabetta; Boz, Valentina; Del Ben, Maria; De Marco, Luigi; Pignatelli, Pasquale; Violi, Francesco

    2014-11-01

    Platelets generate oxidized LDL (ox-LDL) via NOX2-derived oxidative stress. We investigated if once generated by activated platelets ox-LDL can propagate platelet activation. Experiments were performed in platelets from healthy subjects (HS), hyper-cholesterolemic patients and patients with NOX2 hereditary deficiency. Agonist-stimulated platelets from HS added with LDL were associated with a dose-dependent increase of reactive oxidant species and ox-LDL. Agonist-stimulated platelets from HS added with a fixed dose of LDL (57.14 μmol/L) or added with homogenized human atherosclerotic plaque showed enhanced ox-LDL formation (approximately +50% and +30% respectively), which was lowered by a NOX2 inhibitor (approximately -35% and -25% respectively). Compared to HS, ox-LDL production was more pronounced in agonist-stimulated platelet rich plasma (PRP) from hyper-cholesterolemic patients but was almost absent in PRP from NOX2-deficient patients. Platelet aggregation and 8-iso-PGF2α-ΙΙΙ formation increased in LDL-treated washed platelets (+42% and +53% respectively) and PRP (+31% and +53% respectively). Also, LDL enhanced platelet-dependent thrombosis at arterial shear rate (+33%) but did not affect platelet activation in NOX2-deficient patients. Platelet activation by LDL was significantly inhibited by CD36 or LOX1 blocking peptides, two ox-LDL receptor antagonists, or by a NOX2 inhibitor. LDL-added platelets showed increased p38MAPK (+59%) and PKC (+51%) phosphorylation, p47(phox) translocation to platelet membrane (+34%) and NOX2 activation (+30%), which were inhibited by ox-LDL receptor antagonists. Platelets oxidize LDL, which in turn amplify platelet activation via specific ox-LDL receptors; both effects are mediated by NOX2 activation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Combination of neutrophil lymphocyte ratio and platelet lymphocyte ratio is a useful predictor of postoperative survival in patients with esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Feng JF

    2013-11-01

    Full Text Available Ji-Feng Feng,1 Ying Huang,2 Jin-Shi Liu1 1Department of Thoracic Surgery, 2Department of Operating Theatre, Zhejiang Cancer Hospital, Hangzhou, People's Republic of China Background: Recent studies have shown that the presence of systemic inflammation correlates with poor survival in various types of cancers. This study investigated the usefulness of a novel inflammation-based prognostic system, using the combination of neutrophil lymphocyte ratio (NLR and platelet lymphocyte ratio (PLR, collectively named the CNP, for predicting survival in patients with esophageal squamous cell carcinoma (ESCC. Materials and methods: The CNP was calculated on the basis of data obtained on the day of admission: patients with both elevated NLR (>3.45 and PLR (>166.5 were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively. Results: The CNP was associated with tumor length (P<0.001, differentiation (P=0.021, depth of invasion (P<0.001, and nodal metastasis (P<0.001. No significant differences were found between the CNP and morbidity. However, significant differences were found between the CNP and mortality (P<0.001. The overall survival in the CNP 0, CNP 1, and CNP 2 groups were 63.4%, 50.0%, and 20.2%, respectively (CNP 0 versus CNP 1, P=0.014; CNP 1 versus CNP 2, P<0.001. Multivariate analyses showed that CNP was a significant predictor of overall survival. CNP 1–2 had a hazard ratio (HR of 1.964 (95% confidence interval [CI]: 1.371–2.814, P<0.001 for overall survival. CNP (HR =1.964, P<0.001 is superior to NLR (HR =1.310, P=0.053 or PLR (HR =1.751, P<0.001 as a predictive factor. Conclusion: The CNP is considered a useful predictor of postoperative survival in patients with ESCC. The CNP is superior to NLR or PLR as a predictive factor in patients with ESCC. Keywords: esophageal squamous cell carcinoma (ESCC, neutrophil lymphocyte ratio (NLR, platelet lymphocyte ratio (PLR, overall survival

  9. Platelet degranulation and monocyte-platelet complex formation are increased in the acute and convalescent phases after ischaemic stroke or transient ischaemic attack.

    LENUS (Irish Health Repository)

    McCabe, Dominick J H

    2004-06-01

    Flow cytometric studies suggest that platelets are activated in ischaemic stroke or transient ischaemic attack (TIA). However, few studies have measured circulating leucocyte-platelet complexes in this patient population. Whole blood flow cytometry was used to quantify the expression of CD62P-, CD63-, and PAC1-binding, and the percentages of leucocyte-platelet complexes in acute (1-27 d, n = 79) and convalescent (79-725 d, n = 70) ischaemic cerebrovascular disease (CVD) patients compared with controls without CVD (n = 27). We performed a full blood count, and measured plasma levels of soluble P-selectin, soluble E-selectin, and von Willebrand factor antigen (VWF:Ag) as additional markers of platelet and\\/or endothelial cell activation. The median percentage CD62P expression and the median percentage monocyte-platelet complexes were higher in both acute and convalescent CVD patients than controls (P <\\/= 0.02). The mean white cell count and mean VWF:Ag levels were significantly elevated in the acute and convalescent phases after ischaemic stroke or TIA (P <\\/= 0.02). Otherwise, there was no significant increase in any other marker of platelet or endothelial activation in CVD patients. There was a positive correlation between the percentage expression of CD62P and the percentages of both neutrophil-platelet and monocyte-platelet complexes in the acute phase, and the percentages of all leucocyte-platelet complexes in the convalescent phase after ischaemic CVD. This study provides evidence for ongoing excessive platelet and\\/or endothelial activation in ischaemic CVD patients despite treatment with antithrombotic therapy.

  10. Transcellular lipoxygenase metabolism between monocytes and platelets

    Energy Technology Data Exchange (ETDEWEB)

    Bigby, T.D.; Meslier, N. (Univ. of California, San Francisco (USA))

    1989-09-15

    We have examined the effects of co-culture and in vitro co-stimulation on lipoxygenase metabolism in monocytes and platelets. Monocytes were obtained from the peripheral blood of normal volunteers by discontinuous gradient centrifugation and adherence to tissue culture plastic. Platelets were obtained from the platelet-rich plasma of the same donor. When 10(9) platelets and 2.5 x 10(6) monocytes were co-stimulated with 1 microM A23187, these preparations released greater quantities of 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid, 5(S),12-(S)dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid, and leukotriene C4, 5(S)-hydroxy-6(R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic (LTC4) when compared with monocytes alone. Release of arachidonic acid, 5-HETE, delta 6-trans-LTB4, and delta 6-trans-12-epi-LTB4 from monocytes was decreased in the presence of platelets. A dose-response curve was constructed and revealed that the above changes became evident when the platelet number exceeded 10(7). Dual radiolabeling experiments with 3H- and 14C-arachidonic acid revealed that monocytes provided arachidonic acid, 5-HETE, and LTA4 for further metabolism by the platelet. Monocytes did not metabolize platelet intermediates detectably. In addition, as much as 1.2 microM 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid and 12(S)-hydroperoxy-10-trans-5,8,14-cis-eicosatetraenoic acid had no effect on monocyte lipoxygenase metabolism. Platelets were capable of converting LTA4 to LTC4, but conversion of LTA4 to LTB4 was not detected. We conclude that the monocyte and platelet lipoxygenase pathways undergo a transcellular lipoxygenase interaction that differs from the interaction of the neutrophil and platelet lipoxygenase pathways. In this interaction monocytes provide intermediate substrates for further metabolic conversion by platelets in an unidirectional manner.

  11. Predictive role of neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios for diagnosis of acute appendicitis during pregnancy

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    Fatih Mehmet Yazar

    2015-11-01

    Full Text Available Acute appendicitis (AA is not uncommon during pregnancy but can be difficult to diagnose. This study evaluated the neutrophil-to-lymphocyte ratio (NLR and platelet-to-lymphocyte ratio (PLR in addition to conventional diagnostic indicators of the disease to diagnose AA during pregnancy. Age, gestational age, white blood cell (WBC count, Alvarado scores, C-reactive protein (CRP, lymphocyte count, NLR and PLR were compared among 28 pregnant women who underwent surgery for AA, 35 pregnant women wrongly suspected as having AA, 29 healthy pregnant women, and 30 nonpregnant healthy women. Mean WBC counts and CRP levels were higher in women with proven AA than in those of control groups (all p < 0.05. Among all the groups, the median NLR and PLR were significantly different in women with proven AA (all p < 0.05. Receiver operating characteristic analysis was used to determine cut-off values for WBC count, CRP, lymphocyte count, NLR and PLR, and multiple logistic regression analysis showed that NLR and PLR used with routine methods could diagnose AA with 90.5% accuracy. Used in addition to routine diagnostic methods, NLR and PLR increased the accuracy of the diagnosis of AA in pregnant women.

  12. Neutrophils in Cancer: Two Sides of the Same Coin.

    Science.gov (United States)

    Uribe-Querol, Eileen; Rosales, Carlos

    2015-01-01

    Neutrophils are the most abundant leukocytes in blood and are considered to be the first line of defense during inflammation and infections. In addition, neutrophils are also found infiltrating many types of tumors. Tumor-associated neutrophils (TANs) have relevant roles in malignant disease. Indeed neutrophils may be potent antitumor effector cells. However, increasing clinical evidence shows TANs correlate with poor prognosis. The tumor microenvironment controls neutrophil recruitment and in turn TANs help tumor progression. Hence, TANs can be beneficial or detrimental to the host. It is the purpose of this review to highlight these two sides of the neutrophil coin in cancer and to describe recent studies that provide some light on the mechanisms for neutrophil recruitment to the tumor, for neutrophils supporting tumor progression, and for neutrophil activation to enhance their antitumor functions.

  13. Induction of hyperresponsiveness in human airway tissue by neutrophils--mechanism of action.

    Science.gov (United States)

    Anticevich, S Z; Hughes, J M; Black, J L; Armour, C L

    1996-05-01

    The two main features of asthma are bronchial hyperresponsiveness and inflammation. The inflammatory response in asthma consists of infiltration and activation of a variety of inflammatory cells including neutrophils. Our previous studies have shown that stimulated neutrophil supernatants cause hyperresponsiveness of human bronchial tissue in vitro. To investigate the effect of the sensitization status of the tissue and the albumin concentration used to prepare supernatants on the response of human bronchial tissue to stimulated neutrophil supernatants. Neutrophil supernatants were prepared from human isolated blood in the presence of varying concentrations of albumin (0%, 0.1% and 4%). Neutrophil supernatants were added to sensitized and non-sensitized human isolated bronchial tissue which was stimulated with electrical field stimulation (EFS) (20 s every 4 min). Receptor antagonists specific for the prostaglandin and thromboxane (10(-7) M GR32191), platelet activating factor (10(-6) M WEB 2086), leukotriene D4 (10(-6) M MK-679) and neurokinin A (10(-7) M SR48968) receptors were used to identify neutrophil products responsible for the effects observed in the bronchial tissue. In non-sensitized human bronchial tissue, stimulated neutrophil supernatants induced a direct contraction in the presence of 0% and 0.1% but not 4% albumin. This contraction was due to leukotriene D4 as MK-679 completely inhibited the contraction. In contrast, stimulated neutrophil supernatants increased responsiveness of sensitized human bronchial tissue to EFS. The increased responsiveness was observed only in the presence of 0.1% albumin, with the site of modulation likely to be prejunctional on the parasympathetic nerve. The increased responsiveness was not inhibited by any of the antagonists tested. Sensitization status of the tissue and albumin concentration effect the responsiveness of human bronchial tissue to stimulated neutrophil supernatant. Our results suggest a possible role for

  14. Preoperative platelet-lymphocyte ratio is superior to neutrophil-lymphocyte ratio as a prognostic factor for soft-tissue sarcoma

    International Nuclear Information System (INIS)

    Que, Yi; Qiu, Haibo; Li, Yuanfang; Chen, Yongming; Xiao, Wei; Zhou, Zhiwei; Zhang, Xing

    2015-01-01

    Inflammation can promote tumor growth, invasion, angiogenesis and even metastasis. Inflammatory markers have been identified as prognostic indicators in various malignances. This study compared the usefulness of platelet-lymphocyte ratio (PLR) with that of neutrophil-lymphocyte ratio (NLR) for predicting outcomes of patients who underwent radical resection for soft tissue sarcoma (STS). We included 222 STS patients in this retrospective study. Kaplan-Meier curves and multivariate Cox proportional models were used to calculate overall survival (OS) and disease free survival (DFS). In univariate analysis, elevated PLR and NLR were both significantly associated with decreased OS. In multivariate analysis, PLR (HR: 2.60; 95 % CI: 1.17–5.74, P = 0.019) but not NLR was still identified as independent predictors of outcome. Median OS was 62 and 76 months for the high PLR and low PLR groups, respectively. High PLR and NLR were both significantly associated with shorter DFS in univariate analysis, with median DFS of 18 and 57 months in the high PLR and low PLR groups. In multivariate analysis, elevated PLR (HR: 1.77; 95 % CI: 1.05–2.97, P = 0.032) was also related to decreased DFS. Our findings provide a new and valuable clue for diagnosing and monitoring STS. Prediction of disease progression is not only determined by the use of clinical or histopathological factors including tumor grade, tumor size, and tumor site but also by host-response factors such as performance status, weight loss, and systemic inflammatory response. They also significantly affect clinical outcomes. Thus, PLR can be used to enhance clinical prognostication. Furthermore, the PLR can be assessed from peripheral blood tests that are routinely available without any other complicated expenditure, thus providing lower cost and greater convenience for the prognostication. Elevated preoperative PLR as an independent prognostic factor is superior to NLR in predicting clinical outcome in patients with STS

  15. The relationship between mean platelet volume and neutrophil/lymphocyte ratio with inflammation and proteinuria in chronic kidney disease

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    Gulay Yilmaz

    2017-01-01

    Full Text Available Atherosclerosis, which develops as a result of inflammation, is the most important cause of morbidity and mortality in chronic kidney disease (CKD. In this study, we investigated the relationship of mean platelet volume (MPV and neutrophil/lymphocyte ratio (NLR with inflammation and proteinuria in patients with CKD Stage 3-4. Healthy individuals who applied to nephrology clinic for checkup purposes acted as controls. Fifty-three patients and 30 healthy controls were included in the study. Patients with diabetes mellitus, active infection, malignancy, and coronary artery disease were excluded from the study. Biochemistry values and hemograms were recorded for all patients and for control group. NLR was calculated. The relationship between MPV/NLR and protein, fibrinogen, and proteinuria was evaluated. Our study showed a statistically significant difference between CKD group and healthy control (HC group in uric acid, fibrinogen, C-reactive protein, and NLR values (P <0.01, P <0.01, P = 0.01, P <0.01, respectively. No statistically significant difference was found between CKD and HC groups for MPV (P = 0.307. Correlation analysis revealed a statistically significant relationship between NLR and creatinine (P <0.00, r = 0.571, uric acid (P <0.00, r = 0.436, glomerular filtration rate (P <0.00, r = −0.418, 24 h urine protein (P = 0.004, r = 0.311, and 24 h urine microalbumin (P = 0.001, r = 0.354. A statistically significant relationship was detected between MPV and platelet count (P <0.001, r = −0.422, age (P = 0.004, r = −0.312, uric acid (P = 0.04, r = −0.226, and fibrinogen (P = 0.023, r = −0.249. Whereas, a statistically significant relationship was detected between NLR and microalbuminuria/proteinuria, there was no statistically significant relationship between MPV and microalbuminuria/proteinuria. Our study showed that the NLR is high in CKD group and is correlated with uric acid and proteinuria, which are known to be associated

  16. Platelet factor XIII increases the fibrinolytic resistance of platelet-rich clots by accelerating the crosslinking of alpha 2-antiplasmin to fibrin

    Science.gov (United States)

    Reed, G. L.; Matsueda, G. R.; Haber, E.

    1992-01-01

    Platelet clots resist fibrinolysis by plasminogen activators. We hypothesized that platelet factor XIII may enhance the fibrinolytic resistance of platelet-rich clots by catalyzing the crosslinking of alpha 2-antiplasmin (alpha 2AP) to fibrin. Analysis of plasma clot structure by polyacrylamide gel electrophoresis and immunoblotting revealed accelerated alpha 2AP-fibrin crosslinking in platelet-rich compared with platelet-depleted plasma clots. A similar study of clots formed with purified fibrinogen (depleted of factor XIII activity), isolated platelets, and specific factor XIII inhibitors indicated that this accelerated crosslinking was due to the catalytic activity of platelet factor XIII. Moreover, when washed platelets were aggregated by thrombin, there was evidence of platelet factor XIII-mediated crosslinking between platelet alpha 2AP and platelet fibrin(ogen). Specific inhibition (by a monoclonal antibody) of the alpha 2AP associated with washed platelet aggregates accelerated the fibrinolysis of the platelet aggregate. Thus in platelet-rich plasma clots, and in thrombin-induced platelet aggregates, platelet factor XIII actively formed alpha 2AP-fibrin crosslinks, which appeared to enhance the resistance of platelet-rich clots to fibrinolysis.

  17. Neutrophils in Cancer: Two Sides of the Same Coin

    Directory of Open Access Journals (Sweden)

    Eileen Uribe-Querol

    2015-01-01

    Full Text Available Neutrophils are the most abundant leukocytes in blood and are considered to be the first line of defense during inflammation and infections. In addition, neutrophils are also found infiltrating many types of tumors. Tumor-associated neutrophils (TANs have relevant roles in malignant disease. Indeed neutrophils may be potent antitumor effector cells. However, increasing clinical evidence shows TANs correlate with poor prognosis. The tumor microenvironment controls neutrophil recruitment and in turn TANs help tumor progression. Hence, TANs can be beneficial or detrimental to the host. It is the purpose of this review to highlight these two sides of the neutrophil coin in cancer and to describe recent studies that provide some light on the mechanisms for neutrophil recruitment to the tumor, for neutrophils supporting tumor progression, and for neutrophil activation to enhance their antitumor functions.

  18. Characterization of a receptor for human monocyte-derived neutrophil chemotactic factor/interleukin-8

    International Nuclear Information System (INIS)

    Grob, P.M.; David, E.; Warren, T.C.; DeLeon, R.P.; Farina, P.R.; Homon, C.A.

    1990-01-01

    Monocyte-derived neutrophil chemotactic factor/interleukin-8 (MDNCF/IL-8) is an 8,000-dalton protein produced by monocytes which exhibits activity as a chemoattractant for neutrophils with maximal activity achieved at a concentration of 50 ng/ml. This polypeptide has been iodinated by chloramine-T methodology (350 Ci/mM), and specific receptors for MDNCF/IL-8 have been detected on human neutrophils, U937 cells, THP-1 cells, and dimethyl sulfoxide-differentiated HL-60 cells. The binding of MDNCF/IL-8 to human neutrophils is not inhibited by interleukin-1 alpha, tumor necrosis factor-alpha, insulin, or epidermal growth factor. In addition, chemoattractants such as C5a, fMet-Leu-Phe, leukotriene B4, and platelet-activating factor fail to inhibit binding, suggesting that MDNCF/IL-8 utilizes a unique receptor. The receptor for MDNCF/IL-8 is apparently glycosylated since ligand binding is inhibited by the presence of wheat germ agglutinin, a lectin with a binding specificity for N-acetylglucosamine and neuraminic acid. Steady state binding experiments indicate Kd values of 4 and 0.5 nM and receptor numbers of 75,000 and 7,400 for human neutrophils and differentiated HL-60 cells, respectively. 125I-MDNCF/IL-8 bound to human neutrophils is rapidly internalized and subsequently released from cells as trichloroacetic acid-soluble radioactivity. Affinity labeling experiments suggest that the human neutrophil MDNCF/IL-8 receptor exhibits a mass of approximately 58,000 daltons

  19. Neutrophils reduce the parasite burden in Leishmania (Leishmania amazonensis-infected macrophages.

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    Erico Vinícius de Souza Carmo

    2010-11-01

    Full Text Available Studies on the role of neutrophils in Leishmania infection were mainly performed with L. (L major, whereas less information is available for L. (L amazonensis. Previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to L. (L. amazonensis (C3H/HePas. In contrast, the susceptible strain (BALB/c displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. These findings led us to investigate the interaction of inflammatory neutrophils with L. (L. amazonensis-infected macrophages in vitro.Mouse peritoneal macrophages infected with L. (L. amazonensis were co-cultured with inflammatory neutrophils, and after four days, the infection was quantified microscopically. Data are representative of three experiments with similar results. The main findings were 1 intracellular parasites were efficiently destroyed in the co-cultures; 2 the leishmanicidal effect was similar when cells were obtained from mouse strains resistant (C3H/HePas or susceptible (BALB/c to L. (L. amazonensis; 3 parasite destruction did not require contact between infected macrophages and neutrophils; 4 tumor necrosis factor alpha (TNF-α, neutrophil elastase and platelet activating factor (PAF were involved with the leishmanicidal activity, and 5 destruction of the parasites did not depend on generation of oxygen or nitrogen radicals, indicating that parasite clearance did not involve the classical pathway of macrophage activation by TNF-α, as reported for other Leishmania species.The present results provide evidence that neutrophils in concert with macrophages play a previously unrecognized leishmanicidal effect on L. (L. amazonensis. We believe these findings may help to understand the mechanisms involved in innate immunity in cutaneous infection by this Leishmania species.

  20. Interval and continuous exercise regimens suppress neutrophil-derived microparticle formation and neutrophil-promoted thrombin generation under hypoxic stress.

    Science.gov (United States)

    Chen, Yi-Ching; Ho, Ching-Wen; Tsai, Hsing-Hua; Wang, Jong-Shyan

    2015-04-01

    Acute hypoxic exposure increases vascular thrombotic risk. The release of procoagulant-rich microparticles from neutrophils accelerates the pathogenesis of inflammatory thrombosis. The present study explicates the manner in which interval and continuous exercise regimens affect neutrophil-derived microparticle (NDMP) formation and neutrophil/NDMP-mediated thrombin generation (TG) under hypoxic condition. A total of 60 sedentary males were randomized to perform either aerobic interval training [AIT; 3-min intervals at 40% and 80% V̇O2max (maximal O2 consumption)] or moderate continuous training (MCT; sustained 60% V̇O2max) for 30 min/day, 5 days/week for 5 weeks, or to a control (CTL) group who did not receive any form of training. At rest and immediately after hypoxic exercise test (HE, 100 W under 12% O2 for 30 min), the NDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. Before the intervention, HE (i) elevated coagulant factor VIII/fibrinogen concentrations and shortened activated partial thromboplastin time (aPTT), (ii) increased total and tissue factor (TF)-rich/phosphatidylserine (PS)-exposed NDMP counts and (iii) enhanced the peak height and rate of TG promoted by neutrophils/NDMPs. Following the 5-week intervention, AIT exhibited higher enhancement of V̇O2max than did MCT. Notably, both MCT and AIT attenuated the extents of HE-induced coagulant factor VIII/fibrinogen elevations and aPTT shortening. Furthermore, the two exercise regimens significantly decreased TF-rich/PS-exposed NDMP formation and depressed neutrophil/NDMP-mediated dynamic TG at rest and following HE. Hence, we conclude that AIT is superior to MCT for enhancing aerobic capacity. Moreover, either AIT or MCT effectively ameliorates neutrophil/NDMP-promoted TG by down-regulating expression of procoagulant factors during HE, which may reduce thrombotic risk evoked by hypoxia. Moreover, either AIT or MCT effectively ameliorates neutrophil

  1. Platelets and their chemokines in atherosclerosis – clinical applications

    Directory of Open Access Journals (Sweden)

    Philipp evon Hundelshausen

    2014-08-01

    Full Text Available The concept of platelets as important players in the process of atherogenesis has become increasingly accepted due to accumulating experimental and clinical evidence. Despite the progress in understanding the molecular details of atherosclerosis, particularly by using animal models, the inflammatory and thrombotic roles of activated platelet s especially in the human system remain difficult to dissect, as often only the complications of atherosclerosis i.e. stroke and myocardial infarction are definable but not the plaque burden.Platelet indices including platelet count and mean platelet volume and soluble mediators released by activated platelets are associated with atherosclerosis. The chemokine CXCL4 has multiple atherogenic activities e.g. altering the differentiation of T cells and macrophages by inhibiting neutrophil and monocyte apoptosis and by increasing the uptake of oxLDL and synergizing with CCL5. CCL5 is released and deposited on endothelium by activated platelets thereby triggering atherogenic monocyte recruitment, which can be attenuated by blocking the corresponding chemokine receptor CCR5. Atheroprotective and plaque stabilizing properties are attributed to CXCL12, which plays an important role in regenerative processes by attracting progenitor cells. Its release from luminal attached platelets accelerates endothelial healing after injury. Platelet surface molecules GPIIb/IIIa, GP1bα, P-selectin, JAM-A and the CD40/CD40L dyade are crucially involved in the interaction with endothelial cells, leukocytes and matrix molecules affecting atherogenesis. Beyond the effects on the arterial inflammatory infiltrate, platelets affect cholesterol metabolism by binding, modifying and endocytosing LDL particles via their scavenger receptors and contribute to the formation of lipid laden macrophages. Current medical therapies for the prevention of atherosclerotic therapies enable the elucidation of mechanisms linking platelets to inflammation

  2. Blood platelets in the progression of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Nina S Gowert

    Full Text Available Alzheimer's disease (AD is characterized by neurotoxic amyloid-ß plaque formation in brain parenchyma and cerebral blood vessels known as cerebral amyloid angiopathy (CAA. Besides CAA, AD is strongly related to vascular diseases such as stroke and atherosclerosis. Cerebrovascular dysfunction occurs in AD patients leading to alterations in blood flow that might play an important role in AD pathology with neuronal loss and memory deficits. Platelets are the major players in hemostasis and thrombosis, but are also involved in neuroinflammatory diseases like AD. For many years, platelets were accepted as peripheral model to study the pathophysiology of AD because platelets display the enzymatic activities to generate amyloid-ß (Aß peptides. In addition, platelets are considered to be a biomarker for early diagnosis of AD. Effects of Aß peptides on platelets and the impact of platelets in the progression of AD remained, however, ill-defined. The present study explored the cellular mechanisms triggered by Aß in platelets. Treatment of platelets with Aß led to platelet activation and enhanced generation of reactive oxygen species (ROS and membrane scrambling, suggesting enhanced platelet apoptosis. More important, platelets modulate soluble Aß into fibrillar structures that were absorbed by apoptotic but not vital platelets. This together with enhanced platelet adhesion under flow ex vivo and in vivo and platelet accumulation at amyloid deposits of cerebral vessels of AD transgenic mice suggested that platelets are major contributors of CAA inducing platelet thrombus formation at vascular amyloid plaques leading to vessel occlusion critical for cerebrovascular events like stroke.

  3. Can Serum Neutrophil-to-Lymphocyte Ratio Be a Predictive Biomarker to Help Differentiate Active Chronic Otitis Media From Inactive Chronic Otitis Media?

    Science.gov (United States)

    Tansuker, Hasan Deniz; Eroğlu, Sinan; Yenigün, Alper; Taşkin, Ümit; Oktay, Mehmet Faruk

    2017-05-01

    The authors' aim was to investigate whether serum neutrophil to lymphocyte ratio might be used as a predictive biomarker to help differentiate active from inactive chronic otitis media (COM). Two hundred fifty-nine patients having inactive COM received tympanoplasty without mastoidectomy and were identified as Group 1. On the other hand, 254 patients having active COM received tympanoplasty with mastoidectomy and were identified as Group 2. Routine hemogram tests were performed preoperatively for both the groups. By performing a chart review, white blood cell count, red blood cell count, hemoglobin, hematocrit, platelet, and mean platelet volume values were compared between the groups in an age-matched and sex-matched manner. A total of 513 COM patients with age range of 7 to 65 years were included in the study. Two hundred seventy-five patients (53.6%) were male, 238 were (46.4%) female. Preoperatively both serum neutrophil and lymphocyte counts were significantly higher in Group 2 (P = 0.015 and P = 0.004, respectively). However, the neutrophil-to-lymphocyte ratios between the groups were not significantly different (P = 0.511). No statistically significant differences were identified from preoperative neutrophil-to-lymphocyte ratios between patients having active COM and inactive COM. Level NA.

  4. Protectin DX, a double lipoxygenase product of DHA, inhibits both ROS production in human neutrophils and cyclooxygenase activities

    Science.gov (United States)

    Liu, Miao; Boussetta, Tarek; Makni-Maalej, Karama; Fay, Michèle; Driss, Fathi; El-Benna, Jamel; Lagarde, Michel; Guichardant, Michel

    2014-01-01

    Neutrophils play a major role in inflammation by releasing large amounts of reactive oxygen species (ROS) produced by NADPH oxidase (NOX) and myeloperoxidase (MPO). This ROS overproduction is mediated by phosphorylation of the NOX subunits with an uncontrolled manner. Therefore, targeting neutrophil subunits would represent a promising strategy to moderate NOX activity, lower ROS, and other inflammatory agents, such as cytokines and leukotrienes, produced by neutrophils. For this purpose, we investigated the effects of protectin DX (PDX) - a docosahexaenoic acid (DHA) di-hydroxylated product which inhibits blood platelet aggregation - on neutrophil activation in vitro. We found that PDX decreases ROS production, inhibits NOX activation and MPO release from neutrophils. We also confirm, that PDX is an anti-aggregatory and anti-inflammatory agent by inhibiting both cyclooxygenase-1 and -2 (COX-1 and COX-2, E.C. 1.14.99.1) as well as COX-2 in lipopolysaccharides (LPS)-treated human neutrophils. However, PDX has no effect on the 5-lipoxygenase pathway that produces the chemotactic agent leukotriene B4 (LTB4). Taken together, our results suggest that PDX could be a protective agent against neutrophil invasion in chronic inflammatory diseases. PMID:24254970

  5. Effect of moderate exercise on peritoneal neutrophils from juvenile rats.

    Science.gov (United States)

    Braz, Glauber Ruda; Ferreira, Diorginis Soares; Pedroza, Anderson Apolonio; da Silva, Aline Isabel; Sousa, Shirley Maria; Pithon-Curi, Tania Cristina; Lagranha, Claudia

    2015-09-01

    Previous studies showed that moderate exercise in adult rats enhances neutrophil function, although no studies were performed in juvenile rats. We evaluated the effects of moderate exercise on the neutrophil function in juvenile rats. Viability and neutrophils function were evaluated. Moderate exercise did not impair the viability and mitochondrial transmembrane potential of neutrophils, whereas there was greater reactive oxygen species production (164%; p < 0.001) and phagocytic capacity (29%; p < 0.05). Our results suggest that moderate exercise in juvenile rats improves neutrophil function, similar to adults.

  6. Prognostic value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in acute pulmonary embolism: a systematic review and meta-analysis.

    Science.gov (United States)

    Wang, Qian; Ma, Junfen; Jiang, Zhiyun; Ming, Liang

    2018-02-01

    Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been reported to predict prognosis of acute pulmonary embolism (PE). However, the prognostic value of NLR and PLR remained inconsistent between studies. The aim of this meta-analysis was to assess the prognostic role of NLR and PLR in acute PE. We systematically searched Pubmed, Embase, Web of Science and CNKI for relative literature up to March 2017. The pooled statistics for all outcomes were expressed as odds ratio (OR) and 95% confidence intervals (95% CI). The statistical analyses were performed using Review Manager 5.3.5 analysis software and Stata software. Totally 7 eligible studies consisting of 2323 patients were enrolled in our meta-analysis. Elevated NLR was significantly associated with overall (short-term and long-term) mortality (OR 10.13, 95% CI 6.57-15.64, Panalysis revealed that NLR and PLR are promising biomarkers in predicting prognosis in acute PE patients. We suggest NLR and PLR be used routinely in the PE prognostic assessment.

  7. New Predictive Parameters of Bell"s Palsy: Neutrophil to Lymphocyte Ratio and Platelet to Lymphocyte Ratio

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    Doğan Atan

    2015-06-01

    Full Text Available Background: Bell’s palsy is the most frequent cause of unilateral facial paralysis. Inflammation is thought to play an important role in the pathogenesis of Bell’s palsy. Aims: Neutrophil to lymphocyte ratio (NLR and platelet to lymphocyte ratio (PLR are simple and inexpensive tests which are indicative of inflammation and can be calculated by all physicians. The aim of this study was to reveal correlations of Bell’s palsy and degree of paralysis with NLR and PLR. Study Design: Case-control study. Methods: The retrospective study was performed January 2010 and December 2013. Ninety-nine patients diagnosed as Bell’s palsy were included in the Bell’s palsy group and ninety-nine healthy individuals with the same demographic characteristics as the Bell’s palsy group were included in the control group. As a result of analyses, NLR and PLR were calculated. Results: The mean NLR was 4.37 in the Bell’s palsy group and 1.89 in the control group with a statistically significant difference (p<0.001. The mean PLR was 137.5 in the Bell’s palsy group and 113.75 in the control group with a statistically significant difference (p=0.008. No statistically significant relation was detected between the degree of facial paralysis and NLR and PLR. Conclusion: The NLR and the PLR were significantly higher in patients with Bell’s palsy. This is the first study to reveal a relation between Bell’s palsy and PLR. NLR and PLR can be used as auxiliary parameters in the diagnosis of Bell’s palsy.

  8. A bioactive molecule in a complex wound healing process: platelet-derived growth factor.

    Science.gov (United States)

    Kaltalioglu, Kaan; Coskun-Cevher, Sule

    2015-08-01

    Wound healing is considered to be particularly important after surgical procedures, and the most important wounds related to surgical procedures are incisional, excisional, and punch wounds. Research is ongoing to identify methods to heal non-closed wounds or to accelerate wound healing; however, wound healing is a complex process that includes many biological and physiological events, and it is affected by various local and systemic factors, including diabetes mellitus, infection, ischemia, and aging. Different cell types (such as platelets, macrophages, and neutrophils) release growth factors during the healing process, and platelet-derived growth factor is a particularly important mediator in most stages of wound healing. This review explores the relationship between platelet-derived growth factor and wound healing. © 2014 The International Society of Dermatology.

  9. Effects of acrolein on leukotriene biosynthesis in human neutrophils.

    Science.gov (United States)

    Berry, Karin A Zemski; Henson, Peter M; Murphy, Robert C

    2008-12-01

    Acrolein is a toxic, highly reactive alpha,beta-unsaturated aldehyde that is present in high concentrations in cigarette smoke. In the current study, the effect of acrolein on eicosanoid synthesis in stimulated human neutrophils was examined. Eicosanoid synthesis in neutrophils was initiated by priming with granulocyte-macrophage colony-stimulating factor (GM-CSF) and subsequent stimulation with formyl-methionyl-leucyl-phenylalanine (fMLP) and 5-lipoxygenase (5-LO) products in addition to small amounts of cyclooxygenase (COX) products were detected using LC/MS/MS. A dose-dependent decrease in the formation of 5-LO products was observed in GM-CSF/fMLP-stimulated neutrophils when acrolein (0-50 microM) was present with almost complete inhibition at > or = 25 microM acrolein. The production of COX products was not affected by acrolein in these cells. The effect of acrolein was examined on key parts of the eicosanoid pathway, such as arachidonic acid release, intracellular calcium ion concentration, and adenosine production. In addition, the direct effect of acrolein on 5-LO enzymatic activity was probed using a recombinant enzyme. Some of these factors were affected by acrolein but did not completely explain the almost complete inhibition of 5-LO product formation in GM-CSF/fMLP-treated cells with acrolein. In addition, the effect of acrolein on different stimuli that initiate the 5-LO pathway [platelet-activating factor (PAF)/fMLP, GM-CSF/PAF, opsonized zymosan, and A23187] was examined. Acrolein had no significant effect on the leukotriene production in neutrophils stimulated with PAF/fMLP, GM-CSF/ PAF, or OPZ. Additionally, 50% inhibition of the 5-LO pathway was observed in A23187-stimulated neutrophils. Our results suggest that acrolein has a profound effect on the 5-LO pathway in neutrophils, which may have implications in disease states, such as chronic obstructive pulmonary disease and other pulmonary disease, where both activated neutrophils and acrolein are

  10. Swarm Intelligence-Enhanced Detection of Non-Small-Cell Lung Cancer Using Tumor-Educated Platelets

    NARCIS (Netherlands)

    Best, Myron G.; Sol, Nik; In ‘t Veld, Sjors G.J.G.; Vancura, Adrienne; Muller, Mirte; Niemeijer, Anna Larissa N.; Fejes, Aniko V.; Tjon Kon Fat, Lee Ann; Huis in 't Veld, Anna E; Leurs, Cyra; Le Large, Tessa Y.; Meijer, Laura L.; Kooi, Irsan E.; Rustenburg, François; Schellen, Pepijn; Verschueren, Heleen; Post, Edward; Wedekind, Laurine E.; Bracht, Jillian; Esenkbrink, Michelle; Wils, Leon; Favaro, Francesca; Schoonhoven, Jilian D.; Tannous, Jihane; Meijers-Heijboer, Hanne; Kazemier, Geert; Giovannetti, Elisa; Reijneveld, Jaap C.; Idema, Sander; Killestein, Joep; Heger, Michal; de Jager, Saskia C.; Urbanus, Rolf T.; Hoefer, Imo E.; Pasterkamp, Gerard; Mannhalter, Christine; Gomez-Arroyo, Jose; Bogaard, Harm-Jan; Noske, David P.; Vandertop, W. Peter; van den Broek, Daan; Ylstra, Bauke; Nilsson, R. Jonas A; Wesseling, Pieter; Karachaliou, Niki; Rosell, Rafael; Lee-Lewandrowski, Elizabeth; Lewandrowski, Kent B.; Tannous, Bakhos A.; de Langen, Adrianus J.; Smit, Egbert F.; van den Heuvel, Michel M; Wurdinger, Thomas

    2017-01-01

    Blood-based liquid biopsies, including tumor-educated blood platelets (TEPs), have emerged as promising biomarker sources for non-invasive detection of cancer. Here we demonstrate that particle-swarm optimization (PSO)-enhanced algorithms enable efficient selection of RNA biomarker panels from

  11. Platelet indices and platelet-to-lymphocyte ratio predict coronary chronic total occlusion in patients with acute ST-elevation myocardial infarction

    Directory of Open Access Journals (Sweden)

    Hadadi Laszlo

    2015-12-01

    Full Text Available Coronary chronic total occlusion (CTO is caused by organized thrombi or atherosclerotic plaque progression. The presence of a CTO is an independent predictor of mortality in patients presenting with ST-segment elevation myocardial infarction (STEMI. Platelets have a crucial role in the pathophysiology of atherosclerosis. The aim of this retrospective study was to investigate platelet indices as predictors of CTO in patients with STEMI treated with primary percutaneous coronary intervention (pPCI. A total number of 334 patients admitted for STEMI between January 2011 and December 2013 were included and divided in two groups based on the presence of CTO (48 patients in CTO+ group, 286 patients in CTO-group. Platelet count, mean platelet volume (MPV, platelet distribution width (PDW, platelet-large cell ratio (P-LCR, lymphocyte and neutrophil count determined on admission were analyzed. MPV was larger in patients with CTO compared with patients without CTO (p=0.02, as were PDW (p=0.03 and P-LCR (p=0.01. Platelet-to-lymphocyte ratio (PLT/LYM was lower in patients with CTO: 105.2 (75.86-159.1 compared to 137 (97-188.1, p<0.01. Receiver-operator characteristic curve analysis identified an area under the curve of 0.61 (95%CI=0.57-0.67, p< 0.01 for PLT/LYM in predicting the presence of a CTO, with a cut-off value at 97.73. Lower values than this were independent predictors of a CTO in multivariate logistic regression analysis, with an Odds Ratio of 2.2 (95%CI=1.15-4.20, p=0.02. Our results support the use of platelet indices and PLT/LYM as predictors of CTO in patients presenting with STEMI.

  12. EMMPRIN (CD147) is a novel receptor for platelet GPVI and mediates platelet rolling via GPVI-EMMPRIN interaction.

    Science.gov (United States)

    Seizer, Peter; Borst, Oliver; Langer, Harald F; Bültmann, Andreas; Münch, Götz; Herouy, Yared; Stellos, Konstantinos; Krämer, Björn; Bigalke, Boris; Büchele, Berthold; Bachem, Max G; Vestweber, Dietmar; Simmet, Thomas; Gawaz, Meinrad; May, Andreas E

    2009-04-01

    The Extracellular Matrix Metalloproteinase Inducer (EMMPRIN, CD147, basigin) is an immunoglobulin-like receptor expressed in various cell types. During cellular interactions homotypic EMMPRIN-EMMPRIN interactions are known to induce the synthesis of matrix metalloproteinases. Recently, we have identified EMMPRIN as a novel receptor on platelets. To our knowledge EMMPRIN has not been shown to serve as adhesion receptor, yet. Here we characterise platelet glycoprotein VI (GPVI) as a novel adhesion receptor for EMMPRIN. Human platelets were prestimulated with ADP and perfused over immobilised recombinant EMMPRIN-Fc or Fc-fragments under arterial shear conditions. ADP-stimulated platelets showed significantly enhanced rolling (but not enhanced firm adhesion) on immobilised EMMPRIN-Fc compared to Fc. Pretreatment of platelets with blocking mAbs anti-EMMPRIN or anti-GPVI leads to a significant reduction of rolling platelets on immobilised EMMPRIN-Fc, whereas pretreatment with blocking mAbs anti-p-selectin, anti-alpha4-integrin or anti-GPIIb/IIIa complex (20 microg/ml each) had no effect. Consistently, chinese hamster ovary (CHO) cells stably transfected with GPVI showed enhanced rolling (but not adhesion) on immobilised EMMPRIN-Fc in comparison to non-transfected CHO cells. Similarly, CHO cells stably transfected with EMMPRIN showed enhanced rolling on immobilised GPVI-Fc (or EMMPRIN-Fc) compared to non transfected CHO-cells. Finally, specific binding of EMMPRIN to GPVI was demonstrated by a modified ELISA and surface plasmon resonance technology with a dissociation constant of 88 nM. Platelet GPVI is a novel receptor for EMMPRIN and can mediate platelet rolling via GPVI-EMMPRIN interaction.

  13. Antimicrobial effect of platelet-rich plasma and platelet-rich fibrin.

    Science.gov (United States)

    Badade, Pallavi S; Mahale, Swapna A; Panjwani, Alisha A; Vaidya, Prutha D; Warang, Ayushya D

    2016-01-01

    Platelet concentrates have been extensively used in a variety of medical fields to promote soft- and hard-tissue regeneration. The significance behind their use lies in the abundance of growth factors (GFs) in platelets α-granules that promote wound healing. Other than releasing a pool of GFs upon activation, platelets also have many features that indicate their role in the anti-infective host defense. The aim of this study is to evaluate the antimicrobial activities of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) against periodontal disease-associated bacteria. Blood samples were obtained from ten adult male patients. PRP and PRF were procured using centrifugation. The antimicrobial activity of PRP and PRF was evaluated by microbial culturing using bacterial strains of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. P. gingivalis and A. actinomycetemcomitans were inhibited by PRP but not by PRF. PRP is a potentially useful substance in the fight against periodontal pathogens. This might represent a valuable property in adjunct to the enhancement of tissue regeneration.

  14. Swarm Intelligence-Enhanced Detection of Non-Small-Cell Lung Cancer Using Tumor-Educated Platelets.

    Science.gov (United States)

    Best, Myron G; Sol, Nik; In 't Veld, Sjors G J G; Vancura, Adrienne; Muller, Mirte; Niemeijer, Anna-Larissa N; Fejes, Aniko V; Tjon Kon Fat, Lee-Ann; Huis In 't Veld, Anna E; Leurs, Cyra; Le Large, Tessa Y; Meijer, Laura L; Kooi, Irsan E; Rustenburg, François; Schellen, Pepijn; Verschueren, Heleen; Post, Edward; Wedekind, Laurine E; Bracht, Jillian; Esenkbrink, Michelle; Wils, Leon; Favaro, Francesca; Schoonhoven, Jilian D; Tannous, Jihane; Meijers-Heijboer, Hanne; Kazemier, Geert; Giovannetti, Elisa; Reijneveld, Jaap C; Idema, Sander; Killestein, Joep; Heger, Michal; de Jager, Saskia C; Urbanus, Rolf T; Hoefer, Imo E; Pasterkamp, Gerard; Mannhalter, Christine; Gomez-Arroyo, Jose; Bogaard, Harm-Jan; Noske, David P; Vandertop, W Peter; van den Broek, Daan; Ylstra, Bauke; Nilsson, R Jonas A; Wesseling, Pieter; Karachaliou, Niki; Rosell, Rafael; Lee-Lewandrowski, Elizabeth; Lewandrowski, Kent B; Tannous, Bakhos A; de Langen, Adrianus J; Smit, Egbert F; van den Heuvel, Michel M; Wurdinger, Thomas

    2017-08-14

    Blood-based liquid biopsies, including tumor-educated blood platelets (TEPs), have emerged as promising biomarker sources for non-invasive detection of cancer. Here we demonstrate that particle-swarm optimization (PSO)-enhanced algorithms enable efficient selection of RNA biomarker panels from platelet RNA-sequencing libraries (n = 779). This resulted in accurate TEP-based detection of early- and late-stage non-small-cell lung cancer (n = 518 late-stage validation cohort, accuracy, 88%; AUC, 0.94; 95% CI, 0.92-0.96; p swarm intelligence may also benefit the optimization of diagnostics readout of other liquid biopsy biosources. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. The pro-inflammatory effects of platelet contamination in plasma and mitigation strategies for avoidance

    Science.gov (United States)

    Bercovitz, R. S.; Kelher, M. R.; Khan, S. Y.; Land, K. J.; Berry, T. H.; Silliman, C. C.

    2013-01-01

    Background and Objectives Plasma and platelet concentrates are disproportionately implicated in transfusion-related acute lung injury (TRALI). Platelet-derived pro-inflammatory mediators, including soluble CD40 ligand (sCD40L), accumulate during storage. We hypothesized that platelet contamination induces sCD40L generation that causes neutrophil [polymorphonuclear leucocyte (PMN)] priming and PMN-mediated cytotoxicity. Materials and Methods Plasma was untreated, centrifuged (12 500 g) or separated from leucoreduced whole blood (WBLR) prior to freezing. Platelet counts and sCD40L concentrations were measured 1–5 days post-thaw. The plasma was assayed for PMN priming activity and was used in a two-event in vitro model of PMN-mediated human pulmonary microvascular endothelial cell (HMVEC) cytotoxicity. Results Untreated plasma contained 42 ± 4.2 × 103/μl platelets, which generated sCD40L accumulation (1.6-eight-fold vs. controls). Priming activity and HMVEC cytotoxicity were directly proportional to sCD40L concentration. WBLR and centrifugation reduced platelet and sCD40L contamination, abrogating the pro-inflammatory potential. Conclusion Platelet contamination causes sCD40L accumulation in stored plasma that may contribute to TRALI. Platelet reduction is potentially the first TRALI mitigation effort in plasma manufacturing. PMID:22092073

  16. Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration.

    Science.gov (United States)

    Pazos, Michael A; Lanter, Bernard B; Yonker, Lael M; Eaton, Alex D; Pirzai, Waheed; Gronert, Karsten; Bonventre, Joseph V; Hurley, Bryan P

    2017-08-01

    Excessive neutrophil infiltration of the lungs is a common contributor to immune-related pathology in many pulmonary disease states. In response to pathogenic infection, airway epithelial cells produce hepoxilin A3 (HXA3), initiating neutrophil transepithelial migration. Migrated neutrophils amplify this recruitment by producing a secondary gradient of leukotriene B4 (LTB4). We sought to determine whether this two-step eicosanoid chemoattractant mechanism could be exploited by the pathogen Pseudomonas aeruginosa. ExoU, a P. aeruginosa cytotoxin, exhibits phospholipase A2 (PLA2) activity in eukaryotic hosts, an enzyme critical for generation of certain eicosanoids. Using in vitro and in vivo models of neutrophil transepithelial migration, we evaluated the impact of ExoU expression on eicosanoid generation and function. We conclude that ExoU, by virtue of its PLA2 activity, augments and compensates for endogenous host neutrophil cPLA2α function, leading to enhanced transepithelial migration. This suggests that ExoU expression in P. aeruginosa can circumvent immune regulation at key signaling checkpoints in the neutrophil, resulting in exacerbated neutrophil recruitment.

  17. Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration.

    Directory of Open Access Journals (Sweden)

    Michael A Pazos

    2017-08-01

    Full Text Available Excessive neutrophil infiltration of the lungs is a common contributor to immune-related pathology in many pulmonary disease states. In response to pathogenic infection, airway epithelial cells produce hepoxilin A3 (HXA3, initiating neutrophil transepithelial migration. Migrated neutrophils amplify this recruitment by producing a secondary gradient of leukotriene B4 (LTB4. We sought to determine whether this two-step eicosanoid chemoattractant mechanism could be exploited by the pathogen Pseudomonas aeruginosa. ExoU, a P. aeruginosa cytotoxin, exhibits phospholipase A2 (PLA2 activity in eukaryotic hosts, an enzyme critical for generation of certain eicosanoids. Using in vitro and in vivo models of neutrophil transepithelial migration, we evaluated the impact of ExoU expression on eicosanoid generation and function. We conclude that ExoU, by virtue of its PLA2 activity, augments and compensates for endogenous host neutrophil cPLA2α function, leading to enhanced transepithelial migration. This suggests that ExoU expression in P. aeruginosa can circumvent immune regulation at key signaling checkpoints in the neutrophil, resulting in exacerbated neutrophil recruitment.

  18. Peptide-Mediated Platelet Capture at Gold Micropore Arrays.

    Science.gov (United States)

    Adamson, Kellie; Spain, Elaine; Prendergast, Una; Moran, Niamh; Forster, Robert J; Keyes, Tia E

    2016-11-30

    Ordered spherical cap gold cavity arrays with 5.4, 1.6, and 0.98 μm diameter apertures were explored as capture surfaces for human blood platelets to investigate the impact of surface geometry and chemical modification on platelet capture efficiency and their potential as platforms for surface enhanced Raman spectroscopy of single platelets. The substrates were chemically modified with single-constituent self-assembled monolayers (SAM) or mixed SAMs comprised of thiol-functionalized arginine-glycine-aspartic acid (RGD, a platelet integrin target) with or without 1-octanethiol (adhesion inhibitor). As expected, platelet adhesion was promoted and inhibited at RGD and alkanethiol modified surfaces, respectively. Platelet adhesion was reversible, and binding efficiency at the peptide modified substrates correlated inversely with pore diameter. Captured platelets underwent morphological change on capture, the extent of which depended on the topology of the underlying substrate. Regioselective capture of the platelets enabled study for the first time of the surface enhanced Raman spectroscopy of single blood platelets, yielding high quality Raman spectroscopy of individual platelets at 1.6 μm diameter pore arrays. Given the medical importance of blood platelets across a range of diseases from cancer to psychiatric illness, such approaches to platelet capture may provide a useful route to Raman spectroscopy for platelet related diagnostics.

  19. Platelet CLEC-2 protects against lung injury via effects of its ligand podoplanin on inflammatory alveolar macrophages in the mouse.

    Science.gov (United States)

    Lax, Siân; Rayes, Julie; Wichaiyo, Surasak; Haining, Elizabeth J; Lowe, Kate; Grygielska, Beata; Laloo, Ryan; Flodby, Per; Borok, Zea; Crandall, Edward D; Thickett, David R; Watson, Steve P

    2017-12-01

    There is no therapeutic intervention proven to prevent acute respiratory distress syndrome (ARDS). Novel mechanistic insights into the pathophysiology of ARDS are therefore required. Platelets are implicated in regulating many of the pathogenic processes that occur during ARDS; however, the mechanisms remain elusive. The platelet receptor CLEC-2 has been shown to regulate vascular integrity at sites of acute inflammation. Therefore the purpose of this study was to establish the role of CLEC-2 and its ligand podoplanin in a mouse model of ARDS. Platelet-specific CLEC-2-deficient, as well as alveolar epithelial type I cell (AECI)-specific or hematopoietic-specific podoplanin deficient, mice were established using cre-loxP strategies. Combining these with intratracheal (IT) instillations of lipopolysaccharide (LPS), we demonstrate that arterial oxygen saturation decline in response to IT-LPS in platelet-specific CLEC-2-deficient mice is significantly augmented. An increase in bronchoalveolar lavage (BAL) neutrophils and protein was also observed 48 h post-IT-LPS, with significant increases in pro-inflammatory chemokines detected in BAL of platelet-specific CLEC-2-deficient animals. Deletion of podoplanin from hematopoietic cells but not AECIs also reduces lung function and increases pro-inflammatory chemokine expression following IT-LPS. Furthermore, we demonstrate that following IT-LPS, platelets are present in BAL in aggregates with neutrophils, which allows for CLEC-2 interaction with podoplanin expressed on BAL inflammatory alveolar macrophages. Taken together, these data suggest that the platelet CLEC-2-podoplanin signaling axis regulates the severity of lung inflammation in mice and is a possible novel target for therapeutic intervention in patients at risk of developing ARDS. Copyright © 2017 the American Physiological Society.

  20. Predictive contribution of neutrophil/lymphocyte ratio in diagnosis of brucellosis.

    Science.gov (United States)

    Olt, Serdar; Ergenç, Hasan; Açıkgöz, Seyyid Bilal

    2015-01-01

    Here we wanted to investigate predictive value of neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) in the diagnosis of brucellosis. Thirty-two brucellosis patients diagnosed with positive serum agglutination test and thirty-two randomized healthy subjects were enrolled in this study retrospectively. Result with ROC analyzes the baseline NLR and hemoglobin values were found to be significantly associated with brucellosis (P = 0.01, P = 0.01, resp.). Herein we demonstrated for the first time that NLR values were significantly associated with brucellosis. This situation can help clinicians during diagnosis of brucellosis.

  1. Autophagy Primes Neutrophils for Neutrophil Extracellular Trap Formation during Sepsis.

    Science.gov (United States)

    Park, So Young; Shrestha, Sanjeeb; Youn, Young-Jin; Kim, Jun-Kyu; Kim, Shin-Yeong; Kim, Hyun Jung; Park, So-Hee; Ahn, Won-Gyun; Kim, Shin; Lee, Myung Goo; Jung, Ki-Suck; Park, Yong Bum; Mo, Eun-Kyung; Ko, Yousang; Lee, Suh-Young; Koh, Younsuck; Park, Myung Jae; Song, Dong-Keun; Hong, Chang-Won

    2017-09-01

    Neutrophils are key effectors in the host's immune response to sepsis. Excessive stimulation or dysregulated neutrophil functions are believed to be responsible for sepsis pathogenesis. However, the mechanisms regulating functional plasticity of neutrophils during sepsis have not been fully determined. We investigated the role of autophagy in neutrophil functions during sepsis in patients with community-acquired pneumonia. Neutrophils were isolated from patients with sepsis and stimulated with phorbol 12-myristate 13-acetate (PMA). The levels of reactive oxygen species generation, neutrophil extracellular trap (NET) formation, and granule release, and the autophagic status were evaluated. The effect of neutrophil autophagy augmentation was further evaluated in a mouse model of sepsis. Neutrophils isolated from patients who survived sepsis showed an increase in autophagy induction, and were primed for NET formation in response to subsequent PMA stimulation. In contrast, neutrophils isolated from patients who did not survive sepsis showed dysregulated autophagy and a decreased response to PMA stimulation. The induction of autophagy primed healthy neutrophils for NET formation and vice versa. In a mouse model of sepsis, the augmentation of autophagy improved survival via a NET-dependent mechanism. These results indicate that neutrophil autophagy primes neutrophils for increased NET formation, which is important for proper neutrophil effector functions during sepsis. Our study provides important insights into the role of autophagy in neutrophils during sepsis.

  2. Supramolecular Chitosan Micro-Platelets Synergistically Enhance Anti-Candida albicans Activity of Amphotericin B Using an Immunocompetent Murine Model.

    Science.gov (United States)

    Grisin, Tiphany; Bories, Christian; Bombardi, Martina; Loiseau, Philippe M; Rouffiac, Valérie; Solgadi, Audrey; Mallet, Jean-Maurice; Ponchel, Gilles; Bouchemal, Kawthar

    2017-05-01

    The aim of this work is to design new chitosan conjugates able to self-organize in aqueous solution in the form of micrometer-size platelets. When mixed with amphotericin B deoxycholate (AmB-DOC), micro-platelets act as a drug booster allowing further improvement in AmB-DOC anti-Candida albicans activity. Micro-platelets were obtained by mixing oleoyl chitosan and α-cyclodextrin in water. The formulation is specifically-engineered for mucosal application by dispersing chitosan micro-platelets into thermosensitive pluronic ® F127 20 wt% hydrogel. The formulation completely cured C. albicans vaginal infection in mice and had a superior activity in comparison with AmB-DOC without addition of chitosan micro-platelets. In vitro studies showed that the platelets significantly enhance AmB-DOC antifungal activity since the IC 50 and the MIC 90 decrease 4.5 and 4.8-times. Calculation of fractional inhibitory concentration index (FICI = 0.198) showed that chitosan micro-platelets act in a synergistic way with AmB-DOC against C. albicans. No synergy is found between spherical nanoparticles composed poly(isobutylcyanoacrylate)/chitosan and AmB-DOC. These results demonstrate for the first time the ability of flattened chitosan micro-platelets to have synergistic activity with AmB-DOC against C. albicans candidiasis and highlight the importance of rheological and mucoadhesive behaviors of hydrogels in the efficacy of the treatment.

  3. IFN-γ-producing NKT cells exacerbate sepsis by enhancing C5a generation via IL-10-mediated inhibition of CD55 expression on neutrophils.

    Science.gov (United States)

    Kim, Ji Hyung; Oh, Sae Jin; Ahn, Sehee; Chung, Doo Hyun

    2014-07-01

    A role for NKT cells has been implicated in sepsis, but the mechanism by which NKT cells contribute to sepsis remains unclear. Here, we examined WT and NKT-cell-deficient mice of C57BL/6 background during cecal ligation and puncture-induced sepsis. The levels of C5a, IFN-γ, and IL-10 were higher in the serum and peritoneal fluid of WT mice than in those of CD1d(-/-) mice, while the mortality rate was lower in CD1d(-/-) mice than in WT mice. C5a blockade decreased mortality of WT mice during sepsis, whereas it did not alter that of CD1d(-/-) mice. As assessed by intracellular staining, NKT cells expressed IFN-γ, while neutrophils expressed IL-10. Upon coculture, IL-10-deficient NKT cells enhanced IL-10 production by WT, but not IFN-γR-deficient, neutrophils. Meanwhile, CD1d(-/-) mice exhibited high CD55 expression on neutrophils during sepsis, whereas those cells from WT mice expressed minimal levels of CD55. Recombinant IL-10 administration into CD1d(-/-) mice reduced CD55 expression on neutrophils. Furthermore, adoptive transfer of sorted WT, but not IFN-γ-deficient, NKT cells into CD1d(-/-) mice suppressed CD55 expression on neutrophils, but increased IL-10 and C5a levels. Taken together, IFN-γ-producing NKT cells enhance C5a generation via IL-10-mediated inhibition of CD55 expression on neutrophils, thereby exacerbating sepsis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Platelet activation in outpatients undergoing esophagogastroduodenoscopy

    International Nuclear Information System (INIS)

    Sagripanti, A.; Polloni, A.; Materazzi, F.; Ferdeghini, M.; Pinori, E.; Bianchi, R.

    1989-01-01

    To evaluate the influence of emotional stress on platelet function mesured by radioimmunoassay in plasma two platelet factor 4, in a series of outpatients undergoing esophagogastroduodenoscopy for upper digestive complaints has been measured. The plasma levels of β-thromboglobulin and platelet factor 4, determined just before the instrumental examination, were significantly more elevated as compared to basal values, checked a week later. These results provide evidence of enhanced in vivo platelet release reaction during emotional stress

  5. GMP-140 binds to a glycoprotein receptor on human neutrophils: Evidence for a lectin-like interaction

    International Nuclear Information System (INIS)

    Moore, K.L.; Varki, A.; McEver, R.P.

    1991-01-01

    GMP-140 is a rapidly inducible receptor for neutrophils and monocytes expressed on activated platelets and endothelial cells. It is a member of the selectin family of lectin-like cell surface molecules that mediate leukocyte adhesion. We used a radioligand binding assay to characterize the interaction of purified GMP-140 with human neutrophils. Unstimulated neutrophils rapidly bound [125I]GMP-140 at 4 degrees C, reaching equilibrium in 10-15 min. Binding was Ca2+ dependent, reversible, and saturable at 3-6 nM free GMP-140 with half-maximal binding at approximately 1.5 nM. Receptor density and apparent affinity were not altered when neutrophils were stimulated with 4 beta-phorbol 12-myristate 13-acetate. Treatment of neutrophils with proteases abolished specific binding of [125I]GMP-140. Binding was also diminished when neutrophils were treated with neuraminidase from Vibrio cholerae, which cleaves alpha 2-3-, alpha 2-6-, and alpha 2-8-linked sialic acids, or from Newcastle disease virus, which cleaves only alpha 2-3- and alpha 2-8-linked sialic acids. Binding was not inhibited by an mAb to the abundant myeloid oligosaccharide, Lex (CD15), or by the neoglycoproteins Lex-BSA and sialyl-Lex-BSA. We conclude that neutrophils constitutively express a glycoprotein receptor for GMP-140, which contains sialic acid residues that are essential for function. These findings support the concept that GMP-140 interacts with leukocytes by a lectin-like mechanism

  6. FLow-Induced PRotrusions ( FLIPRs) A Platelet-Derived Platform for the Retrieval of Microparticles by Monocytes and Neutrophils

    NARCIS (Netherlands)

    Tersteeg, Claudia; Heijnen, Harry F.; Eckly, Anita; Pasterkamp, Gerard; Urbanus, Rolf T.; Maas, Coen; Hoefer, Imo E.; Nieuwland, Rienk; Farndale, Richard W.; Gachet, Christian; de Groot, Philip G.; Roest, Mark

    2014-01-01

    Rationale: Platelets are the most important cells in the primary prevention of blood loss after injury. In addition, platelets are at the interface between circulating leukocytes and the (sub)endothelium regulating inflammatory responses. Objective: Our aim was to study the dynamic process that

  7. Releasing growth factors from activated human platelets after chitosan stimulation: a possible bio-material for platelet-rich plasma preparation.

    Science.gov (United States)

    Shen, E-Chin; Chou, Tz-Chong; Gau, Ching-Hwa; Tu, Hsiao-Pei; Chen, Yen-Teen; Fu, Earl

    2006-10-01

    Thrombin is commonly used for activating the platelets and releasing the growth factors on the application of platelet-rich plasma (PRP). We have previously reported that chitosan can enhance rabbit platelet aggregation. In this study, the effects of chitosan on the subsequent growth factors release after human platelets activation were examined to evaluate the possibility of chitosan being used as a substitute for thrombin during PRP preparation. Human platelet activation was determined by aggregation, adhesion and alpha-granule membrane glycoprotein expression. Platelet aggregation was measured by the turbidimetric method, the adhesion was directly examined on chitosan-coated glass plates under light microscope and scanning electron microscope (SEM), and the alpha-granule membrane glycoprotein was detected by fluorescent isothiocyanate (FITC)-conjugated anti-CD61 antibody through flow cytometry. The subsequent epidermal growth factor (EGF), platelet-derived growth factor (PDGF)-AB and transforming growth factor (TGF)-beta1 release from platelets were assayed by ELISA after mixing with chitosan. The enhancing effects on the platelet adhesion and the aggregation from chitosan were observed. Under both microscopes, the adhesive platelets on the chitosan-coated plates were not only greater in number but also earlier in activation than those on the control plates. With flow cytometry, increased glycoprotein IIIa expression in platelets was detected after chitosan treatment. Greater concentrations of growth factors were measured from PRP after chitosan treatment than after the solvent treatment. Because of the observations of growth factors releasing from activated human platelets after chitosan stimulation, we suggest that chitosan may be an appropriate substitute for thrombin in PRP preparation.

  8. Enhanced basophil histamine release and neutrophil chemotactic activity predispose grain dust-induced airway obstruction.

    Science.gov (United States)

    Park, H; Jung, K; Kang, K; Nahm, D; Cho, S; Kim, Y

    1999-04-01

    The pathogenic mechanism of grain dust (GD)-induced occupational asthma (OA) remains unclear. To understand further the mechanism of GD-induced OA. Fifteen employees working in a same GD industry, complaining of work-related respiratory symptoms, were enrolled and were divided into two groups according to the GD-bronchoprovocation test (BPT) result: six positive responders were grouped as group III, nine negative responders as group II and five healthy controls as group I. Serum GD-specific immunoglobulin (Ig)E (sIgE), specific IgG (sIgG) and specific IgG4 (sIgG4) antibodies were detected by enzyme-linked immunosorbent assay. Basophil histamine release was measured by the autofluorometric method, and changes of serum neutrophil chemotactic activity were observed by the Boyden chamber method. For clinical parameters such as degree of airway hyperresponsiveness to methacholine, duration of respiratory symptoms, exposure duration, and prevalences of serum sIgE, sIgG and sIgG4 antibodies, there were no significant differences between group II and III (P > 0.05, respectively). Serum neutrophil chemotactic activity increased significantly at 30 min and decreased at 240 min after the GD-BPT in group III subjects (P 0.05). Basophil histamine release induced by GD was significantly higher in group III than those of group I or group II (P < 0.05, respectively), while minimal release of anti-IgG4 antibodies was noted in all three groups. These results suggest that enhanced basophil histamine release and serum neutrophil chemotactic activity might contribute to the development of GD-induced occupational asthma.

  9. Assessment of neutrophil to lymphocyte ratio and mean platelet volume in pediatric familial Mediterranean fever patients

    Directory of Open Access Journals (Sweden)

    Ozge Basaran

    2017-01-01

    Full Text Available Background: Blood neutrophil to lymphocyte ratio (NLR and mean platelet volume (MPV both have been used as a simple marker of inflammation in many disorders. Here, we aimed to investigate the relationship between NLR, MPV, and familial Mediterranean fever (FMF. Materials and Methods: In this retrospective study, the files of FMF patients in pediatric rheumatology outpatient clinic were reviewed. There were 160 participants (68.4% in the FMF patient group and 74 participants (31.6% in the control group. Ninety of patients were in attack-free period, and 70 were in attack period. Results: The highest values of NLR were found in the patients at attack period. Patients in attack-free period and the participants in control group had similar levels of NLR (1.71 ± 0.83 and 1.91 ± 1.86 respectively (P = 0.457, and they had lower ratios than the patients did at attack period (4.10 ± 3.11 (P < 0.001 for both. There was no significant difference between MPV values of attack patients (8.35 ± 4.91 and attack-free patients (8.43 ± 1.15 (P = 0.074. MPV values of attack patients and attack-free patients were significantly higher than control group (7.99 ± 0.81 (P < 0.001 for both. Conclusion: NLR ratio may indicate FMF attack period. Since there was no significant difference between attack-free patients and control groups, NLR ratio cannot be used as a subclinical inflammation marker. However, NLR could be a useful predictor of inflammation in FMF patients. On the other hand, since our attack and attack-free patients have similar MPV values and both had greater MPV values than control group, we suggest that MPV may be used to show subclinical inflammation.

  10. Mean platelet volume in bipolar disorder: the search for an ideal biomarker

    Directory of Open Access Journals (Sweden)

    Mert DG

    2016-08-01

    Full Text Available Derya Guliz Mert,1 Hatice Terzi2 1Department of Psychiatry, 2Department of Hematology, Faculty of Medicine, Cumhuriyet University, Sivas, Turkey Background: The pathophysiology of bipolar disorder (BD remains a mystery. In this context, interest in the role of the immune and inflammatory systems in BD has been increasing. We aimed to compare the routine hemogram values of BD patients with those of the participants in the healthy control group, to assess the inflammation levels of the two groups. Mean platelet volume (MPV can be obtained as routine hemogram parameters and may aid in the detection of systemic inflammation. Subjects and methods: This study was conducted with BD (manic episode inpatients (n=132 and healthy controls (n=135. Abnormally distributed variables (ie, neutrophil–lymphocyte ratio [NLR], platelet–lymphocyte ratio [PLR], neutrophils, lymphocytes, hemoglobin, hematocrit [HCT], mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], mean corpuscular hemoglobin concentration [MCHC], red cell distribution width [RDW], MPV, and plateletcrit [PCT] were compared using the Mann–Whitney U-test. Student’s t-test was used to compare the mean ages and white blood cell, red blood cell, and platelet counts of the patients with BD against those of the participants in the control group. Results: The comparisons revealed that while the mean WBC and the median NLR, PLR, neutrophil, lymphocyte, MPV, and PCT values were significantly higher in the patients with BD (P<0.05, the median hemoglobin, RBC, HCT, and MCHC values were significantly higher in the control group (P<0.05. Conclusion: Comparisons of hemogram values of patients with BD against those of the healthy control group revealed that inflammatory cells (absolute neutrophil count, platelet count, PCT, and MPV and ratios (NLR, PLR seem to be altered during manic episodes. These findings support the hypothesis that inflammatory activation occurs in BD during manic

  11. Stimulus-response coupling in platelets

    International Nuclear Information System (INIS)

    Huang, E.M.

    1986-01-01

    To understand the mechanism of stimulus-response coupling in platelets, the potentiating effect of succinate and lithium on platelet activation was examined. The action of succinate was immediate; preincubation with succinate did not lead to desensitization. Succinate was comparable to ADP in lowering cAMP levels previously elevated by PGl 2 . Since inhibition of cAMP is not a prerequisite for platelet activation, the mechanism of potentiation of succinate remains undefined. Lithium has also been shown to inhibit adenylate cyclase in PGl 2 -pretreated platelets. Lithium, however, can also inhibit inositol phosphate (InsP) phosphatase and lead to an accumulation of InsP. In human platelets, lithium also enhanced the thrombin-induced accumulation of [ 3 H]inositol-labelled inositol trisphosphate (InsP 3 ), and inositol bisphosphate (InsP 2 ). One hour after thrombin addition, all 3 inositol phosphates returned to near basal levels. In the presence of lithium, while labelled InsP 2 and InsP 3 returned to their respective basal levels, the InsP level remained elevated, consistent with the known inhibitory effect of lithium on InsP phosphatase. In thrombin-stimulated platelets prelabeled with [ 32 P]phosphate, lithium led to a decrease in labelled phosphatidylinositol 4-phosphate (PtdIns4P) as well as an enhanced production of labelled lysophosphatidylinositol, suggesting multiple effects of lithium on platelet phosphoinositide metabolism. These observed effects, however, occurred too slowly to be the mechanism by which lithium potentiated agonist-induced platelet activation. To study the agonist-receptor interaction, the effect of the specific, high affinity thrombin inhibitor, hirudin, on thrombin-induced accumulation of [ 3 H]inositol-labelled inositol phosphates was studied

  12. Native High Density Lipoproteins (HDL Interfere with Platelet Activation Induced by Oxidized Low Density Lipoproteins (OxLDL

    Directory of Open Access Journals (Sweden)

    Ivo Volf

    2013-05-01

    Full Text Available Platelets and lipoproteins play a crucial role in atherogenesis, in part by their ability to modulate inflammation and oxidative stress. While oxidized low density lipoproteins (OxLDL play a central role in the development of this disease, high density lipoproteins (HDL represent an atheroprotective factor of utmost importance. As platelet function is remarkably sensitive to the influence of plasma lipoproteins, it was the aim of this study to clarify if HDL are able to counteract the stimulating effects of OxLDL with special emphasis on aspects of platelet function that are relevant to inflammation. Therefore, HDL were tested for their ability to interfere with pro-thrombotic and pro-inflammatory aspects of platelet function. We are able to show that HDL significantly impaired OxLDL-induced platelet aggregation and adhesion. In gel-filtered platelets, HDL decreased both the formation of reactive oxygen species and CD40L expression. Furthermore, HDL strongly interfered with OxLDL-induced formation of platelet-neutrophil aggregates in whole blood, suggesting that platelets represent a relevant and sensitive target for HDL. The finding that HDL effectively competed with the binding of OxLDL to the platelet surface might contribute to their atheroprotective and antithrombotic properties.

  13. Identification of functional VEGF receptors on human platelets.

    Science.gov (United States)

    Selheim, Frode; Holmsen, Holm; Vassbotn, Flemming S

    2002-02-13

    Platelets secrete platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) upon stimulation. We have demonstrated that platelets have functionally active PDGF alpha-receptors, a transmembrane tyrosine kinase involved in negative feedback regulation. Here we demonstrate the presence of the related VEGF receptors fms-like tyrosine kinase-1 and kinase-insert domain region on human platelets. VEGF itself did not cause platelet aggregation. However, addition of exogenous VEGF to SFRLLN or thrombin-stimulated platelets potentiated platelet aggregation. Moreover, thrombin-induced phosphoinositide 3-kinase and mitogen-activated protein kinase activity were enhanced in the presence of VEGF.

  14. The relationship between neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in patients with obstructive sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Hülya Günbatar

    2015-09-01

    Full Text Available Objective: There is a strong relationship between obstructive sleep apnea syndrome (OSAS and cardiovascular disease (CVD. Chronic intermittent hypoxia, inflammation, oxidative stress, and endothelial dysfunction may create etiologic mechanisms, connection between OSAS to CVD. Inflammation play an important role in the development of CVD. Platelet- Lymphocyte Ratio (PLR and Neutrophil-lymphocyte Ratio (NLR are new biomarkers showing inflammation. This study was designed to investigate the association between PLR, NLR and relationship between severity of OSAS, polysomnographic parameters and PLR. Methods: This was a cohort study in which patients who had undergone a full night polysomnography for diagnosis of OSA were recruited. Patients were divided according to their apnea hypopnea index (AHI scores into OSAS negative simple snoring (Group 1; AHI 30 groups. Results: A total of 111 patients were included in this study. There were 26, 22 and 63 patients in Groups 1, 2 and 3, respectively. PLR were significantly different between groups (Group 1: 87.12, Group 2: 103.6, Group 3: 112.5, p < 0.05. PLR were significantly correlated with NLR, AHI, oxygen desaturation index, average and minimum O2 saturation values (p < 0.05. Multiple regression analysis demonstrated that PLR is an independent predictor of CVD. PLR cut-off value for demonstrating the presence of CVD is higher than 86.03. Conclusion: In the light of these findings, PLR is strongly associated with the severity of OSAS. PLR might be used as a biomarker to predict CVD in OSAS patients.

  15. Effects of acute and chronic psychological stress on platelet aggregation in mice.

    Science.gov (United States)

    Matsuhisa, Fumikazu; Kitamura, Nobuo; Satoh, Eiki

    2014-03-01

    Although psychological stress has long been known to alter cardiovascular function, there have been few studies on the effect of psychological stress on platelets, which play a pivotal role in cardiovascular disease. In the present study, we investigated the effects of acute and chronic psychological stress on the aggregation of platelets and platelet cytosolic free calcium concentration ([Ca(2+)]i). Mice were subjected to both transportation stress (exposure to novel environment, psychological stress) and restraint stress (psychological stress) for 2 h (acute stress) or 3 weeks (2 h/day) (chronic stress). In addition, adrenalectomized mice were subjected to similar chronic stress (both transportation and restraint stress for 3 weeks). The aggregation of platelets from mice and [Ca(2+)]i was determined by light transmission assay and fura-2 fluorescence assay, respectively. Although acute stress had no effect on agonist-induced platelet aggregation, chronic stress enhanced the ability of the platelet agonists thrombin and ADP to stimulate platelet aggregation. However, chronic stress failed to enhance agonist-induced increase in [Ca(2+)]i. Adrenalectomy blocked chronic stress-induced enhancement of platelet aggregation. These results suggest that chronic, but not acute, psychological stress enhances agonist-stimulated platelet aggregation independently of [Ca(2+)]i increase, and the enhancement may be mediated by stress hormones secreted from the adrenal glands.

  16. Platelet kinetics with indium-111 platelets: comparison with chromium-51 platelets

    International Nuclear Information System (INIS)

    Peters, A.M.; Lavender, J.P.

    1983-01-01

    The application of 111In-oxine to platelet labeling has contributed to the understanding of platelet kinetics along three lines: 1. It allows the measurement of new parameters of splenic function, such as the intrasplenic platelet transit time, which has shed new light on the physiology of splenic blood cell handling. 2. It facilitates the measurement of platelet life span in conditions, such as ITP, in which 51Cr may undergo undesirable elution from the platelet as a result of platelet-antibody interaction. 3. It allows the determination of the fate of platelets, that is, the site of platelet destruction in conditions in which reduced platelet life span is associated with abnormal platelet consumption, as a result of either premature destruction of ''abnormal'' platelets by the RE system, or the consumption (or destruction) of normal platelets after their interaction with an abnormal vasculature. Future research using 111In platelets may yield further valuable information on the control as well as the significance of intrasplenic platelet pooling, on the role of platelets in the development of chronic vascular lesions, and on the sites of platelet destruction in ITP. With regard to the latter, methods will have to be developed for harvesting sufficient platelets representative of the total circulating platelet population from severely thrombocytopenic patients for autologous platelet labeling. This would avoid the use of homologous platelets, which is likely to be responsible for some of the contradictory data relating to the use of radiolabeled platelet studies for the prediction of the response of patients with ITP to splenectomy

  17. fMLP-Induced IL-8 Release Is Dependent on NADPH Oxidase in Human Neutrophils

    Directory of Open Access Journals (Sweden)

    María A. Hidalgo

    2015-01-01

    Full Text Available N-Formyl-methionyl-leucyl-phenylalanine (fMLP and platelet-activating factor (PAF induce similar intracellular signalling profiles; but only fMLP induces interleukin-8 (IL-8 release and nicotinamide adenine dinucleotide phosphate reduced (NADPH oxidase activity in neutrophils. Because the role of ROS on IL-8 release in neutrophils is until now controversial, we assessed if NADPH oxidase is involved in the IL-8 secretions and PI3K/Akt, MAPK, and NF-κB pathways activity induced by fMLP. Neutrophils were obtained from healthy volunteers. IL-8 was measured by ELISA, IL-8 mRNA by qPCR, and ROS production by luminol-amplified chemiluminescence, reduction of ferricytochrome c, and FACS. Intracellular pH changes were detected by spectrofluorescence. ERK1/2, p38 MAPK, and Akt phosphorylation were analysed by immunoblotting and NF-κB was analysed by immunocytochemistry. Hydroxy-3-methoxyaceto-phenone (HMAP, diphenyleneiodonium (DPI, and siRNA Nox2 reduced the ROS and IL-8 release in neutrophils treated with fMLP. HMAP, DPI, and amiloride (a Na+/H+ exchanger inhibitor inhibited the Akt phosphorylation and did not affect the p38 MAPK and ERK1/2 activity. DPI and HMAP reduced NF-κB translocation induced by fMLP. We showed that IL-8 release induced by fMLP is dependent on NADPH oxidase, and ROS could play a redundant role in cell signalling, ultimately activating the PI3K/Akt and NF-κB pathways in neutrophils.

  18. Platelet-rich fibrin matrix for facial plastic surgery.

    Science.gov (United States)

    Sclafani, Anthony P; Saman, Masoud

    2012-05-01

    Platelets are known primarily for their role in hemostasis, but there is increasing interest in the effect of platelets on wound healing. Platelet isolates such as platelet-rich plasma have been advocated to enhance and accelerate wound healing. This article describes the use of a novel preparation, platelet-rich fibrin matrix (PRFM), for facial plastic surgery applications such as volume augmentation, fat transfer supplementation, and as an adjunct to open surgical procedures. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Platelets promote osteosarcoma cell growth through activation of the platelet-derived growth factor receptor-Akt signaling axis.

    Science.gov (United States)

    Takagi, Satoshi; Takemoto, Ai; Takami, Miho; Oh-Hara, Tomoko; Fujita, Naoya

    2014-08-01

    The interactions of tumor cells with platelets contribute to the progression of tumor malignancy, and the expression levels of platelet aggregation-inducing factors positively correlate with the metastatic potential of osteosarcoma cells. However, it is unclear how tumor-platelet interaction contributes to the proliferation of osteosarcomas. We report here that osteosarcoma-platelet interactions induce the release of platelet-derived growth factor (PDGF) from platelets, which promotes the proliferation of osteosarcomas. Co-culture of platelets with MG63 or HOS osteosarcoma cells, which could induce platelet aggregation, enhanced the proliferation of each cell line in vitro. Analysis of phospho-antibody arrays revealed that co-culture of MG63 cells with platelets induced the phosphorylation of platelet derived growth factor receptor (PDGFR) and Akt. The addition of supernatants of osteosarcoma-platelet reactants also increased the growth of MG63 and HOS cells as well as the level of phosphorylated-PDGFR and -Akt. Sunitinib or LY294002, but not erlotinib, significantly inhibited the platelet-induced proliferation of osteosarcoma cells, indicating that PDGF released from platelets plays an important role in the proliferation of osteosarcomas by activating the PDGFR and then Akt. Our results suggest that inhibitors that specifically target osteosarcoma-platelet interactions may eradicate osteosarcomas. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  20. Platelet RNA as a circulating biomarker trove for cancer diagnostics.

    Science.gov (United States)

    Best, M G; Vancura, A; Wurdinger, T

    2017-07-01

    Platelets are multifunctional cell fragments, circulating in blood in high abundance. Platelets assist in thrombus formation, sensing of pathogens entering the blood stream, signaling to immune cells, releasing vascular remodeling factors, and, negatively, enhancing cancer metastasis. Platelets are 'educated' by their environment, including in patients with cancer. Cancer cells appear to initiate intraplatelet signaling, resulting in splicing of platelet pre-mRNAs, and enhance secretion of cytokines. Platelets can induce leukocyte and endothelial cell modeling factors, for example, through adenine nucleotides (ATP), thereby facilitating extravasation of cancer cells. Besides releasing factors, platelets can also sequester RNAs and proteins released by cancer cells. Thus, platelets actively respond to queues from local and systemic conditions, thereby altering their transcriptome and molecular content. Platelets contain a rich repertoire of RNA species, including mRNAs, small non-coding RNAs and circular RNAs; although studies regarding the functionality of the various platelet RNA species require more attention. Recent advances in high-throughput characterization of platelet mRNAs revealed 10 to > 1000 altered mRNAs in platelets in the presence of disease. Hence, platelet RNA appears to be dynamically affected by pathological conditions, thus possibly providing opportunities to use platelet RNA as diagnostic, prognostic, predictive, or monitoring biomarkers. In this review, we cover the literature regarding the platelet RNA families, processing of platelet RNAs, and the potential application of platelet RNA as disease biomarkers. © 2017 International Society on Thrombosis and Haemostasis.

  1. Gamma-glutamyl-transpeptidase to platelet ratio is not superior to APRI,FIB-4 and RPR for diagnosing liver fibrosis in CHB patients in China

    OpenAIRE

    Huang, Rui; Wang, Guiyang; Tian, Chen; Liu, Yong; Jia, Bei; Wang, Jian; Yang, Yue; Li, Yang; Sun, Zhenhua; Yan, Xiaomin; Xia, Juan; Xiong, Yali; Song, Peixin; Zhang, Zhaoping; Ding, Weimao

    2017-01-01

    The gamma-glutamyl transpeptidase to platelet ratio (GPR) is a novel index to estimate liver fibrosis in chronic hepatitis B (CHB). Few studies compared diagnostic accuracy of GPR with other non-invasive fibrosis tests based on blood parameters. We analyzed diagnostic values of GPR for detecting liver fibrosis and compared diagnostic performances of GPR with APRI (aspartate aminotransferase-to-platelet ratio index), FIB-4 (fibrosis index based on the four factors), NLR (neutrophil-to-lymphocy...

  2. Inhibition of PAF-induced expression of CD11b and shedding of L-selectin on human neutrophils and eosinophils by the type IV selective PDE inhibitor, rolipram

    NARCIS (Netherlands)

    Dijkhuizen, B; deMonchy, JGR; Dubois, AEJ; Gerritsen, J; Kauffman, HF

    We quantitatively determined whether the selective phosphodiesterase (PDE) inhibitor, rolipram, inhibits changes in the adhesion molecules CD11b and L-selectin on platelet-activating factor (PAF)-stimulated human neutrophils and eosinophils in vitro. Incubations were performed in human whole blood

  3. Increasing platelet concentration in platelet-rich plasma inhibits anterior cruciate ligament cell function in three-dimensional culture.

    Science.gov (United States)

    Yoshida, Ryu; Cheng, Mingyu; Murray, Martha M

    2014-02-01

    Tissue engineering is one new strategy being developed to treat ACL ruptures. One such approach is bio-enhanced ACL repair, where a suture repair is supplemented with a bio-active scaffold containing platelets. However, the optimal concentration of platelets to stimulate ACL healing is not known. We hypothesized that increasing platelet concentrations in the scaffold would enhance critical cell behaviors. Porcine ACL fibroblasts were obtained from explant culture and suspended in platelet poor plasma (PPP), 1× platelet-rich plasma (PRP), 3× PRP, 5× PRP, or phosphate buffered saline (PBS). The cell suspensions were cultured in a 3D collagen scaffold. Cellular metabolism (MTT assay), apoptosis (TUNEL assay), and gene expression for type I and type III collagen were measured. 1× PRP significantly outperformed 5× PRP in all parameters studied: Type I and III collagen gene expression, apoptosis prevention, and cell metabolism stimulation. ACL fibroblasts cultured with 1× PRP had the highest type I and type III collagen gene expression. 1× PRP and PPP groups had the highest cell metabolism and lowest apoptosis rates. Concentration of platelets had significant effects on the behavior of ACL fibroblasts; thus, it is an important parameter that should be specified in clinical or basic science studies. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  4. Anti-neutrophil cytoplasmic antibodies stimulate release of neutrophil microparticles.

    LENUS (Irish Health Repository)

    Hong, Ying

    2012-01-01

    The mechanisms by which anti-neutrophil cytoplasmic antibodies (ANCAs) may contribute to the pathogenesis of ANCA-associated vasculitis are not well understood. In this study, both polyclonal ANCAs isolated from patients and chimeric proteinase 3-ANCA induced the release of neutrophil microparticles from primed neutrophils. These microparticles expressed a variety of markers, including the ANCA autoantigens proteinase 3 and myeloperoxidase. They bound endothelial cells via a CD18-mediated mechanism and induced an increase in endothelial intercellular adhesion molecule-1 expression, production of endothelial reactive oxygen species, and release of endothelial IL-6 and IL-8. Removal of the neutrophil microparticles by filtration or inhibition of reactive oxygen species production with antioxidants abolished microparticle-mediated endothelial activation. In addition, these microparticles promoted the generation of thrombin. In vivo, we detected more neutrophil microparticles in the plasma of children with ANCA-associated vasculitis compared with that in healthy controls or those with inactive vasculitis. Taken together, these results support a role for neutrophil microparticles in the pathogenesis of ANCA-associated vasculitis, potentially providing a target for future therapeutics.

  5. Neutrophils in atherosclerosis. A brief overview

    NARCIS (Netherlands)

    Hartwig, H.; Silvestre Roig, C.; Daemen, M.; Lutgens, E.; Soehnlein, O.

    2015-01-01

    Atherosclerosis is a chronic inflammation of the arterial wall and the continuous infiltration of leukocytes into the plaque enhances the progression of the lesion. Because of the scarce detection of neutrophils in atherosclerotic plaques compared to other immune cells, their contribution was

  6. The Application of Dextran Sedimentation as an Initial Step in Neutrophil Purification Promotes Their Stimulation, due to the Presence of Monocytes

    Science.gov (United States)

    Ferrante, Antonio

    2017-01-01

    The purification of human neutrophils for in vitro studies is challenging as they are easily activated through ex vivo manipulations. The technique of erythrocyte sedimentation combined with density gradient centrifugation remains widely practiced and was the subject of this study. Since in the sedimentation step the leukocytes are incubated with dextran, we have raised the likelihood that cellular activation would occur with mediator release leading to neutrophil activation. By comparing the activity of neutrophils purified from whole blood by the classical 2-step method of dextran sedimentation followed by low-density Ficoll-Hypaque (1.077 g/mL) medium, and the 1-step high-density Ficoll-Hypaque (1.114 g/mL) gradient centrifugation, we found that neutrophils from the 2-step method had a significant increase in cell surface CD11b expression and CD62L shedding and a marked increase in adhesion. Decreased random migration and chemotaxis and raised baseline oxidative burst activity were also observed. The effect was not specific to dextran, as using Ficoll for erythrocyte sedimentation replicated the elevated neutrophil adherence. Through the depletion of monocytes, lymphocytes, and platelets prior to sedimentation, we deduced that monocytes were responsible for the neutrophil activation. Our findings suggest that care needs to be exercised in choosing the method of neutrophil purification for functional studies. PMID:29164154

  7. Chronic neutrophilic leukemia.

    Science.gov (United States)

    Bredeweg, Arthur; Burch, Micah; Krause, John R

    2018-01-01

    Chronic neutrophilic leukemia is a rare myeloproliferative disorder characterized by a sustained peripheral blood neutrophilia, absence of the BCR/ABL oncoprotein, bone marrow hypercellularity with less than 5% myeloblasts and normal neutrophil maturation, and no dysplasia. This leukemia has been associated with mutations in the colony-stimulating factor 3 receptor (CSF3R) that may activate this receptor, leading to the proliferation of neutrophils that are the hallmark of chronic neutrophilic leukemia. We present a case of chronic neutrophilic leukemia and discuss the criteria for diagnosis and the significance of mutations found in this leukemia.

  8. Plasma kallikrein enhances platelet aggregation response by subthreshold doses of ADP.

    Science.gov (United States)

    Ottaiano, Tatiana F; Andrade, Sheila S; de Oliveira, Cleide; Silva, Mariana C C; Buri, Marcus V; Juliano, Maria A; Girão, Manoel J B C; Sampaio, Misako U; Schmaier, Alvin H; Wlodawer, Alexander; Maffei, Francisco H A; Oliva, Maria Luiza V

    2017-04-01

    Human plasma kallikrein (huPK) potentiates platelet responses to subthreshold doses of ADP, although huPK itself, does not induce platelet aggregation. In the present investigation, we observe that huPK pretreatment of platelets potentiates ADP-induced platelet activation by prior proteolysis of the G-protein-coupled receptor PAR-1. The potentiation of ADP-induced platelet activation by huPK is mediated by the integrin α IIb β 3 through interactions with the KGD/KGE sequence motif in huPK. Integrin α IIb β 3 is a cofactor for huPK binding to platelets to support PAR-1 hydrolysis that contributes to activation of the ADP signaling pathway. This activation pathway leads to phosphorylation of Src, AktS 473 , ERK1/2, and p38 MAPK, and to Ca 2+ release. The effect of huPK is blocked by specific antagonists of PAR-1 (SCH 19197) and α IIb β 3 (abciximab) and by synthetic peptides comprising the KGD and KGE sequence motifs of huPK. Further, recombinant plasma kallikrein inhibitor, rBbKI, also blocks this entire mechanism. These results suggest a new function for huPK. Formation of plasma kallikrein lowers the threshold for ADP-induced platelet activation. The present observations are consistent with the notion that plasma kallikrein promotes vascular disease and thrombosis in the intravascular compartment and its inhibition may ameliorate cardiovascular disease and thrombosis. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  9. Bioactivity and stability of endogenous fibrogenic factors in platelet-rich fibrin

    DEFF Research Database (Denmark)

    Lundquist, R.; Dziegiel, M.H.; Agren, M.S.

    2008-01-01

    Platelet-rich fibrin (PRF) is an autologous fibrin sealant (FS) enriched with a platelet concentrate (> 1,000,000 platelets/microL) produced by the automated Vivostat system and used to enhance wound healing. The effects of PRF were compared with supernatant from thrombin-activated platelet conce...

  10. Mechanisms of the priming effect of low doses of lipopoly-saccharides on leukocyte-dependent platelet aggregation in whole blood.

    Science.gov (United States)

    Montrucchio, Giuseppe; Bosco, Ornella; Del Sorbo, Lorenzo; Fascio Pecetto, Paolo; Lupia, Enrico; Goffi, Alberto; Omedè, Paola; Emanuelli, Giorgio; Camussi, Giovanni

    2003-11-01

    Several studies focused on the ability of bacterial lipopolysac-charides (LPS) in triggering platelet and/or leukocyte activation. The aim of this study was to investigate the molecular mechanisms involved in the aggregation of platelets and in their interaction with leukocytes in whole blood after stimulation with low doses of LPS. LPS did not directly induce platelet aggregation in whole blood, but they primed the aggregation of platelets induced by epinephrine, adenosine diphosphate and arachidonic acid. As shown by cytofluorimetry, platelets neither bind FITC-LPS, nor express the LPS-receptors CD14 and toll-like receptor 4 (TLR4). On the contrary, LPS primed monocytes and to a lesser extent polymorphonuclear neutrophils to adhere to platelets. Both platelet-leukocyte interaction and platelet aggregation in whole blood were inhibited by blockade of CD14 and TLR4. Moreover, the interaction between platelets and leukocytes was inhibited by P-selectin, and by blockade of PAF and reactive oxygen species, suggesting a role of P-selectin and of leukocyte-derived mediators. In conclusion, these results elucidate the mechanisms leading to platelet activation and interaction with leukocytes triggered by LPS. They suggest that the activation of platelets by LPS is mainly dependent on leukocytes and especially monocytes as a result of CD14 and TLR4 engagement. Moreover, we found that leukocyte-platelet interaction was triggered by the synthesis of PAF and the generation of oxygen radicals that induced upregulation of surface expression of P-selectin.

  11. [The significances of peripheral neutrophils CD(55) and myeloperoxidase expression in patients with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody associated vasculitis].

    Science.gov (United States)

    Zhou, X L; Zheng, M J; Shuai, Z W; Zhang, L; Zhang, M M; Chen, S Y

    2017-06-01

    linear regression analysis showed there was statistically significant positive correlation between MFI of CD(55) expressed on neutrophils and BVAS-V3 (β=0.001, P =0.027). Conclusions: In MPO-AAV, CD(55) expression on neutrophils is markedly enhanced, which is one of the independent risk factors related to disease activity. It might protect neutrophils from attacking AAV, CD(55) expression on neutrophils is markedly enhanced, which is one of the independent risk factors related to disease activity. It might protect neutrophils from attacking by complement alternative pathway. Activated neutrophils release more MPO and lysosome to intensify the inflammation reaction and aggravate the disease. Thus CD(55) might become a new potential target for the treatment of this disease in the future.

  12. d(− Lactic Acid-Induced Adhesion of Bovine Neutrophils onto Endothelial Cells Is Dependent on Neutrophils Extracellular Traps Formation and CD11b Expression

    Directory of Open Access Journals (Sweden)

    Pablo Alarcón

    2017-08-01

    Full Text Available Bovine ruminal acidosis is of economic importance as it contributes to reduced milk and meat production. This phenomenon is mainly attributed to an overload of highly fermentable carbohydrate, resulting in increased d(− lactic acid levels in serum and plasma. Ruminal acidosis correlates with elevated acute phase proteins in blood, along with neutrophil activation and infiltration into various tissues leading to laminitis and aseptic polysynovitis. Previous studies in bovine neutrophils indicated that d(− lactic acid decreased expression of L-selectin and increased expression of CD11b to concentrations higher than 6 mM, suggesting a potential role in neutrophil adhesion onto endothelia. The two aims of this study were to evaluate whether d(− lactic acid influenced neutrophil and endothelial adhesion and to trigger neutrophil extracellular trap (NET production (NETosis in exposed neutrophils. Exposure of bovine neutrophils to 5 mM d(− lactic acid elevated NET release compared to unstimulated neutrophil negative controls. Moreover, this NET contains CD11b and histone H4 citrullinated, the latter was dependent on PAD4 activation, a critical enzyme in DNA decondensation and NETosis. Furthermore, NET formation was dependent on d(− lactic acid plasma membrane transport through monocarboxylate transporter 1 (MCT1. d(− lactic acid enhanced neutrophil adhesion onto endothelial sheets as demonstrated by in vitro neutrophil adhesion assays under continuous physiological flow conditions, indicating that cell adhesion was a NET- and a CD11b/ICAM-1-dependent process. Finally, d(− lactic acid was demonstrated for the first time to trigger NETosis in a PAD4- and MCT1-dependent manner. Thus, d(− lactic acid-mediated neutrophil activation may contribute to neutrophil-derived pro-inflammatory processes, such as aseptic laminitis and/or polysynovitis in animals suffering acute ruminal acidosis.

  13. Extracellular histones promote thrombin generation through platelet-dependent mechanisms: involvement of platelet TLR2 and TLR4

    Science.gov (United States)

    Semeraro, Fabrizio; Ammollo, Concetta T.; Morrissey, James H.; Dale, George L.; Friese, Paul; Esmon, Naomi L.

    2011-01-01

    The release of histones from dying cells is associated with microvascular thrombosis and, because histones activate platelets, this could represent a possible pathogenic mechanism. In the present study, we assessed the influence of histones on the procoagulant potential of human platelets in platelet-rich plasma (PRP) and in purified systems. Histones dose-dependently enhanced thrombin generation in PRP in the absence of any trigger, as evaluated by calibrated automated thrombinography regardless of whether the contact phase was inhibited. Activation of coagulation required the presence of fully activatable platelets and was not ascribable to platelet tissue factor, whereas targeting polyphosphate with phosphatase reduced thrombin generation even when factor XII (FXII) was blocked or absent. In the presence of histones, purified polyphosphate was able to induce thrombin generation in plasma independently of FXII. In purified systems, histones induced platelet aggregation; P-selectin, phosphatidylserine, and FV/Va expression; and prothrombinase activity. Blocking platelet TLR2 and TLR4 with mAbs reduced the percentage of activated platelets and lowered the amount of thrombin generated in PRP. These data show that histone-activated platelets possess a procoagulant phenotype that drives plasma thrombin generation and suggest that TLR2 and TLR4 mediate the activation process. PMID:21673343

  14. Neutrophils at work

    DEFF Research Database (Denmark)

    Nauseef, William M; Borregaard, Niels

    2014-01-01

    In this Review we discuss data demonstrating recently recognized aspects of neutrophil homeostasis in the steady state, granulopoiesis in 'emergency' conditions and interactions of neutrophils with the adaptive immune system. We explore in vivo observations of the recruitment of neutrophils from ...

  15. Lipoxin A4 and platelet activating factor are involved in E. coli or LPS-induced lung inflammation in CFTR-deficient mice.

    Directory of Open Access Journals (Sweden)

    Haiya Wu

    Full Text Available CFTR (cystic fibrosis transmembrane conductance regulator is expressed by both neutrophils and platelets. Lack of functional CFTR could lead to severe lung infection and inflammation. Here, we found that mutation of CFTR (F508del or inhibition of CFTR in mice led to more severe thrombocytopenia, alveolar neutrocytosis and bacteriosis, and lower lipoxin A4/MIP-2 (macrophage inhibitory protein-2 or lipoxin A4/neutrophil ratios in the BAL (bronchoalveolar lavage during acute E. coli pneumonia. In vitro, inhibition of CFTR promotes MIP-2 production in LPS-stimulated neutrophils; however, lipoxin A4 could dose-dependently suppress this effect. In LPS-induced acute lung inflammation, blockade of PSGL-1 (P-selectin glycoprotein ligand-1 or P-selectin, antagonism of PAF by WEB2086, or correction of mutated CFTR trafficking by KM11060 could significantly increase plasma lipoxin A4 levels in F508del relevant to wildtype mice. Concurrently, F508del mice had higher plasma platelet activating factor (PAF levels and PAF-AH activity compared to wildtype under LPS challenge. Inhibiting hydrolysis of PAF by a specific PAF-AH (PAF-acetylhydrolase inhibitor, MAFP, could worsen LPS-induced lung inflammation in F508del mice compared to vehicle treated F508del group. Particularly, depletion of platelets in F508del mice could significantly decrease plasma lipoxin A4 and PAF-AH activity and deteriorate LPS-induced lung inflammation compared to control F508del mice. Taken together, lipoxin A4 and PAF are involved in E. coli or LPS-induced lung inflammation in CFTR-deficient mice, suggesting that lipoxin A4 and PAF might be therapeutic targets for ameliorating CFTR-deficiency deteriorated lung inflammation.

  16. Neutrophils in critical illness.

    Science.gov (United States)

    McDonald, Braedon

    2018-03-01

    During critical illness, dramatic alterations in neutrophil biology are observed including abnormalities of granulopoeisis and lifespan, cell trafficking and antimicrobial effector functions. As a result, neutrophils transition from powerful antimicrobial protectors into dangerous mediators of tissue injury and organ dysfunction. In this article, the role of neutrophils in the pathogenesis of critical illness (sepsis, trauma, burns and others) will be explored, including pathological changes to neutrophil function during critical illness and the utility of monitoring aspects of the neutrophil phenotype as biomarkers for diagnosis and prognostication. Lastly, we review findings from clinical trials of therapies that target the harmful effects of neutrophils, providing a bench-to-bedside perspective on neutrophils in critical illness.

  17. Dose- and time-related platelet response with apheresis platelet concentrates and pooled platelets

    Directory of Open Access Journals (Sweden)

    Mohammad Mizanur Rahman

    2017-02-01

    Full Text Available This study was carried out to compare the post-transfusion platelet increment between the apheresis platelet concentrate (n=74 and pooled platelets (n=54. Pre- and post-transfusion platelet count of the recipient were carried out by automated hematology analyzer. In apheresis platelet concentrate group, the mean 24 hours post-transfusion platelet increment was 47 x 109/L which was statistically significant (p<0.001. On the other hand, in pooled platelets group, the mean 24 hours post–transfusions platelet count increment was 11.0 x 109/L which was also statistically significant (p<0.001. This study concluded that the transfusion of apheresis platelet concentrate was more useful than the transfusion of pooled platelets in terms of platelet count increment and requirement of donor.

  18. Regulation of apoptosis and priming of neutrophil oxidative burst by diisopropyl fluorophosphate

    Directory of Open Access Journals (Sweden)

    Tsang Jennifer LY

    2010-07-01

    Full Text Available Abstract Background Diisopropyl fluorophosphate (DFP is a serine protease inhibitor that is widely used as an inhibitor of endogenous proteases in in vitro neutrophil studies. Its effects on neutrophil function are unclear. We sought to determine the biological effects of DFP on human neutrophil apoptosis and oxidative burst. Methods We isolated neutrophils from healthy volunteers, incubated them with DFP (2.5 mM, and evaluated neutrophil elastase (NE activity, neutrophil degranulation, apoptosis as reflected in hypodiploid DNA formation and exteriorization of phosphatidylserine (PS, processing and activity of caspases-3 and -8, oxidative burst activity and hydrogen peroxide release. Results Consistent with its activity as a serine protease inhibitor, DFP significantly inhibited NE activity but not the degranulation of azurophilic granules. DFP inhibited constitutive neutrophil apoptosis as reflected in DNA fragmentation, and the processing and activity of caspases-3 and -8. DFP also inhibited priming of neutrophils for oxidative burst activity and hydrogen peroxide release. However, DFP enhanced the exteriorization of PS in a dose-dependent manner. Conclusion We conclude that DFP exerts significant effects on neutrophil inflammatory function that may confound the interpretation of studies that use it for its antiprotease activity. We further conclude that endogenous proteases play a role in the biology of constitutive neutrophil apoptosis.

  19. Platelet-rich plasma: a biomimetic approach to enhancement of surgical wound healing.

    Science.gov (United States)

    Fernandez-Moure, Joseph S; Van Eps, Jeffrey L; Cabrera, Fernando J; Barbosa, Zonia; Medrano Del Rosal, Guillermo; Weiner, Bradley K; Ellsworth, Warren A; Tasciotti, Ennio

    2017-01-01

    Platelets are small anucleate cytoplasmic cell bodies released by megakaryocytes in response to various physiologic triggers. Traditionally thought to be solely involved in the mechanisms of hemostasis, platelets have gained much attention due to their involvement wound healing, immunomodulation, and antiseptic properties. As the field of surgery continues to evolve so does the need for therapies to aid in treating the increasingly complex patients seen. With over 14 million obstetric, musculoskeletal, and urological and gastrointestinal surgeries performed annually, the healing of surgical wounds continues to be of upmost importance to the surgeon and patient. Platelet-rich plasma, or platelet concentrate, has emerged as a possible adjuvant therapy to aid in the healing of surgical wounds and injuries. In this review, we will discuss the wound healing properties of platelet-rich plasma and various surgical applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Blood platelet kinetics and platelet transfusion.

    Science.gov (United States)

    Aster, Richard H

    2013-11-01

    The discovery of citrate anticoagulant in the 1920s and the development of plastic packs for blood collection in the 1960s laid the groundwork for platelet transfusion therapy on a scale not previously possible. A major limitation, however, was the finding that platelet concentrates prepared from blood anticoagulated with citrate were unsuitable for transfusion because of platelet clumping. We found that this could be prevented by simply reducing the pH of platelet-rich plasma to about 6.5 prior to centrifugation. We used this approach to characterize platelet kinetics and sites of platelet sequestration in normal and pathologic states and to define the influence of variables such as anticoagulant and ABO incompatibility on post-transfusion platelet recovery. The "acidification" approach enabled much wider use of platelet transfusion therapy until alternative means of producing concentrates suitable for transfusion became available.

  1. Neutrophil transmigration mediated by the neutrophil-specific antigen CD177 is influenced by the endothelial S536N dimorphism of platelet endothelial cell adhesion molecule-1.

    Science.gov (United States)

    Bayat, Behnaz; Werth, Silke; Sachs, Ulrich J H; Newman, Debra K; Newman, Peter J; Santoso, Sentot

    2010-04-01

    The human neutrophil-specific adhesion molecule CD177 (also known as the NB1 alloantigen) becomes upregulated on the cell surface in a number of inflammatory settings. We recently showed that CD177 functions as a novel heterophilic counterreceptor for the endothelial junctional protein PECAM-1 (CD31), an interaction that is mediated by membrane-proximal PECAM-1 IgD 6, which is known to harbor an S(536)N single nucleotide polymorphism of two major isoforms V(98)N(536)G(643) and L(98)S(536)R(643) and a yet-to-be-determined region on CD177. In vitro transendothelial migration experiments revealed that CD177(+) neutrophils migrated significantly faster through HUVECs expressing the LSR, compared with the VNG, allelic variant of PECAM-1 and that this correlated with the decreased ability of anti-PECAM-1 Ab of ITIM tyrosine phosphorylation in HUVECs expressing the LSR allelic variant relative to the VNG allelic variant. Moreover, engagement of PECAM-1 with rCD177-Fc (to mimic heterophilic CD177 binding) suppressed Ab-induced tyrosine phosphorylation to a greater extent in cells expressing the LSR isoform compared with the VNG isoform, with a corresponding increased higher level of beta-catenin phosphorylation. These data suggest that heterophilic PECAM-1/CD177 interactions affect the phosphorylation state of PECAM-1 and endothelial cell junctional integrity in such a way as to facilitate neutrophil transmigration in a previously unrecognized allele-specific manner.

  2. Neutrophil extracellular traps - the dark side of neutrophils

    DEFF Research Database (Denmark)

    Sørensen, Ole E.; Borregaard, Niels

    2016-01-01

    Neutrophil extracellular traps (NETs) were discovered as extracellular strands of decondensed DNA in complex with histones and granule proteins, which were expelled from dying neutrophils to ensnare and kill microbes. NETs are formed during infection in vivo by mechanisms different from those ori...

  3. Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as predictors of wound healing failure in head and neck reconstruction.

    Science.gov (United States)

    Maruyama, Yoko; Inoue, Keita; Mori, Keita; Gorai, Katsuya; Shimamoto, Ryo; Onitsuka, Tetsuro; Iguchi, Hiroyoshi; Okazaki, Mutsumi; Nakagawa, Masahiro

    2017-01-01

    In microsurgical head and neck reconstruction, a higher rate of post-operative wound complication could be predicted by a lower pre-operative neutrophil ratio (wound complications in microsurgical head and neck reconstruction. Patients who were undergoing tumor ablation and microsurgical reconstruction from April 2011 to March 2014 were analyzed retrospectively. The pre-operative hematological data, age, sex, co-morbidities, body mass index (BMI), adjuvant therapies, smoking, operation time, blood loss, total protein, T-stage, and Anesthesiologists Performance Status (ASA-PS) score were collected. Cases of post-operative wound healing failure were reviewed. One hundred and three consecutive patients were enrolled. Among these, the results of 77 patients who were younger than 70 years of age were analyzed. The distributions of the neutrophil ratio (p = .0005), lymphocyte ratio (p = .0166), monocyte ratio (p = .0341), NLR (p = .005), and PLR (p = .008) differed significantly between the patients with and without post-operative wound healing failure. Neutrophil ratio, NLR, and PLR cut-off values of 64.9, 3.5, and 160 were significantly associated with the rate of wound healing failure rate (p = .0002, .00021, .0042, respectively).

  4. Overhauser-enhanced MRI of elastase activity from in vitro human neutrophil degranulation.

    Directory of Open Access Journals (Sweden)

    Elodie Parzy

    Full Text Available Magnetic resonance imaging can reveal exquisite anatomical details. However several diseases would benefit from an imaging technique able to specifically detect biochemical alterations. In this context protease activity imaging is one of the most promising areas of research.We designed an elastase substrate by grafting stable nitroxide free radicals on soluble elastin. This substrate generates a high Overhauser magnetic resonance imaging (OMRI contrast upon digestion by the target proteases through the modulation of its rotational correlation time. The sensitivity is sufficient to generate contrasted images of the degranulation of neutrophils induced by a calcium ionophore from 2×10(4 cells per milliliter, well under the physiological neutrophils concentrations.These ex-vivo experiments give evidence that OMRI is suitable for imaging elastase activity from neutrophil degranulation. Provided that a fast protease-substrate is used these results open the door to better diagnoses of a number of important pathologies (cystic fibrosis, inflammation, pancreatitis by OMRI or Electron Paramagnetic Resonance Imaging in vivo. It also provides a long-expected method to monitor anti-protease treatments efficiency and help pharmaceutical research.

  5. Platelet size and age determine platelet function independently

    International Nuclear Information System (INIS)

    Thompson, C.B.; Jakubowski, J.A.; Quinn, P.G.; Deykin, D.; Valeri, C.R.

    1984-01-01

    A study was undertaken to examine the interaction of platelet size and age in determining in vitro platelet function. Baboon megakaryocytes were labeled in vivo by the injection of 75Se-methionine. Blood was collected when the label was predominantly associated with younger platelets (day 2) and with older platelets (day 9). Size-dependent platelet subpopulations were prepared on both days by counterflow centrifugation. The reactivity of each platelet subpopulation was determined on both days by measuring thrombin-induced aggregation. Platelets were fixed after partial aggregation had occurred by the addition of EDTA/formalin. After removal of the aggregated platelets by differential centrifugation, the supernatant medium was assayed for remaining platelets and 75Se radioactivity. Comparing day 2 and day 9, no significant difference was seen in the rate of aggregation of a given subpopulation. However, aggregation was more rapid in the larger platelet fractions than in the smaller ones on both days. A greater percentage of the 75Se radioactivity appeared in the platelet aggregates on day 2 than on day 9. This effect was independent of platelet size, as it occurred to a similar extent in the unfractionated platelets and in each of the size-dependent platelet subpopulations. The data indicate that young platelets are more active than older platelets. This study demonstrates that size and age are both determinants of platelet function, but by independent mechanisms

  6. Impaired platelet adhesion to lysed fibrin, whereas neutrophil adhesion remains intact under conditions of flow

    NARCIS (Netherlands)

    Remijn, Jasper A.; da Costa Martins, Paula; Ijsseldijk, Martin J. W.; Sixma, Jan J.; de Groot, Philip G.; Zwaginga, Jaap J.

    2006-01-01

    Vessel wall injury induces the formation of a haemostatic plug. Restoration of vascular integrity should involve cessation of further platelet and fibrin deposition and subsequent removal of these thrombi by both the fibrinolytic system and proteases delivered by infiltrating inflammatory cells. We

  7. Targeting neutrophilic inflammation in severe neutrophilic asthma : can we target the disease-relevant neutrophil phenotype?

    NARCIS (Netherlands)

    Bruijnzeel, Piet L B; Uddin, Mohib; Koenderman, Leo

    2015-01-01

    In severe, neutrophilic asthma, neutrophils are thought to have an important role in both the maintenance of the disease and during exacerbations. These patients often display excessive, mucosal airway inflammation with unresolving neutrophilia. Because this variant of asthma is poorly controlled by

  8. A taurine-supplemented vegan diet may blunt the contribution of neutrophil activation to acute coronary events.

    Science.gov (United States)

    McCarty, Mark F

    2004-01-01

    Neutrophils are activated in the coronary circulation during acute coronary events (unstable angina and myocardial infarction), often prior to the onset of ischemic damage. Moreover, neutrophils infiltrate coronary plaque in these circumstances, and may contribute to the rupture or erosion of this plaque, triggering thrombosis. Activated neutrophils secrete proteolytic enzymes in latent forms which are activated by the hypochlorous acid (HOCl) generated by myeloperoxidase. These phenomena may help to explain why an elevated white cell count has been found to be an independent coronary risk factor. Low-fat vegan diets can decrease circulating leukocytes--neutrophils and monocytes--possibly owing to down-regulation of systemic IGF-I activity. Thus, a relative neutropenia may contribute to the coronary protection afforded by such diets. However, vegetarian diets are devoid of taurine - the physiological antagonist of HOCl--and tissue levels of this nutrient are relatively low in vegetarians. Taurine has anti-atherosclerotic activity in animal models, possibly reflecting a role for macrophage-derived myeloperoxidase in the atherogenic process. Taurine also has platelet-stabilizing and anti-hypertensive effects that presumably could reduce coronary risk. Thus, it is proposed that a taurine-supplemented low-fat vegan diet represents a rational strategy for diminishing the contribution of activated neutrophils to acute coronary events; moreover, such a regimen would work in a number of other complementary ways to promote cardiovascular health. Moderate alcohol consumption, the well-tolerated drug pentoxifylline, and 5-lipoxygenase inhibitors--zileuton, boswellic acids, fish oil--may also have potential in this regard. Copyright 2004 Elsevier Ltd.

  9. Platelet concentrates: Bioengineering dentistry′s regenerative dreams

    Directory of Open Access Journals (Sweden)

    Sushma Naag

    2015-01-01

    Full Text Available Technological advances in the fields of medicine and allied sciences had given much needed momentum into the field of molecular biology and regenerative medicine. They indeed provided a boost to innovate new yields for both hard tissue and soft tissue regeneration in dentistry. One among them is the use of platelet concentrates (platelet rich plasma [PRP], platelet rich fibrin [PRF]. Autologous concentrate of blood platelets with a suspension of growth factors offers an enhanced healing of hard and soft tissues. It is an auxiliary benefit for an operator to be aware of platelet concentrates and its healing properties for delivering unsurpassed oral health care to patients. The current article outlines the principles, objectives and clinical insight to the regenerative potential of platelet concentrates in various fields of dentistry. The search words of the PubMed data base were PRF and other permutations of keywords such as "PRP dentistry", PRF dentistry, PRF regenerative dentistry.

  10. Cervico-vaginal immunoglobulin G levels increase post-ovulation independently of neutrophils.

    Directory of Open Access Journals (Sweden)

    Katrein Schaefer

    Full Text Available The prevalence of sexually transmitted infections (STIs is often higher in females than in males. Although the reproductive cycle profoundly modulates local immunity in the female reproductive tract (FRT system, significant gaps in our knowledge of the immunobiology of the FRT still exist. An intriguing and frequently observed characteristic of the FRT is the predominant presence of immunoglobulin (Ig G in cervico-vaginal secretions. We show here that in the mouse, IgG accumulation was enhanced approximately 5-fold post-ovulation, and was accompanied by an influx of neutrophils into the FRT. To determine whether these two events were causally related, we performed short-term neutrophil depletion experiments at individual stages throughout the estrous cycle. Our results demonstrate that neutrophils were not necessary for cycle-dependent tissue remodeling and cycle progression and that cycle-dependent IgG accumulation occurred independent of neutrophils. We thus conclude that neutrophil influx and IgG accumulation are independent events that occur in the FRT during the reproductive cycle.

  11. Storage of platelets: effects associated with high platelet content in platelet storage containers.

    Science.gov (United States)

    Gulliksson, Hans; Sandgren, Per; Sjödin, Agneta; Hultenby, Kjell

    2012-04-01

    A major problem associated with platelet storage containers is that some platelet units show a dramatic fall in pH, especially above certain platelet contents. The aim of this study was a detailed investigation of the different in vitro effects occurring when the maximum storage capacity of a platelet container is exceeded as compared to normal storage. Buffy coats were combined in large-volume containers to create primary pools to be split into two equal aliquots for the preparation of platelets (450-520×10(9) platelets/unit) in SSP+ for 7-day storage in two containers (test and reference) with different platelet storage capacity (n=8). Exceeding the maximum storage capacity of the test platelet storage container resulted in immediate negative effects on platelet metabolism and energy supply, but also delayed effects on platelet function, activation and disintegration. Our study gives a very clear indication of the effects in different phases associated with exceeding the maximum storage capacity of platelet containers but throw little additional light on the mechanism initiating those negative effects. The problem appears to be complex and further studies in different media using different storage containers will be needed to understand the mechanisms involved.

  12. A role for protein phosphatase-2A in p38 mitogen-activated protein kinase-mediated regulation of the c-Jun NH(2)-terminal kinase pathway in human neutrophils.

    Science.gov (United States)

    Avdi, Natalie J; Malcolm, Kenneth C; Nick, Jerry A; Worthen, G Scott

    2002-10-25

    Human neutrophil accumulation in inflammatory foci is essential for the effective control of microbial infections. Although exposure of neutrophils to cytokines such as tumor necrosis factor-alpha (TNFalpha), generated at sites of inflammation, leads to activation of MAPK pathways, mechanisms responsible for the fine regulation of specific MAPK modules remain unknown. We have previously demonstrated activation of a TNFalpha-mediated JNK pathway module, leading to apoptosis in adherent human neutrophils (Avdi, N. J., Nick, J. A., Whitlock, B. B., Billstrom, M. A., Henson, P. M., Johnson, G. L., and Worthen, G. S. (2001) J. Biol. Chem. 276, 2189-2199). Herein, evidence is presented linking regulation of the JNK pathway to p38 MAPK and the Ser/Thr protein phosphatase-2A (PP2A). Inhibition of p38 MAPK by SB 203580 and M 39 resulted in significant augmentation of TNFalpha-induced JNK and MKK4 (but not MKK7 or MEKK1) activation, whereas prior exposure to a p38-activating agent (platelet-activating factor) diminished the TNFalpha-induced JNK response. TNFalpha-induced apoptosis was also greatly enhanced upon p38 inhibition. Studies with a reconstituted cell-free system indicated the absence of a direct inhibitory effect of p38 MAPK on the JNK module. Neutrophil exposure to the Ser/Thr phosphatase inhibitors okadaic acid and calyculin A induced JNK activation. Increased phosphatase activity following TNFalpha stimulation was shown to be PP2A-associated and p38-dependent. Furthermore, PP2A-induced dephosphorylation of MKK4 resulted in its inactivation. Thus, in neutrophils, p38 MAPK, through a PP2A-mediated mechanism, regulates the JNK pathway, thus determining the extent and nature of subsequent responses such as apoptosis.

  13. Increasing platelet concentrations in leukocyte-reduced platelet-rich plasma decrease collagen gene synthesis in tendons.

    Science.gov (United States)

    Boswell, Stacie G; Schnabel, Lauren V; Mohammed, Hussni O; Sundman, Emily A; Minas, Tom; Fortier, Lisa A

    2014-01-01

    minimizing leukocytes in PRP is more important than maximizing platelet numbers with respect to decreasing inflammation and enhancing matrix gene synthesis. This study suggests that reducing leukocytes to minimize catabolic signaling appears to be more important than increasing platelets in an effort to maximize anabolic signaling. Further, a maximum biological threshold of benefit was demonstrated with regard to the number of platelets beyond which further increases in platelet concentration did not result in further anabolic upregulation. In vivo investigations documenting the use of platelets for the treatment of tendinopathy are justified as well as further in vitro characterization of the ideal PRP product for the treatment of tendinopathy and other musculoskeletal applications.

  14. Platelet growth factors from allogeneic platelet-rich plasma for clinical improvement in split-thickness skin graft.

    Science.gov (United States)

    Sonker, Atul; Dubey, Anju; Bhatnagar, Ankur; Chaudhary, Rajendra

    2015-01-01

    Platelets are a source of numerous growth factors which facilitate repair and healing. Thus platelet rich plasma has been increasingly used as a treatment modality in the field of reconstructive surgeries for wound healing. This preliminary study was carried out to explore whether platelet growth factors from platelet rich plasma could be used for enhancement of split thickness skin graft survival. Twenty patients (13 males and 7 females) requiring split thickness skin graft for various clinical reasons were enrolled in the study. Platelet rich plasma was collected by apheresis and frozen at -80° C. It was thawed at room temperature immediately before its intended application. PRP was applied only on one half of the wound, while another half served as control. Patient was followed for 6 weeks. The effect was assessed at first dressing in terms of graft uptake and subsequently as time taken for complete healing. There was 100% uptake of the graft in the area where platelet rich plasma was applied. In the control area, there was complete graft loss in 4 cases, partial loss in 7 cases and complete uptake in 9 cases. This study demonstrated promising results on application of PRP to split thickness skin grafts. Further randomized studies with greater sample size may be undertaken to establish platelet rich plasma as a validated treatment modality.

  15. The membrane attack complex of complement contributes to plasmin-induced synthesis of platelet-activating factor by endothelial cells and neutrophils.

    Science.gov (United States)

    Lupia, Enrico; Del Sorbo, Lorenzo; Bergerone, Serena; Emanuelli, Giorgio; Camussi, Giovanni; Montrucchio, Giuseppe

    2003-08-01

    Thrombolytic agents, used to restore blood flow to ischaemic tissues, activate several enzymatic systems with pro-inflammatory effects, thus potentially contributing to the pathogenesis of ischaemia-reperfusion injury. Platelet-activating factor (PAF), a phospholipid mediator of inflammation, has been implicated in the pathogenesis of this process. We previously showed that the infusion of streptokinase (SK) induces the intravascular release of PAF in patients with acute myocardial infarction (AMI), and that cultured human endothelial cells (EC) synthesized PAF in response to SK and plasmin (PLN). In the present study, we investigated the role of the membrane attack complex (MAC) of complement in the PLN-induced synthesis of PAF. In vivo, we showed a correlation between the levels of soluble terminal complement components (sC5b-9) and the concentrations of PAF detected in blood of patients with AMI infused with SK. In vitro both EC and polymorphonuclear neutrophils (PMN), incubated in the presence of PLN and normal human serum, showed an intense staining for the MAC neoepitope, while no staining was detected when they were incubated with PLN in the presence of heat-inactivated normal human serum. Moreover, the insertion of MAC on EC and PMN plasmamembrane elicited the synthesis of PAF. In conclusion, our results elucidate the mechanisms involved in PAF production during the activation of the fibrinolytic system, showing a role for complement products in this setting. The release of PAF may increase the inflammatory response, thus limiting the beneficial effects of thrombolytic therapy. Moreover, it may have a pathogenic role in other pathological conditions, such as transplant rejection, tumoral angiogenesis, and septic shock, where fibrinolysis is activated.

  16. Doxycycline induced photodamage to human neutrophils and tryptophan

    International Nuclear Information System (INIS)

    Sandberg, S.; Glette, J.; Hopen, G.; Solberg, C.O.

    1984-01-01

    Neutrophil function were studied following irradiation (340-380 nm) of the cells in the presence of 22 μM doxycycline. At increasing light fluence the locomotion, chemiluminescence and glucose oxidation (by the hexose monophosphate shunt) of the neutrophils steadily decreased. The photodamage increased with increasing preincubation temperature and time and was enhanced in D 2 O, reduced in azide and abolished in anaerobiosis. Superoxide dismutase, catalase or mannitol did not influence the photodamage. Photooxidation of tryptophan in the presence of doxycycline was increased 9-10-fold in D 2 O and nearly abolished in the presence of 0.25 mM NaN 3 , indicating that singlet oxygen is the most important reactive oxygen species in the doxycycline-induced photodamage. The results may explain some of the features of tetracycline-induced photosensitivity and why other authors have obtained diverging results when studying the influence of tetracyclines on neutrophil functions. (author)

  17. New Insights into the Pro-Inflammatory Activities of Ang1 on Neutrophils: Induction of MIP-1β Synthesis and Release.

    Directory of Open Access Journals (Sweden)

    Elizabeth Dumas

    Full Text Available We reported the expression of angiopoietin Tie2 receptor on human neutrophils and the capacity of angiopoietins (Ang1 and Ang2 to induce pro-inflammatory activities, such as platelet-activating factor synthesis, β2-integrin activation and neutrophil migration. Recently, we observed differential effects between both angiopoietins, namely, the capacity of Ang1, but not Ang2, to promote rapid interleukin-8 synthesis and release, as well as neutrophil viability. Herein, we addressed whether Ang1 and/or Ang2 could modulate the synthesis and release of macrophage inflammatory protein-1β (MIP-1β by neutrophils. Neutrophils were isolated from blood of healthy volunteers; intracellular and extracellular MIP-1β protein concentrations were assessed by ELISA. After 24 hours, the basal intracellular and extracellular MIP-1β protein concentrations were ≈500 and 100 pg/106 neutrophils, respectively. Treatment with Ang1 (10 nM increased neutrophil intracellular and extracellular MIP-1β concentrations by 310 and 388% respectively. Pretreatment with PI3K (LY294002, p38 MAPK (SB203580 and MEK (U0126 inhibitors completely inhibited Ang1-mediated increase of MIP-1β intracellular and extracellular protein levels. Pretreatment with NF-κB complex inhibitors, namely Bay11-7085 and IKK inhibitor VII or with a transcription inhibitor (actinomycin D and protein synthesis inhibitor (cycloheximide, did also abrogate Ang1-mediated increase of MIP-1β intracellular and extracellular protein levels. We validated by RT-qPCR analyses the effect of Ang1 on the induction of MIP-1β mRNA levels. Our study is the first one to report Ang1 capacity to induce MIP-1β gene expression, protein synthesis and release from neutrophils, and that these effects are mediated by PI3K, p38 MAPK and MEK activation and downstream NF-κB activation.

  18. Platelet function in the postprandial period

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    Sinzinger Helmut

    2012-09-01

    Full Text Available Abstract Background Postprandial hyperlipidemia and hyperglycemia have been related to cardiovascular events. Among different underlying mechanisms platelet activation seems to be responsible too. No comparable data between various tests in normo- vs. hyperlipidemics before and at different time intervals are available after a fat meal. We aimed to compare 9 of them within the same patients at several time points in postprandial hyperlipidemia. Results For some tests baseline values between the groups were significantly different (TXB2, platelet sensitivity, sedimentation and WU-test. However, hyperlipidemia revealed a variable influence on the tests examined. Some of the available tests apparently sensitive to show platelet activation reflect the increase in triglycerides (TG, such as the sedimentation index. ADP-induced platelet aggregatory activity in count adjusted washed isolated platelet samples during postprandial hyperlipidemia indicates mildly enhanced platelet activity, but does not seem to induce significant changes in aggregation. In patients with severe hypertriglyceridemia (> 400 mg/dl fasting changes in platelet function are more pronounced due to delayed decay and may last up to 16 hours paralleling TG reaching the prevalue. The overwhelming majority of platelet function tests do not significantly respond to postprandial hyperlipidemia. The correlation between the tests applied is poor. For standardization purpose, platelet aggregation tests, aimed to examine proaggregatory capacity in atherosclerosis, should only be performed at the same time of the day after a fasting period > 6 hours. The great variation in preanalytical work-up on comparison of various tests, large number of platelet tests available and their respective potential value are discussed. Conclusions At present, the suspicion that platelet function is significantly activated in the postprandial period cannot be supported by any of the tests used. The

  19. Platelet content of nitric oxide synthase 3 phosphorylated at Serine 1177 is associated with the functional response of platelets to aspirin.

    Directory of Open Access Journals (Sweden)

    Javier Modrego

    Full Text Available OBJECTIVE: To analyse if platelet responsiveness to aspirin (ASA may be associated with a different ability of platelets to generate nitric oxide (NO. PATIENTS/METHODS: Platelets were obtained from 50 patients with stable coronary ischemia and were divided into ASA-sensitive (n = 26 and ASA-resistant (n = 24 using a platelet functionality test (PFA-100. RESULTS: ASA-sensitive platelets tended to release more NO (determined as nitrite + nitrate than ASA-resistant platelets but it did not reach statistical significance. Protein expression of nitric oxide synthase 3 (NOS3 was higher in ASA-sensitive than in ASA-resistant platelets but there were no differences in the platelet expression of nitric oxide synthase 2 (NOS2 isoform. The highest NOS3 expression in ASA-sensitive platelets was independent of the presence of T-to-C mutation at nucleotide position -786 (T(-786 → C in the NOS3-coding gene. However, platelet content of phosphorylated NOS3 at Serine (Ser(1177, an active form of NOS3, was higher in ASA-sensitive than in ASA-resistant platelets. The level of platelet NOS3 Ser(1177 phosphorylation was positively associated with the closure time in the PFA-100 test. In vitro, collagen failed to stimulate the aggregation of ASA-sensitive platelets, determined by lumiaggregometry, and it was associated with a significant increase (p = 0.018 of NOS3 phosphorylation at Ser(1177. On the contrary, collagen stimulated the aggregation of ASA-resistant platelets but did not significantly modify the platelet content of phosphorylated NOS3 Ser(1177. During collagen stimulation the release of NO from ASA-sensitive platelets was significantly enhanced but it was not modified in ASA-resistant platelets. CONCLUSIONS: Functional platelet responsiveness to ASA was associated with the platelet content of phosphorylated NOS3 at Ser(1177.

  20. Measurement of platelet aggregation, independently of patient platelet count

    DEFF Research Database (Denmark)

    Vinholt, P J; Frederiksen, H; Hvas, A-M

    2017-01-01

    with collagen-related peptide). Platelet aggregation had a negative predictive value of 100% for a bleeding tendency among patients. Conclusion The established platelet aggregation assay was applicable for thrombocytopenic patients, and improved the identification of bleeding risk.......Essentials •Platelet function may influence bleeding risk in thrombocytopenia, but useful tests are needed. •A flow cytometric platelet aggregation test independent of the patient platelet count was made. •Platelet aggregation was reduced in thrombocytopenic patients with hematological cancer....... •High platelet aggregation ruled out bleeding tendency in thrombocytopenic patients. Summary Background Methods for testing platelet aggregation in thrombocytopenia are lacking. Objective To establish a flow-cytometric test of in vitro platelet aggregation independently of the patient's platelet count...

  1. The measurement of platelet activation by radioimmunoassay in asthma

    International Nuclear Information System (INIS)

    Wu Guoxin; Sun Jian; Li Jianyong; Ruan Changgeng

    1992-02-01

    Radioimmunoassay with specific monoclonal antibody was used to evaluate the platelet activation in 14 cases of acute bronchial asthma. The result showed that the number of molecules of alpha-granule membrane protein (GMP-140) which was exposed on the surface of platelet following secretion significantly increased on the surface of platelet and in plasma, while the number of molecules of glycoprotein (GP) I b and GPIII a did not change significantly; the concentration of thromboxane B 2 in plasma was raised, while the concentration of 6-keto-PGF 1a was within the normal limits; the concentrations of β-thromboglobulin (β-TG) and platelet factor 4(PF 4 ) in plasma increased significantly; the number of platelets decreased. These results strongly confirmed that the degree of platelet activation was enhanced during acute asthmatic attack. The significance of platelet activation in the pathogenesis of asthma should be further investigated

  2. Radiolabeled platelets

    International Nuclear Information System (INIS)

    Datz, F.L.; Taylor, A.T.

    1986-01-01

    Initial interest in developing techniques to radiolabel platelets was spurred by the lack of an accurate method for measuring platelet life span in both normals and in thrombocytopenic patients. Early investigators could obtain only rough estimates of platelet life spans by monitoring the platelet counts of thrombocytopenic patients undergoing platelet transfusions. Labels were also sought that would allow imaging of platelets in vivo in order to better understand the pathophysiology of atherosclerosis, thrombophlebitis, and clotting disorders, and to improve the clinical diagnosis of these diseases. Two types of platelet labels were investigated: cohort (pulse) labels and random labels. Cohort labels are taken up by megakaryocytes in the bone marrow and incorporated in the DNA and other components of the forming platelet. In theory, only freshly released platelets of a uniform age are labeled. Random labels, on the other hand, tag platelets in the peripheral blood, labeling platelets of all ages

  3. Are neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as effective as Fournier's gangrene severity index for predicting the number of debridements in Fourner's gangrene?

    Science.gov (United States)

    Kahramanca, Sahin; Kaya, Oskay; Özgehan, Gülay; Irem, Burak; Dural, Ibrahim; Küçükpınar, Tevfik; Kargıcı, Hülagü

    2014-03-01

    Fournier's gangrene (FG) is a rapidly progressive and necrotizing infection of the subcutaneous and fascial tissues with a high mortality rate. In the present study, we aimed to investigate prognostic factors and analyze the outcomes of 68 patients in a tertiary reference hospital. Patients admitted to the emergency department were investigated retrospectively between January 2006 and January 2013 and divided into two groups. The patients in Group I (G1) required one debridement, and Group II (G2) patients required more than one. Patient demographic and clinical characteristics were encoded. Fournier's Gangrene Severity Index (FGSI) scores, neutrophil-lymphocyte ratios (NLR), and platelet-lymphocyte ratios (PLR) were calculated. Prognostic factors were compared between the groups. There were no statistically significant differences between the groups in terms of mean age, female-male ratio, or duration of symptoms on admission; however, there were more infection sources, predisposal factors, and positive culture results in G2. Additionally, hospital stay, total cost, and mortality rate values were high in G2. We found statistically higher NLR and PLR ratios in G2, but there was no significant difference in FGSI scores between the groups. The FGSI scoring system was not found to be valuable in determining prognosis. However, NLR and PLR were valuable, and previous use of NLR and PLR for determining Fournier's gangrene prognosis could not be found in the English literature.

  4. Targeting Neutrophil Protease-Mediated Degradation of Tsp-1 to Induce Metastatic Dormancy

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-1-0615 TITLE: Targeting Neutrophil Protease-Mediated Degradation of Tsp-1 to Induce Metastatic Dormancy PRINCIPAL...29 Sep 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Targeting Neutrophil Protease-Mediated Degradation of Tsp-1 to Induce Metastatic Dormancy...infection or cigarette smoke enhanced pulmonary metastasis from breast cancer in humans and mice. Similarly, autoimmune arthritis, characterized by

  5. Platelet size does not correlate with platelet age.

    Science.gov (United States)

    Thompson, C B; Love, D G; Quinn, P G; Valeri, C R

    1983-08-01

    The relationship between platelet size and in vivo aging was investigated in the baboon using size-dependent platelet subpopulations separated by counterflow centrifugation. The separation characteristics, size, lactate dehydrogenase (LDH) activity, and dense-body content of the baboon platelet subpopulations were similar to those previously observed in studies of human platelets. Three independent labeling techniques were used: (1) in vivo labeling with 75Se-methionine, (2) in vitro labeling with 51Cr, and (3) in vivo labeling with 14C-serotonin. Maximal incorporation of all three labels showed a close correlation between the mean platelet volume (MPV) of each fraction and the platelet radioactivity. The onset of incorporation and rate of accumulation of 75Se-methionine were comparable in all fractions when corrected for differences in volume, suggesting that platelet size heterogeneity was present from the time of release of the platelets from the bone marrow. Survival studies using 51Cr and 14C-serotonin showed no translocation of the label from one fraction to another in the circulation over time. In vivo survival values for the three radionuclides showed a slight but significant correlation between the lifespan and the MPV of the fractions. The data suggest that large platelets were not younger platelets, but rather platelets with a longer life-span. Platelet size heterogeneity is the result of production factors in the bone marrow and not maturation in the circulation.

  6. Platelet size does not correlate with platelet age

    International Nuclear Information System (INIS)

    Thompson, C.B.; Love, D.G.; Quinn, P.G.; Valeri, C.R.

    1983-01-01

    The relationship between platelet size and in vivo aging was investigated in the baboon using size-dependent platelet subpopulations separated by counterflow centrifugation. The separation characteristics, size, lactate dehydrogenase (LDH) activity, and dense-body content of the baboon platelet subpopulations were similar to those previously observed in studies of human platelets. Three independent labeling techniques were used: (1) in vivo labeling with 75 Se-methionine, (2) in vitro labeling with 51 Cr, and (3) in vivo labeling with 14C-serotonin. Maximal incorporation of all three labels showed a close correlation between the mean platelet volume (MPV) of each fraction and the platelet radioactivity. The onset of incorporation and rate of accumulation of 75 Se-methionine were comparable in all fractions when corrected for differences in volume, suggesting that platelet size heterogeneity was present from the time of release of the platelets from the bone marrow. Survival studies using 51 Cr and 14 C-serotonin showed no translocation of the label from one fraction to another in the circulation over time. In vivo survival values for the three radionuclides showed a slight but significant correlation between the lifespan and the MPV of the fractions. The data suggest that large platelets were not younger platelets, but rather platelets with a longer life-span. Platelet size heterogeneity is the result of production factors in the bone marrow and not maturation in the circulation

  7. Platelet survival in idiopathic thrombocytopenic purpura and response to splenectomy

    International Nuclear Information System (INIS)

    Monteiro, M.E.; Verhaeghe, R.; Devos, P.

    Platelet survival combined with surface counting was performed in 9 patients with idiopathic thrombocytopenic purpura, resistent to steroid therapy. All patients had a markedly enhanced platelet turnover, five of them showed an augmented trapping of radioactivity over the spleen compared to liver and heart. These five patients underwent splenectomy: the platelet count increased in all of them but this increase was not always sustained. (Author) [pt

  8. Platelet proteome reveals novel pathways of platelet activation and platelet-mediated immunoregulation in dengue.

    Directory of Open Access Journals (Sweden)

    Monique Ramos de Oliveira Trugilho

    2017-05-01

    Full Text Available Dengue is the most prevalent human arbovirus disease worldwide. Dengue virus (DENV infection causes syndromes varying from self-limiting febrile illness to severe dengue. Although dengue pathophysiology is not completely understood, it is widely accepted that increased inflammation plays important roles in dengue pathogenesis. Platelets are blood cells classically known as effectors of hemostasis which have been increasingly recognized to have major immune and inflammatory activities. Nevertheless, the phenotype and effector functions of platelets in dengue pathogenesis are not completely understood. Here we used quantitative proteomics to investigate the protein content of platelets in clinical samples from patients with dengue compared to platelets from healthy donors. Our assays revealed a set of 252 differentially abundant proteins. In silico analyses associated these proteins with key molecular events including platelet activation and inflammatory responses, and with events not previously attributed to platelets during dengue infection including antigen processing and presentation, proteasome activity, and expression of histones. From these results, we conducted functional assays using samples from a larger cohort of patients and demonstrated evidence for platelet activation indicated by P-selectin (CD62P translocation and secretion of granule-stored chemokines by platelets. In addition, we found evidence that DENV infection triggers HLA class I synthesis and surface expression by a mechanism depending on functional proteasome activity. Furthermore, we demonstrate that cell-free histone H2A released during dengue infection binds to platelets, increasing platelet activation. These findings are consistent with functional importance of HLA class I, proteasome subunits, and histones that we found exclusively in proteome analysis of platelets in samples from dengue patients. Our study provides the first in-depth characterization of the platelet

  9. Prognostic Significance of Combination of Preoperative Platelet Count and Neutrophil-Lymphocyte Ratio (COP-NLR in Patients with Non-Small Cell Lung Cancer: Based on a Large Cohort Study.

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    Full Text Available The aim of this study was to investigate the prognostic significance of the combination of the preoperative platelet count and neutrophil-lymphocyte ratio (COP-NLR for predicting postoperative survival of patients undergoing complete resection for non-small cell lung cancer (NSCLC.The preoperative COP-NLR was calculated on the basis of data obtained.Patients with both an increased platelet count (>30.0 × 104 mm(-3 and an elevated NLR (>2.3 were assigned a score of 2, and patients with one or neither were assigned as a score of 1 or 0, respectively.A total of 1238 NSCLC patients were enrolled in this analysis. Multivariate analysis using the 15 clinicolaboratory variables selected by univariate analyses demonstrated that the preoperative COP-NLR was an independent prognostic factor for DFS (HR: 1.834, 95%CI: 1.536 to 2.200, P<0.001 and OS (HR: 1.810, 95%CI: 1.587 to 2.056, P<0.001. In sub-analyses by tumor stage (I, II, IIIA, a significant association was found between DFS and OS and level of COP-NLR in each subgroup (P<0.001, P=0.002, P<0.001 for DFS, respectively; P<0.001, P=0.001, P<0.001 for OS. When the subgroup of patients with high-risk COP-NLR (score of 2 was analyzed, no benefit of adjuvant chemotherapy could be found (P=0.237 for DFS and P=0.165 for OS.The preoperative COP-NLR is able to predict the prognosis of patients with NSCLC and divide these patients into three independent groups before surgery. Our results also demonstrate that high-risk patients based on the COP-NLR do not benefit from adjuvant chemotherapy. Independent validation of our findings is warranted.

  10. A novel bacterial transport mechanism of Acinetobacter baumannii via activated human neutrophils through interleukin-8.

    Science.gov (United States)

    Kamoshida, Go; Tansho-Nagakawa, Shigeru; Kikuchi-Ueda, Takane; Nakano, Ryuichi; Hikosaka, Kenji; Nishida, Satoshi; Ubagai, Tsuneyuki; Higashi, Shouichi; Ono, Yasuo

    2016-12-01

    Hospital-acquired infections as a result of Acinetobacter baumannii have become problematic because of high rates of drug resistance. Although neutrophils play a critical role in early protection against bacterial infection, their interactions with A. baumannii remain largely unknown. To elucidate the interactions between A. baumannii and human neutrophils, we cocultured these cells and analyzed them by microscopy and flow cytometry. We found that A. baumannii adhered to neutrophils. We next examined neutrophil and A. baumannii infiltration into Matrigel basement membranes by an in vitro transmigration assay. Neutrophils were activated by A. baumannii, and invasion was enhanced. More interestingly, A. baumannii was transported together by infiltrating neutrophils. Furthermore, we observed by live cell imaging that A. baumannii and neutrophils moved together. In addition, A. baumannii-activated neutrophils showed increased IL-8 production. The transport of A. baumannii was suppressed by inhibiting neutrophil infiltration by blocking the effect of IL-8. A. baumannii appears to use neutrophils for transport by activating these cells via IL-8. In this study, we revealed a novel bacterial transport mechanism that A. baumannii exploits human neutrophils by adhering to and inducing IL-8 release for bacterial portage. This mechanism might be a new treatment target. © Society for Leukocyte Biology.

  11. Oral neutrophil responses to acute prolonged exercise may not be representative of blood neutrophil responses.

    Science.gov (United States)

    Davison, Glen; Jones, Arwel Wyn

    2015-03-01

    Neutrophil numbers and function (oxidative burst) were assessed in peripheral blood and oral samples before and after prolonged exercise. Blood neutrophil count increased (∼3.5-fold, P < 0.001) and function decreased (30% ± 19% decrease, P = 0.005) postexercise. Oral neutrophil count (P = 0.392) and function (P = 0.334) were unchanged. Agreement between oral and blood neutrophil function responses to exercise was poor. These findings highlight the importance of studying neutrophils within various compartments/sample types.

  12. Blood platelet kinetics and platelet transfusion

    OpenAIRE

    Aster, Richard H.

    2013-01-01

    The discovery of citrate anticoagulant in the 1920s and the development of plastic packs for blood collection in the 1960s laid the groundwork for platelet transfusion therapy on a scale not previously possible. A major limitation, however, was the finding that platelet concentrates prepared from blood anticoagulated with citrate were unsuitable for transfusion because of platelet clumping. We found that this could be prevented by simply reducing the pH of platelet-rich plasma to about 6.5 pr...

  13. Combined aspirin and cilostazol treatment is associated with reduced platelet aggregation and prevention of exercise-induced platelet activation.

    Science.gov (United States)

    Cleanthis, M; Bhattacharya, V; Smout, J; Ashour, H; Stansby, G

    2009-05-01

    Cilostazol has proven efficacy in increasing walking distance in claudicants, but it has not been demonstrated to be more effective than placebo in secondary cardiovascular prevention. The direct effect of exercise on platelet function remains less well defined. We have investigated the effect of combination treatment with aspirin and cilostazol on platelet activity in claudicants subjected to repeated treadmill exercise. Nineteen claudicants completed a double-blind, randomised, controlled, cross-over trial. Each subject received a 2-week course of aspirin (75mg) and placebo and aspirin and cilostazol (100mg twice daily). Following each 2-week treatment period, patients participated in a standardised treadmill test (3.2kmh(-1), 10 degrees incline) walking to maximal claudication distance. The exercise was repeated thrice in total, and blood was sampled before and after exercise. Platelet activation was measured using free platelet counting aggregation, flow cytometry for surface markers of platelet activation and soluble P-selectin assay. Compared to aspirin and placebo, combination treatment with aspirin and cilostazol was associated with reduced arachidonic-acid-induced platelet aggregation (pWilcoxon signed-rank test). Aspirin and placebo treatment were associated with elevated P-selectin expression, platelet-monocyte aggregation and reduced CD42b expression (pWilcoxon signed-rank test) post-exercise. No difference was seen in spontaneous platelet aggregation whilst soluble P-selectin was reduced post-exercise with combination treatment with aspirin and cilostazol (pWilcoxon signed-rank test). Combination treatment with aspirin and cilostazol results in suppression of platelet activation and reduces the effect of exercise on platelets. The benefit seen may be a result of cilostazol enhancing the inhibitory effect of aspirin on the cyclo-oxygenase pathway.

  14. Hypercholesterolemia Increases the Production of Leukotriene B4 in Neutrophils by Enhancing the Nuclear Localization of 5-Lipoxygenase

    Directory of Open Access Journals (Sweden)

    Xiao-Feng Lai

    2014-11-01

    Full Text Available Aims: Neutrophils can synthesize leukotriene B4 (LTB4 by activating the 5-lipoxygenase (5-LOsignaling pathway. LTB4 is a pro-inflammatory mediator associated with the etiology and progression of atherosclerosis. It can increase function and number of neutrophils in an autocrine manner. Since hypercholesterolemia is associated with an increase in the number and function of neutrophils, we hypothesized that this effect could be mediated through increased production of LTB4 in neutrophils. Methods/Results: Hypercholesterolemia was modeled in Wistar rats by feeding them with a high cholesterol diet. The induction of hypercholesterolemia caused an increase in the plasma levels of LTB4, following lipopolysaccharide stimulation. This effect was recapitulated in vitro, both in the presence and absence of stimulation with the activator of 5-LO, A23187. Neutrophils in hypercholesterolemia rats expressed similar total levels of 5-LO as control rats, but displayed increased nuclear localization of 5-LO, as well as elevated levels of phosphorylated 5-LO and ERK1/2. In vitro, MβCD/cholesterol complexes enriched cholesterol in neutrophils, resulted in similar changes in 5-LO/LTB4. In addition, these alterations could be inhibited with the ERK inhibitor PD98059. Conclusion: Hypercholesterolemia increases LTB4 production in neutrophils by increasing the nuclear localization of 5-LO, which is the result of its phosphorylation by activated ERK1/2.

  15. Oral antibiotics increase blood neutrophil maturation and reduce bacteremia and necrotizing enterocolitis in the immediate postnatal period of preterm pigs

    DEFF Research Database (Denmark)

    Nguyen, Duc Ninh; Fuglsang, Eva; Jiang, Pingping

    2016-01-01

    in blood parameters and bacterial composition in the intestine, blood and immune organs were analyzed. Newborn preterm pigs had few blood neutrophils and a high frequency of progenitor cells. Neutrophils gradually matured after preterm birth with increasing CD14 and decreasing CD172a expressions. Preterm...... neutrophil and monocyte TLR2 expression and TLR2-mediated blood cytokine responses were low relative to adults. ORA pigs showed enhanced blood neutrophil maturation with reduced cell size and CD172a expression. Only ORA pigs, but not SYS pigs, were protected from a high density of gut Gram-positive bacteria......, high gut permeability, Gram-positive bacteremia and NEC. Neonatal oral antibiotics may benefit mucosal and systemic immunity via delayed gut colonization and enhanced blood neutrophil maturation just after preterm birth....

  16. Platelet Lysate-Modified Porous Silicon Microparticles for Enhanced Cell Proliferation in Wound Healing Applications.

    Science.gov (United States)

    Fontana, Flavia; Mori, Michela; Riva, Federica; Mäkilä, Ermei; Liu, Dongfei; Salonen, Jarno; Nicoletti, Giovanni; Hirvonen, Jouni; Caramella, Carla; Santos, Hélder A

    2016-01-13

    The new frontier in the treatment of chronic nonhealing wounds is the use of micro- and nanoparticles to deliver drugs or growth factors into the wound. Here, we used platelet lysate (PL), a hemoderivative of platelets, consisting of a multifactorial cocktail of growth factors, to modify porous silicon (PSi) microparticles and assessed both in vitro and ex vivo the properties of the developed microsystem. PL-modified PSi was assessed for its potential to induce proliferation of fibroblasts. The wound closure-promoting properties of the microsystem were then assessed in an in vitro wound healing assay. Finally, the PL-modified PSi microparticles were evaluated in an ex vivo experiment over human skin. It was shown that PL-modified PSi microparticles were cytocompatible and enhanced the cell proliferation in different experimental settings. In addition, this microsystem promoted the closure of the gap between the fibroblast cells in the wound healing assay, in periods of time comparable with the positive control, and induced a proliferation and regeneration process onto the human skin in an ex vivo experiment. Overall, our results show that PL-modified PSi microparticles are suitable microsystems for further development toward applications in the treatment of chronic nonhealing wounds.

  17. Anti-platelet activity of water dispersible curcuminoids in rat platelets.

    Science.gov (United States)

    Maheswaraiah, Anikisetty; Rao, Lingamallu Jaganmohan; Naidu, Kamatham Akhilender

    2015-03-01

    Curcuminoids are active principle of turmeric with plethora of health beneficial properties. In this study, we have evaluated for the first time the effect of water dispersible curcuminoids on rat platelet aggregation. Curcuminoids (10-30 µg/mL) significantly inhibited platelet aggregation induced by agonists viz., collagen, ADP and arachidonic acid. Curcuminoids were found to be two-fold more potent than curcumin in inhibiting platelet aggregation. Intracellular curcuminoid concentration was relatively higher than curcumin in rat platelets. Curcuminoids significantly attenuated thromboxane A2 , serotonin levels in rat platelets which play an important role in platelet aggregation. Curcuminoid treatment increased nitric oxide (NO) levels in platelets treated with agonists. Curcuminoids inhibited free radicals such as superoxide anion released from activated platelets, which ultimately inhibits platelet aggregation. Further, curcuminoids inhibited 12-lipoxygenase activity and formation of 12-hydroperoxyeicosatetraenoic acid (12-HPETE) in activated rat platelets which regulates platelet aggregation. The results suggest that curcuminoids have remarkable anti-platelet activity by modulating multiple mechanisms involved in platelet aggregation. Thus curcuminoids may have a therapeutic potential to prevent platelet activation related disorders. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Platelet-derived growth factor inhibits platelet activation in heparinized whole blood.

    Science.gov (United States)

    Selheim, F; Holmsen, H; Vassbotn, F S

    1999-08-15

    We previously have demonstrated that human platelets have functionally active platelet-derived growth factor alpha-receptors. Studies with gel-filtered platelets showed that an autocrine inhibition pathway is transduced through this tyrosine kinase receptor during platelet activation. The physiological significance of this inhibitory effect of platelet-derived growth factor on gel-filtered platelets activation is, however, not known. In the present study, we investigated whether platelet-derived growth factor inhibits platelet activation under more physiological conditions in heparinized whole blood, which represents a more physiological condition than gel-filtered platelets. Using flow cytometric assays, we demonstrate here that platelet-derived growth factor inhibits thrombin-, thrombin receptor agonist peptide SFLLRN-, and collagen-induced platelet aggregation and shedding of platelet-derived microparticles from the platelet plasma membrane during platelet aggregation in stirred heparinized whole blood. The inhibitory effect of platelet-derived growth factor was dose dependent. However, under nonaggregating conditions (no stirring), we could not demonstrate any significant effect of platelet-derived growth factor on thrombin- and thrombin receptor agonist peptide-induced platelet surface expression of P-selectin. Our results demonstrate that platelet-derived growth factor appears to be a true antithrombotic agent only under aggregating conditions in heparinized whole blood.

  19. The effect of platelet-rich plasma on composite graft survival.

    Science.gov (United States)

    Jeon, Yeo Reum; Kang, Eun Hye; Yang, Chae Eun; Yun, In Sik; Lee, Won Jai; Lew, Dae Hyun

    2014-08-01

    Composite grafts are suitable for facial reconstruction because of good color matching, low donor-site morbidity, acceptable texture, and easy surgical techniques. However, their use is limited to small defects and by unpredictable survival rates. As platelet-rich plasma contains large numbers of growth factors and has been widely used for tissue regeneration, this study aimed to investigate platelet-rich plasma as an adjuvant to enhance composite graft survival. Twenty New Zealand White rabbits were used, and chondrocutaneous composite grafts were applied to their ears. The grafts were then returned to their original positions after rotation to block the original circulation from the base of the graft. Each of the individual ears was assigned randomly into one of two groups: experimental (n=20; platelet-rich plasma group) or control (n=20; control group). The surrounding skin of the composite graft was injected with either 1.0 ml of platelet-rich plasma derived from autologous whole blood in the platelet-rich plasma group or normal saline in the control group. Graft survival, cutaneous blood flow, CD31-stained vessels, and vascular endothelial growth factor protein levels were examined. Twelve days after surgery, graft viability in the platelet-rich plasma group was higher than in the control group. Blood perfusion was also higher in the platelet-rich plasma group. Compared with the control group, the number of CD31 blood vessels and vascular endothelial growth factor expression levels were significantly increased in the platelet-rich plasma group. The authors' results suggest that platelet-rich plasma restores the perfusion of composite grafts by enhancing revascularization and may exert therapeutic effects on the survival of composite grafts.

  20. Entrapment of platelets in the penis during and after erection

    International Nuclear Information System (INIS)

    Bornman, M.S.; Du Plessis, D.J.; Dormehl, I.C.; Du Plessis, M.; Jacobs, D.J.; Maree, M.

    1986-01-01

    Because of the development of hypercoagulability and the deposition of fibrin in the penis during erection a study of the possible role of platelets in this process was undertaken. Platelets response was studied in 9 adult chacma baboons (Papio ursinus) using autologous in vitro indium-111-labelled platelets and sequential scintigraphy of the penis during erection. The blood pooling pattern was obtained using in vivo technetium-99m-labelled red cells in a similar investigation. A statistically significant retention of platelets occured during and after erection, wich could not be attributed to blood pooling (P < 0,05). Entrapment of platelets could lead to enhanced activation, and might play a significant role in hypercoagulability and fibrin deposition during erection. Therefore platelets could be an important factor in the pathogenesis of ageing impotence

  1. Purinergic control of inflammation and thrombosis: Role of P2X1 receptors

    Directory of Open Access Journals (Sweden)

    Cécile Oury

    2015-01-01

    Full Text Available Inflammation shifts the hemostatic mechanisms in favor of thrombosis. Upon tissue damage or infection, a sudden increase of extracellular ATP occurs, that might contribute to the crosstalk between inflammation and thrombosis. On platelets, P2X1 receptors act to amplify platelet activation and aggregation induced by other platelet agonists. These receptors critically contribute to thrombus stability in small arteries. Besides platelets, studies by our group indicate that these receptors are expressed by neutrophils. They promote neutrophil chemotaxis, both in vitro and in vivo. In a laser-induced injury mouse model of thrombosis, it appears that neutrophils are required to initiate thrombus formation and coagulation activation on inflamed arteriolar endothelia. In this model, by using P2X1−/− mice, we recently showed that P2X1 receptors, expressed on platelets and neutrophils, play a key role in thrombus growth and fibrin generation. Intriguingly, in a model of endotoxemia, P2X1−/− mice exhibited aggravated oxidative tissue damage, along with exacerbated thrombocytopenia and increased activation of coagulation, which translated into higher susceptibility to septic shock. Thus, besides its ability to recruit neutrophils and platelets on inflamed endothelia, the P2X1 receptor also contributes to limit the activation of circulating neutrophils under systemic inflammatory conditions. Taken together, these data suggest that P2X1 receptors are involved in the interplay between platelets, neutrophils and thrombosis. We propose that activation of these receptors by ATP on neutrophils and platelets represents a new mechanism that regulates thrombo-inflammation.

  2. Platelet-Derived Short-Chain Polyphosphates Enhance the Inactivation of Tissue Factor Pathway Inhibitor by Activated Coagulation Factor XI.

    Directory of Open Access Journals (Sweden)

    Cristina Puy

    Full Text Available Factor (F XI supports both normal human hemostasis and pathological thrombosis. Activated FXI (FXIa promotes thrombin generation by enzymatic activation of FXI, FIX, FX, and FV, and inactivation of alpha tissue factor pathway inhibitor (TFPIα, in vitro. Some of these reactions are now known to be enhanced by short-chain polyphosphates (SCP derived from activated platelets. These SCPs act as a cofactor for the activation of FXI and FV by thrombin and FXIa, respectively. Since SCPs have been shown to inhibit the anticoagulant function of TFPIα, we herein investigated whether SCPs could serve as cofactors for the proteolytic inactivation of TFPIα by FXIa, further promoting the efficiency of the extrinsic pathway of coagulation to generate thrombin.Purified soluble SCP was prepared by size-fractionation of sodium polyphosphate. TFPIα proteolysis was analyzed by western blot. TFPIα activity was measured as inhibition of FX activation and activity in coagulation and chromogenic assays. SCPs significantly accelerated the rate of inactivation of TFPIα by FXIa in both purified systems and in recalcified plasma. Moreover, platelet-derived SCP accelerated the rate of inactivation of platelet-derived TFPIα by FXIa. TFPIα activity was not affected by SCP in recalcified FXI-depleted plasma.Our data suggest that SCP is a cofactor for TFPIα inactivation by FXIa, thus, expanding the range of hemostatic FXIa substrates that may be affected by the cofactor functions of platelet-derived SCP.

  3. GMP-grade platelet lysate enhances proliferation and migration of tenon fibroblasts.

    Science.gov (United States)

    Carducci, Augusto; Scafetta, Gaia; Siciliano, Camilla; Carnevale, Roberto; Rosa, Paolo; Coccia, Andrea; Mangino, Giorgio; Bordin, Antonella; Vingolo, Enzo Maria; Pierelli, Luca; Lendaro, Eugenio; Ragona, Giuseppe; Frati, Giacomo; De Falco, Elena

    2016-01-01

    Tenon's fibroblasts (TFs), widely employed as in vitro model for many ophthalmological studies, are routinely cultured with FBS. Platelet Lysate (PL), a hemoderivate enriched with growth factors and cytokines has been largely tested in several clinical applications and as substitute of FBS in culture. Here, we investigate whether PL can exert biological effects on TF populations similarly to other cell types. Results show that PL significantly enhances cell proliferation and migration vs. FBS, without influencing cell size/granularity. Upregulation of EGF, VEGF, KDR, MMP2-9, FAK mRNA levels also occurs and phosphorylation of AKT but not of ERK1/2 is significantly enhanced. The inhibition of the PI3kinase/AKT pathway with the specific inhibitor wortmannin, decreases PL-induced cell migration but not proliferation. Condition supernatants containing PL show increased bioavailability of Nitric Oxide and reduced levels of 8-Iso-PGF2-alpha, correlating with cell proliferation and migration. Pro-angiogenic/inflammatory soluble factors (GRO, Angiogenin, EGF, I-309, PARC) are exclusively or greater expressed in media containing PL than FBS. GMP-grade PL preparations positively influence in vitro biological effects of TFs representing a suitable and safer alternative to FBS.

  4. G-CSF maintains controlled neutrophil mobilization during acute inflammation by negatively regulating CXCR2 signaling

    Science.gov (United States)

    Bajrami, Besnik; Zhu, Haiyan; Zhang, Yu C.

    2016-01-01

    Cytokine-induced neutrophil mobilization from the bone marrow to circulation is a critical event in acute inflammation, but how it is accurately controlled remains poorly understood. In this study, we report that CXCR2 ligands are responsible for rapid neutrophil mobilization during early-stage acute inflammation. Nevertheless, although serum CXCR2 ligand concentrations increased during inflammation, neutrophil mobilization slowed after an initial acute fast phase, suggesting a suppression of neutrophil response to CXCR2 ligands after the acute phase. We demonstrate that granulocyte colony-stimulating factor (G-CSF), usually considered a prototypical neutrophil-mobilizing cytokine, was expressed later in the acute inflammatory response and unexpectedly impeded CXCR2-induced neutrophil mobilization by negatively regulating CXCR2-mediated intracellular signaling. Blocking G-CSF in vivo paradoxically elevated peripheral blood neutrophil counts in mice injected intraperitoneally with Escherichia coli and sequestered large numbers of neutrophils in the lungs, leading to sterile pulmonary inflammation. In a lipopolysaccharide-induced acute lung injury model, the homeostatic imbalance caused by G-CSF blockade enhanced neutrophil accumulation, edema, and inflammation in the lungs and ultimately led to significant lung damage. Thus, physiologically produced G-CSF not only acts as a neutrophil mobilizer at the relatively late stage of acute inflammation, but also prevents exaggerated neutrophil mobilization and the associated inflammation-induced tissue damage during early-phase infection and inflammation. PMID:27551153

  5. Granulocyte-platelet interactions and platelet fibrinogen receptor exposure

    International Nuclear Information System (INIS)

    Kornecki, E.; Ehrlich, Y.H.; Egbring, R.; Gramse, M.; Seitz, R.; Eckardt, A.; Lukasiewicz, H.; Niewiarowski, S.

    1988-01-01

    The authors have examined the interaction of human granulocyte elastase with human platelets. Incubation of human platelets with human granulocyte elastase exposed active fibrinogen-binding sites as evidenced by 125 I-labeled fibrinogen binding and spontaneous fibrinogen-induced platelet aggregation. The aggregation of platelets by fibrinogen occurred at low concentrations of human granulocyte elastase. Platelets pretreated with human granulocyte elastase exposed an average of 10,500 fibrinogen-binding sites per platelet, i.e., about one-third the number of binding sites exposed by optimal concentrations of ADP. With the use of a polyclonal antiplatelet membrane antibody, the glycoproteins IIb (GPIIb), IIIa (GPIIIa), and a 60,000-Da (60 kDa) protein (66 kDa in a reduced system) derived from GPIIIa were immunoprecipitated from the surface of detergent extracts of human 125 I-radiolabeled platelets pretreated with increasing concentrations of human granulocyte elastase. They conclude that (1) the proteolytic action of human granulocyte elastase on platelet GPIIIa results in the formation of two major hydrolytic products, and (2) human granulocyte elastase exposes active fibrongen-binding sites associated with the GPIIb/GPIIIa complex, resulting in direct platelet aggregation by fibrinogen

  6. Mean platelet volume (MPV) predicts middle distance running performance.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Skafidas, Spyros; Tarperi, Cantor; Guidi, Gian Cesare; Schena, Federico

    2014-01-01

    Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners. The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years), who successfully concluded a 21.1 km half-marathon at 75-85% of their maximal aerobic power (VO2max). Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection. The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV), platelets, mean platelet volume (MPV), white blood cells (WBCs), neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW), MPV, reticulocyte hemoglobin concentration (RetCHR), and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042), but not thereafter (p = 0.247), remained significantly associated with running

  7. Mean platelet volume (MPV predicts middle distance running performance.

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    Full Text Available Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners.The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years, who successfully concluded a 21.1 km half-marathon at 75-85% of their maximal aerobic power (VO2max. Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection.The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV, platelets, mean platelet volume (MPV, white blood cells (WBCs, neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH, red blood cell distribution width (RDW, MPV, reticulocyte hemoglobin concentration (RetCHR, and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042, but not thereafter (p = 0.247, remained significantly associated with running

  8. Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving.

    Science.gov (United States)

    Yang, Ming; Barak, Otto F; Dujic, Zeljko; Madden, Dennis; Bhopale, Veena M; Bhullar, Jasjeet; Thom, Stephen R

    2015-08-15

    Predicated on evidence that diving-related microparticle generation is an oxidative stress response, this study investigated the role that oxygen plays in augmenting production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid. Following a cross-over study design, 14 male subjects ingested placebo and 2-3 wk later ascorbic acid (2 g) daily for 6 days prior to performing either a 47-min dive to 18 m of sea water while breathing air (∼222 kPa N2/59 kPa O2) or breathing a mixture of 60% O2/balance N2 from a tight-fitting face mask at atmospheric pressure for 47 min (∼40 kPa N2/59 kPa O2). Within 30 min after the 18-m dive in the placebo group, neutrophil activation, and platelet-neutrophil interactions occurred, and the total number of microparticles, as well as subgroups bearing CD66b, CD41, CD31, CD142 proteins or nitrotyrosine, increased approximately twofold. No significant elevations occurred among divers after ingesting ascorbic acid, nor were elevations identified in either group after breathing 60% O2. Ascorbic acid had no significant effect on post-dive intravascular bubble production quantified by transthoracic echocardiography. We conclude that high-pressure nitrogen plays a key role in neutrophil and microparticle-associated changes with diving and that responses can be abrogated by dietary ascorbic acid supplementation. Copyright © 2015 the American Physiological Society.

  9. Neutrophil to lymphocyte with monocyte to lymphocyte ratio and white blood cell count in prediction of lung cancer

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    Thang Thanh Phan

    2018-04-01

    Full Text Available Background Lung cancer is the most common cause of cancer deaths in both sexes, while it is very difficult for screenings and early detection. Aims This study aims to clarify the role of systematic inflammation markers, including white blood cell (WBC, neutrophil (NEU, monocyte (MONO, platelet (PLT, neutrophil to lymphocyte ratio (NLR, monocyte to lymphocyte ratio (MLR and platelet to lymphocyte ratio (PLR in prediction of lung cancer. Methods A case-control study was conducted on 1,315 primary lung cancer patients and 1,315 healthy adults with matched age and gender at Cho Ray hospital. NLR, MLR and PLR were calculated by using neutrophil, lymphocyte, monocyte and platelet count which were recalled from laboratory database. With 600 cases in the derivation set, the logistic regression with univariate analysis was used to identify the impacted marker, then developing the optimal prediction model for lung cancer by logistic regression with multivariate method. The diagnostic values of optimal model consisting of sensitivity (Sen, specificity (Spe, positive predictive value (PPV, negative predictive value (NPV and the area under the ROC curve (AUC value were extracted and verified on all data, in validation set. Results The median values of WBC, NEU, MONO, PLT, NLR, MLR and PLR in lung cancer were not significantly difference between histological subtypes and clinical stages (p > 0.05, but higher than the values in control group (p < 0.01. Multivariates analysis shows that NLR, MLR and WBC were three parameters that have the significant impact of the optimal prediction model (p < 0.01. The AUC value, sensitivity and specificity of the optimal model for lung cancer detection were 0.881, 73.5 per cent (95 per cent CI:70.3–76.6 and 87.7 per cent (95 per centCI:85.2–89.9, respectively. Whereas, the PPV and NPV values of prediction model were 85.7 per cent (95 per cent CI:82.8–88.2 and 76.8 (95 per centCI:73.9–79.5, respectively. Among three

  10. Formation of neutrophil extracellular traps under low oxygen level

    Directory of Open Access Journals (Sweden)

    Katja Branitzki-Heinemann

    2016-11-01

    Full Text Available Since their discovery, neutrophil extracellular traps (NETs have been characterized as a fundamental host innate immune defense mechanism. Conversely, excessive NET release may have a variety of detrimental consequences for the host. A fine balance between NET formation and elimination is necessary to sustain a protective effect during an infectious challenge. Our own recently published data revealed that stabilization of hypoxia inducible factor 1α (HIF-1α by the iron chelating HIF-1α-agonist desferoxamine or AKB-4924 enhanced the release of phagocyte extracellular traps. Since HIF-1α is a global regulator of the cellular response to low oxygen, we hypothesized that NET formation may be similarly increased under low oxygen conditions. Hypoxia occurs in tissues during infection or inflammation, mostly due to overconsumption of oxygen by pathogens and recruited immune cells. Therefore, experiments were performed to characterize the formation of NETs under hypoxic oxygen conditions compared to normoxia. Human blood-derived neutrophils were isolated and incubated under normoxic (21% oxygen level and compared to hypoxic (1% conditions. Dissolved oxygen levels were monitored in the primary cell culture using a Fibox4-PSt3 measurement system. The formation of NETs was quantified by fluorescence microscopy in response to the known NET-inducer phorbol 12-myristate 13-acetate (PMA or S. aureus wildtype and a nuclease-deficient mutant. In contrast to our hypothesis, spontaneous NET formation of neutrophils incubated under hypoxia was distinctly reduced compared to control neutrophils incubated under normoxia. Furthermore, neutrophils incubated under hypoxia showed significantly reduced formation of NETs in response to PMA. Gene expression analysis revealed that mRNA level of hif-1α as well as hif-1α target genes was not altered. However, in good correlation to the decreased NET formation under hypoxia, the cholesterol content of the neutrophils was

  11. Human neutrophils in auto-immunity.

    Science.gov (United States)

    Thieblemont, Nathalie; Wright, Helen L; Edwards, Steven W; Witko-Sarsat, Véronique

    2016-04-01

    Human neutrophils have great capacity to cause tissue damage in inflammatory diseases via their inappropriate activation to release reactive oxygen species (ROS), proteases and other tissue-damaging molecules. Furthermore, activated neutrophils can release a wide variety of cytokines and chemokines that can regulate almost every element of the immune system. In addition to these important immuno-regulatory processes, activated neutrophils can also release, expose or generate neoepitopes that have the potential to break immune tolerance and result in the generation of autoantibodies, that characterise a number of human auto-immune diseases. For example, in vasculitis, anti-neutrophil cytoplasmic antibodies (ANCA) that are directed against proteinase 3 or myeloperoxidase are neutrophil-derived autoantigens and activated neutrophils are the main effector cells of vascular damage. In other auto-immune diseases, these neutrophil-derived neoepitopes may arise from a number of processes that include release of granule enzymes and ROS, changes in the properties of components of their plasma membrane as a result of activation or apoptosis, and via the release of Neutrophil Extracellular Traps (NETs). NETs are extracellular structures that contain chromatin that is decorated with granule enzymes (including citrullinated proteins) that can act as neo-epitopes to generate auto-immunity. This review therefore describes the processes that can result in neutrophil-mediated auto-immunity, and the role of neutrophils in the molecular pathologies of auto-immune diseases such as vasculitis, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We discuss the potential role of NETs in these processes and some of the debate in the literature regarding the role of this phenomenon in microbial killing, cell death and auto-immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Studies on the Biological Effects of Ozone: 10. Release of Factors from Ozonated Human Platelets

    Directory of Open Access Journals (Sweden)

    G. Valacchi

    1999-01-01

    Full Text Available In a previous work we have shown that heparin, in the presence of ozone (O3, promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF, transforming growth factor β1 (TGF-β1 and interleukin-8(IL-8 are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limbischemia treated with O3 autohaemoteraphy (O3-AHT.

  13. Application of gelatin zymography for evaluating low levels of contaminating neutrophils in red blood cell samples.

    Science.gov (United States)

    Achilli, Cesare; Ciana, Annarita; Balduini, Cesare; Risso, Angela; Minetti, Giampaolo

    2011-02-15

    Supposedly "homogeneous" red blood cell (RBC) samples are commonly obtained by "washing" whole blood free of plasma, platelets, and white cells with physiological solutions, a procedure that does not result, however, in sufficient removal of polymorphonuclear neutrophils (PMNs), leading to possible artifactual results. Pure RBC samples can be obtained only by leukodepletion procedures. Proposed here is a version of gelatin zymography adapted to detect matrix metalloproteinase 9 (MMP-9), selectively expressed by PMNs, in heterogeneous mixtures of RBCs and PMNs that can reveal contamination at levels as low as 1 PMN/10⁶ RBCs. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Platelet-biased stem cells reside at the apex of the haematopoietic stem-cell hierarchy.

    Science.gov (United States)

    Sanjuan-Pla, Alejandra; Macaulay, Iain C; Jensen, Christina T; Woll, Petter S; Luis, Tiago C; Mead, Adam; Moore, Susan; Carella, Cintia; Matsuoka, Sahoko; Bouriez Jones, Tiphaine; Chowdhury, Onima; Stenson, Laura; Lutteropp, Michael; Green, Joanna C A; Facchini, Raffaella; Boukarabila, Hanane; Grover, Amit; Gambardella, Adriana; Thongjuea, Supat; Carrelha, Joana; Tarrant, Paul; Atkinson, Deborah; Clark, Sally-Ann; Nerlov, Claus; Jacobsen, Sten Eirik W

    2013-10-10

    The blood system is maintained by a small pool of haematopoietic stem cells (HSCs), which are required and sufficient for replenishing all human blood cell lineages at millions of cells per second throughout life. Megakaryocytes in the bone marrow are responsible for the continuous production of platelets in the blood, crucial for preventing bleeding--a common and life-threatening side effect of many cancer therapies--and major efforts are focused at identifying the most suitable cellular and molecular targets to enhance platelet production after bone marrow transplantation or chemotherapy. Although it has become clear that distinct HSC subsets exist that are stably biased towards the generation of lymphoid or myeloid blood cells, we are yet to learn whether other types of lineage-biased HSC exist or understand their inter-relationships and how differently lineage-biased HSCs are generated and maintained. The functional relevance of notable phenotypic and molecular similarities between megakaryocytes and bone marrow cells with an HSC cell-surface phenotype remains unclear. Here we identify and prospectively isolate a molecularly and functionally distinct mouse HSC subset primed for platelet-specific gene expression, with enhanced propensity for short- and long-term reconstitution of platelets. Maintenance of platelet-biased HSCs crucially depends on thrombopoietin, the primary extrinsic regulator of platelet development. Platelet-primed HSCs also frequently have a long-term myeloid lineage bias, can self-renew and give rise to lymphoid-biased HSCs. These findings show that HSC subtypes can be organized into a cellular hierarchy, with platelet-primed HSCs at the apex. They also demonstrate that molecular and functional priming for platelet development initiates already in a distinct HSC population. The identification of a platelet-primed HSC population should enable the rational design of therapies enhancing platelet output.

  15. Platelet inhibition by nitrite is dependent on erythrocytes and deoxygenation.

    Directory of Open Access Journals (Sweden)

    Sirada Srihirun

    Full Text Available Nitrite is a nitric oxide (NO metabolite in tissues and blood, which can be converted to NO under hypoxia to facilitate tissue perfusion. Although nitrite is known to cause vasodilation following its reduction to NO, the effect of nitrite on platelet activity remains unclear. In this study, the effect of nitrite and nitrite+erythrocytes, with and without deoxygenation, on platelet activity was investigated.Platelet aggregation was studied in platelet-rich plasma (PRP and PRP+erythrocytes by turbidimetric and impedance aggregometry, respectively. In PRP, DEANONOate inhibited platelet aggregation induced by ADP while nitrite had no effect on platelets. In PRP+erythrocytes, the inhibitory effect of DEANONOate on platelets decreased whereas nitrite at physiologic concentration (0.1 µM inhibited platelet aggregation and ATP release. The effect of nitrite+erythrocytes on platelets was abrogated by C-PTIO (a membrane-impermeable NO scavenger, suggesting an NO-mediated action. Furthermore, deoxygenation enhanced the effect of nitrite as observed from a decrease of P-selectin expression and increase of the cGMP levels in platelets. The ADP-induced platelet aggregation in whole blood showed inverse correlations with the nitrite levels in whole blood and erythrocytes.Nitrite alone at physiological levels has no effect on platelets in plasma. Nitrite in the presence of erythrocytes inhibits platelets through its reduction to NO, which is promoted by deoxygenation. Nitrite may have role in modulating platelet activity in the circulation, especially during hypoxia.

  16. Improved viability and activity of neutrophils differentiated from HL-60 cells by co-culture with adipose tissue-derived mesenchymal stem cells

    International Nuclear Information System (INIS)

    Park, Yoon Shin; Lim, Goh-Woon; Cho, Kyung-Ah; Woo, So-Youn; Shin, Meeyoung; Yoo, Eun-Sun; Chan Ra, Jeong; Ryu, Kyung-Ha

    2012-01-01

    Highlights: ► Neutropenia is a principal complication of cancer treatment. ► Co-culture of neutrophils with AD-MSC retained cell survival and proliferation and inhibited neutrophil apoptosis under serum starved conditions. ► AD-MSC increased functions of neutrophil. ► AD-MSC promoted the viability of neutrophils by enhancing respiratory burst through the expression of IFN-α, G-CSF, and TGF-β. ► AD-MSC can be used to improve immunity for neutropenia treatment. -- Abstract: Neutropenia is a principal complication of cancer treatment. We investigated the supportive effect of adipose tissue-derived mesenchymal stem cells (AD-MSCs) on the viability and function of neutrophils. Neutrophils were derived from HL-60 cells by dimethylformamide stimulation and cultured with or without AD-MSCs under serum-starved conditions to evaluate neutrophil survival, proliferation, and function. Serum starvation resulted in the apoptosis of neutrophils and decreased cell survival. The co-culture of neutrophils and AD-MSCs resulted in cell survival and inhibited neutrophil apoptosis under serum-starved conditions. The survival rate of neutrophils was prolonged up to 72 h, and the expression levels of interferon (IFN)-α, granulocyte colony-stimulating factor (G-CSF), granulocyte–macrophage colony-stimulating factor, and transforming growth factor (TGF)-β in AD-MSCs were increased after co-culture with neutrophils. AD-MSCs promoted the viability of neutrophils by inhibiting apoptosis as well as enhancing respiratory burst, which could potentially be mediated by the increased expression of IFN-α, G-CSF, and TGF-β. Thus, we conclude that the use of AD-MSCs may be a promising cell-based therapy for increasing immunity by accelerating neutrophil function.

  17. Heterogeneity of rabbit platelets

    International Nuclear Information System (INIS)

    Karpatkin, S.

    1978-01-01

    Rabbits were injected intravenously with a cohort platelet label, 75 Se-selenomethionine. Platelet-rich plasma was separated into five different platelet density fractions on each of seven days by repetitively centrifuging the same sample of platelet-rich plasma at increasing gravitational force. The heaviest platelet sediment fraction was enriched with larger platelets. The lightest platelet sediment fraction was enriched with smaller platelets. Incorporation of isotope into the heaviest platelet fraction was considerably greater than incorporation into the lightest platelet fraction. The mean platelet survival of the lightest two fractions was significantly shorter than that of the heaviest three fractions. SDS-polyacrylamide gel electrophoresis of the platelet cell sap generally revealed 10 prominent protein bands for the heaviest platelet fractions. The lightest platelet fraction had six absent to markedly diminished platelet proteins. The data are compatible with two models, (1) heavy-large platelets are, on average, young platelets which become lighter-smaller platelets while losing platelet membranes and cell sap components with time. (2) Heavy-large platelets and light-small platelets are produced independently by specific megakarocytes. The heavy-large platelets incorporate more isotope that lighter-smaller platelets (possibly because of their megakarocyte precursor). However, they are released earlier into the circulation than lighter-smaller platelets and are therefore younger platelets. The light-smaller platelets which are released later into the circulation have a shorter survival. (author)

  18. Modified expression of surface glyconjugates in stored human platelets

    International Nuclear Information System (INIS)

    Dhar, A.; Ganguly, P.

    1987-01-01

    Platelets are anucleated cells which play an important part in blood coagulation and thrombosis. These cells may be stored in the blood bank for only 4/5 days. In order to improve the storage of platelets, it is essential to first understand the changes in these cells due to storage. In this work, human platelets were stored in autologous plasma at 4 0 or 22 0 and their surface changes were monitored with three lectins - wheat germ afflutinin (WGA), concanavalin A (Con A) and lentil lectin (LL). Blood was drawn from healthy donors and platelet rich plasma (PRP) was collected by slow speed centrifugation. Platelets stored at either temperature for different times showed increased sensitivity to agglutination by WGA after 34-48 hrs. Lectins, Con A and LL, which were not agglutinating to fresh platelets readily caused agglutination after 48-72 hrs. The platelets stored for 25 hrs or longer period were insensitive to thrombin but showed enhanced aggregation with WGA. Labelling of surface glycoconjugates of stored platelets with 3 H-boro-hydride revealed progressive loss of a glycoprotein of Mr 150,000 (GPIb infinity) together with the appearance of components of Mr 69,000; Mr 60,000; Mr 25,000. New high molecular weight glycoproteins were also detected only in stored platelets. The author studies clearly indicate that modification or altered expression of platelets surface glycoproteins may be one factor of storage related dysfunction of platelets

  19. Modified expression of surface glyconjugates in stored human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, A.; Ganguly, P.

    1987-05-01

    Platelets are anucleated cells which play an important part in blood coagulation and thrombosis. These cells may be stored in the blood bank for only 4/5 days. In order to improve the storage of platelets, it is essential to first understand the changes in these cells due to storage. In this work, human platelets were stored in autologous plasma at 4/sup 0/ or 22/sup 0/ and their surface changes were monitored with three lectins - wheat germ afflutinin (WGA), concanavalin A (Con A) and lentil lectin (LL). Blood was drawn from healthy donors and platelet rich plasma (PRP) was collected by slow speed centrifugation. Platelets stored at either temperature for different times showed increased sensitivity to agglutination by WGA after 34-48 hrs. Lectins, Con A and LL, which were not agglutinating to fresh platelets readily caused agglutination after 48-72 hrs. The platelets stored for 25 hrs or longer period were insensitive to thrombin but showed enhanced aggregation with WGA. Labelling of surface glycoconjugates of stored platelets with /sup 3/H-boro-hydride revealed progressive loss of a glycoprotein of Mr 150,000 (GPIb infinity) together with the appearance of components of Mr 69,000; Mr 60,000; Mr 25,000. New high molecular weight glycoproteins were also detected only in stored platelets. The author studies clearly indicate that modification or altered expression of platelets surface glycoproteins may be one factor of storage related dysfunction of platelets.

  20. The Beta-2-Adrenoreceptor Agonists, Formoterol and Indacaterol, but Not Salbutamol, Effectively Suppress the Reactivity of Human Neutrophils In Vitro

    Directory of Open Access Journals (Sweden)

    Ronald Anderson

    2014-01-01

    Full Text Available The clinical relevance of the anti-inflammatory properties of beta-2 agonists remains contentious possibly due to differences in their molecular structures and agonist activities. The current study has compared the effects of 3 different categories of β2-agonists, namely, salbutamol (short-acting, formoterol (long-acting and indacaterol (ultra-long-acting, at concentrations of 1–1000 nM, with human blood neutrophils in vitro. Neutrophils were activated with either N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP, 1 µM or platelet-activating factor (PAF, 200 nM in the absence and presence of the β2-agonists followed by measurement of the generation of reactive oxygen species and leukotriene B4, release of elastase, and expression of the β2-integrin, CR3, using a combination of chemiluminescence, ELISA, colorimetric, and flow cytometric procedures respectively. These were correlated with alterations in the concentrations of intracellular cyclic-AMP and cytosolic Ca2+. At the concentrations tested, formoterol and indacaterol caused equivalent, significant (P<0.05 at 1–10 nM dose-related inhibition of all of the pro-inflammatory activities tested, while salbutamol was much less effective (P<0.05 at 100 nM and higher. Suppression of neutrophil reactivity was accompanied by elevations in intracellular cAMP and accelerated clearance of Ca2+ from the cytosol of activated neutrophils. These findings demonstrate that β2-agonists vary with respect to their suppressive effects on activated neutrophils.

  1. Use of hematological parameters in evaluation of treatment efficacy in cutaneous leishmaniasis

    Directory of Open Access Journals (Sweden)

    Bilal Sula

    2015-12-01

    Full Text Available Objective: In the present study we investigated the role of hematological parameters, including neutrophil/lymphocyte ratio and platelet/lymphocyte ratio, mean platelet volume and platelet distribution width in the evaluation of treatment efficacy in adult patients diagnosed with cutaneous leishmaniasis. Methods: The study group included 45 adult patients diagnosed with cutaneous leishmaniasis and treated as inpatients in the dermatology clinic between 2011 and 2014. A group of 45 healthy adults served as a control group. Results: Pre- and post-treatment white blood cell count, neutrophils, and lymphocytes were significantly reduced among the patient group relative to the control group. Platelet distribution width, red cell distribution width, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio were significantly elevated among the patients compared to the healthy subjects. Pre-treatment white blood cell, lymphocyte and platelet counts were significantly elevated compared to post-treatment counts among the patient cohort. Treatment was associated with reduced eosinophil count, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio relative to pre-treatment status. Conclusion: Routine hematological testing results such as platelet/lymphocyte ratio, white blood cell count, neutrophil count, red cell distribution width, platelet distribution width, and mean platelet volume may be clinically significant markers of the inflammatory state useful in the evaluation of early treatment efficacy among patients with cutaneous leishmaniasis. J Microbiol Infect Dis 2015;5(4: 167-172

  2. Biomechanics of P-selectin PSGL-1 bonds: Shear threshold and integrin-independent cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Zhihua; Goldsmith, Harry L.; MacIntosh, Fiona A.; Shankaran, Harish; Neelamegham, Sriram

    2006-03-01

    Platelet-leukocyte adhesion may contribute to thrombosis and inflammation. We examined the heterotypic interaction between unactivated neutrophils and either thrombin receptor activating peptide (TRAP) stimulated platelets or P-selectin bearing beads (Ps-beads) in suspension. Cone-plate viscometers were used to apply controlled shear rates from 14-3000/s. Platelet-neutrophil and bead-neutrophil adhesion analysis was performed using both flow cytometry and high-speed videomicroscopy. We observed that while blocking antibodies against either P-selectin or P-selectin glycoprotein ligand-1 (PSGL-1) alone inhibited platelet-neutrophil adhesion by ~60% at 140/s, these reagents completely blocked adhesion at 3000/s. Anti-Mac-1 alone did not alter platelet-neutrophil adhesion rates at any shear rate, though in synergy with selectin antagonists it abrogated cell binding. Unstimulated neutrophils avidly bound Ps-beads and activated platelets in an integrin-independent manner, suggesting that purely selectin-dependent cell adhesion is possible. In support of this, antagonists against P-selectin or PSGL-1 dissociated previously formed platelet-neutrophil and Ps-bead neutrophil aggregates under shear in a variety of experimental systems, including in assays performed with whole blood. In studies where medium viscosity and shear rate were varied, a subtle shear threshold for P-selectin PSGL-1 binding was also noted at shear rates<100/s and at force loading rates of ~300pN/sec. Results are discussed in light of biophysical computations that characterize the collision between unequal size particles in linear shear flow. Overall, our studies reveal an integrin-independent regime for cell adhesion that may be physiologically relevant.

  3. The role of platelet factor 4 in local and remote tissue damage in a mouse model of mesenteric ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Peter H Lapchak

    Full Text Available The robust inflammatory response that occurs during ischemia reperfusion (IR injury recruits factors from both the innate and adaptive immune systems. However the contribution of platelets and their products such as Platelet Factor 4 (PF4; CXCL4, during the pathogenesis of IR injury has not been thoroughly investigated. We show that a deficiency in PF4 protects mice from local and remote tissue damage after 30 minutes of mesenteric ischemia and 3 hours of reperfusion in PF4-/- mice compared to control B6 mice. This protection was independent from Ig or complement deposition in the tissues. However, neutrophil and monocyte infiltration were decreased in the lungs of PF4-/- mice compared with B6 control mice. Platelet-depleted B6 mice transfused with platelets from PF4-/- mice displayed reduced tissue damage compared with controls. In contrast, transfusion of B6 platelets into platelet depleted PF4-/- mice reconstituted damage in both intestine and lung tissues. We also show that PF4 may modulate the release of IgA. Interestingly, we show that PF4 expression on intestinal epithelial cells is increased after IR at both the mRNA and protein levels. In conclusion, these findings demonstrate that may PF4 represent an important mediator of local and remote tissue damage.

  4. The effects of ropivacaine hydrochloride on platelet function: an assessment using the platelet function analyser (PFA-100).

    LENUS (Irish Health Repository)

    Porter, J

    2012-02-03

    Amide local anaesthetics impair blood clotting in a concentration-dependent manner by inhibition of platelet function and enhanced fibrinolysis. We hypothesised that the presence of ropivacaine in the epidural space could decrease the efficacy of an epidural blood patch, as this technique requires that the injected blood can clot in order to be effective. Ropivacaine is an aminoamide local anaesthetic used increasingly for epidural analgesia during labour. The concentration of local anaesthetic in blood achieved in the epidural space during the performance of an epidural blood patch is likely to be the greatest which occurs (intentionally) in any clinical setting. This study was undertaken to investigate whether concentrations of ropivacaine in blood, which could occur: (i) clinically in the epidural space and (ii) in plasma during an epidural infusion of ropivacaine, alter platelet function. A platelet function analyser (Dade PFA-100, Miami) was employed to assess the effects of ropivacaine-treated blood on platelet function. The greater concentrations of ropivacaine studied (3.75 and 1.88 mg x ml(-1)), which correspond to those which could occur in the epidural space, produced significant inhibition of platelet aggregation. We conclude that the presence of ropivacaine in the epidural space may decrease the efficacy of an early or prophylactic epidural blood patch.

  5. Reproducibility of Manual Platelet Estimation Following Automated Low Platelet Counts

    Directory of Open Access Journals (Sweden)

    Zainab S Al-Hosni

    2016-11-01

    Full Text Available Objectives: Manual platelet estimation is one of the methods used when automated platelet estimates are very low. However, the reproducibility of manual platelet estimation has not been adequately studied. We sought to assess the reproducibility of manual platelet estimation following automated low platelet counts and to evaluate the impact of the level of experience of the person counting on the reproducibility of manual platelet estimates. Methods: In this cross-sectional study, peripheral blood films of patients with platelet counts less than 100 × 109/L were retrieved and given to four raters to perform manual platelet estimation independently using a predefined method (average of platelet counts in 10 fields using 100× objective multiplied by 20. Data were analyzed using intraclass correlation coefficient (ICC as a method of reproducibility assessment. Results: The ICC across the four raters was 0.840, indicating excellent agreement. The median difference of the two most experienced raters was 0 (range: -64 to 78. The level of platelet estimate by the least-experienced rater predicted the disagreement (p = 0.037. When assessing the difference between pairs of raters, there was no significant difference in the ICC (p = 0.420. Conclusions: The agreement between different raters using manual platelet estimation was excellent. Further confirmation is necessary, with a prospective study using a gold standard method of platelet counts.

  6. Sulfur mustard primes human neutrophils for increased degranulation and stimulates cytokine release via TRPM2/p38 MAPK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Hwa-Yong [Department of Pharmacology, Infectious Diseases Medical Research Center, College of Medicine, Hallym University, Chuncheon (Korea, Republic of); Hong, Chang-Won, E-mail: chyj7983@hallym.ac.kr [Department of Chemical and Biological Warfare Research, The Armed Forces Medical Research Institute, Daejeon (Korea, Republic of); Lee, Si-Nae [Department of Pharmacology, Infectious Diseases Medical Research Center, College of Medicine, Hallym University, Chuncheon (Korea, Republic of); Kwon, Min-Soo [Department of Pharmacology, School of Medicine, CHA University, Seongnam (Korea, Republic of); Kim, Yeon-Ja [Department of Pharmacology, Infectious Diseases Medical Research Center, College of Medicine, Hallym University, Chuncheon (Korea, Republic of); Song, Dong-Keun, E-mail: dksong@hallym.ac.kr [Department of Pharmacology, Infectious Diseases Medical Research Center, College of Medicine, Hallym University, Chuncheon (Korea, Republic of)

    2012-01-01

    Sulfur mustard (2,2′-bis-chloroethyl-sulfide; SM) has been a military threat since the World War I. The emerging threat of bioterrorism makes SM a major threat not only to military but also to civilian world. SM injury elicits an inflammatory response characterized by infiltration of neutrophils. Although SM was reported to prime neutrophils, the mechanism has not been identified yet. In the present study, we investigated the mechanism of SM-induced priming in human neutrophils. SM increased [Ca{sup 2+}]{sub i} in human neutrophils in a concentration-dependent fashion. Transient receptor potential melastatin (TRPM) 2 inhibitors (clotrimazole, econazole and flufenamic acid) and silencing of TRPM2 by shRNA attenuated SM-induced [Ca{sup 2+}]{sub i} increase. SM primed degranulation of azurophil and specific granules in response to activation by fMLP as previously reported. SB203580, an inhibitor of p38 MAPK, inhibited SM-induced priming. Neither PD98057, an ERK inhibitor, nor SP600215, a JNK inhibitor, inhibited SM-induced priming. In addition, SM enhanced phosphorylation of NF-kB p65 and release of TNF-α, interleukin (IL)-6 and IL-8. SB203580 inhibited SM-induced NF-kB phosphorylation and cytokine release. These results suggest the involvement of TRPM2/p38 MAPK pathway in SM-induced priming and cytokines release in neutrophils. -- Highlights: ► SM increased [Ca{sup 2+}]{sub i} in human neutrophils through TPRM2-mediated calcium influx. ► SM primed degranulation of azurophil and specific granules. ► SM enhanced p38 MAPK and NF-κB p65 phosphorylation in human neutrophils. ► SM enhanced release of TNF-α, interleukin (IL)-6 and IL-8 from human neutrophils. ► SB203580 inhibited SM-induced priming, NF-κB p65 phosphorylation and cytokine release.

  7. Mean platelet volume and mean platelet volume/platelet count ratio

    African Journals Online (AJOL)

    Amira M. Elsayed

    2016-03-30

    Mar 30, 2016 ... The aim of this study was to compare the MPV and mean platelet volume/platelet count ... brain stroke, both in the acute phase and long after disease.17 ... males, while the healthy controls comprised 12 females and 8.

  8. Improved viability and activity of neutrophils differentiated from HL-60 cells by co-culture with adipose tissue-derived mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yoon Shin; Lim, Goh-Woon [Department of Pediatrics, Ewha Womans University, School of Medicine, Ewha Medical Research Center, Seoul (Korea, Republic of); Cho, Kyung-Ah; Woo, So-Youn; Shin, Meeyoung [Department of Microbiology, Ewha Womans University, School of Medicine, Ewha Medical Research Center, Seoul (Korea, Republic of); Yoo, Eun-Sun [Department of Pediatrics, Ewha Womans University, School of Medicine, Ewha Medical Research Center, Seoul (Korea, Republic of); Chan Ra, Jeong [Stem Cell Research Center, RNL BIO, Seoul 153-768 (Korea, Republic of); Ryu, Kyung-Ha, E-mail: ykh@ewha.ac.kr [Department of Pediatrics, Ewha Womans University, School of Medicine, Ewha Medical Research Center, Seoul (Korea, Republic of)

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer Neutropenia is a principal complication of cancer treatment. Black-Right-Pointing-Pointer Co-culture of neutrophils with AD-MSC retained cell survival and proliferation and inhibited neutrophil apoptosis under serum starved conditions. Black-Right-Pointing-Pointer AD-MSC increased functions of neutrophil. Black-Right-Pointing-Pointer AD-MSC promoted the viability of neutrophils by enhancing respiratory burst through the expression of IFN-{alpha}, G-CSF, and TGF-{beta}. Black-Right-Pointing-Pointer AD-MSC can be used to improve immunity for neutropenia treatment. -- Abstract: Neutropenia is a principal complication of cancer treatment. We investigated the supportive effect of adipose tissue-derived mesenchymal stem cells (AD-MSCs) on the viability and function of neutrophils. Neutrophils were derived from HL-60 cells by dimethylformamide stimulation and cultured with or without AD-MSCs under serum-starved conditions to evaluate neutrophil survival, proliferation, and function. Serum starvation resulted in the apoptosis of neutrophils and decreased cell survival. The co-culture of neutrophils and AD-MSCs resulted in cell survival and inhibited neutrophil apoptosis under serum-starved conditions. The survival rate of neutrophils was prolonged up to 72 h, and the expression levels of interferon (IFN)-{alpha}, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, and transforming growth factor (TGF)-{beta} in AD-MSCs were increased after co-culture with neutrophils. AD-MSCs promoted the viability of neutrophils by inhibiting apoptosis as well as enhancing respiratory burst, which could potentially be mediated by the increased expression of IFN-{alpha}, G-CSF, and TGF-{beta}. Thus, we conclude that the use of AD-MSCs may be a promising cell-based therapy for increasing immunity by accelerating neutrophil function.

  9. Pathogenic Bacterium Acinetobacter baumannii Inhibits the Formation of Neutrophil Extracellular Traps by Suppressing Neutrophil Adhesion

    Science.gov (United States)

    Kamoshida, Go; Kikuchi-Ueda, Takane; Nishida, Satoshi; Tansho-Nagakawa, Shigeru; Ubagai, Tsuneyuki; Ono, Yasuo

    2018-01-01

    Hospital-acquired infections caused by Acinetobacter baumannii have become problematic because of high rates of drug resistance. A. baumannii is usually harmless, but it may cause infectious diseases in an immunocompromised host. Although neutrophils are the key players of the initial immune response against bacterial infection, their interactions with A. baumannii remain largely unknown. A new biological defense mechanism, termed neutrophil extracellular traps (NETs), has been attracting attention. NETs play a critical role in bacterial killing by bacterial trapping and inactivation. Many pathogenic bacteria have been reported to induce NET formation, while an inhibitory effect on NET formation is rarely reported. In the present study, to assess the inhibition of NET formation by A. baumannii, bacteria and human neutrophils were cocultured in the presence of phorbol 12-myristate 13-acetate (PMA), and NET formation was evaluated. NETs were rarely observed during the coculture despite neutrophil PMA stimulation. Furthermore, A. baumannii prolonged the lifespan of neutrophils by inhibiting NET formation. The inhibition of NET formation by other bacteria was also investigated. The inhibitory effect was only apparent with live A. baumannii cells. Finally, to elucidate the mechanism of this inhibition, neutrophil adhesion was examined. A. baumannii suppressed the adhesion ability of neutrophils, thereby inhibiting PMA-induced NET formation. This suppression of cell adhesion was partly due to suppression of the surface expression of CD11a in neutrophils. The current study constitutes the first report on the inhibition of NET formation by a pathogenic bacterium, A. baumannii, and prolonging the neutrophil lifespan. This novel pathogenicity to inhibit NET formation, thereby escaping host immune responses might contribute to a development of new treatment strategies for A. baumannii infections. PMID:29467765

  10. Pathogenic Bacterium Acinetobacter baumannii Inhibits the Formation of Neutrophil Extracellular Traps by Suppressing Neutrophil Adhesion

    Directory of Open Access Journals (Sweden)

    Go Kamoshida

    2018-02-01

    Full Text Available Hospital-acquired infections caused by Acinetobacter baumannii have become problematic because of high rates of drug resistance. A. baumannii is usually harmless, but it may cause infectious diseases in an immunocompromised host. Although neutrophils are the key players of the initial immune response against bacterial infection, their interactions with A. baumannii remain largely unknown. A new biological defense mechanism, termed neutrophil extracellular traps (NETs, has been attracting attention. NETs play a critical role in bacterial killing by bacterial trapping and inactivation. Many pathogenic bacteria have been reported to induce NET formation, while an inhibitory effect on NET formation is rarely reported. In the present study, to assess the inhibition of NET formation by A. baumannii, bacteria and human neutrophils were cocultured in the presence of phorbol 12-myristate 13-acetate (PMA, and NET formation was evaluated. NETs were rarely observed during the coculture despite neutrophil PMA stimulation. Furthermore, A. baumannii prolonged the lifespan of neutrophils by inhibiting NET formation. The inhibition of NET formation by other bacteria was also investigated. The inhibitory effect was only apparent with live A. baumannii cells. Finally, to elucidate the mechanism of this inhibition, neutrophil adhesion was examined. A. baumannii suppressed the adhesion ability of neutrophils, thereby inhibiting PMA-induced NET formation. This suppression of cell adhesion was partly due to suppression of the surface expression of CD11a in neutrophils. The current study constitutes the first report on the inhibition of NET formation by a pathogenic bacterium, A. baumannii, and prolonging the neutrophil lifespan. This novel pathogenicity to inhibit NET formation, thereby escaping host immune responses might contribute to a development of new treatment strategies for A. baumannii infections.

  11. Quality assessment of platelet concentrates prepared by platelet rich plasma-platelet concentrate, buffy coat poor-platelet concentrate (BC-PC and apheresis-PC methods

    Directory of Open Access Journals (Sweden)

    Singh Ravindra

    2009-01-01

    Full Text Available Background: Platelet rich plasma-platelet concentrate (PRP-PC, buffy coat poor-platelet concentrate (BC-PC, and apheresis-PC were prepared and their quality parameters were assessed. Study Design: In this study, the following platelet products were prepared: from random donor platelets (i platelet rich plasma - platelet concentrate (PRP-PC, and (ii buffy coat poor- platelet concentrate (BC-PC and (iii single donor platelets (apheresis-PC by different methods. Their quality was assessed using the following parameters: swirling, volume of the platelet concentrate, platelet count, WBC count and pH. Results: A total of 146 platelet concentrates (64 of PRP-PC, 62 of BC-PC and 20 of apheresis-PC were enrolled in this study. The mean volume of PRP-PC, BC-PC and apheresis-PC was 62.30±22.68 ml, 68.81±22.95 ml and 214.05±9.91 ml and ranged from 22-135 ml, 32-133 ml and 200-251 ml respectively. The mean platelet count of PRP-PC, BC-PC and apheresis-PC was 7.6±2.97 x 1010/unit, 7.3±2.98 x 1010/unit and 4.13±1.32 x 1011/unit and ranged from 3.2-16.2 x 1010/unit, 0.6-16.4 x 1010/unit and 1.22-8.9 x 1011/unit respectively. The mean WBC count in PRP-PC (n = 10, BC-PC (n = 10 and apheresis-PC (n = 6 units was 4.05±0.48 x 107/unit, 2.08±0.39 x 107/unit and 4.8±0.8 x 106/unit and ranged from 3.4 -4.77 x 107/unit, 1.6-2.7 x 107/unit and 3.2 - 5.2 x 106/unit respectively. A total of 26 units were analyzed for pH changes. Out of these units, 10 each were PRP-PC and BC-PC and 6 units were apheresis-PC. Their mean pH was 6.7±0.26 (mean±SD and ranged from 6.5 - 7.0 and no difference was observed among all three types of platelet concentrate. Conclusion: PRP-PC and BC-PC units were comparable in terms of swirling, platelet count per unit and pH. As expected, we found WBC contamination to be less in BC-PC than PRP-PC units. Variation in volume was more in BC-PC than PRP-PC units and this suggests that further standardization is required for preparation of BC

  12. Neutrophil activation during acetaminophen hepatotoxicity and repair in mice and humans

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C. David; Bajt, Mary Lynn [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Sharpe, Matthew R. [Department of Internal Medicine, University of Kansas Hospital, Kansas City, KS (United States); McGill, Mitchell R. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Farhood, Anwar [Department of Pathology, St. David' s North Austin Medical Center, Austin, TX 78756 (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2014-03-01

    Following acetaminophen (APAP) overdose there is an inflammatory response triggered by the release of cellular contents from necrotic hepatocytes into the systemic circulation which initiates the recruitment of neutrophils into the liver. It has been demonstrated that neutrophils do not contribute to APAP-induced liver injury, but their role and the role of NADPH oxidase in injury resolution are controversial. C57BL/6 mice were subjected to APAP overdose and neutrophil activation status was determined during liver injury and liver regeneration. Additionally, human APAP overdose patients (ALT: > 800 U/L) had serial blood draws during the injury and recovery phases for the determination of neutrophil activation. Neutrophils in the peripheral blood of mice showed an increasing activation status (CD11b expression and ROS priming) during and after the peak of injury but returned to baseline levels prior to complete injury resolution. Hepatic sequestered neutrophils showed an increased and sustained CD11b expression, but no ROS priming was observed. Confirming that NADPH oxidase is not critical to injury resolution, gp91{sup phox}−/− mice following APAP overdose displayed no alteration in injury resolution. Peripheral blood from APAP overdose patients also showed increased neutrophil activation status after the peak of liver injury and remained elevated until discharge from the hospital. In mice and humans, markers of activation, like ROS priming, were increased and sustained well after active liver injury had subsided. The similar findings between surviving patients and mice indicate that neutrophil activation may be a critical event for host defense or injury resolution following APAP overdose, but not a contributing factor to APAP-induced injury. - Highlights: • Neutrophil (PMN) function increases during liver repair after acetaminophen overdose. • Liver repair after acetaminophen (APAP)-overdose is not dependent on NADPH oxidase. • Human PMNs do not appear

  13. Equipoise in the enhanced supression of the platelet IIb/IIIa receptor with integrilin trial (ESPRIT): a critical appraisal.

    Science.gov (United States)

    Mann, Howard; London, Alex John; Mann, Jeffrey

    2005-01-01

    Enhanced Supression of the Platelet IIb/IIIa Receptor with Integrilin Trial (ESPRIT) was a multicenter randomized controlled clinical trial in which participants were randomized between eptifibatide and placebo. A "clinical hold" was initially placed on the trial by the US Food and Drug Administration (FDA), which was concerned about the placebo-only control arm. The hold was lifted after additional information concerning the use of platelet glycoprotein IIb/IIIa inhibitors in clinical practice, derived from a survey of interventional cardiologists, was provided. The trial's principal investigator and colleagues have described how these issues were resolved, and advance a claim of equipoise for the trial. In this critical appraisal we examine the information and arguments proffered in support of the trial design and conclude that they evidence a misunderstanding of equipoise. We believe that a placebo-only control arm was not justified by the information provided by the trialists.

  14. Neutrophil Extracellular Traps in Ulcerative Colitis

    DEFF Research Database (Denmark)

    Bjerg Bennike, Tue; Carlsen, Thomas Gelsing; Ellingsen, Torkell

    2015-01-01

    microscopy and confocal microscopy. RESULTS: We identified and quantified 5711 different proteins with proteomics. The abundance of the proteins calprotectin and lactotransferrin in the tissue correlated with the degree of tissue inflammation as determined by histology. However, fecal calprotectin did...... not correlate. Forty-six proteins were measured with a statistically significant differences in abundances between the UC colon tissue and controls. Eleven of the proteins with increased abundances in the UC biopsies were associated with neutrophils and neutrophil extracellular traps. The findings were...... validated by microscopy, where an increased abundance of neutrophils and the presence of neutrophil extracellular traps by extracellular DNA present in the UC colon tissue were confirmed. CONCLUSIONS: Neutrophils, induced neutrophil extracellular traps, and several proteins that play a part in innate...

  15. With Friends Like These: The Complex Role of Neutrophils in the Progression of Severe Pneumonia

    Directory of Open Access Journals (Sweden)

    Roger D. Pechous

    2017-05-01

    Full Text Available Pneumonia is a leading cause of death from infection in the United States and across the globe. During pulmonary infection, clear resolution of host inflammatory responses occurs in the absence of appreciable lung damage. Neutrophils are the first wave of leukocytes to arrive in the lung upon infection. After activation, neutrophils traffic from the vasculature via transendothelial migration through the lung interstitium and into the alveolar space. Successful pulmonary immunity requires neutrophil-mediated killing of invading pathogens by phagocytosis and release of a myriad of antimicrobial molecules, followed by resolution of inflammation, neutrophil apoptosis, and clearing of dead or dying neutrophils by macrophages. In addition to their antimicrobial role, it is becoming clear that neutrophils are also important modulators of innate and adaptive immune responses, primarily through the release of cytokines and recruitment of additional waves of neutrophils into the airways. Though typically essential to combating severe pneumonia, neutrophil influx into the airways is a double-edged sword: Overzealous neutrophil activation can cause severe tissue damage as a result of the release of toxic agents including proteases, cationic polypeptides, cytokines, and reactive oxygen species (ROS aimed at killing invading microbes. In extreme cases, the damage caused by neutrophils and other innate immune mediators become the primary source of morbidity and mortality. Here, we review the complex role of neutrophils during severe pneumonia by highlighting specific molecules and processes that contribute to pulmonary immunity, but can also drive progression of severe disease. Depending on the identity of the infectious agent, enhancing or suppressing neutrophil-mediated responses may be key to effectively treating severe and typically lethal pneumonia.

  16. Neutrophils: potential therapeutic targets in tularemia?

    Directory of Open Access Journals (Sweden)

    Lee-Ann H Allen

    2013-12-01

    Full Text Available The central role of neutrophils in innate immunity and host defense has long been recognized, and the ability of these cells to efficiently engulf and kill invading bacteria has been extensively studied, as has the role of neutrophil apoptosis in resolution of the inflammatory response. In the past few years additional immunoregulatory properties of neutrophils were discovered, and it is now clear that these cells play a much greater role in control of the immune response than was previously appreciated. In this regard, it is noteworthy that Francisella tularensis is one of relatively few pathogens that can successfully parasitize neutrophils as well as macrophages, DC and epithelial cells. Herein we will review the mechanisms used by F. tularensis to evade elimination by neutrophils. We will also reprise effects of this pathogen on neutrophil migration and lifespan as compared with other infectious and inflammatory disease states. In addition, we will discuss the evidence which suggests that neutrophils contribute to disease progression rather than effective defense during tularemia, and consider whether manipulation of neutrophil migration or turnover may be suitable adjunctive therapeutic strategies.

  17. Metformin reduces hyper-reactivity of platelets from patients with polycystic ovary syndrome by improving mitochondrial integrity.

    Science.gov (United States)

    Randriamboavonjy, Voahanginirina; Mann, W Alexander; Elgheznawy, Amro; Popp, Rüdiger; Rogowski, Paul; Dornauf, Imke; Dröse, Stefan; Fleming, Ingrid

    2015-08-31

    Polycystic ovary syndrome (PCOS) is associated with decreased fertility, insulin resistance and an increased risk of developing cardiovascular disease. Treating PCOS patients with metformin improves fertility and decreases cardiovascular complications. Given that platelet activation contributes to both infertility and cardiovascular disease development, we assessed platelet reactivity in PCOS patients and the consequences of metformin treatment. Compared to washed platelets from healthy donors, platelets from PCOS patients demonstrated enhanced reactivity and impaired activation of the AMP-activated kinase (AMPK). PCOS platelets also demonstrated enhanced expression of mitochondrial proteins such as the cytochrome c reductase, ATP synthase and the voltage-dependent anion channel-1. However, mitochondrial function was impaired as demonstrated by a decreased respiration rate. In parallel, the phosphorylation of dynamin-related protein-1 (Drp-1) on Ser616 was increased while that on Ser637 decreased. The latter changes were accompanied by decreased mitochondrial size. In insulin-resistant PCOS patients (HOMA-IR> 2) metformin treatment (1.7 g per day for 4 weeks to 6 months) improved insulin sensitivity, restored mitochondrial integrity and function and normalised platelet aggregation. Treatment was without effect in PCOS patients with HOMA-IRtreatment of megakaryocytes with metformin enhanced mitochondrial content and in the same cells metformin enhanced the phosphorylation of the Drp-1 on Ser637 via an AMPKα1-dependent mechanism. In conclusion, the improvement of mitochondrial integrity and platelet reactivity may contribute to the beneficial effects of metformin on cardiovascular disease.

  18. Alpha-1-antitrypsin is produced by human neutrophil granulocytes and their precursors and liberated during granule exocytosis

    DEFF Research Database (Denmark)

    Clemmensen, Stine N; Jacobsen, Lars C; Rørvig, Sara

    2011-01-01

    Alpha-1-antitrypsin (A1AT) is an important inhibitor of neutrophil proteases including elastase, cathepsin G, and proteinase 3. Transcription profiling data suggest that A1AT is expressed by human neutrophil granulocytes during all developmental stages. A1AT has hitherto only been found associate...... significantly to the antiprotease levels in tissues during inflammation. Impaired binding of neutrophil A1AT to serine proteases in patients with (PI)ZZ mutations may enhance their susceptibility to the development of emphysema....

  19. Effect of sevoflurane on human neutrophil apoptosis.

    LENUS (Irish Health Repository)

    Tyther, R

    2012-02-03

    BACKGROUND AND OBJECTIVE: Both chronic occupational exposure to volatile anaesthetic agents and acute in vitro exposure of neutrophils to isoflurane have been shown to inhibit the rate of apoptosis of human neutrophils. It is possible that inhibition of neutrophil apoptosis arises through delaying mitochondrial membrane potential collapse. We assessed mitochondrial depolarization and apoptosis in unexposed neutrophils and neutrophils exposed to sevoflurane in vivo. METHODS: A total of 20 mL venous blood was withdrawn pre- and postinduction of anaesthesia, the neutrophils isolated and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide. Mitochondrial depolarization was measured using the dual emission styryl dye JC-1. RESULTS: Apoptosis was significantly inhibited in neutrophils exposed to sevoflurane in vivo at 24 (exposed: 38 (12)% versus control: 28 (11)%, P = 0.001), but not at 1 or 12 h, in culture. Mitochondrial depolarization was not delayed in neutrophils exposed to sevoflurane. CONCLUSIONS: The most important findings are that sevoflurane inhibits neutrophil apoptosis in vivo and that inhibition is not mediated primarily by an effect on mitochondrial depolarization.

  20. Revascularization of Immature Necrotic Teeth: Platelet rich Fibrin an Edge over Platelet rich Plasma

    Directory of Open Access Journals (Sweden)

    Neelam Mittal

    2012-03-01

    Full Text Available Introduction: Revascularization is one such entity that has found its clinical application in the field of endodontics for the manage-ment of immature permanent necrotic teeth. The protocols for revascularization of such teeth focus especially on delivery of stem cells and scaffolds in a nonsurgical manner rather than concentrated growth micro molecules.The hypothesis: This article proposes the role of platelet concentrates such as platelet rich fibrin (PRF and platelet rich plasma (PRP in accelerating the regenerative process in such teeth. PRF unlike PRP is associated with slow, continuous and substantial re-lease of morphogens. It is hypothesized further if PRF instead of PRP when placed through immature apices in an orthograde manner can open newer gates for fast and controlled growth in young, ne-crotic, non-infected teeth.Evaluation of the hypothesis: Enhancement of the healing kinetics can be evaluated by change in size of periapical radiolucency, thickness of the dentinal walls, root elongation and apical closure compared between preoperative and postoperative standardized two dimensional/three dimensional radiographs taken on regular follow ups.

  1. Neutrophil programming dynamics and its disease relevance.

    Science.gov (United States)

    Ran, Taojing; Geng, Shuo; Li, Liwu

    2017-11-01

    Neutrophils are traditionally considered as first responders to infection and provide antimicrobial host defense. However, recent advances indicate that neutrophils are also critically involved in the modulation of host immune environments by dynamically adopting distinct functional states. Functionally diverse neutrophil subsets are increasingly recognized as critical components mediating host pathophysiology. Despite its emerging significance, molecular mechanisms as well as functional relevance of dynamically programmed neutrophils remain to be better defined. The increasing complexity of neutrophil functions may require integrative studies that address programming dynamics of neutrophils and their pathophysiological relevance. This review aims to provide an update on the emerging topics of neutrophil programming dynamics as well as their functional relevance in diseases.

  2. Further studies on the relationship between platelet buoyant density and platelet age

    International Nuclear Information System (INIS)

    Boneu, B.; Vigoni, F.; Boneu, A.; Caranobe, C.; Sie, P.

    1982-01-01

    The relationship between platelet buoyant density and platelet age was investigated in eight human subjects submitted to an autologous chromium labeled platelet survival study. Platelets were isolated after isopycnic centrifugation using eight discontinuous isoosmotic stractan gradients (five subjects), or various continuous and linear isoosmolar gradients (three subjects). A paradoxical radioactivity enrichment of the dense platelets and a premature loss of radioactivity in the light platelets were observed. These results are explained by a shift of the radioactivity distribution curve toward higher densities during the 3-4 days after platelet injection, while the standard deviation of the distribution was conserved throughout the platelet life span. These results suggest that young platelets are heterogeneous and slightly less dense than the total platelet population

  3. Insomnia, platelet serotonin and platelet monoamine oxidase in chronic alcoholism.

    Science.gov (United States)

    Nenadic Sviglin, Korona; Nedic, Gordana; Nikolac, Matea; Mustapic, Maja; Muck-Seler, Dorotea; Borovecki, Fran; Pivac, Nela

    2011-08-18

    Insomnia is a common sleep disorder frequently occurring in chronic alcoholic patients. Neurobiological basis of insomnia, as well as of alcoholism, is associated with disrupted functions of the main neurotransmitter systems, including the serotonin (5-hydroxytryptamine, 5-HT) system. Blood platelets are considered a limited peripheral model for the central 5-HT neurons, since both platelets and central 5-HT synaptosomes have similar dynamics of 5-HT. Platelet 5-HT concentration and platelet monoamine oxidase type B (MAO-B) are assumed to represent biomarkers for particular symptoms and behaviors in psychiatric disorders. The hypothesis of this study was that platelet 5-HT concentration and platelet MAO-B activity will be altered in chronic alcoholic patients with insomnia compared to comparable values in patients without insomnia. The study included 498 subjects: 395 male and 103 female medication-free patients with alcohol dependence and 502 healthy control subjects: 325 men and 177 women. The effects of early, middle and late insomnia (evaluated using the Hamilton Depression Rating Scale), as well as sex, age and smoking on platelet 5-HT concentration and platelet MAO-B activity were evaluated using one-way ANOVA and multiple regression analysis by the stepwise method. Platelet 5-HT concentration, but not platelet MAO-B activity, was significantly reduced in alcoholic patients with insomnia compared to patients without insomnia. Multiple regression analysis revealed that platelet 5-HT concentration was affected by middle insomnia, smoking and sex, while platelet MAO activity was affected only by sex and age. The present and previous data suggest that platelet 5-HT concentration might be used, after controlling for sex and smoking, as a biomarker for insomnia in alcoholism, PTSD and in rotating shift workers. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Platelet biomechanics, platelet bioenergetics, and applications to clinical practice and translational research.

    Science.gov (United States)

    George, Mitchell J; Bynum, James; Nair, Prajeeda; Cap, Andrew P; Wade, Charles E; Cox, Charles S; Gill, Brijesh S

    2018-07-01

    The purpose of this review is to explore the relationship between platelet bioenergetics and biomechanics and how this relationship affects the clinical interpretation of platelet function devices. Recent experimental and technological advances highlight platelet bioenergetics and biomechanics as alternative avenues for collecting clinically relevant data. Platelet bioenergetics drive energy production for key biomechanical processes like adhesion, spreading, aggregation, and contraction. Platelet function devices like thromboelastography, thromboelastometry, and aggregometry measure these biomechanical processes. Platelet storage, stroke, sepsis, trauma, or the activity of antiplatelet drugs alters measures of platelet function. However, the specific mechanisms governing these alterations in platelet function and how they relate to platelet bioenergetics are still under investigation.

  5. Ensemble models of neutrophil trafficking in severe sepsis.

    Directory of Open Access Journals (Sweden)

    Sang Ok Song

    Full Text Available A hallmark of severe sepsis is systemic inflammation which activates leukocytes and can result in their misdirection. This leads to both impaired migration to the locus of infection and increased infiltration into healthy tissues. In order to better understand the pathophysiologic mechanisms involved, we developed a coarse-grained phenomenological model of the acute inflammatory response in CLP (cecal ligation and puncture-induced sepsis in rats. This model incorporates distinct neutrophil kinetic responses to the inflammatory stimulus and the dynamic interactions between components of a compartmentalized inflammatory response. Ensembles of model parameter sets consistent with experimental observations were statistically generated using a Markov-Chain Monte Carlo sampling. Prediction uncertainty in the model states was quantified over the resulting ensemble parameter sets. Forward simulation of the parameter ensembles successfully captured experimental features and predicted that systemically activated circulating neutrophils display impaired migration to the tissue and neutrophil sequestration in the lung, consequently contributing to tissue damage and mortality. Principal component and multiple regression analyses of the parameter ensembles estimated from survivor and non-survivor cohorts provide insight into pathologic mechanisms dictating outcome in sepsis. Furthermore, the model was extended to incorporate hypothetical mechanisms by which immune modulation using extracorporeal blood purification results in improved outcome in septic rats. Simulations identified a sub-population (about 18% of the treated population that benefited from blood purification. Survivors displayed enhanced neutrophil migration to tissue and reduced sequestration of lung neutrophils, contributing to improved outcome. The model ensemble presented herein provides a platform for generating and testing hypotheses in silico, as well as motivating further experimental

  6. Platelet Function Tests

    Science.gov (United States)

    ... Patient Resources For Health Professionals Subscribe Search Platelet Function Tests Send Us Your Feedback Choose Topic At ... Also Known As Platelet Aggregation Studies PFT Platelet Function Assay PFA Formal Name Platelet Function Tests This ...

  7. The hemostatic agent ethamsylate promotes platelet/leukocyte aggregate formation in a model of vascular injury.

    Science.gov (United States)

    Hernandez, Maria Rosa; Alvarez-Guerra, Miriam; Escolar, Ginés; Chiavaroli, Carlo; Hannaert, Patrick; Garay, Ricardo P

    2004-08-01

    The hemostatic agent ethamsylate enhances membrane expression of P-selectin in human platelets, but whether this promotes platelet-leukocyte aggregate formation is unknown. Here we investigated this point by flow cytometry determination of human platelet-leukocyte aggregates under basal conditions and after whole-blood perfusion through a damaged rabbit aorta segment. Actions of ethamsylate on adhesive molecules of platelets and leukocytes were investigated in parallel. Under basal conditions, ethamsylate was unable to modify whole-blood platelet-leukocyte aggregation, but following whole-blood perfusion through a damaged vessel, ethamsylate produced a modest, but significant increase in platelet-leukocyte aggregates (48+/-21 and 45+/-26% above control levels at ethamsylate 20 and 40 microm respectively). In isolated leukocyte plasma membranes, 14C-ethamsylate specifically bound up to an amount of 660 pmol/mg protein. Moreover, at concentrations > or =1 microm, ethamsylate induced an important (100-200%) and significant increase in the P-selectin glycoprotein ligand 1 (PSGL-1) fluorescence signal in isolated leukocytes and was unable to significantly modify the percentage of CD11b-positive cells. However, no significant changes in aggregate formation were found when ethamsylate was incubated with isolated leukocytes and blood was reconstituted and perfused. In isolated platelet cell membranes, anti-P-selectin antibody and the anti-integrin RGD-containing pentapeptide (GRDGS) were unable to displace 14C-ethamsylate binding. In conclusion, ethamsylate specifically binds to plasma membranes of leukocytes, enhances membrane PSGL-1 expression and promotes leukocyte-platelet aggregation in whole-blood perfused through a damaged vascular segment. These results together with the previously observed enhancement of platelet P-selectin membrane expression [Thromb. Res. (2002)107:329-335] confirms and extends the view that ethamsylate acts on the first step of hemostasis, by

  8. The Antidepressant 5-HT2A Receptor Antagonists Pizotifen and Cyproheptadine Inhibit Serotonin-Enhanced Platelet Function

    Science.gov (United States)

    Lin, Olivia A.; Karim, Zubair A.; Vemana, Hari Priya; Espinosa, Enma V. P.; Khasawneh, Fadi T.

    2014-01-01

    There is considerable interest in defining new agents or targets for antithrombotic purposes. The 5-HT2A receptor is a G-protein coupled receptor (GPCR) expressed on many cell types, and a known therapeutic target for many disease states. This serotonin receptor is also known to regulate platelet function. Thus, in our FDA-approved drug repurposing efforts, we investigated the antiplatelet activity of cyproheptadine and pizotifen, two antidepressant 5-HT2A Receptor antagonists. Our results revealed that cyproheptadine and pizotifen reversed serotonin-enhanced ADP-induced platelet aggregation in vitro and ex vivo. And the inhibitory effects of these two agents were found to be similar to that of EMD 281014, a 5-HT2A Receptor antagonist under development. In separate experiments, our studies revealed that these 5-HT2A receptor antagonists have the capacity to reduce serotonin-enhanced ADP-induced elevation in intracellular calcium levels and tyrosine phosphorylation. Using flow cytometry, we also observed that cyproheptadine, pizotifen, and EMD 281014 inhibited serotonin-enhanced ADP-induced phosphatidylserine (PS) exposure, P-selectin expression, and glycoprotein IIb-IIIa activation. Furthermore, using a carotid artery thrombosis model, these agents prolonged the time for thrombotic occlusion in mice in vivo. Finally, the tail-bleeding time was investigated to assess the effect of cyproheptadine and pizotifen on hemostasis. Our findings indicated prolonged bleeding time in both cyproheptadine- and pizotifen-treated mice. Notably, the increases in occlusion and bleeding times associated with these two agents were comparable to that of EMD 281014, and to clopidogrel, a commonly used antiplatelet drug, again, in a fashion comparable to clopidogrel and EMD 281014. Collectively, our data indicate that the antidepressant 5-HT2A antagonists, cyproheptadine and pizotifen do exert antiplatelet and thromboprotective effects, but similar to clopidogrel and EMD 281014, their

  9. Association of the Preoperative Neutrophil-to-ymphocyte Count Ratio and Platelet-to-Lymphocyte Count Ratio with Clinicopathological Characteristics in Patients with Papillary Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Sang Mi Kim

    2015-12-01

    Full Text Available BackgroundSeveral inflammatory biomarkers, especially a high preoperative neutrophil-to-lymphocyte count ratio (NLR and platelet-to-lymphocyte count ratio (PLR, are known to be indicator of poor prognosis in several cancers. However, very few studies have evaluated the significance of the NLR and PLR in papillary thyroid cancer (PTC. We evaluated the association of the preoperative NLR and PLR with clinicopathological characteristics in patients with PTC.MethodsThis study included 1,066 female patients who underwent total thyroidectomy for PTC. Patients were stratified into 4 quartiles by preoperative NLR and PLR. And the combination of preoperative NLR and PLR was calculated on the basis of data obtained value of tertile as follows: patients with both an elevated PLR and an elevated NLR were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively.ResultsThe preoperative NLR and PLR were significantly lower in patients aged ≥45 years and in patients with Hashimoto's thyroiditis. The PLR was significantly higher in patients with tumor size >1 cm (P=0.021.When the patients were categorized into the aforementioned four groups, the group with the higher preoperative PLR was found to have a significantly increased incidence of lateral lymph node metastasis (LNM (P=0.018. However, there are no significant association between the combination of preoperative NLR and PLR and prognostic factors in PTC patients.ConclusionThese results suggest that a preoperative high PLR were significant associated with lateral LNM in female patients with PTC.

  10. Altered Innate Immune Responses in Neutrophils from Patients with Well- and Suboptimally Controlled Asthma

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    Francesca S. M. Tang

    2015-01-01

    Full Text Available Background. Respiratory infections are a major cause of asthma exacerbations where neutrophilic inflammation dominates and is associated with steroid refractory asthma. Structural airway cells in asthma differ from nonasthmatics; however it is unknown if neutrophils differ. We investigated neutrophil immune responses in patients who have good (AGood and suboptimal (ASubopt asthma symptom control. Methods. Peripheral blood neutrophils from AGood (ACQ 0.75, n=7, and healthy controls (HC (n=9 were stimulated with bacterial (LPS (1 μg/mL, fMLF (100 nM, and viral (imiquimod (3 μg/mL, R848 (1.5 μg/mL, and poly I:C (10 μg/mL surrogates or live rhinovirus (RV 16 (MOI1. Cell-free supernatant was collected after 1 h for neutrophil elastase (NE and matrix metalloproteinase- (MMP- 9 measurements or after 24 h for CXCL8 release. Results. Constitutive NE was enhanced in AGood neutrophils compared to HC. fMLF stimulated neutrophils from ASubopt but not AGood produced 50% of HC levels. fMLF induced MMP-9 was impaired in ASubopt and AGood compared to HC. fMLF stimulated CXCL8 but not MMP-9 was positively correlated with FEV1 and FEV1/FVC. ASubopt and AGood responded similarly to other stimuli. Conclusions. Circulating neutrophils are different in asthma; however, this is likely to be related to airflow limitation rather than asthma control.

  11. The Vi capsular polysaccharide enables Salmonella enterica serovar typhi to evade microbe-guided neutrophil chemotaxis.

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    Tamding Wangdi

    2014-08-01

    Full Text Available Salmonella enterica serovar Typhi (S. Typhi causes typhoid fever, a disseminated infection, while the closely related pathogen S. enterica serovar Typhimurium (S. Typhimurium is associated with a localized gastroenteritis in humans. Here we investigated whether both pathogens differ in the chemotactic response they induce in neutrophils using a single-cell experimental approach. Surprisingly, neutrophils extended chemotactic pseudopodia toward Escherichia coli and S. Typhimurium, but not toward S. Typhi. Bacterial-guided chemotaxis was dependent on the presence of complement component 5a (C5a and C5a receptor (C5aR. Deletion of S. Typhi capsule biosynthesis genes markedly enhanced the chemotactic response of neutrophils in vitro. Furthermore, deletion of capsule biosynthesis genes heightened the association of S. Typhi with neutrophils in vivo through a C5aR-dependent mechanism. Collectively, these data suggest that expression of the virulence-associated (Vi capsular polysaccharide of S. Typhi obstructs bacterial-guided neutrophil chemotaxis.

  12. Correlations between plasma noradrenaline concentrations, antioxidants, and neutrophil counts after submaximal resistance exercise in men

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    Ramel, A; Wagner, K; Elmadfa, I

    2004-01-01

    Objectives: To investigate noradrenaline concentrations, neutrophil counts, plasma antioxidants, and lipid oxidation products before and after acute resistance exercise. Methods: 17 male participants undertook a submaximal resistance exercise circuit (10 exercises; 75% of the one repetition maximum; mean (SD) exercise time, 18.6 (1.1) minutes). Blood samples were taken before and immediately after exercise and analysed for plasma antioxidants, noradrenaline, neutrophils, and lipid oxidation products. Wilcoxon's signed-rank test and Pearson's correlation coefficient were used for calculations. Results: Neutrophils, noradrenaline, fat soluble antioxidants, and lipid oxidation products increased after exercise. Noradrenaline concentrations were associated with higher antioxidant concentrations. Neutrophils were related to higher concentrations of conjugated dienes. Conclusions: Submaximal resistance exercise increases plasma antioxidants. This might reflect enhanced antioxidant defence in response to the oxidative stress of exercise, though this is not efficient for inhibiting lipid oxidation. The correlation between noradrenaline concentrations and plasma antioxidants suggests a modulating role of the stress hormone. Neutrophils are a possible source of oxidative stress after resistance exercise. PMID:15388566

  13. Dynamic interactions of neutrophils and biofilms

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    Josefine Hirschfeld

    2014-12-01

    Full Text Available Background: The majority of microbial infections in humans are biofilm-associated and difficult to treat, as biofilms are highly resistant to antimicrobial agents and protect themselves from external threats in various ways. Biofilms are tenaciously attached to surfaces and impede the ability of host defense molecules and cells to penetrate them. On the other hand, some biofilms are beneficial for the host and contain protective microorganisms. Microbes in biofilms express pathogen-associated molecular patterns and epitopes that can be recognized by innate immune cells and opsonins, leading to activation of neutrophils and other leukocytes. Neutrophils are part of the first line of defense and have multiple antimicrobial strategies allowing them to attack pathogenic biofilms. Objective/design: In this paper, interaction modes of neutrophils with biofilms are reviewed. Antimicrobial strategies of neutrophils and the counteractions of the biofilm communities, with special attention to oral biofilms, are presented. Moreover, possible adverse effects of neutrophil activity and their biofilm-promoting side effects are discussed. Results/conclusion: Biofilms are partially, but not entirely, protected against neutrophil assault, which include the processes of phagocytosis, degranulation, and formation of neutrophil extracellular traps. However, virulence factors of microorganisms, microbial composition, and properties of the extracellular matrix determine whether a biofilm and subsequent microbial spread can be controlled by neutrophils and other host defense factors. Besides, neutrophils may inadvertently contribute to the physical and ecological stability of biofilms by promoting selection of more resistant strains. Moreover, neutrophil enzymes can degrade collagen and other proteins and, as a result, cause harm to the host tissues. These parameters could be crucial factors in the onset of periodontal inflammation and the subsequent tissue breakdown.

  14. The effect of interleukin-8 and granulocyte macrophage colony stimulating factor on the response of neutrophils to formyl methionyl leucyl phenylalanine.

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    Mikami, M; Llewellyn-Jones, C G; Stockley, R A

    1998-08-14

    Neutrophils isolated from patients with chronic bronchitis and emphysema have been shown to have enhanced responses to formyl peptides when assessed in vitro compared to age, sex matched controls. It is currently unclear whether the observed differences are due to a 'priming' effect by a second agent in vivo, or whether this is a primary difference in the neutrophils. We have studied the effects of interleukin-8, which is thought to be one of the major pro-inflammatory cytokines in chronic lung disease and granulocyte macrophage colony stimulating factor (GMCSF), in order to assess their effects on neutrophil chemotaxis and connective tissue degradation. In addition, we have assessed the effect of preincubation of these agents with neutrophils for 30 min followed by stimulation with F-Met-Leu-Phe (FMLP) to investigate any possible 'priming' effect that may be relevant to our clinical data. We report suppression of neutrophil chemotaxis to FMLP following incubation of the neutrophils with both IL-8 and GMCSF. However, we have observed an additive effect of IL-8 and FMLP for neutrophil degranulation leading to fibronectin degradation. The results suggest that IL-8 does not 'prime' neutrophils for subsequent FMLP stimulation as observed in vivo. Although the results for GMCSF were similar for the chemotactic response, the agent also had a synergistic effect on connective tissue degradation. However, it is concluded that neither agent could explain the enhanced neutrophil responses seen in our patients.

  15. Imaging experimental coronary artery thrombosis with indium-111 platelets

    International Nuclear Information System (INIS)

    Riba, A.L.; Thakur, M.L.; Gottschalk, A.; Zaret, B.L.

    1979-01-01

    The ability of cardiac scintigraphy with indium-111 ( 111 In)-labeled platelets to detect coronary artery thrombosis (CAT) was assessed in a canine model. Cardiac imaging and tissue distribution studies were performed shortly after administering 111 In-labeled platelets to 12 dogs (group 1) with acute CAT. Four dogs (group 2) with acute CAT were studied 2 and 22 hours after administering 111 In platelets. In addition, four dogs (group 3) with 24-hour-old CAT were similarly evaluated. In all group 1 animals, in vivo imaging 1 to 2 hours after 111 In platelet administration revealed intense uptake in the region of thrombus-containing left anterior descending arteries that was readily discernible from background blood pool activity. Sequential imaging of the four group 2 animals over a 22-hour period revealed no change in the scintigraphic pattern of the thrombosed arteries. In contrast, 111 In platelet imaging in the four group 3 animals with 24-hour-old CAT failed to reveal enhanced activity within the region of the thrombus-containing coronary artery. In the 12 group 1 animals, the CAT accumulated 69 +- 10 (mean +- SEM) times greater activity than present in blood and 651 +- 135 times greater activity than normal left ventricular myocardium. There was 24 +- 7 times greater 111 In activity in the damaged left anterior descending arteries compared with normal circumflex arteries. Similar uptake ratios were seen in group 2 animals. The 24-hour old thrombi from group 3 animals showed no enhanced 111 In uptake. This study demonstrates that experimental acute CAT can be detected readily with 111 In platelet cardiac scintigraphy

  16. Biomaterial associated impairment of local neutrophil function.

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    Kaplan, S S; Basford, R E; Kormos, R L; Hardesty, R L; Simmons, R L; Mora, E M; Cardona, M; Griffith, B L

    1990-01-01

    The effect of biomaterials on neutrophil function was studied in vitro to determine if these materials activated neutrophils and to determine the subsequent response of these neutrophils to further stimulation. Two biomaterials--polyurethane, a commonly used substance, and Velcro pile (used in the Jarvik 7 heart)--were evaluated. Two control substances, polyethylene and serum-coated polystyrene, were used for comparison. Neutrophil superoxide release was measured following incubation with these materials for 10, 30, and 120 min in the absence of additional stimulation and after stimulation with formylmethionylleucylphenylalanine (fMLP) or phorbol myristate acetate (PMA). The authors observed that the incubation of neutrophils on both polyurethane and Velcro resulted in substantially increased superoxide release that was greater after the 10 min than after the 30 or 120 min association. These activated neutrophils exhibited a poor additional response to fMLP but responded well to PMA. The effect of implantation of the Novacor left ventricular assist device on peripheral blood neutrophil function was also evaluated. The peripheral blood neutrophils exhibited normal superoxide release and chemotaxis. These studies suggest that biomaterials may have a profound local effect on neutrophils, which may predispose the patient to periprosthetic infection, but that the reactivity of circulating neutrophils is unimpaired.

  17. Neutrophils Compromise Retinal Pigment Epithelial Barrier Integrity

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    Jiehao Zhou

    2010-01-01

    Full Text Available We hypothesized that neutrophils and their secreted factors mediate breakdown of the integrity of the outer blood-retina-barrier by degrading the apical tight junctions of the retinal pigment epithelium (RPE. The effect of activated neutrophils or neutrophil cell lysate on apparent permeability of bovine RPE-Choroid explants was evaluated by measuring [H] mannitol flux in a modified Ussing chamber. The expression of matrix metalloproteinase- (MMP- 9 in murine peritoneal neutrophils, and the effects of neutrophils on RPE tight-junction protein expression were assessed by confocal microscopy and western blot. Our results revealed that basolateral incubation of explants with neutrophils decreased occludin and ZO-1 expression at 1 and 3 hours and increased the permeability of bovine RPE-Choroid explants by >3-fold (P<.05. Similarly, basolateral incubation of explants with neutrophil lysate decreased ZO-1 expression at 1 and 3 hours (P<.05 and increased permeability of explants by 75%. Further, we found that neutrophils prominently express MMP-9 and that incubation of explants with neutrophils in the presence of anti-MMP-9 antibody inhibited the increase in permeability. These data suggest that neutrophil-derived MMP-9 may play an important role in disrupting the integrity of the outer blood-retina barrier.

  18. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are associated with chronic hepatitis B virus (HBV) infection.

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    Zhao, Zhidan; Liu, Jianhua; Wang, Jiaxin; Xie, Tinyan; Zhang, Qiuhuan; Feng, Sisi; Deng, Hui; Zhong, Baiyun

    2017-10-01

    This retrospective study aimed to investigate the associations between the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) and disease severity in patients with chronic HBV infection-related liver disease (CHB). Patients with CHB were retrospectively identified. Clinical data for 172 HBV-infected patients and 40 healthy controls were collected from the electronic patient medical record system database of our hospital. HBV-related-compensated-cirrhosis patients (HBV-CC patients) had a significantly lower mean PLR than did other patients (PHBV-related-decompensated-cirrhosis patients (HBV-DC patients) had a significantly higher mean NLR than did any other patients (PHBV DNA (r=0.264, PHBV DNA in both HBV-CC patients (r=-0.116, P=0.044) and HBV-DC patients (r=0.456, P=0.008). In HBV-Active-Carriers patients (HBV-AC patients), the PLR was positively correlated with serum HBeAg level (r=0.321, P=0.023). In HBV-DC patients, the NLR was positively correlated with serum HBeAg level (r=0.372, P=0.033). In the logistic regression prediction model, a predictive probability cutoff of 0.392 had the highest sensitivity and specificity (sensitivity, 91.2%; specificity, 84.0%) in distinguishing between HBV-CC and HBV-AC patients. A NLR cutoff value of 2.94 had the highest sensitivity and specificity (sensitivity, 81.8%; specificity, 88.2%) in distinguishing between HBV-DC and HBV-CC patients. The PLR and NLR partially reflect the amounts of serum HBV DNA and serum HBeAg levels circulating in CHB patients. The logistic regression model including the PLR and age most accurately distinguished between HBV-CC and HBV-AC patients. The NLR may be useful for follow-up in HBV-CC patients to predict disease progression. In summary, the PLR and NLR provided a supplementary means for effectively managing chronic HBV infection and disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Visceral leishmaniasis patients display altered composition and maturity of neutrophils as well as impaired neutrophil effector functions

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    Endalew Yizengaw

    2016-11-01

    Full Text Available Immunologically, active visceral leishmaniasis (VL is characterised by profound immunosuppression, severe systemic inflammatory responses and an impaired capacity to control parasite replication. Neutrophils are highly versatile cells, which play a crucial role in the induction as well as the resolution of inflammation, the control of pathogen replication and the regulation of immune responses. Neutrophil functions have been investigated in human cutaneous leishmaniasis, however, their role in human visceral leishmaniasis is poorly understood.In the present study we evaluated the activation status and effector functions of neutrophils in patients with active VL and after successful anti-leishmanial treatment. Our results show that neutrophils are highly activated and have degranulated; high levels of arginase, myeloperoxidase and elastase, all contained in neutrophils’ granules, were found in the plasma of VL patients. In addition, we show that a large proportion of these cells are immature. We also analysed effector functions of neutrophils that are essential for pathogen clearance and show that neutrophils have an impaired capacity to release neutrophil extracellular traps, produce reactive oxygen species and phagocytose bacterial particles, but not Leishmania parasites.Our results suggest that impaired effector functions, increased activation and immaturity of neutrophils play a key role in the pathogenesis of VL.

  20. Cytoplasmic lipid bodies of human neutrophilic leukocytes

    International Nuclear Information System (INIS)

    Weller, P.F.; Ackerman, S.J.; Nicholson-Weller, A.; Dvorak, A.M.

    1989-01-01

    The morphology and function of cytoplasmic lipid bodies in human neutrophils were evaluated. By transmission electron microscopy, neutrophil lipid bodies were cytoplasmic inclusions, usually several microns in diameter, that occasionally coalesced to attain a diameter up to 7 microM. Neutrophil lipid bodies were not enveloped by membrane but were often surrounded by a more electron-dense shell at their periphery. Normal peripheral blood neutrophils contained an average of approximately one lipid body per cell. Lipid bodies appeared in greater numbers in neutrophils from inflammatory lesions. Perturbation of neutrophils during conventional methods of cell isolation and purification modestly increased lipid body numbers in neutrophils, whereas incubation of neutrophils with 1 microM oleic acid rapidly induced lipid body formation over 30 to 60 minutes. After granulocytes were incubated for 2 hours with 3H-fatty acids, including arachidonic, oleic, and palmitic acids, electron microscopic autoradiography demonstrated that lipid bodies represented the predominant intracellular sites of localization of each of the three 3H-fatty acids. There was lesser labeling noted in the perinuclear cisterna, but not in cell membranes. Virtually all of each of the three 3H-fatty acids incorporated by the neutrophils were esterified into chromatographically resolved classes of neutral lipids or phospholipids. These findings indicate that cytoplasmic lipid bodies are more prominent in neutrophils in vivo engaged in inflammatory responses and that these organelles in human neutrophils function as sites of deposition of esterified, incorporated fatty acids

  1. Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major.

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    Ricci-Azevedo, Rafael; Oliveira, Aline Ferreira; Conrado, Marina C A V; Carvalho, Fernanda Caroline; Roque-Barreira, Maria Cristina

    2016-04-01

    ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an

  2. Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major.

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    Rafael Ricci-Azevedo

    2016-04-01

    Full Text Available ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1 immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS, form neutrophil extracellular traps (NETs and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF and interleukin-1beta (IL-1β release; otherwise, transforming growth factor-beta (TGF-β production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be

  3. Functional display of platelet-binding VWF fragments on filamentous bacteriophage.

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    Andrew Yee

    Full Text Available von Willebrand factor (VWF tethers platelets to sites of vascular injury via interaction with the platelet surface receptor, GPIb. To further define the VWF sequences required for VWF-platelet interaction, a phage library displaying random VWF protein fragments was screened against formalin-fixed platelets. After 3 rounds of affinity selection, DNA sequencing of platelet-bound clones identified VWF peptides mapping exclusively to the A1 domain. Aligning these sequences defined a minimal, overlapping segment spanning P1254-A1461, which encompasses the C1272-C1458 cystine loop. Analysis of phage carrying a mutated A1 segment (C1272/1458A confirmed the requirement of the cystine loop for optimal binding. Four rounds of affinity maturation of a randomly mutagenized A1 phage library identified 10 and 14 unique mutants associated with enhanced platelet binding in the presence and absence of botrocetin, respectively, with 2 mutants (S1370G and I1372V common to both conditions. These results demonstrate the utility of filamentous phage for studying VWF protein structure-function and identify a minimal, contiguous peptide that bind to formalin-fixed platelets, confirming the importance of the VWF A1 domain with no evidence for another independently platelet-binding segment within VWF. These findings also point to key structural elements within the A1 domain that regulate VWF-platelet adhesion.

  4. Elevated platelet count as predictor of recurrence in rectal cancer patients undergoing preoperative chemoradiotherapy followed by surgery.

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    Toiyama, Yuji; Inoue, Yasuhiro; Kawamura, Mikio; Kawamoto, Aya; Okugawa, Yoshinaga; Hiro, Jyunichiro; Saigusa, Susumu; Tanaka, Koji; Mohri, Yasuhiko; Kusunoki, Masato

    2015-02-01

    The impact of systemic inflammatory response (SIR) on prognostic and predictive outcome in rectal cancer after neoadjuvant chemoradiotherapy (CRT) has not been fully investigated. This retrospective study enrolled 89 patients with locally advanced rectal cancer who underwent neoadjuvant CRT and for whom platelet (PLT) counts and SIR status [neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR)] were available. Both clinical values of PLT and SIR status in rectal cancer patients were investigated. Elevated PLT, NLR, PLR, and pathologic TNM stage III [ypN(+)] were associated with significantly poor overall survival (OS). Elevated PLT, NLR, and ypN(+) were shown to independently predict OS. Elevated PLT and ypN(+) significantly predicted poor disease-free survival (DFS). Elevated PLT was identified as the only independent predictor of DFS. PLT counts are a promising pre-CRT biomarker for predicting recurrence and poor prognosis in rectal cancer.

  5. [Platelet function in acute myeloid leukemia. II. Aggregation of isolated platelets].

    Science.gov (United States)

    Zawilska, K; Komarnicki, M; Mańka, B

    1978-01-01

    In 22 patients with acute myeloid leukaemia (17 cases of myeloblastic leukaemia, 4 cases of myelomonocytic leukaemia and 1 case of undifferentiated-cell leukaemia) platelets were isolated from the plasma by the method of Nicholls and Hampton as modified by Levy-Toledano by centrifugation in albumin gradient. The aim of platelet isolation was their "concentration" in cases of thrombocytopenia to values making possible aggregation tests, and platelet separation from the influence of plasma factors. Then aggregation of isolated platelets caused by ADP was studied. In 16 out of 22 patients a fall of aggregation was observed, with the mean values of aggregation rate and intensity were significantly lower. Parallelly done determinations of aggregating activity released from the platelets by thrombin showed lower values as compared with platelets from healthy subjects. In might be thought, in this connection, that the demonstrated reduction of isolated platelets is associated with a diminution of the nucleotide pool or disturbances of the platelet release reaction. The disturbances of the platelet release reaction. The disturbances of aggregation of isolated platelets and reduction of the aggregating activity were most pronounced in acute myelomonocytic leukaemia.

  6. Leukotriene B4-Neutrophil Elastase Axis Drives Neutrophil Reverse Transendothelial Cell Migration In Vivo.

    Science.gov (United States)

    Colom, Bartomeu; Bodkin, Jennifer V; Beyrau, Martina; Woodfin, Abigail; Ody, Christiane; Rourke, Claire; Chavakis, Triantafyllos; Brohi, Karim; Imhof, Beat A; Nourshargh, Sussan

    2015-06-16

    Breaching endothelial cells (ECs) is a decisive step in the migration of leukocytes from the vascular lumen to the extravascular tissue, but fundamental aspects of this response remain largely unknown. We have previously shown that neutrophils can exhibit abluminal-to-luminal migration through EC junctions within mouse cremasteric venules and that this response is elicited following reduced expression and/or functionality of the EC junctional adhesion molecule-C (JAM-C). Here we demonstrate that the lipid chemoattractant leukotriene B4 (LTB4) was efficacious at causing loss of venular JAM-C and promoting neutrophil reverse transendothelial cell migration (rTEM) in vivo. Local proteolytic cleavage of EC JAM-C by neutrophil elastase (NE) drove this cascade of events as supported by presentation of NE to JAM-C via the neutrophil adhesion molecule Mac-1. The results identify local LTB4-NE axis as a promoter of neutrophil rTEM and provide evidence that this pathway can propagate a local sterile inflammatory response to become systemic. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Neutrophil Protease Cleavage of Von Willebrand Factor in Glomeruli – An Anti-thrombotic Mechanism in the Kidney

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    Ramesh Tati

    2017-02-01

    Full Text Available Adequate cleavage of von Willebrand factor (VWF prevents formation of thrombi. ADAMTS13 is the main VWF-cleaving protease and its deficiency results in development of thrombotic microangiopathy. Besides ADAMTS13 other proteases may also possess VWF-cleaving activity, but their physiological importance in preventing thrombus formation is unknown. This study investigated if, and which, proteases could cleave VWF in the glomerulus. The content of the glomerular basement membrane (GBM was studied as a reflection of processes occurring in the subendothelial glomerular space. VWF was incubated with human GBMs and VWF cleavage was assessed by multimer structure analysis, immunoblotting and mass spectrometry. VWF was cleaved into the smallest multimers by the GBM, which contained ADAMTS13 as well as neutrophil proteases, elastase, proteinase 3 (PR3, cathepsin-G and matrix-metalloproteinase 9. The most potent components of the GBM capable of VWF cleavage were in the serine protease or metalloprotease category, but not ADAMTS13. Neutralization of neutrophil serine proteases inhibited GBM-mediated VWF-cleaving activity, demonstrating a marked contribution of elastase and/or PR3. VWF-platelet strings formed on the surface of primary glomerular endothelial cells, in a perfusion system, were cleaved by both elastase and the GBM, a process blocked by elastase inhibitor. Ultramorphological studies of the human kidney demonstrated neutrophils releasing elastase into the GBM. Neutrophil proteases may contribute to VWF cleavage within the subendothelium, adjacent to the GBM, and thus regulate thrombus size. This anti-thrombotic mechanism would protect the normal kidney during inflammation and could also explain why most patients with ADAMTS13 deficiency do not develop severe kidney failure.

  8. A Nuclease from Streptococcus mutans Facilitates Biofilm Dispersal and Escape from Killing by Neutrophil Extracellular Traps.

    Science.gov (United States)

    Liu, Jia; Sun, Luping; Liu, Wei; Guo, Lihong; Liu, Zhaohui; Wei, Xi; Ling, Junqi

    2017-01-01

    Streptococcus mutans is the primary etiologic agent of dental caries and occasionally infective endocarditis, with the ability to form biofilms and disperse cells into distal sites to exacerbate and spread infection. In this study, we identified a nuclease (DeoC) as a S. mutans biofilm dispersal modulating factor through microarray analysis. In vitro assays revealed a dispersal defect of a deoC deletion mutant, and functional studies with purified protein were indicative of the biofilm dispersal activity of DeoC. Neutrophils are a key host response factor restraining bacterial spreading through the formation of neutrophil extracellular traps (NETs), which consist of a nuclear DNA backbone associated with antimicrobial peptides. Therefore, we hypothesized that the dispersed S. mutans might utilize DeoC to degrade NETs and escape killing by the immune system. It was found that S. mutans induced NET formation upon contact with neutrophils, while the presence of NETs in turn enhanced the deoC expression of S. mutans . Fluorescence microscopy inspection showed that deoC deletion resulted in a decreased NET degradation ability of S. mutans and enhanced susceptibility to neutrophil killing. Data obtained from this study assigned two important roles for DeoC in S. mutans : contributing to the spread of infection through mediating biofilm dispersal, and facilitating the escape of S. mutans from neutrophil killing through NET degradation.

  9. Tamoxifen induces apoptotic neutrophil efferocytosis in horses.

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    Olave, C; Morales, N; Uberti, B; Henriquez, C; Sarmiento, J; Ortloff, A; Folch, H; Moran, G

    2018-03-01

    Macrophages and neutrophils are important cellular components in the process of acute inflammation and its subsequent resolution, and evidence increasingly suggests that they play important functions during the resolution of chronic, adaptive inflammatory processes. Exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to describe if TX induces in vitro efferocytosis of neutrophils by alveolar macrophages. Efferocytosis assay, myeloperoxidase (MPO) detection and translocation phosphatidylserine (PS) were performed on neutrophils isolated from peripheral blood samples from five healthy horses. In in vitro samples from heathy horses, TX treatment increases the phenomenon of efferocytosis of peripheral neutrophils by alveolar macrophages. Similar increases in supernatant MPO concentration and PS translocation were observed in TX-treated neutrophils, compared to control cells. In conclusion, these results confirm that tamoxifen has a direct effect on equine peripheral blood neutrophils, through stimulation of the engulfment of apoptotic neutrophils by alveolar macrophages.

  10. PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Vlasova, Irina I., E-mail: irina.vlasova@yahoo.com [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Vakhrusheva, Tatyana V. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Sokolov, Alexey V.; Kostevich, Valeria A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Research Institute for Experimental Medicine, Russian Academy of Medical Science, Saint Petersburg (Russian Federation); Gusev, Alexandr A.; Gusev, Sergey A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Melnikova, Viktoriya I. [Institute of Developmental Biology, Russian Academy of Science, Moscow (Russian Federation); Lobach, Anatolii S. [Institute of Problems of Chemical Physics, Russian Academy of Science, Chernogolovka (Russian Federation)

    2012-10-01

    Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H{sub 2}O{sub 2} system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes. -- Highlights: ► Myeloperoxidase (MPO) product hypochlorous acid is able to degrade CNTs. ► PEGylated SWCNTs stimulate isolated neutrophils to produce hypochlorous acid. ► SWCNTs are capable of activating neutrophils in blood samples. ► Activation of

  11. Mitochondria in neutrophil apoptosis

    NARCIS (Netherlands)

    van Raam, B. J.; Verhoeven, A. J.; Kuijpers, T. W.

    2006-01-01

    Central in the regulation of the short life span of neutrophils are their mitochondria. These organelles hardly contribute to the energy status of neutrophils but play a vital role in the apoptotic process. Not only do the mitochondria contain cytotoxic proteins that are released during apoptosis

  12. Neutrophil Responses to Sterile Implant Materials.

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    Siddharth Jhunjhunwala

    Full Text Available In vivo implantation of sterile materials and devices results in a foreign body immune response leading to fibrosis of implanted material. Neutrophils, one of the first immune cells to be recruited to implantation sites, have been suggested to contribute to the establishment of the inflammatory microenvironment that initiates the fibrotic response. However, the precise numbers and roles of neutrophils in response to implanted devices remains unclear. Using a mouse model of peritoneal microcapsule implantation, we show 30-500 fold increased neutrophil presence in the peritoneal exudates in response to implants. We demonstrate that these neutrophils secrete increased amounts of a variety of inflammatory cytokines and chemokines. Further, we observe that they participate in the foreign body response through the formation of neutrophil extracellular traps (NETs on implant surfaces. Our results provide new insight into neutrophil function during a foreign body response to peritoneal implants which has implications for the development of biologically compatible medical devices.

  13. Neutrophil migration under normal and sepsis conditions.

    Science.gov (United States)

    Lerman, Yelena V; Kim, Minsoo

    2015-01-01

    Neutrophil migration is critical for pathogen clearance and host survival during severe sepsis. Interaction of neutrophil adhesion receptors with ligands on endothelial cells results in firm adhesion of the circulating neutrophils, followed by neutrophil activation and directed migration to sites of infection through the basement membrane and interstitial extracellular matrix. Proteolytic enzymes and reactive oxygen species are produced and released by neutrophils in response to a variety of inflammatory stimuli. Although these mediators are important for host defense, they also promote tissue damage. Excessive neutrophil migration during the early stages of sepsis may lead to an exaggerated inflammatory response with associated tissue damage and subsequent organ dysfunction. On the other hand, dysregulation of migration and insufficient migratory response that occurs during the latter stages of severe sepsis contributes to neutrophils' inability to contain and control infection and impaired wound healing. This review discusses the major steps and associated molecules involved in the balance of neutrophil trafficking, the precise regulation of which during sepsis spells life or death for the host.

  14. A Preliminary Evaluation of Lyophilized Gelatin Sponges, Enhanced with Platelet-Rich Plasma, Hydroxyapatite and Chitin Whiskers for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Andrew J. Spence

    2013-04-01

    Full Text Available The purpose of this study was to perform a number of preliminary in vitro evaluations on an array of modified gelatin gel sponge scaffolds for use in a bone graft application. The gelatin gels were modified through the addition of a number of components which each possess unique properties conducive to the creation and regeneration of bone: a preparation rich in growth factors (PRGF, a bioactive, lyophilized form of platelet-rich plasma, hydroxyapatite, and chitin whiskers. Platelet-rich plasma therapy is an emerging practice that has proven effective in a number of clinical applications, including enhancing bone repair through improved deposition of new bony matrix and angiogenesis. As such, the inclusion of PRGF in our gelatin scaffolds was intended to significantly enhance scaffold bioactivity, while the addition of hydroxyapatite and chitin whiskers were anticipated to increase scaffold strength. Additionally, the gelatin sponges, which readily dissolve in aqueous solutions, were subjected to 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC cross-linking, either during or post-gelation, to control their rate of degradation. Scaffolds were evaluated in vitro with respect to compressive strength, mass loss/degradation, protein release, and cellular interaction, with results demonstrating the potential of the gelatin gel sponge scaffold for use in the regeneration of bone.

  15. A Preliminary Evaluation of Lyophilized Gelatin Sponges, Enhanced with Platelet-Rich Plasma, Hydroxyapatite and Chitin Whiskers for Bone Regeneration

    Science.gov (United States)

    Rodriguez, Isaac A.; Sell, Scott A.; McCool, Jennifer M.; Saxena, Gunjan; Spence, Andrew J.; Bowlin, Gary L.

    2013-01-01

    The purpose of this study was to perform a number of preliminary in vitro evaluations on an array of modified gelatin gel sponge scaffolds for use in a bone graft application. The gelatin gels were modified through the addition of a number of components which each possess unique properties conducive to the creation and regeneration of bone: a preparation rich in growth factors (PRGF, a bioactive, lyophilized form of platelet-rich plasma), hydroxyapatite, and chitin whiskers. Platelet-rich plasma therapy is an emerging practice that has proven effective in a number of clinical applications, including enhancing bone repair through improved deposition of new bony matrix and angiogenesis. As such, the inclusion of PRGF in our gelatin scaffolds was intended to significantly enhance scaffold bioactivity, while the addition of hydroxyapatite and chitin whiskers were anticipated to increase scaffold strength. Additionally, the gelatin sponges, which readily dissolve in aqueous solutions, were subjected to 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) cross-linking, either during or post-gelation, to control their rate of degradation. Scaffolds were evaluated in vitro with respect to compressive strength, mass loss/degradation, protein release, and cellular interaction, with results demonstrating the potential of the gelatin gel sponge scaffold for use in the regeneration of bone. PMID:24709699

  16. Platelet activation during preparation of platelet concentrates: a comparison of the platelet-rich plasma and the buffy coat methods

    NARCIS (Netherlands)

    Fijnheer, R.; Pietersz, R. N.; de Korte, D.; Gouwerok, C. W.; Dekker, W. J.; Reesink, H. W.; Roos, D.

    1990-01-01

    The activation of platelets during the preparation of platelet concentrates (PCs) by two methods was compared. To eliminate interdonor differences, 2 units of whole blood were pooled and subsequently divided into two batches. From one batch, the platelets were harvested as pelleted platelets from

  17. Sphingosine 1-phosphate induces neutrophil chemoattractant IL-8: repression by steroids.

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    Md Mostafizur Rahman

    Full Text Available The bioactive sphingolipid sphingosine 1-phosphate (S1P is found in increased amounts in the airways of asthmatics. S1P can regulate airway smooth muscle functions associated with asthmatic inflammation and remodeling, including cytokine secretion. To date however, whether S1P induces secretion of an important chemokine responsible for neutrophilia in airway inflammation--IL-8--was unexplored. The aim of this study was to investigate whether S1P induces IL-8 gene expression and secretion to enhance neutrophil chemotaxis in vitro, as well as examine the molecular mechanisms responsible for repression by the corticosteroid dexamethasone. We show that S1P upregulates IL-8 secretion from ASM cells and enhance neutrophil chemotaxis in vitro. The corticosteroid dexamethasone significantly represses IL-8 mRNA expression and protein secretion in a concentration- and time-dependent manner. Additionally, we reveal that S1P-induced IL-8 secretion is p38 MAPK and ERK-dependent and that these key phosphoproteins act on the downstream effector mitogen- and stress-activated kinase 1 (MSK1 to control secretion of the neutrophil chemoattractant cytokine IL-8. The functional relevance of this in vitro data was demonstrated by neutrophil chemotaxis assays where S1P-induced effects can be significantly attenuated by pretreatment with dexamethasone, pharmacological inhibition of p38 MAPK- or ERK-mediated pathways, or by knocking down MSK-1 with siRNA. Taken together, our study reveals the molecular pathways responsible for IL-8 secretion from ASM cells in response to S1P and indicates ways in which the impact on IL-8-driven neutrophilia may be lessened.

  18. Overview of platelet physiology and laboratory evaluation of platelet function.

    Science.gov (United States)

    Rodgers, G M

    1999-06-01

    Appropriate laboratory testing for the platelet-type bleeding disorders hinges on an adequate assessment in the history and physical examination. Patients with histories and screening laboratory results consistent with coagulation disorders (hemophilia, disseminated intravascular coagulation) are not appropriate candidates for platelet function testing. In contrast, patients with a lifelong history of platelet-type bleeding symptoms and perhaps a positive family history of bleeding would be appropriate for testing. Figure 6 depicts one strategy to evaluate these patients. Platelet morphology can easily be evaluated to screen for two uncommon qualitative platelet disorders: Bernard-Soulier syndrome (associated with giant platelets) and gray platelet syndrome, a subtype of storage pool disorder in which platelet granulation is morphologically abnormal by light microscopy. If the bleeding disorder occurred later in life (no bleeding with surgery or trauma early in life), the focus should be on acquired disorders of platelet function. For those patients thought to have an inherited disorder, testing for vWD should be done initially because approximately 1% of the population has vWD. The complete vWD panel (factor VIII coagulant activity, vWf antigen, ristocetin cofactor activity) should be performed because many patients will have abnormalities of only one particular panel component. Patients diagnosed with vWD should be classified using multimeric analysis to identify the type 1 vWD patients likely to respond to DDAVP. If vWD studies are normal, platelet aggregation testing should be performed, ensuring that no antiplatelet medications have been ingested at least 1 week before testing. If platelet aggregation tests are normal and if suspicion for an inherited disorder remains high, vWD testing should be repeated. The evaluation of thrombocytopenia may require bone marrow examination to exclude primary hematologic disorders. If future studies with thrombopoietin assays

  19. Platelet antibodies of the IgM class in immune thrombocytopenic purpura

    International Nuclear Information System (INIS)

    Cines, D.B.; Wilson, S.B.; Tomaski, A.; Schreiber, A.D.

    1985-01-01

    The clinical course and response to therapy of patients with immune thrombocytopenic purpura (ITP) are not completely determined by the level of IgG present on the platelet surface. It is possible that antibodies of other immunoglobulin classes also play a role in platelet destruction in some of these patients. Therefore, the authors studied 175 patients with ITP for the presence of IgM anti-platelet antibodies using radiolabeled polyclonal or monoclonal anti-IgM. They observed that 57% of patients with clinical ITP had increased levels of IgM on their platelets, compared with normal controls and patients with thrombocytopenia who did not have ITP. They obtained similar results using either radiolabeled polyclonal or monoclonal anti-IgM, reagents whose integrity was first characterized using erythrocytes coated with defined amounts of IgM antibody. Among patients with increased platelet-IgM there was a significant correlation both with the presence of increased platelet-C3 as well as the amount of platelet-C3. The authors demonstrated the presence of warm-reacting IgM anti-platelet antibodies in the plasma of two of these patients who were further studied. These studies demonstrate the presence of warm-reacting IgM anti-platelet antibodies in some patients with ITP. They suggest that the binding of complement to platelets by IgM antibodies may initiate platelet clearance as well as enhance the effect of IgG antibodies in ITP

  20. Genetic analysis of the role of protein kinase Ctheta in platelet function and thrombus formation.

    Directory of Open Access Journals (Sweden)

    Kellie J Hall

    2008-09-01

    Full Text Available PKCtheta is a novel protein kinase C isozyme, predominately expressed in T cells and platelets. PKCtheta(-/- T cells exhibit reduced activation and PKCtheta(-/- mice are resistant to autoimmune disease, making PKCtheta an attractive therapeutic target for immune modulation. Collagen is a major agonist for platelets, operating through an immunoreceptor-like signalling pathway from its receptor GPVI. Although it has recently been shown that PKCtheta positively regulates outside-in signalling through integrin alpha(IIbbeta(3 in platelets, the role of PKCtheta in GPVI-dependent signalling and functional activation of platelets has not been assessed.In the present study we assessed static adhesion, cell spreading, granule secretion, integrin alpha(IIbbeta(3 activation and platelet aggregation in washed mouse platelets lacking PKCtheta. Thrombus formation on a collagen-coated surface was assessed in vitro under flow. PKCtheta(-/- platelets exhibited reduced static adhesion and filopodia generation on fibrinogen, suggesting that PKCtheta positively regulates outside-in signalling, in agreement with a previous report. In contrast, PKCtheta(-/- platelets also exhibited markedly enhanced GPVI-dependent alpha-granule secretion, although dense granule secretion was unaffected, suggesting that PKCtheta differentially regulates these two granules. Inside-out regulation of alpha(IIbbeta(3 activation was also enhanced downstream of GPVI stimulation. Although this did not result in increased aggregation, importantly thrombus formation on collagen under high shear (1000 s(-1 was enhanced.These data suggest that PKCtheta is an important negative regulator of thrombus formation on collagen, potentially mediated by alpha-granule secretion and alpha(IIbbeta(3 activation. PKCtheta therefore may act to restrict thrombus growth, a finding that has important implications for the development and safe clinical use of PKCtheta inhibitors.

  1. Differences in levels of platelet-derived microparticles in platelet components prepared using the platelet rich plasma, buffy coat, and apheresis procedures.

    Science.gov (United States)

    Noulsri, Egarit; Udomwinijsilp, Prapaporn; Lerdwana, Surada; Chongkolwatana, Viroje; Permpikul, Parichart

    2017-04-01

    There has been an increased interest in platelet-derived microparticles (PMPs) in transfusion medicine. Little is known about PMP status during the preparation of platelet concentrates for transfusion. The aim of this study is to compare the PMP levels in platelet components prepared using the buffy coat (BC), platelet-rich plasma platelet concentrate (PRP-PC), and apheresis (AP) processes. Platelet components were prepared using the PRP-PC and BC processes. Apheresis platelets were prepared using the Trima Accel and Amicus instruments. The samples were incubated with annexin A5-FITC, CD41-PE, and CD62P-APC. At day 1 after processing, the PMPs and activated platelets were determined using flow cytometry. Both the percentage and number of PMPs were higher in platelet components prepared using the Amicus instrument (2.6±1.8, 32802±19036 particles/μL) than in platelet components prepared using the Trima Accel instrument (0.5±0.4, 7568±5298 particles/μL), BC (1.2±0.6, 12,920±6426 particles/μL), and PRP-PC (0.9±0.6, 10731±5514 particles/μL). Both the percentage and number of activated platelets were higher in platelet components prepared using the Amicus instrument (33.2±13.9, 427553±196965 cells/μL) than in platelet components prepared using the Trima Accel instrument (16.2±6.1, 211209±87706 cells/μL), BC (12.9±3.2, 140624±41003 cells/μL), and PRP-PC (21.1±6.3, 265210±86257 cells/μL). The study suggests high variability of PMPs and activated platelets in platelet components prepared using different processes. This result may be important in validating the instruments involved in platelet blood collection and processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. ICAM-1-expressing neutrophils exhibit enhanced effector functions in murine models of endotoxemia

    NARCIS (Netherlands)

    Woodfin, Abigail; Beyrau, Martina; Voisin, Mathieu-Benoit; Ma, Bin; Whiteford, James R.; Hordijk, Peter L.; Hogg, Nancy; Nourshargh, Sussan

    2016-01-01

    Intracellular adhesion molecule-1 (ICAM-1) is a transmembrane glycoprotein expressed on the cell surface of numerous cell types such as endothelial and epithelial cells, vascular smooth muscle cells, and certain leukocyte subsets. With respect to the latter, ICAM-1 has been detected on neutrophils

  3. Chronic Prosopis Glandulosa Treatment Blunts Neutrophil Infiltration and Enhances Muscle Repair after Contusion Injury

    Directory of Open Access Journals (Sweden)

    Cindy George

    2015-01-01

    Full Text Available The current treatment options for soft tissue injuries remain suboptimal and often result in delayed/incomplete recovery of damaged muscle. The current study aimed to evaluate the effects of oral Prosopis glandulosa treatment on inflammation and regeneration in skeletal muscle after contusion injury, in comparison to a conventional treatment. The gastrocnemius muscle of rats was subjected to mass-drop injury and muscle samples collected after 1-, 3 h, 1- and 7 days post-injury. Rats were treated with P. glandulosa (100 mg/kg/day either for 8 weeks prior to injury (up until day 7 post-injury, only post-injury, or with topically applied diclofenac post-injury (0.57 mg/kg. Neutrophil (His48-positive and macrophage (F4/80-positive infiltration was assessed by means of immunohistochemistry. Indicators of muscle satellite cell proliferation (ADAM12 and regeneration (desmin were used to evaluate muscle repair. Chronic P. glandulosa and diclofenac treatment (p < 0.0001 was associated with suppression of the neutrophil response to contusion injury, however only chronic P. glandulosa treatment facilitated more effective muscle recovery (increased ADAM12 (p < 0.05 and desmin (p < 0.001 expression, while diclofenac treatment had inhibitory effects on repair, despite effective inhibition of neutrophil response. Data indicates that P. glandulosa treatment results in more effective muscle repair after contusion.

  4. Targeting Neutrophilic Inflammation Using Polymersome-Mediated Cellular Delivery.

    Science.gov (United States)

    Robertson, James D; Ward, Jon R; Avila-Olias, Milagros; Battaglia, Giuseppe; Renshaw, Stephen A

    2017-05-01

    Neutrophils are key effector cells in inflammation and play an important role in neutralizing invading pathogens. During inflammation resolution, neutrophils undergo apoptosis before they are removed by macrophages, but if apoptosis is delayed, neutrophils can cause extensive tissue damage and chronic disease. Promotion of neutrophil apoptosis is a potential therapeutic approach for treating persistent inflammation, yet neutrophils have proven difficult cells to manipulate experimentally. In this study, we deliver therapeutic compounds to neutrophils using biocompatible, nanometer-sized synthetic vesicles, or polymersomes, which are internalized by binding to scavenger receptors and subsequently escape the early endosome through a pH-triggered disassembly mechanism. This allows polymersomes to deliver molecules into the cell cytosol of neutrophils without causing cellular activation. After optimizing polymersome size, we show that polymersomes can deliver the cyclin-dependent kinase inhibitor (R)-roscovitine into human neutrophils to promote apoptosis in vitro. Finally, using a transgenic zebrafish model, we show that encapsulated (R)-roscovitine can speed up inflammation resolution in vivo more efficiently than the free drug. These results show that polymersomes are effective intracellular carriers for drug delivery into neutrophils. This has important consequences for the study of neutrophil biology and the development of neutrophil-targeted therapeutics. Copyright © 2017 The Authors.

  5. Neutrophil Reverse Migration Becomes Transparent with Zebrafish

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    Taylor W. Starnes

    2012-01-01

    Full Text Available The precise control of neutrophil-mediated inflammation is critical for both host defense and the prevention of immunopathology. In vivo imaging studies in zebrafish, and more recently in mice, have made the novel observation that neutrophils leave a site of inflammation through a process called neutrophil reverse migration. The application of advanced imaging techniques to the genetically tractable, optically transparent zebrafish larvae was critical for these advances. Still, the mechanisms underlying neutrophil reverse migration and its effects on the resolution or priming of immune responses remain unclear. Here, we review the current knowledge of neutrophil reverse migration, its potential roles in host immunity, and the live imaging tools that make zebrafish a valuable model for increasing our knowledge of neutrophil behavior in vivo.

  6. Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Novel Markers for Diagnosis of Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-analysis

    Directory of Open Access Journals (Sweden)

    Mohammad Amin Bahrami

    2016-04-01

    Full Text Available Background: Sudden sensorineural hearing loss (SSNHL is a common otologic disease characterized by a loss of hearing greater than 30 dB in three consecutive frequen­cies which occurs in less than 72 hours. Objective: To investigate the role of neutrophil-to-lymphocyte ratio (NLR and platelet-to-lymphocyte ratio (PLR on sudden sensorineural hearing loss (SSNHL. Search strategy: A PubMed, Science Direct, Scopus, OVID, EMBASE and Google Scholar search (date last searched April 2016 without any time, language and location restriction was done. Inclusion criteria: All case-control studies, which have been investigated the relationship of NLR and PLR with the occurrence of SSNHL were included in our meta-analysis. Results: A total of 5 case-control studies were included in the study. All 5 studies have been reported NLR of patients and control groups (611 patients and 804 controls. Our analysis showed that the mean NLR of patients is 1.12 (0.82-1.43 unit higher than that of controls with 95% CI which is statistically significant. Also, 3 studies have been reported PLR of patients and control groups (512 patients and 705 controls. Our analysis showed that the mean PLR of patients is 0.57 (0.08-1.05 unit higher than that of controls with 95% CI which is statistically significant too. Conclusions: This meta-analysis confirmed the relationship of NLR and PLR with SSNHL. Therefore, these parameters can be considered as new markers in diagnosis of SSNHL. 

  7. Enhancement of the repair of dog alveolar cleft by an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture.

    Science.gov (United States)

    Yuanzheng, Chen; Yan, Gao; Ting, Li; Yanjie, Fu; Peng, Wu; Nan, Bai

    2015-05-01

    Autologous bone graft has been regarded as the criterion standard for the repair of alveolar cleft. However, the most prominent issue in alveolar cleft treatment is the high absorption rate of the bone graft. The authors' objective was to investigate the effects of an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture on the repair of dog alveolar cleft. Twenty beagle dogs with unilateral alveolar clefts created by surgery were divided randomly into four groups: group A underwent repair with an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture; group B underwent repair with autologous iliac bone and bone marrow-derived mesenchymal stem cells; group C underwent repair with autologous iliac bone and platelet-rich fibrin; and group D underwent repair with autologous iliac bone as the control. One day and 6 months after transplantation, the transplant volumes and bone mineral density were assessed by quantitative computed tomography. All of the transplants were harvested for hematoxylin and eosin staining 6 months later. Bone marrow-derived mesenchymal stem cells and platelet-rich fibrin transplants formed the greatest amounts of new bone among the four groups. The new bone formed an extensive union with the underlying maxilla in groups A, B, and C. Transplants with the bone marrow-derived mesenchymal stem cells, platelet-rich fibrin, and their mixture retained the majority of their initial volume, whereas the transplants in the control group showed the highest absorption rate. Bone mineral density of transplants with the bone marrow-derived mesenchymal stem cells, platelet-rich fibrin, and their mixture 6 months later was significantly higher than in the control group (p platelet-rich fibrin mixed transplants. Hematoxylin and eosin staining showed that the structure of new bones formed the best in group A. Both bone marrow-derived mesenchymal stem cells and platelet

  8. Cortactin deficiency is associated with reduced neutrophil recruitment but increased vascular permeability in vivo.

    Science.gov (United States)

    Schnoor, Michael; Lai, Frank P L; Zarbock, Alexander; Kläver, Ruth; Polaschegg, Christian; Schulte, Dörte; Weich, Herbert A; Oelkers, J Margit; Rottner, Klemens; Vestweber, Dietmar

    2011-08-01

    Neutrophil extravasation and the regulation of vascular permeability require dynamic actin rearrangements in the endothelium. In this study, we analyzed in vivo whether these processes require the function of the actin nucleation-promoting factor cortactin. Basal vascular permeability for high molecular weight substances was enhanced in cortactin-deficient mice. Despite this leakiness, neutrophil extravasation in the tumor necrosis factor-stimulated cremaster was inhibited by the loss of cortactin. The permeability defect was caused by reduced levels of activated Rap1 (Ras-related protein 1) in endothelial cells and could be rescued by activating Rap1 via the guanosine triphosphatase (GTPase) exchange factor EPAC (exchange protein directly activated by cAMP). The defect in neutrophil extravasation was caused by enhanced rolling velocity and reduced adhesion in postcapillary venules. Impaired rolling interactions were linked to contributions of β(2)-integrin ligands, and firm adhesion was compromised by reduced ICAM-1 (intercellular adhesion molecule 1) clustering around neutrophils. A signaling process known to be critical for the formation of ICAM-1-enriched contact areas and for transendothelial migration, the ICAM-1-mediated activation of the GTPase RhoG was blocked in cortactin-deficient endothelial cells. Our results represent the first physiological evidence that cortactin is crucial for orchestrating the molecular events leading to proper endothelial barrier function and leukocyte recruitment in vivo.

  9. Postoperative neutrophil-to-lymphocyte ratio of living-donor liver transplant: Association with graft size

    Directory of Open Access Journals (Sweden)

    Hironori Hayashi

    2016-04-01

    Full Text Available Issues related to small-for-size grafts in living donor liver transplantation (LDLT are highly important. The neutrophil lymphocyte ratio (NLR has been reported to be an inexpensive index of systemic inflammation for various diseases. We retrospectively evaluated the relationship between NLR and clinical course of 61 adult LDLT recipients in our institute until post-operative day 14. Patients were classified into two groups based on the graft volume divided by standard liver volume, as over 35% of graft volume divided by standard liver volume (GV/SLV (Group L; n = 55 and under 35% of GV/SLV (Group S; n = 6. No differences were seen in background of the patients between the two groups. Also, absolute neutrophil, lymphocyte and platelet counts in both the groups showed no significant differences. In contrast, the NLR between the groups differed significantly from post-operative day 3 to 10, being higher in the Group S. In addition, the incidence of prolonged hyperbilirubinemia and small for size graft syndrome differed significantly between the two groups. Therefore, the elevation of post-operative NLR in the smaller graft group reflect suggestive pathophysiology of endothelial injuries that related to small for size graft syndrome in LDLT.

  10. Comparative evaluation of platelet count and antimicrobial efficacy of injectable platelet-rich fibrin with other platelet concentrates: An in vitro study

    Directory of Open Access Journals (Sweden)

    Prerna Ashok Karde

    2017-01-01

    Full Text Available Background: Platelet concentrates are used in various medical procedures to promote soft- and hard-tissue regeneration. In recent times, their antimicrobial efficacy is also explored. However, various platelet concentrates have evolved which differ in the centrifugation protocols. One such recently introduced platelet concentrate is injectable platelet-rich fibrin (i-PRF concentrate. Hence, the aim was to evaluate the antimicrobial property, and platelet count of i-PRF in comparison to other platelet concentrates, i.e., PRF, platelet-rich plasma (PRP, and control (whole blood. Materials and Methods: Blood samples were obtained from 10 chronic generalized marginal gingivitis patients. Platelet concentrates were prepared using standardized centrifugation protocol. Platelet count was evaluated by manual counting method using smear preparation of each sample. Subsequently, antimicrobial activity against oral bacteria was examined on blood agar using disc diffusion method to quantify the inhibitory effects. Results: Statistical significance was analyzed by one-way analysis of variance (ANOVA. P 0.05. i-PRF showed statistically significant difference (P < 0.001 in platelet count when compared to control. It was also significant when compared to PRP (P < 0.01, PRF (P < 0.001. Conclusion: i-PRF has maximum antimicrobial efficacy and higher platelet count in comparison to other platelet concentrates, thereby indicating to have a better regenerative potential then others.

  11. Neutrophils degrade subendothelial matrices in the presence of alpha-1-proteinase inhibitor. Cooperative use of lysosomal proteinases and oxygen metabolites.

    OpenAIRE

    Weiss, S J; Regiani, S

    1984-01-01

    Triggered neutrophils rapidly degraded labeled matrices secreted by cultured, venous endothelial cells via a process dependent on elastase but not oxygen metabolites. In the presence of high concentrations of alpha-1-proteinase inhibitor, the ability of the stimulated neutrophil to solubilize the matrix was impaired. However, at lower concentrations of alpha-1-proteinase inhibitor the neutrophil could enhance the degradative potential of its released elastase by a H2O2-dependent process. Coin...

  12. Real-Time Live Confocal Fluorescence Microscopy as a New Tool for Assessing Platelet Vitality.

    Science.gov (United States)

    Hermann, Martin; Nussbaumer, Oliver; Knöfler, Ralf; Hengster, Paul; Nussbaumer, Walter; Streif, Werner

    2010-01-01

    BACKGROUND: Assessment of platelet vitality is important for patients presenting with inherited or acquired disorders of platelet function and for quality assessment of platelet concentrates. METHODS: Herein we combined live stains with intra-vital confocal fluorescence microscopy in order to obtain an imaging method that allows fast and accurate assessment of platelet vitality. Three fluorescent dyes, FITC-coupled wheat germ agglutinin (WGA), tetramethylrhodamine methyl ester perchlorate (TMRM) and acetoxymethylester (Rhod-2), were used to assess platelet morphology, mitochondrial activity and intra-platelet calcium levels. Microscopy was performed with a microlens-enhanced Nipkow spinning disk-based system allowing live confocal imaging. RESULTS: Comparison of ten samples of donor platelets collected before apheresis and platelets collected on days 5 and 7 of storage showed an increase in the percentage of Rhod-2-positive platelets from 3.6 to 47 and finally to 71%. Mitochondrial potential was demonstrated in 95.4% of donor platelets and in 92.5% of platelets stored for 7 days. CONCLUSION: Such fast and accurate visualization of known key parameters of platelet function could be of relevance for studies addressing the quality of platelets after storage and additional manipulation, such as pathogen inactivation, as well as for the analysis of inherited platelet function disorders.

  13. Interleukin-17 Promotes Neutrophil-Mediated Immunity by Activating Microvascular Pericytes and Not Endothelium

    Science.gov (United States)

    Liu, Rebecca; Lauridsen, Holly M.; Amezquita, Robert A.; Pierce, Richard W.; Jane-wit, Dan; Fang, Caodi; Pellowe, Amanda S.; Kirkiles-Smith, Nancy C.; Gonzalez, Anjelica L.; Pober, Jordan S.

    2016-01-01

    A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multi-step process that involves sequential cell-cell interactions of circulating leukocytes with interleukin (IL)-1- or tumor necrosis factor-α (TNF)-activated microvascular endothelial cells (ECs) and pericytes (PCs) that form the wall of the postcapillary venules. The initial infiltrating cells accumulate perivascularly in close proximity to PCs. IL-17, a pro-inflammatory cytokine that acts on target cells via a heterodimeric receptor formed by IL-17RA and IL-17RC subunits, also promotes neutrophilic inflammation but its effects on vascular cells are less clear. We report that both cultured human ECs and PCs strongly express IL-17RC and, while neither cell type expresses much IL-17RA, PCs express significantly more than ECs. IL-17, alone or synergistically with TNF, significantly alters inflammatory gene expression in cultured human PCs but not ECs. RNA-seq analysis identifies many IL-17-induced transcripts in PCs encoding proteins known to stimulate neutrophil-mediated immunity. Conditioned media (CM) from IL-17-activated PCs, but not ECs, induce pertussis toxin-sensitive neutrophil polarization, likely mediated by PC-secreted chemokines, and also stimulate neutrophil production of pro-inflammatory molecules, including TNF, IL-1α, IL-1β, and IL-8. Furthermore, IL-17-activated PCs but not ECs can prolong neutrophil survival by producing G-CSF and GM-CSF, delaying the mitochondria outer membrane permeabilization and caspase 9 activation. Importantly, neutrophils exhibit enhanced phagocytic capacity after activation by CM from IL-17-treated PCs. We conclude that PCs, not ECs, are the major target of IL-17 within the microvessel wall and that IL-17-activated PCs can modulate neutrophil functions within the perivascular tissue space. PMID:27534549

  14. Platelet-rich fibrin: Evolution of a second-generation platelet concentrate

    Directory of Open Access Journals (Sweden)

    Sunitha Raja V

    2008-01-01

    Full Text Available Platelet-rich plasma (PRP is a platelet concentrate that has been used widely to accelerate soft-tissue and hard-tissue healing. The preparation of PRP has been described by several authors. Platelet-rich fibrin (PRF was first described by Choukroun et al. in France. It has been referred to as a second-generation platelet concentrate, which has been shown to have several advantages over traditionally prepared PRP. Its chief advantages include ease of preparation and lack of biochemical handling of blood, which makes this preparation strictly autologous. This article describes the evolution of this novel platelet concentrate, referred to as PRF.

  15. Neutrophil depletion improves diet-induced non-alcoholic fatty liver disease in mice.

    Science.gov (United States)

    Ou, Rongying; Liu, Jia; Lv, Mingfen; Wang, Jingying; Wang, Jinmeng; Zhu, Li; Zhao, Liang; Xu, Yunsheng

    2017-07-01

    Non-alcoholic fatty liver disease is highly associated with morbidity and mortality in population. Although studies have already demonstrated that the immune response plays a pivotal role in the development of non-alcoholic fatty liver disease, the comprehensive regulation is unclear. Therefore, present study was carried out to investigate the non-alcoholic fatty liver disease development under neutrophil depletion. To achieve the aim of the study, C57BL/6 J mice were fed with high fat diet for 6 weeks before treated with neutrophil deplete antibody 1A8 or isotype control (200 μg/ mouse every week) for another 4 weeks. Treated with 1A8 antibody, obese mice exhibited better whole body metabolic parameters, including reduction of body weight gain and fasting blood glucose levels. Neutrophil depletion also effectively reduced hepatic structural disorders, dysfunction and lipid accumulation. Lipid β-oxidative markers, phosphorylated-AMP-activated protein kinase α and phosphorylated-acetyl-CoA carboxylase levels were increased in 1A8 antibody-treated obese mouse group. The mitochondrial number and function were also reversed after 1A8 antibody treatment, including increased mitochondrial number, reduced lipid oxidative damage and enhanced mitochondrial activity. Furthermore, the expression of inflammatory cytokines, tumor necrosis factor-α, interleukin-6, and monocyte chemoattractant protein-1 were obviously reduced after neutrophil depletion, accompanied with decreased F4/80 mRNA level and macrophage percentage in liver. The decreased NF-κB signaling activity was also involved in the beneficial effect of neutrophil depletion. Taken together, neutrophil depletion could attenuate metabolic syndromes and hepatic dysfunction.

  16. Metabolism of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine in the human neutrophil

    International Nuclear Information System (INIS)

    Triggiani, M.; D'Souza, D.M.; Chilton, F.H.

    1991-01-01

    The biosynthesis of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine (1-acyl-2-acetyl-GPC) together with that of 1-alkyl-2-acetyl-GPC (platelet-activating factor) has been demonstrated in a variety of inflammatory cells and tissues. It has been hypothesized that the relative proportion of these phospholipids produced upon cell activation may be influenced by their rates of catabolism. We studied the catabolism of 1-acyl-2-acetyl-GPC in resting and activated human neutrophils and compared it to that of 1-alkyl-2-acetyl-GPC. Neutrophils rapidly catabolize both 1-alkyl-2-acetyl-GPC and 1-acyl-2-acetyl-GPC; however, the rate of catabolism of 1-acyl-2-acetyl-GPC is approximately 2-fold higher than that of 1-alkyl-2-acetyl-GPC. In addition, most of 1-acyl-2-acetyl-GPC is catabolized through a pathway different from that of 1-alkyl-2-acetyl-GPC. The main step in the catabolism of 1-acyl-2-acetyl-GPC is the removal of the long chain at the sn-1 position; the long chain residue is subsequently incorporated either into triglycerides or into phosphatidylcholine. The 1-lyso-2-acetyl-GPC formed in this reaction is then further degraded to glycerophosphocholine, choline, or phosphocholine. 1-Acyl-2-acetyl-GPC is also catabolized, to a lesser extent, through deacetylation at the sn-2 position and reacylation with a long chain fatty acid. Stimulation of neutrophils by A23187 results in a higher rate of catabolism of 1-acyl-2-acetyl-GPC by increasing both the removal of the long chain at the sn-1 position and the deacetylation-reacylation at the sn-2 position. In a broken cell preparation, the cytosolic fraction of the neutrophil was shown to contain an enzyme activity which cleaved the sn-1 position of 1-acyl-2-acetyl-GPC and 1-acyl-2-lyso-GPC but not of 1,2-diacyl-GPC

  17. Targeting Neutrophilic Inflammation using Polymersome-Mediated Cellular Delivery

    OpenAIRE

    Robertson, J.D.; Ward, J.R.; Avila-Olias, M.; Battaglia, G.; Renshaw, S.A.

    2017-01-01

    Neutrophils are key effector cells in inflammation and play an important role in neutralizing invading pathogens. During inflammation resolution, neutrophils undergo apoptosis before they are removed by macrophages, but if apoptosis is delayed, neutrophils can cause extensive tissue damage and chronic disease. Promotion of neutrophil apoptosis is a potential therapeutic approach for treating persistent inflammation, yet neutrophils have proven difficult cells to manipulate experimentally. In ...

  18. Leukotriene B4-Neutrophil Elastase Axis Drives Neutrophil Reverse Transendothelial Cell Migration In Vivo

    Science.gov (United States)

    Colom, Bartomeu; Bodkin, Jennifer V.; Beyrau, Martina; Woodfin, Abigail; Ody, Christiane; Rourke, Claire; Chavakis, Triantafyllos; Brohi, Karim; Imhof, Beat A.; Nourshargh, Sussan

    2015-01-01

    Summary Breaching endothelial cells (ECs) is a decisive step in the migration of leukocytes from the vascular lumen to the extravascular tissue, but fundamental aspects of this response remain largely unknown. We have previously shown that neutrophils can exhibit abluminal-to-luminal migration through EC junctions within mouse cremasteric venules and that this response is elicited following reduced expression and/or functionality of the EC junctional adhesion molecule-C (JAM-C). Here we demonstrate that the lipid chemoattractant leukotriene B4 (LTB4) was efficacious at causing loss of venular JAM-C and promoting neutrophil reverse transendothelial cell migration (rTEM) in vivo. Local proteolytic cleavage of EC JAM-C by neutrophil elastase (NE) drove this cascade of events as supported by presentation of NE to JAM-C via the neutrophil adhesion molecule Mac-1. The results identify local LTB4-NE axis as a promoter of neutrophil rTEM and provide evidence that this pathway can propagate a local sterile inflammatory response to become systemic. PMID:26047922

  19. Neutrophil to Lymphocyte and Platelet to Lymphocyte Ratios Are More Effective than the Fournier's Gangrene Severity Index for Predicting Poor Prognosis in Fournier's Gangrene.

    Science.gov (United States)

    Yim, Sang Un; Kim, Sun Woo; Ahn, Ji Hoon; Cho, Yang Hyun; Chung, Hoseok; Hwang, Eu Chang; Yu, Ho Song; Oh, Kyung Jin; Kim, Sun-Ouck; Jung, Seung Il; Kang, Taek Won; Kwon, Dong Deuk; Park, Kwangsung

    2016-04-01

    We investigated the value of the neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) as markers of mortality in patients with Fournier's gangrene. Records from 62 patients treated for Fournier's gangrene between 2003 and 2014 were reviewed retrospectively. Data were collected regarding medical history, symptoms, physical examination findings, admission laboratory tests, and the extent of body surface area involved (%). Fournier's Gangrene Severity Index score, NLR, and PLR were calculated. The data were assessed separately for surviving and deceased patients. Of the 62 patients, 36 survived (58%, group 1) and 26 died (42%, group 2). Parameters that were statistically different between the two groups (p Fournier's Gangrene Severity Index score, and admission laboratory parameters, including body temperature, heart rate, bicarbonate, albumin, and serum calcium. The average body surface area affected in group 2 was statistically different from that of group 1 (6.0% versus 2.3%, p = 0.001). A high Fournier's Gangrene Severity Index score (>9), high NLR (>8), and high PLR (>140) were associated more frequently with group 2 patients. Multivariable regression analysis showed that high NLR (adjusted odds ratio [OR], 4.66; 95% confidence interval [CI], 1.25-17.3; p = 0.022) and high PLR (adjusted OR, 11.6; 95% CI, 2.7-49.5; p = 0.001) were independent prognostic factors for poor prognosis from Fournier's gangrene. However, the Fournier's Gangrene Severity Index score did not shown any statistically significant effect on mortality (p = 0.086). The Fournier's Gangrene Severity Index scoring system was not associated with determining poor prognosis, however, high NLR and high PLR were associated with predictors of mortality in patients with Fournier's gangrene.

  20. GROUP B STREPTOCOCCUS CIRCUMVENTS NEUTROPHILS AND NEUTROPHIL EXTRACELLULAR TRAPS DURING AMNIOTIC CAVITY INVASION AND PRETERM LABOR

    Science.gov (United States)

    Boldenow, Erica; Gendrin, Claire; Ngo, Lisa; Bierle, Craig; Vornhagen, Jay; Coleman, Michelle; Merillat, Sean; Armistead, Blair; Whidbey, Christopher; Alishetti, Varchita; Santana-Ufret, Veronica; Ogle, Jason; Gough, Michael; Srinouanprachanh, Sengkeo; MacDonald, James W; Bammler, Theo K; Bansal, Aasthaa; Liggitt, H. Denny; Rajagopal, Lakshmi; Waldorf, Kristina M Adams

    2016-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. Although microbial invasion of the amniotic cavity (MIAC) is associated with the majority of early preterm births, the temporal events that occur during MIAC and preterm labor are not known. Group B Streptococci (GBS) are β-hemolytic, gram-positive bacteria, which commonly colonize the vagina but have been recovered from the amniotic fluid in preterm birth cases. To understand temporal events that occur during MIAC, we utilized a unique chronically catheterized nonhuman primate model that closely emulates human pregnancy. This model allows monitoring of uterine contractions, timing of MIAC and immune responses during pregnancy-associated infections. Here, we show that adverse outcomes such as preterm labor, MIAC, and fetal sepsis were observed more frequently during infection with hemolytic GBS when compared to nonhemolytic GBS. Although MIAC was associated with systematic progression in chorioamnionitis beginning with chorionic vasculitis and progressing to neutrophilic infiltration, the ability of the GBS hemolytic pigment toxin to induce neutrophil cell death and subvert killing by neutrophil extracellular traps (NETs) in placental membranes in vivo facilitated MIAC and fetal injury. Furthermore, compared to maternal neutrophils, fetal neutrophils exhibit decreased neutrophil elastase activity and impaired phagocytic functions to GBS. Collectively, our studies demonstrate how a unique bacterial hemolytic lipid toxin enables GBS to circumvent neutrophils and NETs in placental membranes to induce fetal injury and preterm labor. PMID:27819066

  1. Platelet collection efficiencies of three different platelet-rich plasma preparation systems.

    Science.gov (United States)

    Aydin, Fatma; Pancar Yuksel, Esra; Albayrak, Davut

    2015-06-01

    Different systems have been used for the preparation of platelet-rich plasma (PRP), but platelet collection efficiencies of these systems are not clear. To evaluate the platelet collection efficiencies of three different PRP preparation systems. Blood samples were obtained from the same 16 volunteers for each system. The samples were centrifuged and PRP was prepared by three systems. The ratio of the total number of platelets in PRP to the total number of platelets of the venous blood sample of the patient expressed in percentage was named as platelet collection efficiency and calculated for each system. Mean platelet collection efficiencies were 66.6 (min: 56.9, max: 76.9), 58.3 (min: 27.3, max: 102.8), 50.8 (min: 27.2, max: 73) for top and bottom bag system, system using citrated tube, and the system using tube with Ficoll and cell extraction kit, respectively. Statistically significant difference was found only between the platelet collection efficiencies of systems using the tube with ficoll and cell extraction kit and the top and bottom bag system (p = 0.002). All three systems could be used for PRP preparation, but top and bottom bag system offers a slight advantage over the system using Ficoll and cell extraction kit regarding the platelet collection efficiency.

  2. Neutrophil labeling with [99mTc]-technetium stannous colloid is complement receptor 3-mediated and increases the neutrophil priming response to lipopolysaccharide

    International Nuclear Information System (INIS)

    Gallagher, Hayley; Ramsay, Stuart C.; Barnes, Jodie; Maggs, Jacqueline; Cassidy, Nathan; Ketheesan, Natkunam

    2006-01-01

    Introduction: [ 99m Tc]-technetium stannous colloid (TcSnC)-labeled white cells are used to image inflammation. Neutrophil labeling with TcSnC is probably phagocytic, but the phagocytic receptor involved is not known. We hypothesised that complement receptor 3 (CR3) plays a key role. Phagocytic labeling could theoretically result in neutrophil activation or priming, affecting the behaviour of labeled cells. Fluorescence-activated cell sorter (FACS) analysis side scatter measurements can assess neutrophil activation and priming. Methods: We tested whether TcSnC neutrophil labeling is CR3-mediated by assessing if neutrophil uptake of TcSnC was inhibited by a monoclonal antibody (mAb) directed at the CD11b component of CR3. We tested if TcSnC-labeled neutrophils show altered activation or priming status, comparing FACS side scatter in labeled and unlabeled neutrophils and examining the effect of lipopolysaccharide (LPS), a known priming agent. Results: Anti-CD11b mAb reduced neutrophil uptake of TcSnC in a dose-dependent fashion. Labeled neutrophils did not show significantly increased side scatter compared to controls. LPS significantly increased side scatter in control cells and labeled neutrophils. However, the increase was significantly greater in labeled neutrophils than unlabeled cells. Conclusions: Neutrophil labeling with TcSnC is related to the function of CR3, a receptor which plays a central role in phagocytosis. TcSnC labeling did not significantly activate or prime neutrophils. However, labeled neutrophils showed a greater priming response to LPS. This could result in labeled neutrophils demonstrating increased adhesion on activated endothelium at sites of infection

  3. Study on platelet kinetics

    International Nuclear Information System (INIS)

    Yui, Tokuo

    1981-01-01

    Fundamental study: Factors influencing the labeling on human platelets were evaluated and optimal labeling conditions were chosen. Then, platelet survival times were measured and organ distribution of labeled platelets was observed in rat by four different methods. These results were compared with each other. Based on the findings of those studies, the protocol of human platelet labeling with 111 In-oxine for clinical use was established. Clinical study: In normal cases, a platelet survival time and a platelet turnover rate were quite similar to the results from 51 Cr method. In gamma camera imaging, a radioactivity on the heart decreased with the lapse of time, while that on the spleen and liver gradually increased. In patients with idiopathic thrombocytopenic purpura, platelet survival time was markedly shortened and both a platelet turnover rate and an effective production increased. In patient with congestive splenomegaly, a platelet survival time was normal, whereas a platelet pooling on the spleen markedly increased. In patients who were implanted dacron-graft for abdominal aortic aneurysm, a radioactivity accumulated to the graft and a platelet survival time shortened. In a patient with myocardial infarction, the camera imaging clearly showed the thrombus in the left ventricular aneurysm. In three patients with mitral stenosis, thrombi in left atrium were observed at the camera images. Imaging of a platelet distribution and measurement of platelet survival time using 111 In-oxine labeled platelets are considered to be an excellent method for the diagnosis and decision of treatment on various disorders with thrombocytopenia and thrombosis. (J.P.N.)

  4. Evidence that platelet buoyant density, but not size, correlates with platelet age in man

    International Nuclear Information System (INIS)

    Mezzano, D.; Hwang, K.; Catalano, P.; Aster, R.H.

    1981-01-01

    Following infusion of 51Cr-labeled autologous platelets into normal subjects, high-density (HD) and low-density (LD) platelet cohorts were isolated by prolonged centrifugation in isosmotic arabino-galactan (Stractan). Specific radio-activity of LD platelets declined rapidly post-infusion (T1/2 . 1.5 days), but specific radioactivity of HD platelets remained constant or increased over a 3--4-day period and gradually declined for 6--7 days thereafter. These differences were exaggerated when platelet cohorts enriched in LD or HD cells by slow centrifugation in high-density albumin were labeled and transfused. Mean survival of a platelet cohort enriched with HD cells was significantly (P less than 0.02) shorter (7.73 days) than that of a cohort enriched with LD cells (9.33) days). In normal subjects treated with aspirin, capacity for thromboxane synthesis was regained more rapidly (P less than 0.05) in LD than in HD platelets. HD and LD platelets differed only slightly in mean volume (HD platelets . 7.57 mu3, LD platelets . 6.87 mu3, 0.05 less than P less than 0.01). We believe the most logical interpretation of these findings is that under normal conditions in man, newly formed platelets are less dense on the average than total platelets and become more dense as they age in the circulation. Thus, specific radioactivity of LD platelets declines rapidly as these platelets move into a more dense compartment and are replaced by newly formed, unlabelled cells; specific radioactivity of HD platelets remains constant or increases as labelled platelets enter this compartment in numbers equal to or greater than the number leaving it at the end of their life span. The similarity in mean volumes of LD and HD platelets suggests that platelet size is unrelated to platelet age under normal conditions

  5. Effect of the dimetilsulfoxido in the response chemiluminescent and the consumption of oxygen of neutrophils activated human

    International Nuclear Information System (INIS)

    Garcia, J.

    2001-01-01

    Dimethylsulfoxide (DMSO), a hydroxyl radical scavenger, exerted a dose dependent inhibition on the luminol and lucigenin-enhanced chemiluminescent responses of human neutrophils activated with soluble and particulate stimulants. DMSO inhibition of the luminol chemiluminescense induced by calcium ionophore A23187 was probably due to OH scavenging, whereas inhibition of the lucigenin chemiluminescence suggested DMSO negatively affects the NADPH-dependent membrane oxidase of neutrophils. In agreement with this, DMSO moderately inhibited O2 consumption in PMN suspensions stimulated with chemotactic peptide and opsonized zymosan-induced luminol chemiluminescense was observed only when added before or in conjunction with stimulants, whereas A23187-induced chemiluminescense was inhibited by DMSO regardless of time of addition. Washing of DMSO-treated PMN resulted in increased luminol enhanced chemiluminescense in response to chemotactic peptide and opsonized zymosan. This is consistent with the idea that DMSO may be interfering with activation of the membrane subunits of the oxidase by translocation and docking of the cytoplasmic, regulatory subunits. These data imply that DMSO inhibits neutrophil chemiluminescense both by OH scavenging and interfering with oxidase activation. Key words:Dimethylsulfoxide, chemiluminescent, luminol, lucigenin,neutrophils [es

  6. Platelet density per monocyte predicts adverse events in patients after percutaneous coronary intervention.

    Science.gov (United States)

    Rutten, Bert; Roest, Mark; McClellan, Elizabeth A; Sels, Jan W; Stubbs, Andrew; Jukema, J Wouter; Doevendans, Pieter A; Waltenberger, Johannes; van Zonneveld, Anton-Jan; Pasterkamp, Gerard; De Groot, Philip G; Hoefer, Imo E

    2016-01-01

    Monocyte recruitment to damaged endothelium is enhanced by platelet binding to monocytes and contributes to vascular repair. Therefore, we studied whether the number of platelets per monocyte affects the recurrence of adverse events in patients after percutaneous coronary intervention (PCI). Platelet-monocytes complexes with high and low median fluorescence intensities (MFI) of the platelet marker CD42b were isolated using cell sorting. Microscopic analysis revealed that a high platelet marker MFI on monocytes corresponded with a high platelet density per monocyte while a low platelet marker MFI corresponded with a low platelet density per monocyte (3.4 ± 0.7 vs 1.4 ± 0.1 platelets per monocyte, P=0.01). Using real-time video microscopy, we observed increased recruitment of high platelet density monocytes to endothelial cells as compared with low platelet density monocytes (P=0.01). Next, we classified PCI scheduled patients (N=263) into groups with high, medium and low platelet densities per monocyte and assessed the recurrence of adverse events. After multivariate adjustment for potential confounders, we observed a 2.5-fold reduction in the recurrence of adverse events in patients with a high platelet density per monocyte as compared with a low platelet density per monocyte [hazard ratio=0.4 (95% confidence interval, 0.2-0.8), P=0.01]. We show that a high platelet density per monocyte increases monocyte recruitment to endothelial cells and predicts a reduction in the recurrence of adverse events in patients after PCI. These findings may imply that a high platelet density per monocyte protects against recurrence of adverse events.

  7. Sexy again: the renaissance of neutrophils in psoriasis.

    Science.gov (United States)

    Schön, Michael P; Broekaert, Sigrid M C; Erpenbeck, Luise

    2017-04-01

    Notwithstanding their prominent presence in psoriatic skin, the functional role of neutrophilic granulocytes still remains somewhat enigmatic. Sparked by exciting scientific discoveries regarding neutrophil functions within the last years, the interest in these short-lived cells of the innate immune system has been boosted recently. While it had been known for some time that neutrophils produce and respond to a number of inflammatory mediators, recent research has linked neutrophils with the pathogenic functions of IL-17, possibly in conjunction with the formation of NETs (neutrophil extracellular traps). Antipsoriatic therapies exert their effects, at least in part, through interference with neutrophils. Neutrophils also appear to connect psoriasis with comorbid diseases. However, directly tampering with neutrophil functions is not trivial as evinced by the failure of therapeutic approaches targeting redundantly regulated cellular communication networks. It has also become apparent that neutrophils link important pathogenic functions of the innate and the adaptive immune system and that they are intricately involved in regulatory networks underlying the pathophysiology of psoriasis. In order to advocate intensified research into the role of this interesting cell population, we here highlight some features of neutrophils and put them into perspective with our current view of the pathophysiology of psoriasis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Genetic Analysis of the Role of Protein Kinase Cθ in Platelet Function and Thrombus Formation

    Science.gov (United States)

    Hall, Kellie J.; Harper, Matthew T.; Gilio, Karen; Cosemans, Judith M.; Heemskerk, Johan W. M.; Poole, Alastair W.

    2008-01-01

    Background PKCθ is a novel protein kinase C isozyme, predominately expressed in T cells and platelets. PKCθ−/− T cells exhibit reduced activation and PKCθ−/− mice are resistant to autoimmune disease, making PKCθ an attractive therapeutic target for immune modulation. Collagen is a major agonist for platelets, operating through an immunoreceptor-like signalling pathway from its receptor GPVI. Although it has recently been shown that PKCθ positively regulates outside-in signalling through integrin αIIbβ3 in platelets, the role of PKCθ in GPVI-dependent signalling and functional activation of platelets has not been assessed. Methodology/Principal Findings In the present study we assessed static adhesion, cell spreading, granule secretion, integrin αIIbβ3 activation and platelet aggregation in washed mouse platelets lacking PKCθ. Thrombus formation on a collagen-coated surface was assessed in vitro under flow. PKCθ−/− platelets exhibited reduced static adhesion and filopodia generation on fibrinogen, suggesting that PKCθ positively regulates outside-in signalling, in agreement with a previous report. In contrast, PKCθ−/− platelets also exhibited markedly enhanced GPVI-dependent α-granule secretion, although dense granule secretion was unaffected, suggesting that PKCθ differentially regulates these two granules. Inside-out regulation of αIIbβ3 activation was also enhanced downstream of GPVI stimulation. Although this did not result in increased aggregation, importantly thrombus formation on collagen under high shear (1000 s−1) was enhanced. Conclusions/Significance These data suggest that PKCθ is an important negative regulator of thrombus formation on collagen, potentially mediated by α-granule secretion and αIIbβ3 activation. PKCθ therefore may act to restrict thrombus growth, a finding that has important implications for the development and safe clinical use of PKCθ inhibitors. PMID:18815612

  9. GSK3β-dependent inhibition of AMPK potentiates activation of neutrophils and macrophages and enhances severity of acute lung injury

    Science.gov (United States)

    Park, Dae Won; Jiang, Shaoning; Liu, Yanping; Siegal, Gene P.; Inoki, Ken; Abraham, Edward

    2014-01-01

    Although AMP-activated protein kinase (AMPK) is involved in regulating carbohydrate and lipid metabolism, activated AMPK also plays an anti-inflammatory role in many cell populations. However, despite the ability of AMPK activation to diminish the severity of inflammatory responses, previous studies have found that AMPK activity is diminished in LPS-treated neutrophils and also in lungs of mice with LPS-induced acute lung injury (ALI). Since GSK3β participates in regulating AMPK activity, we examined potential roles for GSK3β in modulating LPS-induced activation of neutrophils and macrophages and in influencing severity of ALI. We found that GSK3β-dependent phosphorylation of T479-AMPK was associated with pT172 dephosphorylation and inactivation of AMPK following TLR4 engagement. GSK3β inhibitors BIO (6-bromoindirubin-3′-oxime), SB216763, or siRNA knockdown of GSK3β, but not the PI3K/AKT inhibitor LY294002, prevented Thr172-AMPK dephosphorylation. Exposure to LPS resulted in rapid binding between IKKβ and AMPKα, and phosphorylation of S485-AMPK by IKKβ. These results suggest that IKKβ-dependent phosphorylation of S485-AMPK was an essential step in subsequent phosphorylation and inactivation AMPK by GSK3β. Inhibition of GSK3β activity delayed IκBα degradation and diminished expression of the proinflammatory TNF-α in LPS-stimulated neutrophils and macrophages. In vivo, inhibition of GSK3β decreased the severity of LPS-induced lung injury as assessed by development of pulmonary edema, production of TNF-α and MIP-2, and release of the alarmins HMGB1 and histone 3 in the lungs. These results show that inhibition of AMPK by GSK3β plays an important contributory role in enhancing LPS-induced inflammatory responses, including worsening the severity of ALI. PMID:25239914

  10. An investigation on platelet transport during thrombus formation at micro-scale stenosis.

    Directory of Open Access Journals (Sweden)

    Francisco Javier Tovar-Lopez

    Full Text Available This paper reports on an investigation of mass transport of blood cells at micro-scale stenosis where local strain-rate micro-gradients trigger platelet aggregation. Using a microfluidic flow focusing platform we investigate the blood flow streams that principally contribute to platelet aggregation under shear micro-gradient conditions. We demonstrate that relatively thin surface streams located at the channel wall are the primary contributor of platelets to the developing aggregate under shear gradient conditions. Furthermore we delineate a role for red blood cell hydrodynamic lift forces in driving enhanced advection of platelets to the stenosis wall and surface of developing aggregates. We show that this novel microfluidic platform can be effectively used to study the role of mass transport phenomena driving platelet recruitment and aggregate formation and believe that this approach will lead to a greater understanding of the mechanisms underlying shear-gradient dependent discoid platelet aggregation in the context of cardiovascular diseases such as acute coronary syndromes and ischemic stroke.

  11. Decreased activity of neutrophils in the presence of diferuloylmethane (curcumin) involves protein kinase C inhibition.

    Science.gov (United States)

    Jancinová, Viera; Perecko, Tomás; Nosál, Radomír; Kostálová, Daniela; Bauerová, Katarína; Drábiková, Katarína

    2009-06-10

    Diferuloylmethane (curcumin) has been shown to act beneficially in arthritis, particularly through downregulated expression of proinflammatory cytokines and collagenase as well as through the modulated activities of T lymphocytes and macrophages. In this study its impact on activated neutrophils was investigated both in vitro and in experimental arthritis. Formation of reactive oxygen species in neutrophils was recorded on the basis of luminol- or isoluminol-enhanced chemiluminescence. Phosphorylation of neutrophil protein kinases C alpha and beta II was assessed by Western blotting, using phosphospecific antibodies. Adjuvant arthritis was induced in Lewis rats by heat-killed Mycobacterium butyricum. Diferuloylmethane or methotrexate was administered over a period of 28 days after arthritis induction. Under in vitro conditions, diferuloylmethane (1-100 microM) reduced dose-dependently oxidant formation both at extra- and intracellular level and it effectively reduced protein kinase C activation. Adjuvant arthritis was accompanied by an increased number of neutrophils in blood and by a more pronounced spontaneous as well as PMA (phorbol myristate acetate) stimulated chemiluminescence. Whereas the arthritis-related alterations in neutrophil count and in spontaneous chemiluminescence were not modified by diferuloylmethane, the increased reactivity of neutrophils to PMA was less evident in diferuloylmethane-treated animals. The effects of diferuloylmethane were comparable with those of methotrexate. Diferuloylmethane was found to be a potent inhibitor of neutrophil functions both in vitro and in experimental arthritis. As neutrophils are considered to be cells with the greatest capacity to inflict damage within diseased joints, the observed effects could represent a further mechanism involved in the antirheumatic activity of diferuloylmethane.

  12. Platelet antibodies blood test

    Science.gov (United States)

    This blood test shows if you have antibodies against platelets in your blood. Platelets are a part of the blood ... Chernecky CC, Berger BJ. Platelet antibody - blood. In: Chernecky ... caused by platelet destruction, hypersplenism, or hemodilution. ...

  13. Flow Cytometric Evaluation of Human Neutrophil Apoptosis During Nitric Oxide Generation In Vitro: The Role of Exogenous Antioxidants

    Directory of Open Access Journals (Sweden)

    Zofia Sulowska

    2005-01-01

    in vitro. The effect of exogenous supply of NO donors such as SNP, SIN-1, and GEA-3162 on the course of human neutrophil apoptosis and the role of extracellular antioxidants in this process was investigated. Isolated from peripheral blood, neutrophils were cultured in the presence or absence of NO donor compounds and antioxidants for 8, 12, and 20 hours. Apoptosis of neutrophils was determined in vitro by flow cytometric analysis of cellular DNA content and Annexin V protein binding to the cell surface. Exposure of human neutrophils to GEA-3162 and SIN-1 significantly accelerates and enhances their apoptosis in vitro in a time-dependent fashion. In the presence of SNP, intensification of apoptosis has not been revealed until 12 hours after the culture. The inhibition of GEA-3162- and SIN-1-mediated neutrophil apoptosis by superoxide dismutase (SOD but not by catalase (CAT was observed. Our results show that SOD and CAT can protect neutrophils against NO-donors-induced apoptosis and suggest that the interaction of NO and oxygen metabolites signals may determine the destructive or protective role of NO donor compounds during apoptotic neutrophil death.

  14. Sulfite induces release of lipid mediators by alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Beck-Speier, I.; Dayal, N.; Maier, L. [GSF - National Research Center for Environment and Health, Neuherberg (Germany). Inst. for Inhalation Biology; Denzlinger, C. [Tuebingen Univ. (Germany). Dept. II, Medical Clinic; Haberl, C. [Tuebingen Univ. (Germany). Dept. III, Medical Clinic

    1998-03-01

    Air pollutants are supposed to modulate physiological responses of alveolar macrophages (AM). This study was addressed to the question whether at neutral pH sulfur(IV) species in comparison to sulfur(VI) species cause AM to release proinflammatory mediators and which pathways are involved in their generation. Supernatants obtained from canine AM treated with sulfite (0.1 mM to 2 mM) enhanced the respiratory burst of canine neutrophils, measured by lucigenin-dependent chemiluminescence, whereas supernatants derived from AM treated with sulfate (1 mM) did not. The neutrophil-stimulating activity released by sulfite-treated AM consisted of platelet-activating factor (PAF) and leukotriene B{sub 4} (LTB{sub 4}) as shown by desensitization of the platelet-activating factor (PAF) and leukotriene B{sub 4} (LTB{sub 4}) as shown by desensitization of the corresponding receptors. Inhibitors of phospholipase A{sub 2} substantially suppressed release of neutrophil-stimulating activity by sulfite-treated AM. Inhibition of 5-lipoxygenase in sulfite-treated AM also reduced neutrophil-stimulating activity, while inhibition of cyclooxygenase had no effect. In conclusion, sulfite induces AM to release lipid mediators via phospholipase A{sub 2}- and 5-lipoxygenase-dependent pathways. These mediators activate neutrophils via the receptors for PAF and LTB{sub 4}. (orig.)

  15. Selection of donor platelets for alloimmunized patients using a platelet-associated IgG assay

    International Nuclear Information System (INIS)

    Myers, T.J.; Kim, B.K.; Steiner, M.; Baldini, M.G.

    1981-01-01

    A quantitative immunofluorescence platelet-associated immunoglobulin-G (PA-IgG) assay was used to detect alloimmunity to platelets in 8/12 multitransfused patients and to perform platelet crossmatching in the 8 alloimmunized patients. The correct separation of multitransfused patients into alloimmune and nonalloimmune groups was substantiated with chromium-51-labeled platelet survival studies. For 5 alloimmunized patients, compatible and incompatible donor platelets were demonstrated by PA-IgG crossmatching and were confirmed by platelet survival studies. With the other 3 alloimmunized patients, only Pa-IgG incompatible donor platelets were found. Survival studies with 5 of these incompatible donor platelets showed markedly reduced survival times on 4 occasions. Pa-IgG compatible donor platelets survived 3.5 to 8.7 days, while Pa-IgG incompatible platelets showed survival times of 0.1 to 2.4 days

  16. Neutrophil-to-Lymphocyte Ratio as a Marker in Patients with Non-arteritic Anterior Ischemic Optic Neuropathy

    Directory of Open Access Journals (Sweden)

    Onur Polat

    2015-12-01

    Full Text Available Background: Non-arteritic anterior ischemic optic neuropathy (NAION is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Although the precise cause of NAION remains elusive, the etiology of NAION is believed to be multifactorial. Aims: To evaluate the utility of neutrophil-to-lymphocyte ratio (NLR as a simple and readily available prognostic factor for clinical disease activity in patients with NAION. Study Design: Case-control study. Methods: Forty-five patients with the diagnosis of NAION and 50 age- and sex-matched controls with/without any systemic or ocular diseases except cataract were retrospectively enrolled in the study. Demographic characteristics and laboratory findings including complete blood count of all patients and control subjects were obtained from the electronic medical record. The neutrophil and lymphocyte counts were recorded and the NLR was calculated. Results: White blood cell, neutrophil, NLR and platelet values of the NAION patients were significantly higher than those of the controls (p<0.001, p<0.001, p=0.004, p=0.037, respectively. Initial NLR values were negatively correlated with initial and the third month best corrected visual acuity levels in the study group. The optimum NLR cut-off point for NAION was 1.94. Conclusion: NLR could be considered as a new inflammatory marker for assessment of the severity of inflammation in NAION patients with its quick, cheap, easily measurable property with routine complete blood count analysis.

  17. Regulation of neutrophil senescence by microRNAs.

    Directory of Open Access Journals (Sweden)

    Jon R Ward

    2011-01-01

    Full Text Available Neutrophils are rapidly recruited to sites of tissue injury or infection, where they protect against invading pathogens. Neutrophil functions are limited by a process of neutrophil senescence, which renders the cells unable to respond to chemoattractants, carry out respiratory burst, or degranulate. In parallel, aged neutrophils also undergo spontaneous apoptosis, which can be delayed by factors such as GMCSF. This is then followed by their subsequent removal by phagocytic cells such as macrophages, thereby preventing unwanted inflammation and tissue damage. Neutrophils translate mRNA to make new proteins that are important in maintaining functional longevity. We therefore hypothesised that neutrophil functions and lifespan might be regulated by microRNAs expressed within human neutrophils. Total RNA from highly purified neutrophils was prepared and subjected to microarray analysis using the Agilent human miRNA microarray V3. We found human neutrophils expressed a selected repertoire of 148 microRNAs and that 6 of these were significantly upregulated after a period of 4 hours in culture, at a time when the contribution of apoptosis is negligible. A list of predicted targets for these 6 microRNAs was generated from http://mirecords.biolead.org and compared to mRNA species downregulated over time, revealing 83 genes targeted by at least 2 out of the 6 regulated microRNAs. Pathway analysis of genes containing binding sites for these microRNAs identified the following pathways: chemokine and cytokine signalling, Ras pathway, and regulation of the actin cytoskeleton. Our data suggest that microRNAs may play a role in the regulation of neutrophil senescence and further suggest that manipulation of microRNAs might represent an area of future therapeutic interest for the treatment of inflammatory disease.

  18. Radiation-induced muscositis and neutrophil granulocytes in oral mucosa; Strahleninduzierte Mukositis und neutrophile Granulozyten in der Mundschleimhaut

    Energy Technology Data Exchange (ETDEWEB)

    Schmidberger, H.; Rave-Fraenk, M.; Kim, S.; Hille, A.; Pradier, O.; Hess, C.F. [Klinik fuer Strahlentherapie und Radioonkologie, Univ. Goettingen (Germany)

    2003-10-01

    Background: Chemotherapy-induced mucositis can be related to a decrease in oral neutrophils. We tested the relationship between radiation-induced mucositis and oral neutrophil counts. Patients and Methods: Oral neutrophil counts were obtained for ten patients with head and neck cancer who received radiotherapy of the pharynx and oral cavity. Four patients received additional chemotherapy (5-FU, Mitomycin). Counts were obtained before and during treatment; four healthy volunteers were included in the study as well. For evaluation, a quantitative mouth rinse assay, including neutrophil-staining with acridin-orange, was applied. Results: We observed large inter-individual variations with respect to neutrophil counts for patients and control persons (Table 1). During treatment (irradiation or chemoirradiation), large intra-individual variations were seen additionally (Figure 1). We found a correlation between neutrophil counts and clinical reaction grade. Neutrophil counts increased with increasing mucositis (Figure 2). This increase was more pronounced for patients treated with chemoirradiation compared to radiation alone. Treatment breaks at weekends had no clear influence on neutrophil counts. Conclusions: We observed a weak correlation between neutrophil counts and clinical reaction grade. However, the variations in neutrophil counts are too large to utilize this parameter as a surrogate for clinical mucositis grading. The assumption that a decrease in oral neutrophils is associated with radiation-induced mucositis was clearly negated. (orig.) [German] Hintergrund: Die chemotherapieinduzierte Mukositis kann mit einer Verarmung der Mundschleimhaut an neutrophilen Granulozyten vergesellschaftet sein. Wir ueberprueften den Zusammenhang zwischen der radiogenen Mukositis und der Anzahl neutrophiler Granulozyten. Patienten und Methoden: Bei zehn Patienten mit Tumoren der Kopf-Hals-Region, die sich einer Strahlentherapie unterzogen, wurde die Anzahl enoraler neutrophiler

  19. Comparison of point-of-care methods for preparation of platelet concentrate (platelet-rich plasma).

    Science.gov (United States)

    Weibrich, Gernot; Kleis, Wilfried K G; Streckbein, Philipp; Moergel, Maximilian; Hitzler, Walter E; Hafner, Gerd

    2012-01-01

    This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production. The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay. The principal differences between the analyzed PRP production methods (blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte, and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor β1 (TGF-β1) showed no differences with regard to age or gender. Platelet counts and TGF-β1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies. TGF-β1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i.

  20. Neutrophil labeling with [{sup 99m}Tc]-technetium stannous colloid is complement receptor 3-mediated and increases the neutrophil priming response to lipopolysaccharide

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, Hayley [School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland 4811 (Australia); Ramsay, Stuart C. [School of Medicine, James Cook University, Townsville, Queensland (Australia) and Townsville Nuclear Medicine, Mater Hospital, Townsville, Queensland 4812 (Australia)]. E-mail: stuart.ramsey@jcu.edu.au; Barnes, Jodie [School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland 4811 (Australia); Maggs, Jacqueline [Department of Nuclear Medicine, Townsville Hospital, Townsville, Queensland 4814 (Australia); Cassidy, Nathan [Townsville Nuclear Medicine, Mater Hospital, Townsville, Queensland 4812 (Australia); Ketheesan, Natkunam [School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland 4811 (Australia); School of Medicine, James Cook University, Townsville, Queensland (Australia)

    2006-04-15

    Introduction: [{sup 99m}Tc]-technetium stannous colloid (TcSnC)-labeled white cells are used to image inflammation. Neutrophil labeling with TcSnC is probably phagocytic, but the phagocytic receptor involved is not known. We hypothesised that complement receptor 3 (CR3) plays a key role. Phagocytic labeling could theoretically result in neutrophil activation or priming, affecting the behaviour of labeled cells. Fluorescence-activated cell sorter (FACS) analysis side scatter measurements can assess neutrophil activation and priming. Methods: We tested whether TcSnC neutrophil labeling is CR3-mediated by assessing if neutrophil uptake of TcSnC was inhibited by a monoclonal antibody (mAb) directed at the CD11b component of CR3. We tested if TcSnC-labeled neutrophils show altered activation or priming status, comparing FACS side scatter in labeled and unlabeled neutrophils and examining the effect of lipopolysaccharide (LPS), a known priming agent. Results: Anti-CD11b mAb reduced neutrophil uptake of TcSnC in a dose-dependent fashion. Labeled neutrophils did not show significantly increased side scatter compared to controls. LPS significantly increased side scatter in control cells and labeled neutrophils. However, the increase was significantly greater in labeled neutrophils than unlabeled cells. Conclusions: Neutrophil labeling with TcSnC is related to the function of CR3, a receptor which plays a central role in phagocytosis. TcSnC labeling did not significantly activate or prime neutrophils. However, labeled neutrophils showed a greater priming response to LPS. This could result in labeled neutrophils demonstrating increased adhesion on activated endothelium at sites of infection.

  1. Platelets as a Novel Source of Pro-Inflammatory Chemokine CXCL14

    Directory of Open Access Journals (Sweden)

    Alexander Witte

    2017-03-01

    Full Text Available Objective: Platelets are a major source of chemokines. Here, we demonstrate for the first time that platelets express significant amounts of CXCL14 and disclose powerful effects of platelet-derived CXCL14 on monocyte and endothelial migration. Methods: The expression of CXCL14 in platelets and in the supernatant of activated platelets was analysed by immunoblotting, ELISA, and flow cytometry. The effect of platelet-derived CXCL14 on monocyte migration was evaluated using a modified Boyden chamber. The effect of CXCL14 on monocyte phagocytosis was tested by using fluorochrome-labelled E.coli particles. The effect of platelet-derived CXCL14 on endothelial migration was explored by the use of an endothelial scratch assay. Results: Hitherto unrecognized expression of CXCL14 in human and murine platelets was uncovered by immunoblotting. Activation with platelet agonists such as adenosine-di-phosphate (ADP, collagen-related peptide (CRP, or thrombin-receptor activating peptide (TRAP, increased CXCL14 surface expression (flow cytometry and release into the supernatant (immunoblotting, ELISA. Since CXCL14 is known to be chemotactic for CD14+ monocytes, we investigated the chemotactic potential of platelet-derived CXCL14 on human monocytes. Activated platelet supernatant induced monocyte migration, which was counteracted upon neutralization of platelet-derived CXCL14 as compared to IgG control. Blocking of the chemokine receptor CXCR4, but not CXCR7, reduced the number of migratory monocytes towards recombinant CXCL14, suggesting the involvement of CXCR4 in the CXCL14-directed monocyte chemotaxis. Recombinant CXCL14 enhanced the phagocytic uptake of E.coli particles by monocytes. In scratch assays with cultured endothelial cells (HUVECs, platelet-derived CXCL14 counteracted the pro-angiogenic effects of VEGF, supporting its previously recognized angiostatic potential. Conclusions: Platelets are a relevant source of CXCL14. Platelet-derived CXCL14 at the

  2. Apheresis platelet concentrates contain platelet-derived and endothelial cell-derived microparticles

    NARCIS (Netherlands)

    Rank, A.; Nieuwland, R.; Liebhardt, S.; Iberer, M.; Grützner, S.; Toth, B.; Pihusch, R.

    2011-01-01

    Background and Objectives Microparticles (MP) are membrane vesicles with thrombogenic and immunomodulatory properties. We determined MP subgroups from resting platelets, activated platelets and endothelial cells in donors and apheresis platelet concentrates (PC). Material and Methods MP were double

  3. Neutrophil Interactions with Epithelial Expressed ICAM-1 Enhances Intestinal Mucosal Wound Healing

    Science.gov (United States)

    Sumagin, R; Brazil, JC; Nava, P; Nishio, H; Alam, A; Luissint, AC; Weber, DA; Neish, AS; Nusrat, A; Parkos, CA

    2015-01-01

    A characteristic feature of gastrointestinal tract inflammatory disorders, such as inflammatory bowel disease, is polymorphonuclear neutrophil (PMN) transepithelial migration (TEM) and accumulation in the gut lumen. PMN accumulation within the intestinal mucosa contributes to tissue injury. While epithelial infiltration by large numbers of PMNs results in mucosal injury, we found that PMN interactions with luminal epithelial membrane receptors may also play a role in wound healing. Intercellular adhesion molecule-1 (ICAM-1) is a PMN ligand that is upregulated on apical surfaces of intestinal epithelial cells under inflammatory conditions. In our study, increased expression of ICAM-1 resulted in enhanced PMN binding to the apical epithelium, which was associated with reduced PMN apoptosis. Following TEM, PMN adhesion to ICAM-1 resulted in activation of Akt and β-catenin signaling, increased epithelial-cell proliferation, and wound healing. Such responses were ICAM-1 dependent as engagement of epithelial ICAM-1 by antibody-mediated cross-linking yielded similar results. Furthermore, using an in-vivo biopsy-based, colonic-mucosal-injury model, we demonstrated epithelial ICAM-1 plays an important role in activation of epithelial Akt and β-catenin signaling and wound healing. These findings suggest that post-migrated PMNs within the intestinal lumen can regulate epithelial homeostasis, thereby identifying ICAM-1 as a potential therapeutic target for promoting mucosal wound healing. PMID:26732677

  4. Neutrophil interactions with epithelial-expressed ICAM-1 enhances intestinal mucosal wound healing.

    Science.gov (United States)

    Sumagin, R; Brazil, J C; Nava, P; Nishio, H; Alam, A; Luissint, A C; Weber, D A; Neish, A S; Nusrat, A; Parkos, C A

    2016-09-01

    A characteristic feature of gastrointestinal tract inflammatory disorders, such as inflammatory bowel disease, is polymorphonuclear neutrophil (PMN) transepithelial migration (TEM) and accumulation in the gut lumen. PMN accumulation within the intestinal mucosa contributes to tissue injury. Although epithelial infiltration by large numbers of PMNs results in mucosal injury, we found that PMN interactions with luminal epithelial membrane receptors may also play a role in wound healing. Intercellular adhesion molecule-1 (ICAM-1) is a PMN ligand that is upregulated on apical surfaces of intestinal epithelial cells under inflammatory conditions. In our study, increased expression of ICAM-1 resulted in enhanced PMN binding to the apical epithelium, which was associated with reduced PMN apoptosis. Following TEM, PMN adhesion to ICAM-1 resulted in activation of Akt and β-catenin signaling, increased epithelial-cell proliferation, and wound healing. Such responses were ICAM-1 dependent as engagement of epithelial ICAM-1 by antibody-mediated cross-linking yielded similar results. Furthermore, using an in-vivo biopsy-based, colonic-mucosal-injury model, we demonstrated epithelial ICAM-1 has an important role in activation of epithelial Akt and β-catenin signaling and wound healing. These findings suggest that post-migrated PMNs within the intestinal lumen can regulate epithelial homeostasis, thereby identifying ICAM-1 as a potential therapeutic target for promoting mucosal wound healing.

  5. Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination

    Directory of Open Access Journals (Sweden)

    Yutaka Kitamura

    2018-02-01

    Full Text Available Platelet-rich fibrin (PRF clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP fractions were clotted with CaCl2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix.

  6. Reference intervals for platelet aggregation assessed by multiple electrode platelet aggregometry

    DEFF Research Database (Denmark)

    Rubak, Peter; Villadsen, Kirsten; Hvas, Anne-Mette

    2012-01-01

    Abstract Introduction Analyses of platelet aggregation in hirudin whole blood using Multiplate® was validated. Reference intervals for the most commonly used agonists were established, and the association between platelet aggregation, age, gender and haematological values was analysed. Material...... and methods We included 121 healthy individuals to establish reference intervals and six healthy individuals for evaluation of the day-to-day variation. Platelet aggregation was evaluated on hirudin whole blood employing Multiplate® induced by arachidonic acid, ADP, collagen and ristocetin (RISTOlow...... after adjusting for age and gender except for RISTOhigh. A positive significant association was found between platelet count and platelet aggregation (p

  7. Evaluation of platelet aggregation in platelet concentrates: storage implications

    Directory of Open Access Journals (Sweden)

    Neiva Teresinha J.C.

    2003-01-01

    Full Text Available The use of hemo-derivatives is nowadays a fundamentally important therapeutic modality in the exercise of medicine. Among the various hemo-components employed, we have the platelet concentrate (PC, indicated in cases of hemorrhagic disturbances. We previously showed that platelet function in blood donors is reduced in their screening phase and after the separation process of PCs. Currently, we are providing evidence for the existence of biochemical and functional changes in PC preparations stored for three days at temperatures of 20 ± 2 ºC. Platelet concentrates from 40 healthy donors, collected in CPD anticoagulant and PL-146 polyvinylchloride containers, were examined in order to determine the pH value, pCO2 ,pO2 and lactate concentrations. In addition, the aggregation of platelets with thrombin and collagen were examined to evaluate platelet function. A pH increase from 7.07 ± 0.04 to 7.36 ± 0.07 (p < 0.01 was observed. The pCO2 concentration decreased progressively from 69.2 ± 7.7 mmHg to 28.8 ± 6.2 mmHg (p < 0.001 during the storage period. In contrast, pO2 value increase from 103.4 ± 30.6 to 152.3 ± 24.6 mmHg (p < 0.001 was evidenced during the 48 hours of storage. The lactate concentration increased from 17.97 ± 5.2 to 57.21 ± 5.7 mg/dl (p < 0.001. Platelet aggregation using 0.25 U/ml-thrombin and 2.0 µg/ml-collagen showed significant hypofunction from 61.8 ± 2.7% to 24.8 ± 9.8% and 62.7±5.0 to 33.4± 6.2 (p < 0.001, respectively. We concluded that the evaluated biochemical parameters and the platelet function changed significantly when the platelets were kept under routine storage conditions.

  8. Neutrophils in Tuberculosis: Heterogeneity Shapes the Way?

    Science.gov (United States)

    2017-01-01

    Infection with M. tuberculosis remains one of the most common infections in the world. The outcome of the infection depends on host ability to mount effective protection and balance inflammatory responses. Neutrophils are innate immune cells implicated in both processes. Accordingly, during M. tuberculosis infection, they play a dual role. Particularly, they contribute to the generation of effector T cells, participate in the formation of granuloma, and are directly involved in tissue necrosis, destruction, and infection dissemination. Neutrophils have a high bactericidal potential. However, data on their ability to eliminate M. tuberculosis are controversial, and the results of neutrophil depletion experiments are not uniform. Thus, the overall roles of neutrophils during M. tuberculosis infection and factors that determine these roles are not fully understood. This review analyzes data on neutrophil defensive and pathological functions during tuberculosis and considers hypotheses explaining the dualism of neutrophils during M. tuberculosis infection and tuberculosis disease. PMID:28626346

  9. Platelet glycoprotein VI binds to polymerized fibrin and promotes thrombin generation.

    Science.gov (United States)

    Mammadova-Bach, Elmina; Ollivier, Véronique; Loyau, Stéphane; Schaff, Mathieu; Dumont, Bénédicte; Favier, Rémi; Freyburger, Geneviève; Latger-Cannard, Véronique; Nieswandt, Bernhard; Gachet, Christian; Mangin, Pierre H; Jandrot-Perrus, Martine

    2015-07-30

    Fibrin, the coagulation end product, consolidates the platelet plug at sites of vascular injury and supports the recruitment of circulating platelets. In addition to integrin αIIbβ3, another as-yet-unidentified receptor is thought to mediate platelet interaction with fibrin. Platelet glycoprotein VI (GPVI) interacts with collagen and several other adhesive macromolecules. We evaluated the hypothesis that GPVI could be a functional platelet receptor for fibrin. Calibrated thrombin assays using platelet-rich plasma (PRP) showed that tissue factor-triggered thrombin generation was impaired in GPVI-deficient patients and reduced by the anti-GPVI Fab 9O12. Assays on reconstituted PRP and PRP from fibrinogen-deficient patients revealed a fibrinogen-dependent enhancement of thrombin generation, which relied on functional GPVI. The effect of GPVI was found to depend on fibrin polymerization. A binding assay showed a specific interaction between GPVI-Fc and fibrin, inhibited by the Fab 9O12. This Fab also reduced platelet adhesion to fibrin at low (300 s(-1)) and high (1500 s(-1)) wall shear rates. Platelets adherent to fibrin displayed shape change, exposure of procoagulant phospholipids, and the formation of small clots. When hirudinated blood was perfused at 1500 s(-1) over preformed fibrin-rich clots, the Fab 9O12 decreased the recruitment of platelets by up to 85%. This study identifies GPVI as a platelet receptor for polymerized fibrin with 2 major functions: (1) amplification of thrombin generation and (2) recruitment of circulating platelets to clots. These so-far-unrecognized properties of GPVI confer on it a key role in thrombus growth and stabilization. © 2015 by The American Society of Hematology.

  10. Secreted Immunomodulatory Proteins of Staphylococcus aureus Activate Platelets and Induce Platelet Aggregation.

    Science.gov (United States)

    Binsker, Ulrike; Palankar, Raghavendra; Wesche, Jan; Kohler, Thomas P; Prucha, Josephine; Burchhardt, Gerhard; Rohde, Manfred; Schmidt, Frank; Bröker, Barbara M; Mamat, Uwe; Pané-Farré, Jan; Graf, Anica; Ebner, Patrick; Greinacher, Andreas; Hammerschmidt, Sven

    2018-04-01

    Staphylococcus aureus can cause bloodstream infections associated with infective endocarditis (IE) and disseminated intravascular coagulopathy (DIC). Both complications involve platelets. In view of an increasing number of antibiotic-resistant strains, new approaches to control systemic S. aureus infection are gaining importance. Using a repertoire of 52 recombinant S. aureus proteins in flow cytometry-based platelet activation and aggregation assays, we identified, in addition to the extracellular adherence protein Eap, three secreted staphylococcal proteins as novel platelet activating proteins. Eap and the chemotaxis inhibitory protein of S. aureus (CHIPS), the formyl peptide receptor-like 1 inhibitory protein (FLIPr) and the major autolysin Atl induced P-selectin expression in washed platelets and platelet-rich plasma. Similarly, AtlA, CHIPS and Eap induced platelet aggregation in whole blood. Fluorescence microscopy illustrated that P-selectin expression is associated with calcium mobilization and re-organization of the platelet actin cytoskeleton. Characterization of the functionally active domains of the major autolysin AtlA and Eap indicates that the amidase domain of Atl and the tandem repeats 3 and 4 of Eap are crucial for platelet activation. These results provide new insights in S. aureus protein interactions with platelets and identify secreted proteins as potential treatment targets in case of antibiotic-resistant S. aureus infection. Schattauer GmbH Stuttgart.

  11. Quality of harvested autologous platelets compared with stored donor platelets for use after cardiopulmonary bypass procedures.

    Science.gov (United States)

    Crowther, M; Ford, I; Jeffrey, R R; Urbaniak, S J; Greaves, M

    2000-10-01

    Platelet dysfunction has a major contribution in bleeding after cardiopulmonary bypass (CPB) and transfusion of platelets is frequently used to secure haemostasis. Allogeneic platelets prepared for transfusion are functionally impaired. Autologous platelets harvested preoperatively require a shorter storage time before transfusion and their use also avoids the risks associated with transfusion of allogeneic blood products. For the first time, we have compared the functional quality of autologous platelets with allogeneic platelets prepared by two methods, immediately before infusion. Platelet activation was assessed by P-selectin expression and fibrinogen binding using flow cytometry. We also monitored the effects of CPB surgery and re-infusion of autologous platelets on platelet function. Autologous platelet-rich plasma (PRP) contained a significantly lower (P platelets compared with allogeneic platelet preparations, and also contained a significantly higher (P platelets. Allogeneic platelets prepared by donor apheresis were more activated and less responsive than those produced by centrifugation of whole blood. In patients' blood, the percentage of platelets expressing P-selectin or binding fibrinogen increased significantly after CPB (P platelets responsive to in vitro agonists was decreased (P platelet activation during the procedure. The percentage of activated platelets decreased (statistically not significant) after re-infusion of autologous PRP. P-selectin expression had returned to pre-CPB levels 24 h post-operatively. Autologous platelet preparations display minimal activation, but remain responsive. Conservation of platelet function may contribute to the potential clinical benefits of autologous transfusion in cardiopulmonary bypass.

  12. Three-dimensional structure and cytokine distribution of platelet-rich fibrin.

    Science.gov (United States)

    Bai, Meng-Yi; Wang, Ching-Wei; Wang, Jyun-Yi; Lin, Ming-Fang; Chan, Wing P

    2017-02-01

    Previous reports have revealed that several cytokines (including platelet-derived growth factor-BB, transforming growth factors-β1 and insulin-like growth factor-1) can enhance the rate of bone formation and synthesis of extracellular matrix in orthopaedics or periodontology. This study aimed to determine the concentration of cytokines within platelet-rich fibrin microstructures and investigate whether there are differences in the different portions of platelet-rich fibrin, which has implications for proper clinical use of platelet-rich fibrin gel. Whole blood was obtained from six New Zealand rabbits (male, 7 to 39 weeks old, weight 2.7-4 kg); it was then centrifuged for preparation of platelet-rich fibrin gels and harvest of plasma. The resultant platelet-rich fibrin gels were used for cytokine determination, histological analyses and scanning electron microscopy. All plasmas obtained were subject to the same cytokine determination assays for the purpose of comparison. Cytokines platelet-derived growth factor-BB and transforming growth factor-β1 formed concentration gradients from high at the red blood cell end of the platelet-rich fibrin gel (p=1.88×10-5) to low at the plasma end (p=0.19). Insulin-like growth factor-1 concentrations were similar at the red blood cell and plasma ends. The porosities of the platelet-rich fibrin samples taken in sequence from the red blood cell end to the plasma end were 6.5% ± 4.9%, 24.8% ± 7.5%, 30.3% ± 8.5%, 41.4% ± 12.3%, and 40.3% ± 11.7%, respectively, showing a gradual decrease in the compactness of the platelet-rich fibrin network. Cytokine concentrations are positively associated with platelet-rich fibrin microstructure and portion in a rabbit model. As platelet-rich fibrin is the main entity currently used in regenerative medicine, assessing cytokine concentration and the most valuable portion of PRF gels is essential and recommended to all physicians.

  13. Three-dimensional structure and cytokine distribution of platelet-rich fibrin

    Directory of Open Access Journals (Sweden)

    Meng-Yi Bai

    Full Text Available OBJECTIVES: Previous reports have revealed that several cytokines (including platelet-derived growth factor-BB, transforming growth factors-β1 and insulin-like growth factor-1 can enhance the rate of bone formation and synthesis of extracellular matrix in orthopaedics or periodontology. This study aimed to determine the concentration of cytokines within platelet-rich fibrin microstructures and investigate whether there are differences in the different portions of platelet-rich fibrin, which has implications for proper clinical use of platelet-rich fibrin gel. METHODS: Whole blood was obtained from six New Zealand rabbits (male, 7 to 39 weeks old, weight 2.7-4 kg; it was then centrifuged for preparation of platelet-rich fibrin gels and harvest of plasma. The resultant platelet-rich fibrin gels were used for cytokine determination, histological analyses and scanning electron microscopy. All plasmas obtained were subject to the same cytokine determination assays for the purpose of comparison. RESULTS: Cytokines platelet-derived growth factor-BB and transforming growth factor-β1 formed concentration gradients from high at the red blood cell end of the platelet-rich fibrin gel (p=1.88×10-5 to low at the plasma end (p=0.19. Insulin-like growth factor-1 concentrations were similar at the red blood cell and plasma ends. The porosities of the platelet-rich fibrin samples taken in sequence from the red blood cell end to the plasma end were 6.5% ± 4.9%, 24.8% ± 7.5%, 30.3% ± 8.5%, 41.4% ± 12.3%, and 40.3% ± 11.7%, respectively, showing a gradual decrease in the compactness of the platelet-rich fibrin network. CONCLUSION: Cytokine concentrations are positively associated with platelet-rich fibrin microstructure and portion in a rabbit model. As platelet-rich fibrin is the main entity currently used in regenerative medicine, assessing cytokine concentration and the most valuable portion of PRF gels is essential and recommended to all physicians.

  14. Platelets subvert T cell immunity against cancer via GARP-TGFβ axis.

    Science.gov (United States)

    Rachidi, Saleh; Metelli, Alessandra; Riesenberg, Brian; Wu, Bill X; Nelson, Michelle H; Wallace, Caroline; Paulos, Chrystal M; Rubinstein, Mark P; Garrett-Mayer, Elizabeth; Hennig, Mirko; Bearden, Daniel W; Yang, Yi; Liu, Bei; Li, Zihai

    2017-05-05

    Cancer-associated thrombocytosis has long been linked to poor clinical outcome, but the underlying mechanism is enigmatic. We hypothesized that platelets promote malignancy and resistance to therapy by dampening host immunity. We show that genetic targeting of platelets enhances adoptive T cell therapy of cancer. An unbiased biochemical and structural biology approach established transforming growth factor β (TGFβ) and lactate as major platelet-derived soluble factors to obliterate CD4 + and CD8 + T cell functions. Moreover, we found that platelets are the dominant source of functional TGFβ systemically as well as in the tumor microenvironment through constitutive expression of the TGFβ-docking receptor glycoprotein A repetitions predominant (GARP) rather than secretion of TGFβ per se. Platelet-specific deletion of the GARP-encoding gene Lrrc32 blunted TGFβ activity at the tumor site and potentiated protective immunity against both melanoma and colon cancer. Last, this study shows that T cell therapy of cancer can be substantially improved by concurrent treatment with readily available antiplatelet agents. We conclude that platelets constrain T cell immunity through a GARP-TGFβ axis and suggest a combination of immunotherapy and platelet inhibitors as a therapeutic strategy against cancer. Copyright © 2017, American Association for the Advancement of Science.

  15. Chlamydia pneumoniae hides inside apoptotic neutrophils to silently infect and propagate in macrophages.

    Directory of Open Access Journals (Sweden)

    Jan Rupp

    Full Text Available BACKGROUND: Intracellular pathogens have developed elaborate strategies for silent infection of preferred host cells. Chlamydia pneumoniae is a common pathogen in acute infections of the respiratory tract (e.g. pneumonia and associated with chronic lung sequelae in adults and children. Within the lung, alveolar macrophages and polymorph nuclear neutrophils (PMN are the first line of defense against bacteria, but also preferred host phagocytes of chlamydiae. METHODOLOGY/PRINCIPAL FINDINGS: We could show that C. pneumoniae easily infect and hide inside neutrophil granulocytes until these cells become apoptotic and are subsequently taken up by macrophages. C. pneumoniae infection of macrophages via apoptotic PMN results in enhanced replicative activity of chlamydiae when compared to direct infection of macrophages, which results in persistence of the pathogen. Inhibition of the apoptotic recognition of C. pneumoniae infected PMN using PS- masking Annexin A5 significantly lowered the transmission of chlamydial infection to macrophages. Transfer of apoptotic C. pneumoniae infected PMN to macrophages resulted in an increased TGF-ss production, whereas direct infection of macrophages with chlamydiae was characterized by an enhanced TNF-alpha response. CONCLUSIONS/SIGNIFICANCE: Taken together, our data suggest that C. pneumoniae uses neutrophil granulocytes to be silently taken up by long-lived macrophages, which allows for efficient propagation and immune protection within the human host.

  16. A comprehensive proteomics study on platelet concentrates: Platelet proteome, storage time and Mirasol pathogen reduction technology.

    Science.gov (United States)

    Salunkhe, Vishal; De Cuyper, Iris M; Papadopoulos, Petros; van der Meer, Pieter F; Daal, Brunette B; Villa-Fajardo, María; de Korte, Dirk; van den Berg, Timo K; Gutiérrez, Laura

    2018-03-19

    Platelet concentrates (PCs) represent a blood transfusion product with a major concern for safety as their storage temperature (20-24°C) allows bacterial growth, and their maximum storage time period (less than a week) precludes complete microbiological testing. Pathogen inactivation technologies (PITs) provide an additional layer of safety to the blood transfusion products from known and unknown pathogens such as bacteria, viruses, and parasites. In this context, PITs, such as Mirasol Pathogen Reduction Technology (PRT), have been developed and are implemented in many countries. However, several studies have shown in vitro that Mirasol PRT induces a certain level of platelet shape change, hyperactivation, basal degranulation, and increased oxidative damage during storage. It has been suggested that Mirasol PRT might accelerate what has been described as the platelet storage lesion (PSL), but supportive molecular signatures have not been obtained. We aimed at dissecting the influence of both variables, that is, Mirasol PRT and storage time, at the proteome level. We present comprehensive proteomics data analysis of Control PCs and PCs treated with Mirasol PRT at storage days 1, 2, 6, and 8. Our workflow was set to perform proteomics analysis using a gel-free and label-free quantification (LFQ) approach. Semi-quantification was based on LFQ signal intensities of identified proteins using MaxQuant/Perseus software platform. Data are available via ProteomeXchange with identifier PXD008119. We identified marginal differences between Mirasol PRT and Control PCs during storage. However, those significant changes at the proteome level were specifically related to the functional aspects previously described to affect platelets upon Mirasol PRT. In addition, the effect of Mirasol PRT on the platelet proteome appeared not to be exclusively due to an accelerated or enhanced PSL. In summary, semi-quantitative proteomics allows to discern between proteome changes due to

  17. Apheresis platelet concentrates contain platelet-derived and endothelial cell-derived microparticles.

    Science.gov (United States)

    Rank, A; Nieuwland, R; Liebhardt, S; Iberer, M; Grützner, S; Toth, B; Pihusch, R

    2011-02-01

    Microparticles (MP) are membrane vesicles with thrombogenic and immunomodulatory properties. We determined MP subgroups from resting platelets, activated platelets and endothelial cells in donors and apheresis platelet concentrates (PC). MP were double stained with annexin V and CD61 (platelet-derived MP; PMP), P-selectin or CD63 (MP from activated platelets) and CD144 plus E-selectin (endothelial cell-derived MP; EMP) and detected by flow cytometry in platelet donors (n=36) and apheresis PC (n=11; Trima™). PC contained MP, mainly from resting platelets [93% (90-95)], and minor fractions of PMP from activated platelets [P-selectin(+) or CD63(+); 4·8% (3·2-7·7) and 2·6% (2·0-4·0)]. Compared to donors, levels of annexin V+ MP, PMP, P-selectin(+) and CD63(+) MP were 1·7-, 2·3-, 8·6- and 3·1-fold higher in PC (all P<0·05). During storage (1-5 days), levels of annexin V+ MP and PMP did not increase, although small increases in the fraction of P-selectin(+) or CD63(+) MP occurred (both P<0·05). PC also contained EMP, which were 2·6- to 3·7-fold enriched in PC compared to donors (P<0·05). Transfusion of apheresis PC also results in transfusion of HLA-carrying PMP and EMP. This might counteract the aim of reducing transfused HLA load by leucodepletion. The increases in PMP exposing P-selectin or CD63 reflect mild platelet activation during storage. We conclude that in leucodepleted platelet apheresis using fluidized particle bed technology, MP are harvested mainly from the donor by apheresis. Improvement in apheresis technology might reduce MP load. © 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.

  18. Platelet concentration in platelet concentrates and periodontal regeneration-unscrambling the ambiguity

    Directory of Open Access Journals (Sweden)

    A Suchetha

    2015-01-01

    Full Text Available Context: Platelet-rich-plasma (PRP and Platelet-rich-fibrin (PRF are extensively used autologous platelet concentrates in periodontal regeneration, and PRF has a better efficacy as compared to PRP. The rationale for this difference has often been attributed to the difference in the structure of the fibrin matrix. However, the effect of concentration of platelets on the regenerative potential of these concentrates is obscure. Aims: The study was conducted to evaluate and compare, clinically and radiographically, the efficacy of PRF and PRP in the treatment of periodontal endosseous defects and to assess the effect of platelet concentration on periodontal regeneration. Materials and Methods: Twenty intrabony defects were selected and divided into two groups randomly by the coin toss method. Group I received PRP and Group II subjects were treated with PRF. The platelet counts in PRP and PRF were analyzed. Clinical and radiological parameters were assessed at baseline and 3, 6, and 9 months postoperatively. Statistical Analysis: Kruskal–Wallis Chi-square test, Wilcoxon signed rank test, t-test, and Spearman's rank correlation were used for statistical analysis of data. Results: There was statistically significant improvement in all the parameters in the two groups except in relation to gingival recession. There was a statistically significant difference between the platelet count in Group I and Group II (P = 0.002. Conclusion: PRP and PRF appear to have nearly comparable effects in terms of periodontal regeneration. The concentration of platelets appears to play a paradoxical role in regeneration. The regenerative potential of platelets appears to be optimal within a limited range.

  19. Increased platelet activation in early symptomatic versus asymptomatic carotid stenosis and relationship with microembolic status: Results from the Platelets And Carotid Stenosis (PACS) Study.

    LENUS (Irish Health Repository)

    Kinsella, Ja

    2013-04-26

    -negative patients (2.8 vs. 2.3%; p=0.0085). DISCUSSION: Recently symptomatic carotid stenosis patients have higher platelet counts (potentially reflecting increased platelet production, mobilisation or reduced clearance) and platelet activation status than asymptomatic patients. MES were more frequently detected in early symptomatic than asymptomatic patients, but the differences between late symptomatic and asymptomatic groups were not significant. Increased lymphocyte-platelet complex formation in recently symptomatic vs. asymptomatic MES-negative patients indicates enhanced platelet activation in this early symptomatic subgroup. Platelet biomarkers, in combination with TCD, have the potential to aid risk-stratification in asymptomatic and symptomatic carotid stenosis patients. This article is protected by copyright. All rights reserved.

  20. Fibrinogen Motif Discriminates Platelet and Cell Capture in Peptide-Modified Gold Micropore Arrays.

    Science.gov (United States)

    Adamson, Kellie; Spain, Elaine; Prendergast, Una; Moran, Niamh; Forster, Robert J; Keyes, Tia E

    2018-01-16

    Human blood platelets and SK-N-AS neuroblastoma cancer-cell capture at spontaneously adsorbed monolayers of fibrinogen-binding motifs, GRGDS (generic integrin adhesion), HHLGGAKQAGDV (exclusive to platelet integrin α IIb β 3 ), or octanethiol (adhesion inhibitor) at planar gold and ordered 1.6 μm diameter spherical cap gold cavity arrays were compared. In all cases, arginine/glycine/aspartic acid (RGD) promoted capture, whereas alkanethiol monolayers inhibited adhesion. Conversely only platelets adhered to alanine/glycine/aspartic acid (AGD)-modified surfaces, indicating that the AGD motif is recognized preferentially by the platelet-specific integrin, α IIb β 3 . Microstructuring of the surface effectively eliminated nonspecific platelet/cell adsorption and dramatically enhanced capture compared to RGD/AGD-modified planar surfaces. In all cases, adhesion was reversible. Platelets and cells underwent morphological change on capture, the extent of which depended on the topography of the underlying substrate. This work demonstrates that both the nature of the modified interface and its underlying topography influence the capture of cancer cells and platelets. These insights may be useful in developing cell-based cancer diagnostics as well as in identifying strategies for the disruption of platelet cloaks around circulating tumor cells.

  1. Breaking the mold: transcription factors in the anucleate platelet and platelet-derived microparticles

    Directory of Open Access Journals (Sweden)

    Katie L Lannan

    2015-02-01

    Full Text Available Platelets are small anucleate blood cells derived from megakaryocytes. In addition to their pivotal roles in hemostasis, platelets are the smallest, yet most abundant, immune cell and regulate inflammation, immunity, and disease progression. Although platelets lack DNA, and thus no functional transcriptional activities, they are nonetheless rich sources of RNAs, possess an intact spliceosome, and are thus capable of synthesizing proteins. Previously, it was thought that platelet RNAs and translational machinery were remnants from the megakaryocyte. We now know that the initial description of platelets as cellular fragments is an antiquated notion, as mounting evidence suggests otherwise. Therefore, it is reasonable to hypothesize that platelet transcription factors are not vestigial remnants from megakaryoctes, but have important, if only partly understood functions. Proteins play multiple cellular roles to minimize energy expenditure for maximum cellular function; thus, the same can be expected for transcription factors. In fact, numerous transcription factors have non-genomic roles, both in platelets and in nucleated cells. Our lab and others have discovered the presence and nongenomic roles of transcription factors in platelets, such as the nuclear factor kappa β (NFκB family of proteins and peroxisome proliferator activated receptor gamma (PPARγ. In addition to numerous roles in regulating platelet activation, functional transcription factors can be transferred to vascular and immune cells through platelet microparticles. This method of transcellular delivery of key immune molecules may be a vital mechanism by which platelet transcription factors regulate inflammation and immunity. At the very least, platelets are an ideal model cell to dissect out the nongenomic roles of transcription factors in nucleated cells. There is abundant evidence to suggest that transcription factors in platelets play key roles in regulating inflammatory and

  2. Nucleobindin co-localizes and associates with cyclooxygenase (COX-2 in human neutrophils.

    Directory of Open Access Journals (Sweden)

    Patrick Leclerc

    2008-05-01

    Full Text Available The inducible cyclooxygenase isoform (COX-2 is associated with inflammation, tumorigenesis, as well as with physiological events. Despite efforts deployed in order to understand the biology of this multi-faceted enzyme, much remains to be understood. Nucleobindin (Nuc, a ubiquitous Ca(2+-binding protein, possesses a putative COX-binding domain. In this study, we investigated its expression and subcellular localization in human neutrophils, its affinity for COX-2 as well as its possible impact on PGE(2 biosynthesis. Complementary subcellular localization approaches including nitrogen cavitation coupled to Percoll fractionation, immunofluorescence, confocal and electron microscopy collectively placed Nuc, COX-2, and all of the main enzymes involved in prostanoid synthesis, in the Golgi apparatus and endoplasmic reticulum of human neutrophils. Immunoprecipitation experiments indicated a high affinity between Nuc and COX-2. Addition of human recombinant (hr Nuc to purified hrCOX-2 dose-dependently caused an increase in PGE(2 biosynthesis in response to arachidonic acid. Co-incubation of Nuc with COX-2-expressing neutrophil lysates also increased their capacity to produce PGE(2. Moreover, neutrophil transfection with hrNuc specifically enhanced PGE(2 biosynthesis. Together, these results identify a COX-2-associated protein which may have an impact in prostanoid biosynthesis.

  3. Activation of bovine neutrophils by Brucella spp.

    Science.gov (United States)

    Keleher, Lauren L; Skyberg, Jerod A

    2016-09-01

    Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Effects of Docosahexaenoic Supplementation and In Vitro Vitamin C on the Oxidative and Inflammatory Neutrophil Response to Activation

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    Xavier Capó

    2015-01-01

    Full Text Available We studied the effects of diet supplementation with docosahexaenoic (DHA and in vitro vitamin C (VitC at physiological concentrations on oxidative and inflammatory neutrophil response to phorbol myristate acetate (PMA. Fifteen male footballers ingested a beverage enriched with DHA or a placebo for 8 weeks in a randomized double-blind study. Neutrophils were isolated from blood samples collected in basal conditions at the end of nutritional intervention. Neutrophils were cultured for 2 hours at 37°C in (a control media, (b media with PMA, and (c media with PMA + VitC. PMA induces neutrophil degranulation with increased extracellular myeloperoxidase and catalase activities, nitric oxide production, expression of the inflammatory genes cyclooxygenase-2, nuclear factor κβ, interleukin 8 and tumor necrosis factor α, and interleukin 6 production. DHA diet supplementation boosts the exit of CAT from neutrophils but moderates the degranulation of myeloperoxidase granules induced by PMA. VitC facilitates azurophilic degranulation of neutrophils and increases gene expression of myeloperoxidase induced by PMA. VitC and DHA diet supplementation prevent PMA effects on inflammatory gene expression, although together they do not produce additional effects. DHA diet supplementation enhances antioxidant defences and anti-inflammatory neutrophil response to in vitro PMA activation. VitC facilitates neutrophil degranulation but prevents an inflammatory response to PMA.

  5. Stanniocalcin 2 Regulates Non-capacitative Ca2+ Entry and Aggregation in Mouse Platelets

    Directory of Open Access Journals (Sweden)

    Esther López

    2018-03-01

    Full Text Available Stanniocalcin 2 (STC2 is a fish protein that controls body Ca2+ and phosphate metabolism. STC2 has also been described in mammals, and as platelet function highly depends on both extracellular and intracellular Ca2+, we have explored its expression and function in these cells. STC2−/− mice exhibit shorter tail bleeding time than WT mice. Platelets from STC2-deficient mice showed enhanced aggregation, as well as enhanced Ca2+ mobilization in response to the physiological agonist thrombin (Thr and the diacylglycerol analog, OAG, a selective activator of the non-capacitative Ca2+ entry channels. Interestingly, platelets from STC2−/− mice exhibit attenuated interaction between STIM1 and Orai1 in response to Thr, thus suggesting that STC2 is required for Thr-evoked STIM1-Orai1 interaction and the subsequent store-operated Ca2+ entry (SOCE. We have further assessed possible changes in the expression of the most relevant channels involved in non-capacitative Ca2+ entry in platelets. Then, protein expression of Orai3, TRPC3 and TRPC6 were evaluated by Western blotting, and the results revealed that while the expression of Orai3 was enhanced in the STC2-deficient mice, others like TRPC3 and TRPC6 remains almost unaltered. Summarizing, our results provide for the first time evidence for a role of STC2 in platelet physiology through the regulation of agonist-induced Ca2+ entry, which might be mediated by the regulation of Orai3 channel expression.

  6. Platelet lysate and chondroitin sulfate loaded contact lenses to heal corneal lesions.

    Science.gov (United States)

    Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Delfino, Alessio; Riva, Federica; Icaro Cornaglia, Antonia; Marrubini, Giorgio; Musitelli, Giorgio; Del Fante, Claudia; Perotti, Cesare; Caramella, Carla; Ferrari, Franca

    2016-07-25

    Hemoderivative tear substitutes contain various ephiteliotrophic factors, such as growth factors (GF), involved in ocular surface homeostasis without immunogenic properties. The aim of the present work was the loading of platelet lysate into contact lenses to improve the precorneal permanence of platelet lysate growth factors on the ocular surface to enhance the treatment of corneal lesions. To this purpose, chondroitin sulfate, a sulfated glycosaminoglycan, which is normally present in the extracellular matrix, was associated with platelet lysate. In fact, chondroitin sulfate is capable of electrostatic interaction with positively charged growth factors, in particular, with bFGF, IGF, VEGF, PDGF and TGF-β, resulting in their stabilization and reduced degradation in solution. In the present work, various types of commercially available contact lenses have been loaded with chondroitin sulfate or chondroitin sulfate in association with platelet lysate to achieve a release of growth factors directly onto the corneal surface lesions. One type of contact lenses (PureVision(®)) showed in vitro good proliferation properties towards corneal cells and were able to enhance cut closure in cornea constructs. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Assessment of neutrophil / lymphocyte ratio in patients with myocardial bridge

    Directory of Open Access Journals (Sweden)

    Abdulkadir Yıldız

    2014-03-01

    Full Text Available Objective: Myocardial bridge (MB is a congenital anomaly characterized by systolic narrowing of the epicardial coronary arterial segment while traveling in the myocardium. It is a benign entity but previous studies showed that the proximal portion is prone to an enhanced atherosclerosis. Neutrophil/lymphocyte ratio (NLR is a sensitive marker of systemic inflammation used as a predictor for adverse cardiovascular outcomes in atherosclerotic heart disease. So in this study, we sought to evaluate the association between NLR and myocardial bridging. Methods: A total of 172 patients (mean age: 50.8 ± 11.5 years, 77.3% men with either angiographically proven MB or normal coronary arteries were included in the study. For the entire study population, hematologic parameters were measured using an automatic blood counter. Results: The study population consisted of 71 patients with MB (mean age: 51.4 ± 11.9 years, 80.3% male and 101 patients with normal coronary arteries (mean age: 50.5 ± 11.3 years, 75.2% male. There were no significant differences between groups regarding hemoglobin level, platelet count, glucose and creatinine. Compared to the control group, NLR was significantly higher in patients with MB (2.45 ± 1.19 vs. 1.72 ± 0.48; p 1.82 predicted myocardial bridge presence with 70% sensitivity and 71% specificity (ROC area under curve: 0.733, 95% CI: 0.654-0.811, p < 0.001. Conclusion: Our study findings demonstrated that MB is associated with elevated NLR, which is used to assess inflammatory status of the body. J Clin Exp Invest 2014; 5 (1: 24-28

  8. The complex interplay between neutrophils and cancer.

    Science.gov (United States)

    Rakic, Andrea; Beaudry, Paul; Mahoney, Douglas J

    2018-03-01

    Neutrophils are the most abundant type of white blood cell, and are an essential component of the innate immune system. They characteristically arrive rapidly at sites of infection and injury, and release a variety of cytokines and toxic molecules to eliminate pathogens and elicit an acute inflammatory response. Research into the function of neutrophils in cancer suggest they have divergent roles. Indeed, while most studies have found neutrophils to be associated with cancer progression, others have also documented anticancer effects. In this review, we describe the investigations into neutrophil populations that have been implicated in promoting tumor growth and metastasis as well those demonstrating antitumor functions. The collective research suggests a complex role for neutrophils in cancer biology, which raises the prospect of their targeting for the treatment of cancer.

  9. Platelet aggregation and quality control of platelet concentrates produced in the Amazon Blood Bank

    Directory of Open Access Journals (Sweden)

    Maria José Dantas Coêlho

    2011-01-01

    Full Text Available BACKGROUND: The study of platelet aggregation is essential to assess in vitro platelet function by different platelet activation pathways. OBJECTIVE: To assess aggregation and biochemical parameters of random platelet concentrates produced at the Fundação HEMOAM using the quality control tests defined by law. METHODS: Whole blood samples from 80 donors and the respective platelet concentrate units were tested. Platelet concentrates were tested (platelet count, aggregation and pH on days 1, 3 and 5 of storage. Additionally a leukocyte count was done only on day 1 and microbiological tests on day 5 of storage. Collagen and adenosine diphosphate were used as inducing agonists for platelet aggregation testing. RESULTS: Donor whole blood had normal aggregation (aggregation with adenosine diphosphate = 67% and with collagen = 78%. The median aggregation in platelet concentrates with adenosine diphosphate was low throughout storage (18% on day 1, 7% on day 3 and 6% on day 5 and the median aggregation with collagen was normal only on day 1 and low thereafter (54.4% on day 1, 20.5% on day 3 and 9% on day 5. CONCLUSION: Although the results were within the norms required by law, platelet concentrates had low aggregation rates. We suggest the inclusion of a functional assessment test for the quality control of platelet concentrates for a more effective response to platelet replacement therapy.

  10. Platelet aggregation during targeted temperature management after out-of-hospital cardiac arrest

    DEFF Research Database (Denmark)

    Jeppesen, Anni Nørgaard; Hvas, Anne-Mette; Grejs, Anders Morten

    2017-01-01

    Some studies conclude that mild hypothermia causes platelet dysfunction leading to an increased bleeding risk, whereas others state that platelet aggregation is enhanced during mild hypothermia. Therefore, the aim of this study was to clarify whether standard or prolonged duration of targeted...... temperature management affected platelet aggregation. We randomised 82 comatose patients resuscitated after out-of-hospital cardiac arrest to either 24 hours (standard group) or 48 hours (prolonged group) of targeted temperature management at 33±1°C. Blood samples were collected 22 hours, 46 hours and 70......® decreased by 14% (95% CI -8%;-20%), p management....

  11. Platelet lysate obtained via plateletpheresis performed in standing and awake equine donors.

    Science.gov (United States)

    Sumner, Scarlett M; Naskou, Maria C; Thoresen, Merrilee; Copland, Ian; Peroni, John F

    2017-07-01

    Platelet preparations containing growth factors, attachment factors, and enzymes are appealing to enhance healing of injured tissues and as an alternative to xenogenic serum in cell culture media. Plateletpheresis is commonly used to collect platelets in human medicine but has not been validated in horses. Plateletpheresis to collect platelet concentrate was performed on six female, mixed breed, chemically restrained horses using commercially available apheresis equipment. Before and immediately after plateletpheresis, we performed physical examinations and collected blood for chemistry and coagulation panels and then again at 8, 16, 24, and 48 hours after the procedure. To produce platelet lysate, the platelet concentrate underwent two freeze-thaw cycles followed by centrifugation and filtration processing. The platelet lysate was then analyzed for cellular debris, fibrinogen, and growth factors. The collected platelet concentration contained a mean platelet yield of 390 × 10 3 /μL. Donor platelet count decreased from a mean of 193 × 10 3 /μL to 138 × 10 3 /μL after plateletpheresis, but no individual was at risk for hemorrhage. Pooled platelet lysate had minimal cellular residue and contained growth factor concentrations at 6.1 ng/mL for transforming growth factor-β1, at 3.5 ng/mL for platelet-derived growth factor-BB, and at 13.8 ng/mL for vascular endothelial growth factor-A. Plateletpheresis using commercially available apheresis equipment is a feasible option for collecting platelet concentrate from equine donors. The lysate generated from the apheresis product contains growth factors and has potential to be used as a fetal bovine serum substitute for cell culture. © 2017 AABB.

  12. Inhibition of the plasma SCUBE1, a novel platelet adhesive protein, protects mice against thrombosis.

    Science.gov (United States)

    Wu, Meng-Ying; Lin, Yuh-Charn; Liao, Wei-Ju; Tu, Cheng-Fen; Chen, Ming-Huei; Roffler, Steve R; Yang, Ruey-Bing

    2014-07-01

    Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1), a secreted and surface-exposed glycoprotein on activated platelets, promotes platelet-platelet interaction and supports platelet-matrix adhesion. Its plasma level is a biomarker of platelet activation in acute thrombotic diseases. However, the exact roles of plasma SCUBE1 in vivo remain undefined. We generated new mutant (Δ) mice lacking the soluble but retaining the membrane-bound form of SCUBE1. Plasma SCUBE1-depleted Δ/Δ mice showed normal hematologic and coagulant features and expression of major platelet receptors, but Δ/Δ platelet-rich plasma showed impaired platelet aggregation in response to ADP and collagen treatment. The addition of purified recombinant SCUBE1 protein restored the aggregation of platelets in Δ/Δ platelet-rich plasma and further enhanced platelet aggregation in +/+ platelet-rich plasma. Plasma deficiency of SCUBE1 diminished arterial thrombosis in mice and protected against lethal thromboembolism induced by collagen-epinephrine treatment. Last, antibodies directed against the epidermal growth factor-like repeats of SCUBE1, which are involved in trans-homophilic protein-protein interactions, protected mice against fatal thromboembolism without causing bleeding in vivo. We conclude that plasma SCUBE1 participates in platelet aggregation by bridging adjacent activated platelets in thrombosis. Blockade of soluble SCUBE1 might represent a novel antithrombotic strategy. © 2014 American Heart Association, Inc.

  13. EXTENDED STORAGE OF BUFFY-COAT PLATELET CONCENTRATES IN PLASMA OR A PLATELET ADDITIVE SOLUTION

    Science.gov (United States)

    Slichter, Sherrill J.; Bolgiano, Doug; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Bailey, S. Lawrence; Pellham, Esther

    2014-01-01

    Background Platelet concentrates prepared from whole blood in the U.S. are made using the platelet-rich-plasma (PRP) method. The platelet concentrates must be made within 8 hours of blood collection and stored for only 5 days. In Europe and Canada, platelet concentrates are made using the buffy-coat (BC) method from whole blood held overnight at 22°C and storage times may be up to 7 days. Our studies were designed to determine how long BC platelets can be stored in plasma or Plasmalyte while meeting the FDA’s post-storage viability criteria. Study Design, Materials, And Methods Normal subjects donated whole blood that was stored at 22°C for 22 ± 2 hours prior to preparation of BC platelets. Platelets were stored for 5 to 8 days in either plasma or Plasmalyte concentrations of 65% or 80%. Radiolabeled autologous stored versus fresh platelet recoveries and survivals were assessed as well as post-storage in vitro assays. Results BC platelets stored in either plasma or 65% Plasmalyte met FDA post-storage platelet recovery criteria for 7 days but survivals for only 6 days, while storage in 80% Plasmalyte gave very poor results. Both stored platelet recoveries and survivals correlated with the same donor’s fresh results, but the correlation was much stronger between recoveries than survivals. In vitro measures of extent of shape change, morphology score, and pH best predicted post-storage platelet recoveries, while annexin V binding best predicted platelet survivals. Conclusion BC platelets stored in either plasma or 65% Plasmalyte meet FDA’s post-storage viability criteria for 6 days. PMID:24673482

  14. Spontaneous neutrophil migration patterns during sepsis after major burns.

    Science.gov (United States)

    Jones, Caroline N; Moore, Molly; Dimisko, Laurie; Alexander, Andrew; Ibrahim, Amir; Hassell, Bryan A; Warren, H Shaw; Tompkins, Ronald G; Fagan, Shawn P; Irimia, Daniel

    2014-01-01

    Finely tuned to respond quickly to infections, neutrophils have amazing abilities to migrate fast and efficiently towards sites of infection and inflammation. Although neutrophils ability to migrate is perturbed in patients after major burns, no correlations have yet been demonstrated between altered migration and higher rate of infections and sepsis in these patients when compared to healthy individuals. To probe if such correlations exist, we designed microfluidic devices to quantify the neutrophil migration phenotype with high precision. Inside these devices, moving neutrophils are confined in channels smaller than the neutrophils and forced to make directional decisions at bifurcations and around posts. We employed these devices to quantify neutrophil migration across 18 independent parameters in 74 blood samples from 13 patients with major burns and 3 healthy subjects. Blinded, retrospective analysis of clinical data and neutrophil migration parameters revealed that neutrophils isolated from blood samples collected during sepsis migrate spontaneously inside the microfluidic channels. The spontaneous neutrophil migration is a unique phenotype, typical for patients with major burns during sepsis and often observed one or two days before the diagnosis of sepsis is confirmed. The spontaneous neutrophil migration phenotype is rare in patients with major burns in the absence of sepsis, and is not encountered in healthy individuals. Our findings warrant further studies of neutrophils and their utility for early diagnosing and monitoring sepsis in patients after major burns.

  15. An oral Hemokine™, α-methylhydrocinnamate, enhances myeloid and neutrophil recovery following irradiation in vivo

    Science.gov (United States)

    Faller, Douglas V.; Castaneda, Serguei A.; Zhou, Daohong; Vedamony, Merriline; Newburger, Peter E.; White, Gary L.; Kosanke, Stanley; Plett, P. Artur; Orschell, Christie M.; Boosalis, Michael S.; Perrine, Susan P.

    2017-01-01

    An oral therapeutic which reduces duration of cytopenias and is active following accidental radiation exposures is an unmet need in radiation countermeasures. Alpha methylhydrocinnamate (ST7) prolongs STAT-5 phosphorylation, reduces growth-factor dependency of multi-lineage cell lines, and stimulates erythropoiesis. Here, ST7 and its isomers were studied for their effects on myeloid progenitors and hematopoietic stem cells (HSCs) following radiation, in nonhuman primates, and murine irradiation models. Addition of ST7 or ST7-S increased CFU-GM production by 1.7-fold (p200/mm3 and neutropenia recovered in 6 days with ST7 treatment and 18 days in controls (p<0.05). In lethally-irradiated mice, marrow pathology at 15 days was hypocellular (10% cellularity) in controls, but normal (55–75% cellularity) with complete neutrophil maturation with ST7-S treatment. Following lethal irradiation, ST7, given orally for 4 days, reduced mortality, with 30% survival in ST7-animals vs 8% in controls, (p<0.05). Collectively, the studies indicate that ST7 and ST7-S enhance myeloid recovery post-radiation and merit further evaluation to accelerate hematologic recovery in conditions of radiation-related and other marrow hypoplasias. PMID:27888688

  16. Pathophysiology of neutrophil-mediated extracellular redox reactions.

    Science.gov (United States)

    Jaganjac, Morana; Cipak, Ana; Schaur, Rudolf Joerg; Zarkovic, Neven

    2016-01-01

    Neutrophil granulocyte leukocytes (neutrophils) play fundamental role in the innate immune response. In the presence of adequate stimuli, neutrophils release excessive amount of reactive oxygen species (ROS) that may induce cell and tissue injury. Oxidative burst of neutrophils acts as a double-edged sword. It may contribute to the pathology of atherosclerosis and brain injury but is also necessary in resolving infections. Moreover, neutrophil-derived ROS may also have both a tumor promoting and tumor suppressing role. ROS have a specific activities and diffusion distance, which is related to their short lifetime. Therefore, the manner in which ROS will act depends on the cells targeted and the intra- and extracellular levels of individual ROS, which can further cause production of reactive aldehydes like 4-hydroxynonenal (HNE) that act as a second messengers of ROS. In this review we discuss the influence of neutrophil mediated extracellular redox reactions in ischemia reperfusion injury, transplant rejection and chronic diseases (atherosclerosis, inflammatory bowel diseases and cancer). At the end a brief overview of cellular mechanisms to maintain ROS homeostasis is given.

  17. FlnA binding to PACSIN2 F-BAR domain regulates membrane tubulation in megakaryocytes and platelets.

    Science.gov (United States)

    Begonja, Antonija Jurak; Pluthero, Fred G; Suphamungmee, Worawit; Giannini, Silvia; Christensen, Hilary; Leung, Richard; Lo, Richard W; Nakamura, Fumihiko; Lehman, William; Plomann, Markus; Hoffmeister, Karin M; Kahr, Walter H A; Hartwig, John H; Falet, Hervé

    2015-07-02

    Bin-Amphiphysin-Rvs (BAR) and Fes-CIP4 homology BAR (F-BAR) proteins generate tubular membrane invaginations reminiscent of the megakaryocyte (MK) demarcation membrane system (DMS), which provides membranes necessary for future platelets. The F-BAR protein PACSIN2 is one of the most abundant BAR/F-BAR proteins in platelets and the only one reported to interact with the cytoskeletal and scaffold protein filamin A (FlnA), an essential regulator of platelet formation and function. The FlnA-PACSIN2 interaction was therefore investigated in MKs and platelets. PACSIN2 associated with FlnA in human platelets. The interaction required FlnA immunoglobulin-like repeat 20 and the tip of PACSIN2 F-BAR domain and enhanced PACSIN2 F-BAR domain membrane tubulation in vitro. Most human and wild-type mouse platelets had 1 to 2 distinct PACSIN2 foci associated with cell membrane GPIbα, whereas Flna-null platelets had 0 to 4 or more foci. Endogenous PACSIN2 and transfected enhanced green fluorescent protein-PACSIN2 were concentrated in midstage wild-type mouse MKs in a well-defined invagination of the plasma membrane reminiscent of the initiating DMS and dispersed in the absence of FlnA binding. The DMS appeared less well defined, and platelet territories were not readily visualized in Flna-null MKs. We conclude that the FlnA-PACSIN2 interaction regulates membrane tubulation in MKs and platelets and likely contributes to DMS formation. © 2015 by The American Society of Hematology.

  18. Localization and Functionality of the Inflammasome in Neutrophils

    DEFF Research Database (Denmark)

    Bakele, Martina; Joos, Melanie; Burdi, Sofia

    2014-01-01

    Neutrophils represent the major fraction of circulating immune cells and are rapidly recruited to sites of infection and inflammation. The inflammasome is a multiprotein complex that regulates the generation of IL-1 family proteins. The precise subcellular localization and functionality...... of the inflammasome in human neutrophils are poorly defined. Here we demonstrate that highly purified human neutrophils express key components of the NOD-like receptor family, pyrin domain containing 3 (NLRP3), and absent in melanoma 2 (AIM2) inflammasomes, particularly apoptosis-associated speck-like protein...... and released as protein, highly purified neutrophils neither expressed nor released IL-1α at baseline or upon stimulation. Upon inflammasome activation, highly purified neutrophils released substantially lower levels of IL-1β protein compared with partially purified neutrophils. Serine proteases and caspases...

  19. Platelet destruction in autoimmune thrombocytopenic purpura: kinetics and clearance of indium-111-labeled autologous platelets

    International Nuclear Information System (INIS)

    Stratton, J.R.; Ballem, P.J.; Gernsheimer, T.; Cerqueira, M.; Slichter, S.J.

    1989-01-01

    Using autologous 111 In-labeled platelets, platelet kinetics and the sites of platelet destruction were assessed in 16 normal subjects (13 with and three without spleens), in 17 studies of patients with primary autoimmune thrombocytopenic purpura (AITP), in six studies of patients with secondary AITP, in ten studies of patients with AITP following splenectomy, and in five thrombocytopenic patients with myelodysplastic syndromes. In normal subjects, the spleen accounted for 24 +/- 4% of platelet destruction and the liver for 15 +/- 2%. Untreated patients with primary AITP had increased splenic destruction (40 +/- 14%, p less than 0.001) but not hepatic destruction (13 +/- 5%). Compared with untreated patients, prednisone treated patients did not have significantly different spleen and liver platelet sequestration. Patients with secondary AITP had similar platelet counts, platelet survivals, and increases in splenic destruction of platelets as did patients with primary AITP. In contrast, patients with myelodysplastic syndromes had a normal pattern of platelet destruction. In AITP patients following splenectomy, the five nonresponders all had a marked increase (greater than 45%) in liver destruction compared to five responders (all less than 40%). Among all patients with primary or secondary AITP, there was an inverse relationship between the percent of platelets destroyed in the liver plus spleen and both the platelet count (r = 0.75, p less than 0.001) and the platelet survival (r = 0.86, p less than 0.001). In a stepwise multiple linear regression analysis, total liver plus spleen platelet destruction, the platelet survival and the platelet turnover were all significant independent predictors of the platelet count. Thus platelet destruction is shifted to the spleen in primary and secondary AITP. Failure of splenectomy is associated with a marked elevation in liver destruction

  20. Treatment with Rutin - A Therapeutic Strategy for Neutrophil-Mediated Inflammatory and Autoimmune Diseases - Anti-inflammatory Effects of Rutin on Neutrophils -

    Directory of Open Access Journals (Sweden)

    Bahareh Abd Nikfarjam

    2017-03-01

    Full Text Available Objectives: Neutrophils represent the front line of human defense against infections. Immediately after stimulation, neutrophilic enzymes are activated and produce toxic mediators such as pro-inflammatory cytokines, nitric oxide (NO and myeloperoxidase (MPO. These mediators can be toxic not only to infectious agents but also to host tissues. Because flavonoids exhibit antioxidant and anti-inflammatory effects, they are subjects of interest for pharmacological modulation of inflammation. In the present study, the effects of rutin on stimulus-induced NO and tumor necrosis factor (TNF-α productions and MPO activity in human neutrophils were investigated. Methods: Human peripheral blood neutrophils were isolated using Ficoll-Hypaque density gradient centrifugation coupled with dextran T500 sedimentation. The cell preparations containing > 98% granulocytes were determined by morphological examination through Giemsa staining. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI medium, pre-incubated with or without rutin (25 μM for 45 minutes, and stimulated with phorbol 12-myristate 13-acetate (PMA. Then, the TNF-α, NO and MPO productions were analyzed using enzyme-linked immunosorbent assay (ELISA, Griess Reagent, and MPO assay kits, respectively. Also, the viability of human neutrophils was assessed using tetrazolium salt 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT, and neutrophils were treated with various concentrations of rutin (1 - 100 μM, after which MTT was appended and incubated at 37ºC for 4 hour. Results: Rutin at concentrations up to 100 μM did not affect neutrophil viability during the 4-hour incubation period. Rutin significantly decreased the NO and TNF-α productions in human peripheral blood neutrophils compared to PMA-control cells (P < 0.001. Also, MPO activity was significantly reduced by rutin (P < 0.001. Conclusion: In this in vitro study, rutin had an anti-inflammatory effect

  1. In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

    Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. The present study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, CSM Medical University, Lucknow. Random donor platelets were prepared by platelet rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators, with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7, with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution, whereas platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that platelet viability and aggregation were best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

  2. In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

    Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. This study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, C S M Medical University, Lucknow. Random donor platelets were prepared by the platelet-rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7 with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution while platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that the platelet viability and aggregation were the best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

  3. Platelet adhesiveness: the effect of centrifugation on the measurement of adhesiveness in platelet-rich plasma

    Science.gov (United States)

    McBride, J. A.

    1968-01-01

    Platelet adhesiveness has been measured in citrated whole blood and in platelet-rich plasma obtained from normal subjects, splenectomized patients, and from patients in whom the diagnosis of recurrent venous thrombosis had been made. The duration of centrifugation used in the preparation of platelet-rich plasma was found to have a profound effect on the measurement of platelet adhesiveness because the figure for platelet adhesiveness measured in platelet-rich plasma obtained by centrifugation was considerably lower than that found in citrated whole blood. This effect was particularly marked when platelet-rich plasma was obtained from subjects in whom platelet adhesiveness measured in whole blood was increased. PMID:5699080

  4. A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

    OpenAIRE

    Mustafa Tunalı; Hakan Özdemir; Zafer Küçükodacı; Serhan Akman; Emre Yaprak; Hülya Toker; Erhan Fıratlı

    2014-01-01

    We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn us...

  5. The use of autologous platelet-leukocyte gels to enhance the healing process in surgery, a review

    NARCIS (Netherlands)

    Everts, P. A.; Overdevest, E. P.; Jakimowicz, J. J.; Oosterbos, C. J.; Schonberger, J. P.; Knape, J. T.; van Zundert, A.

    2007-01-01

    Background: The therapeutic use of autologously prepared, platelet-leukocyte-enriched gel (PLG) is a relatively new technology for the stimulation and acceleration of soft tissue and bone healing. The effectiveness of this procedure lies in the delivery of a wide range of platelet growth factors

  6. Platelet turnover and kinetics in immune thrombocytopenic purpura: results with autologous 111In-labeled platelets and homologous 51Cr-labeled platelets differ

    International Nuclear Information System (INIS)

    Heyns A du, P.; Badenhorst, P.N.; Loetter, M.G.P.; Pieters, H.; Wessels, P.; Kotze, H.F.

    1986-01-01

    Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr-labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP

  7. Platelet lysate enhances synovial fluid multipotential stromal cells functions: Implications for therapeutic use.

    Science.gov (United States)

    Altaie, Ala; Baboolal, Thomas G; Wall, Owen; Jones, Elena; McGonagle, Dennis

    2018-03-01

    Although intra-articular injection of platelet products is increasingly used for joint regenerative approaches, there are few data on their biological effects on joint-resident multipotential stromal cells (MSCs), which are directly exposed to the effects of these therapeutic strategies. Therefore, this study investigated the effect of platelet lysate (PL) on synovial fluid-derived MSCs (SF-MSCs), which in vivo have direct access to sites of cartilage injury. SF-MSCs were obtained during knee arthroscopic procedures (N = 7). Colony forming unit-fibroblast (CFU-F), flow-cytometric phenotyping, carboxyfluorescein succinimidyl ester-based immunomodulation for T-cell and trilineage differentiation assays were performed using PL and compared with standard conditions. PL-enhanced SF-MSC (PL-MSC) proliferation as CFU-F colonies was 1.4-fold larger, and growing cultures had shorter population-doubling times. PL-MSCs and fetal calf serum (FCS)-MSCs had the same immunophenotype and similar immunomodulation activities. In chondrogenic and osteogenic differentiation assays, PL-MSCs produced 10% more sulfated-glycosaminoglycan (sGAG) and 45% less Ca ++ compared with FCS-MSCs, respectively. Replacing chondrogenic medium transforming growth factor-β3 with 20% or 50% PL further increased sGAG production of PL-MSCs by 69% and 95%, respectively, compared with complete chondrogenic medium. Also, Dulbecco's Modified Eagle's Medium high glucose (HG-DMEM) plus 50% PL induced more chondrogenesis compared with HG-DMEM plus 10% FCS and was comparable to complete chondrogenic medium. This is the first study to assess SF-MSC responses to PL and provides biological support to the hypothesis that PL may be capable of modulating multiple functional aspects of joint resident MSCs with direct access to injured cartilage. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  8. Survival of density subpopulations of rabbit platelets: use of 51Cr-or 111In-labeled platelets to measure survival of least dense and most dense platelets concurrently

    International Nuclear Information System (INIS)

    Rand, M.L.; Packham, M.A.; Mustard, J.F.

    1983-01-01

    The origin of the density heterogeneity of platelets was studied by measuring the survival of density subpopulations of rabbit platelets separated by discontinuous Stractan density gradient centrifugation. When a total population of 51 Cr-labelled platelets was injected into recipient rabbits, the relative specific radioactivity of the most dense platelets decreased rapidly. In contrast, that of the least dense platelets had not changed 24 hr after injection, and then decreased slowly. To distinguish between the possibilities that most dense platelets are cleared from the circulation more quickly than least dense platelets or that platelets decrease in density as they age in the circulation, the concurrent survival of least dense and most dense platelets, labelled with either 51 Cr or 111 In-labelled total platelet populations, determined concurrently in the same rabbits, are identical, calculated from 1 hr values as 100%. However, the 1-hr recovery of 111 In-labelled platelets was slightly but significantly less than that of 51 Cr-labelled platelets. Therefore, researchers studied the survival of 51 Cr-labelled least dense and 111 In-labelled most dense platelets as well as that of 111 In-labelled least dense and 51 Cr-labelled most dense platelets. Mean 1-hr recovery of least dense platelets, labelled with either isotope (78% +/- 7%, SD) was similar to that of most dense platelets, labelled with either isotope (77% +/- 8%; SD). Mean survival of least dense platelets was 47.3 +/- 18.7 hr (SD), which was significantly less than that of most dense platelets (76.1 +/- 21.6 hr; SD) (p less than 0.0025). These results indicate that platelets decrease in buoyant density as they age in the circulation and that most dense platelets are enriched in young platelets, and least dense in old

  9. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

    Energy Technology Data Exchange (ETDEWEB)

    Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. (Mt. Sinai Medical Center, New York, NY (USA))

    1989-09-01

    Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.

  10. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

    International Nuclear Information System (INIS)

    Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V.

    1989-01-01

    Blood-pool subtraction has been proposed to enhance 111 In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging

  11. Responsiveness of platelets during storage studied with flow cytometry--formation of platelet subpopulations and LAMP-1 as new markers for the platelet storage lesion.

    Science.gov (United States)

    Södergren, A L; Tynngård, N; Berlin, G; Ramström, S

    2016-02-01

    Storage lesions may prevent transfused platelets to respond to agonists and arrest bleeding. The aim of this study was to evaluate and quantify the capacity of platelet activation during storage using flow cytometry and new markers of platelet activation. Activation responses of platelets prepared by apheresis were measured on days 1, 5, 7 and 12. In addition, comparisons were made for platelet concentrates stored until swirling was affected. Lysosome-associated membrane protein-1 (LAMP-1), P-selectin and phosphatidylserine (PS) exposure were assessed by flow cytometry on platelets in different subpopulations in resting state or following stimulation with platelet agonists (cross-linked collagen-related peptide (CRP-XL), PAR1- and PAR4-activating peptides). The ability to form subpopulations upon activation was significantly decreased already at day 5 for some agonist combinations. The agonist-induced exposure of PS and LAMP-1 also gradually decreased with time. Spontaneous exposure of P-selectin and PS increased with time, while spontaneous LAMP-1 exposure was unchanged. In addition, agonist-induced LAMP-1 expression clearly discriminated platelet concentrates with reduced swirling from those with retained swirling. This suggests that LAMP-1 could be a good marker to capture changes in activation capacity in stored platelets. The platelet activation potential seen as LAMP-1 exposure and fragmentation into platelet subpopulations is potential sensitive markers for the platelet storage lesion. © 2015 International Society of Blood Transfusion.

  12. Changes of platelet GMP-140 in diabetic nephropathy and its multi-factor regression analysis

    International Nuclear Information System (INIS)

    Wang Zizheng; Du Tongxin; Wang Shukui

    2001-01-01

    The relation of platelet GMP-140 and its related factors with diabetic nephropathy was studied. 144 patients of diabetic mellitus without nephropathy (group without DN, mean suffering duration of 25.5 +- 18.6 months); 80 with diabetic nephropathy (group DN, mean suffering duration of 58.7 +- 31.6 months) and 50 normal controls were chosen in the research. Platelet GMP-140, plasma α 1 -MG, β 2 -MG, and 24 hour urine albumin (ALB), IgG, α 1 -MG, β 2 -MG were detected by RIA, while HBA 1 C via chromatographic separation and FBG, PBG, Ch, TG, HDL, FG via biochemical methods. All the data had been processed with software on computer with t-test and linear regression, and multi-factor analysis were done also. The levels of platelet GMP-140, FG, DBP, TG, HBA 1 C and PBG in group DN were significantly higher than those of group without DN and normal control (P 0.05), while they were higher than those of normal controls. Multi-factor analysis of platelet GMP-140 with TG, DBP and HBA 1 C were performed in 80 patients with DN (P 1 C are the independent factors enhancing the activation of platelets. The disturbance of lipid metabolism in type II diabetic mellitus may also enhance the activation of platelets. Elevation of blood pressure may accelerate the initiation and deterioration of DN in which change of platelet GMP-140 is an independent factor. Elevation of HBA 1 C and blood glucose are related closely to the diabetic nephropathy

  13. Age is the work of art? Impact of neutrophil and organism age on neutrophil extracellular trap formation.

    Science.gov (United States)

    Ortmann, Weronika; Kolaczkowska, Elzbieta

    2018-03-01

    Neutrophil extracellular traps or NETs are released by highly activated neutrophils in response to infectious agents, sterile inflammation, autoimmune stimuli and cancer. In the cells, the nuclear envelop disintegrates and decondensation of chromatin occurs that depends on peptidylarginine deiminase 4 (PAD4) and neutrophil elastase (NE). Subsequently, proteins from neutrophil granules (e.g., NE, lactoferrin and myeloperoxidase) and the nucleus (histones) bind to decondensed DNA and the whole structure is ejected from the cell. The DNA decorated with potent antimicrobials and proteases can act to contain dissemination of infection and in sterile inflammation NETs were shown to degrade cytokines and chemokines via serine proteases. On the other hand, overproduction of NETs, or their inadequate removal and prolonged presence in vasculature or tissues, can lead to bystander damage or even initiation of diseases. Considering the pros and cons of NET formation, it is of relevance if the stage of neutrophil maturation (immature, mature and senescent cells) affects the capacity to produce NETs as the cells of different age-related phenotypes dominate in given (pathological) conditions. Moreover, the immune system of neonates and elderly individuals is weaker than in adulthood. Is the same pattern followed when it comes to NETs? The overall importance of individual and neutrophil age on the capacity to release NETs is reviewed in detail and the significance of these facts is discussed.

  14. Crucial involvement of tumor-associated neutrophils in the regulation of chronic colitis-associated carcinogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Kun Shang

    Full Text Available Ulcerative colitis (UC is a major form of chronic inflammation that can frequently progress to colon cancer. Several studies have demonstrated massive infiltration of neutrophils and macrophages into the lamina propria and submucosa in the progression of UC-associated colon carcinogenesis. Macrophages contribute to the development of colitis-associated colon cancer (CAC. However, the role of neutrophils is not well understood. To better understand the involvement of tumor-associated neutrophils (TANs in the regulation of CAC, we used a mouse CAC model produced by administering azoxymethane (AOM, followed by repeated dextran sulfate sodium (DSS ingestion. This causes severe colonic inflammation and subsequent development of multiple tumors in mice colon. We observed that colorectal mucosal inflammation became increasingly severe with AOM and DSS treatment. Macrophages infiltrated the lamina propria and submucosa, together with a marked increase in neutrophil infiltration. The chemokine CXCL2 increased in the lamina propria and submucosal regions of the colons of the treated mice, together with the infiltration of neutrophils expressing CXCR2, a specific receptor for CXCL2. This process was followed by neoplastic transformation. After AOM and DSS treatment, the mice showed enhanced production of metalloproteinase (MMP-9 and neutrophil elastase (NE, accompanied by excessive vessel generation and cell proliferation. Moreover, CXCL2 promoted neutrophil recruitment and induced neutrophils to express MMP-9 and NE in vitro. Furthermore, administration of neutrophil-neutralizing antibodies after the last DSS cycle markedly reduced the number and size of tumors and decreased the expression of CXCR2, CXCL2, MMP-9, and NE. These observations indicate a crucial role for TANs in the initiation and progression of CAC and suggest that the CXCL2-CXCR2 axis might be useful in reducing the risk of UC-associated colon cancer.

  15. Crucial Involvement of Tumor-Associated Neutrophils in the Regulation of Chronic Colitis-Associated Carcinogenesis in Mice

    Science.gov (United States)

    Wang, Chen; Wang, Zhen; Gu, Hong-Yu; Du, Xiang; Zhou, Xiao-Yan; Zheng, Chun-Lei; Chi, Ya-Yun; Mukaida, Naofumi; Li, Ying-Yi

    2012-01-01

    Ulcerative colitis (UC) is a major form of chronic inflammation that can frequently progress to colon cancer. Several studies have demonstrated massive infiltration of neutrophils and macrophages into the lamina propria and submucosa in the progression of UC-associated colon carcinogenesis. Macrophages contribute to the development of colitis-associated colon cancer (CAC). However, the role of neutrophils is not well understood. To better understand the involvement of tumor-associated neutrophils (TANs) in the regulation of CAC, we used a mouse CAC model produced by administering azoxymethane (AOM), followed by repeated dextran sulfate sodium (DSS) ingestion. This causes severe colonic inflammation and subsequent development of multiple tumors in mice colon. We observed that colorectal mucosal inflammation became increasingly severe with AOM and DSS treatment. Macrophages infiltrated the lamina propria and submucosa, together with a marked increase in neutrophil infiltration. The chemokine CXCL2 increased in the lamina propria and submucosal regions of the colons of the treated mice, together with the infiltration of neutrophils expressing CXCR2, a specific receptor for CXCL2. This process was followed by neoplastic transformation. After AOM and DSS treatment, the mice showed enhanced production of metalloproteinase (MMP)-9 and neutrophil elastase (NE), accompanied by excessive vessel generation and cell proliferation. Moreover, CXCL2 promoted neutrophil recruitment and induced neutrophils to express MMP-9 and NE in vitro. Furthermore, administration of neutrophil-neutralizing antibodies after the last DSS cycle markedly reduced the number and size of tumors and decreased the expression of CXCR2, CXCL2, MMP-9, and NE. These observations indicate a crucial role for TANs in the initiation and progression of CAC and suggest that the CXCL2–CXCR2 axis might be useful in reducing the risk of UC-associated colon cancer. PMID:23272179

  16. Modulation of neutrophil and monocyte function by recombinant human granulocyte macrophage colony-stimulating factor in patients with lymphoma

    DEFF Research Database (Denmark)

    Kharazmi, A; Nielsen, H; Hovgaard, D

    1991-01-01

    by up to 43-fold. rhGM-CSF treatment did not affect degranulation of the neutrophils as measured by release of vitamin B12 binding protein. Degree of modulation of neutrophil and monocyte function by rhGM-CSF was independent of rhGM-CSF dosages administered. These data suggest that phagocytic defence...... and chemiluminescence responses to f-Met-Leu-Phe, zymosan activated serum (ZAS) and opsonized zymosan (OZ) were determined. It was observed that chemotactic response of neutrophils to f-Met-Leu-Phe and ZAS was reduced, whereas the chemiluminescence response of both cell types to f-Met-Leu-Phe and zymosan was enhanced...

  17. Platelet count

    Science.gov (United States)

    The normal number of platelets in the blood is 150,000 to 400,000 platelets per microliter (mcL) or 150 to 400 × 10 9 /L. Normal value ranges may vary slightly. Some lab use different measurements or ...

  18. Platelet mimicry

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Hunter, Alan Christy; Peer, Dan

    2016-01-01

    Here we critically examine whether coating of nanoparticles with platelet membranes can truly disguise them against recognition by elements of the innate immune system. We further assess whether the "cloaking technology" can sufficiently equip nanoparticles with platelet-mimicking functionalities...

  19. Comparative Effects of Platelet-Rich Plasma, Platelet Lysate, and Fetal Calf Serum on Mesenchymal Stem Cells.

    Science.gov (United States)

    Lykov, A P; Bondarenko, N A; Surovtseva, M A; Kim, I I; Poveshchenko, O V; Pokushalov, E A; Konenkov, V I

    2017-10-01

    We studied the effects of human platelet-rich plasma and platelet lysate on proliferation, migration, and colony-forming properties of rat mesenchymal stem cells. Platelet-rich plasma and platelet lysate stimulated the proliferation, migration, and colony formation of mesenchymal stem cells. A real-time study showed that platelet-rich plasma produces the most potent stimulatory effect, while both platelet-rich plasma and platelet lysate stimulated migration of cells.

  20. In Vitro Evaluation of the Link Between Cell Activation State and Its Rheological Impact on the Microscale Flow of Neutrophil Suspensions

    Science.gov (United States)

    Akenhead, Michael L.; Horrall, Nolan M.; Rowe, Dylan; Sethu, Palaniappan; Shin, Hainsworth Y.

    2015-01-01

    Activated neutrophils have been reported to affect peripheral resistance, for example, by plugging capillaries or adhering to the microvasculature. In vivo and ex vivo data indicate that activated neutrophils circulating in the blood also influence peripheral resistance. We used viscometry and microvascular mimics for in vitro corroboration. The rheological impact of differentiated neutrophil-like HL-60 promyelocytes (dHL60s) or human neutrophil suspensions stimulated with 10 nM fMet-Leu-Phe (fMLP) was quantified using a cone-plate rheometer (450 s−1 shear rate). To evaluate their impact on microscale flow resistance, we used 10-μm Isopore® membranes to model capillaries as well as single 200 × 50 μm microchannels and networks of twenty 20 × 50 μm microfluidic channels to mimic noncapillary microvasculature. Stimulation of dHL60 and neutrophil populations significantly altered their flow behavior as evidenced by their impact on suspension viscosity. Notably, hematocrit abrogated the impact of leukocyte activation on blood cell suspension viscosity. In micropore filters, activated cell suspensions enhanced flow resistance. This effect was further enhanced by the presence of erythrocytes. The resistance of our noncapillary microvascular mimics to flow of activated neutrophil suspensions was significantly increased only with hematocrit. Notably, it was elevated to a higher extent within the micronetwork chambers compared to the single-channel chambers. Collectively, our findings provide supportive evidence that activated neutrophils passing through the microcirculation may alter hemodynamic resistance due to their altered rheology in the noncapillary microvasculature. This effect is another way neutrophil activation due to chronic inflammation may, at least in part, contribute to the elevated hemodynamic resistance associated with cardiovascular diseases (e.g., hypertension and hypercholesterolemia). PMID:26065495

  1. In Vitro Evaluation of the Link Between Cell Activation State and Its Rheological Impact on the Microscale Flow of Neutrophil Suspensions.

    Science.gov (United States)

    Akenhead, Michael L; Horrall, Nolan M; Rowe, Dylan; Sethu, Palaniappan; Shin, Hainsworth Y

    2015-09-01

    Activated neutrophils have been reported to affect peripheral resistance, for example, by plugging capillaries or adhering to the microvasculature. In vivo and ex vivo data indicate that activated neutrophils circulating in the blood also influence peripheral resistance. We used viscometry and microvascular mimics for in vitro corroboration. The rheological impact of differentiated neutrophil-like HL-60 promyelocytes (dHL60s) or human neutrophil suspensions stimulated with 10 nM fMet-Leu-Phe (fMLP) was quantified using a cone-plate rheometer (450 s(-1) shear rate). To evaluate their impact on microscale flow resistance, we used 10-μm Isopore® membranes to model capillaries as well as single 200 × 50 μm microchannels and networks of twenty 20 × 50 μm microfluidic channels to mimic noncapillary microvasculature. Stimulation of dHL60 and neutrophil populations significantly altered their flow behavior as evidenced by their impact on suspension viscosity. Notably, hematocrit abrogated the impact of leukocyte activation on blood cell suspension viscosity. In micropore filters, activated cell suspensions enhanced flow resistance. This effect was further enhanced by the presence of erythrocytes. The resistance of our noncapillary microvascular mimics to flow of activated neutrophil suspensions was significantly increased only with hematocrit. Notably, it was elevated to a higher extent within the micronetwork chambers compared to the single-channel chambers. Collectively, our findings provide supportive evidence that activated neutrophils passing through the microcirculation may alter hemodynamic resistance due to their altered rheology in the noncapillary microvasculature. This effect is another way neutrophil activation due to chronic inflammation may, at least in part, contribute to the elevated hemodynamic resistance associated with cardiovascular diseases (e.g., hypertension and hypercholesterolemia).

  2. Platelet receptor polymorphisms do not influence Staphylococcus aureus–platelet interactions or infective endocarditis

    Science.gov (United States)

    Daga, Shruti; Shepherd, James G.; Callaghan, J. Garreth S.; Hung, Rachel K.Y.; Dawson, Dana K.; Padfield, Gareth J.; Hey, Shi Y.; Cartwright, Robyn A.; Newby, David E.; Fitzgerald, J. Ross

    2011-01-01

    Cardiac vegetations result from bacterium–platelet adherence, activation and aggregation, and are associated with increased morbidity and mortality in infective endocarditis. The GPIIb/IIIa and FcγRIIa platelet receptors play a central role in platelet adhesion, activation and aggregation induced by endocarditis pathogens such as Staphylococcus aureus, but the influence of known polymorphisms of these receptors on the pathogenesis of infective endocarditis is unknown. We determined the GPIIIa platelet antigen PlA1/A2 and FcγRIIa H131R genotype of healthy volunteers (n = 160) and patients with infective endocarditis (n = 40), and investigated the influence of these polymorphisms on clinical outcome in infective endocarditis and S. aureus–platelet interactions in vitro. Platelet receptor genotype did not correlate with development of infective endocarditis, vegetation characteristics on echocardiogram or the composite clinical end-point of embolism, heart failure, need for surgery or mortality (P > 0.05 for all), even though patients with the GPIIIa PlA1/A1 genotype had increased in vivo platelet activation (P = 0.001). Furthermore, neither GPIIIa PlA1/A2 nor FcγRIIa H131R genotype influenced S. aureus-induced platelet adhesion, activation or aggregation in vitro (P > 0.05). Taken together, our data suggest that the GPIIIa and FcγRIIa platelet receptor polymorphisms do not influence S. aureus–platelet interactions in vitro or the clinical course of infective endocarditis. PMID:21044892

  3. Differential stimulation of luminol-enhanced chemiluminescence (CL) and arachidonic acid metabolism in rat peritoneal neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, R.J.; Adams, L.M.; Cullinan, C.A.; Berkenkopf, J.W.; Weichman, B.M.

    1986-03-05

    Phorbol 12-myristate, 13-acetate (PMA) induced the production of radical oxygen species (ROS) from rat peritoneal neutrophils as assessed by CL. ROS generation occurred in a time- (maximum at 13.5 min) and dose- (concentration range of 1.7-498 nM) related fashion. However, 166 nM PMA did not induce either cyclooxygenase (CO) or lipoxygenase (LPO) product formation by 20 min post-stimulation. Conversely, A23187, at concentrations between 0.1 and 10 ..mu..M, stimulated both pathways of arachidonic acid metabolism, but had little or no effect upon ROS production. When suboptimal concentrations of PMA (5.5 nM) and A23187 (0.1-1 ..mu..M) were coincubated with the neutrophils, a synergistic ROS response was elicited. However, arachidonic acid metabolism in the presence of PMA was unchanged relative to A12187 alone. Nordihydroguaiaretic acid (NDGA) inhibited both PMA-induced CL (IC/sub 50/ = 0.9 ..mu..M) and A23187-induced arachidonic acid metabolism (IC/sub 50/ = 1.7 ..mu..M and 6.0 ..mu..M for LPO and CO, respectively). The mixed LPO-CO inhibitor, BW755C, behaved in a qualitatively similar manner to NDGA, whereas the CO inhibitors, indomethacin, piroxicam and naproxen had no inhibitory effect on ROS generation at concentrations as high as 100 ..mu..M. These results suggest that NDGA and BW755C may inhibit CL and arachidonic acid metabolism by distinct mechanisms in rat neutrophils.

  4. Platelet factor 4 impairs the anticoagulant activity of activated protein C.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2012-02-01

    Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated. In this study we demonstrate that PF4 significantly inhibits APC anti-coagulant activity. PF4 inhibited both protein S-dependent APC anticoagulant function in plasma and protein S-dependent factor Va (FVa) proteolysis 3- to 5-fold, demonstrating that PF4 impairs protein S cofactor enhancement of APC anticoagulant function. Using recombinant factor Va variants FVa-R506Q\\/R679Q and FVa-R306Q\\/R679Q, PF4 was shown to impair APC proteolysis of FVa at position Arg(306) by 3-fold both in the presence and absence of protein S. These data suggest that PF4 contributes to the poorly understood APC resistance phenotype associated with activated platelets. Finally, despite PF4 binding to the APC Gla domain, we show that APC in the presence of PF4 retains its ability to initiate PAR-1-mediated cytoprotective signaling. In summary, we propose that PF4 acts as a critical regulator of APC generation, but also differentially targets APC toward cytoprotective, rather than anticoagulant function at sites of vascular injury with concurrent platelet activation.

  5. Platelet factor 4 impairs the anticoagulant activity of activated protein C.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2009-02-27

    Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated. In this study we demonstrate that PF4 significantly inhibits APC anti-coagulant activity. PF4 inhibited both protein S-dependent APC anticoagulant function in plasma and protein S-dependent factor Va (FVa) proteolysis 3- to 5-fold, demonstrating that PF4 impairs protein S cofactor enhancement of APC anticoagulant function. Using recombinant factor Va variants FVa-R506Q\\/R679Q and FVa-R306Q\\/R679Q, PF4 was shown to impair APC proteolysis of FVa at position Arg(306) by 3-fold both in the presence and absence of protein S. These data suggest that PF4 contributes to the poorly understood APC resistance phenotype associated with activated platelets. Finally, despite PF4 binding to the APC Gla domain, we show that APC in the presence of PF4 retains its ability to initiate PAR-1-mediated cytoprotective signaling. In summary, we propose that PF4 acts as a critical regulator of APC generation, but also differentially targets APC toward cytoprotective, rather than anticoagulant function at sites of vascular injury with concurrent platelet activation.

  6. Congenital platelet function defects

    Science.gov (United States)

    ... pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... Congenital platelet function defects are bleeding disorders that cause reduced platelet function. Most of the time, people with these disorders have ...

  7. Flavanols and Platelet Reactivity

    Directory of Open Access Journals (Sweden)

    Debra A. Pearson

    2005-01-01

    Full Text Available Platelet activity and platelet-endothelial cell interactions are important in the acute development of thrombosis, as well as in the pathogenesis of cardiovascular disease. An increasing number of foods have been reported to have platelet-inhibitory actions, and research with a number of flavanol-rich foods, including, grape juice, cocoa and chocolate, suggests that these foods may provide some protection against thrombosis. In the present report, we review a series of in vivo studies on the effects of flavanol-rich cocoa and chocolate on platelet activation and platelet-dependent primary hemostasis. Consumption of flavanol-rich cocoa inhibited several measures of platelet activity including, epinephrine- and ADP-induced glycoprotein (GP IIb/IIIa and P-Selectin expression, platelet microparticle formation, and epinephrine-collagen and ADP-collagen induced primary hemostasis. The epinephrine-induced inhibitory effects on GP IIb/IIIa and primary hemostasis were similar to, though less robust than those associated with the use of low dose (81 mg aspirin. These data, coupled with information from other studies, support the concept that flavanols present in cocoa and chocolate can modulate platelet function through a multitude of pathways.

  8. Cryptococcus neoformans modulates extracellular killing by neutrophils

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    Asfia eQureshi

    2011-09-01

    Full Text Available We recently established a key role for host sphingomyelin synthase (SMS in the regulation of the killing activity of neutrophils against Cryptococcus neoformans. In this work, we studied the effect of C. neoformans on the killing activity of neutrophils and whether SMS would still be a player against C. neoformans in immunocompromised mice lacking T and NK cells (Tgε26 mice. To this end, we analyzed whether C. neoformans would have any effect on neutrophil survival and killing in vitro and in vivo. We show that unlike C. albicans, neither the presence nor the capsule size of C. neoformans cells have any effect on neutrophil viability. Interestingly, melanized C. neoformans cells totally abrogated the killing activity of neutrophils. Next, we monitored how exposure of neutrophils to C. neoformans cells would interfere with any further killing activity of the medium and found that pre-incubation with live but not heat-killed fungal cells significantly inhibits further killing activity of the medium. We next studied whether activation of SMS at the site of C. neoformans infection is dependent on T and NK cells. Using matrix-assisted laser desorption-ionization (MALDI tissue imaging in infected lung we found that similarly to previous observations in the isogenic wild type CBA/J mice, SM 16:0 levels are significantly elevated at the site of infection in mice lacking T and NK cells but only at early time points. This study highlights that C. neoformans may negatively regulate the killing activity of neutrophils and that SMS activation in neutrophils appears to be partially independent of T and/or NK cells.

  9. Contribution of neutrophils to acute lung injury.

    Science.gov (United States)

    Grommes, Jochen; Soehnlein, Oliver

    2011-01-01

    Treatment of acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), remain unsolved problems of intensive care medicine. ALI/ARDS are characterized by lung edema due to increased permeability of the alveolar-capillary barrier and subsequent impairment of arterial oxygenation. Lung edema, endothelial and epithelial injury are accompanied by an influx of neutrophils into the interstitium and broncheoalveolar space. Hence, activation and recruitment of neutrophils are regarded to play a key role in progression of ALI/ARDS. Neutrophils are the first cells to be recruited to the site of inflammation and have a potent antimicrobial armour that includes oxidants, proteinases and cationic peptides. Under pathological circumstances, however, unregulated release of these microbicidal compounds into the extracellular space paradoxically can damage host tissues. This review focuses on the mechanisms of neutrophil recruitment into the lung and on the contribution of neutrophils to tissue damage in ALI.

  10. Phenotypic Diversity and Plasticity in Circulating Neutrophil Subpopulations in Cancer

    Directory of Open Access Journals (Sweden)

    Jitka Y. Sagiv

    2015-02-01

    Full Text Available Controversy surrounds neutrophil function in cancer because neutrophils were shown to provide both pro- and antitumor functions. We identified a heterogeneous subset of low-density neutrophils (LDNs that appear transiently in self-resolving inflammation but accumulate continuously with cancer progression. LDNs display impaired neutrophil function and immunosuppressive properties, characteristics that are in stark contrast to those of mature, high-density neutrophils (HDNs. LDNs consist of both immature myeloid-derived suppressor cells (MDSCs and mature cells that are derived from HDNs in a TGF-β-dependent mechanism. Our findings identify three distinct populations of circulating neutrophils and challenge the concept that mature neutrophils have limited plasticity. Furthermore, our findings provide a mechanistic explanation to mitigate the controversy surrounding neutrophil function in cancer.

  11. Enhanced ex vivo inhibition of platelet function following addition of dipyridamole to aspirin after transient ischaemic attack or ischaemic stroke: first results from the TRinity AntiPlatelet responsiveness (TrAP) study.

    LENUS (Irish Health Repository)

    Tobin, William Oliver

    2012-02-01

    Ex vivo dipyridamole \\'non-responsiveness\\' has not been extensively studied in ischaemic cerebrovascular disease. Platelet surface marker expression, leucocyte-platelet complex formation and inhibition of platelet function at high shear stress as detected by the PFA-100(R) Collagen-Adenosine-diphosphate (C-ADP) and Collagen-Epinephrine cartridges was assessed in 52 patients within 4 weeks of transient ischaemic attack (TIA) or ischaemic stroke on aspirin, and then 14 d (14 d) and >90 d (90 d) after adding dipyridamole. A novel definition of \\'Dipyridamole non-responsiveness\\' was used. The median C-ADP closure time increased following addition of dipyridamole, remained elevated at 90 d (P <\\/= 0.03), and was unaffected by aspirin dose. 59% at 14 d and 56% at 90 d were \\'dipyridamole non-responders\\' on the PFA-100. The proportion of non-responders at 14 and 90 d was similar (P= 0.9). Compared with baseline (4.6%), median monocyte-platelet complexes increased at 14 d (5.0%, P= 0.03) and 90 d (4.9%, P= 0.04). Low C-ADP closure times were associated with increased monocyte-platelet complexes at 14 d (r= -0.32, P= 0.02) and 90 d (r= -0.33, P = 0.02). Monocyte-platelet complexes increased in the subgroup of dipyridamole non-responders on the PFA-100 (P<\\/= 0.045), but not in responders (P >\\/= 0.5), at 14 and 90 d versus baseline. Additional inhibition of platelet function has been detected with the PFA-100 when dipyridamole is added to aspirin. Elevated monocyte-platelet complexes may contribute to ex vivo dipyridamole non-responsiveness.

  12. Differential Effect of Viable Versus Necrotic Neutrophils on Mycobacterium tuberculosis Growth and Cytokine Induction in Whole Blood

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    David M. Lowe

    2018-04-01

    Full Text Available Neutrophils exert both positive and negative influences on the host response to tuberculosis, but the mechanisms by which these differential effects are mediated are unknown. We studied the impact of live and dead neutrophils on the control of Mycobacterium tuberculosis using a whole blood bioluminescence-based assay, and assayed supernatant cytokine concentrations using Luminex™ technology and ELISA. CD15+ granulocyte depletion from blood prior to infection with M. tuberculosis-lux impaired control of mycobacteria by 96 h, with a greater effect than depletion of CD4+, CD8+, or CD14+ cells (p < 0.001. Augmentation of blood with viable granulocytes significantly improved control of mycobacteria by 96 h (p = 0.001, but augmentation with necrotic granulocytes had the opposite effect (p = 0.01. Both augmentations decreased supernatant concentrations of tumor necrosis factor and interleukin (IL-12 p40/p70, but necrotic granulocyte augmentation also increased concentrations of IL-10, G-CSF, GM-CSF, and CCL2. Necrotic neutrophil augmentation reduced phagocytosis of FITC-labeled M. bovis BCG by all phagocytes, whereas viable neutrophil augmentation specifically reduced early uptake by CD14+ cells. The immunosuppressive effect of dead neutrophils required necrotic debris rather than supernatant. We conclude that viable neutrophils enhance control of M. tuberculosis in blood, but necrotic neutrophils have the opposite effect—the latter associated with induction of IL-10, growth factors, and chemoattractants. Our findings suggest a mechanism by which necrotic neutrophils may exert detrimental effects on the host response in active tuberculosis.

  13. Platelet oxidative stress and its relationship with cardiovascular diseases in type 2 diabetes mellitus patients.

    Science.gov (United States)

    El Haouari, Mohammed

    2017-10-05

    Enhanced platelet activation and thrombosis are linked to various cardiovascular diseases. Among other mechanisms, oxidative stress seems to play a pivotal role in platelet hyperactivity. Indeed, upon stimulation by physiological agonists, human platelets generate and release several types of reactive oxygen species (ROS) such as O2-, H2O2 or OH- , further amplifying the platelet activation response via various signalling pathways, including, formation of isoprostanes, Ca2+ mobilization and NO inactivation. Furthermore, excessive platelet ROS generation, incorporation of free radicals from environment and/or depletion of antioxidants induce pro-oxidant, pro-inflammatory and platelet hyperaggregability effects, leading to the incidence of cardiovascular events. Here, we review the current knowledge regarding the effect of oxidative stress on platelet signaling pathways and its implication in CVD such as type 2 diabetes mellitus. We also summarize the role of natural antioxidants included in vegetables, fruits and medicinal herbs in reducing platelet function via an oxidative stress-mediated mechanism. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Alternatives to allogeneic platelet transfusion.

    Science.gov (United States)

    Desborough, Michael J R; Smethurst, Peter A; Estcourt, Lise J; Stanworth, Simon J

    2016-11-01

    Allogeneic platelet transfusions are widely used for the prevention and treatment of bleeding in thrombocytopenia. Recent evidence suggests platelet transfusions have limited efficacy and are associated with uncertain immunomodulatory risks and concerns about viral or bacterial transmission. Alternatives to transfusion are a well-recognised tenet of Patient Blood Management, but there has been less focus on different strategies to reduce bleeding risk by comparison to platelet transfusion. Direct alternatives to platelet transfusion include agents to stimulate endogenous platelet production (thrombopoietin mimetics), optimising platelet adhesion to endothelium by treating anaemia or increasing von Willebrand factor levels (desmopressin), increasing formation of cross-linked fibrinogen (activated recombinant factor VII, fibrinogen concentrate or recombinant factor XIII), decreasing fibrinolysis (tranexamic acid or epsilon aminocaproic acid) or using artificial or modified platelets (cryopreserved platelets, lyophilised platelets, haemostatic particles, liposomes, engineered nanoparticles or infusible platelet membranes). The evidence base to support the use of these alternatives is variable, but an area of active research. Much of the current randomised controlled trial focus is on evaluation of the use of thrombopoietin mimetics and anti-fibrinolytics. It is also recognised that one alternative strategy to platelet transfusion is choosing not to transfuse at all. © 2016 John Wiley & Sons Ltd.

  15. Azurophil granule proteins constitute the major mycobactericidal proteins in human neutrophils and enhance the killing of mycobacteria in macrophages.

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    Prajna Jena

    Full Text Available Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule proteins (AZP were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane resulting in killing of mycobacteria. Exogenous addition of AZP to murine macrophage RAW 264.7, THP-1 and peripheral blood monocyte-derived macrophages significantly reduced the intracellular survival of mycobacteria without exhibiting cytotoxic activity on macrophages. Immunofluorescence studies showed that macrophages actively endocytose neutrophil granular proteins. Treatment with AZP resulted in increase in co-localization of BCG containing phagosomes with lysosomes but not in increase of autophagy. These data demonstrate that neutrophil azurophil proteins may play an important role in controlling intracellular survival of mycobacteria in macrophages.

  16. Hidden truth of circulating neutrophils (polymorphonuclear neutrophil function in periodontally healthy smoker subjects

    Directory of Open Access Journals (Sweden)

    Chitra Agarwal

    2016-01-01

    Full Text Available Context: Tobacco smoking is considered to be a major risk factor associated with periodontal disease. Smoking exerts a major effect on the protective elements of the immune response, resulting in an increase in the extent and severity of periodontal destruction. Aims: The aim of the present study was to assess viability and phagocytic function of neutrophils in circulating blood of the smokers and nonsmokers who are periodontally healthy. Settings and Design: Two hundred subjects in the mean range of 20–30 years of age were included in the study population. It was a retrospective study carried out for 6 months. Materials and Methods: Two hundred subjects were divided into four groups: 50 nonsmokers, 50 light smokers (15 cigarettes/day. Full mouth plaque index, sulcus bleeding index, and probing depths were measured. Percentage viability of circulating neutrophils and average number of phagocytosed Candida albicans were recorded. Statistical Analysis Used: Means and standard deviations were calculated from data obtained within the groups. Comparison between the smokers and nonsmokers was performed by Kruskal–Wallis ANOVA analysis. Comparison between smoker groups was performed using Mann–Whitney–Wilcoxon test. Results: Percentage viability of neutrophils was significantly less in heavy smokers (66.9 ± 4.0, moderate (76.6 ± 4.2, light smokers (83.1 ± 2.5 as compared to nonsmokers (92.3 ± 2.6 (P < 0.01. The ability of neutrophils to phagocytose, i.e., mean particle number was significantly less in light smokers (3.5 ± 0.5, moderate smokers (2.3 ± 0.5, and heavy smokers (1.4 ± 0.5 compared to nonsmokers (4.9 ± 0.7 (P < 0.01 with evidence of dose-response effect. Conclusions: Smoking significantly affects neutrophils viability and phagocytic function in periodontally healthy population.

  17. Platelet activation, adhesion, inflammation, and aggregation potential are altered in the presence of electronic cigarette extracts of variable nicotine concentrations.

    Science.gov (United States)

    Hom, Sarah; Chen, Li; Wang, Tony; Ghebrehiwet, Berhane; Yin, Wei; Rubenstein, David A

    2016-11-01

    Tobacco smoke extracts prepared from both mainstream and sidestream smoking have been associated with heightened platelet activation, aggregation, adhesion, and inflammation. Conversely, it has been shown that pure nicotine inhibits similar platelet functions. In this work, we 1) evaluated the effects of e-cigarette extracts on platelet activities and 2) elucidated the differences between the nicotine-dependent and non-nicotine dependent (e.g. fine particulate matter or toxic compounds) effects of tobacco and e-cigarette products on platelet activities. To accomplish these goals, platelets from healthy volunteers (n = 50) were exposed to tobacco smoke extracts, e-cigarette vapor extracts, and pure nicotine and changes in platelet activation, adhesion, aggregation, and inflammation were evaluated, using optical aggregation, flow cytometry, and ELISA methods. Interestingly, the exposure of platelets to e-vapor extracts induced a significant up-regulation in the expression of the pro-inflammatory gC1qR and cC1qR and induced a marked increase in the deposition of C3b as compared with traditional tobacco smoke extracts. Similarly, platelet activation, as measured by a prothrombinase based assay, and platelet aggregation were also significantly enhanced after exposure to e-vapor extracts. Finally, platelet adhesion potential toward fibrinogen, von Willebrand factor, and other platelets was also enhanced after exposure to e-cigarette vapor extracts. In the presence of pure nicotine, platelet functions were observed to be inhibited, which further suggests that other constituents of tobacco smoke and electronic vapor can antagonize platelet functions, however, the presence of nicotine in extracts somewhat perpetuated the platelet functional changes in a dose-dependent manner.

  18. Peroxiredoxin II is an antioxidant enzyme that negatively regulates collagen-stimulated platelet function.

    Science.gov (United States)

    Jang, Ji Yong; Wang, Su Bin; Min, Ji Hyun; Chae, Yun Hee; Baek, Jin Young; Yu, Dae-Yeul; Chang, Tong-Shin

    2015-05-01

    Collagen-induced platelet signaling is mediated by binding to the primary receptor glycoprotein VI (GPVI). Reactive oxygen species produced in response to collagen have been found to be responsible for the propagation of GPVI signaling pathways in platelets. Therefore, it has been suggested that antioxidant enzymes could down-regulate GPVI-stimulated platelet activation. Although the antioxidant enzyme peroxiredoxin II (PrxII) has emerged as having a role in negatively regulating signaling through various receptors by eliminating H2O2 generated upon receptor stimulation, the function of PrxII in collagen-stimulated platelets is not known. We tested the hypothesis that PrxII negatively regulates collagen-stimulated platelet activation. We analyzed PrxII-deficient murine platelets. PrxII deficiency enhanced GPVI-mediated platelet activation through the defective elimination of H2O2 and the impaired protection of SH2 domain-containing tyrosine phosphatase 2 (SHP-2) against oxidative inactivation, which resulted in increased tyrosine phosphorylation of key components for the GPVI signaling cascade, including Syk, Btk, and phospholipase Cγ2. Interestingly, PrxII-mediated antioxidative protection of SHP-2 appeared to occur in the lipid rafts. PrxII-deficient platelets exhibited increased adhesion and aggregation upon collagen stimulation. Furthermore, in vivo experiments demonstrated that PrxII deficiency facilitated platelet-dependent thrombus formation in injured carotid arteries. This study reveals that PrxII functions as a protective antioxidant enzyme against collagen-stimulated platelet activation and platelet-dependent thrombosis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Collagen induced aggregation of platelets and release of 14C serotonin from platelets depending on temperature and pH during in vitro storage of platelets

    International Nuclear Information System (INIS)

    Krause, J.

    1978-01-01

    The paper investigates collagen-induced platelet aggregation and 14 C serotonin release in dependence of age, temperature, and pH value during the storage of the conserved platelets. The optimum pH (with adjusted CO 2 /air mixture) for platelet storage is found to be pH 6.9. The optimum temperature for platelet storage is 4-8 0 C. After 12, 24, or 48 hours of storage at pH 6.9 and 4-8 0 C and subsequent heating of the platelet-rich plasma to 37 0 C for 30 minutes, the values determined for collagen-induced platelet aggregation and 14 C serotonin release rarely differed from the initial values before storage. Cold-induced spontaneous platelet aggregation and serotonin release of the platelets stored at 4-8 0 C can be avoided by 30-60 minutes pre-incubation of the platelets at 37 0 C before transfusions. The in vitro findings for collagen-induced platelet aggregation and 14 C serotonin release indicate that platelet storage for 24-48 hours at pH 6.9 and 4-8 0 C may be permissible also for clinical purposes. The problem remains open whether the clinical effect of these platelets is still sufficient after 48 hours of storage, but literature findings suggest that this may well be the case. (orig.) [de

  20. Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method

    International Nuclear Information System (INIS)

    Vallabhajosula, S.; Machac, J.; Badimon, L.; Lipszyc, H.; Goldsmith, S.J.; Fuster, V.

    1985-01-01

    The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37 0 C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient

  1. Indium-111 platelet imaging for detection of platelet deposition in abdominal aneurysms and prosthetic arterial grafts

    International Nuclear Information System (INIS)

    Ritchie, J.L.; Stratton, J.R.; Thiele, B.; Haminton, G.W.; Warrick, L.N.; Huang, T.W.; Harker, L.A.

    1981-01-01

    Thirty-four platelet imaging studies were performed in 23 patients to determine whether platelet deposition could be detected in patients with vascular aneurysms (18 patients) or in patients in whom Dacron prosthetic grafts had been placed (5 patients). In patients in whom abnormal platelet deposition was detected, the effect of administration of platelet-active drugs on platelet deposition was examined. Of the 18 patients with an aneurysm, 12 had equivocally positive studies on initial imaging and 2 had equivocally positive images. Of five patients with Dacron arterial grafts in place, four had diffuse platelet deposition in the grafts; the fifth patient had a platelet deposition only in a pseudoaneurysm. Eight patients with an abdominal aneurysm and positive or equivocally positive baseline images were restudied during platelet-active drug therapy either with aspirin plus dipyridamole (seven patients) or with sulfinpyrazone (four patients). No patient studied during treatment with aspirin plus dipyridamole had detectably decreased platelet deposition compared with baseline determinations. In contrast, two of four patients studied while receiving sulfinpyrazone showed decreased platelet deposition. Thus, platelet imaging may be of value for studying platelet physiology in vivo and for assessing platelet-active drugs and the thrombogenicity of prosthetic graft materials in human beings

  2. The role of neutrophils in the upper and lower respiratory tract during influenza virus infection of mice

    Directory of Open Access Journals (Sweden)

    Reading Patrick C

    2008-08-01

    Full Text Available Abstract Background Neutrophils have been shown to play a role in host defence against highly virulent and mouse-adapted strains of influenza virus, however it is not clear if an effective neutrophil response is an important factor moderating disease severity during infection with other virus strains. In this study, we have examined the role of neutrophils during infection of mice with influenza virus strain HKx31, a virus strain of the H3N2 subtype and of moderate virulence for mice, to determine the role of neutrophils in the early phase of infection and in clearance of influenza virus from the respiratory tract during the later phase of infection. Methods The anti-Gr-1 monoclonal antibody (mAb RB6-8C5 was used to (i identify neutrophils in the upper (nasal tissues and lower (lung respiratory tract of uninfected and influenza virus-infected mice, and (ii deplete neutrophils prior to and during influenza virus infection of mice. Results Neutrophils were rapidly recruited to the upper and lower airways following influenza virus infection. We demonstrated that use of mAb RB6-8C5 to deplete C57BL/6 (B6 mice of neutrophils is complicated by the ability of this mAb to bind directly to virus-specific CD8+ T cells. Thus, we investigated the role of neutrophils in both the early and later phases of infection using CD8+ T cell-deficient B6.TAP-/- mice. Infection of B6.TAP-/- mice with a low dose of influenza virus did not induce clinical disease in control animals, however RB6-8C5 treatment led to profound weight loss, severe clinical disease and enhanced virus replication throughout the respiratory tract. Conclusion Neutrophils play a critical role in limiting influenza virus replication during the early and later phases of infection. Furthermore, a virus strain of moderate virulence can induce severe clinical disease in the absence of an effective neutrophil response.

  3. Platelet transfusions reduce fibrinolysis but do not restore platelet function during trauma hemorrhage.

    Science.gov (United States)

    Vulliamy, Paul; Gillespie, Scarlett; Gall, Lewis S; Green, Laura; Brohi, Karim; Davenport, Ross A

    2017-09-01

    Platelets play a critical role in hemostasis with aberrant function implicated in trauma-induced coagulopathy. However, the impact of massive transfusion protocols on platelet function during trauma hemorrhage is unknown. The aim of this study was to characterize the effects of platelet transfusion on platelet aggregation and fibrinolytic markers during hemostatic resuscitation. Trauma patients enrolled into the prospective Activation of Coagulation and Inflammation in Trauma study between January 2008 and November 2015 who received at least four units of packed red blood cells (PRBCs) were included. Blood was drawn in the emergency department within 2 hours of injury and at intervals after every four units of PRBCs transfused. Platelet aggregation was assessed in whole blood with multiple electrode aggregometry. Plasma proteins were quantified by enzyme-linked immunosorbent assay. Of 161 patients who received four or more PRBCs as part of their initial resuscitation, 44 received 8 to 11 units and 28 received 12 units or more. At each timepoint during bleeding, platelet aggregation was similar in patients who had received a platelet transfusion compared with those who had only received other blood products (p > 0.05 for all timepoints). Platelet transfusion during the four PRBC intervals was associated with a decrease in maximum lysis on rotational thromboelastometry (start of interval, 6% [2-12] vs. end of interval, 2% [0-5]; p = 0.001), an increase in plasminogen activator inhibitor-1 (start of interval, 35.9 ± 14.9 vs. end of interval, 66.7 ± 22.0; p = 0.007) and a decrease in tissue plasminogen activator (start of interval, 26.2 ± 10.5 vs. end of interval, 19.0 +/- 5.1; p = 0.04). No statistically significant changes in these parameters occurred in intervals which did not contain platelets. Current hemostatic resuscitation strategies do not appear to restore platelet aggregation during active hemorrhage. However, stored platelets may attenuate fibrinolysis

  4. Superoxide anion production by human neutrophils activated by Trichomonas vaginalis.

    Science.gov (United States)

    Song, Hyun-Ouk; Ryu, Jae-Sook

    2013-08-01

    Neutrophils are the predominant inflammatory cells found in vaginal discharges of patients infected with Trichomonas vaginalis. In this study, we examined superoxide anion (O2 (.-)) production by neutrophils activated by T. vaginalis. Human neutrophils produced superoxide anions when stimulated with either a lysate of T. vaginalis, its membrane component (MC), or excretory-secretory product (ESP). To assess the role of trichomonad protease in production of superoxide anions by neutrophils, T. vaginalis lysate, ESP, and MC were each pretreated with a protease inhibitor cocktail before incubation with neutrophils. Superoxide anion production was significantly decreased by this treatment. Trichomonad growth was inhibited by preincubation with supernatants of neutrophils incubated for 3 hr with T. vaginalis lysate. Furthermore, myeloperoxidase (MPO) production by neutrophils was stimulated by live trichomonads. These results indicate that the production of superoxide anions and MPO by neutrophils stimulated with T. vaginalis may be a part of defense mechanisms of neutrophils in trichomoniasis.

  5. Myeloperoxidase modulates human platelet aggregation via actin cytoskeleton reorganization and store-operated calcium entry

    Directory of Open Access Journals (Sweden)

    Irina V. Gorudko

    2013-07-01

    Myeloperoxidase (MPO is a heme-containing enzyme released from activated leukocytes into the extracellular space during inflammation. Its main function is the production of hypohalous acids that are potent oxidants. MPO can also modulate cell signaling and inflammatory responses independently of its enzymatic activity. Because MPO is regarded as an important risk factor for cardiovascular diseases associated with increased platelet activity, we studied the effects of MPO on human platelet functional properties. Laser scanning confocal microscopy was used to reveal carbohydrate-independent MPO binding to human platelet membrane. Adding MPO to platelets did not activate their aggregation under basal conditions (without agonist. In contrast, MPO augmented agonist-induced platelet aggregation, which was not prevented by MPO enzymatic activity inhibitors. It was found that exposure of platelets to MPO leads to actin cytoskeleton reorganization and an increase in their elasticity. Furthermore, MPO evoked a rise in cytosolic Ca2+ through enhancement of store-operated Ca2+ entry (SOCE. Together, these findings indicate that MPO is not a direct agonist but rather a mediator that binds to human platelets, induces actin cytoskeleton reorganization and affects the mechanical stiffness of human platelets, resulting in potentiating SOCE and agonist-induced human platelet aggregation. Therefore, an increased activity of platelets in vascular disease can, at least partly, be provided by MPO elevated concentrations.

  6. Advanced Role of Neutrophils in Common Respiratory Diseases

    Directory of Open Access Journals (Sweden)

    Jinping Liu

    2017-01-01

    Full Text Available Respiratory diseases, always being a threat towards the health of people all over the world, are most tightly associated with immune system. Neutrophils serve as an important component of immune defense barrier linking innate and adaptive immunity. They participate in the clearance of exogenous pathogens and endogenous cell debris and play an essential role in the pathogenesis of many respiratory diseases. However, the pathological mechanism of neutrophils remains complex and obscure. The traditional roles of neutrophils in severe asthma, chronic obstructive pulmonary diseases (COPD, pneumonia, lung cancer, pulmonary fibrosis, bronchitis, and bronchiolitis had already been reviewed. With the development of scientific research, the involvement of neutrophils in respiratory diseases is being brought to light with emerging data on neutrophil subsets, trafficking, and cell death mechanism (e.g., NETosis, apoptosis in diseases. We reviewed all these recent studies here to provide you with the latest advances about the role of neutrophils in respiratory diseases.

  7. Delta neutrophil index: A reliable marker to differentiate perforated appendicitis from non-perforated appendicitis in the elderly.

    Science.gov (United States)

    Shin, Dong Hyuk; Cho, Young Suk; Kim, Yoon Sung; Ahn, Hee Cheol; Oh, Young Taeck; Park, Sang O; Won, Moo-Ho; Cho, Jun Hwi; Kim, Young Myeong; Seo, Jeong Yeol; Lee, Young Hwan

    2018-01-01

    Delta neutrophil index (DNI) is a new inflammatory marker and the present study aimed to evaluate the predictive value of the DNI for the presence of a perforation in elderly with acute appendicitis. This retrospective observational study was conducted on 108 consecutive elderly patients (≥65 years old) with acute appendicitis treated over a 24-month period. Sixty-nine of the 108 patients (median, IQR: 72, 67-77 years) were allocated to the perforated appendicitis group (63.9%) and 39 to the non-perforated appendicitis group (36.1%). WBC, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and DNI were significantly higher in the perforated group. In multiple logistic regression analyses, initial DNI was the only independent marker that can significantly predict the presence of perforation in multiple regression [odds ratio 9.38, 95% confidence interval (2.51-35.00), P=.001]. Receiver operator characteristic curve analysis showed that DNI is a good predictor for the presence of appendiceal perforation at an optimal cut-off for DNI being 1.4% (sensitivity 67.7%, specificity 90.0%, AUC 0.807). Clinicians can reliably differentiate acute perforated appendicitis from non-perforated appendicitis by DNI level of 1.4 or more in elderly patients. © 2017 Wiley Periodicals, Inc.

  8. Characterization of Yersinia pestis Interactions with Human Neutrophils In vitro

    Directory of Open Access Journals (Sweden)

    Sophia C. Dudte

    2017-08-01

    Full Text Available Yersinia pestis is a gram-negative, zoonotic, bacterial pathogen, and the causative agent of plague. The bubonic form of plague occurs subsequent to deposition of bacteria in the skin by the bite of an infected flea. Neutrophils are recruited to the site of infection within the first few hours and interactions between neutrophils and Y. pestis have been demonstrated in vivo. In contrast to macrophages, neutrophils have been considered non-permissive to Y. pestis intracellular survival. Several studies have shown killing of the vast majority of Y. pestis ingested by human neutrophils. However, survival of 10–15% of Y. pestis after phagocytosis by neutrophils is consistently observed. Furthermore, these surviving bacteria eventually replicate within and escape from the neutrophils. We set out to further characterize the interactions between Y. pestis and human neutrophils by (1 determining the effects of known Y. pestis virulence factors on bacterial survival after uptake by neutrophils, (2 examining the mechanisms employed by the neutrophil to kill the majority of intracellular Y. pestis, (3 determining the activation phenotype of Y. pestis-infected neutrophils, and (4 characterizing the Y. pestis-containing phagosome in neutrophils. We infected human neutrophils in vitro with Y. pestis and assayed bacterial survival and uptake. Deletion of the caf1 gene responsible for F1 capsule production resulted in significantly increased uptake of Y. pestis. Surprisingly, while the two-component regulator PhoPQ system is important for survival of Y. pestis within neutrophils, pre-induction of this system prior to infection did not increase bacterial survival. We used an IPTG-inducible mCherry construct to distinguish viable from non-viable intracellular bacteria and determined the association of the Y. pestis-containing phagosome with neutrophil NADPH-oxidase and markers of primary, secondary and tertiary granules. Additionally, we show that inhibition of

  9. Neutrophil extracellular trap formation in supragingival biofilms.

    Science.gov (United States)

    Hirschfeld, Josefine; Dommisch, Henrik; Skora, Philipp; Horvath, Gabor; Latz, Eicke; Hoerauf, Achim; Waller, Tobias; Kawai, Toshihisa; Jepsen, Søren; Deschner, James; Bekeredjian-Ding, Isabelle

    2015-01-01

    Oral biofilms are the causative agents of the highly prevalent oral diseases periodontitis and caries. Additionally, the host immune response is thought to play a critical role in disease onset. Neutrophils are known to be a key host response factor to bacterial challenge on host surfaces. Release of neutrophil extracellular traps (NETs) as a novel antimicrobial defense strategy has gained increasing attention in the past years. Here, we investigated the influx of neutrophils into the dental plaque and the ability of oral bacteria to trigger intra-biofilm release of NETs and intracellular proteins. Supragingival biofilms and whole saliva were sampled from systemically healthy subjects participating in an experimental gingivitis study. Biofilms were analysed by immunofluorescence followed by confocal and fluorescence microscopy. Moreover, concentrations of cytokines and immune-associated proteins in biofilm suspensions and saliva were assessed by ELISA. Neutrophils obtained from blood were stimulated with twelve bacterial species isolated from cultured biofilms or with lipopolysaccharide to monitor NET formation. Neutrophils, NETs, neutrophil-associated proteins (myeloperoxidase, elastase-2, cathepsin G, cathelicidin LL-37), interleukin-8, interleukin-1β and tumor necrosis factor were detected within plaque samples and saliva. All tested bacterial species as well as the polymicrobial samples isolated from the plaque of each donor induced release of NETs and interleukin-8. The degree of NET formation varied among different subjects and did not correlate with plaque scores or clinical signs of local inflammation. Our findings indicate that neutrophils are attracted towards dental biofilms, in which they become incorporated and where they are stimulated by microbes to release NETs and immunostimulatory proteins. Thus, neutrophils and NETs may be involved in host biofilm control, although their specific role needs to be further elucidated. Moreover, inter

  10. Effects of hormones on platelet aggregation.

    Science.gov (United States)

    Farré, Antonio López; Modrego, Javier; Zamorano-León, José J

    2014-04-01

    Platelets and their activation/inhibition mechanisms play a central role in haemostasis. It is well known agonists and antagonists of platelet activation; however, during the last years novel evidences of hormone effects on platelet activation have been reported. Platelet functionality may be modulated by the interaction between different hormones and their platelet receptors, contributing to sex differences in platelet function and even in platelet-mediated vascular damage. It has suggested aspects that apparently are well established should be reviewed. Hormones effects on platelet activity are included among them. This article tries to review knowledge about the involvement of hormones in platelet biology and activity.

  11. Platelets and the innate immune system: Mechanisms of bacterial-induced platelet activation.

    OpenAIRE

    Cox, Dermot; Kerrigan, Steven W; Watson, Steve

    2011-01-01

    It has become clear that platelets are not simply cell fragments that can plug the leak in a damaged blood vessel, they are in fact key components in the innate immune system which is supported by the presence of Toll-like receptors (TLRs) on platelets. As the first responding cell to a site of injury they are well placed to direct the immune response to deal with any resulting exposure to pathogens. The response is triggered by bacteria binding to platelets which usually triggers platelet ac...

  12. Gβ1 is required for neutrophil migration in zebrafish.

    Science.gov (United States)

    Ke, Wenfan; Ye, Ding; Mersch, Kacey; Xu, Hui; Chen, Songhai; Lin, Fang

    2017-08-01

    Signaling mediated by G protein-coupled receptors (GPCRs) is essential for the migration of cells toward chemoattractants. The recruitment of neutrophils to injured tissues in zebrafish larvae is a useful model for studying neutrophil migration and trafficking in vivo. Indeed, the study of this process led to the discovery that PI3Kγ is required for the polarity and motility of neutrophils, features that are necessary for the directed migration of these cells to wounds. However, the mechanism by which PI3Kγ is activated remains to be determined. Here we show that signaling by specifically the heterotrimeric G protein subunit Gβ1 is critical for neutrophil migration in response to wounding. In embryos treated with small-molecule inhibitors of Gβγ signaling, neutrophils failed to migrate to wound sites. Although both the Gβ1 and Gβ4 isoforms are expressed in migrating neutrophils, only deficiency for the former (morpholino-based knockdown) interfered with the directed migration of neutrophils towards wounds. The Gβ1 deficiency also impaired the ability of cells to change cell shape and reduced their general motility, defects that are similar to those in neutrophils deficient for PI3Kγ. Transplantation assays showed that the requirement for Gβ1 in neutrophil migration is cell autonomous. Finally, live imaging revealed that Gβ1 is required for polarized activation of PI3K, and for the actin dynamics that enable neutrophil migration. Collectively, our data indicate that Gβ1 signaling controls proper neutrophil migration by activating PI3K and modulating actin dynamics. Moreover, they illustrate a role for a specific Gβ isoform in chemotaxis in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Biokinetics of indium-111 labeled platelets after cryotherapy of hepatic metastases

    International Nuclear Information System (INIS)

    Alexander, C.; Kirsch, C.-M.; Pistorius, G.; Feifel, G.

    2002-01-01

    Full text: The present investigation was performed to evaluate mean platelet live-span and the proportion of platelet disposal in different organs in patients after hepatic cryotherapy. Seven patients with advanced colorectal cancer and liver metastases were included. Directly before the surgical procedure a blood specimen was drawn and an in vitro labeling of patients platelets with 18 MBq Indium-111 oxime was performed. Reinjection was done intraoperatively just before cryotherapy. Blood specimen were drawn at 1, 2, 3, 24 und 48 h p.i.. Whole-body scintigraphy was acquired on day two alter operation. The evaluation comprised the calculation of mean platelet live-span and of organ activities as percentage of whole-body activity. The local disposal of platelets at the site of cryotherapy ranged from 0 to 35.2 percent, the mean value was 16,2 ± 12,2 percent (mean ± SD). The mean half-time of time-activity curve gave 0.6 to 2.4 days (mean ± SD: 1.6 ± 0.6 d; normal value: 3.5-6 d), the mean platelet life-span was between 2.1 and 5.2 days corresponding to a mean value of 3.4 ± 1.0 days (normal value: 7-11 d). The evaluation of SPECT slices of large liver metastases demonstrated that platelet disposal takes place at the border zone of the metastases just around the necrotic center. We conclude that the enhanced local platelet trapping is a major cause for cryothermia-induced systemic thrombocytopenia. (author)

  14. Responsiveness of platelets during storage studied with flow cytometry - formation of platelet subpopulations and LAMP-1 as new markers for the platelet storage lesion

    OpenAIRE

    Södergren, Anna; Tynngård, Nahreen; Berlin, Gösta; Ramström, Sofia

    2016-01-01

    Background and ObjectivesStorage lesions may prevent transfused platelets to respond to agonists and arrest bleeding. The aim of this study was to evaluate and quantify the capacity of platelet activation during storage using flow cytometry and new markers of platelet activation. Materials and MethodsActivation responses of platelets prepared by apheresis were measured on days 1, 5, 7 and 12. In addition, comparisons were made for platelet concentrates stored until swirling was affected. Lyso...

  15. Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

    1988-01-01

    Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of (1-/sup 14/C)arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva.

  16. Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

    1988-01-01

    Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of [1- 14 C]arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva. (author)

  17. Prevention of vascular inflammation by nanoparticle targeting of adherent neutrophils

    Science.gov (United States)

    Wang, Zhenjia; Li, Jing; Cho, Jaehyung; Malik, Asrar B.

    2014-03-01

    Inflammatory diseases such as acute lung injury and ischaemic tissue injury are caused by the adhesion of a type of white blood cell--polymorphonuclear neutrophils--to the lining of the circulatory system or vascular endothelium and unchecked neutrophil transmigration. Nanoparticle-mediated targeting of activated neutrophils on vascular endothelial cells at the site of injury may be a useful means of directly inactivating neutrophil transmigration and hence mitigating vascular inflammation. Here, we report a method employing drug-loaded albumin nanoparticles, which efficiently deliver drugs into neutrophils adherent to the surface of the inflamed endothelium. Using intravital microscopy of tumour necrosis factor-α-challenged mouse cremaster post-capillary venules, we demonstrate that fluorescently tagged albumin nanoparticles are largely internalized by neutrophils adherent to the activated endothelium via cell surface Fcɣ receptors. Administration of albumin nanoparticles loaded with the spleen tyrosine kinase inhibitor, piceatannol, which blocks `outside-in' β2 integrin signalling in leukocytes, detached the adherent neutrophils and elicited their release into the circulation. Thus, internalization of drug-loaded albumin nanoparticles into neutrophils inactivates the pro-inflammatory function of activated neutrophils, thereby offering a promising approach for treating inflammatory diseases resulting from inappropriate neutrophil sequestration and activation.

  18. OP9 bone marrow stroma cells differentiate into megakaryocytes and platelets.

    Directory of Open Access Journals (Sweden)

    Yumiko Matsubara

    Full Text Available Platelets are essential for hemostatic plug formation and thrombosis. The mechanisms of megakaryocyte (MK differentiation and subsequent platelet production from stem cells remain only partially understood. The manufacture of megakaryocytes (MKs and platelets from cell sources including hematopoietic stem cells and pluripotent stem cells have been highlighted for studying the platelet production mechanisms as well as for the development of new strategies for platelet transfusion. The mouse bone marrow stroma cell line OP9 has been widely used as feeder cells for the differentiation of stem cells into MK lineages. OP9 cells are reported to be pre-adipocytes. We previously reported that 3T3-L1 pre-adipocytes differentiated into MKs and platelets. In the present study, we examined whether OP9 cells differentiate into MKs and platelets using MK lineage induction (MKLI medium previously established to generate MKs and platelets from hematopoietic stem cells, embryonic stem cells, and pre-adipocytes. OP9 cells cultured in MKLI medium had megakaryocytic features, i.e., positivity for surface markers CD41 and CD42b, polyploidy, and distinct morphology. The OP9-derived platelets had functional characteristics, providing the first evidence for the differentiation of OP9 cells into MKs and platelets. We then analyzed gene expressions of critical factors that regulate megakaryopoiesis and thrombopoiesis. The gene expressions of p45NF-E2, FOG, Fli1, GATA2, RUNX1, thrombopoietin, and c-mpl were observed during the MK differentiation. Among the observed transcription factors of MK lineages, p45NF-E2 expression was increased during differentiation. We further studied MK and platelet generation using p45NF-E2-overexpressing OP9 cells. OP9 cells transfected with p45NF-E2 had enhanced production of MKs and platelets. Our findings revealed that OP9 cells differentiated into MKs and platelets in vitro. OP9 cells have critical factors for megakaryopoiesis and

  19. Candida albicans escapes from mouse neutrophils

    DEFF Research Database (Denmark)

    Ermert, David; Niemiec, Maria J; Röhm, Marc

    2013-01-01

    is the most widely used model organism. Neutrophils are essential immune cells to prevent opportunistic mycoses. To explore potential differences between the rodent infection model and the human host, we compared the interactions of C. albicans with neutrophil granulocytes from mice and humans. We revealed...

  20. Differential Use of Human Neutrophil Fcγ Receptors for Inducing Neutrophil Extracellular Trap Formation.

    Science.gov (United States)

    Alemán, Omar Rafael; Mora, Nancy; Cortes-Vieyra, Ricarda; Uribe-Querol, Eileen; Rosales, Carlos

    2016-01-01

    Neutrophils (PMN) are the most abundant leukocytes in the blood. PMN migrate from the circulation to sites of infection, where they are responsible for antimicrobial functions. PMN use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to kill microbes. NETs are fibers composed of chromatin and neutrophil-granule proteins. Several pathogens, including bacteria, fungi, and parasites, and also some pharmacological stimuli such as phorbol 12-myristate 13-acetate (PMA) are efficient inducers of NETs. Antigen-antibody complexes are also capable of inducing NET formation. However the particular Fcγ receptor involved in triggering this function is a matter of controversy. In order to provide some insight into what Fcγ receptor is responsible for NET formation, each of the two human Fcγ receptors was stimulated individually by specific monoclonal antibodies and NET formation was evaluated. FcγRIIa cross-linking did not promote NET formation. Cross-linking other receptors such as integrins also did not promote NET formation. In contrast FcγRIIIb cross-linking induced NET formation similarly to PMA stimulation. NET formation was dependent on NADPH-oxidase, PKC, and ERK activation. These data show that cross-linking FcγRIIIb is responsible for NET formation by the human neutrophil.

  1. Differential Use of Human Neutrophil Fcγ Receptors for Inducing Neutrophil Extracellular Trap Formation

    Directory of Open Access Journals (Sweden)

    Omar Rafael Alemán

    2016-01-01

    Full Text Available Neutrophils (PMN are the most abundant leukocytes in the blood. PMN migrate from the circulation to sites of infection, where they are responsible for antimicrobial functions. PMN use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs to kill microbes. NETs are fibers composed of chromatin and neutrophil-granule proteins. Several pathogens, including bacteria, fungi, and parasites, and also some pharmacological stimuli such as phorbol 12-myristate 13-acetate (PMA are efficient inducers of NETs. Antigen-antibody complexes are also capable of inducing NET formation. However the particular Fcγ receptor involved in triggering this function is a matter of controversy. In order to provide some insight into what Fcγ receptor is responsible for NET formation, each of the two human Fcγ receptors was stimulated individually by specific monoclonal antibodies and NET formation was evaluated. FcγRIIa cross-linking did not promote NET formation. Cross-linking other receptors such as integrins also did not promote NET formation. In contrast FcγRIIIb cross-linking induced NET formation similarly to PMA stimulation. NET formation was dependent on NADPH-oxidase, PKC, and ERK activation. These data show that cross-linking FcγRIIIb is responsible for NET formation by the human neutrophil.

  2. Theophylline and adenosine modulate the inflammatory functions of the human neutrophil by exerting an opposing influence on the stimulus-induced increase in intracellular calcium

    International Nuclear Information System (INIS)

    Schmeichel Morley, C.J.

    1988-01-01

    Based on evidence that endogenously-produced adenosine inhibited neutrophil responses, the influence of methylxanthine bronchodilators on neutrophil responses stimulated in vitro by n-formyl-methionyl-leucyl-phenylalanine (fMLP) was examined. At concentrations between 10/sup /minus/5/ M and 10/sup /minus/4/ M, theophylline potentiated lysosomal enzyme release by 30 to 50%, superoxide anion formation by 30 to 60%, and neutrophil aggregation. Theophylline at concentrations >10/sup /minus/4/ M inhibited the same responses by >90%. Adenosine deaminase mimicked, whereas adenosine reversed the theophylline potentiation. A potential role for calcium in the modulation of the neutrophil responses by theophylline and adenosine was explored. Theophylline enhanced by >150% the fMLP-stimulated increase in cytoplasmic calcium concentration ([Ca 2+ ]/sub i/) at time points between 5 and 90 sec as measured by Fura-2. Adenosine deaminase induced a comparable enhancement, whereas 3 /times/ 10/sup /minus/7/ M adenosine and 10/sup /minus/7/ M N-ethylcarboxamideadenosine decreased the [Ca 2+ ]/sub i/ in fMLP-stimulated neutrophils. Extracellular calcium was not required for the opposing influences of theophylline and adenosine and neither compound altered fMLP-stimulated 45 Ca uptake at the early time points

  3. Neutrophilic dermatoses in a patient with collagenous colitis

    Directory of Open Access Journals (Sweden)

    Didac Barco

    2010-01-01

    Full Text Available We report the case of a 75-year old woman with collagenous colitis who presented with erythematous and edematous plaques on the periorbital and eyelid regions, accompanied by oral ulcers. Histopathology showed a dermal neutrophilic infiltrate plus mild septal and lobular panniculitis with lymphocytes, neutrophils and eosinophils. Five years earlier she had presented a flare of papules and vesicles on the trunk, together with oral ulcers; a skin biopsy revealed a neutrophilic dermal infiltrate and Sweet’s syndrome was diagnosed. Both the neutrophilic panniculitis and the Sweet’s syndrome were accompanied by fever, malaise and diarrhea. Cutaneous and intestinal symptoms disappeared with corticoid therapy. The two types of neutrophilic dermatoses that appeared in periods of colitis activity suggest that intestinal and cutaneous manifestations may be related.

  4. Platelets and the innate immune system: mechanisms of bacterial-induced platelet activation.

    Science.gov (United States)

    Cox, D; Kerrigan, S W; Watson, S P

    2011-06-01

    It has become clear that platelets are not simply cell fragments that plug the leak in a damaged blood vessel; they are, in fact, also key components in the innate immune system, which is supported by the presence of Toll-like receptors (TLRs) on platelets. As the cells that respond first to a site of injury, they are well placed to direct the immune response to deal with any resulting exposure to pathogens. The response is triggered by bacteria binding to platelets, which usually triggers platelet activation and the secretion of antimicrobial peptides. The main platelet receptors that mediate these interactions are glycoprotein (GP)IIb-IIIa, GPIbα, FcγRIIa, complement receptors, and TLRs. This process may involve direct interactions between bacterial proteins and the receptors, or can be mediated by plasma proteins such as fibrinogen, von Willebrand factor, complement, and IgG. Here, we review the variety of interactions between platelets and bacteria, and look at the potential for inhibiting these interactions in diseases such as infective endocarditis and sepsis. © 2011 International Society on Thrombosis and Haemostasis.

  5. In vitro effect of sodium nitrite on platelet aggregation in human platelet rich plasma--preliminary report.

    Science.gov (United States)

    Kadan, M; Doğanci, S; Yildirim, V; Özgür, G; Erol, G; Karabacak, K; Avcu, F

    2015-10-01

    The role of nitrates and nitric oxide on platelet functions has obtained an increasing attention with respect to their potential effects on cardiovascular disorders. In this study we aimed to analyze the effect of sodium nitrite on platelet functions in human platelets. This in vitro study was designed to show the effect of sodium nitrite on platelet functions in seven healthy volunteers. Blood samples were centrifuged to prepare platelet rich plasma and platelet poor plasma. Platelet rich plasma was diluted with the platelet poor plasma to have a final count of 300,000 ± 25,000 platelets. Platelet rich plasma was incubated with six different increasing doses (from 10 μM to 5 mM) of sodium nitrite for 1 hour at 37°C. Then stimulating agents including collagen (3 μg ml-1), adenosine diphosphate (10 μM), and epinephrine (10 μM) were added to the cuvette. Changes in light transmission were observed for 10 minutes. In addition spontaneous aggregation were performed in control group with all aggregating agents separately. Effect of sodium nitrite on agonist-induced platelet aggregation depends on the concentration of sodium nitrite. Compared with control group, agonist-induced platelet aggregations were significantly suppressed by sodium nitrite at the concentration of 5, 1.0 and 0.5 mM. Our results suggested that sodium nitrite has inhibitory effects in vitro on platelet aggregation in a dose-dependent manner.

  6. Taurine and platelet aggregation

    International Nuclear Information System (INIS)

    Nauss-Karol, C.; VanderWende, C.; Gaut, Z.N.

    1986-01-01

    Taurine is a putative neurotransmitter or neuromodulator. The endogenous taurine concentration in human platelets, determined by amino acid analysis, is 15 μM/g. In spite of this high level, taurine is actively accumulated. Uptake is saturable, Na + and temperature dependent, and suppressed by metabolic inhibitors, structural analogues, and several classes of centrally active substances. High, medium and low affinity transport processes have been characterized, and the platelet may represent a model system for taurine transport in the CNS. When platelets were incubated with 14 C-taurine for 30 minutes, then resuspended in fresh medium and reincubated for one hour, essentially all of the taurine was retained within the cells. Taurine, at concentrations ranging from 10-1000 μM, had no effect on platelet aggregation induced by ADP or epinephrine. However, taurine may have a role in platelet aggregation since 35-39% of the taurine taken up by human platelets appears to be secreted during the release reaction induced by low concentrations of either epinephrine or ADP, respectively. This release phenomenon would imply that part of the taurine taken up is stored directly in the dense bodies of the platelet

  7. Neutrophil adhesion and chemotaxis depend on substrate mechanics

    International Nuclear Information System (INIS)

    Jannat, Risat A; Hammer, Daniel A; Robbins, Gregory P; Ricart, Brendon G; Dembo, Micah

    2010-01-01

    Neutrophil adhesion to the vasculature and chemotaxis within tissues play critical roles in the inflammatory response to injury and pathogens. Unregulated neutrophil activity has been implicated in the progression of numerous chronic and acute diseases such as rheumatoid arthritis, asthma and sepsis. Cell migration of anchorage-dependent cells is known to depend on both chemical and mechanical interactions. Although neutrophil responses to chemical cues have been well characterized, little is known about the effect of underlying tissue mechanics on neutrophil adhesion and migration. To address this question, we quantified neutrophil migration and traction stresses on compliant hydrogel substrates with varying elasticity in a micromachined gradient chamber in which we could apply either a uniform concentration or a precise gradient of the bacterial chemoattractant fMLP. Neutrophils spread more extensively on substrates of greater stiffness. In addition, increasing the stiffness of the substrate leads to a significant increase in the chemotactic index for each fMLP gradient tested. As the substrate becomes stiffer, neutrophils generate higher traction forces without significant changes in cell speed. These forces are often displayed in pairs and focused in the uropod. Increases in the mean fMLP concentration beyond the K D of the receptor lead to a decrease in chemotactic index on all surfaces. Blocking with an antibody against β 2 -integrins leads to a significant reduction, but not an elimination, of directed motility on stiff materials, but no change in motility on soft materials, suggesting neutrophils can display both integrin-dependent and integrin-independent motility. These findings are critical for understanding how neutrophil migration may change in different mechanical environments in vivo and can be used to guide the design of migration inhibitors that more efficiently target inflammation.

  8. Neutrophil adhesion and chemotaxis depend on substrate mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Jannat, Risat A; Hammer, Daniel A [Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33rd Street, Philadelphia, PA 19104 (United States); Robbins, Gregory P; Ricart, Brendon G [Department of Chemical and Biomolecular Engineering, University of Pennsylvania, 311A Towne Building, 220 South 33rd Street, Philadelphia, PA 19104 (United States); Dembo, Micah, E-mail: hammer@seas.upenn.ed [Department of Biomedical Engineering, Boston University, 44 Cummington Street, Boston, MA 02215 (United States)

    2010-05-19

    Neutrophil adhesion to the vasculature and chemotaxis within tissues play critical roles in the inflammatory response to injury and pathogens. Unregulated neutrophil activity has been implicated in the progression of numerous chronic and acute diseases such as rheumatoid arthritis, asthma and sepsis. Cell migration of anchorage-dependent cells is known to depend on both chemical and mechanical interactions. Although neutrophil responses to chemical cues have been well characterized, little is known about the effect of underlying tissue mechanics on neutrophil adhesion and migration. To address this question, we quantified neutrophil migration and traction stresses on compliant hydrogel substrates with varying elasticity in a micromachined gradient chamber in which we could apply either a uniform concentration or a precise gradient of the bacterial chemoattractant fMLP. Neutrophils spread more extensively on substrates of greater stiffness. In addition, increasing the stiffness of the substrate leads to a significant increase in the chemotactic index for each fMLP gradient tested. As the substrate becomes stiffer, neutrophils generate higher traction forces without significant changes in cell speed. These forces are often displayed in pairs and focused in the uropod. Increases in the mean fMLP concentration beyond the K{sub D} of the receptor lead to a decrease in chemotactic index on all surfaces. Blocking with an antibody against {beta}{sub 2}-integrins leads to a significant reduction, but not an elimination, of directed motility on stiff materials, but no change in motility on soft materials, suggesting neutrophils can display both integrin-dependent and integrin-independent motility. These findings are critical for understanding how neutrophil migration may change in different mechanical environments in vivo and can be used to guide the design of migration inhibitors that more efficiently target inflammation.

  9. Platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro

    Directory of Open Access Journals (Sweden)

    van Bladel Esther R

    2012-09-01

    Full Text Available Abstract Background In patients with chronic kidney disease studies focusing on platelet function and properties often are non-conclusive whereas only few studies use functional platelet tests. In this study we evaluated a recently developed functional flow cytometry based assay for the analysis of platelet function in chronic kidney disease. Methods Platelet reactivity was measured using flow cytometric analysis. Platelets in whole blood were triggered with different concentrations of agonists (TRAP, ADP, CRP. Platelet activation was quantified with staining for P-selectin, measuring the mean fluorescence intensity. Area under the curve and the concentration of half-maximal response were determined. Results We studied 23 patients with chronic kidney disease (9 patients with cardiorenal failure and 14 patients with end stage renal disease and 19 healthy controls. Expression of P-selectin on the platelet surface measured as mean fluorescence intensity was significantly less in chronic kidney disease patients compared to controls after maximal stimulation with TRAP (9.7 (7.9-10.8 vs. 11.4 (9.2-12.2, P = 0.032, ADP (1.6 (1.2-2.1 vs. 2.6 (1.9-3.5, P = 0.002 and CRP (9.2 (8.5-10.8 vs. 11.5 (9.5-12.9, P = 0.004. Also the area under the curve was significantly different. There was no significant difference in half-maximal response between both groups. Conclusion In this study we found that patients with chronic kidney disease show reduced platelet reactivity in response of ADP, TRAP and CRP compared to controls. These results contribute to our understanding of the aberrant platelet function observed in patients with chronic kidney disease and emphasize the significance of using functional whole blood platelet activation assays.

  10. Chemotactic Activity on Human Neutrophils to Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Tetiana Haniastuti

    2013-07-01

    Full Text Available Objective: The aim of this study was to evaluate chemotactic activity o neutrophil to S. mutans. Chemotaxis assay was performed in blind well chambers. Materials and Methods: Hanks balanced salt solution (HBSS containing 106 S. mutans,  108 S. mutans, 10-8 M fMLP, or HBSS alone were placed in the lower wells of the chamber and covered with polycorbonate membrane filter. Neutrophils suspension (2x105 cells was then placed in the upper compartment. After incubation for 60 mins at 37ºC in a humidified atmosphere with 5% CO2, the filters were removed and stained with Giemsa. Result: ANOVA revealed statistically significant differences among groups (p<0.05, indicating that S. mutans induced neutrophils chemotaxis. The number of neutrophils migration in response to 108 S. mutans and 106 S. mutans were signifiantly greater compared to fMLP (p<0.05. Conclusion: S. mutans may activate human neutrophils, resulting in the chemotaxis of the neutrophils.DOI: 10.14693/jdi.v16i2.99

  11. Effect of Isolation Techniques on Viability of Bovine Blood Neutrophils

    Directory of Open Access Journals (Sweden)

    P. Sláma

    2006-01-01

    Full Text Available The effect of selected isolation methods on the viability of neutrophil granulocytes (neutrophils from the blood of healthy Holstein x Bohemian Red Pied crossbred heifers was evaluated. Two methods of neutrophil isolation were used: a neutrophil isolation on the basis of hypotonic erythrocyte lysis (in two variants: after the erythrocyte lysis proper, the cells were centrifuged at either 200 g or 1000 g, and b neutrophil isolation with FACS Lysing Solution as the lysing agent. The viability of the isolated neutrophils was evaluated on the basis of apoptosis and necrosis. The results obtained with flow cytometry (FCM suggest that, from the isolation techniques used, the method based on FACS Lysing Solution impaired the neutrophil viability least. After the application of this method, 5.36 ± 2.15% of neutrophils were apoptotic and 0.51 ± 0.12% were necrotic. In contrast, when the hypotonic erythrocyte lysis was used, the proportion of apoptotic neutrophils amounted to 42.14 ± 7.12% and 49.00 ± 14.70%, respectively, and 41.12 ± 5.55% and 36.91 ± 24.38% respectively of necrotic neutrophils (P < 0.01. This was also confirmed by the light microscopy. After the isolation with FASC Lysing Solution, 1.92 ± 1.74% of neutrophils were apoptotic and 1.05 ± 0.76% were necrotic, as distinct from after the hypotonic erythrocyte lysis where 9.43 ± 3.69% of neutrophils were apoptotic and 12.67 ± 4.74% of necrotic after centrifugation at 200 g, while 12.60 ± 4.35 were apoptotic and 14.96 ± 12.64% were necrotic after centrifugation at 1000 g. It follows from the above-mentioned data that hypotonic lysis is not a suitable method for the isolation of neutrophils, as the method itself markedly affects cell viability.

  12. Platelet Concentrates: Past, Present and Future

    OpenAIRE

    Prakash, Shobha; Thakur, Aditi

    2011-01-01

    Platelets play a crucial role in hemostasis and wound healing, platelet growth factors are well known source of healing cytokines. Numerous techniques of autologous platelet concentrates have been developed and applied in oral and maxillofacial surgery. This review describes the evolution of the first and second generation of platelet concentrates (platelet rich plasma and platelet rich fibrin respectively) from their fore runner-fibrin sealants.

  13. Aspirin inhibition of platelet deposition at angioplasty sites: demonstration by platelet scintigraphy

    International Nuclear Information System (INIS)

    Cuningham, D.A.; Kumar, B.; Siegel, B.A.; Gilula, L.A.; Totty, W.G.; Welch, M.J.

    1984-01-01

    In-111 platelet scintigraphy was used to evaluate the effects of prior aspirin administration on the accumulation of In-111-labeled autologous platelets at sites of arterial injury resulting from iliac, femoral, or popliteal transluminal angioplasty in a nonrandomized study of 17 men. The degree of platelet localization at angioplasty sites was significantly less in nine men who had received aspirin in varying doses within the 4 days before angioplasty than in eight men who had not received aspirin for at least two weeks. The results suggest that aspirin treatment before angioplasty limits the early platelet deposition at the angioplasty site in men

  14. Platelet function in dogs

    DEFF Research Database (Denmark)

    Nielsen, Line A.; Zois, Nora Elisabeth; Pedersen, Henrik D.

    2007-01-01

    Background: Clinical studies investigating platelet function in dogs have had conflicting results that may be caused by normal physiologic variation in platelet response to agonists. Objectives: The objective of this study was to investigate platelet function in clinically healthy dogs of 4...... different breeds by whole-blood aggregometry and with a point-of-care platelet function analyzer (PFA-100), and to evaluate the effect of acetylsalicylic acid (ASA) administration on the results from both methods. Methods: Forty-five clinically healthy dogs (12 Cavalier King Charles Spaniels [CKCS], 12...... applied. However, the importance of these breed differences remains to be investigated. The PFA-100 method with Col + Epi as agonists, and ADP-induced platelet aggregation appear to be sensitive to ASA in dogs....

  15. The cystic fibrosis neutrophil: a specialized yet potentially defective cell.

    LENUS (Irish Health Repository)

    Hayes, Elaine

    2012-02-01

    Cystic fibrosis (CF) is one of the commonest genetically inherited diseases in the world. It is characterized by recurrent respiratory tract infections eventually leading to respiratory failure. One of the hallmarks of this disease is a persistent and predominantly neutrophil driven inflammation. Neutrophils provide the first line of defence by killing and digesting phagocytosed bacteria and fungi, yet despite advances in our understanding of the molecular and cellular basis of CF, there remains a paradox of why recruited CF neutrophils fail to eradicate bacterial infections in the lung. This review describes mechanisms involved in neutrophil migration, microbial killing and apoptosis leading to inflammatory resolution. We discuss dysregulated neutrophil activity and consider genetic versus inflammatory neutrophil reprogramming in CF and ultimately pharmacological modulation of the CF neutrophil for therapeutic intervention.

  16. The cystic fibrosis neutrophil: a specialized yet potentially defective cell.

    LENUS (Irish Health Repository)

    Hayes, Elaine

    2011-04-01

    Cystic fibrosis (CF) is one of the commonest genetically inherited diseases in the world. It is characterized by recurrent respiratory tract infections eventually leading to respiratory failure. One of the hallmarks of this disease is a persistent and predominantly neutrophil driven inflammation. Neutrophils provide the first line of defence by killing and digesting phagocytosed bacteria and fungi, yet despite advances in our understanding of the molecular and cellular basis of CF, there remains a paradox of why recruited CF neutrophils fail to eradicate bacterial infections in the lung. This review describes mechanisms involved in neutrophil migration, microbial killing and apoptosis leading to inflammatory resolution. We discuss dysregulated neutrophil activity and consider genetic versus inflammatory neutrophil reprogramming in CF and ultimately pharmacological modulation of the CF neutrophil for therapeutic intervention.

  17. Platelet Preparations for Use in Facial Rejuvenation and Wound Healing: A Critical Review of Current Literature.

    Science.gov (United States)

    Sclafani, Anthony P; Azzi, James

    2015-08-01

    In facial plastic surgery, the potential for direct delivery of growth factors from platelet preparations has been of particular interest for use in facial rejuvenation, recovery after facial surgery, and wound healing. A literature search was conducted through PubMed for the terms PRP, PRFM, platelet-rich plasma, platelet-rich fibrin matrix, platelet preparations, platelet therapy, growth factors, platelet facial, platelet facial rejuvenation, platelet wound healing, platelet plastic surgery. Articles pertaining to the use of platelet preparations in facial surgery and wound healing in plastic surgery after 2001 were included. Thirteen in vitro studies showed use of platelet-rich plasma (PRP) and platelet-rich fibrin matrix (PRFM) had a significant effect on cellular activity. Twenty-four out of 28 animal studies exhibited favorable results with use of a platelet preparation, including five of six studies that showed enhanced fat graft survival with addition of a platelet preparation. Twenty-three case series and clinical trials were identified, only two of which showed no differences. Twenty-one reported favorable results with use of various platelet preparations. A total of 47 studies used PRP, four studies evaluated Leukocyte-rich PRP, and fourteen studies used PRFM. The vast majority of studies examined show a significant and measurable effect on cellular changes, wound healing, and facial esthetic outcomes with use of platelet preparations, both topical and injectable. One must also consider possible publication bias against null results that may have had an influence on the data that were available for review. However, the preponderance of studies suggests that platelet preparations might represent an as-of-yet untapped adjunct in facial plastic surgery.

  18. Different innate neutrophil responses in controlled and uncontrolled asthma

    NARCIS (Netherlands)

    Tang, Francesca; Foxley, Gloria; Gibson, Peter; Burgess, Janette; Baines, Katherine; Oliver, Brian

    2015-01-01

    Introduction: Respiratory viruses are a major cause of asthma exacerbations. Neutrophilic inflammation occurs during infections and is associated with difficult to treat asthma. The role of neutrophils in viral infections and whether neutrophil dysfunction contributes to exacerbation pathogenesis

  19. Effects of Ingestion of Different Amounts of Carbohydrate after Endurance Exercise on Circulating Cytokines and Markers of Neutrophil Activation

    Directory of Open Access Journals (Sweden)

    Kumpei Tanisawa

    2018-04-01

    Full Text Available We aimed to examine the effects of ingestion of different amounts of carbohydrate (CHO after endurance exercise on neutrophil count, circulating cytokine levels, and the markers of neutrophil activation and muscle damage. Nine participants completed three separate experimental trials consisting of 1 h of cycling exercise at 70% V · O2 max, followed by ingestion of 1.2 g CHO·kg body mass−1·h−1 (HCHO trial, 0.2 g CHO·kg body mass−1·h−1 (LCHO trial, or placebo (PLA trial during the 2 h recovery phase in random order. Circulating glucose, insulin, and cytokine levels, blood cell counts, and the markers of neutrophil activation and muscle damage were measured. The concentrations of plasma glucose and serum insulin at 1 h after exercise were higher in the HCHO trial than in the LCHO and PLA trials. Although there were significant main effects of time on several variables, including neutrophil count, cytokine levels, and the markers of neutrophil activation and muscle damage, significant time × trial interactions were not observed for any variables. These results suggest that CHO ingestion after endurance exercise does not enhance exercise-induced increase in circulating neutrophil and cytokine levels and markers of neutrophil activation and muscle damage, regardless of the amount of CHO ingested.

  20. Platelet lysates produced from expired platelet concentrates support growth and osteogenic differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Sandra Mjoll Jonsdottir-Buch

    Full Text Available BACKGROUND: Mesenchymal stem cells are promising candidates in regenerative cell therapy. Conventional culture methods involve the use of animal substances, specifically fetal bovine serum as growth supplement. Since the use of animal-derived products is undesirable for human applications, platelet lysates produced from human platelets are an attractive alternative. This is especially true if platelet lysates from already approved transfusion units at blood banks can be utilized. The purpose of this study was to produce human platelet lysates from expired, blood bank-approved platelet concentrates and evaluate their use as growth supplement in the culture of mesenchymal stem cells. METHODOLOGY/PRINCIPAL FINDINGS: In this study, bone marrow-derived mesenchymal stem cells were cultured with one of three culture supplements; fetal bovine serum, lysates from freshly prepared human platelet concentrates, or lysates from expired human platelet concentrates. The effects of these platelet-derived culture supplements on basic mesenchymal stem cell characteristics were evaluated. All cultures maintained the typical mesenchymal stem cell surface marker expression, trilineage differentiation potential, and the ability to suppress in vitro immune responses. However, mesenchymal stem cells supplemented with platelet lysates proliferated faster than traditionally cultured cells and increased the expression of the osteogenic marker gene RUNX-2; yet no difference between the use of fresh and expired platelet concentrates was observed. CONCLUSION/SIGNIFICANCE: Our findings suggest that human platelet lysates produced from expired platelet concentrates can be used as an alternative to fetal bovine serum for mesenchymal stem cell culture to the same extent as lysates from fresh platelets.

  1. Inhibition of nitric oxide synthesis enhances leukocyte rolling and adhesion in human microvasculature

    Directory of Open Access Journals (Sweden)

    Hossain Mokarram

    2012-07-01

    Full Text Available Abstract Background Nitric oxide (NO is a multifunctional signaling molecule that regulates important cellular events in inflammation including leukocyte recruitment. Previous studies have shown that pharmacological inhibition of NO synthesis induces leukocyte recruitment in various in vitro and animal models. However, it is not known whether NO modulation has similar effects on leukocyte-endothelial cell interactions within the human microvasculature. The present study explored the effect of systemic L-NAME treatment on leukocyte recruitment in the SCID-hu mouse model. Methods Human skin xenografts were transplanted in SCID mice to study human leukocyte dynamics in human vasculature. Early events of human leukocyte recruitment in human vasculature were studied using intravital microscopy. NO synthesis was pharmacologically inhibited using NG-nitro-L-arginine methyl ester (L-NAME. Immunohistochemical analysis was performed to elucidate E-selectin expression in human xenograft skin. Human neutrophil-endothelial cell interactions were also studied in an in vitro flow chamber assay system. P- and E-selectin expression on cultured human umbilical vein endothelial cells (HUVECs was measured using ELISA. Platelet-activating factor (PAF synthesis was detected using a TLC-based assay. Results L-NAME treatment significantly enhanced the rolling and adhesion of human leukocytes to the human vasculature. Functional blocking of P- and E-selectins significantly inhibited rolling but not adhesion induced by inhibition of NO synthesis. Systemic L-NAME treatment enhanced E-selectin expression in human xenograft skin. L-NAME treatment significantly enhanced P- and E-selectin expression on HUVECs. L-NAME treatment did not significantly modify neutrophil rolling or adhesion to HUVECs indicating that L-NAME−induced subtle P- and E-selectin expression was insufficient to elicit dynamic neutrophil-HUVEC interactions in vitro. Moreover, synthesis of endothelial

  2. Proliferation-promoting effect of platelet-rich plasma on human adipose-derived stem cells and human dermal fibroblasts.

    Science.gov (United States)

    Kakudo, Natsuko; Minakata, Tatsuya; Mitsui, Toshihito; Kushida, Satoshi; Notodihardjo, Frederik Zefanya; Kusumoto, Kenji

    2008-11-01

    This study evaluated changes in platelet-derived growth factor (PDGF)-AB and transforming growth factor (TGF)-beta1 release from platelets by platelet-rich plasma activation, and the proliferation potential of activated platelet-rich plasma and platelet-poor plasma on human adipose-derived stem cells and human dermal fibroblasts. Platelet-rich plasma was prepared using a double-spin method, with the number of platelets counted in each preparation stage. Platelet-rich and platelet-poor plasma were activated with autologous thrombin and calcium chloride, and levels of platelet-released PDGF-AB and TGF-beta1 were determined by enzyme-linked immunosorbent assay. Cells were cultured for 1, 4, or 7 days in serum-free Dulbecco's Modified Eagle Medium supplemented with 5% whole blood plasma, nonactivated platelet-rich plasma, nonactivated platelet-poor plasma, activated platelet-rich plasma, or activated platelet-poor plasma. In parallel, these cells were cultured for 1, 4, or 7 days in serum-free Dulbecco's Modified Eagle Medium supplemented with 1%, 5%, 10%, or 20% activated platelet-rich plasma. The cultured human adipose-derived stem cells and human dermal fibroblasts were assayed for proliferation. Platelet-rich plasma contained approximately 7.9 times as many platelets as whole blood, and its activation was associated with the release of large amounts of PDGF-AB and TGF-beta1. Adding activated platelet-rich or platelet-poor plasma significantly promoted the proliferation of human adipose-derived stem cells and human dermal fibroblasts. Adding 5% activated platelet-rich plasma to the medium maximally promoted cell proliferation, but activated platelet-rich plasma at 20% did not promote it. Platelet-rich plasma can enhance the proliferation of human adipose-derived stem cells and human dermal fibroblasts. These results support clinical platelet-rich plasma application for cell-based, soft-tissue engineering and wound healing.

  3. Superoxide dismutase of human platelets

    International Nuclear Information System (INIS)

    Kimura, Akiro; Fujimura, Kingo; Kuramoto, Atsushi

    1979-01-01

    Superoxide dismutase (S.O.D.) is the enzyme to protect from destructive effect of superoxide (O 2 -) produced in many metabolic pathways related to oxygen. The purpose of this study was to investigate the possibility that S.O.D. may play an important role in the platelet function. The cytoplasmic and mitochondrial S.O.D. has been investigated spectrophotometrically and gel electrophoretically in human platelets from eleven patients of chronic myelogenous leukemia (CML) and three patients of primary thrombocythemia (P.Th.). Neither deficiency nor abnormality of cytoplasmic and mitochondrial S.O.D. has been found electrophoretically in any case compared to normal platelets. However, the total activity from three of the CML patients and one of the P.Th. patients were above 3 unit/mg platelet protein (normal subject: 2.11 - 2.70 unit/mg protein), suggesting the possibility either that more O 2 -production occurs in the platelets or that rather little O 2 -production due to much O 2 -deprivation by the increased S.O.D. The S.O.D. activity of human platelets has been also investigated in several conditions, where much O 2 -generation might occur in platelets. Sodium fluoride (2 mM), which increases platelet O 2 -production about 3 fold, had no effect on platelet S.O.D. The aggregated platelets induced by ADP (10 -5 M), epinephrin (50 μg/ml), ristocetin (1.5 mg/ml) or collagen (1 - 20 μg/ml) had no increase of S.O.D. activity compared to that from non aggregated platelets. X-ray irradiation (1,000 - 20,000R) had not induced its activity increase or decrease. These findings indicated the induction of platelet S.O.D. was not brought about under these conditions. (author)

  4. A novel platelet concentrate: titanium-prepared platelet-rich fibrin.

    Science.gov (United States)

    Tunalı, Mustafa; Özdemir, Hakan; Küçükodacı, Zafer; Akman, Serhan; Yaprak, Emre; Toker, Hülya; Fıratlı, Erhan

    2014-01-01

    We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF) was processed with a scanning electron microscope (SEM). The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

  5. A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

    Directory of Open Access Journals (Sweden)

    Mustafa Tunalı

    2014-01-01

    Full Text Available We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF. The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun’s leukocyte- and platelet-rich fibrin (L-PRF method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF was processed with a scanning electron microscope (SEM. The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

  6. Application of platelet-rich plasma and platelet-rich fibrin in fat grafting: basic science and literature review.

    Science.gov (United States)

    Liao, Han-Tsung; Marra, Kacey G; Rubin, J Peter

    2014-08-01

    Due to the natural properties of fat, fat grafting remains a popular procedure for soft tissue volume augmentation and reconstruction. However, clinical outcome varies and is technique dependent. Platelet-rich plasma (PRP) contains α-granules, from which multiple growth factors such as platelet-derived growth factor, transforming growth factor-β, vascular endothelial growth factor, and epidermal growth factor can be released after activation. In recent years, the scope of PRP therapies has extended from bone regeneration, wound healing, and healing of musculoskeletal injuries, to enhancement of fat graft survival. In this review, we focus on the definition of PRP, the different PRP preparation and activation methods, and growth factor concentrations. In addition, we discuss possible mechanisms for the role of PRP in fat grafting by reviewing in vitro studies with adipose-derived stem cells, preadipocytes, and adipocytes, and preclinical and clinical research. We also review platelet-rich fibrin, a so-called second generation PRP, and its slow-releasing biology and effects on fat grafts compared to PRP in both animal and clinical research. Finally, we provide a general foundation on which to critically evaluate earlier studies, discuss the limitations of previous research, and direct plans for future experiments to improve the optimal effects of PRP in fat grafting.

  7. Thromboelastometric and platelet responses to silk biomaterials.

    Science.gov (United States)

    Kundu, Banani; Schlimp, Christoph J; Nürnberger, Sylvia; Redl, Heinz; Kundu, S C

    2014-05-13

    Silkworm's silk is natural biopolymer with unique properties including mechanical robustness, all aqueous base processing and ease in fabrication into different multifunctional templates. Additionally, the nonmulberry silks have cell adhesion promoting tri-peptide (RGD) sequences, which make it an immensely potential platform for regenerative medicine. The compatibility of nonmulberry silk with human blood is still elusive; thereby, restricts its further application as implants. The present study, therefore, evaluate the haematocompatibility of silk biomaterials in terms of platelet interaction after exposure to nonmulberry silk of Antheraea mylitta using thromboelastometry (ROTEM). The mulberry silk of Bombyx mori and clinically used Uni-Graft W biomaterial serve as references. Shortened clotting time, clot formation times as well as enhanced clot strength indicate the platelet mediated activation of blood coagulation cascade by tested biomaterials; which is comparable to controls.

  8. Negative feedback regulation of human platelets via autocrine activation of the platelet-derived growth factor alpha-receptor.

    Science.gov (United States)

    Vassbotn, F S; Havnen, O K; Heldin, C H; Holmsen, H

    1994-05-13

    Human platelets contain platelet-derived growth factor (PDGF) in their alpha-granules which is released during platelet exocytosis. We show by immunoprecipitation and 125I-PDGF binding experiments that human platelets have functionally active PDGF alpha-receptors, but not beta-receptors. The PDGF alpha-receptor (PDGFR-alpha) was identified as a 170-kDa glycosylated protein-tyrosine kinase as found in other cell types. Stimulation of platelets with 0.1 unit/ml thrombin resulted in a significant increase (2-5-fold) of the tyrosine phosphorylation of the PDGFR-alpha, as determined by immunoprecipitation with phosphotyrosine antiserum as well as with PDGFR-alpha antiserum. The observed thrombin-induced autophosphorylation of the PDGFR-alpha was inhibited by the addition of a neutralizing monoclonal PDGF antibody. Thus, our results suggest that the platelet PDGFR-alpha is stimulated in an autocrine manner by PDGF secreted during platelet activation. Preincubation of platelets with PDGF inhibited thrombin-induced platelet aggregation and secretion of ATP + ADP and beta-hexosaminidase. Thrombin-induced platelet aggregation was also reversed when PDGF was added 30 s after thrombin stimulation. Inhibition of the autocrine PDGF pathway during platelet activation by the PDGF antibody led to a potentiation of thrombin-induced beta-hexosaminidase secretion. Thus, the PDGFR-alpha takes part in a negative feedback regulation during platelet activation. Our demonstration of PDGF alpha-receptors on human platelets and its inhibitory function during platelet activation identifies a new possible role of PDGF in the regulation of thrombosis.

  9. Platelet-rich plasma and chronic wounds: remaining fibronectin may influence matrix remodeling and regeneration success.

    Science.gov (United States)

    Moroz, Andrei; Deffune, Elenice

    2013-11-01

    Platelet-rich plasma has been largely used as a therapeutic option for the treatment of chronic wounds of different etiologies. The enhanced regeneration observed after the use of platelet-rich plasma has been systematically attributed to the growth factors that are present inside platelets' granules. We hypothesize that the remaining plasma and platelet-bound fibronectin may act as a further bioactive protein in platelet-rich plasma preparations. Recent reports were analyzed and presented as direct evidences of this hypotheses. Fibronectin may directly influence the extracellular matrix remodeling during wound repair. This effect is probably through matrix metalloproteinase expression, thus exerting an extra effect on chronic wound regeneration. Physicians should be well aware of the possible fibronectin-induced effects in their future endeavors with PRP in chronic wound treatment. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  10. Gasdermin D Exerts Anti-inflammatory Effects by Promoting Neutrophil Death

    Directory of Open Access Journals (Sweden)

    Hiroto Kambara

    2018-03-01

    Full Text Available Summary: Gasdermin D (GSDMD is considered a proinflammatory factor that mediates pyroptosis in macrophages to protect hosts from intracellular bacteria. Here, we reveal that GSDMD deficiency paradoxically augmented host responses to extracellular Escherichia coli, mainly by delaying neutrophil death, which established GSDMD as a negative regulator of innate immunity. In contrast to its activation in macrophages, in which activated inflammatory caspases cleave GSDMD to produce an N-terminal fragment (GSDMD-cNT to trigger pyroptosis, GSDMD cleavage and activation in neutrophils was caspase independent. It was mediated by a neutrophil-specific serine protease, neutrophil elastase (ELANE, released from cytoplasmic granules into the cytosol in aging neutrophils. ELANE-mediated GSDMD cleavage was upstream of the caspase cleavage site and produced a fully active ELANE-derived NT fragment (GSDMD-eNT that induced lytic cell death as efficiently as GSDMD-cNT. Thus, GSDMD is pleiotropic, exerting both pro- and anti-inflammatory effects that make it a potential target for antibacterial and anti-inflammatory therapies. : Kambara et al. find that GSDMD deficiency augments host responses to extracellular Escherichia coli, mainly by delaying neutrophil death, establishing GSDMD as a negative regulator of innate immunity. GSDMD cleavage and activation in neutrophils is mediated by ELANE, released from cytoplasmic granules into the cytosol in aging neutrophils. Keywords: GSDMD, neutrophil death, neutrophil elastase, innate immunity, host defense

  11. Platelets promote osteosarcoma cell growth through activation of the platelet-derived growth factor receptor-Akt signaling axis

    OpenAIRE

    Takagi, Satoshi; Takemoto, Ai; Takami, Miho; Oh-hara, Tomoko; Fujita, Naoya

    2014-01-01

    The interactions of tumor cells with platelets contribute to the progression of tumor malignancy, and the expression levels of platelet aggregation-inducing factors positively correlate with the metastatic potential of osteosarcoma cells. However, it is unclear how tumor-platelet interaction contributes to the proliferation of osteosarcomas. We report here that osteosarcoma-platelet interactions induce the release of platelet-derived growth factor (PDGF) from platelets, which promotes the pro...

  12. Flow cytometric assessment of activation of peripheral blood platelets in dogs with normal platelet count and asymptomatic thrombocytopenia.

    Science.gov (United States)

    Żmigrodzka, M; Guzera, M; Winnicka, A

    2016-01-01

    Platelets play a crucial role in hemostasis. Their activation has not yet been evaluated in healthy dogs with a normal and low platelet count. The aim of this study was to determine the influence of activators on platelet activation in dogs with a normal platelet count and asymptomatic thrombocytopenia. 72 clinically healthy dogs were enrolled. Patients were allocated into three groups. Group 1 consisted of 30 dogs with a normal platelet count, group 2 included 22 dogs with a platelet count between 100 and 200×109/l and group 3 consisted of 20 dogs with a platelet count lower than 100×109/l. Platelet rich-plasma (PRP) was obtained from peripheral blood samples using tripotassium ethylenediaminetetraacetic acid (K3-EDTA) as anticoagulant. Next, platelets were stimulated using phorbol-12-myristate-13-acetate or thrombin, stabilized using procaine or left unstimulated. The expression of CD51 and CD41/CD61 was evaluated. Co-expression of CD41/CD61 and Annexin V served as a marker of platelet activation. The expression of CD41/CD61 and CD51 did not differ between the 3 groups. Thrombin-stimulated platelets had a significantly higher activity in dogs with a normal platelet count than in dogs with asymptomatic thrombocytopenia. Procaine inhibited platelet activity in all groups. In conclusion, activation of platelets of healthy dogs in vitro varied depending on the platelet count and platelet activator.

  13. Neutrophils, a candidate biomarker and target for radiation therapy?

    Science.gov (United States)

    Schernberg, Antoine; Blanchard, Pierre; Chargari, Cyrus; Deutsch, Eric

    2017-11-01

    Neutrophils are the most abundant blood-circulating white blood cells, continuously generated in the bone marrow. Growing evidence suggests they regulate the innate and adaptive immune system during tumor evolution. This review will first summarize the recent findings on neutrophils as a key player in cancer evolution, then as a potential biomarker, and finally as therapeutic targets, with respective focuses on the interplay with radiation therapy. A complex interplay: Neutrophils have been associated with tumor progression through multiple pathways. Ionizing radiation has cytotoxic effects on cancer cells, but the sensitivity to radiation therapy in vivo differ from isolated cancer cells in vitro, partially due to the tumor microenvironment. Different microenvironmental states, whether baseline or induced, can modulate or even attenuate the effects of radiation, with consequences for therapeutic efficacy. Inflammatory biomarkers: Inflammation-based scores have been widely studied as prognostic biomarkers in cancer patients. We have performed a large retrospective cohort of patients undergoing radiation therapy (1233 patients), with robust relationship between baseline blood neutrophil count and 3-year's patient's overall survival in patients with different cancer histologies. (Pearson's correlation test: p = .001, r = -.93). Therapeutic approaches: Neutrophil-targeting agents are being developed for the treatment of inflammatory and autoimmune diseases. Neutrophils either can exert antitumoral (N1 phenotype) or protumoral (N2 phenotype) activity, depending on the Tumor Micro Environment. Tumor associated N2 neutrophils are characterized by high expression of CXCR4, VEGF, and gelatinase B/MMP9. TGF-β within the tumor microenvironment induces a population of TAN with a protumor N2 phenotype. TGF-β blockade slows tumor growth through activation of CD8 + T cells, macrophages, and tumor associated neutrophils with an antitumor N1 phenotype. This supports

  14. Plaqueta e leptina em adolescentes com obesidade Platelet and leptin in obese adolescents

    Directory of Open Access Journals (Sweden)

    Denis Foschini

    2008-12-01

    Full Text Available OBJETIVOS: Analisar a influência de obesidade na contagem de células imunológicas e na concentração dos hormônios cortisol e leptina, a fim de estabelecer uma relação entre as variáveis analisadas. MÉTODOS: Foram recrutados 27 adolescentes obesos [índice de massa corporal (IMC ≥ percentil 95[ e 21 não-obesos (IMC ≤ percentil 75, de ambos os sexos, com idade entre 15 e 19 anos, na fase pós-púbere. O IMC foi calculado através da divisão do peso pela altura ao quadrado e a composição corporal foi estimada por pletismografia no sistema Bod PodTM. Amostras de sangue foram colhidas para análise de leucócitos, neutrófilos, linfócitos, monócitos, plaquetas, cortisol e leptina. O teste de Kolmogorov-Smirnov foi utilizado, seguido pelo teste t de Student independente supondo distribuição normal. O nível de significância estabelecido foi p OBJECTIVE: To analyze the influence of obesity status on immune cell count and concentration of the hormones cortisol and leptin, in order to establish a relationship among the variables analyzed. METHODS: We recruited 27 obese [body mass index (BMI ≥ 95th percentile[ and 21 non-obese (BMI ≤ 75th percentile adolescent boys and girls, aged 15-19 years at the post-pubertal stage. BMI was calculated as body weight divided by height squared, and body composition was estimated by plethysmography in the Bod PodTM system. Blood samples were collected to analyze leukocytes, neutrophils, lymphocytes, monocytes, platelets, cortisol, and leptin. The Kolmogorov-Smirnov test was performed, followed by the independent Student t test in case of normal distribution. Significance values were set at p < 0.05 and expressed as means ± standard deviation. The statistical package SPSS for Windows version 12.0 was used. RESULTS: There was no difference between obese and non-obese adolescents in terms of leukocyte, neutrophil, lymphocyte, monocyte and cortisol serum concentrations. The group of obese

  15. Platelet alpha-2 adrenergic receptor-mediated phosphoinositide responses in endogenous depression

    International Nuclear Information System (INIS)

    Mori, Hideki; Koyama, Tsukasa; Yamashita, Itaru

    1991-01-01

    We have previously indicated that epinephrine stimulates phosphoinositide (PI) hydrolysis by activating alpha-2 adrenergic receptors in human platelets. This method involves the measurement of the accumulation of [ 3 H]-inositol-1-phosphate (IP-1) as an index of Pl hydrolysis; lithium is added to inhibit the metabolism of IP-1, thus giving an enhanced signal. In the present study, we assessed the platelet alpha-2 adrenergic receptor-mediated PI responses in samples from 15 unmedicated patients with endogenous depression and 15 age- and sex-matched control subjects. The responses to epinephrine in the depressed patients were significantly higher than those of the controls, whereas the basal values did not differ significantly. These results support the hypothesis that platelet alpha-2 adrenergic receptors may be supersensitive in patients with endogenous depression

  16. The content of bone morphogenetic proteins in platelets varies greatly between different platelet donors

    International Nuclear Information System (INIS)

    Kalen, Anders; Wahlstroem, Ola; Linder, Cecilia Halling; Magnusson, Per

    2008-01-01

    Platelet derivates and platelet rich plasma have been used to stimulate bone formation and wound healing because of the rich content of potent growth factors. However, not all reports have been conclusive since some have not been able to demonstrate a positive effect. We investigated the interindividual variation of bone morphogenetic proteins (BMPs) in platelets from healthy donors, and the pH-dependent effect on the release of BMPs in preparations of lysed platelets in buffer (LPB). Platelet concentrates from 31 healthy donors were prepared in pH 4.3 and pH 7.4 buffers and investigated with respect to BMP-2, -4, -6, and -7. BMP-2 and BMP-4 were significantly more common in acidic LPBs in comparison with neutral preparations. We also observed a considerable variation among platelet donors with respect to the release of BMPs at pH 4.3 and 7.4. In conclusion, a considerable variation was found among platelet donors, which may be of importance considering the ambiguous results previously reported on osteoblast proliferation and differentiation

  17. The role of platelets during reproduction.

    Science.gov (United States)

    Isermann, Berend; Nawroth, Peter P

    2006-01-01

    The availability of mice with defined defects within the hemostatic system enabled researchers to identify a role the coagulation system for embryonic and placental development. However, the role of platelets during development has only recently been experimentally addressed, giving some insight into potential functions of platelets during development. Thus, a quantitative embryonic platelet defect (severe thrombopenia secondary to NF-E2 deficiency) is associated with an embryonic growth retardation and reduced vascularisation of the placenta. Maternal platelet deficiency is associated with placental hemorrhage, which, however, does not impair embryonic or maternal survival. In vitro studies established that platelets or platelet conditioned medium regulate the invasive properties of human extravillous trophoblast cells and induce a phenotypical switch of trophoblast cells. These data imply that platelets are of relevance during placentation. Conversely, platelets and the formation of platelet-fibrin aggregates are dispensable for the development of the embryo proper, establishing that the lethal phenotypes observed in some embryo slacking coagulation regulators does not result from an inability to form platelet-fibrin aggregates, but likely reflects altered protease dependent signaling during vascular development.

  18. Clot lysis time in platelet-rich plasma: method assessment, comparison with assays in platelet-free and platelet-poor plasmas, and response to tranexamic acid.

    Science.gov (United States)

    Panes, Olga; Padilla, Oslando; Matus, Valeria; Sáez, Claudia G; Berkovits, Alejandro; Pereira, Jaime; Mezzano, Diego

    2012-01-01

    Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma

  19. Granule protein processing and regulated secretion in neutrophils

    Directory of Open Access Journals (Sweden)

    Avinash eSheshechalam

    2014-09-01

    Full Text Available Neutrophils are part of a family of granulocytes that, together with eosinophils and basophils, play an essential role in innate immunity. Neutrophils are the most abundant circulating leukocytes and are vital for rapid immune responses, being recruited to sites of injury or infection within minutes, where they can act as specialized phagocytic cells. However, another prominent function of neutrophils is the release of pro-inflammatory compounds, including cytokines, chemokines and digestive enzymes, which are stored in intracellular compartments and released through regulated exocytosis. Hence, an important feature that contributes to rapid immune responses is capacity of neutrophils to synthesize and store pre-formed pro-inflammatory mediators in specialized intracellular vesicles and thus no new synthesis is required. This review will focus on advancement in three topics relevant to neutrophil secretion. First we will examine what is known about basal level pro-inflammatory mediator synthesis, trafficking and storage in secretory compartments. Second, we will review recent advancements in the mechanisms that control vesicle mobilization and the release of pre-formed mediators. Third, we will examine the upregulation and de novo synthesis of pro-inflammatory mediators by neutrophils engaged at sites of infection.

  20. UV-C irradiation disrupts platelet surface disulfide bonds and activates the platelet integrin alphaIIbbeta3

    NARCIS (Netherlands)

    Verhaar, Robin; Dekkers, David W. C.; de Cuyper, Iris M.; Ginsberg, Mark H.; de Korte, Dirk; Verhoeven, Arthur J.

    2008-01-01

    UV-C irradiation has been shown to be effective for pathogen reduction in platelet concentrates, but preliminary work indicated that UV-C irradiation of platelets can induce platelet aggregation. In this study, the mechanism underlying this phenomenon was investigated. Irradiation of platelets with

  1. Swell activated chloride channel function in human neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, Michael D. [Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom); Ahluwalia, Jatinder, E-mail: j.ahluwalia@uel.ac.uk [Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom)

    2009-04-17

    Non-excitable cells such as neutrophil granulocytes are the archetypal inflammatory immune cell involved in critical functions of the innate immune system. The electron current generated (I{sub e}) by the neutrophil NADPH oxidase is electrogenic and rapidly depolarises the membrane potential. For continuous function of the NADPH oxidase, I{sub e} has to be balanced to preserve electroneutrality, if not; sufficient depolarisation would prevent electrons from leaving the cell and neutrophil function would be abrogated. Subsequently, the depolarisation generated by the neutrophil NADPH oxidase I{sub e} must be counteracted by ion transport. The finding that depolarisation required counter-ions to compensate electron transport was followed by the observation that chloride channels activated by swell can counteract the NADPH oxidase membrane depolarisation. In this mini review, we discuss the research findings that revealed the essential role of swell activated chloride channels in human neutrophil function.

  2. Platelet-activating factor increases platelet-dependent glycoconjugate secretion from tracheal submucosal gland

    International Nuclear Information System (INIS)

    Sasaki, T.; Shimura, S.; Ikeda, K.; Sasaki, H.; Takishima, T.

    1989-01-01

    Using isolated glands from feline trachea, we examined the effect of platelet-activating factor (PAF) on radiolabeled glycoconjugate release and glandular contraction by measuring induced tension in the absence or presence of platelets. PAF alone did not produce any significant glandular contraction nor any significant change in glycoconjugate release from isolated glands. In the presence of purified platelets containing no plasma, PAF (10(-8) to 10(-5) M) produced significant glycoconjugate secretion in a dose-dependent fashion, but it produced no significant glandular contraction. PAF-evoked glycoconjugate secretion was time dependent, reaching a peak response of 277% of control 15-30 min after the exposure of isolated glands to 10(-5) M PAF in the presence of platelets and returning to 135% of controls at 2 h. Platelets alone did not produce any significant stimulation in glycoconjugate release. CV-3988, a known PAF antagonist, inhibited the secretory response to PAF. Methysergide, a known antagonist to receptors for 5-hydroxytryptamine, did not alter PAF-evoked glycoconjugate secretion. Both indomethacin and SQ 29,548, a thromboxane receptor antagonist, abolished the PAF-evoked glycoconjugate secretion from isolated submucosal glands. Epithiomethanothromboxane A2, a stable thromboxane A2 analogue, produced a significant increase in glycoconjugate secretion in a dose-dependent fashion. These findings indicate that PAF increases glycoconjugate release in the presence of platelets and that the increase is dependent on some aspect of platelet function, namely thromboxane generation

  3. Platelet Count and Plateletcrit

    African Journals Online (AJOL)

    strated that neonates with late onset sepsis (bacteremia after 3 days of age) had a dramatic increase in MPV and. PDW18. We hypothesize that as the MPV and PDW increase and platelet count and PCT decrease in sick children, intui- tively, the ratio of MPV to PCT; MPV to Platelet count,. PDW to PCT, PDW to platelet ...

  4. Assessment of quality of platelets preserved in plasma and platelet additive solution: A Malaysian experience

    Directory of Open Access Journals (Sweden)

    Munirah Binti Mokhtar

    2016-01-01

    Full Text Available Background: A use of platelet additives solution (PAS improves storage conditions so as to give increased shelf life to platelets and to maintain hemostatic function. Objective: The present study was aimed to compare in vitro quality of platelet rich plasma (PRP-derived platelet concentrate (PC during extended period of storage in plasma and in additive solution (Composol PS and Fresenius. Study Design: Randomized 19 PCs each were used in the study for plasma and PAS as the storage medium. The measurement parameters, including pH, total white blood cell (WBC count, total platelet count, and platelet activation rate, were studied on day 1, day 5, and day 8 of the storage period. The sterility test was carried out on the eighth day of storage. Results: pH of PC suspended in PAS was significantly lower as compared to that in plasma (P < 0.001 for all the three days of sampling. The WBC count, both in plasma and in PAS, showed an acceptable values of being <0.2 Χ 10 9 /unit during the storage period. Platelet count in PAS was higher as compared to that in plasma, though it was not statistically significant. While both the groups showed increased platelet activation rate during the storage, the PCs suspended in PAS showed significantly higher platelet activation rate (p0.001. Results from sterility test showed no bacterial growth in the PCs in both the groups. Conclusion: Most parameters studied on platelet storage in suspending medium of native plasma and PAS remained well within the acceptable limits. However, the pH values and platelet activation rate significantly differed in PAS as compared with plasma.

  5. Demodex-associated bacterial proteins induce neutrophil activation.

    LENUS (Irish Health Repository)

    2012-02-01

    Background: Patients with rosacea demonstrate a higher density of Demodex mites in their skin than controls. A bacterium isolated from a Demodex mite from a patient with papulopustular rosacea (PPR) was previously shown to provoke an immune response in patients with PPR or ocular rosacea thus suggesting a possible role for bacterial proteins in the etiology of this condition. Objectives: To examine the response of neutrophils to proteins derived from a bacterium isolated from a Demodex mite. Methods: Bacterial cells were lysed and proteins were partially purified by AKTA-FPLC. Isolated neutrophils were exposed to bacterial proteins and monitored for alterations in migration, degranulation and cytokine production. Results: Neutrophils exposed to proteins from Bacillus cells demonstrated increased levels of migration and elevated release of MMP-9, an enzyme known to degrade collagen and cathelicidin, an antimicrobial peptide. In addition neutrophils exposed to the bacterial proteins demonstrated elevated rates of Il-8 and TNF-alpha production. Conclusions: Proteins produced by a bacterium isolated from a Demodex mite have the ability to increase the migration, degranulation and cytokine production abilities of neutrophils. These results suggest that bacteria may play a role in the inflammatory erythema associated with rosacea.

  6. Genetics Home Reference: gray platelet syndrome

    Science.gov (United States)

    ... disorder, platelet-type, 4 deficient alpha granule syndrome GPS grey platelet syndrome platelet alpha-granule deficiency platelet ... on PubMed Central Kahr WH, Hinckley J, Li L, Schwertz H, Christensen H, Rowley JW, Pluthero FG, ...

  7. Subpopulations in purified platelets adhering on glass.

    Science.gov (United States)

    Donati, Alessia; Gupta, Swati; Reviakine, Ilya

    2016-06-22

    Understanding how platelet activation is regulated is important in the context of cardiovascular disorders and their management with antiplatelet therapy. Recent evidence points to different platelet subpopulations performing different functions. In particular, procoagulant and aggregating subpopulations have been reported in the literature in platelets treated with the GPVI agonists. How the formation of platelet subpopulations upon activation is regulated remains unclear. Here, it is shown that procoagulant and aggregating platelet subpopulations arise spontaneously upon adhesion of purified platelets on clean glass surfaces. Calcium ionophore treatment of the adhering platelets resulted in one platelet population expressing both the procoagulant and the adherent population markers phosphatidylserine and the activated form of GPIIb/IIIa, while all of the platelets expressed CD62P independently of the ionophore treatment. Therefore, all platelets have the capacity to express all three activation markers. It is concluded that platelet subpopulations observed in various studies reflect the dynamics of the platelet activation process.

  8. Platelet count and platelet indices in women with preeclampsia.

    Science.gov (United States)

    AlSheeha, Muneera A; Alaboudi, Rafi S; Alghasham, Mohammad A; Iqbal, Javed; Adam, Ishag

    2016-01-01

    Although the exact pathophysiology of preeclampsia is not completely understood, the utility of different platelets indices can be utilized to predict preeclampsia. To compare platelet indices, namely platelet count (PC), mean platelet volume (MPV), platelet distribution width (PDW), and PC to MPV ratio in women with preeclampsia compared with healthy controls. Qassim Hospital, Kingdom of Saudi Arabia. A case-control study. Sixty preeclamptic women were the cases and an equal number of healthy pregnant women were the controls. There was no significant difference in age, parity, and body mass index between the study groups. Sixteen and 44 of the cases were severe and mild preeclampsia, respectively. There was no significant difference in PDW and MPV between the preeclamptic and control women. Both PC and PC to MPV ratios were significantly lower in the women with preeclampsia compared with the controls. There was no significant difference in the PC, PDW, MPV, and PC to MPV ratio when women with mild and severe preeclampsia were compared. Using receiver operating characteristic (ROC) curves, the PC cutoff was 248.0×10 3 /µL for diagnosis of pre-eclampsia ( P =0.019; the area under the ROC curve was 62.4%). Binary regression suggests that women with PC preeclampsia (odds ratio =2.2, 95% confidence interval =1.08-4.6, P =0.03). The PC/MPV cutoff was 31.2 for diagnosis of preeclampsia ( P =0.035, the area under the ROC curve was 62.2%). PC preeclampsia.

  9. Relationship between platelet phospholipid FA and mean platelet volume in healthy men.

    Science.gov (United States)

    Li, Duo; Turner, Alan; Sinclair, Andrew J

    2002-09-01

    Increased mean platelet volume (MPV) has been suggested as an independent risk factor for acute myocardial infarction and the increased reactivity of large platelets. The aim of this study was to investigate the correlation between platelet phospholipid (PL) PUFA composition and MPV in 139 free-living healthy men ages 20-55 yr (vegans, n = 18; ovolacto vegetarians, n = 43; moderate meat-eaters, n = 60; and high meateaters, n = 18). Each subject completed a semiquantitative Food Frequency Questionnaire and gave a blood sample. Platelet PL FA composition and MPV were determined by standard methods. MPV was significantly greater in the vegans than in the ovolacto vegetarian, moderate, or high meat-eater groups (P vegan and ovolacto vegetarian groups had significantly higher platelet PL 18:2n-6 and 22:4n-6, and lower 20:5n-3 and 22:6n-3 compared with the moderate and high meat-eater groups. The vegans demonstrated a significant reduction in 20:4n-6 and 22:5n-3 compared with the ovolacto vegetarian, high meat-eater, and moderate meat-eater groups. Bivariate analysis results showed that MPV was significantly positively correlated with platelet PL 18:2n-6 (P = 0.048) and negatively correlated with 20:3n-6 (P = 0.02), 20:5n-3 (P = 0.005), and 22:5n-3 (P< 0.0001), respectively. In a multiple linear regression analysis, after controlling for potential confounding factors such as dietary group, age, exercise, body mass index, and dietary polyunsaturated and saturated fat, cholesterol, carbohydrate, and fiber intake, the MPV was still strongly negatively correlated with platelet PL 20:3n-6 (P = 0.003) and 22:5n-3 (P = 0.001). The present data suggest that 22:5n-3 and 20:3n-6 may play a role in the structural function of the platelet membrane.

  10. Increased platelet reactivity is associated with circulating platelet-monocyte complexes and macrophages in human atherosclerotic plaques.

    Directory of Open Access Journals (Sweden)

    Bert Rutten

    Full Text Available Platelet reactivity, platelet binding to monocytes and monocyte infiltration play a detrimental role in atherosclerotic plaque progression. We investigated whether platelet reactivity was associated with levels of circulating platelet-monocyte complexes (PMCs and macrophages in human atherosclerotic carotid plaques.Platelet reactivity was determined by measuring platelet P-selectin expression after platelet stimulation with increasing concentrations of adenosine diphosphate (ADP, in two independent cohorts: the Circulating Cells cohort (n = 244 and the Athero-Express cohort (n = 91. Levels of PMCs were assessed by flow cytometry in blood samples of patients who were scheduled for percutaneous coronary intervention (Circulating Cells cohort. Monocyte infiltration was semi-quantitatively determined by histological examination of atherosclerotic carotid plaques collected during carotid endarterectomy (Athero-Express cohort.We found increased platelet reactivity in patients with high PMCs as compared to patients with low PMCs (median (interquartile range: 4153 (1585-11267 area under the curve (AUC vs. 9633 (3580-21565 AUC, P<0.001. Also, we observed increased platelet reactivity in patients with high macrophage levels in atherosclerotic plaques as compared to patients with low macrophage levels in atherosclerotic plaques (mean ± SD; 8969 ± 3485 AUC vs. 7020 ± 3442 AUC, P = 0.02. All associations remained significant after adjustment for age, sex and use of drugs against platelet activation.Platelet reactivity towards ADP is associated with levels of PMCs and macrophages in human atherosclerotic carotid plaques.

  11. Functional divergence of platelet protein kinase C (PKC) isoforms in thrombus formation on collagen.

    Science.gov (United States)

    Gilio, Karen; Harper, Matthew T; Cosemans, Judith M E M; Konopatskaya, Olga; Munnix, Imke C A; Prinzen, Lenneke; Leitges, Michael; Liu, Qinghang; Molkentin, Jeffery D; Heemskerk, Johan W M; Poole, Alastair W

    2010-07-23

    Arterial thrombosis, a major cause of myocardial infarction and stroke, is initiated by activation of blood platelets by subendothelial collagen. The protein kinase C (PKC) family centrally regulates platelet activation, and it is becoming clear that the individual PKC isoforms play distinct roles, some of which oppose each other. Here, for the first time, we address all four of the major platelet-expressed PKC isoforms, determining their comparative roles in regulating platelet adhesion to collagen and their subsequent activation under physiological flow conditions. Using mouse gene knock-out and pharmacological approaches in human platelets, we show that collagen-dependent alpha-granule secretion and thrombus formation are mediated by the conventional PKC isoforms, PKCalpha and PKCbeta, whereas the novel isoform, PKC, negatively regulates these events. PKCdelta also negatively regulates thrombus formation but not alpha-granule secretion. In addition, we demonstrate for the first time that individual PKC isoforms differentially regulate platelet calcium signaling and exposure of phosphatidylserine under flow. Although platelet deficient in PKCalpha or PKCbeta showed reduced calcium signaling and phosphatidylserine exposure, these responses were enhanced in the absence of PKC. In summary therefore, this direct comparison between individual subtypes of PKC, by standardized methodology under flow conditions, reveals that the four major PKCs expressed in platelets play distinct non-redundant roles, where conventional PKCs promote and novel PKCs inhibit thrombus formation on collagen.

  12. Functional Divergence of Platelet Protein Kinase C (PKC) Isoforms in Thrombus Formation on Collagen*

    Science.gov (United States)

    Gilio, Karen; Harper, Matthew T.; Cosemans, Judith M. E. M.; Konopatskaya, Olga; Munnix, Imke C. A.; Prinzen, Lenneke; Leitges, Michael; Liu, Qinghang; Molkentin, Jeffery D.; Heemskerk, Johan W. M.; Poole, Alastair W.

    2010-01-01

    Arterial thrombosis, a major cause of myocardial infarction and stroke, is initiated by activation of blood platelets by subendothelial collagen. The protein kinase C (PKC) family centrally regulates platelet activation, and it is becoming clear that the individual PKC isoforms play distinct roles, some of which oppose each other. Here, for the first time, we address all four of the major platelet-expressed PKC isoforms, determining their comparative roles in regulating platelet adhesion to collagen and their subsequent activation under physiological flow conditions. Using mouse gene knock-out and pharmacological approaches in human platelets, we show that collagen-dependent α-granule secretion and thrombus formation are mediated by the conventional PKC isoforms, PKCα and PKCβ, whereas the novel isoform, PKCθ, negatively regulates these events. PKCδ also negatively regulates thrombus formation but not α-granule secretion. In addition, we demonstrate for the first time that individual PKC isoforms differentially regulate platelet calcium signaling and exposure of phosphatidylserine under flow. Although platelet deficient in PKCα or PKCβ showed reduced calcium signaling and phosphatidylserine exposure, these responses were enhanced in the absence of PKCθ. In summary therefore, this direct comparison between individual subtypes of PKC, by standardized methodology under flow conditions, reveals that the four major PKCs expressed in platelets play distinct non-redundant roles, where conventional PKCs promote and novel PKCs inhibit thrombus formation on collagen. PMID:20479008

  13. Extended shelf life of random donor platelets stored for 7 days in platelet additive solution at different temperatures

    Directory of Open Access Journals (Sweden)

    Tulika Chandra

    2014-08-01

    Full Text Available Background: Platelets are routinely stored in plasma for 5 days at an average temperature of 22°C. In the present study, the shelf life of random donor platelets was extended by storing for 7 days with and without additive solution at temperatures of 22°C, 18°C, and 16°C. Methods: Random donor platelets were stored in 100% plasma and 20%/80% platelet additive solution. The data were compared using paired "t"- test. The confidence limit was kept at 95%, hence a "p" < 0.05 was considered to be statistically significant. Results: Out of total 150 samples, 148 samples were analyzed and 2 were discarded due to the bacterial contamination on day 7 at 22°C without platelet additive solution. A significant difference in platelet count, platelet factor 3 (PF 3, glucose, lactate dehydrogenase (LDH, and platelet aggregation was observed on day 7 (p < 0.001 at 16°C in without platelet additive solution. In platelet additive solution, the mean values of platelet count, platelet distribution width (PDW, LDH, and pH showed no significant difference on day 7 at 22°C, 18°C, and 16°C. Only significant differences were observed in the levels of mean platelet volume (MPV, PF 3, glucose, and platelet aggregation on day 7 (p < 0.001 at 16°C of the storage period. Conclusion: Random donor platelets functions are better maintained in platelet additive solution as compared to plasma at a lower temperature of 18°C but not at 16°C, on the 7 th day.

  14. Platelets promote tumor growth and metastasis via direct interaction between Aggrus/podoplanin and CLEC-2.

    Directory of Open Access Journals (Sweden)

    Satoshi Takagi

    Full Text Available The platelet aggregation-inducing factor Aggrus, also known as podoplanin, is frequently upregulated in several types of tumors and enhances hematogenous metastasis by interacting with and activating the platelet receptor CLEC-2. Thus, Aggrus-CLEC-2 binding could be a therapeutic molecular mechanism for cancer therapy. We generated a new anti-human Aggrus monoclonal antibody, MS-1, that suppressed Aggrus-CLEC-2 binding, Aggrus-induced platelet aggregation, and Aggrus-mediated tumor metastasis. Interestingly, the MS-1 monoclonal antibody attenuated the growth of Aggrus-positive tumors in vivo. Moreover, the humanized chimeric MS-1 antibody, ChMS-1, also exhibited strong antitumor activity against Aggrus-positive lung squamous cell carcinoma xenografted into NOD-SCID mice compromising antibody-dependent cellular cytotoxic and complement-dependent cytotoxic activities. Because Aggrus knockdown suppressed platelet-induced proliferation in vitro and tumor growth of the lung squamous cell carcinoma in vivo, Aggrus may be involved in not only tumor metastasis but also tumor growth by promoting platelet-tumor interaction, platelet activation, and secretion of platelet-derived factors in vivo. Our results indicate that molecular target drugs inhibiting specific platelet-tumor interactions can be developed as antitumor drugs that suppress both metastasis and proliferation of tumors such as lung squamous cell carcinoma.

  15. Redox Proteomics and Platelet Activation: Understanding the Redox Proteome to Improve Platelet Quality for Transfusion

    Science.gov (United States)

    Sonego, Giona; Abonnenc, Mélanie; Tissot, Jean-Daniel; Prudent, Michel; Lion, Niels

    2017-01-01

    Blood banks use pathogen inactivation (PI) technologies to increase the safety of platelet concentrates (PCs). The characteristics of PI-treated PCs slightly differ from those of untreated PCs, but the underlying reasons are not well understood. One possible cause is the generation of oxidative stress during the PI process. This is of great interest since reactive oxygen species (ROS) act as second messengers in platelet functions. Furthermore, there are links between protein oxidation and phosphorylation, another mechanism that is critical for cell regulation. Current research efforts focus on understanding the underlying mechanisms and identifying new target proteins. Proteomics technologies represent powerful tools for investigating signaling pathways involving ROS and post-translational modifications such as phosphorylation, while quantitative techniques enable the comparison of the platelet resting state versus the stimulated state. In particular, redox cysteine is a key player in platelet activation upon stimulation by different agonists. This review highlights the experiments that have provided insights into the roles of ROS in platelet function and the implications for platelet transfusion, and potentially in diseases such as inflammation and platelet hyperactivity. The review also describes the implication of redox mechanism in platelet storage considerations. PMID:28208668

  16. Radioimmune assay of human platelet prostaglandin synthetase

    International Nuclear Information System (INIS)

    Roth, G.J.; Machuga, E.T.

    1982-01-01

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH 2 from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and [ 125 I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [ 125 I]antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 10 9 platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency

  17. Preparing Platelet-Rich Plasma with Whole Blood Harvested Intraoperatively During Spinal Fusion.

    Science.gov (United States)

    Shen, Bin; Zhang, Zheng; Zhou, Ning-Feng; Huang, Yu-Feng; Bao, Yu-Jie; Wu, De-Sheng; Zhang, Ya-Dong

    2017-07-22

    BACKGROUND Platelet-rich plasma (PRP) has gained growing popularity in use in spinal fusion procedures in the last decade. Substantial intraoperative blood loss is frequently accompanied with spinal fusion, and it is unknown whether blood harvested intraoperatively qualifies for PRP preparation. MATERIAL AND METHODS Whole blood was harvested intraoperatively and venous blood was collected by venipuncture. Then, we investigated the platelet concentrations in whole blood and PRP, the concentration of growth factors in PRP, and the effects of PRP on the proliferation and viability of human bone marrow-derived mesenchymal stem cells (HBMSCs). RESULTS Our results revealed that intraoperatively harvested whole blood and whole blood collected by venipuncture were similar in platelet concentration. In addition, PRP formulations prepared from both kinds of whole blood were similar in concentration of platelet and growth factors. Additional analysis showed that the similar concentrations of growth factors resulted from the similar platelet concentrations of whole blood and PRP between the two groups. Moreover, these two kinds of PRP formulations had similar effects on promoting cell proliferation and enhancing cell viability. CONCLUSIONS Therefore, intraoperatively harvested whole blood may be a potential option for preparing PRP spinal fusion.

  18. Hypertonic Saline Suppresses NADPH Oxidase-Dependent Neutrophil Extracellular Trap Formation and Promotes Apoptosis

    Directory of Open Access Journals (Sweden)

    Ajantha Nadesalingam

    2018-03-01

    solutions do not suppress NOX2-independent NETosis. Although hypertonic saline partially suppresses ionomycin-induced NETosis, it enhances A23187-induced NETosis, and it does not alter S. aureus-induced NETosis. Overall, this study determined that hypertonic saline suppresses NOX2-dependent NETosis induced by several agonists; in contrast, it has variable effects on neutrophil death induced by NOX2-independent NETosis agonists. These findings are important in understanding the regulation of NETosis and apoptosis in neutrophils.

  19. Multiple alterations of platelet functions dominated by increased secretion in mice lacking Cdc42 in platelets

    DEFF Research Database (Denmark)

    Pleines, Irina; Eckly, Anita; Elvers, Margitta

    2010-01-01

    formation and exocytosis in various cell types, but its exact function in platelets is not established. Here, we show that the megakaryocyte/platelet-specific loss of Cdc42 leads to mild thrombocytopenia and a small increase in platelet size in mice. Unexpectedly, Cdc42-deficient platelets were able to form...

  20. Neutrophils, dendritic cells and Toxoplasma.

    Science.gov (United States)

    Denkers, Eric Y; Butcher, Barbara A; Del Rio, Laura; Bennouna, Soumaya

    2004-03-09

    Toxoplasma gondii rapidly elicits strong Type 1 cytokine-based immunity. The necessity for this response is well illustrated by the example of IFN-gamma and IL-12 gene knockout mice that rapidly succumb to the effects of acute infection. The parasite itself is skilled at sparking complex interactions in the innate immune system that lead to protective immunity. Neutrophils are one of the first cell types to arrive at the site of infection, and the cells release several proinflammatory cytokines and chemokines in response to Toxoplasma. Dendritic cells are an important source of IL-12 during infection with T. gondii and other microbial pathogens, and they are also specialized for high-level antigen presentation to T lymphocytes. Tachyzoites express at least two types of molecules that trigger innate immune cell cytokine production. One of these involves Toll-like receptor/MyD88 pathways common to many microbial pathogens. The second pathway is less conventional and involves molecular mimicry between a parasite cyclophilin and host CC chemokine receptor 5-binding ligands. Neutrophils, dendritic cells and Toxoplasma work together to elicit the immune response required for host survival. Cytokine and chemokine cross-talk between parasite-triggered neutrophils and dendritic cells results in recruitment, maturation and activation of the latter. Neutrophil-empowered dendritic cells possess properties expected of highly potent antigen presenting cells that drive T helper 1 generation.