111-Indium-labelled platelets for diagnosis of acute kidney transplant rejection and monitoring of prostacyclin anti-rejection treatment

International Nuclear Information System (INIS)

Leithner, C.; Pohanka, E.; Schwarz, M.; Sinzinger, H.; Syre, G.

1984-01-01

33 patients were examined daily under a gamma camera after weekly injections of 111-In-labelled autologous platelets over a period of at least 4 weeks after transplantation. A group of 33 patients with long-term stable and well-functioning grafts served as controls. By means of a computerized recording technique, platelet trapping in the graft was measured and expressed as platelet-uptake index (PUI). The method worked well for the early diagnosis of acute rejection signified by an increase in PUI, accompanied by a shortening of platelet half life (t/2). 6 patients suffering from acute rejection received infusions of prostacyclin in addition to conventional high-dose methylprednisolone therapy. In 4 cases the PUI decreased again and an improvement in graft function was observed. Prostacyclin infusion treatment was applied also in 12 patients with histologically-proven chronic transplant rejection. Decreased platelet consumption by the graft and a temporary improvement in transplant function were achieved. We suggest that prostacyclin could enrich the possibilities of anti-rejection treatment by providing a tool for the suppression of platelet trapping in the graft. The platelet scan served as a useful method for the early detection of acute rejection, as well as the monitoring of prostacyclin anti-rejection treatment. (Autor)

Dose-dependent platelet stimulation and inhibition induced by anti-PIA1 IgG

International Nuclear Information System (INIS)

Ryu, T.; Davis, J.M.; Schwartz, K.A.

1990-01-01

The PIA1 antibody produces several clinically distinct and severe thrombocytopenias. Investigations have demonstrated divergent effects on platelet function; prior reports demonstrated inhibition, while a conflicting publication showed platelet activation. We have resolved this conflict using anti-PIA1 IgG produced by a patient with posttransfusion purpura. Relatively low concentrations stimulated platelet aggregation and release of adenosine triphosphate (ATP) whereas high concentrations inhibited platelet function, producing a thrombasthenia-like state. The number of molecules of platelet-associated IgG necessary to initiate aggregation and ATP release (2,086 +/- 556) or produce maximum aggregation (23,420 +/- 3,706) or complete inhibition (63,582 +/- 2654) were measured with a quantitative radiometric assay for bound anti-PIA1. Preincubation of platelets with high concentrations of PIA1 antibody inhibited platelet aggregation with 10 mumol/L adenosine diphosphate and blocked 125I-labeled fibrinogen platelet binding. Platelet activation with nonfibrinogen dependent agonist, 1 U/ml thrombin, was not inhibited by this high concentration of PIA1 IgG. In conclusion, anti-PIAI IgG produces (1) stimulation of platelet aggregation and ATP release that is initiated with 2000 molecules IgG per platelet and is associated with an increase of 125I-fibrinogen binding; (2) conversely, inhibition of platelet aggregation is observed with maximum antibody binding, 63,000 molecules IgG per platelet, and is mediated via a blockade of fibrinogen binding

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

Directory of Open Access Journals (Sweden)

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. 

Rare platelet GPCR variants: what can we learn?

Science.gov (United States)

Nisar, S P; Jones, M L; Cunningham, M R; Mumford, A D; Mundell, S J

2015-07-01

Platelet-expressed GPCRs are critical regulators of platelet function. Pharmacological blockade of these receptors forms a powerful therapeutic tool in the treatment and prevention of arterial thrombosis associated with coronary atherosclerosis and ischaemic stroke. However, anti-thrombotic drug therapy is associated with high inter-patient variability in therapeutic response and adverse bleeding side effects. In order to optimize the use of existing anti-platelet drugs and to develop new therapies, more detailed knowledge is required relating to the molecular mechanisms that regulate GPCR and therefore platelet function. One approach has been to identify rare, function-disrupting mutations within key platelet proteins in patients with bleeding disorders. In this review, we describe how an integrated functional genomics strategy has contributed important structure-function information about platelet GPCRs with specific emphasis upon purinergic and thromboxane A2 receptors. We also discuss the potential implications these findings have for pharmacotherapy and for understanding the molecular basis of mild bleeding disorders. © 2014 The British Pharmacological Society.

Novel direct factor Xa inhibitory compounds from Tenebrio molitor with anti-platelet aggregation activity.

Science.gov (United States)

Lee, Wonhwa; Kim, Mi-Ae; Park, InWha; Hwang, Jae Sam; Na, MinKyun; Bae, Jong-Sup

2017-11-01

Tenebrio molitor is an edible insect that has antimicrobial, anticancer, and antihypertensive effects. The aim of this study was to identify the unreported bioactive compounds from T. molitor larvae with inhibitory activities against factor Xa (FXa) and platelet aggregation. Isolated compounds were evaluated for their anti-FXa and anti-platelet aggregation properties by monitoring clotting time, platelet aggregation, FXa activity, and thrombus formation. A diketopiperazine (1, cyclo( L -Pro- L -Tyr)) and a phenylethanoid (2, N-acetyltyramine) were isolated and inhibited the catalytic activity of FXa in a mixed inhibition model and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and U46619. They inhibited ADP- and U46619-induced phosphorylation of myristoylated alanine-rich C kinase substrate (MARCKS) and the expression of P-selectin and PAC-1 in platelets. They also improved the production of nitric oxide and inhibited the oversecretion of endothelin-1 compared to that of the ADP- or U46619-treated group. In an animal model of arterial and pulmonary thrombosis, the isolated compounds showed enhanced antithrombotic effects. They also elicited anticoagulant effects in mice. Compounds 1-2 inhibited ADP-, collagen-, or U46619-induced platelet aggregation and showed similar anti-thrombotic efficacy to rivaroxaban, a positive control. Therefore, 1-2 could serve as candidates and provide scaffolds for the development of new anti-FXa and anti-platelet drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-aggregation action of ultraviolet irradiation on platelet-rich plasma in the presence of antioxidants

International Nuclear Information System (INIS)

Roshchupkin, D.I.; Anosov, A.K.; Potapenko, A.Ya.

1983-01-01

UV irradiation of platelet-rich plasma (PRP) results in the inhibition of ADP-induced platelet aggregation. This is accounted for by the long-living photoproducts formed in plasma. Platelets destruct these photoproducts in the dark after irradiation. Lipid antioxidants α-tocopherol and BHT administered in PRP before irradiation reduce the anti-aggregation effect of UV light. Lipid photo-peroxidation is supposed to be responsible for the anti-aggregation effect of UV irradiation on platelet-rich plasma. (Auth.)

Anti-aggregation action of ultraviolet irradiation on platelet-rich plasma in the presence of antioxidants

International Nuclear Information System (INIS)

Roshchupkin, D.I.; Anosov, A.K.; Potapenko, A.Ya.

1983-01-01

UV irradiation of platelet-rich plasma (PRP) results in the inhibition of ADP-induced platelets aggregation. This is accounted for by the long-living photoproducts formed in plasma. Platelets destruct these photoproducts in the dark after irradiation. Lipid antioxidants α-tocopherol and BHT administered in PRP before irradiation reduce the anti-aggregation effect of UV light. Lipid photo-peroxidation is supposed to be responsible for the anti-aggregation effect of UV irradiation on platelet-rich plasma. (Auth.)

Optimisation of a double-centrifugation method for preparation of canine platelet-rich plasma.

Science.gov (United States)

Shin, Hyeok-Soo; Woo, Heung-Myong; Kang, Byung-Jae

2017-06-26

Platelet-rich plasma (PRP) has been expected for regenerative medicine because of its growth factors. However, there is considerable variability in the recovery and yield of platelets and the concentration of growth factors in PRP preparations. The aim of this study was to identify optimal relative centrifugal force and spin time for the preparation of PRP from canine blood using a double-centrifugation tube method. Whole blood samples were collected in citrate blood collection tubes from 12 healthy beagles. For the first centrifugation step, 10 different run conditions were compared to determine which condition produced optimal recovery of platelets. Once the optimal condition was identified, platelet-containing plasma prepared using that condition was subjected to a second centrifugation to pellet platelets. For the second centrifugation, 12 different run conditions were compared to identify the centrifugal force and spin time to produce maximal pellet recovery and concentration increase. Growth factor levels were estimated by using ELISA to measure platelet-derived growth factor-BB (PDGF-BB) concentrations in optimised CaCl 2 -activated platelet fractions. The highest platelet recovery rate and yield were obtained by first centrifuging whole blood at 1000 g for 5 min and then centrifuging the recovered platelet-enriched plasma at 1500 g for 15 min. This protocol recovered 80% of platelets from whole blood and increased platelet concentration six-fold and produced the highest concentration of PDGF-BB in activated fractions. We have described an optimised double-centrifugation tube method for the preparation of PRP from canine blood. This optimised method does not require particularly expensive equipment or high technical ability and can readily be carried out in a veterinary clinical setting.

In vivo quantitation of platelet deposition on human peripheral arterial bypass grafts using indium-111-labeled platelets. Effect of dipyridamole and aspirin

International Nuclear Information System (INIS)

Pumphrey, C.W.; Chesebro, J.H.; Dewanjee, M.K.; Wahner, H.W.; Hollier, L.H.; Pairolero, P.C.; Fuster, V.

1983-01-01

Indium-111-labeled autologous platelets, injected 48 hours after operation, were used to evaluate the thrombogenicity of prosthetic material and the effect of platelet inhibitor therapy in vivo. Dacron double-velour (Microvel) aortofemoral artery bifurcation grafts were placed in 16 patients and unilateral polytetrafluoroethylene femoropopliteal grafts were placed in 10 patients. Half the patients in each group received platelet inhibitors before operation (dipyridamole, 100 mg 4 times a day) and after operation (dipyridamole, 75 mg, and acetylsalicylic acid, 325 mg 3 times a day); the rest of the patients served as control subjects. Five-minute scintigrams of the graft region were taken with a gamma camera interfaced with a computer 48, 72, and 96 hours after injection of the labeled platelets. Platelet deposition was estimated from the radioactivities of the grafts and expressed as counts per 100 pixels per microcurie injected. Dipyridamole and aspirin therapy significantly reduced the number of platelets deposited on Dacron grafts and prevented platelet accumulation over 3 days. With the small amount of platelet deposition on polytetrafluoroethylene femoropopliteal artery grafts even in control patients, platelet inhibitor therapy had no demonstrable effect on platelet deposition on these grafts. It is concluded that (1) platelet deposition on vascular grafts in vivo can be quantitated by noninvasive methods, and (2) dipyridamole and aspirin therapy reduced platelet deposition on Dacron aortofemoral artery grafts

A short history of anti-rheumatic therapy. II. Aspirin

Directory of Open Access Journals (Sweden)

P. Marson

2011-06-01

Full Text Available The discovery of aspirin, an antipyretic, anti-inflammatory and analgesic drug, undoubtedly represents a milestone in the history of medical therapy. Since ancient times the derivatives of willow (Salix alba were used to treat a variety of fevers and pain syndromes, although the first report dates back to 1763 when the English Reverend Edward Stone described the effect of an extract of the bark willow in treating malaria. In the XIX century many apothecaries and chemists, including the Italian Raffaele Piria and Cesare Bertagnini, developed the biological processes of extraction and chemical synthesis of salicylates, and then analyzed their therapeutic properties and pharmacokinetic and pharmacodynamic characteristics. In 1899 the Bayer Company, where Felix Hoffmann, Heinrich Dreser and Arthur Eichengrün worked, recorded acetyl-salicylic acid under the name “Aspirin”. In the XX century, besides the definition of the correct applications of aspirin in the anti-rheumatic therapy being defined, Lawrence L. Crawen identified the property of this drug as an anti-platelet agent, thus opening the way for more widespread uses in cardiovascular diseases.

Clinical outcomes, health resource use, and cost in patients with early versus late dual or triple anti-platelet treatment for acute coronary syndrome.

Science.gov (United States)

Friedman, Howard; Mollon, Patrick; Lian, Jean; Navaratnam, Prakash

2013-08-01

Acute coronary syndrome (ACS) guidelines recommend early dual anti-platelet therapy (thienopyridines + acetylsalicylic acid [aspirin]). However, triple therapy (thienopyridines + aspirin + glycoprotein IIb/IIIa receptor inhibitors [GRIs]) has shown benefit in clinical trials. This study assessed real-world ACS treatment patterns and outcomes in the acute care setting. A retrospective analysis of patients admitted to hospital with ACS (index event) from January 2007 to December 2009 was conducted (Thomson's MarketScan Hospital Drug Database). Eligible patients were ≥18 years of age, of either sex, and had primary admission and discharge diagnoses of ACS. Cohorts were defined by anti-platelet treatment and then by the timing of treatment initiation (early initiation: within ≤2 days of admission; late initiation: ≥2 days post-admission). Patient characteristics, clinical outcomes, resource utilization, and costs were assessed using descriptive statistics. A total of 249,907 eligible patients were placed into four treatment cohorts (aspirin assumed for all patients): aspirin only; clopidogrel only (dual therapy); GRI only (dual therapy); and clopidogrel + GRI (triple therapy). Patients in the 'clopidogrel-only' cohort were more likely to be older, female, and have more co-morbidities than those in other cohorts; stroke (6.2 %) and re-hospitalization (15.4 %) rates were higher than in the 'GRI-only' and 'triple therapy' cohorts. The GRI-only cohort had higher major bleeding rates (3.3 %), mortality (7.6 %), and costs ($US21,975 [year 2010 values]) than the clopidogrel-only and triple-therapy cohorts. Late initiation cohorts were more likely to be older, female, and have more co-morbidities than early initiation cohorts. Major bleeding was more likely with GRI-only patients (regardless of initiation timing) than with other cohorts. Late-treated clopidogrel-only patients had higher rates of stroke (6.9 %), ACS-related re-admissions (6.1 %), and all

Dentists' approach to patients on anti-platelet agents and warfarin: a survey of practice.

LENUS (Irish Health Repository)

Murphy, James

2010-04-23

In everyday practice, dentists are confronted with the dilemma of patients on anti-platelet agents and warfarin who require invasive dental procedures and, more pertinently, dental extractions. There may be a divergence of opinion among dentists regarding how they manage these patients. AIMS: To assess general dental practitioners\\' approach to the management of patients taking anti-platelet agents and\\/or warfarin who are undergoing invasive dental procedures. METHODS AND DATA: A semi-structured questionnaire was designed to survey general dental practitioners in a large Irish urban area. RESULTS: A response rate of 89% was achieved in a study population of 54 general dental practitioners. A total of 25% of respondents who carry out extractions on warfarinised patients do not check the INR prior to invasive dental procedures. Some 90% of respondents stop anti-platelet agents prior to extractions. CONCLUSIONS: A significant proportion of respondents fail to check warfarinised patients\\' INR prior to invasive dental procedures. Furthermore, a trend of stopping anti-platelet agents was noted, which is in contrast with current recommendations in the dental literature. Certain practices in this small study population proved alarming and highlight the need for improved awareness of current guidelines. A further large-scale study may be justified, as variation in practice may have clinical and medico-legal repercussions.

Description of a double centrifugation tube method for concentrating canine platelets

OpenAIRE

Perazzi, Anna; Busetto, Roberto; Martinello, Tiziana; Drigo, Michele; Pasotto, Daniela; Cian, Francesco; Patruno, Marco; Iacopetti, Ilaria

2013-01-01

Background To evaluate the efficiency of platelet-rich plasma preparations by means of a double centrifugation tube method to obtain platelet-rich canine plasma at a concentration at least 4 times higher than the baseline value and a concentration of white blood cells not exceeding twice the reference range. A complete blood count was carried out for each sample and each concentrate. Whole blood samples were collected from 12 clinically healthy dogs (consenting blood donors). Blood was proces...

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

Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

Directory of Open Access Journals (Sweden)

Kavita Hotwani

2014-02-01

Full Text Available Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

The important role of von Willebrand factor in platelet-derived FVIII gene therapy for murine hemophilia A in the presence of inhibitory antibodies.

Science.gov (United States)

Shi, Q; Schroeder, J A; Kuether, E L; Montgomery, R R

2015-07-01

Our previous studies have demonstrated that targeting FVIII expression to platelets results in FVIII storage together with von Willebrand factor (VWF) in platelet α-granules and that platelet-derived FVIII (2bF8) corrects the murine hemophilia A phenotype even in the presence of high-titer anti-FVIII inhibitory antibodies (inhibitors). To explore how VWF has an impact on platelet gene therapy for hemophilia A with inhibitors. 2bF8 transgenic mice in the FVIII(-/-) background (2bF8(tg+/-) F8(-/-) ) with varying VWF phenotypes were used in this study. Animals were analyzed by VWF ELISA, FVIII activity assay, Bethesda assay and tail clip survival test. Only 18% of 2bF8(tg+/-) F8(-/-) VWF(-/-) animals, in which VWF was deficient, survived the tail clip challenge with inhibitor titers of 3-8000 BU mL(-1) . In contrast, 82% of 2bF8(tg+/-) F8(-/-) VWF(+/+) mice, which had normal VWF levels, survived tail clipping with inhibitor titers of 10-50,000 BU mL(-1) . All 2bF8(tg+/-) F8(-/-) VWF(-/-) mice without inhibitors survived tail clipping and no VWF(-/-) F8(-/-) mice survived this challenge. Because VWF is synthesized by endothelial cells and megakaryocytes and is distributed in both plasma and platelets in peripheral blood, we further investigated the effect of each compartment of VWF on platelet-FVIII gene therapy for hemophilia A with inhibitors. In the presence of inhibitors, 42% of animals survived tail clipping in the group with plasma-VWF and 50% survived in the platelet-VWF group. VWF is essential for platelet gene therapy for hemophilia A with inhibitors. Both platelet-VWF and plasma-VWF are required for optimal platelet-derived FVIII gene therapy for hemophilia A in the presence of inhibitors. © 2015 International Society on Thrombosis and Haemostasis.

Point of care platelet activity measurement in primary PCI [PINPOINT-PPCI]: a protocol paper.

Science.gov (United States)

Johnson, Thomas W; Marsden, Debbie; Mumford, Andrew; Pike, Katie; Mundell, Stuart; Butler, Mark; Strange, Julian W; Bowles, Ruth; Rogers, Chris; Baumbach, Andreas; Reeves, Barnaby C

2014-04-04

Optimal treatment of acute ST-elevation myocardial infarction (STEMI) involves rapid diagnosis, and transfer to a cardiac centre capable of percutaneous coronary intervention (PCI) for immediate mechanical revascularisation. Successful treatment requires rapid return of perfusion to the myocardium achieved by thromboaspiration, passivation of the culprit lesion with stent scaffolding and systemic inhibition of thrombosis and platelet activation. A delicate balance exists between thrombosis and bleeding and consequently anti-thrombotic and antiplatelet treatment regimens continue to evolve. The desire to achieve reperfusion as soon as possible, in the setting of high platelet reactivity, requires potent and fast-acting anti-thrombotic/anti-platelet therapies. The associated bleeding risk may be minimised by use of short-acting anti-thrombotic intravenous agents. However, effective oral platelet inhibition is required to prevent recurrent thrombosis. The interaction between baseline platelet reactivity, timing of revascularisation and effective inhibition of thrombosis is yet to be formally investigated. We present a protocol for a prospective observational study in patients presenting with acute STEMI treated with primary PCI (PPCI) and receiving bolus/infusion bivalirudin and prasugrel therapy. The objective of this study is to describe variation in platelet reactivity, as measured by the multiplate platelet function analyser, at presentation, the end of the PPCI procedure and 1, 2, & 24 hours post-procedure. We intend to assess the prevalence of high residual platelet reactivity within 24 hours of PPCI in acute STEMI patients receiving prasugrel and bivalirudin. Additionally, we will investigate the association between high platelet reactivity before and after PPCI and the door-to-procedure completion time.This is a single centre study with a target sample size of 108 participants. The baseline platelet reactivity on presentation with a STEMI may impact on the

A randomized, double-blind, placebo- controlled study on the anti-haemostatic effects of Curcuma longa, Angelica sinensis and Panax ginseng.

Science.gov (United States)

Fung, Foon Yin; Wong, Wan Hui; Ang, Seng Kok; Koh, Hwee Ling; Kun, Mei Ching; Lee, Lai Heng; Li, Xiaomei; Ng, Heng Joo; Tan, Chuen Wen; Zhao, Yan; Linn, Yeh Ching

2017-08-15

Herbs with "blood-activating" properties by traditional medicine theory often raise concerns for their possible anti-platelet or anticoagulation effects based on reports from in vitro studies. Such herbs have been implicated for bleeding manifestations based on only anecdotal reports. In particular, the combination of such herbs with anti-platelet agents is often empirically advised against despite lack of good clinical evidence. Here we studied 3 commonly used herbal preparations Curcuma longa, Angelica sinensis and Panax ginseng on their respective anti-platelet and anticoagulation effect, alone and in combination with aspirin. This is a randomized, double-blind, placebo-controlled trial involving 25 healthy volunteers for each herbal preparation. Each subject underwent 3 phases comprising of herbal product alone, aspirin alone and aspirin with herbal product, where each phase lasted for 3 weeks with 2 weeks of washout between phases. PT/APTT, platelet function by light transmission aggregometry and thrombin generation assay by calibrated automated thrombogram were measured at baseline and after each phase. Information on adverse reaction including bleeding manifestations was collected after each phase. On the whole there was no clinically relevant impact on platelet and coagulation function. With the exception of 5 of 24 subjects in the Curcuma longa group, 2 of 24 subjects in the Angelica sinensis group and 1 of 23 subjects in the Panax ginseng group who had an inhibition in arachidonic-acid induced platelet aggregation, there was no effect of these 3 herbals products on platelet aggregation by other agonists. Combination of these herbal products with aspirin respectively did not further aggravate platelet inhibition caused by aspirin. None of the herbs impaired PT/APTT or thrombin generation. There was no significant bleeding manifestation. This study on healthy volunteers provides good evidence on the lack of bleeding risks of Curcuma longa, Angelica sinensis

Failure of sulfinpyrazone to affect platelet survival in patients with rheumatic heart valvular disease: a double blind study using 75Se-methionine labelled platelets

International Nuclear Information System (INIS)

Fabris, F.; Casonato, A.; Randi, M.L.; Schivazappa, L.; Schiavinato, L.; Girolami, A.

1983-01-01

Platelet survival time was studied in 18 patients suffering from valvular heart disease using a modified 75 Se-methionine method. 9 of 18 patients underwent surgery for heart valve replacement. Platelet survival time was determined before and 6 months after treatment with placebo of sulfinpyrazone in a double blind study. Before treatment and surgery, platelet survival time was significantly reduced in patients with a history of embolism (P < 0.0048). In patients receiving valve replacement, platelet survival time was shortened both in the sulfinpyrazone and placebo groups 6 months after surgery. Of the 9 patients not receiving prostheses and with a thrombotic history, treatment with placebo and sulfinpyrazone resulted in improved platelet survival times. (author)

Failure of sulfinpyrazone to affect platelet survival in patients with rheumatic heart valvular disease: a double blind study using /sup 75/Se-methionine labelled platelets

Energy Technology Data Exchange (ETDEWEB)

Fabris, F.; Casonato, A.; Randi, M.L.; Schivazappa, L.; Schiavinato, L.; Girolami, A. (Padua Univ. (Italy))

1983-01-01

Platelet survival time was studied in 18 patients suffering from valvular heart disease using a modified /sup 75/Se-methionine method. 9 of 18 patients underwent surgery for heart valve replacement. Platelet survival time was determined before and 6 months after treatment with placebo of sulfinpyrazone in a double blind study. Before treatment and surgery, platelet survival time was significantly reduced in patients with a history of embolism (P < 0.0048). In patients receiving valve replacement, platelet survival time was shortened both in the sulfinpyrazone and placebo groups 6 months after surgery. Of the 9 patients not receiving prostheses and with a thrombotic history, treatment with placebo and sulfinpyrazone resulted in improved platelet survival times.

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.

Effects of Clopidogrel Therapy on Oxidative Stress, Inflammation, Vascular Function and Progenitor Cells in Stable Coronary Artery Disease

Science.gov (United States)

Ramadan, Ronnie; Dhawan, Saurabh S.; Syed, Hamid; Pohlel, F. Khan; Binongo, Jose Nilo G.; Ghazzal, Ziyad B.; Quyyumi, Arshed A.

2014-01-01

Background Traditional cardiovascular risk factors lead to endothelial injury and activation of leucocytes and platelets that initiate and propagate atherosclerosis. We proposed that clopidogrel therapy in patients with stable CAD imparts a pleiotropic effect that extends beyond anti-platelet aggregation to other athero-protective processes. Methods Forty-one subjects were randomized in a double-blind, placebo-controlled crossover study to either clopidogrel 75 mg daily or placebo for 6-weeks, and then transitioned immediately to the other treatment for an additional 6 weeks. We assessed 1) endothelial function as flow-mediated dilation of the brachial artery, 2) arterial stiffness and central augmentation index using applanation tonometry, 3) vascular function as fingertip reactive hyperemia index, 4) inflammation by measuring plasma CD40 ligand and serum high-sensitivity c-reactive protein levels, 5) oxidative stress by measuring plasma aminothiols, and 6) circulating progenitor cells, at baseline and at the end of each 6-week treatment period. Results Clopidogrel therapy resulted in a significant reduction in soluble CD40 ligand (p=0.03), a pro-thrombotic and pro-inflammatory molecule derived mainly from activated platelets. However, clopidogrel therapy had no effect on endothelial function, arterial stiffness, inflammatory and oxidative stress markers, or progenitor cells. Conclusions Our findings suggest a solitary anti-platelet effect of clopidogrel therapy in patients with stable CAD, with no effect on other sub-clinical markers of cardiovascular disease risk. PMID:24336012

Molecular spectroscopic and thermodynamic studies on the interaction of anti-platelet drug ticlopidine with calf thymus DNA

Science.gov (United States)

Afrin, Shumaila; Rahman, Yusra; Sarwar, Tarique; Husain, Mohammed Amir; Ali, Abad; Shamsuzzaman; Tabish, Mohammad

2017-11-01

Ticlopidine is an anti-platelet drug which belongs to the thienopyridine structural family and exerts its effect by functioning as an ADP receptor inhibitor. Ticlopidine inhibits the expression of TarO gene in S. aureus and may provide protection against MRSA. Groove binding agents are known to disrupt the transcription factor DNA complex and consequently inhibit gene expression. Understanding the mechanism of interaction of ticlopidine with DNA can prove useful in the development of a rational drug designing system. At present, there is no such study on the interaction of anti-platelet drugs with nucleic acids. A series of biophysical experiments were performed to ascertain the binding mode between ticlopidine and calf thymus DNA. UV-visible and fluorescence spectroscopic experiments confirmed the formation of a complex between ticlopidine and calf thymus DNA. Moreover, the values of binding constant were found to be in the range of 103 M- 1, which is indicative of groove binding between ticlopidine and calf thymus DNA. These results were further confirmed by studying the effect of denaturation on double stranded DNA, iodide quenching, viscometric studies, thermal melting profile as well as CD spectral analysis. The thermodynamic profile of the interaction was also determined using isothermal titration calorimetric studies. The reaction was found to be endothermic and the parameters obtained were found to be consistent with those of known groove binders. In silico molecular docking studies further corroborated well with the experimental results.

Effect of hyperbaric oxygen therapy combined with autologous platelet concentrate applied in rabbit fibula fraction healing

Directory of Open Access Journals (Sweden)

Paulo Cesar Fagundes Neves

2013-09-01

Full Text Available OBJECTIVES: The purpose is to study the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing the fibula bone of rabbits after induced fractures. METHODS: A total of 128 male New Zealand albino rabbits, between 6-8 months old, were subjected to a total osteotomy of the proximal portion of the right fibula. After surgery, the animals were divided into four groups (n = 32 each: control group, in which animals were subjected to osteotomy; autologous platelet concentrate group, in which animals were subjected to osteotomy and autologous platelet concentrate applied at the fracture site; hyperbaric oxygen group, in which animals were subjected to osteotomy and 9 consecutive daily hyperbaric oxygen therapy sessions; and autologous platelet concentrate and hyperbaric oxygen group, in which animals were subjected to osteotomy, autologous platelet concentrate applied at the fracture site, and 9 consecutive daily hyperbaric oxygen therapy sessions. Each group was divided into 4 subgroups according to a pre-determined euthanasia time points: 2, 4, 6, and 8 weeks postoperative. After euthanasia at a specific time point, the fibula containing the osseous callus was prepared histologically and stained with hematoxylin and eosin or picrosirius red. RESULTS: Autologous platelet concentrates and hyperbaric oxygen therapy, applied together or separately, increased the rate of bone healing compared with the control group. CONCLUSION: Hyperbaric oxygen therapy and autologous platelet concentrate combined increased the rate of bone healing in this experimental model.

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

Iliac artery mural thrombus formation. Effect of antiplatelet therapy on 111In-platelet deposition in baboons

International Nuclear Information System (INIS)

Hanson, S.R.; Paxton, L.D.; Harker, L.A.

1986-01-01

To measure the rate, extent, and time course of arterial mural thrombus formation in vivo and to assess the effects of antiplatelet therapy in that setting, we have studied autologous 111 In-platelet deposition induced by experimental iliac artery aneurysms in baboons. Scintillation camera imaging analyses were performed at 1, 24, 48, and 72 hours after implantation of the device. Correction for tissue attenuation was determined by using a small, comparably located 111 In source implanted at the time of surgery. In five animals, 111 In-platelet activity accumulated progressively after device implantation, reaching a maximum after the third day. Repeat image analysis carried out 2 weeks after the surgical procedure also showed progressive accumulation of 111 In-platelets over 3 days but at markedly reduced amounts as compared with the initial study. In five additional animals, treatment with a combination of aspirin and dipyridamole begun 1 hour after surgical implantation reduced 111 In-platelet deposition to negligible levels by the third day. Although platelet survival time was shortened and platelet turnover was reciprocally increased in all operated animals, platelet survival and turnover were not affected by antiplatelet therapy. We conclude that, in contrast to platelet survival and turnover measurements, 111 In-platelet imaging is a reliable and sensitive method for localizing and quantifying focal arterial thrombi and for assessing the effects of antiplatelet therapy

Assessment of warfarin therapy under full dose using indium-111 platelet scintigraphy in patients with intracardiac thrombi

Energy Technology Data Exchange (ETDEWEB)

Yamada, Makoto; Onishi, Kenji; Fukunami, Masatake and others

1988-12-01

Twenty patients in whom intracardiac thrombi were detected by indium-111 platelet scintigraphy (the first platelet scintigraphy) were prospectively studied to examine the effect of warfarin therapy under full dose on the intracardiac thrombogenecity. Eleven patients (group I) who received 2-6 mg/day of warfarin and 9 patients (group II) who did not received warfarin had the second platelet scintigraphies 14-71 days after the first platelet scintigraphies. In group I, 10 platelet scintigraphies became negative and one remained positive for intracardiac thrombi after administration of warfarin, while in group II 8 platelet scintigraphies remained positive and only one changed to negative. The incidence of negative image at the second platelet scintigraphy was significantly lower in group II than that in group I. In group I, the degree of accumulation of platelets onto the surface of the thrombus (%IE), showed significant reduction (0.69+-0.48 to 0.11+-0.21) after warfarin therapy, while in group II %IE at the second scintigraphy (1.07+-1.03) were not significantly different from those at the first scintigraphy (1.13+-0.79). These results indicated that warfarin therapy under full dose inhibited the deposition of platelets on the intracardiac thrombi and thrombogenecity in the patients with intracardiac thrombi which were detected by indium-111 platelet scintigraphy.

Assessment of warfarin therapy under full dose using indium-111 platelet scintigraphy in patients with intracardiac thrombi

International Nuclear Information System (INIS)

Yamada, Makoto; Onishi, Kenji; Fukunami, Masatake

1988-01-01

Twenty patients in whom intracardiac thrombi were detected by indium-111 platelet scintigraphy (the first platelet scintigraphy) were prospectively studied to examine the effect of warfarin therapy under full dose on the intracardiac thrombogenecity. Eleven patients (group I) who received 2-6 mg/day of warfarin and 9 patients (group II) who did not received warfarin had the second platelet scintigraphies 14-71 days after the first platelet scintigraphies. In group I, 10 platelet scintigraphies became negative and one remained positive for intracardiac thrombi after administration of warfarin, while in group II 8 platelet scintigraphies remained positive and only one changed to negative. The incidence of negative image at the second platelet scintigraphy was significantly lower in group II than that in group I. In group I, the degree of accumulation of platelets onto the surface of the thrombus (%IE), showed significant reduction (0.69±0.48 to 0.11±0.21) after warfarin therapy, while in group II %IE at the second scintigraphy (1.07±1.03) were not significantly different from those at the first scintigraphy (1.13±0.79). These results indicated that warfarin therapy under full dose inhibited the deposition of platelets on the intracardiac thrombi and thrombogenecity in the patients with intracardiac thrombi which were detected by indium-111 platelet scintigraphy. (author)

The effect of alpha-interferon on bone marrow megakaryocytes and platelet production rate in essential thrombocythemia

International Nuclear Information System (INIS)

Wadenvik, H.; Kutti, J.; Ridell, B.; Revesz, P.; Jacobsson, S.; Magnusson, B.; Westin, J.; Vilen, L.

1991-01-01

In 10 patients with previously untreated essential thrombocythemia (ET), by using 111 In-labeled platelets and megakaryocyte morphometry, the relation between platelet production rate and bone marrow megakaryocytes was evaluated before and during alpha-2b-interferon (IFN) therapy. A highly significant decrease in platelet count occurred during IFN therapy; the platelet counts, at baseline and after 2 and 6 months of IFN therapy, were 1,102 +/- 345 x 10(9)/L, 524 +/- 169 x 10(9)/L (P less than .0001), and 476 +/- 139 x 10(9)/L (P less than .0001), respectively. The decrement in platelet count was mainly a result of diminished platelet production rate, which at baseline and after 2 and 6 months of IFN therapy was 89 +/- 30 x 10(10) platelets/d, 53 +/- 18 x 10(10) platelets/d (P = .0033), and 45 +/- 20 x 10(10) platelets/d (P less than .0001), respectively. Also, a slight shortening of platelet mean life-span (MLS) was observed in response to IFN treatment; platelet MLS was 7.96 +/- 0.69 days at baseline and 6.68 +/- 1.30 days (P = .012) after 6 months of IFN therapy. IFN induced a significant decrease in bone marrow megakaryocyte volume; both megakaryocyte nuclear and cytoplasmatic volumes were affected. The mean megakaryocyte volume was 372 +/- 126 x 10(2) pL/microL at baseline and 278 +/- 147 x 10(2) pL/microL (P = .049) after 6 months of IFN therapy. However, the number of megakaryocytes did not show any significant change in response to IFN. It is concluded that alpha-IFN reduces platelet production rate and the peripheral platelet count in ET mainly through an anti-proliferative action on the megakaryocytes and to a considerably lesser degree by a shortening of platelet MLS

The Addition of Platelet-Rich Plasma to Facial Lipofilling: A Double-Blind, Placebo-Controlled, Randomized Trial.

Science.gov (United States)

Willemsen, Joep C N; Van Dongen, Joris; Spiekman, Maroesjka; Vermeulen, Karin M; Harmsen, Martin C; van der Lei, Berend; Stevens, H P Jeroen

2018-02-01

Lipofilling is a treatment modality to restore tissue volume, but it may also rejuvenate the aging skin. Platelet-rich plasma has been reported to augment the efficacy of lipofilling, both on graft take and rejuvenation, by altering the adipose-derived stem cells. The authors hypothesized that addition of platelet-rich plasma would increase the rejuvenating effect and shorten recovery time. The study conducted was a single-center, double-blind, placebo-controlled, randomized trial (2012 to 2015). In total, a well-defined cohort of 32 healthy female patients enrolled in the study, with 25 completing the follow-up. All patients underwent aesthetic facial lipofilling with either saline or platelet-rich plasma added. Outcome was determined by changes in skin elasticity, volumetric changes of the nasolabial fold, recovery time, and patient satisfaction during follow-up (1 year). Platelet-rich plasma did not improve the outcome of facial lipofilling when looking at skin elasticity improvement, graft volume maintenance in the nasolabial fold. Reversal of the correlation between age and elasticity, however, might suggest a small effect size, and thus might not be significant with our small study population. This randomized, double-blind, placebo-controlled study clearly has shown that platelet-rich plasma significantly reduces postoperative recovery time but does not improve patient outcome when looking at skin elasticity, improvement of the nasolabial fold, or patient satisfaction. The reversal of the correlation between age and elasticity might indicate some effect on skin but requires more power in future studies. Therapeutic, II.

Platelet responses to pharmacological and physiological interventions in middle-aged men with different habitual physical activity levels

DEFF Research Database (Denmark)

Lundberg Slingsby, Martina Helena; Gliemann, Lasse; Thrane, Mette Nørmark

2018-01-01

into 3 groups; untrained, moderately- and well-trained. Their platelet reactivity (agonist-induced %aggregation) was investigated in platelet rich plasma at rest and after inhibition with aspirin and ticagrelor and/or prostacyclin and nitric oxide added to the blood in vitro, and after physiological...... tests of vascular function; passive movement of the leg, flow-mediated dilation and one-leg knee-extensor exercise. Vascular function of the femoral artery (changes in arterial blood flow) was assessed by ultrasound doppler. RESULTS: Platelets from the well-trained subjects had lower basal reactivity......, a higher sensitivity to the anti-aggregatory effects of prostacyclin and were more potently inhibited by dual anti-platelet therapy compared to the untrained subjects. The moderately- and well-trained subjects had a superior vascular function compared to untrained subjects and their platelets were more...

Optimisation of platelet concentrates therapy: Composition, localisation, and duration of action

Directory of Open Access Journals (Sweden)

Yuk-Lin Yung

2017-01-01

Full Text Available Platelet concentrates (PC generally refers to a group of products that are prepared from autologous blood intended to enhance healing activities. PC therapy is now very popular in treating musculoskeletal injuries; however, inconsistent clinical results urge the need to understand the working mechanism of PC. It is generally believed that the platelet-derived bioactive factors are the active constituents, and their bioavailability in the vicinity of the lesion sites determines the treatment efficacies. Therefore, the composition, localisation, and duration of the action of PC would be key determinants. In this review, we discuss how different preparations and delivery methods of PC would affect the treatment outcomes with respect to clinical evidence about PC therapy for osteoarthritis, tendinopathies, rotator cuff tears, anterior cruciate ligament injuries, and bone fractures. This review can be used as a quick guide for the use of PC therapy and provide insights for the further optimisation of the therapy in the near future.

A Study of Platelet Inhibition, Using a 'Point of Care' Platelet Function Test, following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction [PINPOINT-PPCI].

Science.gov (United States)

Johnson, Thomas W; Mumford, Andrew D; Scott, Lauren J; Mundell, Stuart; Butler, Mark; Strange, Julian W; Rogers, Chris A; Reeves, Barnaby C; Baumbach, Andreas

2015-01-01

Rapid coronary recanalization following ST-elevation myocardial infarction (STEMI) requires effective anti-platelet and anti-thrombotic therapies. This study tested the impact of door to end of procedure ('door-to-end') time and baseline platelet activity on platelet inhibition within 24hours post-STEMI. 108 patients, treated with prasugrel and procedural bivalirudin, underwent Multiplate® platelet function testing at baseline, 0, 1, 2 and 24hours post-procedure. Major adverse cardiac events (MACE), bleeding and stent thrombosis (ST) were recorded. Baseline ADP activity was high (88.3U [71.8-109.0]), procedural time and consequently bivalirudin infusion duration were short (median door-to-end time 55minutes [40-70] and infusion duration 30minutes [20-42]). Baseline ADP was observed to influence all subsequent measurements of ADP activity, whereas door-to-end time only influenced ADP immediately post-procedure. High residual platelet reactivity (HRPR ADP>46.8U) was observed in 75% of patients immediately post-procedure and persisted in 24% of patients at 2hours. Five patients suffered in-hospital MACE (4.6%). Acute ST occurred in 4 patients, all were <120mins post-procedure and had HRPR. No significant bleeding was observed. In a post-hoc analysis, pre-procedural morphine use was associated with significantly higher ADP activity following intervention. Baseline platelet function, time to STEMI treatment and opiate use all significantly influence immediate post-procedural platelet activity.

The role of point-of-care assessment of platelet function in predicting postoperative bleeding and transfusion requirements after coronary artery bypass grafting.

Science.gov (United States)

Mishra, Pankaj Kumar; Thekkudan, Joyce; Sahajanandan, Raj; Gravenor, Mike; Lakshmanan, Suresh; Fayaz, Khazi Mohammed; Luckraz, Heyman

2015-01-01

OBJECTIVE platelet function assessment after cardiac surgery can predict postoperative blood loss, guide transfusion requirements and discriminate the need for surgical re-exploration. We conducted this study to assess the predictive value of point-of-care testing platelet function using the Multiplate® device. Patients undergoing isolated coronary artery bypass grafting were prospectively recruited ( n = 84). Group A ( n = 42) patients were on anti-platelet therapy until surgery; patients in Group B ( n = 42) stopped anti-platelet treatment at least 5 days preoperatively. Multiplate® and thromboelastography (TEG) tests were performed in the perioperative period. Primary end-point was excessive bleeding (>2.5 ml/kg/h) within first 3 h postoperative. Secondary end-points included transfusion requirements, re-exploration rates, intensive care unit and in-hospital stays. Patients in Group A had excessive bleeding (59% vs. 33%, P = 0.02), higher re-exploration rates (14% vs. 0%, P function testing was the most significant predictor of excessive bleeding (odds ratio [OR]: 2.3, P = 0.08), need for blood (OR: 5.5, P functional assessment with Multiplate® was the strongest predictor for bleeding and transfusion requirements in patients on anti-platelet therapy until the time of surgery.

A time course study on prothrombotic parameters and their modulation by anti-platelet drugs in hyperlipidemic hamsters.

Science.gov (United States)

Singh, Vishal; Jain, Manish; Prakash, Prem; Misra, Ankita; Khanna, Vivek; Tiwari, Rajiv Lochan; Keshari, Ravi Shankar; Singh, Shivendra; Dikshit, Madhu; Barthwal, Manoj Kumar

2011-06-01

The present study was undertaken to assess the chronology of major pathological events associated with high cholesterol (HC) diet and their modulation by anti-platelet drugs. Male Golden Syrian hamsters were fed HC diet up to 90 days. Plasma lipid, glucose and coagulation parameters (commercial kits), platelet activation (whole blood aggregation and static adhesion), endothelial dysfunction (aortic ring vasoreactivity), splenocyte TNF-α, IFN-γ and iNOS mRNA transcripts (RT-PCR), and ferric chloride (time to occlusion) induced thrombosis were monitored at 15, 30, 60, and 90 days after HC feeding and compared with normolipidemic hamsters. A significant increase in plasma lipid levels was observed at 15 days of HC feeding, but other parameters remain unaltered. Enhanced ADP, collagen, and thrombin-induced platelet aggregation, splenocyte TNF-α expression along with endothelial dysfunction were observed from 30 to 90 days of HC feeding. Platelet adhesion on collagen-/fibrinogen-coated surface and IFN-γ expression were augmented only after 60 days, while enhanced iNOS expression, reduction in thrombin time, and potentiation of ferric chloride-induced thrombosis was observed only at 90 days of HC feeding. Thus, pathological changes induced by HC diet depend on the duration and extent of hyperlipidemia. Moreover, hamsters treated with anti-platelet drugs aspirin (5 mg/kg) or clopidogrel (10 mg/kg) along with HC feeding exhibited reduction in platelet activation as well as subsequent changes observed in the abovementioned parameters following HC feeding. Since reduction in TNF-α was associated with reversion in endothelial dysfunction and prothrombotic state, the role of platelets is implicated in the pathological changes associated with HC feeding.

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...

Double-chain phospholipid end-capped polyurethanes: Synthesis, characterization and platelet adhesion study

International Nuclear Information System (INIS)

Tan Dongsheng; Zhang Xiaoqing; Li Jiehua; Tan Hong; Fu Qiang

2012-01-01

A novel phospholipid containing double chains and phosphotidylcholine polar head groups, 2-(10-(2-aminoethylamino)-10-oxodecanamido)-3-(decyloxy)-3-oxopropyl phosphorylcholine (ADDPC), was synthesized and characterized. Two kinds of double-chain phospholipid end-capped polyurethanes with different soft segments were prepared. The structure of prepared polyurethanes was characterized by X-ray photoelectron spectroscopic (XPS), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometry and atomic force microscope (AFM), which indicated that the double-chain phospholipids enriched onto the top surface of the prepared polyurethane films. The preliminary evaluation of blood compatibility showed that these novel phospholipid end-capped polyurethanes could suppress platelet adhesion and activation effectively. This property did not depend on the chemical structure of polyurethanes. In addition, according to tensile test results, the phospholipid polyurethanes kept good mechanical properties in comparison with original polyurethanes. It is suggested that double-chain phospholipid end-caption has good potential for achieving both hemocompatibility and good mechanical properties simultaneously for polyurethanes.

Membranoproliferative glomerulonephritis. A prospective clinical trial of platelet-inhibitor therapy

International Nuclear Information System (INIS)

Donadio, J.V. Jr.; Anderson, C.F.; Mitchell, J.C.; Holley, K.E.; Ilstrup, D.M.; Fuster, V.; Chesebro, J.H.

1984-01-01

Forty patients with Type I membranoproliferative glomerulonephritis were treated for one year with dipyridamole, 225 mg per day, and aspirin, 975 mg per day, in a prospective, randomized, double-blind, placebo-controlled study. At the base line, the half-life of 51 Cr-labeled platelets was reduced in 12 of 17 patients. The platelet half-life became longer and renal function stabilized in the treated group, as compared with the placebo group, suggesting a relation between platelet consumption and the glomerulopathy. The glomerular filtration rate, determined by iothalamate clearance, was better maintained in the treated group (average decrease, 1.3 ml per minute per 1.73 m 2 of body-surface area per 12 months) than in the placebo group (average decrease, 19.6). Fewer patients in the treated group than in the placebo group had progression to end-stage renal disease (3 of 21 after 62 months as compared with 9 of 19 after 33 months). The data suggest that dipyridamole and aspirin slowed the deterioration of renal function and the development of end-stage renal disease

Association between Platelet Counts before and during Pharmacological Therapy for Patent Ductus Arteriosus and Treatment Failure in Preterm Infants.

Science.gov (United States)

Sallmon, Hannes; Weber, Sven C; Dirks, Juliane; Schiffer, Tamara; Klippstein, Tamara; Stein, Anja; Felderhoff-Müser, Ursula; Metze, Boris; Hansmann, Georg; Bührer, Christoph; Cremer, Malte; Koehne, Petra

2018-01-01

The role of platelets for mediating closure of the ductus arteriosus in human preterm infants is controversial. Especially, the effect of low platelet counts on pharmacological treatment failure is still unclear. In this retrospective study of 471 preterm infants [0.6). However, ROC curve analysis did not reveal a specific platelet cutoff-value that could predict PDA treatment failure. Multivariate logistic regression analysis showed that lower platelet counts, a lower BW, and preeclampsia were independently associated with COXI treatment failure. We provide further evidence for an association between low platelet counts during pharmacological therapy for symptomatic PDA and treatment failure, while platelet counts before initiation of therapy did not affect treatment outcome.

A Study of Platelet Inhibition, Using a 'Point of Care' Platelet Function Test, following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction [PINPOINT-PPCI].

Directory of Open Access Journals (Sweden)

Thomas W Johnson

Full Text Available Rapid coronary recanalization following ST-elevation myocardial infarction (STEMI requires effective anti-platelet and anti-thrombotic therapies. This study tested the impact of door to end of procedure ('door-to-end' time and baseline platelet activity on platelet inhibition within 24hours post-STEMI.108 patients, treated with prasugrel and procedural bivalirudin, underwent Multiplate® platelet function testing at baseline, 0, 1, 2 and 24hours post-procedure. Major adverse cardiac events (MACE, bleeding and stent thrombosis (ST were recorded. Baseline ADP activity was high (88.3U [71.8-109.0], procedural time and consequently bivalirudin infusion duration were short (median door-to-end time 55minutes [40-70] and infusion duration 30minutes [20-42]. Baseline ADP was observed to influence all subsequent measurements of ADP activity, whereas door-to-end time only influenced ADP immediately post-procedure. High residual platelet reactivity (HRPR ADP>46.8U was observed in 75% of patients immediately post-procedure and persisted in 24% of patients at 2hours. Five patients suffered in-hospital MACE (4.6%. Acute ST occurred in 4 patients, all were <120mins post-procedure and had HRPR. No significant bleeding was observed. In a post-hoc analysis, pre-procedural morphine use was associated with significantly higher ADP activity following intervention.Baseline platelet function, time to STEMI treatment and opiate use all significantly influence immediate post-procedural platelet activity.

Anti-Platelet Aggregation and Vasorelaxing Effects of the Constituents of the Rhizomes of Zingiber officinale

Directory of Open Access Journals (Sweden)

Tian-Shung Wu

2012-07-01

Full Text Available In the present study, the chemical investigation of the bioactive fractions of the rhizomes of Zingiber officinale has resulted in the identification of twenty-nine compounds including one new compound, O-methyldehydrogingerol (1. Some of the isolates were subjected into the evaluation of their antiplatelet aggregation and vasorelaxing bioactivities. Among the tested compounds, [6]-gingerol (13 and [6]-shogaol (17 exhibited potent anti-platelet aggregation bioactivity. In addition, [10]-gingerol (15 inhibited the Ca²⁺-dependent contractions in high K⁺ medium. According to the results in the present research, the bioactivity of ginger could be related to the anti-platelet aggregation and vasorelaxing mechanism.

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.

RESIDUAL PLATELET REACTIVITY DURING THERAPY WITH INHIBITORS OF CYCLOOXIGENASE OR ADENOSINE DIPHOSPHATE RECEPTORS

Directory of Open Access Journals (Sweden)

A. A. Lomonosova

2012-01-01

Full Text Available Aim. To compare effects of acetylsalicylic acid (ASA and two clopidogrel drugs on residual platelet aggregative reactivity (RPAR. Material and methods. Patients (n=40 with ischemic heart disease aged under 70 years were involved into the crossover study. Clinical examination included questionnaire survey , blood pressure (BP measurement, ECG registration, 24-hour ECG and BP monitoring, determination of blood levels of total cholesterol, high density lipoproteins, triglycerides, transaminases, and creatinine, complete blood cell count, including platelets number and hemoglobin level. Besides evaluation of the platelet aggregation by optical aggregometry was performed initially , after one week ASA treatment and after every next 3 week clopidogrel treatment period.  Results. RPAR during ASA monotherapy was 56.4±0.3%. There were no significant differences in effects of original and generic clopidogrel on RPAR. Сlopidogrel therapy reduced RPAR more significantly (42.2±0.2% than ASA monotherapy did (p=0.0003. Authors proposed definition for high level of RPAR during therapy - it is platelet aggregation more than 46%. Data analysis taking into account this criterion showed that a number of patients with high RPAR was 70 and 30% among patients treated with enterosoluble ASA and clopidogrel, respectively. Conclusion. Study results show that a significant number of patients receiving antiplatelet monotherapy does not achieve the target level of RPAR(<46%. These results may be a rationale for combined therapy in patients of this type.

Selective and rapid monitoring of dual platelet inhibition by aspirin and P2Y12 antagonists by using multiple electrode aggregometry

Directory of Open Access Journals (Sweden)

Lorenz Reinhard

2010-05-01

Full Text Available Abstract Background Poor platelet inhibition by aspirin or clopidogrel has been associated with adverse outcomes in patients with cardiovascular diseases. A reliable and facile assay to measure platelet inhibition after treatment with aspirin and a P2Y12 antagonist is lacking. Multiple electrode aggregometry (MEA, which is being increasingly used in clinical studies, is sensitive to platelet inhibition by aspirin and clopidogrel, but a critical evaluation of MEA monitoring of dual anti-platelet therapy with aspirin and P2Y12 antagonists is missing. Design and Methods By performing in vitro and ex vivo experiments, we evaluated in healthy subjects the feasibility of using MEA to monitor platelet inhibition of P2Y12 antagonists (clopidogrel in vivo, cangrelor in vitro and aspirin (100 mg per day in vivo, and 1 mM or 5.4 mM in vitro alone, and in combination. Statistical analyses were performed by the Mann-Whitney rank sum test, student' t-test, analysis of variance followed by the Holm-Sidak test, where appropriate. Results ADP-induced platelet aggregation in hirudin-anticoagulated blood was inhibited by 99.3 ± 1.4% by in vitro addition of cangrelor (100 nM; p 95% and 100 ± 3.2%, respectively (p in vitro or ex vivo. Oral intake of clopidogrel did not significantly reduce AA-induced aggregation, but P2Y12 blockade by cangrelor (100 nM in vitro diminished AA-stimulated aggregation by 53 ± 26% (p Conclusions Selective platelet inhibition by aspirin and P2Y12 antagonists alone and in combination can be rapidly measured by MEA. We suggest that dual anti-platelet therapy with these two types of anti-platelet drugs can be optimized individually by measuring platelet responsiveness to ADP and AA with MEA before and after drug intake.

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.

Association between Platelet Counts before and during Pharmacological Therapy for Patent Ductus Arteriosus and Treatment Failure in Preterm Infants

Directory of Open Access Journals (Sweden)

Hannes Sallmon

2018-03-01

Full Text Available BackgroundThe role of platelets for mediating closure of the ductus arteriosus in human preterm infants is controversial. Especially, the effect of low platelet counts on pharmacological treatment failure is still unclear.MethodsIn this retrospective study of 471 preterm infants [<1,500 g birth weight (BW], who were treated for a patent ductus arteriosus (PDA with indomethacin or ibuprofen, we investigated whether platelet counts before or during pharmacological treatment had an impact on the successful closure of a hemodynamically significant PDA. The effects of other factors, such as sepsis, preeclampsia, gestational age, BW, and gender, were also evaluated.ResultsPlatelet counts before initiation of pharmacological PDA treatment did not differ between infants with later treatment success or failure. However, we found significant associations between low platelet counts during pharmacological PDA therapy and treatment failure (p < 0.05. Receiver operating characteristic (ROC curve analysis showed that platelet counts after the first, and before and after the second cyclooxygenase inhibitor (COXI cycle were significantly associated with treatment failure (area under the curve of >0.6. However, ROC curve analysis did not reveal a specific platelet cutoff-value that could predict PDA treatment failure. Multivariate logistic regression analysis showed that lower platelet counts, a lower BW, and preeclampsia were independently associated with COXI treatment failure.ConclusionWe provide further evidence for an association between low platelet counts during pharmacological therapy for symptomatic PDA and treatment failure, while platelet counts before initiation of therapy did not affect treatment outcome.

Clinicopathological correlations of podoplanin (gp38 expression in rheumatoid synovium and its potential contribution to fibroblast platelet crosstalk.

Directory of Open Access Journals (Sweden)

Manuel J Del Rey

Full Text Available Synovial fibroblasts (SF undergo phenotypic changes in rheumatoid arthritis (RA that contribute to inflammatory joint destruction. This study was undertaken to evaluate the clinical and functional significance of ectopic podoplanin (gp38 expression by RA SF.Expression of gp38 and its CLEC2 receptor was analyzed by immunohistochemistry in synovial arthroscopic biopsies from RA patients and normal and osteoarthritic controls. Correlation between gp38 expression and RA clinicopathological variables was analyzed. In patients rebiopsied after anti-TNF-α therapy, changes in gp38 expression were determined. Platelet-SF coculture and gp38 silencing in SF were used to analyze the functional contribution of gp38 to SF migratory and invasive properties, and to SF platelet crosstalk.gp38 was abundantly but variably expressed in RA, and it was undetectable in normal synovial tissues. Among clinicopathologigal RA variables, significantly increased gp38 expression was only found in patients with lymphoid neogenesis (LN, and RF or ACPA autoantibodies. Cultured synovial but not dermal fibroblasts showed strong constitutive gp38 expression that was further induced by TNF-α. In RA patients, anti-TNF-α therapy significantly reduced synovial gp38 expression. In RA synovium, CLEC2 receptor expression was only observed in platelets. gp38 silencing in cultured SF did not modify their migratory and invasive properties but reduced the expression of IL-6 and IL-8 genes induced by SF-platelet interaction.In RA, synovial expression of gp38 is strongly associated to LN and it is reduced after anti-TNF-α therapy. Interaction between gp38 and CLEC2 platelet receptor is feasible in RA synovium in vivo and can specifically contribute to gene expression by SF.

Microparticle counts in platelet-rich and platelet-free plasma, effect of centrifugation and sample-processing protocols.

Science.gov (United States)

Chandler, Wayne L

2013-03-01

This study provides the first estimates of microparticle numbers in platelet-rich plasma (PRP) from normal individuals, closer to in-vivo levels, using higher-resolution flow cytometry. We measured platelet (CD41+) and annexin V+ microparticles in fresh and frozen aliquots of PRP, platelet-poor plasma, platelet-free plasma (PFP), and microparticles isolated by high-speed centrifugation. PRP from healthy individuals contained 730,000/μl total microparticles based on light-scattering measurements. A median of 27,000/μl microparticles in PRP were of platelet origin and 120,000/μl annexin V+, and of these, 24,000/μl were dual-positive procoagulant platelet microparticles. Double centrifugation of PRP removed 99% of platelets, but also 80% of annexin V+ CD41+, 93% of annexin V+ CD41-, and 58% of annexin V- CD41+ microparticles. Loss of microparticles with centrifugation varied from individual to individual. Microparticle counts after isolation by centrifugation and double washing were not significantly different than counts in the original PFP sample, but lower than in PRP. Freeze-thawing of PFP had no effect on platelet microparticle counts, but slightly increased annexin V+, CD41- counts. Freeze-thawing of isolated washed microparticles resulted in a 30-50% increase in annexin V+ microparticles. PRP contains large numbers of cellular microparticles, including platelet and annexin V+ microparticles, which are lost to varying degrees when PRP is double centrifuged to remove platelets. Microparticles remaining in PFP can be recovered by high-speed centrifugation without loss compared to the original PFP sample. Freeze-thawing has variable effects on microparticle counts depending on the sample preparation used.

Cross-Linking GPVI-Fc by Anti-Fc Antibodies Potentiates Its Inhibition of Atherosclerotic Plaque- and Collagen-Induced Platelet Activation

Directory of Open Access Journals (Sweden)

Janina Jamasbi, RPh

2016-04-01

Full Text Available To enhance the antithrombotic properties of recombinant glycoprotein VI fragment crystallizable (GPVI-Fc, the authors incubated GPVI-Fc with anti-human Fc antibodies to cross-link the Fc tails of GPVI-Fc. Cross-linking potentiated the inhibition of human plaque- and collagen-induced platelet aggregation by GPVI-Fc under static and flow conditions without increasing bleeding time in vitro. Cross-linking with anti-human-Fc Fab2 was even superior to anti-human-Fc immunoglobulin G (IgG. Advanced optical imaging revealed a continuous sheath-like coverage of collagen fibers by cross-linked GPVI-Fc complexes. Cross-linking of GPVI into oligomeric complexes provides a new, highly effective, and probably safe antithrombotic treatment as it suppresses platelet GPVI-plaque interaction selectively at the site of acute atherothrombosis.

Equid herpesvirus type 1 activates platelets.

Directory of Open Access Journals (Sweden)

Tracy Stokol

Full Text Available Equid herpesvirus type 1 (EHV-1 causes outbreaks of abortion and neurological disease in horses. One of the main causes of these clinical syndromes is thrombosis in placental and spinal cord vessels, however the mechanism for thrombus formation is unknown. Platelets form part of the thrombus and amplify and propagate thrombin generation. Here, we tested the hypothesis that EHV-1 activates platelets. We found that two EHV-1 strains, RacL11 and Ab4 at 0.5 or higher plaque forming unit/cell, activate platelets within 10 minutes, causing α-granule secretion (surface P-selectin expression and platelet microvesiculation (increased small events double positive for CD41 and Annexin V. Microvesiculation was more pronounced with the RacL11 strain. Virus-induced P-selectin expression required plasma and 1.0 mM exogenous calcium. P-selectin expression was abolished and microvesiculation was significantly reduced in factor VII- or X-deficient human plasma. Both P-selectin expression and microvesiculation were re-established in factor VII-deficient human plasma with added purified human factor VIIa (1 nM. A glycoprotein C-deficient mutant of the Ab4 strain activated platelets as effectively as non-mutated Ab4. P-selectin expression was abolished and microvesiculation was significantly reduced by preincubation of virus with a goat polyclonal anti-rabbit tissue factor antibody. Infectious virus could be retrieved from washed EHV-1-exposed platelets, suggesting a direct platelet-virus interaction. Our results indicate that EHV-1 activates equine platelets and that α-granule secretion is a consequence of virus-associated tissue factor triggering factor X activation and thrombin generation. Microvesiculation was only partly tissue factor and thrombin-dependent, suggesting the virus causes microvesiculation through other mechanisms, potentially through direct binding. These findings suggest that EHV-1-induced platelet activation could contribute to the thrombosis

Comparison of VerifyNow-P2Y12 test and Flow Cytometry for monitoring individual platelet response to clopidogrel. What is the cut-off value for identifying patients who are low responders to clopidogrel therapy?

Directory of Open Access Journals (Sweden)

Castelli Alfredo

2009-05-01

Full Text Available Abstract Background Dual anti-platelet therapy with aspirin and a thienopyridine (DAT is used to prevent stent thrombosis after percutaneous coronary intervention (PCI. Low response to clopidogrel therapy (LR occurs, but laboratory tests have a controversial role in the identification of this condition. Methods We studied LR in patients with stable angina undergoing elective PCI, all on DAT for at least 7 days, by comparing: 1 Flow cytometry (FC to measure platelet membrane expression of P-selectin (CD62P and PAC-1 binding following double stimulation with ADP and collagen type I either in the presence of prostaglandin (PG E1; 2 VerifyNow-P2Y12 test, in which results are reported as absolute P2Y12-Reaction-Units (PRU or % of inhibition (% inhibition. Results Thirty controls and 52 patients were analyzed. The median percentage of platelets exhibiting CD62P expression and PAC-1 binding by FC evaluation after stimulation in the presence of PG E1 was 25.4% (IQR: 21.4–33.1% and 3.5% (1.7–9.4%, respectively. Only 6 patients receiving DAT (11.5% had both values above the 1st quartile of controls, and were defined as LR. Evaluation of the same patients with the VerifyNow-P2Y12 test revealed that the area under the receiver-operating-characteristic (ROC curve was 0.94 (95% CI: 0.84–0.98, p 213 PRU gave the maximum accuracy for the detection of patients defined as having LR by FC. Conclusion In conclusion our findings show that a cut-off value of ≤ 15% inhibition or > 213 PRU in the VerifyNow-P2Y12 test may provide the best accuracy for the identification of patients with LR.

Weight Gain and Hair Loss during Anti-TNF Therapy

Directory of Open Access Journals (Sweden)

Abdo Lutf

2012-01-01

Full Text Available Objectives. To investigate the incidence of weight gain and hair loss as adverse effects of anti-TNF therapy in rheumatic diseases. Methods. Patients using anti-TNF therapy, who are followed in rheumatology clinic, were interviewed using a questionnaire to investigate the side effects of anti-TNF therapy. Patients who complained of hair loss and weight gain were asked additional questions concerning the relationship of these adverse effects to anti-TNF use, whether therapy was stopped because of these adverse effects and if the adverse effects reversed after stopping therapy. The files were reviewed to follow the weight change before, during, and after discontinuation of anti-TNF. Results. One hundred fifty consecutive patients (82 RA, 34 ankylosing spondylitis, 32 psoriatic arthritis, and 4 for other indications were interviewed .Weight gain was observed in 20 patients (13.3% with average gain of 5.5 Kg. Anti-TNF was stopped in five patients because of this adverse effect. Hair loss during anti-TNf therapy was reported in five females (3.3% and anti-TNF therapy was stopped in all of them. Conclusion. Weight gain and hair loss appear to be associated with anti-TNF therapy and may be one reason for discontinuing the therapy.

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.

Application of Feedback System Control Optimization Technique in Combined Use of Dual Antiplatelet Therapy and Herbal Medicines

Directory of Open Access Journals (Sweden)

Wang Liu

2018-05-01

Full Text Available Aim: Combined use of herbal medicines in patients underwent dual antiplatelet therapy (DAPT might cause bleeding or thrombosis because herbal medicines with anti-platelet activities may exhibit interactions with DAPT. In this study, we tried to use a feedback system control (FSC optimization technique to optimize dose strategy and clarify possible interactions in combined use of DAPT and herbal medicines.Methods: Herbal medicines with reported anti-platelet activities were selected by searching related references in Pubmed. Experimental anti-platelet activities of representative compounds originated from these herbal medicines were investigated using in vitro assay, namely ADP-induced aggregation of rat platelet-rich-plasma. FSC scheme hybridized artificial intelligence calculation and bench experiments to iteratively optimize 4-drug combination and 2-drug combination from these drug candidates.Results: Totally 68 herbal medicines were reported to have anti-platelet activities. In the present study, 7 representative compounds from these herbal medicines were selected to study combinatorial drug optimization together with DAPT, i.e., aspirin and ticagrelor. FSC technique first down-selected 9 drug candidates to the most significant 5 drugs. Then, FSC further secured 4 drugs in the optimal combination, including aspirin, ticagrelor, ferulic acid from DangGui, and forskolin from MaoHouQiaoRuiHua. Finally, FSC quantitatively estimated the possible interactions between aspirin:ticagrelor, aspirin:ferulic acid, ticagrelor:forskolin, and ferulic acid:forskolin. The estimation was further verified by experimentally determined Combination Index (CI values.Conclusion: Results of the present study suggested that FSC optimization technique could be used in optimization of anti-platelet drug combinations and might be helpful in designing personal anti-platelet therapy strategy. Furthermore, FSC analysis could also identify interactions between different

Lea blood group antigen on human platelets

International Nuclear Information System (INIS)

Dunstan, R.A.; Simpson, M.B.; Rosse, W.F.

1985-01-01

One- and two-stage radioligand assays were used to determine if human platelets possess the Lea antigen. Goat IgG anti-Lea antibody was purified by multiple adsorptions with Le(a-b-) human red blood cells, followed by affinity chromatography with synthetic Lea substance and labeling with 125 I. Human IgG anti-Lea antibody was used either in a two stage radioassay with 125 I-labeled mouse monoclonal IgG anti-human IgG as the second antibody or, alternatively, purified by Staph protein A chromatography, labeled with 125 I, and used in a one-stage radioassay. Platelets from donors of appropriate red blood cell phenotypes were incubated with the antisera, centrifuged through phthalate esters, and assayed in a gamma scintillation counter. Dose response and saturation curve analysis demonstrate the presence of Lewis a antigen on platelets from Lea+ donors. Furthermore, platelets from an Le(a-b-) donor incubated in Le (a+b-) plasma adsorb Lea antigen in a similar manner to red blood cells. The clinical significance of these antigens in platelet transfusion remains undefined

Anti-double dipping rules for federal tax incentives

Energy Technology Data Exchange (ETDEWEB)

Ing, E.T.C. [Law Office of Edwin T.C. Ing, Washington, DC (United States)

1997-12-31

Political as well as technological changes are now reshaping the electric utility industry. While accommodating these changes, state legislative and regulatory agencies have the opportunity to promote public policies. In this regard, various state entities are evaluating appropriate incentives for renewable energy development so as to introduce greater competition in electric generation. For example, the California legislature is considering a supplemental production payment and the State of Iowa has instituted a low-interest loan program for wind and other alternative energy generation. By complementing the existing federal tax incentives, state incentives can spur the wind industry`s growth. If structured in the wrong way, however, state assistance programs will undercut the value of the federal tax incentives. The federal anti-double dipping rules apply to certain state programs. If a developer utilizes the wrong type of state assistance for a wind project, the anti-double dipping rules will reduce the federal tax incentives and this in turn will decrease the project`s profitability. Rather than suffer these results, very few if any developer will use the state program. Despite the time and effort a state may expend to enact a program for alternative energy development, the state assistance will be ineffectual. This paper reviews the counterproductive results which state assistance can have on a wind project because of the federal anti-double dipping rules.

Targeting factor VIII expression to platelets for hemophilia A gene therapy does not induce an apparent thrombotic risk in mice.

Science.gov (United States)

Baumgartner, C K; Mattson, J G; Weiler, H; Shi, Q; Montgomery, R R

2017-01-01

Essentials Platelet-Factor (F) VIII gene therapy is a promising treatment in hemophilia A. This study aims to evaluate if platelet-FVIII expression would increase the risk for thrombosis. Targeting FVIII expression to platelets does not induce or elevate thrombosis risk. Platelets expressing FVIII are neither hyper-activated nor hyper-responsive. Background Targeting factor (F) VIII expression to platelets is a promising gene therapy approach for hemophilia A, and is successful even in the presence of inhibitors. It is well known that platelets play important roles not only in hemostasis, but also in thrombosis and inflammation. Objective To evaluate whether platelet-FVIII expression might increase thrombotic risk and thereby compromise the safety of this approach. Methods In this study, platelet-FVIII-expressing transgenic mice were examined either in steady-state conditions or under prothrombotic conditions induced by inflammation or the FV Leiden mutation. Native whole blood thrombin generation assay, rotational thromboelastometry analysis and ferric chloride-induced vessel injury were used to evaluate the hemostatic properties. Various parameters associated with thrombosis risk, including D-dimer, thrombin-antithrombin complexes, fibrinogen, tissue fibrin deposition, platelet activation status and activatability, and platelet-leukocyte aggregates, were assessed. Results We generated a new line of transgenic mice that expressed 30-fold higher levels of platelet-expressed FVIII than are therapeutically required to restore hemostasis in hemophilic mice. Under both steady-state conditions and prothrombotic conditions induced by lipopolysaccharide-mediated inflammation or the FV Leiden mutation, supratherapeutic levels of platelet-expressed FVIII did not appear to be thrombogenic. Furthermore, FVIII-expressing platelets were neither hyperactivated nor hyperactivatable upon agonist activation. Conclusion We conclude that, in mice, more than 30-fold higher levels of

Autologous Blood and Platelet-Rich Plasma Injections for Treatment of Lateral Epicondylitis.

Science.gov (United States)

Calandruccio, James H; Steiner, Murphy M

2017-07-01

Lateral epicondylitis (tennis elbow) is a frequent cause of elbow pain; most patients (80%-90%) are successfully treated with standard nonoperative methods (rest, nonsteroidal anti-inflammatory drugs, bracing, and physical therapy). Autologous blood injections and platelet-rich plasma injections are the two most frequently used orthobiologic techniques in the treatment of lateral epicondylitis. Studies of the effectiveness of autologous blood injections and platelet-rich plasma report varying outcomes, some citing significant clinical relief and others reporting no beneficial effect. More research is needed to determine how to best use orthobiologics in the treatment of lateral epicondylitis. Copyright © 2017 Elsevier Inc. All rights reserved.

A prospective randomized trial of aspirin-clopidogrel combination therapy and dose-adjusted warfarin on indices of thrombogenesis and platelet activation in atrial fibrillation.

Science.gov (United States)

Kamath, Sridhar; Blann, Andrew D; Chin, Bernard S P; Lip, Gregory Y H

2002-08-07

This study was designed to investigate whether or not combination aspirin-clopidogrel therapy would reduce markers of thrombogenesis and platelet activation in atrial fibrillation (AF), in a manner similar to warfarin. Dose-adjusted warfarin is beneficial as thromboprophylaxis in AF, but potentially serious side effects and regular monitoring leave room for alternative therapies. METHODS; We randomized 70 patients with nonvalvular AF who were not on any antithrombotic therapy to either dose-adjusted warfarin (international normalized ratio 2 to 3) (Group I) or combination therapy with aspirin 75 mg and clopidogrel 75 mg (Group II). Plasma indices of thrombogenesis (fibrin D-dimer, prothrombin fragment 1+2) and platelet activation (beta-thromboglobulin [TG] and soluble P-selectin) were quantified, along with platelet aggregation responses to standard agonists, at baseline (pretreatment) and at six weeks posttreatment. RESULTS; Pretreatment levels of fibrin D-dimer (p = 0.001), beta-TG (p = 0.01) and soluble P-selectin (p = 0.03) were raised in patients with AF, whereas plasma prothrombin fragment 1+2 levels and platelet aggregation were not significantly different compared with controls. Dose-adjusted warfarin reduced plasma levels of fibrin D-dimer, prothrombin fragment 1+2 and beta-thromboglobulin levels at six weeks (all p failed to reduce plasma indices of thrombogenesis and platelet activation in AF, although some aspects of ex vivo platelet aggregation were altered. Anticoagulation with warfarin may be superior to combination aspirin-clopidogrel therapy as thromboprophylaxis in AF.

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.

Decreasing trends in hospitalizations during anti-TNF therapy are associated with time to anti-TNF therapy: Results from two referral centres.

Science.gov (United States)

Mandel, Michael D; Balint, Anita; Golovics, Petra A; Vegh, Zsuzsanna; Mohas, Anna; Szilagyi, Blanka; Szabo, Agnes; Kurti, Zsuzsanna; Kiss, Lajos S; Lovasz, Barbara D; Gecse, Krisztina B; Farkas, Klaudia; Molnar, Tamas; Lakatos, Peter L

2014-11-01

Hospitalization is an important outcome measure and a major driver of costs in patients with inflammatory bowel disease. We analysed medical and surgical hospitalization rates and predictors of hospitalization before and during anti-TNF therapy. Data from 194 consecutive patients were analysed retrospectively (males, 45.4%, median age at diagnosis, 24.0 years, infliximab/adalimumab: 144/50) in whom anti-TNF therapy was started after January 1, 2008. Total follow-up was 1874 patient-years and 474 patient-years with anti-TNF exposure. Hospitalization rates hospitalization decreased only in Crohn's disease (odds ratio: 0.59, 95% confidence interval: 0.51-0.70, median 2-years' anti-TNF exposure) with a same trend for surgical interventions (p=0.07), but not in ulcerative colitis. Need for hospitalization decreased in Crohn's disease with early (within 3-years from diagnosis, p=0.016 by McNemar test), but not late anti-TNF exposure. At logistic regression analysis complicated disease behaviour (p=0.03), concomitant azathioprine (p=0.02) use, but not anti-TNF type, gender, perianal disease or previous surgeries were associated with the risk of hospitalization during anti-TNF therapy. Hospitalization rate decreased significantly in patients with Crohn's disease but not ulcerative colitis after the introduction of anti-TNF therapy and was associated with time to therapy. Complicated disease phenotype and concomitant azathioprine use were additional factors defining the risk of hospitalization. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy

Energy Technology Data Exchange (ETDEWEB)

Camargo, L.M.; França, C.N.; Izar, M.C.; Bianco, H.T.; Lins, L.S.; Barbosa, S.P.; Pinheiro, L.F.; Fonseca, F.A.H. [Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Medicina, São Paulo, SP, Brasil, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

2014-04-15

It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1therapy. Simvastatin/ezetimibe diphosphate did not change platelet aggregation, the amount of circulating endothelial and platelet microparticles, or endothelial progenitor cells. Cardiovascular protection following therapy with simvastatin/ezetimibe seems restricted to lipid changes and improvement of endothelial function not affecting the release of microparticles, mobilization of endothelial progenitor cells or decreased platelet aggregation.

Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy

International Nuclear Information System (INIS)

Camargo, L.M.; França, C.N.; Izar, M.C.; Bianco, H.T.; Lins, L.S.; Barbosa, S.P.; Pinheiro, L.F.; Fonseca, F.A.H.

2014-01-01

It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1therapy. Simvastatin/ezetimibe diphosphate did not change platelet aggregation, the amount of circulating endothelial and platelet microparticles, or endothelial progenitor cells. Cardiovascular protection following therapy with simvastatin/ezetimibe seems restricted to lipid changes and improvement of endothelial function not affecting the release of microparticles, mobilization of endothelial progenitor cells or decreased platelet aggregation

Spray-dried Eudragit® L100 microparticles containing ferulic acid: Formulation, in vitro cytoprotection and in vivo anti-platelet effect

International Nuclear Information System (INIS)

Nadal, Jessica Mendes; Gomes, Mona Lisa Simionatto; Borsato, Débora Maria; Almeida, Martinha Antunes; Barboza, Fernanda Malaquias; Zawadzki, Sônia Faria; Kanunfre, Carla Cristine; Farago, Paulo Vitor; Zanin, Sandra Maria Warumby

2016-01-01

This paper aimed to obtain new spray-dried microparticles containing ferulic acid (FA) prepared by using a methacrylic polymer (Eudragit® L100). Microparticles were intended for oral use in order to provide a controlled release, and improved in vitro and in vivo biological effects. FA-loaded Eudragit® L100 microparticles were obtained by spray-drying. Physicochemical properties, in vitro cell-based effects, and in vivo platelet aggregation were investigated. FA-loaded Eudragit® L100 microparticles were successfully prepared by spray-drying. Formulations showed suitable encapsulation efficiency, i.e. close to 100%. Microparticles were of spherical and almost-spherical shape with a smooth surface and a mean diameter between 2 and 3 μm. Fourier-transformed infrared spectra demonstrated no chemical bond between FA and polymer. X-ray diffraction and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. FA-loaded microparticles showed a slower dissolution rate than pure drug. The chosen formulation demonstrated higher in vitro cytoprotection, anti-inflammatory and immunomodulatory potential and also improved in vivo anti-platelet effect. These results support an experimental basis for the use of FA spray-dried microparticles as a feasible oral drug delivery carrier for the controlled release of FA and improved cytoprotective and anti-platelet effects. - Highlights: • Ferulic acid-loaded Eudragit® L100 microparticles with high drug-loading were obtained. • Spray-dried Eudragit® L100 microparticles containing ferulic acid showed improved in vitro cytoprotective effect. • Ferulic acid spray-dried microparticles had potential as in vitro anti-inflammatory and immunomodulatory. • In vivo studies demonstrated an enhanced antiplatelet effect for ferulic acid-loaded Eudragit® L100 microparticles.

Spray-dried Eudragit® L100 microparticles containing ferulic acid: Formulation, in vitro cytoprotection and in vivo anti-platelet effect

Energy Technology Data Exchange (ETDEWEB)

Nadal, Jessica Mendes; Gomes, Mona Lisa Simionatto [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmacy, Federal University of Paraná (Brazil); Borsato, Débora Maria [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Ponta Grossa (Brazil); Almeida, Martinha Antunes [Postgraduate Program in Chemistry, Department of Chemistry, Federal University of Paraná (Brazil); Barboza, Fernanda Malaquias [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Ponta Grossa (Brazil); Zawadzki, Sônia Faria [Postgraduate Program in Chemistry, Department of Chemistry, Federal University of Paraná (Brazil); Kanunfre, Carla Cristine [Postgraduate Program in Biomedical Science, Department of General Biology, State University of Ponta Grossa (Brazil); Farago, Paulo Vitor, E-mail: pvfarago@gmail.com [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Ponta Grossa (Brazil); Zanin, Sandra Maria Warumby [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmacy, Federal University of Paraná (Brazil)

2016-07-01

This paper aimed to obtain new spray-dried microparticles containing ferulic acid (FA) prepared by using a methacrylic polymer (Eudragit® L100). Microparticles were intended for oral use in order to provide a controlled release, and improved in vitro and in vivo biological effects. FA-loaded Eudragit® L100 microparticles were obtained by spray-drying. Physicochemical properties, in vitro cell-based effects, and in vivo platelet aggregation were investigated. FA-loaded Eudragit® L100 microparticles were successfully prepared by spray-drying. Formulations showed suitable encapsulation efficiency, i.e. close to 100%. Microparticles were of spherical and almost-spherical shape with a smooth surface and a mean diameter between 2 and 3 μm. Fourier-transformed infrared spectra demonstrated no chemical bond between FA and polymer. X-ray diffraction and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. FA-loaded microparticles showed a slower dissolution rate than pure drug. The chosen formulation demonstrated higher in vitro cytoprotection, anti-inflammatory and immunomodulatory potential and also improved in vivo anti-platelet effect. These results support an experimental basis for the use of FA spray-dried microparticles as a feasible oral drug delivery carrier for the controlled release of FA and improved cytoprotective and anti-platelet effects. - Highlights: • Ferulic acid-loaded Eudragit® L100 microparticles with high drug-loading were obtained. • Spray-dried Eudragit® L100 microparticles containing ferulic acid showed improved in vitro cytoprotective effect. • Ferulic acid spray-dried microparticles had potential as in vitro anti-inflammatory and immunomodulatory. • In vivo studies demonstrated an enhanced antiplatelet effect for ferulic acid-loaded Eudragit® L100 microparticles.

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

Directory of Open Access Journals (Sweden)

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.

Static platelet adhesion, flow cytometry and serum TXB2 levels for monitoring platelet inhibiting treatment with ASA and clopidogrel in coronary artery disease: a randomised cross-over study

Science.gov (United States)

Eriksson, Andreas C; Jonasson, Lena; Lindahl, Tomas L; Hedbäck, Bo; Whiss, Per A

2009-01-01

Background Despite the use of anti-platelet agents such as acetylsalicylic acid (ASA) and clopidogrel in coronary heart disease, some patients continue to suffer from atherothrombosis. This has stimulated development of platelet function assays to monitor treatment effects. However, it is still not recommended to change treatment based on results from platelet function assays. This study aimed to evaluate the capacity of a static platelet adhesion assay to detect platelet inhibiting effects of ASA and clopidogrel. The adhesion assay measures several aspects of platelet adhesion simultaneously, which increases the probability of finding conditions sensitive for anti-platelet treatment. Methods With a randomised cross-over design we evaluated the anti-platelet effects of ASA combined with clopidogrel as well as monotherapy with either drug alone in 29 patients with a recent acute coronary syndrome. Also, 29 matched healthy controls were included to evaluate intra-individual variability over time. Platelet function was measured by flow cytometry, serum thromboxane B2 (TXB2)-levels and by static platelet adhesion to different protein surfaces. The results were subjected to Principal Component Analysis followed by ANOVA, t-tests and linear regression analysis. Results The majority of platelet adhesion measures were reproducible in controls over time denoting that the assay can monitor platelet activity. Adenosine 5'-diphosphate (ADP)-induced platelet adhesion decreased significantly upon treatment with clopidogrel compared to ASA. Flow cytometric measurements showed the same pattern (r2 = 0.49). In opposite, TXB2-levels decreased with ASA compared to clopidogrel. Serum TXB2 and ADP-induced platelet activation could both be regarded as direct measures of the pharmacodynamic effects of ASA and clopidogrel respectively. Indirect pharmacodynamic measures such as adhesion to albumin induced by various soluble activators as well as SFLLRN-induced activation measured by flow

Dimerization of glycoprotein Ibα is not sufficient to induce platelet clearance.

Science.gov (United States)

Liang, X; Syed, A K; Russell, S R; Ware, J; Li, R

2016-02-01

ESSENTIALS: Many anti-glycoprotein (GP)Ibα antibodies induce platelet clearance in a dimer-dependent manner. Characterization of monoclonal antibodies that bind the mechanosensitive domain (MSD) of GPIbα. An anti-MSD antibody binds two copies of GPIbα in platelets but does not induce platelet clearance. The prevailing clustering model of GPIbα signaling is incorrect or needs revision. The mechanism of platelet clearance is not clear. Many antibodies binding the membrane-distal ligand-binding domain of glycoprotein (GP)Ibα induce rapid clearance of platelets and acute thrombocytopenia, which requires the bifurcated antibody structure. It was thought that binding of these antibodies induced lateral dimerization or clustering of GPIbα in the plasma membrane, which leads to downstream signaling and platelet clearance. However, many antibodies targeting GPIbβ and GPIX, which are associated with GPIbα in the GPIb-IX complex, do not induce platelet clearance, which is in contradiction to the clustering model. To test whether dimerization or clustering of GPIbα is sufficient to transmit the signal that leads to platelet clearance. We have recently raised several mAbs targeting the mechanosensitive domain (MSD) of GPIbα. Binding of these anti-MSD antibodies was characterized with biochemical methods. Their ability to stimulate platelets and induce platelet clearance in mice was assessed. Infusion of anti-MSD antibodies does not cause thrombocytopenia in mice. These antibodies show no detectable effects on platelet activation and aggregation in vitro. Further biochemical investigation showed that the anti-MSD antibody 3D1 binds two copies of GPIbα on the platelet surface. Therefore, lateral dimerization of GPIbα induced by antibody binding is not sufficient to initiate GPIb-IX signaling and induce platelet clearance. Our results suggest that a factor other than or in addition to clustering of GPIbα is required to induce platelet clearance. © 2015 International

HPA antibodies in Algerian multitransfused patients: Prevalence and involvement in platelet refractoriness.

Science.gov (United States)

Brouk, Hacene; Bertrand, Gérald; Zitouni, Selma; Djenouni, Amel; Martageix, Corinne; Griffi, Fatiha; Kaplan, Cecile; Ouelaa, Hanifa

2015-06-01

Patients receiving cellular blood components may form HLA or HPA antibodies. The frequency and the specificity of HPA antibodies after a series of blood transfusions have never been reported in the Algerian population which is ethnically diverse and runs a higher risk of platelet alloimmunization due to high b allelic frequencies observed for the HPA systems. 117 polytransfused patients were included in this study; the detection of HPA antibodies was performed by the Monoclonal Antibody-specific Immobilization of Platelet Antigens method (MAIPA). Post-transfusion platelet effectiveness was evaluated by the calculation of corrected count increment (CCI). The antibodies against platelets were detected in 10.26% of the patients. In this study, the platelet systems concerned by the alloimmunizations were specifically HPA-1, -3 and -5 with particular predominance of HPA-1. Twenty two patients were refractory to platelet transfusion, as assessed by a CCI; in which 64% have factors associated with increased platelet consumption. Platelet Immunization was found in 14% of platelet refractoriness (PTR) cases. 03 Anti-platelet antibodies were directed against GPIb-IX (n = 1), anti-HPA-1b (n = 1) and anti HPA-5b (n = 1) associated with anti-HLA antibodies in two cases. HLA and HPA alloimmunization is common among chronically transfused patients. PTR detection, identification of the underlying causes, and selection of the appropriate product for transfusion are fundamental to reduce the risk of major bleedings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Overcoming the bottleneck of platelet lysate supply in large-scale clinical expansion of adipose-derived stem cells: A comparison of fresh versus three types of platelet lysates from outdated buffy coat-derived platelet concentrates.

Science.gov (United States)

Glovinski, Peter V; Herly, Mikkel; Mathiasen, Anders B; Svalgaard, Jesper D; Borup, Rehannah; Talman, Maj-Lis M; Elberg, Jens J; Kølle, Stig-Frederik T; Drzewiecki, Krzysztof T; Fischer-Nielsen, Anne

2017-02-01

Platelet lysates (PL) represent a promising replacement for xenogenic growth supplement for adipose-derived stem cell (ASC) expansions. However, fresh platelets from human blood donors are not clinically feasible for large-scale cell expansion based on their limited supply. Therefore, we tested PLs prepared via three methods from outdated buffy coat-derived platelet concentrates (PCs) to establish an efficient and feasible expansion of ASCs for clinical use. PLs were prepared by the freeze-thaw method from freshly drawn platelets or from outdated buffy coat-derived PCs stored in the platelet additive solution, InterSol. Three types of PLs were prepared from outdated PCs with platelets suspended in either (1) InterSol (not manipulated), (2) InterSol + supplemented with plasma or (3) plasma alone (InterSol removed). Using these PLs, we compared ASC population doubling time, cell yield, differentiation potential and cell surface markers. Gene expression profiles were analyzed using microarray assays, and growth factor concentrations in the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA). Of the three PL compositions produced from outdated PCs, removal of Intersol and resuspension in plasma prior to the first freezing process was overall the best. This specific outdated PL induced ASC growth kinetics, surface markers, plastic adherence and differentiation potentials comparable with PL from fresh platelets. ASCs expanded in PL from fresh versus outdated PCs exhibited different expressions of 17 overlapping genes, of which 10 were involved in cellular proliferation, although not significantly reflected by cell growth. Only minor differences in growth factor turnover were observed. PLs from outdated platelets may be an efficient and reliable source of human growth supplement allowing for large-scale ASC expansion for clinical use. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights

Effects of combined therapy of traditional Chinese medicine and western medicine on platelets, coagulative functions and inflammatory cytokines with ulcerative colitis

Directory of Open Access Journals (Sweden)

Yun-Xia Lei

2016-07-01

Full Text Available Objective: To explore the effects of combined therapy of traditional Chinese medicine and western medicine on platelets, coagulative functions and inflammatory cytokines in patients with ulcerative colitis (UC. Methods: A total of 267 patients with UC were collected. 137 patients were treated with combined therapy of traditional Chinese medicine and western medicine as experimental group and 130 patients were treated with only western medicine as controls. Platelet count, coagulation function indexes and inflammatory cytokines were measured before and 15 d after the treatment. Results: No significantly differences were found in all indexes before treatment between two groups. After different treatments, platelet count (PLT, platelet distribution width (PDW were significantly decreased in both groups, but mean platelet volumn (MPV were significantly increased than before treatment. PLT and PDW were significantly lower and MPV were significantly higher in experimental group than control group. Fibrinogen (Fib and D-dimer (DD decreased significantly after treatment. Fib and DD in experimental group were significantly lower than controls. No significantly differences were found in activated partial thromboplastin time (APTT and prothrobin time (PT. Tumor necrosisi factor-α (TNF-α, interleukin-6 (IL-6 and interleukin-8 (IL-8 decreased significantly in both group after treatment. TNF-毩, IL-6 and IL-8 were significantly lower in experimental group than controls. Conclusion: Combined therapy of traditional Chinese medicine and western medicine can more effectively improve the cogulation, fibrinolysis and inflammation in patients with UC than only western medicine therapy.

What's happening? The expanding role of apheresis platelet support in neonatal alloimmune thrombocytopenia: current status and future trends.

Science.gov (United States)

Bessos, Hagop; Seghatchian, Jerard

2005-10-01

Despite some unresolved problems that may be associated with platelet transfusion, such as alloimmunisation, refractoriness, bacterial contamination, and the potential side effects related to the development of some biological response modifiers during storage, platelet therapy remains the most effective treatment for the management and prevention of severe thrombocytopenia and hemorrhage [Seghatchian J, Snyder EL, Krailadsiri P, editors. Platelet therapy: current status and future trends. Amsterdam, The Netherlands: Elsevier; 2000]. This appears to be particularly the case in neonatal alloimmune thrombocytopenia (NAIT), which arises due to an incompatibility of the platelet specific antigens between the pregnant mother and her baby. Over 80% of severe NAIT cases in the Caucasian population occur when the mother and baby differ in their HPA-1 epitope (HPA-1a negative and positive respectively) leading, in 10% of cases, to the production of anti-HPA-1a which can cross the placenta and cause NAIT in utero or post-partum. Anti-HPA-5b is the second most cause of NAIT, although severe cases occur only after the first pregnancy. Clinical manifestations of NAIT vary from mild (petechia and bruises) to severe (intracranial haemorrhage with possible death or life long morbidity). A recent study in Scotland indicated that the cost per case of severe NAIT detected during screening of pregnant women, where anti-HPA-1a is detected for the first time, would amount to $98,771 [Turner M, Bessos H, et al. Prospective epidemiological study of the outcome and cost effectiveness of antenatal screening to detect neonatal alloimmune thrombocytopenia (NAIT) due to anti-HPA-1a. Transfusion, in press. Yet, unlike the case with Rhesus hemolytic disease of the new born, the cost-effectiveness of HPA-1 screening in NAIT remains unresolved, as does the most optimal mode of treatment. Therefore, in the absence of a consensus on the screening and optimal management of NAIT, the availability and

ELISA with double antigen sandwich for screening specific serum anti-TP antibody in blood donors

International Nuclear Information System (INIS)

Wang Yiqing; Shi Zhixu

2002-01-01

Objective: To select a sensitive and specific laboratory examination suitable for screening serum anti-TP antibody in blood donors. Methods: The serum anti-TP antibody in 11271 blood donors were detected using ELISA with double antigen sandwich and the outcomes were compared with those using RPR assay. The conflicting specimen were confirmed by repeating the test with TPHA assay. Results: The positive rates of serum anti-TP antibody by ELISA with double antigen sandwich and RPR was 0.36% (41/11271) and 0.26% (29/11271), respectively. The coincidence of the detecting outcomes by ELISA with double antigen sandwich and RPR with TPHA was 97.5% (40/41) and 63.41%(26/41) respectively. Conclusion: Compared with RPR assay, ELISA with double antigen sandwich has higher sensibility and specificity for screening serum anti-TP antibody in blood donors

The origin and function of platelet glycosyltransferases

DEFF Research Database (Denmark)

Wandall, Hans H; Rumjantseva, Viktoria; Sørensen, Anne Louise Tølbøll

2012-01-01

Platelets are megakaryocyte subfragments that participate in hemostatic and host defense reactions and deliver pro- and anti-angiogenic factors throughout the vascular system. Platelets are anucleated cells and lack a complex secretory apparatus with distinct Golgi/endoplasmic reticulum compartme...

Mechanisms of andrographolide-induced platelet apoptosis in human platelets: regulatory roles of the extrinsic apoptotic pathway.

Science.gov (United States)

Lien, Li-Ming; Su, Cheng-Chen; Hsu, Wen-Hsien; Lu, Wan-Jung; Chung, Chi-Li; Yen, Ting-Lin; Chiu, Hou-Chang; Sheu, Joen-Rong; Lin, Kuan-Hung

2013-11-01

Andrographolide, a novel nuclear factor-κB (NF-κB) inhibitor, is isolated from the leaves of Andrographis paniculata. Platelet activation is relevant to a variety of coronary heart diseases. Our recent studies revealed that andrographolide possesses potent antiplatelet activity by inhibition of the p38 MAPK/(●) HO-NF-κB-ERK2 cascade. Although platelets are anucleated cells, apoptotic machinery apparatus recently has been found to regulate platelet activation and limit platelet lifespan. Therefore, we further investigated the regulatory effects of andrographolide on platelet apoptotic events. In this study, apoptotic signaling events for caspase-3, -8, and Bid were time (10-60 min)- and dose (25-100 μΜ)-dependently activated by andrographolide in human platelets. Andrographolide could also disrupt mitrochondrial membrane potential. In addition, caspase-8 inhibitor (z-IETD-fmk, 50 μΜ) was found to reverse andrographolide-induced caspase-8 activation, whereas the antagonistic anti-Fas receptor (ZB4, 500 ng/mL) and anti-tumor necrosis factor-R1 (H398, 10 µg/mL) monoclonal antibodies did not. In conclusion, this study for the first time demonstrated that andrographolide might limit platelet lifespan by initiating the caspase-8-dependent extrinsic apoptotic pathway, in spite of no direct evidence that death receptors are involved in this process proved. Overall, the various medicinal properties of andrographolide suggest its potential value in treating patients with thromboembolic disorders. Copyright © 2012 John Wiley & Sons, Ltd.

Static platelet adhesion, flow cytometry and serum TXB2 levels for monitoring platelet inhibiting treatment with ASA and clopidogrel in coronary artery disease: a randomised cross-over study

Directory of Open Access Journals (Sweden)

Hedbäck Bo

2009-06-01

Full Text Available Abstract Background Despite the use of anti-platelet agents such as acetylsalicylic acid (ASA and clopidogrel in coronary heart disease, some patients continue to suffer from atherothrombosis. This has stimulated development of platelet function assays to monitor treatment effects. However, it is still not recommended to change treatment based on results from platelet function assays. This study aimed to evaluate the capacity of a static platelet adhesion assay to detect platelet inhibiting effects of ASA and clopidogrel. The adhesion assay measures several aspects of platelet adhesion simultaneously, which increases the probability of finding conditions sensitive for anti-platelet treatment. Methods With a randomised cross-over design we evaluated the anti-platelet effects of ASA combined with clopidogrel as well as monotherapy with either drug alone in 29 patients with a recent acute coronary syndrome. Also, 29 matched healthy controls were included to evaluate intra-individual variability over time. Platelet function was measured by flow cytometry, serum thromboxane B2 (TXB2-levels and by static platelet adhesion to different protein surfaces. The results were subjected to Principal Component Analysis followed by ANOVA, t-tests and linear regression analysis. Results The majority of platelet adhesion measures were reproducible in controls over time denoting that the assay can monitor platelet activity. Adenosine 5'-diphosphate (ADP-induced platelet adhesion decreased significantly upon treatment with clopidogrel compared to ASA. Flow cytometric measurements showed the same pattern (r2 = 0.49. In opposite, TXB2-levels decreased with ASA compared to clopidogrel. Serum TXB2 and ADP-induced platelet activation could both be regarded as direct measures of the pharmacodynamic effects of ASA and clopidogrel respectively. Indirect pharmacodynamic measures such as adhesion to albumin induced by various soluble activators as well as SFLLRN

Platelet transfusion therapy: from 1973 to 2005.

NARCIS (Netherlands)

Brand, A.; Novotny, V.M.J.; Tomson, B.

2006-01-01

Platelet transfusions are indispensable for supportive care of patients with hematological diseases. We describe the developments in platelet products for transfusion since the 1970s, when, in particular, support for patients with allo-antibodies against human leukocyte antigens was a laborious

Frequency of anti-glycoprotein Ia/IIa (anti-HPA-5b,-5a and anti-glycoprotein IIb/IIIa (anti-HPA-1a,-3a,-4a alloantibodies in multiparous women of African descent

Directory of Open Access Journals (Sweden)

Zaccheaus A Jeremiah

2010-05-01

Full Text Available Zaccheaus A Jeremiah1, Justina E Oburu2, Osaro Erhabor1, Fiekumo I Buseri1, Teddy C Adias31Haematology and Blood Transfusion Science Unit, Department of Medical Laboratory Sciences, College of Health Sciences, Niger Delta University, Wilberforce Island, Nigeria; 2Department of Haematology and Blood Transfusion, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria; 3Rivers State University of Science and Technology, Port Harcourt, NigeriaBackground: Human platelet antibodies are often implicated in some disease conditions, such as neonatal alloimmune thrombocytopenia (NAIT, idiopathic thrombocytopenic purpura (ITP and platelet refractoriness. The frequencies of these alloantibodies have not been reported in Nigeria and West Africa.Methods: Screening for allontibodies to human platelet antigens (HPA was undertaken using the GTI PakPlus® qualitative solid phase ELISA reagent. Platelet count was done using the ICSH approved procedure using 1% ammonium oxalate reagent.Study design: A cross-section of apparently healthy adult Nigerian multiparous non-pregnant women, who were staff of a tertiary health facility in the Niger Delta, Nigeria, were screened for alloantibodies to human platelet antigens.Results: Of the one hundred (100 women screened, the prevalence of anti-glycoprotein IIb/IIIa (anti-HPA-Ia,-3a,-4a was zero percent (0%, anti-glycoprotein Ia/IIa (anti-HPA-5b accounted for 30% of results, while anti-glycoprotein Ia/IIa (anti-HPA-5a was 18%. Parity was found to exert significant influence on the development to HPA antibodies (Fisher’s Exact Test = 11.683, P < 0.05; 13.577, P < 0.01. The platelet count of the women did not appear to exert any influence on the development of the antibodies (P > 0.05.Conclusion: This study has observed a high prevalence of anti-HPA-5b in our sample population. The prevalence of alloantibodies to HPA antigens was found to associate strongly with parity. These results indicate that there is a

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.

Platelet Function Tests: Preanalytical Variables, Clinical Utility, Advantages, and Disadvantages.

Science.gov (United States)

Hvas, Anne-Mette; Grove, Erik Lerkevang

2017-01-01

Platelet function tests are mainly used in the diagnostic work-up of platelet disorders. During the last decade, the additional use of platelet function tests to evaluate the effect of antiplatelet therapy has also emerged in an attempt to identify patients with an increased risk of arterial thrombosis. Furthermore, platelet function tests are increasingly used to measure residual effect of antiplatelet therapy prior to surgery with the aim of reducing the risk of bleeding. To a limited extend, platelet function tests are also used to evaluate hyperaggregability as a potential marker of a prothrombotic state outside the setting of antiplatelet therapy. This multifaceted use of platelet function tests and the development of simpler point-of-care tests with narrower application have increased the use of platelet function testing and also facilitated the use of platelet function tests outside the highly specialized laboratories. The present chapter describes the preanalytical variables, which should be taken into account when planning platelet function testing. Also, the most widely used platelet function tests are introduced, and their clinical utility and their relative advantages and disadvantages are discussed.

Synthesis of Analogues of Gingerol and Shogaol, the Active Pungent Principles from the Rhizomes of Zingiber officinale and Evaluation of Their Anti-Platelet Aggregation Effects

Science.gov (United States)

Shih, Hung-Cheng; Chern, Ching-Yuh; Kuo, Ping-Chung; Wu, You-Cheng; Chan, Yu-Yi; Liao, Yu-Ren; Teng, Che-Ming; Wu, Tian-Shung

2014-01-01

The present study was aimed at discovering novel biologically active compounds based on the skeletons of gingerol and shogaol, the pungent principles from the rhizomes of Zingiber officinale. Therefore, eight groups of analogues were synthesized and examined for their inhibitory activities of platelet aggregation induced by arachidonic acid, collagen, platelet activating factor, and thrombin. Among the tested compounds, [6]-paradol (5b) exhibited the most significant anti-platelet aggregation activity. It was the most potent candidate, which could be used in further investigation to explore new drug leads. PMID:24599082

Synthesis of Analogues of Gingerol and Shogaol, the Active Pungent Principles from the Rhizomes of Zingiber officinale and Evaluation of Their Anti-Platelet Aggregation Effects

Directory of Open Access Journals (Sweden)

Hung-Cheng Shih

2014-03-01

Full Text Available The present study was aimed at discovering novel biologically active compounds based on the skeletons of gingerol and shogaol, the pungent principles from the rhizomes of Zingiber officinale. Therefore, eight groups of analogues were synthesized and examined for their inhibitory activities of platelet aggregation induced by arachidonic acid, collagen, platelet activating factor, and thrombin. Among the tested compounds, [6]-paradol (5b exhibited the most significant anti-platelet aggregation activity. It was the most potent candidate, which could be used in further investigation to explore new drug leads.

Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors.

Science.gov (United States)

Amable, Paola Romina; Carias, Rosana Bizon Vieira; Teixeira, Marcus Vinicius Telles; da Cruz Pacheco, Italo; Corrêa do Amaral, Ronaldo José Farias; Granjeiro, José Mauro; Borojevic, Radovan

2013-06-07

Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 10(6) to 1.9 × 10(6) platelets/μl). Platelets were highly purified, because only platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of several growth factors, including platelet-derived growth factor and TGF. Our study resulted in a consistent PRP preparation method that yielded a cytokine and growth factor pool

Anti-retroviral therapy induced diabetes in a Nigerian | Bakari ...

African Journals Online (AJOL)

African Health Sciences ... Background:Anti-retroviral therapy (ART) using Highly Active Anti-retroviral Therapy (HAART) has led to ... HIV infected individuals on one hand, and side effects of chronic administration of these drugs on the other.

The influence of environmental variables on platelet concentration in horse platelet-rich plasma.

Science.gov (United States)

Rinnovati, Riccardo; Romagnoli, Noemi; Gentilini, Fabio; Lambertini, Carlotta; Spadari, Alessandro

2016-07-04

Platelet-rich plasma (PRP) commonly refers to blood products which contain a higher platelet (PLT) concentration as compared to normal plasma. Autologous PRP has been shown to be safe and effective in promoting the natural processes of soft tissue healing or reconstruction in humans and horses. Variability in PLT concentration has been observed in practice between PRP preparations from different patients or from the same individual under different conditions. A change in PLT concentration could modify PRP efficacy in routine applications. The aim of this study was to test the influence of environmental, individual and agonistic variables on the PLT concentration of PRP in horses. Six healthy Standardbred mares were exposed to six different variables with a one-week washout period between variables, and PRP was subsequently obtained from each horse. The variables were time of withdrawal during the day (morning/evening), hydration status (overhydration/dehydration) treatment with anti-inflammatory drugs and training periods on a treadmill. The platelet concentration was significantly higher in horses treated with a non-steroidal anti-inflammatory drug (P = 0.03). The leukocyte concentration increased 2-9 fold with respect to whole blood in the PRP which was obtained after exposure to all the variable considered. Environmental variation in platelet concentration should be taken into consideration during PRP preparation.

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.

HMG-CoA reductase inhibitors, other lipid-lowering medication, antiplatelet therapy, and the risk of venous thrombosis

NARCIS (Netherlands)

Ramcharan, A.S.; van Stralen, K.J.; Snoep, J.D.; Mantel-Teeuwisse, A.K.; Doggen, Catharina Jacoba Maria

2009-01-01

Background: Statins [3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors] and antiplatelet therapy reduce the risk of atherosclerotic disease. Besides a reduction of lipid levels, statins might also have antithrombotic and anti-inflammatory properties, and anti-platelet

Method to obtain platelet-rich plasma from rabbits (Oryctolagus cuniculus

Directory of Open Access Journals (Sweden)

Josiane M. Pazzini

2016-01-01

Full Text Available Abstract: Platelet-rich plasma (PRP is a product easy and inxpesnsive, and stands out to for its growth factors in tissue repair. To obtain PRP, centrifugation of whole blood is made with specific time and gravitational forces. Thus, the present work aimed to study a method of double centrifugation to obtain PRP in order to evaluate the effective increase of platelet concentration in the final product, the preparation of PRP gel, and to optimize preparation time of the final sample. Fifteen female White New Zealand rabbits underwent blood sampling for the preparation of PRP. Samples were separated in two sterile tubes containing sodium citrate. Tubes were submitted to the double centrifugation protocol, with lid closed and 1600 revolutions per minute (rpm for 10 minutes, resulting in the separation of red blood cells, plasma with platelets and leucocytes. After were opened and plasma was pipetted and transferred into another sterile tube. Plasma was centrifuged again at 2000rpm for 10 minutes; as a result it was split into two parts: on the top, consisting of platelet-poor plasma (PPP and at the bottom of the platelet button. Part of the PPP was discarded so that only 1ml remained in the tube along with the platelet button. This material was gently agitated to promote platelets resuspension and activated when added 0.3ml of calcium gluconate, resulting in PRP gel. Double centrifugation protocol was able to make platelet concentration 3 times higher in relation to the initial blood sample. The volume of calcium gluconate used for platelet activation was 0.3ml, and was sufficient to coagulate the sample. Coagulation time ranged from 8 to 20 minutes, with an average of 17.6 minutes. Therefore, time of blood centrifugation until to obtain PRP gel took only 40 minutes. It was concluded that PRP was successfully obtained by double centrifugation protocol, which is able to increase the platelet concentration in the sample compared with whole blood

[Applications of platelets in studies on traditional Chinese medicines promoting blood circulation to remove blood stasis].

Science.gov (United States)

Wang, Feng-Qin; Chen, Cen; Xia, Zhi-Ning; Yang, Feng-Qing

2014-08-01

Thrombotic diseases in different forms become a great threat to human health. Such anti-platelet aggregation drugs as aspirin and clopidogrel are common drugs in clinic. However, along with the appearance of resistance and side effects of western anti-platelet aggregation drugs, anti-platelet aggregation traditional Chinese medicines promoting blood circulation to remove blood stasis have gradually become an important study orientation. Platelet is one of major participant in thrombosis, and plays an important role as a bioactive material in studies on traditional Chinese medicines promoting blood circulation to remove blood stasis, mainly involving two aspects--the evaluation for the anti-platelet aggregation activity of traditional Chinese medicines and the screening of their active components. This paper summarized the applications of platelets in studies on traditional Chinese medicines promoting blood circulation to remove blood stasis, so as to provide basis for further studies.

Effectiveness and Safety of Immunomodulators with Anti-TNF Therapy in Crohn's Disease

Science.gov (United States)

Osterman, Mark T.; Haynes, Kevin; Delzell, Elizabeth; Zhang, Jie; Bewtra, Meenakshi; Brensinger, Colleen M.; Chen, Lang; Xie, Fenglong; Curtis, Jeffrey R.; Lewis, James D.

2015-01-01

Background & Aims The benefit of continuing immunomodulators when “stepping up” to anti-tumor necrosis factor (anti-TNF) therapy for Crohn's disease (CD) is uncertain. This study assessed the effectiveness and safety of immunomodulators with anti-TNF therapy in CD. Methods We conducted a retrospective cohort study of new users of anti-TNF therapy for CD in Medicare. Users of anti-TNF combination therapy with immunomodulators were matched to up to 3 users of anti-TNF monotherapy via propensity score and compared using 3 metrics of effectiveness – surgery, hospitalization, and discontinuation of anti-TNF therapy or surgery – and 2 metrics of safety – serious infection and non-Candida opportunistic infection. Cox regression was used for all analyses. Results Among new users of infliximab, we matched 381 users of combination therapy to 912 users of monotherapy; among new users of adalimumab, we matched 196 users of combination therapy to 505 users of monotherapy. Combination therapy occurred predominantly as “step up” after thiopurine therapy. The rates of surgery (hazard ratio [HR] 1.20, 95% CI 0.73-1.96), hospitalization (HR 0.82 [0.57-1.19]), discontinuation of anti-TNF therapy or surgery (HR 1.09, [0.88-1.34]), and serious infection (HR 0.93 [0.88-1.34]) did not differ between users of anti-TNF combination therapy and monotherapy. However, the risk of opportunistic infection (HR 2.64 [1.21-5.73]) and herpes zoster (HR 3.16 [1.25-7.97]) were increased with combination therapy. Conclusions We found that continuation of immunomodulators after “stepping up” to anti-TNF therapy did not improve outcomes but was associated with an increased risk of opportunistic infection. PMID:25724699

Monitoring aspirin therapy with the Platelet Function Analyzer-100

DEFF Research Database (Denmark)

Mortensen, Jette; Poulsen, Tina Svenstrup; Grove, Erik Lerkevang

2008-01-01

OBJECTIVE: Low platelet response to aspirin has been reported to be associated with a high incidence of vascular events. The reported prevalence of aspirin low-responsiveness varies, which may be explained by poor reproducibility of the methods used to evaluate aspirin response and low compliance....... The Platelet Function Analyzer-100 (PFA-100) is a commonly used platelet function test. We aimed to assess the reproducibility of the PFA-100 and the agreement with optical platelet aggregometry (OPA) in healthy volunteers and in patients with coronary artery disease (CAD) treated with low-dose aspirin....... MATERIAL AND METHODS: Twenty-one healthy volunteers and 43 patients with CAD took part in the study. During treatment with aspirin 75 mg daily, all participants had platelet function assessed in duplicate with the PFA-100 and OPA on 4 consecutive days. Additionally, platelet function was assessed before...

Advancements in anti-inflammatory therapy for dry eye syndrome.

Science.gov (United States)

McCabe, Erin; Narayanan, Srihari

2009-10-01

The goal of this literature review is to discuss recent discoveries in the pathophysiology of dry eye and the subsequent evolution of diagnostic and management techniques. The mechanisms of various anti-inflammatory treatments are reviewed, and the efficacy of common pharmacologic agents is assessed. Anti-inflammatory therapy is evaluated in terms of its primary indications, target population, and utility within a clinical setting. The Medline PubMed database and the World Wide Web were searched for current information regarding dry eye prevalence, pathogenesis, diagnosis, and management. After an analysis of the literature, major concepts were integrated to generate an updated portrayal of the status of dry eye syndrome. Inflammation appears to play a key role in perpetuating and sustaining dry eye. Discoveries of inflammatory markers found within the corneal and conjunctival epithelium of dry eye patients have triggered recent advancements in therapy. Pharmacologic anti-inflammatory therapy for dry eye includes 2 major categories: corticosteroids and immunomodulatory agents. Fatty acid and androgen supplementation and oral antibiotics have also shown promise in dry eye therapy because of their anti-inflammatory effects. Anti-inflammatory pharmacologic agents have shown great success in patients with moderate to severe dry eye when compared with alternative treatment modalities. A deeper understanding of the link between inflammation and dry eye validates the utilization of anti-inflammatory therapy in everyday optometric practice.

Measurement of anti-double-stranded DNA antibodies in major immunoglobulin classes

Energy Technology Data Exchange (ETDEWEB)

Aotsuka, S; Okawa, M; Ikebe, K; Yokohari, R [Division of Clinical Immunology, Clinical Research Institute, National Medical Center Hospital, Shinjuku-ku, Tokyo, Japan

1979-07-10

A solid-phase radioimmunoassay for quantitating anti-double-stranded deoxyribonucleic acid antibodies (anti-dsDNA) in IgG, IgM and IgA classes has been devised. A distinct feature of the method is an application of polystyrene tubes coated with poly-L-lysine, through which dsDNA could be bound firmly to a solid phase. Studies on patients sera as well as normal sera revealed that anti-dsDNA was not qualitatively but quantitatively characteristic of systematic lupus erythematosus (SLE) and that IgG anti-dsDNA levels correlated well with the disease activity.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

Science.gov (United States)

Jat, Kana R; Walia, Dinesh K; Khairwa, Anju

2018-03-18

study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively. There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

The Emerging Role of miR-223 in Platelet Reactivity: Implications in Antiplatelet Therapy

Science.gov (United States)

Shi, Rui; Zhou, Xin; Ji, Wen-Jie; Zhang, Ying-Ying; Ma, Yong-Qiang; Zhang, Jian-Qi

2015-01-01

Platelets are anuclear cells and are devoid of genomic DNA, but they are capable of de novo protein synthesis from mRNA derived from their progenitor cells, megakaryocytes. There is mounting evidence that microRNA (miRNA) plays an important role in regulating gene expression in platelets. miR-223 is the most abundant miRNAs in megakaryocytes and platelets. One of the miR-223-regulated genes is ADP P2Y12, a key target for current antiplatelet drug therapy. Recent studies showed that a blunted response to P2Y12 antagonist, that is, high on-treatment platelet reactivity (HTPR), is a strong predictor of major cardiovascular events (MACEs) in coronary heart disease (CHD) patients receiving antiplatelet treatment. Recent clinical cohort study showed that the level of circulating miR-223 is inversely associated with MACE in CHD patients. In addition, our recent data demonstrated that the level of both intraplatelet and circulating miR-223 is an independent predictor for HTPR, thus providing a link between miR-223 and MACE. These lines of evidence indicate that miR-223 may serve as a potential regulatory target for HTPR, as well as a diagnostic tool for identification of HTPR in clinical settings. PMID:26221610

Platelet rich plasma versus laser therapy in lateral epicondylitis of elbow.

Science.gov (United States)

Tonk, Gyaneshwar; Kumar, Anish; Gupta, Amit

2014-07-01

Platelet rich plasma (PRP) extract has shown to be a general stimulation for repair and currently used widely in various sports injury. A prospective observational study was done to assess the efficacy of autologous PRP injection in lateral epicondylitis of elbow, and compare the result with low level laser therapy. The trial was conducted at a tertiary care center for a period of 2 years. Eighty-one patients with chronic lateral epicondylitis were divided into two groups. PRP group (n = 39) and laser therapy group (n = 42). The primary analysis included Nirschl pain score, local tenderness, pain on wrist extension, grip strength, elbow swelling were clinically assessed at different interval of followup (minimum followup: 52 weeks) and; clinical and functional outcome evaluated at final followup. The statistical analysis were done. The mean Nirschl pain score decreased significantly from baseline in PRP when compared with low level laser therapy (P ≤ 0.05). Treatment of patients with chronic lateral epicondylitis with PRP extract reduced pain and significantly increased function, exceeding the effect of low level laser therapy on long term followup. Low-level laser therapy is better in the short term period, but on long term followup injection PRP therapy is better than laser therapy in lateral epicondylitis.

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.

Force-activatable biosensor enables single platelet force mapping directly by fluorescence imaging.

Science.gov (United States)

Wang, Yongliang; LeVine, Dana N; Gannon, Margaret; Zhao, Yuanchang; Sarkar, Anwesha; Hoch, Bailey; Wang, Xuefeng

2018-02-15

Integrin-transmitted cellular forces are critical for platelet adhesion, activation, aggregation and contraction during hemostasis and thrombosis. Measuring and mapping single platelet forces are desired in both research and clinical applications. Conventional force-to-strain based cell traction force microscopies have low resolution which is not ideal for cellular force mapping in small platelets. To enable platelet force mapping with submicron resolution, we developed a force-activatable biosensor named integrative tension sensor (ITS) which directly converts molecular tensions to fluorescent signals, therefore enabling cellular force mapping directly by fluorescence imaging. With ITS, we mapped cellular forces in single platelets at 0.4µm resolution. We found that platelet force distribution has strong polarization which is sensitive to treatment with the anti-platelet drug tirofiban, suggesting that the ITS force map can report anti-platelet drug efficacy. The ITS also calibrated integrin molecular tensions in platelets and revealed two distinct tension levels: 12-54 piconewton (nominal values) tensions generated during platelet adhesion and tensions above 54 piconewton generated during platelet contraction. Overall, the ITS is a powerful biosensor for the study of platelet mechanobiology, and holds great potential in antithrombotic drug development and assessing platelet activity in health and disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Thrombus imaging in a primate model with antibodies specific for an external membrane protein of activated platelets

International Nuclear Information System (INIS)

Palabrica, T.M.; Furie, B.C.; Konstam, M.A.; Aronovitz, M.J.; Connolly, R.; Brockway, B.A.; Ramberg, K.L.; Furie, B.

1989-01-01

The activated platelet is a potential target for the localization of thrombi in vivo since, after stimulation and secretion of granule contents, activated platelets are concentrated at sites of blood clot formation. In this study, we used antibodies specific for a membrane protein of activated platelets to detect experimental thrombi in an animal model. PADGEM (platelet activation-dependent granule-external membrane protein), a platelet alpha-granule membrane protein, is translocated to the plasma membrane during platelet activation and granule secretion. Since PADGEM is internal in unstimulated platelets, polyclonal anti-PADGEM and monoclonal KC4 antibodies do not bind to circulating resting platelets but do interact with activated platelets. Dacron graft material incubated with radiolabeled KC4 or anti-PADGEM antibodies in the presence of thrombin-activated platelet-rich plasma bound most of the antibody. Imaging experiments with 123I-labeled anti-PADGEM in baboons with an external arterial-venous Dacron shunt revealed rapid uptake in the thrombus induced by the Dacron graft; control experiments with 123I-labeled nonimmune IgG exhibited minimal uptake. Deep venous thrombi, formed by using percutaneous balloon catheters to stop blood flow in the femoral vein of baboons, were visualized with 123I-labeled anti-PADGEM. Thrombi were discernible against blood pool background activity without subtraction techniques within 1 hr. No target enhancement was seen with 123I-labeled nonimmune IgG. 123I-labeled anti-PADGEM cleared the blood pool with an initial half-disappearance time of 6 min and did not interfere with hemostasis. These results indicate that radioimmunoscintigraphy with anti-PADGEM antibodies can visualize thrombi in baboon models and is a promising technique for clinical thrombus detection in humans

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial

OpenAIRE

Madurantakam, Parthasarathy; Yoganarasimha, Suyog; Hasan, Fadi K.

2015-01-01

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in...

Lansoprazole for secondary prevention of gastric or duodenal ulcers associated with long-term non-steroidal anti-inflammatory drug (NSAID) therapy: results of a prospective, multicenter, double-blind, randomized, double-dummy, active-controlled trial.

Science.gov (United States)

Sugano, Kentaro; Kontani, Teiji; Katsuo, Shinichi; Takei, Yoshinori; Sakaki, Nobuhiro; Ashida, Kiyoshi; Mizokami, Yuji; Asaka, Masahiro; Matsui, Shigeyuki; Kanto, Tatsuya; Soen, Satoshi; Takeuchi, Tsutomu; Hiraishi, Hideyuki; Hiramatsu, Naoki

2012-05-01

Low-dose lansoprazole has not been intensively evaluated for its efficacy in the prevention of recurrent gastric or duodenal ulcers in patients receiving long-term non-steroidal anti-inflammatory drug (NSAID) therapy for pain relief in such diseases as rheumatoid arthritis, osteoarthritis, and low back pain. This multi-center, prospective, double-blind, randomized, active-controlled study involving 99 sites in Japan was designed to compare the efficacy of lansoprazole (15 mg daily) with gefarnate (50 mg twice daily). Patients with a history of gastric or duodenal ulcers who required long-term NSAID therapy were randomized to receive lansoprazole 15 mg daily (n = 185) or gefarnate 50 mg twice daily (n = 181) and followed up for 12 months or longer prospectively. The cumulative incidence of gastric or duodenal ulcer at days 91, 181, and 361 from the start of the study was calculated by the Kaplan-Meier method as 3.3, 5.9, and 12.7%, respectively, in the lansoprazole group versus 18.7, 28.5, and 36.9%, respectively, in the gefarnate group. The risk for ulcer development was significantly (log-rank test, P lansoprazole group than in the gefarnate group, with the hazard ratio being 0.2510 (95% CI 0.1400-0.4499). A long-term follow-up study showed an acceptable safety profile for low-dose lansoprazole therapy, with diarrhea as the most frequent adverse event. Lansoprazole was superior to gefarnate in reducing the risk of gastric or duodenal ulcer recurrence in patients with a definite history of gastric or duodenal ulcers who required long-term NSAID therapy.

Evaluation of aspirin therapy on intracardiac thrombi using indium-111-oxine platelet scintigraphy, two-dimentional echocardiography and left ventriculography

International Nuclear Information System (INIS)

Shibuya, Masanori; Irino, Tadayoshi; Yoshioka, Toshiharu; Sugimoto, Tsuyoshi; Tsuji, Kazuo; Naka, Masashi; Arai, Hidekazu.

1984-01-01

Left ventriculography (LVG), two-dimensional echocardiography (2-DE) and indium-111-oxine platelet scintigraphy were performed in five patients with intracardiac thrombi. Thrombi were visible in 7 sites (5 in the ventricle and 2 in the atrium) by platelet scintigraphy, in 4 sites (3 in the ventricle and 1 in the atrium) by 2-DE, and in 4 sites (4 in the ventricle) by LVG. When aspirin was administered to the patients, platelet scintigraphy had become negative for thrombi in 5 sites and false-negative for them in 2 sites. However, thrombi were detected in 6 sites after the withdrawal of aspirin. On the other hand, thrombi were detected in 4 sites by 2-DE, irrespective of the administration of aspirin. Indium-111-oxine platelet scintigraphy has proved to not only have higher sensitivity for detecting thrombi but also to be capable of observing the coagulation status of platelets on the thrombi. It is therefore considered very helpful in assessing anticoagulation therapy. (Namekawa, K)

Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors

Science.gov (United States)

2013-01-01

Introduction Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. Methods PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Results Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 106 to 1.9 × 106 platelets/μl). Platelets were highly purified, because only blood cells and leukocytes was present in the final PRP preparation. We also quantified growth factors, cytokines and chemokines secreted by the concentrated platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of

Flavonoids and platelet aggregation: A brief review.

Science.gov (United States)

Faggio, Caterina; Sureda, Antoni; Morabito, Silvia; Sanches-Silva, Ana; Mocan, Andrei; Nabavi, Seyed Fazel; Nabavi, Seyed Mohammad

2017-07-15

Platelets are small anucleated fragments derived from a megakaryocyte precursor. Platelets play a key role in many physiological functions especially in hemostasis and wound healing processes in order to maintain the integrity of the circulatory system. In addition, activated platelets release cytokines and chemokines which modulate the immune response and, in some cases of hyperactivation, they could be associated to the pathogenesis of inflammatory diseases. Flavonoids are polyphenolic compounds ubiquosly found in plants known to be potent antioxidants with positive effects against diverse diseases such as cancer, neurodegenerative or cardiovascular disease. It has been reported that some flavonoids possess anti-platelet aggregation effects though different pathways, being the inhibition of the arachidonic acid-based pathway the most representative mechanism of action. In the present review, the main sources of flavonoids, as well as their bioavailability and metabolism are summarized. Moreover, the available data about the anti-aggregation effects of flavonoids and the different mechanisms of action that has been proposed until now are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Platelet-released growth factors can accelerate tenocyte proliferation and activate the anti-oxidant response element.

Science.gov (United States)

Tohidnezhad, M; Varoga, D; Wruck, C J; Brandenburg, L O; Seekamp, A; Shakibaei, M; Sönmez, T T; Pufe, Thomas; Lippross, S

2011-05-01

Little is know about the pathophysiology of acute and degenerative tendon injuries. Although most lesions are uncomplicated, treatment is long and unsatisfactory in a considerable number of cases. Besides the common growth factors that were shown to be relevant for tendon integrity more recently protection against oxidative stress was shown to promote tendon healing. To improve tendon regeneration, many have advocated the use of platelet-rich plasma (PRP), a thrombocyte concentrate that can serve as an autologous source of growth factors. In this study, we investigated the effect of platelet-released growth factors (PRGF) on tenocytes. Tenocytes were isolated from the Achilles tendon of postnatal rats. Tenocyte cell cultures were stimulated with PRGF. We used a CyQuant assay and WST assay to analyse tendon cell growth and viability in different concentrations of PRGF. Migration and proliferation of cells grown in PRGF were assessed by a scratch test. A dual-luciferase assay was used to demonstrate the activation of the anti-oxidant response element (ARE) in tenocytes. A positive effect of PRGF could be shown on tendon cell growth and migratory capacity. PRGF activated the Nrf2-ARE pathway in a dose-dependent manner. Here, we provide evidence of a biological effect of PRGF on tenocytes by the promotion of tenocyte growth and activation of the Nrf2-ARE pathway. This is a novel aspect of the action of platelet concentrates on tendon growth.

Direct anti-atherosclerotic therapy; development of natural anti-atherosclerotic drugs preventing cellular cholesterol retention.

Science.gov (United States)

Orekhov, Alexander N

2013-01-01

The results of numerous clinical trials with statins and other drugs have demonstrated the principal possibility of the prevention and regression of atherosclerosis by pharmacotherapy. This review describes the use of cultured human arterial cells for the mass screening of anti-atherosclerotic substances, the investigation of the mechanisms responsible for their atherosclerosis-related effects, and the optimization of anti-atherosclerotic and anti-atherogenic drug and dietary therapies. Natural products can be considered promising drugs for anti-atherosclerotic therapy. Our basic studies have shown that cellular lipidosis is the principal event in the genesis of atherosclerotic lesions. Using cellular models and natural products, we have developed an approach to prevent lipid accumulation in arterial cells. Based on our knowledge of atherosclerosis, we developed drugs that possess direct anti-atherosclerotic activity. Two-year treatment with allicor (garlic powder) has a direct anti-atherosclerotic effect on carotid atherosclerosis in asymptomatic men. Inflaminat (calendula, elder, and violet), which possesses anti-cytokine activity, has been shown to cause the regression of carotid atherosclerosis following the treatment of asymptomatic men for one year. The phytoestrogen-rich drug karinat (garlic powder, extract of grape seeds, green tea leaves, hop cones, β-carotene, α-tocopherol, and ascorbic acid) prevents the development of carotid atherosclerosis in postmenopausal women. Thus, our basic findings were successfully translated into clinical practice. Because of this translation, a novel approach to antiatherosclerotic therapy was developed. Our clinical trial confirmed the efficacy of both the novel approach and the novel drugs.

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.

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.

Anti-D treatment for pediatric immune thrombocytopenia: Is the bad reputation justified?

Science.gov (United States)

Yacobovich, Joanne; Abu-Ahmed, Sabreen; Steinberg-Shemer, Orna; Goldberg, Tracie; Cohen, Miriam; Tamary, Hannah

2016-04-01

The purpose of this study was to assess the efficacy and side effect profile of the repeated use of anti-D for the treatment of pediatric immune thrombocytopenia (ITP) in a large pediatric hematology center. We performed a retrospective analysis of patient records for children (aged 4 months-18 years) treated for ITP at Schneider Children's Medical Center of Israel from 1995-2015. Demographic and clinical data, reported adverse events, and therapy response were extracted from written and electronic files for all patients having received anti-D. Therapy response was defined as time to platelet count >30 x 10(9)/L. Thirty-six patients received 170 treatments of anti-D at a dose of 75 μg/kg. The majority were previously treated with corticosteroids and/or intravenous immunoglobulin (IVIG). Minimal adverse events were recorded including fever (3.5%), vomiting (2.9%), and headaches (1.7%). Notably only 1/170 treatments required blood transfusion and no life-threatening events occurred. The average time to platelets >30 x 10(9)/L was 2.3 days, with a median of 1 day, range 1-12 days. Despite the reported severe adverse events in mainly elderly patients, the use of anti-D can be safe and effective in carefully chosen, low-risk pediatric patients with ITP. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of four methods for platelet compatibility testing

International Nuclear Information System (INIS)

McFarland, J.G.; Aster, R.H.

1987-01-01

Four platelet compatibility assays were performed on serum and platelet or lymphocyte samples from 38 closely HLA-matched donor/recipient pairs involved in 55 single-donor platelet transfusions. The 22 patients studied were refractory to transfusions of pooled random-donor platelets. Of the four assays (platelet suspension immunofluorescence, PSIFT; 51 Cr release; microlymphocytotoxicity; and a monoclonal anti-IgG assay, MAIA), the MAIA was most predictive of platelet transfusion outcome (predictability, 74% for one-hour posttransfusion platelet recovery and 76% for 24-hour recovery). The only other assay to reach statistical significance was the PSIFT (63% predictability for one-hour posttransfusion recovery). The degree of HLA compatibility between donor and recipient (exact matches v those utilizing cross-reactive associations) was unrelated to the ability of the MAIA to predict transfusion results. The MAIA may be capable of differentiating HLA antibodies, ABO antibodies, and platelet-specific antibodies responsible for failure of HLA-matched and selectively mismatched single-donor platelet transfusions

Non-redundant roles of phosphoinositide 3-kinase isoforms alpha and beta in glycoprotein VI-induced platelet signaling and thrombus formation.

Science.gov (United States)

Gilio, Karen; Munnix, Imke C A; Mangin, Pierre; Cosemans, Judith M E M; Feijge, Marion A H; van der Meijden, Paola E J; Olieslagers, Servé; Chrzanowska-Wodnicka, Magdalena B; Lillian, Rivka; Schoenwaelder, Simone; Koyasu, Shigeo; Sage, Stewart O; Jackson, Shaun P; Heemskerk, Johan W M

2009-12-04

Platelets are activated by adhesion to vascular collagen via the immunoglobulin receptor, glycoprotein VI (GPVI). This causes potent signaling toward activation of phospholipase Cgamma2, which bears similarity to the signaling pathway evoked by T- and B-cell receptors. Phosphoinositide 3-kinase (PI3K) plays an important role in collagen-induced platelet activation, because this activity modulates the autocrine effects of secreted ADP. Here, we identified the PI3K isoforms directly downstream of GPVI in human and mouse platelets and determined their role in GPVI-dependent thrombus formation. The targeting of platelet PI3Kalpha or -beta strongly and selectively suppressed GPVI-induced Ca(2+) mobilization and inositol 1,4,5-triphosphate production, thus demonstrating enhancement of phospholipase Cgamma2 by PI3Kalpha/beta. That PI3Kalpha and -beta have a non-redundant function in GPVI-induced platelet activation and thrombus formation was concluded from measurements of: (i) serine phosphorylation of Akt, (ii) dense granule secretion, (iii) intracellular Ca(2+) increases and surface expression of phosphatidylserine under flow, and (iv) thrombus formation, under conditions where PI3Kalpha/beta was blocked or p85alpha was deficient. In contrast, GPVI-induced platelet activation was insensitive to inhibition or deficiency of PI3Kdelta or -gamma. Furthermore, PI3Kalpha/beta, but not PI3Kgamma, contributed to GPVI-induced Rap1b activation and, surprisingly, also to Rap1b-independent platelet activation via GPVI. Together, these findings demonstrate that both PI3Kalpha and -beta isoforms are required for full GPVI-dependent platelet Ca(2+) signaling and thrombus formation, partly independently of Rap1b. This provides a new mechanistic explanation for the anti-thrombotic effect of PI3K inhibition and makes PI3Kalpha an interesting new target for anti-platelet therapy.

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.

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

Use of photoactivated disinfection and platelet-rich fibrin in regenerative Endodontics

Science.gov (United States)

Johns, Dexton Antony; Shivashankar, Vasundara Yayathi; Krishnamma, Shoba; Johns, Manu

2014-01-01

Aim: Photoactivated disinfection has been used as an adjunct to conventional endodontic treatment. Its use in regenerative endodontics is not reported in literature. The aim of this case report was to describe a new proposal for pulp revascularization with disinfection of pulp canal space using a unique combination of a photosensitizer solution and low-power laser light. Materials and Methods: A 9-year-old boy came with the chief complaint of discolored upper central incisors (#8, #9). A diagnosis of pulp necrosis was made on the basis of clinical and radiographic findings. The canal was irrigated with 5.25% sodium hypochlorite solution and dried with paper points. Photodynamic therapy was used to disinfect the root canal and platelet-rich fibrin was used to revitalize the pulp. Three millimeters of gray mineral trioxide aggregate was placed directly over the platelet-rich plasma clot. Three days later, the tooth was double-sealed with permanent filling materials. Results: Clinical examination revealed no sensitivity to percussion or palpation tests. Radiograph revealed continued thickening of the dentinal walls, root lengthening, regression of the peri-apical lesion and apical closure. Both the roots showed complete apical closure at the 10-month follow-up. However, the teeth were not responsive to electric pulp test. Conclusion: This report of pulp revascularization shows that disinfection with photodynamic therapy combined with platelet-rich fibrin leads to satisfactory root development in necrotic immature teeth. PMID:25298655

Clopidogrel discontinuation and platelet reactivity following coronary stenting

LENUS (Irish Health Repository)

2011-01-01

Summary. Aims: Antiplatelet therapy with aspirin and clopidogrel is recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient ‘rebound’ increase in platelet reactivity within 3 months of clopidogrel discontinuation. Methods and Results: In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, and 20 μm) and epinephrine (5 and 20 μm) was significantly increased at 1 month compared with 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation. Conclusions: This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations.

A Multi-centric, Double-blind, Placebo-controlled, Randomized, Prospective Study to Evaluate the Efficacy and Safety of Carica papaya Leaf Extract, as Empirical Therapy for Thrombocytopenia associated with Dengue Fever.

Science.gov (United States)

Kasture, Prabhu Nagnathappa; Nagabhushan, K H; Kumar, Arun

2016-06-01

Dengue is a rapidly expanding global health problem. Approximately 2.5 billion people live in dengue-risk regions with about 100 million new cases each year worldwide. The cumulative dengue diseases burden has attained an unprecedented proportion in recent times with sharp increase in the size of human population at risk. The management of dengue virus infection is essentially supportive and symptomatic and no specific treatment is available for increasing the fallen platelets, which have a significant role in causing the mortality of dengue patient.This study was conducted to evaluate the platelet increasing efficacy of Carica papaya leaf extract (CPLE) in patients with dengue fever (DF). The administration of Carica papaya leaf extract should significantly increase the platelet count in cases of thrombocytopenia associated with dengue, preventing the patient to go in DHF or DSS conditions. A Multi-centric, Double blind, Placebo controlled, Randomized, prospective study was conducted in 300 patients across 5 centres', to evaluate the Efficacy and Safety of Carica Papaya Leaf Extract, as empirical therapy for thrombocytopenia associated with dengue fever. The subjects were randomized into two groups, as control and intervention group. Both the groups were managed by the standard management guidelines for dengue except steroid administration. In addition to this, the intervention group received CPLE tablet three times daily for five days. All of them were followed daily with platelet monitoring. This study has been registered in the clinical trial registry-India (CTRI Registration number: CTRI/2015/05/005806). The results indicate that CPLE had significant increase(p< 0.01) in the platelet count over the therapy duration, in dengue fever patients, confirming CPLE accelerates the increase in platelet count compared to the control group. There were few adverse events related to GI disturbance like nausea and vomiting which were similar in both groups. Thus this study

Feasibility and Efficiency of Human Bone Marrow Stromal Cell Culture with Allogeneic Platelet Lysate-Supplementation for Cell Therapy against Stroke

Directory of Open Access Journals (Sweden)

Chengbo Tan

2016-01-01

Full Text Available Currently, there is increasing interest in human bone marrow stromal cells (hBMSCs as regeneration therapy against cerebral stroke. The aim of the present study was to evaluate the feasibility and validity of hBMSC cultures with allogeneic platelet lysates (PLs. Platelet concentrates (PC were harvested from healthy volunteers and made into single donor-derived PL (sPL. The PL mixtures (mPL were made from three different sPL. Some growth factors and platelet cell surface antigens were detected by enzyme-linked immunosorbent assay (ELISA. The hBMSCs cultured with 10% PL were analyzed for their proliferative potential, surface markers, and karyotypes. The cells were incubated with superparamagnetic iron oxide (SPIO agents and injected into a pig brain. MRI and histological analysis were performed. Consequently, nine lots of sPL and three mPL were prepared. ELISA analysis showed that PL contained adequate growth factors and a particle of platelet surface antigens. Cell proliferation capacity of PLs was equivalent to or higher than that of fetal calf serum (FCS. No contradiction in cell surface markers and no chromosomal aberrations were found. The MRI detected the distribution of SPIO-labeled hBMSCs in the pig brain. In summary, the hBMSCs cultured with allogeneic PL are suitable for cell therapy against stroke.

Effectiveness and Safety of Immunomodulators With Anti-Tumor Necrosis Factor Therapy in Crohn's Disease.

Science.gov (United States)

Osterman, Mark T; Haynes, Kevin; Delzell, Elizabeth; Zhang, Jie; Bewtra, Meenakshi; Brensinger, Colleen M; Chen, Lang; Xie, Fenglong; Curtis, Jeffrey R; Lewis, James D

2015-07-01

The benefit of continuing immunomodulators when "stepping up" to anti-tumor necrosis factor (anti-TNF) therapy for Crohn's disease (CD) is uncertain. This study assessed the effectiveness and safety of immunomodulators with anti-TNF therapy in CD. We conducted a retrospective cohort study of new users of anti-TNF therapy for CD in Medicare. Users of anti-TNF combination therapy with immunomodulators were matched to up to 3 users of anti-TNF monotherapy via propensity score and compared by using 3 metrics of effectiveness-surgery, hospitalization, and discontinuation of anti-TNF therapy or surgery-and 2 metrics of safety-serious infection and non-Candida opportunistic infection. Cox regression was used for all analyses. Among new users of infliximab, we matched 381 users of combination therapy to 912 users of monotherapy; among new users of adalimumab, we matched 196 users of combination therapy to 505 users of monotherapy. Combination therapy occurred predominantly as "step up" after thiopurine therapy. The rates of surgery (hazard ratio [HR], 1.20; 95% confidence interval, 0.73-1.96), hospitalization (HR, 0.82; 0.57-1.19), discontinuation of anti-TNF therapy or surgery (HR, 1.09; 0.88-1.34), and serious infection (HR, 0.93; 0.88-1.34) did not differ between users of anti-TNF combination therapy and monotherapy. However, the risks of opportunistic infection (HR, 2.64; 1.21-5.73) and herpes zoster (HR, 3.16; 1.25-7.97) were increased with combination therapy. We found that continuation of immunomodulators after "stepping up" to anti-TNF therapy did not improve outcomes but was associated with an increased risk of opportunistic infection. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

Anti-Platelet Factor 4/Heparin Antibody Formation Occurs Endogenously and at Unexpected High Frequency in Polycythemia Vera

Directory of Open Access Journals (Sweden)

Sara C. Meyer

2017-01-01

Full Text Available Background. Myeloproliferative neoplasms (MPN encounter thromboses due to multiple known risk factors. Heparin-induced thrombocytopenia (HIT is a thrombotic syndrome mediated by anti-platelet factor 4 (PF4/heparin antibodies with undetermined significance for thrombosis in MPN. We hypothesized that anti-PF4/heparin Ab might occur in MPN and promote thrombosis. Methods. Anti-PF4/heparin antibodies were analyzed in 127 MPN patients including 76 PV and 51 ET. Screening, validation testing, and isotype testing of anti-PF4/heparin Ab were correlated with disease characteristics. Results. Anti-PF4/heparin antibodies were detected in 21% of PV and 12% of ET versus 0.3–3% in heparin-exposed patients. Validation testing confirmed anti-PF4/heparin immunoglobulins in 15% of PV and 10% of ET. Isotype testing detected 9.2% IgG and 5.3% IgM in PV and exclusively IgM in ET. IgG-positive PV patients encountered thromboses in 57.1% suggesting anti-PF4/heparin IgG may contribute to higher risk for thrombosis in MPN. Overall, 45% of PV patients experienced thromboses with 11.8% positive for anti-PF4/heparin IgG versus 7.1% in PV without thrombosis. Conclusion. Anti-PF4/heparin antibodies occur endogenously and more frequently in MPN than upon heparin exposure. Thrombotic risk increases in anti-PF4/heparin IgG-positive PV reflecting potential implications and calling for larger, confirmatory cohorts. Anti-PF4/heparin IgG should be assessed upon thrombosis in PV to facilitate avoidance of heparin in anti-PF4/heparin IgG-positive PV.

Anti-atherosclerotic effects of tomatoes

Directory of Open Access Journals (Sweden)

Hidekatsu Yanai

2017-06-01

Full Text Available Tomatoes are rich in lycopene, which causes the red coloring of tomatoes. Several reports have suggested lycopene plays a role in the prevention of cardiovascular diseases. In this study, we systematically reviewed the interventional studies using tomatoes or tomato products to understandtheanti-atherosclerotic effects of the tomatoas a functional food. We found that a significantnumber of interventional studies reportedtheanti-atherosclerotic effects of tomatoes, includinganti-obesity effects, hypotensiveeffects, improvement of lipid/glucose metabolismand endothelial function, anti-oxidative and anti-inflammatory effect, and anti-platelet effect; however, the anti-platelet effect was disagreed uponby some studies. Furthermore, we discoveredcooking methods significantlyaffect anti-atherosclerotic effects of tomatoes.

Prevalence of risk factors for platelet transfusion refractoriness in multitransfused hemato-oncological patients at tertiary care center in North India

Directory of Open Access Journals (Sweden)

Vijay Kumawat

2015-01-01

Full Text Available Background: This study was designed to determine the prevalence and assess the risk factors responsible for platelet transfusion refractoriness in hemato-oncological patients. Materials and Methods: The study included 30 patients. Twelve were clinically diagnosed as aplastic anemia and the 18 were of acute myeloid leukemia. A prospective 3 months follow-up was planned to monitor the response of platelet transfusion therapy, based on their posttransfusion corrected count increment at 1 st and 24 th h. Based on the observations, patients were categorized into refractory and nonrefractory groups. Common nonimmunological causes such as fever, sepsis, bleeding, disseminated intravascular coagulation, chemotherapy, splenomegaly, ABO mismatch, and antithymocyte globulin therapy were monitored. Among the immunological causes, presence of antihuman leukocyte antigen (HLA class I antibodies and platelet glycoprotein antibodies in patient′s serum were monitored. Results: During the study period, 17 (56.66% patients did not show desired platelet count increment. Transfusion requirements of refractory group for both red cell and platelet product were significantly higher (P < 0.05 in comparison to nonrefractory group. Among immunological causes, anti HLA class I antibodies (P < 0.013, antihuman platelet antigen-5b antibodies (P < 0.033 were significantly associated with refractoriness. Among nonimmunological causes, bleeding (P < 0.019, odd ratio 8.7, fever (P < 0.08, odd ratio 5.2, and infection (P < 0.07, odd ratio 5.4 were found to associated with refractoriness. Conclusion: Platelet refractoriness should be suspected in multitransfused patients not showing expected increment in platelet counts and thoroughly investigated to frame further guidelines in order to ensure proper management of these kind of patients.

Prospects for Foamy Viral Vector Anti-HIV Gene Therapy

Directory of Open Access Journals (Sweden)

Arun K. Nalla

2016-03-01

Full Text Available Stem cell gene therapy approaches for Human Immunodeficiency Virus (HIV infection have been explored in clinical trials and several anti-HIV genes delivered by retroviral vectors were shown to block HIV replication. However, gammaretroviral and lentiviral based retroviral vectors have limitations for delivery of anti-HIV genes into hematopoietic stem cells (HSC. Foamy virus vectors have several advantages including efficient delivery of transgenes into HSC in large animal models, and a potentially safer integration profile. This review focuses on novel anti-HIV transgenes and the potential of foamy virus vectors for HSC gene therapy of HIV.

Effect of Atorvastatin intensive therapy on the serum inflammatory factors, platelet activity and fibrinolytic activity in patients with acute coronary syndrome

Directory of Open Access Journals (Sweden)

Xiao-Li Zhu

2016-05-01

Full Text Available Objective: To observe the effect of Atorvastatin intensive therapy on the serum inflammatory factors, platelet activity and fibrinolytic activity in patients with acute coronary syndrome (ACS. Methods: A total of 92 patients with ACS were randomly divided into observation group (47 cases and control group (45 cases. The control group was given Atorvastatin (10mg/d based on the conventional therapy, while the observation group was given Atorvastatin at an intensive dose (40 mg/d based on the conventional therapy. Half a month later, the changes of IL-6, IL-8, hs-CRP, TNF-α, TXB2, GMP-140, PAI-1 and t-PA were observed and compared between the two groups. Results: After treatment, the inflammatory factors (IL-6, IL-8, hs-CRP and TNF-α and the indicators of platelet activity (TXB2, GMP-140 and PAI-1 were obviously decreased, while the indicator of fibrinolytic activity (t-PA was apparently increased in the two groups. Besides, the amplitudes of change referring to these indicators in the observation group were bigger than those in the control group after treatment, and the differences were statistically significant. Conclusion: The intensive therapy with the administration of Atorvastatin at a dose of 40 mg/d was better than the conventional therapy (Atorvastatin: 10 mg/d in aspects of reducing inflammatory factors, inhibiting platelet activity and correcting the high coagulation state of fibrinolytic system.

Laboratory assessment of anti-thrombotic therapy in heart failure, atrial fibrillation and coronary artery disease: insights using thrombelastography and a micro-titre plate assay of thrombogenesis and fibrinolysis.

Science.gov (United States)

Lau, Y C; Xiong, Q; Ranjit, P; Lip, G Y H; Blann, A D

2016-08-01

As heart failure, coronary artery disease and atrial fibrillation all bring a risk of thrombosis, anti-thrombotic therapy is recommended. Despite such treatment, major cardiovascular events such as myocardial infarction and stroke still occur, implying inadequate suppression of thrombus formation. Accordingly, identification of patients whose haemostasis remains unimpaired by treatment is valuable. We compared indices for assessing thrombogenesis and fibrinolysis by two different techniques in patients on different anti-thrombotic agents, i.e. aspirin or warfarin. We determined fibrin clot formation and fibrinolysis by a microplate assay and thromboelastography, and platelet marker soluble P selectin in 181 patients with acute or chronic heart failure, coronary artery disease who were taking either aspirin or warfarin. Five thromboelastograph indices and four microplate assay indices were different on aspirin versus warfarin (p indices rate of clot formation and rate of clot dissolution were independently related to aspirin or warfarin use (p ≤ 0.001). Five microplate assay indices, but no thrombelastograph index, were different (p indices were different (p ≤ 0.002) in warfarin users. The microplate assay indices of lag time and rate of clot formation were abnormal in chronic heart failure patients on aspirin, suggesting increased risk of thrombosis despite anti-platelet use. Soluble P selectin was lower in patients on aspirin (p = 0.0175) but failed to correlate with any other index of haemostasis. The microplate assay shows promise as a tool for dissecting thrombogenesis and fibrinolysis in cardiovascular disease, and the impact of antithrombotic therapy. Prospective studies are required to determine a role in predicting thrombotic risk.

On the short-distance double penguin contribution to the K0 - anti K0 mixing

International Nuclear Information System (INIS)

Eeg, J.O.

1985-04-01

The short-distance contribution of the double penguin box diagram to the K 0 - anti K 0 mixing is investigated. Compared with previous work of other authors, the present paper takes into account the momentum dependence of the box loop, both the non-local part of the penguin and the previously considered local part and the crossed diagrams, which make a class of double penguin diagrams complete. With such new ingredients, is is concluded that the short-distance part of the double penguin is physically irrelevant. After eliminating this particular mechanism for the K 0 - anti K 0 mixing, other potentially relevant mechanisms are pointed out

On the short-distance double penguin contribution to the K0-anti K0 mixing

International Nuclear Information System (INIS)

Eeg, J.O.

1985-01-01

We investigate the short-distance contribution of the double penguin box diagram to the K 0 -anti K 0 mixing. Compared with previous work of other authors, the present paper takes into account (i) the momentum dependence of the box loop, (ii) both the non-local part of the penguin and the previously considered local part and (iii) the crossed diagrams, which make a class of double penguin diagrams complete. With such new ingredients, we arrive at the conclusion that the SD part of the double penguin is physically irrelevant. After eliminating this particular mechanism for the K 0 -anti K 0 mixing, we point out other potentially relevant mechanisms. (orig.)

Myelosuppression of Thrombocytes and Monocytes Is Associated with a Lack of Synergy between Chemotherapy and Anti-VEGF Treatment

Directory of Open Access Journals (Sweden)

Patrick Starlinger

2011-05-01

Full Text Available Purpose: Chemotherapeutic agents that have shown improved patient outcome when combined with anti-vascular endothelial growth factor (VEGF therapy were recently identified to induce the mobilization of proangiogenic Tie-2-expressing monocytes (TEMs and endothelial progenitor cells (EPCs by platelet release of stromal cell-derived factor 1α (SDF-1α. VEGF blockade was found to counteract cell mobilization. We aimed to determine why agents like gemcitabine do not elicit TEM and EPC recruitment and may therefore lack synergy with anti-VEGF therapy. Experimental Design: Locally advanced pancreatic cancer patients (n = 20 were monitored during 16 weeks of neoadjuvant therapy. Treatment was based on gemcitabine with or without the addition of bevacizumab. Blood levels of proangiogenic cell populations and angiogenesis factors were determined in 2-week intervals. Results: The lack of EPC mobilization during gemcitabine therapy was associated with severe thrombocytopenia and reduced SDF-1α blood concentrations. Furthermore, myelosuppression by gemcitabine correlated significantly with loss of TEMs. With respect to angiogenic factors stored and released by platelets, plasma levels of the angiogenesis inhibitor thrombospondin 1 (TSP-1 were selectively decreased and correlated significantly with thrombocytopenia in response to gemcitabine therapy. Conclusions: A thorough literature screen identified thrombocytopenia as a common feature of chemotherapeutic agents that lack synergy with anti-VEGF treatment. Our results on gemcitabine therapy indicate that myelosuppression (in particular, with respect to thrombocytes and monocytes interferes with the mobilization of proangiogenic cell types targeted by bevacizumab and may further counteract antiangiogenic therapy by substantially reducing the angiogenesis inhibitor TSP-1.

Stapled peptides as a new technology to investigate protein-protein interactions in human platelets.

Science.gov (United States)

Iegre, Jessica; Ahmed, Niaz S; Gaynord, Josephine S; Wu, Yuteng; Herlihy, Kara M; Tan, Yaw Sing; Lopes-Pires, Maria E; Jha, Rupam; Lau, Yu Heng; Sore, Hannah F; Verma, Chandra; O' Donovan, Daniel H; Pugh, Nicholas; Spring, David R

2018-05-28

Platelets are blood cells with numerous crucial pathophysiological roles in hemostasis, cardiovascular thrombotic events and cancer metastasis. Platelet activation requires the engagement of intracellular signalling pathways that involve protein-protein interactions (PPIs). A better understanding of these pathways is therefore crucial for the development of selective anti-platelet drugs. New strategies for studying PPIs in human platelets are required to overcome limitations associated with conventional platelet research methods. For example, small molecule inhibitors can lack selectivity and are often difficult to design and synthesise. Additionally, development of transgenic animal models is costly and time-consuming and conventional recombinant techniques are ineffective due to the lack of a nucleus in platelets. Herein, we describe the generation of a library of novel, functionalised stapled peptides and their first application in the investigation of platelet PPIs. Moreover, the use of platelet-permeable stapled Bim BH3 peptides confirms the part of Bim in phosphatidyl-serine (PS) exposure and reveals a role for the Bim protein in platelet activatory processes. Our work demonstrates that functionalised stapled peptides are a complementary alternative to conventional platelet research methods, and could make a significant contribution to the understanding of platelet signalling pathways and hence to the development of anti-platelet drugs.

Targeting Metabolic Symbiosis to Overcome Resistance to Anti-angiogenic Therapy

Directory of Open Access Journals (Sweden)

Laura Pisarsky

2016-05-01

Full Text Available Despite the approval of several anti-angiogenic therapies, clinical results remain unsatisfactory, and transient benefits are followed by rapid tumor recurrence. Here, we demonstrate potent anti-angiogenic efficacy of the multi-kinase inhibitors nintedanib and sunitinib in a mouse model of breast cancer. However, after an initial regression, tumors resume growth in the absence of active tumor angiogenesis. Gene expression profiling of tumor cells reveals metabolic reprogramming toward anaerobic glycolysis. Indeed, combinatorial treatment with a glycolysis inhibitor (3PO efficiently inhibits tumor growth. Moreover, tumors establish metabolic symbiosis, illustrated by the differential expression of MCT1 and MCT4, monocarboxylate transporters active in lactate exchange in glycolytic tumors. Accordingly, genetic ablation of MCT4 expression overcomes adaptive resistance against anti-angiogenic therapy. Hence, targeting metabolic symbiosis may be an attractive avenue to avoid resistance development to anti-angiogenic therapy in patients.

Effectiveness of the double interventional therapy for portal hypertension in liver cirrhosis

International Nuclear Information System (INIS)

Du Wei; Chen Lei; Yuan Guibin; Ouyang Tianzhao; Duan Wenshuai

2011-01-01

Objective: To assess the value of double interventional therapy for upper gastrointestinal bleeding and hypersplenism caused by portal hypertension. Methods: 32 patients with upper gastrointestinal bleeding and hypersplenism due to portal hypertension in liver cirrhosis were enrolled in the study. Ultrasound-guided percutaneous punctures of both the intrahepatic portal varices and femoral artery were performed on all patients. The catheters were inserted into the vena coronaria ventriculi and branches of splenic artery selectively and then embolized using mixture of alcohol, gelatin sponge and metal coin. Results: The overall success rate of percutaneous transhepatic variceal puncture was 100% with single puncture in 66% and the success rate of embolization was 100%. Partial splenic artery embolization was performed involving 40%-70% of the vascular lumen. White blood cell and platelet counts increased significantly 24 hours and 1 week after embolization. The cumulative incidences of rebleeding were 0, 3.1%, 12.5%, 25% and 31.3% in the 1 month, 6 month, 1 year, 2 year and follow-up respectively. Causes of recurrent bleeding included varices rupture (26.1%), portal hypertensive gastropathy (56.5%), and peptic ulcer (17.4%). All of the patients had various degrees of fever, abdominal pain, nausea and vomiting after embolization. These symptoms subsided without further complications. Conclusion: The double interventional approach is useful in the treatment of upper digestive tract hemorrhage and hypersplenism from portal hypertension. The method is relatively simple with low invasiveness especially for patients with poor liver function who cannot tolerate surgical shunt and de-vascularization operation. (authors)

Effects of drugs on platelet function.

Science.gov (United States)

Morse, E E

1977-01-01

Numerous drugs and chemicals affect the function of human blood platelets. The mechanism of action of some medications is partly understood. Aspirin is the most frequently involved drug. It appears to interfere with the platelet release reaction by acetylation of a platelet membrane protein which may be involved in the synthesis of prostaglandins. Other anti-inflammatory drugs, including indomethacin, phenylbutazone, ibuprophen (Motrin) and clonixin, also interfere with the release reaction but have a shorter acting course than aspirin. Some drugs stimulate adenylcyclase (gliclazide) or block phosphodiesterase, (dipyridamole, caffeine) both of which actions lead to an increase in adenosine cyclic 3':5' monophosphate (cAMP) and decrease aggregation by adenosine diphosphate (ADP). These interactions should be known to clinical scientists since patients using these medicaments may manifest abnormal platelet function tests in the laboratory and mild hemorrhagic syndromes in the clinic.

A single-cell analysis platform for electrochemiluminescent detection of platelets adhesion to endothelial cells based on Au@DL-ZnCQDs nanoprobes.

Science.gov (United States)

Long, Dongping; Shang, Yunfei; Qiu, Youyi; Zhou, Bin; Yang, Peihui

2018-04-15

A novel single-cell analysis platform (SCA) was developed for the investigation of platelets adhesion to single human umbilical vein endothelial cell (HUVEC) via using the adhesion molecule (E-selectin) on the damaged HUVEC as the marker site, and integrating electrochemiluminescence (ECL) with the ultrasensitive Au@DL-ZnCQDs nanoprobes. The Au@DL-ZnCQDs nanocomposite, a kind of double layer zinc-coadsorbed carbon quantum dot (ZnCQDs) core-shell nanoprobe, was firstly constructed by using gold nanoparticles (AuNPs) as the core to load with ZnCQDs and then the citrate-modified silver nanoparticles (AgNPs) as the bridge to link AuNPs-ZnCQDs with ZnCQDs to form the core-shell with double layer ZnCQDs (DL-ZnCQDs) nanoprobe, revealed a 10-fold signal amplification. The H 2 O 2 -induced oxidative damage HUVECs were utilized as the cellular model on which anti-E-selectin functionalized nanoprobes specially recognized E-selectin, the SCA showed that the ECL signals decreased with platelets adhesion to single HUVEC. The proposed SCA could effectively and dynamically monitor the adhesion between single HUVEC and platelets in the absence and presence of collagen activation, moreover, be able to quantitatively detect the number of platelets adhesion to single HUVEC, and show a good analytical performance with linear range from 1 to 15 platelets. In contrast, the HUVEC was down-regulated the expression of adhesion molecules by treating with quercetin inhibitor, and the SCA also exhibited the feasibility for analysis of platelets adhesion to single HUVEC. Therefore, the single-cell analysis platform provided a novel and promising protocol for analysis of the single intercellular adhesion, and it will be beneficial to elucidate the pathogenesis of cardiovascular diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

The clinical use of platelet scintigraphy with 111-In-oxine

International Nuclear Information System (INIS)

Kessler, C.; Reuther, R.; Berentelg, J.; Kimmig, B.

1983-01-01

Platelet scintigraphy was performed on 62 patients with cerebral ischaemia. Pathological scintigraphic images were obtained in 29 of the 62 patients. In 79.3% of these 29 patients the scan was abnormal in the vessel clinically affected. Platelet scintigraphy was abnormal in 21 of 34 patients with normal angiogram or only slight atherosclerosis. In patients undergoing antiplatelet therapy, platelet scintigraphy was less often positive than in untreated patients. It is suggested that platelet scintigraphy could be an appropriate technique for detecting small mural thrombi of the carotid artery, which are the source of arterio-arterial emboli, and for controlling the efficiency of antiplatelet therapy. (orig.) [de

Myelosuppression of Thrombocytes and Monocytes Is Associated with a Lack of Synergy between Chemotherapy and Anti-VEGF Treatment1

Science.gov (United States)

Starlinger, Patrick; Brugger, Philipp; Schauer, Dominic; Sommerfeldt, Silvia; Tamandl, Dietmar; Kuehrer, Irene; Schoppmann, Sebastian F; Gnant, Michael; Brostjan, Christine

2011-01-01

Purpose Chemotherapeutic agents that have shown improved patient outcome when combined with anti-vascular endothelial growth factor (VEGF) therapy were recently identified to induce the mobilization of proangiogenic Tie-2-expressing monocytes (TEMs) and endothelial progenitor cells (EPCs) by platelet release of stromal cell-derived factor 1α (SDF-1α). VEGF blockade was found to counteract cell mobilization. We aimed to determine why agents like gemcitabine do not elicit TEM and EPC recruitment and may therefore lack synergy with anti-VEGF therapy. Experimental Design Locally advanced pancreatic cancer patients (n = 20) were monitored during 16 weeks of neoadjuvant therapy. Treatment was based on gemcitabine with or without the addition of bevacizumab. Blood levels of proangiogenic cell populations and angiogenesis factors were determined in 2-week intervals. Results The lack of EPC mobilization during gemcitabine therapy was associated with severe thrombocytopenia and reduced SDF-1α blood concentrations. Furthermore, myelosuppression by gemcitabine correlated significantly with loss of TEMs. With respect to angiogenic factors stored and released by platelets, plasma levels of the angiogenesis inhibitor thrombospondin 1 (TSP-1) were selectively decreased and correlated significantly with thrombocytopenia in response to gemcitabine therapy. Conclusions A thorough literature screen identified thrombocytopenia as a common feature of chemotherapeutic agents that lack synergy with anti-VEGF treatment. Our results on gemcitabine therapy indicate that myelosuppression (in particular, with respect to thrombocytes and monocytes) interferes with the mobilization of proangiogenic cell types targeted by bevacizumab and may further counteract antiangiogenic therapy by substantially reducing the angiogenesis inhibitor TSP-1. PMID:21532882

Extracorporeal Shockwave Therapy Increases Growth Factor Release from Equine Platelet-Rich Plasma In Vitro

Directory of Open Access Journals (Sweden)

Kathryn A. Seabaugh

2017-12-01

Full Text Available IntroductionExtracorporeal shockwave therapy (ESWT and platelet-rich plasma (PRP are common treatments for soft tissue injuries in horses. Shockwave triggers cell specific responses to promote healing. Growth factors released from PRP also promote healing. It has been hypothesized that greater growth factor release would amplify the healing process. The combination of ESWT and PRP could promote healing in injured tendons and ligaments in the horse. The objective of this study was to determine if application of shockwaves to PRP samples increases the concentration of transforming growth factor-β1 (TGF-β1 and platelet-derived growth factor ββ (PDGF-ββ released from the platelets in vitro.Materials and methodsPRP was produced from blood drawn from six horses. The PRP from each horse was exposed to the following treatments: (1 positive control (freeze-thaw cycle, (2 untreated negative control, or shockwaves with either (3 a “standard probe” (ESWT-S with a 2 cm focal width and medium energy density or (4 a “power probe” (ESWT-P with a 1 cm focal width and high energy density. After each treatment, the samples were centrifuged, and the supernatant was harvested. The supernatant was then used for growth factor quantification via commercially available ELISA kits for TGF-β1 and PDGF-ββ.ResultsConcentrations of TGF-β1 and PDGF-ββ in PRP that underwent a freeze-thaw cycle were significantly increased compared with all other treatments. Both ESWT-S and ESWT-P resulted in significantly increased TGF-β1 concentrations, 46 and 33%, respectively, when compared with the negative control. Both ESWT-S and ESWT-P resulted in significantly increased PDGF-ββ concentrations, 219 and 190%, respectively, when compared with the negative control.DiscussionThese data indicate that the application of ESWT to PRP increases the expression of growth factors in vitro. This suggests that the combination therapy of local PRP injection followed by ESWT

Platelet-rich plasma, an adjuvant biological therapy to assist peripheral nerve repair

Directory of Open Access Journals (Sweden)

Mikel Sánchez

2017-01-01

Full Text Available Therapies such as direct tension-free microsurgical repair or transplantation of a nerve autograft, are nowadays used to treat traumatic peripheral nerve injuries (PNI, focused on the enhancement of the intrinsic regenerative potential of injured axons. However, these therapies fail to recreate the suitable cellular and molecular microenvironment of peripheral nerve repair and in some cases, the functional recovery of nerve injuries is incomplete. Thus, new biomedical engineering strategies based on tissue engineering approaches through molecular intervention and scaffolding offer promising outcomes on the field. In this sense, evidence is accumulating in both, preclinical and clinical settings, indicating that platelet-rich plasma products, and fibrin scaffold obtained from this technology, hold an important therapeutic potential as a neuroprotective, neurogenic and neuroinflammatory therapeutic modulator system, as well as enhancing the sensory and motor functional nerve muscle unit recovery.

Current trends in platelet transfusions practice: The role of ABO-RhD and human leukocyte antigen incompatibility

Directory of Open Access Journals (Sweden)

Serena Valsami

2015-01-01

Full Text Available Platelet transfusions have contributed to the revolutionary modern treatment of hypoproliferative thrombocytopenia. Despite the long-term application of platelet transfusion in therapeutics, all aspects of their optimal use (i.e., in cases of ABO and/or Rh (D incompatibility have not been definitively determined yet. We reviewed the available data on transfusion practices and outcome in ABO and RhD incompatibility and platelet refractoriness due to anti-human leukocyte antigen (HLA antibodies. Transfusion of platelets with major ABO-incompatibility is related to reduced posttransfusion platelet (PLT count increments, compared to ABO-identical and minor, but still are equally effective in preventing clinical bleeding. ABO-minor incompatible transfusions pose the risk of an acute hemolytic reaction of the recipient that is not always related to high anti-A, B donor titers. ABO-identical PLT transfusion seems to be the most effective and safest therapeutic strategy. Exclusive ABO-identical platelet transfusion policy could be feasible, but alternative approaches could facilitate platelet inventory management. Transfusion of platelets from RhD positive donors to RhD negative patients is considered to be effective and safe though is associated with low rate of anti-D alloimmunization due to contaminating red blood cells. The prevention of D alloimmunization is recommended only for women of childbearing age. HLA alloimmunization is a major cause of platelet refractoriness. Managing patients with refractoriness with cross-matched or HLA-matched platelets is the current practice although data are still lacking for the efficacy of this practice in terms of clinical outcome. Leukoreduction contributes to the reduction of both HLA and anti-D alloimmunization.

Production of human platelet lysate by use of ultrasound for ex vivo expansion of human bone marrow-derived mesenchymal stromal cells.

Science.gov (United States)

Bernardi, Martina; Albiero, Elena; Alghisi, Alberta; Chieregato, Katia; Lievore, Chiara; Madeo, Domenico; Rodeghiero, Francesco; Astori, Giuseppe

2013-08-01

A medium supplemented with fetal bovine serum (FBS) is of common use for the expansion of human mesenchymal stromal cells (MSCs). However, its use is discouraged by regulatory authorities because of the risk of zoonoses and immune reactions. Human platelet lysate (PL) obtained by freezing/thawing disruption of platelets has been proposed as a possible substitute of FBS. The process is time-consuming and not well standardized. A new method for obtaining PL that is based on the use of ultrasound is proposed. Platelet sonication was performed by submerging platelet-containing plastic bags in an ultrasonic bath. To evaluate platelet lysis we measured platelet-derived growth factor-AB release. PL efficiency was tested by expanding bone marrow (BM)-MSCs, measuring population doubling time, differentiation capacity and immunogenic properties. Safety was evaluated by karyotyping expanded cells. After 30 minutes of sonication, 74% of platelet derived growth factor-AB was released. PL enhanced BM-MSC proliferation rate compared with FBS. The mean cumulative population doubling (cPD) of cells growth in PL at 10%, 7.5% and 5% was better compared with cPD obtained with 10% FBS. PD time (hours) of MSCs with PL obtained by sonication was shorter than for cPD with PL obtained by freezing/thawing (18.9 versus 17.4, P < 0.01). BM mononucleated cells expressed MSC markers and were able to differentiate into adipogenic, osteogenic and chondrogenic lineages. When BM-MSCs and T cells were co-cultured in close contact, immunosuppressive activity of BM-MSCs was maintained. Cell karyotype showed no genetic alterations. The proposed method for the production of PL by sonication could be a safe, efficient and fast substitute of FBS, without the potential risks of FBS. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

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.

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.

Effects of altered platelet number on pulmonary hypertension and platelet sequestration in monocrotaline pyrrole-treated rats

International Nuclear Information System (INIS)

White, S.M.; Wagner, J.G.; Roth, R.A.

1989-01-01

To study the role of platelets in monocrotaline pyrrole (MCTP)-induced pulmonary hypertension, pulmonary sequestration of 111In-labeled platelets in rats treated with MCTP and anti-rat platelet serum (PAS) was examined. Lung injury from a single, intravenous injection of MCTP (3.5 mg/kg) at Day 8 was evident as elevated lung weight and lavage fluid protein and lactate dehydrogenase activity. Additionally, right ventricular hypertrophy and elevated pulmonary arterial pressures (PAP) occurred. Treatment with PAS on Days 6-8 did not affect the lung injury but resulted in an attenuation of the pulmonary hypertensive response. Pulmonary platelet sequestration was also decreased in PAS-treated rats, yet the sequestration in the lungs of MCTP-treated rats that received PAS was significantly higher than that in the lungs of N,N-dimethylformamide (DMF) controls. MCTP-treated rats receiving control serum (CS) tended to sequester more 111In-labeled platelets than respective DMF controls, but this was not statistically significant. Blood platelet half-life was unaltered in rats receiving CS. When rats were treated similarly with MCTP and PAS and were killed at 18 days, the attenuation of the pulmonary hypertensive response previously described was not observed, and lung injury was more extensive than when CS was given. Apparently, platelet depletion delayed the development of the pulmonary hypertensive response. Supranormal platelet numbers produced by splenectomy did not affect MCTP-induced lung injury or the elevation in PAP. These results support the hypothesis that the development of MCTP-induced pulmonary hypertension is mediated in part by platelets

Deposition of Fibrinogen on the Surface of in vitro Thrombi Prevents Platelet Adhesion

OpenAIRE

Owaynat, Hadil; Yermolenko, Ivan S.; Turaga, Ramya; Lishko, Valeryi K.; Sheller, Michael R.; Ugarova, Tatiana P.

2015-01-01

The initial accumulation of platelets after vessel injury is followed by thrombin-mediated generation of fibrin which is deposited around the plug. While numerous in vitro studies have shown that fibrin is highly adhesive for platelets, the surface of experimental thrombi in vivo contains very few platelets suggesting the existence of natural anti-adhesive mechanisms protecting stabilized thrombi from platelet accumulation and continuous thrombus propagation. We previously showed that adsorpt...

Antibiotic and Anti-Inflammatory Therapies for Cystic Fibrosis

Science.gov (United States)

Chmiel, James F.; Konstan, Michael W.; Elborn, J. Stuart

2013-01-01

Cystic fibrosis (CF) lung disease is characterized by chronic bacterial infection and an unremitting inflammatory response, which are responsible for most of CF morbidity and mortality. The median expected survival has increased from 38 yr now. This dramatic improvement, although not great enough, is due to the development of therapies directed at secondary disease pathologies, especially antibiotics. The importance of developing treatments directed against the vigorous inflammatory response was realized in the 1990s. New therapies directed toward the basic defect are now visible on the horizon. However, the impact of these drugs on downstream pathological consequences is unknown. It is likely that antibiotics and anti-inflammatory drugs will remain an important part of the maintenance regimen for CF in the foreseeable future. Current and future antibiotic and anti-inflammatory therapies for CF are reviewed. PMID:23880054

Grafting of phosphorylcholine functional groups on polycarbonate urethane surface for resisting platelet adhesion

Energy Technology Data Exchange (ETDEWEB)

Gao, Bin [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@hotmail.com [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Weijin Road 92, 300072 Tianjin (China); Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Lu, Jian; Zhang, Li; Zhao, Miao; Shi, Changcan; Khan, Musammir [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Guo, Jintang [School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Weijin Road 92, 300072 Tianjin (China)

2013-07-01

In order to improve the resistance of platelet adhesion on material surface, 2-methacryloyloxyethyl phosphorylcholine (MPC) was grafted onto polycarbonate urethane (PCU) surface via Michael reaction to create biomimetic structure. After introducing primary amine groups via coupling tris(2-aminoethyl)amine (TAEA) onto the polymer surface, the double bond of MPC reacted with the amino group to obtain MPC modified PCU. The modified surface was characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results verified that MPC was grafted onto PCU surface by Michael reaction method. The MPC grafted PCU surface had a low water contact angle and a high water uptake. This means that the hydrophilic PC functional groups improved the surface hydrophilicity significantly. In addition, surface morphology of MPC grafted PCU film was imaged by atomic force microscope (AFM). The results showed that the grafted surface was rougher than the blank PCU surface. In addition, platelet adhesion study was evaluated by scanning electron microscopy (SEM) observation. The PCU films after treated with platelet-rich plasma demonstrated that much fewer platelets adhered to the MPC-grafted PCU surface than to the blank PCU surface. The antithrombogenicity of the MPC-grafted PCU surface was determined by the activated partial thromboplastin time (APTT). The result suggested that the MPC modified PCU may have potential application as biomaterials in blood-contacting and some subcutaneously implanted devices. - Highlights: • MPC was successfully grafted onto polycarbonate urethane surface via Michael reaction. • High concentration of PC functional groups on the surface via TAEA molecule • Biomimetic surface modification • The modified surface showed high hydrophilicity and anti-platelet adhesion.

Therapeutic genes for anti-HIV/AIDS gene therapy.

Science.gov (United States)

Bovolenta, Chiara; Porcellini, Simona; Alberici, Luca

2013-01-01

The multiple therapeutic approaches developed so far to cope HIV-1 infection, such as anti-retroviral drugs, germicides and several attempts of therapeutic vaccination have provided significant amelioration in terms of life-quality and survival rate of AIDS patients. Nevertheless, no approach has demonstrated efficacy in eradicating this lethal, if untreated, infection. The curative power of gene therapy has been proven for the treatment of monogenic immunodeficiensies, where permanent gene modification of host cells is sufficient to correct the defect for life-time. No doubt, a similar concept is not applicable for gene therapy of infectious immunodeficiensies as AIDS, where there is not a single gene to be corrected; rather engineered cells must gain immunotherapeutic or antiviral features to grant either short- or long-term efficacy mostly by acquisition of antiviral genes or payloads. Anti-HIV/AIDS gene therapy is one of the most promising strategy, although challenging, to eradicate HIV-1 infection. In fact, genetic modification of hematopoietic stem cells with one or multiple therapeutic genes is expected to originate blood cell progenies resistant to viral infection and thereby able to prevail on infected unprotected cells. Ultimately, protected cells will re-establish a functional immune system able to control HIV-1 replication. More than hundred gene therapy clinical trials against AIDS employing different viral vectors and transgenes have been approved or are currently ongoing worldwide. This review will overview anti-HIV-1 infection gene therapy field evaluating strength and weakness of the transgenes and payloads used in the past and of those potentially exploitable in the future.

A novel β-lactam derivative, albactam from the flowers of Albizia lebbeck with platelets anti-aggregatory activity in vitro.

Science.gov (United States)

El-Gamal, Ali Ali; Abd-El-Halim, Mohamed Farag; Kalil, Ashraf Taha; Basudan, Omer Ahmed; Al-Rehaily, Adnan Jathlan; Ahmad, Mohamed Shamim; El-Tahir, Kamal Hussin; Al-Massarani, Shaza Mohamed; Abdel-Mageed, Wael Moustafa

2015-03-01

A novel β-lactam derivative, albactam, was isolated from the alcoholic extract of the flowers of Albizia lebbeck. It showed a significant anti-aggregatory activity against adenosine diphosphate and arachidonic acid induced guinea-pigs' platelets aggregation in vitro. Six more known compounds were also isolated and fully characterized by measuring 1D and 2D NMR, two of them are the triterpenes β-amyrin and 11α, 12α-oxidotaraxerol, two ceramide derivatives and two flavonoids, kampferol 3-O-rutinoside and rutin.

Using the Platelet Function Analyzer-100 for monitoring aspirin therapy

DEFF Research Database (Denmark)

Poulsen, Tina Svenstrup; Mickley, Hans; Korsholm, Lars

2007-01-01

INTRODUCTION: The aim of the study was to evaluate the test characteristics of the Platelet Function Analyzer-100 (PFA-100) in patients treated with aspirin. METHODS AND RESULTS: The study consisted of two sub-studies. In study 1, 10 patients with ischemic heart disease (IHD) and 10 controls had...... platelet function assessed by optical platelet aggregation and the PFA-100 method in two 5-week periods. Patients with IHD were treated with aspirin 150 mg/day (first 5-week period), and 300 mg/day (second 5-week period), whereas the controls only received aspirin (150 mg/day) during the second 5-week...... period. From the results of study 1, we found that a cut-off value for the PFA-100 collagen/epinephrine cartridge PFA-100 method and optical platelet aggregation was found. Within...

Y2O3:Yb,Er@mSiO2-CuxS double-shelled hollow spheres for enhanced chemo-/photothermal anti-cancer therapy and dual-modal imaging

Science.gov (United States)

Yang, Dan; Yang, Guixin; Wang, Xingmei; Lv, Ruichan; Gai, Shili; He, Fei; Gulzar, Arif; Yang, Piaoping

2015-07-01

Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large specific surface area and uniform shape is composed of an inner shell of luminescent Y2O3:Yb,Er and an outer mesoporous silica shell. Ultra small CuxS nanoparticles (about 2.5 nm) served as photothermal agents, and a chemotherapeutic agent (doxorubicin, DOX) was then attached onto the surface of mesoporous silica, forming a DOX-DSHS-CuxS composite. The composite exhibits high anti-cancer efficacy due to the synergistic photothermal therapy (PTT) induced by the attached CuxS nanoparticles and the enhanced chemotherapy promoted by the heat from the CuxS-based PTT when irradiated by 980 nm near-infrared (NIR) light. Moreover, the composite shows excellent in vitro and in vivo X-ray computed tomography (CT) and up-conversion fluorescence (UCL) imaging properties owing to the doped rare earth ions, thus making it possible to achieve the target of imaging-guided synergistic therapy.Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large

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.

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)

Simultaneous splenectomy during liver transplantation augments anti-viral therapy in patients infected with hepatitis C virus.

Science.gov (United States)

Chu, Heng-Cheng; Hsieh, Chung-Bao; Hsu, Kuo-Feng; Fan, Hsiu-Lung; Hsieh, Tsai-Yuan; Chen, Teng-Wei

2015-01-01

Simultaneous splenectomy in liver transplantation (LT) is selectively indicated because of splenoportal venous thromboses and increased sepsis. Therefore, its impact should be further investigated. Of the 160 liver transplant patients, only 40 underwent simultaneous splenectomy. Clinicopathologic characteristics and outcomes were compared between the splenectomy and non-splenectomy group using retrospective analysis. Although the groups were similar and had no significant difference in the intra- and postoperative data, non-splenectomy group had more male patients. However, splenectomy group showed significantly higher platelet and leukocyte counts at 1 month and 6 months after the transplantation and higher hepatitis C virus anti-viral therapy completion. Furthermore, 3 patients developed portal or splenic vein thrombosis during the postoperative follow-up, but the overall survival rate did not significantly differ between these groups. Simultaneous splenectomy in LT can be safely performed, particularly in patients with hepatitis C virus cirrhosis, small-for-size grafts, hypersplenism, and ABO blood group incompatible (ABO - incompatible) LT. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Effects of an injectable platelet-rich fibrin on osteoblast behavior and bone tissue formation in comparison to platelet-rich plasma.

Science.gov (United States)

Wang, Xuzhu; Zhang, Yufeng; Choukroun, Joseph; Ghanaati, Shahram; Miron, Richard J

2018-01-01

Platelet-rich plasma (PRP) has been utilized for many years as a regenerative agent capable of inducing vascularization of various tissues using blood-derived growth factors. Despite this, drawbacks mostly related to the additional use of anti-coagulants found in PRP have been shown to inhibit the wound healing process. For these reasons, a novel platelet concentrate has recently been developed with no additives by utilizing lower centrifugation speeds. The purpose of this study was therefore to investigate osteoblast behavior of this novel therapy (injectable-platelet-rich fibrin; i-PRF, 100% natural with no additives) when compared to traditional PRP. Human primary osteoblasts were cultured with either i-PRF or PRP and compared to control tissue culture plastic. A live/dead assay, migration assay as well as a cell adhesion/proliferation assay were investigated. Furthermore, osteoblast differentiation was assessed by alkaline phosphatase (ALP), alizarin red and osteocalcin staining, as well as real-time PCR for genes encoding Runx2, ALP, collagen1 and osteocalcin. The results showed that all cells had high survival rates throughout the entire study period irrespective of culture-conditions. While PRP induced a significant 2-fold increase in osteoblast migration, i-PRF demonstrated a 3-fold increase in migration when compared to control tissue-culture plastic and PRP. While no differences were observed for cell attachment, i-PRF induced a significantly higher proliferation rate at three and five days when compared to PRP. Furthermore, i-PRF induced significantly greater ALP staining at 7 days and alizarin red staining at 14 days. A significant increase in mRNA levels of ALP, Runx2 and osteocalcin, as well as immunofluorescent staining of osteocalcin was also observed in the i-PRF group when compared to PRP. In conclusion, the results from the present study favored the use of the naturally-formulated i-PRF when compared to traditional PRP with anti

Platelet Immunology in China: Research and Clinical Applications.

Science.gov (United States)

Wu, Guoguang; Zhou, Yan; Li, Lilan; Zhong, Zhoulin; Li, Hengchong; Li, Haiyan; Yu, Mei; Shen, Weidong; Ni, Heyu

2017-04-01

Immunization against human platelet alloantigens (HPAs) is associated with a number of clinical complications. The detection and identification of clinically relevant platelet antibodies are important for the diagnosis and management of patients affected with immune-mediated thrombocytopenias. Human platelet alloantigen frequencies and the characteristics of antiplatelet antibodies vary widely between ethnic groups. Since 2008, the importance of platelet immunology in the field of transfusion medicine has gained greater recognition by clinical laboratories in China. Laboratories in China have established and improved methods for platelet antibody detection and HPA genotyping techniques, which are used for the diagnosis of alloimmune platelet disorders in clinic and research environments. Research has revealed the frequencies of HPA alleles in different Chinese ethnic groups and compared the differences in HPA gene frequencies between the Chinese Han and other ethnic groups of the world. Production of anti-CD36 isoantibodies is an important risk factor for immune-mediated thrombocytopenia in the Chinese population. Advances in research and clinical application of platelet immunology have significantly improved the clinical diagnosis, treatment including transfusion support, and prevention of alloimmune platelet disorders in the Chinese population. Copyright © 2017. Published by Elsevier Inc.

Controlling pain during orthodontic fixed appliance therapy with non-steroidal anti-inflammatory drugs (NSAID): a randomized, double-blinded, placebo-controlled study.

Science.gov (United States)

Gupta, Mudit; Kandula, Srinivas; Laxmikanth, Sarala M; Vyavahare, Shreyas S; Reddy, Satheesha B H; Ramachandra, Chanila S

2014-11-01

Despite all the technological advances in orthodontics, orthodontic treatment still seems to involve some degree of discomfort and/or pain. Pain control during orthodontic therapy is of great concern to both orthodontists and patients. However, there has been limited research into controlling such pain. The purpose of this work was to assess patient-perceived pain following fixed orthodontic treatment and to evaluate the comparative analgesic efficacy of non-steroidal anti-inflammatory drugs for controlling pain. A total of 45 patients about to undergo fixed appliance orthodontic treatment were enrolled in this double-blind prospective study. Patients were evenly and randomly distributed in a blinded manner to one of three groups as follows: paracetamol/acetaminophen 500 mg thrice daily; placebo in the form of empty capsules; and etoricoxib 60 mg once daily. Drug administration began 1 h before initiating the bonding procedure and archwire placement, and given until the day 3. The pain perceived was recorded by the patients on a linear and graded Visual Analogue Scale at time intervals of 2 h after insertion of the appliance; 6 h thereafter and again at nighttime of the same day of the appointment; 24 h later and on the 2nd day at nighttime; 48 h after the appointment and on day 3 at nighttime. Our results revealed that moderately intense pain is associated with routine orthodontic treatment, and that the amount of pain individuals perceive varies widely. We observed statistically significant differences in the pain control among the three groups, and that etoricoxib 60 mg proved most efficient. Etoricoxib 60 mg is highly efficacious for controlling pain during fixed orthodontic appliance therapy.

Identification of anti-HPA-1a allo-antibodies using IgG platelet antibody detection and crossmatch system assay with Galileo Echo.

Science.gov (United States)

Di Cristofaro, Julie; Frassati, Coralie; Montagnie, Rolande; Basire, Agnes; Merieux, Yves; Picard, Christophe

2015-01-01

Fetal/neonatal allo-immune thrombocytopenia is the most frequent and the most dangerous clinical condition involving anti-human platelet antigens (HPA)-1a allo-antibodies. Anti-HPA-1a allo-immunization requires rapid and accurate diagnosis to determine appropriate treatment. The Capture-P Ready-Screen assay (C-PRS) is a new qualitative immunoassay to detect IgG anti-human leukocyte antigen (HLA) and anti-HPA allo-antibodies. The aim of this study is to assess the identification of anti-HPA-1a allo-antibodies using the C-PRS assay, associated with HLA class I stripping reagents, on the automated benchtop analyzer Galileo Echo. Forty-nine sera were analyzed: without anti-HLA class I or anti-HPA allo-antibodies, with anti-HLA class I allo-antibodies, with anti-HPA-1a allo-antibodies, among which with anti-HLA class I allo-antibodies. None of the samples without allo-antibodies were reactive. Only anti-HLA antibodies, detected by cytotoxicity-dependent complement and not by Luminex, remained positive before and after stripping reagents. Of the 13 samples, anti-HPA-1a allo-antibodies that were correctly identified before and after incubation with HLA assassin reagent were 70% and 85%, respectively. Anti-glycoprotein auto-antibodies and anti-HLA allo-antibodies do not interfere with the detection of anti-HPA-1a antibodies. This preliminary study indicates that further improvement of the test will be helpful in developing a clinically useful assay in the future.

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

DMSO inhibits human platelet activation through cyclooxygenase-1 inhibition. A novel agent for drug eluting stents?

International Nuclear Information System (INIS)

Asmis, Lars; Tanner, Felix C.; Sudano, Isabella; Luescher, Thomas F.; Camici, Giovanni G.

2010-01-01

Background: DMSO is routinely infused together with hematopoietic cells in patients undergoing myeloablative therapy and was recently found to inhibit smooth muscle cells proliferation and arterial thrombus formation in the mouse by preventing tissue factor (TF), a key activator of the coagulation cascade. This study was designed to investigate whether DMSO prevents platelet activation and thus, whether it may represent an interesting agent to be used on drug eluting stents. Methods and results: Human venous blood from healthy volunteers was collected in citrated tubes and platelet activation was studied by cone and platelet analyzer (CPA) and rapid-platelet-function-assay (RPFA). CPA analysis showed that DMSO-treated platelets exhibit a lower adherence in response to shear stress (-15.54 ± 0.9427%, n = 5, P < 0.0001 versus control). Additionally, aggregometry studies revealed that DMSO-treated, arachidonate-stimulated platelets had an increased lag phase (18.0% ± 4.031, n = 9, P = 0.0004 versus control) as well as a decreased maximal aggregation (-6.388 ± 2.212%, n = 6, P = 0.0162 versus control). Inhibitory action of DMSO could be rescued by exogenous thromboxane A2 and was mediated, at least in part, by COX-1 inhibition. Conclusions: Clinically relevant concentrations of DMSO impair platelet activation by a thromboxane A2-dependent, COX-1-mediated effect. This finding may be crucial for the previously reported anti-thrombotic property displayed by DMSO. Our findings support a role for DMSO as a novel drug to prevent not only proliferation, but also thrombotic complications of drug eluting stents.

Effects of Pycnogenol on endothelial function in patients with stable coronary artery disease: a double-blind, randomized, placebo-controlled, cross-over study.

Science.gov (United States)

Enseleit, Frank; Sudano, Isabella; Périat, Daniel; Winnik, Stephan; Wolfrum, Mathias; Flammer, Andreas J; Fröhlich, Georg M; Kaiser, Priska; Hirt, Astrid; Haile, Sarah R; Krasniqi, Nazmi; Matter, Christian M; Uhlenhut, Klaus; Högger, Petra; Neidhart, Michel; Lüscher, Thomas F; Ruschitzka, Frank; Noll, Georg

2012-07-01

Extracts from pine tree bark containing a variety of flavonoids have been used in traditional medicine. Pycnogenol is a proprietary bark extract of the French maritime pine tree (Pinus pinaster ssp. atlantica) that exerts antioxidative, anti-inflammatory, and anti-platelet effects. However, the effects of Pycnogenol on endothelial dysfunction, a precursor of atherosclerosis and cardiovascular events, remain still elusive. Twenty-three patients with coronary artery disease (CAD) completed this randomized, double-blind, placebo-controlled cross-over study. Patients received Pycnogenol (200 mg/day) for 8 weeks followed by placebo or vice versa on top of standard cardiovascular therapy. Between the two treatment periods, a 2-week washout period was scheduled. At baseline and after each treatment period, endothelial function, non-invasively assessed by flow-mediated dilatation (FMD) of the brachial artery using high-resolution ultrasound, biomarkers of oxidative stress and inflammation, platelet adhesion, and 24 h blood pressure monitoring were evaluated. In CAD patients, Pycnogenol treatment was associated with an improvement of FMD from 5.3 ± 2.6 to 7.0 ± 3.1 (P effect 2.75; 95% confidence interval (CI): 1.75, 3.75, P < 0.0001]. 15-F(2t)-Isoprostane, an index of oxidative stress, significantly decreased from 0.71 ± 0.09 to 0.66 ± 0.13 after Pycnogenol treatment, while no change was observed in the placebo group (mean difference 0.06 pg/mL with an associated 95% CI (0.01, 0.11), P = 0.012]. Inflammation markers, platelet adhesion, and blood pressure did not change after treatment with Pycnogenol or placebo. This study provides the first evidence that the antioxidant Pycnogenol improves endothelial function in patients with CAD by reducing oxidative stress.

A systematic review of anti-thrombotic therapy in epistaxis.

Science.gov (United States)

Musgrave, K M; Powell, J

2016-12-01

There is limited guidance available to clinicians regarding the management of antithrombotic therapy during epistaxis, whilst there has been an increase in the use of anticoagulation and antiplatelet therapy. In addition, the introduction of direct oral anticoagulants (DOACs), such as dabigatran and rivaroxaban, over the last decade has significantly increased the complexity of managing the anticoagulated epistaxis patient. We undertook a systemic literature review investigating potential management strategies for each class of anti-thrombotic therapy during epistaxis. A PubMED and Cochrane Library search was performed on 10/03/16 using, but not limited to, the search terms epistaxis, nosebleed, nose bleeding, nasal haemorrhage, nasal bleeding AND each of the following search terms: antithrombotic, anticoagulant, antiplatelet, aspirin, clopidogrel, warfarin, dabigatran, rivaroxaban, apixaban and tranexamic acid. This yielded 3815 results, of which 29 were considered relevant. Other sources such as national and international guidelines related to the management of anti-thrombotics were also utilised. We present the findings related to the management of each class of anti-thrombotic therapy during epistaxis. Overall we found a lack of evidence regarding this topic and further high quality research is needed. This is an area growing in complexity and the support of colleagues in Haematology and Cardiology is increasingly important.

Suppression of Aggrus/podoplanin-induced platelet aggregation and pulmonary metastasis by a single-chain antibody variable region fragment

International Nuclear Information System (INIS)

Miyata, Kenichi; Takagi, Satoshi; Sato, Shigeo; Morioka, Hiroshi; Shiba, Kiyotaka; Minamisawa, Tamiko; Takami, Miho; Fujita, Naoya

2014-01-01

Almost all highly metastatic tumor cells possess high platelet aggregating abilities, thereby form large tumor cell-platelet aggregates in the microvasculature. Embolization of tumor cells in the microvasculature is considered to be the first step in metastasis to distant organs. We previously identified the platelet aggregation-inducing factor expressed on the surfaces of highly metastatic tumor cells and named as Aggrus. Aggrus was observed to be identical to the marker protein podoplanin (alternative names, T1α, OTS-8, and others). Aggrus is frequently overexpressed in several types of tumors and enhances platelet aggregation by interacting with the platelet receptor C-type lectin-like receptor 2 (CLEC-2). Here, we generated a novel single-chain antibody variable region fragment (scFv) by linking the variable regions of heavy and light chains of the neutralizing anti-human Aggrus monoclonal antibody MS-1 with a flexible peptide linker. Unfortunately, the generated KM10 scFv failed to suppress Aggrus-induced platelet aggregation in vitro. Therefore, we performed phage display screening and finally obtained a high-affinity scFv, K-11. K-11 scFv was able to suppress Aggrus-induced platelet aggregation in vitro. Moreover, K-11 scFv prevented the formation of pulmonary metastasis in vivo. These results suggest that K-11 scFv may be useful as metastasis inhibitory scFv and is expected to aid in the development of preclinical and clinical examinations of Aggrus-targeted cancer therapies

Platelet count kinetics following interruption of antiretroviral treatment.

Science.gov (United States)

Zetterberg, Eva; Neuhaus, Jacqueline; Baker, Jason V; Somboonwit, Charurut; Llibre, Josep M; Palfreeman, Adrian; Chini, Maria; Lundgren, Jens D

2013-01-02

To investigate the mechanisms of platelet kinetics in the Strategies for Management of Antiretroviral Therapy (SMART) study that demonstrated excess mortality with CD4 guided episodic antiretroviral therapy (ART) drug conservation compared with continuous treatment viral suppression. Follow-up analyses of stored plasma samples demonstrated increased activation of both inflammatory and coagulation pathways after stopping ART. SMART patients from sites that determined platelets routinely. Platelet counts were retrospectively collected from 2206 patients from visits at study entry, and during follow-up. D-dimer levels were measured at study entry, month 1, and 2. Platelet levels decreased in the drug conservation group following randomization, but remained stable in the viral suppression group [median (IQR) decline from study entry to month 4: -24 000/μl (-54 000 to 4000) vs. 3000 (-22 000 to 24 000), respectively, P conservation vs. the viral suppression arm (unadjusted drug conservation/viral suppression [HR (95%CI) = 1.8 (1.2-2.7)]. The decline in platelet count among drug conservation participants on fully suppressive ART correlated with the rise in D-dimer from study entry to either month 1 or 2 (r = -0.41; P = 0.02). Among drug conservation participants who resumed ART 74% recovered to their study entry platelet levels. Interrupting ART increases the risk of thrombocytopenia, but reinitiation of ART typically reverses it. Factors contributing to declines in platelets after interrupting ART may include activation of coagulation pathways or HIV-1 replication itself. The contribution of platelets in HIV-related procoagulant activity requires further study.

Subcutaneous Administration of Low-Molecular-Weight Heparin to Horses Inhibits Ex Vivo Equine Herpesvirus Type 1-Induced Platelet Activation

Directory of Open Access Journals (Sweden)

Tracy Stokol

2018-05-01

Full Text Available Equine herpesvirus type 1 (EHV-1 is a major cause of infectious respiratory disease, abortion and neurologic disease. Thrombosis in placental and spinal vessels and subsequent ischemic injury in EHV-1-infected horses manifests clinically as abortion and myeloencephalopathy. We have previously shown that addition of heparin anticoagulants to equine platelet-rich plasma (PRP can abolish ex vivo EHV-1-induced platelet activation. The goal of this study was to test whether platelets isolated from horses treated with unfractionated heparin (UFH or low-molecular-weight heparin (LMWH were resistant to ex vivo EHV-1-induced activation. In a masked, block-randomized placebo-controlled cross-over trial, 9 healthy adult horses received 4 subcutaneous injections at q. 12 h intervals of one of the following treatments: UFH (100 U/kg loading dose, 3 maintenance doses of 80 U/kg, 2 doses of LMWH (enoxaparin 80 U/kg 24 h apart with saline at the intervening 12 h intervals, or 4 doses of saline. Blood samples were collected before treatment and after 36 h, 40 h (4 h after the last injection and 60 h (24 h after the last injection. Two strains of EHV-1, Ab4 and RacL11, were added to PRP ex vivo and platelet membrane expression of P selectin was measured as a marker of platelet activation. Drug concentrations were monitored in a Factor Xa inhibition (anti-Xa bioassay. We found that LMWH, but not UFH, inhibited platelet activation induced by low concentrations (1 × 106 plaque forming units/mL of both EHV-1 strains at 40 h. At this time point, all horses had anti-Xa activities above 0.1 U/ml (range 0.15–0.48 U/ml with LMWH, but not UFH. By 60 h, a platelet inhibitory effect was no longer detected and anti-Xa activity had decreased (range 0.03 to 0.07 U/ml in LMWH-treated horses. Neither heparin inhibited platelet activation induced by high concentrations (5 × 106 plaque forming units/mL of the RacL11 strain. We found substantial between horse

Randomized Trial Evaluating the Impact of Ribavirin Mono-Therapy and Double Dosing on Viral Kinetics, Ribavirin Pharmacokinetics and Anemia in Hepatitis C Virus Genotype 1 Infection

DEFF Research Database (Denmark)

Waldenström, Jesper; Westin, Johan; Nyström, Kristina

2016-01-01

In this pilot study (RibaC), 58 hepatitis C virus (HCV) genotype 1 infected treatment-naïve patients were randomized to (i) 2 weeks ribavirin double dosing concomitant with pegylated interferon-α (pegIFN-α), (ii) 4 weeks ribavirin mono-therapy prior to adding pegIFN-α, or (iii) standard-of-care (......In this pilot study (RibaC), 58 hepatitis C virus (HCV) genotype 1 infected treatment-naïve patients were randomized to (i) 2 weeks ribavirin double dosing concomitant with pegylated interferon-α (pegIFN-α), (ii) 4 weeks ribavirin mono-therapy prior to adding pegIFN-α, or (iii) standard......, by day 14, double dosing entailed a greater hemoglobin decline as compared to SOC (2.2 vs. 1.4 g/dL; P = 0.03). Conclusion: Ribavirin down-regulates IP-10, and may have an anti-viral effect differently regulated across IL28B genotypes....

Platelet concentration in platelet-rich plasma affects tenocyte behavior in vitro.

Science.gov (United States)

Giusti, Ilaria; D'Ascenzo, Sandra; Mancò, Annalisa; Di Stefano, Gabriella; Di Francesco, Marianna; Rughetti, Anna; Dal Mas, Antonella; Properzi, Gianfranco; Calvisi, Vittorio; Dolo, Vincenza

2014-01-01

Since tendon injuries and tendinopathy are a growing problem, sometimes requiring surgery, new strategies that improve conservative therapies are needed. Platelet-rich plasma (PRP) seems to be a good candidate by virtue of its high content of growth factors, most of which are involved in tendon healing. This study aimed to evaluate if different concentrations of platelets in PRP have different effects on the biological features of normal human tenocytes that are usually required during tendon healing. The different platelet concentrations tested (up to 5 × 10(6) plt/µL) stimulated differently tenocytes behavior; intermediate concentrations (0.5 × 10(6), 1 × 10(6) plt/µL) strongly induced all tested processes (proliferation, migration, collagen, and MMPs production) if compared to untreated cells; on the contrary, the highest concentration had inhibitory effects on proliferation and strongly reduced migration abilities and overall collagen production but, at the same time, induced increasing MMP production, which could be counterproductive because excessive proteolysis could impair tendon mechanical stability. Thus, these in vitro data strongly suggest the need for a compromise between extremely high and low platelet concentrations to obtain an optimal global effect when inducing in vivo tendon healing.

[Effects of lysine clonixinate on platelet function. Comparison with other non-steroidal anti-inflammatory agents].

Science.gov (United States)

Kramer, E H; Sassetti, B; Kaminker, A J; De Los Santos, A R; Martí, M L; Di Girolamo, G

2001-01-01

One of the mechanisms of action of non steroid antiinflammatory drugs (NSAIDs) consists of inhibition of prostaglandin synthesis. This explains many of the pharmacological effects and adverse events observed in medical practice. Administration of NSAIDs to patients with hemostatic disorders or perioperative conditions entails the risk of bleeding due to inhibition of platelet function. This study deals with platelet changes induced by lysine clonixinate vs diclofenac, ibuprofen and aspirin in classical tests such as platelet count, platelet factor 3 (PF3) activity and platelet aggregation with various inductors and more recent procedures such as P-selectin measurement by flow cytometry. Unlike control drugs, lysine clonixinate did not induce changes in platelet count or function when administered to healthy volunteers at the commonly used therapeutic doses.

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.

Functional characterization of recombinant snake venom rhodocytin: rhodocytin mutant blocks CLEC-2/podoplanin-dependent platelet aggregation and lung metastasis.

Science.gov (United States)

Sasaki, T; Shirai, T; Tsukiji, N; Otake, S; Tamura, S; Ichikawa, J; Osada, M; Satoh, K; Ozaki, Y; Suzuki-Inoue, K

2018-02-28

Essentials We generated recombinant rhodocytin that could aggregate platelets via CLEC-2. Recombinant wild-type rhodocytin formed heterooctamer with four α- and β-subunits. Asp 4 in α-subunit of rhodocytin was required for binding to CLEC-2. Inhibitory mutant of rhodocytin blocked podoplanin-dependent hematogenous metastasis. Background Rhodocytin, a disulfide-linked heterodimeric C-type lectin from Calloselasma rhodostoma consisting of α-subunits and β-subunits, induces platelet aggregation through C-type lectin-like receptor 2 (CLEC-2). CLEC-2 is a physiological binding partner of podoplanin (PDPN), which is expressed on some tumor cell types, and is involved in tumor cell-induced platelet aggregation and tumor metastasis. Thus, modified rhodocytin may be a possible source of anti-CLEC-2 drugs for both antiplatelet and antimetastasis therapy. However, its molecular function has not been well characterized, because of the lack of recombinant rhodocytin that induces platelet aggregation. Objective To produce recombinant rhodocytin, in order to verify its function with mutagenesis, and to develop an anti-CLEC-2 drug based on the findings. Methods We used Chinese hamster ovary cells to express recombinant rhodocytin (wild-type [WT] and mutant), which was analyzed for induction/inhibition of platelet aggregation with light transmission aggregometry, the formation of multimers with blue native PAGE, and binding to CLEC-2 with flow cytometry. Finally, we investigated whether mutant rhodocytin could suppress PDPN-induced metastasis in an experimental lung metastasis mouse model. Results Functional WT] rhodocytin (αWTβWT) was obtained by coexpression of both subunits. Asp4 in α-subunits of rhodocytin was required for CLEC-2 binding. αWTβWT formed a heterooctamer similarly to native rhodocytin. Moreover, an inhibitory mutant of rhodocytin (αWTβK53A/R56A), forming a heterotetramer, bound to CLEC-2 without inducing platelet aggregation, and blocked CLEC-2-PDPN

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

Platelet adhesion and degranulation induce pro-survival and pro-angiogenic signalling in ovarian cancer cells.

Directory of Open Access Journals (Sweden)

Karl Egan

Full Text Available Thrombosis is common in ovarian cancer. However, the interaction of platelets with ovarian cancer cells has not been critically examined. To address this, we investigated platelet interactions in a range of ovarian cancer cell lines with different metastatic potentials [HIO-80, 59M, SK-OV-3, A2780, A2780cis]. Platelets adhered to ovarian cancer cells with the most significant adhesion to the 59M cell line. Ovarian cancer cells induced platelet activation [P-selectin expression] in a dose dependent manner, with the most significant activation seen in response to the 59M cell line. The platelet antagonists [cangrelor, MRS2179, and apyrase] inhibited 59M cell induced activation suggesting a P2Y12 and P2Y1 receptor mediated mechanism of platelet activation dependent on the release of ADP by 59M cells. A2780 and 59M cells potentiated PAR-1, PAR-4, and TxA2 receptor mediated platelet activation, but had no effect on ADP, epinephrine, or collagen induced activation. Analysis of gene expression changes in ovarian cancer cells following treatment with washed platelets or platelet releasate showed a subtle but valid upregulation of anti-apoptotic, anti-autophagy pro-angiogenic, pro-cell cycle and metabolic genes. Thus, ovarian cancer cells with different metastatic potential adhere and activate platelets differentially while both platelets and platelet releasate mediate pro-survival and pro-angiogenic signals in ovarian cancer cells.

Availability of 111In-labeled platelet scintigraphy in patients with postinfarction left ventricular aneurysm

International Nuclear Information System (INIS)

Tsuda, Takatoshi; Kubota, Masahiro; Iwakubo, Akifumi

1989-01-01

Eighteen patients with postinfarction left ventricular aneurysm (LVA) were examined with indium-111-labeled autologous platelet scintigraphy to identify intracardiac thrombi and to investigate the effect of antithrombotic agents on thrombogenesitiy within the LVA. Indium-111-platelet scintigraphy had a sensitivity of 60% and a specificity of 100% in detecting LVA mural thrombi. Among 6 patients showing false-negative scintigraphic studies, 4 was managed on antiplatelet therapy. Of 9 patients showing active platelet deposition on initial study, including 8 not receiving antiplatelet therapy, 5 were treated with tichlopidine (300 mg/day) for 29.8±5.0 days. For the 5 patients, 2 had resolution and the 3 others had interruption of intraaneurysmal deposition in the second platelet study. For one patient receiving the third platelet study after warfarin therapy, it took two weeks to completely interrupt platelet deposition within the LVA. ECG gated radionuclide ventriculography and thallium-201 myocardial SPECT were also performed to assess left ventricular wall motion of left ventricular ejection fraction (LVEF) and myocardial blood perfusion. Thallium-201 SPECT showed apical or anteroapical perfusion defects. Radionuclide ventriculography pinpointed all 18 apical and anteroseptal aneurysms. A comparison between the thrombus positive group and the thrombus negative group revealed no statistical differences in LVEF and the period from the last myocardial infarction to the initial platelet scanning. These results suggest that indium-111 labeled platelet scintigraphy may be useful for identifying active left ventricular mural thrombi and for judging antiplatelet and anticoagulant therapy. (Namekawa, K)

Platelet-rich fibrin: a boon in regenerative endodontics.

Science.gov (United States)

Rebentish, Priyanka D; Umashetty, Girish; Kaur, Harpreet; Doizode, Trupthi; Kaslekar, Mithun; Chowdhury, Shouvik

2016-12-01

Research into regenerative dentistry has contributed momentum to the field of molecular biology. Periapical surgery aims at removing periapical pathology to achieve complete wound healing and regeneration of bone and periodontal tissue. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. Platelet-rich fibrin (PRF) is a wonderful tissue-engineering product and has recently gained much popularity due its promising results in wound healing bone induction. The features of this product are an attribute of platelets which, after cellular interactions, release growth factors and have shown application in diverse disciplines of dentistry. This paper is intended to shed light onto the various prospects of PRF and to provide clinical insight into regenerative endodontic therapy.

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial.

Science.gov (United States)

Madurantakam, Parthasarathy; Yoganarasimha, Suyog; Hasan, Fadi K

2015-09-29

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in surgeries because of its superior handling characteristics as well as its suturability to the wound bed. The goal of the study is to demonstrate generation as well as provide detailed characterization of relevant properties of L-PRF that underlie its clinical success.

Beyond COX-1: the effects of aspirin on platelet biology and potential mechanisms of chemoprevention.

Science.gov (United States)

Ornelas, Argentina; Zacharias-Millward, Niki; Menter, David G; Davis, Jennifer S; Lichtenberger, Lenard; Hawke, David; Hawk, Ernest; Vilar, Eduardo; Bhattacharya, Pratip; Millward, Steven

2017-06-01

After more than a century, aspirin remains one of the most commonly used drugs in western medicine. Although mainly used for its anti-thrombotic, anti-pyretic, and analgesic properties, a multitude of clinical studies have provided convincing evidence that regular, low-dose aspirin use dramatically lowers the risk of cancer. These observations coincide with recent studies showing a functional relationship between platelets and tumors, suggesting that aspirin's chemopreventive properties may result, in part, from direct modulation of platelet biology and biochemistry. Here, we present a review of the biochemistry and pharmacology of aspirin with particular emphasis on its cyclooxygenase-dependent and cyclooxygenase-independent effects in platelets. We also correlate the results of proteomic-based studies of aspirin acetylation in eukaryotic cells with recent developments in platelet proteomics to identify non-cyclooxygenase targets of aspirin-mediated acetylation in platelets that may play a role in its chemopreventive mechanism.

Association of Alpha Tocopherol and Ag Sulfadiazine Chitosan Oleate Nanocarriers in Bioactive Dressings Supporting Platelet Lysate Application to Skin Wounds.

Science.gov (United States)

Bonferoni, Maria Cristina; Sandri, Giuseppina; Rossi, Silvia; Dellera, Eleonora; Invernizzi, Alessandro; Boselli, Cinzia; Cornaglia, Antonia Icaro; Del Fante, Claudia; Perotti, Cesare; Vigani, Barbara; Riva, Federica; Caramella, Carla; Ferrari, Franca

2018-02-09

Chitosan oleate was previously proposed to encapsulate in nanocarriers some poorly soluble molecules aimed to wound therapy, such as the anti-infective silver sulfadiazine, and the antioxidant α tocopherol. Because nanocarriers need a suitable formulation to be administered to wounds, in the present paper, these previously developed nanocarriers were loaded into freeze dried dressings based on chitosan glutamate. These were proposed as bioactive dressings aimed to support the application to wounds of platelet lysate, a hemoderivative rich in growth factors. The dressings were characterized for hydration capacity, morphological aspect, and rheological and mechanical behavior. Although chitosan oleate nanocarriers clearly decreased the mechanical properties of dressings, these remained compatible with handling and application to wounds. Preliminary studies in vitro on fibroblast cell cultures demonstrated good compatibility of platelet lysate with nanocarriers and bioactive dressings. An in vivo study on a murine wound model showed an accelerating wound healing effect for the bioactive dressing and its suitability as support of the platelet lysate application to wounds.

Association of Alpha Tocopherol and Ag Sulfadiazine Chitosan Oleate Nanocarriers in Bioactive Dressings Supporting Platelet Lysate Application to Skin Wounds

Directory of Open Access Journals (Sweden)

Maria Cristina Bonferoni

2018-02-01

Full Text Available Chitosan oleate was previously proposed to encapsulate in nanocarriers some poorly soluble molecules aimed to wound therapy, such as the anti-infective silver sulfadiazine, and the antioxidant α tocopherol. Because nanocarriers need a suitable formulation to be administered to wounds, in the present paper, these previously developed nanocarriers were loaded into freeze dried dressings based on chitosan glutamate. These were proposed as bioactive dressings aimed to support the application to wounds of platelet lysate, a hemoderivative rich in growth factors. The dressings were characterized for hydration capacity, morphological aspect, and rheological and mechanical behavior. Although chitosan oleate nanocarriers clearly decreased the mechanical properties of dressings, these remained compatible with handling and application to wounds. Preliminary studies in vitro on fibroblast cell cultures demonstrated good compatibility of platelet lysate with nanocarriers and bioactive dressings. An in vivo study on a murine wound model showed an accelerating wound healing effect for the bioactive dressing and its suitability as support of the platelet lysate application to wounds.

Platelet rich plasma in dermatology and aesthetic medicine

OpenAIRE

Neerja Puri

2015-01-01

Platelet rich plasma is a promising therapy in dermatology and aesthetic medicine. In this article we will discuss the pros and cons of platelet rich plasma (PRP) and the usage of PRP in aesthetics. PRP is especially used for conditions like facial and neck rejuvenation, fine lines and wrinkles, abdominal striae and facial scarring.

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

The effect of erythropoietin on platelet function and fibrinolysis in chronic renal failure

DEFF Research Database (Denmark)

Stenver, Doris Irene; Jeppesen, L; Nielsen, B

1994-01-01

The influence of erythropoietin therapy on platelet function and fibrinolysis was evaluated in 12 anemic hemodialysis patients. Six months of therapy with human erythropoietin (50 to 80 IU/kg initially) raised the hemoglobin level to 10.8 g/dl but did not increase platelet activity in vivo as mea...

Aspirin therapy reduces the ability of platelets to promote colon and pancreatic cancer cell proliferation: Implications for the oncoprotein c-MYC

Science.gov (United States)

Sylman, Joanna L.; Ngo, Anh T. P.; Pang, Jiaqing; Sears, Rosalie C.; Williams, Craig D.; McCarty, Owen J. T.

2017-01-01

Aspirin, an anti-inflammatory and antithrombotic drug, has become the focus of intense research as a potential anticancer agent owing to its ability to reduce tumor proliferation in vitro and to prevent tumorigenesis in patients. Studies have found an anticancer effect of aspirin when used in low, antiplatelet doses. However, the mechanisms through which low-dose aspirin works are poorly understood. In this study, we aimed to determine the effect of aspirin on the cross talk between platelets and cancer cells. For our study, we used two colon cancer cell lines isolated from the same donor but characterized by different metastatic potential, SW480 (nonmetastatic) and SW620 (metastatic) cancer cells, and a pancreatic cancer cell line, PANC-1 (nonmetastatic). We found that SW480 and PANC-1 cancer cell proliferation was potentiated by human platelets in a manner dependent on the upregulation and activation of the oncoprotein c-MYC. The ability of platelets to upregulate c-MYC and cancer cell proliferation was reversed by an antiplatelet concentration of aspirin. In conclusion, we show for the first time that inhibition of platelets by aspirin can affect their ability to induce cancer cell proliferation through the modulation of the c-MYC oncoprotein. PMID:27903583

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

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.

Platelet rich plasma in dermatology and aesthetic medicine

Directory of Open Access Journals (Sweden)

Neerja Puri

2015-04-01

Full Text Available Platelet rich plasma is a promising therapy in dermatology and aesthetic medicine. In this article we will discuss the pros and cons of platelet rich plasma (PRP and the usage of PRP in aesthetics. PRP is especially used for conditions like facial and neck rejuvenation, fine lines and wrinkles, abdominal striae and facial scarring.

Platelet function testing: methods of assessment and clinical utility.

LENUS (Irish Health Repository)

Mylotte, Darren

2012-02-01

Platelets play a central role in the regulation of both thrombosis and haemostasis yet tests of platelet function have, until recently, been exclusively used in the diagnosis and management of bleeding disorders. Recent advances have demonstrated the clinical utility of platelet function testing in patients with cardiovascular disease. The ex vivo measurement of response to antiplatelet therapies (aspirin and clopidogrel), by an ever-increasing array of platelet function tests, is with some assays, predictive of adverse clinical events and thus, represents an emerging area of interest for both the clinician and basic scientist. This review article will describe the advantages and disadvantages of the currently available methods of measuring platelet function and discuss both the limitations and emerging data supporting the role of platelet function studies in clinical practice.

Platelet function testing: methods of assessment and clinical utility.

LENUS (Irish Health Repository)

Mylotte, Darren

2011-01-01

Platelets play a central role in the regulation of both thrombosis and haemostasis yet tests of platelet function have, until recently, been exclusively used in the diagnosis and management of bleeding disorders. Recent advances have demonstrated the clinical utility of platelet function testing in patients with cardiovascular disease. The ex vivo measurement of response to antiplatelet therapies (aspirin and clopidogrel), by an ever-increasing array of platelet function tests, is with some assays, predictive of adverse clinical events and thus, represents an emerging area of interest for both the clinician and basic scientist. This review article will describe the advantages and disadvantages of the currently available methods of measuring platelet function and discuss both the limitations and emerging data supporting the role of platelet function studies in clinical practice.

Anti-Platelet Treatment of Middle-Sized Abdominal Aortic Aneurysms

DEFF Research Database (Denmark)

Lindholt, Jen S; Björck, Martin; Michel, Jean B

2012-01-01

between the luminal side of the thrombus and flowing blood is a site of constant thrombus renewal, which is linked to platelet aggregation-induced fibrin generation and accumulation. In addition, red blood cells are entrapped causing an oxidative response. Through centrifugal convection are factors...

Availability of /sup 111/In-labeled platelet scintigraphy in patients with postinfarction left ventricular aneurysm

Energy Technology Data Exchange (ETDEWEB)

Tsuda, Takatoshi; Kubota, Masahiro; Iwakubo, Akifumi and others

1989-03-01

Eighteen patients with postinfarction left ventricular aneurysm (LVA) were examined with indium-111-labeled autologous platelet scintigraphy to identify intracardiac thrombi and to investigate the effect of antithrombotic agents on thrombogenesitiy within the LVA. Indium-111-platelet scintigraphy had a sensitivity of 60% and a specificity of 100% in detecting LVA mural thrombi. Among 6 patients showing false-negative scintigraphic studies, 4 was managed on antiplatelet therapy. Of 9 patients showing active platelet deposition on initial study, including 8 not receiving antiplatelet therapy, 5 were treated with tichlopidine (300 mg/day) for 29.8+-5.0 days. For the 5 patients, 2 had resolution and the 3 others had interruption of intraaneurysmal deposition in the second platelet study. For one patient receiving the third platelet study after warfarin therapy, it took two weeks to completely interrupt platelet deposition within the LVA. ECG gated radionuclide ventriculography and thallium-201 myocardial SPECT were also performed to assess left ventricular wall motion of left ventricular ejection fraction (LVEF) and myocardial blood perfusion. Thallium-201 SPECT showed apical or anteroapical perfusion defects. Radionuclide ventriculography pinpointed all 18 apical and anteroseptal aneurysms. A comparison between the thrombus positive group and the thrombus negative group revealed no statistical differences in LVEF and the period from the last myocardial infarction to the initial platelet scanning. These results suggest that indium-111 labeled platelet scintigraphy may be useful for identifying active left ventricular mural thrombi and for judging antiplatelet and anticoagulant therapy. (Namekawa, K).

Anti-retroviral therapy-induced status epilepticus in "pseudo-HIV serodeconversion".

Science.gov (United States)

Etgen, Thorleif; Eberl, Bernhard; Freudenberger, Thomas

2010-01-01

Diligence in the interpretation of results is essential as information gained from the psychiatric patient's history might often be restricted. Nonobservance of established guidelines may lead to a wrong diagnosis, induce a false therapy and result in life-threatening situations. Communication errors between hospitals and doctors and uncritical acceptance of prior diagnoses add substantially to this problem. We present a patient with alcohol-related dementia who received anti-retroviral therapy that promoted a non-convulsive status epilepticus. HIV serodeconversion was considered after our laboratory result yielded a HIV-negative status. Critical review of previous diagnostic investigations revealed several errors in the diagnosis of HIV infection leading to a "pseudo-serodeconversion." Finally, anti-retroviral therapy could be discontinued. Copyright © 2010 Elsevier Inc. All rights reserved.

OFFICIAL MEDICATIONS FOR ANTI-TUMOR GENE THERAPY

Directory of Open Access Journals (Sweden)

E. R. Nemtsova

2016-01-01

Full Text Available This is a review of modern literature data of official medications for anti-tumor gene therapy as well as of medications that finished clinical trials.The article discusses the concept of gene therapy, the statistical analysis results of initiated clinical trials of gene products, the most actively developing directions of anticancer gene therapy, and the characteristics of anti-tumor gene medications.Various delivery systems for gene material are being examined, including viruses that are defective in  replication (Gendicine™ and Advexin and oncolytic (tumor specific conditionally replicating viruses (Oncorine™, ONYX-015, Imlygic®.By now three preparations for intra-tumor injection have been introduced into oncology clinical practice: two of them – Gendicine™ and Oncorine™ have been registered in China, and one of them – Imlygic® has been registered in the USA. Gendicine™ and Oncorine™ are based on the wild type p53 gene and are designed for treatment of patients with head and neck malignancies. Replicating adenovirus is the delivery system in Gendicine™, whereas oncolytic adenovirus is the vector for gene material in Oncorine™. Imlygic® is based on the  recombinant replicating HSV1 virus with an introduced GM–CSF gene and is designed for treatment of  melanoma patients. These medications are well tolerated and do not cause any serious adverse events. Gendicine™ and Oncorine™ are not effective in monotherapy but demonstrate pronounced synergism with chemoand radiation therapy. Imlygic® has just started the post marketing trials.

Platelet Rich Plasma- mechanism of action and clinical applications

OpenAIRE

Cristina N. Cozma; Laura Raducu; Cristian R. Jecan

2016-01-01

Platelet-rich plasma (PRP) is a blood-derived fraction containing high level of platelets, a high concentration of leukocytes and growth factors. PRP therapy has been growing as a viable treatment alternative for a number of clinical applications and has a potential benefit for use in wound healing. Nowadays platelet rich plasma is used in stimulating wound healing in skin and soft tissue ulcerations, accelerating wound healing in diabetic patients and facilitating bone proliferation in ortho...

Platelet count kinetics following interruption of antiretroviral treatment

DEFF Research Database (Denmark)

Zetterberg, Eva; Neuhaus, Jacqueline; Baker, Jason V

2013-01-01

To investigate the mechanisms of platelet kinetics in the Strategies for Management of Antiretroviral Therapy (SMART) study that demonstrated excess mortality with CD4 guided episodic antiretroviral therapy (ART) drug conservation compared with continuous treatment viral suppression. Follow...

Topotactic Synthesis of Porous Cobalt Ferrite Platelets from a Layered Double Hydroxide Precursor and Their Application in Oxidation Catalysis.

Science.gov (United States)

Ortega, Klaus Friedel; Anke, Sven; Salamon, Soma; Özcan, Fatih; Heese, Justus; Andronescu, Corina; Landers, Joachim; Wende, Heiko; Schuhmann, Wolfgang; Muhler, Martin; Lunkenbein, Thomas; Behrens, Malte

2017-09-12

Monocrystalline, yet porous mosaic platelets of cobalt ferrite, CoFe 2 O 4 , can be synthesized from a layered double hydroxide (LDH) precursor by thermal decomposition. Using an equimolar mixture of Fe 2+ , Co 2+ , and Fe 3+ during co-precipitation, a mixture of LDH, (Fe II Co II ) 2/3 Fe III 1/3 (OH) 2 (CO 3 ) 1/6 ⋅m H 2 O, and the target spinel CoFe 2 O 4 can be obtained in the precursor. During calcination, the remaining Fe II fraction of the LDH is oxidized to Fe III leading to an overall Co 2+ :Fe 3+ ratio of 1:2 as required for spinel crystallization. This pre-adjustment of the spinel composition in the LDH precursor suggests a topotactic crystallization of cobalt ferrite and yields phase pure spinel in unusual anisotropic platelet morphology. The preferred topotactic relationship in most particles is [111] Spinel ∥[001] LDH . Due to the anion decomposition, holes are formed throughout the quasi monocrystalline platelets. This synthesis approach can be used for different ferrites and the unique microstructure leads to unusual chemical properties as shown by the application of the ex-LDH cobalt ferrite as catalyst in the selective oxidation of 2-propanol. Compared to commercial cobalt ferrite, which mainly catalyzes the oxidative dehydrogenation to acetone, the main reaction over the novel ex-LDH cobalt is dehydration to propene. Moreover, the oxygen evolution reaction (OER) activity of the ex-LDH catalyst was markedly higher compared to the commercial material. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Activated platelets release sphingosine 1-phosphate and induce hypersensitivity to noxious heat stimuli in vivo

Directory of Open Access Journals (Sweden)

Daniela eWeth

2015-04-01

Full Text Available At the site of injury activated platelets release various mediators, one of which is sphingosine 1-phosphate (S1P. It was the aim of this study to explore whether activated human platelets had a pronociceptive effect in an in vivo mouse model and whether this effect was based on the release of S1P and subsequent activation of neuronal S1P receptors 1 or 3. Human platelets were prepared in different concentrations (105/µl, 106/µl, 107/µl and assessed in mice with different genetic backgrounds (WT, S1P1fl/fl, SNS-S1P1-/-, S1P3-/-. Intracutaneous injections of activated human platelets induced a significant, dose-dependent hypersensitivity to noxious thermal stimulation. The degree of heat hypersensitivity correlated with the platelet concentration as well as the platelet S1P content and the amount of S1P released upon platelet activation as measured with LC MS/MS. Despite the significant correlations between S1P and platelet count, no difference in paw withdrawal latency (PWL was observed in mice with a global null mutation of the S1P3 receptor or a conditional deletion of the S1P1 receptor in nociceptive primary afferents. Furthermore, neutralisation of S1P with a selective anti-S1P antibody did not abolish platelet induced heat hypersensitivity. Our results suggest that activated platelets release S1P and induce heat hypersensitivity in vivo. However, the platelet induced heat hypersensitivity was caused by mediators other than S1P.

Effect of steroids on the activation status of platelets in patients with Immune thrombocytopenia (ITP).

Science.gov (United States)

Bhoria, Preeti; Sharma, Saniya; Varma, Neelam; Malhotra, Pankaj; Varma, Subhash; Luthra-Guptasarma, Manni

2015-01-01

The activation status of platelets in Immune Thrombocytopenia (ITP) patients--which is still somewhat controversial--is of potential interest, because activated platelets tend to aggregate (leading to excessive clotting or thromboembolic events) but cannot do so when platelet numbers are low, as in ITP. Although corticosteroids are the first line of therapy in ITP, the effect of steroids on activation of platelets has not been evaluated so far. We examined the status of platelet activation (with and without stimulation with ADP) in ITP patients, at the start of therapy (pre-steroid treatment, naive) and post-steroid treatment (classified on the basis of steroid responsiveness). We used flow cytometry to evaluate the levels of expression of P-selectin, and PAC-1 binding to platelets of 55 ITP patients and a similar number of healthy controls, treated with and without ADP. We found that platelets in ITP patients exist in an activated state. In patients who are responsive to steroids, the treatment reverses this situation. Also, the fold activation of platelets upon treatment with ADP is more in healthy controls than in ITP patients; treatment with steroids causes platelets in steroid-responsive patients to become more responsive to ADP-activation, similar to healthy controls. Thus steroids may cause changes in the ability of platelets to get activated with an agonist like ADP. Our results provide new insights into how, and why, steroid therapy helps in the treatment of ITP.

Anti-TNFα therapy for inflammatory bowel diseases is associated with Epstein-Barr virus lytic activation.

Science.gov (United States)

Lapsia, Sameer; Koganti, Siva; Spadaro, Salvatore; Rajapakse, Ramona; Chawla, Anupama; Bhaduri-McIntosh, Sumita

2016-02-01

Anti-TNFα therapy, known to suppress T-cell immunity, is increasingly gaining popularity for treatment of autoimmune diseases including inflammatory bowel diseases (IBD). T-cell suppression increases the risk of B-cell EBV-lymphoproliferative diseases and lymphomas. Since EBV-lytic activation is essential for development of EBV-lymphomas and there have been reports of EBV-lymphomas in patients treated with anti-TNFα therapy, we investigated if patients treated with anti-TNFα antibodies demonstrate greater EBV-lytic activity in blood. Peripheral blood mononuclear cells from 10 IBD patients solely on anti-TNFα therapy compared to 3 control groups (10 IBD patients not on immunosuppressive therapy, 10 patients with abdominal pain but without IBD, and 10 healthy subjects) were examined for the percentage of T-cells, EBV load and EBV-lytic transcripts. Patients on anti-TNFα therapy had significantly fewer T-cells, greater EBV load, and increased levels of transcripts from EBV-lytic genes of all kinetic classes compared to controls. Furthermore, exposure of EBV-infected B-cell lines to anti-TNFα antibodies resulted in increased levels of BZLF1 mRNA; BZLF1 encodes for ZEBRA, the viral latency-to-lytic cycle switch. Thus, IBD patients treated with anti-TNFα antibodies have greater EBV loads likely due to enhanced EBV-lytic gene expression and anti-TNFα antibodies may be sufficient to activate the EBV lytic cycle. Findings from this pilot study lay the groundwork for additional scientific and clinical investigation into the effects of anti-TNFα therapy on the life cycle of EBV, a ubiquitous oncovirus that causes lymphomas in the setting of immunocompromise. © 2015 Wiley Periodicals, Inc.

Use of an anti-platelet monoclonal antibody F (ab')2 fragment for imaging thrombus

International Nuclear Information System (INIS)

Loutfi, I.; Stuttle, A.W.J.; Peters, A.M.; George, P.; Lavender, J.P.; Lumley, P.

1990-01-01

Ten patients with suspected thrombus have been studied using 111 In-labelled F (ab')2 fragments of P256, a monoclonal antibody which recognizes an epitope on the platelet membrane glycoprotein IIb/IIIa complex. The F (ab')2 fragment was radiolabelled with 111 In via diethylenetri-aminepentamacetic acid to give a specific activity of up to 190 MBq (5mCi) mg - 1 without impairment of immunoreactivity. In vitro platelet aggregation studies showed that the F (ab')2 fragment caused less platelet aggregation than the whole antibody on a molar ratio and was without significant effect upon the sensitivity of platelets to a range of aggregating agents. Platalets were labelled in ten patients by intravenous injection of approximately 100 μg P256 F (ab')2. Of the ten patients studies, six showed localization of activity consistent with platelet accumulation. Localization was clearly seen when associated with thrombus of the lower limbs (three patients: deep vein thrombosis; one patient: aortofemoral graft), and was apparent although less marked in two other cases, one of aortic aneurysm and one of carotid stenosis. Use of radiolabelled P256 F (ab')2 offers a means of non-invasive detection of thrombus which, from in vitro studies, would appear to have less direct effect of platelet behaviour than the whole antibody. (author). 9 refs. 8 figs. 1 tab

Piperine Inhibits the Activities of Platelet Cytosolic Phospholipase A2 and Thromboxane A2 Synthase without Affecting Cyclooxygenase-1 Activity: Different Mechanisms of Action Are Involved in the Inhibition of Platelet Aggregation and Macrophage Inflammatory Response

Directory of Open Access Journals (Sweden)

Dong Ju Son

2014-08-01

Full Text Available PURPOSE: Piperine, a major alkaloid of black pepper (Piper nigrum and long pepper (Piper longum, was shown to have anti-inflammatory activity through the suppression of cyclooxygenase (COX-2 gene expression and enzyme activity. It is also reported to exhibit anti-platelet activity, but the mechanism underlying this action remains unknown. In this study, we investigated a putative anti-platelet aggregation mechanism involving arachidonic acid (AA metabolism and how this compares with the mechanism by which it inhibits macrophage inflammatory responses; METHODS: Rabbit platelets and murine macrophage RAW264.7 cells were treated with piperine, and the effect of piperine on the activity of AA-metabolizing enzymes, including cytosolic phospholipase A2 (cPLA2, COX-1, COX-2, and thromboxane A2 (TXA2 synthase, as well as its effect on AA liberation from the plasma membrane components, were assessed using isotopic labeling methods and enzyme immunoassay kit; RESULTS: Piperine significantly suppressed AA liberation by attenuating cPLA2 activity in collagen-stimulated platelets. It also significantly inhibited the activity of TXA2 synthase, but not of COX-1, in platelets. These results suggest that piperine inhibits platelet aggregation by attenuating cPLA2 and TXA2 synthase activities, rather than through the inhibition of COX-1 activity. On the other hand, piperine significantly inhibited lipopolysaccharide-induced generation of prostaglandin (PGE2 and PGD2 in RAW264.7 cells by suppressing the activity of COX-2, without effect on cPLA2; CONCLUSION: Our findings indicate that piperine inhibits platelet aggregation and macrophage inflammatory response by different mechanisms.

Recent insights in nanotechnology-based drugs and formulations designed for effective anti-cancer therapy.

Science.gov (United States)

Piktel, Ewelina; Niemirowicz, Katarzyna; Wątek, Marzena; Wollny, Tomasz; Deptuła, Piotr; Bucki, Robert

2016-05-26

The rapid development of nanotechnology provides alternative approaches to overcome several limitations of conventional anti-cancer therapy. Drug targeting using functionalized nanoparticles to advance their transport to the dedicated site, became a new standard in novel anti-cancer methods. In effect, the employment of nanoparticles during design of antineoplastic drugs helps to improve pharmacokinetic properties, with subsequent development of high specific, non-toxic and biocompatible anti-cancer agents. However, the physicochemical and biological diversity of nanomaterials and a broad spectrum of unique features influencing their biological action requires continuous research to assess their activity. Among numerous nanosystems designed to eradicate cancer cells, only a limited number of them entered the clinical trials. It is anticipated that progress in development of nanotechnology-based anti-cancer materials will provide modern, individualized anti-cancer therapies assuring decrease in morbidity and mortality from cancer diseases. In this review we discussed the implication of nanomaterials in design of new drugs for effective antineoplastic therapy and describe a variety of mechanisms and challenges for selective tumor targeting. We emphasized the recent advantages in the field of nanotechnology-based strategies to fight cancer and discussed their part in effective anti-cancer therapy and successful drug delivery.

Aspirin mono-therapy continuation does not result in more bleeding after knee arthroplasty.

Science.gov (United States)

Schwab, Pierre-Emmanuel; Lavand'homme, Patricia; Yombi, JeanCyr; Thienpont, Emmanuel

2017-08-01

Current clinical practice guidelines sometimes still recommend stopping aspirin five to seven days before knee arthroplasty surgery. Literature regarding multimodal blood management and continuation of anti-platelet therapy in this type of surgery is scant. The study hypothesis was that knee arthroplasty under low-dose aspirin mono-therapy continuation does not cause more total blood loss than knee arthroplasty performed without aspirin. Blood loss would be measured by haemoglobin (Hb) and haematocrit (HTC) levels drop at day 2 or day 4 for patients who benefit from multimodal bleeding control measures. A database of all patients undergoing knee arthroplasty between 2006 and 2014 was analysed. Demographic, surgical and complete blood workup data were collected. A retrospective comparison study analysed both groups in terms of blood loss, by mean calculated blood loss as haemoglobin or haematocrit drop between the preoperative Nadir value and the postoperative day 2 and 4 value. A group of 198 (44 UKA and 154 TKA) patients underwent surgery without interrupting their aspirin therapy for cardiovascular prevention. Mean (SD) age was 71 (8) and the mean (SD) BMI was 29 (5.5) kg/m 2 . The control group consisted of 403 (102 UKA and 301 TKA) patients who were not under aspirin, or any other anti-platelet agent. Mean (SD) age was 65 (10) (p aspirin mono-therapy for cardiovascular prevention. III.

Detection of intracardiac thrombi by scintiphotography with 111In-labeled autologous platelets

International Nuclear Information System (INIS)

Yui, Tokuo; Uchida, Tatsumi; Matsuda, Shin

1982-01-01

Detection of intracardiac thrombi by scintigraphy with In-111-oxine labeled autologous platelets was studied in 14 patients with various heart diseases. The results of platelet scintigraphy were compared with those of two dimensional echocardiography. In 4 of the 14 patients, the findings on platelet scintigraphy and echocardiography were both positive. Left atrial thrombi were detected in 3 patients with mitral valve disease (MVD), and left ventricular thrombus in a patient with myocardial infarction with left ventricular aneurysm (MI). The scintigraphy after antiplatelet therapy in the patient with MI did not show any radioactivity on the thrombus. In one of the 14 patients with MVD, the finding on platelet scintigraphy was positive, on the other hand echocardiography was negative. In one of the 14 patients with MVD, the finding on platelet scintigraphy was negative, on the other hand that on echocardiography was positive. The thrombus in this case may be hematologically nonactive thrombus. In-111 platelet scintigraphy is considered to be an excellent method for the diagnosis and in vivo assessment of antithrombotic therapy on intracardiac thrombosis. (J.P.N.)

Use of acid-suppressive therapy before anti-reflux surgery in 2922 patients

DEFF Research Database (Denmark)

Lødrup, A; Pottegård, A; Hallas, J

2015-01-01

BACKGROUND: Guidelines recommend that patients with gastro-oesophageal reflux disease are adequately treated with acid-suppressive therapy before undergoing anti-reflux surgery. Little is known of the use of acid-suppressive drugs before anti-reflux surgery. AIM: To determine the use of proton pump...... inhibitors and H2 -receptor antagonists in the year before anti-reflux surgery. METHODS: A nationwide retrospective study of all patients aged ≥18 undergoing first-time anti-reflux surgery in Denmark during 2000-2012 using data from three different sources: the Danish National Register of Patients......, the Danish National Prescription Register, and the Danish Person Register. RESULTS: The study population thus included 2922 patients (median age: 48 years, 55.7% male). The annual proportion of patients redeeming ≥180 DDD of acid-suppressive therapy increased from 17.0% 5 years before anti-reflux surgery...

Intramuscular anti-D in chronic immune thrombocytopenia children with severe thrombocytopenia.

Science.gov (United States)

Sirachainan, Nongnuch; Anurathapan, Usanarat; Chuansumrit, Ampaiwan; Songdej, Duantida; Wongwerawattanakoon, Pakawan; Hutspardol, Sakara; Kitpoka, Pimpun

2013-12-01

Nine patients with chronic immune thrombocytopenia and platelet counts anti-D. Phase 1 was anti-D daily for 5 days, followed by phase 2, anti-D weekly for 12 weeks and withheld when platelet counts ≥ 20 × 10(9) /L, and then phase 3 was anti-D once every 2 weeks for 24 weeks. According to the International Working Group criteria, in phase 1, 66.7% of patients responded to the treatment. In phases 2 and 3, 11.1% (0-41.7%) and 7.7% (0-33.3%) of total episodes of follow up, respectively, responded to the treatment. Therefore, intramuscular anti-D given at a dose of 10 mcg/kg for 5 days is an alternative method to raise platelet counts in chronic immune thrombocytopenia children with severe thrombocytopenia where the intravenous form of anti-D is not available. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

Anti-B cell antibody therapies for inflammatory rheumatic diseases

DEFF Research Database (Denmark)

Faurschou, Mikkel; Jayne, David R W

2014-01-01

Several monoclonal antibodies targeting B cells have been tested as therapeutics for inflammatory rheumatic diseases. We review important observations from randomized clinical trials regarding the efficacy and safety of anti-B cell antibody-based therapies for rheumatoid arthritis, systemic lupus...... and functions in rheumatic disorders. Future studies should also evaluate how to maintain disease control by means of conventional and/or biologic immunosuppressants after remission-induction with anti-B cell antibodies....

Progranulin inhibits platelet aggregation and prolongs bleeding time in rats.

Science.gov (United States)

Al-Yahya, A M; Al-Masri, A A; El Eter, E A; Hersi, A; Lateef, R; Mawlana, O

2018-05-01

Several adipokines secreted by adipose tissue have an anti-thrombotic and anti-atherosclerotic function. Recently identified adipokine progranulin was found to play a protective role in atherosclerosis. Bearing in mind the central role of platelets in inflammation and atherosclerosis, we aimed, in this study, to examine the effect of progranulin on platelet function and coagulation profile in rats. Healthy male albino Wistar rats weighing (250-300 g) were divided into 4 groups. Three groups were given increasing doses of progranulin (0.001 µg, 0.01 µg, and 0.1 µg) intraperitoneally, while the control group received phosphate-buffered saline (PBS). Bleeding time, prothrombin time, activated partial thromboplastin time and platelet aggregation responses to adenosine diphosphate and arachidonic acid were assessed. Administration of progranulin resulted in a significant inhibition of platelet aggregation in response to both adenosine diphosphate, and arachidonic acid. Bleeding time, prothrombin time and activated partial thromboplastin time were significantly prolonged in all groups that received progranulin, in particular, the 0.1 µg dose, in comparison to the control group. This preliminary data is first suggesting that the antiplatelet and anticoagulant action of progranulin could have a physiological protective function against thrombotic disorders associated with obesity and atherosclerosis. However, these results merit further exploration.

Combined anti-tumor necrosis factor-α therapy and DMARD therapy in rheumatoid arthritis patients reduces inflammatory gene expression in whole blood compared to DMARD therapy alone

Directory of Open Access Journals (Sweden)

Carl K Edwards

2012-12-01

Full Text Available Periodic assessment of gene expression for diagnosis and monitoring in rheumatoid arthritis (RA may provide a readily available and useful method to detect subclinical disease progression and follow responses to therapy with disease modifying anti-rheumatic agents (DMARDs or anti-TNF-α therapy. We used quantitative real-time PCR to compare peripheral blood gene expression profiles in active ("unstable" RA patients on DMARDs, stable RA patients on DMARDs, and stable RA patients treated with a combination of a DMARD and an anti-TNF-α agent (infliximab or etanercept to healthy human controls. The expression of 48 inflammatory genes were compared between healthy controls (N=122, unstable DMARD patients (N=18, stable DMARD patients (N=26, and stable patients on combination therapy (N=20. Expression of 13 genes was very low or undetectable in all study groups. Compared to healthy controls, patients with unstable RA on DMARDs exhibited increased expression of 25 genes, stable DMARD patients exhibited increased expression of 14 genes and decreased expression of five genes, and combined therapy patients exhibited increased expression of six genes and decreased expression of 10 genes. These findings demonstrate that active RA is associated with increased expression of circulating inflammatory markers whereas increases in inflammatory gene expression are diminished in patients with stable disease on either DMARD or anti-TNF-α therapy. Furthermore, combination DMARD and anti-TNF-α therapy is associated with greater reductions in circulating inflammatory gene expression compared to DMARD therapy alone. These results suggest that assessment of peripheral blood gene expression may prove useful to monitor disease progression and response to therapy.

Rapid resolution of cellulitis in patients managed with combination antibiotic and anti-inflammatory therapy.

Science.gov (United States)

Dall, Lawrence; Peterson, Sandford; Simmons, Tom; Dall, Amy

2005-03-01

There is some evidence to suggest that host inflammatory response has some effect on the clinical manifestations of cellulitis. The objective of this pilot study was to investigate whether the addition of oral nonsteroidal anti-inflammatory (NSAI) therapy to antibiotic treatment hastens resolution of cellulitis-related inflammation. Patients presenting in the emergency department with signs and symptoms of class II cellulitis were assigned to receive treatment with either antibiotic therapy alone (intravenous, supplemented with oral cephalexin or an equivalent) for 10 days (n = 33) or antibiotic therapy for 10 days plus an oral anti-inflammatory (ibuprofen 400 mg every 6 hours) for 5 days (n = 31). Patients were discharged as soon as possible to complete their therapy on an outpatient basis. The addition of an oral anti-inflammatory agent significantly (P < .05) shortened the time to regression of inflammation and complete resolution of cellulitis. Twenty-four of 29 evaluable patients (82.8%) who received supplemental anti-inflammatory treatment showed regression of inflammation within 1 to 2 days compared with only 3 of 33 patients (9.1%) treated without an anti-inflammatory in the same time frame. All patients receiving adjunctive anti-inflammatory treatment experienced complete resolution of cellulitis in 4 to 5 days or less, while 24.2% (8/33) of patients treated with antibiotic alone required 6 to 7 days, and 6.1% (2/33) required 7 days or more (P < .05). This small preliminary study provides some promising data, suggesting that the supplemental use of anti-inflammatory therapy may hasten the time to regression of inflammation and complete resolution of cellulitis.

Monitoring of anti-cancer therapies and chemoresistance

Czech Academy of Sciences Publication Activity Database

Martinková, Jiřina; Hrabáková, Rita; Skalníková, Helena; Novák, Petr; Džubák, P.; Hajdúch, M.; Gadher, S. J.; Kovářová, Hana

2009-01-01

Roč. 6, č. 1 (2009), s. 63-63 ISSN 1109-6535. [International Conference of the Hellenic Proteomic Society /3./. 30.03.2009-01.04.2009, Nafplio] R&D Projects: GA MŠk LC07017 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : anti-cancer therapies Subject RIV: CE - Biochemistry

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

Anti-leukemic therapies induce cytogenetic changes of human bone marrow-derived mesenchymal stem cells.

Science.gov (United States)

Yeh, Su-Peng; Lo, Wen-Jyi; Lin, Chiao-Lin; Liao, Yu-Min; Lin, Chen-Yuan; Bai, Li-Yuan; Liang, Ji-An; Chiu, Chang-Fang

2012-02-01

Both bone marrow hematopoietic cells (BM-HCs) and mesenchymal stem cells (BM-MSCs) may have cytogenetic aberrations in leukemic patients, and anti-leukemic therapy may induce cytogenetic remission of BM-HCs. The impact of anti-leukemic therapy on BM-MSCs remains unknown. Cytogenetic studies of BM-MSCs from 15 leukemic patients with documented cytogenetic abnormalities of BM-HCs were investigated. To see the influence of anti-leukemic therapy on BM-MSCs, cytogenetic studies were carried out in seven of them after the completion of anti-leukemic therapy, including anthracycline/Ara-C-based chemotherapy in two patients, high-dose busulfan/cyclophosphamide-based allogeneic transplantation in two patients, and total body irradiation (TBI)-based allogeneic transplantation in three patients. To simulate the effect of TBI in vitro, three BM-MSCs from one leukemic patient and two normal adults were irradiated using the same dosage and dosing schedule of TBI and cytogenetics were re-examined after irradiation. At the diagnosis of leukemia, two BM-MSCs had cytogenetic aberration, which were completely different to their BM-HCs counterpart. After the completion of anti-leukemic therapy, cytogenetic aberration was no longer detectable in one patient. Unexpectedly, BM-MSCs from three patients receiving TBI-based allogeneic transplantation acquired new, clonal cytogenetic abnormalities after transplantation. Similarly, complex cytogenetic abnormalities were found in all the three BM-MSCs exposed to in vitro irradiation. In conclusion, anti-leukemic treatments induce not only "cytogenetic remission" but also new cytogenetic abnormalities of BM-MSCs. TBI especially exerts detrimental effect on the chromosomal integrity of BM-MSCs and highlights the equal importance of investigating long-term adverse effect of anti-leukemic therapy on BM-MSCs as opposed to beneficial effect on BM-HCs.

[27- Hydroxycholesterol reverses estradiol induced inhibition of platelet aggregation in postmenopausal women].

Science.gov (United States)

Rocha, Gladys; Sierralta, Walter; Valladares, Luis

2016-11-01

The decline of estrogen levels increases cardiovascular risk in women. Platelets express estrogen receptors and 17β-estradiol- (E2) can produce a protective effect on thrombus formation. The hydroxylation of cholesterol generates several sterols and 27-hydroxycholesterol (27HC) predominates in circulation. To evaluate the effect of 27HC as an endogenous antagonist of the anti-aggregating properties of E2 in platelets of postmenopausal women. Platelet function of postmenopausal women was evaluated ex-vivo. Platelets pre-incubated with 27HC in the presence or absence of E2, were stimulated with collagen. Aggregation was evaluated using turbidimetry using a Chrono-log aggregometer. Collagen-stimulated platelet aggregation was significantly inhibited by E2. The inhibitory effect of E2 on collagen-stimulated platelet aggregation was significantly reversed in the presence of 27HC. The suppressive effect of E2 on platelet aggregation is inhibited by 27HC, which could contribute to increase cardiovascular risk in postmenopausal women.

Prevalence of Ex Vivo High On-treatment Platelet Reactivity on Antiplatelet Therapy after Transient Ischemic Attack or Ischemic Stroke on the PFA-100(®) and VerifyNow(®).

LENUS (Irish Health Repository)

Kinsella, Justin A

2012-09-12

BACKGROUND: The prevalence of ex vivo high on-treatment platelet reactivity (HTPR) to commonly prescribed antiplatelet regimens after transient ischemic attack (TIA) or ischemic stroke is uncertain. METHODS: Platelet function inhibition was simultaneously assessed with modified light transmission aggregometry (VerifyNow; Accumetrics Inc, San Diego, CA) and with a moderately high shear stress platelet function analyzer (PFA-100; Siemens Medical Solutions USA, Inc, Malvern, PA) in a pilot, cross-sectional study of TIA or ischemic stroke patients. Patients were assessed on aspirin-dipyridamole combination therapy (n = 51) or clopidogrel monotherapy (n = 25). RESULTS: On the VerifyNow, HTPR on aspirin was identified in 4 of 51 patients (8%) on aspirin-dipyridamole combination therapy (≥550 aspirin reaction units on the aspirin cartridge). Eleven of 25 (44%) patients had HTPR on clopidogrel (≥194 P2Y12 reaction units on the P2Y12 cartridge). On the PFA-100, 21 of 51 patients (41%) on aspirin-dipyridamole combination therapy had HTPR on the collagen-epinephrine (C-EPI) cartridge. Twenty-three of 25 patients (92%) on clopidogrel had HTPR on the collagen-adenosine diphosphate (C-ADP) cartridge. The proportion of patients with antiplatelet HTPR was lower on the VerifyNow than PFA-100 in patients on both regimens (P < .001). CONCLUSIONS: The prevalence of ex vivo antiplatelet HTPR after TIA or ischemic stroke is markedly influenced by the method used to assess platelet reactivity. The PFA-100 C-ADP cartridge is not sensitive at detecting the antiplatelet effects of clopidogrel ex vivo. Larger prospective studies with the VerifyNow and with the PFA-100 C-EPI and recently released Innovance PFA P2Y cartridges (Siemens Medical Solutions USA, Inc) in addition to newer tests of platelet function are warranted to assess whether platelet function monitoring predicts clinical outcome in ischemic cerebrovascular disease.

A randomized, double-blind, placebo-controlled study of oral antioxidant supplement therapy in patients with dry eye syndrome.

Science.gov (United States)

Huang, Jehn-Yu; Yeh, Po-Ting; Hou, Yu-Chih

2016-01-01

To evaluate the efficacy of oral antioxidant supplementation in the treatment of patients with dry eye syndrome (DES). A prospective, randomized, double-blinded study compared the effects of an antioxidant supplement (containing anthocyanosides, astaxanthin, vitamins A, C, and E, and several herbal extracts, including Cassiae semen and Ophiopogonis japonicus) with placebo on patients with DES. We assessed dry eye symptoms, visual acuity, Schirmer's test, tear film breakup time, cornea and conjunctiva fluorescein staining, serum anti-SSA/anti-SSB antibodies, and the level of reactive oxygen species (ROS) in tears. The supplementation period was 8 weeks and patients were followed up every 4 weeks for 16 weeks. A linear mixed model was used to compare the groups, while within-group differences were tested by repeated-measures analysis of variance. Forty-three patients, 20 and 23 in treatment and placebo groups, respectively, completed the study. Liver and renal functions were normal. Diastolic blood pressure decreased in the treatment group. There were no significant differences in systolic blood pressure, dry eye symptoms, serum anti-SSA and anti-SSB, visual acuity, intraocular pressure, or fluorescein corneal staining between the groups. Tear film breakup time scores and Schirmer's test without topical anesthesia significantly improved in the treatment group. Tear ROS level differed between the groups and decreased after treatment. Overall subjective impression revealed a significant improvement with treatment compared with placebo. Oral antioxidant supplementations may increase tear production and improve tear film stability by reducing tear ROS. The vegetable-based antioxidant supplement used in this study is safe and can be utilized as an adjuvant therapy to conventional artificial tear therapy for patients with DES.

Anti-TNF-alpha therapy for sight threatening uveitis.

NARCIS (Netherlands)

E.W. Lindstedt (Eric); G.S. Baarsma (Seerp); R.W.A.M. Kuijpers (Robert); P.M. van Hagen (Martin)

2005-01-01

textabstractAIM: To describe the effect of additional treatment with anti-TNF-alpha therapy in a case series of 13 patients with serious sight threatening uveitis. METHODS: 13 patients with serious sight threatening uveitis were included, of whom six had Behcet's disease, five had idiopathic

Detection of thrombi by 111In-oxine platelet scintigraphy

International Nuclear Information System (INIS)

Makino, Katsutoshi; Yamamuro, Masashi; Ichikawa, Takehiko; Futagami, Yasuo; Konishi, Tokuji; Nakano, Takeshi; Takezawa, Hideo

1985-01-01

For 52 patients with cardiac disease and 11 patients with vascular disease, In-111-oxine platelet scintigraphy was performed to assess its clinical usefulness for detecting thrombi. Using Hayashida's method, platelets were separated in 43 ml peripheral blood, washed and labeled with 1 mCi In-111-oxine. In addition to planar images in the anterior, 45 deg left anterior oblique and left lateral views, single photon emission computed tomography (SPECT) was performed in some cases by rotating a dual gamma camera 24 and 72 hours after labeled platelet injection. The functions of platelet and coagulability were examined 36 hours after the injection of labeled platelets. Medical therapy was not changed during this study. Intracardiac thrombi were documented in 16 of 52 cases with cardiac disease and intravascular thrombi in 10 cases with vascular disease by angiography, CT and two-dimensional echocardiography. Positive images were obtained in 10 cases with cardiac disease and in eight cases with vascular disease by scintigraphy. Therefore, sensitivity, specificity, and overall accuracy were 63 %, 100 % and 88 % in intracardiac thrombi; 80 %, 100 % and 82 % in intravascular thrombi; and totally 69 %, 100 % and 87 %, respectively. In the detection of intracardiac thrombi by scintigraphy, the sensitivity seemed to be lower and the specificity higher than those by other graphic studies. In 52 cases with cardiac disease, five out of six cases with false negative images had received antiplatelet and/or anticoagulant drugs, and in these cases, platelet and coagulation functions tended to be decreased compared with those of true positive cases or true negative cases. We conclude that positive images in scintigraphy indicate the existence of growing thrombi, and that In-111-oxine platelet scintigraphy has clinical usefulness, not only for detecting thrombi, but for estimating platelet activity and effect of medical therapy. (author)

Evaluation of two platelet-rich plasma processing methods and two platelet-activation techniques for use in llamas and alpacas.

Science.gov (United States)

Semevolos, Stacy A; Youngblood, Cori D; Grissom, Stephanie K; Gorman, M Elena; Larson, Maureen K

2016-11-01

OBJECTIVE To evaluate 2 processing methods (commercial kit vs conical tube centrifugation) for preparing platelet rich plasma (PRP) for use in llamas and alpacas. SAMPLES Blood samples (30 mL each) aseptically collected from 6 healthy llamas and 6 healthy alpacas. PROCEDURES PRP was prepared from blood samples by use of a commercial kit and by double-step conical tube centrifugation. A CBC was performed for blood and PRP samples. Platelets in PRP samples were activated by means of a freeze-thaw method with or without 23mM CaCl 2 , and concentrations of platelet-derived growth factor-BB and transforming growth factor-β 1 were measured. Values were compared between processing methods and camelid species. RESULTS Blood CBC values for llamas and alpacas were similar. The commercial kit yielded a significantly greater degree of platelet enrichment (mean increase, 8.5 fold vs 2.8 fold) and WBC enrichment (mean increase, 3.7 fold vs 1.9 fold) than did conical tube centrifugation. Llamas had a significantly greater degree of platelet enrichment than alpacas by either processing method. No difference in WBC enrichment was identified between species. Concentrations of both growth factors were significantly greater in PRP samples obtained by use of the commercial kit versus those obtained by conical tube centrifugation. CONCLUSIONS AND CLINICAL RELEVANCE For blood samples from camelids, the commercial kit yielded a PRP product with a higher platelet and WBC concentration than achieved by conical tube centrifugation. Optimal PRP platelet and WBC concentrations for various applications need to be determined for llamas and alpacas.

Evaluation of the TEG® platelet mappingTM assay in blood donors

DEFF Research Database (Denmark)

Bochsen, Louise; Wiinberg, Bo; Kjelgaard-Hansen, Mads Jens

2007-01-01

for quantification of platelet function, including the contribution of the adenosine diphosphate (ADP) and thromboxane A2 (TxA2) receptors to clot formation. Methods In 43 healthy blood donors, the analytical (CVa) and inter-individual variability (CVg) of the TEG® Platelet MappingTM assay were determined together......Background Monitoring of antiplatelet therapy in patients at cardiovascular risk is difficult because existing platelet function tests are too sophisticated for clinical routine. The whole blood TEG® Platelet MappingTM assay measures clot strength as maximal amplitude (MA) and enables...

Patients double-seropositive for ANCA and anti-GBM antibodies have varied renal survival, frequency of relapse, and outcomes compared to single-seropositive patients.

Science.gov (United States)

McAdoo, Stephen P; Tanna, Anisha; Hrušková, Zdenka; Holm, Lisa; Weiner, Maria; Arulkumaran, Nishkantha; Kang, Amy; Satrapová, Veronika; Levy, Jeremy; Ohlsson, Sophie; Tesar, Vladimir; Segelmark, Mårten; Pusey, Charles D

2017-09-01

Co-presentation with both ANCA and anti-GBM antibodies is thought to be relatively rare. Current studies of such 'double-positive' cases report small numbers and variable outcomes. To study this further we retrospectively analyzed clinical features and long-term outcomes of a large cohort of 568 contemporary patients with ANCA-associated vasculitis, 41 patients with anti-GBM disease, and 37 double-positive patients with ANCA and anti-GBM disease from four European centers. Double-positive patients shared characteristics of ANCA-associated vasculitis (AAV), such as older age distribution and longer symptom duration before diagnosis, and features of anti-GBM disease, such as severe renal disease and high frequency of lung hemorrhage at presentation. Despite having more evidence of chronic injury on renal biopsy compared to patients with anti-GBM disease, double-positive patients had a greater tendency to recover from being dialysis-dependent after treatment and had intermediate long-term renal survival compared to the single-positive patients. However, overall patient survival was similar in all three groups. Predictors of poor patient survival included advanced age, severe renal failure, and lung hemorrhage at presentation. No single-positive anti-GBM patients experienced disease relapse, whereas approximately half of surviving patients with AAV and double-positive patients had recurrent disease during a median follow-up of 4.8 years. Thus, double-positive patients have a truly hybrid disease phenotype, requiring aggressive early treatment for anti-GBM disease, and careful long-term follow-up and consideration for maintenance immunosuppression for AAV. Since double-positivity appears common, further work is required to define the underlying mechanisms of this association and define optimum treatment strategies. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Effect of eltrombopag on platelet counts and bleeding during treatment of chronic idiopathic thrombocytopenic purpura: a randomised, double-blind, placebo-controlled trial.

Science.gov (United States)

Bussel, James B; Provan, Drew; Shamsi, Tahir; Cheng, Gregory; Psaila, Bethan; Kovaleva, Lidia; Salama, Abdulgabar; Jenkins, Julian M; Roychowdhury, Debasish; Mayer, Bhabita; Stone, Nicole; Arning, Michael

2009-02-21

Eltrombopag is an oral, non-peptide, thrombopoietin-receptor agonist that stimulates thrombopoiesis, leading to increased platelet production. This study assessed the efficacy, safety, and tolerability of once daily eltrombopag 50 mg, and explored the efficacy of a dose increase to 75 mg. In this phase III, randomised, double-blind, placebo-controlled study, adults from 63 sites in 23 countries with chronic idiopathic thrombocytopenic purpura (ITP), platelet counts less than 30 000 per muL of blood, and one or more previous ITP treatment received standard care plus once-daily eltrombopag 50 mg (n=76) or placebo (n=38) for up to 6 weeks. Patients were randomly assigned in a 2:1 ratio of eltrombopag:placebo by a validated randomisation system. After 3 weeks, patients with platelet counts less than 50 000 per microL could increase study drug to 75 mg. The primary endpoint was the proportion of patients achieving platelet counts 50 000 per microL or more at day 43. All participants who received at least one dose of their allocated treatment were included in the analysis. This study is registered with ClinicalTrials.gov, number NCT00102739. 73 patients in the eltrombopag group and 37 in the placebo group were included in the efficacy population and were evaluable for day-43 analyses. 43 (59%) eltrombopag patients and six (16%) placebo patients responded (ie, achieved platelet counts >/=50 000 per microL; odds ratio [OR] 9.61 [95% CI 3.31-27.86]; ptime during the study than did those receiving placebo (OR 0.49 [95% CI 0.26-0.89]; p=0.021). The frequency of grade 3-4 adverse events during treatment (eltrombopag, two [3%]; placebo, one [3%]) and adverse events leading to study discontinuation (eltrombopag, three [4%]; placebo, two [5%]), were similar in both groups. Eltrombopag is an effective treatment for managment of thrombocytopenia in chronic ITP.

Cell labelling. Granule and platelet kinetics. Recent concepts

International Nuclear Information System (INIS)

Najean, Y.; Dresch, C.; Dassin, E.

Some unsolved problems are reviewed concerning the lifetime of blood platelets, with special reference to excessive platelet consumption and its possible correction by anti-aggregation agents, in many vascular diseases. Regarding the production of platelets it is considered that the 75 Se-methionine labelling method alone offers a quantitative approach to the process and could be used for the physiological study of thrombopoietic factors. A short chapter is devoted to a survey of the points of agreement and disagreement regarding the lifetime of polynuclear cells and a tentative analysis of the reasons explaining the quite different results obtained with DFP and radiochromium labelling. Finally the methods used to study granule formation are criticized, though it is acknowledged that certain ideas useful in physiopathology have emerged from these different procedures [fr

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.

Platelet-Released Growth Factors Modulate the Secretion of Cytokines in Synoviocytes under Inflammatory Joint Disease

Science.gov (United States)

Rasuo, Biljana; Hock, Jennifer Vanessa Phi; Kweider, Nisreen; Fragoulis, Athanassios; Sönmez, Tolga Taha; Jahr, Holger; Pufe, Thomas; Lippross, Sebastian

2017-01-01

The etiology and pathogenesis of rheumatoid arthritis (RA) are marked by a complex interplay of various cell populations and is mediated by different signaling pathways. Traditionally, therapies have primarily focused on pain relief, reducing inflammation and the recovery of joint function. More recently, however, researchers have discussed the therapeutic efficacy of autologous platelet-rich plasma (PRP). The main objective of this work is to examine the influences of platelet-released growth factor (PRGF) on human synoviocytes under inflammatory conditions. Additionally, it is checked to which extend treatment with platelet concentrate influences the release of cytokines form synoviocytes. For this purpose, an in vitro RA model was created by stimulating the cells with the TNF-α. The release of cytokines was measured by ELISA. The cytokine gene expression was analyzed by real-time PCR. It has been observed that the stimulation concentration of 10 ng/ml TNF-α resulted in a significantly increased endogenous secretion and gene expression of IL-6 and TNF-α. The anti-inflammatory effect of PRGF could be confirmed through significant reduction of TNF-α and IL-1β. An induced inflammatory condition seems to cause PRGF to inhibit the release of proinflammatory cytokines. Further study is required to understand the exact effect mechanism of PRGF on synoviocytes. PMID:29348703

Platelet-Released Growth Factors Modulate the Secretion of Cytokines in Synoviocytes under Inflammatory Joint Disease

Directory of Open Access Journals (Sweden)

Mersedeh Tohidnezhad

2017-01-01

Full Text Available The etiology and pathogenesis of rheumatoid arthritis (RA are marked by a complex interplay of various cell populations and is mediated by different signaling pathways. Traditionally, therapies have primarily focused on pain relief, reducing inflammation and the recovery of joint function. More recently, however, researchers have discussed the therapeutic efficacy of autologous platelet-rich plasma (PRP. The main objective of this work is to examine the influences of platelet-released growth factor (PRGF on human synoviocytes under inflammatory conditions. Additionally, it is checked to which extend treatment with platelet concentrate influences the release of cytokines form synoviocytes. For this purpose, an in vitro RA model was created by stimulating the cells with the TNF-α. The release of cytokines was measured by ELISA. The cytokine gene expression was analyzed by real-time PCR. It has been observed that the stimulation concentration of 10 ng/ml TNF-α resulted in a significantly increased endogenous secretion and gene expression of IL-6 and TNF-α. The anti-inflammatory effect of PRGF could be confirmed through significant reduction of TNF-α and IL-1β. An induced inflammatory condition seems to cause PRGF to inhibit the release of proinflammatory cytokines. Further study is required to understand the exact effect mechanism of PRGF on synoviocytes.

[Effect of anti-inflammatory therapy on the treatment of dry eye syndrome].

Science.gov (United States)

Mrukwa-Kominek, Ewa; Rogowska-Godela, Anna; Gierek-Ciaciura, Stanisława

2007-01-01

Dry eye syndrome is a common chronic disease; agents and strategies for its effective management are still lacking. The syndrome tends to be accompanied by ocular surface inflammation; therefore, the use of anti-inflammatory agents might prove beneficial. The authors present up-to-date guidelines, strategies, and efficacy of dry eye syndrome management, including anti-inflammatory treatment. As no diagnostic tests are now available to assess ocular surface inflammation severity, the right timing to launch an anti-inflammatory agent is difficult to determine. Patients with mild intermittent bouts of symptoms which can be alleviated with ophthalmic lubricants do not typically require anti-inflammatory therapy. The latter should be considered in those who do not respond to lubricating drops, obtain poor results on clinical tests, and show symptoms of ocular surface irritation (eg. conjunctivae redness). Anti-inflammatory treatment of dry eye syndrome may include short-term corticosteroids, cyclosporine A emulsion, oral tetracycline therapy, oral omega-3 fatty acid supplements, and autologous serum eye drops. Anti-inflammatory treatment should be safe and effective; potential benefits should be evaluated for each individual patient. The authors have reviewed the advantages of anti-inflammatory treatment in dry eye syndrome, presented in literature.

Transformation of ATLA-negative leukocytes by blood components from anti-ATLA-positive donors in vitro.

Science.gov (United States)

Miyamoto, K; Tomita, N; Ishii, A; Nishizaki, T; Kitajima, K; Tanaka, T; Nakamura, T; Watanabe, S; Oda, T

1984-06-15

Anti-ATLA-positive blood components transformed healthy human leukocytes in vitro. Blood components examined were packed red cells, whole blood, platelet concentrate and fresh frozen plasma. Leukocytes present in anti-ATLA-positive blood components such as packed red cells, whole blood and platelet concentrate easily transformed anti-ATLA-negative leukocytes. Co-culture in fresh frozen plasma, however, did not transform recipient leukocytes, and leukocytes of anti-ATLA-positive recipients proved refractory to transformation. The transformed cells were morphologically lymphoid, grew in suspension, and possessed normal recipient karyotypes except in the case of three platelet concentrates. A high proportion of all the transformed populations formed E-rosettes with neuraminidase-treated sheep erythrocytes. The cytoplasm of over 90% of each recipient was stained brilliantly with antibodies against ATLV-determined antigens. Electron microscopy of these transformed cells revealed many C-type virus particles in the extracellular space. Blood components, such as packed red cells, whole blood and platelet concentrate, containing leukocytes from anti-ATLA-positive donors, should be used cautiously to prevent the transmission on ATLV to anti-ATLA-negative recipients.

Correlation between Platelet Gelsolin and Platelet Activation Level in Acute Myocardial Infarction Rats and Intervention Effect of Effective Components of Chuanxiong Rhizome and Red Peony Root

Directory of Open Access Journals (Sweden)

Yue Liu

2013-01-01

Full Text Available The biological role of platelet gelsolin in platelet activation of acute myocardial infarction is not defined. In order to provide a potential new antiplatelet target for Chinese medicine and to elucidate the contribution of Xiongshao capsule, the effective components of Chuanxiong rhizome and red peony root, in this study, we randomly allocated Sprague Dawley rats to left anterior descending coronary artery ligation or sham surgery and different drug prophylaxis as control. We found that gelsolin is highly expressed in platelet rich plasma and lowly expressed in platelet poor plasma, accompanied by the high platelet activation level in model rats; plasma actin filaments and mean fluorescence intensity (MFI of platelet calcium ion increased and plasma vitamin D binding protein decreased in model rats. Xiongshao capsule could inhibit the gelsolin expression in platelet rich plasma and ischemic heart tissue simultaneously and reduce the level of plasma F-actin and MFI of platelet calcium ion. Our study concludes that platelet gelsolin is an important contributor to platelet activation, and platelet gelsolin inhibition may form a novel target for antiplatelet therapy. Xiongshao capsule may be a promising Chinese medicine drug for antiplatelet and aspirin-like cardioprotection effect.

Anti-TNFα therapy for chronic inflammatory disease in kidney transplant recipients: Clinical outcomes.

Science.gov (United States)

Garrouste, Cyril; Anglicheau, Dany; Kamar, Nassim; Bachelier, Claire; Rivalan, Joseph; Pereira, Bruno; Caillard, Sophie; Aniort, Julien; Gatault, Philippe; Soubrier, Martin; Sayegh, Johnny; Colosio, Charlotte; Buisson, Anthony; Thervet, Eric; Bouvier, Nicolas; Heng, Anne Elisabeth

2016-10-01

Anti-tumor necrosis factor-α (TNFα) therapy has improved the prognosis of many chronic inflammatory diseases. It appears to be well-tolerated by liver-transplant patients. However, their use and their safety in kidney-transplant patients have yet to be determined.In this retrospective study, we identified 16 adult kidney-transplant patients aged 46.5 years (34-51.8) who received anti-TNFα therapy from 7 kidney transplantation centers. The indications for this treatment included: chronic inflammatory bowel disease (n = 8), inflammatory arthritis (n = 5), AA amyloidosis (n = 1), psoriasis (n = 1), and microscopic polyangiitis (n = 1).Anti-TNFα therapies resulted in a clinical response in 13/16 patients (81%). Estimated glomerular filtration rates (MDRD-4) were similar on day 0 and at 24 months (M24) after anti-TNFα treatment had been initiated (41 [12-55] and 40 [21-53] mL/min/1.73 m, respectively). Two allograft losses were observed. The 1st case was due to antibody-mediated rejection (M18), while the 2nd was the result of AA amyloidosis recurrence (M20). There were several complications: 8 patients (50%) developed 23 serious infections (18 bacterial, 4 viral, and 1 fungal) and 4 developed cancer. Five patients died (infection n = 2, cardiac AA amyloidosis n = 1, intraalveolar hemorrhage following microscopic polyangiitis n = 1, and acute respiratory distress syndrome n = 1). On univariate analysis, recipient age associated with death (P = 0.009) and infection development (P = 0.06).Using anti-TNFα therapies, remission can be achieved in chronic inflammatory diseases in kidney-transplant patients. However, concommitant anti-TNFα and immunosuppresive therapies must be used with caution due to the high risk of infection, particularly after the age of 50.

Bitistatin-functionalized fluorescent nanodiamond particles specifically bind to purified human platelet integrin receptor αIIbβ3 and activated platelets.

Science.gov (United States)

Marcinkiewicz, Cezary; Gerstenhaber, Jonathan A; Sternberg, Mark; Lelkes, Peter I; Feuerstein, Giora

2017-01-01

Thromboembolic events (TEE) underwrite key causes of death in developed countries. While advanced imaging technologies such as computed tomography scans serve to diagnose blood clots during acute cardiovascular events, no such technology is available in routine primary care for TEE risk assessment. Here, we describe an imaging platform technology based on bioengineered fluorescent nanodiamond particles (F-NDPs) functionalized with bitistatin (Bit), a disintegrin that specifically binds to the α IIb β 3 integrin, platelet fibrinogen receptor (PFR) on activated platelets. Covalent linkage of purified Bit to F-NDP was concentration-dependent and saturable, as validated by enzyme-linked immunosorbent assay using specific anti-Bit antibodies. F-NDP-Bit interacted with purified PFR, either in immobilized or soluble form. Lotrafiban, a nonpeptide, α IIb β 3 receptor antagonist, specifically blocked F-NDP-Bit-PFR complex formation. Moreover, F-NDP-Bit specifically binds to activated platelets incorporated into a clot generated by thrombin-activated rat platelet-rich plasma (PRP). Our results suggest that engineered F-NDP-Bit particles could serve as noninvasive, "real-time" optical diagnostics for clots present in blood vessels.

Retrograde placement of double-J ureteral stent with interventional therapy for the treatment of ureteral stricture

International Nuclear Information System (INIS)

Kong Jian; Xu Linfeng; Liang Huimin; Zheng Chuansheng; Zheng Jinlong; Feng Gansheng

2000-01-01

Objective: To evaluate the retrograde placement of Double-J ureteral stent with interventional therapy for the treatment of ureteral stricture. Methods: Twenty patients with ureteral stricture of various causes were treated with retrograde placing Double-J ureteral stent by interventional therapy. Results: The Double-J stent was successfully performed in all twenty patients. The successful rate of placing stent was 100%. The cure rate was 90% (18/20). The complications such as urinary leakage, wound infection, and bleeding were markedly decreased. The indication, duration of indwelling and complication of the indwelling stent were discussed. Conclusion: Retrograde placing Double-J stent with interventional therapy is simple and less invasive. It is believed to be a safe and effective method for the treatment of ureteral stricture

Predictors of work disability after start of anti-TNF therapy in a national cohort of Swedish patients with rheumatoid arthritis: does early anti-TNF therapy bring patients back to work?

Science.gov (United States)

Olofsson, T; Petersson, I F; Eriksson, J K; Englund, M; Nilsson, J A; Geborek, P; Jacobsson, L T H; Askling, J; Neovius, M

2017-07-01

To examine predictors of work ability gain and loss after anti-tumour necrosis factor (TNF) start, respectively, in working-age patients with rheumatoid arthritis (RA) with a special focus on disease duration. Patients with RA, aged 19-62 years, starting their first TNF inhibitor 2006-2009 with full work ability (0 sick leave/disability pension days during 3 months before bio-start; n=1048) or no work ability (90 days; n=753) were identified in the Swedish biologics register (Anti-Rheumatic Treatment In Sweden, ARTIS) and sick leave/disability pension days retrieved from the Social Insurance Agency. Outcome was defined as work ability gain ≥50% for patients without work ability at bio-start and work ability loss ≥50% for patients with full work ability, and survival analyses conducted. Baseline predictors including disease duration, age, sex, education level, employment, Health Assessment Questionnaire, Disease Activity Score 28 and relevant comorbidities were estimated using Cox regression. During 3 years after anti-TNF start, the probability of regaining work ability for totally work-disabled patients was 35% for those with disease duration start, disease duration did not predict work ability loss. Baseline disability pension was also a strong predictor of work ability gain after treatment start. A substantial proportion of work-disabled patients with RA who start anti-TNF therapy regain work ability. Those initiating treatment within 5 years of symptom onset have a more than doubled 3-year probability of regaining work ability compared with later treatment starts. This effect seems largely due to the impact of disease duration on disability pension status. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Randomised controlled trial examining the effect of exercise in people with rheumatoid arthritis taking anti-TNFα therapy medication.

LENUS (Irish Health Repository)

Reid, Angela

2011-01-01

Substantial progress has been made in the medical management of rheumatoid arthritis (RA) over the past decade with the introduction of biologic therapies, including anti-tumour necrosis factor alpha (anti-TNFα) therapy medications. However, individuals with RA taking anti-TNFα medication continue to experience physical, psychological and functional consequences, which could potentially benefit from rehabilitation. There is evidence that therapeutic exercise should be included as an intervention for people with RA, but to date there is little evidence of the benefits of therapeutic exercise for people with RA on anti-TNFα therapy medication. A protocol for a multicentre randomised controlled three-armed study which aims to examine the effect of dynamic group exercise therapy on land or in water for people with RA taking anti-TNFα therapy medication is described.

Circulating anti-retinal antibodies in response to anti-angiogenic therapy in exudative age-related macular degeneration.

Science.gov (United States)

Kubicka-Trząska, Agnieszka; Wilańska, Joanna; Romanowska-Dixon, Bożena; Sanak, Marek

2014-12-01

To determine changes in anti-retinal antibodies (ARAs) during anti-VEGF therapy in patients with exudative age-related macular degeneration (AMD) and to assess the correlations between ARAs and disease activity. The study comprised 98 patients treated with intravitreal bevacizumab. The ophthalmic examination included best corrected visual acuity (BCVA), slit lamp biomicroscopy, fundoscopy, fluorescein angiography (FA), and optical coherence tomography (OCT). Serum ARAs levels were assessed by indirect immunofluorescence (IIF) on normal monkey retina substrate. These studies were repeated at 4 week intervals within 8 months of a follow-up. The sera of 50 sex- and age-matched healthy subjects were used as controls. At baseline examination, 94 (95.5%) of the 98 patients were positive for ARAs. The ARAs titres were significantly higher (p = 0.0000) than in controls. A positive correlation was found between titres of ARAs and the diameter of choroidal neovascularization (CNV) as measured by FA (p = 0.0000), and central retinal thickness (CRT) assessed by OCT (p = 0.0000). A positive correlation was also found between the diameter of CNV, CRT and the complexity of circulating ARAs. Following treatment all patients demonstrated significant decrease in ARAs levels as well as improvement of BCVA, reduction of subretinal fluid on OCT and decreased leakage on FA. Changes in serum ARAs levels occurred in parallel with clinical outcomes of anti-VEGF therapy. Treatment reduced serum levels of ARAs, with the greatest reduction occurring during the 'loading' phase. This study demonstrated that ARAs may act as a serum biomarker of the efficacy of anti-VEGF therapy. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Inhibition of platelet aggregation and in vitro free radical scavenging activity of dried fruiting bodies of Pleurotus eous.

Science.gov (United States)

Suseem, S R; Saral, Mary

2015-07-01

To evaluate the ethyl acetate, methanol and aqueous extracts of dried fruiting bodies of Pleurotus eous for its anti-platelet activity on human volunteer's blood. And also to analyze the free radical scavenging property of the extracts of P.eous by using various in vitro models. Anti-platelet activity of dried fruiting bodies of P.eous was evaluated by in vitro model using blood platelets. Inhibition of platelet aggregation was monitored after pre-incubation of platelets with the crude extracts of mushroom P.eous. Antioxidant activities of extracts of P.eous were evaluated by different in vitro experiments, namely, 1, 1-diphenyl-2-picryl hydrazyl (DPPH), superoxide, hydroxyl radical and lipid peroxide radical models. Crude extracts of mushroom P.eous inhibited platelet aggregation dose-dependently which was induced by adenosine diphosphate (ADP). At a maximum concentration of 10 mg/mL, methanol extract effected 64.02% inhibition of lipid per-oxidation and 50.12% scavenging effect on superoxide anion radical. Aqueous extract of P.eous have shown 69.43% chelating ability on ferrous ions, 24.27% scavenging effect on hydroxyl radical and 49.57% scavenging effect on DPPH radical at 10 mg/mL. Increasing concentrations of the extract were found to cause progressively decreasing of the intensity of absorbance. Anti-platelet effects could be related in part to the polyphenolic compounds present in the extracts. Antioxidant activity results indicated the free radical scavenging property of the extracts of P.eous which might be due to the high content of phenolic compounds and flavonoids.

Platelet-activating factor podoplanin: from discovery to drug development.

Science.gov (United States)

Takemoto, Ai; Miyata, Kenichi; Fujita, Naoya

2017-06-01

Tumor cell-induced platelet aggregation facilitates hematogenous metastasis by promoting tumor embolization, preventing immunological assaults and shear stress, and the platelet-releasing growth factors support tumor growth and invasion. Podoplanin, also known as Aggrus, is a type I transmembrane mucin-like glycoprotein and is expressed on wide range of tumor cells. Podoplanin has a role in platelet aggregation and metastasis formation through the binding to its platelet receptor, C-type lectin-like receptor 2 (CLEC-2). The podoplanin research was originally started from the cloning of highly metastatic NL-17 subclone from mouse colon 26 cancer cell line and from the establishment of 8F11 monoclonal antibody (mAb) that could neutralize NL-17-induced platelet aggregation and hematogenous metastasis. Later on, podoplanin was identified as the antigen of 8F11 mAb, and its ectopic expression brought to cells the platelet-aggregating abilities and hematogenous metastasis phenotypes. From the 8F11 mAb recognition epitopes, podoplanin is found to contain tandemly repeated, highly conserved motifs, designated platelet aggregation-stimulating (PLAG) domains. Series of analyses using the cells expressing the mutants and the established neutralizing anti-podoplanin mAbs uncovered that both PLAG3 and PLAG4 domains are associated with the CLEC-2 binding. The neutralizing mAbs targeting PLAG3 or PLAG4 could suppress podoplanin-induced platelet aggregation and hematogenous metastasis through inhibiting the podoplanin-CLEC-2 binding. Therefore, these domains are certainly functional in podoplanin-mediated metastasis through its platelet-aggregating activity. This review summarizes the platelet functions in metastasis formation, the role of platelet aggregation-inducing factor podoplanin in pathological and physiological situations, and the possibility to develop podoplanin-targeting drugs in the future.

Quantification of platelets obtained by different centrifugation protocols in SHR rats

OpenAIRE

João Alberto Yazigi Junior; João Baptista Gomes dos Santos; Bruno Rodrigues Xavier; Marcela Fernandes; Sandra Gomes Valente; Vilnei Mattiolli Leite

2015-01-01

ABSTRACT OBJECTIVE: To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is. METHODS: We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × gand 400 × g; and double centrifugation, usin...

Comparison of Modified Impedance Whole Blood Platelet Aggregation Method Detecting Platelet Function in ACS Patients with Different CYP2C19 Genotypes.

Science.gov (United States)

Cui, Chanjuan; Qiao, Rui; Zhang, Jie

2016-01-01

A reliable laboratory test to monitor onclopidogrel platelet reactivity (PR) is very necessary. In addition, genetic factors also play an important part in onclopidogrel PR. This study aimed to modify the original impedance whole blood platelet aggregation assay associated with the release assay to monitor onclopidogrel PR and assess their relationship with genotype. We adjusted the concentration of calcium in the in vitro reaction system of platelet aggregation to modify the original impedance whole blood platelet aggregation assay. Meanwhile, chronolume, which quantified the adenosine triphosphate (ATP) released from platelet dense granules, is added to this reaction system to reflect the platelet release function. In the modified assay, platelet magnified activation time (MAT) and the maximal platelet ATP release value (RV) were used to reflect platelet function parameters. In the original assay, the electrical resistance (omega) and RV were used to reflect platelet function parameters. Onclopidogrel PR was detected by the original impedance whole blood platelet aggregation assay, modified assay, and flow cytometric vasodilator stimulated phosphoprotein (VASP) assay in 168 patients with acute coronary syndromes (ACS). CYP2C19*2 and CYP2C19*3 polymorphisms were also detected in all of these patients. This modified method showed that when 12.5 microL CaCl2 (0.2 mmol/L) was added to the reaction system, MAT was appropriate (93 +/- 23 seconds). The CVs for the modified impedance assay and release assay were 9.31% and 6.13%, respectively. The mean VASP-PRI in the patient group treated with clopidogrel was significantly lower than that in the control group without antiplatelet therapy (54.88 +/- 16.81% vs. 79.86 +/- 10.24%, p 50% group were shorter than that in the PRI 50% group were higher than that in the PRI omega) and RV of the original method showed no differences between the two groups [0 (0-2) vs. 0 (0-1.25), 0.05 (0-0.25) vs. 0.08 (0-0.24); p > 0.05, p > 0

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...

Proteolysis of platelet receptors in humans and other species.

Science.gov (United States)

Qiao, Jian L; Shen, Yang; Gardiner, Elizabeth E; Andrews, Robert K

2010-08-01

In the past 5 years, metalloproteinase-mediated ectodomain shedding of platelet receptors has emerged as a new mechanism for modulating platelet function. By regulating surface expression of the platelet-specific receptors, glycoprotein (GP)VI that binds collagen, and GPIbalpha (the major ligand-binding subunit of the GPIb-IX-V complex) that binds von Willebrand factor (VWF) and other procoagulant and proinflammatory ligands, shedding not only irreversibly downregulates GPVI/GPIbalpha function, but generates proteolytic fragments that might be unique biomarkers or modulators in plasma. This is potentially significant because GPVI and GPIbalpha are involved in initiating thrombotic diseases such as heart attack and stroke, as well as autoimmune diseases where anti-platelet antibodies result in thrombocytopenia. Altered expression levels of GPIbalpha/GPVI are associated with both thrombotic propensity and platelet aging, suggesting an additional role in platelet clearance. Although emerging data are elucidating molecular mechanisms underlying GPIbalpha/GPVI shedding, evidence for the functional consequences of shedding in vivo, either clinically or in animal models, is far more limited. Here we consider recent published evidence for GPVI or GPIbalpha shedding in humans, nonhuman primates and mice, and whether conservation of sheddase cleavage sites across species points to a functional role for metalloproteolytic shedding in vivo.

Availability of platelet scintigraphy for evaluation of arteriosclerosis obliterans

International Nuclear Information System (INIS)

Morimoto, Yoshihisa; Sugimoto, Takashi; Okada, Masayoshi; Mukai, Tomoichiro

1998-01-01

We reviewed the availability of platelet scintigraphy which can detect thrombotic activity to evaluate arteriosclerosis obliterans (ASO). During the past 13 months, 15 cases with ASO were studied. Among them, 6 cases (40%) showed acute aggravations of ischemic symptoms along with abnormal accumulation on scintigram. These cases have instantly more intensive antiplatelet and anticoagulant therapy, and obtained a remarkable recuperation together with disappearance of abnormal accumulation. In contrast, 9 cases without abnormal accumulation had a stable course without any ischemic complaints. In conclusion, platelet scintigraphy is very useful to evaluate the clinical effects of conservative or surgical therapy during the follow-up period in patients with ASO. (author)

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

Nurses' perceptions about Botswana patients' anti-retroviral therapy ...

African Journals Online (AJOL)

Anti-retroviral drugs(ARVs) are supplied free of charge in Botswana. Lifelong adherence to antiretroviral therapy (ART) is vital to improve the patient's state of well-being and to prevent the development of strains of the human immunodefi ciency virus (HIV) that are resistant to ART. Persons with ART-resistant strains of HIV ...

On-treatment platelet reactivity: State of the art and perspectives.

Science.gov (United States)

Marcucci, Rossella; Grifoni, Elisa; Giusti, Betti

2016-02-01

High on-clopidogrel platelet reactivity (HcPR) during dual-antiplatelet therapy is a marker of vascular risk, in particular stent thrombosis, in patients with acute coronary syndromes (ACS). Genetic determinants (CYP2C19*2 polymorphism), advanced age, female gender, diabetes and reduced ventricular function are related to a higher risk to develop HcPR. In addition, inflammation and increased platelet turnover, as revealed by the elevated percentage of reticulated platelets in patients' blood, that characterize the acute phase of acute coronary syndromes, are associated with HcPR. To overcome the limitation of clopidogrel, new antiplatelet agents (prasugrel and ticagrelor) were developed and the demonstration of their superiority over clopidogrel was obtained in the two randomized trials, TRITON TIMI 38 and PLATO. Emerging evidence is accumulating on the role of high-on aspirin platelet reactivity (HaPR), especially in the clinical context of diabetes. Finally, the presence of new, potent antiplatelet drugs has shifted the focus from thrombotic to bleeding risk. Recent data document that low on-treatment platelet reactivity (LPR) is associated with a significantly higher bleeding risk. Due to the current possibility to choose between multiple antiplatelet strategies, the future perspective is to include in the management of ACS, in addition to clinical data and classical risk factors, the definition of platelet function during treatment in order to set a tailored therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

cDNA cloning of a snake venom metalloproteinase from the eastern diamondback rattlesnake (Crotalus adamanteus), and the expression of its disintegrin domain with anti-platelet effects

Science.gov (United States)

Suntravat, Montamas; Jia, Ying; Lucena, Sara E.; Sánchez, Elda E.; Pérez, John C.

2013-01-01

A 5′ truncated snake venom metalloproteinase was identified from a cDNA library constructed from venom glands of an eastern diamondback rattlesnake (Crotalus adamanteus). The 5′-rapid amplification of cDNA ends (RACE) was used to obtain the 1865 bp full-length cDNA sequence of a snake venom metalloproteinase (CamVMPII). CamVMPII encodes an open reading frame of 488 amino acids, which includes a signal peptide, a pro-domain, a metalloproteinase domain, a spacer, and an RGD-disintegrin domain. The predicted amino acid sequence of CamVMPII showed a 91%, 90%, 83%, and 82% sequence homology to the P-II class enzymes of C. adamanteus metalloproteinase 2, C. atrox CaVMP-II, Gloydius halys agkistin, and Protobothrops jerdonii jerdonitin, respectively. Disintegrins are potent inhibitors of both platelet aggregation and integrin-dependent cell adhesion. Therefore, the disintegrin domain (Cam-dis) of CamVMPII was amplified by PCR, cloned into a pET-43.1a vector, and expressed in Escherichia coli BL21. Affinity purified recombinantly modified Cam-dis (r-Cam-dis) with a yield of 8.5 mg/L culture medium was cleaved from the fusion tags by enterokinase cleavage. r-Cam-dis was further purified by two-step chromatography consisting of HiTrap™ Benzamidine FF column, followed by Talon Metal affinity column with a final yield of 1 mg/L culture. r-Cam-dis was able to inhibit all three processes of platelet thrombus formation including platelet adhesion with an estimated IC50 of 1 nM, collagen- and ADP-induced platelet aggregation with the estimated IC50s of 18 and 6 nM, respectively, and platelet function on clot retraction. It is a potent anti-platelet inhibitor, which should be further investigated for drug discovery to treat stroke patients or patients with thrombotic disorders. PMID:23313448

Platelet Rich Plasma- mechanism of action and clinical applications

Directory of Open Access Journals (Sweden)

Cristina N. Cozma

2016-11-01

Full Text Available Platelet-rich plasma (PRP is a blood-derived fraction containing high level of platelets, a high concentration of leukocytes and growth factors. PRP therapy has been growing as a viable treatment alternative for a number of clinical applications and has a potential benefit for use in wound healing. Nowadays platelet rich plasma is used in stimulating wound healing in skin and soft tissue ulcerations, accelerating wound healing in diabetic patients and facilitating bone proliferation in orthopedic and trauma surgery. It has also applications in maxillofacial surgery, spinal surgery, plastic and esthetic surgery, heart surgery and burns. This review of the literature shows a limited number of studies realized on humans that sustain PRP applications in orthopedic and plastic surgery. As the use of PRP increases, more properly structured clinical studies are necessary to confirm the results and to establish clearly the techniques of preparing, the conditions and the clinical indications of applying this therapy.

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

The optimal management of anti-thrombotic therapy after valve replacement: certainties and uncertainties.

Science.gov (United States)

Iung, Bernard; Rodés-Cabau, Josep

2014-11-07

Anti-thrombotic therapy after valve replacement encompasses a number of different situations. Long-term anticoagulation of mechanical prostheses uses vitamin K antagonists with a target international normalized ratio adapted to the characteristics of the prosthesis and the patient. The association of low-dose aspirin is systematic in the American guidelines and more restrictive in the European guidelines. Early heparin therapy is frequently used early after mechanical valve replacement, although there are no precise recommendations regarding timing, type, and dose of drug. Direct oral anticoagulants are presently contraindicated in patients with mechanical prosthesis. The main advantage of bioprostheses is the absence of long-term anticoagulant therapy. Early anticoagulation is indicated after valve replacement for mitral bioprostheses, whereas aspirin is now favoured early after bioprosthetic valve replacement in the aortic position. Early dual antiplatelet therapy is indicated after transcatheter aortic valve implantation, followed by single antiplatelet therapy. However, this relies on low levels of evidence and optimization of anti-thrombotic therapy is warranted in these high-risk patients. Although guidelines are consistent in most instances, discrepancies and the low-level of evidence of certain recommendations highlight the need for further controlled trials, in particular with regard to the combination of antiplatelet therapy with oral anticoagulant and the early post-operative anti-thrombotic therapy following the procedure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Rheumatoid arthritis risk allele PTPRC is also associated with response to anti-tumor necrosis factor alpha therapy

NARCIS (Netherlands)

Cui, Jing; Saevarsdottir, Saedis; Thomson, Brian; Padyukov, Leonid; van der Helm-van Mil, Annette H. M.; Nititham, Joanne; Hughes, Laura B.; de Vries, Niek; Raychaudhuri, Soumya; Alfredsson, Lars; Askling, Johan; Wedrén, Sara; Ding, Bo; Guiducci, Candace; Wolbink, Gert Jan; Crusius, J. Bart A.; van der Horst-Bruinsma, Irene E.; Herenius, Marieke; Weinblatt, Michael E.; Shadick, Nancy A.; Worthington, Jane; Batliwalla, Franak; Kern, Marlena; Morgan, Ann W.; Wilson, Anthony G.; Isaacs, John D.; Hyrich, Kimme; Seldin, Michael F.; Moreland, Larry W.; Behrens, Timothy W.; Allaart, Cornelia F.; Criswell, Lindsey A.; Huizinga, Tom W. J.; Tak, Paul P.; Bridges, S. Louis; Toes, Rene E. M.; Barton, Anne; Klareskog, Lars; Gregersen, Peter K.; Karlson, Elizabeth W.; Plenge, Robert M.

2010-01-01

OBJECTIVE: Anti-tumor necrosis factor alpha (anti-TNF) therapy is a mainstay of treatment in rheumatoid arthritis (RA). The aim of the present study was to test established RA genetic risk factors to determine whether the same alleles also influence the response to anti-TNF therapy. METHODS: A total

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.

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

Platelet Dysfunction in Patients with Chronic Myeloid Leukemia: Does Imatinib Mesylate Improve It?

Directory of Open Access Journals (Sweden)

Olga Meltem Akay

2016-05-01

Full Text Available Objective: The aim of this study was to investigate the effects of imatinib mesylate on platelet aggregation and adenosine triphosphate (ATP release in chronic myeloid leukemia patients. Materials and Methods: Platelet aggregation and ATP release induced by 5.0 mM adenosine diphosphate, 0.5 mM arachidonic acid, 1.0 mg/ mL ristocetin, and 2 µg/mL collagen were studied by whole blood platelet lumi-aggregometer in 20 newly diagnosed chronic myeloid leukemia patients before and after imatinib mesylate treatment. Results: At the time of diagnosis, 17/20 patients had abnormal platelet aggregation results; 8 (40% had hypoactivity, 6 (30% had hyperactivity, and 3 (15% had mixed hypo- and hyperactivity. Repeat platelet aggregation studies were performed after a mean of 19 months (min: 5 months-max: 35 months in all patients who received imatinib mesylate during this period. After therapy, 18/20 (90% patients had abnormal laboratory results; 12 (60% had hypoactive platelets, 4 (20% had mixed hypo- and hyperactive platelets, and 2 (10% had hyperactive platelets. Three of the 8 patients with initial hypoactivity remained hypoactive, while 2 developed a mixed picture, 2 became hyperactive, and 1 normalized. Of the 6 patients with initial hyperactivity, 4 became hypoactive and 2 developed a mixed pattern. All of the 3 patients with initial hypo- and hyperactivity became hypoactive. Finally, 2 of the 3 patients with initial normal platelets became hypoactive while 1 remained normal. There was a significant decrease in ristocetin-induced platelet aggregation after therapy (p0.05. Conclusion: These findings indicate that a significant proportion of chronic myeloid leukemia patients have different patterns of platelet function abnormalities and imatinib mesylate has no effect on these abnormalities, with a significant impairment in ristocetin-induced platelet aggregation.

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

Non-invasive imaging for studying anti-angiogenic therapy effects

NARCIS (Netherlands)

Ehling, J.; Lammers, Twan Gerardus Gertudis Maria; Kiessling, F.

2013-01-01

Noninvasive imaging plays an emerging role in preclinical and clinical cancer research and has high potential to improve clinical translation of new drugs. This article summarises and discusses tools and methods to image tumour angiogenesis and monitor anti-angiogenic therapy effects. In this

Effects of pathogen reduction systems on platelet microRNAs, mRNAs, activation, and function.

Science.gov (United States)

Osman, Abdimajid; Hitzler, Walter E; Meyer, Claudius U; Landry, Patricia; Corduan, Aurélie; Laffont, Benoit; Boilard, Eric; Hellstern, Peter; Vamvakas, Eleftherios C; Provost, Patrick

2015-01-01

Pathogen reduction (PR) systems for platelets, based on chemically induced cross-linking and inactivation of nucleic acids, potentially prevent transfusion transmission of infectious agents, but can increase clinically significant bleeding in some clinical studies. Here, we documented the effects of PR systems on microRNA and mRNA levels of platelets stored in the blood bank, and assessed their impact on platelet activation and function. Unlike platelets subjected to gamma irradiation or stored in additive solution, platelets treated with Intercept (amotosalen+ ultraviolet-A [UVA] light) exhibited significantly reduced levels of 6 of the 11 microRNAs, and 2 of the 3 anti-apoptotic mRNAs (Bcl-xl and Clusterin) that we monitored, compared with platelets stored in plasma. Mirasol (riboflavin+ UVB light) treatment of platelets did not produce these effects. PR neither affected platelet microRNA synthesis or function nor induced cross-linking of microRNA-sized endogenous platelet RNA species. However, the reduction in the platelet microRNA levels induced by Intercept correlated with the platelet activation (p < 0.05) and an impaired platelet aggregation response to ADP (p < 0.05). These results suggest that Intercept treatment may induce platelet activation, resulting in the release of microRNAs and mRNAs from platelets. The clinical implications of this reduction in platelet nucleic acids secondary to Intercept remain to be established.

Fatal infections in older patients with inflammatory bowel disease on anti-tumor necrosis factor therapy

Directory of Open Access Journals (Sweden)

Way-Seah Lee

2017-10-01

Full Text Available Anti-tumor necrosis factor (anti-TNF is highly effective in inflammatory bowel disease (IBD; however, it is associated with an increased risk of infections, particularly in older adults. We reviewed 349 patients with IBD, who were observed over a 12-month period, 74 of whom had received anti-TNF therapy (71 patients were aged <60 years and 3 were aged ≥60 years. All the 3 older patients developed serious infectious complications after receiving anti-TNFs, although all of them were also on concomitant immunosuppressive therapy. One patient developed disseminated tuberculosis, another patient developed cholera diarrhea followed by nosocomial pneumonia, while the third patient developed multiple opportunistic infections (Pneumocystis pneumonia, cryptococcal septicemia and meningitis, Klebsiella septicemia. All 3 patients died within 1 year from the onset of the infection(s. We recommend that anti-TNF, especially when combined with other immunosuppressive therapy, should be used with extreme caution in older adult patients with IBD.

Lipid nano-bubble combined with ultrasound for anti-keloids therapy.

Science.gov (United States)

Wang, Xiao Qing; Li, Zhou-Na; Wang, Qi-Ming; Jin, Hong-Yan; Gao, Zhonggao; Jin, Zhe-Hu

2018-03-01

Keloids were characterized by excessive growth of fibrous tissues, and shared several pathological characteristics with cancer. They did put physical and emotional stress on patients in that keloids could badly change appearance of patients. N-(4-hydroxyphenyl) retinamide (4HPR) showed cytotoxic activity on a wide variety of invasive-growth cells. Our work was aim to prepare N-(4-hydroxyphenyl) retinamide-loaded lipid microbubbles (4HPR-LM) combined with ultrasound for anti-keloid therapy. 4HPR-loaded liposomes (4HPR-L) were first prepared by film evaporation method, and then 4HPR-LM were manufactured by mixing 4HPR-L and perfluoropentane (PFP) with ultrasonic cavitation method. The mean particle size and entrapment efficiency 4HPR-LM were 113 nm and 95%, respectively. The anti-keloids activity of 4HPR-LM was assessed with BALB/c nude mice bearing subcutaneous xenograft keloids model. 4HPR-LM, combined with ultrasound, could significantly induce apoptosis of keloid fibroblasts in vitro and inhibited growth of keloids in vivo. Thus, 4HPR-LM could be considered as a promising agent for anti-keloids therapy.

Crosstalk between Platelets and the Immune System: Old Systems with New Discoveries

Directory of Open Access Journals (Sweden)

Conglei Li

2012-01-01

Full Text Available Platelets are small anucleate cells circulating in the blood. It has been recognized for more than 100 years that platelet adhesion and aggregation at the site of vascular injury are critical events in hemostasis and thrombosis; however, recent studies demonstrated that, in addition to these classic roles, platelets also have important functions in inflammation and the immune response. Platelets contain many proinflammatory molecules and cytokines (e.g., P-selectin, CD40L, IL-1β, etc., which support leukocyte trafficking, modulate immunoglobulin class switch, and germinal center formation. Platelets express several functional Toll-like receptors (TLRs, such as TLR-2, TLR-4, and TLR-9, which may potentially link innate immunity with thrombosis. Interestingly, platelets also contain multiple anti-inflammatory molecules and cytokines (e.g., transforming growth factor-β and thrombospondin-1. Emerging evidence also suggests that platelets are involved in lymphatic vessel development by directly interacting with lymphatic endothelial cells through C-type lectin-like receptor 2. Besides the active contributions of platelets to the immune system, platelets are passively targeted in several immune-mediated diseases, such as autoimmune thrombocytopenia, infection-associated thrombocytopenia, and fetal and neonatal alloimmune thrombocytopenia. These data suggest that platelets are important immune cells and may contribute to innate and adaptive immunity under both physiological and pathological conditions.

Maternal hepatitis C (HCV) infection and Anti-D immunoglobulin therapy: study testing antibodies, RNA and Genotype of HCV in Baghdad.

Science.gov (United States)

Al-Kubaisy, Waqar; Daud, Suzanna; Al-Kubaisi, Mustafa Waseem; Al-Kubaisi, Omar Waseem; Abdullah, Nik Nairan

2018-04-30

Hepatitis C virus (HCV) infection is a serious health problem. It is a major contributor to end-stage liver disease. Worldwide, 1-8% of all pregnant women were infected. Women with viral hepatitis may be at an increased risk of pregnancy complications. There are several obstetrics intervention acts as risk factors, which are specific to women pertaining the HCV infection; anti-D immunoglobulin (Ig) therapy may be one of them. Our objectives were to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. A cross sectional study was conducted. A sample of 154 Rhesus negative (Rh - ve) pregnant women regardless of the anti-D Ig therapy was collected. Anti-HCV were tested using third generation enzyme immunoassay (EIA-3) and immunoblot assay (Lia Tek-111), subsequently. In addition, 89 serum samples were subjected to molecular analysis using RT-PCR and DNA enzyme immunoassay (DEIA) method for the detection of HCV-RNA and genotypes. Anti-HCV, and HCV-RNA seroprevalence were significantly higher (17.1, 35.5%) among women with anti-D Ig than their counter group (6.4, 13.16%), p = .038, .018, respectively. Significant direct positive dose response correlation (r = 0.78, p = .005) had been seen between number of anti-D Ig therapy and anti-HCV seropositive rate. Anti-D Ig therapy act as a risk factor (odds ratio (OR) = 3.01, 95%CI: 1.01-8.9) especially from the third dose onward. Women with anti-D Ig therapy were at higher risk (3.6 times more) of positive HCV-RNA (OR =3.6, 95%CI =1.19-10.837). Genotype HCV-1b showed higher prevalent (52.9%) among the recipients of anti-D Ig therapy while genotype HCV-3a (6.6%) was the lowest. Our study showed that Anti-D immunoglobulin therapy acts as a risk factor for acquiring HCV infection. Screening for HCV should be recommended for all recipients of anti-D Ig. Not only HCV antibodies but HCV-RNA detection being recommended for the diagnosis of HCV

Biomarkers for Anti-Angiogenic Therapy in Cancer

Directory of Open Access Journals (Sweden)

Markus Wehland

2013-04-01

Full Text Available Angiogenesis, the development of new vessels from existing vasculature, plays a central role in tumor growth, survival, and progression. On the molecular level it is controlled by a number of pro- and anti-angiogenic cytokines, among which the vascular endothelial growth factors (VEGFs, together with their related VEGF-receptors, have an exceptional position. Therefore, the blockade of VEGF signaling in order to inhibit angiogenesis was deemed an attractive approach for cancer therapy and drugs interfering with the VEGF-ligands, the VEGF receptors, and the intracellular VEGF-mediated signal transduction were developed. Although promising in pre-clinical trials, VEGF-inhibition proved to be problematic in the clinical context. One major drawback was the generally high variability in patient response to anti-angiogenic drugs and the rapid development of therapy resistance, so that, in total, only moderate effects on progression-free and overall survival were observed. Biomarkers predicting the response to VEGF-inhibition might attenuate this problem and help to further individualize drug and dosage determination. Although up to now no definitive biomarker has been identified for this purpose, several candidates are currently under investigation. This review aims to give an overview of the recent developments in this field, focusing on the most prevalent tumor species.

New Onset of Dermatomyositis/Polymyositis during Anti-TNF-α Therapies: A Systematic Literature Review

Directory of Open Access Journals (Sweden)

Alexandra Maria Giovanna Brunasso

2014-01-01

Full Text Available We performed a systematic search of databases from 1990 to 2013 to identify articles concerning the new onset of dermatomyositis/polymyositis (DM/PM in patients treated with anti-TNF-α therapy. We retrieved 13 publications describing 20 patients where the new onset of DM/PM after anti-TNF-α therapy was recorded. 17 patients were affected by rheumatoid arthritis (RA, one by Crohn’s disease, one by ankylosing spondilytis, and one by seronegative arthritis. In 91% of the cases antinuclear autoantibodies were detected after the introduction of anti-TNF-α therapy. In 6 patients antisynthetase antibodies were detected and other clinical findings as interstitial lung disease (ILD were recorded. Improvement of DM/PM after anti-TNF suspension (with the concomitant use of other immunosuppressors was recorded in 94% of cases. The emergence of DM/PM and antisynthetase syndrome seem to be associated with the use of anti-TNF-α agents, especially in patients with chronic inflammatory diseases (mainly RA with positive autoantibodies before therapy initiation. In particular, physicians should pay attention to patients affected by RA with positive antisynthetase antibodies and/or history of ILD. In those cases, the use of the TNF-α blocking agents may trigger the onset of PM/DM or antisynthetase syndrome or may aggravate/trigger the lung disease.

Anti-stiction coating of PDMS moulds for rapid microchannel fabrication by double replica moulding

DEFF Research Database (Denmark)

Zhuang, Guisheng; Kutter, Jörg Peter

2011-01-01

), which resulted in an anti-stiction layer for the improved release after PDMS casting. The deposition of FDTS on an O2 plasma-activated surface of PDMS produced a reproducible and well-performing anti-stiction monolayer of fluorocarbon, and we used the FDTS-coated moulds as micro-masters for rapid......In this paper, we report a simple and precise method to rapidly replicate master structures for fast microchannel fabrication by double replica moulding of polydimethylsiloxane (PDMS). A PDMS mould was surface-treated by vapour phase deposition of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS...

Methods for genetic modification of megakaryocytes and platelets.

Science.gov (United States)

Pendaries, Caroline; Watson, Stephen P; Spalton, Jennifer C

2007-09-01

During recent decades there have been major advances in the fields of thrombosis and haemostasis, in part through development of powerful molecular and genetic technologies. Nevertheless, genetic modification of megakaryocytes and generation of mutant platelets in vitro remains a highly specialized area of research. Developments are hampered by the low frequency of megakaryocytes and their progenitors, a poor efficiency of transfection and a lack of understanding with regard to the mechanism by which megakaryocytes release platelets. Current methods used in the generation of genetically modified megakaryocytes and platelets include mutant mouse models, cell line studies and use of viruses to transform primary megakaryocytes or haematopoietic precursor cells. This review summarizes the advantages, limitations and technical challenges of such methods, with a particular focus on recent successes and advances in this rapidly progressing field including the potential for use in gene therapy for treatment of patients with platelet disorders.

Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation.

Science.gov (United States)

Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung; Rhee, Man Hee; Kim, Yun-Bae

2013-12-01

The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow.

Anti-EGFR Therapy: Mechanism and Advances in Clinical Efficacy in Breast Cancer

Directory of Open Access Journals (Sweden)

John F. Flynn

2009-01-01

Full Text Available This review will focus on recent advances in the application of antiepidermal growth factor receptor (anti-EGFR for the treatment of breast cancer. The choice of EGFR, a member of the ErbB tyrosine kinase receptor family, stems from evidence pinpointing its role in various anti-EGFR therapies. Therefore, an increase in our understanding of EGFR mechanism and signaling might reveal novel targets amenable to intervention in the clinic. This knowledge base might also improve existing medical treatment options and identify research gaps in the design of new therapeutic agents. While the approved use of drugs like the dual kinase inhibitor Lapatinib represents significant advances in the clinical management of breast cancer, confirmatory studies must be considered to foster the use of anti-EGFR therapies including safety, pharmacokinetics, and clinical efficacy.

A radiolabeled antiglobulin test for crossmatching platelet transfusions

International Nuclear Information System (INIS)

Kickler, T.S.; Braine, H.G.; Ness, P.M.; Koester, A.; Bias, W.

1983-01-01

Despite the use of HLA-matched platelets for alloimmunized recipients, transfusion failures occur. In order to reduce these failures, researchers investigated the use of a radiolabeled antiglobulin technique for platelet crossmatching. The principle of the test is that of an indirect Coombs test using 125 I labeled goat anti-human IgG. Incompatibility is determined by calculating a radioactivity antiglobulin test (RAGT) index. Using this technique, researchers performed 89 crossmatches on 19 leukemic or aplastic patients who were refractory to random donor platelets and receiving varying degrees of HLA-matched platelets. Effectiveness of the transfusion was assessed from the posttransfusion corrected platelet count increment (CCI) determined at 1 and 20 hr. When the RAGT index was 1.9 or less, the mean CCI at 1 lhr was 17,570 +/- 7003/cu mm, n . 55. When the RAGT index was 2.0 or greater, the mean CCI was 4237 +/- 4100/cu mm, n . 34. At 20 hr when the RAGT index was 1.9 or less, the mean CCI was 8722 +/- 3143/cu mm, n . 33, and when the index was 2.0 or greater, the mean CCI was 571 +/- 1286/cu mm, n . 23. Using this technique, one false negative resulted. Nine positive crossmatches with good increments at 1 hr were found; at 20 hr, however, the survival of these units was zero. These data suggest that this method is a useful adjunct in the selection of platelets in the refractory patient

Update: Acute coronary syndromes (V). Personalized antiplatelet therapy.

Science.gov (United States)

Gurbel, Paul A; Rafeedheen, Rahil; Tantry, Udaya S

2014-06-01

It is well established that high on-treatment platelet reactivity to adenosine diphosphate during clopidogrel therapy is an independent risk factor for ischemic event occurrences in a postpercutaneous coronary intervention patients. However, the precise role of platelet function testing remains debated. Platelet function testing to ensure optimal platelet inhibition has been recommended by some authorities to improve outcomes in patients treated with clopidogrel. Recent prospective, randomized trials of personalized antiplatelet therapy have failed to demonstrate a benefit of platelet function testing in improving outcomes. In this review article, we discuss the mechanisms responsible for clopidogrel nonreponsiveness, recent trials of platelet function testing, and other new developments in the field of personalized antiplatelet therapy. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

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.

Dynamics of tumor growth and combination of anti-angiogenic and cytotoxic therapies

Science.gov (United States)

Kohandel, M.; Kardar, M.; Milosevic, M.; Sivaloganathan, S.

2007-07-01

Tumors cannot grow beyond a certain size (about 1-2 mm in diameter) through simple diffusion of oxygen and other essential nutrients into the tumor. Angiogenesis, the formation of blood vessels from pre-existing vessels, is a crucial and observed step, through which a tumor obtains its own blood supply. Thus, strategies that interfere with the development of this tumor vasculature, known as anti-angiogenic therapy, represent a novel approach to controlling tumor growth. Several pre-clinical studies have suggested that currently available angiogenesis inhibitors are unlikely to yield significant sustained improvements in tumor control on their own, but rather will need to be used in combination with conventional treatments to achieve maximal benefit. Optimal sequencing of anti-angiogenic treatment and radiotherapy or chemotherapy is essential to the success of these combined treatment strategies. Hence, a major challenge to mathematical modeling and computer simulations is to find appropriate dosages, schedules and sequencing of combination therapies to control or eliminate tumor growth. Here, we present a mathematical model that incorporates tumor cells and the vascular network, as well as their interplay. We can then include the effects of two different treatments, conventional cytotoxic therapy and anti-angiogenic therapy. The results are compared with available experimental and clinical data.

Recognition and management of platelet-refractory bleeding in patients with Glanzmann’s thrombasthenia and other severe platelet function disorders

Directory of Open Access Journals (Sweden)

Chitlur M

2017-04-01

Full Text Available Meera Chitlur,1 Madhvi Rajpurkar,1 Michael Recht,2 Michael D Tarantino,3 Donald L Yee,4 David L Cooper,5 Sriya Gunawardena5 1Carman and Ann Adams Department of Pediatrics, Wayne State University and Children’s Hospital of Michigan, Detroit, MI, USA; 2Oregon Health and Science University, Portland, OR, USA; 3Bleeding and Clotting Disorders Institute, Peoria, IL, USA; 4Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; 5Clinical Development, Medical and Regulatory Affairs, Novo Nordisk Inc., Plainsboro, NJ, USA Abstract: Patients with rare qualitative platelet disorders or platelet function disorders (PFDs may present to the hospital physician with severe bleeding episodes or excessive surgical bleeding. Although standard treatment consists of platelet transfusions, repeated transfusions may result in the development of antiplatelet antibodies (APA or clinical refractoriness, rendering further platelet therapy ineffective. In such settings, an approved treatment option for patients with Glanzmann’s thrombasthenia (GT, one of the well-known rare PFDs, is recombinant activated coagulation factor VII (rFVIIa. Data regarding the efficacy of rFVIIa in patients with GT and platelet refractoriness are available from a large patient registry, an international survey, and multiple case reports and demonstrate efficacy in patients with and without refractoriness or APA. This article reviews the rFVIIa clinical data in patients with GT and platelet refractoriness and discusses clinical implications relevant to the hospital-based physician. Because uncontrolled bleeding can be life-threatening, hospital physicians should be alert to the signs of platelet refractoriness, be able to recognize continued internal or external bleeding, and know how to adapt treatment regimens for the effective management of bleeding. The management of patients who receive rFVIIa should occur in consultation with a hematologist with experience in PFDs, and

Platelet antibody in prolonged remission of childhood idiopathic thrombocytopenic purpura

International Nuclear Information System (INIS)

Ware, R.; Kinney, T.R.; Rosse, W.

1985-01-01

Evaluations were performed in 20 patients with childhood idiopathic thrombocytopenic purpura (ITP) who remained in remission longer than 12 months. The mean duration of follow-up from diagnosis was 39 months (range 17 to 87 months). Eleven patients (four girls) in group 1 had an acute course of ITP, defined as platelet count greater than 150 X 10(9)/L within 6 months of diagnosis. Nine patients (five girls) in group 2 had a chronic course, defined as platelet count less than 150 X 10(9)/L for greater than or equal to 1 year or requiring splenectomy in an attempt to control hemorrhagic symptoms. Platelet count and serum (indirect) platelet-associated IgG (PAIgG) levels were normal in all 20 patients at follow-up. Both direct and indirect PAIgG levels were measured using a 125 I-monoclonal anti-IgG antiglobulin assay. All had normal direct PAIgG levels, except for one patient in group 1 who had a borderline elevated value of 1209 molecules per platelet. These data suggest that the prevalence of elevated platelet antibodies is low during sustained remission without medication in patients with a history of childhood ITP. These data may be relevant for pregnant women with a history of childhood ITP, with regard to the risk of delivering an infant with thrombocytopenia secondary to transplacental passage of maternal platelet antibody

Patients' perceptions of a rural decentralised anti-retroviral therapy ...

African Journals Online (AJOL)

Background: Geographical and financial barriers hamper accessibility to HIV services for rural communities. The government has introduced the nurse initiated management of anti-retroviral therapy at primary health care level, in an effort to improve patient access and reduce patient loads on facilities further up the system.

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.

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.

[Anti-FGF23 antibody therapy for patients with tumor-induced osteomalacia].

Science.gov (United States)

Kinoshita, Yuka; Fukumoto, Seiji

2014-08-01

Tumor-induced osteomalacia (TIO) is a disease caused by fibroblast growth factor 23 (FGF23) secreted from the causative tumor. This disease is cured by complete surgical removal of the tumor. However, there are several difficult cases in which the responsible tumors cannot be found, are incompletely removed, or relapse after the surgery. Anti-FGF23 antibody is being studied as a novel therapy for FGF23-related hypophosphatemic diseases. The efficacy of anti-FGF23 antibodies were confirmed using a murine model of X-linked hypophosphatemic rickets (XLHR) , which is the most common heritable form of FGF23-related hypophosphatemic disease. In addition, results of phase I study of single injection of humanized anti-FGF23 antibody for adult patients with XLHR were recently published and the safety and effectiveness of this antibody was shown. This antibody therapy may be useful for patients with TIO with similar pathogenesis to that of XLHR.

Anti-hLAMP2-antibodies and dual positivity for anti-GBM and MPO-ANCA in a patient with relapsing pulmonary-renal syndrome

Directory of Open Access Journals (Sweden)

Kistler Thomas

2011-06-01

Full Text Available Abstract Background Pulmonary-renal syndrome associated with anti-glomerular basement membrane (GBM antibodies, also known as Goodpasture's syndrome, is a rare but acute and life-threatening condition. One third of patients presenting as anti-GBM antibody positive pulmonary-renal syndrome or rapidly progressive glomerulonephritis are also tested positive for anti-neutrophil cytoplasmic antibodies (ANCA. Whilst anti-GBM disease is considered a non-relapsing condition, the long-term course of double-positive patients is less predictable. Case Presentation We report a patient with such dual positivity, who presented with pulmonary hemorrhage, crescentic glomerulonephritis and membranous nephropathy. Plasmapheresis in combination with immunosuppresive therapy led to a rapid remission but the disease relapsed after two years. The serum of the patient was tested positive for antibodies to human lysosomal membrane protein 2 (hLAMP2, a novel autoantigen in patients with active small-vessel vasculitis (SVV. The anti-hLAMP2 antibody levels correlated positively with clinical disease activity in this patient. Conclusion We hypothesize that this antibody may indicate a clinical course similar to ANCA-associated vasculitis in double-positive patients. However, this needs to be confirmed on comprehensive patient cohorts.

An introduction to application of Platelet Rich Plasma (PRP in skin rejuvenation

Directory of Open Access Journals (Sweden)

Mahnaz Banihashemi

2014-04-01

Full Text Available Platelet-rich plasma (PRP is an autologous concentration of human platelets contained in a small volume of plasma characterized by haemostatic and tissue repairing effects. Tissue repairing effects and being enriched by various kind of growth factors, has made them the focus of attention for different procedures. PRP has been effective in bony defects, wound healing and recently for aesthetic procedures in plastic surgery. The purpose of this review is to evaluate and summarize the applications of PRP in the dermatology literature, with particular focus on rejuvenizaton process, advances and limitations of current PRP therapies. We studied literature related to PRP therapy, these include regeneration of soft tissue, skin aging mechanisms, as well as wound healing. Some studies have shown promising results, with favorable outcomes about PRP clinical application for skin rejuvenization. This article summarizes our current understanding regarding photoaging process and the role of PRP in the skin rejuvenization process. PRP has been shown to be useful in skin rejuvenization. Further studies are needed to elucidate both basic and clinical aspects of PRP therapies. In particular, platelet preparation methods, different application methods, platelet mechanism of action in rejuvenation field, interactions with the skin components, long-term efficacy and safety are necessary to be determined.

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

Matrix metalloproteinase content and activity in low-platelet, low-leukocyte and high-platelet, high-leukocyte platelet rich plasma (PRP) and the biologic response to PRP by human ligament fibroblasts.

Science.gov (United States)

Pifer, Matthew A; Maerz, Tristan; Baker, Kevin C; Anderson, Kyle

2014-05-01

Recent work has shown the presence of catabolic cytokines in platelet-rich plasma (PRP), but little is known about endogenous catabolic proteases such as matrix metalloproteinases (MMPs). Hypothesis/ To quantify MMP content in 2 commercially available PRP preparation systems: Arthrex Double Syringe System autologous conditioned plasma (ACP) and Biomet GPS (GPS). The hypothesis was that MMPs are actively secreted from PRP immediately after preparation. Controlled laboratory study. PRP was prepared using either ACP (low platelet, low leukocyte) or GPS (high platelet, high leukocyte). MMP-2, MMP-3, and MMP-9 concentrations were measured using multiplex enzyme-linked immunosorbent assays for up to 6 days in 2 donors, and MMP activity was measured in 3 donors using kinetic activity kits able to detect the enzymatic cleavage of a fluorogenic peptide. Human ligament fibroblasts were cultured and exposed to both ACP and GPS from 1 donor each. MMP-2, -3, and -9 concentrations were assayed in culture media at 24 and 48 hours after exposure. GPS exhibited higher total MMP-2, -3, and -9 concentrations for up to 144 hours of release, while ACP had higher platelet-normalized MMP-2 and MMP-3 concentrations. GPS had significantly higher total and endogenous MMP-2 activity (P = .004 and .014, respectively), MMP-3 activity (P = .020 and .015, respectively), and MMP-9 activity (P = .004 and .002, respectively) compared with ACP. Once normalized to platelet count, differences in MMP activity were not significant between ACP and GPS. Compared with controls, cells stimulated with interleukin-1 beta (IL-1β) and treated with ACP showed significantly higher fold changes of MMP-2 (P = .001) and MMP-3 (P = .003) concentrations at 24 hours than did cells treated with GPS. Total MMP-9 content was higher in the media of GPS-treated, IL-1β-stimulated cells compared with ACP-treated cells (P = .001). At 48 hours, IL-1β-stimulated cells treated with GPS exhibited higher fold changes of MMP-2

Intramammary administration of platelet concentrate as an unconventional therapy in bovine mastitis: first clinical application.

Science.gov (United States)

Lange-Consiglio, A; Spelta, C; Garlappi, R; Luini, M; Cremonesi, F

2014-10-01

Bovine udder infections induce a variety of changes in gene expression of different growth factors that may suggest their possible role in glandular tissue protection or repair processes. Growth factors and also chemokines and cytokines may act synergistically to increase the infiltration of neutrophils and macrophages to promote angiogenesis, fibroplasia, matrix deposition, and, ultimately, re-epithelialization. Considering the vast applications, typically in human medicine, of platelet concentrate (PC) and its ease of preparation, the aim of our study was to evaluate an alternative therapy to stimulate the regeneration of glandular tissue, administering a concentration in excess of the growth factors contained in the PC. In each one of the 3 farms examined in the trial, PC was prepared from donor cows in good health, free from infections, and with no records of medications administered during the previous 2 mo. The platelet produced in one farm was used only for treating the cows of the same farm in a heterologous way. A total of 229 mastitic quarters were divided in 3 groups: antibiotic group (treated with intramammary antibiotic), antibiotic and PC group (treated intramammarily with antibiotics in association with PC), and PC group (treated with intramammary PC alone). The diagnosis of mastitis was based on somatic cell count and bacteriological evaluation of the milk from the affected quarter. Platelet concentrate, alone or in association with antibiotic, was used for 3 consecutive days as an unconventional therapy in bovine acute and chronic mastitis. Our data show that the associated action of antibiotic and PC performed significantly better than the antibiotic alone, either for the recovery of the affected mammary quarters or for somatic cell count reduction. In the same way, the association antibiotic plus PC showed significantly fewer relapses compared with the antibiotic alone, either for acute or chronic mastitis. The treatment with only PC did not show

Assessment of immature platelet fraction in the diagnosis of Wiskott-Aldrich syndrome

Directory of Open Access Journals (Sweden)

Robert eSokolic

2015-06-01

Full Text Available Children with Wiskott-Aldrich syndrome (WAS are often first diagnosed with immune thrombocytopenia (ITP, potentially leading to both inappropriate treatment and the delay of life-saving definitive therapy. WAS is traditionally differentiated from ITP based on the small size of WAS platelets. In practice, microthrombocytopenia is often not present or not appreciated in children with WAS. To develop an alternative method of differentiating WAS from ITP, we retrospectively reviewed all complete blood counts and measurements of immature platelet fraction (IPF in 18 subjects with WAS and 38 subjects with a diagnosis of ITP treated at our hospital. Examination of peripheral blood smears revealed a wide range of platelet sizes in subjects with WAS. Mean platelet volume (MPV was not reported in 26% of subjects, and subjects in whom MPV was not reported had lower platelet counts than did subjects in whom MPV was reported. Subjects with WAS had a lower immature platelet fraction (IPF than would be expected for their level of thrombocytopenia, and the IPF in subjects with WAS was significantly lower than in subjects with a diagnosis of ITP. Using logistic regression, we developed and validated a rule based on platelet count and IPF that was more sensitive for the diagnosis of WAS than was the MPV, and was applicable regardless of the level of platelets or the availability of the MPV. Our observations demonstrate that MPV is often not available in severely thrombocytopenic subjects, which may hinder the diagnosis of WAS. In addition, subjects with WAS have a low IPF, which is consistent with the notion that a platelet production defect contributes to the thrombocytopenia of WAS. Knowledge of this detail of WAS pathophysiology allows to differentiate WAS from ITP with increased sensitivity, thereby allowing a physician to spare children with WAS from inappropriate treatment, and make definitive therapy available in a timely manner.

Deletion of GLUT1 and GLUT3 Reveals Multiple Roles for Glucose Metabolism in Platelet and Megakaryocyte Function

Directory of Open Access Journals (Sweden)

Trevor P. Fidler

2017-07-01

Full Text Available Anucleate platelets circulate in the blood to facilitate thrombosis and diverse immune functions. Platelet activation leading to clot formation correlates with increased glycogenolysis, glucose uptake, glucose oxidation, and lactic acid production. Simultaneous deletion of glucose transporter (GLUT 1 and GLUT3 (double knockout [DKO] specifically in platelets completely abolished glucose uptake. In DKO platelets, mitochondrial oxidative metabolism of non-glycolytic substrates, such as glutamate, increased. Thrombosis and platelet activation were decreased through impairment at multiple activation nodes, including Ca2+ signaling, degranulation, and integrin activation. DKO mice developed thrombocytopenia, secondary to impaired pro-platelet formation from megakaryocytes, and increased platelet clearance resulting from cytosolic calcium overload and calpain activation. Systemic treatment with oligomycin, inhibiting mitochondrial metabolism, induced rapid clearance of platelets, with circulating counts dropping to zero in DKO mice, but not wild-type mice, demonstrating an essential role for energy metabolism in platelet viability. Thus, substrate metabolism is essential for platelet production, activation, and survival.

Anti-inflammatory therapy for urinary tract infection in children

Directory of Open Access Journals (Sweden)

A. A. Vyalkova

2015-01-01

Full Text Available Objective: to substantiate the importance of an etiological approach to diagnosing urinary tract infection in children in terms of the species and biological properties of an infectious agent and to evaluate the efficiency of anti-inflammatory therapy. The study included 116 patients aged 3-15 years with chronic pyelonephritis (Group 1 and isolated bacteriuria (Group 2. After 10-14-day antibiotic therapy, Group 1 patients were allocated to two subgroups: Subgroup la («=30 took furamag 5 mg/kg/day; Subgroup lb («=30 received furamag at the same dose in combination with canephron. The treatment cycle lasted 10-14 days. Subgroup 2a («=26 children had furamag 5 mgДg/day and Subgroup 2b (« =30 took furamag in combination with canephron. The duration of treatment was 14 days. The investigators established the high efficiency of therapy with furamag for renal infection in the children with the active and decrement phases and that of the drug of choice for its monotherapy of isolated highly virulent bacteriuria. Therapeutic efficiency was proven to be related to the species and biological characteristics of an infectious agent. Anti-inflammatory therapy for pyelonephritis in terms of the species of pathogenic bacteria was ascertained to improve the efficiency of treatment. A rationale was provided for the individual choice of antibiotics, followed by the use of furamag, eubiotics, and drugs aimed at inhibiting virulence factors and persistence of the pathogen to sanitize the primary focus of infection.

Platelet-rich plasma differs according to preparation method and human variability.

Science.gov (United States)

Mazzocca, Augustus D; McCarthy, Mary Beth R; Chowaniec, David M; Cote, Mark P; Romeo, Anthony A; Bradley, James P; Arciero, Robert A; Beitzel, Knut

2012-02-15

Varying concentrations of blood components in platelet-rich plasma preparations may contribute to the variable results seen in recently published clinical studies. The purposes of this investigation were (1) to quantify the level of platelets, growth factors, red blood cells, and white blood cells in so-called one-step (clinically used commercial devices) and two-step separation systems and (2) to determine the influence of three separate blood draws on the resulting components of platelet-rich plasma. Three different platelet-rich plasma (PRP) separation methods (on blood samples from eight subjects with a mean age [and standard deviation] of 31.6 ± 10.9 years) were used: two single-spin processes (PRPLP and PRPHP) and a double-spin process (PRPDS) were evaluated for concentrations of platelets, red and white blood cells, and growth factors. Additionally, the effect of three repetitive blood draws on platelet-rich plasma components was evaluated. The content and concentrations of platelets, white blood cells, and growth factors for each method of separation differed significantly. All separation techniques resulted in a significant increase in platelet concentration compared with native blood. Platelet and white blood-cell concentrations of the PRPHP procedure were significantly higher than platelet and white blood-cell concentrations produced by the so-called single-step PRPLP and the so-called two-step PRPDS procedures, although significant differences between PRPLP and PRPDS were not observed. Comparing the results of the three blood draws with regard to the reliability of platelet number and cell counts, wide variations of intra-individual numbers were observed. Single-step procedures are capable of producing sufficient amounts of platelets for clinical usage. Within the evaluated procedures, platelet numbers and numbers of white blood cells differ significantly. The intra-individual results of platelet-rich plasma separations showed wide variations in

Discontinuation of anti-VEGF cancer therapy promotes metastasis through a liver revascularization mechanism

DEFF Research Database (Denmark)

Yang, Yunlong; Zhang, Yin; Iwamoto, Hideki

2016-01-01

The impact of discontinuation of anti-VEGF cancer therapy in promoting cancer metastasis is unknown. Here we show discontinuation of anti-VEGF treatment creates a time-window of profound structural changes of liver sinusoidal vasculatures, exhibiting hyper-permeability and enlarged open-pore size...

Anti-tumor effects of Egr-IFN gamma gene therapy combined with {sup 125}I-UdR radionuclide therapy

Energy Technology Data Exchange (ETDEWEB)

Jingguo, Zhao [No.403 Hospital of PLA, Dalian (China); Yanjun, Ni; Xiangfu, Song; Yanyi, Li; Wei, Yang; Ting, Sun; Qingjie, Ma; Fengtong, Gao

2008-12-15

Objective: To explore the anti-tumor effects of Egr-IFNgamma gene therapy combined with {sup 125}I-UdR radionuclide therapy in mice bearing H22 hepatocarcinoma and its mechanism. Methods: The recombinant plasmid pcDNAEgr-IFNgamma mixed with liposome was injected into tumor. 48 h later, 370 kBq {sup 125}I-UdR was injected into tumor. The tumor growth rates at different times were observed. After 3 d gene-radionuclide therapy, the concentration of IFNgamma in cytoplasm of H22 cells and cytotoxic activities of splenic CTL of the mice in different groups were examined. Results: The tumor growth rates of pcDNAEgr-IFNgamma + {sup 125}I-UdR group were obviously lower than those of control group, {sup 125}I-UdR group and pcDNAEgr-1 + {sup 125}I-UdR group 6-15 d after gene-radionuclide therapy. IFNgamma protein was found in cytoplasm of H22 cells in pcDNAEgr-IFNgamma + {sup 125}I-UdR group after 3 d gene-radionuclide therapy. Cytotoxic activity of splenic CTL in pcDNAEgr-IFNgamma + {sup 125}I-UdR group was significantly higher than that in the other groups (P<0.01). Conclusions: The anti-tumor effects in vivo of pcDNAEgr-IFNgamma gene therapy combined with {sup 125}I-UdR radionuclide therapy are better than those of {sup 125}I-UdR therapy. (authors)

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.

PKCalpha regulates platelet granule secretion and thrombus formation in mice.

Science.gov (United States)

Konopatskaya, Olga; Gilio, Karen; Harper, Matthew T; Zhao, Yan; Cosemans, Judith M E M; Karim, Zubair A; Whiteheart, Sidney W; Molkentin, Jeffery D; Verkade, Paul; Watson, Steve P; Heemskerk, Johan W M; Poole, Alastair W

2009-02-01

Platelets are central players in atherothrombosis development in coronary artery disease. The PKC family provides important intracellular mechanisms for regulating platelet activity, and platelets express several members of this family, including the classical isoforms PKCalpha and PKCbeta and novel isoforms PKCdelta and PKCtheta. Here, we used a genetic approach to definitively demonstrate the role played by PKCalpha in regulating thrombus formation and platelet function. Thrombus formation in vivo was attenuated in Prkca-/- mice, and PKCalpha was required for thrombus formation in vitro, although this PKC isoform did not regulate platelet adhesion to collagen. The ablation of in vitro thrombus formation in Prkca-/- platelets was rescued by the addition of ADP, consistent with the key mechanistic finding that dense-granule biogenesis and secretion depend upon PKCalpha expression. Furthermore, defective platelet aggregation in response to either collagen-related peptide or thrombin could be overcome by an increase in agonist concentration. Evidence of overt bleeding, including gastrointestinal and tail bleeding, was not seen in Prkca-/- mice. In summary, the effects of PKCalpha ablation on thrombus formation and granule secretion may implicate PKCalpha as a drug target for antithrombotic therapy.

Dual-specificity phosphatase 3 deficiency or inhibition limits platelet activation and arterial thrombosis.

Science.gov (United States)

Musumeci, Lucia; Kuijpers, Marijke J; Gilio, Karen; Hego, Alexandre; Théâtre, Emilie; Maurissen, Lisbeth; Vandereyken, Maud; Diogo, Catia V; Lecut, Christelle; Guilmain, William; Bobkova, Ekaterina V; Eble, Johannes A; Dahl, Russell; Drion, Pierre; Rascon, Justin; Mostofi, Yalda; Yuan, Hongbin; Sergienko, Eduard; Chung, Thomas D Y; Thiry, Marc; Senis, Yotis; Moutschen, Michel; Mustelin, Tomas; Lancellotti, Patrizio; Heemskerk, Johan W M; Tautz, Lutz; Oury, Cécile; Rahmouni, Souad

2015-02-17

A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. A better understanding of the molecular mechanisms leading to platelet activation is important for the development of improved therapies. Recently, protein tyrosine phosphatases have emerged as critical regulators of platelet function. This is the first report implicating the dual-specificity phosphatase 3 (DUSP3) in platelet signaling and thrombosis. This phosphatase is highly expressed in human and mouse platelets. Platelets from DUSP3-deficient mice displayed a selective impairment of aggregation and granule secretion mediated by the collagen receptor glycoprotein VI and the C-type lectin-like receptor 2. DUSP3-deficient mice were more resistant to collagen- and epinephrine-induced thromboembolism compared with wild-type mice and showed severely impaired thrombus formation on ferric chloride-induced carotid artery injury. Intriguingly, bleeding times were not altered in DUSP3-deficient mice. At the molecular level, DUSP3 deficiency impaired Syk tyrosine phosphorylation, subsequently reducing phosphorylation of phospholipase Cγ2 and calcium fluxes. To investigate DUSP3 function in human platelets, a novel small-molecule inhibitor of DUSP3 was developed. This compound specifically inhibited collagen- and C-type lectin-like receptor 2-induced human platelet aggregation, thereby phenocopying the effect of DUSP3 deficiency in murine cells. DUSP3 plays a selective and essential role in collagen- and C-type lectin-like receptor 2-mediated platelet activation and thrombus formation in vivo. Inhibition of DUSP3 may prove therapeutic for arterial thrombosis. This is the first time a protein tyrosine phosphatase, implicated in platelet signaling, has been targeted with a small-molecule drug. © 2014 American Heart Association, Inc.

Anti-lipopolysaccharide toxin therapy for whole body X-irradiation overdose

Energy Technology Data Exchange (ETDEWEB)

Gaffin, S.L.; Wells, M.; Jordan, J.P.

1985-09-01

Death in humans from ionising radiation overexposure in the 3-8 Gy (300-800 rad) range is in part due to the toxaemia caused by the entry of gram-negative bacteria and/or their lipopolysaccharide toxin (LPS) into the blood circulation through the walls of partially denuded gut. Anti-LPS hyperimmune equine plasma was evaluated for its ability to lower irradiation-induced lethality. Mice were irradiated with 6.3 Gy (630 rad) and six days later received equine Anti-LPS hyperimmune plasma, control plasma or saline. Mortalities in the three groups were 58%, 92% and 79% (p < 0.01) respectively. Thus Anti-LPS may prove useful as an adjunct to conventional therapy in treating radiation sickness.

Anti-lipopolysaccharide toxin therapy for whole body X-irradiation overdose

International Nuclear Information System (INIS)

Gaffin, S.L.; Wells, M.; Jordan, J.P.

1985-01-01

Death in humans from ionising radiation overexposure in the 3-8 Gy (300-800 rad) range is in part due to the toxaemia caused by the entry of gram-negative bacteria and/or their lipopolysaccharide toxin (LPS) into the blood circulation through the walls of partially denuded gut. Anti-LPS hyperimmune equine plasma was evaluated for its ability to lower irradiation-induced lethality. Mice were irradiated with 6.3 Gy (630 rad) and six days later received equine Anti-LPS hyperimmune plasma, control plasma or saline. Mortalities in the three groups were 58%, 92% and 79% (p<0.01) respectively. Thus Anti-LPS may prove useful as an adjunct to conventional therapy in treating radiation sickness. (author)

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.

Anti-HPA-1b Mediated Posttransfusion Purpura: A Case Report

Directory of Open Access Journals (Sweden)

O. P. Arewa

2013-01-01

Full Text Available Posttransfusion purpura (PTP is an uncommon, but potentially fatal, transfusion reaction characterized by profound thrombocytopenia and bleeding. PTP is caused by alloimmunization to human platelet specific antigens following blood component transfusion. Although there is evidence of a wide serological spectrum of culprit antibodies implicated, Anti-human-platelet-antigen- (HPA- 1a is the most common antibody in cases reported. We report a case of posttransfusion purpura in an African American. The patient was negative for HPA-1a antibodies, but anti-HPA-1b was identified with a platelet phenotype of HPA-1a/HPA-1a. Although less common, HPA-1b antibody may be an important consideration in posttransfusion purpura diagnosed in patients of African descent.

Radioimmunotherapy of indolent non-Hodgkin's lymphoma with Yttrium-90 labeled anti-CD20 monoclonal antibody therapy does not preclude subsequent chemotherapy or autologous hematologic stem cell transplantation therapy in most patients

International Nuclear Information System (INIS)

Wiseman, G.A.; Witzig, T.E.; Ansell, S.M.; Ristow, K.M.

2002-01-01

Introduction: Yttrium-90 (Y-90) labeled anti-CD20 monoclonal antibody (ibritumomab tiuxetan or Zevalin TM ) is a novel therapy for patients with relapsed CD20+ B-cell non-Hodgkin's lymphoma (NHL). Patients treated with Zevalin radioimmunotherapy (RIT) are limited from higher doses due to transient and reversible platelet and neutrophil suppression. Patients with indolent NHL who relapse or are refractory to chemotherapy have a 70-80% overall response rate and a 20-30% complete response rate when treated with Zevalin RIT. Therefore additional treatment is required in a minority of patients shortly after Zevalin therapy and in many others at relapse. Relapsed patients are generally treated with chemotherapy alone or high dose chemotherapy followed by autologous transplantation. We wanted to evaluate the ability of patients to tolerate subsequent therapy given at relapse following Zevalin RIT. Methods: We had 58 patients who relapsed after receiving Zevalin RIT and later received additional therapy. The clinical records and lab results were reviewed and compared with a matched control group of patients treated prior to Zevalin availability who received chemotherapy without prior Zevalin RIT. Results: The toxicity in 58 patients treated with Zevalin RIT and subsequent therapy was not significantly different from the control group who did not receive Zevalin RIT. Patients had a median of two subsequent therapies (range, 1-7) after Zevalin. Twenty eight percent required blood cell growth factor support with subsequent chemotherapy and 2 patients required reductions from the standard chemotherapy doses due to prolonged myelosuppression. Eight patients subsequently had successful autologous hematologic stem cell transplant with cells collected after Zevalin. Thirteen of the 58 patients (28%) treated with standard dose chemotherapy were hospitalized for neutropenic fever or thrombocytopenia. Conclusions: Chemotherapy or high dose chemotherapy with autologous transplantation

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)

Clinical features and effect of antiviral therapy on anti-liver/kidney microsomal antibody type 1 positive chronic hepatitis C.

Science.gov (United States)

Ferri, Silvia; Muratori, Luigi; Quarneti, Chiara; Muratori, Paolo; Menichella, Rita; Pappas, Georgios; Granito, Alessandro; Ballardini, Giorgio; Bianchi, Francesco B; Lenzi, Marco

2009-06-01

Anti-liver/kidney microsomal antibody type 1 (anti-LKM1), a serological marker of type 2 autoimmune hepatitis, is also detected in a small proportion of patients with hepatitis C. This study aimed to evaluate clinical features and effect of antiviral therapy in patients with hepatitis C who are anti-LKM1 positive. Sixty consecutive anti-LKM1 positive and 120 age and sex-matched anti-LKM1 negative chronic hepatitis C patients were assessed at diagnosis and during follow-up. Of these, 26 anti-LKM1 positive and 72 anti-LKM1 negative received antiviral therapy. Anti-LKM1 was detected by indirect immunofluorescence and immunoblot. Number of HCV-infected hepatocytes and intrahepatic CD8+ lymphocytes was determined by immunohistochemistry. At diagnosis anti-LKM1 positive patients had higher IgG levels and more intrahepatic CD8+ lymphocytes (p 0.022 and 0.046, respectively). Viral genotypes distribution and response to therapy were identical. Hepatic flares during antiviral treatment only occurred in a minority of patients in concomitance with anti-LKM1 positivity. Immune system activation is more pronounced in anti-LKM1 positive patients with hepatitis C, possibly representing the expression of autoimmune mechanisms of liver damage. Antiviral treatment is as beneficial in these patients as in anti-LKM1 negative patients, and the rare necroinflammatory flares are effectively controlled by corticosteroids, allowing subsequent resumption of antiviral therapy.

Selected anti-tumor vaccines merit a place in multimodal tumor therapies

Energy Technology Data Exchange (ETDEWEB)

Weiss, Eva-Maria; Wunderlich, Roland [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen (Germany); Ebel, Nina [Department of Process Technology and Machinery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen (Germany); Rubner, Yvonne [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen (Germany); Schlücker, Eberhard [Department of Process Technology and Machinery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen (Germany); Meyer-Pittroff, Roland [Competence Pool Weihenstephan, Technische Universität München, Freising (Germany); Ott, Oliver J.; Fietkau, Rainer; Gaipl, Udo S.; Frey, Benjamin, E-mail: benjamin.frey@uk-erlangen.de [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen (Germany)

2012-10-09

Multimodal approaches are nowadays successfully applied in cancer therapy. Primary locally acting therapies such as radiotherapy (RT) and surgery are combined with systemic administration of chemotherapeutics. Nevertheless, the therapy of cancer is still a big challenge in medicine. The treatments often fail to induce long-lasting anti-tumor responses. Tumor recurrences and metastases result. Immunotherapies are therefore ideal adjuncts to standard tumor therapies since they aim to activate the patient's immune system against malignant cells even outside the primary treatment areas (abscopal effects). Especially cancer vaccines may have the potential both to train the immune system against cancer cells and to generate an immunological memory, resulting in long-lasting anti-tumor effects. However, despite promising results in phase I and II studies, most of the concepts finally failed. There are some critical aspects in development and application of cancer vaccines that may decide on their efficiency. The time point and frequency of medication, usage of an adequate immune adjuvant, the vaccine's immunogenic potential, and the tumor burden of the patient are crucial. Whole tumor cell vaccines have advantages compared to peptide-based ones since a variety of tumor antigens (TAs) are present. The master requirements of cell-based, therapeutic tumor vaccines are the complete inactivation of the tumor cells and the increase of their immunogenicity. Since the latter is highly connected with the cell death modality, the inactivation procedure of the tumor cell material may significantly influence the vaccine's efficiency. We therefore also introduce high hydrostatic pressure (HHP) as an innovative inactivation technology for tumor cell-based vaccines and outline that HHP efficiently inactivates tumor cells by enhancing their immunogenicity. Finally studies are presented proving that anti-tumor immune responses can be triggered by combining RT with selected

Survival benefit of anti-HER2 therapy after whole-brain radiotherapy in HER2-positive breast cancer patients with brain metastasis.

Science.gov (United States)

Zhang, Qian; Chen, Jian; Yu, Xiaoli; Cai, Gang; Yang, Zhaozhi; Cao, Lu; Hu, Chaosu; Guo, Xiaomao; Sun, Jing; Chen, Jiayi

2016-09-01

We aimed to assess the survival benefit of epidermal growth factor receptor 2 (HER2)-positive breast cancer patients with brain metastasis (BM) after whole-brain radiotherapy (WBRT) in combination with systemic treatments, especially anti-HER2 therapy. This retrospective study analyzed the overall survival (OS) of 60 HER2-positive breast cancer patients with BM after WBRT in combination with systemic treatments. Among them, 42 patients received chemotherapy while 18 patients did not receive after WBRT. With regard to anti-HER2 therapy, after WBRT, 17 patients received anti-HER2 treatment without prior adjuvant trastuzumab-based therapy, 7 patients received anti-HER2 treatment with prior adjuvant trastuzumab-based therapy, and 36 patients did not receive further anti-HER2 treatment. All patients were followed up regularly until January 23, 2013. The median OS of patients with BM was 12 months. Patients who received anti-HER2 therapy and chemotherapy after WBRT had significantly better survival compared with patients who did not receive further treatment. Patients who received anti-HER2 treatment after WBRT but did not receive adjuvant trastuzumab-based therapy for early breast cancer had better OS, followed by patients who received anti-HER2 agent both in adjuvant treatment and after WBRT and patients who did not receive anti-HER2 treatment. Multivariate analysis showed that Karnofsky Performance Status, control of extracranial metastases, chemotherapy after WBRT, and anti-HER2 therapy combined with WBRT were all independent predictors for OS. Both chemotherapy and anti-HER2 therapy after WBRT could improve OS. Moreover, patients without prior exposure to adjuvant anti-HER2 treatment may have survival benefit superior to those of patients with prior exposure.

Anti-EGFR immunonanoparticles containing IL12 and salmosin genes for targeted cancer gene therapy.

Science.gov (United States)

Kim, Jung Seok; Kang, Seong Jae; Jeong, Hwa Yeon; Kim, Min Woo; Park, Sang Il; Lee, Yeon Kyung; Kim, Hong Sung; Kim, Keun Sik; Park, Yong Serk

2016-09-01

Tumor-directed gene delivery is of major interest in the field of cancer gene therapy. Varied functionalizations of non-viral vectors have been suggested to enhance tumor targetability. In the present study, we prepared two different types of anti-EGF receptor (EGFR) immunonanoparticles containing pDNA, neutrally charged liposomes and cationic lipoplexes, for tumor-directed transfection of cancer therapeutic genes. Even though both anti-EGFR immunonanoparticles had a high binding affinity to the EGFR-positive cancer cells, the anti-EGFR immunolipoplex formulation exhibited approximately 100-fold higher transfection to the target cells than anti-EGFR immunoliposomes. The lipoplex formulation also showed a higher transfection to SK-OV-3 tumor xenografts in mice. Thus, IL12 and/or salmosin genes were loaded in the anti-EGFR immunolipoplexes and intravenously administered to mice carrying SK-OV-3 tumors. Co-transfection of IL12 and salmosin genes using anti-EGFR immunolipoplexes significantly reduced tumor growth and pulmonary metastasis. Furthermore, combinatorial treatment with doxorubicin synergistically inhibited tumor growth. These results suggest that anti-EGFR immunolipoplexes containing pDNA encoding therapeutic genes could be utilized as a gene-transfer modality for cancer gene therapy.

The Clinical Efficacy of Autologous Platelet-Rich Plasma Combined with Ultra-Pulsed Fractional CO2 Laser Therapy for Facial Rejuvenation.

Science.gov (United States)

Hui, Qiang; Chang, Peng; Guo, Bingyu; Zhang, Yu; Tao, Kai

2017-02-01

Ultra-pulsed fractional CO 2 laser is an efficient, precise, and safe therapeutic intervention for skin refreshing, although accompanied with prolonged edema and erythema. In recent years, autologous platelet-rich plasma (PRP) has been proven to promote wound and soft tissue healing and collagen regeneration. To investigate whether the combination of PRP and ultra-pulsed fractional CO 2 laser had a synergistic effect on therapy for facial rejuvenation. Totally, 13 facial aging females were treated with ultra-pulsed fractional CO 2 laser. One side of the face was randomly selected as experimental group and injected with PRP, the other side acted as the control group and was injected with physiological saline at the same dose. Comprehensive assessment of clinical efficacy was performed by satisfaction scores, dermatologists' double-blind evaluation and the VISIA skin analysis system. After treatment for 3 months, subjective scores of facial wrinkles, skin texture, and skin elasticity were higher than that in the control group. Similarly, improvement of skin wrinkles, texture, and tightness in the experimental group was better compared with the control group. Additionally, the total duration of erythema, edema, and crusting was decreased, in the experimental group compared with the control group. PRP combined with ultra-pulsed fractional CO 2 laser had a synergistic effect on facial rejuvenation, shortening duration of side effects, and promoting better therapeutic effect.

Bitistatin-functionalized fluorescent nanodiamond particles specifically bind to purified human platelet integrin receptor αIIbβ3 and activated platelets

Directory of Open Access Journals (Sweden)

Marcinkiewicz C

2017-05-01

Full Text Available Cezary Marcinkiewicz,1,2 Jonathan A Gerstenhaber,1 Mark Sternberg,2 Peter I Lelkes,1 Giora Feuerstein1,2 1Department of Bioengineering, College of Engineering, Temple University, Philadelphia, 2Debina Diagnostic, Inc., Newton Square, PA, USA Abstract: Thromboembolic events (TEE underwrite key causes of death in developed countries. While advanced imaging technologies such as computed tomography scans serve to diagnose blood clots during acute cardiovascular events, no such technology is available in routine primary care for TEE risk assessment. Here, we describe an imaging platform technology based on bioengineered fluorescent nanodiamond particles (F-NDPs functionalized with bitistatin (Bit, a disintegrin that specifically binds to the αIIbβ3 integrin, platelet fibrinogen receptor (PFR on activated platelets. Covalent linkage of purified Bit to F-NDP was concentration-dependent and saturable, as validated by enzyme-linked immunosorbent assay using specific anti-Bit antibodies. F-NDP–Bit interacted with purified PFR, either in immobilized or soluble form. Lotrafiban, a nonpeptide, αIIbβ3 receptor antagonist, specifically blocked F-NDP–Bit–PFR complex formation. Moreover, F-NDP–Bit specifically binds to activated platelets incorporated into a clot generated by thrombin-activated rat platelet-rich plasma (PRP. Our results suggest that engineered F-NDP–Bit particles could serve as noninvasive, “real-time” optical diagnostics for clots present in blood vessels. Keywords: carbon nanoparticles, blood clots, imaging, platelet fibrinogen receptor, fluorescence, disintegrin, thromboembolic complications, thrombosis

Surviving and fatal Elephant Endotheliotropic Herpesvirus-1A infections in juvenile Asian elephants - lessons learned and recommendations on anti-herpesviral therapy.

Science.gov (United States)

Dastjerdi, Akbar; Seilern-Moy, Katharina; Darpel, Karin; Steinbach, Falko; Molenaar, Fieke

2016-08-27

Elephant Endotheliotropic Herpesviruses (EEHVs) can cause acute haemorrhagic disease in young Asian elephants (Elephas maximus) and clinical EEHV infections account for the majority of their fatalities. The anti-herpesviral drug famciclovir (FCV) has been used routinely to treat viraemic at-risk elephants, but thus far without proven efficacy. This paper presents clinical and virological investigations of two EEHV-1A infected elephants treated with FCV, and discusses anti-herpesvirus therapies of viraemic elephants. Two 1.5 year old male Asian elephants at a zoological collection in the UK developed clinical EEHV-1A infections. Case 1 showed signs of myalgia for the duration of 24 hours before returning back to normal. EEHV-1A DNAemia was confirmed on the day of clinical signs and continued to be present for 18 days in total. Trunk shedding of the virus commenced 10 days after detection of initial DNAemia. Case 2 tested positive for EEHV-1A DNAemia in a routine blood screening sample in the absence of clinical signs. The blood viral load increased exponentially leading up to fatal clinical disease seven days after initial detection of DNAemia. Both calves were treated with 15 mg/kg FCV per rectum on detection of DNAemia and penciclovir, the FCV metabolite, could be detected in the blood at assumed therapeutic levels. The early indicators for clinical disease were a marked absolute and relative drop in white blood cells, particularly monocytes prior to the detection of viraemia. The most prognostic haematological parameter at later stages of the disease was the platelet count showing a continuous sharp decline throughout, followed by a dramatic drop at the time of death. The EEHV-1A viraemic animals investigated here further highlight the ongoing threat posed by these viruses to juvenile Asian elephants. The findings call into question the efficacy of rectal FCV in clinical cases and direct towards the use of alternative anti-herpesvirus drugs and complementary

[Clinical effect of anti-D immunoglobulin in treatment of childhood immune thrombocytopenia: a Meta analysis].

Science.gov (United States)

Qin, Wei; Huang, Shao-Ling; Li, Ting-Ting

2017-10-01

To investigate the clinical effect and safety of anti-D immunoglobulin (anti-D) in the treatment of children with newly diagnosed acute immune thrombocytopenia (ITP) through a Meta analysis. PubMed, EMBASE, Cohrane Library, Ovid, CNKI, and Wanfang Data were searched for randomized controlled trials (RCTs) published up to April 2017. Review Manager 5.3 was used for the Meta analysis. Seven RCTs were included. The Meta analysis showed that after 72 hours and 7 days of treatment, the intravenous immunoglobulin (IVIG) group had a significantly higher percentage of children who achieved platelet count >20×10 9 /L than the anti-D group (Panti-D (50 μg/kg) group and the IVIG group (P>0.05), and there were also no significant differences in platelet count after 24 hours and 7 days of treatment between the 50 μg/kg and 75 μg/kg anti-D groups (P>0.05). The anti-D group had a significantly greater reduction in the hemoglobin level than the IVIG group after treatment, but did not need transfusion. No children in the anti-D group or the IVIG group experienced serious adverse reactions. Intravenous injection of anti-D may have a similar effect as IVIG in improving platelet count in children with acute ITP, but it may be slightly inferior to IVIG in the rate of platelet increase after treatment. The anti-D dose of 50 μg/kg may have a similar effect as 75 μg/kg. The recommended dose of anti-D for treatment of ITP is safe.

The inflammatory role of platelets via their TLRs and Siglec receptors

Directory of Open Access Journals (Sweden)

Fabrice eCOGNASSE

2015-03-01

Full Text Available Platelets are non-nucleated cells that play central roles in the processes of haemostasis, innate immunity and inflammation; however, several reports show that these distinct functions are more closely linked than initially thought. Platelets express numerous receptors and contain hundreds of secretory products. These receptors and secretory products are instrumental to the platelet functional responses. The capacity of platelets to secrete copious amounts of cytokines, chemokines and related molecules appears intimately related to the role of the platelet in inflammation. Platelets exhibit non-self-infectious danger detection molecules on their surfaces, including those belonging to the ‘‘Toll-Like Receptor family’’, as well as pathogen sensors of other natures (Ig- or complement receptors etc.. These receptors permit platelets to both bind infectious agents and deliver differential signals leading to the secretion of cytokines/chemokines, under the control of specific intracellular regulatory pathways. In contrast, dysfunctional receptors or dysregulation of the intracellular pathway may increase the susceptibility to pathological inflammation. Physiological vs pathological inflammation is tightly controlled by the sensors of danger expressed in resting, as well as in activated, platelets. These sensors, referred to as Pathogen Recognition Receptors (PRRs, primarily sense danger signals termed Pathogen Associated Molecular Patterns (PAMPs. As platelets are found in inflamed tissues and are involved in auto-immune disorders, it is possible that they can also be stimulated by internal pathogens. In such cases, platelets can also sense danger signals using Damage Associated Molecular Patterns (DAMPs. Some of the most significant DAMP family members are the alarmins, to which the Siglec family of molecules belongs. This review examines the role of platelets in anti-infection immunity via their TLRs and Siglec receptors.

111In platelet imaging of left ventricular thrombi. Predictive value for systemic emboli

International Nuclear Information System (INIS)

Stratton, J.R.; Ritchie, J.L.

1990-01-01

To determine whether a positive indium 111 platelet image for a left ventricular thrombus, which indicates ongoing thrombogenic activity, predicts an increased risk of systemic embolization, we compared the embolic rate in 34 patients with positive 111 In platelet images with that in 69 patients with negative images during a mean follow-up of 38 +/- 31 (+/- SD) months after platelet imaging. The positive and negative image groups were similar with respect to age (59 +/- 11 vs. 62 +/- 10 years), prevalence of previous infarction (94% vs. 78%, p less than 0.05), time from last infarction (28 +/- 51 vs. 33 +/- 47 months), ejection fraction (29 +/- 14 vs. 33 +/- 14), long-term or paroxysmal atrial fibrillation (15% vs. 26%), warfarin therapy during follow-up (26% vs. 20%), platelet-inhibitory therapy during follow-up (50% vs. 33%), injected 111 In dose (330 +/- 92 vs. 344 +/- 118 microCi), and latest imaging time (greater than or equal to 48 hours in all patients). During follow-up, embolic events occurred in 21% (seven of 34) of patients with positive platelet images for left ventricular thrombi as compared with 3% (two of 69) of patients with negative images (p = 0.002). By actuarial methods, at 42 months after platelet imaging, only 86% of patients with positive images were embolus free as compared with 98% of patients with negative images (p less than 0.01)

A randomized, double-blind, placebo-controlled study of oral antioxidant supplement therapy in patients with dry eye syndrome

Directory of Open Access Journals (Sweden)

Huang JY

2016-05-01

Full Text Available Jehn-Yu Huang, Po-Ting Yeh, Yu-Chih Hou Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan Purpose: To evaluate the efficacy of oral antioxidant supplementation in the treatment of patients with dry eye syndrome (DES. Methods: A prospective, randomized, double-blinded study compared the effects of an antioxidant supplement (containing anthocyanosides, astaxanthin, vitamins A, C, and E, and several herbal extracts, including Cassiae semen and Ophiopogonis japonicus with placebo on patients with DES. We assessed dry eye symptoms, visual acuity, Schirmer’s test, tear film breakup time, cornea and conjunctiva fluorescein staining, serum anti-SSA/anti-SSB antibodies, and the level of reactive oxygen species (ROS in tears. The supplementation period was 8 weeks and patients were followed up every 4 weeks for 16 weeks. A linear mixed model was used to compare the groups, while within-group differences were tested by repeated-measures analysis of variance. Results: Forty-three patients, 20 and 23 in treatment and placebo groups, respectively, completed the study. Liver and renal functions were normal. Diastolic blood pressure decreased in the treatment group. There were no significant differences in systolic blood pressure, dry eye symptoms, serum anti-SSA and anti-SSB, visual acuity, intraocular pressure, or fluorescein corneal staining between the groups. Tear film breakup time scores and Schirmer’s test without topical anesthesia significantly improved in the treatment group. Tear ROS level differed between the groups and decreased after treatment. Overall subjective impression revealed a significant improvement with treatment compared with placebo. Conclusion: Oral antioxidant supplementations may increase tear production and improve tear film stability by reducing tear ROS. The vegetable-based antioxidant supplement used in this study is safe and can be utilized as

Anti-vascular endothelial growth factor therapy-induced glioma invasion is associated with accumulation of Tie2-expressing monocytes

Science.gov (United States)

Hossain, Mohammad B.; Conrad, Charles A.; Aldape, Kenneth D.; Fuller, Gregory N.; Marini, Frank C.; Alonso, Marta M.; Idoate, Miguel Angel; Gilbert, Mark R.; Fueyo, Juan; Gomez-Manzano, Candelaria

2014-01-01

The addition of anti-angiogenic therapy to the few treatments available to patients with malignant gliomas was based on the fact that these tumors are highly vascularized and on encouraging results from preclinical and clinical studies. However, tumors that initially respond to this therapy invariably recur with the acquisition of a highly aggressive and invasive phenotype. Although several myeloid populations have been associated to this pattern of recurrence, a specific targetable population has not been yet identified. Here, we present evidence for the accumulation of Tie2-expressing monocytes/macrophages (TEMs) at the tumor/normal brain interface of mice treated with anti-VEGF therapies in regions with heightened tumoral invasion. Furthermore, we describe the presence of TEMs in malignant glioma surgical specimens that recurred after bevacizumab treatment. Our studies showed that TEMs enhanced the invasive properties of glioma cells and secreted high levels of gelatinase enzymatic proteins. Accordingly, Tie2+MMP9+ monocytic cells were consistently detected in the invasive tumor edge upon anti-VEGF therapies. Our results suggest the presence of a specific myeloid/monocytic subpopulation that plays a pivotal role in the mechanism of escape of malignant gliomas from anti-VEGF therapies and therefore constitutes a new cellular target for combination therapies in patients selected for anti-angiogenesis treatment. PMID:24809734

Bio markers and Anti-EGFR therapies for Krads wild-type tumors in metastatic colorectal cancer patients

International Nuclear Information System (INIS)

Diaz Rubio Garcia, E.

2009-01-01

The natural history of metastasis colorectal cancer has being clearly modified in terms of response rate, time to progression and overall survival, once the antiEGFR monoclonal antibodies (cetuximab and panitumumab) have emerged in combination with the standard cytotoxic chemotherapy (FOLFOX and FOLFIRI). However, the benefit from cetuximab and panitumumab is only confined to KRAS-wild type (KRAS-wt) colorectal tumors, while KRAS mutated tumors do not respond to these drugs. The 65 % of colorectal tumors are KRAS-wt tumors, but efficacy of antiEGFR therapies is detected only in 60-70 % of these KRAS-wt tumors. Other biomarkers and molecular pathways must be involved in the response of the antiEGFR therapies for the KRAS-wt colorectal tumors, such as the EGFR ligands, the EGFR-phosphorilated levels, the number of EGFR copies, the status of the KRAS effected B-RAF and the alternative intracellular signaling pathways PIK3CA/PTEN/AKT and JAK/STAT. A battery of these biomarkers is needed to select the most sensitive patients to the antiEGFR therapies. This pattern may represent a novel favorable cost-effectiveness tool to develop tailored treatments. A review of these biomarkers and molecular pathways, involved in the antiEGFR therapies response, is performed. (Author) 68 refs.

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.

Development of lipid-shell and polymer core nanoparticles with water-soluble salidroside for anti-cancer therapy.

Science.gov (United States)

Fang, Dai-Long; Chen, Yan; Xu, Bei; Ren, Ke; He, Zhi-Yao; He, Li-Li; Lei, Yi; Fan, Chun-Mei; Song, Xiang-Rong

2014-02-25

Salidroside (Sal) is a potent antitumor drug with high water-solubility. The clinic application of Sal in cancer therapy has been significantly restricted by poor oral absorption and low tumor cell uptake. To solve this problem, lipid-shell and polymer-core nanoparticles (Sal-LPNPs) loaded with Sal were developed by a double emulsification method. The processing parameters including the polymer types, organic phase, PVA types and amount were systemically investigated. The obtained optimal Sal-LPNPs, composed of PLGA-PEG-PLGA triblock copolymers and lipids, had high entrapment efficiency (65%), submicron size (150 nm) and negatively charged surface (-23 mV). DSC analysis demonstrated the successful encapsulation of Sal into LPNPs. The core-shell structure of Sal-LPNPs was verified by TEM. Sal released slowly from the LPNPs without apparent burst release. MTT assay revealed that 4T1 and PANC-1 cancer cell lines were sensitive to Sal treatment. Sal-LPNPs had significantly higher antitumor activities than free Sal in 4T1 and PANC-1 cells. The data indicate that LPNPs are a promising Sal vehicle for anti-cancer therapy and worthy of further investigation.

Development of Lipid-Shell and Polymer Core Nanoparticles with Water-Soluble Salidroside for Anti-Cancer Therapy

Directory of Open Access Journals (Sweden)

Dai-Long Fang

2014-02-01

Full Text Available Salidroside (Sal is a potent antitumor drug with high water-solubility. The clinic application of Sal in cancer therapy has been significantly restricted by poor oral absorption and low tumor cell uptake. To solve this problem, lipid-shell and polymer-core nanoparticles (Sal-LPNPs loaded with Sal were developed by a double emulsification method. The processing parameters including the polymer types, organic phase, PVA types and amount were systemically investigated. The obtained optimal Sal-LPNPs, composed of PLGA-PEG-PLGA triblock copolymers and lipids, had high entrapment efficiency (65%, submicron size (150 nm and negatively charged surface (−23 mV. DSC analysis demonstrated the successful encapsulation of Sal into LPNPs. The core-shell structure of Sal-LPNPs was verified by TEM. Sal released slowly from the LPNPs without apparent burst release. MTT assay revealed that 4T1 and PANC-1 cancer cell lines were sensitive to Sal treatment. Sal-LPNPs had significantly higher antitumor activities than free Sal in 4T1 and PANC-1 cells. The data indicate that LPNPs are a promising Sal vehicle for anti-cancer therapy and worthy of further investigation.

Chronic idiopathic thrombocytopenic purpura (ITP): site of platelet sequestration and results of splenectomy

International Nuclear Information System (INIS)

Gugliotta, L.; Guarini, A.; Motta, M.R.; Bachetti, G.; Tura, S.; Isacchi, G.; Ciccone, F.; Lattarini, C.; Mazzucconi, M.G.; Mandelli, F.; Baccarani, M.

1981-01-01

51 Cr-platelet kinetics study was performed in 197 patients with chronic ITP after corticosteroid therapy had failed to induce a long lasting remission. The incidence of splenic, spleno-hepatic, hepatic and diffuse platelet sequestration site was 58%, 17%, 6% and 19%, respectively. Splenic and spleno-hepatic sequestration sites were more frequent in patients less than 30 years old and in patients with a platelet count lower than 50 x 10 9 /l. 111 patients were splenectomized shortly after the study. Normalization of the platelet count was obtained more frequently in patients with splenic and spleno-hepatic sequestration than in the others. Labelled platelet sequestration site was the best predictor of the outcome of splenectomy. Platelet kinetics is a non-invasive investigation that should be performed early after the diagnosis of chronic ITP in all patients eligible for splenectomy. (author)

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.

Anti-double strand (ds) DNA antibody formation by NZB/W (F1) spleen cells in a microculture system detected by solid phase radioimmunoassay.

Science.gov (United States)

Okudaira, H; Terada, E; Ogita, T; Aotsuka, S; Yokohari, R

1981-01-01

A solid-phase radioimmunoassay method was devised to detect mouse anti-double strand (ds) DNA antibody. This method could easily detect the anti-dsDNA antibody in 1 : 10,000 dilutions (1 unit) of pooled 9-10-month-old female NZB/W F1 sera. The sensitivity was about 10(3)- and 10(2)-fold higher than that of the modified Farr method and of the double antibody technique respectively. NZB/W mice developed high titer anti-dsDNA antibody as they grew older. Spleen cells brought to a microculture system using flat-bottomed polystyrene plates produced anti-dsDNA antibody clearly detectable by solid-phase radioimmunoassay. Anti-dsDNA antibody produced in vitro (y units) was in close correlation with the anti-dsDNA antibody titer of the spleen donor (x units) (y = 4.8 X 10(-2) x -65, gamma = 0.94, P less than 0.001). A combination of the microculture system and solid-phase radioimmunoassay was recommended for the characterization of anti-dsDNA antibody-forming cells.

Anti-double strand (ds) DNA antibody formation by NZB/W (F1) spleen cells in a microculture system detected by solid-phase radioimmunoassay

International Nuclear Information System (INIS)

Okudaira, H.; Terada, E.; Ogita, T.; Aotsuka, S.; Yokohari, R.

1981-01-01

A solid-phase radioimmunoassay method was devised to detect mouse anti-double strand (ds) DNA antibody. This method could easily detect the anti-ds DNA antibody in 1 : 10,000 dilutions (1 unit) of pooled 9-10 month-old female NZB/W F1 sera. The sensitivity was about 10 3 and 10 2 -fold higher than that of the modified Farr method and of the double antibody technique respectively. NZB/W mice developed high titer anti-dsDNA antibody as they grew older. Spleen cells brought to a microculture system using flat-bottomed polystyrene plates produced anti-dsDNA antibody clearly detectable by solid-phase radioimmunoassay. Anti-dsDNA antibody produced in vitro (y units) was in close correlation with the anti-dsDNA antibody titer of the spleen donor (x units) (y = 4.8 X 10 -2 x-65, γ = 0.94, P < 0.001). A combination of the microculture system and solid-phase radioimmunoassay was recommended for the characterization of anti-dsDNA antibody-forming cells. (Auth.)

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

Biologic variability and correlation of platelet function testing in healthy dogs.

Science.gov (United States)

Blois, Shauna L; Lang, Sean T; Wood, R Darren; Monteith, Gabrielle

2015-12-01

Platelet function tests are influenced by biologic variability, including inter-individual (CVG ) and intra-individual (CVI ), as well as analytic (CVA ) variability. Variability in canine platelet function testing is unknown, but if excessive, would make it difficult to interpret serial results. Additionally, the correlation between platelet function tests is poor in people, but not well described in dogs. The aims were to: (1) identify the effect of variation in preanalytic factors (venipuncture, elapsed time until analysis) on platelet function tests; (2) calculate analytic and biologic variability of adenosine diphosphate (ADP) and arachidonic acid (AA)-induced thromboelastograph platelet mapping (TEG-PM), ADP-, AA-, and collagen-induced whole blood platelet aggregometry (WBA), and collagen/ADP and collagen/epinephrine platelet function analysis (PFA-CADP, PFA-CEPI); and (3) determine the correlation between these variables. In this prospective observational trial, platelet function was measured once every 7 days, for 4 consecutive weeks, in 9 healthy dogs. In addition, CBC, TEG-PM, WBA, and PFA were performed. Overall coefficients of variability ranged from 13.3% to 87.8% for the platelet function tests. Biologic variability was highest for AA-induced maximum amplitude generated during TEG-PM (MAAA; CVG = 95.3%, CVI = 60.8%). Use of population-based reference intervals (RI) was determined appropriate only for PFA-CADP (index of individuality = 10.7). There was poor correlation between most platelet function tests. Use of population-based RI appears inappropriate for most platelet function tests, and tests poorly correlate with one another. Future studies on biologic variability and correlation of platelet function tests should be performed in dogs with platelet dysfunction and those treated with antiplatelet therapy. © 2015 American Society for Veterinary Clinical Pathology.

Perforated Gastric Ulcer Associated with Anti-Angiogenic Therapy

Directory of Open Access Journals (Sweden)

Diogo Libânio

2017-08-01

Full Text Available Anti-angiogenic therapy with bevacizumab, an inhibitor of vascular endothelial growth factor, is commonly used in metastatic colorectal cancer and is rarely associated with gastrointestinal perforation, perforation being more frequent in the primary tumor site or at the anastomotic level. We present the case of a 64-year-old male with stage IV rectal adenocarcinoma who was on palliative chemotherapy with FOLFOX and bevacizumab. After the 4th chemotherapy cycle, our patient started fever and epigastric pain. He was hemodynamically stable, and signs of peritoneal irritation were absent. There were no alterations in the abdominal X-ray, and C-reactive protein was markedly elevated. A CT scan revealed a de novo thickness in the gastric antrum. Upper digestive endoscopy showed an ulcerated 40-mm lesion in the angulus, with a 20-mm orifice communicating with an exsudative cavity revested by the omentum. A conservative approach was decided including fasting, broad-spectrum intravenous antibiotics, and proton-pump inhibitors. Subsequent gastroduodenal series showed no contrast extravasation, allowing the resumption of oral nutrition. Esophagogastroduodenoscopy after 8 weeks showed perforation closure. Biopsies did not show neoplastic cells or Heliobacter pylori infection. Although the success in the conservative management of perforation allowing the maintenance of palliative chemotherapy (without bevacizumab, the patient died after 4 months due to liver failure. The reported case shows an uncommon endoscopic finding due to a rare complication of anti-angiogenic therapy. Additionally, it reminds clinicians that a history of gastroduodenal ulcers should be actively sought before starting anti-angiogenic treatment and that suspicion for perforation should be high in these cases.

Parsley extract inhibits in vitro and ex vivo platelet aggregation and prolongs bleeding time in rats.

Science.gov (United States)

Gadi, Dounia; Bnouham, Mohamed; Aziz, Mohammed; Ziyyat, Abderrahim; Legssyer, Abdelkhaleq; Legrand, Chantal; Lafeve, Françoise Fauvel; Mekhfi, Hassane

2009-08-17

Many cardiovascular diseases are associated with an increase in blood platelet activity. In Morocco, parsley (Petroselinum crispum, Apiaceae) is one of the medicinal herbs used to treat cardiovascular diseases such as arterial hypertension. In this study, crude aqueous extract (CAE) of parsley was evaluated for its anti-platelet activity in experimental animals on platelet aggregation in vitro and ex vivo; and on bleeding time in vivo. The in vitro aggregation was monitored after pre-incubation of platelets with CAE. The bleeding time and ex vivo aggregation were performed after oral treatment. CAE inhibited dose dependently platelet aggregation in vitro induced by thrombin, ADP, collagen and epinephrine. The oral administration of CAE (3g/kg) inhibited significantly (pparsley may be benefit in the normalization of platelet hyperactivation, in the nutritional prevention of cardiovascular diseases and are potentially interesting in the development of new prevention strategies.

Non anti-coagulant factors associated with filter life in continuous renal replacement therapy (CRRT): a systematic review and meta-analysis.

Science.gov (United States)

Brain, Matthew; Winson, Elizabeth; Roodenburg, Owen; McNeil, John

2017-02-20

ventilation, elevated SOFA or LOD score, elevations in ionized calcium, elevated platelet count, red cell transfusion, platelet factor 4 (PF-4) antibodies, and elevated fibrinogen. Majority of studies are observational or report circuit factors in sub-analysis. Risk of bias is high and findings require targeted investigations to confirm. The interaction of patient, pathology, anticoagulation, vascular access, circuit and staff factors contribute to CRRT filter life. There remains an ambiguity from published data as to which site and side should be the first choice for vascular access placement and what interaction this has with patient factors and timing. Early consideration of tunnelled semi-permanent access may provide optimal filter life if longer periods of CRRT are anticipated. There remains an absence of robust evidence outside of anti-coagulation strategies despite over 20 years of therapy delivery however trends favour CVVHD-F over CVVH.

Steroids block the anti-inflammatory effects of low level laser therapy

Science.gov (United States)

Lopes-Martins, Rodrigo Alvaro B.; Albertini, Regiane; Lopes-Martins, Patricia Sardinha L.; Iversen, Vegard V.; Bjordal, Jan M.

2006-02-01

Objective: Concomitant use of multiple therapies is common in musculoskeletal and airway disorders. Low level laser therapy (LLLT) is considered a promising therapy in arthritis, tendinopathies and rhinitis. We designed two animal studies to assess if the expected anti-inflammatory effect LLLT could be affected by resection of the adrenal gland or concomitant use of the cortisol antagonist mifepristone. Methods: Two studies were performed, with 40 male Wistar rats and with 40 Balb C male mice respectively.. In both studies, four groups received carrageenan and one control group received saline. At 1, 2, and 3 hours after injections, LLLT irradiation was performed with a dose of 7.5 J/cm2. In the rat study, two of the carrageenan groups had the adrenal gland dissected. In the mice study, two of the carrageenan-injected groups were in addition pre-treated with orally administered mifepristone. Results: In the rat paw study, LLLT reduced edema significantly compared to the carrageenan only group (1.5 vs 0.9 ml, peffect of LLLT could be totally blocked by adding the cortisol antagonist mifepristone ( pSteroid therapy should not be used concomitantly with LLLT, as the anti-inflammatory effect of LLLT is lost if cortisol receptors are downregulated.

Non-Steroidal Anti-inflammatory Drugs As Host-Directed Therapy for Tuberculosis : A Systematic Review

NARCIS (Netherlands)

Kroesen, Vera M.; Gröschel, Matthias I.; Martinson, Neil; Zumla, Alimuddin; Maeurer, Markus; van der Werf, Tjip S.; Vilaplana, Cristina

2017-01-01

Lengthy, antimicrobial therapy targeting the pathogen is the mainstay of conventional tuberculosis treatment, complicated by emerging drug resistances. Host-directed therapies, including non-steroidal anti-inflammatory drugs (NSAIDs), in contrast, target host factors to mitigate disease severity. In

Evaluating Platelet-Rich Therapy for Facial Aesthetics and Alopecia: A Critical Review of the Literature.

Science.gov (United States)

Motosk O, Catherine C; Khouri, Kimberly S; Poudrier, Grace; Sinno, Sammy; Hazen, Alexes

2018-05-01

Despite the growing popularity of platelet-rich plasma, existing evidence supporting its efficacy remains controversial due to the lack of large-scale studies and standardized protocols for preparation and application. This article reviews its use in facial rejuvenation, fat grafting, acne scarring, and androgenic alopecia. Emphasis is placed on comparing methods of platelet-rich plasma preparation and application across studies. A systematic review was performed for articles published between 2006 and 2015. All clinical studies and case reports that addressed platelet-rich plasma alone and/or in combination with fat grafting for facial rejuvenation, acne scarring, or androgenic alopecia were included. Of the 22 articles included in the analysis, seven studies used platelet-rich plasma alone for facial rejuvenation, seven in combination with fat grafting, two for treatment of acne scarring, and six for treatment of androgenic alopecia. Individual study procedures, means of evaluation, and significant results are summarized. Although the majority of studies in this review report positive results, significant variation exists in preparation protocols and in the number and frequency of clinical treatments. The majority of studies report positive results for all indications evaluated in this review, but the procedure is limited by the lack of a standardized method for preparation and application of platelet-rich plasma. The extent to which significant variability in platelet-rich plasma preparation and/or application methods may affect clinical outcomes is not completely clear. In the interim, we present a consolidation of platelet-rich plasma treatment techniques and outcomes currently in use to help guide physicians in their clinical practice.

Anti-adhesion therapy following operative hysteroscopy for treatment of female subfertility

NARCIS (Netherlands)

Bosteels, Jan; Weyers, Steven; D'Hooghe, Thomas M.; Torrance, Helen; Broekmans, Frank J.; Chua, Su Jen; Mol, Ben Willem J.

2017-01-01

Background: Observational evidence suggests a potential benefit with several anti-adhesion therapies in women undergoing operative hysteroscopy (e.g. insertion of an intrauterine device or balloon, hormonal treatment, barrier gels or human amniotic membrane grafting) for decreasing intrauterine

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

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.

How useful is determination of anti-factor Xa activity to guide bridging therapy with enoxaparin? A pilot study.

Science.gov (United States)

Hammerstingl, Christoph; Omran, Heyder; Tripp, Christian; Poetzsch, Bernd

2009-02-01

Low-molecular-weight heparins (LMWH) are commonly used as peri-procedural bridging anticoagulants. The usefulness of measurement of anti-factor Xa activity (anti-Xa) to guide bridging therapy with LMWH is unknown. It was the objective of this study to determine levels of anti-Xa during standard bridging therapy with enoxaparin, and to examine predictors for residual anti-Xa. Consecutive patients receiving enoxaparin at a dosage of 1 mg/kg body weight/12 hours for temporary interruption of phenprocoumon were prospectively enrolled to the study. Blood-samples were obtained 14 hours after LMWH-application immediately pre- procedurally. Procedural details, clinical and demographic data were collected and subsequently analyzed. Seventy patients were included (age 75.2 +/- 10.8 years, Cr Cl 55.7 +/- 21.7ml/min, body mass index [BMI] 27.1 +/- 4.9). LMWH- therapy was for a mean of 4.2 +/- 1.6 days; overall anti-Xa was 0.58 +/- 0.32 U/ml. In 37 (52.8%) of patients anti-Xa was > or U/ml, including 10 (14.3%) patients with anti-Xa > 1U/ml. Linear regression analysis of single variables and logistic multivariable regression analysis failed to prove a correlation between anti-Xa and single or combined factors. No major bleeding, no thromboembolism and four (5.7%) minor haemorrhages were observed. When bridging OAC with therapeutic doses of enoxaparin a high percentage of patients undergo interventions with high residual anti-Xa. The levels of anti-Xa vary largely and are independent of single or combined clinical variables. Since the anti-Xa-related outcome of patients receiving bridging therapy with LMWH is not investigated, no firm recommendation on the usefulness of monitoring of anti-Xa can be given at this stage.

Do methodological differences account for the current controversy on tissue factor expression in platelets?

Science.gov (United States)

Brambilla, Marta; Rossetti, Laura; Zara, Chiara; Canzano, Paola; Giesen, Peter L A; Tremoli, Elena; Camera, Marina

2018-06-01

Tissue factor (TF), the key activator of the blood coagulation cascade and of thrombus formation, is also expressed by circulating human platelets. Despite the documented in-depth characterization of platelet TF carried out in the past 15 years, some authors still fail to identify TF in platelets, especially when assessment in platelet-rich plasma (PRP) or washed platelets is carried out. This study aims to extend the characterization of the subset of TF-positive platelets in PRP from healthy subjects and to verify how different centrifugation forces, used to prepare the PRP, could affect the analysis of TF-positive platelets. Data indicate that large-size platelets express significantly higher amount of TF compared to small-size cells, in terms of both TF protein and TF mRNA. Upon stimulation, large platelets readily expose on the cell membrane TF, which is functionally active, i.e., able to generate factor Xa (FXa) as well as thrombin. By contrast, TF activity in small platelets is almost completely quenched by tissue factor pathway inhibitor (TFPI), becoming indeed detectable only after treatment with an anti-TFPI antibody. Our data highlight that particular attention must be paid to the preparation and collection of the PRP since such preanalytical variables may influence the platelet recovery and in turn affect subsequent analysis, whether it is flow cytometry, functional activity tests, proteome, or transcriptome analysis. Indeed, the TF-positive subset of large platelets can easily be lost if centrifugation protocols are not optimized, thus erroneously leading to a false-negative result.

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.

Interpretation US Elastography in Chronic Hepatitis B with or without Anti-HBV Therapy

Directory of Open Access Journals (Sweden)

Cheng-Han Lee

2017-11-01

Full Text Available Inflammation has significant impacts on liver fibrosis measurement by ultrasound elastography. The interpretation requires further optimization in patients with or without anti-viral therapy. We prospectively enrolled a consecutive series of patients with chronic hepatitis B who received liver histology analysis and acoustic radiation force impulse (ARFI. 146 patients who underwent liver biopsy (50.9% or tumor resection (49.1% were enrolled. 34 patients (23.3% had been receiving anti-hepatitis B therapy of various duration. The areas under the receiver-operating characteristic (AUROC for the diagnosis of Metavir F4 by mean ARFI was 0.820 in the non-treatment group and 0.796 in the treatment group. The ARFI tended to be not lower (100% than the corresponding Metavir grading in patients with treatment within 12 months, equal (75% from 13 to 31 months, and lower (71.4% after 32 months. We conclude that ARFI is a reliable tool for measurement of liver fibrosis in chronic hepatitis B patients with ALT (alanine aminotransferase <5x the upper limit of normal. For those patients under anti-HBV therapy, the optimal timing for ARFI analysis will be over 1–2.5 years of nucleos(tide analogue therapy. The ARFI measurement after 2.5 years tends to be lower than the corresponding histology grading.

The clinical significance and risk factors of anti-platelet factor 4/heparin antibody on maintenance hemodialysis patients: a two-year prospective follow-up.

Directory of Open Access Journals (Sweden)

Delong Zhao

Full Text Available BACKGROUND: Heparin-induced thrombocytopenia is an immune response mediated by anti-PF4/heparin antibody, which is clinically characterized by thrombocytopenia and thromboembolic events. In this study, a prospective and multi-center clinical investigation 1 determined the positive rate of anti-PF4/heparin antibody in maintenance hemodialysis patients in China, 2 identified the related risk factors, and 3 further explored the effect of the anti-PF4/heparin antibody on bleeding, thromboembolic events, and risk of death in the patients. METHODS: The serum anti-PF4/heparin antibody was measured in 661 patients from nine hemodialysis centers, detected by IgG-specific ELISA and followed by confirmation with excess heparin. Risk factors of these patients were analyzed. Based on a two-year follow-up, the association between the anti-PF4/heparin antibody and bleeding, thromboembolic events, and risk of death in the patients was investigated. RESULTS: 1 The positivity rate of the anti-PF4/heparin antibody in maintenance hemodialysis patients was 5.6%. With diabetes as an independent risk factor, the positivity rate of the anti-PF4/heparin antibody decreased in the patients undergoing weekly dialyses ≥3 times. 2 The positivity rate of the anti-PF4/heparin antibody was not related to the occurrence of clinical thromboembolic events and was not a risk factor for death within two years in maintenance hemodialysis patients. 3 Negativity for the anti-PF4/heparin antibody combined with a reduction of the platelet count or combined with the administration of antiplatelet drugs yielded a significant increase in bleeding events. However, the composite determination of the anti-PF4/heparin antibody and thrombocytopenia, as well as the administration of antiplatelet drugs, was not predictive for the risk of thromboembolic events in the maintenance hemodialysis patients. CONCLUSIONS: A single detection of the anti-PF4/heparin antibody did not predict the occurrence

Role of anti-angiogenesis therapy in the management of hepatocellular carcinoma: The jury is still out

Institute of Scientific and Technical Information of China (English)

Hong; Sun; Man-Sheng; Zhu; Wen-Rui; Wu; Xiang-De; Shi; Lei-Bo; Xu

2014-01-01

As the leading cause of disease-related deaths,cancer is a major public health threat worldwide.Surgical resection is still the first-line therapy for patients with early-stage cancers.However,postoperative relapse and metastasis remain the cause of 90%of deaths of patients with solid organ malignancies,including hepatocellular carcinoma(HCC).With the rapid development of molecular biology techniques in recent years,molecularly targeted therapies using monoclonal antibodies,small molecules,and vaccines have become a milestone in cancer therapeutic by significantly improv-ing the survival of cancer patients,and have opened a window of hope for patients with advanced cancer.Hypervascularization is a major characteristic of HCC.It has been reported that anti-angiogenic treatments,which inhibit blood vessel formation,are highly effective for treating HCC.However,the efficacy and safety of anti-angiogenesis therapies remain controversial.Sorafenib is an oral multikinase inhibitor with antiproliferative and anti-angiogenic effects and is the first molecular target drug approved for the treatment of advanced HCC.While sorafenib has shown promising therapeutic effects,substantial evidence of primary and acquired resistance to sorafenib has been reported.Numerous clinical trials have been conducted to evaluate a large number of molecularly targeted drugs for treating HCC,but most drugs exhibited less efficacy and/or higher toxicity compared to sorafenib.Therefore,understanding the mechanism(s)underlying sorafenib resistance of cancer cells is highlighted for efficiently treating HCC.This concise review aims to provide an overview of anti-angiogenesis therapy in the management of HCC and to discuss the common mechanisms of resistance to anti-angiogenesis therapies.

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 ...

Use of 8-methoxypsoralen and ultraviolet-A pretreated platelet concentrates to prevent alloimmunization against class I major histocompatibility antigens

International Nuclear Information System (INIS)

Grana, N.H.; Kao, K.J.

1991-01-01

The use of 8-methoxypsoralen (8-MOP) and UV-A irradiation to inactivate contaminating donor leukocytes in platelet concentrates and to prevent primary alloimmunization against donor class I major histocompatibility (MHC) antigens in mice was investigated. CBA/CaH-T6J mice with the H2k haplotype and BALB/cByJ mice with the H2d haplotype were used as donors and recipients, respectively. The mixed leukocyte reaction between these two strains of mice showed that treatment of spleen cells with 500 ng/mL 8-MOP and 5J/cm2 UV-A inhibited 99% of responder and 92% of stimulator function. There was no measurable loss of platelet aggregating activity after the treatment. After two weekly transfusions of platelets without any treatment, 93% of control mice (n = 15) developed anti-H2k antibody. In contrast, only 33% of mice (n = 15) receiving platelets treated with 8-MOP and UV-A became alloimmunized. After six weekly platelet transfusions, all mice became alloimmunized. Nevertheless, the mean titers of anti-H2k antibody in sera of the treated groups were significantly lower than the control groups. One hour posttransfusion recoveries of 51Cr-labeled donor platelets were also higher in mice transfused with the treated platelets. Thus, the pretreatment of platelet concentrates with 8-MOP and UV-A irradiation effectively reduced the alloantigenicity of class I MHC molecules. The implication of this finding in relation to the mechanism by which donor leukocytes allosensitize recipients is discussed

Exosomes: novel effectors of human platelet lysate activity

Directory of Open Access Journals (Sweden)

E Torreggiani

2014-09-01

Full Text Available Despite the popularity of platelet-rich plasma (PRP and platelet lysate (PL in orthopaedic practice, the mechanism of action and the effectiveness of these therapeutic tools are still controversial. So far, the activity of PRP and PL has been associated with different growth factors (GF released during platelet degranulation. This study, for the first time, identifies exosomes, nanosized vesicles released in the extracellular compartment by a number of elements, including platelets, as one of the effectors of PL activity. Exosomes were isolated from human PL by differential ultracentrifugation, and analysed by electron microscopy and Western blotting. Bone marrow stromal cells (MSC treated with three different exosome concentrations (0.6 μg, 5 μg and 50 μg showed a significant, dose-dependent increase in cell proliferation and migration compared to the control. In addition, osteogenic differentiation assays demonstrated that exosome concentration differently affected the ability of MSC to deposit mineralised matrix. Finally, the analysis of exosome protein content revealed a higher amount of basic fibroblast growth factor (bFGF, vascular endothelial growth factor (VEGF, platelet-derived growth factor (PDGF-BB and transforming growth factor beta 1 (TGF-β1 as compared to PL. In regards to RNA content, an enrichment of small RNAs in exosomes as compared to donor platelets has been found. These results suggest that exosomes consistently contribute to PL activity and could represent an advantageous nanodelivery system for cell-free regeneration therapies.

Baicalin benefits the anti-HBV therapy via inhibiting HBV viral RNAs

International Nuclear Information System (INIS)

Huang, Hai; Zhou, Wei; Zhu, Haiyan; Zhou, Pei; Shi, Xunlong

2017-01-01

Background: Although current antiviral treatments (nucleoside analogs, NAs) for chronic hepatitis B virus (HBV) infection are effective in suppressing HBV-DNA replication, their clinical outcomes can be compromised by the increasing drug resistance and the inefficiency in promoting HBsAg/HBeAg seroconversion. Objectives: In this study, we will explore possible effects and mechanism of a natural product baicalin (BA) with the anti-HBV efficacy of entecavir (ETV), a first-line anti-HBV drug, in HBV-DNA, HBsAg/HBeAg seroconversion and drug-resistance. Methods: The co-effects of BA and ETV were conducted in wild-type/NA-resistance mutant HBV cell lines and DHBV-infected duckling models. HBV-DNA/RNAs, HBsAg/HBeAg, host factors (hepatocyte nuclear factors) were explored for possible anti-HBV mechanism. Results and discussion: BA could significantly enhance and reduced HBsAg and HBeAg in hepG2.2.15, a wild-type HBV cell line. Co-treatment of BA and ETV had a more dramatic effect in NA-resistant HBV rtM204V/rtLl80M transfected hepG2 cells. Our study further revealed that BA mainly inhibited the production of HBV RNAs (3.5, 2.4, 2.1 kb), the templates for viral proteins and HBV-DNA synthesis. BA blocked HBV RNAs transcription possibly by down-regulating transcription and expression of HBV replication dependent hepatocyte nuclear factors (HNF1α and HNF4α). Thus, BA may benefit the anti-HBV therapy via inhibiting HBV viral RNAs. - Highlights: • Baicalin benefits the anti-HBV therapy. • Baicalin enhances ETV antiviral efficacy and overcomes NA-resistant HBV mutation. • The anti-HBV effect of baicalin is achieved by inhibiting HBV RNAs. • Baicalin down-regulates HBV replication-dependent host factors HNF 1α and HNF 4α.

Baicalin benefits the anti-HBV therapy via inhibiting HBV viral RNAs

Energy Technology Data Exchange (ETDEWEB)

Huang, Hai, E-mail: HHai3552@sina.cn [Department of Microbiology and Biopharmacy, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203 (China); Zhou, Wei, E-mail: zhouw@fudan.edu.cn [Department of Chemistry, Fudan University, 220 Han Dan Road, Shanghai 200433 (China); Zhu, Haiyan, E-mail: haiyanzhu@fudan.edu.cn [Department of Microbiology and Biopharmacy, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203 (China); Zhou, Pei, E-mail: pzhou@shmu.edu.cn [Department of Microbiology and Biopharmacy, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203 (China); Shi, Xunlong, E-mail: xunlongshi@fudan.edu.cn [Department of Microbiology and Biopharmacy, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203 (China)

2017-05-15

Background: Although current antiviral treatments (nucleoside analogs, NAs) for chronic hepatitis B virus (HBV) infection are effective in suppressing HBV-DNA replication, their clinical outcomes can be compromised by the increasing drug resistance and the inefficiency in promoting HBsAg/HBeAg seroconversion. Objectives: In this study, we will explore possible effects and mechanism of a natural product baicalin (BA) with the anti-HBV efficacy of entecavir (ETV), a first-line anti-HBV drug, in HBV-DNA, HBsAg/HBeAg seroconversion and drug-resistance. Methods: The co-effects of BA and ETV were conducted in wild-type/NA-resistance mutant HBV cell lines and DHBV-infected duckling models. HBV-DNA/RNAs, HBsAg/HBeAg, host factors (hepatocyte nuclear factors) were explored for possible anti-HBV mechanism. Results and discussion: BA could significantly enhance and reduced HBsAg and HBeAg in hepG2.2.15, a wild-type HBV cell line. Co-treatment of BA and ETV had a more dramatic effect in NA-resistant HBV{sup rtM204V/rtLl80M} transfected hepG2 cells. Our study further revealed that BA mainly inhibited the production of HBV RNAs (3.5, 2.4, 2.1 kb), the templates for viral proteins and HBV-DNA synthesis. BA blocked HBV RNAs transcription possibly by down-regulating transcription and expression of HBV replication dependent hepatocyte nuclear factors (HNF1α and HNF4α). Thus, BA may benefit the anti-HBV therapy via inhibiting HBV viral RNAs. - Highlights: • Baicalin benefits the anti-HBV therapy. • Baicalin enhances ETV antiviral efficacy and overcomes NA-resistant HBV mutation. • The anti-HBV effect of baicalin is achieved by inhibiting HBV RNAs. • Baicalin down-regulates HBV replication-dependent host factors HNF 1α and HNF 4α.

Platelets in thrombosis and hemostasis: old topic with new mechanisms.

Science.gov (United States)

Wang, Yiming; Andrews, Marc; Yang, Yan; Lang, Sean; Jin, Joseph W; Cameron-Vendrig, Alison; Zhu, Guangheng; Reheman, Adili; Ni, Heyu

2012-12-01

Platelets are small anucleate cells generated from megakaryocytes in the bone marrow. After being released into the circulation, platelets play key roles in the surveillance of vascular injury, and can quickly adhere and aggregate at the site of injury, which are critical events for vascular repair and hemostasis. However, the same biological processes of platelet adhesion and aggregation may also cause thrombotic disorders. The formation of a platelet plug at sites of atherosclerotic lesion rupture is the most common mechanism leading to myocardial or cerebral infarction. Platelet-related deep vein thrombosis is also one of the leading causes of mortality worldwide. The contribution of several platelet receptors and their ligands has been highlighted in these processes. In platelet adhesion, particularly at high shear stress, GPIbα-von Willebrand factor (VWF) interaction may initiate this event, which is followed by GPVI signalling and firm platelet adhesion mediated by members of the integrin family, such as β3 (αIIbβ3) and β1 (α2β1, α5β1) integrins. In platelet aggregation, although GPIbα-VWF, P selectin-sulfatides, and other molecules, may be involved, the process is mainly mediated by β3 (αIIbβ3) integrin and its ligands, such as fibrinogen and VWF. It is intriguing that platelet adhesion and aggregation still occur in mice lacking both fibrinogen and VWF, suggesting that other unforeseen molecule(s) may also be important in these processes. Identification and characterization of these molecules will enrich our knowledge in the basic science of hemostasis and thrombosis, and may lead to the development of new therapies against bleeding disorders and thrombotic diseases.

Selective elution of HLA antigens and beta 2-microglobulin from human platelets by chloroquine diphosphate

International Nuclear Information System (INIS)

Kao, K.J.

1988-01-01

To determine whether chloroquine can specifically elute HLA antigens and beta 2-microglobulin (beta 2-M) from the platelet surface, quantitative immunofluorescence flow cytometry and monoclonal antibodies were used to show that HLA antigens and beta 2-M were proportionally eluted from the platelet surface without affecting the membrane glycoproteins IIb and IIIa. Second, an autoradiogram of electrophoresed I-125-labeled platelets showed that only beta 2-M but not other I-125-labeled membrane proteins could be eluted. Although HLA antigens were poorly labeled by I-125 and could not be detected on the autoradiogram, the eluted HLA antigens could be detected by anti-HLA monoclonal antibody and immunoblotting techniques. No loss of plasma membrane integrity was observed by transmission electron microscopy after chloroquine treatment of platelets. The results indicate that chloroquine selectively elutes HLA antigens and their noncovalently associated beta 2-M without affecting other integral platelet membrane proteins

The multifunctionality of berries toward blood platelets and the role of berry phenolics in cardiovascular disorders.

Science.gov (United States)

Olas, Beata

2017-09-01

Diet and nutrition have an important influence on the prophylaxis and progression of cardiovascular disease; one example is the inhibition of blood platelet functions by specific components of fruits and vegetables. Garlic, onion, ginger, dark chocolate and polyunsaturated fatty acids all reduce blood platelet aggregation. A number of fruits contain a range of cardioprotective antioxidants and vitamins, together with a large number of non-nutrient phytochemicals such as phenolic compounds, which may possess both antioxidant properties and anti-platelet activity. Fresh berries and berry extracts possess high concentrations of phenolic compounds, i.e. phenolic acid, stilbenoids, flavonoids and lignans. The aim of this review article is to provide an overview of current knowledge of the anti-platelet activity of berries, which form an integral part of the human diet. It describes the effects of phenolic compounds present in a number of berries, i.e. black chokeberries - aronia berries (Aronia melanocarpa), blueberries (Vaccinium myrtillus), cranberries (Vaccinium sect. Oxycoccus), sea buckthorn berries (Hippophae rhamnoides) and grapes (Vitis), as well as various commercial products from berries (i.e. juices), on platelets and underlying mechanisms. Studies show that the effects of berries on platelet activity are dependent on not only the concentrations of the phenolic compounds in the berries or the class of phenolic compounds, but also the types of berry and the form (fresh berry, juice or medicinal product). Different results indicate that berries may play a role in the prevention of cardiovascular disorders, but the development of well-controlled clinical studies with berries is encouraged.

Experiences and needs for work participation in employees with rheumatoid arthritis treated with anti-tumour necrosis factor therapy

NARCIS (Netherlands)

van der Meer, Marrit; Hoving, Jan L.; Vermeulen, Marjolein I. M.; Herenius, Marieke M. J.; Tak, Paul P.; Sluiter, Judith K.; Frings-Dresen, Monique H. W.

2011-01-01

To investigate the experiences and needs with respect to work participation of employees with rheumatoid arthritis (RA) treated with anti-tumour necrosis factor (TNF) therapy. Face-to-face interviews in 14 employees with RA on anti-TNF therapy focused on experiences, offered support and needs with

Effect of montelukast on platelet activating factor- and tachykinin induced mucus secretion in the rat

Directory of Open Access Journals (Sweden)

Groneberg David A

2008-02-01

Full Text Available Abstract Background Platelet activating factor and tachykinins (substance P, neurokinin A, neurokinin B are important mediators contributing to increased airway secretion in the context of different types of respiratory diseases including acute and chronic asthma. Leukotriene receptor antagonists are recommended as add-on therapy for this disease. The cys-leukotriene-1 receptor antagonist montelukast has been used in clinical asthma therapy during the last years. Besides its inhibitory action on bronchoconstriction, only little is known about its effects on airway secretions. Therefore, the aim of this study was to evaluate the effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity. Methods The effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity in the rat were assessed by quantification of secreted 35SO4 labelled mucus macromolecules using the modified Ussing chamber technique. Results Platelet activating factor potently stimulated airway secretion, which was completely inhibited by the platelet activating factor receptor antagonist WEB 2086 and montelukast. In contrast, montelukast had no effect on tachykinin induced tracheal secretory activity. Conclusion Cys-leukotriene-1 receptor antagonism by montelukast reverses the secretagogue properties of platelet activating factor to the same degree as the specific platelet activating factor antagonist WEB 2086 but has no influence on treacheal secretion elicited by tachykinins. These results suggest a role of montelukast in the signal transduction pathway of platelet activating factor induced secretory activity of the airways and may further explain the beneficial properties of cys-leukotriene-1 receptor antagonists.

The effect of variation in donor platelet function on transfusion outcome: a semirandomized controlled trial.

Science.gov (United States)

Kelly, Anne M; Garner, Stephen F; Foukaneli, Theodora; Godec, Thomas R; Herbert, Nina; Kahan, Brennan C; Deary, Alison; Bakrania, Lekha; Llewelyn, Charlotte; Ouwehand, Willem H; Williamson, Lorna M; Cardigan, Rebecca A

2017-07-13

The effect of variation in platelet function in platelet donors on patient outcome following platelet transfusion is unknown. This trial assessed the hypothesis that platelets collected from donors with highly responsive platelets to agonists in vitro assessed by flow cytometry (high-responder donors) are cleared more quickly from the circulation than those from low-responder donors, resulting in lower platelet count increments following transfusion. This parallel group, semirandomized double-blinded trial was conducted in a single center in the United Kingdom. Eligible patients were those 16 or older with thrombocytopenia secondary to bone marrow failure, requiring prophylactic platelet transfusion. Patients were randomly assigned to receive a platelet donation from a high- or low-responder donor when both were available, or when only 1 type of platelet was available, patients received that. Participants, investigators, and those assessing outcomes were masked to group assignment. The primary end point was the platelet count increment 10 to 90 minutes following transfusion. Analysis was by intention to treat. Fifty-one patients were assigned to receive platelets from low-responder donors, and 49 from high-responder donors (47 of which were randomized and 53 nonrandomized). There was no significant difference in platelet count increment 10 to 90 minutes following transfusion in patients receiving platelets from high-responder (mean, 21.0 × 10 9 /L; 95% confidence interval [CI], 4.9-37.2) or low-responder (mean, 23.3 × 10 9 /L; 95% CI, 7.8-38.9) donors (mean difference, 2.3; 95% CI, -1.1 to 5.7; P = .18). These results support the current policy of not selecting platelet donors on the basis of platelet function for prophylactic platelet transfusion. © 2017 by The American Society of Hematology.

Aspirin resistance may be identified by miR-92a in plasma combined with platelet distribution width

DEFF Research Database (Denmark)

Binderup, Helle Glud; Houlind, Kim; Madsen, Jonna Skov

2016-01-01

OBJECTIVE: Aspirin is a widely used drug for prevention of thrombotic events in cardiovascular patients, but approximately 25% of patients experience insufficient platelet inhibition due to aspirin, and remain in risk of cardiovascular events. This study aimed to investigate the value...... of circulating miR-92a and platelet size as biomarkers of the individual response to aspirin therapy. METHODS: Blood samples were collected from 50 healthy blood donors without antithrombotic medication and 50 patients with intermittent claudication on daily aspirin therapy. Based on results from the arachidonic...... acid stimulated aggregation test on Multiplate®analyzer (ASPItest), patients were defined as aspirin resistant (n=10) or aspirin responders (n=40). Plasma levels of miR-92a were evaluated by RT-qPCR analysis and platelet distribution width (PDW) was used to assess platelet size variability. Receiver...

Sports medicine applications of platelet rich plasma.

Science.gov (United States)

Mishra, Allan; Harmon, Kimberly; Woodall, James; Vieira, Amy

2012-06-01

Platelet rich plasma (PRP) is a powerful new biologic tool in sports medicine. PRP is a fraction of autologous whole blood containing and increased number of platelets and a wide variety of cytokines such as platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and transforming growth factor beta-1 (TGF-B1), fibroblast growth factor (FGF), Insulin-like growth factor-1 (IGF-1) among many others. Worldwide interest in this biologic technology has recently risen sharply. Basic science and preclinical data support the use of PRP for a variety of sports related injuries and disorders. The published, peer reviewed, human data on PRP is limited. Although the scientific evaluation of clinical efficacy is in the early stages, elite and recreational athletes already use PRP in the treatment of sports related injuries. Many questions remain to be answered regarding the use of PRP including optimal formulation, including of leukocytes, dosage and rehabilitation protocols. In this review, a classification for platelet rich plasma is proposed and the in-vitro, preclinical and human investigations of PRP applications in sports medicine will be reviewed as well as a discussion of rehabilitation after a PRP procedure. The regulation of PRP by the World Anti-Doping Agency will also be discussed. PRP is a promising technology in sports medicine; however, it will require more vigorous study in order to better understand how to apply it most effectively.

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.

Soluble Tie2 overrides the heightened invasion induced by anti-angiogenesis therapies in gliomas.

Science.gov (United States)

Cortes-Santiago, Nahir; Hossain, Mohammad B; Gabrusiewicz, Konrad; Fan, Xuejun; Gumin, Joy; Marini, Frank C; Alonso, Marta M; Lang, Frederick; Yung, W K; Fueyo, Juan; Gomez-Manzano, Candelaria

2016-03-29

Glioblastoma recurrence after treatment with the anti-vascular endothelial growth factor (VEGF) agent bevacizumab is characterized by a highly infiltrative and malignant behavior that renders surgical excision and chemotherapy ineffective. Our group has previously reported that Tie2-expressing monocytes (TEMs) are aberrantly present at the tumor/normal brain interface after anti-VEGF therapies and their significant role in the invasive outgrowth of these tumors. Here, we aimed to further understand the mechanisms leading to this pro-invasive tumor microenvironment. Examination of a U87MG xenogeneic glioma model and a GL261 murine syngeneic model showed increased tumor expression of angiopoietin 2 (Ang2), a natural ligand of Tie2, after anti-angiogenesis therapies targeting VEGF or VEGF receptor (VEGFR), as assessed by immunohistochemical analysis, immunofluorescence analysis, and enzyme-linked immunosorbent assays of tumor lysates. Migration and gelatinolytic assays showed that Ang2 acts as both a chemoattractant of TEMs and an enhancing signal for their tumor-remodeling properties. Accordingly, in vivo transduction of Ang2 into intracranial gliomas increased recruitment of TEMs into the tumor. To reduce invasive tumor outgrowth after anti-angiogenesis therapy, we targeted the Ang-Tie2 axis using a Tie2 decoy receptor. Using syngeneic models, we observed that overexpression of soluble Tie2 within the tumor prevented the recruitment of TEMs to the tumor and the development of invasion after anti-angiogenesis treatment. Taken together, these data indicate an active role for the Ang2-Tie2 pathway in invasive glioma recurrence after anti-angiogenesis treatment and provide a rationale for testing the combined targeting of VEGF and Ang-Tie2 pathways in patients with glioblastoma.

Flow cytometric immunobead assay for quantitative detection of platelet autoantibodies in immune thrombocytopenia patients.

Science.gov (United States)

Zhai, Juping; Ding, Mengyuan; Yang, Tianjie; Zuo, Bin; Weng, Zhen; Zhao, Yunxiao; He, Jun; Wu, Qingyu; Ruan, Changgeng; He, Yang

2017-10-23

Platelet autoantibody detection is critical for immune thrombocytopenia (ITP) diagnosis and prognosis. Therefore, we aimed to establish a quantitative flow cytometric immunobead assay (FCIA) for ITP platelet autoantibodies evaluation. Capture microbeads coupled with anti-GPIX, -GPIb, -GPIIb, -GPIIIa and P-selectin antibodies were used to bind the platelet-bound autoantibodies complex generated from plasma samples of 250 ITP patients, 163 non-ITP patients and 243 healthy controls, a fluorescein isothiocyanate (FITC)-conjugated secondary antibody was the detector reagent and mean fluorescence intensity (MFI) signals were recorded by flow cytometry. Intra- and inter-assay variations of the quantitative FCIA assay were assessed. Comparisons of the specificity, sensitivity and accuracy between quantitative and qualitative FCIA or monoclonal antibody immobilization of platelet antigen (MAIPA) assay were performed. Finally, treatment process was monitored by our quantitative FCIA in 8 newly diagnosed ITPs. The coefficient of variations (CV) of the quantitative FCIA assay were respectively 9.4, 3.8, 5.4, 5.1 and 5.8% for anti-GPIX, -GPIb, -GPIIIa, -GPIIb and -P-selectin autoantibodies. Elevated levels of autoantibodies against platelet glycoproteins GPIX, GPIb, GPIIIa, GPIIb and P-selectin were detected by our quantitative FCIA in ITP patients compared to non-ITP patients or healthy controls. The sensitivity, specificity and accuracy of our quantitative assay were respectively 73.13, 81.98 and 78.65% when combining all 5 autoantibodies, while the sensitivity, specificity and accuracy of MAIPA assay were respectively 41.46, 90.41 and 72.81%. A quantitative FCIA assay was established. Reduced levels of platelet autoantibodies could be confirmed by our quantitative FCIA in ITP patients after corticosteroid treatment. Our quantitative assay is not only good for ITP diagnosis but also for ITP treatment monitoring.

short history of anti-rheumatic therapy. IV. Corticosteroids

Directory of Open Access Journals (Sweden)

P. Marson

2011-06-01

Full Text Available In 1948 a corticosteroid compound was administered for the first time to a patient affected by rheumatoid arthritis by Philip Showalter Hench, a rheumatologist at the Mayo Clinic in Rochester, Minnesota (USA. He was investigating since 1929 the role of adrenal gland-derived substances in rheumatoid arthritis. For the discovery of cortisone and its applications in anti-rheumatic therapy, Hench, along with Edward Calvin Kendall and Tadeusz Reichstein, won the 1950 Nobel Prize for Medicine. In this review we summarize the main stages that led to the identification of the so-called compound E, which was used by Hench. We also consider the subsequent development of steroid therapy in rheumatic diseases, through the introduction of new molecules with less mineralocorticoid effects, such as prednisone, and more recently, deflazacort.

[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.

What do we miss? ASAS non-responders on anti-TNF therapy show improvement in performance-based physical function

NARCIS (Netherlands)

van Weely, S.F.E.; van Denderen, J.C.; Steultjens, M.P.M.; Nurmohamed, M.T.; Dijkmans, B.A.C.; Dekker, J.; van der Horst-Bruinsma, I.E.

2013-01-01

Objective: A prospective study was conducted in order to establish whether AS patients, who are defined as non-responders after 3 months of anti-TNF therapy, show improvement on performance-based tests of physical functioning. Methods: At baseline and 3 months after the start of anti-TNF therapy, AS

Human platelet releasates combined with polyglycolic acid scaffold ...

Indian Academy of Sciences (India)

2015-02-04

Feb 4, 2015 ... rated thanks to the development of culture conditions based ... 61. Keywords. Chondrocyte; growth factors; PGA; platelet-rich plasma; tissue engineering. Published ... PRPr was then obtained by two cycles of freezing (−20°C ..... therapies for sports muscle injuries: any evidence behind clinical practice?

Vitamin D as an anti-microbial and anti-inflammatory therapy for Cystic Fibrosis.

Science.gov (United States)

Herscovitch, K; Dauletbaev, N; Lands, Larry C

2014-06-01

Cystic fibrosis (CF) is characterized by chronic infection and inflammation in the airways that lead to progressive lung damage and early death. Current anti-inflammatory therapies are limited by extensive adverse effects or insufficient efficacy. There is a large body of studies indicating beneficial anti-microbial and anti-inflammatory properties of vitamin D. Since most patients with CF present with vitamin D deficiency, and serum vitamin D levels demonstrate a positive correlation with lung function and negative correlation with airway inflammation and infection, correcting vitamin D deficiency may be an attractive therapeutic strategy in CF. The function of vitamin D is intricately tied to its metabolism, which may be impaired at multiple steps in patients with CF, with a potential to limit the efficacy of vitamin D supplementation. It is likely that the aforementioned beneficial properties of vitamin D require supplementation with doses of vitamin D markedly higher than those recommended to maintain proper bone function. This review will illustrate the potential for supplementation with vitamin D or its metabolites to modulate inflammation and improve defence against chronic infection in CF lung, as well as appropriate vitamin D supplementation strategies for improving lung function in CF. Copyright © 2013 Elsevier Ltd. All rights reserved.

Noninvasive detection of coronary thrombi with 111In platelets: concise communication

International Nuclear Information System (INIS)

Bergmann, S.R.; Lerch, R.A.; Mathias, C.J.; Sobel, B.E.; Welch, M.J.

1983-01-01

The need for rapid, definitive identification of coronary thrombosis has been intensified by the advent of thrombolytic therapy and by interest in the role of thrombosis in the etiology of coronary artery disease. To determine whether platelet thrombi can be detected noninvasively with 111 In platelets, a method was developed in which /sup 99m/Tc-tagged red blood cells were used to correct for activity within the blood attributable to platelets circulating but not associated with thrombus. In 18 dogs coronary thrombi were induced closed-chest with a copper coil introduced into the coronary artery. 111 In platelets and /sup 99m/Tc RBCs were administered either before or 1 hr after induction of thrombus, and serial scintigrams obtained. Coronary thrombus was identified readily in the processed scintigrams. In six dogs, thrombolysis was achieved with intracoronary streptokinase. In each case serial scintigraphy demonstrated resolution of the clot. The dual radiotracer technique should permit serial noninvasive delineation of the temporal relationship between platelet deposition and coronary heart disease in patients, and should facilitate the evaluation of interventions designed to prevent platelet aggregation or to lyse existing thrombi

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.

Patch: platelet transfusion in cerebral haemorrhage: study protocol for a multicentre, randomised, controlled trial

Directory of Open Access Journals (Sweden)

Dijkgraaf Marcel G

2010-03-01

Full Text Available Abstract Background Patients suffering from intracerebral haemorrhage have a poor prognosis, especially if they are using antiplatelet therapy. Currently, no effective acute treatment option for intracerebral haemorrhage exists. Limiting the early growth of intracerebral haemorrhage volume which continues the first hours after admission seems a promising strategy. Because intracerebral haemorrhage patients who are on antiplatelet therapy have been shown to be particularly at risk of early haematoma growth, platelet transfusion may have a beneficial effect. Methods/Design The primary objective is to investigate whether platelet transfusion improves outcome in intracerebral haemorrhage patients who are on antiplatelet treatment. The PATCH study is a prospective, randomised, multi-centre study with open treatment and blind endpoint evaluation. Patients will be randomised to receive platelet transfusion within six hours or standard care. The primary endpoint is functional health after three months. The main secondary endpoints are safety of platelet transfusion and the occurrence of haematoma growth. To detect an absolute poor outcome reduction of 20%, a total of 190 patients will be included. Discussion To our knowledge this is the first randomised controlled trial of platelet transfusion for an acute haemorrhagic disease. Trial registration The Netherlands National Trial Register (NTR1303

Detection of intracardiac thrombi by 111In-oxine platelet imaging

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Hayashi, Makoto; Hayashida, Kohei; Uehara, Toshiisa; Naito, Hiroaki; Kozuka, Takahiro; Boku, Eidai; Sakakibara, Hiroshi

1985-01-01

111 In-oxine platelet imaging (RI) was undertaken in 55 patients with suspected intracardiac thrombi. The results were compared with those from echocardiography (US) and computed tomography (CT). Sensitivity and specificity of RI were 71 % and 92 %, respectively. Visualizing thrombi on RI was seen in 10 (56 %) of 18 patients receiving anticoagulant therapy such as Warfarin (Group A) and in 12 (92 %) of 13 patients without it (Group B). This implied that active platelet deposition is inhibited by giving Warfarin. Regarding the size of thrombi, three methods showed the same size in 11 (85 %) of Group B. RI showed smaller thrombi than US and CT in 7 (39 %) of Group A, and failed to reveal them in 8 (44 %). Unlike morphological diagnosis by US and CT, RI proved to be of value in the evaluation of the activity of platelets (platelet deposition on the surface of thrombus). This method can also be used in the evaluation of thrombogenity. (Namekawa, K.)