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Sample records for platelet volume increased

  1. Increased mean platelet volume in type 2 diabetes mellitus

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    Ezgi Coşkun Yenigün

    2014-03-01

    Full Text Available Objective: Platelet functions have important roles in the development of vascular complications in diabetic patients. Platelets with increased volume have increased activity compared to smaller ones; therefore, mean platelet volume (MPV is used as a marker for platelet activity. In the present study, we evaluated MPV in patients with type II diabetes mellitus (DM and its associations with diabetic microvascular and macrovascular complications. Methods: Consecutive type II diabetic patients were screened from outpatient clinic of Internal Medicine Department of Diskapı Yıldırım Beyazıt Education and Researsch Hospital, Ankara, Turkey. A total of 48 patients with type II DM and 30 age and gender matched healthy subjects constituted the study population. For all subjects a complete blood count including MPV, fasting blood glucose level and lipid parameters were studied. In diabetic patients, duration of diabetes and HbA1C level, presence of microvascular and macrovascular complications were noted additively. Mean platelet volume was compared between diabetic patients and healthy counterparents. Then, among diabetic patients, MPV was compared between the ones with and without microvascular and macrovascular complications. Results: Mean platelet volume was found significantly higher in diabetic patients compared to non-diabetic healthy subjects. Diabetic patients with at least one of the microvascular complications had significantly higher MPV than those without microvascular damage.Higher MPV levels have also been shown in diabetics with macrovascular complications compared to the ones without macrovascular disease. Conclusion: Mean platelet volume was found to be higher in type II diabetics and those having any of microvascular or macrovascular diabetic complications.

  2. Increase in mean platelet volume in patients with myocardial bridge.

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    Bilen, Emine; Tanboga, Ibrahim Halil; Kurt, Mustafa; Kocak, Umran; Ayhan, Huseyin; Keles, Telat; Bozkurt, Engin

    2013-01-01

    Myocardial bridge is associated with atherosclerosis altered in shear stress and endothelial dysfunction. Mean platelet volume (MPV), a determinant of platelet activation, is shown to be related with atherosclerosis and endothelial dysfunction. In this study, we aimed to evaluate platelet function assessed by MPV in patients with myocardial bridge. Forty-two patients with myocardial bridge in the left anterior descending artery (LAD) and 43 age- and gender-matched healthy participants were included in the study. Myocardial bridging was defined as an intramyocardial systolic compression or milking of a segment of an epicardial coronary artery on angiography. For the entire study population, MPV was measured using an automatic blood counter. The study population consisted of 42 patients with myocardial bridge (52.7 ± 10.2, 76.2% male) and 43 age- and sex-matched healthy control participants (52.1 ± 10.4, 74.4% male). Compared to the control group, MPV value was significantly higher in patients with myocardial bridge (8.9 ± 1.24 vs 8.3 ± 0.78; P = .01). Further, there were no significant differences between groups regarding hemoglobin level, platelet count, fasting blood glucose, and creatinine levels. Our study findings indicated that myocardial bridge is associated with elevated MPV values. Our results might partly explain the increased cardiovascular events in patients with myocardial bridge.

  3. The Increase of The Mean Platelet Volume in Patients With Intracerebral Haemorrhage

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    Adalet Arıkanoğlu

    2012-06-01

    Full Text Available OBJECTIVE: The mean platelet volume (MPV is a biomarker of platelet function and activity. The influence of platelet function disorders on the aetiology of intracerebral haemorrhages (ICH and mortality is not clear yet. The purpose of this study is to investigate the change in the MPV values in patients with ICH and to observe its influence on mortality in a retrospective manner. METHODS: Sixty-six patients with intracerebral haemorrhage (32 males, 34 females; mean age: 61.9± 16.9 were enrolled in the study. Patients with ICH were divided into two groups as those who died within the first 10 days and those who survived. The MPV values and the haematoma volumes were compared between the groups. Also, the MPV values and platelet counts of the patients with ICH were compared with the values of healthy volunteers from similar age and sex groups (27 males, 17 females; mean age: 59.9 ±3.2. RESULTS: The MPV values of the patients with ICH measured within 24 hours following the intracerebral haemorrhage (8.33 ± 1.27 fl/mL were statistically significantly higher than the MPV values of the control group (7.76 ± 1.14 fl/mL (p=0.018. The platelet counts of the patients with ICH also measured within the first 24 hours (235.8±94.9 x103/mL were statistically significantly lower than the platelet counts of the control group (279.1 ± 94.9 x103/mL (p=0.022. No statistically significant difference in terms of the MPV values and platelet counts was observed between the patients with ICH who died within the first 10 days and those who survived (p>0.05. However, the difference observed in the haematoma volume between the patients with ICH who died within the first 10 days (31.1 ±33.7 ml and those who survived (8.7± 13.4 ml was statistically significant (p<0.001. No correlation was found between the haematoma volume and the MPV value in the patients with ICH. CONCLUSION: The increase observed in the mean platelet volume in patients with ICH may point to a

  4. An increase in mean platelet volume from baseline is associated with mortality in patients with severe sepsis or septic shock.

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    Chan Ho Kim

    Full Text Available Mean platelet volume (MPV is suggested as an index of inflammation, disease activity, and anti-inflammatory treatment efficacy in chronic inflammatory disorders; however, the effect of MPV on sepsis mortality remains unclear. Therefore, we investigated whether the change in MPV between hospital admission and 72 hours (ΔMPV72h-adm predicts 28-day mortality in severe sepsis and/or septic shock.We prospectively enrolled 345 patients admitted to the emergency department (ED who received standardized resuscitation (early goal-directed therapy for severe sepsis and/or septic shock between November 2007 and December 2011. Changes in platelet indices, including ΔMPV72h-adm, were compared between survivors and non-survivors by linear mixed model analysis. The prognostic value of ΔMPV72h-adm for 28-day mortality was ascertained by Cox proportional hazards model analysis.Thirty-five (10.1% patients died within 28 days after ED admission. MPV increased significantly during the first 72 hours in non-survivors (P = 0.001 and survivors (P < 0.001; however, the rate of MPV increase was significantly higher in non-survivors (P = 0.003. Nonetheless, the difference in the platelet decline rate over the first 72 hours did not differ significantly between groups (P = 0.360. In multivariate analysis, ΔMPV72h-adm was an independent predictor of 28-day mortality, after adjusting for plausible confounders (hazard ratio, 1.44; 95% confidence interval, 1.01-2.06; P = 0.044.An increase in MPV during the first 72 hours of hospitalization is an independent risk factor for adverse clinical outcomes. Therefore, continuous monitoring of MPV may be useful to stratify mortality risk in patients with severe sepsis and/or septic shock.

  5. MEAN PLATELET VOLUME AND RISK OF THROMBOTIC STROKE

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    Prasantha Kumar Thankappan

    2017-07-01

    Full Text Available BACKGROUND Stroke is a major cause of long term morbidity and mortality. Several factors are known to increase the liability to stroke. Platelets play a crucial role in the pathogenesis of atherosclerotic complications, contributing to thrombus formation. Platelet size (mean platelet volume, MPV is a marker and possible determinant of platelet function, large platelets being potentially more reactive. Hence an attempt has-been made to study the association if any between mean platelet volume and thrombotic stroke. The aim of this study was to determine whether an association exists between Mean Platelet Volume (MPV and thrombotic stroke. MATERIALS AND METHODS The study is a case control study and data was collected at Government Medical College Hospital, Kottayam, Kerala a tertiary care referral centre. The study was carried out among fifty patients diagnosed with thrombotic stroke and presenting to the hospital within forty eight hours of onset of symptoms. Fifty age group and sex matched controls were also recruited. Mean platelet volume was obtained using a SYSMEX automated analyser. RESULTS This study has shown a statistically significant relation between mean platelet volume and risk of thrombotic stroke but no statistically significant correlation between clinical severity of stroke and mean platelet volume. CONCLUSION This study has shown an elevation of MPV in acute phase of thrombotic stroke. Platelet mass was found to be more or less a constant. This study did not find a statistically significant correlation between clinical severity of stroke and mean platelet volume.

  6. 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.

  7. Decreased mean platelet volume in panic disorder

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    Göğçegöz Gül I

    2014-09-01

    Full Text Available Işil Göğçegöz Gül, Gül Eryilmaz, Eylem Özten, Gökben Hizli Sayar Neuropsychiatry Health, Practice, and Research Center, Uskudar University, Istanbul, Turkey Aim: The relationship between psychological stress and platelet activation has been widely studied. It is well known that platelets may reflect certain biochemical changes that occur in the brain when different mental conditions occur. Platelet 5-hydroxytryptamine (5-HT is also extensively studied in psychiatry. The mean platelet volume (MPV, the accurate measure of platelet size, has been considered a marker and determinant of platelet function. The aim of the present study was to search for any probable difference in the MPV of subjects with panic disorder (PD.Methods: A total of 37 drug-free subjects, aged 18 to 65 years, diagnosed with PD, with or without agoraphobia, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV criteria and 45 healthy control subjects were included in the study. Platelet count and MPV were measured and recorded for each subject.Results: There were no statistically significant differences between groups in terms of female/male ratio, age, or body mass index between the PD group and control group (P=0.91, P=0.82, and P=0.93, respectively. The MPV was found to be significantly lower in the PD group compared with the control group (8.8±0.9 fL vs 9.2±0.8 fL; P=0.02. All the participants had MPV values in the standard range of 6.9–10.8 fL.Conclusion: We concluded that abnormalities of the 5-HT1A receptor function in the central nervous system of subjects with a diagnosis of PD are also mirrored in as an alteration in platelet activity. Measurements of platelet activity may be used as a tool for neuropsychiatric and psychopharmacological research and for studying how certain mental diseases and medications affect the central nervous system. Keywords: 5-HT, thrombocyte, anxiety 

  8. Platelet-Rich Plasma Increases Pigmentation.

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    Uysal, Cagri A; Ertas, Nilgun Markal

    2017-11-01

    Platelet-rich plasma (PRP) is an autologous solution of plasma containing 4 to 7 times the baseline concentration of human platelets. Platelet-rich plasma has been widely popular in facial rejuvenation to attenuate wrinkles and has been practically used. The authors have been encountering various patients of increased hiperpigmentation following PRP applications that were performed to attenuate the postinflammatory hiperpigmentation especially after laser treatment. The authors have been using PRP for facial rejuvenation in selected patients and in 1 patient the authors have encountered increased pigmentation over the pigmented skin lesions that were present before the application. The authors recommend that the PRP might increase pigmentation especially in the face region and precautions might be taken before and after the application. Platelet-rich plasma should not be used for the treatment of post inflammatory hiperpigmentation.

  9. Letter to editor Platelet volume evaluation in patients with sepsis ...

    African Journals Online (AJOL)

    I have read the article published by Guclu et al. with a great interest.1 They examined platelet indices in patients with sepsis. Mean platelet volume (MPV) and platelet distribution width (PDW) were significantly higher in patients with sepsis than in controls. MPV and PDW were significantly higher in patients with severe ...

  10. Multiple alterations of platelet functions dominated by increased secretion in mice lacking Cdc42 in platelets

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    Pleines, Irina; Eckly, Anita; Elvers, Margitta

    2010-01-01

    formation and exocytosis in various cell types, but its exact function in platelets is not established. Here, we show that the megakaryocyte/platelet-specific loss of Cdc42 leads to mild thrombocytopenia and a small increase in platelet size in mice. Unexpectedly, Cdc42-deficient platelets were able to form...

  11. Relationship between platelet phospholipid FA and mean platelet volume in healthy men.

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    Li, Duo; Turner, Alan; Sinclair, Andrew J

    2002-09-01

    Increased mean platelet volume (MPV) has been suggested as an independent risk factor for acute myocardial infarction and the increased reactivity of large platelets. The aim of this study was to investigate the correlation between platelet phospholipid (PL) PUFA composition and MPV in 139 free-living healthy men ages 20-55 yr (vegans, n = 18; ovolacto vegetarians, n = 43; moderate meat-eaters, n = 60; and high meateaters, n = 18). Each subject completed a semiquantitative Food Frequency Questionnaire and gave a blood sample. Platelet PL FA composition and MPV were determined by standard methods. MPV was significantly greater in the vegans than in the ovolacto vegetarian, moderate, or high meat-eater groups (P vegan and ovolacto vegetarian groups had significantly higher platelet PL 18:2n-6 and 22:4n-6, and lower 20:5n-3 and 22:6n-3 compared with the moderate and high meat-eater groups. The vegans demonstrated a significant reduction in 20:4n-6 and 22:5n-3 compared with the ovolacto vegetarian, high meat-eater, and moderate meat-eater groups. Bivariate analysis results showed that MPV was significantly positively correlated with platelet PL 18:2n-6 (P = 0.048) and negatively correlated with 20:3n-6 (P = 0.02), 20:5n-3 (P = 0.005), and 22:5n-3 (P< 0.0001), respectively. In a multiple linear regression analysis, after controlling for potential confounding factors such as dietary group, age, exercise, body mass index, and dietary polyunsaturated and saturated fat, cholesterol, carbohydrate, and fiber intake, the MPV was still strongly negatively correlated with platelet PL 20:3n-6 (P = 0.003) and 22:5n-3 (P = 0.001). The present data suggest that 22:5n-3 and 20:3n-6 may play a role in the structural function of the platelet membrane.

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

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

    2014-01-01

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

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

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    Giuseppe Lippi

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

  14. Simple platelet markers: Mean platelet volume and congestive heart failure coexistent with periodontal disease. Pilot studies.

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    Czerniuk, Maciej R; Bartoszewicz, Zbigniew; Dudzik-Niewiadomska, Iwona; Pilecki, Tomasz; Górska, Renata; Filipiak, Krzysztof J

    2017-07-17

    Conducted pilot study concerning mean platelet volume parameter among patients suffering from congestive heart failure and periodontal disease. Examination of dynamic changes of platelet and periodontal markers in group of 50 patients before and an average of 6 months subsequent to professional periodontal treatment. Both platelet and periodontal parameters decreased after periodontal treatment, what is more, the decrease of mean platelet volume (MPV) value due to periodontal disease/mm improvement was shown to be statistically significant (p = 0.05). Improvement of periodontal status may influence decrease of MPV value andincrease of congestive heart failure treatment efficacy and effect patient comfort. It is a new, not frequently used pattern of chronic disease treatment optimalization.

  15. Evaluation of mean platelet volume in localized scleroderma.

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    Bahali, Anil Gulsel; Su, Ozlem; Emiroglu, Nazan; Cengiz, Fatma Pelin; Kaya, Mehmet Onur; Onsun, Nahide

    2017-01-01

    Localized scleroderma is a chronic inflammatory skin disease characterized by sclerosis of the dermis and subcutaneous tissue. Platelets play an important role in inflammation. Following activation, platelets rapidly release numerous mediators and cytokines, which contribute to inflammation. To evaluate whether there was any relation between localized scleroderma and platelet parameters. Forty-one patients with localized scleroderma were enrolled in the study. The control group consisted of 30 healthy subjects. The mean platelet volume level in the patient group was 9.9 ± 1.3 fl and in the control group was 7.6 ± 1.1 fl. This difference was statistically significant (pscleroderma. Platelet parameters may be used as markers for evaluating disease severity and inflammatory processes. Thus, there is a need for more detailed and prospective studies.

  16. Mean Platelet Volume in Patients with Chronic Venous Insufficiency

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    Mehmet Akif Sarıca

    2016-03-01

    Full Text Available Objective: the mean platelet volume (MPV is a good indicator of platelet activity; it is reported to increase in diseases associated with inflammatory processes and in vascular diseases. This study investigated the importance of mean platelet volume in patients with chronic venous insufficiency (CVI and whether the MPV was likely to be a predictor of the CVI. Methods: 117 patients who were diagnosed as CVI by colored Doppler Ultrasound (CDU method and 49 healthy volunteers (forming the control group were en­rolled to this study, which was planned retrospectively. The patients’ blood count values taken within one month before and after the CDU evaluation were recorded by the hospital information system. The complete blood count, routine biochemical tests and thyroid function tests of the patients diagnosed with CVI were compared to the control group. Results: Significant differences were not detected be­tween the patients and the control group in terms of the levels of creatinine, aspartate aminotransferase, total cholesterol, LDL cholesterol, HDL cholesterol, triglycer­ides, erythrocyte, sedimentation speed, leukocyte, hae­moglobin and thrombocyte (p>0.05. The thyroid stimulat­ing hormone and the MPV levels were significantly lower in the control group (p<0.05. Conclusion: MPV levels as an easy, cheap and practi­cal data extracted from complete blood count, were found higher in patients diagnosed with CVI compared to the control group. This may be originated from endothelium changes as an answer to venous hypertension and dila­tation in CVI. MPV can be used as a follow-up marker in CVI patients. J Clin Exp Invest 2016; 7 (1: 73-77

  17. Nephropathy in type 1 diabetes is associated with increased circulating activated platelets and platelet hyperreactivity

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    Tarnow, Inge; Michelson, Alan D.; Barnard, Marc R.

    2009-01-01

    Patients with diabetes mellitus (DM) have increased platelet activation compared to non-diabetic controls. Platelet hyperreactivity has been associated with adverse cardiovascular outcomes in Type 2 DM, and with diabetic nephropathy. We investigated the relationship between platelet activation...... and nephropathy in Type 1 DM. Patients with Type 1 DM and diabetic nephropathy (n = 35), age- and sex-matched Type 1 DM patients with persistent normoalbuminuria (n = 51), and healthy age- and sex-matched controls (n = 30) were studied. Platelet surface P-selectin, platelet surface activated GPIIb/IIIa, monocyte...... controls (P = 0.0075). There were no differences between groups in activated GPIIb/IIIa or in response to TRAP at any end-point. More patients with nephropathy received aspirin (71.4%) compared to normoalbuminuric patients (27.4%) (P Type 1 diabetic nephropathy, as compared with normoalbuminuria...

  18. Mean Platelet volume in diagnosis of acute appendicitis in children ...

    African Journals Online (AJOL)

    Background: The clinical diagnosis of acute appendicitis (AA) in children is still problematic in status. Objectives: To investigate the diagnostic value of mean platelet volume (MPV) in acute AA at childhood. Methods: One hundred patients diagnosed as AA patients and 100 healthy individuals. Laboratory tests were studied ...

  19. Platelet-activating factor increases platelet-dependent glycoconjugate secretion from tracheal submucosal gland

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    Sasaki, T.; Shimura, S.; Ikeda, K.; Sasaki, H.; Takishima, T.

    1989-01-01

    Using isolated glands from feline trachea, we examined the effect of platelet-activating factor (PAF) on radiolabeled glycoconjugate release and glandular contraction by measuring induced tension in the absence or presence of platelets. PAF alone did not produce any significant glandular contraction nor any significant change in glycoconjugate release from isolated glands. In the presence of purified platelets containing no plasma, PAF (10(-8) to 10(-5) M) produced significant glycoconjugate secretion in a dose-dependent fashion, but it produced no significant glandular contraction. PAF-evoked glycoconjugate secretion was time dependent, reaching a peak response of 277% of control 15-30 min after the exposure of isolated glands to 10(-5) M PAF in the presence of platelets and returning to 135% of controls at 2 h. Platelets alone did not produce any significant stimulation in glycoconjugate release. CV-3988, a known PAF antagonist, inhibited the secretory response to PAF. Methysergide, a known antagonist to receptors for 5-hydroxytryptamine, did not alter PAF-evoked glycoconjugate secretion. Both indomethacin and SQ 29,548, a thromboxane receptor antagonist, abolished the PAF-evoked glycoconjugate secretion from isolated submucosal glands. Epithiomethanothromboxane A2, a stable thromboxane A2 analogue, produced a significant increase in glycoconjugate secretion in a dose-dependent fashion. These findings indicate that PAF increases glycoconjugate release in the presence of platelets and that the increase is dependent on some aspect of platelet function, namely thromboxane generation

  20. Association of Adiposity Indices with Platelet Distribution Width and Mean Platelet Volume in Chinese Adults.

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    Jian Hou

    Full Text Available Hypoxia is a prominent characteristic of inflammatory tissue lesions. It can affect platelet function. While mean platelet volume (MPV and platelet distribution width (PDW are sample platelet indices, they may reflect subcinical platelet activation. To investigated associations between adiposity indices and platelet indices, 17327 eligible individuals (7677 males and 9650 females from the Dongfeng-Tongji Cohort Study (DFTJ-Cohort Study, n=27009 were included in this study, except for 9682 individuals with missing data on demographical, lifestyle, physical indicators and diseases relative to PDW and MPV. Associations between adiposity indices including waist circumstance (WC, waist-to-height ratio (WHtR, body mass index (BMI, and MPV or PDW in the participants were analyzed using multiple logistic regressions. There were significantly negative associations between abnormal PDW and WC or WHtR for both sexes (ptrend<0.001 for all, as well as abnormal MPV and WC or WHtR among female participants (ptrend<0.05 for all. In the highest BMI groups, only females with low MPV or PDW were at greater risk for having low MPV (OR=1.33, 95% CI=1.10, 1.62 ptrend<0.001 or PDW (OR=1.34, 95% CI=1.14, 1.58, ptrend<0.001 than those who had low MPV or PDW in the corresponding lowest BMI group. The change of PDW seems more sensitive than MPV to oxidative stress and hypoxia. Associations between reduced PDW and MPV values and WC, WHtR and BMI values in Chinese female adults may help us to further investigate early changes in human body.

  1. Investigation of the relationship between mean platelet volume and obstructive sleep apnea syndrome

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    Ersin Şükrü Erden

    2013-12-01

    Full Text Available Objective: Obstructive sleep apnea syndrome (OSAS is characterized by recurrent upper airway obstruction and intermittent hypoxia during sleep. Intermittent hypoxia and increased inflammatory activity plays a role in increased risk of cardiovascular disease in the OSAS. OSAS is an important cause of morbidity and mortality and cardiovascular disorders are the most important complications of OSAS. Mean platelet volume (MPV is a marker of platelet activation and function, and increased platelet volume is associated with increased platelet activity. Different diseases related with inflammation, hypoxia, vascular injury, thrombosis and atherosclerosis were found to be associated with MPV. In this study, we aimed to investigate the relationship between OSAS and MPV. Methods: In this retrospective study, data of sex and age matched 33 patients with moderate OSAS, 34 patients with severe OSAS and 30 healthy subjects were evaluated. Results: The mean MPV was found in control, moderate OSAS and severe OSAS groups as 7.83±1.00, 8.26±1.40 and 8.94±1.20 (fL respectively. The mean MPV value was significantly higher in severe OSAS group than control subjects (p=0.001. In correlation analysis, there were positive correlation between MPV with apnea-hypopnea index and total sleep time, and negative correlation between MPV with platelet count and minimum oxygen saturation (Respectively, p=0.003 / R=0.295, p=0.030 / R=0.221, p=0.011 / R= -0.257, p=0.019 / R= -0.238. Conclusion: In this study, the increased MPV was associated with severe OSAS and the results of this study suggest that the platelet activation is increased in OSAS. Hypoxia caused by OSAS, due to the activated platelets, may play a role in the development of cardiovascular diseases which is an important cause of morbidity and mortality in OSAS. J Clin Exp Invest 2013; 4 (4: 492-496

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

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    Mehmet Ünal

    2015-06-01

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

  3. Increased platelet reactivity is associated with circulating platelet-monocyte complexes and macrophages in human atherosclerotic plaques.

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    Bert Rutten

    Full Text Available Platelet reactivity, platelet binding to monocytes and monocyte infiltration play a detrimental role in atherosclerotic plaque progression. We investigated whether platelet reactivity was associated with levels of circulating platelet-monocyte complexes (PMCs and macrophages in human atherosclerotic carotid plaques.Platelet reactivity was determined by measuring platelet P-selectin expression after platelet stimulation with increasing concentrations of adenosine diphosphate (ADP, in two independent cohorts: the Circulating Cells cohort (n = 244 and the Athero-Express cohort (n = 91. Levels of PMCs were assessed by flow cytometry in blood samples of patients who were scheduled for percutaneous coronary intervention (Circulating Cells cohort. Monocyte infiltration was semi-quantitatively determined by histological examination of atherosclerotic carotid plaques collected during carotid endarterectomy (Athero-Express cohort.We found increased platelet reactivity in patients with high PMCs as compared to patients with low PMCs (median (interquartile range: 4153 (1585-11267 area under the curve (AUC vs. 9633 (3580-21565 AUC, P<0.001. Also, we observed increased platelet reactivity in patients with high macrophage levels in atherosclerotic plaques as compared to patients with low macrophage levels in atherosclerotic plaques (mean ± SD; 8969 ± 3485 AUC vs. 7020 ± 3442 AUC, P = 0.02. All associations remained significant after adjustment for age, sex and use of drugs against platelet activation.Platelet reactivity towards ADP is associated with levels of PMCs and macrophages in human atherosclerotic carotid plaques.

  4. Evaluation of Mean Platelet Volume values in lean women with polycystic ovary syndrome.

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    Silfeler, Dilek Benk; Kurt, Raziye Keskin; Yengil, Erhan; Un, Burak; Arica, Secil; Baloglu, Ali

    2014-05-01

    Mean Platelet Volume (MPV) is an important indicator of platelet activation. It is known that MPV increases in patients with coronory artery disease, diabetes mellitus, atherosclerosis and Polycystic ovary syndrome (PCOS). Our aim was to measure the MPV in lean patients with polycystic ovary syndrome. The present study was designed to examine the platelet function by measuring MPV in non-obese women with PCOS. A total of 50 outpatients with PCOS were included. The control group consisted of 50 healthy subjects. Serum platelet, MPV, and white blood cell (WBC) levels were compared and evaluated retrospectively in all participants. These values were compared by statistical analysis. There were no statistically significant difference in between groups regarding MPV (p═0.357), WBC (p═0,414) and platelet (p═0,666). There are studies implying MPV increase in PCOS patients, in our patients MPV levels did not correlate with PCOS except for patients with obesity. We think that PCOS itself has no effect on MPV levels and obesity changes MPV levels.

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

    Science.gov (United States)

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

    2014-01-01

    Platelet-rich plasma (PRP) is used for the treatment of tendinopathy. There are numerous PRP preparations, and the optimal combination of platelets and leukocytes is not known. Within leukocyte-reduced PRP (lrPRP), there is a plateau effect of platelet concentration, with increasing platelet concentrations being detrimental to extracellular matrix synthesis. Controlled laboratory study. Different formulations of lrPRP with respect to the platelet:leukocyte ratio were generated from venous blood of 8 horses. Explants of the superficial digital flexor tendon were cultured in lrPRP products for 96 hours. Platelet-derived growth factor-BB (PDGF-BB), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin-1β (IL-1β) concentrations were determined in the media by enzyme-linked immunosorbent assay. Gene expression in tendon tissue for collagen type I and III (COL1A1 and COL3A1, respectively), matrix metalloproteinase-3 and -13 (MMP-3 and MMP-13, respectively), cartilage oligomeric matrix protein (COMP), and IL-1β was determined. Data were divided into 3 groups of lrPRP based on the ratio of platelets:leukocytes and evaluated to determine the effect of platelet concentration. Complete blood counts verified leukocyte reduction and platelet enrichment in all PRP preparations. In the lrPRP preparation, the anabolic growth factors PDGF-BB and TGF-β1 were increased with increasing platelet concentrations, and the catabolic cytokine IL-1β was decreased with increasing platelet concentrations. Increasing the platelet concentration resulted in a significant reduction in COL1A1 and COL3A1 synthesis in tendons. Increasing the platelet concentration within lrPRP preparations results in the delivery of more anabolic growth factors and less proinflammatory cytokines, but the biological effect on tendons is diminished metabolism as indicated by a decrease in the synthesis of both COL1A1 and COL3A1. Together, this information suggests that

  6. Platelet Count and Mean Platelet Volume in Patients with Nasal Polyposis

    Directory of Open Access Journals (Sweden)

    Asli Tanrivermis Sayit

    2014-12-01

    Full Text Available Aim: Nasal polyps (NPs are the most common reason for nasal obstruction, with a prevalence of 1-4%. Although the etiology is not clearly known, chronic infections and mechanical, immunological, and biochemical factors can play a role in the etiology. Recently, mean platelet volume (MPV was recognized as a simple inflammatory marker in the inflammatory disease. In this study, we aimed to evaluate platelet (PLT and MPV in patients with NPs. Material and Method: This study included 80 histopathologically proven patients with NPs and 80 age- and sex-matched healthy subjects as controls. The Lund-Mackay staging system was used to evalute paranasal sinus CT scans, in patients with NPs, and paranasal sinus CT scores were recorded. Values of MPV, platelet (PLT, platelet crit (PCT and platelet distribution width (PDW were assessed in NP and control groups. Results: MPV and PLT values were found to be low in patients with NPs, at 8.57±1.62 fL and 259.99±62.03 x103/µL, respectively, compared with the control groups, at 8.79±1.49fL and 270.29±61.82 x103/µL. These findings were not statistically significant. PDW values were found to be slightly high in patients with NPs, at 17.1±1.36 fL, compared with the control group, at 16.78±1.04 fL (p=0.075. But PCT values were found to be low in patients with NPs, at 0.21±0.065, compared with the control group, at 0.23±0.069 (p=0.044. This finding was statistically significant. Discussion: In our study, the MPV and PLT values were lower in patients with NPs, but the difference was not statistically significant. According to our findings, the use of MPV as an inflammation marker in patients with NPs does not seem to be reliable.

  7. Change of mean platelet volume values in asthmatic children as an inflammatory marker.

    Science.gov (United States)

    Tuncel, T; Uysal, P; Hocaoglu, A B; Erge, D O; Karaman, O; Uzuner, N

    2012-01-01

    Asthma is the most common chronic disease of childhood in industrialised countries. T helper-2 (Th-2) cells, mast cells and eosinophils have a role in inflammation of asthma. Recently it was shown that platelets also play a role in asthma. Mean platelet volume shows platelet size and reflects platelet activation. The aim of this retrospective study is to evaluate levels of mean platelet volume in asthmatic patients during asymptomatic periods and exacerbations compared with healthy controls. The study consisted of 100 asthmatic patients (male/female: 55/45, mean age: 8.2±3.3) and 49 age and sex matched healthy children as a control group. Mean platelet volume values of asthmatic patients during asymptomatic period were 7.7±0.8fL while mean platelet volume values in asthmatics during exacerbation were 7.8±0.9fL. Comparison of mean platelet volume values of asthmatic patients and healthy controls both in acute asthmatic attack and asymptomatic period showed no difference (p>0.05). Comparison of mean platelet volume values at asthmatic attack and asymptomatic period also had no difference (p>0.05). The presence of atopy, infection, eosinophilia, elevated immunoglobulin E, and severity of acute asthmatic attack did not influence mean platelet volume values. The results of our study suggest that mean platelet volume values may not be used as a marker in bronchial asthma, although prospective studies with larger number of patients are needed to evaluate the role of mean platelet volume in asthma. Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.

  8. Reference intervals for mean platelet volume and immature platelet fraction determined on a sysmex XE5000 hematology analyzer

    DEFF Research Database (Denmark)

    Jørgensen, Mikala Klok; Bathum, L.

    2016-01-01

    Background New parameters describing the platelet population of the blood are mean platelet volume (MPV), which is a crude estimate of thrombocyte reactivity, and immature platelet fraction (IPF), which reflects megakaryopoietic activity. This study aimed to define reference intervals for MPV...... and IPF and to investigate whether separate reference intervals according to smoking status, age or sex are necessary.Methods Blood samples were obtained from subjects participating in The Danish General Suburban Population Study. MPV and IPF measurements were performed by the use of the Sysmex XE-5000...

  9. The value of serum mean platelet volume in ischaemic stroke patient

    International Nuclear Information System (INIS)

    Tamer, F.; Fevzi, Y.; Deniz, A.E.; Cemil, K.; Cihat, Y.; Muhittin, Y.; Serkan, Y.M.; Ali, C.M.; Faith, B.

    2013-01-01

    Objective: To investigate the value of serum Mean Platelet Volume in acute ischaemic stroke patients. Method: The retrospective case-control study was conducted at Ankara Numune Training and Research Hospital in Turkey and comprised record of patients of acute ischaemic stroke admitted to the Emergency Department between June 2010 and January 2012. The two groups were statistically compared using SPSS 18.0. Result: Overall, there were 482 stroke patients (Group 1) and 315 subjects as controls (Group 2). The median value in Group 1 was 9.0 (2.1) (fL), while in Group 2 it was 8.80 (2.4) (fL). The difference was statistically significant (Z=-2.80; p<0.05). Conclusion: Mean Platelet Volume increased in the stroke patients. (author)

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

    EB

    2013-09-03

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

  12. Mean platelet volume as a risk stratification tool in the Emergency Department for evaluating patients with ischaemic stroke and TIA

    International Nuclear Information System (INIS)

    Dogan, N.O.; Karakurt, K.

    2013-01-01

    Objective: To investigate the variations of mean platelet volume in patients with ischaemic cerebrovascular complaints, and to find out its diagnostic utility in an acute setting to help risk stratification in patients with ischaemic stroke and transient ischaemic attacks. Methods: The prospective cross-sectional study was conducted at the Gazi University Hospital, Ankara, Turkey, from November 2009 to June 2010. It comprised 143 consecutive patients of acute ischaemic stroke, 39 patients of transient ischaemic attacks and 60 healthy volunteers. SPSS 13 was used for statistical analysis, and so were t-test, one-way analysis of variance test and correlation analysis. Statistical significance was accepted at p <0.05. Results: Mean platelet volume results were significantly higher in patients with cortical infarction and transient ischaemic attack compared to the control group (p <0.001 and p <0.002). A statistically significant increase was also noted in hospitalised patients when compared with discharged patients from the emergency department (p <0.036). A weak positive correlation was identified between the National Institute of Health Stroke Scores and mean platelet volume levels (r=0.207; p <0.001). A significant relationship was identified between mean platelet volume levels and previous stroke (p <0.005). Conclusion: The measurement of mean platelet volume levels may provide useful diagnostic and prognostic information to emergency physicians caring for patients with transient ischaemic attack and ischaemic stroke. In patients with suspected neurological ischaemic symptoms, high levels may be considered as an atherosclerotic risk factor. (author)

  13. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

  14. Mean platelet volume is elevated in patients with patent foramen ovale.

    Science.gov (United States)

    Demir, Bulent; Caglar, Ilker Murat; Ungan, Ismail; Ugurlucan, Murat; Tureli, Hande Oktay; Karakaya, Osman

    2013-12-30

    Platelets play a major role in thromboembolic events. Increased mean platelet volume (MPV) indicates higher platelet reactivity and also a tendency to thrombosis. Patent foramen ovale (PFO), persistence of the fetal anatomic shunt between right and left atria, is strongly associated with cryptogenic stroke. The aim of this study is to determine the relationship between MPV and PFO and if such an association exists, whether higher MPV levels may require antiplatelet therapy before a thromboembolic event happens, together with a literature review. Thirty patients (15 women, 15 men), free of any cerebrovascular events, were diagnosed with PFO by transesophageal echocardiography (TEE), enrolled as the study group. Thirty consecutive patients (16 women and 14 men), who were diagnosed as normal in TEE, were enrolled as the control group. These two groups were compared according to MPV and anatomical features of the right atrium. There was no significant difference between study and control groups in clinical features and also no difference was observed in platelet counts; however, MPV in the PFO group was significantly higher than the control group (8.38 ±0.93 fl and 7.45 ±0.68 fl respectively). Our results indicate that elevated MPV may be detected in patients with PFO. This might be one of the explanations for the relationship between PFO and cryptogenic stroke; however, larger cohorts are warranted in order to define further mechanisms.

  15. Can mean platelet volume and mean platelet volume/platelet count ratio be used as a diagnostic marker for sepsis and systemic inflammatory response syndrome?

    Science.gov (United States)

    Ates, Selma; Oksuz, Hafıze; Dogu, Bırsen; Bozkus, Fulsen; Ucmak, Hasan; Yanıt, Fadime

    2015-01-01

    Objectives: To determine whether the mean platelet volume (MPV) and MPV/platelet (PLT) values can be used in the study of sepsis and systemic inflammatory response syndrome (SIRS). Methods: In this retrospective case-controlled study, 69 sepsis, 69 SIRS patients, and 72 control group who were treated in the years 2012-2013 were reviewed, and both the MPV and MPV/PLT rates were evaluated in all groups at Kahramanmaras Sutcu Imam University Intensive Care Unit, Kahramanmaras, Turkey. Results: Statistically significant difference was found between sepsis, SIRS, and control groups when comparing the MPV and MPV/PLT ratio (p0.05). Mean platelet volume values for sepsis and control groups was 10.07/8.731 femtoliter (fL) (p=0.000), and 9.45/8.731 fL (p=0.000) for SIRS and control groups. In the group of sepsis patients, the MPV was found to be at cut-off 8.915, sensitivity 71%, and specificity 63.9%. In the group of patients with SIRS, MPV was found to be at cut-off 8.85, sensitivity 69.6%, and specificity 62.5%. For the MPV/PLT values, the specificity and sensitivity were found to be insignificant. Conclusion: This study shows that although there was no significant reduction in the PLT values between the sepsis and SIRS patients, the MPV and MPV/PLT ratio values were found to have significant differences. However, the specificity and sensitivity of the values were not reliable standard to be used as a test. PMID:26446329

  16. Increase in density and accumulation of serotonin by human aging platelets

    International Nuclear Information System (INIS)

    Mezzano, D.; Aranda, E.; Rodriguez, S.; Foradori, A.; Lira, P.

    1984-01-01

    51 Cr-labeled autologous platelets were infused into splenectomized subjects and the specific radioactivities of high-density (HD) and low-density (LD) platelet subpopulations were determined sequentially in postinfusion samples. These findings confirm previous observations in eusplenic individuals and support the hypothesis that human LD platelets are, on the average, younger than HD platelets. LD platelets contain 33.8 +/- 13.5 ng serotonin (5HT)/10(8) platelets and HD platelets 76.8 +/- 9.5 ng 5HT/10(8) platelets. Sequential measurements of 5HT in PRP platelets were performed during the recovery phase of thrombocytopenia following splenectomy in patients with idiopathic thrombocytopenic purpura (ITP), a condition associated with aging of platelets in circulation. Presplenectomy platelet 5HT was 17.7 ng/10(8) platelets and on days 1, 6, and 12 after surgery it increased to 18.1, 37.8, and 61.0 ng/10(8) platelets. When three healthy volunteers were given aspirin (500 mg/day) for up to 15 days, no significant change in the 5HT content of circulating platelets was observed. The observation that human HD platelets, enriched with older cells, contain more 5HT than LD platelets taken together with the parallel increase in platelet 5HT and age during the recovery from thrombocytopenia in ITP patients and the lack of effect of aspirin on platelet 5HT content, provides initial evidence that human platelets accumulate 5HT during their life-span in circulation

  17. Mean Platelet Volume as an Indicator of Platelet Rejuvenation Following Bone Marrow Transplantation.

    Science.gov (United States)

    1986-07-01

    diameter N I Estes, 1968 Mucopolysaccharidosis diameter N I Estes, 1968 Osteogenesis imperfecta diameter N N Estes, 1968 Montreal Platelet Syndrome...6. Inherited Disorders of Connective Tissue: Platelet size was evaluated in 31 families with the following disorders: Osteogenesis imperfecta ...controlled by factors regulating the passage of platelets in and out of the pool. The splenic pool is known to be mobilized following exercise or epinephrine

  18. The Effects of Smoking on Platelet Count, Mean Platelet Volume and Cardiovascular Risk Factors: A Case-control Study

    Directory of Open Access Journals (Sweden)

    Ruhuşen Kutlu

    2017-12-01

    Full Text Available Aim: Smoking and cholesterol levels are two important components of atherosclerosis. Mean platelet volume (MPV is an indicator of platelet function and activation and a potential marker of cardiovascular disease. In this study, we aimed to investigate the effects of cigarette-smoking on platelet count, MPV and cardiovascular risk factors. Methods: This research was planned as a case-control study. Patients who attended our family medicine outpatient clinic were included in the study. Sociodemographic characteristics, smoking status, hematological and biochemical parameters of the patients were recorded. Results: The mean age of 880 patients who participated in the study was 35.85±11.6 years (17-77. 54.5% (n=480 of participants were smokers and 45.5% (n=400 were non-smokers. The number of smokers among working individuals was higher than in non-workers. The white blood cell, hemoglobin, hematocrit, red blood cell, mean corpuscular volume and MPV values in the smokers were higher than in the non-smokers, while platelet count was higher in non-smokers (p<0.001. There was a statistically significant relationship between MPV levels and the number of daily cigarette smoking among smokers (p=0.014. Conclusion: MPV levels in smokers were significantly higher than in non-smokers. Platelet count and MPV levels should be investigated in larger patient groups in terms of atherosclerosis and other defined cardiovascular risk factors. It is therefore should take its rightful place in clinical practice.

  19. Mean platelet volume and red cell distribution width levels in initial evaluation of panic disorder

    Directory of Open Access Journals (Sweden)

    Asoglu M

    2016-09-01

    .003, respectively. However, there was no significant difference in the platelet number between the patients with PD and healthy controls (P>0.05.Conclusion: Our study results are the first to demonstrate that the RDW levels combined with MPV levels significantly increase among patients with PD. We believe that increased RDW and MPV levels can be used as a novel marker for PD. Keywords: panic disorder, mean platelet volume, red cell distribution width, white blood cell count, platelet number

  20. Accurate measurement of volume and shape of resting and activated blood platelets from light scattering.

    Science.gov (United States)

    Moskalensky, Alexander E; Yurkin, Maxim A; Konokhova, Anastasiya I; Strokotov, Dmitry I; Nekrasov, Vyacheslav M; Chernyshev, Andrei V; Tsvetovskaya, Galina A; Chikova, Elena D; Maltsev, Valeri P

    2013-01-01

    We introduce a novel approach for determination of volume and shape of individual blood platelets modeled as an oblate spheroid from angle-resolved light scattering with flow-cytometric technique. The light-scattering profiles (LSPs) of individual platelets were measured with the scanning flow cytometer and the platelet characteristics were determined from the solution of the inverse light-scattering problem using the precomputed database of theoretical LSPs. We revealed a phenomenon of parameter compensation, which is partly explained in the framework of anomalous diffraction approximation. To overcome this problem, additional a priori information on the platelet refractive index was used. It allowed us to determine the size of each platelet with subdiffraction precision and independent of the particular value of the platelet aspect ratio. The shape (spheroidal aspect ratio) distributions of platelets showed substantial differences between native and activated by 10 μM adenosine diphosphate samples. We expect that the new approach may find use in hematological analyzers for accurate measurement of platelet volume distribution and for determination of the platelet activation efficiency.

  1. The mean platelet volume levels in children with PFAPA syndrome.

    Science.gov (United States)

    Tekin, Mehmet; Toplu, Yuksel; Kahramaner, Zelal; Erdemir, Aydin; Gulyuz, Abdulgani; Konca, Capan; Uckardes, Fatih

    2014-05-01

    To assess whether mean platelet volume (MPV) can be used as a marker in the differential diagnosis of periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome. The leucocyte counts, thrombocyte counts, and MPV values of 57 children with PFAPA syndrome were recorded during an attack and an attack free period. These values were compared with a healthy control group of 55 individuals. Demographic features of the PFAPA patients group including age, gender and age of first attack, age at diagnosis, frequency of attacks, serum reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were also recorded. The MPV values of the children with PFAPA both during an attack and attack free period were found significantly lower than the MPV values of healthy control group (pchildren with PFAPA during an attack were significantly lower than in attack free periods (pchildren with PFAPA. The MPV values during an attack and attack free period of patients with PFAPA is lower than in controls. The MPV values may be used as a marker in the differential diagnosis of PFAPA syndrome but more studies are needed and they should be prospective in order to validate this data. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. An Investigation of the Effects of the Mean Platelet Volume, Platelet ...

    African Journals Online (AJOL)

    2018-05-22

    May 22, 2018 ... ratio (PLR), and platelet values for predicting mortality in patients with sepsis. Materials and Methods: This .... Rheumatoid arthritis. Table 2: The .... et al. reported in their study conducted on hemodialysis patients that the PLR ...

  3. Evaluation of QT and P wave dispersion and mean platelet volume among inflammatory bowel disease patients.

    Science.gov (United States)

    Dogan, Yuksel; Soylu, Aliye; Eren, Gulay A; Poturoglu, Sule; Dolapcioglu, Can; Sonmez, Kenan; Duman, Habibe; Sevindir, Isa

    2011-01-01

    In inflammatory bowel disease (IBD) number of thromboembolic events are increased due to hypercoagulupathy and platelet activation. Increases in mean platelet volume (MPV) can lead to platelet activation, this leads to thromboembolic events and can cause acute coronary syndromes. In IBD patients, QT-dispersion and P-wave dispersion are predictors of ventricular arrhythmias and atrial fibrilation; MPV is accepted as a risk factor for acute coronary syndromes, we aimed at evaluating the correlations of these with the duration of disease, its localization and activity. The study group consisted of 69 IBD (Ulcerative colitis n: 54, Crohn's Disease n: 15) patients and the control group included 38 healthy individuals. Disease activity was evaluated both endoscopically and clinically. Patients with existing cardiac conditions, those using QT prolonging medications and having systemic diseases, anemia and electrolyte imbalances were excluded from the study. QT-dispersion, P-wave dispersion and MPV values of both groups were compared with disease activity, its localization, duration of disease and the antibiotics used. The P-wave dispersion values of the study group were significantly higher than those of the control group. Duration of the disease was not associated with QT-dispersion, and MPV levels. QT-dispersion, P-wave dispersion, MPV and platelet count levels were similar between the active and in mild ulcerative colitis patients. QT-dispersion levels were similar between IBD patients and the control group. No difference was observed between P-wave dispersion, QT-dispersion and MPV values; with regards to disease duration, disease activity, and localization in the study group (p>0.05). P-wave dispersion which is accepted as a risk factor for the development of atrial fibirilation was found to be high in our IBD patients. This demonstrates us that the risk of developing atrial fibrillation may be high in patients with IBD. No significant difference was found in the QT

  4. Relation of mean platelet volume and red blood cell distribution width with epistaxis.

    Science.gov (United States)

    Kemal, Ozgur; Müderris, Togay; Sevil, Ergün; Kutlar, Gökhan

    2015-04-01

    Mean platelet volume is the measurement of the average size of platelets in the blood, and red blood cell distribution width is the variability of the size of red blood cells in circulation. This study aimed to investigate if there was any relationship between mean platelet volume, red blood cell distribution, and epistaxis. Prospective controlled trial. The study included 90 patients admitted to Ankara Atatürk Hospital and Samsun Medicana Hospital with complaints of recurrent epistaxis, and a control group of 90 healthy subjects. Blood samples were taken from all patients and control group subjects. Mean platelet volume and red blood cell distribution parameters were examined and compared between the two groups. The mean platelet volume levels were determined as 8.86 ± 0.1 in the control group and 8.36 ± 0.1 in the patient group. The difference between the two groups with respect to mean platelet volume was statistically significant (P epistaxis. These findings could be beneficial in new investigations into epistaxis mechanisms. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

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

    Science.gov (United States)

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

    2014-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Mert DG

    2016-08-01

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

  7. Assessment of red blood cell distribution width and mean platelet volume in children with epistaxis.

    Science.gov (United States)

    Üstün Bezgin, Selin; Çakabay, Taliye; Odaman Al, Işık

    2017-04-01

    This study aimed to investigate whether there is a relationship between red blood cell distribution width, mean platelet volume and epistaxis in children. Between January 2015 and July 2016, 105 children who were referred to our clinic with epistaxis and 100 sex- and age-matched controls were retrospectively analyzed. Red blood cell distribution width (RDW) and mean platelet volume (MPV) values were determined in both groups. RDW values were found significantly (P epistaxis than in the control group (11.95 ± 1.31 vs. 12.74 ± 1.21). MPV was 7.49 ± 1.33 in the group with epistaxis and 7.23 ± 1.06 in the control group, and there was no significant difference between the groups (p > 0.05). We found no difference between MPV values of both groups and significantly lower RDW values in children with epistaxis. Decreased RDW values were considered as an accompanying marker rather than a result of epistaxis. In addition, it may be thought that low RDW values may increase the bleeding tendency by disrupting the thrombotic activities. Further studies are needed to validate the relation of these parameters with epistaxis and its mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effect of Subclinical Hypothyroidism on the Mean Platelet Volume of Pregnant Women

    OpenAIRE

    Sari, Oktay; Tanoglu, Alpaslan; Mahmutoglu, Onur; Aydogan, Umit; Beyazit, Fatma; Akpak, Yasam Kemal; Keskin, Ugur

    2016-01-01

    Subclinical hypothyroidism (SH) is a frequently seen clinical disorder, which needs to be managed strictly in the pregnant population. SH is closely related with newborn complications and also suggested to be risk factor for cardiovascular events. Mean platelet volume (MPV), a determinant of platelet function, is a newly emerging risk marker for cardiovascular events. The aim of this study was to evaluate how MPV values and other hematological parameters are influenced in pregnants with subcl...

  9. Increased deoposition of 111indium labelled platelets in chronically rejected kidney transplants

    International Nuclear Information System (INIS)

    Leithner, C.; Syre, G.

    1982-01-01

    Increased deposition of 111 In-oxine labelled autologous platelets in chronically rejected kidney transplants was demonstrated using a gamma-camera and by measurement of a platelet uptake index (PUI). In this group of patients the PUI correlated indirectly with the platelet half-life and was statistically different from the PUI found in stable transplant patients who acted as controls. It is therefore suggested that platelets may play a key role in chronic rejection by the release of a mitogenic factor which promotes the development of obliterative arterial lesions in the transplant. (orig.)

  10. Investigation of Mean Platelet Volume, Platelet Distribution Width and Erythrocyte Distribution Width in Patients with Hepatitis B Virus Infection

    Directory of Open Access Journals (Sweden)

    Kazım KIRATLI

    2017-12-01

    Full Text Available Objective: Hepatitis B virus (HBV infection is an important public health issue all over the world, and it has a high morbidity and mortality rates caused by chronic liver disease. Liver biopsy is the primary procedure for evaluating the fibrosis grade. Recently, non-invasive methods are used to predict liver histology. Complete blood count (CBC is one of the most needed and used laboratory tests in clinics. CBC parameters have been used in various studies to estimate the severity of the disease and the risk of mortality. In the present study, we aimed to determine the relationship of HBV infection with mean platelet volume (MPV, platelet distribution width (PDW and red cell distribution width (RDW. Materials and Methods: Two hundred fifty-nine hepatitis B surface antigen (HBsAg-positive patients, who attended the Infectious Diseases outpatient Clinic at Van Military Hospital between October 2013 and December 2014, were included in the study group. A total of 245 food handlers with similar socio-demographic characteristics with the study group, who applied at the same period, formed the control group. HBsAg-positive patients were studied in two groups as chronic active hepatitis and inactive carriers according to their follow-up. CBC results of the patients and the healthy controls were screened from the hospital information system and they were evaluated retrospectively. Results: The average platelet count in HBsAg-positive patients and controls was 262.59±62.13x103/mm3 and 245.28±60.78x103/mm3, respectively and the difference between the groups was statistically significant (p=0.002. There was also statistically significant difference in RDW values between the two groups. The average RDW was 12.14±1.05 in HBV group, while it was 12.49±1.28 in control group (p=0.001. On the other hand, no significant difference was observed in PDW and MPV between the groups. Conclusion: It is thought that simple, inexpensive and routinely used platelet and

  11. The Effect of Carbon Monoxide Poisoning on Platelet Volume in Children

    Directory of Open Access Journals (Sweden)

    Halise Akça

    2017-04-01

    Full Text Available Introduction: Carbon monoxide poisoning is one of the most important causes of morbidity and mortality. There is increasing evidence supporting the important role of mean platelet volume (MPV as a marker of hypoxia and inflammation. In this study, we aimed to determine changes in MPV values in pediatric patients with carbon monoxide poisoning. Methods: We retrospectively evaluated children who were diagnosed with carbon monoxide poisoning in our hospital between January 2005 and 2014. Results: We included 228 children with carbon monoxide poisoning (49% male in this retrospective, controlled study. The mean age of the patients was 88±56 months. Control group consisted of 200 age-matched healthy children. There was no statistically significant difference in MPV levels between the study and control groups (8.43±1.1 fL and 8.26±0.7 fL, respectively. No correlation of MPV and platelet count with carboxyhemoglobin (COHb was found. Conclusion: In our study, it was determined that MPV value was not a helpful parameter for predicting the diagnosis of acute carbon monoxide poisoning in childhood. The difference between the MPV values and the lack of significance and the absence of correlation between MPV value and COHb level led to the fact that MPV was not a guide indicating the clinical severity of the condition.

  12. Correlation between increased platelet ADP aggregability and silent brain infarcts

    International Nuclear Information System (INIS)

    Ono, Kenichiro; Arimoto, Hirohiko; Shirotani, Toshiki

    2012-01-01

    The purpose of this study was to investigate the correlation between platelet aggregability and silent brain infarcts. The study subjects were 445 people (264 men, 181 women; mean age, 53±14 years) with no neurologic signs, history of brain tumor, trauma, cerebrovascular disease, or antiplatelet medications. Adenosine diphosphate (ADP)-induced platelet aggregation was measured by the aggregation-size analytic method. Platelet aggregability was classified into 9 classes. The presence of headache/vertigo, hypertension, diabetes mellitus, hyperlipidemia, or smoking was elicited by questioning or blood sampling. A head MRI scan was performed, and if marked atherosclerosis or obvious stenosis in the intracranial vessels was detected, it was defined as a positive MR angiography (MRA) finding. Silent brain infarcts were detected in 26.3% of subjects. Hyperaggregability defined as that above class 6, 7, and 8 was present in 43.8%, 30.8%, and 15.7% of subjects, respectively. The risk factors for silent brain infarcts by multiple logistic regression analysis were aging, hypertension, positive MRA findings, and hyperaggregability. Platelet ADP hyperaggregability might be a risk factor for silent brain infarcts. (author)

  13. Cystic fibrosis heterozygotes do not have increased platelet activation

    DEFF Research Database (Denmark)

    Tarnow, Inge; Michelson, Alan D.; Frelinger III, Andrew L.

    2007-01-01

    Introduction: We have previously demonstrated platelet hyperreactivity in cystic fibrosis (CF) patients. Carriers of one CF m utation (heterozygotes) have been shown to have abnormalities related to the presence of only one-half the normal amount of CF transmembrane conductance regulator protein...

  14. Increased platelet expression of FcGammaRIIa and its potential impact on platelet reactivity in patients with end stage renal disease

    Directory of Open Access Journals (Sweden)

    Sobel Burton E

    2007-06-01

    Full Text Available Abstract Background Increased platelet reactivity has been implicated in cardiovascular disease – the major cause of death in patients with end stage renal disease (ESRD. FcGammaRIIA is a component of glycoprotein VI and Ib-IX-V that mediate activation of platelets by collagen and von Willebrand factor. To determine whether expression of FcGammaRIIA impacts platelet reactivity we quantified its expression and platelet reactivity in 33 patients with ESRD who were undergoing hemodialysis. Methods Blood samples were obtained from patients immediately before hemodialysis and before administration of heparin. Platelet expression of FcGammaRIIA and the activation of platelets in response to low concentrations of convulxin (1 ng/ml, selected to mimic effects of collagen, thrombin (1 nM, adenosine diphosphate (ADP, 0.2 uM, or platelet activating factor (PAF, 1 nM were determined with the use of flow cytometry in samples of whole blood anticoagulated with corn trypsin inhibitor (a specific inhibitor of Factor XIIa. Results Patients were stratified with respect to the median expression of FcGammaRIIA. Patients with high platelet expression of FcGammaRIIA exhibited 3-fold greater platelet reactivity compared with that in those with low expression in response to convulxin (p Conclusion Increased platelet reactivity in response to low concentrations of diverse agonists is associated with high expression of FcGammaRIIA and may contribute to an increased risk of thrombosis in patients with ESRD.

  15. Chitosan inhibits platelet-mediated clot retraction, increases platelet-derived growth factor release, and increases residence time and bioactivity of platelet-rich plasma in vivo.

    Science.gov (United States)

    Deprés-Tremblay, Gabrielle; Chevrier, Anik; Tran-Khanh, Nicolas; Nelea, Monica; Buschmann, Michael D

    2017-11-10

    Platelet-rich plasma (PRP) has been used to treat different orthopedic conditions, however, the clinical benefits of using PRP remain uncertain. Chitosan (CS)-PRP implants have been shown to improve meniscus, rotator cuff and cartilage repair in pre-clinical models. The purpose of this current study was to investigate in vitro and in vivo mechanisms of action of CS-PRP implants. Freeze-dried formulations containing 1% (w/v) CS (80% degree of deacetylation and number average molar mass 38 kDa), 1% (w/v) trehalose as a lyoprotectant and 42.2 mM calcium chloride as a clot activator were solubilized in PRP. Gravimetric measurements and molecular/cellular imaging studies revealed that clot retraction is inhibited in CS-PRP hybrid clots through physical coating of platelets, blood cells and fibrin strands by chitosan, which interferes with platelet aggregation and platelet-mediated clot retraction. Flow cytometry and ELISA assays revealed that platelets are activated and granules secreted in CS-PRP hybrid clots and that cumulative release of platelet-derived growth factor (PDGF-AB) and epidermal growth factor is higher from CS-PRP hybrid clots compared to PRP clots in vitro. Finally, CS-PRP implants resided for up to 6 weeks in a subcutaneous implantation model and induced cell recruitment and granulation tissue synthesis, confirming greater residency and bioactivity compared to PRP in vivo.

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

    Directory of Open Access Journals (Sweden)

    Rauf Oguzhan Kum

    2015-12-01

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

  17. Increased platelet activation in early symptomatic versus asymptomatic carotid stenosis and relationship with microembolic status: Results from the Platelets And Carotid Stenosis (PACS) Study.

    LENUS (Irish Health Repository)

    Kinsella, Ja

    2013-04-26

    BACKGROUND: Cerebral microembolic signals (MES) may predict increased stroke risk in carotid stenosis. However, the relationship between platelet counts or platelet activation status and MES in symptomatic versus asymptomatic carotid stenosis has not been comprehensively assessed. SETTING: University teaching hospitals. METHODS: This prospective, pilot observational study assessed platelet counts and platelet activation status, and the relationship between platelet activation and MES in asymptomatic versus early (≤4 weeks after TIA\\/stroke) and late phase (≥3 months) symptomatic moderate or severe (≥50%) carotid stenosis patients. Full blood count measurements were performed, and whole blood flow cytometry was used to quantify platelet surface activation marker expression (CD62P and CD63) and circulating leucocyte-platelet complexes. Bilateral simultaneous transcranial Doppler ultrasound monitoring of the middle cerebral arteries was performed for 1 hour to classify patients as MES-positive or MES-negative. RESULTS: Data from 31 asymptomatic patients were compared with 46 symptomatic patients in the early phase, and 35 of these patients followed up to the late phase after symptom onset. The median platelet count (211 vs. 200 x 10(9) \\/L; p=0.03) and the median% lymphocyte-platelet complexes were higher in early symptomatic than asymptomatic patients (2.8 vs. 2.4%, p=0.001). The% lymphocyte-platelet complexes was higher in early symptomatic than asymptomatic patients with ≥70% carotid stenosis (p=0.0005), and in symptomatic patients recruited within 7 days of symptom onset (p=0.028). Complete TCD data were available in 25 asymptomatic and 31 early phase symptomatic, and 27 late phase symptomatic patients. 12% of asymptomatic versus 32% of early phase symptomatic (p=0.02) and 19% of late phase symptomatic patients (p=0.2) were MES-positive. Early symptomatic MES-negative patients had a higher% lymphocyte-platelet complexes than asymptomatic MES

  18. Association of Mean Platelet Volume with Severity, Serology & Treatment Outcome in Dengue Fever: Prognostic Utility.

    Science.gov (United States)

    Sharma, Kritika; Yadav, Ajay

    2015-11-01

    Dengue is the most rapidly spreading mosquito-borne viral disease in the world. Dengue fever (DF) with its severe manifestations such as dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) has emerged as a major public health problem of international concern. Thrombocytopenia and bleeding are common complications of dengue fever, hence besides platelet counts, there is a need to assess the role of mean platelet volume. Studying association of mean platelet volume (MPV) with severity, serology & treatment outcome to assess its prognostic utility, which can be of great help in limiting morbidity & mortality associated with dengue fever. The present study was conducted in Central Pathology Lab of SMS Medical College & Hospital, Jaipur, Rajasthan from the period of March 2013 till October 2013. Blood samples were collected from 200 patients with NS 1 Antigen positivity experiencing febrile illness, clinically consistent with dengue infection. Evaluation of platelet counts, MPV, IgM and IgG antibodies was done in all these cases. Categorical data were presented as numbers (percent) and were compared among groups using Chi-square test. Groups compared for demographic data were presented as mean and standard deviation and were compared using student t-test, ANOVA and Post-Hoc Test, Tukey Test using SPSS, version 20 for Windows. A total of 200 Dengue fever cases were studied. Out of which, 68% cases were of DF, 23% DHF & 9% DSS i.e. classical dengue fever was most common presentation. Maximum (44%) cases were in age group of 15-24 years. Fever was the presenting complaint in all cases (100%). 98% cases of dengue had thrombocytopenia. MPV showed no significant correlation with severity, serology & treatment outcome, thus excluding its role in dengue cases. Mean platelet volume is not important as prognostic parameter in dengue fever.

  19. Deletion of Crry and DAF on murine platelets stimulates thrombopoiesis and increases factor H-dependent resistance of peripheral platelets to complement attack.

    Science.gov (United States)

    Barata, Lidia; Miwa, Takashi; Sato, Sayaka; Kim, David; Mohammed, Imran; Song, Wen-Chao

    2013-03-15

    Complement receptor 1-related gene/protein y (Crry) and decay-accelerating factor (DAF) are two murine membrane C3 complement regulators with overlapping functions. Crry deletion is embryonically lethal whereas DAF-deficient mice are generally healthy. Crry(-/-)DAF(-/-) mice were viable on a C3(-/-) background, but platelets from such mice were rapidly destroyed when transfused into C3-sufficient mice. In this study, we used the cre-lox system to delete platelet Crry in DAF(-/-) mice and studied Crry/DAF-deficient platelet development in vivo. Rather than displaying thrombocytopenia, Pf4-Cre(+)-Crry(flox/flox) mice had normal platelet counts and their peripheral platelets were resistant to complement attack. However, chimera mice generated with Pf4-Cre(+)-Crry(flox/flox) bone marrows showed platelets from C3(-/-) but not C3(+/+) recipients to be sensitive to complement activation, suggesting that circulating platelets in Pf4-Cre(+)-Crry(flox/flox) mice were naturally selected in a complement-sufficient environment. Notably, Pf4-Cre(+)-Crry(flox/flox) mouse platelets became complement susceptible when factor H function was blocked. Examination of Pf4-Cre(+)-Crry(flox/flox) mouse bone marrows revealed exceedingly active thrombopoiesis. Thus, under in vivo conditions, Crry/DAF deficiency on platelets led to abnormal platelet turnover, but peripheral platelet count was compensated for by increased thrombopoiesis. Selective survival of Crry/DAF-deficient platelets aided by factor H protection and compensatory thrombopoiesis demonstrates the cooperation between membrane and fluid phase complement inhibitors and the body's ability to adaptively respond to complement regulator deficiencies.

  20. Basketball training increases striatum volume.

    Science.gov (United States)

    Park, In Sung; Lee, Kea Joo; Han, Jong Woo; Lee, Nam Joon; Lee, Won Teak; Park, Kyung Ah; Rhyu, Im Joo

    2011-02-01

    The striatum is associated with the learning and retention of motor skills. Several studies have shown that motor learning induces neuronal changes in the striatum. We investigated whether macroscopic change in striatum volume occurs in a segment of the human population who learned basketball-related motor skills and practiced them throughout their entire athletic life. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players and healthy controls, and striatum volumes were compared based on basketball proficiency, region and side. We identified morphological enlargement in the striatum of basketball players in comparison with controls. Our results suggest that continued practice and repetitive performance of basketball-related motor skills may induce plastic structural changes in the human striatum. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Can mean platelet volume be used as a biomarker for asthma?

    Directory of Open Access Journals (Sweden)

    Hikmet Tekin Nacaroglu

    2016-06-01

    Full Text Available Introduction : Platelets play important roles in airway inflammation and are activated in inflammatory lung diseases, including asthma. Aim :We evaluated the mean platelet volume (MPV, used as a marker of platelet activation, in asthmatic patients during asymptomatic periods and exacerbations compared to healthy controls to determine whether MPV can be used as an indicator of inflammation. Material and methods :Our patient group consisted of95 children with exacerbation of asthma who were admitted to our allergy clinic. The control group consisted of 100 healthy children matched for age, gender, and ethnicity. Mean platelet volume values of the patient group obtained during exacerbation of asthma were compared to those of the same group during the asymptomatic period and with the control group. We investigated factors that can affect the MPV values of asthma patients, including infection, atopy, immunotherapy treatment, and severity of asthma exacerbation. Results :The patient group consisted of 50 (52.6% boys and 45 (47.4% girls with a mean age of 125 ±38 months old. Mean MPV values in the exacerbation period, the healthy period, and in the control group were 8.1 ±0.8 fl, 8.1 ±1.06 fl, and 8.2 ±0.9 fl, respectively; there were no significant differences between groups (p > 0.05. The severity of asthma, severity of asthma exacerbation, immunotherapy, coinfection, eosinophil count, and IgE level also had no effect on MPV (p > 0.05. Conclusions : Although platelets play a rolein the pathophysiology of asthma, MPV measurement is insufficient to detect inflammation through platelets

  2. Correlation of symptom depression levels with mean platelet volume rate on patients of acute coronary syndrome

    Science.gov (United States)

    Hasugian, L.; Hanum, H.; Hanida, W.; Safri, Z.

    2018-03-01

    Patients with Depression and the acute coronary syndrome (ACS) is rarely detected, although in some studies say that depression can worsen cardiovascularly and increase mortality. From research, Canan F et al found that increasing levels of Mean platelet volume (MPV) as a risk factor for atherosclerosis and MPV was higher in patients with depression compared with patients without depression. In this study used observational methods of measurement of cross-sectional data. Research began in November 2015 - May 2016 against General Hospital inpatients H. Adam Malik Medan. There are 64 patients with a diagnosis of ACS were given quieter Beck Depression Inventory (BDI), then calculated a score of BDI patients and MPV levels were seen when they first entered the hospital before being given treatment. Patients answered quieter on days 3-7 after diagnosis ACS. ACS Patients were divided into 3 groups: acute myocardial infarction with ST elevation, acute myocardial infarction with non-ST elevation and unstable angina pectoris. The level of depression is grouped into not depression, mild depression, moderate depression and severe depression. Statistically significant with p-value<0.05Based on the linear correlation analysis, it was found a positive correlation with r=0.542. And the relationship is statistically significant with p-value 0.000003.

  3. Podoplanin expression in primary brain tumors induces platelet aggregation and increases risk of venous thromboembolism.

    Science.gov (United States)

    Riedl, Julia; Preusser, Matthias; Nazari, Pegah Mir Seyed; Posch, Florian; Panzer, Simon; Marosi, Christine; Birner, Peter; Thaler, Johannes; Brostjan, Christine; Lötsch, Daniela; Berger, Walter; Hainfellner, Johannes A; Pabinger, Ingrid; Ay, Cihan

    2017-03-30

    Venous thromboembolism (VTE) is common in patients with brain tumors, and underlying mechanisms are unclear. We hypothesized that podoplanin, a sialomucin-like glycoprotein, increases the risk of VTE in primary brain tumors via its ability to induce platelet aggregation. Immunohistochemical staining against podoplanin and intratumoral platelet aggregates was performed in brain tumor specimens of 213 patients (mostly high-grade gliomas [89%]) included in the Vienna Cancer and Thrombosis Study, a prospective observational cohort study of patients with newly diagnosed cancer or progressive disease aimed at identifying patients at risk of VTE. Platelet aggregation in response to primary human glioblastoma cells was investigated in vitro. During 2-year follow-up, 29 (13.6%) patients developed VTE. One-hundred fifty-one tumor specimens stained positive for podoplanin (33 high expression, 47 medium expression, 71 low expression). Patients with podoplanin-positive tumors had lower peripheral blood platelet counts ( P < .001) and higher D-dimer levels ( P < .001). Podoplanin staining intensity was associated with increasing levels of intravascular platelet aggregates in tumor specimens ( P < .001). High podoplanin expression was associated with an increased risk of VTE (hazard ratio for high vs no podoplanin expression: 5.71; 95% confidence interval, 1.52-21.26; P = 010), independent of age, sex, and tumor type. Podoplanin-positive primary glioblastoma cells induced aggregation of human platelets in vitro, which could be abrogated by an antipodoplanin antibody. In conclusion, high podoplanin expression in primary brain tumors induces platelet aggregation, correlates with hypercoagulability, and is associated with increased risk of VTE. Our data indicate novel insights into the pathogenesis of VTE in primary brain tumors. © 2017 by The American Society of Hematology.

  4. Increased platelet count and reticulated platelets in recently symptomatic versus asymptomatic carotid artery stenosis and in cerebral microembolic signal-negative patient subgroups: results from the HaEmostasis In carotid STenosis (HEIST) study.

    Science.gov (United States)

    Murphy, S J X; Lim, S T; Kinsella, J A; Murphy, D; Enright, H M; McCabe, Dominick J H

    2018-02-23

    The pathophysiological mechanisms responsible for the disparity in stroke risk between asymptomatic and symptomatic carotid stenosis patients are not fully understood. The functionally important reticulated platelet fraction and reticulocytes could play a role. We performed a prospective, multi-centre, observational analytical study comparing full blood count parameters and platelet production/turnover/activation markers in patients with asymptomatic versus recently symptomatic moderate (≥ 50-69%) or severe (≥ 70-99%) carotid stenosis. Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Reticulated platelets were quantified by whole blood flow cytometry and reticulated platelets and red cell reticulocytes by 'automated assays' (Sysmex XE-2100™). Bilateral simultaneous transcranial Doppler ultrasound monitoring classified patients as micro-embolic signal (MES)+ve or MES-ve. Mean platelet count was higher in early (216 × 10 9 /L; P = 0.04) and late symptomatic (219 × 10 9 /L; P = 0.044) than asymptomatic patients (194 × 10 9 /L). Mean platelet volume was higher in early symptomatic than asymptomatic patients (10.8 vs. 10.45 fl; P = 0.045). Automated assays revealed higher % reticulated platelet fractions in early (5.78%; P < 0.001) and late symptomatic (5.11%; P = 0.01) than asymptomatic patients (3.48%). Red cell reticulocyte counts were lower in early (0.92%; P = 0.035) and late symptomatic (0.93%; P = 0.036) than asymptomatic patients (1.07%). The automated % reticulated platelet fraction was also higher in early symptomatic than asymptomatic MES-ve patients (5.7 vs. 3.55%; P = 0.001). The combination of increased platelet counts and a shift towards production of an increased population of larger, young, reticulated platelets could contribute to a higher risk of first or recurrent

  5. Increased intracranial volume in Parkinson's disease

    DEFF Research Database (Denmark)

    Krabbe, Katja; Karlsborg, Merete; Hansen, Andreas

    2005-01-01

    segmentation and outlining of regions in order to identify regional volume changes that might be useful in the diagnosis of the two diseases. RESULTS: Patients with PD had significantly larger intracranial volumes (ICVs) and significantly smaller putaminal and sustantia nigra volumes than controls. MSA...... patients had significantly smaller substantia nigra and caudate volumes than controls but normal intracranial volume. In both patient groups there was a further trend towards smaller amygdala volumes. DISCUSSION: Increased ICV in PD patients is a new finding that may be explained by genetic factors...

  6. 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.

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

    Science.gov (United States)

    Sclafani, Anthony P; Saman, Masoud

    2012-05-01

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

  8. 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)

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  10. Optimizing donor scheduling before recruitment: An effective approach to increasing apheresis platelet collections.

    Science.gov (United States)

    Lokhandwala, Parvez M; Shike, Hiroko; Wang, Ming; Domen, Ronald E; George, Melissa R

    2018-01-01

    Typical approach for increasing apheresis platelet collections is to recruit new donors. Here, we investigated the effectiveness of an alternative strategy: optimizing donor scheduling, prior to recruitment, at a hospital-based blood donor center. Analysis of collections, during the 89 consecutive months since opening of donor center, was performed. Linear regression and segmented time-series analyses were performed to calculate growth rates of collections and to test for statistical differences, respectively. Pre-intervention donor scheduling capacity was 39/month. In the absence of active donor recruitment, during the first 29 months, the number of collections rose gradually to 24/month (growth-rate of 0.70/month). However, between month-30 and -55, collections exhibited a plateau at 25.6 ± 3.0 (growth-rate of -0.09/month) (pcollection days/week (month-72). Consequently, the scheduling capacity increased to 130/month. Post-interventions, apheresis platelet collections between month-56 and -81 exhibited a spontaneous renewed growth at a rate of 0.62/month (pcollections. Apheresis platelet collections plateau at nearly 2/3rd of the scheduling capacity. Optimizing the scheduling capacity prior to active donor recruitment is an effective strategy to increase platelet collections at a hospital-based donor center.

  11. Evaluation of plasma eosinophil count and mean platelet volume in patients with coronary slow flow

    Directory of Open Access Journals (Sweden)

    Mehmet Demir

    2014-01-01

    Full Text Available OBJECTIVE: The pathophysiology of coronary slow flow has not been clearly defined, although multiple abnormalities including arteritis, endothelial dysfunction, and atherothrombosis, have been reported. It is known that eosinophils play an important role in inflammation, endothelial dysfunction, and thrombosis. We aimed to compare the eosinophil counts of coronary slow flow patients versus healthy controls. METHODS: This study included 50 coronary slow flow patients (19 males, mean age 65.6±13.7 years and 30 healthy controls (10 males, mean age 57.86±11.6 years. These participants were evaluated using concurrent routine biochemical tests as well as neutrophil, lymphocyte, and eosinophil counts and mean platelet volume (MPV, which were obtained from the whole blood count. These parameters were compared between groups. RESULTS: The baseline characteristics of the study groups were comparable. The coronary slow flow patients had a higher mean platelet volume and eosinophil count than the control group (8.38±0.86 vs 6.28±1.6 fL and 0.31±0.42 vs 0.09±0.05; p<0.001 and 0.008, respectively. CONCLUSION: Our study demonstrated a relationship between eosinophil count and MPV in patients with coronary slow flow.

  12. Relation between the Change in Mean Platelet Volume and Clopidogrel Resistance in Patients Undergoing Percutaneous Coronary Intervention.

    Science.gov (United States)

    Koh, Young-Youp; Kim, Hyung Ho; Choi, Dong-Hyun; Lee, Young-Min; Ki, Young-Jae; Kang, Seong-Ho; Park, Geon; Chung, Joong-Wha; Chang, Kyong-Sig; Hong, Soon-Pyo

    2015-01-01

    We aimed to determine the association between the change in mean platelet volume (MPV) over time and aspirin/ clopidogrel resistance in patients undergoing percutaneous coronary intervention (PCI). The MPV and platelet function were analysed in 302 patients who underwent PCI. MPV changes were associated with increased aspirin reaction units (ARU, r = 0.114; P = 0.047), increased P2Y12 reaction units (PRU, r = 0.193; P = 0.001), and decreased P2Y12% inhibition (PI%, r = - 0.273; P resistant group (≥235 PRU or ≤15% of PI%) showed a significantly higher positive change in MPV (ΔMPV) values than the clopidogrel responder group (0.53 ± 0.78 vs. 0.13 ± 0.69 fL, P resistant and responder groups were 72.6% and 59.3%, respectively. After adjusting for traditional risk factors, the odds ratio in the clopidogrel resistant group with ΔMPV ≥0.2 fL was 4.10 (95% confidence interval; 1.84-9.17). In conclusion, ΔMPV was associated with PRU and PI%; a positive ΔMPV was an independent predictive marker for clopidogrel resistance after PCI.

  13. Increased platelet count and leucocyte-platelet complex formation in acute symptomatic compared with asymptomatic severe carotid stenosis.

    LENUS (Irish Health Repository)

    McCabe, D J H

    2005-09-01

    The risk of stroke in patients with recently symptomatic carotid stenosis is considerably higher than in patients with asymptomatic stenosis. In the present study it was hypothesised that excessive platelet activation might partly contribute to this difference.

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

    Directory of Open Access Journals (Sweden)

    Sevil Alan

    2015-12-01

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

  15. Assessment of Platelet Profile of Healthy Volunteers in the ...

    African Journals Online (AJOL)

    ADOWIE PERE

    A similar pattern was observed for Mean Platelet Volume (MPV). However, Platelet ... Keywords: Platelet Count, Plateletcrit, Mean Platelet Volume, Platelet Distribution Width, Trimesters, ... bleeding disorders, diabetes and drugs capable of.

  16. Prognostic value of elevated mean platelet volume in patients undergoing primary angioplasty for ST-elevation myocardial infarction.

    Science.gov (United States)

    Akgul, Ozgur; Uyarel, Huseyin; Pusuroglu, Hamdi; Gul, Mehmet; Isiksacan, Nilgun; Turen, Selahattin; Erturk, Mehmet; Surgit, Ozgur; Cetin, Mustafa; Bulut, Umit; Baycan, Omer Faruk; Uslu, Nevzat

    2013-06-01

    The aim of this study was to evaluate the prognostic value of mean platelet volume (MPV) in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). We prospectively enrolled 495 consecutive STEMI patients.The study population was divided into tertiles based on admission MPV values. The high MPV group (n= 148) was defined as a value in the third tertile (> 8.9), and the low MPV group (n = 347) included those patients with a value in the lower two tertiles ( 8.9) was found to be a powerful independent predictor of six-month all-cause mortality. These results suggest that a high admission MPV level was associated with increased six-month all-cause mortality in patients with STEMI undergoing primary PCI.

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

    Directory of Open Access Journals (Sweden)

    Ayse Balkarli

    2016-09-01

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

  18. The predictive value of mean platelet volume, plateletcrit and red cell distribution width in the differentiation of autoimmune gastritis patients with and without type I gastric carcinoid tumors.

    Science.gov (United States)

    Tüzün, Ali; Keskin, Onur; Yakut, Mustafa; Kalkan, Cagdas; Soykan, Irfan

    2014-01-01

    Autoimmune gastritis is an autoimmune and inflammatory condition that may predispose to gastric carcinoid tumors or adenocarcinomas. The early diagnosis of these tumors is important in order to decrease morbidity and mortality. Platelet indices such as mean platelet volume and plateletcrit levels increase in inflammatory, infectious and malign conditions. The primary aim of this study was to explore wheter platelet indices and red cell distribution width have any predictive role in the discrimination of autoimmune gastritis patients with and without gastric carcinoid tumors. Also secondary aim of this study was to investigate whether any changes exist betwenn autoimmune gastritis and functional dyspepsia patients by means of platelet indices. Plateletcrit (0.22 ± 0.06 vs. 0.20 ± 0.03%, p gastritis patients compared to control group. Receiver operating curve analysis suggested that optimum plateletcrit cut-off point was 0.20% (AUC: 0.646), and 13.95% as the cut off value for red cell distribution width (AUC: 0.860). Although plateletcrit (0.22 ± 0.06 vs. 0.21 ± 0.04%, p = 0.220) and mean platelet volume (8.94 ± 1.44 vs. 8.68 ± 0.89 fl, p = 0.265) were higher in autoimmune gastritis patients without carcinoid tumor compared to patients with carcinoid tumors, these parameters were not statistically significant. Changes in plateletcrit and red cell distribution width values may be used as a marker in the discrimination of autoimmune gastritis and fucntional dyspepsia patients but not useful in patients with gastric carcinoid tumor type I.

  19. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multifrequency EM

    Science.gov (United States)

    Hoppmann, Mario; Hunkeler, Priska A.; Hendricks, Stefan; Kalscheuer, Thomas; Gerdes, Rüdiger

    2016-04-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise, accumulate beneath nearby sea ice, and subsequently form a several meter thick, porous sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator of the health of an ice shelf. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions within the platelet layer using Archie's Law. The thickness results agreed well with drillhole validation datasets within the uncertainty range, and the ice-volume fraction yielded results comparable to other studies. Both parameters together enable an estimation of the total ice volume within the platelet layer, which was found to be comparable to the volume of landfast sea ice in this region, and corresponded to more than a quarter of the annual basal melt volume of the nearby Ekström Ice Shelf. Our findings show that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties, with important implications for research into ocean/ice-shelf/sea-ice interactions. However, a successful application of this

  20. Increased serum levels of hyaluronic acid in pregnancies complicated by preeclampsia or hemolysis, elevated liver enzymes, and low platelets syndrome.

    Science.gov (United States)

    Osmers, R G; Schütz, E; Diedrich, F; Wehry, B; Krauss, T; Oellerich, M; Kuhn, W

    1998-02-01

    Fifteen percent of patients who later have hemolysis, elevated liver enzymes, and low platelets syndrome develop initially have nonspecific symptoms. Early diagnosis could ensure adequate obstetric management; however, prognostic biochemical tests are lacking. We hypothesized that elevated hyaluronic acid serum levels might be an early indicator of hemolysis, elevated liver enzymes, and low platelets syndrome because it is known to be a sensitive marker of liver cell function. Hyaluronic acid in serum was measured in patients with normal pregnancies (n = 109) and in those patients with pregnancies complicated by preeclampsia (n = 14) or hemolysis, elevated liver enzymes, and low platelets syndrome (n = 11). A significant increase in hyaluronic acid serum concentrations was observed in patients with hemolysis, elevated liver enzymes, and low platelets syndrome or with preeclampsia (p hyaluronic acid serum levels in hemolysis, elevated liver enzymes, and low platelets syndrome correlated with the clinical severity of the individual course of disease as measured by intensive care unit time (r = 0.72; p hyaluronic acid in preeclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome are significantly elevated and might play an important diagnostic and prognostic role in patients with hemolysis, elevated liver enzymes, and low platelets syndrome.

  1. The plant cytoskeleton controls regulatory volume increase.

    Science.gov (United States)

    Liu, Qiong; Qiao, Fei; Ismail, Ahmed; Chang, Xiaoli; Nick, Peter

    2013-09-01

    The ability to adjust cell volume is required for the adaptation to osmotic stress. Plant protoplasts can swell within seconds in response to hypoosmotic shock suggesting that membrane material is released from internal stores. Since the stability of plant membranes depends on submembraneous actin, we asked, whether this regulatory volume control depends on the cytoskeleton. As system we used two cell lines from grapevine which differ in their osmotic tolerance and observed that the cytoskeleton responded differently in these two cell lines. To quantify the ability for regulatory volume control, we used hydraulic conductivity (Lp) as readout and demonstrated a role of the cytoskeleton in protoplast swelling. Chelation of calcium, inhibition of calcium channels, or manipulation of membrane fluidity, did not significantly alter Lp, whereas direct manipulation of the cytoskeleton via specific chemical reagents, or indirectly, through the bacterial elicitor Harpin or activation of phospholipase D, was effective. By optochemical engineering of actin using a caged form of the phytohormone auxin we can break the symmetry of actin organisation resulting in a localised deformation of cell shape indicative of a locally increased Lp. We interpret our findings in terms of a model, where the submembraneous cytoskeleton controls the release of intracellular membrane stores during regulatory volume change. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. 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

  3. Red Wine Inhibits Aggregation and Increases ATP-diphosphohydrolase (CD39) Activity of Rat Platelets in Vitro.

    Science.gov (United States)

    Caiazzo, Elisabetta; Tedesco, Idolo; Spagnuolo, Carmela; Russo, Gian Luigi; Ialenti, Armando; Cicala, Carla

    2016-06-01

    Moderate consumption of red wine has been shown to exert a peculiar cardioprotective effect compared with other alcoholic beverages; inhibition of platelet aggregation seems to be one of the mechanisms underlying this beneficial effect. CD39/ATP-diphosphohydrolase is an integral membrane glycoprotein metabolizing ATP and ADP to AMP; in concert with CD73/ecto-5'-nucleotidase, it contributes to extracellular adenosine accumulation. CD39 is considered a key modulator of thrombus formation; it inhibits platelet aggregation by promoting ADP hydrolysis. There is evidence that red wine consumption increases CD39 activity in platelets from streptozotocin-induced diabetic rats. Here we show that two kinds of Aglianico red wines inhibit aggregation and increase ATP--and ADPase activity in rat platelets.

  4. Increased platelet mitochondrial respiration after cardiac arrest and resuscitation as a potential peripheral biosignature of cerebral bioenergetic dysfunction.

    Science.gov (United States)

    Ferguson, Michael A; Sutton, Robert M; Karlsson, Michael; Sjövall, Fredrik; Becker, Lance B; Berg, Robert A; Margulies, Susan S; Kilbaugh, Todd J

    2016-06-01

    Cardiac arrest (CA) results in a sepsis-like syndrome with activation of the innate immune system and increased mitochondrial bioenergetics. To determine if platelet mitochondrial respiration increases following CA in a porcine pediatric model of asphyxia-associated ventricular fibrillation (VF) CA, and if this readily obtained biomarker is associated with decreased brain mitochondrial respiration. CA protocol: 7 min of asphyxia, followed by VF, protocolized titration of compression depth to systolic blood pressure of 90 mmHg and vasopressor administration to a coronary perfusion pressure greater than 20 mmHg. platelet integrated mitochondrial electron transport system (ETS) function evaluated pre- and post-CA/ROSC four hours after return of spontaneous circulation (ROSC). Secondary outcome: correlation of platelet mitochondrial bioenergetics to cerebral bioenergetic function. Platelet maximal oxidative phosphorylation (OXPHOSCI+CII), P respiration through Complex II (OXPHOSCII, P respiration was not due to uncoupling, as the LEAKCI + CII respiration (mitochondrial respiration independent of ATP-production) was unchanged after CA/ROSC. Larger increases in platelet mitochondrial respiratory control ratio (RCR) compared to pre-CA RCR were significantly correlated with lower RCRs in the cortex (P respiration. Platelet mitochondrial respiration is significantly increased four hours after ROSC. Future studies will identify mechanistic relationships between this serum biomarker and altered cerebral bioenergetics function following cardiac arrest.

  5. Evaluation of the relationship between serum apelin levels and vitamin D and mean platelet volume in diabetic patients.

    Science.gov (United States)

    Kiskac, Muharrem; Zorlu, Mehmet; Cakirca, Mustafa; Karatoprak, Cumali; Kesgin, Sıdıka; Büyükaydın, Banu; Yavuz, Erdinc; Ardic, Cuneyt; Camli, Ahmet Adil; Cikrikcioglu, Mehmet Ali

    2014-09-01

    It was reported that Vitamin D deficiency was associated with a greater risk of cardiometabolic diseases, obesity, impaired glucose tolerance and diabetes mellitus type 2, arterial hypertension, and dyslipidemia. Apelin is an adipocytokine suspected to have a role in skeletal muscle glucose utilization and glycemic regulation which may be a promising treatment modality for diabetes. It was recently reported that increased mean platelet volume (MPV) was emerging as an independent risk factor for thromboembolism, stroke, and myocardial infarction. In patients with diabetes, MPV was higher compared with the normal glycemic controls; in addition, it has been proposed that an increase in MPV may play a role in the micro- and macro-vascular complications related to diabetes. We postulated that deficiency in Vitamin D levels might be associated with higher MPV and lower serum apelin levels leading a further increase in insulin resistance in diabetic patients. So, we aimed to investigate Vitamin D levels, MPV and serum apelin levels in diabetic patients and their correlations between each other. This is a cross-sectional study design. Seventy-eight patients with Diabetes Mellitus type 2, admitted to our outpatient clinic of internal medicine department at Bezmialem Vakif University, were included in our study. Forty-one patients were female; 37 patients were male. Serum apelin levels, fasting glucose levels, urea, creatinine, triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting serum insulin level, HbA1c, free T3, free T4, TSH, vitamin D (25-OH Vitamin D) and complete blood counts were analyzed in all subjects. Each sex was analyzed separately. We found that a positive correlation existed between serum apelin levels and BMI in female patients. (r: 0.380, P: 0.014) There was also a significant positive correlation between MPV and HbA1c and fasting glucose levels and a negative correlation

  6. Increased platelet expression of glycoprotein IIIa following aspirin treatment in aspirin-resistant but not aspirin-sensitive subjects

    Science.gov (United States)

    Floyd, Christopher N; Goodman, Timothy; Becker, Silke; Chen, Nan; Mustafa, Agnesa; Schofield, Emma; Campbell, James; Ward, Malcolm; Sharma, Pankaj; Ferro, Albert

    2014-01-01

    Aims Aspirin is widely used as an anti-platelet agent for cardiovascular prophylaxis. Despite aspirin treatment, many patients experience recurrent thrombotic events, and aspirin resistance may contribute to this. We examined the prevalence of aspirin resistance in a healthy population, and investigated whether the platelet proteome differed in aspirin-resistant subjects. Methods Ninety-three healthy subjects received aspirin 300 mg daily for 28 days. Before and at the end of treatment, urine was taken to determine 11-dehydrothromboxane B2, and blood was taken to measure arachidonic acid (AA)-induced aggregation of platelet-rich plasma and to interrogate the platelet proteome by mass spectrometric analysis with further confirmation of findings using Western blotting. Results In two of the 93 subjects, neither AA-induced aggregation nor urinary 11-dehydrothromboxane B2 was effectively suppressed by aspirin, despite measurable plasma salicylate concentrations, suggesting the presence of true aspirin resistance. Despite no detectable differences in the platelet proteome at baseline, following aspirin a marked increase was seen in platelet glycoprotein IIIa expression in the aspirin-resistant but not aspirin-sensitive subjects. An increase in platelet glycoprotein IIIa expression with aspirin resistance was confirmed in a separate cohort of 17 patients with stable coronary artery disease on long term aspirin treatment, four of whom exhibited aspirin resistance. Conclusions In a healthy population, true aspirin resistance is uncommon but exists. Resistance is associated with an increase in platelet glycoprotein IIIa expression in response to aspirin. These data shed new light on the mechanism of aspirin resistance, and provide the potential to identify aspirin-resistant subjects using a novel biomarker. PMID:25099258

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

    Science.gov (United States)

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

    1992-01-01

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

  8. Soluble glycoprotein VI, a specific marker of platelet activation is increased in the plasma of subjects with seropositive rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    John R Stack

    Full Text Available Anti-citrullinated protein antibodies (ACPA have been shown to cause platelet activation in vitro, through the low-affinity immunoglobulin G (IgG receptor (FcγRIIa on platelets. Platelet activation via engagement of FcγRIIa results in proteolytic cleavage and shedding of platelet specific glycoprotein VI (GPVI which can be detected in the plasma as soluble GPVI (sGPVI. We hypothesized that plasma levels of sGPVI would be increased among patients with seropositive RA as a consequence of antibody-induced platelet activation and GPVI shedding.Samples from 84 patients with RA (65 seropositive and 19 seronegative and 67 healthy controls were collected prospectively and analysed for sGPVI using a standardised ELISA.Patients with seropositive RA had significantly higher levels of sGPVI compared to seronegative RA and controls. Median (IQR sGPVI levels were 4.2 ng/ml (3.2, 8.0 in seropositve RA, 2.2 ng/ml (1.5, 3.5 in seronegative RA and 2.2 ng/ml (1.6, 3.4 in controls (p<0.0001. sGPVI levels correlated with ACPA titres (r = 0.32, p = 0.0026 and with RF titres (r = 0.48, p<0.0001.Plasma sGPVI, a specific marker of platelet activation is increased among patients with seropositive RA.

  9. Diagnostic value of mean platelet volume (MPV) to troponin T inpatients with acute coronary syndrome

    Science.gov (United States)

    Aryanto, D.; Isnanta, R.; Safri, Z.; Hasan, R.

    2018-03-01

    Acute Coronary Syndrome (ACS) is used to describe the spectrum of coronary artery disease (CAD). Troponin T is the determinant of the most sensitive marker of ACS, but there aren’t all hospitals have this because of expensiveness. Mean Platelet Volume (MPV) is one of the components of a complete blood routine examination and relatively cheap as a marker in ACS. Determining the sensitivity and specificity of MPV in detecting cases of the acute coronary syndrome, 325 subjects’ medical records were from the period of July 2013 to June 2014; 228 ACS patients met the inclusion criteria. 228 subjects showed a risk factor for age ≥45years of more 195 (85.5%). 122 subjects with hypertension (53.5%) and subjects who smoked 118 (51.8%) that suffered most ACS. Subjects with risk factors for diabetes mellitus, obesity, menopause and dyslipidemia in this study was lower than non-diabetic 161 (70.6%), obese189 (82.9%), nonmenopause 196 (86%) and normal lipid 210 (92.1%). But there was norelation between risk factor with MPV and troponin T statistically. The results of diagnostic tests MPV for the evaluation of patients with ACS, sensitivity 92%, specificity 71%, positive predictive value 95% and negative predictive value 58%.

  10. Mean platelet volume is decreased in adults with active lupus disease

    Directory of Open Access Journals (Sweden)

    Guillermo Delgado-García

    Full Text Available ABSTRACT Background: Only a few biomarkers are available for assessing disease activity in systemic lupus erythematosus (SLE. Mean platelet volume (MPV has been recently studied as an inflammatory biomarker. It is currently unclear whether MPV may also play a role as a biomarker of disease activity in adult patients with SLE. Objective: We investigated the association between MPV and disease activity in adult patients with SLE. Methods: In this retrospective study, we compared two groups of adult patients divided according to disease activity (36 per group. Subjects were age- and gender-matched. Results: MPV was significantly decreased with respect to those of inactive patients (7.16 ± 1.39 vs. 8.16 ± 1.50, p = 0.005. At a cutoff level of 8.32 fL, MPV has a sensitivity of 86% and a specificity of 41% for the detection of disease activity. A modest positive correlation was found between MPV and albumin (r = 0.407, p = 0.001, which in turn is inversely associated with disease activity. Conclusions: In summary, MPV is decreased in adult patients with active lupus disease, and positively correlated with albumin, another biomarker of disease activity. Prospective studies are needed to evaluate the prognostic value of this biomarker.

  11. The relationship between mean platelet volume and coronary collateral vessels in patients with acute coronary syndromes

    Directory of Open Access Journals (Sweden)

    Gaurav Singhal

    2016-01-01

    Full Text Available Background: Elevated mean platelet volume (MPV has been proposed as a risk factor for coronary artery disease (CAD and is associated with poor clinical outcome in acute coronary syndrome (ACS. However, some studies have contradictory findings. Hence, we aimed to evaluate the association of MPV with the presence of coronary collateral vessel (CCV in patients with ACS. Objective: To find MPV value in ACS patients and to find the predictive value of MPV in the spectrum of CAD and to examine whether levels of MPV predict the presence of CCVs. Methods: A total of 180 patients with first ACS were included in the study. MPV was measured. All patients underwent coronary angiography to know disease severity and CCVs. The CCVs are graded according to the Rentrop scoring system and according to coronary angiography results; patients were divided into two groups as Group 1 (poor CCV and Group 2 (good CCV. Results: The MPV was 10.74 ± 2 fl in poor collateral group patients and 11.01 ± 1.7 fl in good collateral group (P = 0.421. The presence of CCV was not significantly associated with high levels of MPV. MPV value did not show any prediction of the spectrum of CAD. Conclusion: MPV on admission was not associated with the development of CCV positively in patients with ACS. Furthermore, it is not associated with a number of vessel involvements.

  12. Mean platelet volume is decreased in adults with active lupus disease.

    Science.gov (United States)

    Delgado-García, Guillermo; Galarza-Delgado, Dionicio Ángel; Colunga-Pedraza, Iris; Borjas-Almaguer, Omar David; Mandujano-Cruz, Ilse; Benavides-Salgado, Daniel; Martínez-Granados, Rolando Jacob; Atilano-Díaz, Alexandro

    Only a few biomarkers are available for assessing disease activity in systemic lupus erythematosus (SLE). Mean platelet volume (MPV) has been recently studied as an inflammatory biomarker. It is currently unclear whether MPV may also play a role as a biomarker of disease activity in adult patients with SLE. We investigated the association between MPV and disease activity in adult patients with SLE. In this retrospective study, we compared two groups of adult patients divided according to disease activity (36 per group). Subjects were age- and gender-matched. MPV was significantly decreased with respect to those of inactive patients (7.16±1.39 vs. 8.16±1.50, p=0.005). At a cutoff level of 8.32fL, MPV has a sensitivity of 86% and a specificity of 41% for the detection of disease activity. A modest positive correlation was found between MPV and albumin (r=0.407, p=0.001), which in turn is inversely associated with disease activity. In summary, MPV is decreased in adult patients with active lupus disease, and positively correlated with albumin, another biomarker of disease activity. Prospective studies are needed to evaluate the prognostic value of this biomarker. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

  13. Mean Platelet Volume, Red Cell Distribution Width to Platelet Count Ratio, Globulin Platelet Index, and 16 Other Indirect Noninvasive Fibrosis Scores: How Much Do Routine Blood Tests Tell About Liver Fibrosis in Chronic Hepatitis C?

    Science.gov (United States)

    Thandassery, Ragesh B; Al Kaabi, Saad; Soofi, Madiha E; Mohiuddin, Syed A; John, Anil K; Al Mohannadi, Muneera; Al Ejji, Khalid; Yakoob, Rafie; Derbala, Moutaz F; Wani, Hamidullah; Sharma, Manik; Al Dweik, Nazeeh; Butt, Mohammed T; Kamel, Yasser M; Sultan, Khaleel; Pasic, Fuad; Singh, Rajvir

    2016-07-01

    Many indirect noninvasive scores to predict liver fibrosis are calculated from routine blood investigations. Only limited studies have compared their efficacy head to head. We aimed to compare these scores with liver biopsy fibrosis stages in patients with chronic hepatitis C. From blood investigations of 1602 patients with chronic hepatitis C who underwent a liver biopsy before initiation of antiviral treatment, 19 simple noninvasive scores were calculated. The area under the receiver operating characteristic curves and diagnostic accuracy of each of these scores were calculated (with reference to the Scheuer staging) and compared. The mean age of the patients was 41.8±9.6 years (1365 men). The most common genotype was genotype 4 (65.6%). Significant fibrosis, advanced fibrosis, and cirrhosis were seen in 65.1%, 25.6, and 6.6% of patients, respectively. All the scores except the aspartate transaminase (AST) alanine transaminase ratio, Pohl score, mean platelet volume, fibro-alpha, and red cell distribution width to platelet count ratio index showed high predictive accuracy for the stages of fibrosis. King's score (cutoff, 17.5) showed the highest predictive accuracy for significant and advanced fibrosis. King's score, Göteborg university cirrhosis index, APRI (the AST/platelet count ratio index), and Fibrosis-4 (FIB-4) had the highest predictive accuracy for cirrhosis, with the APRI (cutoff, 2) and FIB-4 (cutoff, 3.25) showing the highest diagnostic accuracy.We derived the study score 8.5 - 0.2(albumin, g/dL) +0.01(AST, IU/L) -0.02(platelet count, 10/L), which at a cutoff of >4.7 had a predictive accuracy of 0.868 (95% confidence interval, 0.833-0.904) for cirrhosis. King's score for significant and advanced fibrosis and the APRI or FIB-4 score for cirrhosis could be the best simple indirect noninvasive scores.

  14. Short-term dehydroepiandrosterone treatment increases platelet cGMP production in elderly male subjects.

    Science.gov (United States)

    Martina, Valentino; Benso, Andrea; Gigliardi, Valentina Ramella; Masha, Andi; Origlia, Carla; Granata, Riccarda; Ghigo, Ezio

    2006-03-01

    Several clinical and population-based studies suggest that dehydroepiandrosterone (DHEA) and its sulphate (DHEA-S) play a protective role against atherosclerosis and coronary artery disease in human. However, the mechanisms underlying this action are still unknown. It has recently been suggested that DHEA-S could delay atheroma formation through an increase in nitric oxide (NO) production. Twenty-four aged male subjects [age (mean +/- SEM): 65.4 +/- 0.7 year; range: 58.2-67.6 years] underwent a blinded placebo controlled study receiving DHEA (50 mg p.o. daily at bedtime) or placebo for 2 months. Platelet cyclic guanosine-monophosphate (cGMP) concentration (as marker of NO production) and serum levels of DHEA-S, DHEA, IGF-I, insulin, glucose, oestradiol (E(2)), testosterone, plasminogen activator inhibitor (PAI)-1 antigen (PAI-1 Ag), homocysteine and lipid profile were evaluated before and after the 2-month treatment with DHEA or placebo. At the baseline, all variables in the two groups were overlapping. All parameters were unchanged after treatment with placebo. Conversely, treatment with DHEA (a) increased (P < 0.001 vs. baseline) platelet cGMP (111.9 +/- 7.1 vs. 50.1 +/- 4.1 fmol/10(6) plts), DHEA-S (13.6 +/- 0.8 vs. 3.0 +/- 0.3 micromol/l), DHEA (23.6 +/- 1.7 vs. 15.3 +/- 1.4 nmol/l), testosterone (23.6 +/- 1.0 vs. 17.7 +/- 1.0 nmol/l) and E(2) (72.0 +/- 5.0 vs. 60.0 +/- 4.0 pmol/l); and (b) decreased (P < 0.05 vs. baseline) PAI-1 Ag (27.4 +/- 3.8 vs. 21.5 +/- 2.5 ng/ml) and low-density lipoprotein (LDL) cholesterol (3.4 +/- 0.2 vs. 3.0 +/- 0.2 mmol/l). IGF-I, insulin, glucose, triglycerides, total cholesterol, HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and homocysteine levels were not modified by DHEA treatment. This study shows that short-term treatment with DHEA increased platelet cGMP production, a marker of NO production, in healthy elderly subjects. This effect is coupled with a decrease in PAI-1

  15. Altered mean platelet volume in patients with polymyositis and its association with disease severity

    Directory of Open Access Journals (Sweden)

    Y.-F. Peng

    2016-01-01

    Full Text Available Polymyositis (PM is an autoimmune disease characterized by chronic inflammation in skeletal muscle. Mean platelet volume (MPV, a marker in the assessment of systemic inflammation, is easily measured by automatic blood count equipment. However, to our knowledge, there are no data in the literature with respect to MPV levels in PM patients. Therefore, in this study we aimed to investigate MPV levels in patients with PM. This study included 92 newly diagnosed PM patients and 100 healthy individuals. MPV levels were found to be significantly lower compared with healthy controls (10.3±1.23 vs 11.5±0.74 fL, P<0.001. Interestingly, MPV was found to be positively correlated with manual muscle test (MMT score and negatively correlated with erythrocyte sedimentation rate (ESR in patients with PM (r=0.239, P=0.022; r=−0.268, P=0.010, respectively. In addition, MPV was significantly lower in active PM patients compared with inactive PM patients (9.9±1.39 vs 10.6±0.92 fL, P=0.010. MPV was independently associated with PM in multivariate regression analyses, when controlling for hemoglobin and ESR (OR=0.312, P=0.031, 95%CI=0.108 to 0.899. The ROC curve analysis for MPV in estimating PM patients resulted in an area under the curve of 0.800, with sensitivity of 75.0% and specificity of 67.4%. Our results suggest that MPV is inversely correlated with disease activity in patients with PM. MPV might be a useful tool for rapid assessment of disease severity in PM patients.

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

    Directory of Open Access Journals (Sweden)

    Ozge Basaran

    2017-01-01

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

  17. How medical treatment affects mean platelet volume as a cardiovascular risk marker in polycystic ovary syndrome?

    Science.gov (United States)

    Kabil Kucur, Suna; Gozukara, Ilay; Aksoy, Aysenur; Uludag, Eda U; Keskin, Havva; Kamalak, Zeynep; Carlioglu, Ayse

    2015-12-01

    Polycystic ovary syndrome (PCOS) is a prevalent disease with many potential long-term metabolic and cardiovascular risks if not managed appropriately. Mean platelet volume (MPV) is a marker associated with adverse cardiovascular events. In this study, we aimed to investigate MPV levels under ethinyl estradiol/cyproterone acetate or metformin therapy for the previous 6 months in PCOS. A total of 114 individuals [metformin treatment (n = 18), ethinyl estradiol/cyproterone acetate treatment (n = 29), newly diagnosed PCOS patient with no treatment (n = 35), and control group of eumenorrheic healthy individuals (n = 32)] were included in the current study. Hematologic parameters other than MPV were similar in all groups. The MPV value was significantly higher in the newly diagnosed PCOS patients compared with the other three groups independent of age, BMI, and C-reactive protein level in multiple regression analysis (P < 0.01). The MPV value of control group was comparable to the groups under ethinyl estradiol/cyproterone acetate or metformin therapy (P = 1.0). There was no statistically significant difference in the white blood cell count among the groups. The MPV values were positively correlated with the homeostatic model assessment-insulin resistance and Ferriman-Gallwey Score (P = 0.044, r = 0.261; P = 0.037, r = 0.229, respectively). Ethinyl estradiol/cyproterone acetate and metformin similarly appear to decrease MPV, a marker of cardiovascular risk. Therefore, a possible beneficial effect of ethinyl estradiol/cyproterone acetate and metformin on long-term cardiovascular morbidities in PCOS may be suggested.

  18. The effect of centrifugation speed and time on pre-analytical platelet activation.

    Science.gov (United States)

    Söderström, Anna C; Nybo, Mads; Nielsen, Christian; Vinholt, Pernille J

    2016-12-01

    The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore evaluated the effect of centrifugation speed and time on pre-analytical platelet activation. Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean platelet volume (MPV), immature platelet fraction (IPF), and platelet distribution width (PDW) were measured. Platelet aggregation in platelet-rich plasma induced by arachidonic acid (AA), ADP or thrombin receptor activator peptide-6 (TRAP) was tested by 96-well aggregometry. The median percentage of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), pcentrifuged. In platelet-rich plasma, increasing centrifugation speed significantly increased platelet yield but decreased contamination from other blood cells, platelet composition was altered as platelet parameters (MPV, IPF, and PDW) was lowered. Platelet aggregation was not affected by the centrifugation speed platelet-rich plasma was prepared. Proportional to centrifugation speed, platelets in plasma and platelet-rich plasma were activated with centrifugation speed, cell content and composition changed while platelet aggregation was unaltered.

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

    Directory of Open Access Journals (Sweden)

    Derya Koçer

    2015-01-01

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

  20. CONGESTIVE HEART FAILURE IN DOGS IS ASSOCIATED WITH INCREASED PLATELET LEUKOCYTE AGGREGATION MEASURED BY FLOW CYTOMETRY

    DEFF Research Database (Denmark)

    Tarnow, Inge; Andreasen, Susanne SH; Olsen, Lisbeth Høier

    2010-01-01

    Sciences, Faculty of Life Science, University of Copenhagen, Denmark. Chronic congestive heart failure (CHF) in humans is associated with abnormal hemostasis, and changes in hemostatic biomarkers carry a poor prognosis. CHF in dogs has been associated with plasma markers of hypercoagulability, however......CONGESTIVE HEART FAILURE IN DOGS IS ASSOCIATED WITH ENHANCED PLATELET-LEUKOCYTE AGGREGATES - A MARKER FOR PLATELET ACTIVATION. I Tarnow1, LH Olsen2, SHS Andreasen2, SG Moesgaard2, CE Rasmussen2, AT Kristensen1, T Falk2. 1Departments of Small Animal Clinical Sciences and 2Animal and Veterinary Basic......, platelet activation markers have not been investigated in dogs with clinical signs of heart disease. We hypothesized that platelet surface activation markers are higher in dogs with CHF compared to age-matched controls without clinical signs of heart failure. Dogs with compensated congestive heart failure...

  1. Platelet turnover in stable coronary artery disease - influence of thrombopoietin and low-grade inflammation.

    Directory of Open Access Journals (Sweden)

    Sanne Bøjet Larsen

    Full Text Available BACKGROUND: Newly formed platelets are associated with increased aggregation and adverse outcomes in patients with coronary artery disease (CAD. The mechanisms involved in the regulation of platelet turnover in patients with CAD are largely unknown. AIM: To investigate associations between platelet turnover parameters, thrombopoietin and markers of low-grade inflammation in patients with stable CAD. Furthermore, to explore the relationship between platelet turnover parameters and type 2 diabetes, prior myocardial infarction, smoking, age, gender and renal insufficiency. METHODS: We studied 581 stable CAD patients. Platelet turnover parameters (immature platelet fraction, immature platelet count, mean platelet volume, platelet distribution width and platelet large cell-ratio were determined using automated flow cytometry (Sysmex XE-2100. Furthermore, we measured thrombopoietin and evaluated low-grade inflammation by measurement of high-sensitive CRP and interleukin-6. RESULTS: We found strong associations between the immature platelet fraction, immature platelet count, mean platelet volume, platelet distribution width and platelet large cell ratio (r = 0.61-0.99, p<0.0001. Thrombopoietin levels were inversely related to all of the platelet turnover parameters (r = -0.17--0.25, p<0.0001. Moreover, thrombopoietin levels were significantly increased in patients with diabetes (p = 0.03 and in smokers (p = 0.003. Low-grade inflammation evaluated by high-sensitive CRP correlated significantly, yet weakly, with immature platelet count (r = 0.10, p = 0.03 and thrombopoietin (r = 0.16, p<0.001. Also interleukin-6 correlated with thrombopoietin (r = 0.10, p = 0.02. CONCLUSION: In stable CAD patients, thrombopoietin was inversely associated with platelet turnover parameters. Furthermore, thrombopoietin levels were increased in patients with diabetes and in smokers. However, low-grade inflammation did not seem to have a

  2. Treatment with a histone deacetylase inhibitor, valproic acid, is associated with increased platelet activation in a large animal model of traumatic brain injury and hemorrhagic shock

    DEFF Research Database (Denmark)

    Dekker, Simone E; Sillesen, Martin; Bambakidis, Ted

    2014-01-01

    synergistic benefits. In this study, we hypothesized that VPA administration would be associated with a conservation of platelet function as measured by increased platelet activation after resuscitation. MATERIALS AND METHODS: Ten swine (42-50 kg) were subjected to TBI and HS (40% blood loss). Animals were...... neuroprotective effects of VPA may be due to a conservation of platelet function as measured by a higher platelet activation response after resuscitation....... left in shock for 2 h before resuscitation with either FFP or FFP + VPA (300 mg/kg). Serum levels of platelet activation markers transforming growth factor beta, CD40 L, P-selectin, and platelet endothelial cell adhesion molecule (PECAM) 1 were measured at baseline, postresuscitation, and after a 6-h...

  3. Increased intracranial volume in Parkinson's disease

    DEFF Research Database (Denmark)

    Krabbe, Katja; Karlsborg, Merete; Hansen, Andreas

    2005-01-01

    Parkinson's disease (PD) and multiple system atrophy (MSA) are neurodegenerative diseases that can be difficult to diagnose and distinguish from each other. STUDY AIMS AND METHODS: Patients with PD and MSA and controls were studied with magnetic resonance imaging (MRI) using tissue segmentation a...... and outlining of regions in order to identify regional volume changes that might be useful in the diagnosis of the two diseases....

  4. Platelet activation in pregnancy-induced hypertension.

    Science.gov (United States)

    Karalis, Ioannis; Nadar, Sunil K; Al Yemeni, Eman; Blann, Andrew D; Lip, Gregory Y H

    2005-01-01

    Although excess platelet activation, as indicated by increased plasma beta thromboglobulin (beta-TG), has been shown in pregnancy-induced hypertension (PIH), platelet adhesion, platelet morphology and a comparison of platelet and soluble (plasma) levels of the adhesion molecules P-selectin (pPsel and sPsel, respectively) have not been studied. We conducted a cross-sectional study of 35 consecutive women with PIH (age 31+/-6 years), 31 consecutive women with normotensive pregnancies (age 29+/-5 years) and 30 normotensive non pregnant women (age 30+/-5 years). Platelet adhesion was studied in vitro by binding to fibrinogen-coated microwells, platelet morphology [mass and volume by flow cytometry], whole-platelet P-selectin (pPsel) by ELISA of the lysate of 2 x 10(8) cells, and the plasma markers soluble P-selectin (sP-sel) and beta-TG, by ELISA. The women with PIH had significantly raised sPsel, pPsel and (as expected) beta-TG (all p<0.05), when compared to the normotensive pregnant women and controls. However, in PIH platelet adhesion was similar to that in the normotensive pregnancy, but still higher than the normal controls (p<0.001). There was no difference among the three groups with respect to platelet mass and volume. pPsel and platelet adhesion correlated with gestational age and with systolic and diastolic blood pressure (all p<0.05). Increased platelet activation and adhesion develop during normal pregnancy, with some indices being further altered in PIH.

  5. Platelet indices in dogs with Babesia rossi infection

    DEFF Research Database (Denmark)

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

    2015-01-01

    BACKGROUND: Thrombocytopenia without clinical bleeding is a consistent finding in virulent canine babesiosis. OBJECTIVES: The purpose of the study was to investigate the platelet index phenotype in Babesia rossi-infected dogs and the association with disease outcome. We hypothesized that an incre......BACKGROUND: Thrombocytopenia without clinical bleeding is a consistent finding in virulent canine babesiosis. OBJECTIVES: The purpose of the study was to investigate the platelet index phenotype in Babesia rossi-infected dogs and the association with disease outcome. We hypothesized...... that an increased proportion of large, activated platelets would be present. METHODS: Ninety-six infected and 15 control dogs were included. Babesia-infected dogs were further divided into survivors and nonsurvivors. Platelet count, mean platelet volume (MPV), platelet volume distribution width (PDW), plateletcrit...

  6. Increased platelet aggregation and turnover in the acute phase of ST-elevation myocardial infarction

    DEFF Research Database (Denmark)

    Jensen, Kristian Løkke Funck; Dalsgaard, Jens; Grove, Erik Lerkevang

    2013-01-01

    Newly produced platelets are present in the acute phase of ST-elevation myocardial infarction (STEMI). This may influence the antiplatelet effect of aspirin and clopidogrel administered prior to primary percutaneous coronary intervention (PPCI). The aims of this study were to investigate the anti...... turnover may partly explain the reduced efficacy of antiplatelet drugs in the acute phase of STEMI....... the antiplatelet effect of aspirin and clopidogrel and evaluate platelet turnover in the acute phase of STEMI compared to a stable phase 3 months later. In this observational follow-up study on 48 STEMI patients transferred for PPCI, loading doses of aspirin (300 mg) and clopidogrel (600 mg) were given orally...... in the ambulance. Blood samples were obtained immediately prior to PPCI, at 4 and 12 hours after administration of bolus doses and at follow-up after 3 months. Residual platelet aggregation was evaluated by Multiplate® and VerifyNow® aggregometry. Platelet turnover was evaluated by automated flow cytometry...

  7. Platelet size and density affect shear-induced thrombus formation in tortuous arterioles

    Science.gov (United States)

    Chesnutt, Jennifer K. W.; Han, Hai-Chao

    2013-10-01

    Thrombosis accounts for 80% of deaths in patients with diabetes mellitus. Diabetic patients demonstrate tortuous microvessels and larger than normal platelets. Large platelets are associated with increased platelet activation and thrombosis, but the physical effects of large platelets in the microscale processes of thrombus formation are not clear. Therefore, the objective of this study was to determine the physical effects of mean platelet volume (MPV), mean platelet density (MPD) and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A computational model of the transport, shear-induced activation, collision, adhesion and aggregation of individual platelets was used to simulate platelet interactions and thrombus formation in tortuous arterioles. Our results showed that an increase in MPV resulted in a larger number of activated platelets, though MPD and level of tortuosity made little difference on platelet activation. Platelets with normal MPD yielded the lowest amount of mural thrombus. With platelets of normal MPD, the amount of mural thrombus decreased with increasing level of tortuosity but did not have a simple monotonic relationship with MPV. The physical mechanisms associated with MPV, MPD and arteriole tortuosity play important roles in platelet activation and thrombus formation.

  8. Portal vein thrombosis in cirrhosis is not associated with intestinal barrier disruption or increased platelet aggregability.

    Science.gov (United States)

    Wosiewicz, Piotr; Żorniak, Michał; Hartleb, Marek; Barański, Kamil; Hartleb, Maciej; Onyszczuk, Magdalena; Pilch-Kowalczyk, Joanna; Kyrcz-Krzemień, Sławomira

    2016-12-01

    Portal vein thrombosis (PVT) is a common complication of cirrhosis, but its pathogenesis is unclear. We tested the hypotheses that PVT is the result of platelet hyperactivity or intestinal barrier disruption. This study included 49 patients with cirrhosis (15 females) of mixed etiology. Based on spiral computed-tomography, the patients were divided into two groups: with PVT (n=16) and without PVT (n=33). Serum biomarkers of intestinal barrier integrity were endotoxins and zonulin, and platelet activity was assessed with multiple electrode aggregometry. The levels of endotoxin (43.5±18.3ng/ml vs. 36.9±7.5ng/ml; P=0.19) and zonulin (56.3±31.1ng/ml vs. 69.3±63.1ng/ml; P=0.69) were not different between the patients with and without PVT. Moreover, endotoxin and zonulin did not correlate with the coagulation and platelet parameters. The platelet aggregability measured with the TRAP and the ADP tests was decreased in PVT patients. In the logistic regression analysis the PVT incidence was related to the levels of D-dimer and bilirubin as well as the TRAP test results. Patients with PVT presented with significantly higher levels of D-dimer (4.45±2.59 vs. 3.03±2.97mg/l; P<0.05) and prothrombin levels (175±98.8μg/ml vs. 115±72.9μg/ml; P<0.05) than patients without thrombosis. PVT could be excluded with a 90% negative predictive value when the D-dimer level was below 1.82mg/l. Endotoxemia and platelet activity are not determinants of PVT in patients with cirrhosis. The D-dimer measurement has diagnostic significance for PVT in patients with liver cirrhosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. The evaluation of mean platelet volume levels in patients with primary and secondary Raynaud’s Phenomenon

    Directory of Open Access Journals (Sweden)

    Mehmet Erdem Memetoğlu

    2014-03-01

    Full Text Available Background — Mean platelet volume (MPV is an indicator of platelet activation. The pathophysiology of the primary and secondary Raynaud’s Phenomenon (RP have not been completely established. The aim of this study was to investigate the relationship between MPV and RP. Materials and Methods — Our study was a prospective randomized study carried out from January 2011 to March 2012. The study group consisted of 39 patients: 27 (70% patients having primary, 12 (30% patients having secondary RP. An age-, gender-, and body mass index-matched control group consisted of 40 healthy participants. We compared the MPV in patients with RP and control participants statistically. Results — MPV of RP group was 8.79±1.37 femtoliter (fL while MPV of control group was 8.39±1.36 fL. Comparison of MPV of RP group and control group showed no difference (p=0.274. The mean of MPV was significantly higher among patients with secondary RP (9.76±1.68 fl when compared with patients with primary RP (8.37±0.96 fl (p=0.018. Conclusion — The results of our study suggest that MPV may be used as a marker in secondary RP.

  10. Platelet Count and Plateletcrit

    African Journals Online (AJOL)

    strated that neonates with late onset sepsis (bacteremia after 3 days of age) had a dramatic increase in MPV and. PDW18. We hypothesize that as the MPV and PDW increase and platelet count and PCT decrease in sick children, intui- tively, the ratio of MPV to PCT; MPV to Platelet count,. PDW to PCT, PDW to platelet ...

  11. Branched-chain amino acid-enriched nutrient increases blood platelet count in patients after endoscopic injection sclerotherapy.

    Science.gov (United States)

    Furuichi, Yoshihiro; Imai, Yasuharu; Miyata, Yuki; Sugimoto, Katsutoshi; Sano, Takatomo; Taira, Junichi; Kojima, Mayumi; Kobayashi, Yoshiyuki; Nakamura, Ikuo; Moriyasu, Fuminori

    2016-10-01

    Protein and energy malnutrition is a severe problem for patients with liver cirrhosis (LC) and fasting often induces starvation which is a vitally important outcome. Dietary restriction is essential for endoscopic injection sclerotherapy (EIS) in patients with risky esophageal varices, thereby creating the possible exacerbation of nutritional state and inducing liver dysfunction. Whether EIS induces nutritional deficiency in LC patients and the effects of branched-chain amino acid (BCAA)-enriched nutrient are prospectively investigated. A total of 61 LC patients were randomly divided into an EIS monotherapy group (non-BCAA group, n = 31) and an EIS combined with BCAA therapy group (n = 30). Platelet count, blood chemistry and somatometry values were prospectively measured at five time points. The platelet counts before treatment were at the same level in both groups (P = 0.72). Three months after treatment, the counts decreased in the non-BCAA group; however, they increased in the BCAA group (P = 0.019). Body mass index, triceps skin fold thickness and arm muscle circumference significantly decreased in both groups. The BCAA and tyrosine ratio value increased only in the BCAA group (P BCAA group (P BCAA. Administration of BCAA had some effect in maintaining the nutritional state, and may improve the platelet count. Taking a greater amount of nutrients and shorter dietary restriction period or hospitalization was desirable. © 2016 The Japan Society of Hepatology.

  12. Effect of High-Volume Injection, Platelet-Rich Plasma, and Sham Treatment in Chronic Midportion Achilles Tendinopathy

    DEFF Research Database (Denmark)

    Boesen, Anders Ploug; Hansen, Rudi; Boesen, Morten Ilum

    2017-01-01

    with eccentric training in chronic AT seems more effective in reducing pain, improving activity level, and reducing tendon thickness and intratendinous vascularity than eccentric training alone. HVI may be more effective in improving outcomes of chronic AT than PRP in the short term. Registration: NCT02417987......BACKGROUND: Injection therapies are often considered alongside exercise for chronic midportion Achilles tendinopathy (AT), although evidence of their efficacy is sparse. PURPOSE: To determine whether eccentric training in combination with high-volume injection (HVI) or platelet-rich plasma (PRP......) injections improves outcomes in AT. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 60 men (age, 18-59 years) with chronic (>3 months) AT were included and followed for 6 months (n = 57). All participants performed eccentric training combined with either (1) one HVI...

  13. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multi-frequency EM

    Science.gov (United States)

    Hendricks, S.; Hoppmann, M.; Hunkeler, P. A.; Kalscheuer, T.; Gerdes, R.

    2015-12-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise and accumulate beneath nearby sea ice to form a several meter thick sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator for ice - ocean interactions. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and sub-ice platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions from platelet-layer conductivities using Archie's Law. The thickness results agreed well with drill-hole validation datasets within the uncertainty range, and the ice-volume fraction also yielded plausible results. Our findings imply that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties. However, we emphasize that the successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

  14. Increasing fill volume reduces cardiac performance in peritoneal dialysis

    DEFF Research Database (Denmark)

    Ivarsen, Per; Povlsen, Johan V; Jensen, Jens Dam

    2007-01-01

    BACKGROUND: It is generally accepted that peritoneal dialysis (PD) affects systemic haemodynamics less than haemodialysis, but little is known about changes in haemodynamics during PD. It is unknown if increasing PD volume causes changes in cardiovascular haemodynamics possibly increasing...

  15. Radiotherapy for head and neck malignancies is associated with increased salivary platelet-activating factor content

    International Nuclear Information System (INIS)

    Hlavaty, T.E.; Fisher, R.; Robbins, M.E.C.; Wheeler, J.; Funk, G.; Hussey, D.H.

    1996-01-01

    Purpose/Objective: Oral mucositis, characterized by pronounced erythema, edema, atrophy, and ulceration, remains a common complication of radiotherapeutic treatment of head and neck malignancies. These radiation-induced morbidities can cause a temporary cessation or indeed reduction in the extent of radiotherapy dose employed, compromising the likelihood of tumor cure. The precise pathogenic mechanisms involved in the development of radiation mucositis remain ill-defined. Platelet-activating factor (PAF), a pivotal mediator of acute inflammatory reactions, has been implicated in radiation-induced mucositis (McManus et al Lab Invest 68:118-124 1993). However, these data are limited in terms both of patient numbers, and time-course. The present study evaluated saliva PAF levels in patients receiving radiotherapy for head and neck malignancies in terms of levels prior to, during, and after the completion of radiotherapy. Materials and Methods: Saliva samples (1-2 mL) were obtained from 14 patients with oral cancer, and from 14 control non-malignant individuals. Saliva samples from the oral cancer patients were collected prior to the initiation of treatment, after the administration of 30 Gy, and at the completion of the course of radiotherapy. PAF was extracted from the saliva samples using a chloroform methanol mixture (2:1). Further purification was accomplished by washing the extracts through silica minicolumns. Measurements of PAF content were performed using a scintillation proximity assay system (Amersham, UK). This combined the use of a high specific activity 3 H-PAF with an antibody specific for PAF. Results: The PAF content of saliva obtained from patients prior to the initiation of radiotherapy was 226 ± 55 ng/mL, (mean ± SE). This was significantly greater than the value of 25 ± 11 ng/mL (p value = 0.003; 2-tail t test) measured in the saliva from the control individuals. Irradiation was associated with a significant increase in the PAF content of saliva

  16. Relationship between the Increased Haemostatic Properties of Blood Platelets and Oxidative Stress Level in Multiple Sclerosis Patients with the Secondary Progressive Stage

    Directory of Open Access Journals (Sweden)

    Agnieszka Morel

    2015-01-01

    Full Text Available Multiple sclerosis (MS is the autoimmune disease of the central nervous system with complex pathogenesis, different clinical courses and recurrent neurological relapses and/or progression. Despite various scientific papers that focused on early stage of MS, our study targets selective group of late stage secondary progressive MS patients. The presented work is concerned with the reactivity of blood platelets in primary hemostasis in SP MS patients. 50 SP MS patients and 50 healthy volunteers (never diagnosed with MS or other chronic diseases were examined to evaluate the biological activity of blood platelets (adhesion, aggregation, especially their response to the most important physiological agonists (thrombin, ADP, and collagen and the effect of oxidative stress on platelet activity. We found that the blood platelets from SP MS patients were significantly more sensitive to all used agonists in comparison with control group. Moreover, the platelet hemostatic function was advanced in patients suffering from SP MS and positively correlated with increased production of O2-∙ in these cells, as well as with Expanded Disability Status Scale. We postulate that the increased oxidative stress in blood platelets in SP MS may be primarily responsible for the altered haemostatic properties of blood platelets.

  17. Mean Platelet Volume, Vitamin D and C Reactive Protein Levels in Normal Weight Children with Primary Snoring and Obstructive Sleep Apnea Syndrome.

    Science.gov (United States)

    Zicari, Anna Maria; Occasi, Francesca; Di Mauro, Federica; Lollobrigida, Valeria; Di Fraia, Marco; Savastano, Vincenzo; Loffredo, Lorenzo; Nicita, Francesco; Spalice, Alberto; Duse, Marzia

    2016-01-01

    Studies on Mean Platelet Volume (MPV) in children with Sleep Disordered Breathing (SDB) report conflicting results and the hypothesis of an intermittent hypoxemia leading to a systemic inflammation is reaching consensus. Vitamin D exerts anti-inflammatory properties and its deficiency has been supposed to play a role in sleep disorders. Emerging interest is rising about Primary Snoring (PS) since it is reasonable that also undetectable alteration of hypoxia might predispose to an increased production of inflammatory mediators. In this perspective, in a group of children affected by SDB, our aim was to investigate MPV, vitamin D and C Reactive Protein (CRP) levels, which had been previously evaluated separately in different studies focused only on Obstructive Sleep Apnea Syndrome (OSAS). We enrolled 137 children: 70 healthy controls (HC), 67 affected by SDB undergoing a polysomnographic evaluation, 22 with a diagnosis of PS and 45 with a diagnosis of OSAS. All patients underwent routine biochemical evaluations including blood cell counts, CRP and vitamin D. Children affected by SDB had a mean age of 8.49±2.19 and were prevalently males (23 females, 34%; 44 males, 66%). MPV levels were higher in OSAS and PS when compared to HC; platelet count (PLT) and CRP levels were higher while Vitamin D levels were lower in children with SDB when compared to HC. MPV levels were correlated with PLT (r = -0.54; pchildren with PS as well as in children with OSAS, and supports the underlying inflammation, hence, highlighting the importance of an early diagnosis of this previously considered benign form of SDB.

  18. PPARγ ligands decrease hydrostatic pressure-induced platelet aggregation and proinflammatory activity.

    Directory of Open Access Journals (Sweden)

    Fang Rao

    Full Text Available Hypertension is known to be associated with platelet overactivity, but the direct effects of hydrostatic pressure on platelet function remain unclear. The present study sought to investigate whether elevated hydrostatic pressure is responsible for platelet activation and to address the potential role of peroxisome proliferator-activated receptor-γ (PPARγ. We observed that hypertensive patients had significantly higher platelet volume and rate of ADP-induced platelets aggregation compared to the controls. In vitro, Primary human platelets were cultured under standard (0 mmHg or increased (120, 180, 240 mmHg hydrostatic pressure for 18 h. Exposure to elevated pressure was associated with morphological changes in platelets. Platelet aggregation and PAC-1 (the active confirmation of GPIIb/IIIa binding were increased, CD40L was translocated from cytoplasm to the surface of platelet and soluble CD40L (sCD40L was released into the medium in response to elevated hydrostatic pressure (180 and 240 mmHg. The PPARγ activity was up-regulated as the pressure was increased from 120 mmHg to 180 mmHg. Pressure-induced platelet aggregation, PAC-1 binding, and translocation and release of CD40L were all attenuated by the PPARγ agonist Thiazolidinediones (TZDs. These results demonstrate that platelet activation and aggregation are increased by exposure to elevated pressure and that PPARγ may modulate platelet activation induced by high hydrostatic pressure.

  19. PPARγ ligands decrease hydrostatic pressure-induced platelet aggregation and proinflammatory activity.

    Science.gov (United States)

    Rao, Fang; Yang, Ren-Qiang; Chen, Xiao-Shu; Xu, Jin-Song; Fu, Hui-Min; Su, Hai; Wang, Ling

    2014-01-01

    Hypertension is known to be associated with platelet overactivity, but the direct effects of hydrostatic pressure on platelet function remain unclear. The present study sought to investigate whether elevated hydrostatic pressure is responsible for platelet activation and to address the potential role of peroxisome proliferator-activated receptor-γ (PPARγ). We observed that hypertensive patients had significantly higher platelet volume and rate of ADP-induced platelets aggregation compared to the controls. In vitro, Primary human platelets were cultured under standard (0 mmHg) or increased (120, 180, 240 mmHg) hydrostatic pressure for 18 h. Exposure to elevated pressure was associated with morphological changes in platelets. Platelet aggregation and PAC-1 (the active confirmation of GPIIb/IIIa) binding were increased, CD40L was translocated from cytoplasm to the surface of platelet and soluble CD40L (sCD40L) was released into the medium in response to elevated hydrostatic pressure (180 and 240 mmHg). The PPARγ activity was up-regulated as the pressure was increased from 120 mmHg to 180 mmHg. Pressure-induced platelet aggregation, PAC-1 binding, and translocation and release of CD40L were all attenuated by the PPARγ agonist Thiazolidinediones (TZDs). These results demonstrate that platelet activation and aggregation are increased by exposure to elevated pressure and that PPARγ may modulate platelet activation induced by high hydrostatic pressure.

  20. Mean Platelet Volume, Vitamin D and C Reactive Protein Levels in Normal Weight Children with Primary Snoring and Obstructive Sleep Apnea Syndrome.

    Directory of Open Access Journals (Sweden)

    Anna Maria Zicari

    Full Text Available Studies on Mean Platelet Volume (MPV in children with Sleep Disordered Breathing (SDB report conflicting results and the hypothesis of an intermittent hypoxemia leading to a systemic inflammation is reaching consensus. Vitamin D exerts anti-inflammatory properties and its deficiency has been supposed to play a role in sleep disorders. Emerging interest is rising about Primary Snoring (PS since it is reasonable that also undetectable alteration of hypoxia might predispose to an increased production of inflammatory mediators. In this perspective, in a group of children affected by SDB, our aim was to investigate MPV, vitamin D and C Reactive Protein (CRP levels, which had been previously evaluated separately in different studies focused only on Obstructive Sleep Apnea Syndrome (OSAS.We enrolled 137 children: 70 healthy controls (HC, 67 affected by SDB undergoing a polysomnographic evaluation, 22 with a diagnosis of PS and 45 with a diagnosis of OSAS. All patients underwent routine biochemical evaluations including blood cell counts, CRP and vitamin D.Children affected by SDB had a mean age of 8.49±2.19 and were prevalently males (23 females, 34%; 44 males, 66%. MPV levels were higher in OSAS and PS when compared to HC; platelet count (PLT and CRP levels were higher while Vitamin D levels were lower in children with SDB when compared to HC. MPV levels were correlated with PLT (r = -0.54; p<0.001, vitamin D (r = -0.39; p<0.001 and CRP (r = 0.21; p<0.01. A multiple regression was run to predict MPV levels from vitamin D, CRP and PLT and these variables significantly predicted MPV (F = 17.42, p<0.0001; adjusted R2 = 0.37. Only platelet count and vitamin D added statistically significantly to the prediction (p<0.05.The present study provides evidence of higher MPV and lower vitamin D levels in children with PS as well as in children with OSAS, and supports the underlying inflammation, hence, highlighting the importance of an early diagnosis of this

  1. 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

  2. Combination of Mean Platelet Volume/Platelet Count Ratio and the APACHE II Score Better Predicts the Short-Term Outcome in Patients with Acute Kidney Injury Receiving Continuous Renal Replacement Therapy.

    Science.gov (United States)

    Li, Junhui; Li, Yingchuan; Sheng, Xiaohua; Wang, Feng; Cheng, Dongsheng; Jian, Guihua; Li, Yongguang; Feng, Liang; Wang, Niansong

    2018-03-29

    Both the Acute physiology and Chronic Health Evaluation (APACHE II) score and mean platelet volume/platelet count Ratio (MPR) can independently predict adverse outcomes in critically ill patients. This study was aimed to investigate whether the combination of them could have a better performance in predicting prognosis of patients with acute kidney injury (AKI) who received continuous renal replacement therapy (CRRT). Two hundred twenty-three patients with AKI who underwent CRRT between January 2009 and December 2014 in a Chinese university hospital were enrolled. They were divided into survivals group and non-survivals group based on the situation at discharge. Receiver Operating Characteristic (ROC) curve was used for MPR and APACHE II score, and to determine the optimal cut-off value of MPR for in-hospital mortality. Factors associated with mortality were identified by univariate and multivariate logistic regression analysis. The mean age of the patients was 61.4 years, and the overall in-hospital mortality was 48.4%. Acute cardiorenal syndrome (ACRS) was the most common cause of AKI. The optimal cut-off value of MPR for mortality was 0.099 with an area under the ROC curve (AUC) of 0.636. The AUC increased to 0.851 with the addition of the APACHE II score. The mortality of patients with of MPR > 0.099 was 56.4%, which was significantly higher than that of the control group with of ≤ 0.099 (39.6%, P= 0.012). Logistic regression analysis showed that average number of organ failure (OR = 2.372), APACHE II score (OR = 1.187), age (OR = 1.028) and vasopressors administration (OR = 38.130) were significantly associated with poor prognosis. Severity of illness was significantly associated with prognosis of patients with AKI. The combination of MPR and APACHE II score may be helpful in predicting the short-term outcome of AKI. © 2018 The Author(s). Published by S. Karger AG, Basel.

  3. Combination of Mean Platelet Volume/Platelet Count Ratio and the APACHE II Score Better Predicts the Short-Term Outcome in Patients with Acute Kidney Injury Receiving Continuous Renal Replacement Therapy

    Directory of Open Access Journals (Sweden)

    Junhui Li

    2018-03-01

    Full Text Available Background/Aims: Both the Acute physiology and Chronic Health Evaluation (APACHE II score and mean platelet volume/platelet count Ratio (MPR can independently predict adverse outcomes in critically ill patients. This study was aimed to investigate whether the combination of them could have a better performance in predicting prognosis of patients with acute kidney injury (AKI who received continuous renal replacement therapy (CRRT. Methods: Two hundred twenty-three patients with AKI who underwent CRRT between January 2009 and December 2014 in a Chinese university hospital were enrolled. They were divided into survivals group and non-survivals group based on the situation at discharge. Receiver Operating Characteristic (ROC curve was used for MPR and APACHE II score, and to determine the optimal cut-off value of MPR for in-hospital mortality. Factors associated with mortality were identified by univariate and multivariate logistic regression analysis. Results: The mean age of the patients was 61.4 years, and the overall in-hospital mortality was 48.4%. Acute cardiorenal syndrome (ACRS was the most common cause of AKI. The optimal cut-off value of MPR for mortality was 0.099 with an area under the ROC curve (AUC of 0.636. The AUC increased to 0.851 with the addition of the APACHE II score. The mortality of patients with of MPR > 0.099 was 56.4%, which was significantly higher than that of the control group with of ≤ 0.099 (39.6%, P= 0.012. Logistic regression analysis showed that average number of organ failure (OR = 2.372, APACHE II score (OR = 1.187, age (OR = 1.028 and vasopressors administration (OR = 38.130 were significantly associated with poor prognosis. Conclusion: Severity of illness was significantly associated with prognosis of patients with AKI. The combination of MPR and APACHE II score may be helpful in predicting the short-term outcome of AKI.

  4. Study on platelet kinetics

    International Nuclear Information System (INIS)

    Yui, Tokuo

    1981-01-01

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

  5. Endoscopic stenting in bile duct cancer increases liver volume.

    Science.gov (United States)

    Lee, Chang Hun; Kim, Seong Hun; Kim, In Hee; Kim, Sang Wook; Lee, Soo Teik; Kim, Dae Ghon; Yang, Jae Do; Yu, Hee Chul; Cho, Baik Hwan; Lee, Seung Ok

    2014-09-01

    Objective evaluation tools for assessing the effectiveness of stenting in palliative treatment of malignant biliary obstruction are not satisfactory. Effects of biliary stenting on liver volume change have never been studied. We aimed to use volumetry to analyze liver volume changes after endoscopic stenting in bile duct cancer according to the location and number of stents. Retrospective review. University hospital. Patients with a diagnosis of hilar or distal bile duct cancer and who underwent biliary metal stenting. ERCP with self-expandable metal stent placement. Liver volume change after biliary stenting and its comparison according to the location (hilar vs distal common bile duct) and number (hilar bilateral vs hilar unilateral). There were 60 patients; 31 were treated for hilar bile duct cancer (13 for bilateral stent and 18 for unilateral stent) and 29 for distal bile duct cancer. Overall mean follow-up duration was 11.7 ± 4.9 weeks. Liver volume increased 17.4 ± 24.1%. The rate of liver growth was rapid during the early period from 4 to 8 weeks. Stenting in hilar bile duct cancer tended to increase liver volume more than distal biliary stents (22.5% vs 11.9%, P = .091). In hilar bile duct cancer, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; P = .512). Single center, retrospective. Biliary stenting markedly increased liver volume in both hilar and distal bile duct cancer. Our data suggest that liver volume assessment could be a useful tool for evaluating stent efficacy. Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  6. Quantitative Glycoproteomic Analysis Identifies Platelet-Induced Increase of Monocyte Adhesion via the Up-Regulation of Very Late Antigen 5.

    Science.gov (United States)

    Huang, Jiqing; Kast, Juergen

    2015-08-07

    Physiological stimuli, such as thrombin, or pathological stimuli, such as lysophosphatidic acid (LPA), activate platelets circulating in blood. Once activated, platelets bind to monocytes via P-selectin-PSGL-1 interactions but also release the stored contents of their granules. These platelet releasates, in addition to direct platelet binding, activate monocytes and facilitate their recruitment to atherosclerotic sites. Consequently, understanding the changes platelet releasates induce in monocyte membrane proteins is critical. We studied the glyco-proteome changes of THP-1 monocytic cells affected by LPA- or thrombin-induced platelet releasates. We employed lectin affinity chromatography combined with filter aided sample preparation to achieve high glyco- and membrane protein and protein sequence coverage. Using stable isotope labeling by amino acids in cell culture, we quantified 1715 proteins, including 852 membrane and 500 glycoproteins, identifying the up-regulation of multiple proteins involved in monocyte extracellular matrix binding and transendothelial migration. Flow cytometry indicated expression changes of integrin α5, integrin β1, PECAM-1, and PSGL-1. The observed increase in monocyte adhesion to fibronectin was determined to be mediated by the up-regulation of very late antigen 5 via a P-selectin-PSGL-1 independent mechanism. This novel aspect could be validated on CD14+ human primary monocytes, highlighting the benefits of the improved enrichment method regarding high membrane protein coverage and reliable quantification.

  7. 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.

  8. 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

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

    Directory of Open Access Journals (Sweden)

    Gulay Yilmaz

    2017-01-01

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

  10. 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

  11. Increased concentrations of soluble CD40 ligand platelet in patients with primary antiphospholipidic syndrome.

    Science.gov (United States)

    Galicia López, Aida; Olguín Ortega, Lourdes; Saavedra, Miguel A; Méndez Cruz, René; Jimenez Flores, Rafael; García de la Peña, Maximiliano

    2013-01-01

    To determine the concentrations of sCD40L in patients with PAPS, and establish its association with the number of thrombosis. We included patients with PAPS and healthy controls of the same age and sex. For analysis, patients with PAPS were divided into 2 groups: 1) patients with 1 thrombosis, and 2) patients with >1 thrombosis. Soluble CD40L concentrations were determined by ELISA method. sCD40L concentrations were significantly higher in patients with PAPS compared with the controls (9.72 ng ± 11.23 ng/ml vs. 4.69 ± 4.04 ng/ml) (P=.04) There was no association between serum levels of sCD40L and the number of thrombosis (1 thrombosis: 9.81 ± 9.87 ng/ml vs 9.63 ± 12.75 ng/ml in ≥ 1thrombosis (P=.13). In women with pregnancy and abortions, (13 patients) concentrations of sCD40L were higher than in those patients without a history of abortion (26 patients) but without statically significant difference (12.11 ± 16.46 ng/ml vs. 8.80 ± 8.61 ng/ml) (P=.33). There was no correlation between levels of sCD40L and the total number of thrombosis. Patients with PAPS have higher concentrations of sCD40L compared with healthy subjects, although this is not associated with a greater number of thrombosis. Among patients with PAPS, there is a tendency to higher concentrations of sCD40L in women with pregnancy and history of abortion. Since the platelet is the main cellular source of sCD40L, is possible that this pathway plays a pathogenic role in patients with PAPS. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  12. Increased putamen volume in adults with autism spectrum disorder

    Directory of Open Access Journals (Sweden)

    Wataru eSato

    2014-11-01

    Full Text Available Basal ganglia (BG abnormalities are implicated in the pathophysiology of autism spectrum disorder (ASD. However, studies measuring the volume of the entire BG in individuals with ASD have reported discrepant findings, and no study conducted volume measurement of the entire substructures of the BG (the caudate, putamen, nucleus accumbens, and globus pallidus in individuals with ASD. We delineated the BG substructures and measured their volumes in 29 adults with ASD without intellectual disabilities and 29 age- and gender-matched typically developed adult controls. We acquired T1-weighted anatomical images and performed semi-automated delineation and volume measurements of the above-mentioned subregions. Total cerebral volumes, sex, and ages were partialed out. Compared with controls, the putamen was significantly larger in the ASD group. The increased volume of the putamen found in high-functioning adults with ASD suggests that structural or histological abnormalities of the putamen may underlie the pathologies of ASD such as repetitive and stereotyped behaviors and impaired social interactions.

  13. High lung volume increases stress failure in pulmonary capillaries

    Science.gov (United States)

    Fu, Z.; Costello, M. L.; Tsukimoto, K.; Prediletto, R.; Elliott, A. R.; Mathieu-Costello, O.; West, J. B.

    1992-01-01

    We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological

  14. Platelet rich plasma (PRP) induces chondroprotection via increasing autophagy, anti-inflammatory markers, and decreasing apoptosis in human osteoarthritic cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, Mayssam, E-mail: Moussa-mayssam@hotmail.com [Regenerative medicine and inflammation Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon); Lajeunesse, Daniel, E-mail: daniel.lajeunesse@umontreal.ca [Research Centre in Osteoarthritis, Research Centre in Monteral University (Canada); Hilal, George, E-mail: George2266@gmail.com [Cancer and metabolism Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon); El Atat, Oula, E-mail: oulaatat@hotmail.com [Regenerative medicine and inflammation Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon); Haykal, Gaby, E-mail: Gaby.haykal@hdf.usj.edu.lb [Hotel Dieu de France, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon); Serhal, Rim, E-mail: rim.basbous@gmail.com [Regenerative medicine and inflammation Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon); Chalhoub, Antonio, E-mail: Mava.o@hotmail.com [Carantina Hospital, Beirut (Lebanon); Khalil, Charbel, E-mail: charbelk3@hotmail.com [Regenerative medicine and inflammation Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon); Alaaeddine, Nada, E-mail: Nada.aladdin@gmail.com [Regenerative medicine and inflammation Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut (Lebanon)

    2017-03-01

    Objectives: Autophagy constitutes a defense mechanism to overcome aging and apoptosis in osteoarthritic cartilage. Several cytokines and transcription factors are linked to autophagy and play an important role in the degradative cascade in osteoarthritis (OA). Cell therapy such as platelet rich plasma (PRP) has recently emerged as a promising therapeutic tool for many diseases including OA. However, its mechanism of action on improving cartilage repair remains to be determined. The purpose of this study is to investigate the effect of PRP on osteoarthritic chondrocytes and to elucidate the mechanism by which PRP contributes to cartilage regeneration. Methods: Osteoarthritic chondrocytes were co-cultured with an increasing concentration of PRP obtained from healthy donors. The effect of PRP on the proliferation of chondrocytes was performed using cell counting and WST8 proliferation assays. Autophagy, apoptosis and intracellular level of IL-4, IL-10, and IL-13 were determined using flow cytometry analyses. Autophagy markers BECLIN and LC3II were also determined using quantitative polymerase chain reaction (qPCR). qPCR and ELISA were used to measure the expression of ADAMDTS-5, MMP3, MMP13, TIMP-1–2–3, aggregan, Collagen type 2, TGF-β, Cox-2, Il-6, FOXO1, FOXO3, and HIF-1 in tissues and co-cultured media. Results: PRP increased significantly the proliferation of chondrocytes, decreased apoptosis and increased autophagy and its markers along with its regulators FOXO1, FOXO3 and HIF-1 in osteoarthritic chondrocytes. Furthermore, PRP caused a dose-dependent significant decrease in MMP3, MMP13, and ADAMTS-5, IL-6 and COX-2 while increasing TGF-β, aggregan, and collagen type 2, TIMPs and intracellular IL-4, IL-10, IL-13. Conclusion: These results suggest that PRP could be a potential therapeutic tool for the treatment of OA. - Highlights: • Platelet Rich Plasma is suggested as a new treatment for osteoarthritis. • The proposed therapeutic effect is

  15. Platelet rich plasma (PRP) induces chondroprotection via increasing autophagy, anti-inflammatory markers, and decreasing apoptosis in human osteoarthritic cartilage

    International Nuclear Information System (INIS)

    Moussa, Mayssam; Lajeunesse, Daniel; Hilal, George; El Atat, Oula; Haykal, Gaby; Serhal, Rim; Chalhoub, Antonio; Khalil, Charbel; Alaaeddine, Nada

    2017-01-01

    Objectives: Autophagy constitutes a defense mechanism to overcome aging and apoptosis in osteoarthritic cartilage. Several cytokines and transcription factors are linked to autophagy and play an important role in the degradative cascade in osteoarthritis (OA). Cell therapy such as platelet rich plasma (PRP) has recently emerged as a promising therapeutic tool for many diseases including OA. However, its mechanism of action on improving cartilage repair remains to be determined. The purpose of this study is to investigate the effect of PRP on osteoarthritic chondrocytes and to elucidate the mechanism by which PRP contributes to cartilage regeneration. Methods: Osteoarthritic chondrocytes were co-cultured with an increasing concentration of PRP obtained from healthy donors. The effect of PRP on the proliferation of chondrocytes was performed using cell counting and WST8 proliferation assays. Autophagy, apoptosis and intracellular level of IL-4, IL-10, and IL-13 were determined using flow cytometry analyses. Autophagy markers BECLIN and LC3II were also determined using quantitative polymerase chain reaction (qPCR). qPCR and ELISA were used to measure the expression of ADAMDTS-5, MMP3, MMP13, TIMP-1–2–3, aggregan, Collagen type 2, TGF-β, Cox-2, Il-6, FOXO1, FOXO3, and HIF-1 in tissues and co-cultured media. Results: PRP increased significantly the proliferation of chondrocytes, decreased apoptosis and increased autophagy and its markers along with its regulators FOXO1, FOXO3 and HIF-1 in osteoarthritic chondrocytes. Furthermore, PRP caused a dose-dependent significant decrease in MMP3, MMP13, and ADAMTS-5, IL-6 and COX-2 while increasing TGF-β, aggregan, and collagen type 2, TIMPs and intracellular IL-4, IL-10, IL-13. Conclusion: These results suggest that PRP could be a potential therapeutic tool for the treatment of OA. - Highlights: • Platelet Rich Plasma is suggested as a new treatment for osteoarthritis. • The proposed therapeutic effect is

  16. 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

  17. Consumption of both low and high (-)-epicatechin apple puree attenuates platelet reactivity and increases plasma concentrations of nitric oxide metabolites: A randomized controlled trial

    NARCIS (Netherlands)

    Gasper, A.; Hollands, W.; Casgrain, A.; Saha, S.; Teucher, B.; Dainty, J.R.; Venema, D.P.; Hollman, P.C.H.

    2014-01-01

    We hypothesised that consumption of flavanol-containing apple puree would modulate platelet activity and increase nitric oxide metabolite status, and that high flavanol apple puree would exert a greater effect than low flavanol apple puree. 25 subjects consumed 230 g of apple puree containing 25 and

  18. The effect of Platelet Lysate on osteoblast proliferation associated with a transient increase of the inflammatory response in bone regeneration.

    Science.gov (United States)

    Ruggiu, Alessandra; Ulivi, Valentina; Sanguineti, Francesca; Cancedda, Ranieri; Descalzi, Fiorella

    2013-12-01

    Platelet Lysate (PL) contains a cocktail of growth factors and cytokines, which actively participates in tissue repair and its clinical application has been broadly described. The aim of this study was to assess the regenerative potential of PL for bone repair. We demonstrated that PL stimulation induces a transient increase of the inflammatory response in quiescent human osteoblasts, via NF-kB activation, COX-2 induction, PGE2 production and secretion of pro-inflammatory cytokines. Furthermore, we showed that long-term PL stimulation enhances proliferation of actively replicating osteoblasts, without affecting their differentiation potential, along with changes of cell morphology, resulting in increased cell density at confluence. In confluent resting osteoblasts, PL treatment induced resumption of proliferation, change in cell morphology and increase of cell density at confluence. A burst of PL treatment (24-h) was sufficient to trigger such processes in both conditions. These results correlated with up-regulation of the proliferative and survival pathways ERKs and Akt and with cell cycle re-activation via induction of CyclinD1 and phosphorylation of Rb, following PL stimulation. Our findings demonstrate that PL treatment results in activation and expansion of resting osteoblasts, without affecting their differentiation potential. Therefore PL represents a good therapeutic candidate in regenerative medicine for bone repair. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Association of mean platelet volume with androgens and insulin resistance in nonobese patients with polycystic ovary syndrome.

    Science.gov (United States)

    Dogan, Bercem Aycicek; Arduc, Ayse; Tuna, Mazhar Muslum; Karakılıc, Ersen; Dagdelen, Iffet; Tutuncu, Yasemin; Berker, Dilek; Guler, Serdar

    2014-10-01

    Mean platelet volume (MPV) is generally accepted as a new marker of cardiovascular disease risk in several studies. This study aimed to determine the association of MPV with androgen hormones and insulin resistance (IR) in nonobese patients with polycystic ovary syndrome (PCOS). A total of 136 patients with newly diagnosed reproductive-age PCOS (regarding the criteria of new PCOS phenotypes, based on the Rotterdam criteria) who were nonobese with the mean age of 25 years (25.39 ± 5.51) and mean body mass index (BMI) of 21 kg/m(2) (22.07 ± 2.13) were included. In addition, 59 healthy subjects with mean age of 26 years (22.07 ± 2.13) and mean BMI of 22 kg/m(2) (21.52 ± 3.84) were recruited as control. Total blood count (including MPV), total testosterone, free testosterone, dehydroepiandrosterone-sulfate (DHEAS), and androstenedione levels were recorded. IR was calculated from blood chemistry measurements of fasting insulin and glucose according to updated homeostasis model assessment. No differences were observed in mean MPV values between patients and control group (9.02 fL (8.5-10.1) and 8.9 fL (7.7-9.1), respectively; P = 0.777). MPV values were similar among nonobese patients with and without IR and control subjects (P > 0.05). We detected significantly lower values of MPV in patients with hyperandrogenemia in comparison to patients with normal androgen levels (8.7 and 9.5 fL, P = 0.012). There was a negative correlation between total testosterone, DHEAS, and MPV (P = 0.016, r = -0.229; and P = 0.006, r = -0.261, respectively). Multiple logistic regression analyses confirmed the independence of these associations. Our study revealed that nonobese women with and without PCOS have similar MPV values. While IR does not have any effect on MPV, elevated androgen levels are associated with a low MPV in nonobese patients with PCOS.

  20. Mean Platelet Volume

    African Journals Online (AJOL)

    2014-03-01

    Mar 1, 2014 ... congestive heart failure, significant valvular heart disease, pacemaker implantation, atrial flutter or fibrillation, peripheral vascular diseases, pulmonary or neurological disease, pericarditis, malignancy, infection, pregnancy, overt hypothyroidism or hyperthyroidism, chronic renal or hepatic disease and ...

  1. Platelet mimicry

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Hunter, Alan Christy; Peer, Dan

    2016-01-01

    Here we critically examine whether coating of nanoparticles with platelet membranes can truly disguise them against recognition by elements of the innate immune system. We further assess whether the "cloaking technology" can sufficiently equip nanoparticles with platelet-mimicking functionalities...

  2. Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes.

    Science.gov (United States)

    Clarke, Michael W; Ward, Natalie C; Wu, Jason H Y; Hodgson, Jonathan M; Puddey, Ian B; Croft, Kevin D

    2006-01-01

    Some studies have shown potential benefit of vitamin E on platelet function, but several clinical trials failed to show improved cardiovascular outcome with alpha-tocopherol supplementation. Gamma-tocopherol, a major dietary form of vitamin E, may have protective properties different from those of alpha-tocopherol. We compared the effects of supplementation with alpha-tocopherol (500 mg) and a gamma-tocopherol-rich compound (500 mg, containing 60% gamma-tocopherol) on serum and cellular tocopherol concentrations, urinary tocopherol metabolite excretion, and in vivo platelet activation in subjects with type 2 diabetes. Fifty-eight subjects were randomly assigned to receive either 500 mg alpha-tocopherol/d, 500 mg mixed tocopherols/d, or matching placebo. Serum, erythrocyte, and platelet tocopherol and urinary metabolite concentrations were measured at baseline and after the 6-wk intervention. Soluble CD40 ligand, urinary 11-dehydro-thromboxane B2, serum thromboxane B2, soluble P-selectin, and von Willebrand factor were measured as biomarkers of in vivo platelet activation. Serum alpha-tocopherol increased with both tocopherol treatments. Serum and cellular gamma-tocopherol increased 4-fold (P tocopherol group, whereas red blood cell gamma-tocopherol decreased significantly after alpha-tocopherol supplementation. Excretion of alpha-carboxyethyl-hydroxychroman increased significantly after supplementation with alpha-tocopherol and mixed tocopherols. Excretion of gamma-carboxyethyl-hydroxychroman increased significantly after supplementation with mixed tocopherols and after that with alpha-tocopherol, which may reflect the displacement of gamma-tocopherol by alpha-tocopherol due to incorporation of the latter into lipoproteins in the liver. Neither treatment had any significant effect on markers of platelet activation. Supplementation with alpha-tocopherol decreased red blood cell gamma-tocopherol, whereas mixed tocopherols increased both serum alpha-tocopherol and

  3. Acute effects of 30 minutes of exposure to a smartphone call on in vitro platelet function.

    Science.gov (United States)

    Lippi, Giuseppe; Danese, Elisa; Brocco, Giorgio; Gelati, Matteo; Salvagno, Gian Luca; Montagnana, Martina

    2017-05-01

    Significant concerns are now regularly raised about the safety of excessive mobile phone use. This study was aimed to assess the acute effects of radiofrequency waves emitted by a commercial smartphone on platelet function. Two sequential citrated blood samples were collected from 16 healthy volunteers recruited from laboratory staff. The first sample was placed in a plastic rack, 1 cm distant from a commercial smartphone receiving a 30-min call and emitting 900 MHz radiofrequency waves. The second sample was placed in another plastic rack, isolated from radiofrequency wave sources, for the same period. The platelet count and the mean platelet volume were then assessed in all blood samples, whereas platelet function was evaluated using the platelet function analyser-100 (PFA-100). A 30-min exposure of citrated blood to smartphone radiofrequency waves induced significant prolongation of collagen-epinephrine aggregation (median increase, 10%) and a considerable increase of mean platelet volume (median increase, 5%), whereas collagen-adenosine diphosphate aggregation and platelet count remained unchanged. This study demonstrates that smartphone radiofrequency waves induce significant perturbation of platelet structure and function, thus providing further support to concerns regarding excessive use of mobile phones. Caution should also be taken with regards to blood products containing platelets, which should be kept far away from mobile phones and smartphones throughout the production pipeline and storage period.

  4. Quality of harvested autologous platelets compared with stored donor platelets for use after cardiopulmonary bypass procedures.

    Science.gov (United States)

    Crowther, M; Ford, I; Jeffrey, R R; Urbaniak, S J; Greaves, M

    2000-10-01

    Platelet dysfunction has a major contribution in bleeding after cardiopulmonary bypass (CPB) and transfusion of platelets is frequently used to secure haemostasis. Allogeneic platelets prepared for transfusion are functionally impaired. Autologous platelets harvested preoperatively require a shorter storage time before transfusion and their use also avoids the risks associated with transfusion of allogeneic blood products. For the first time, we have compared the functional quality of autologous platelets with allogeneic platelets prepared by two methods, immediately before infusion. Platelet activation was assessed by P-selectin expression and fibrinogen binding using flow cytometry. We also monitored the effects of CPB surgery and re-infusion of autologous platelets on platelet function. Autologous platelet-rich plasma (PRP) contained a significantly lower (P platelets compared with allogeneic platelet preparations, and also contained a significantly higher (P platelets. Allogeneic platelets prepared by donor apheresis were more activated and less responsive than those produced by centrifugation of whole blood. In patients' blood, the percentage of platelets expressing P-selectin or binding fibrinogen increased significantly after CPB (P platelets responsive to in vitro agonists was decreased (P platelet activation during the procedure. The percentage of activated platelets decreased (statistically not significant) after re-infusion of autologous PRP. P-selectin expression had returned to pre-CPB levels 24 h post-operatively. Autologous platelet preparations display minimal activation, but remain responsive. Conservation of platelet function may contribute to the potential clinical benefits of autologous transfusion in cardiopulmonary bypass.

  5. Increase of volume swelling by a temperature gradient

    International Nuclear Information System (INIS)

    Herschbach, K.; Schneider, W.; Stober, T.

    1996-11-01

    The temperature gradient in the cladding of a Fast Reactor fuel pin leads to increased dilatation compared to material irradiations. Investigations of a specially designed fuel pin reached the conclusion that the cause is enhanced volume swelling. It is induced by He-bubbles, which migrate upwards the temperature gradient and coalesce. The critical size of nuclei for void swelling is thus reached much faster. Consequently, the p in deformation is larger than expected from materials irradiations, in the present case (DIN 1.4981 sa) by about 50%. (orig.) [de

  6. Increasing the information acquisition volume in iris recognition systems.

    Science.gov (United States)

    Barwick, D Shane

    2008-09-10

    A significant hurdle for the widespread adoption of iris recognition in security applications is that the typically small imaging volume for eye placement results in systems that are not user friendly. Separable cubic phase plates at the lens pupil have been shown to ameliorate this disadvantage by increasing the depth of field. However, these phase masks have limitations on how efficiently they can capture the information-bearing spatial frequencies in iris images. The performance gains in information acquisition that can be achieved by more general, nonseparable phase masks is demonstrated. A detailed design method is presented, and simulations using representative designs allow for performance comparisons.

  7. Platelet rich plasma (PRP) induces chondroprotection via increasing autophagy, anti-inflammatory markers, and decreasing apoptosis in human osteoarthritic cartilage.

    Science.gov (United States)

    Moussa, Mayssam; Lajeunesse, Daniel; Hilal, George; El Atat, Oula; Haykal, Gaby; Serhal, Rim; Chalhoub, Antonio; Khalil, Charbel; Alaaeddine, Nada

    2017-03-01

    Autophagy constitutes a defense mechanism to overcome aging and apoptosis in osteoarthritic cartilage. Several cytokines and transcription factors are linked to autophagy and play an important role in the degradative cascade in osteoarthritis (OA). Cell therapy such as platelet rich plasma (PRP) has recently emerged as a promising therapeutic tool for many diseases including OA. However, its mechanism of action on improving cartilage repair remains to be determined. The purpose of this study is to investigate the effect of PRP on osteoarthritic chondrocytes and to elucidate the mechanism by which PRP contributes to cartilage regeneration. Osteoarthritic chondrocytes were co-cultured with an increasing concentration of PRP obtained from healthy donors. The effect of PRP on the proliferation of chondrocytes was performed using cell counting and WST8 proliferation assays. Autophagy, apoptosis and intracellular level of IL-4, IL-10, and IL-13 were determined using flow cytometry analyses. Autophagy markers BECLIN and LC3II were also determined using quantitative polymerase chain reaction (qPCR). qPCR and ELISA were used to measure the expression of ADAMDTS-5, MMP3, MMP13, TIMP-1-2-3, aggregan, Collagen type 2, TGF-β, Cox-2, Il-6, FOXO1, FOXO3, and HIF-1 in tissues and co-cultured media. PRP increased significantly the proliferation of chondrocytes, decreased apoptosis and increased autophagy and its markers along with its regulators FOXO1, FOXO3 and HIF-1 in osteoarthritic chondrocytes. Furthermore, PRP caused a dose-dependent significant decrease in MMP3, MMP13, and ADAMTS-5, IL-6 and COX-2 while increasing TGF-β, aggregan, and collagen type 2, TIMPs and intracellular IL-4, IL-10, IL-13. These results suggest that PRP could be a potential therapeutic tool for the treatment of OA. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Importância clínica e laboratorial do volume plaquetário médio The clinical and laboratory importance of mean platelet volume

    Directory of Open Access Journals (Sweden)

    Mariela Granero Farias

    2010-08-01

    Full Text Available Os índices plaquetários fornecidos pelos analisadores hematológicos são provavelmente os parâmetros mais ignorados pela maioria dos laboratórios clínicos, em virtude da dificuldade de sua padronização. Desses índices, o volume plaquetário médio (VPM vem merecendo destaque por sua grande utilidade, não só em casos de trombose e hemostasia, mas também em uma série de patologias, como diabetes, doenças da tireoide, doenças vasculares, entre outras. O VPM é um parâmetro plaquetário fornecido no hemograma que não gera custos adicionais para o laboratório. Junto com a contagem de plaquetas, ele é um sensível indicador de desordens plaquetárias in vivo, mas pode ser tecnicamente difícil de analisá-lo in vitro por causa dos interferentes pré-analíticos, como tempo de armazenamento da amostra e artefatos gerados pelos anticoagulantes. Neste artigo descrevemos as principais metodologias e seus interferentes na determinação da contagem plaquetária e do VPM, destacando a importância do laboratório de análises clínicas em validar esse parâmetro, proporcionando sua utilização no diagnóstico de desordens hematológicas e de outras patologias.The platelet indices provided by the hematological analyzers are probably the parameters mostly ignored by most clinical laboratories due to standardization difficulties. Among those indices, the mean platelet volume (MPV has stood out due to its usefulness not only in cases of thrombosis and hemostasy, but also in a series of pathologies, such as diabetes, thyroid and vascular diseases, among others. MPV is a platelet parameter provided by the hemogram, which does not represent additional costs to the laboratory. Along with platelet count, it is a sensitive indicator of platelet disorders in vivo. However, it may be technically difficult to analyze it in vitro owing to preanalytical interferences, such as sample storage time and anticoagulant artifacts. In this article we described

  9. 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.

  10. Flavanols and Platelet Reactivity

    Directory of Open Access Journals (Sweden)

    Debra A. Pearson

    2005-01-01

    Full Text Available Platelet activity and platelet-endothelial cell interactions are important in the acute development of thrombosis, as well as in the pathogenesis of cardiovascular disease. An increasing number of foods have been reported to have platelet-inhibitory actions, and research with a number of flavanol-rich foods, including, grape juice, cocoa and chocolate, suggests that these foods may provide some protection against thrombosis. In the present report, we review a series of in vivo studies on the effects of flavanol-rich cocoa and chocolate on platelet activation and platelet-dependent primary hemostasis. Consumption of flavanol-rich cocoa inhibited several measures of platelet activity including, epinephrine- and ADP-induced glycoprotein (GP IIb/IIIa and P-Selectin expression, platelet microparticle formation, and epinephrine-collagen and ADP-collagen induced primary hemostasis. The epinephrine-induced inhibitory effects on GP IIb/IIIa and primary hemostasis were similar to, though less robust than those associated with the use of low dose (81 mg aspirin. These data, coupled with information from other studies, support the concept that flavanols present in cocoa and chocolate can modulate platelet function through a multitude of pathways.

  11. Platelet-Rich Plasma Increases the Levels of Catabolic Molecules and Cellular Dedifferentiation in the Meniscus of a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Hye-Rim Lee

    2016-01-01

    Full Text Available Despite the susceptibility to frequent intrinsic and extrinsic injuries, especially in the inner zone, the meniscus does not heal spontaneously owing to its poor vascularity. In this study, the effect of platelet-rich plasma (PRP, containing various growth factors, on meniscal mechanisms was examined under normal and post-traumatic inflammatory conditions. Isolated primary meniscal cells of New Zealand white (NZW rabbits were incubated for 3, 10, 14 and 21 days with PRP(−, 10% PRP (PRP(+, IL(+ or IL(+PRP(+. The meniscal cells were collected and examined using reverse-transcription polymerase chain reaction (RT-PCR. Culture media were examined by immunoblot analyses for matrix metalloproteinases (MMP catabolic molecules. PRP containing growth factors improved the cellular viability of meniscal cells in a concentration-dependent manner at Days 1, 4 and 7. However, based on RT-PCR, meniscal cells demonstrated dedifferentiation, along with an increase in type I collagen in the PRP(+ and in IL(+PRP(+. In PRP(+, the aggrecan expression levels were lower than in the PRP(− until Day 21. The protein levels of MMP-1 and MMP-3 were higher in each PRP group, i.e., PRP(+ and IL(+PRP(+, at each culture time. A reproducible 2-mm circular defect on the meniscus of NZW rabbit was used to implant fibrin glue (control or PRP in vivo. After eight weeks, the lesions in the control and PRP groups were occupied with fibrous tissue, but not with meniscal cells. This study shows that PRP treatment of the meniscus results in an increase of catabolic molecules, especially those related to IL-1α-induced inflammation, and that PRP treatment for an in vivo meniscus injury accelerates fibrosis, instead of meniscal cartilage.

  12. Platelet function testing in pediatric patients

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Favaloro, Emmanuel J

    2017-01-01

    Introduction: Platelets play a key role in primary hemostasis and are also intricately linked to secondary hemostasis. Investigation of platelet function in children, especially in neonates, is seriously challenged by the volumes required to perform the majority of platelet function tests and due...

  13. Increased rainfall volume from future convective storms in the US

    Science.gov (United States)

    Prein, Andreas F.; Liu, Changhai; Ikeda, Kyoko; Trier, Stanley B.; Rasmussen, Roy M.; Holland, Greg J.; Clark, Martyn P.

    2017-12-01

    Mesoscale convective system (MCS)-organized convective storms with a size of 100 km have increased in frequency and intensity in the USA over the past 35 years1, causing fatalities and economic losses2. However, their poor representation in traditional climate models hampers the understanding of their change in the future3. Here, a North American-scale convection-permitting model which is able to realistically simulate MSCs4 is used to investigate their change by the end-of-century under RCP8.5 (ref. 5). A storm-tracking algorithm6 indicates that intense summertime MCS frequency will more than triple in North America. Furthermore, the combined effect of a 15-40% increase in maximum precipitation rates and a significant spreading of regions impacted by heavy precipitation results in up to 80% increases in the total MCS precipitation volume, focussed in a 40 km radius around the storm centre. These typically neglected increases substantially raise future flood risk. Current investments in long-lived infrastructures, such as flood protection and water management systems, need to take these changes into account to improve climate-adaptation practices.

  14. Platelet adhesiveness: the effect of centrifugation on the measurement of adhesiveness in platelet-rich plasma

    Science.gov (United States)

    McBride, J. A.

    1968-01-01

    Platelet adhesiveness has been measured in citrated whole blood and in platelet-rich plasma obtained from normal subjects, splenectomized patients, and from patients in whom the diagnosis of recurrent venous thrombosis had been made. The duration of centrifugation used in the preparation of platelet-rich plasma was found to have a profound effect on the measurement of platelet adhesiveness because the figure for platelet adhesiveness measured in platelet-rich plasma obtained by centrifugation was considerably lower than that found in citrated whole blood. This effect was particularly marked when platelet-rich plasma was obtained from subjects in whom platelet adhesiveness measured in whole blood was increased. PMID:5699080

  15. 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.

  16. Nanomolar concentrations of adrenaline induce platelet adhesion in vitro.

    Science.gov (United States)

    Eriksson, Andreas C; Whiss, Per A

    2013-01-01

    Adrenaline is a platelet activator having a resting plasma concentration of adrenaline in micromolar concentrations. This makes it difficult to estimate the relevance of in vitro data for the in vivo situation. The aim of this study was to investigate experimental conditions in vitro that could detect platelet effects of adrenaline in nanomolar concentrations. Platelet adhesion to albumin and collagen was evaluated with a static platelet adhesion assay. Our results show that 10 nmol/l adrenaline induced platelet adhesion to albumin in platelet-rich plasma (PRP) prepared at 140 × g, while 100 nmol/l was necessary in order to increase adhesion of platelets prepared at 220 × g. The mean platelet volume was increased after preparation at 140 × g, suggesting that large reactive platelets contributed to the increased adrenaline sensitivity. At optimal Mg(2+)-concentration, adhesion to collagen was increased by 10 nmol/l adrenaline irrespective of centrifugal force applied during PRP preparation. More specifically, we defined two populations where adhesion to collagen was increased by 10 nmol/l adrenaline either upon centrifugation at 140 × g but not 220 × g or vice versa. In some experiments, platelet adhesion to collagen was induced by 3 nmol/l adrenaline, which corresponds to concentrations achieved during stress in vivo. In summary, the static adhesion assay is able to detect platelet activating effects of adrenaline very close to physiological concentrations. This is rare for in vitro assays and motivates further research about adrenergic signalling in platelets.

  17. Increased cerebellar gray matter volume in head chefs.

    Directory of Open Access Journals (Sweden)

    Antonio Cerasa

    Full Text Available Chefs exert expert motor and cognitive performances on a daily basis. Neuroimaging has clearly shown that that long-term skill learning (i.e., athletes, musicians, chess player or sommeliers induces plastic changes in the brain thus enabling tasks to be performed faster and more accurately. How a chef's expertise is embodied in a specific neural network has never been investigated.Eleven Italian head chefs with long-term brigade management expertise and 11 demographically-/ psychologically- matched non-experts underwent morphological evaluations.Voxel-based analysis performed with SUIT, as well as, automated volumetric measurement assessed with Freesurfer, revealed increased gray matter volume in the cerebellum in chefs compared to non-experts. The most significant changes were detected in the anterior vermis and the posterior cerebellar lobule. The magnitude of the brigade staff and the higher performance in the Tower of London test correlated with these specific gray matter increases, respectively.We found that chefs are characterized by an anatomical variability involving the cerebellum. This confirms the role of this region in the development of similar expert brains characterized by learning dexterous skills, such as pianists, rock climbers and basketball players. However, the nature of the cellular events underlying the detected morphological differences remains an open question.

  18. A pilot study evaluating the prognostic utility of platelet indices in dogs with septic peritonitis.

    Science.gov (United States)

    Llewellyn, Efa A; Todd, Jeffrey M; Sharkey, Leslie C; Rendahl, Aaron

    2017-09-01

    To characterize platelet indices at time of diagnosis of septic peritonitis in dogs and to assess the relationship between platelet parameter data and survival to discharge in dogs treated surgically. Retrospective, observational, descriptive pilot study from 2009 to 2014. University teaching hospital. Forty-eight dogs diagnosed with septic peritonitis were included in this study. Thirty-six dogs had surgical source control. Blood samples from 46 healthy control dogs were used for reference interval (RI) generation. None. Dogs with septic peritonitis had significantly increased mean values for mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) with increased proportions of dogs having values above the RI compared to healthy dogs. A significantly increased proportion of dogs with septic peritonitis had platelet counts above (12.5%) and below (8.3%) the RI, with no significant difference in mean platelet count compared to healthy dogs. No significant differences in the mean platelet count, MPV, PCT, or PDW were found between survivors and nonsurvivors in dogs with surgical source control; however, dogs with MPV values above the RI had significantly increased mortality compared to dogs within the RI (P = 0.025). Values outside the RI for other platelet parameters were not associated with significant differences in mortality. Dogs with septic peritonitis have increased frequency of thrombocytosis and thrombocytopenia with increased MPV, PCT, and PDW. An increased MPV may be a useful indicator of increased risk of mortality in dogs treated surgically. © Veterinary Emergency and Critical Care Society 2017.

  19. Ultrastructure and growth factor content of equine platelet-rich fibrin gels.

    Science.gov (United States)

    Textor, Jamie A; Murphy, Kaitlin C; Leach, J Kent; Tablin, Fern

    2014-04-01

    To compare fiber diameter, pore area, compressive stiffness, gelation properties, and selected growth factor content of platelet-rich fibrin gels (PRFGs) and conventional fibrin gels (FGs). PRFGs and conventional FGs prepared from the blood of 10 healthy horses. Autologous fibrinogen was used to form conventional FGs. The PRFGs were formed from autologous platelet-rich plasma of various platelet concentrations (100 × 10³ platelets/μL, 250 × 10³ platelets/μL, 500 × 10³ platelets/μL, and 1,000 × 10³ platelets/μL). All gels contained an identical fibrinogen concentration (20 mg/mL). Fiber diameter and pore area were evaluated with scanning electron microscopy. Maximum gelation rate was assessed with spectrophotometry, and gel stiffness was determined by measuring the compressive modulus. Gel weights were measured serially over 14 days as an index of contraction (volume loss). Platelet-derived growth factor-BB and transforming growth factor-β1 concentrations were quantified with ELISAs. Fiber diameters were significantly larger and mean pore areas were significantly smaller in PRFGs than in conventional FGs. Gel weight decreased significantly over time, differed significantly between PRFGs and conventional FGs, and was significantly correlated with platelet concentration. Platelet-derived growth factor-BB and transforming growth factor-β1 concentrations were highest in gels and releasates derived from 1,000 × 10³ platelets/μL. The inclusion of platelets in FGs altered the architecture and increased the growth factor content of the resulting scaffold. Platelets may represent a useful means of modifying these gels for applications in veterinary and human regenerative medicine.

  20. 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

  1. Serum Levels of Platelet Released CD40 Ligand Are Increased in Early Onset Occlusive Carotid Artery Disease

    Directory of Open Access Journals (Sweden)

    József Balla

    2006-01-01

    Full Text Available Objective: Soluble CD40 ligand (sCD40L has been suggested as a key mediator between inflammation and atherosclerosis, and the CD40-CD40L interaction has a role in atherosclerotic lesion progression. We evaluated if platelet released serum sCD40L and sCD40 levels differ between patients with early onset occlusive carotid artery disease and age-matched controls.

  2. Platelet count

    Science.gov (United States)

    The normal number of platelets in the blood is 150,000 to 400,000 platelets per microliter (mcL) or 150 to 400 × 10 9 /L. Normal value ranges may vary slightly. Some lab use different measurements or ...

  3. 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.

  4. Stereological observations of platelet-reinforced mullite- and zirconia-matrix composites

    International Nuclear Information System (INIS)

    Cherian, I.K.; Kriven, W.M.; Lehigh, M.D.; Nettleship, I.

    1996-01-01

    Recently, the effect of solid inclusions on the sintering of ceramic powders has been explained in terms of a back-stress that opposes densification. Several analyses have been proposed to describe this problem. However, little quantitative information exists concerning the effect of reinforcement on microstructural evolution. This study compares the microstructural development of zirconia and mullite matrices in the presence of alumina platelets. The effect of platelet loading on density is similar for both composites. Quantitative stereological examinations reveal that the average grain size and pore size are finer for the zirconia-matrix composite. The platelet loading does not have any noticeable effect on the average grain size of the matrix in either composite. However, the average pore size increases as the volume fraction of platelets increases for both materials. Contiguity measurements have detected some aggregation of platelets in the zirconia-matrix composite

  5. Natural pomegranate juice reduces inflammation, muscle damage and increase platelets blood levels in active healthy Tunisian aged men

    Directory of Open Access Journals (Sweden)

    Ammar Achraf

    2018-03-01

    Paired simple t-test showed a significant difference between PLA and POMj supplementation effects on systolic blood pressure (SAP, creatinine (CRE, hematological and muscle damage parameters and C-reactive protein (CRP (p < 0.01 with lower values using POMj. Similarly, a significant differences were shown for platelets PLT (p < 0.01 with higher values using POMj supplementation. POMj rich in polyphenols seems to have a power anti-inflammatory effect and to be an effective treatment for patients who suffer from the thrombocyto-penia disease. Therefore, aged populations are advised to add natural POMj to their daily nutrition behavior.

  6. On infinitesimal increase of volumes of morphological transforms

    DEFF Research Database (Denmark)

    Kiderlen, Markus; Rataj, Jan

    2007-01-01

    Let B (“black”) and W (“white”) be disjoint compact test sets in the d-dimensional Euclidean space and consider the volume of all its simultaneous shifts keeping B inside and W outside a compact set A. If the union of B and W is rescaled by a factor tending to zero, then the rescaled volume...... for the hit-or-miss function. Secondly, in a design based setting, different random digitizations of a deterministic set A are treated. It is shown how the number of configurations in such a digitization is related to the surface area measure of A as the lattice distance converges to zero....

  7. Superoxide dismutase of human platelets

    International Nuclear Information System (INIS)

    Kimura, Akiro; Fujimura, Kingo; Kuramoto, Atsushi

    1979-01-01

    Superoxide dismutase (S.O.D.) is the enzyme to protect from destructive effect of superoxide (O 2 -) produced in many metabolic pathways related to oxygen. The purpose of this study was to investigate the possibility that S.O.D. may play an important role in the platelet function. The cytoplasmic and mitochondrial S.O.D. has been investigated spectrophotometrically and gel electrophoretically in human platelets from eleven patients of chronic myelogenous leukemia (CML) and three patients of primary thrombocythemia (P.Th.). Neither deficiency nor abnormality of cytoplasmic and mitochondrial S.O.D. has been found electrophoretically in any case compared to normal platelets. However, the total activity from three of the CML patients and one of the P.Th. patients were above 3 unit/mg platelet protein (normal subject: 2.11 - 2.70 unit/mg protein), suggesting the possibility either that more O 2 -production occurs in the platelets or that rather little O 2 -production due to much O 2 -deprivation by the increased S.O.D. The S.O.D. activity of human platelets has been also investigated in several conditions, where much O 2 -generation might occur in platelets. Sodium fluoride (2 mM), which increases platelet O 2 -production about 3 fold, had no effect on platelet S.O.D. The aggregated platelets induced by ADP (10 -5 M), epinephrin (50 μg/ml), ristocetin (1.5 mg/ml) or collagen (1 - 20 μg/ml) had no increase of S.O.D. activity compared to that from non aggregated platelets. X-ray irradiation (1,000 - 20,000R) had not induced its activity increase or decrease. These findings indicated the induction of platelet S.O.D. was not brought about under these conditions. (author)

  8. Platelet Donation

    Science.gov (United States)

    ... During your donation you can relax, watch a movie, listen to music…in a few hours you’ ... requirements may become eligible to donate platelets. Please review our eligibility requirements as some states require parental ...

  9. 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

  10. Troglitazone treatment increases bone marrow adipose tissue volume but does not affect trabecular bone volume in mice

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Mosekilde, Leif; Justesen, J

    2001-01-01

    proliferator activated receptor-gamma (PPARgamma). Histomorphometric analysis of proximal tibia was performed in order to quantitate the amount of trabecular bone volume per total volume (BV/TV %), adipose tissue volume per total volume (AV/TV %), and hematopoietic marrow volume per total volume (HV......Aging is associated with decreased trabecular bone mass and increased adipocyte formation in bone marrow. As osteoblasts and adipocytes share common precursor cells present in the bone marrow stroma, it has been proposed that an inverse relationship exists between adipocyte and osteoblast....../TV %) using the point-counting technique. Bone size did not differ between the two groups. In troglitazone-treated mice, AV/TV was significantly higher than in control mice (4.7+/-2.1% vs. 0.2+/-0.3%, respectively, mean +/- SD, P

  11. 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 ...

  12. Platelet antibodies blood test

    Science.gov (United States)

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

  13. Relationship of maternal mean platelet volume with fetal Doppler parameters and neonatal complications in pregnancies with and without intrauterine growth restriction.

    Science.gov (United States)

    Ureyen, Isin; Ozyuncu, Ozgur; Sahin-Uysal, Nihal; Kara, Ozgur; Basaran, Derman; Turgal, Mert; Deren, Ozgur

    2017-02-01

    In this study, we investigated the relationship of mean platelet volume (MPV) with the presence and the severity of intrauterine growth restriction (IUGR) and with neonatal complications. The pregnancies with and without IUGR, that were followed-up in our hospital between 2003 and 2009 were analyzed retrospectively. Pregnancies which resulted in birth of a newborn with a birthweight less than 10th percentile for the gestational age were selected for IUGR group. IUGR cases were divided into three groups according to the Doppler parameters. There was no significant difference between the MPV values in the groups. There was no association between MPV and Doppler parameters that can be used in predicting the severity of IUGR. There was no significant relation between MPV and the perinatal complications such as intracranial hemorrhage (ICH), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), the development of sepsis, postpartum exitus (PPEX) and intrauterine exitus (IUEX). Higher MPV values were associated with hospitalization in the neonatal intensive care unit (NICU) and respiratory distress syndrome (RDS) in the IUGR group. Analysis of MPV is a simple and readily available laboratory test. Prospective researches employing standard measurement technics are required to clarify the relationship between MPV and IUGR.

  14. Stormwater Volume Control to Prevent Increases in Lake Flooding and Dam Failure Risk

    Science.gov (United States)

    Potter, K. W.

    2017-12-01

    Urban expansion is not often considered a major factor contributing to dam failure. But if urbanization occurs without mitigation of the hydrologic impacts, the risk of dam failure will increase. Of particular concern are increases in the volume of storm runoff resulting from increases in the extent of impervious surfaces. Storm runoff volumes are not regulated for much the U.S, and where they are, the required control is commonly less than 100%. Unmitigated increases in runoff volume due to urbanization can pose a risk to dams. A recent technical advisory committee of Dane County has recommended that the county require 100% control of stormwater volumes for new developments. The primary motivation was to prevent increases in the water levels in the Yahara Lakes, slowly draining lakes that are highly sensitive to runoff volume. The recommendations included the use of "volume trading" to achieve efficient compliance. Such recommendations should be considered for other slowly draining lakes, including those created by artificial structures.

  15. White Rose development plan amendment production volume increase

    International Nuclear Information System (INIS)

    2006-09-01

    In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada, submitted a Benefits Plan for the White Rose Development to the Canada- Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB). This revised document provided the case for requesting an increase in the facility maximum daily production rate and the average annual production rate for the White Rose field from 100,000 barrels per day (bpd) as stated in the approved White Rose Development Plan to 140,000 bpd. In order to determine the potential for increasing oil production through the Floating Production, Storage and Offloading (FPSO) vessel, two things were considered, namely the proper reservoir management of the White Rose field to ensure optimum resource recovery, and the capacity of the FPSO topsides processing system and supporting utilities to accommodate increased production. This document presented a detailed review of all the implications of increased production on the South White Rose Reservoir. In addition, the results from FPSO performance testing were reviewed, including a study of options for de-bottlenecking the process plant on the topsides and capacity testing of selected process streams and support systems. Vibration analysis was conducted before and during performance testing in July 2006 and a small number of areas addressed. The document also addressed flow metering, resource management, certifying authority review, safety plan revisions, environmental effects, as well as benefits to Canada and Newfoundland. 21 tabs., 60 refs

  16. Platelet Donation

    Science.gov (United States)

    ... time’ to unwind from the daily stresses of life while helping save lives. What are the benefits to donating platelets? Knowing you’re helping cancer ... of your arm. That pinch is similar to what you will feel when the needle is ... compared to a traditional whole blood donation so some donors find it to ...

  17. Analysis of increasing trend of mortgage volume in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Petra Střelcová

    2009-01-01

    Full Text Available The aim of this paper is an empirical analysis of mortgage volume in the Czech Republic and factors identification of the increasing trend of the mortgage volume in the period from 2001 to 2007. Firstly, analysis of quarterly time series of mortgage volume and average mortgage rate are performed. Consequently, causality between mortgage volume and average mortgage rate is analysed. The morgage rate is the most important factor for economic subjects decision of residential investment. Afterwards, it is analysed causality between mortgage volume and selected factors via multiple regression analysis. Based on this analysis, influencing factors for multiple regression analysis describing mortgage volume are selected. Our empirical analysis validate the causality between mortgage volume and mortgage rate, unemployment rate and price level of real estates. Part of this paper is also economic eduction of causality and estimation of expect progress of mortgage volume especially in connection with present economic and business recession.

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

    Science.gov (United States)

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

    2015-03-01

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

  19. Increased sinusoidal volume and solute extraction during retrograde liver perfusion

    International Nuclear Information System (INIS)

    Bass, N.M.; Manning, J.A.; Weisiger, R.A.

    1989-01-01

    Retrograde isolated liver perfusion has been used to probe acinar functional heterogeneity, but the hemodynamic effects of backward flow have not been characterized. In this study, extraction of a long-chain fatty acid derivative, 12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (12-NBDS), was greater during retrograde than during anterograde perfusion of isolated rat liver. To determine whether hemodynamic differences between anterograde and retrograde perfused livers could account for this finding, the hepatic extracellular space was measured for both directions of flow by means of [ 14 C]sucrose washout during perfusion as well as by direct measurement of [ 14 C]sucrose entrapped during perfusion. A three- to fourfold enlargement of the total hepatic extracellular space was found during retrograde perfusion by both approaches. Examination of perfusion-fixed livers by light microscopy and morphometry revealed that marked distension of the sinusoids occurred during retrograde perfusion and that this accounts for the observed increase in the [ 14 C]sucrose space. These findings support the hypothesis that maximum resistance to perfusate flow in the isolated perfused rat liver is located at the presinusoidal level. In addition, increased transit time of perfusate through the liver and greater sinusoidal surface area resulting from sinusoidal distension may account for the higher extraction of 12-NBDS and possibly other compounds by retrograde perfused liver

  20. Brief Report: Platelet-Poor Plasma Serotonin in Autism

    Science.gov (United States)

    Anderson, George M.; Hertzig, Margaret E.; McBride, P. A.

    2012-01-01

    Possible explanations for the well-replicated platelet hyperserotonemia of autism include an alteration in the platelet's handling of serotonin (5-hydroxyserotonin, 5-HT) or an increased exposure of the platelet to 5-HT. Measurement of platelet-poor plasma (PPP) levels of 5-HT appears to provide the best available index of in vivo exposure of the…

  1. Platelet destruction in autoimmune thrombocytopenic purpura: kinetics and clearance of indium-111-labeled autologous platelets

    International Nuclear Information System (INIS)

    Stratton, J.R.; Ballem, P.J.; Gernsheimer, T.; Cerqueira, M.; Slichter, S.J.

    1989-01-01

    Using autologous 111 In-labeled platelets, platelet kinetics and the sites of platelet destruction were assessed in 16 normal subjects (13 with and three without spleens), in 17 studies of patients with primary autoimmune thrombocytopenic purpura (AITP), in six studies of patients with secondary AITP, in ten studies of patients with AITP following splenectomy, and in five thrombocytopenic patients with myelodysplastic syndromes. In normal subjects, the spleen accounted for 24 +/- 4% of platelet destruction and the liver for 15 +/- 2%. Untreated patients with primary AITP had increased splenic destruction (40 +/- 14%, p less than 0.001) but not hepatic destruction (13 +/- 5%). Compared with untreated patients, prednisone treated patients did not have significantly different spleen and liver platelet sequestration. Patients with secondary AITP had similar platelet counts, platelet survivals, and increases in splenic destruction of platelets as did patients with primary AITP. In contrast, patients with myelodysplastic syndromes had a normal pattern of platelet destruction. In AITP patients following splenectomy, the five nonresponders all had a marked increase (greater than 45%) in liver destruction compared to five responders (all less than 40%). Among all patients with primary or secondary AITP, there was an inverse relationship between the percent of platelets destroyed in the liver plus spleen and both the platelet count (r = 0.75, p less than 0.001) and the platelet survival (r = 0.86, p less than 0.001). In a stepwise multiple linear regression analysis, total liver plus spleen platelet destruction, the platelet survival and the platelet turnover were all significant independent predictors of the platelet count. Thus platelet destruction is shifted to the spleen in primary and secondary AITP. Failure of splenectomy is associated with a marked elevation in liver destruction

  2. Effect of High-Volume Injection, Platelet-Rich Plasma, and Sham Treatment in Chronic Midportion Achilles Tendinopathy: A Randomized Double-Blinded Prospective Study.

    Science.gov (United States)

    Boesen, Anders Ploug; Hansen, Rudi; Boesen, Morten Ilum; Malliaras, Peter; Langberg, Henning

    2017-07-01

    Injection therapies are often considered alongside exercise for chronic midportion Achilles tendinopathy (AT), although evidence of their efficacy is sparse. To determine whether eccentric training in combination with high-volume injection (HVI) or platelet-rich plasma (PRP) injections improves outcomes in AT. Randomized controlled trial; Level of evidence, 1. A total of 60 men (age, 18-59 years) with chronic (>3 months) AT were included and followed for 6 months (n = 57). All participants performed eccentric training combined with either (1) one HVI (steroid, saline, and local anesthetic), (2) four PRP injections each 14 days apart, or (3) placebo (a few drops of saline under the skin). Randomization was stratified for age, function, and symptom severity (Victorian Institute of Sports Assessment-Achilles [VISA-A]). Outcomes included function and symptoms (VISA-A), self-reported tendon pain during activity (visual analog pain scale [VAS]), tendon thickness and intratendinous vascularity (ultrasonographic imaging and Doppler signal), and muscle function (heel-rise test). Outcomes were assessed at baseline and at 6, 12, and 24 weeks of follow-up. VISA-A scores improved in all groups at all time points ( P Tendon thickness showed a significant decrease only in HVI and PRP groups during the intervention, and this was greater in the HVI versus PRP and placebo groups at 6 and 12 weeks ( P eccentric training in chronic AT seems more effective in reducing pain, improving activity level, and reducing tendon thickness and intratendinous vascularity than eccentric training alone. HVI may be more effective in improving outcomes of chronic AT than PRP in the short term. Registration: NCT02417987 ( ClinicalTrials.gov identifier).

  3. Inward flux of lactate⁻ through monocarboxylate transporters contributes to regulatory volume increase in mouse muscle fibres.

    Directory of Open Access Journals (Sweden)

    Michael I Lindinger

    Full Text Available Mouse and rat skeletal muscles are capable of a regulatory volume increase (RVI after they shrink (volume loss resultant from exposure to solutions of increased osmolarity and that this RVI occurs mainly by a Na-K-Cl-Cotransporter (NKCC-dependent mechanism. With high-intensity exercise, increased extracellular osmolarity is accompanied by large increases in extracellular [lactate⁻]. We hypothesized that large increases in [lactate⁻] and osmolarity augment the NKCC-dependent RVI response observed with a NaCl (or sucrose-induced increase in osmolarity alone; a response that is dependent on lactate⁻ influx through monocarboxylate transporters (MCTs. Single mouse muscle fibres were isolated and visualized under light microscopy under varying osmolar conditions. When solution osmolarity was increased by adding NaLac by 30 or 60 mM, fibres lost significantly less volume and regained volume sooner compared to when NaCl was used. Phloretin (MCT1 inhibitor accentuated the volume loss compared to both NaLac controls, supporting a role for MCT1 in the RVI response in the presence of elevated [lactate⁻]. Inhibition of MCT4 (with pCMBS resulted in a volume loss, intermediate to that seen with phloretin and NaLac controls. Bumetanide (NKCC inhibitor, in combination with pCMBS, reduced the magnitude of volume loss, but volume recovery was complete. While combined phloretin-bumetanide also reduced the magnitude of the volume loss, it also largely abolished the cell volume recovery. In conclusion, RVI in skeletal muscle exposed to raised tonicity and [lactate⁻] is facilitated by inward flux of solute by NKCC- and MCT1-dependent mechanisms. This work demonstrates evidence of a RVI response in skeletal muscle that is facilitated by inward flux of solute by MCT-dependent mechanisms. These findings further expand our understanding of the capacities for skeletal muscle to volume regulate, particularly in instances of raised tonicity and lactate

  4. Effect of Puumala hantavirus infection on Human Umbilical Vein Endothelial Cell hemostatic function: platelet interactions, increased tissue factor expression and fibrinolysis regulator release

    Directory of Open Access Journals (Sweden)

    Marco Goeijenbier

    2015-03-01

    Full Text Available Puumala virus (PUUV infection causes over 5000 cases of hemorrhagic fever in Europe annually and can influence the hemostatic balance extensively. Infection might lead to hemorrhage, while a recent study showed an increased risk of myocardial infarction during or shortly after PUUV infection. The mechanism by which this hantavirus influences the coagulation system remains unknown. Therefore we aimed to elucidate mechanisms explaining alterations seen in primary and secondary hemostasis during PUUV infection. By using low passage PUUV isolates to infect primary human umbilical vein endothelial cells (HUVECs we were able to show alterations in the regulation of primary- and secondary hemostasis and in the release of fibrinolysis regulators. Our main finding was an activation of secondary hemostasis due to increased tissue factor expression leading to increased thrombin generation in a functional assay. Furthermore, we showed that during infection platelets adhered to HUVECs and subsequently specifically to PUUV virus particles. Infection of HUVECs with PUUV did not result in increased von Willebrand factor while they produced more plasminogen activator inhibitor type-1 (PAI-1 compared to controls. The PAI-1 produced in this model formed complexes with vitronectin. This is the first report that reveals a potential mechanism behind the pro-coagulant changes in PUUV patients, which could be the result of increased thrombin generation due to an increased tissue factor expression on endothelial cells during infection. Furthermore, we provide insight into the contribution of endothelial cell responses regarding hemostasis in PUUV pathogenesis.

  5. Depressed reticuloendothelial clearance of platelets in rats after trauma.

    Science.gov (United States)

    Kaplan, J E; Moon, D G; Minnear, F L; Saba, T M

    1984-02-01

    Platelet microembolization may contribute to microcirculatory and organ damage following trauma and shock. It is hypothesized that posttraumatic reticuloendothelial depression predisposes to such microembolization by failure to clear altered platelets from the circulation. The present study evaluated the short-term (1 h) clearance and organ localization of radiolabeled homologous damaged platelets in normal rats and in rats following sublethal Noble-Collip drum trauma. Platelets were collected in citrated platelet-rich plasma from normal rats and labeled with 51Cr in citrated saline. Platelets were altered by repeated centrifugation in protein-free medium. These platelets differed functionally and morphologically from normal platelets. Disappearance of iv injected damaged platelets conformed to a two-compartment exponential clearance. Velocity of clearance in the rapid compartment correlated with hepatic platelet localization, whereas velocity of clearance in the second compartment correlated with splenic platelet localization. Clearance rate of the rapid compartment was depressed at 1 h after trauma and elevated at 24 h. These changes were associated with a decrease in hepatic platelet localization at 1 h and an increase above normal at 24 h. Splenic platelet localization was decreased by 3 h following trauma. Pulmonary platelet localization was increased at all times following trauma. It is concluded that the posttrauma state is associated with a defect in the reticuloendothelial system clearance of altered platelets, which may augment embolization of platelets in the lung.

  6. Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination

    Directory of Open Access Journals (Sweden)

    Yutaka Kitamura

    2018-02-01

    Full Text Available Platelet-rich fibrin (PRF clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP fractions were clotted with CaCl2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix.

  7. Does price efficiency increase with trading volume? Evidence of nonlinearity and power laws in ETFs

    Science.gov (United States)

    Caginalp, Gunduz; DeSantis, Mark

    2017-02-01

    Whether efficiency increases with increasing volume is an important issue that may illuminate trader strategies and distinguish between market theories. This relationship is tested using 124,236 daily observations comprising 68 large and liquid U.S. equity exchange traded funds (ETFs). ETFs have the advantage that efficiency can be measured in terms of the deviation between the trading price and the underlying net asset value that is reported each day. Our findings support the hypothesis that the relationship between volume and efficiency is nonlinear. Indeed, efficiency increases as volume increases from low to moderately high levels, but then decreases as volume increases further. The first part tends to support the idea that higher volume simply facilitates transactions and maintains efficiency, while the latter part, i.e., even higher volumes, supports the ansatz that increased volume is associated with increased speculation that ignores valuation and decreases efficiency. The results are consistent with the hypothesis that valuation is only part of the motivation for traders. Our methodology accounts for fund heterogeneity and contemporaneous correlations. Similar results are obtained when daily price volatility is introduced as an additional independent variable.

  8. Congenital platelet function defects

    Science.gov (United States)

    ... pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... Congenital platelet function defects are bleeding disorders that cause reduced platelet function. Most of the time, people with these disorders have ...

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

    Science.gov (United States)

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

    2014-11-01

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

  10. Physiopathology of blood platelets and development of platelet substitutes. Progress report, August 1, 1975--July 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, M G

    1976-04-28

    Progress is reported on studies on the physiology of blood platelets in thrombocytopenic patients and rabbits. Methods for the detection of platelet antibodies and the preservation of platelets in vitro were investigated. Studies on the effect of low doses of x irradiation (up to 1000 R) on platelet function indicate that platelets exposed to ionizing radiation have increased functional activity. A list is included of publications that report the results of the studies in detail.

  11. Physiopathology of blood platelets and development of platelet substitutes. Progress report, August 1, 1975--July 31, 1976

    International Nuclear Information System (INIS)

    Baldini, M.G.

    1976-01-01

    Progress is reported on studies on the physiology of blood platelets in thrombocytopenic patients and rabbits. Methods for the detection of platelet antibodies and the preservation of platelets in vitro were investigated. Studies on the effect of low doses of x irradiation (up to 1000 R) on platelet function indicate that platelets exposed to ionizing radiation have increased functional activity. A list is included of publications that report the results of the studies in detail

  12. Effect of increases in lung volume on clearance of aerosolized solute from human lungs

    Energy Technology Data Exchange (ETDEWEB)

    Marks, J.D.; Luce, J.M.; Lazar, N.M.; Wu, J.N.; Lipavsky, A.; Murray, J.F.

    1985-10-01

    To study the effect of increases in lung volume on solute uptake, we measured clearance of /sup 99m/Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) at different lung volumes in 19 healthy humans. Seven subjects inhaled aerosols (1 micron activity median aerodynamic diam) at ambient pressure; clearance and functional residual capacity (FRC) were measured at ambient pressure (control) and at increased lung volume produced by positive pressure (12 cmH2O continuous positive airway pressure (CPAP)) or negative pressure (voluntary breathing). Six different subjects inhaled aerosol at ambient pressure; clearance and FRC were measured at ambient pressure and CPAP of 6, 12, and 18 cmH2O pressure. Six additional subjects inhaled aerosol at ambient pressure or at CPAP of 12 cmH2O; clearance and FRC were determined at CPAP of 12 cmH2O. According to the results, Tc-DTPA clearance from human lungs is accelerated exponentially by increases in lung volume, this effect occurs whether lung volume is increased by positive or negative pressure breathing, and the effect is the same whether lung volume is increased during or after aerosol administration. The effect of lung volume must be recognized when interpreting the results of this method.

  13. Effect of increases in lung volume on clearance of aerosolized solute from human lungs

    International Nuclear Information System (INIS)

    Marks, J.D.; Luce, J.M.; Lazar, N.M.; Wu, J.N.; Lipavsky, A.; Murray, J.F.

    1985-01-01

    To study the effect of increases in lung volume on solute uptake, we measured clearance of /sup 99m/Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) at different lung volumes in 19 healthy humans. Seven subjects inhaled aerosols (1 micron activity median aerodynamic diam) at ambient pressure; clearance and functional residual capacity (FRC) were measured at ambient pressure (control) and at increased lung volume produced by positive pressure [12 cmH 2 O continuous positive airway pressure (CPAP)] or negative pressure (voluntary breathing). Six different subjects inhaled aerosol at ambient pressure; clearance and FRC were measured at ambient pressure and CPAP of 6, 12, and 18 cmH 2 O pressure. Six additional subjects inhaled aerosol at ambient pressure or at CPAP of 12 cmH 2 O; clearance and FRC were determined at CPAP of 12 cmH 2 O. According to the results, Tc-DTPA clearance from human lungs is accelerated exponentially by increases in lung volume, this effect occurs whether lung volume is increased by positive or negative pressure breathing, and the effect is the same whether lung volume is increased during or after aerosol administration. The effect of lung volume must be recognized when interpreting the results of this method

  14. 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.

  15. Long-Term Expansion in Platelet Lysate Increases Growth of Peripheral Blood-Derived Endothelial-Colony Forming Cells and Their Growth Factor-Induced Sprouting Capacity.

    Science.gov (United States)

    Tasev, Dimitar; van Wijhe, Michiel H; Weijers, Ester M; van Hinsbergh, Victor W M; Koolwijk, Pieter

    2015-01-01

    Efficient implementation of peripheral blood-derived endothelial-colony cells (PB-ECFCs) as a therapeutical tool requires isolation and generation of a sufficient number of cells in ex vivo conditions devoid of animal-derived products. At present, little is known how the isolation and expansion procedure in xenogeneic-free conditions affects the therapeutical capacity of PB-ECFCs. The findings presented in this study indicate that human platelet lysate (PL) as a serum substitute yields twice more colonies per mL blood compared to the conventional isolation with fetal bovine serum (FBS). Isolated ECFCs displayed a higher proliferative ability in PL supplemented medium than cells in FBS medium during 30 days expansion. The cells at 18 cumulative population doubling levels (CPDL) retained their proliferative capacity, showed higher sprouting ability in fibrin matrices upon stimulation with FGF-2 and VEGF-A than the cells at 6 CPDL, and displayed low β-galactosidase activity. The increased sprouting of PB-ECFCs at 18 CPDL was accompanied by an intrinsic activation of the uPA/uPAR fibrinolytic system. Induced deficiency of uPA (urokinase-type plasminogen activator) or uPAR (uPA receptor) by siRNA technology completely abolished the angiogenic ability of PB-ECFCs in fibrin matrices. During the serial expansion, the gene induction of the markers associated with inflammatory activation such as VCAM-1 and ICAM-1 did not occur or only to limited extent. While further propagation up to 31 CPDL proceeded at a comparable rate, a marked upregulation of inflammatory markers occurred in all donors accompanied by a further increase of uPA/uPAR gene induction. The observed induction of inflammatory genes at later stages of long-term propagation of PB-ECFCs underpins the necessity to determine the right time-point for harvesting of sufficient number of cells with preserved therapeutical potential. The presented isolation method and subsequent cell expansion in platelet lysate

  16. Long-Term Expansion in Platelet Lysate Increases Growth of Peripheral Blood-Derived Endothelial-Colony Forming Cells and Their Growth Factor-Induced Sprouting Capacity.

    Directory of Open Access Journals (Sweden)

    Dimitar Tasev

    Full Text Available Efficient implementation of peripheral blood-derived endothelial-colony cells (PB-ECFCs as a therapeutical tool requires isolation and generation of a sufficient number of cells in ex vivo conditions devoid of animal-derived products. At present, little is known how the isolation and expansion procedure in xenogeneic-free conditions affects the therapeutical capacity of PB-ECFCs.The findings presented in this study indicate that human platelet lysate (PL as a serum substitute yields twice more colonies per mL blood compared to the conventional isolation with fetal bovine serum (FBS. Isolated ECFCs displayed a higher proliferative ability in PL supplemented medium than cells in FBS medium during 30 days expansion. The cells at 18 cumulative population doubling levels (CPDL retained their proliferative capacity, showed higher sprouting ability in fibrin matrices upon stimulation with FGF-2 and VEGF-A than the cells at 6 CPDL, and displayed low β-galactosidase activity. The increased sprouting of PB-ECFCs at 18 CPDL was accompanied by an intrinsic activation of the uPA/uPAR fibrinolytic system. Induced deficiency of uPA (urokinase-type plasminogen activator or uPAR (uPA receptor by siRNA technology completely abolished the angiogenic ability of PB-ECFCs in fibrin matrices. During the serial expansion, the gene induction of the markers associated with inflammatory activation such as VCAM-1 and ICAM-1 did not occur or only to limited extent. While further propagation up to 31 CPDL proceeded at a comparable rate, a marked upregulation of inflammatory markers occurred in all donors accompanied by a further increase of uPA/uPAR gene induction. The observed induction of inflammatory genes at later stages of long-term propagation of PB-ECFCs underpins the necessity to determine the right time-point for harvesting of sufficient number of cells with preserved therapeutical potential.The presented isolation method and subsequent cell expansion in platelet

  17. Flow cytometric and radioisotopic determinations of platelet survival time in normal cats and feline leukemia virus-infected cats

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, R.M.; Boyce, J.T.; Kociba, G.J.

    1986-01-01

    This study demonstrates the potential usefulness of a flow cytometric technique to measure platelet survival time in cats utilizing autologous platelets labeled in vitro with fluorescein isothiocyanate (FITC). When compared with a 51Cr method, no significant differences in estimated survival times were found. Both the 51Cr and FITC-labeling procedures induced similar changes in platelet shape and collagen-induced aggregation. Platelets labeled with FITC had significantly greater volumes compared with those of glutaraldehyde-fixed platelets. These changes were primarily related to the platelet centrifugation and washing procedures rather than the labels themselves. This novel technique potentially has wide applicability to cell circulation time studies as flow cytometry equipment becomes more readily available. Problems with the technique are discussed. In a preliminary study of the platelet survival time in feline leukemia virus (FeLV)-infected cats, two of three cats had significantly reduced survival times using both flow cytometric and radioisotopic methods. These data suggest increased platelet turnover in FeLV-infected cats.

  18. Flow cytometric and radioisotopic determinations of platelet survival time in normal cats and feline leukemia virus-infected cats

    International Nuclear Information System (INIS)

    Jacobs, R.M.; Boyce, J.T.; Kociba, G.J.

    1986-01-01

    This study demonstrates the potential usefulness of a flow cytometric technique to measure platelet survival time in cats utilizing autologous platelets labeled in vitro with fluorescein isothiocyanate (FITC). When compared with a 51Cr method, no significant differences in estimated survival times were found. Both the 51Cr and FITC-labeling procedures induced similar changes in platelet shape and collagen-induced aggregation. Platelets labeled with FITC had significantly greater volumes compared with those of glutaraldehyde-fixed platelets. These changes were primarily related to the platelet centrifugation and washing procedures rather than the labels themselves. This novel technique potentially has wide applicability to cell circulation time studies as flow cytometry equipment becomes more readily available. Problems with the technique are discussed. In a preliminary study of the platelet survival time in feline leukemia virus (FeLV)-infected cats, two of three cats had significantly reduced survival times using both flow cytometric and radioisotopic methods. These data suggest increased platelet turnover in FeLV-infected cats

  19. Topical application of recombinant platelet-derived growth factor increases the rate of healing and the level of proteins that regulate this response.

    Science.gov (United States)

    Gowda, Santosh; Weinstein, David A; Blalock, Timothy D; Gandhi, Kavita; Mast, Bruce A; Chin, Gloria; Schultz, Gregory S

    2015-10-01

    A bipedicle ischaemic rat skin flap model was used to study the effects of daily topical applications of platelet-derived growth factor (PDGF) on the healing of ischaemic wounds. Levels of tumour necrosis factor-alpha (TNFA), interleukin 1-beta (IL1B) and both the latent and active forms of matrix metalloproteinase 2 (MMP2) and 9 (MMP9) were measured. Full-thickness wounds were made on a total of 72 adult male Sprague-Dawley rats. Each group of 18 rats with normal and ischaemic wounds received either vehicle or 0·01% recombinant PDGF-BB. Additional applications were made on the wounds on a daily basis. Wound areas were measured at 0, 1, 3, 5, 7 9 and 13 days after wounding. Ischaemia caused a delay in wound healing as well as an increase in TNFA, IL1B and both the pro and active forms of MMP2 and MMP9. PDGF accelerated the rate of wound healing in both normal and ischaemic wounds and negated the effect of ischaemia. PDGF reduced the TNFA concentration in both normal and ischaemic wounds, and the rate of wound healing closely resembled the pattern of TNFA protein expression. PDGF also reduced both the magnitude and duration of the increases in IL1B and both the pro and active forms of MMP2 and MMP9 induced by ischaemia. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  20. Superoxide Dismutase 2 is dispensable for platelet function.

    Science.gov (United States)

    Fidler, Trevor P; Rowley, Jesse W; Araujo, Claudia; Boudreau, Luc H; Marti, Alex; Souvenir, Rhonda; Dale, Kali; Boilard, Eric; Weyrich, Andrew S; Abel, E Dale

    2017-10-05

    Increased intracellular reactive oxygen species (ROS) promote platelet activation. The sources of platelet-derived ROS are diverse and whether or not mitochondrial derived ROS, modulates platelet function is incompletely understood. Studies of platelets from patients with sickle cell disease, and diabetes suggest a correlation between mitochondrial ROS and platelet dysfunction. Therefore, we generated mice with a platelet specific knockout of superoxide dismutase 2 (SOD2-KO) to determine if increased mitochondrial ROS increases platelet activation. SOD2-KO platelets demonstrated decreased SOD2 activity and increased mitochondrial ROS, however total platelet ROS was unchanged. Mitochondrial function and content were maintained in non-stimulated platelets. However SOD2-KO platelets demonstrated decreased mitochondrial function following thrombin stimulation. In vitro platelet activation and spreading was normal and in vivo, deletion of SOD2 did not change tail-bleeding or arterial thrombosis indices. In pathophysiological models mediated by platelet-dependent immune mechanisms such as sepsis and autoimmune inflammatory arthritis, SOD2-KO mice were phenotypically identical to wildtype controls. These data demonstrate that increased mitochondrial ROS does not result in platelet dysfunction.

  1. Influence of Oxidative Stress on Stored Platelets

    Directory of Open Access Journals (Sweden)

    K. Manasa

    2016-01-01

    Full Text Available Platelet storage and its availability for transfusion are limited to 5-6 days. Oxidative stress (OS is one of the causes for reduced efficacy and shelf-life of platelets. The studies on platelet storage have focused on improving the storage conditions by altering platelet storage solutions, temperature, and materials. Nevertheless, the role of OS on platelet survival during storage is still unclear. Hence, this study was conducted to investigate the influence of storage on platelets. Platelets were stored for 12 days at 22°C. OS markers such as aggregation, superoxides, reactive oxygen species, glucose, pH, lipid peroxidation, protein oxidation, and antioxidant enzymes were assessed. OS increased during storage as indicated by increments in aggregation, superoxides, pH, conjugate dienes, and superoxide dismutase and decrements in glucose and catalase. Thus, platelets could endure OS till 6 days during storage, due to the antioxidant defense system. An evident increase in OS was observed from day 8 of storage, which can diminish the platelet efficacy. The present study provides an insight into the gradual changes occurring during platelet storage. This lays the foundation towards new possibilities of employing various antioxidants as additives in storage solutions.

  2. Detection of microbial contamination in platelets

    Science.gov (United States)

    Berg, Tracy L.; Leparc, German; Huffman, Debra E.; Gennaccaro, Angela L.; Garcia-Lopez, Alicia; Klungness, Greta; Stephans, Christie; Garcia-Rubio, Luis H.

    2005-03-01

    In the United States, approximately 100 patients develop fatal sepsis associated with platelet transfusions every year. Current culture methods take 24-48 hours to acquire results, which in turn decrease the shelf life of platelets. Many of the microorganisms that contaminate platelets can replicate easily at room temperature, which is the necessary storage temperature to keep platelets functional. Therefore, there is a need for in-situ quality control assessment of the platelet quality. For this purpose, a real time spectrophotometric technique has been developed. The Spectral Acquisition Processing Detection (SAPD) method, comprised of a UV-vis spectrophotometer and modeling algorithms, is a rapid method that can be performed prior to platelet transfusion to decrease the risk of bacterial infection to patients. The SAPD method has been used to determine changes in cell suspensions, based on size, shape, chemical composition and internal structure. Changes in these cell characteristics can in turn be used to determine microbial contamination, platelet aging and other physiologic changes. Detection limits of this method for platelet suspensions seeded with bacterial contaminants were identified to be less than 100 cfu/ml of sample. Bacterial counts below 1000 cfu/ml are not considered clinically significant. The SAPD method can provide real-time identification of bacterial contamination of platelets affording patients an increased level of safety without causing undue strain on laboratory budgets or personnel while increasing the time frame that platelets can be used by dramatically shortening contaminant detection time.

  3. Increase in hippocampal water diffusion and volume during experimental pneumococcal meningitis is aggravated by bacteremia

    DEFF Research Database (Denmark)

    Holler, Jon G; Brandt, Christian T; Leib, Stephen L

    2014-01-01

    BACKGROUND: The hippocampus undergoes apoptosis in experimental pneumococcal meningitis leading to neurofunctional deficits in learning and memory function. The aim of the present study was 1) to investigate hippocampal apparent diffusion coefficient (ADC) and volume with MRI during the course...... and the volume and size of brain ventricles were positively correlated (Spearman Rank, p volume and the extent of apoptosis (p > 0.05). CONCLUSIONS: In experimental meningitis increase in volume and water diffusion of the hippocampus are significantly...... of experimental pneumococcal meningitis, 2) to explore the influence of accompanying bacteremia on hippocampal water distribution and volume, 3) and to correlate these findings to the extent of apoptosis in the hippocampus. METHODS: Experimental meningitis in rats was induced by intracisternal injection of live...

  4. 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.

  5. Leukoreduction of platelet concentrates using a 'polishing' filter

    NARCIS (Netherlands)

    van der Meer, P. F.; Pietersz, R. N.; Reesink, H. W.

    2000-01-01

    BACKGROUND AND OBJECTIVES: Filters for removal of leukocytes from platelet concentrates (PCs) usually have a large volume to guarantee sufficient leukoreduction. In this study, a small filter, with a volume of only 8 ml and therefore minimal platelet loss, for leukoreduction of PCs was investigated.

  6. Flow cytometric analysis of platelet cyclooxygenase-1 and -2 and surface glycoproteins in patients with immune thrombocytopenia and healthy individuals.

    Science.gov (United States)

    Rubak, Peter; Kristensen, Steen D; Hvas, Anne-Mette

    2017-06-01

    Immature platelets may contain more platelet enzymes such as cyclooxygenase (COX)-1 and COX-2 than mature platelets. Patients with immune thrombocytopenia (ITP) have a higher fraction of immature platelets and can therefore be utilized as a biological model for investigating COX-1 and COX-2 platelet expression. The aims were to develop flow cytometric assays for platelet COX-1 and COX-2 and to investigate the COX-1 and COX-2 platelet expression, platelet turnover, and platelet glycoproteins in ITP patients (n = 10) compared with healthy individuals (n = 30). Platelet count and platelet turnover parameters (mean platelet volume (MPV), immature platelet fraction (IPF), and immature platelet count (IPC)) were measured by flow cytometry (Sysmex XE-5000). Platelet COX-1, COX-2, and the glycoproteins (GP)IIb, IX, Ib, Ia, and IIIa were all analyzed by flow cytometry (Navios) and expressed as median fluorescence intensity. COX analyses were performed in both whole blood and platelet rich plasma (PRP), whereas platelet glycoproteins were analyzed in whole blood only. ITP patients had significantly lower platelet count (55 × 10 9 /L) than healthy individuals (240 × 10 9 /L, p platelet count and IPC (both p-values Platelet COX-1 expression was higher in ITP patients than healthy individuals using whole blood (p COX-1 platelet turnover and COX-1 expression (all p-values platelet turnover and COX-1 and COX-2 expressions (all p-values platelet turnover in ITP patients (all p-values 0.14, rho = 0.11-0.28). In conclusion, ITP patients expressed higher COX-1 and platelet glycoprotein levels than healthy individuals. COX-1 and platelet glycoproteins demonstrated positive correlations with platelet turnover in ITP patients. In healthy individuals, COX-1 and COX-2 expression correlated positively with platelet turnover. PRP was more sensitive compared with whole blood as regards determination of COX. Therefore, PRP is the recommended matrix for investigating COX-1 and COX-2 in

  7. Does bipolar pacemaker current activate blood platelets?

    DEFF Research Database (Denmark)

    Gjesdal, Grunde; Hansen, Annebirthe Bo; Brandes, Axel

    2009-01-01

    OBJECTIVE: The aim of this study was to investigate whether bipolar pacemaker current lead can activate blood platelets. The null hypothesis was that 1 minute of electrical stimulation of platelets would not influence their subsequent reactivity to adenosine diphosphate (ADP). BACKGROUND: Both...... platelets and muscle cells contain actin and myosin filaments, and both cells are activated following calcium influx. Muscle cells open their calcium channels and contract when exposed to an electric current. Current through a bipolar pacemaker lead will expose a small volume of blood, including platelets......, to the depolarizing current. Platelet activation may ensue, resulting in aggregation, release reaction, and contraction. In contrast, a unipolar pacemaker system will not depolarize blood, but transmit current directly into the myocardium, and the current afterward passes through other tissues before returning...

  8. Increasing volume and complexity of pediatric epilepsy surgery with stable seizure outcome between 2008 and 2014

    DEFF Research Database (Denmark)

    Barba, Carmen; Specchio, Nicola; Guerrini, Renzo

    2017-01-01

    Objective The objective of the study was to assess common practice in pediatric epilepsy surgery in Italy between 2008 and 2014. Methods A survey was conducted among nine Italian epilepsy surgery centers to collect information on presurgical and postsurgical evaluation protocols, volumes and type...... and facilities. Significance This survey reveals an increase in volume and complexity of pediatric epilepsy surgery in Italy between 2008 and 2014, associated with a stable seizure outcome....

  9. Iron deficiency alters megakaryopoiesis and platelet phenotype independent of thrombopoietin.

    Science.gov (United States)

    Evstatiev, Rayko; Bukaty, Adam; Jimenez, Kristine; Kulnigg-Dabsch, Stefanie; Surman, Lidia; Schmid, Werner; Eferl, Robert; Lippert, Kathrin; Scheiber-Mojdehkar, Barbara; Kvasnicka, Hans Michael; Khare, Vineeta; Gasche, Christoph

    2014-05-01

    Iron deficiency is a common cause of reactive thrombocytosis, however, the exact pathways have not been revealed. Here we aimed to study the mechanisms behind iron deficiency-induced thrombocytosis. Within few weeks, iron-depleted diet caused iron deficiency in young Sprague-Dawley rats, as reflected by a drop in hemoglobin, mean corpuscular volume, hepatic iron content and hepcidin mRNA in the liver. Thrombocytosis established in parallel. Moreover, platelets produced in iron deficient animals displayed a higher mean platelet volume and increased aggregation. Bone marrow studies revealed subtle alterations that are suggestive of expansion of megakaryocyte progenitors, an increase in megakaryocyte ploidy and accelerated megakaryocyte differentiation. Iron deficiency did not alter the production of hematopoietic growth factors such as thrombopoietin, interleukin 6 or interleukin 11. Megakaryocytic cell lines grown in iron-depleted conditions exhibited reduced proliferation but increased ploidy and cell size. Our data suggest that iron deficiency increases megakaryopoietic differentiation and alters platelet phenotype without changes in megakaryocyte growth factors, specifically TPO. Iron deficiency-induced thrombocytosis may have evolved to maintain or increase the coagulation capacity in conditions with chronic bleeding. Copyright © 2014 Wiley Periodicals, Inc.

  10. Freezing of Apheresis Platelet Concentrates in 6% Dimethyl Sulfoxide: The First Preliminary Study in Turkey

    Directory of Open Access Journals (Sweden)

    Soner Yılmaz

    2016-03-01

    Full Text Available Objective: Transfusion of platelet suspensions is an essential part of patient care for certain clinical indications. In this pioneering study in Turkey, we aimed to assess the in vitro hemostatic functions of platelets after cryopreservation. Materials and Methods: Seven units of platelet concentrates were obtained by apheresis. Each apheresis platelet concentrate (APC was divided into 2 equal volumes and frozen with 6% dimethyl sulfoxide (DMSO. The 14 frozen units of APCs were kept at -80 °C for 1 day. APCs were thawed at 37 °C and diluted either with autologous plasma or 0.9% NaCl. The volume and residual numbers of leukocytes and platelets were tested in both before-freezing and post-thawing periods. Aggregation and thrombin generation tests were used to analyze the in vitro hemostatic functions of platelets. Flow-cytometric analysis was used to assess the presence of frozen treated platelets and their viability. Results: The residual number of leukocytes in both dilution groups was <1x106. The mean platelet recovery rate in the plasma-diluted group (88.1±9.5% was higher than that in the 0.9% NaCl-diluted group (63±10%. These results were compatible with the European Directorate for the Quality of Medicines quality criteria. Expectedly, there was no aggregation response to platelet aggregation test. The mean thrombin generation potential of postthaw APCs was higher in the plasma-diluted group (2411 nmol/L per minute when compared to both the 0.9% NaCl-diluted group (1913 nmol/L per minute and the before-freezing period (1681 nmol/L per minute. The flowcytometric analysis results for the viability of APCs after cryopreservation were 94.9% and 96.6% in the plasma and 0.9% NaCl groups, respectively. Conclusion: Cryopreservation of platelets with 6% DMSO and storage at -80 °C increases their shelf life from 7 days to 2 years. Besides the increase in hemostatic functions of platelets, the cryopreservation process also does not affect their

  11. Heparin-associated thrombocytopenia: antibody binding specificity to platelet antigens.

    Science.gov (United States)

    Lynch, D M; Howe, S E

    1985-11-01

    Sera from four patients with heparin-associated thrombocytopenia (HAT) were evaluated by a quantitative enzyme-linked immunosorbent assay (ELISA) to detect heparin-dependent serum platelet-bindable immunoglobulin (S-PBIg) and by Western blotting and immunoprecipitation to investigate the specificity of the antibody binding. All HAT sera showed mildly increased S-PBIg (mean, 7.8 fg per platelet; normal, less than 6.0 fg per platelet) to intact target platelets in the ELISA, which was markedly increased in the presence of heparin (mean, 20.9 fg per platelet). This increase was 20-fold greater than normal control sera, which showed a mean differential increase of only 0.5 fg per platelet. Immunoglobulin binding specificity to platelet antigens was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of platelet lysate with transfer of the platelet fractions onto nitrocellulose strips (Western blotting) and subsequent immunoassay using HAT and normal sera. In the presence of heparin, the four HAT patients demonstrated increased binding of immunoglobulin to platelet antigens of apparent molecular weights of 180, 124, and 82 kd. Radiolabeled heparin when incubated with HAT sera, normal sera, or albumin blanks bound to platelet proteins of the same apparent molecular weights. These observations are consistent with current hypotheses suggesting that HAT antibody is directed to heparin-platelet complexes or, alternatively, that heparin induces conformational change of antigenic sites on the platelet membrane.

  12. Evaluating the effects of increasing surgical volume on emergency department patient access.

    Science.gov (United States)

    Levin, S; Dittus, R; Aronsky, D; Weinger, M; France, D

    2011-02-01

    To determine how increases in surgical patient volume will affect emergency department (ED) access to inpatient cardiac services. To compare how strategies to increase cardiology inpatient throughput can either accommodate increases in surgical volume or improve ED patient access. A stochastic discrete event simulation was created to model patient flow through a cardiology inpatient system within a US, urban, academic hospital. The simulation used survival analysis to examine the relationship between anticipated increases in surgical volume and ED patient boarding time (ie, time interval from cardiology admission request to inpatient bed placement). ED patients boarded for a telemetry and cardiovascular intensive care unit (CVICU) bed had a mean boarding time of 5.3 (median 3.1, interquartile range 1.5-6.9) h and 2.7 (median 1.7, interquartile range 0.8-3.0) h, respectively. Each 10% incremental increase in surgical volume resulted in a 37 and 33 min increase in mean boarding time to the telemetry unit and CVICU, respectively. Strategies to increase cardiology inpatient throughput by increasing capacity and decreasing length of stay for specific inpatients was compared. Increasing cardiology capacity by one telemetry and CVICU bed or decreasing length of stay by 1 h resulted in a 7-9 min decrease in average boarding time or an 11-19% increase in surgical patient volume accommodation. Simulating competition dynamics for hospital admissions provides prospective planning (ie, decision making) information and demonstrates how interventions to increase inpatient throughput will have a much greater effect on higher priority surgical admissions compared with ED admissions.

  13. Absolute hypoxic exercise training enhances in vitro thrombin generation by increasing procoagulant platelet-derived microparticles under high shear stress in sedentary men.

    Science.gov (United States)

    Chen, Yu-Wen; Chen, Yi-Ching; Wang, Jong-Shyan

    2013-05-01

    HS (high shear) stress associated with artery stenosis facilitates TG (thrombin generation) by increasing the release of procoagulant PDMPs (platelet-derived microparticles). Physical exercise and hypoxia may paradoxically modulate vascular thrombotic risks. The aim of the present study was to investigate how exercise training with/without hypoxia affected TG mediated by PDMPs under physio-pathological shear flows. A total of 75 sedentary males were randomly divided into five groups (n=15 in each group): 21% O2 [NC (normoxic control)] or 15% O2 [HC (hypoxic control)] at rest or were trained at 50% of peak work rate under 21% O2 [NT (normoxic training)] or 15% O2 [HAT (hypoxic-absolute training)], or 50% of HR (heart rate) reserve under 15% O2 [HRT (hypoxic-relative training)] for 30 min/day, 5 days/week for 4 weeks. The PDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. Before the intervention, strenuous exercise markedly increased the PDMP count (14.8%) and TG rate (19.5%) in PDMP-rich plasma at 100 dynes/cm2 of shear stress (Pexercise. Conversely, HAT notably promoted the PDMP count (37.3%) and TG rate (38.9%) induced by HS (Pexercise. We conclude that both HRT and NT depress similarly HS-mediated TG during exercise, but HAT accelerates the prothrombotic response to vigorous exercise. These findings provide new insights into how exercise training under a hypoxic condition influences the risk of thrombosis associated with stenotic arteries.

  14. Polyphosphate nanoparticles on the platelet surface trigger contact system activation

    NARCIS (Netherlands)

    Verhoef, Johan J F; Barendrecht, Arjan D; Nickel, Katrin F; Dijkxhoorn, Kim; Kenne, Ellinor; Labberton, Linda; McCarty, Owen J T; Schiffelers, Raymond; Heijnen, Harry F G; Hendrickx, Antoni P A; Schellekens, Huub; Fens, Marcel H; de Maat, Steven; Renné, Thomas; Maas, Coen

    2017-01-01

    Polyphosphate is an inorganic polymer that can potentiate several interactions in the blood coagulation system. Blood platelets contain polyphosphate, and the secretion of platelet-derived polyphosphate has been associated with increased thrombus formation and activation of coagulation factor XII.

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

    Directory of Open Access Journals (Sweden)

    Sirada Srihirun

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

  16. Constitutive modeling of the rheological behavior of platelet suspensions

    Science.gov (United States)

    Sommer, Drew E.

    Compression molding of chopped fiber composites is used to manufacture complex 3D geometries with high fiber volume fractions of 50-60% and long, discontinuous fibers and thermoplastic matrices. When prepreg, chopped into platelets, is used as a charge material, the individual platelets remain intact during the molding process and flow relative to one another, as experimental observations show. Heterogeneity of the platelet/resin suspension cannot be considered at the structural scale of molding simulation. Instead, the suspension should be idealized into the homogenized anisotropic and viscous system which obeys the prescribed anisotropic stress-strain rate constitutive relation. The viscosity tensor of the aforementioned constitutive law was analytically evaluated in this work through the representative volume element (RVE) based analysis. An idealized microstructure of platelets was developed to perform such an analysis. The platelets were aligned and arranged in a planar configuration with periodic boundary conditions. Analytic expressions for the effective, anisotropic viscosities were derived by micromechanical analysis for the idealized microstructure of rigid platelets. In this analysis, the load transfer mechanisms and their contribution to the viscosity of the platelet assembly were investigated. The kinematic assumption of linear velocity distributions consistent with the mechanism of shearing rate was adopted. While the platelets were assumed to be rigid, the resin was taken as an incompressible, isotropic fluid which provided for the platelet-to-platelet load transfer. Strain rate and temperature dependence were included by modeling the polymer matrix as a Carreau fluid. Shear strain in the resin was developed due to the relative motion of adjacent platelets. The resin shear strain rate was expressed in terms of the corresponding platelet velocities. Equilibrium of the platelet was used to relate the applied far-field stress to the average strain rate

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

    Czech Academy of Sciences Publication Activity Database

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

    2003-01-01

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

  18. CYP2C19*17 increases clopidogrel-mediated platelet inhibition but does not alter the pharmacokinetics of the active metabolite of clopidogrel

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Steen; Nielsen, Flemming; Stage, Tore Bjerregaard

    2014-01-01

    *1/*1, 11 CYP2C19*1/*17 and nine CYP2C19*17/*17). In Phase A, the pharmacokinetics of the derivatized active metabolite of clopidogrel (CAMD) and platelet function were determined after administration of a single oral dose of 600 mg clopidogrel (Plavix; Sanofi-Avensis, Horsholm, Denmark). In Phase B...

  19. Effect of operator and institutional volume on clinical outcomes after percutaneous coronary interventions performed in Canada and the United States: a brief report from the Enhanced Suppression of the Platelet glycoprotein IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) study.

    Science.gov (United States)

    Madan, Mina; Nikhil, Janarthan; Hellkamp, Anne S; Pieper, Karen S; Labinaz, Marino; Cohen, E A; Buller, Christopher E; Cantor, Warren J; Seidelin, Peter; Ducas, John; Carere, Ronald G; Natarajan, Madhu K; O'Shea, J Conor; Tcheng, James E

    2009-08-01

    The Enhanced Suppression of the Platelet glycoprotein IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial compared the use of eptifibatide with placebo in 2064 coronary intervention patients. It was previously reported that Canadian patients had reduced rates of 30-day and one-year death, myocardial infarction (MI) or target vessel revascularization (TVR) compared with patients in the United States (US). To examine whether operator or institutional volume differences explain the regional variation in clinical outcome. Each site received an operator and institutional volume survey. Fifty-seven sites (62%) returned complete data on 1338 patients. In this smaller cohort, Canadian patients had reduced rates of 30-day and one-year death, MI or TVR compared with US patients (6.3% versus 10.3% and 14.9% versus 20.1%, respectively; PESPRIT study, institutional volume was associated with a modest reduction in risk of death, MI or TVR over short- and long-term follow-up periods. The Canadian and US investigators and institutions selected in ESPRIT had similar annual procedural volumes. Therefore, volume variables did not explain the differential risk of clinical events observed for patients enrolled in the two countries.

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

    Science.gov (United States)

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

    2014-08-01

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

  1. 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

  2. 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...

  3. Extended shelf life of random donor platelets stored for 7 days in platelet additive solution at different temperatures

    Directory of Open Access Journals (Sweden)

    Tulika Chandra

    2014-08-01

    Full Text Available Background: Platelets are routinely stored in plasma for 5 days at an average temperature of 22°C. In the present study, the shelf life of random donor platelets was extended by storing for 7 days with and without additive solution at temperatures of 22°C, 18°C, and 16°C. Methods: Random donor platelets were stored in 100% plasma and 20%/80% platelet additive solution. The data were compared using paired "t"- test. The confidence limit was kept at 95%, hence a "p" < 0.05 was considered to be statistically significant. Results: Out of total 150 samples, 148 samples were analyzed and 2 were discarded due to the bacterial contamination on day 7 at 22°C without platelet additive solution. A significant difference in platelet count, platelet factor 3 (PF 3, glucose, lactate dehydrogenase (LDH, and platelet aggregation was observed on day 7 (p < 0.001 at 16°C in without platelet additive solution. In platelet additive solution, the mean values of platelet count, platelet distribution width (PDW, LDH, and pH showed no significant difference on day 7 at 22°C, 18°C, and 16°C. Only significant differences were observed in the levels of mean platelet volume (MPV, PF 3, glucose, and platelet aggregation on day 7 (p < 0.001 at 16°C of the storage period. Conclusion: Random donor platelets functions are better maintained in platelet additive solution as compared to plasma at a lower temperature of 18°C but not at 16°C, on the 7 th day.

  4. Trastuzumab Induces an Immediate, Transient Volume Increase in Humans: A Randomised Placebo-Controlled Trial

    Directory of Open Access Journals (Sweden)

    Joannes A.A. Reijers

    2015-08-01

    Interpretation: Single dose administration of trastuzumab in humans is associated with an immediate, transient extracellular volume increase, either as a primary or secondary (compensatory response, which can be detected easily using routine clinical assessments. Echocardiographic changes, both short and long term, could not be found after single dose administration to drug-naive patients.

  5. Hypersensitivity to thrombin of platelets from hypercholesterolemic rats

    International Nuclear Information System (INIS)

    Winocour, P.D.; Rand, M.L.; Kinlough-Rathbone, R.L.; Mustard, J.F.

    1986-01-01

    Hypersensitivity of platelets to thrombin has been associated with hypercholesterolemia. The authors have examined the mechanisms involved in this hypersensitivity. Rats were given diets rich in milk fat and containing added cholesterol and taurocholate to produce hypercholesterolemia (HC) (262 +/- 25 mg%) or added sitosterol as a normocholesterolemic control (NC) (89 +/- 6 mg%). Washed platelets were prelabelled with 14 C-serotonin. In the presence of acetylsalicyclic acid (ASA) (to inhibit thromboxane A 2 (TXA 2 ) formation) and creatine phosphate/creatine phosphokinase (CP/CPK) (to remove released ADP), HC platelets aggregated more (26 +/- 1%) and released more 14 C (9.1 +/- 2.0%) than NC platelets (aggregation: 0%, p 14 C release: 1.5 +/- 0.5%, p 2 formation is involved in the hypersensitivity of HC platelets to thrombin. Total binding of 125 I-thrombin to HC platelets was less than that to NC platelets but HC platelets were smaller and had less protein than NC platelets; the thrombin binding per mg platelet protein was the same for HC and NC platelets, indicating that hypersensitivity to thrombin of HC platelets does not result from increased thrombin binding. Thus, hypersensitivity of HC platelets to thrombin is not due to TXA 2 formation, the action of released ADP or increased thrombin binding

  6. Wiskott-Aldrich Syndrome With Normal-Sized Platelets in an Eighteen-Month-Old Boy: A Rare Mutation

    Directory of Open Access Journals (Sweden)

    Jayitri Mazumdar

    2015-07-01

    Full Text Available Introduction: Wiskott-Aldrich syndrome (WAS is an X-linked recessive disorder characterized by thrombocytopenia, eczema, and recurrent infections. The disease is usually associated with small defective platelets. Case Presentation: We described an 18-month-old boy who presented with lower gastrointestinal bleeding, eczema, and recurrent infections. There was pancytopenia with normal-sized platelets. In addition, the CD4 count was significantly low and serum IgA and IgE levels were increased. The diagnosis of WAS was confirmed by detecting a mutation of WAS gene, which was due to a deletion mutation resulting in frameshift (c.177DelT. Conclusions: Usually microplatelets with mean platelet volume of 4-5 fL are seen in WAS, but in this case, the patient had normal-sized platelets with a rare mutation of WAS gene. Therefore, high index of clinical suspicion is needed to diagnose WAS.

  7. In vitro effect of sodium nitrite on platelet aggregation in human platelet rich plasma--preliminary report.

    Science.gov (United States)

    Kadan, M; Doğanci, S; Yildirim, V; Özgür, G; Erol, G; Karabacak, K; Avcu, F

    2015-10-01

    The role of nitrates and nitric oxide on platelet functions has obtained an increasing attention with respect to their potential effects on cardiovascular disorders. In this study we aimed to analyze the effect of sodium nitrite on platelet functions in human platelets. This in vitro study was designed to show the effect of sodium nitrite on platelet functions in seven healthy volunteers. Blood samples were centrifuged to prepare platelet rich plasma and platelet poor plasma. Platelet rich plasma was diluted with the platelet poor plasma to have a final count of 300,000 ± 25,000 platelets. Platelet rich plasma was incubated with six different increasing doses (from 10 μM to 5 mM) of sodium nitrite for 1 hour at 37°C. Then stimulating agents including collagen (3 μg ml-1), adenosine diphosphate (10 μM), and epinephrine (10 μM) were added to the cuvette. Changes in light transmission were observed for 10 minutes. In addition spontaneous aggregation were performed in control group with all aggregating agents separately. Effect of sodium nitrite on agonist-induced platelet aggregation depends on the concentration of sodium nitrite. Compared with control group, agonist-induced platelet aggregations were significantly suppressed by sodium nitrite at the concentration of 5, 1.0 and 0.5 mM. Our results suggested that sodium nitrite has inhibitory effects in vitro on platelet aggregation in a dose-dependent manner.

  8. Hypothermia and Platelet Dysfunction

    National Research Council Canada - National Science Library

    Michelson, Alan

    1993-01-01

    ... (the OPlib-Illa complex).3 Circulating platelets are normally in a resting state and, despite the presence of platelet surface GPTh-IX and OPlib-Illa complexes, they bind neither plasma von Willebrand factor nor plasma fibrinogen...

  9. Hypothermia and Platelet Dysfunction

    National Research Council Canada - National Science Library

    Michelson, A

    1994-01-01

    ... (the GPIIb-IIIa complex). Circulating platelets are normally in a resting state and, despite the presence of platelet surface GPIb-IX and GPIIb-IIIa complexes, they bind neither plasma von Willebrand factor nor plasma fibrinogen...

  10. Reduced interference in working memory following mindfulness training is associated with increases in hippocampal volume.

    Science.gov (United States)

    Greenberg, Jonathan; Romero, Victoria L; Elkin-Frankston, Seth; Bezdek, Matthew A; Schumacher, Eric H; Lazar, Sara W

    2018-03-17

    Proactive interference occurs when previously relevant information interferes with retaining newer material. Overcoming proactive interference has been linked to the hippocampus and deemed critical for cognitive functioning. However, little is known about whether and how this ability can be improved or about the neural correlates of such improvement. Mindfulness training emphasizes focusing on the present moment and minimizing distraction from competing thoughts and memories. It improves working memory and increases hippocampal density. The current study examined whether mindfulness training reduces proactive interference in working memory and whether such improvements are associated with changes in hippocampal volume. 79 participants were randomized to a 4-week web-based mindfulness training program or a similarly structured creative writing active control program. The mindfulness group exhibited lower proactive interference error rates compared to the active control group following training. No group differences were found in hippocampal volume, yet proactive interference improvements following mindfulness training were significantly associated with volume increases in the left hippocampus. These results provide the first evidence to suggest that (1) mindfulness training can protect against proactive interference, and (2) that these benefits are related to hippocampal volumetric increases. Clinical implications regarding the application of mindfulness training in conditions characterized by impairments to working memory and reduced hippocampal volume such as aging, depression, PTSD, and childhood adversity are discussed.

  11. Impulsive-antisocial psychopathic traits linked to increased volume and functional connectivity within prefrontal cortex.

    Science.gov (United States)

    Korponay, Cole; Pujara, Maia; Deming, Philip; Philippi, Carissa; Decety, Jean; Kosson, David S; Kiehl, Kent A; Koenigs, Michael

    2017-07-01

    Psychopathy is a personality disorder characterized by callous lack of empathy, impulsive antisocial behavior, and criminal recidivism. Studies of brain structure and function in psychopathy have frequently identified abnormalities in the prefrontal cortex. However, findings have not yet converged to yield a clear relationship between specific subregions of prefrontal cortex and particular psychopathic traits. We performed a multimodal neuroimaging study of prefrontal cortex volume and functional connectivity in psychopathy, using a sample of adult male prison inmates (N = 124). We conducted volumetric analyses in prefrontal subregions, and subsequently assessed resting-state functional connectivity in areas where volume was related to psychopathy severity. We found that overall psychopathy severity and Factor 2 scores (which index the impulsive/antisocial traits of psychopathy) were associated with larger prefrontal subregion volumes, particularly in the medial orbitofrontal cortex and dorsolateral prefrontal cortex. Furthermore, Factor 2 scores were also positively correlated with functional connectivity between several areas of the prefrontal cortex. The results were not attributable to age, race, IQ, substance use history, or brain volume. Collectively, these findings provide evidence for co-localized increases in prefrontal cortex volume and intra-prefrontal functional connectivity in relation to impulsive/antisocial psychopathic traits. © The Author (2017). Published by Oxford University Press.

  12. 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

  13. Platelet function and HIV: a case-control study.

    LENUS (Irish Health Repository)

    Satchell, Claudette S

    2010-03-13

    Cardiovascular disease and myocardial infarction are of increasing concern in HIV-infected populations. Although platelets mediate arterial thrombosis, central to myocardial infarction, data on platelet function in HIV infection are lacking. We hypothesized that HIV-infected patients would have altered platelet reactivity.

  14. The Role of Platelets in Liver Inflammation and Regeneration

    NARCIS (Netherlands)

    Lisman, Ton; Porte, Robert J.

    Platelets play a pivotal role in thrombosis and hemostasis, but an increasing variety of extra-hemostatic functions of platelets are being recognized. This review summarizes recent advances in the understanding of the role of platelets in various pathologies involving the liver. In

  15. Factors Affecting Canagliflozin-Induced Transient Urine Volume Increase in Patients with Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Tanaka, Hiroyuki; Takano, Kazuhiko; Iijima, Hiroaki; Kubo, Hajime; Maruyama, Nobuko; Hashimoto, Toshio; Arakawa, Kenji; Togo, Masanori; Inagaki, Nobuya; Kaku, Kohei

    2017-02-01

    Sodium glucose co-transporter 2 (SGLT2) inhibitors exhibit diuretic activity, which is a possible mechanism underlying the cardiovascular benefit of these inhibitors. However, the osmotic diuresis-induced increase in urine volume, and the risk of dehydration have been of concern with SGLT2 inhibitor treatment. This study aimed to investigate the mechanism underlying SGLT2 inhibitor canagliflozin-induced diuresis in Japanese type 2 diabetes mellitus (T2DM) patients. Thirteen T2DM patients received a daily oral dose of 100 mg canagliflozin before breakfast for 6 days. Blood and urine samples were collected at predetermined time points. The primary endpoint was evaluation of correlations between changes from baseline in urine volume and factors that are known to affect urine volume and between actual urine volume and these factors. Canagliflozin transiently increased urine volume and urinary sodium excretion on Day 1 with a return to baseline levels thereafter. Canagliflozin administration increased urinary glucose excretion, which was sustained during repeated-dose administration. Plasma atrial natriuretic peptide (ANP) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels decreased, while plasma renin activity increased. On Day 1 of treatment, changes in sodium and potassium excretion were closely correlated with changes in urine output. A post hoc multiple regression analysis showed changes in sodium excretion and water intake as factors that affected urine volume change at Day 1. Furthermore, relative to that at baseline, canagliflozin decreased blood glucose throughout the day and increased plasma total GLP-1 after breakfast. Canagliflozin induced transient sodium excretion and did not induce water intake at Day 1; hence, natriuresis rather than glucose-induced osmotic diuresis may be a major factor involved in the canagliflozin-induced transient increase in urine output. In addition, canagliflozin decreased plasma ANP and NT-proBNP levels and

  16. Cerebral blood volume changes in cats with acute increased intracranial pressure

    International Nuclear Information System (INIS)

    Kondo, Takashi; Kano, Mitsumasa; Ikeda, Takuya.

    1984-01-01

    We measured the changes in cerebral blood volume in cats with increased intracranial pressure with a high-speed CT scanner, employing contrast effects by the iodine agent. In acute increased intracranial pressure caused by raising the extradural pressure by 20 mmHg, cerebral blood volume showed a significant decrease by 32% in comparison with that at normal intracranial pressure. There was also a tendency that a decline of iodine was delayed with time at increased intracranial pressure than that at normal pressure. This was supposed to be a delay of cerebral circulation due to venous congestion. This experimental model and measuring method provide the changes in CBV in the same individual without any tedious procedure, and therefore this is a reliable method with respect to precision. (author)

  17. Increasing the Air Charge and Scavenging the Clearance Volume of a Compression-Ignition Engine

    Science.gov (United States)

    Spanogle, J A; Hicks, C W; Foster, H H

    1934-01-01

    The object of the investigation presented in this report was to determine the effects of increasing the air charge and scavenging the clearance volume of a 4-stroke-cycle compression-ignition engine having a vertical-disk form combustion chamber. Boosting the inlet-air pressure with normal valve timing increased the indicated engine power in proportion to the additional air inducted and resulted in smoother engine operation with less combustion shock. Scavenging the clearance volume by using a valve overlap of 145 degrees and an inlet-air boost pressure of approximately 2 1/2 inches of mercury produced a net increase in performance for clear exhaust operation of 33 percent over that obtained with normal valve timing and the same boost pressure. The improved combustion characteristics result in lower specific fuel consumption, and a clearer exhaust.

  18. Responsiveness of platelets during storage studied with flow cytometry--formation of platelet subpopulations and LAMP-1 as new markers for the platelet storage lesion.

    Science.gov (United States)

    Södergren, A L; Tynngård, N; Berlin, G; Ramström, S

    2016-02-01

    Storage lesions may prevent transfused platelets to respond to agonists and arrest bleeding. The aim of this study was to evaluate and quantify the capacity of platelet activation during storage using flow cytometry and new markers of platelet activation. Activation responses of platelets prepared by apheresis were measured on days 1, 5, 7 and 12. In addition, comparisons were made for platelet concentrates stored until swirling was affected. Lysosome-associated membrane protein-1 (LAMP-1), P-selectin and phosphatidylserine (PS) exposure were assessed by flow cytometry on platelets in different subpopulations in resting state or following stimulation with platelet agonists (cross-linked collagen-related peptide (CRP-XL), PAR1- and PAR4-activating peptides). The ability to form subpopulations upon activation was significantly decreased already at day 5 for some agonist combinations. The agonist-induced exposure of PS and LAMP-1 also gradually decreased with time. Spontaneous exposure of P-selectin and PS increased with time, while spontaneous LAMP-1 exposure was unchanged. In addition, agonist-induced LAMP-1 expression clearly discriminated platelet concentrates with reduced swirling from those with retained swirling. This suggests that LAMP-1 could be a good marker to capture changes in activation capacity in stored platelets. The platelet activation potential seen as LAMP-1 exposure and fragmentation into platelet subpopulations is potential sensitive markers for the platelet storage lesion. © 2015 International Society of Blood Transfusion.

  19. Radiation-induced volatile hydrocarbon production in platelets

    International Nuclear Information System (INIS)

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets

  20. Toward Increasing Micropore Volume between Hybrid Layered Perovskites with Silsesquioxane Interlayers.

    Science.gov (United States)

    Kataoka, Sho; Kamimura, Yoshihiro; Endo, Akira

    2018-04-10

    Hybrid organic-inorganic layered perovskites are typically nonporous solids. However, the incorporation of silsesquioxanes with a cubic cage structure as interlayer materials creates micropores between the perovskite layers. In this study, we increase in the micropore volume in layered perovskites by replacing a portion of the silsesquioxane interlayers with organic amines. In the proposed method, approximately 20% of the silsesquioxane interlayers can be replaced without changing the layer distance owing to the size of the silsesquioxane. When small amines (e.g., ethylamine) are used in this manner, the micropore volume of the obtained hybrid layered perovskites increases by as much as 44%; when large amines (e.g., phenethylamine) are used, their micropore volume decreases by as much as 43%. Through the variation of amine fraction, the micropore volume can be adjusted in the range. Finally, the magnetic moment measurements reveal that the layered perovskites with mixed interlayers exhibit ferromagnetic ordering at temperature below 20 K, thus indicating that the obtained perovskites maintain their functions as layered perovskites.

  1. 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.

  2. Rapid Evaluation of Platelet Function With T2 Magnetic Resonance

    Science.gov (United States)

    Cuker, Adam; Husseinzadeh, Holleh; Lebedeva, Tatiana; Marturano, Joseph E.; Massefski, Walter; Lowery, Thomas J.; Lambert, Michele P.; Abrams, Charles S.; Weisel, John W.

    2016-01-01

    Objectives: The clinical diagnosis of qualitative platelet disorders (QPDs) based on light transmission aggregometry (LTA) requires significant blood volume, time, and expertise, all of which can be barriers to utilization in some populations and settings. Our objective was to develop a more rapid assay of platelet function by measuring platelet-mediated clot contraction in small volumes (35 µL) of whole blood using T2 magnetic resonance (T2MR). Methods: We established normal ranges for platelet-mediated clot contraction using T2MR, used these ranges to study patients with known platelet dysfunction, and then evaluated agreement between T2MR and LTA with arachidonic acid, adenosine diphosphate, epinephrine, and thrombin receptor activator peptide. Results: Blood from 21 healthy donors was studied. T2MR showed 100% agreement with LTA with each of the four agonists and their cognate inhibitors tested. T2MR successfully detected abnormalities in each of seven patients with known QPDs, with the exception of one patient with a novel mutation leading to Hermansky-Pudlak syndrome. T2MR appeared to detect platelet function at similar or lower platelet counts than LTA. Conclusions: T2MR may provide a clinically useful approach to diagnose QPDs using small volumes of whole blood, while also providing new insight into platelet biology not evident using plasma-based platelet aggregation tests. PMID:28028118

  3. Platelet count and platelet indices in women with preeclampsia.

    Science.gov (United States)

    AlSheeha, Muneera A; Alaboudi, Rafi S; Alghasham, Mohammad A; Iqbal, Javed; Adam, Ishag

    2016-01-01

    Although the exact pathophysiology of preeclampsia is not completely understood, the utility of different platelets indices can be utilized to predict preeclampsia. To compare platelet indices, namely platelet count (PC), mean platelet volume (MPV), platelet distribution width (PDW), and PC to MPV ratio in women with preeclampsia compared with healthy controls. Qassim Hospital, Kingdom of Saudi Arabia. A case-control study. Sixty preeclamptic women were the cases and an equal number of healthy pregnant women were the controls. There was no significant difference in age, parity, and body mass index between the study groups. Sixteen and 44 of the cases were severe and mild preeclampsia, respectively. There was no significant difference in PDW and MPV between the preeclamptic and control women. Both PC and PC to MPV ratios were significantly lower in the women with preeclampsia compared with the controls. There was no significant difference in the PC, PDW, MPV, and PC to MPV ratio when women with mild and severe preeclampsia were compared. Using receiver operating characteristic (ROC) curves, the PC cutoff was 248.0×10 3 /µL for diagnosis of pre-eclampsia ( P =0.019; the area under the ROC curve was 62.4%). Binary regression suggests that women with PC preeclampsia (odds ratio =2.2, 95% confidence interval =1.08-4.6, P =0.03). The PC/MPV cutoff was 31.2 for diagnosis of preeclampsia ( P =0.035, the area under the ROC curve was 62.2%). PC preeclampsia.

  4. Novel agents for anti-platelet therapy

    Directory of Open Access Journals (Sweden)

    Ji Xuebin

    2011-11-01

    Full Text Available Abstract Anti-platelet therapy plays an important role in the treatment of patients with thrombotic diseases. The most commonly used anti-platelet drugs, namely, aspirin, ticlopidine, and clopidogrel, are effective in the prevention and treatment of cardio-cerebrovascular diseases. Glycoprotein IIb/IIIa antagonists (e.g., abciximab, eptifibatide and tirofiban have demonstrated good clinical benefits and safety profiles in decreasing ischemic events in acute coronary syndrome. However, adverse events related to thrombosis or bleeding have been reported in cases of therapy with glycoprotein IIb/IIIa antagonists. Cilostazol is an anti-platelet agent used in the treatment of patients with peripheral ischemia, such as intermittent claudication. Presently, platelet adenosine diphosphate P2Y(12 receptor antagonists (e.g., clopidogrel, prasugrel, cangrelor, and ticagrelor are being used in clinical settings for their pronounced protective effects. The new protease-activated receptor antagonists, vorapaxar and atopaxar, potentially decrease the risk of ischemic events without significantly increasing the rate of bleeding. Some other new anti-platelet drugs undergoing clinical trials have also been introduced. Indeed, the number of new anti-platelet drugs is increasing. Consequently, the efficacy of these anti-platelet agents in actual patients warrants scrutiny, especially in terms of the hemorrhagic risks. Hopefully, new selective platelet inhibitors with high anti-thrombotic efficiencies and low hemorrhagic side effects can be developed.

  5. Increased CSF-BACE1 activity associated with decreased hippocampus volume in Alzheimer's disease.

    LENUS (Irish Health Repository)

    Ewers, Michael

    2012-02-01

    The enzyme beta-secretase (BACE1) is essentially involved in the production of cerebral amyloidogenic pathology in Alzheimer\\'s disease (AD). The measurement of BACE1 activity in cerebrospinal fluid (CSF) has been reported, which may render CSF measurement of BACE1 a potential biomarker candidate of AD. In order to investigate whether BACE1 protein activity is correlated with regional brain atrophy in AD, we investigated the association between CSF levels of BACE1 and MRI-assessed hippocampus volume in patients with AD (n = 30). An increase in CSF-BACE1 activity was associated with decreased left and right hippocampus volume corrected for global head volume in the AD patients. Boot-strapped regression analysis showed that increased CSF levels of BACE1 activity were associated with increased CSF concentration of total tau but not amyloid-beta1-42 in AD. White matter hyperintensities did not influence the results. BACE1 activity and protein levels were significantly increased in AD compared to 19 elderly healthy controls. Thus, the CSF biomarker candidate of BACE1 activity was associated with hippocampus atrophy in AD in a robust manner and may reflect neurotoxic amyloid-beta-related processes.

  6. Increased ANF secretion after volume expansion is preserved in rats with heart failure

    International Nuclear Information System (INIS)

    Chien, Young Wei; Barbee, R.W.; MacPhee, A.L.; Frohlich, E.D.; Trippodo, N.C.

    1988-01-01

    To examine whether the failing heart has reached a maximal capacity to increase plasma atrial natriuretic factor (ANF) concentration, the change in plasma immunoreactive ANF, measured by radioimmunoassay level due to acute blood volume expansion was determined in conscious rats with chronic heart failure. Varying degrees of myocardial infarction and thus heart failure were induced by coronary artery ligation 3 wk before study. Compared with controls, infarcted rats had decreases in mean arterial pressure cardiac index, renal blood flow, and peak left ventricle-developed pressure after aortic occlusion, and increases in central venous pressure, left ventricular end-diastolic pressure, total peripheral resistance, plasma ANF level. Plasma ANF was correlated with infarct size, cardiac filling pressures, and left ventricle pressure-generating ability. At 5 min after 25% blood volume expansion, plasma ANF in rats with heart failure increased by 2,281 ± 345 pg/ml; the magnitude of the changes in circulating ANF and hemodynamic measurements was similar in controls. The results suggest that plasma ANF level can be used as a reliable index of the severity of heart failure, and that the capacity to increase plasma ANF concentration after acute volume expansion is preserved in rats with heart failure. There was no evidence of a relative deficiency of circulating ANF in this model of heart failure

  7. Platelet transfusion in chemotherapy patients: comparison of the effect of intravenous infusion pumps versus gravity transfusion.

    Science.gov (United States)

    Meess, A

    2015-01-01

    Platelet concentrates are given to patients suffering with severe thrombocytopenia usually by a gravity transfusion procedure. Increasing patient numbers that are in need of this treatment increase the pressure on hospital staff and space. In order to combat time issues, the use of medical devices such as intravenous infusion pumps are thought to be beneficial for time and simultaneously for safety in transfusion practices. By using infusion pumps, platelet concentrates can be transfused in less time and provide accurate volume measurements. Manufacturers of infusion pumps claim that these devices are safe to be used for blood products including platelet concentrates. However, published studies were performed on older models and newer devices are on the market now. The purpose of this study is to evaluate infusion pumps, which are claimed to be suitable for blood products and to investigate the impact the pumps had on platelets. Furthermore, the study revealed if the intravenous infusion pumps are safe to be used for platelet transfusion as claimed by manufacturers. A simulated transfusion was performed using the Carefusion Alaris GP Plus volumetric pump and Fresenius Kabi Volumat Agilia infusion pump. Samples were taken from expired platelet concentrates before and after passage through the pump. All samples were investigated for full blood count that included platelet count, mean platelet volume (MPV), platelet distribution width (PDW) and a plateletcrit (PCT). The samples were then centrifuged to achieve platelet-poor plasma and then tested for lactate dehydrogenase (LDH). A power calculation performed on the statistical power analysis program G*power indicated a requirement of 82 samples for a power of 80%. Statistical analysis was performed with the IBM SPSS statistic software. A paired sample t-test was used to calculate mean, standard deviation and P values for the infusion pumps used. The Wilcoxon Signed Rank Test was used to evaluate results that had a non

  8. Platelet function in the postprandial period

    Directory of Open Access Journals (Sweden)

    Sinzinger Helmut

    2012-09-01

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

  9. Evaluation of platelet aggregation in platelet concentrates: storage implications

    Directory of Open Access Journals (Sweden)

    Neiva Teresinha J.C.

    2003-01-01

    Full Text Available The use of hemo-derivatives is nowadays a fundamentally important therapeutic modality in the exercise of medicine. Among the various hemo-components employed, we have the platelet concentrate (PC, indicated in cases of hemorrhagic disturbances. We previously showed that platelet function in blood donors is reduced in their screening phase and after the separation process of PCs. Currently, we are providing evidence for the existence of biochemical and functional changes in PC preparations stored for three days at temperatures of 20 ± 2 ºC. Platelet concentrates from 40 healthy donors, collected in CPD anticoagulant and PL-146 polyvinylchloride containers, were examined in order to determine the pH value, pCO2 ,pO2 and lactate concentrations. In addition, the aggregation of platelets with thrombin and collagen were examined to evaluate platelet function. A pH increase from 7.07 ± 0.04 to 7.36 ± 0.07 (p < 0.01 was observed. The pCO2 concentration decreased progressively from 69.2 ± 7.7 mmHg to 28.8 ± 6.2 mmHg (p < 0.001 during the storage period. In contrast, pO2 value increase from 103.4 ± 30.6 to 152.3 ± 24.6 mmHg (p < 0.001 was evidenced during the 48 hours of storage. The lactate concentration increased from 17.97 ± 5.2 to 57.21 ± 5.7 mg/dl (p < 0.001. Platelet aggregation using 0.25 U/ml-thrombin and 2.0 µg/ml-collagen showed significant hypofunction from 61.8 ± 2.7% to 24.8 ± 9.8% and 62.7±5.0 to 33.4± 6.2 (p < 0.001, respectively. We concluded that the evaluated biochemical parameters and the platelet function changed significantly when the platelets were kept under routine storage conditions.

  10. An efficient model to improve the performance of platelet inventory of the blood banks

    Directory of Open Access Journals (Sweden)

    Annista Wijayanayake

    2017-06-01

    Full Text Available Platelet transfusions are vital for the prevention of fatal hemorrhage. Therefore, a stable inventory of platelets is required for an efficient and effective delivery of services in all the hospitals and medical centers. However, over the past decades, the requirement for platelets seems to be continuously increasing, while the number of potential donors is decreasing. Moreover, due to its very short life span of just five days, a large volume of platelets expires while they are on the shelves, resulting unnecessary shortages of platelets. Furthermore, it is very costly and difficult to get platelets from another blood bank in a short notice. Hence, these unexpected shortages put the life of patients at risk. This study is focused on addressing the issues discussed, by developing an efficient blood inventory management model to reduce the platelet shortages, and wastages, while reducing the related inventory costs. Currently, the blood banks are managing platelet inventory according to their own instincts, which result to shortages and wastages. As a solution, we propose a model to manage the daily supply of platelets by forecasting the daily demand. Three different algorithms were developed using lower bound, average and upper bound values and tested to find the optimal solution that best fits to manage platelet inventory. These models were tested using data for 60 days obtained from two different levels of blood banks in Sri Lanka, namely a General Hospital blood bank and a Base Hospital blood bank. In General hospitals, the demand for blood components including platelets is very high when compared to the Base hospitals. The study was able to come up with two different inventory management models for the two different types of blood banks. The model that best fits the General Hospital blood bank where the demand is high and was able to reduce the shortages by 46.74%, wastage by 89.82% and total inventory level by 39.10% and, the model that

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

    Science.gov (United States)

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

    2016-07-01

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

  12. The binding of fibrinogen to platelets in diabetes mellitus

    International Nuclear Information System (INIS)

    Minno, G. di; Cerbone, A.M.; Iride, C.; Mancini, M.

    1986-01-01

    Platelets from diabetics are known to be more sensitive in vitro to a variety of aggregating agents, to produce more prostaglandin endoperoxides and thromboxane and to bind more 125 I-fibrinogen than platelets from normal controls. Fibrinogen binding to platelets is a pre-requisite for platelet aggregation. Previous studies suggested a role for prostaglandins and/or thrombaxane A 2 in the exposure of fibrinogen receptors on platelets. The present study compares fibrinogen binding to hyperaggregable platelets from diabetic patients and to normal platelets when prostaglandin/thromboxane formation is suppressed by aspirin. It was found that pre-treatment with aspirin reduced collagen or thrombin-induced binding to platelets from none-retinopathic diabetics to the values seen in controls. By contrast, aspirin did not normalize binding to platelets obtained from retinopathic diabetics. The combination of aspirin with apyrase (an ADP scavenger) almost completely inhibited binding and aggregation of platelets from normal controls or non-retinophatic diabetics exposed to collagen or thrombin, whereas it only partially affected binding and aggregation of platelets from retinopathics. By using a monoclonal antibody (B59.2) to the platelet receptor for fibrinogen, we determined that this receptor was quantitatively and qualitatively the same on platelets from normal controls and diabetics. We conclude that increased fibrinogen binding and hyperaggregability of platelets from none-retinopathic diabetics is related to their capacity to form more prostaglandin endoperoxides/thromboxane than normal platelets. In contrast, hyperaggregability and increased binding of platelets from retinopathics appear at least partly related to a mechanism independent of ADP release and thromboxane synthesis. (Author)

  13. Aerobic exercise increases hippocampal volume and improves memory in multiple sclerosis: preliminary findings.

    Science.gov (United States)

    Leavitt, V M; Cirnigliaro, C; Cohen, A; Farag, A; Brooks, M; Wecht, J M; Wylie, G R; Chiaravalloti, N D; DeLuca, J; Sumowski, J F

    2014-01-01

    Multiple sclerosis leads to prominent hippocampal atrophy, which is linked to memory deficits. Indeed, 50% of multiple sclerosis patients suffer memory impairment, with negative consequences for quality of life. There are currently no effective memory treatments for multiple sclerosis either pharmacological or behavioral. Aerobic exercise improves memory and promotes hippocampal neurogenesis in nonhuman animals. Here, we investigate the benefits of aerobic exercise in memory-impaired multiple sclerosis patients. Pilot data were collected from two ambulatory, memory-impaired multiple sclerosis participants randomized to non-aerobic (stretching) and aerobic (stationary cycling) conditions. The following baseline/follow-up measurements were taken: high-resolution MRI (neuroanatomical volumes), fMRI (functional connectivity), and memory assessment. Intervention was 30-minute sessions 3 times per week for 3 months. Aerobic exercise resulted in 16.5% increase in hippocampal volume and 53.7% increase in memory, as well as increased hippocampal resting-state functional connectivity. Improvements were specific, with no comparable changes in overall cerebral gray matter (+2.4%), non-hippocampal deep gray matter structures (thalamus, caudate: -4.0%), or in non-memory cognitive functioning (executive functions, processing speed, working memory: changes ranged from -11% to +4%). Non-aerobic exercise resulted in relatively no change in hippocampal volume (2.8%) or memory (0.0%), and no changes in hippocampal functional connectivity. This is the first evidence for aerobic exercise to increase hippocampal volume and connectivity and improve memory in multiple sclerosis. Aerobic exercise represents a cost-effective, widely available, natural, and self-administered treatment with no adverse side effects that may be the first effective memory treatment for multiple sclerosis patients.

  14. Biochemical and functional abnormalities in hypercholesterolemic rabbit platelets

    International Nuclear Information System (INIS)

    Dalal, K.B.; Ebbe, S.; Mazoyer, E.; Carpenter, D.; Yee, T.

    1990-01-01

    This study was designed to elucidate changes in rabbit platelet lipids induced by a cholesterol rich diet and to explore the possible correlation of these lipid changes with platelet abnormalities. Pronounced biochemical alterations were observed when serum cholesterol levels of 700-1000 mg% were reached. Hypercholesterolemic (HC) platelets contained 37% more neutral lipids and 16% less phospholipids than the controls. Lysolecithin, cholesterol esters and phosphatidylinositol (PI) levels were increased in HC platelets, and the levels of phosphatidylcholine (PC) were decreased. The cholesterol/phospholipid molar ratio of lipidemic platelets increased from 0.55 +/- 0.011 to 0.89 +/- 0.016 (P less than 0.01) in eight weeks. HC platelets had 90% more arachidonic acid (AA) in the PI than normal platelets. No significant changes in AA of PC were observed. Platelet function was monitored by the uptake and release of [14C]serotonin in platelet rich plasma (PRP), using varying concentrations of collagen as an aggregating agent. The uptake of [14C]serotonin in HC and normal platelets ranged from 78-94%. The percent of [14C]serotonin released from normal and HC platelets was proportional to the concentration of collagen. However, lipidemic platelets were hyperreactive to low concentrations of collagen. Incorporation of 50 microM acetylsalicylic acid into the aggregating medium suppressed the release of [14C]serotonin in normal PRP by more than 90%, but had only a partial effect on lipidemic PRP

  15. Platelet activation by extracellular matrix proteins in haemostasis and thrombosis.

    Science.gov (United States)

    Watson, Steve P

    2009-01-01

    The prevention of excessive blood loss to avoid fatal haemorrhage is a pivotal process for all organisms possessing a circulatory system. Increased circulating blood volume and pressure, as required in larger animals, make this process all the more important and challenging. It is essential to have a powerful and rapid system to detect damage and generate an effective seal, and which is also exquisitely regulated to prevent unwanted, excessive or systemic activation so as to avoid blockage of vessels. Thus, a highly specialised and efficient haemostatic system has evolved that consists of cellular (platelets) and protein (coagulation factors) components. Importantly, this is able to support haemostasis in both the low shear environment of the venous system and the high shear environment of the arterial system. Endothelial cells, lining the entire circulation system, play a crucial role in the delicate balance between activation and inhibition of the haemostatic system. An intact and healthy endothelium supports blood flow by preventing attachment of cells and proteins which is required for initiation of coagulation and platelet activation. Endothelial cells produce and release the two powerful soluble inhibitors of platelet activation, nitric oxide and prostacyclin, and express high levels of CD39 which rapidly metabolises the major platelet feedback agonist, ADP. This antithrombotic environment however can rapidly change following activation or removal of endothelial cells through injury or rupture of atherosclerotic plaques. Loss of endothelial cells exposes the subendothelial extracellular matrix which creates strong signals for activation of the haemostatic system including powerful platelet adhesion and activation. Quantitative and qualitative changes in the composition of the subendothelial extracellular matrix influence these prothrombotic characteristics with life threatening thrombotic and bleeding complications, as illustrated by formation of

  16. Rapid increase in cystic volume of an anaplastic astrocytoma misdiagnosed as neurocysticercosis: A case report

    Science.gov (United States)

    Li, Hong-Jiang; Han, Hong-Xiu; Feng, Dong-Fu

    2016-01-01

    Reports describing a rapid increase in the cystic volume of anaplastic astrocytoma (AA) in a short time frame are rare. The present study reports the case of a 68-year-old male who was admitted to the No. 9 People's Hospital, Shanghai Jiaotong University School of Medicine (Shanghai, China), with a small cystic brain lesion and positive immunological testing for cysticercosis. Head magnetic resonance imaging (MRI) showed a cystic lesion, 6 mm in diameter, in the left frontal lobe. Neurocysticercosis was suspected and the patient was treated with a clinical trial of albendazole and steroids. A period of 25 days later, the patient's condition had deteriorated, and MRI revealed a cystic lesion in the left frontal lobe; thereafter, the cystic lesion was removed and a diagnosis of AA was established. The tumor was soft, ivory white and gelatinous due to myxoid degeneration. In this case, tumor-related angiogenesis and microvascular extravasation (blood-brain barrier disruption) may have been the main cause of the rapid increase in the cystic volume in such a short time frame. The similarity of the glioma and cysticercus antigens may have been the cause of the positive reactions in the cystic fluid. The present study reports the rare occurrence of a rapid increase of cystic volume and potential diagnostic difficulties. PMID:27698865

  17. Acute extracellular fluid volume changes increase ileocolonic resistance to saline flow in anesthetized dogs

    Directory of Open Access Journals (Sweden)

    Santiago Jr. A.T.

    1997-01-01

    Full Text Available We determined the effect of acute extracellular fluid volume changes on saline flow through 4 gut segments (ileocolonic, ileal, ileocolonic sphincter and proximal colon, perfused at constant pressure in anesthetized dogs. Two different experimental protocols were used: hypervolemia (iv saline infusion, 0.9% NaCl, 20 ml/min, volume up to 5% body weight and controlled hemorrhage (up to a 50% drop in mean arterial pressure. Mean ileocolonic flow (N = 6 was gradually and significantly decreased during the expansion (17.1%, P<0.05 and expanded (44.9%, P<0.05 periods while mean ileal flow (N = 7 was significantly decreased only during the expanded period (38%, P<0.05. Mean colonic flow (N = 7 was decreased during expansion (12%, P<0.05 but returned to control levels during the expanded period. Mean ileocolonic sphincter flow (N = 6 was not significantly modified. Mean ileocolonic flow (N = 10 was also decreased after hemorrhage (retracted period by 17% (P<0.05, but saline flow was not modified in the other separate circuits (N = 6, 5 and 4 for ileal, ileocolonic sphincter and colonic groups, respectively. The expansion effect was blocked by atropine (0.5 mg/kg, iv both on the ileocolonic (N = 6 and ileal (N = 5 circuits. Acute extracellular fluid volume retraction and expansion increased the lower gastrointestinal resistances to saline flow. These effects, which could physiologically decrease the liquid volume being supplied to the colon, are possible mechanisms activated to acutely balance liquid volume deficit and excess.

  18. Intensified training increases salivary free light chains in trained cyclists: Indication that training volume increases oral inflammation.

    Science.gov (United States)

    Heaney, Jennifer L J; Killer, Sophie C; Svendsen, Ida S; Gleeson, Michael; Campbell, John P

    2018-05-01

    Periods of short-term intensified training (IT) are often used by athletes during training cycles over the season and undergoing phases of increased physical stress may impact upon the immune system. This study investigated the effects of a period of IT on free light chains (FLCs) in saliva - an emerging immune biomarker of oral inflammation - and matched serum samples in well-trained athletes. It also examined if IT influences basal FLC levels and FLC flux during acute exercise. Highly trained male cyclists (n = 10) underwent a 9-day period of IT; before and after IT participants performed a 1 h time trial (TT) on a cycle ergometer, with blood and saliva samples collected pre- and post-exercise. FLCs were assessed in serum and saliva, and IgG, IgA, IgM and creatinine were also measured in serum. Weekly training volume increased by 143% (95% CI 114-172%), p training. Following IT, the cyclists demonstrated higher salivary FLC levels. Both salivary lambda FLC concentrations (p training, and we show for the first time that FLCs may have utility as a marker of exercise stress and oral health status. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Platelet cyclooxygenase expression in normal dogs.

    Science.gov (United States)

    Thomason, J; Lunsford, K; Mullins, K; Stokes, J; Pinchuk, L; Wills, R; McLaughlin, R; Langston, C; Pruett, S; Mackin, A

    2011-01-01

    Human platelets express both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Variation in COX-2 expression could be a mechanism for variable response to aspirin. The hypotheses were that circulating canine platelets express COX-1 and COX-2, and that aspirin alters COX expression. The objective was to identify changes in platelet COX expression and in platelet function caused by aspirin administration to dogs. Eight female, intact hounds. A single population, repeated measures design was used to evaluate platelet COX-1 and COX-2 expression by flow cytometry before and after aspirin (10 mg/kg Q12h for 10 days). Platelet function was analyzed via PFA-100(®) (collagen/epinephrine), and urine 11-dehydro-thromboxane B(2) (11-dTXB(2)) was measured and normalized to urinary creatinine. Differences in COX expression, PFA-100(®) closure times, and urine 11-dTXB(2 ): creatinine ratio were analyzed before and after aspirin administration. Both COX-1 and COX-2 were expressed in canine platelets. COX-1 mean fluorescent intensity (MFI) increased in all dogs, by 250% (range 63-476%), while COX-2 expression did not change significantly (P = 0.124) after aspirin exposure, with large interindividual variation. PFA-100(®) closure times were prolonged and urine 11-dTXB(2) concentration decreased in all dogs after aspirin administration. Canine platelets express both COX isoforms. After aspirin exposure, COX-1 expression increased despite impairment of platelet function, while COX-2 expression varied markedly among dogs. Variability in platelet COX-2 expression should be explored as a potential mechanism for, or marker of, variable aspirin responsiveness. Copyright © 2011 by the American College of Veterinary Internal Medicine.

  20. Effects of Platelets on Platelet Concentrate Product on the Activation of Human Peripheral Blood Monocyte Cells

    Directory of Open Access Journals (Sweden)

    N Sadat Razavi Hoseini

    2016-02-01

    Full Text Available Introduction: Monocytes can interact with platelets due to their surface molecules such as P-selectin glycoprotein ligand-1 (PSGL-1, and form monocyte-platelet complex. In the present study, the effects of platelets interaction of platelet concentrates (PCs and peripheral blood monocytes were investigated in vitro as a model to predict the probable interactions of these cells and consequently activation of monocytes. Methods: In this experimental study, units of whole blood and PCs were prepared from Tehran Blood Transfusion Center. After isolation of monocytes from the whole blood, these cells were treated with PC- derived platelets. The activation of monocytes was assessed before and after treatment by the analysis of the respiratory burst of monocytes using dihydrorhodamine 123 (DHR-123. The study data were analyzed using the non-parametric test of Wilcoxon. Results: The purity of monocytes was determined as 86.1±2 using NycoPrep method. The respiratory burst of monocytes was increased after exposure with platelets. In fact, the difference was significant when platelets were used on the 5th day of storage (P=0.001. Conclusions: The study findings revealed that platelets have an efficient capacity to stimulate and activate monocytes. The possible involvement of molecules in the interaction of platelet-monocyte demand to be further studied in future.

  1. Secreted Immunomodulatory Proteins of Staphylococcus aureus Activate Platelets and Induce Platelet Aggregation.

    Science.gov (United States)

    Binsker, Ulrike; Palankar, Raghavendra; Wesche, Jan; Kohler, Thomas P; Prucha, Josephine; Burchhardt, Gerhard; Rohde, Manfred; Schmidt, Frank; Bröker, Barbara M; Mamat, Uwe; Pané-Farré, Jan; Graf, Anica; Ebner, Patrick; Greinacher, Andreas; Hammerschmidt, Sven

    2018-04-01

    Staphylococcus aureus can cause bloodstream infections associated with infective endocarditis (IE) and disseminated intravascular coagulopathy (DIC). Both complications involve platelets. In view of an increasing number of antibiotic-resistant strains, new approaches to control systemic S. aureus infection are gaining importance. Using a repertoire of 52 recombinant S. aureus proteins in flow cytometry-based platelet activation and aggregation assays, we identified, in addition to the extracellular adherence protein Eap, three secreted staphylococcal proteins as novel platelet activating proteins. Eap and the chemotaxis inhibitory protein of S. aureus (CHIPS), the formyl peptide receptor-like 1 inhibitory protein (FLIPr) and the major autolysin Atl induced P-selectin expression in washed platelets and platelet-rich plasma. Similarly, AtlA, CHIPS and Eap induced platelet aggregation in whole blood. Fluorescence microscopy illustrated that P-selectin expression is associated with calcium mobilization and re-organization of the platelet actin cytoskeleton. Characterization of the functionally active domains of the major autolysin AtlA and Eap indicates that the amidase domain of Atl and the tandem repeats 3 and 4 of Eap are crucial for platelet activation. These results provide new insights in S. aureus protein interactions with platelets and identify secreted proteins as potential treatment targets in case of antibiotic-resistant S. aureus infection. Schattauer GmbH Stuttgart.

  2. Pegylated G-CSF Inhibits Blood Cell Depletion, Increases Platelets, Blocks Splenomegaly, and Improves Survival after Whole-Body Ionizing Irradiation but Not after Irradiation Combined with Burn

    Directory of Open Access Journals (Sweden)

    Juliann G. Kiang

    2014-01-01

    Full Text Available Exposure to ionizing radiation alone (radiation injury, RI or combined with traumatic tissue injury (radiation combined injury, CI is a crucial life-threatening factor in nuclear and radiological accidents. As demonstrated in animal models, CI results in greater mortality than RI. In our laboratory, we found that B6D2F1/J female mice exposed to 60Co-γ-photon radiation followed by 15% total-body-surface-area skin burns experienced an increment of 18% higher mortality over a 30-day observation period compared to irradiation alone; that was accompanied by severe cytopenia, thrombopenia, erythropenia, and anemia. At the 30th day after injury, neutrophils, lymphocytes, and platelets still remained very low in surviving RI and CI mice. In contrast, their RBC, hemoglobin, and hematocrit were similar to basal levels. Comparing CI and RI mice, only RI induced splenomegaly. Both RI and CI resulted in bone marrow cell depletion. It was observed that only the RI mice treated with pegylated G-CSF after RI resulted in 100% survival over the 30-day period, and pegylated G-CSF mitigated RI-induced body-weight loss and depletion of WBC and platelets. Peg-G-CSF treatment sustained RBC balance, hemoglobin levels, and hematocrits and inhibited splenomegaly after RI. The results suggest that pegylated G-CSF effectively sustained animal survival by mitigating radiation-induced cytopenia, thrombopenia, erythropenia, and anemia.

  3. Namibia's transition from whole blood-derived pooled platelets to single-donor apheresis platelet collections

    NARCIS (Netherlands)

    Pitman, John P.; Basavaraju, Sridhar V.; Shiraishi, Ray W.; Wilkinson, Robert; von Finckenstein, Bjorn; Lowrance, David W.; Marfin, Anthony A.; Postma, Maarten; Mataranyika, Mary; Smit Sibinga, Cees Th.

    BACKGROUNDFew African countries separate blood donations into components; however, demand for platelets (PLTs) is increasing as regional capacity to treat causes of thrombocytopenia, including chemotherapy, increases. Namibia introduced single-donor apheresis PLT collections in 2007 to increase PLT

  4. The measurement of platelet activation by radioimmunoassay in asthma

    International Nuclear Information System (INIS)

    Wu Guoxin; Sun Jian; Li Jianyong; Ruan Changgeng

    1992-02-01

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

  5. Platelet storage in Fresenius/NPBI polyolefin and BTHC-PVC bags: a direct comparison.

    Science.gov (United States)

    Hornsey, V S; McColl, K; Drummond, O; Macgregor, I R; Prowse, C V

    2008-08-01

    New platelet storage systems, such as changes in the plastic of the storage bags, require validation. In this study, pooled buffy coat platelets stored in Fresenius/NPBI polyolefin bags were compared with those stored in Fresenius/NPBI butyryl-trihexyl citrate (BTHC) plasticized polyvinyl chloride (PVC). The CompoSelect thrombocyte polishing filter system (1000 mL polyolefin bag) and the CompoStop F730 system (1300 mL BTHC-PVC bag) were used to prepare paired, plasma-suspended, buffy coat platelet concentrates. Samples were taken up to day 7 for in vitro analysis. In a separate experiment, 12 units were prepared using the CompoStop F730 system and samples taken after leucofiltration for FXIIa assay. By day 7, platelet concentrates stored in BTHC-PVC demonstrated significantly higher pH levels (7.32 +/- 0.05 vs. 7.26 +/- 0.05) and a greater degree of cell lysis as shown by increased lactate dehydrogenase levels (497 +/- 107 vs. 392 +/- 81 U L(-1)). The supernatants contained higher concentrations of soluble P-selectin and the chemokine 'regulated on activation, normal T-cell expressed and presumably secreted', which are released from the alpha-granules during activation. The ATP concentrations were significantly lower in BTHC-PVC. Platelet counts, mean platelet volume and hypotonic shock response were similar for both bags. FXIIa antigen concentrations were 0.6 +/- 0.2 ng mL(-1) indicating that activation of the contact factor pathway had not occurred. Although the CompoStop F730 leucoreduction filter did not activate the contact system, platelets stored in 100% plasma in BTHC-PVC bags demonstrated different in vitro characteristics from those stored in polyolefin. Further work is required to demonstrate whether these differences will affect in vivo recovery and survival.

  6. Assessment of quality of platelets preserved in plasma and platelet additive solution: A Malaysian experience

    Directory of Open Access Journals (Sweden)

    Munirah Binti Mokhtar

    2016-01-01

    Full Text Available Background: A use of platelet additives solution (PAS improves storage conditions so as to give increased shelf life to platelets and to maintain hemostatic function. Objective: The present study was aimed to compare in vitro quality of platelet rich plasma (PRP-derived platelet concentrate (PC during extended period of storage in plasma and in additive solution (Composol PS and Fresenius. Study Design: Randomized 19 PCs each were used in the study for plasma and PAS as the storage medium. The measurement parameters, including pH, total white blood cell (WBC count, total platelet count, and platelet activation rate, were studied on day 1, day 5, and day 8 of the storage period. The sterility test was carried out on the eighth day of storage. Results: pH of PC suspended in PAS was significantly lower as compared to that in plasma (P < 0.001 for all the three days of sampling. The WBC count, both in plasma and in PAS, showed an acceptable values of being <0.2 Χ 10 9 /unit during the storage period. Platelet count in PAS was higher as compared to that in plasma, though it was not statistically significant. While both the groups showed increased platelet activation rate during the storage, the PCs suspended in PAS showed significantly higher platelet activation rate (p0.001. Results from sterility test showed no bacterial growth in the PCs in both the groups. Conclusion: Most parameters studied on platelet storage in suspending medium of native plasma and PAS remained well within the acceptable limits. However, the pH values and platelet activation rate significantly differed in PAS as compared with plasma.

  7. Parameters of platelet activity in patients with thyrotoxicosis in the presence of chronic hyperglycemia and atrial fibrillation

    Directory of Open Access Journals (Sweden)

    G G Petrik

    2011-06-01

    Full Text Available Object. The study of platelet hemostasis in patients with thyrotoxicosis in the presence of chronic hyperglycemia and atrial fibrillation to prevent coagulation disorders. Material and methods. A comprehensive analysis of the parameters of platelet and coagulation hemostasis in 91 patients (67 women and 24 men with uncomplicated thyrotoxicosis, as well as with the atrial fibrillation or a combination of hyperthyroidism with diabetes has been completed. Results. The aggregation activity of platelets in uncomplicated thyrotoxicosis comparable with that of healthy people. atrial fibrillation, as well as chronic hyperglycemia, modify platelet activity by increasing the average volume of platelets, their ability to aggregate intensification of the release reaction and along with the decrease of disaggregation properties. Regardless of the presence of diabetes or atrial fibrillation, hyperthyroidism is accompanied by the activation of coagulation. Conclusion. The presence of transforming effects of chronic hyperglycemia and atrial fibrillation on the platelet activity determines the feasibility of differentiated approach to the prevent of coagulation disorders in patients with thyrotoxicosis.

  8. Water volume reduction increases eutrophication risk in tropical semi-arid reservoirs

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Nascimento da Rocha Junior

    2018-04-01

    Full Text Available Abstract Aim Global patterns of temperature and precipitation have significantly changed over the last century and nearly all predictions point to even greater changes by the end of 2100. Long periods of drought in semi-arid regions generally reduce reservoirs and lakes water level, increasing the nutrients concentrations in the water. Our principal hypothesis is that water volume reduction, driven by prolonged droughts, will increase reservoirs susceptibility to eutrophication and accordingly an increase in trophic state. To test this hypothesis, we used a comparative analysis of ecosystems in a space-for-time substitution approach, in a Brazilian semi-arid region, to predict the consequences of reservoirs water volume reduction on key limnological variables. Methods We sampled 16 reservoirs located in two sub-basins with contrasting rainfall regimes, inserted on Piranhas-Açu watershed. The Seridó River basin (SB is dry and the Piancó River basin (SB is humid, with annual mean precipitation of 500 and 700 mm, respectively. Linear regressions analyzes were performed to assess whether the percentage of maximum volume stored (%MVS is a good predictor for total phosphorus (TP, total nitrogen (TN and chlorophyll-a (CHLA. In addition, a two factorial analysis of variance (two-way ANOVA was performed to test for period (dry, very dry and extremely dry, basin (SB and PB and their interactions effects on TP, TN, CHLA, conductivity, turbidity, and Secchi depth. Results The results showed a reduction in the reservoirs %MVS both for PB and SB regions. At the extremely dry period, all reservoirs were classified as eutrophic, but TP concentrations reached much higher values in SB than in PB. The linear regressions analyses showed that the TP and TN were negatively related to %MVS during all periods sampled. The two-way ANOVA showed that there were significant basin and period effects on TP, TN, Secchi depth and turbidity, whereas for CHLA and conductivity

  9. Enlarged thalamic volumes and increased fractional anisotropy in the thalamic radiations in Veterans with suicide behaviors

    Directory of Open Access Journals (Sweden)

    Melissa eLopez-Larson

    2013-08-01

    Full Text Available Post-mortem studies have suggested a link between the thalamus, psychiatric disorders, and suicide. We evaluated the thalamus and anterior thalamic radiations (ATR in a group of Veterans with and without a history of suicidal behavior (SB to determine if thalamic abnormalities were associated with an increased risk of SB. Forty Veterans with mild traumatic brain injury (TBI and no SB (TBI-SB, 19 Veterans with mild TBI and a history of SB (TB+SB and 15 healthy controls (HC underwent MRI scanning including a structural and diffusion tensor imaging scan. Suicidal behaviors were evaluated utilizing the Columbia Suicide Rating Scale and impulsivity was measured using the Barratt Impulsiveness Scale (BIS. Differences in thalamic volumes and ATR fractional anisotropy (FA were examined between 1 TBI+SB versus HC and 2 TBI+SB versus combined HC and TBI-SB and 2 between TBI+SB and TBI-SB. Left and right thalamic volumes were significantly increased in those with TBI+SB compared to the HC, TBI-SB and the combined group. Veterans with TBI+SB had increased FA bilaterally compared to the HC, HC and TBI-SB group, and the TBI-SB only group. Significant positive associations were found for bilateral ATR and BIS in the TBI+SB group. Our findings of thalamic enlargement and increased FA in individuals with TBI+SB suggest that this region may be a biomarker for suicide risk. Our findings are consistent with previous evidence indicating that suicide may be associated with behavioral disinhibition and frontal-thalamic-limbic dysfunction and suggest a neurobiologic mechanism that may increase vulnerability to suicide.

  10. Measurement of regional pulmonary blood volume in patients with increased pulmonary blood flow or pulmonary arterial hypertension

    International Nuclear Information System (INIS)

    Wollmer, P.; Rozcovek, A.; Rhodes, C.G.; Allan, R.M.; Maseri, A.

    1984-01-01

    The effects of chronic increase in pulmonary blood flow and chronic pulmonary hypertension on regional pulmonary blood volume was measured in two groups of patients. One group of patients had intracardiac, left-to-right shunts without appreciable pulmonary hypertension, and the other consisted of patients with Eisenmenger's syndrome or primary pulmonary hypertension, i.e. patients with normal or reduced blood flow and severe pulmonary hypertension. A technique based on positron tomography was used to measure lung density (by transmission scanning) and regional pulmonary blood volume (after inhalation of /sup 11/CO). The distribution of pulmonary blood volume was more uniform in patients with chronic increase in pulmonary blood flow than in normal subjects. There were also indications of an absolute increase in intrapulmonary blood volume by about 15%. In patients with chronic pulmonary arterial hypertension, the distribution of pulmonary blood volume was also abnormally uniform. There was, however, no indication that overall intrapulmonary blood volume was substantially different from normal subjects. The abnormally uniform distribution of pulmonary blood volume can be explained by recruitment and/or dilatation of vascular beds. Intrapulmonary blood volume appears to be increased in patients with intracardiac, left-to-right shunts. With the development of pulmonary hypertension, intrapulmonary blood volume falls, which may be explained by reactive changes in the vasculature and/or obliteration of capillaries

  11. Modified expression of surface glyconjugates in stored human platelets

    International Nuclear Information System (INIS)

    Dhar, A.; Ganguly, P.

    1987-01-01

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

  12. Modified expression of surface glyconjugates in stored human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, A.; Ganguly, P.

    1987-05-01

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

  13. Platelet thrombosis in cardiac-valve prostheses

    International Nuclear Information System (INIS)

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs

  14. Platelet thrombosis in cardiac-valve prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs.

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

    Science.gov (United States)

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

    2010-05-01

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

  16. 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

  17. Platelet turnover and kinetics in immune thrombocytopenic purpura: results with autologous 111In-labeled platelets and homologous 51Cr-labeled platelets differ

    International Nuclear Information System (INIS)

    Heyns A du, P.; Badenhorst, P.N.; Loetter, M.G.P.; Pieters, H.; Wessels, P.; Kotze, H.F.

    1986-01-01

    Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr-labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP

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

    Directory of Open Access Journals (Sweden)

    Javier Modrego

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

  19. 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.

  20. Platelet activation and aggregation

    DEFF Research Database (Denmark)

    Jensen, Maria Sander; Larsen, O H; Christiansen, Kirsten

    2013-01-01

    This study introduces a new laboratory model of whole blood platelet aggregation stimulated by endogenously generated thrombin, and explores this aspect in haemophilia A in which impaired thrombin generation is a major hallmark. The method was established to measure platelet aggregation initiated...

  1. Platelet alloimmunization after transfusion

    DEFF Research Database (Denmark)

    Taaning, E; Simonsen, A C; Hjelms, E

    1997-01-01

    BACKGROUND AND OBJECTIVES: The frequency of platelet-specific antibodies after one series of blood transfusions has not been reported, and in multiply transfused patients is controversial. MATERIALS AND METHODS: We studied the frequency of alloimmunization against platelet antigens in 117 patient...

  2. Covalent modification of platelet proteins by palmitate

    International Nuclear Information System (INIS)

    Muszbek, L.; Laposata, M.

    1989-01-01

    Covalent attachment of fatty acid to proteins plays an important role in association of certain proteins with hydrophobic membrane structures. In platelets, the structure of many membrane glycoproteins (GPs) has been examined in detail, but the question of fatty acid acylation of platelet proteins has not been addressed. In this study, we wished to determine (a) whether platelet proteins could be fatty acid acylated; and, if so, (b) whether these modified proteins were present in isolated platelet membranes and cytoskeletal fractions; and (c) if the pattern of fatty acid acylated proteins changed on stimulation of the platelets with the agonist thrombin. We observed that in platelets allowed to incorporate 3H-palmitate, a small percentage (1.37%) of radioactivity incorporated into the cells became covalently bound to protein. Selective cleavage of thioester, thioester plus O-ester, and amide-linked 3H-fatty acids from proteins, and their subsequent analysis by high-performance liquid chromatography (HPLC) indicated that the greatest part of 3H-fatty acid covalently bound to protein was thioester-linked 3H-palmitate. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography, at least ten major radiolabeled proteins were detected. Activation of platelets by thrombin greatly increased the quantity of 3H-palmitoylated proteins associated with the cytoskeleton. Nearly all radiolabeled proteins were recovered in the membrane fraction, indicating that these proteins are either integral or peripheral membrane proteins or proteins tightly associated to membrane constituents. Components of the GPIIb-IIIa complex were not palmitoylated. Thus, platelet proteins are significantly modified posttranslationally by 3H-palmitate, and incorporation of palmitoylated proteins into the cytoskeleton is a prominent component of the platelet response to thrombin stimulation

  3. 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.

  4. Redox Proteomics and Platelet Activation: Understanding the Redox Proteome to Improve Platelet Quality for Transfusion

    Science.gov (United States)

    Sonego, Giona; Abonnenc, Mélanie; Tissot, Jean-Daniel; Prudent, Michel; Lion, Niels

    2017-01-01

    Blood banks use pathogen inactivation (PI) technologies to increase the safety of platelet concentrates (PCs). The characteristics of PI-treated PCs slightly differ from those of untreated PCs, but the underlying reasons are not well understood. One possible cause is the generation of oxidative stress during the PI process. This is of great interest since reactive oxygen species (ROS) act as second messengers in platelet functions. Furthermore, there are links between protein oxidation and phosphorylation, another mechanism that is critical for cell regulation. Current research efforts focus on understanding the underlying mechanisms and identifying new target proteins. Proteomics technologies represent powerful tools for investigating signaling pathways involving ROS and post-translational modifications such as phosphorylation, while quantitative techniques enable the comparison of the platelet resting state versus the stimulated state. In particular, redox cysteine is a key player in platelet activation upon stimulation by different agonists. This review highlights the experiments that have provided insights into the roles of ROS in platelet function and the implications for platelet transfusion, and potentially in diseases such as inflammation and platelet hyperactivity. The review also describes the implication of redox mechanism in platelet storage considerations. PMID:28208668

  5. Platelet function in dogs

    DEFF Research Database (Denmark)

    Nielsen, Line A.; Zois, Nora Elisabeth; Pedersen, Henrik D.

    2007-01-01

    Background: Clinical studies investigating platelet function in dogs have had conflicting results that may be caused by normal physiologic variation in platelet response to agonists. Objectives: The objective of this study was to investigate platelet function in clinically healthy dogs of 4...... different breeds by whole-blood aggregometry and with a point-of-care platelet function analyzer (PFA-100), and to evaluate the effect of acetylsalicylic acid (ASA) administration on the results from both methods. Methods: Forty-five clinically healthy dogs (12 Cavalier King Charles Spaniels [CKCS], 12...... applied. However, the importance of these breed differences remains to be investigated. The PFA-100 method with Col + Epi as agonists, and ADP-induced platelet aggregation appear to be sensitive to ASA in dogs....

  6. 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

  7. Platelet receptor polymorphisms do not influence Staphylococcus aureus–platelet interactions or infective endocarditis

    Science.gov (United States)

    Daga, Shruti; Shepherd, James G.; Callaghan, J. Garreth S.; Hung, Rachel K.Y.; Dawson, Dana K.; Padfield, Gareth J.; Hey, Shi Y.; Cartwright, Robyn A.; Newby, David E.; Fitzgerald, J. Ross

    2011-01-01

    Cardiac vegetations result from bacterium–platelet adherence, activation and aggregation, and are associated with increased morbidity and mortality in infective endocarditis. The GPIIb/IIIa and FcγRIIa platelet receptors play a central role in platelet adhesion, activation and aggregation induced by endocarditis pathogens such as Staphylococcus aureus, but the influence of known polymorphisms of these receptors on the pathogenesis of infective endocarditis is unknown. We determined the GPIIIa platelet antigen PlA1/A2 and FcγRIIa H131R genotype of healthy volunteers (n = 160) and patients with infective endocarditis (n = 40), and investigated the influence of these polymorphisms on clinical outcome in infective endocarditis and S. aureus–platelet interactions in vitro. Platelet receptor genotype did not correlate with development of infective endocarditis, vegetation characteristics on echocardiogram or the composite clinical end-point of embolism, heart failure, need for surgery or mortality (P > 0.05 for all), even though patients with the GPIIIa PlA1/A1 genotype had increased in vivo platelet activation (P = 0.001). Furthermore, neither GPIIIa PlA1/A2 nor FcγRIIa H131R genotype influenced S. aureus-induced platelet adhesion, activation or aggregation in vitro (P > 0.05). Taken together, our data suggest that the GPIIIa and FcγRIIa platelet receptor polymorphisms do not influence S. aureus–platelet interactions in vitro or the clinical course of infective endocarditis. PMID:21044892

  8. Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

    Directory of Open Access Journals (Sweden)

    Yannick Molgat-Seon

    2017-03-01

    Full Text Available The aim of the present study was to determine whether lung volume recruitment (LVR acutely increases respiratory system compliance (Crs in individuals with severe respiratory muscle weakness (RMW. Individuals with RMW resulting from neuromuscular disease or quadriplegia (n=12 and healthy controls (n=12 underwent pulmonary function testing and the measurement of Crs at baseline, immediately after, 1 h after and 2 h after a single standardised session of LVR. The LVR session involved 10 consecutive supramaximal lung inflations with a manual resuscitation bag to the highest tolerable mouth pressure or a maximum of 50 cmH2O. Each LVR inflation was followed by brief breath-hold and a maximal expiration to residual volume. At baseline, individuals with RMW had lower Crs than controls (37±5 cmH2O versus 109±10 mL·cmH2O−1, p0.05. LVR had no significant effect on measures of pulmonary function at any time point in either group (all p>0.05. During inflations, mean arterial pressure decreased significantly relative to baseline by 10.4±2.8 mmHg and 17.3±3.0 mmHg in individuals with RMW and controls, respectively (both p<0.05. LVR acutely increases Crs in individuals with RMW. However, the high airway pressures during inflations cause reductions in mean arterial pressure that should be considered when applying this technique.

  9. Platelet glycoprotein IIb/IIIa polymorphism HPA-3 b/b is associated with increased risk of ischemic stroke in patients under 60 years of age.

    Science.gov (United States)

    Duan, Hao; Cai, Yan; Sun, Xiaojiang

    2012-01-01

    The role of genetic risk factors in ischemic stroke is unclear. Platelet glycoprotein IIb/IIIa (GpIIb-IIIa) has been implicated in the pathogenesis of ischemic stroke. We sought to evaluate the relationship between the GpIIb/IIIa complex gene polymorphism and ischemic stroke. We investigated the association of the GpIIb/IIIa complex gene polymorphism with stroke risk in 306 patients with acute ischemic stroke and 266 control subjects by determining the GpIIb and GpIIIa genotype from leukocyte DNA by polymerase chain reaction (PCR) followed by FokI and ScrFI digestion, respectively. Compared with controls, more patients presented with coronary heart disease, hypertension, smoking history, and diabetes. In addition, the patients had higher levels of cholesterol and glucose compared with the control subjects. All donors in the GpIIIa (n=572) group expressed the GpIIIa PlA1 (HPA-1 aa) phenotype. There were no significant differences between the HPA-3 genotype (GpIIb) patient distribution (aa=39.9%, ab=41.4%, bb=28.7%) and healthy control subjects (aa=36.1%, ab=35.0%, bb=28.9%) (P=0.580). Among study participants ischemic stroke >2-fold (P=0.008). The GpIIb Ile/Ser843 gene polymorphism is associated with ischemic stroke among young and middle-aged adults (ischemic stroke.

  10. Progress in bio-manufacture of platelets for transfusion.

    Science.gov (United States)

    Heazlewood, Shen Y; Nilsson, Susan K; Cartledge, Kellie; Be, Cheang Ly; Vinson, Andrew; Gel, Murat; Haylock, David N

    2017-11-01

    Blood transfusion services face an ever-increasing demand for donor platelets to meet clinical needs. Whilst strategies for increasing platelet storage life and improving the efficiency of donor platelet collection are important, in the longer term, platelets generated by bio-manufacturing processes will be required to meet demands. Production of sufficient numbers of in vitro-derived platelets for transfusion represents a significant bioengineering challenge. In this review, we highlight recent progress in this area of research and outline the main technical and biological obstacles that need to be met before this becomes feasible and economic. A critical consideration is assurance of the functional properties of these cells as compared to their fresh, donor collected, counterparts. We contend that platelet-like particles and in vitro-derived platelets that phenotypically resemble fresh platelets must deliver the same functions as these cells upon transfusion. We also note recent progress with immortalized megakaryocyte progenitor cell lines, molecular strategies for reducing expression of HLA Class I to generate universal donor platelets and the move to early clinical studies with in vitro-derived platelets.

  11. Negative feedback regulation of human platelets via autocrine activation of the platelet-derived growth factor alpha-receptor.

    Science.gov (United States)

    Vassbotn, F S; Havnen, O K; Heldin, C H; Holmsen, H

    1994-05-13

    Human platelets contain platelet-derived growth factor (PDGF) in their alpha-granules which is released during platelet exocytosis. We show by immunoprecipitation and 125I-PDGF binding experiments that human platelets have functionally active PDGF alpha-receptors, but not beta-receptors. The PDGF alpha-receptor (PDGFR-alpha) was identified as a 170-kDa glycosylated protein-tyrosine kinase as found in other cell types. Stimulation of platelets with 0.1 unit/ml thrombin resulted in a significant increase (2-5-fold) of the tyrosine phosphorylation of the PDGFR-alpha, as determined by immunoprecipitation with phosphotyrosine antiserum as well as with PDGFR-alpha antiserum. The observed thrombin-induced autophosphorylation of the PDGFR-alpha was inhibited by the addition of a neutralizing monoclonal PDGF antibody. Thus, our results suggest that the platelet PDGFR-alpha is stimulated in an autocrine manner by PDGF secreted during platelet activation. Preincubation of platelets with PDGF inhibited thrombin-induced platelet aggregation and secretion of ATP + ADP and beta-hexosaminidase. Thrombin-induced platelet aggregation was also reversed when PDGF was added 30 s after thrombin stimulation. Inhibition of the autocrine PDGF pathway during platelet activation by the PDGF antibody led to a potentiation of thrombin-induced beta-hexosaminidase secretion. Thus, the PDGFR-alpha takes part in a negative feedback regulation during platelet activation. Our demonstration of PDGF alpha-receptors on human platelets and its inhibitory function during platelet activation identifies a new possible role of PDGF in the regulation of thrombosis.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. FEE-SCHEDULE INCREASES IN CANADA: IMPLICATION FOR SERVICE VOLUMES AMONG FAMILY AND SPECIALIST PHYSICIANS.

    Science.gov (United States)

    Ariste, Ruolz

    2015-01-01

    Physician spending has substantially increased over the last few years in Canada to reach $27.4 billion in 2010. Total clinical payment to physicians has grown at an average annual rate of 7.6% from 2004 to 2010. The key policy question is whether or not this additional money has bought more physician services. So, the purpose of this study is to understand if we are paying more for the same amount of medical services in Canada or we are getting more bangs for our buck. At the same time, the paper attempts to find out whether or not there is a productivity difference between family physician services and surgical procedures. Using the Baumol theory and data from the National Physician Database for the period 2004-2010, the paper breaks down growth in physician remuneration into growth in unit cost and number of services, both from the physician and the payer perspectives. After removing general inflation and population growth from the 7.6% growth in total clinical payment, we found that real payment per service and volume of services per capita grew at an average annual rate of 3.2% and 1.4% respectively, suggesting that payment per service was the main cost driver of physician remuneration at the national level. Taking the payer perspective, it was found that, for the fee-for-service (FFS) scheme, volume of services per physician decreased at an average annual rate of -0.6%, which is a crude indicator that labour productivity of physicians on FFS has fallen during the period. However, the situation differs for the surgical procedures. Results also vary by province. Overall, our finding is consistent with the Baumol theory, which hypothesizes higher productivity growth in technology-driven sectors.

  17. Taurine and platelet aggregation

    International Nuclear Information System (INIS)

    Nauss-Karol, C.; VanderWende, C.; Gaut, Z.N.

    1986-01-01

    Taurine is a putative neurotransmitter or neuromodulator. The endogenous taurine concentration in human platelets, determined by amino acid analysis, is 15 μM/g. In spite of this high level, taurine is actively accumulated. Uptake is saturable, Na + and temperature dependent, and suppressed by metabolic inhibitors, structural analogues, and several classes of centrally active substances. High, medium and low affinity transport processes have been characterized, and the platelet may represent a model system for taurine transport in the CNS. When platelets were incubated with 14 C-taurine for 30 minutes, then resuspended in fresh medium and reincubated for one hour, essentially all of the taurine was retained within the cells. Taurine, at concentrations ranging from 10-1000 μM, had no effect on platelet aggregation induced by ADP or epinephrine. However, taurine may have a role in platelet aggregation since 35-39% of the taurine taken up by human platelets appears to be secreted during the release reaction induced by low concentrations of either epinephrine or ADP, respectively. This release phenomenon would imply that part of the taurine taken up is stored directly in the dense bodies of the platelet

  18. platelet counts and mean platelet volume amongst elderly

    African Journals Online (AJOL)

    Dr Ahmed

    The haemopoietic modulation becomes imbalanced as a result of progressive reduction in haemopoietic stem cells due to exhaustion of pluripotent cytokines and in production of .... Human Hered., 34: 396-398. Butkiewicz, A. M., Kemona, H., ...

  19. Glucose Transporter 3 Potentiates Degranulation and Is Required for Platelet Activation.

    Science.gov (United States)

    Fidler, Trevor P; Middleton, Elizabeth A; Rowley, Jesse W; Boudreau, Luc H; Campbell, Robert A; Souvenir, Rhonda; Funari, Trevor; Tessandier, Nicolas; Boilard, Eric; Weyrich, Andrew S; Abel, E Dale

    2017-09-01

    On activation, platelets increase glucose uptake, glycolysis, and glucose oxidation and consume stored glycogen. This correlation between glucose metabolism and platelet function is not well understood and even less is known about the role of glucose metabolism on platelet function in vivo. For glucose to enter a cell, it must be transported through glucose transporters. Here we evaluate the contribution of GLUT3 (glucose transporter 3) to platelet function to better understand glucose metabolism in platelets. Platelet-specific knockout of GLUT3 was generated by crossing mice harboring GLUT3 floxed allele to a PF4 (platelet factor 4)-driven Cre recombinase. In platelets, GLUT3 is localized primarily on α-granule membranes and under basal conditions facilitates glucose uptake into α-granules to be used for glycolysis. After activation, platelets degranulate and GLUT3 translocates to the plasma membrane, which is responsible for activation-mediated increased glucose uptake. In vivo, loss of GLUT3 in platelets increased survival in a collagen/epinephrine model of pulmonary embolism, and in a K/BxN model of autoimmune inflammatory disease, platelet-specific GLUT3 knockout mice display decreased disease progression. Mechanistically, loss of GLUT3 decreased platelet degranulation, spreading, and clot retraction. Decreased α-granule degranulation is due in part to an impaired ability of GLUT3 to potentiate exocytosis. GLUT3-mediated glucose utilization and glycogenolysis in platelets promotes α-granule release, platelet activation, and postactivation functions. © 2017 American Heart Association, Inc.

  20. Tai Chi Chuan and Baduanjin Increase Grey Matter Volume in Older Adults: A Brain Imaging Study.

    Science.gov (United States)

    Tao, Jing; Liu, Jiao; Liu, Weilin; Huang, Jia; Xue, Xiehua; Chen, Xiangli; Wu, Jinsong; Zheng, Guohua; Chen, Bai; Li, Ming; Sun, Sharon; Jorgenson, Kristen; Lang, Courtney; Hu, Kun; Chen, Shanjia; Chen, Lidian; Kong, Jian

    2017-01-01

    The aim of this study is to investigate and compare how 12-weeks of Tai Chi Chuan and Baduanjin exercise can modulate brain structure and memory function in older adults. Magnetic resonance imaging and memory function measurements (Wechsler Memory Scale-Chinese revised, WMS-CR) were applied at both the beginning and end of the study. Results showed that both Tai Chi Chuan and Baduanjin could significantly increase grey matter volume (GMV) in the insula, medial temporal lobe, and putamen after 12-weeks of exercise. No significant differences were observed in GMV between the Tai Chi Chuan and Baduanjin groups. We also found that compared to healthy controls, Tai Chi Chuan and Baduanjin significantly improved visual reproduction subscores on the WMS-CR. Baduanjin also improved mental control, recognition, touch, and comprehension memory subscores of the WMS-CR compared to the control group. Memory quotient and visual reproduction subscores were both associated with GMV increases in the putamen and hippocampus. Our results demonstrate the potential of Tai Chi Chuan and Baduanjin exercise for the prevention of memory deficits in older adults.

  1. Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method

    International Nuclear Information System (INIS)

    Vallabhajosula, S.; Machac, J.; Badimon, L.; Lipszyc, H.; Goldsmith, S.J.; Fuster, V.

    1985-01-01

    The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37 0 C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient

  2. Effective ultraviolet irradiation of platelet concentrates in teflon bags

    International Nuclear Information System (INIS)

    Capon, S.M.; Sacher, R.A.; Deeg, H.J.

    1990-01-01

    Several plastic materials used in blood storage were evaluated for their ability to transmit ultraviolet B (UVB) light. A plastic bag manufactured from sheets of transparent Teflon efficiently (78-86%) transmitted UVB light and was employed in subsequent functional studies of lymphocytes and platelets exposed to UVB light while contained in these bags. In vitro experiments showed a UVB dose-dependent abrogation of lymphocyte responder and stimulator functions, with concurrent preservation of platelet aggregation responses. In a phase I pilot study, UVB-treated platelet concentrates were administered to four bone marrow transplant recipients. Adverse effects attributable to the transfusions were not observed, and patients showed clinically effective transfusion responses. No patient developed lymphocytotoxic HLA or platelet antibodies. These studies suggest that platelets can be effectively irradiated with UVB light in a closed system. However, numerous variables, including container material, volume and composition of contents, steady exposure versus agitation, and exact UV wavelength, must be considered

  3. Exogenous modification of platelet membranes with the omega-3 fatty acids EPA and DHA reduces platelet procoagulant activity and thrombus formation.

    Science.gov (United States)

    Larson, Mark K; Tormoen, Garth W; Weaver, Lucinda J; Luepke, Kristen J; Patel, Ishan A; Hjelmen, Carl E; Ensz, Nicole M; McComas, Leah S; McCarty, Owen J T

    2013-02-01

    Several studies have implicated the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in inhibition of normal platelet function, suggesting a role for platelets in EPA- and DHA-mediated cardioprotection. However, it is unclear whether the cardioprotective mechanisms arise from alterations to platelet-platelet, platelet-matrix, or platelet-coagulation factor interactions. Our previous results led us to hypothesize that EPA and DHA alter the ability of platelets to catalyze the generation of thrombin. We tested this hypothesis by exogenously modifying platelet membranes with EPA and DHA, which resulted in compositional changes analogous to increased dietary EPA and DHA intake. Platelets treated with EPA and DHA showed reductions in the rate of thrombin generation and exposure of platelet phosphatidylserine. In addition, treatment of platelets with EPA and DHA decreased thrombus formation and altered the processing of thrombin precursor proteins. Furthermore, treatment of whole blood with EPA and DHA resulted in increased occlusion time and a sharply reduced accumulation of fibrin under flow conditions. These results demonstrate that EPA and DHA inhibit, but do not eliminate, the ability of platelets to catalyze thrombin generation in vitro. The ability of EPA and DHA to reduce the procoagulant function of platelets provides a possible mechanism behind the cardioprotective phenotype in individuals consuming high levels of EPA and DHA.

  4. 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

  5. Giant tumor thrombus in the right atrium clearly detected by /sup 111/In-oxine labeled platelet scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, T; Ishikawa, N; Satoh, A; Masuda, Y; Hiramatsu, Y; Akisada, M; Sakakibara, Y

    1985-07-01

    A 54-year-old man was admitted to hospital with a 3-month history of progressive dyspnea with coughing. A giant right atrial mass, originating from a hepatocellular carcinoma, was visualized by computed tomography, and digital subtraction angiography. The volume if the right atrial mass was increasing rapidly. It was therefore essential to determine whether this giant mass was a tumor thrombus or a multiplication of the hepatocellular carcinoma. /sup 111/In-oxine labeled platelet scintigraphy revealed active accumulation in the right atrium caused by the presence of active platelet deposition, and slight accumulation in the lung fields probably due to embolic showers originating from the tumor thrombus in the right atrium. This is the first case report showing that /sup 111/In-oxine labeled platelet scintigraphy can aid in confirming the nature of a giant tumor thrombus in the right atrium and can clarify the pathogenesis of the respiratory symptoms.

  6. Theoretical prediction and validation of cell recovery rates in preparing platelet-rich plasma through a centrifugation.

    Science.gov (United States)

    Piao, Linfeng; Park, Hyungmin; Jo, Chris Hyunchul

    2017-01-01

    In the present study, we propose a theoretical framework to predict the recovery rates of platelets and white blood cells in the process of centrifugal separation of whole blood contained in a tube for the preparation of platelet-rich plasma. Compared to previous efforts to optimize or standardize the protocols of centrifugation, we try to further the physical background (i.e., based on the multiphase flow phenomena) of analysis to develop a universal approach that can be applied to widely different conditions. That is, one-dimensional quasi-linear partial differential equation to describe the centrifugal sedimentation of dispersed phase (red and white blood cells) in continuous phase (plasma) is derived based on the kinematic-wave theory. With the information of whole blood volume and tube geometry considered, it is possible to determine the positions of interfaces between supernatant/suspension and suspension/sediment, i.e., the particle concentration gradient in a tube, for a wide range of centrifugation parameters (time and acceleration). While establishing a theory to predict the recovery rates of the platelet and white blood cell from the pre-determined interface positions, we also propose a new correlation model between the recovery rates of plasma and platelets, which is found to be a function of the whole blood volume, centrifugal time and acceleration, and tube geometry. The present predictions for optimal condition show good agreements with available human clinical data, obtained from different conditions, indicating the universal applicability of our method. Furthermore, the dependence of recovery rates on centrifugal conditions reveals that there exist a different critical acceleration and time for the maximum recovery rate of platelets and white blood cells, respectively. The other parameters such as hematocrit, whole blood volume and tube geometry are also found to strongly affect the maximum recovery rates of blood cells, and finally, as a strategy

  7. Annealing as grown large volume CZT single crystals for increased spectral resolution

    International Nuclear Information System (INIS)

    Li, Longxia

    2008-01-01

    The spectroscopic performance of current large-volume Cadmium 10% Zinc Telluride, Cd 0.9 Zn 0.1 Te, (CZT) detectors is impaired by cumulative effect of tellurium precipitates (secondary phases) presented in CZT single-crystal grown by low-pressure Bridgman techniques(1). This statistical effect may limit the energy resolution of large-volume CZT detectors (typically 2-5% at 662 keV for 12-mm thick devices). The stochastic nature of the interaction prevents the use of any electronic or digital charge correction techniques without a significant reduction in the detector efficiency. This volume constraint hampers the utility of CZT since the detectors are inefficient at detecting photons >1MeV and/or in low fluency situations. During the project, seven runs CZT ingots have been grown, in these ingots the indium dopant concentrations have been changed in the range between 0.5ppm to 6ppm. The I-R mapping imaging method has been employed to study the Te-precipitates. The Teprecipitates in as-grown CZT wafers, and after annealing wafers have been systematically studied by using I-R mapping system (home installed, resolution of 1.5 (micro)m). We employed our I-R standard annealing CZT (Zn=4%) procedure or two-steps annealing into radiation CZT (Zn=10%), we achieved the 'non'-Te precipitates (size 10 9-10 (Omega)-cm. We believe that the Te-precipitates are the p-type defects, its reducing number causes the CZT became n+-type, therefore we varied or reduced the indium dapant concentration during the growth and changed the Te-precipitates size and density by using different Cd-temperature and different annealing procedures. We have made the comparisons among Te-precipitates size, density and Indium dopant concentrations, and we found that the CZT with smaller size of Te-precipitates is suitable for radiation uses but non-Te precipitates is impossible to be used in the radiation detectors, because the CZT would became un-dopant or 'intrinsic' with non radiation affection (we

  8. Effects of irradiation on platelet function

    International Nuclear Information System (INIS)

    Rock, G.; Adams, G.A.; Labow, R.S.

    1988-01-01

    Current medical practice involves the irradiation of blood components, including platelet concentrates, before their administration to patients with severe immunosuppression. The authors studied the effect of irradiation on in vitro platelet function and the leaching of plasticizers from the bag, both immediately and after 5 days of storage. The platelet count, white cell count, pH, glucose, lactate, platelet aggregation and release reaction, and serotonin uptake were not altered by the irradiation of random-donor or apheresis units with 2000 rads carried out at 0 and 24 hours and 5 days after collection. The leaching of di(2-ethylhexyl)phthalate from the plastic bags followed by the conversion to mono(2-ethylhexyl)phthalate was not increased by irradiation. Therefore, it is possible to irradiate platelet concentrates on the day of collection and subsequently store them for at least 5 days while maintaining in vitro function. This procedure could have considerable benefit for blood banks involved in the provision of many platelet products

  9. Glycans and glycosylation of platelets: current concepts and implications for transfusion

    DEFF Research Database (Denmark)

    Sørensen, Anne Louise; Hoffmeister, Karin M; Wandall, Hans H

    2008-01-01

    by the alphaMbeta2 hepatic lectin receptor. Capping the exposed beta-N-acetylglucosamine residues by enzymatic galactosylation restored the circulation of short-term chilled murine platelets, introducing a novel method that allows for cold storage of platelet. Recent studies have, however, shown...... that galactosylation is not sufficient to restore circulation of long-term refrigerated platelets. Additional data indicate that differential carbohydrate-mediated mechanisms may exist for clearance of short-term and long-term cold-stored platelets. SUMMARY: Room temperature storage of platelet products increases...... the risk of transfusion-mediated sepsis and accelerates platelet deterioration, limiting platelet shelf life. Recent evidence suggests that glycoengineering of platelets might allow for their cold storage, significantly improving the quality of platelet products....

  10. Association between increased epicardial adipose tissue volume and coronary plaque composition.

    Science.gov (United States)

    Yamashita, Kennosuke; Yamamoto, Myong Hwa; Ebara, Seitarou; Okabe, Toshitaka; Saito, Shigeo; Hoshimoto, Koichi; Yakushiji, Tadayuki; Isomura, Naoei; Araki, Hiroshi; Obara, Chiaki; Ochiai, Masahiko

    2014-09-01

    To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or calcified tissue, based on the radiofrequency spectrum. Epicardial adipose tissue was measured as the tissue ranging from -190 to -30 Hounsfield units. EATV, calculated as the sum of the fat areas on short-axis images, was 85.0 ± 34.0 cm(3). There was a positive correlation between EATV and the percentage of necrotic plaque tissue (R (2) = 0.34, P EATV and the percentage of fibrous tissue (R (2) = 0.24, P EATV (β = 0.14, P = 0.02) were independently associated with the percentage of necrotic plaque tissue. An increase in EATV was associated with the development of coronary atherosclerosis and, potentially, with the most dangerous type of plaque.

  11. Platelet transfusions reduce fibrinolysis but do not restore platelet function during trauma hemorrhage.

    Science.gov (United States)

    Vulliamy, Paul; Gillespie, Scarlett; Gall, Lewis S; Green, Laura; Brohi, Karim; Davenport, Ross A

    2017-09-01

    Platelets play a critical role in hemostasis with aberrant function implicated in trauma-induced coagulopathy. However, the impact of massive transfusion protocols on platelet function during trauma hemorrhage is unknown. The aim of this study was to characterize the effects of platelet transfusion on platelet aggregation and fibrinolytic markers during hemostatic resuscitation. Trauma patients enrolled into the prospective Activation of Coagulation and Inflammation in Trauma study between January 2008 and November 2015 who received at least four units of packed red blood cells (PRBCs) were included. Blood was drawn in the emergency department within 2 hours of injury and at intervals after every four units of PRBCs transfused. Platelet aggregation was assessed in whole blood with multiple electrode aggregometry. Plasma proteins were quantified by enzyme-linked immunosorbent assay. Of 161 patients who received four or more PRBCs as part of their initial resuscitation, 44 received 8 to 11 units and 28 received 12 units or more. At each timepoint during bleeding, platelet aggregation was similar in patients who had received a platelet transfusion compared with those who had only received other blood products (p > 0.05 for all timepoints). Platelet transfusion during the four PRBC intervals was associated with a decrease in maximum lysis on rotational thromboelastometry (start of interval, 6% [2-12] vs. end of interval, 2% [0-5]; p = 0.001), an increase in plasminogen activator inhibitor-1 (start of interval, 35.9 ± 14.9 vs. end of interval, 66.7 ± 22.0; p = 0.007) and a decrease in tissue plasminogen activator (start of interval, 26.2 ± 10.5 vs. end of interval, 19.0 +/- 5.1; p = 0.04). No statistically significant changes in these parameters occurred in intervals which did not contain platelets. Current hemostatic resuscitation strategies do not appear to restore platelet aggregation during active hemorrhage. However, stored platelets may attenuate fibrinolysis

  12. The Impact of Hospital Closures and Hospital and Population Characteristics on Increasing Emergency Department Volume: A Geographic Analysis.

    Science.gov (United States)

    Lee, David C; Carr, Brendan G; Smith, Tony E; Tran, Van C; Polsky, Daniel; Branas, Charles C

    2015-12-01

    Emergency visits are rising nationally, whereas the number of emergency departments is shrinking. However, volume has not increased uniformly at all emergency departments. It is unclear what factors account for this variability in emergency volume growth rates. The objective of this study was to test the association of hospital and population characteristics and the effect of hospital closures with increases in emergency department volume. The study team analyzed emergency department volume at New York State hospitals from 2004 to 2010 using data from cost reports and administrative databases. Multivariate regression was used to evaluate characteristics associated with emergency volume growth. Spatial analytics and distances between hospitals were used in calculating the predicted impact of hospital closures on emergency department use. Among the 192 New York hospitals open from 2004 to 2010, the mean annual increase in emergency department visits was 2.7%, but the range was wide (-5.5% to 11.3%). Emergency volume increased nearly twice as fast at tertiary referral centers (4.8%) and nonurban hospitals (3.7% versus urban at 2.1%) after adjusting for other characteristics. The effect of hospital closures also strongly predicted variation in growth. Emergency volume is increasing faster at specific hospitals: tertiary referral centers, nonurban hospitals, and those near hospital closures. This study provides an understanding of how emergency volume varies among hospitals and predicts the effect of hospital closures in a statewide region. Understanding the impact of these factors on emergency department use is essential to ensure that these populations have access to critical emergency services.

  13. 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.

  14. 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.

  15. Immature platelet fraction in bacterial sepsis severity assessment

    Science.gov (United States)

    Djuang, M. H.; Ginting, F.; Hariman, H.

    2018-03-01

    Sepsis is an infection-induced syndrome, mostly caused by bacteria, of organ dysfunctions that caused by host response dysregulations. One of the simplest sepsis-indicator is platelet and its indexes. A new platelet parameter called immature platelet count (IPF) became theinterest in this study. The study aims to see whether IPF could assess sepsis severity by procalcitonin (PCT).Sixty-four of seventy-one patients with increased PCT were included in this cross-sectional study and separated into three groups based on their PCT levels. IPF showed no significance among the three groups (p-value>0.05) while platelet count was significant (p-valuesepsis severity based on PCT showed larger platelet count, as the result of platelet destructions caused by pro-inflammatory cytokines and endotoxins.

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

    Science.gov (United States)

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

    2017-04-01

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

  17. Bringing biofuels on the market. Options to increase EU biofuels volumes beyond the current blending limits

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, B.; Van Grinsven, A.; Croezen, H. [CE Delft, Delft (Netherlands); Verbeek, R.; Van Mensch, P.; Patuleia, A. [TNO, Delft, (Netherlands)

    2013-07-15

    This handbook on biofuels provides a comprehensive overview of different types of biofuels, and the technical options that exist to market the biofuels volumes expected to be consumed in the EU Member States in 2020. The study concludes that by fully utilizing the current blending limits of biodiesel (FAME) in diesel (B7) and bioethanol in petrol (E10) up to 7.9% share of biofuels in the EU transport sector can be technically reached by 2020. Increasing use of advanced biofuels, particularly blending of fungible fuels into diesel (eg. HVO and BTL) and the use of higher ethanol blends in compatible vehicles (e.g. E20), can play an important role. Also, the increased use of biomethane (in particular bio-CNG) and higher blends of biodiesel (FAME) can contribute. However, it is essential for both governments and industry to decide within 1 or 2 years on the way ahead and take necessary actions covering both, the fuels and the vehicles, to ensure their effective and timely implementation. Even though a range of technical options exist, many of these require considerable time and effort to implement and reach their potential. Large scale implementation of the options beyond current blending limits requires new, targeted policy measures, in many cases complemented by new fuel and vehicle standards, adaptation of engines and fuel distribution, etc. Marketing policies for these vehicles, fuels and blends are also likely to become much more important than in the current situation. Each Member State may develop its own strategy tailored to its market and policy objectives, but the EU should play a crucial facilitating role in these developments.

  18. Radioimmunoassay of platelet proteins

    International Nuclear Information System (INIS)

    Pepper, D.S.

    1987-01-01

    The radioimmunoassay of platelet-specific proteins has proven to be an excellent way of monitoring platelet activation in vivo. In contrast to earlier methods such as aggregometry, which has been the major tool used in the evaluation of antiplatelet drugs, the RIAs are capable of working with samples which have been subjected to physiological conditions such as haematocrit, oxygen tension, shear rate and ionized calcium concentration. Also, in contrast to aggregometry, no choice of agonist is necessary. Thus, for the first time it has been possible to monitor the effects of therapeutic intervention with drugs upon the platelet release reaction in vivo. It seems reasonable to equate the release reaction in vivo with activation in vivo, though the stimuli necessarily remain unknown. Nevertheless, the fact that a significant number of the compounds mentioned in Table 3 are indeed capable of reducing platelet activation in vivo and that this effect can be measured objectively is a major step forward in our understanding of platelet pharmacology. Two important goals remain to be achieved, however, the establishment of nonhuman animal models for the evaluation of newer compounds in vivo and longer-term goal of proving in the clinical setting the relevance or otherwise of platelet activation per se to the clinical outcome of a particular disease. In this respect, the availability of accurate, reliable and specific radioimmunoassays has a central role

  19. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus, Prevents Platelet Activation in Human Platelets

    Directory of Open Access Journals (Sweden)

    Ye-Ming Lee

    2012-01-01

    Full Text Available Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.. Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation stimulated by collagen. Xanthohumol inhibited platelet activation accompanied by relative [Ca2+]i mobilization, thromboxane A2 formation, hydroxyl radical (OH● formation, and phospholipase C (PLCγ2, protein kinase C (PKC, mitogen-activated protein kinase (MAPK, and Akt phosphorylation. Neither SQ22536, an inhibitor of adenylate cyclase, nor ODQ, an inhibitor of guanylate cyclase, reversed the xanthohumol-mediated inhibitory effect on platelet aggregation. Furthermore, xanthohumol did not significantly increase nitrate formation in platelets. This study demonstrates for the first time that xanthohumol possesses potent antiplatelet activity which may initially inhibit the PI3-kinase/Akt, p38 MAPK, and PLCγ2-PKC cascades, followed by inhibition of the thromboxane A2 formation, thereby leading to inhibition of [Ca2+]i and finally inhibition of platelet aggregation. Therefore, this novel role of xanthohumol may represent a high therapeutic potential for treatment or prevention of cardiovascular diseases.

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

    Directory of Open Access Journals (Sweden)

    Sinead M Hurley

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

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

    Science.gov (United States)

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

    2006-12-05

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

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

    Science.gov (United States)

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

    2010-01-01

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

  3. Neonatal Platelet Transfusions and Future Areas of Research.

    Science.gov (United States)

    Sola-Visner, Martha; Bercovitz, Rachel S

    2016-10-01

    Thrombocytopenia affects approximately one fourth of neonates admitted to neonatal intensive care units, and prophylactic platelet transfusions are commonly administered to reduce bleeding risk. However, there are few evidence-based guidelines to inform clinicians' decision-making process. Developmental differences in hemostasis and differences in underlying disease processes make it difficult to apply platelet transfusion practices from other patient populations to neonates. Thrombocytopenia is a risk factor for common preterm complications such as intraventricular hemorrhage; however, a causal link has not been established, and platelet transfusions have not been shown to reduce risk of developing intraventricular hemorrhage. Platelet count frequently drives the decision of whether to transfuse platelets, although there is little evidence to demonstrate what a safe platelet nadir is in preterm neonates. Current clinical assays of platelet function often require large sample volumes and are not valid in the setting of thrombocytopenia; however, evaluation of platelet function and/or global hemostasis may aid in the identification of neonates who are at the highest risk of bleeding. Although platelets' primary role is in establishing hemostasis, platelets also carry pro- and antiangiogenic factors in their granules. Aberrant angiogenesis underpins common complications of prematurity including intraventricular hemorrhage and retinopathy of prematurity. In addition, platelets play an important role in host immune defenses. Infectious and inflammatory conditions such as sepsis and necrotizing enterocolitis are commonly associated with late-onset thrombocytopenia in neonates. Severity of thrombocytopenia is correlated with mortality risk. The nature of this association is unclear, but preclinical data suggest that thrombocytopenia contributes to mortality rather than simply being a proxy for disease severity. Neonates are a distinct patient population in whom

  4. Aerobic exercise training lowers platelet reactivity and improves platelet sensitivity to prostacyclin in pre- and postmenopausal women

    DEFF Research Database (Denmark)

    Lundberg Slingsby, Martina Helena; Nyberg, Michael Permin; Egelund, Jon

    2017-01-01

    BACKGROUND: The risk of atherothrombotic events increases after menopause. Regular physical activity has been shown to reduce platelet reactivity in younger women, but it is unknown how regular exercise affects platelet function after menopause. OBJECTIVES: To examine the effects of regular aerobic...... exercise in late pre- and recent postmenopausal women by testing basal platelet reactivity and platelet sensitivity to prostacyclin and nitric oxide. METHODS: 25 sedentary, but healthy, late premenopausal and 24 matched recently postmenopausal women, mean (95% confidence interval) 49.1 (48.2-49.9) and 53...... postmenopausal women, platelet reactivity was tested ex vivo after femoral arterial infusion of prostacyclin, acetylcholine, a cyclooxygenase inhibitor and after acute one-leg knee extensor exercise. RESULTS: Basal platelet reactivity (%aggregation) to TRAP-6(1μM) was higher in the postmenopausal; 59% (50...

  5. Calidad del plasma rico en plaquetas: estudio de la activación plaquetaria Platelet-rich plasma quality: a study on platelet activation

    Directory of Open Access Journals (Sweden)

    C. Sáez-Torres Barroso

    2007-08-01

    Full Text Available Objetivo. El plasma rico en plaquetas (PRP es utilizado de forma cada vez más frecuente en técnicas quirúrgicas de regeneración tisular. No obstante, el procesamiento de la sangre hasta obtener PRP puede desencadenar la activación prematura de las plaquetas y la pérdida de los factores bioactivos. En este trabajo estudiamos la calidad de los concentrados de plaquetas obtenidos siguiendo la técnica de doble centrifugación en tubo. Método. Se someten 50 ml de sangre a una primera centrifugación a 200g 10 minutos, se recoge el sobrenadante y se centrifuga a 700g 15 minutos. Posteriormente, tras eliminar las 2/3 partes del plasma, se resuspenden las plaquetas y se analiza el grado de enriquecimiento, el estado de activación y la reserva funcional de las plaquetas. Resultados. El enriquecimiento en plaquetas del PRP fue de 364±177% (n=45 respecto de los niveles presentes en sangre total. Mediante el estudio de la expresión de CD62 por citometría de flujo se determinó el porcentaje de plaquetas activadas en las muestras de 8 donantes. Mientras que en la sangre no procesada se detectó un 2,7% de plaquetas activadas, tras la preparación del PRP éste era sólo de 3,6%, aumentando hasta el 16% en el concentrado almacenado toda la noche a 22º C. Tras la estimulación con trombina el porcentaje de plaquetas activadas fue de 96,2%. Conclusión. Este protocolo de preparación de PRP no produce una activación significativa de las plaquetas. La respuesta a la estimulación con trombina de los concentrados indica un buen estado de reserva plaquetaria.Objective. Platelet Rich Plasma (PRP is an autologous preparation currently used in oral and maxillofacial reconstructive surgery. Blood collection and preparation of platelet concentrates may lead to platelet activation and the premature loss of their granular load. In this study, we have analyzed the quality of the PRP obtained from a small volume of whole blood through a double centrifugation

  6. Comparison of neutrophil-to-lymphocyte ratio and mean platelet volume in the prediction of adverse events after primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction.

    Science.gov (United States)

    Machado, Guilherme Pinheiro; Araujo, Gustavo Neves de; Carpes, Christian Kunde; Lech, Mateus; Mariani, Stefani; Valle, Felipe Homem; Bergoli, Luiz Carlos Corsetti; Gonçalves, Sandro Cadaval; Wainstein, Rodrigo V; Wainstein, Marco V

    2018-07-01

    Elevated neutrophil-to-lymphocyte ratio (NLR) and mean platelet volume (MPV) are indirect inflammatory markers. There is some evidence that both are associated with worse outcomes in ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PCI). The aim of the present study was to compare the capacity of NLR and MPV to predict adverse events after primary PCI. In a prospective cohort study, 625 consecutive patients with STEMI, who underwent primary PCI, were followed. Receiver operating characteristic (ROC) curve analysis was performed to calculate the area under the curve (AUC) for the occurrence of procedural complications, mortality and major adverse cardiovascular events (MACE). Mean age was 60.7 (±12.1) years, 67.5% were male. The median of NLR was 6.17 (3.8-9.4) and MPV was 10.7 (10.0-11.3). In multivariate analysis, both NLR and MPV remained independent predictors of no-reflow (relative risk [RR] = 2.26; 95%confidence interval [95%CI] = 1.16-4.32; p = 0.01 and RR = 2.68; 95%CI = 1.40-5.10; p  0.05). NLR had an excellent negative predictive value (NPV) of 96.7 for no-reflow and 89.0 for in-hospital MACE. Despite no difference in the ROC curve comparison with MPV, only NLR remained an independent predictor for in-hospital MACE. A low NLR has an excellent NPV for no-reflow and in-hospital MACE, and this could be of clinical relevance in the management of low-risk patients. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Genetics Home Reference: gray platelet syndrome

    Science.gov (United States)

    ... disorder, platelet-type, 4 deficient alpha granule syndrome GPS grey platelet syndrome platelet alpha-granule deficiency platelet ... on PubMed Central Kahr WH, Hinckley J, Li L, Schwertz H, Christensen H, Rowley JW, Pluthero FG, ...

  8. Platelets and hemophilia: A review of the literature.

    Science.gov (United States)

    Riedl, Julia; Ay, Cihan; Pabinger, Ingrid

    2017-07-01

    Hemophilia A and B are inherited bleeding disorders due to deficiencies of the clotting factors VIII and IX, respectively. The severity of the disease correlates with remaining factor levels, although individual differences in bleeding tendency are seen despite similar factor levels. While thrombin generation is severely impaired in persons with hemophilia, primary hemostasis, i.e. platelet function, has been generally considered to be normal. However, some studies reported prolonged bleeding times in hemophilia, suggesting that also primary hemostasis is affected. In several other studies different aspects of platelet function in hemophilia have been investigated in more detail and various alterations were discovered, such as increased platelet P-selectin expression, a lower number of procoagulant, so-called 'coated' platelets, lower aggregation upon co-incubation with tissue factor, or reduced platelet contractile forces during clot formation in comparison to healthy individuals. An influence of platelet function on clinical phenotype was suggested, which might contribute in part to variations in bleeding tendency in hemophilic patients with similar factor levels. However, the available evidence is currently limited and no clear correlations between platelet function parameters and clinical phenotypes have been demonstrated. The impact of alterations of platelet function in hemophilia remains to be better defined. Another interesting role of platelets in hemophilia has been reported recently by establishing a novel gene-therapeutic strategy using platelets as a delivery system for FVIII, showing promising results in animal models. This review gives an overview on the currently published literature on platelet function and the potential roles of platelets in hemophilia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Human plasma fibrinogen adsorption and platelet adhesion to polystyrene.

    Science.gov (United States)

    Tsai, W B; Grunkemeier, J M; Horbett, T A

    1999-02-01

    The purpose of this study was to further investigate the role of fibrinogen adsorbed from plasma in mediating platelet adhesion to polymeric biomaterials. Polystyrene was used as a model hydrophobic polymer; i.e., we expected that the role of fibrinogen in platelet adhesion to polystyrene would be representative of other hydrophobic polymers. Platelet adhesion was compared to both the amount and conformation of adsorbed fibrinogen. The strategy was to compare platelet adhesion to surfaces preadsorbed with normal, afibrinogenemic, and fibrinogen-replenished afibrinogenemic plasmas. Platelet adhesion was determined by the lactate dehydrogenase (LDH) method, which was found to be closely correlated with adhesion of 111In-labeled platelets. Fibrinogen adsorption from afibrinogenemic plasma to polystyrene (Immulon I(R)) was low and polystyrene preadsorbed with fibrinogen-replenished afibrinogenemic plasma. Addition of even small, subnormal concentrations of fibrinogen to afibrinogenemic plasma greatly increased platelet adhesion. In addition, surface-bound fibrinogen's ability to mediate platelet adhesion was different, depending on the plasma concentration from which fibrinogen was adsorbed. These differences correlated with changes in the binding of a monoclonal antibody that binds to the Aalpha chain RGDS (572-575), suggesting alteration in the conformation or orientation of the adsorbed fibrinogen. Platelet adhesion to polystyrene preadsorbed with blood plasma thus appears to be a strongly bivariate function of adsorbed fibrinogen, responsive to both low amounts and altered states of the adsorbed molecule. Copyright 1999 John Wiley & Sons, Inc.

  10. In vitro model of platelet aggregation in stenotic arteries

    International Nuclear Information System (INIS)

    Morley, D.; Santamore, W.P.

    1988-01-01

    Clinical and experimental evidence suggest a strong relationship between arterial stenosis, platelet aggregation, and subsequent thrombus formation. To facilitate the study of platelet accumulation in stenotic arteries, we developed an in vitro preparation. Arterial segments were perfused with whole citrated blood. A stenosis was created by applying an external plastic constrictor to the artery. Platelet accumulation within the stenosis was assessed by scanning electron microscopy and by radioactive counts from Indium-111 labeled platelets. Utilizing this preparation, 30 carotid arterial segments from 10 mongrel dogs were perfused at 100 mmHg for 15 min. In 10 arteries without a stenosis, scanning electron microscopy and radioactive counts demonstrated little platelet accumulation. In contrast, extensive platelet aggregation was observed in 10 arteries with stenoses. Moreover, in 10 stenotic arteries exposed to the thromboxane mimetic, U46619 (Upjohn Diagnostic Group), scanning electron microscopy and radioactive counts demonstrated a significant increase in platelet deposition. Conversely, we demonstrated a dimunition of platelet accumulation in stenosed arterial segments exposed to the prostacyclin analogue platelet inhibitor, Iloprost. The in vitro preparation allows precise control of hemodynamic variables and makes it possible to perform multiple tests on segments of the same vessel from the same animal

  11. Platelet indices in Philadelphia-negative chronic myeloproliferative neoplasms / Indicii plachetari de volum în neoplasmele mieloproliferative cronice Philadelphia-negative

    Directory of Open Access Journals (Sweden)

    Olteanu Ariela-Ligia

    2015-06-01

    Full Text Available Introducere: Neoplasmele mieloproliferative cronice cromozom Philadelphia negative (Ph-MPN -policitemia vera (PV, trombocitemia esenţială (TE şi mielofibroza primară (MP - sunt caracterizate de o rată mare de complicaţii trombotice, parţial date de activarea trombocitară. Trombocitele mari sunt mai active, cu o funcţie procoagulantă crescută şi au rol patogenic demonstrat în tromboza arterială şi venoasă. În studiul nostru am încercat să stabilim dacă indicii trombocitari (MPV, PDW, P-LCR, furnizaţi de analizoarele de hematologie în hemoleucograma completă, sunt modificaţi la pacienţii diagnosticaţi cu Ph-MPN comparativ cu subiecţii sănătoşi. Material şi metodă: Hemoleucograma, ce a inclus şi indicii trombocitari, a fost determinată la 102 pacienţi Ph- MPN şi la 102 subiecţi sănătoşi cu ajutorul analizorului de hematologie Sysmex XS 1000i (metoda impedanţei, iar testele biochimice (glucoza şi parametrii metabolismului lipidic, pe analizorul Architect c8000. Prezenţa mutaţiei JAK2 V617F, la pacienţii cu Ph-MPN, a fost evidenţiată prin tehnica ARMS-PCR. Rezultate: Indicii de volum plachetari (IVP măsuraţi prin metoda impedanţei, nu au fost semnificativ modificaţi la pacienţii cu Ph-MPN comparativ cu cei ai subiecţilor sănătoşi. Totuşi, am observat o moderată corelaţie între valoarea acestor indici şi prezenţa mutaţiei JAK2V617F, fără însă a se atinge o diferenţă semnificativă din punct de vedere statistic. IVP au fost crescuţi la micul subgrup de pacienţi trataţi cu anagrelide şi scăzuţi la cei trataţi cu simvastatin, comparativ cu pacienţii care nu au primit aceste terapii. Concluzii: Folosind metoda impedanţei în determinarea indicilor trombocitari, în studiul nostru nu am demonstrat o diferenţă semnificativă între valorile indicilor trombocitari la pacienţii cu Ph- MPN comparativ cu subiecţii sănătoşi. Sunt necesare studii ulterioare pentru a demonstra o

  12. Potential of pomegranate fruit extract (Punica granatum Linn.) to increase vascular endothelial growth factor and platelet-derived growth factor expressions on the post-tooth extraction wound of Cavia cobaya.

    Science.gov (United States)

    Nirwana, Intan; Rachmadi, Priyawan; Rianti, Devi

    2017-08-01

    Pomegranates fruit extracts have several activities, among others, anti-inflammatory, antibacterial, and antioxidants that have the main content punicalagin and ellagic acid. Pomegranate has the ability of various therapies through different mechanisms. Vascular endothelial growth factor (VEGF) function was to form new blood vessels produced by various cells one of them was macrophages. Platelet-derived growth factor (PDGF) was a growth factor proven chemotactic, increased fibroblast proliferation and collagen matrix production. In addition, VEGF and PDGF synergize in their ability to vascularize tissues. The PDGF function was to stabilize and regulate maturation of new blood vessels. Activities of pomegranate fruit extract were observed by measuring the increased of VEGF and PDGF expression as a marker of wound healing process. To investigate the potential of pomegranate extracts on the tooth extraction wound to increase the expression of VEGF and PDGF on the 4 th day of wound healing process. This study used 12 Cavia cobaya , which were divided into two groups, namely, the provision of 3% sodium carboxymethyl cellulose and pomegranate extract. The 12 C. cobaya would be executed on the 4 th day, the lower jaw of experimental animals was taken, decalcified about 30 days. The expression of VEGF and PDGF was examined using immunohistochemical techniques. The differences of VEGF and PDGF expression were evaluated statistically using t-test. Statistically analysis showed that there were significant differences between control and treatment groups (p<0.05). Pomegranate fruit extract administration increased VEGF and PDGF expression on post-tooth extraction wound.

  13. Platelet-rich preparations to improve healing. Part II: platelet activation and enrichment, leukocyte inclusion, and other selection criteria.

    Science.gov (United States)

    Davis, Vicki L; Abukabda, Alaeddin B; Radio, Nicholas M; Witt-Enderby, Paula A; Clafshenkel, William P; Cairone, J Vito; Rutkowski, James L

    2014-08-01

    Multiple platelet-rich preparations have been reported to improve wound and bone healing, such as platelet-rich plasma (PRP) and platelet rich fibrin (PRF). The different methods employed during their preparation are important, as they influence the quality of the product applied to a wound or surgical site. Besides the general protocol for preparing the platelet-rich product (discussed in Part 1 of this review), multiple choices need to be considered during its preparation. For example, activation of the platelets is required for the release and enmeshment of growth factors, but the method of activation may influence the resulting matrix, growth factor availability, and healing. Additionally, some methods enrich leukocytes as well as platelets, but others are designed to be leukocyte-poor. Leukocytes have many important roles in healing and their inclusion in PRP results in increased platelet concentrations. Platelet and growth factor enrichment reported for the different types of platelet-rich preparations are also compared. Generally, TGF-β1 and PDGF levels were higher in preparations that contain leukocytes compared to leukocyte-poor PRP. However, platelet concentration may be the most reliable criterion for comparing different preparations. These and other criteria are described to help guide dental and medical professionals, in large and small practices, in selecting the best procedures for their patients. The healing benefits of platelet-rich preparations along with the low risk and availability of simple preparation procedures should encourage more clinicians to incorporate platelet-rich products in their practice to accelerate healing, reduce adverse events, and improve patient outcomes.

  14. 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.

  15. Two Alzheimer’s disease risk genes increase entorhinal cortex volume in young adults

    Directory of Open Access Journals (Sweden)

    Amanda Marie Dibattista

    2014-10-01

    Full Text Available Alzheimer’s disease (AD risk genes alter brain structure and function decades before disease onset. Apolipoprotein E (APOE is the strongest known genetic risk factor for Alzheimer’s disease, and a related gene, apolipoprotein J (APOJ, also affects disease risk. However, the extent to which these genes affect brain structure in young adults remains unclear. Here, we report that AD risk alleles of these two genes, APOE-ε4 and APOJ-C, cumulatively alter brain volume in young adults. Using voxel-based morphometry in 57 individuals, we examined the entorhinal cortex, one of the earliest brain regions affected in AD pathogenesis. APOE-ε4 carriers exhibited higher right entorhinal cortex volume compared to non-carriers. Interestingly, APOJ-C risk genotype was associated with higher bilateral entorhinal cortex volume in non-APOE-ε4 carriers. To determine the combined disease risk of APOE and APOJ status per subject, we used cumulative odds ratios as regressors for volumetric measurements. Higher disease risk corresponded to greater right entorhinal cortex volume. These results suggest that, years before disease onset, two key AD genetic risk factors may exert influence on the structure of a brain region where AD pathogenesis takes root.

  16. Two Alzheimer’s disease risk genes increase entorhinal cortex volume in young adults

    Science.gov (United States)

    DiBattista, Amanda Marie; Stevens, Benson W.; Rebeck, G. William; Green, Adam E.

    2014-01-01

    Alzheimer’s disease (AD) risk genes alter brain structure and function decades before disease onset. Apolipoprotein E (APOE) is the strongest known genetic risk factor for AD, and a related gene, apolipoprotein J (APOJ), also affects disease risk. However, the extent to which these genes affect brain structure in young adults remains unclear. Here, we report that AD risk alleles of these two genes, APOE-ε4 and APOJ-C, cumulatively alter brain volume in young adults. Using voxel-based morphometry (VBM) in 57 individuals, we examined the entorhinal cortex, one of the earliest brain regions affected in AD pathogenesis. Apolipoprotein E-ε4 carriers exhibited higher right entorhinal cortex volume compared to non-carriers. Interestingly, APOJ-C risk genotype was associated with higher bilateral entorhinal cortex volume in non-APOE-ε4 carriers. To determine the combined disease risk of APOE and APOJ status per subject, we used cumulative odds ratios as regressors for volumetric measurements. Higher disease risk corresponded to greater right entorhinal cortex volume. These results suggest that, years before disease onset, two key AD genetic risk factors may exert influence on the structure of a brain region where AD pathogenesis takes root. PMID:25339884

  17. Increase in Prefrontal Cortical Volume following Cognitive Behavioural Therapy in Patients with Chronic Fatigue Syndrome

    Science.gov (United States)

    de Lange, Floris P.; Koers, Anda; Kalkman, Joke S.; Bleijenberg, Gijs; Hagoort, Peter; van der Meer, Jos W. M.; Toni, Ivan

    2008-01-01

    Chronic fatigue syndrome (CFS) is a disabling disorder, characterized by persistent or relapsing fatigue. Recent studies have detected a decrease in cortical grey matter volume in patients with CFS, but it is unclear whether this cerebral atrophy constitutes a cause or a consequence of the disease. Cognitive behavioural therapy (CBT) is an…

  18. Rowing increases stroke volume and cardiac output to a greater extent than cycling

    Czech Academy of Sciences Publication Activity Database

    Horn, P.; Ošťádal, P.; Ošťádal, Bohuslav

    2015-01-01

    Roč. 64, č. 2 (2015), s. 203-207 ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : cardiac output * cycling * heart rate * stroke volume Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.643, year: 2015

  19. An Evaluation of the Accuracy of the Subtraction Method Used for Determining Platelet Counts in Advanced Platelet-Rich Fibrin and Concentrated Growth Factor Preparations

    Directory of Open Access Journals (Sweden)

    Taisuke Watanabe

    2017-01-01

    Full Text Available Platelet concentrates should be quality-assured of purity and identity prior to clinical use. Unlike for the liquid form of platelet-rich plasma, platelet counts cannot be directly determined in solid fibrin clots and are instead calculated by subtracting the counts in other liquid or semi-clotted fractions from those in whole blood samples. Having long suspected the validity of this method, we herein examined the possible loss of platelets in the preparation process. Blood samples collected from healthy male donors were immediately centrifuged for advanced platelet-rich fibrin (A-PRF and concentrated growth factors (CGF according to recommended centrifugal protocols. Blood cells in liquid and semi-clotted fractions were directly counted. Platelets aggregated on clot surfaces were observed by scanning electron microscopy. A higher centrifugal force increased the numbers of platelets and platelet aggregates in the liquid red blood cell fraction and the semi-clotted red thrombus in the presence and absence of the anticoagulant, respectively. Nevertheless, the calculated platelet counts in A-PRF/CGF preparations were much higher than expected, rendering the currently accepted subtraction method inaccurate for determining platelet counts in fibrin clots. To ensure the quality of solid types of platelet concentrates chairside in a timely manner, a simple and accurate platelet-counting method should be developed immediately.

  20. 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.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  2. Dual roles for hepatic lectin receptors in the clearance of chilled platelets

    DEFF Research Database (Denmark)

    Rumjantseva, Viktoria; Grewal, Prabhjit K; Wandall, Hans H

    2009-01-01

    -GlcNAc moieties by galactosylation prevents clearance of short-term-cooled platelets, this strategy is ineffective after prolonged refrigeration. We report here that prolonged refrigeration increased the density and concentration of exposed galactose residues on platelets such that hepatocytes, through Ashwell-Morell...... transfusion. Inhibition of chilled platelet clearance by both beta(2) integrin and Ashwell-Morell receptors may afford a potentially simple method for storing platelets in the cold....

  3. 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

  4. Treatment results of combined platelet-rich plasma and fat injection in patients with velopharyngeal insufficiency

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    Hamid Reza Fathi

    2013-10-01

    Full Text Available Background: Velopharyngeal insufficiency causes hypernasal vocal quality and can also result in audible nasal air emission and difficulty in producing pressure consonants. The resulting speech is often socially unacceptable and can be difficult to understand. Platelet-rich plasma is an autologous derivative of whole blood. Today, the importance of clinical use of Platelet-rich plasma in the plastic surgery is considered. This study was designed to evaluate the effectiveness of combined Platelet-rich plasma and fat injection in the treatment of velopharyngeal insufficiency. Methods: In this prospective clinicaltrial study, of 15 patients including 9 males and 6 females and aged 15-20 years with mild/ moderate velopharyngeal insufficiency who were injected with 5 mL of combined Platelet-rich plasma (1 mL and fat (4 mL in the front volume in the posterior pharyngeal wall in the pre-vertebral fascia under sedation. Speech samples were recorded by nasoendoscopy before the injection, and at 6 weeks and 6 months after the injection. Assessment of pathologic speech was done by speech therapist. Results: Velar displacement showed significantly increased at 6 weeks after the injection (P=0.049. Velopharyngeal gap disappeared in 60% of patients at 6 weeks after the injection (P=0.019. Lateral pharyngeal wall movement showed significantly increased in 73.3% of the patients at 6 months after the injection (P=0.04. After the treatment, aerodynamic assessment showed significantly decreased in nasal air escape during phonation and repeat the words (P<0.05. Assessment speech therapist showed significantly improve quality of phonation in these patients (P<0.05. Conclusion: It seems that, combined Platelet-rich plasma and fat injection lead to improve voice resonance and reduce nasal air escape in all treated cases. It can be a promising alternative to major procedures, such as velopharyngoplasties, for the treatment of mild/ moderate velopharyngeal insufficiency.

  5. Increased cartilage volume after injection of hyaluronic acid in osteoarthritis knee patients who underwent high tibial osteotomy.

    Science.gov (United States)

    Chareancholvanich, Keerati; Pornrattanamaneewong, Chaturong; Narkbunnam, Rapeepat

    2014-06-01

    High tibial osteotomy (HTO) is a surgical procedure used to correct abnormal mechanical loading of the knee joint; additionally, intra-articular hyaluronic acid injections have been shown to restore the viscoelastic properties of synovial fluid and balance abnormal biochemical processes. It was hypothesized that combining HTO with intra-articular hyaluronic acid injections would have benefit to improve the cartilage volume of knee joints. Forty patients with medial compartment knee osteoarthritis (OA) were randomly placed into 1 of 2 groups. The study group (n = 20) received 2 cycles (at 6-month intervals) of 5 weekly intra-articular hyaluronic acid injections after HTO operation. The control group (n = 20) did not receive any intra-articular injections after HTO surgery. Cartilage volume (primary outcome) was assessed by magnetic resonance imaging (MRI) pre-operatively and 1 year post-operatively. Treatment efficacy (secondary outcomes) was evaluated with the Western Ontario and McMaster Universities OA Index (WOMAC) and by the comparison of the total rescue medication (paracetamol/diclofenac) used (weeks 6, 12, 24, 48). MRI studies showed a significant increase in total cartilage volume (p = 0.033), lateral femoral cartilage volume (p = 0.044) and lateral tibial cartilage volume (p = 0.027) in the study group. Cartilage volume loss was detected at the lateral tibial plateau in the control group. There were significant improvements after surgery in both groups for all subscales of WOMAC scores (p hyaluronic acid injections may be beneficial for increasing total cartilage volume and preventing the loss of lateral tibiofemoral joint cartilage after HTO. Therapeutic study, Level I.

  6. Long-Term Treatment with Paroxetine Increases Verbal Declarative Memory and Hippocampal Volume in Posttraumatic Stress Disorder

    Science.gov (United States)

    Vermetten, Eric; Vythilingam, Meena; Southwick, Steven M.; Charney, Dennis S.; Bremner, J. Douglas

    2011-01-01

    Background Animal studies have shown that stress is associated with damage to the hippocampus, inhibition of neurogenesis, and deficits in hippocampal-based memory dysfunction. Studies in patients with posttraumatic stress disorder (PTSD) found deficits in hippocampal-based declarative verbal memory and smaller hippocampal volume, as measured with magnetic resonance imaging (MRI). Recent preclinical evidence has shown that selective serotonin reuptake inhibitors promote neurogenesis and reverse the effects of stress on hippocampal atrophy. This study assessed the effects of long-term treatment with paroxetine on hippocampal volume and declarative memory performance in PTSD. Methods Declarative memory was assessed with the Wechsler Memory Scale–Revised and Selective Reminding Test before and after 9–12 months of treatment with paroxetine in PTSD. Hippocampal volume was measured with MRI. Of the 28 patients who started the protocol, 23 completed the full course of treatment and neuropsychological testing. Twenty patients were able to complete MRI imaging. Results Patients with PTSD showed a significant improvement in PTSD symptoms with treatment. Treatment resulted in significant improvements in verbal declarative memory and a 4.6% increase in mean hippocampal volume. Conclusions These findings suggest that long-term treatment with paroxetine is associated with improvement of verbal declarative memory deficits and an increase in hippocampal volume in PTSD. PMID:14512209

  7. Platelet aggregation following trauma

    DEFF Research Database (Denmark)

    Windeløv, Nis A; Sørensen, Anne M; Perner, Anders

    2014-01-01

    We aimed to elucidate platelet function in trauma patients, as it is pivotal for hemostasis yet remains scarcely investigated in this population. We conducted a prospective observational study of platelet aggregation capacity in 213 adult trauma patients on admission to an emergency department (ED...... severity score (ISS) was 17; 14 (7%) patients received 10 or more units of red blood cells in the ED (massive transfusion); 24 (11%) patients died within 28 days of trauma: 17 due to cerebral injuries, four due to exsanguination, and three from other causes. No significant association was found between...... aggregation response and ISS. Higher TRAP values were associated with death due to cerebral injuries (P 

  8. Is automated platelet counting still a problem in thrombocytopenic blood?

    Directory of Open Access Journals (Sweden)

    Raimundo Antônio Gomes Oliveira

    Full Text Available CONTEXT: Reliable platelet counting is crucial for indicating prophylactic platelet transfusion in thrombocytopenic patients. OBJECTIVE: To evaluate the precision and accuracy of platelet counting for thrombocytopenic patients, using four different automated counters in comparison with the Brecher & Cronkite reference method recommended by the International Committee for Standardization in Hematology (ICSH. TYPE OF STUDY: Automated platelet counting assessment in thrombocytopenic patients. SETTING: Hematology Laboratory, Hospital do Servidor Público Estadual de São Paulo, and the Hematology Division of Instituto Adolfo Lutz, São Paulo, SP, Brazil. MAIN MEASUREMENTS: Brecher & Cronkite reference method and four different automated platelet counters. PARTICIPANTS: 43 thrombocytopenic patients with platelet counts of less than 30,000/µl RESULTS: The ADVIA-120 (Bayer, Coulter STKS, H1 System (Technicom-Bayer and Coulter T-890 automatic instruments presented great precision and accuracy in relation to laboratory thrombocytopenic samples obtained by diluting blood from normal donors. However, when thrombocytopenic patients were investigated, all the counters except ADVIA (which is based on volume and refraction index showed low accuracy when compared to the Brecher & Cronkite reference method (ICSH. The ADVIA counter showed high correlation (r = 0.947. However, all counters showed flags in thrombocytopenic samples. CONCLUSION: The Brecher & Cronkite reference method should always be indicated in thrombocytopenic patients for platelet counts below 30,000 plt /µl obtained in one dimensional counters.

  9. Association between increased epicardial adipose tissue volume and coronary plaque composition

    OpenAIRE

    Yamashita, Kennosuke; Yamamoto, Myong Hwa; Ebara, Seitarou; Okabe, Toshitaka; Saito, Shigeo; Hoshimoto, Koichi; Yakushiji, Tadayuki; Isomura, Naoei; Araki, Hiroshi; Obara, Chiaki; Ochiai, Masahiko

    2013-01-01

    To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or ...

  10. Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model

    OpenAIRE

    A. Gnanadesikan; J. P. Dunne; J. John

    2012-01-01

    Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1) shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., su...

  11. 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

  12. Increased gray matter volume of left pars opercularis in male orchestral musicians correlate positively with years of musical performance.

    Science.gov (United States)

    Abdul-Kareem, Ihssan A; Stancak, Andrej; Parkes, Laura M; Sluming, Vanessa

    2011-01-01

    To compare manual volumetry of gray matter (GM) / white matter (WM) of Broca's area subparts: pars opercularis (POP) and pars triangularis (PTR) in both hemispheres between musicians and nonmusician, as it has been shown that these regions are crucial for musical abilities. A previous voxel-based morphometric (VBM) study conducted in our laboratory reported increased GM density in Broca's area of left hemisphere in male orchestral musicians. Functional segregation of POP/PTR justified separate volumetric analysis of these parts. We used the same cohort for the VBM study. Manual morphometry (stereology) was used to compare volumes between 26/26 right-handed orchestral musicians/nonmusicians. As expected, musicians showed significantly increased GM volume in the Broca's area, specifically in the left POP. No significant results were detected in right POP, left/right PTR GM volumes, and WM volumes for all regions. Results were positively correlated with years of musical performance (r = 0.7, P = 0.0001). This result corroborates the VBM study and is in line with the hypothesis of critical involvement of POP in hearing-action integration being an integral component of frontoparietotemporal mirror neuron network. We hypothesize that increased size of musicians' left POP represent use-dependent structural adaptation in response to intensive audiomotor skill acquisition. Copyright © 2010 Wiley-Liss, Inc.

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

    Science.gov (United States)

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

    2016-01-01

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

  14. Blood platelet inventory management

    NARCIS (Netherlands)

    Haijema, R.; van Dijk, N. M.; van der Wal, J.; Boucherie, Richard J.; van Dijk, Nico M.

    2017-01-01

    This paper illustrates how MDP or Stochastic Dynamic Programming (SDP) can be used in practice for blood management at blood banks; both to set regular production quantities for perishable blood products (platelets) and how to do so in irregular periods (as holidays). The state space is too large to

  15. Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

    International Nuclear Information System (INIS)

    Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

    1983-01-01

    Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP (platelet-rich plasma). Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. Results obtained by the two methods were compared using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI 2 (prostacyclin) or PGE 1 (prostaglandin E 1 ) was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a 125 I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP

  16. Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

    International Nuclear Information System (INIS)

    Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

    1983-01-01

    Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP. Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. We have compared the results obtained by the two methods, using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI2 or PGE1 was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a 125 I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP. It is suggested that there are advantages and disadvantages to both methods of measurement of platelet aggregation and that the parameters being measured must be clearly understood to properly interpret the results

  17. Kinetics and biodistribution of In-111 platelets in patients with bone marrow transplants, refractory to platelet transfusions

    International Nuclear Information System (INIS)

    Civelek, C.; Braine, H.; Scheffel, U.; Drew, H.; Koester, A.; LaFrance, N.; Kasecamp, W.; Wagner, H. Jr.

    1984-01-01

    The kinetics and biodistribution of HLA identical In-111 labeled platelets was studied in 10 leukemic patients with bone marrow transplants refractory to HLA matched platelet transfusions. Platelet survival time was short (x-bar +- SEM =1.64 +- 0.83 days). The mean recovery (extrapolated to zero time) was 29.9%, ranging from 14.2 to 63.0%. The deposition of the In-111 platelets in the liver and spleen was quantified by the geometric mean method using anterior and posterior imaging. In 3 patients liver uptake was significantly increased. The highest hepatic accumulation of In-111 occurred 2 hrs after injection (x-bar=76 +- 6% dose (SEM); at 48 hrs 62% of the dose remained in the liver. In 7 patients the spleen was the organ with the highest labeled platelet deposition. The splenic uptake of In-111 platelets in this group correlated with the spleen size (r=+0.95). At 30 min after injection 75+-6% of the dose was found in the spleen. Splenic activity decreased to 62% after 48 hrs. At the same time, In-111 liver accumulation increased from 14 to 31%. This finding suggests that In-111 may be released from the spleen and subsequently sequestered by the liver. Two patients with high splenic uptake underwent splenectomy after the In-111 platelet study. Both benefited from splenectomy in terms of platelet survival after transfusion

  18. Kinetics and biodistribution of In-111 platelets in patients with bone marrow transplants, refractory to platelet transfusions

    Energy Technology Data Exchange (ETDEWEB)

    Civelek, C.; Braine, H.; Scheffel, U.; Drew, H.; Koester, A.; LaFrance, N.; Kasecamp, W.; Wagner, H. Jr.

    1984-01-01

    The kinetics and biodistribution of HLA identical In-111 labeled platelets was studied in 10 leukemic patients with bone marrow transplants refractory to HLA matched platelet transfusions. Platelet survival time was short (x-bar +- SEM =1.64 +- 0.83 days). The mean recovery (extrapolated to zero time) was 29.9%, ranging from 14.2 to 63.0%. The deposition of the In-111 platelets in the liver and spleen was quantified by the geometric mean method using anterior and posterior imaging. In 3 patients liver uptake was significantly increased. The highest hepatic accumulation of In-111 occurred 2 hrs after injection (x-bar=76 +- 6% dose (SEM); at 48 hrs 62% of the dose remained in the liver. In 7 patients the spleen was the organ with the highest labeled platelet deposition. The splenic uptake of In-111 platelets in this group correlated with the spleen size (r=+0.95). At 30 min after injection 75+-6% of the dose was found in the spleen. Splenic activity decreased to 62% after 48 hrs. At the same time, In-111 liver accumulation increased from 14 to 31%. This finding suggests that In-111 may be released from the spleen and subsequently sequestered by the liver. Two patients with high splenic uptake underwent splenectomy after the In-111 platelet study. Both benefited from splenectomy in terms of platelet survival after transfusion.

  19. Combination of platelet rich plasma in fractional carbon dioxide laser treatment increased clinical efficacy of for acne scar by enhancement of collagen production and modulation of laser-induced inflammation.

    Science.gov (United States)

    Min, Seonguk; Yoon, Ji Young; Park, Seon Yong; Moon, Jungyoon; Kwon, Hyuck Hoon; Suh, Dae Hun

    2018-04-01

    Platelet-rich plasma (PRP) which contains large amounts of growth factors has been tried to enhance therapeutic efficacy of laser treatment for acne scar with unknown underlying mechanism. The present study was conducted to investigate the molecular mechanism of increased clinical efficacy of PRP when combined with fractional laser treatment for treating acne scars. Subjects with mild to moderate acne scars were treated with two sessions of fractional CO 2 laser therapy given with and without co-administration of PRP. Skin biopsy specimens were obtained at baseline, 1, 3, 7, and 28 days for investigation of molecular profiles associated with skin changes produced by laser plus PRP treatment. The PRP treatment increased clinical efficacy with decreased severity of adverse effects such as erythema, swelling and oozing. Productions of TGFβ1 and TGFβ3 proteins were more highly elevated on the PRP-treated side of the face compared to the control side at day 28. Furthermore, PRP-treated side showed significant increase of c-myc, TIMP, and HGF expression. Experimental fibroblast culture model was also used. PRP administration after laser irradiation increased expressions of p-Akt, TGFβ1, TGFβ3, β-catenin, collagen 1, and collagen 3 in both dose-dependent and time dependent manners in fibroblast. Moreover, we acquired clinical and histological data through randomized control clinical trial. Taken together with human study results combined with the data from cell experiments we suggest that PRP treatment increased fibrogenetic molecules induced by fractional CO 2 laser, which have association with clinical effect. Lasers Surg. Med. 50:302-310, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Calcium-binding proteins from human platelets

    International Nuclear Information System (INIS)

    Gogstad, G.O.; Krutnes, M.B.; Solum, N.O.

    1983-01-01

    Calcium-binding platelet proteins were examined by crossed immunoelectrophoresis of solubilized platelets against antibodies to whole platelets followed by incubation of the immunoplates with 45 Ca 2 + and autoradiography. When the immunoplates had been pretreated with EDTA at pH 9.0 in order to remove divalent cations, three immunoprecipitates were markedly labelled with 45 Ca 2 + . These corresponded to the glycoprotein IIb-IIIa complex, glycoprotein Ia and a presently unidentified antigen termed G18. These antigens were membrane-bound and surface-oriented. When an excess of EDTA was introduced in the incubation media the results revealed that the glycoprotein IIb-IIIa complex and antigen G18, but not glycoprotein Ia, contained sites with a stronger affinity for calcium than has EDTA at pH 7.4 Immunoprecipitates of the separate glycoproteins IIb and IIIa both bound calcium in the same manner as the glycoprotein IIb-IIIa complex. As another approach, platelet-rich plasma was incubated with 45 Ca 2 + prior to crossed immunoelectrophoresis of the solubilized platelets. A single immunoprecipitate was wekly labelled. This did not correspond to any of the immunoprecipitates which were visible after staining with Coomassie blue. The labelling of this antigen was markedly increased when the platelt-rich plasma had been preincubated with EDTA and in this case a weak labelling of the glycoprotein IIB-IIIa precipitate also became apparent. No increased incorporation of calcium occured in any of these immunoprecipitates when the platelets were aggregated with ADP in the presence of 45 Ca 2 + . (orig.)

  1. Platelets and Multi-Organ Failure in Sepsis

    Directory of Open Access Journals (Sweden)

    Elisabetta Greco

    2017-10-01

    Full Text Available Platelets have received increasing attention for their role in the pathophysiology of infectious disease, inflammation, and immunity. In sepsis, a low platelet count is a well-known biomarker for disease severity and more recently authors have focused their attention on the active role of platelets in the pathogenesis of multi-organ failure. Septic shock is characterised by a dysregulated inflammatory response, which can impair the microcirculation and lead to organ injury. Being at the crossroads between the immune system, clotting cascade, and endothelial cells, platelets seem to be an appealing central mediator and possible therapeutic target in sepsis. This review focuses on the pathogenic role of platelets in septic organ dysfunction in humans and animal models.

  2. Platelets and Multi-Organ Failure in Sepsis.

    Science.gov (United States)

    Greco, Elisabetta; Lupia, Enrico; Bosco, Ornella; Vizio, Barbara; Montrucchio, Giuseppe

    2017-10-20

    Platelets have received increasing attention for their role in the pathophysiology of infectious disease, inflammation, and immunity. In sepsis, a low platelet count is a well-known biomarker for disease severity and more recently authors have focused their attention on the active role of platelets in the pathogenesis of multi-organ failure. Septic shock is characterised by a dysregulated inflammatory response, which can impair the microcirculation and lead to organ injury. Being at the crossroads between the immune system, clotting cascade, and endothelial cells, platelets seem to be an appealing central mediator and possible therapeutic target in sepsis. This review focuses on the pathogenic role of platelets in septic organ dysfunction in humans and animal models.

  3. The haemostatic effect of 51Cr-labelled blood platelets

    International Nuclear Information System (INIS)

    Bjoernson, J.; Aursnes, I.

    1977-01-01

    The haemostatic effect of 51 Cr-labelled platelets was studied in 5 rabbits made thrombocytopenic (35,000/μl blood) by whole body ionizing irradiation. Bleeding times were recorded after standardized cuts on the inner side of the rabbit's ear, a method with an acceptable reproducibility. The animals were then each transfused with concentrates of labelled pletelets from 2 healthy donor rabbits. This increased the platelet counts to about 2 x 10 5 /μl blood. Bleeding time values were markably prolonged before transfusion and became normalized when tested 1 and 4 h after transfusion. In 3 control experiments, where unlabelled platelet rich plasma was transfused to thrombocytopenic recipients, a similar shortening of the bleeding time was observed. It is concluded that 51 Cr-labelled platelets retain haemostatic ability comparable to non-labelled platelets, when circulating in a recipient animal. (author)

  4. PLATELET ADHESION TO POLYURETHANE UREA UNDER PULSATILE FLOW CONDITIONS

    Science.gov (United States)

    Navitsky, Michael A.; Taylor, Joshua O.; Smith, Alexander B.; Slattery, Margaret J.; Deutsch, Steven; Siedlecki, Christopher A.; Manning, Keefe B.

    2014-01-01

    Platelet adhesion to a polyurethane urea surface is a precursor to thrombus formation within blood-contacting cardiovascular devices, and platelets have been found to adhere strongly to polyurethane surfaces below a shear rate of approximately 500 s−1. The aim of the current work is to determine platelet adhesion properties to the polyurethane urea surface as a function of time varying shear exposure. A rotating disk system is used to study the influence of steady and pulsatile flow conditions (e.g. cardiac inflow and sawtooth waveforms) for platelet adhesion to the biomaterial surface. All experiments retain the same root mean square angular rotation velocity (29.63 rad/s) and waveform period. The disk is rotated in platelet rich bovine plasma for two hours with adhesion quantified by confocal microscopy measurements of immunofluorescently labeled bovine platelets. Platelet adhesion under pulsating flow is found to exponentially decay with increasing shear rate. Adhesion levels are found to depend upon peak platelet flux and shear rate regardless of rotational waveform. In combination with flow measurements, these results may be useful for predicting regions susceptible to thrombus formation within ventricular assist devices. PMID:24721222

  5. Platelet aggregation responses in clinically healthy adult llamas.

    Science.gov (United States)

    Gilbert, Rosanne M; Bird, Karyn E; Kutzler, Michelle A

    2009-03-01

    Limited information exists regarding hemostasis in camelids despite the importance of platelet function testing in the accurate identification of platelet disorders. As further importation of llamas to North America is restricted, variability in breeding stock will continue to decrease, potentially leading to an increase in heritable bleeding disorders. The objective of this study was to measure platelet aggregation responses in clinically healthy llamas and provide baseline data to which abnormal platelet function may be compared in the future. Blood samples were collected from 39 healthy adult llamas, citrated, and centrifuged to produce platelet-rich plasma (PRP). Within 4 hours of the blood draw, 20 microL of each agonist reagent were added to 180 microL of PRP. Final concentrations of agonists were 2 x 10(-5) M ADP, 0.19 mg collagen/mL PRP, 1 x 10(-4) M epinephrine, and 500 microg arachidonic acid/mL PRP. Llama platelets were most responsive to ADP and collagen, with a maximum percent aggregation (mean+/-SD) of 71.3+/-18.6% and 55.8+/-19% and aggregation rates of 9.5+/-3.9 and 6.7+/-3.7 cm/min, respectively. Llama platelet aggregation in response to epinephrine and arachidonic acid was minimal to absent. This study is the first of its kind to establish baseline values for platelet aggregation in healthy adult llamas.

  6. New 'ex vivo' radioisotopic method of quantitation of platelet deposition

    International Nuclear Information System (INIS)

    Badimon, L.; Mayo Clinic, Rochester, MN; Thrombosis and Atherosclerosis Unit, Barcelona; Mayo Clinic, Rochester, MN; Fuster, V.; Chesebro, J.H.; Dewanjee, M.K.

    1983-01-01

    We have developed a sensitive and quantitative method of 'ex vivo' evaluation of platelet deposition on collagen strips, from rabbit Achilles tendon, superfused by flowing blood and applied it to four animal species, cat, rabbit, dog and pig. Autologous platelets were labeled with indium-111-tropolone, injected to the animal 24 hr before the superfusion and the number of deposited platelets was quantitated from the tendon gamma-radiation and the blood platelet count. We detected some platelet consumption with superfusion time when blood was reinfused entering the contralateral jugular vein after collagen contact but not if blood was discarded after the contact. Therefore, in order to have a more physiological animal model we decided to discard blood after superfusion of the tendon. In all species except for the cat there was a linear relationship between increase of platelet on the tendon and time of exposure to blood superfusion. The highest number of platelets deposited on the collagen was found in cats, the lowest in dogs. Ultrastructural analysis showed the platelets were deposited as aggregates after only 5 min of superfusion. (orig.)

  7. Concentration of platelets and growth factors in platelet-rich plasma from Goettingen minipigs.

    Science.gov (United States)

    Jungbluth, Pascal; Grassmann, Jan-Peter; Thelen, Simon; Wild, Michael; Sager, Martin; Windolf, Joachim; Hakimi, Mohssen

    2014-01-01

    In minipigs little is known about the concentration of growth factors in plasma, despite their major role in several patho-physiological processes such as healing of fractures. This prompted us to study the concentration of platelets and selected growth factors in plasma and platelet-rich plasma (PRP) preparation of sixteen Goettingen minipigs. Platelet concentrations increased significantly in PRP in comparison to native blood plasma. Generally, significant increase in the concentration of all growth factors tested was observed in the PRP in comparison to the corresponding plasma or serum. Five of the plasma samples examined contained detectable levels of bone morphogenic protein 2 (BMP-2) whereas eleven of the plasma or serum samples contained minimal amounts of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF-bb) respectively. On the other hand variable concentrations of bone morphogenic protein 7 (BMP-7) and transforming growth factor β1 (TGF-β1) were measured in all plasma samples. In contrast, all PRP samples contained significantly increased amounts of growth factors. The level of BMP-2, BMP-7, TGF-β1, VEGF and PDGF-bb increased by 17.6, 1.5, 7.1, 7.2 and 103.3 fold, in comparison to the corresponding non-enriched preparations. Moreover significant positive correlations were found between platelet count and the concentrations of BMP-2 (r=0.62, pplatelet-rich plasma of minipigs which might thus serve as a source of autologous growth factors.

  8. 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.

  9. 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.

  10. Novel approaches for diagnosing inherited platelet disorders.

    Science.gov (United States)

    Bastida Bermejo, José María; Hernández-Rivas, Jesús María; González-Porras, José Ramón

    2017-01-20

    Inherited platelet disorders diagnosis is based on the clinical history and bleeding assessment tools. The laboratory functional assays as well as the molecular test to identify the pathogenic genetic variant are essential to confirm the accurate diagnosis of these disorders. Nowadays, the main challenges to developing a new diagnostic system are involved in reducing the samples' volume, and faster and more helpful analysis. Moreover, there are no widely available and standardised global tests. High throughput genetic testing such as next-generation sequencing has revolutionised DNA sequencing technologies as it allows the simultaneous and faster investigation of multiple genes at a manageable cost. This technology has improved the molecular characterisation of inherited platelet disorders and has been implemented in the research studies and the clinical routine practice. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  11. A scalable, micropore, platelet rich plasma separation device.

    Science.gov (United States)

    Dickson, Mary Nora; Amar, Levy; Hill, Michael; Schwartz, Joseph; Leonard, Edward F

    2012-12-01

    We have designed a novel, low energy platelet-rich-plasma (PRP) separator capable of producing 50 mL of PRP in 30 min, intended for military and emergency applications. Blood flows over a 3 mm length of sieve at high rates of shear. A plasma-platelet filtrate passes through the sieve's pores while erythrocytes remain. The filtrate is flowed over a second 3 mm length of smaller-pored sieve that withdraws plasma. Bulk blood volume is maintained by returning platelet-free plasma to the erythrocyte pool, enabling a nearly complete multi-pass platelet extraction. The total percentage of platelets extracted is:θ(T)=1-exp (-V(f)(T)Φ(P)/V) where V is the original plasma volume, V ( f )(T) is the total filtered volume, and ϕ ( P ) is platelet passage ratio (filtrate concentration/bulk average concentration) taken to be constant. Maximum θ(T) occurs at maximum V ( f )(T)× ϕ ( P ) Test microsieves, 3 mm long × 3 mm wide, were used. ϕ ( P ) values measured at various filtrate flow rates (20-100 uL/min) and utilizing various filter pore sizes (1.2-3.5 μm), was as high as 150 %. Maximum V ( f )(T)× ϕ ( P ) was achieved utilizing the 3.5 um filters at the highest flow rate, 100 uL/min. Erythrocyte leakages were always below 2,000/uL, far below the allowable limit stipulated by the American Association of Blood Banking. These data imply that a 13.7 cm(2) filter area is sufficient to achieve the target separation of 50 mL of platelet concentrate in 30 min. The filtration cartridge would consist of multiple microporous strips of 3 mm width arranged in parallel so that each element would see the conditions used in the prototype experiments presented here. Other microfiltration schemes suggest no method of scaling to practical levels.

  12. A quantitative study of Indium-111-oxine platelet kinetics in acute and chronic renal transplant rejection

    International Nuclear Information System (INIS)

    Heyns, A. du P.; Pieters, H.; Badenhorst, P.N.; Wessels, P.; Loetter, M.G.; Minnaar, P.C.; Pauw, F.H.

    1982-01-01

    Thirteen patients were investigated on 22 occasions at times varying from 1 day to 10 years after living family donor or cadaver renal transplantation. Platelet survival in the circulation, and in vivo platelet distribution and sites of deposition and sequestration was quantitatively determined with Indium-111-oxine (In-111-oxine) labelled platelets and a scintillation camera interfaced with a computer assisted imaging system. In all patients platelet survival was shortened and the platelet survival curve exponential. In patients with no evidence of transplant rejection and those with chronic rejection, there was no measurable or visible accumulation of labelled platelets in the kidney. The sequestration pattern of In-111 labelled platelets at the end of platelet life span was within normal limits and located in the reticuloendothelial system. In those patients with acute transplant rejection, platelet survival was shortened. Labelled platelets accumulated in the kidney: this was clearly visualized on scintigraphy and reflected by a significant increase in the radioactivity count density of the kidney. Platelets not deposited in the transplant were sequestrated in the reticuloendothelial system. This study demonstrates the diagnostic value of In-111 labelled platelet kinetics in the investigation of acute renal failure after renal transplantation. This investigation appears of limited clinical value in chronic rejection. (orig.)

  13. Exposure to acrolein by inhalation causes platelet activation

    International Nuclear Information System (INIS)

    Sithu, Srinivas D.; Srivastava, Sanjay; Siddiqui, Maqsood A.; Vladykovskaya, Elena; Riggs, Daniel W.; Conklin, Daniel J.; Haberzettl, Petra; O'Toole, Timothy E.; Bhatnagar, Aruni; D'Souza, Stanley E.

    2010-01-01

    Acrolein is a common air pollutant that is present in high concentrations in wood, cotton, and tobacco smoke, automobile exhaust and industrial waste and emissions. Exposure to acrolein containing environmental pollutants such as tobacco smoke and automobile exhaust has been linked to the activation of the coagulation and hemostasis pathways and thereby to the predisposition of thrombotic events in human. To examine the effects of acrolein on platelets, adult male C57Bl/6 mice were subjected acute (5 ppm for 6 h) or sub-chronic (1 ppm, 6 h/day for 4 days) acrolein inhalation exposures. The acute exposure to acrolein did not cause pulmonary inflammation and oxidative stress, dyslipidemia or induce liver damage or muscle injury. Platelet GSH levels in acrolein-exposed mice were comparable to controls, but acrolein-exposure increased the abundance of protein-acrolein adducts in platelets. Platelets isolated from mice, exposed to both acute and sub-chronic acrolein levels, showed increased ADP-induced platelet aggregation. Exposure to acrolein also led to an increase in the indices of platelet activation such as the formation of platelet-leukocyte aggregates in the blood, plasma PF4 levels, and increased platelet-fibrinogen binding. The bleeding time was decreased in acrolein exposed mice. Plasma levels of PF4 were also increased in mice exposed to environmental tobacco smoke. Similar to inhalation exposure, acrolein feeding to mice also increased platelet activation and established a pro-thrombotic state in mice. Together, our data suggest that acrolein is an important contributing factor to the pro-thrombotic risk in human exposure to pollutants such as tobacco smoke or automobile exhaust, or through dietary consumption.

  14. Exposure to acrolein by inhalation causes platelet activation

    Energy Technology Data Exchange (ETDEWEB)

    Sithu, Srinivas D [Department of Physiology and Biophysics, University of Louisville, Louisville, KY 40202 (United States); Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202 (United States); Srivastava, Sanjay; Siddiqui, Maqsood A; Vladykovskaya, Elena; Riggs, Daniel W; Conklin, Daniel J; Haberzettl, Petra; O' Toole, Timothy E; Bhatnagar, Aruni [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202 (United States); D' Souza, Stanley E., E-mail: sedsou01@louisville.ed [Department of Physiology and Biophysics, University of Louisville, Louisville, KY 40202 (United States)

    2010-10-15

    Acrolein is a common air pollutant that is present in high concentrations in wood, cotton, and tobacco smoke, automobile exhaust and industrial waste and emissions. Exposure to acrolein containing environmental pollutants such as tobacco smoke and automobile exhaust has been linked to the activation of the coagulation and hemostasis pathways and thereby to the predisposition of thrombotic events in human. To examine the effects of acrolein on platelets, adult male C57Bl/6 mice were subjected acute (5 ppm for 6 h) or sub-chronic (1 ppm, 6 h/day for 4 days) acrolein inhalation exposures. The acute exposure to acrolein did not cause pulmonary inflammation and oxidative stress, dyslipidemia or induce liver damage or muscle injury. Platelet GSH levels in acrolein-exposed mice were comparable to controls, but acrolein-exposure increased the abundance of protein-acrolein adducts in platelets. Platelets isolated from mice, exposed to both acute and sub-chronic acrolein levels, showed increased ADP-induced platelet aggregation. Exposure to acrolein also led to an increase in the indices of platelet activation such as the formation of platelet-leukocyte aggregates in the blood, plasma PF4 levels, and increased platelet-fibrinogen binding. The bleeding time was decreased in acrolein exposed mice. Plasma levels of PF4 were also increased in mice exposed to environmental tobacco smoke. Similar to inhalation exposure, acrolein feeding to mice also increased platelet activation and established a pro-thrombotic state in mice. Together, our data suggest that acrolein is an important contributing factor to the pro-thrombotic risk in human exposure to pollutants such as tobacco smoke or automobile exhaust, or through dietary consumption.

  15. Increased vascularization during early healing after biologic augmentation in repair of chronic rotator cuff tears using autologous leukocyte- and platelet-rich fibrin (L-PRF): a prospective randomized controlled pilot trial.

    Science.gov (United States)

    Zumstein, Matthias A; Rumian, Adam; Lesbats, Virginie; Schaer, Michael; Boileau, Pascal

    2014-01-01

    We hypothesized that arthroscopic rotator cuff repairs using leukocyte- and platelet-rich fibrin (L-PRF) in a standardized, modified protocol is technically feasible and results in a higher vascularization response and watertight healing rate during early healing. Twenty patients with chronic rotator cuff tears were randomly assigned to 2 treatment groups. In the test group (N = 10), L-PRF was added in between the tendon and the bone during arthroscopic rotator cuff repair. The second group served as control (N = 10). They received the same arthroscopic treatment without the use of L-PRF. We used a double-row tension band technique. Clinical examinations including subjective shoulder value, visual analog scale, Constant, and Simple Shoulder Test scores and measurement of the vascularization with power Doppler ultrasonography were made at 6 and 12 weeks. There have been no postoperative complications. At 6 and 12 weeks, there was no significant difference in the clinical scores between the test and the control groups. The mean vascularization index of the surgical tendon-to-bone insertions was always significantly higher in the L-PRF group than in the contralateral healthy shoulders at 6 and 12 weeks (P = .0001). Whereas the L-PRF group showed a higher vascularization compared with the control group at 6 weeks (P = .001), there was no difference after 12 weeks of follow-up (P = .889). Watertight healing was obtained in 89% of the repaired cuffs. Arthroscopic rotator cuff repair with the application of L-PRF is technically feasible and yields higher early vascularization. Increased vascularization may potentially predispose to an increased and earlier cellular response and an increased healing rate. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  16. Generation of Platelet Microparticles after Cryopreservation of Apheresis Platelet Concentrates Contributes to Hemostatic Activity

    Directory of Open Access Journals (Sweden)

    İbrahim Eker

    2017-03-01

    Full Text Available Objective: In the last decade, substantial evidence has accumulated about the use of cryopreserved platelet concentrates, especially in trauma. However, little reference has been made in these studies to the morphological and functional changes of platelets. Recently platelets have been shown to be activated by cryopreservation processes and to undergo procoagulant membrane changes resulting in the generation of platelet-derived microparticles (PMPs, platelet degranulation, and release of platelet-derived growth factors (PDGFs. We assessed the viabilities and the PMP and PDGF levels of cryopreserved platelets, and their relation with thrombin generation. Materials and Methods: Apheresis platelet concentrates (APCs from 20 donors were stored for 1 day and cryopreserved with 6% dimethyl sulfoxide. Cryopreserved APCs were kept at -80 °C for 1 day. Thawed APCs (100 mL were diluted with 20 mL of autologous plasma and specimens were analyzed for viabilities and PMPs by flow cytometry, for thrombin generation by calibrated automated thrombogram, and for PDGFs by enzyme-linked immunosorbent assay testing. Results: The mean PMP and PDGF levels in freeze-thawed APCs were significantly higher (2763±399.4/μL vs. 319.9±80.5/μL, p<0.001 and 550.9±73.6 pg/mL vs. 96.5±49 pg/mL, p<0.001, respectively, but the viability rates were significantly lower (68.2±13.7% vs. 94±7.5%, p<0.001 than those of fresh APCs. The mean endogenous thrombin potential (ETP of freeze-thawed APCs was significantly higher than that of the fresh APCs (3406.1±430.4 nM.min vs. 2757.6±485.7 nM.min, p<0.001. Moreover, there was a significant positive poor correlation between ETP levels and PMP levels (r=0.192, p=0.014. Conclusion: Our results showed that, after cryopreservation, while levels of PMPs were increasing, significantly higher and earlier thrombin formation was occurring in the samples analyzed despite the significant decrease in viability. Considering the damage caused

  17. Effects of hormones on platelet aggregation.

    Science.gov (United States)

    Farré, Antonio López; Modrego, Javier; Zamorano-León, José J

    2014-04-01

    Platelets and their activation/inhibition mechanisms play a central role in haemostasis. It is well known agonists and antagonists of platelet activation; however, during the last years novel evidences of hormone effects on platelet activation have been reported. Platelet functionality may be modulated by the interaction between different hormones and their platelet receptors, contributing to sex differences in platelet function and even in platelet-mediated vascular damage. It has suggested aspects that apparently are well established should be reviewed. Hormones effects on platelet activity are included among them. This article tries to review knowledge about the involvement of hormones in platelet biology and activity.

  18. 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.

  19. Increased serum chemerin concentrations in patients with polycystic ovary syndrome: Relationship between insulin resistance and ovarian volume.

    Science.gov (United States)

    Huang, Rong; Yue, Jiang; Sun, Yun; Zheng, Jun; Tao, Tao; Li, Shengxian; Liu, Wei

    2015-10-23

    Chemerin has been linked to adiposity, and insulin resistance (IR) which are the common characteristics of polycystic ovary syndrome (PCOS). Chemerin also shows inhibitory action on follicular steroidogenesis. We investigated the associations between chemerin and IR or polycystic ovary morphology in patients with PCOS. A total of 148 women with newly diagnosed PCOS using Rotterdam criteria and 88 healthy individuals were enrolled. The recruited patients with PCOS were further stratified by tertiles of serum chemerin concentrations as follows: Group 1 ( 30.27 ng/ml). Compared to controls, women with PCOS in each tertile had higher serum chemerin concentrations. By linear regression analysis, homeostasis model assessment-insulin resistance and ovarian volume showed significant associations with chemerin after adjusting for confounding factors (β = 0.257, P = 0.028; β = 0.276, P = 0.005, respectively). The odds ratios (ORs) for ovarian volume excess gradually increased across increasing tertiles of chemerin in the adjusted model [Group 1: reference; Group 2: OR 1.602; 95% confidence interval (CI): 1.170–2.194; Group 3: OR 1.857; 95% CI: 1.335-2.583]. Patients with PCOS showed increased serum chemerin concentrations as compared to healthy women. Individuals with higher chemerin tended to have higher risk for ovarian volume excess in patients with PCOS, regardless of adiposity.

  20. [Evaluation of Storage Performance of Preserving Bags for Manually Separated Platelets].

    Science.gov (United States)

    Liu, Min-Xia; Duan, Lan; Wang, Jie-Xi; Wang, Yan; Zhuo, Hai-Long; Cai, Li-Na; Yi, Xiao-Yang; Zhou, Jian-Wei; Ang, Jian-Wei; Han, Ying

    2015-08-01

    To evaluate the storage performance of the domestically made platelet storage bags (experimental group) and the United States Trima set platelet storage bags (control group). The manually separated platelets were divided in two equal parts, which was added to control blood bags and experimental blood bags respectively, all samples were stored at a 22 °C ± 2 °C. The platelet count, mean volume, aggregation activity (ADP, THR), pH, glucose, lactate concentration, lactate dehydrogenase concentration, hypotonic shock reaction, CD62P and phosphatidic acid serine content were detected at day 0, 3, 5 and 7 of storage. There was no significant difference of platelet quality at day 5 after storage between the experimental group and the control group (T-test, P > 0.05). Two kinds of platelet storage bags have the similar storage performance.

  1. Viability of platelets following storage in the irradiated state. A pair-controlled study

    International Nuclear Information System (INIS)

    Read, E.J.; Kodis, C.; Carter, C.S.; Leitman, S.F.

    1988-01-01

    Gamma irradiation of blood products is a standard practice recommended for the prevention of posttransfusion graft-versus-host disease in susceptible hosts. We studied the effects of irradiation on stored platelet concentrates and evaluated whether platelets could be stored for 5 days in the irradiated state without adverse effects on their viability. Using a pair-controlled design in which each of six normal subjects acted as his or her own control, we compared in vitro storage characteristics and in vivo kinetics of platelet concentrates exposed to 30 Gy and stored for 5 days with those of platelet concentrates simply stored for 5 days without irradiation. Irradiation had no significant effects on in vitro storage characteristics (platelet count, mean platelet volume, pH, and white cell count) or on in vivo kinetics, including initial recovery and mean platelet survival. Using the multiple-hit model, initial recovery was 49.6 +/- 10.8 percent, and mean platelet survival was 5.6 +/- 1.05 days for irradiated concentrates, compared with 51.3 +/- 13.0 percent and 5.9 +/- 0.50 days, respectively, for the unirradiated control concentrates. We conclude that irradiation of platelet concentrates with up to 30 Gy has no effect on their in vivo recovery or survival, and that irradiation administered before storage of platelet concentrates does not interfere with their clinical efficacy

  2. Spaceflight-Induced Visual Impairment and Globe Deformations in Astronauts Are Linked to Orbital Cerebrospinal Fluid Volume Increase.

    Science.gov (United States)

    Alperin, Noam; Bagci, Ahmet M

    2018-01-01

    Most of the astronauts onboard the International Space Station (ISS) develop visual impairment and ocular structural changes that are not fully reversible upon return to earth. Current understanding assumes that the so-called visual impairments/intracranial pressure (VIIP) syndrome is caused by cephalad vascular fluid shift. This study assesses the roles of cerebrospinal fluid (CSF) and intracranial pressure (ICP) in VIIP. Seventeen astronauts, 9 who flew a short-duration mission on the space shuttle (14.1 days [SD 1.6]) and 7 who flew a long-duration mission on the ISS (188 days [SD 22]) underwent MRI of the brain and orbits to assess the pre-to-post spaceflight changes in four categories: VIIP severity measures: globe flattening and nerve protrusion; orbital and ventricular CSF volumes; cortical gray and white matter volumes; and MR-derived ICP (MRICP). Significant pre-to-post-flight increase in globe flattening and optic nerve protrusion occurred only in the long-duration cohort (0.031 [SD 0.019] vs -0.001 [SD 0.006], and 0.025 [SD 0.013] vs 0.001 [SD 0.006]; p < 0.00002 respectively). The increased globe deformations were associated with significant increases in orbital and ventricular CSF volumes, but not with increased tissue vascular fluid content. Additionally, a moderate increase in MRICP of 6 mmHg was observed in only two ISS astronauts with large ocular structure changes. These findings are evidence for the primary role of CSF and a lesser role for intracranial cephalad fluid-shift in the formation of VIIP. VIIP is caused by a prolonged increase in orbital CSF spaces that compress the globes' posterior pole, even without a large increase in ICP.

  3. 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

  4. 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

  5. Platelets stimulate fibroblast-mediated contraction of collagen gels

    Directory of Open Access Journals (Sweden)

    Lundahl Joachim

    2003-10-01

    Full Text Available Abstract Background Platelets are thought to play a role in a variety of inflammatory conditions in the lung, some of which may lead to fibrosis. In the current study we tested the hypothesis that whole platelets and platelet lysate can mediate remodelling of extracellular matrix in vitro by affecting fibroblast-mediated contraction of a collagen gel. We also sought to determine to what extent platelet-derived growth factor (PDGF and transforming growth factor-β (TGF-β contribute to this effect. Methods Washed platelets, isolated from healthy blood donors, and platelet lysate (freezing and thawing, were cast together with human lung fibroblasts in three-dimensional collagen gels. The gels were then released and cultured for four days. PDGF and TGF-β1 concentrations were measured in culture supernatants by ELISA. Results Both platelets and platelet lysate augmented fibroblast-mediated gel contraction in a time and concentration dependent manner (19.9% ± 0.1 (mean ± SEM of initial area vs. 48.0% ± 0.4 at 48 hours; P 1 and PDGF-AA/AB were released in co-culture. PDGF-AA/AB had a maximum release at 24 hours whereas TGF-β1 release increased with longer culture periods. Neutralising antibodies to these mediators partially inhibited platelet-induced gel contraction. Conclusion We conclude that platelets may promote remodelling of extracellular matrix in vitro and that PDGF and TGF-β partially mediate this effect, also indicating a role for other mediators. The findings may be an important mechanism in regulating repair processes after injury.

  6. 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.

  7. Human Platelet Senescence Study.

    Science.gov (United States)

    1980-03-01

    ability to measure certain enzymes to their oxidation-reduc other enzymes which can be measured by o phosphatase , acid phosphatase , chymotryp...alkaline sin, trypsin, esterases (17)); M use of n A or wheat germ agglutinin in the second etect specific carbohydrate constituents. We have...Von Willebrand factor. Nurden and Caen also demonstrated that GPI was rich in sialic acid (5) and probably responsible for the platelets’ surface

  8. Myostatin (GDF-8) Deficiency Increases Fracture Callus Size, Sox-5 Expression, and Callus Bone Volume

    OpenAIRE

    Kellum, Ethan; Starr, Harlan; Arounleut, Phonepasong; Immel, David; Fulzele, Sadanand; Wenger, Karl; Hamrick, Mark W.

    2008-01-01

    Myostatin (GDF-8) is a negative regulator of skeletal muscle growth and mice lacking myostatin show increased muscle mass. We have previously shown that myostatin deficiency increases bone strength and biomineralization throughout the skeleton, and others have demonstrated that myostatin is expressed during the earliest phase of fracture repair. In order to determine the role of myostatin in fracture callus morphogenesis, we studied fracture healing in mice lacking myostatin. Adult wild-type ...

  9. Evaluation of amotosalem treated platelets over 7 days of storage with an automated cytometry assay panel.

    Science.gov (United States)

    Diquattro, M; De Francisci, G; Bonaccorso, R; Tagliavia, A M; Marcatti, M; Palma, B; Agliastro, R

    2013-12-01

    Pathogen Inactivation allows to overcome microbial contamination and growth related to storage of platelets concentrates (PC) at room temperature. The aim of our study was to evaluate the platelet storage lesion extending the storage period of pathogen inactivated platelet concentrates over 7 days using an automated cytometry assay panel. We analyzed 43 concentrates subjected to pathogen inactivation (CPPI) at 3, 5 and 7 days evaluating: platelet count, mean platelet volume, platelets at low optical density, platelets at high density, GPIIb-IIIa glycoprotein, platelet microparticles, lactate dehydrogenase. The collection bags (Fenwal) and the IBS kit made in PL2410/PL2411 are approved for the conservation of PC up to 7 days. Data analysis was performed with anova test. All the parameters except small platelets and PMP were statistically different among day 7 vs. 3 and day 7 vs. 5. Our study showed a progressive modification of pathogen inactivated platelet concentrates observed up to 7 days. The persistence of the secretory pool and the presence of the platelet membrane fibrinogen receptor suggest the persistence of a potential hemostatic efficacy. Clinical studies are necessary to directly correlate this type of analysis to 24 h recovery or survival of transfused platelets in humans. © 2013 John Wiley & Sons Ltd.

  10. Erythrocyte sedimentation rate and fibrinogen concentration of whole blood influences the cellular composition of platelet-rich plasma obtained from centrifugation methods.

    Science.gov (United States)

    Yin, Wenjing; Xu, Zhengliang; Sheng, Jiagen; Xie, Xuetao; Zhang, Changqing

    2017-09-01

    Erythrocyte sedimentation rate (ESR), which reflects the sedimentation rate of platelets, leukocytes and erythrocytes in response to centrifugal force, may influence the cellular composition of platelet-rich plasma (PRP) obtained via centrifugation methods. However, no relevant studies have substantiated this. In the present study, blood was collected from 40 healthy volunteers and used to prepare PRP with two plasma-based preparation systems [YinPRP and Plasma Rich in Growth Factor (PRGF) systems] and two buffy coat-based systems (RegenPRP and WEGOPRP systems) in a single-donor model. Volumes of PRP and platelet-poor plasma (PPP) that were removed in the preparation process were recorded. Analyses of ESR, haematocrit, C-reaction protein, coagulation, serum glucose and serum lipid of the whole blood used for PRP preparation were performed to evaluate the levels of ESR and the factors known to influence it. Whole blood analysis was performed to evaluate the cellular composition of PRP. Results demonstrated that there were marked positive correlations between the ESR of the whole blood used for PRP preparation and PPP removal efficiencies, platelet concentrations, platelet capture efficiencies and platelet enrichment factors of PRP formulations obtained from plasma-based systems, and PRP yield efficiency of RegenPRP and PPP removal efficiency of WEGOPRP. Furthermore, there were marked negative correlations between ESR and concentrations and enrichment factors of platelets, leukocytes and erythrocytes of RegenPRP. Fibrinogen concentration of the whole blood, which had a marked positive correlation with ESR, also influenced the cellular composition of PRP. These findings may increase the understanding of PRP preparation and provide substantial evidence for the individualised optimisation of PRP preparation systems used in clinical practice.

  11. Comparison of extravascular lung water volume with radiographic findings in dogs with experimentally increased permeability pulmonary edema

    International Nuclear Information System (INIS)

    Takeda, A.; Okumura, S.; Miyamoto, T.; Hagio, M.; Fujinaga, T.

    1995-01-01

    The relationship between extravascular lung water volume (ELWV) and chest radiographical findings was studied in general-anesthetized beagles. The dogs were experimentally injected with oleic acid to increase pulmonary vascular permeability. When the ELWV value in the dogs increased more than approximately 37% from the control value, their chest radiographs began to show signs of pulmonary edema. At this time, the chest X-ray density increased to 10% above the control level. PaO2 decreased, and PaCO2 increased after the administration of oleic acid. This clearly showed that the pulmonary gas exchange function was reduced following increasing ELWV. This comparison showed that probably the thermal-sodium double indicator dilution measurement of ELWV can detect slight hyperpermeability pulmonary edema that does not show on chest radiographs. The chest radiograph was therefore not suitable for the detection of slight pulmonary edema, because it did not show any changes in the early stages in hyperpermeability pulmonary edema

  12. 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.

  13. Plasma volume expansion does not increase maximal cardiac output or VO2 max in lowlanders acclimatized to altitude

    DEFF Research Database (Denmark)

    Calbet, José A L; Rådegran, Göran; Boushel, Robert Christopher

    2004-01-01

    liter of 6% dextran 70 (BV = 6.32 +/- 0.34 liters). PV expansion had no effect on Qmax, maximal O2 consumption (VO2), and exercise capacity. Despite maximal systemic O2 transport being reduced 19% due to hemodilution after PV expansion, whole body VO2 was maintained by greater systemic O2 extraction (P...... VO2 during exercise regardless of PV. Pulmonary ventilation, gas exchange, and acid-base balance were essentially unaffected by PV expansion. Sea......With altitude acclimatization, blood hemoglobin concentration increases while plasma volume (PV) and maximal cardiac output (Qmax) decrease. This investigation aimed to determine whether reduction of Qmax at altitude is due to low circulating blood volume (BV). Eight Danish lowlanders (3 females, 5...

  14. Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model

    Directory of Open Access Journals (Sweden)

    A. Gnanadesikan

    2012-03-01

    Full Text Available Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1 shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., suboxic waters does not increase under global warming, as these waters actually become more oxygenated. We show that the rise in dissolved oxygen in the tropical Pacific is associated with a drop in ventilation time. A term-by-term analysis within the least oxygenated waters shows an increased supply of dissolved oxygen due to lateral diffusion compensating an increase in remineralization within these highly hypoxic waters. This lateral diffusive flux is the result of an increase of ventilation along the Chilean coast, as a drying of the region under global warming opens up a region of wintertime convection in our model. The results highlight the potential sensitivity of suboxic waters to changes in subtropical ventilation as well as the importance of constraining lateral eddy transport of dissolved oxygen in such waters.

  15. Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model

    Science.gov (United States)

    Gnanadesikan, A.; Dunne, J. P.; John, J.

    2012-03-01

    Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1) shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., suboxic) waters does not increase under global warming, as these waters actually become more oxygenated. We show that the rise in dissolved oxygen in the tropical Pacific is associated with a drop in ventilation time. A term-by-term analysis within the least oxygenated waters shows an increased supply of dissolved oxygen due to lateral diffusion compensating an increase in remineralization within these highly hypoxic waters. This lateral diffusive flux is the result of an increase of ventilation along the Chilean coast, as a drying of the region under global warming opens up a region of wintertime convection in our model. The results highlight the potential sensitivity of suboxic waters to changes in subtropical ventilation as well as the importance of constraining lateral eddy transport of dissolved oxygen in such waters.

  16. Effects of alcohol on platelet functions.

    Science.gov (United States)

    Renaud, S C; Ruf, J C

    1996-03-15

    Recent epidemiologic studies have consistently shown that moderate intake of alcoholic beverages protect against morbidity and mortality from coronary heart disease and ischemic stroke. By contrast, alcohol drinking may also predispose to cerebral hemorrhage. These observations suggest an effect of alcohol similar to that of aspirin. Several studies in humans and animals have shown that the immediate effect of alcohol, either added in vitro to platelets or 10 to 20 min after ingestion, is to decrease platelet aggregation in response to most agonists (thrombin, ADP, epinephrine, collagen). Several hours later, as, in free-living populations deprived of drinking since the previous day it is mostly secondary aggregation to ADP and epinephrine and aggregation to collagen that are still inhibited in alcohol drinkers. By contrast, in binge drinkers or in alcoholics after alcohol withdrawal, response to aggregation, especially that induced by thrombin, is markedly increased. This rebound phenomenon, easily reproduced in rats, may explain ischemic strokes or sudden death known to occur after episodes of drunkenness. The platelet rebound effect of alcohol drinking was not observed with moderate red wine consumption in man. The protection afforded by wine has been recently duplicated in rats by grape tannins added to alcohol. This protection was associated with a decrease in the level of conjugated dienes, the first step in lipid peroxidation. In other words, wine drinking does not seem to be associated with the increased peroxidation usually observed with spirit drinking. Although further studies are required, the platelet rebound effect of alcohol drinking could be associated with an excess of lipid peroxides known to increase platelet reactivity, especially to thrombin.

  17. 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

  18. Platelets as a Novel Source of Pro-Inflammatory Chemokine CXCL14

    Directory of Open Access Journals (Sweden)

    Alexander Witte

    2017-03-01

    Full Text Available Objective: Platelets are a major source of chemokines. Here, we demonstrate for the first time that platelets express significant amounts of CXCL14 and disclose powerful effects of platelet-derived CXCL14 on monocyte and endothelial migration. Methods: The expression of CXCL14 in platelets and in the supernatant of activated platelets was analysed by immunoblotting, ELISA, and flow cytometry. The effect of platelet-derived CXCL14 on monocyte migration was evaluated using a modified Boyden chamber. The effect of CXCL14 on monocyte phagocytosis was tested by using fluorochrome-labelled E.coli particles. The effect of platelet-derived CXCL14 on endothelial migration was explored by the use of an endothelial scratch assay. Results: Hitherto unrecognized expression of CXCL14 in human and murine platelets was uncovered by immunoblotting. Activation with platelet agonists such as adenosine-di-phosphate (ADP, collagen-related peptide (CRP, or thrombin-receptor activating peptide (TRAP, increased CXCL14 surface expression (flow cytometry and release into the supernatant (immunoblotting, ELISA. Since CXCL14 is known to be chemotactic for CD14+ monocytes, we investigated the chemotactic potential of platelet-derived CXCL14 on human monocytes. Activated platelet supernatant induced monocyte migration, which was counteracted upon neutralization of platelet-derived CXCL14 as compared to IgG control. Blocking of the chemokine receptor CXCR4, but not CXCR7, reduced the number of migratory monocytes towards recombinant CXCL14, suggesting the involvement of CXCR4 in the CXCL14-directed monocyte chemotaxis. Recombinant CXCL14 enhanced the phagocytic uptake of E.coli particles by monocytes. In scratch assays with cultured endothelial cells (HUVECs, platelet-derived CXCL14 counteracted the pro-angiogenic effects of VEGF, supporting its previously recognized angiostatic potential. Conclusions: Platelets are a relevant source of CXCL14. Platelet-derived CXCL14 at the

  19. Increasing carbon sinks in European forests: effect of afforestation and changes in mean growing stock volume

    NARCIS (Netherlands)

    Vilén, T.; Cienciala, E.; Schelhaas, M.; Verkerk, P.J.; Lindner, M.; Peltola, H.

    2016-01-01

    In Europe, both forest area and growing stock have increased since the 1950s, and European forests have acted as a carbon sink during the last six decades. However, the contribution of different factors affecting the sink is not yet clear. In this study, historical inventory data were combined with

  20. Clot lysis time in platelet-rich plasma: method assessment, comparison with assays in platelet-free and platelet-poor plasmas, and response to tranexamic acid.

    Science.gov (United States)

    Panes, Olga; Padilla, Oslando; Matus, Valeria; Sáez, Claudia G; Berkovits, Alejandro; Pereira, Jaime; Mezzano, Diego

    2012-01-01

    Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma

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

    Science.gov (United States)

    Rodgers, G M

    1999-06-01

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

  2. 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.

  3. New gene functions in megakaryopoiesis and platelet formation

    NARCIS (Netherlands)

    Gieger, Christian; Radhakrishnan, Aparna; Cvejic, Ana; Tang, Weihong; Porcu, Eleonora; Pistis, Giorgio; Serbanovic-Canic, Jovana; Elling, Ulrich; Goodall, Alison H.; Labrune, Yann; Lopez, Lorna M.; Mägi, Reedik; Meacham, Stuart; Okada, Yukinori; Pirastu, Nicola; Sorice, Rossella; Teumer, Alexander; Voss, Katrin; Zhang, Weihua; Ramirez-Solis, Ramiro; Bis, Joshua C.; Ellinghaus, David; Gögele, Martin; Hottenga, Jouke-Jan; Langenberg, Claudia; Kovacs, Peter; O'Reilly, Paul F.; Shin, So-Youn; Esko, Tõnu; Hartiala, Jaana; Kanoni, Stavroula; Murgia, Federico; Parsa, Afshin; Stephens, Jonathan; van der Harst, Pim; van der Schoot, C. Ellen; Allayee, Hooman; Attwood, Antony; Balkau, Beverley; Bastardot, François; Basu, Saonli; Baumeister, Sebastian E.; Biino, Ginevra; Bomba, Lorenzo; Bonnefond, Amélie; Cambien, François; Chambers, John C.; Cucca, Francesco; D'Adamo, Pio; Davies, Gail; de Boer, Rudolf A.; de Geus, Eco J. C.; Döring, Angela; Elliott, Paul; Erdmann, Jeanette; Evans, David M.; Falchi, Mario; Feng, Wei; Folsom, Aaron R.; Frazer, Ian H.; Gibson, Quince D.; Glazer, Nicole L.; Hammond, Chris; Hartikainen, Anna-Liisa; Heckbert, Susan R.; Hengstenberg, Christian; Hersch, Micha; Illig, Thomas; Loos, Ruth J. F.; Jolley, Jennifer; Khaw, Kay Tee; Kühnel, Brigitte; Kyrtsonis, Marie-Christine; Lagou, Vasiliki; Lloyd-Jones, Heather; Lumley, Thomas; Mangino, Massimo; Maschio, Andrea; Mateo Leach, Irene; McKnight, Barbara; Memari, Yasin; Mitchell, Braxton D.; Montgomery, Grant W.; Nakamura, Yusuke; Nauck, Matthias; Navis, Gerjan; Nöthlings, Ute; Nolte, Ilja M.; Porteous, David J.; Pouta, Anneli; Pramstaller, Peter P.; Pullat, Janne; Ring, Susan M.; Rotter, Jerome I.; Ruggiero, Daniela; Ruokonen, Aimo; Sala, Cinzia; Samani, Nilesh J.; Sambrook, Jennifer; Schlessinger, David; Schreiber, Stefan; Schunkert, Heribert; Scott, James; Smith, Nicholas L.; Snieder, Harold; Starr, John M.; Stumvoll, Michael; Takahashi, Atsushi; Tang, W. H. Wilson; Taylor, Kent; Tenesa, Albert; Lay Thein, Swee; Tönjes, Anke; Uda, Manuela; Ulivi, Sheila; van Veldhuisen, Dirk J.; Visscher, Peter M.; Völker, Uwe; Wichmann, H.-Erich; Wiggins, Kerri L.; Willemsen, Gonneke; Yang, Tsun-Po; Hua Zhao, Jing; Zitting, Paavo; Bradley, John R.; Dedoussis, George V.; Gasparini, Paolo; Hazen, Stanley L.; Metspalu, Andres; Pirastu, Mario; Shuldiner, Alan R.; Joost van Pelt, L.; Zwaginga, Jaap-Jan; Boomsma, Dorret I.; Deary, Ian J.; Franke, Andre; Froguel, Philippe; Ganesh, Santhi K.; Jarvelin, Marjo-Riitta; Martin, Nicholas G.; Meisinger, Christa; Psaty, Bruce M.; Spector, Timothy D.; Wareham, Nicholas J.; Akkerman, Jan-Willem N.; Ciullo, Marina; Deloukas, Panos; Greinacher, Andreas; Jupe, Steve; Kamatani, Naoyuki; Khadake, Jyoti; Kooner, Jaspal S.; Penninger, Josef; Prokopenko, Inga; Stemple, Derek; Toniolo, Daniela; Wernisch, Lorenz; Sanna, Serena; Hicks, Andrew A.; Rendon, Augusto; Ferreira, Manuel A.; Ouwehand, Willem H.; Soranzo, Nicole

    2011-01-01

    Platelets are the second most abundant cell type in blood and are essential for maintaining haemostasis. Their count and volume are tightly controlled within narrow physiological ranges, but there is only limited understanding of the molecular processes controlling both traits. Here we carried out a

  4. Variation of the platelet indices of dromedary camel ( Camelus ...

    African Journals Online (AJOL)

    Hematological parameters showed breed, age and intersex differences in mean corpuscular volume and mean corpuscular hemoglobin. Sex and agerelated differences were also found in red cell distribution width in addition to age-related differences in hematocrit and mean corpuscular hemoglobin concentration. Platelet ...

  5. Myocardial extracellular volume quantified by magnetic resonance is increased in cirrhosis and related to poor outcome

    DEFF Research Database (Denmark)

    Wiese, Signe; Hove, Jens; Mo, Silje

    2018-01-01

    .04). Furthermore, ECV increased across the Child Pugh A/B/C classes (26.9±4/ 31.5±5/ 34.4±6%, P=0.02). Four-teen patients experienced the composite end-point of death/LT during follow-up and these patients had higher ECV (33.2±4 vs. 30.4±6%, P=0.04). In a univariate Cox regression analysis ECV was associated...

  6. 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.

  7. Influence of Oxidative Stress on Stored Platelets

    OpenAIRE

    K. Manasa; R. Vani

    2016-01-01

    Platelet storage and its availability for transfusion are limited to 5-6 days. Oxidative stress (OS) is one of the causes for reduced efficacy and shelf-life of platelets. The studies on platelet storage have focused on improving the storage conditions by altering platelet storage solutions, temperature, and materials. Nevertheless, the role of OS on platelet survival during storage is still unclear. Hence, this study was conducted to investigate the influence of storage on platelets. Platele...

  8. Platelet Concentrates: Past, Present and Future

    OpenAIRE

    Prakash, Shobha; Thakur, Aditi

    2011-01-01

    Platelets play a crucial role in hemostasis and wound healing, platelet growth factors are well known source of healing cytokines. Numerous techniques of autologous platelet concentrates have been developed and applied in oral and maxillofacial surgery. This review describes the evolution of the first and second generation of platelet concentrates (platelet rich plasma and platelet rich fibrin respectively) from their fore runner-fibrin sealants.

  9. Empagliflozin Increases Short-Term Urinary Volume Output in Artificially Induced Syndrome of Inappropriate Antidiuresis

    Directory of Open Access Journals (Sweden)

    Julie Refardt

    2017-01-01

    Full Text Available Objective. Syndrome of inappropriate antidiuresis (SIADH is the predominant cause of hyponatremia, but treatment options are unsatisfying. SGLT2 inhibitors increase urinary glucose excretion with concomitant osmotic diuresis. We therefore hypothesized SGLT2-inhibitors as a novel treatment for SIADH. Design. Double-blind placebo-controlled randomised crossover study in 14 healthy volunteers. Methods. We induced an artificial SIADH model by administration of desmopressin and overhydration. Afterwards, empagliflozin 25 mg or placebo was given in random order. The main outcomes were total urinary excretion, glucosuria, and the area under the curve (AUC of serum sodium concentration. Outcome measures were obtained 2–8 hours after administration of study drug. Results. 14 participants (64% males, BMI 23 kg/m2 (±2.4, aged 28.6 years (±9, completed the study. Empagliflozin led to significantly increased total urinary excretion (579.3 ml (±194.8 versus 367.3 ml (±158.8; treatment effect 158 ml (CI 48.29, 267.74, p=0.017 due to glucosuria (74.18 mmol (±22.3 versus 0.12 mmol (±0.04; treatment effect (log scale 2.85 (CI 2.75, 2.96, p<0.001. There was no difference in the AUC of serum sodium concentration (treatment effect 0.2 (CI −7.38, 6.98, p=0.96. Conclusion. In our SIADH model, empagliflozin increased urinary excretion due to osmotic diuresis. Due to the short treatment duration, serum sodium levels remained unchanged. Real-live studies are needed to further examine empagliflozin as a new treatment for SIADH.

  10. Increased epicardial fat volume quantified by 64-multidetector computed tomography is associated with coronary atherosclerosis and totally occlusive lesions

    International Nuclear Information System (INIS)

    Ueno, Koji; Anzai, Toshihisa; Jinzaki, Masahiro

    2009-01-01

    The relationship between the epicardial fat volume measured by 64-slice multidetector computed tomography (MDCT) and the extension and severity of coronary atherosclerosis was investigated. Both MDCT and conventional coronary angiography (CAG) were performed in 71 consecutive patients who presented with effort angina. The volume of epicardial adipose tissue (EAT) was measured by MDCT. The severity of coronary atherosclerosis was assessed by evaluating the extension of coronary plaques in 790 segments using MDCT data, and the percentage diameter stenosis in 995 segments using CAG data. The estimated volume of EAT indexed by body surface area was defined as VEAT. Increased VEAT was associated with advanced age, male sex, degree of metabolic alterations, a history of acute coronary syndrome (ACS) and the presence of total occlusions, and showed positive correlation with the stenosis score r=0.28, P=0.02) and the atheromatosis score (r=0.67, P 3 /m 2 ) to be the strongest independent determinant of the presence of total occlusions odds ratio 4.64. P=0.02). VEAT correlates with the degree of metabolic alterations and coronary atheromatosis. Excessive accumulation of EAT might contribute to the development of ACS and coronary total occlusions. (author)

  11. Effect of 30-Gy irradiation in conjunction with leukocyte reduction filter on platelet and transfusion efficiency

    International Nuclear Information System (INIS)

    Shimojima, Hiromi; Sawada, Umihiko; Horie, Takashi; Itoh, Takeyoshi

    2001-01-01

    To evaluate the effect of 30-Gy irradiation in conjunction with leukocyte reduction filter on platelet and transfusion efficiency, we studied platelet recovery, leukocyte reduction rate, content of platelet factor 4 and β-thromboglobulin in platelet products, platelet functions, and positive rates of platelet surface membranes CD42 and CD62, prior to and after treatment. We also evaluated the efficiency of platelet transfusion by estimating post- transfusion (1 and 24 hour) corrected count increment (CCI), and transfusion side effects. Recovery of platelets was 91.8±6.5% and depletion rate of leukocytes was 1.7±1.1 log. There was no significant difference in platelet activation markers or function tests prior to and after the procedure. The mean post-transfusion CCI and 1 and 24 hours were 16,550 (n=114) and 13,310 (n=93), respectively, with 30-Gy irradiation and leukocyte reduction filter. Those treated solely with leukocyte reduction filter were 14,970 (n=114) and 10,880 (n=118), respectively. There was no increase in transfusion side effects after the treatment of platelet concentrate with 30-Gy irradiation combined with leukocyte reduction filter compared with treatment by leukocyte reduction filter alone. These results indicate that treatment with 30 Gy irradiation in conjunction with leukocyte reduction filter is safe and effective in platelet transfusion. (author)

  12. Glu- and Lys-forms of plasminogen differentially affect phosphatidylserine exposure on the platelet surface

    Directory of Open Access Journals (Sweden)

    D. D. Zhernossekov

    2017-04-01

    Full Text Available Plasminogen/plasmin system is known for its ability to support hemostatic balance of blood. However, plasminogen may be considered as an adhesive ligand and in this way could affect the functioning of blood cells. We showed that exogenous Lys-plasminogen, but not its Glu-form, inhibited platelet aggregation and suppressed platelet α-granule secretion. The aim of this work was to investigate the influence of Glu- and Lys-form of plasminogen on the formation of platelet procoagulant surface using phosphatidylserine exposure as a marker. Human platelets were obtained from human platelet-rich plasma (donors were healthy volunteers, men aged 30-40 years by gel-filtration on Sepharose 2B. Phosphatidylserine exposure on the platelet surface was evaluated by flow cytometry with FITC-conjugated annexin A5. Glu- and Lys-plasminogen have different impact on the platelet functioning. Exogenous Lys-plasminogen has no significant effect on phosphatidylserine exposure, while Glu-plasminogen increases phosphatidylserine exposure on the surface of thrombin- and collagen-activated human platelets. Glu-plasminogen can be considered as a co-stimulator of agonist-induced platelet secretion and procoagulant surface formation. Meanwhile effects of Lys-plasminogen are probably directed at platelet-platelet interactions and not related to agonist-stimulated pro-apoptotic changes. The observed different effects of Glu- and Lys-plasminogen on phosphatidylserine exposure can be explained by their structural peculiarities.

  13. Antiaggregant effects of Arbutus unedo extracts in human platelets.

    Science.gov (United States)

    El Haouari, Mohammed; López, José J; Mekhfi, Hassane; Rosado, Juan A; Salido, Ginés M

    2007-09-05

    Platelet hyperaggregability plays a pivotal role in the pathogenesis of cardiovascular diseases. Thrombin evokes aggregation through Ca(2+) mobilization, tyrosine phosphorylation and generation of reactive oxygen species (ROS). We have investigated the antiaggregant properties of Arbutus unedo extracts in human platelets. Changes in cytosolic Ca(2+) concentration and intracellular oxidants production were registered by espectrofluorimetry using fura-2 and dichlorodihydrofluorescein, respectively, platelet aggregation was assessed by aggregometry and protein tyrosine phosphorylation was detected by Western blotting. Platelet treatment with increasing concentrations (0.015-1.5mg/mL) of crude aqueous, ethyl acetate or diethyl ether extracts reduced platelet aggregation evoked by thrombin (0.5 U/mL) and show a potent ROS scavenger activity, preventing thrombin-evoked endogenous generation of ROS. Treatment with Arbutus unedo extracts did not alter thrombin-evoked Ca(2+) release from the intracellular stores but reduced store-operated Ca(2+) entry induced by thrombin or by selective depletion of the two Ca(2+) stores in platelets, the dense tubular system and the acidic stores. In addition, platelet treatment with extracts reduced both basal and thrombin-stimulated protein tyrosine phosphorylation. We conclude that Arbutus unedo extracts show antiaggregant actions due to attenuation of Ca(2+) mobilization, ROS production and protein tyrosine phosphorylation and might be used for the treatment and/or prevention of cardiovascular diseases.

  14. 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.

  15. Platelet Function Analyzed by Light Transmission Aggregometry

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Favaloro, Emmanuel J

    2017-01-01

    function can also be assessed for hyper-aggregability, but this is less often evaluated. Light transmission aggregometry (LTA) was introduced in the early 1960s and has since been considered the gold standard. This optical detection system is based on changes in turbidity measured as a change in light...... transmission, which is proportional to the extent of platelet aggregation induced by addition of an agonist. LTA is a flexible method, as different agonists can be used in varying concentrations, but performance of the test requires large blood volumes and experienced laboratory technicians as well...

  16. Antibody directed against human YKL-40 increases tumor volume in a human melanoma xenograft model in scid mice

    DEFF Research Database (Denmark)

    Salamon, Johannes; Hoffmann, Tatjana; Elies, Eva

    2014-01-01

    were treated with intraperitoneal injections of anti-YKL-40, isoptype control or PBS. Non-YKL-40 expressing human pancreatic carcinoma cell line PaCa 5061 served as additional control. MR imaging was used for evaluation of tumor growth. Two days after the first injections of anti-YKL-40, tumor volume...... had increased significantly compared with controls, whereas no effects were observed for control tumors from PaCa 5061 cells lacking YKL-40 expression. After 18 days, mean tumor size of the mice receiving repeated anti-YKL-40 injections was 1.82 g, >4 times higher than mean tumor size of the controls...

  17. Increasing volume and complexity of pediatric epilepsy surgery with stable seizure outcome between 2008 and 2014: A nationwide multicenter study.

    Science.gov (United States)

    Barba, Carmen; Specchio, Nicola; Guerrini, Renzo; Tassi, Laura; De Masi, Salvatore; Cardinale, Francesco; Pellacani, Simona; De Palma, Luca; Battaglia, Domenica; Tamburrini, Gianpiero; Didato, Giuseppe; Freri, Elena; Consales, Alessandro; Nozza, Paolo; Zamponi, Nelia; Cesaroni, Elisabetta; Di Gennaro, Giancarlo; Esposito, Vincenzo; Giulioni, Marco; Tinuper, Paolo; Colicchio, Gabriella; Rocchi, Raffaele; Rubboli, Guido; Giordano, Flavio; Lo Russo, Giorgio; Marras, Carlo Efisio; Cossu, Massimo

    2017-10-01

    The objective of the study was to assess common practice in pediatric epilepsy surgery in Italy between 2008 and 2014. A survey was conducted among nine Italian epilepsy surgery centers to collect information on presurgical and postsurgical evaluation protocols, volumes and types of surgical interventions, and etiologies and seizure outcomes in pediatric epilepsy surgery between 2008 and 2014. Retrospective data on 527 surgical procedures were collected. The most frequent surgical approaches were temporal lobe resections and disconnections (133, 25.2%) and extratemporal lesionectomies (128, 24.3%); the most frequent etiologies were FCD II (107, 20.3%) and glioneuronal tumors (105, 19.9%). Volumes of surgeries increased over time independently from the age at surgery and the epilepsy surgery center. Engel class I was achieved in 73.6% of patients (range: 54.8 to 91.7%), with no significant changes between 2008 and 2014. Univariate analyses showed a decrease in the proportion of temporal resections and tumors and an increase in the proportion of FCDII, while multivariate analyses revealed an increase in the proportion of extratemporal surgeries over time. A higher proportion of temporal surgeries and tumors and a lower proportion of extratemporal and multilobar surgeries and of FCD were observed in low (epilepsy surgery in Italy between 2008 and 2014, associated with a stable seizure outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Does increased nerve length within the treatment volume improve trigeminal neuralgia radiosurgery? a prospective double-blind, randomized study

    International Nuclear Information System (INIS)

    Flickinger, John C.; Pollock, Bruce E.; Kondziolka, Douglas; Phuong, Loi K.; Foote, Robert L.; Stafford, Scott L.; Lunsford, L. Dade

    2001-01-01

    Purpose: To test the hypothesis that increasing the nerve length within the treatment volume for trigeminal neuralgia radiosurgery would improve pain relief. Methods and Materials: Eighty-seven patients with typical trigeminal neuralgia were randomized to undergo retrogasserian gamma knife radiosurgery (75 Gy maximal dose with 4-mm diameter collimators) using either one (n=44) or two (n=43) isocenters. The median follow-up was 26 months (range 1-36). Results: Pain relief was complete in 57 patients (45 without medication and 12 with low-dose medication), partial in 15, and minimal in another 15 patients. The actuarial rate of obtaining complete pain relief (with or without medication) was 67.7%±5.1%. The pain relief was identical for one- and two-isocenter radiosurgery. Pain relapsed in 30 of 72 responding patients. Facial numbness and mild and severe paresthesias developed in 8, 5, and 1 two-isocenter patients vs. 3, 4, and 0 one-isocenter patients, respectively (p=0.23). Improved pain relief correlated with younger age (p=0.025) and fewer prior procedures (p=0.039) and complications (numbness or paresthesias) correlated with the nerve length irradiated (p=0.018). Conclusions: Increasing the treatment volume to include a longer nerve length for trigeminal neuralgia radiosurgery does not significantly improve pain relief but may increase complications

  19. Postoperative increase in grey matter volume in visual cortex after unilateral cataract surgery

    DEFF Research Database (Denmark)

    Lou, Astrid R.; Madsen, Kristoffer Hougaard; Julian, Hanne O.

    2013-01-01

    Purpose:  The developing visual cortex has a strong potential to undergo plastic changes. Little is known about the potential of the ageing visual cortex to express plasticity. A pertinent question is whether therapeutic interventions can trigger plastic changes in the ageing visual cortex by res...... of visual input from both eyes. We conclude that activity-dependent cortical plasticity is preserved in the ageing visual cortex and may be triggered by restoring impaired vision.......Purpose:  The developing visual cortex has a strong potential to undergo plastic changes. Little is known about the potential of the ageing visual cortex to express plasticity. A pertinent question is whether therapeutic interventions can trigger plastic changes in the ageing visual cortex...... surgery induces a regional increase in grey matter in areas V1 and V2 of the visual cortex. Results:  In all patients, cataract surgery immediately improved visual acuity, contrast sensitivity and mean sensitivity in the visual field of the operated eye. The improvement in vision was stable throughout...

  20. 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.

  1. Impact of Silver Nanoparticles on Haemolysis, Platelet Function and Coagulation

    Directory of Open Access Journals (Sweden)

    Julie Laloy

    2014-09-01

    Full Text Available Silver nanoparticles (Ag NPs are increasingly used in biomedical applications because of their large antimicrobial spectrum. Data in the literature on the ability of Ag NPs to perform their desired function without eliciting undesirable effects on blood elements are very limited and contradictory. We studied the impact of Ag NPs on erythrocyte integrity, platelet function and blood coagulation. Erythrocyte integrity was assessed by spectrophotometric measurement of haemoglobin release. Platelet adhesion and aggregation was determined by light transmission aggregometry and scanning electron microscopy. The calibrated thrombin generation test was used to study the impact on coagulation cascade. We demonstrated that Ag NPs induced haemolysis. They also increase platelet adhesion without having any impact on platelet aggregation. Finally, they also had procoagulant potential. Bringing all data from these tests together, the no observed effect concentration is 5 μg/mL.

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

    Science.gov (United States)

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

    2015-01-01

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

  3. Anomalous columnar order of charged colloidal platelets

    Science.gov (United States)

    Morales-Anda, L.; Wensink, H. H.; Galindo, A.; Gil-Villegas, A.

    2012-01-01

    Monte Carlo computer simulations are carried out for a model system of like-charged colloidal platelets in the isothermal-isobaric ensemble (NpT). The aim is to elucidate the role of electrostatic interactions on the structure of synthetic clay systems at high particle densities. Short-range repulsions between particles are described by a suitable hard-core model representing a discotic particle. This potential is supplemented with an electrostatic potential based on a Yukawa model for the screened Coulombic potential between infinitely thin disklike macro-ions. The particle aspect-ratio and electrostatic parameters were chosen to mimic an aqueous dispersion of thin, like-charged, rigid colloidal platelets at finite salt concentration. An examination of the fluid phase diagram reveals a marked shift in the isotropic-nematic transition compared to the hard cut-sphere reference system. Several statistical functions, such as the pair correlation function for the center-of-mass coordinates and structure factor, are obtained to characterize the structural organization of the platelets phases. At low salinity and high osmotic pressure we observe anomalous hexagonal columnar structures characterized by interpenetrating columns with a typical intercolumnar distance corresponding to about half of that of a regular columnar phase. Increasing the ionic strength leads to the formation of glassy, disordered structures consisting of compact clusters of platelets stacked into finite-sized columns. These so-called "nematic columnar" structures have been recently observed in systems of charge-stabilized gibbsite platelets. Our findings are corroborated by an analysis of the static structure factor from a simple density functional theory.

  4. Improved platelet survival after cold storage by prevention of glycoprotein Ibα clustering in lipid rafts

    NARCIS (Netherlands)

    Gitz, E.; Koekman, C.A.; van den Heuvel, D.J.|info:eu-repo/dai/nl/355331861; Deckmyn, H.; Akkerman, J.W.N.; Gerritsen, H.C.|info:eu-repo/dai/nl/071548777; Urbanus, R.T

    2012-01-01

    ABSTRACT Background Room temperature storage of platelets for transfusion increases the risk of microbial infection and decreases platelet functionality, leading to out-date discard rates of up to 20%. Cold storage may be a better alternative, but this treatment leads to rapid platelet clearance

  5. Muscle Volume Increases Following 16 Weeks of Resistive Exercise Training with the Advanced Resistive Exercise Device (ARED) and Free Weights

    Science.gov (United States)

    Nash, R. E.; Loehr, J. A.; Lee, S. M. C.; English, K. L.; Evans, H.; Smith, S. A.; Hagan, R. D.

    2009-01-01

    Space flight-induced muscle atrophy, particularly in the postural and locomotorymuscles, may impair task performance during long-duration space missions and planetary exploration. High intensity free weight (FW) resistive exercise training has been shown to prevent atrophy during bed rest, a space flight analog. NASA developed the Advanced Resistive Exercise Device (ARED) to simulate the characteristics of FW exercise (i.e. constant mass, inertial force) and to be used as a countermeasure during International Space Station (ISS) missions. PURPOSE: To compare the efficacy of ARED and FW training to induce hypertrophy in specific muscle groups in ambulatory subjects prior to deploying ARED on the ISS. METHODS: Twenty untrained subjects were assigned to either the ARED (8 males, 3 females) or FW (6 males, 3 females) group and participated in a periodizedtraining protocol consisting of squat (SQ), heel raise (HR), and deadlift(DL) exercises 3 d wk-1 for 16 wks. SQ, HR, and DL muscle strength (1RM) was measured before, after 8 wks, and after 16 wks of training to prescribe exercise and measure strength changes. Muscle volume of the vastigroup (V), hamstring group (H), hip adductor group (ADD), medial gastrocnemius(MG), lateral gastrocnemius(LG), and deep posterior muscles including soleus(DP) was measured using MRI pre-and post-training. Consecutive cross-sectional images (8 mm slices with a 2 mm gap) were analyzed and summed. Anatomical references insured that the same muscle sections were analyzed pre-and post-training. Two-way repeated measures ANOVAs (ptraining devices. RESULTS: SQ, HR, and DL 1RM increased in both FW (SQ: 49+/-6%, HR: 12+/-2%, DL: 23+/-4%) and ARED (SQ: 31+/-4%, HR: 18+/-2%, DL: 23+/-3%) groups. Both groups increased muscle volume in the V (FW: 13+/-2%, ARED: 10+/-2%), H (FW: 3+/-1%, ARED: 3+/-1 %), ADD (FW: 15=/-2%, ARED: 10+/-1%), LG (FW: 7+/-2%, ARED: 4+/-1%), MG (FW: 7+/-2%, ARED: 5+/-2%), and DP (FW: 2+/-1%; ARED: 2+/-1%) after training. There

  6. A three-week traditional altitude training increases hemoglobin mass and red cell volume in elite biathlon athletes.

    Science.gov (United States)

    Heinicke, K; Heinicke, I; Schmidt, W; Wolfarth, B

    2005-06-01

    It is well known that altitude training stimulates erythropoiesis, but only few data are available concerning the direct altitude effect on red blood cell volume (RCV) in world class endurance athletes during exposure to continued hypoxia. The purpose of this study was to evaluate the impact of three weeks of traditional altitude training at 2050 m on total hemoglobin mass (tHb), RCV and erythropoietic activity in highly-trained endurance athletes. Total hemoglobin mass, RCV, plasma volume (PV), and blood volume (BV) from 6 males and 4 females, all members of a world class biathlon team, were determined on days 1 and 20 during their stay at altitude as well as 16 days after returning to sea-level conditions (800 m, only males) by using the CO-rebreathing method. In males tHb (14.0 +/- 0.2 to 15.3 +/- 1.0 g/kg, p altitude and returned to near sea-level values 16 days after descent. Similarly in females, tHb (13.0 +/- 1.0 to 14.2 +/- 1.3 g/kg, p altitude training period, whereas PV was not altered. In male athletes, plasma erythropoietin concentration increased up to day 4 at altitude (11.8 +/- 5.0 to 20.8 +/- 6.0 mU/ml, p altitude training period, both parameters indicating enhanced erythropoietic activity. In conclusion, we show for the first time that a three-week traditional altitude training increases erythropoietic activity even in world class endurance athletes leading to elevated tHb and RCV. Considering the relatively fast return of tHb and RCV to sea-level values after hypoxic exposure, our data suggest to precisely schedule training at altitude and competition at sea level.

  7. Myeloperoxidase modulates human platelet aggregation via actin cytoskeleton reorganization and store-operated calcium entry

    Directory of Open Access Journals (Sweden)

    Irina V. Gorudko

    2013-07-01

    Myeloperoxidase (MPO is a heme-containing enzyme released from activated leukocytes into the extracellular space during inflammation. Its main function is the production of hypohalous acids that are potent oxidants. MPO can also modulate cell signaling and inflammatory responses independently of its enzymatic activity. Because MPO is regarded as an important risk factor for cardiovascular diseases associated with increased platelet activity, we studied the effects of MPO on human platelet functional properties. Laser scanning confocal microscopy was used to reveal carbohydrate-independent MPO binding to human platelet membrane. Adding MPO to platelets did not activate their aggregation under basal conditions (without agonist. In contrast, MPO augmented agonist-induced platelet aggregation, which was not prevented by MPO enzymatic activity inhibitors. It was found that exposure of platelets to MPO leads to actin cytoskeleton reorganization and an increase in their elasticity. Furthermore, MPO evoked a rise in cytosolic Ca2+ through enhancement of store-operated Ca2+ entry (SOCE. Together, these findings indicate that MPO is not a direct agonist but rather a mediator that binds to human platelets, induces actin cytoskeleton reorganization and affects the mechanical stiffness of human platelets, resulting in potentiating SOCE and agonist-induced human platelet aggregation. Therefore, an increased activity of platelets in vascular disease can, at least partly, be provided by MPO elevated concentrations.

  8. Blood coagulation parameters and platelet indices: changes in normal and preeclamptic pregnancies and predictive values for preeclampsia.

    Directory of Open Access Journals (Sweden)

    Lei Han

    Full Text Available Preeclampsia (PE is an obstetric disorder with high morbidity and mortality rates but without clear pathogeny. The dysfunction of the blood coagulation-fibrinolysis system is a salient characteristic of PE that varies in severity, and necessitates different treatments. Therefore, it is necessary to find suitable predictors for the onset and severity of PE.We aimed to evaluate blood coagulation parameters and platelet indices as potential predictors for the onset and severity of PE.Blood samples from 3 groups of subjects, normal pregnant women (n = 79, mild preeclampsia (mPE (n = 53 and severe preeclampsia (sPE (n = 42, were collected during early and late pregnancy. The levels of coagulative parameters and platelet indices were measured and compared among the groups. The receiver-operating characteristic (ROC curves of these indices were generated, and the area under the curve (AUC was calculated. The predictive values of the selected potential parameters were examined in binary regression analysis.During late pregnancy in the normal pregnancy group, the activated partial thromboplastin time (APTT, prothrombin time (PT, thrombin time (TT and platelet count decreased, while the fibrinogen level and mean platelet volume (MPV increased compared to early pregnancy (p<0.05. However, the PE patients presented with increased APTT, TT, MPV and D-dimer (DD during the third trimester. In the analysis of subjects with and without PE, TT showed the largest AUC (0.743 and high predictive value. In PE patients with different severities, MPV showed the largest AUC (0.671 and ideal predictive efficiency.Normal pregnancy causes a maternal physiological hypercoagulable state in late pregnancy. PE may trigger complex disorders in the endogenous coagulative pathways and consume platelets and FIB, subsequently activating thrombopoiesis and fibrinolysis. Thrombin time and MPV may serve as early monitoring markers for the onset and severity of PE

  9. Evaluation of single and double centrifugation tube methods for concentrating equine platelets.

    Science.gov (United States)

    Argüelles, D; Carmona, J U; Pastor, J; Iborra, A; Viñals, L; Martínez, P; Bach, E; Prades, M

    2006-10-01

    The aim of this study was to evaluate single and double centrifugation tube methods for concentrating equine platelets. Whole blood samples were collected from clinically normal horses and processed by use of single and double centrifugation tube methods to obtain four platelet concentrates (PCs): PC-A, PC-B, PC-C, and PC-D, which were analyzed using a flow cytometry hematology system for hemogram and additional platelet parameters (mean platelet volume, platelet distribution width, mean platelet component concentration, mean platelet component distribution width). Concentrations of transforming growth factor beta 1 (TGF-beta(1)) were determined in all the samples. Platelet concentrations for PC-A, PC-B, PC-C, and PC-D were 45%, 44%, 71%, and 21% higher, respectively, compared to the same values for citrated whole blood samples. TGF-beta(1) concentrations for PC-A, PC-B, PC-C, and PC-D were 38%, 44%, 44%, and 37% higher, respectively, compared to citrated whole blood sample values. In conclusion, the single and double centrifugation tube methods are reliable methods for concentrating equine platelets and for obtaining potentially therapeutic TGF-beta(1) levels.

  10. Does unilateral laparoscopic diathermy adjusted to ovarian volume increase the chances of ovulation in women with polycystic ovary syndrome?

    Science.gov (United States)

    Sunj, M; Canic, T; Baldani, D P; Tandara, M; Jeroncic, A; Palada, I

    2013-09-01

    Does unilateral volume-adjusted laparoscopic diathermy increase the chances of ovulation in women with polycystic ovary syndrome (PCOS)? Although unilateral laparoscopic ovarian drilling (ULOD) using adjusted thermal doses was more efficient than bilateral laparoscopic ovarian drilling (BLOD) using fixed doses, the chances of ovulation were improved in patients irrespective of the technique used. The adjustment of the thermal dose to ovarian volume in BLOD increases ovulation and pregnancy rates compared with fixed-dose treatment, but BLOD causes the formation of adhesions, particularly on the left ovary, and increases the risk of damage to ovarian tissue. In contrast, ULOD with a fixed thermal dose minimizes the risk of ovarian tissue damage, and can increase the activity in both right and left ovaries, although this varies in humans and in other species. This prospective, longitudinal, study, between September 2009 and January 2013, included 96 infertile women with PCOS who were unresponsive to clomiphene citrate treatment and had underwent either ULOD or BLOD. After surgery, the groups were followed up for 6 months to assess ovulatory response. Patients were assigned to two groups; one group underwent laparoscopic ovarian drilling of the right ovary alone, while both ovaries were treated in the second group. The ULOD group (n = 49) received thermal doses adjusted to the volume of the right ovary (60 J/cm³). The BLOD group (n = 47) received fixed doses of 600 J per ovary, regardless of its volume. The two treatment groups were matched by the number of participants, age and baseline parameters. The ovulation rate during the first menstrual cycle after LOD was significantly higher in the ULOD group than in the BLOD group [73 versus 49%; absolute risk reduction (ARR), -0.25; 95% confidence interval (CI), -0.44 to -0.03; P = 0.014]. Treatment with ULOD on the right ovary significantly increased the chances of ovulation in patients with a larger right ovary compared

  11. The mitochondrial membrane potential in human platelets: a sensitive parameter for platelet quality

    NARCIS (Netherlands)

    Verhoeven, Arthur J.; Verhaar, Robin; Gouwerok, Eric G. W.; de Korte, Dirk

    2005-01-01

    BACKGROUND: Deterioration of platelet (PLT) quality during storage is accompanied by an increase in lactate production, indicating a decrease in mitochondrial function. In this study, the optimal conditions under which the fluorescent dye JC-1 can be used to detect changes in mitochondrial function

  12. Platelet-Derived MRP-14 Induces Monocyte Activation in Patients With Symptomatic Peripheral Artery Disease.

    Science.gov (United States)

    Dann, Rebecca; Hadi, Tarik; Montenont, Emilie; Boytard, Ludovic; Alebrahim, Dornaszadat; Feinstein, Jordyn; Allen, Nicole; Simon, Russell; Barone, Krista; Uryu, Kunihiro; Guo, Yu; Rockman, Caron; Ramkhelawon, Bhama; Berger, Jeffrey S

    2018-01-02

    Peripheral artery disease (PAD), a diffuse manifestation of atherothrombosis, is a major cardiovascular threat. Although platelets are primary mediators of atherothrombosis, their role in the pathogenesis of PAD remains unclear. The authors sought to investigate the role of platelets in a cohort of symptomatic PAD. The authors profiled platelet activity, mRNA, and effector roles in patients with symptomatic PAD and in healthy controls. Patients with PAD and carotid artery stenosis were recruited into ongoing studies (NCT02106429 and NCT01897103) investigating platelet activity, platelet RNA, and cardiovascular disease. Platelet RNA sequence profiling mapped a robust up-regulation of myeloid-related protein (MRP)-14 mRNA, a potent calcium binding protein heterodimer, in PAD. Circulating activated platelets were enriched with MRP-14 protein, which augmented the expression of the adhesion mediator, P-selectin, thereby promoting monocyte-platelet aggregates. Electron microscopy confirmed the firm interaction of platelets with monocytes in vitro and colocalization of macrophages with MRP-14 confirmed their cross talk in atherosclerotic manifestations of PAD in vivo. Platelet-derived MRP-14 was channeled to monocytes, thereby fueling their expression of key PAD lesional hallmarks and increasing their directed locomotion, which were both suppressed in the presence of antibody-mediated blockade. Circulating MRP-14 was heightened in the setting of PAD, significantly correlated with PAD severity, and was associated with incident limb events. The authors identified a heightened platelet activity profile and unraveled a novel immunomodulatory effector role of platelet-derived MRP-14 in reprograming monocyte activation in symptomatic PAD. (Platelet Activity in Vascular Surgery and Cardiovascular Events [PACE]; NCT02106429; and Platelet Activity in Vascular Surgery for Thrombosis and Bleeding [PIVOTAL]; NCT01897103). Copyright © 2018 American College of Cardiology Foundation

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

    NARCIS (Netherlands)

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

    1990-01-01

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

  14. A comprehensive proteomics study on platelet concentrates: Platelet proteome, storage time and Mirasol pathogen reduction technology.

    Science.gov (United States)

    Salunkhe, Vishal; De Cuyper, Iris M; Papadopoulos, Petros; van der Meer, Pieter F; Daal, Brunette B; Villa-Fajardo, María; de Korte, Dirk; van den Berg, Timo K; Gutiérrez, Laura

    2018-03-19

    Platelet concentrates (PCs) represent a blood transfusion product with a major concern for safety as their storage temperature (20-24°C) allows bacterial growth, and their maximum storage time period (less than a week) precludes complete microbiological testing. Pathogen inactivation technologies (PITs) provide an additional layer of safety to the blood transfusion products from known and unknown pathogens such as bacteria, viruses, and parasites. In this context, PITs, such as Mirasol Pathogen Reduction Technology (PRT), have been developed and are implemented in many countries. However, several studies have shown in vitro that Mirasol PRT induces a certain level of platelet shape change, hyperactivation, basal degranulation, and increased oxidative damage during storage. It has been suggested that Mirasol PRT might accelerate what has been described as the platelet storage lesion (PSL), but supportive molecular signatures have not been obtained. We aimed at dissecting the influence of both variables, that is, Mirasol PRT and storage time, at the proteome level. We present comprehensive proteomics data analysis of Control PCs and PCs treated with Mirasol PRT at storage days 1, 2, 6, and 8. Our workflow was set to perform proteomics analysis using a gel-free and label-free quantification (LFQ) approach. Semi-quantification was based on LFQ signal intensities of identified proteins using MaxQuant/Perseus software platform. Data are available via ProteomeXchange with identifier PXD008119. We identified marginal differences between Mirasol PRT and Control PCs during storage. However, those significant changes at the proteome level were specifically related to the functional aspects previously described to affect platelets upon Mirasol PRT. In addition, the effect of Mirasol PRT on the platelet proteome appeared not to be exclusively due to an accelerated or enhanced PSL. In summary, semi-quantitative proteomics allows to discern between proteome changes due to

  15. The heart rate increase at the onset of high-work intensity exercise is accelerated by central blood volume loading.

    Science.gov (United States)

    Miyamoto, Tadayoshi; Oshima, Yoshitake; Ikuta, Komei; Kinoshita, Hiroshi

    2006-01-01

    Using a water immersion (WI) method, the combined effect of central blood volume (CBV) loading and work intensity on the time course of heart rate (HR) at the onset of upright dynamic exercise was investigated. Seven males cranked a cycle ergometer for 12 min using their un-immersed arms at low-, moderate- and high-work intensities, followed by a 12-min rest. For WI, the pre-exercise resting cardiac output increased by 36%, while HR decreased by 22% [from 76.8 (10.4) to 59.6 (9.8) beats/min]. WI also increased the high-frequency (HF, 0.15-0.40 Hz) component of the HR variability, suggesting an increased vagal activity. During the initial 2 min of the exercise period at low-work intensity, HR increased by 34.9 and 25.8% in the WI and control conditions, respectively. These were 117 and 73% at high-work intensity, indicating more accelerated HR with WI than the control. The plasma norepinephrine concentration increased less during high-work intensity exercise during WI, as compared to exercise during control conditions. In conclusion, the HR increase at the onset of high-work intensity exercise is accelerated by CBV loading but not at low intensity, possibly reflecting vago-sympathetic interaction and reduced baroreflex sensitivity.

  16. Increased platelet-lymphocyte ratio closely relates to inferior clinical features and worse long-term survival in both resected and metastatic colorectal cancer: an updated systematic review and meta-analysis of 24 studies.

    Science.gov (United States)

    Chen, Nan; Li, Wanling; Huang, Kexin; Yang, Wenhao; Huang, Lin; Cong, Tianxin; Li, Qingfang; Qiu, Meng

    2017-05-09

    Colorectal cancer (CRC) is one of the most common cancers worldwide. However, the prognostic and clinical value of platelet-lymphocyte ratio (PLR) in colorectal cancer was still unclear, which attracted more and more researchers' considerable attention. We performed a systematic review and meta-analysis to investigate the relationship between PLR and survival as well as clinical features of CRC update to September 2016. The hazard ratio (HR) or odds ratio (OR) with 95% confidence interval (CI) were calculated to access the association. We included 24 eligible studies with a total of 13719 patients. Elevated PLR predicted shorter overall survival (OS) (HR=1.47; 95%CI, 1.28-1.68; p<0.001), poorer disease-free survival (DFS) (HR=1.51; 95% CI, 1.2-1.91; p=0.001), and worse recurrence-free survival (RFS) (HR=1.39; 95% CI, 1.03-1.86; p=0.03), but had nothing to do with Cancer-specific survival (CSS) (HR=1.14; 95% CI, 0.92-1.42; p=0.223). After trim and fill method, the connection between PLR and DFS disappeared (HR=1.143; 95%CI, 0.903-1.447; p=0.267). By subgroup analyze, we found that increased PLR predicated a worse OS and DFS in patients who underwent surgery, and this prognostic role also shown both in metastatic and nonmetastatic patients. In addition, elevated PLR was associated with poorly differentiated tumor (OR=1.51; 95% CI, 1.26-1.81; p<0.001), higher tumor stage (OR=1.25; 95% CI, 1.05-1.49; p=0.012), lymphovascular invasion (LVI) (OR=1.25; 95% CI, 1.09-1.43; p=0.001), and the recurrence of CRC (OR=2.78; 95% CI, 1.36-5.68; p=0.005). We indicated that pretreatment PLR was a good prognostic marker for CRC patients. High PLR was related to worse OS, RFS and poor clinical characteristics.

  17. Optimizing platelet-rich plasma gel formation by varying time and gravitational forces during centrifugation.

    Science.gov (United States)

    Jo, Chris H; Roh, Young Hak; Kim, Ji Eun; Shin, Sue; Yoon, Kang Sup

    2013-10-01

    Despite the increasing clinical use of topical platelet-rich plasma (PRP) to enhance tissue healing and regeneration, there is no properly standardized method of autologous PRP gel preparation. This study examined the effect of the centrifugation time and gravitational force (g) on the platelet recovery ratio of PRP and determined the most effective centrifugation conditions for preparing PRP. Two-step centrifugations for preparing PRP were used in 39 subjects who had consented prior to the study's start. The separating centrifugation (Step 1, used to separate whole blood into its two main components: red blood cells and plasma) was tested from 500g to 1900g at 200g increments for 5 minutes (min), and from 100g to 1300g at 200g increments for 10 minutes. After separating centrifugation, upper plasma layer was transferred to another plain tube for the condensation centrifugation and remaining lower cell layer was discarded. The condensation centrifugation (Step 2, used to condense the platelets in the separated plasma) was tested at 1000g for 15 min, 1500g for 15 min, 2000g for 5 min and 3000g for 5 min, additionally at 1000g for 10 min and 1500g for 10 min. Platelet gelation was induced by adding 10% calcium gluconate to final PRP with volume ratio of 1:10. The optimal separating centrifugation conditions were followed by 900g for 5 minutes and the condensation conditions were followed by 1500g for 15 minutes, of which recovery ratios were 92.0 ± 3.1% and 84.3 ± 10.0%, respectively.

  18. 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.

  19. A sensitive new method of ex vivo platelet deposition

    International Nuclear Information System (INIS)

    Badimon, L.; Fuster, V.; Dewanjee, M.K.; Romero, J.C.

    1982-01-01

    In 1978, an in vivo quantitative method of platelet aggregation based on the increment of weight of a rabbit tendon when superfused with flowing blood (3 ml/min) derived from a carotid artery of a cat and reentering the contralateral jugular vein was reported. TO increase the sensitivity of the method, researches labeled platelets with indium-111 and reinjected them after two hours; then, with a gamma counter, researches quantitated the 111 In-labeled platelets deposited on the superfused rabbit tendon. Results of the radioactivity method and of the weight method were compared. Researchers found that the 111 In-labeling of platelets was more precise and reproducible method, rendering possible the use of a small amount of blood without need for reentry into the venous system

  20. Increased expression of AQP 1 and AQP 5 in rat lungs ventilated with low tidal volume is time dependent.

    Directory of Open Access Journals (Sweden)

    Gustavo Fabregat

    Full Text Available BACKGROUND AND GOALS: Mechanical ventilation (MV can induce or worsen pulmonary oedema. Aquaporins (AQPs facilitate the selective and rapid bi-directional movement of water. Their role in the development and resolution of pulmonary oedema is controversial. Our objectives are to determine if prolonged MV causes lung oedema and changes in the expression of AQP 1 and AQP 5 in rats. METHODS: 25 male Wistar rats were subjected to MV with a tidal volume of 10 ml/kg, during 2 hours (n = 12 and 4 hours (n = 13. Degree of oedema was compared with a group of non-ventilated rats (n = 5. The expression of AQP 1 and AQP 5 were determined by western immunoblotting, measuring the amount of mRNA (previously amplified by RT-PCR and immunohistochemical staining of AQPs 1 and 5 in lung samples from all groups. RESULTS: Lung oedema and alveolar-capillary membrane permeability did not change during MV. AQP-5 steady state levels in the western blot were increased (p<0.01 at 2 h and 4 h of MV. But in AQP-1 expression these differences were not found. However, the amount of mRNA for AQP-1 was increased at 2 h and 4 h of MV; and for AQP 5 at 4 h of MV. These findings were corroborated by representative immunohistochemical lung samples. CONCLUSION: In lungs from rats ventilated with a low tidal volume the expression of AQP 5 increases gradually with MV duration, but does not cause pulmonary oedema or changes in lung permeability. AQPs may have a protective effect against the oedema induced by MV.

  1. Radioimmune assay of human platelet prostaglandin synthetase

    International Nuclear Information System (INIS)

    Roth, G.J.; Machuga, E.T.

    1982-01-01

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH 2 from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and [ 125 I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [ 125 I]antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 10 9 platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency

  2. Platelet Glycoprotein Ib-IX and Malignancy

    Science.gov (United States)

    2010-09-01

    provide a unique microenvironment supporting the accumulation of more platelets and the elaboration of a fibrin - rich network produced by coagulation...process and can initiate the formation of a platelet - rich thrombus by tethering the platelet to a thrombogenic surface. Several ligands binding to GP Ib... Platelet Glycoprotein Ib-IX and Malignancy PRINCIPAL INVESTIGATOR: Jerry Ware, Ph.D

  3. Analysis of Reparative Activity of Platelet Lysate: Effect on Cell Monolayer Recovery In Vitro and Skin Wound Healing In Vivo.

    Science.gov (United States)

    Sergeeva, N S; Shanskii, Ya D; Sviridova, I K; Karalkin, P A; Kirsanova, V A; Akhmedova, S A; Kaprin, A D

    2016-11-01

    Platelet lysate prepared from donor platelet concentrate and pooled according to a developed technique stimulates migration of multipotent mesenchymal stromal cells of the human adipose tissue and promotes healing of the monolayer defect in cultures of human fibroblasts and multipotent mesenchymal stromal cells in vitro in concentrations close those of fetal calf serum (5-10%). Lysate of platelets from platelet-rich rat blood plasma stimulated healing of the skin defect by promoting epithelialization and granulation tissue formation. The regenerative properties of platelet lysate in vivo increased with increasing its concentration.

  4. 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.

  5. 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.

  6. Niacin and biosynthesis of PGD₂ by platelet COX-1 in mice and humans