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

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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

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

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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.

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

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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...

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.

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

The Effect of Carbon Monoxide Poisoning on Platelet Volume in Children

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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.

Platelet count and platelet indices in women with preeclampsia.

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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.

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.

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 ...

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

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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.

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

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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.

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

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Asoglu M

2016-09-01

Full Text Available Mehmet Asoglu,1 Mehmet Aslan,2 Okan Imre,1 Yuksel Kivrak,3 Oznur Akil,1 Emin Savik,4 Hasan Buyukaslan,5 Ulker Fedai,1 Abdurrahman Altındag6 1Department of Psychiatry, Faculty of Medicine, Harran University, Sanliurfa, 2Department of Internal Medicine, Faculty of Medicine, Yuzuncu Yil University, Van, 3Department of Psychiatry, Faculty of Medicine, Kafkas University, Kars, 4Department of Clinical Biochemistry, Faculty of Medicine, Harran University, 5Department of Emergency Medicine, Faculty of Medicine, Harran University, Sanliurfa, 6Department of Psychiatry, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey Background: As the relationship between psychological stress and platelet activation has been widely studied in recent years, activated platelets lead to certain biochemical changes, which occur in the brain in patients with mental disorders. However, data relating to the mean platelet volume (MPV in patients with panic disorder (PD are both limited and controversial. Herein, we aimed to evaluate, for the first time, the red cell distribution width (RDW levels combined with MPV levels in patients with PD.Patients and methods: Between January 2012 and June 2015, data of 30 treatment-naïve patients (16 females, 14 males; mean age: 37±10 years; range: 18–59 years who were diagnosed with PD and 25 age- and sex-matched healthy volunteers (10 females, 15 males; mean age: 36±13 years; range: 18–59 years (control group were retrospectively analyzed. The white blood cell count (WBC, MPV, and RDW levels were measured in both groups.Results: The mean WBC, MPV, and RDW levels were 9,173.03±2,400.31/mm3, 8.19±1.13 fl, and 12.47±1.14%, respectively, in the PD group. These values were found to be 7,090.24±1,032.61, 6.85±0.67, and 11.63±0.85, respectively, in the healthy controls. The WBC, MPV, and RDW levels were significantly higher in the patients with PD compared to the healthy controls (P=0.001, P=0.001, and P=0

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

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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

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

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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.

The mean platelet volume levels in children with PFAPA syndrome.

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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.

Mean platelet volume is decreased in adults with active lupus disease

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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.

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

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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.

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

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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.

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

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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.

Platelet size does not correlate with platelet age.

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

1983-08-01

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

Platelet size does not correlate with platelet age

International Nuclear Information System (INIS)

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

1983-01-01

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

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

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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

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.

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

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Derya Koçer

2015-01-01

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

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

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Sevil Alan

2015-12-01

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

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 ...

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

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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.

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

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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.

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

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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.

Diagnostic Accuracy of Platelet Count and Platelet Indices in Noninvasive Assessment of Fibrosis in Nonalcoholic Fatty Liver Disease Patients

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Tamara Milovanovic Alempijevic

2017-01-01

Full Text Available Objective. Keeping in mind the rising prevalence of nonalcoholic fatty liver disease (NAFLD and the need to establish noninvasive tests for its detection, the aim of our study was to investigate whether platelet count (PC, mean platelet volume (MPV, and platelet distribution width (PDW can predict the presence of liver fibrosis in this group of patients. Methods. In 98 patients with NAFLD and 60 healthy volunteers, complete blood counts with automated differential counts were performed and values of PC, PDW, MPV, and PCT were analyzed. Results. Patients with NAFLD had lower PC and higher MPV, PCT, and PDW compared to the controls (P < 0.05. When NAFLD group was stratified according to severity of liver fibrosis, there was a statistically significant difference in the average values of PDW and PC between the groups (P < 0.05. Conclusion. Patients with NAFLD have significantly higher values of PCT, PDW, and MPV when compared to the healthy controls. Further studies are needed to establish their potential use for prediction of the degree of liver steatosis and fibrosis in NAFLD patients.

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

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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.

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

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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

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

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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.

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

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Aktürk, Semra; Büyükavcı, Raikan

2017-08-01

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

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

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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

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

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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.

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

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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.

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

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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.

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

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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

Conservation and viability of refrigerated platelet-rich plasma from New Zealand rabbits

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Lucas Vilela Perroni Silva

2016-08-01

Full Text Available Fifteen male New Zealand rabbits were used in this study, with the aim of storing their platelet-rich plasma (PRP for 30 days at 4-6 °C to investigate its conservation and viability during this period. Thirty samples of PRP were prepared and sorted into three equal groups (G1, G2, and G3, and every three days a sample was taken out for evaluationof the number of platelets, mean platelet volume (MPV, pH of the plasma, aggregation post addition of calcium thromboplastin, and for the presence of bacterial and fungal contamination. Results suggested that, for the number of platelets, there was no linear relationship over time. However, when comparing the number of platelets pre-storage to that post-storage, a statistical difference was observed. The hemogram MPV variables, pre and post-storage, also did not relate with time however, there was a statistical difference between the MPV of hemogram and MPV pre-storage, and between MPV pre-storage and MPV post-storage. From the pH evaluation, no influence of time on the variables was found, but statistical differences were found in the samples after storage between 30 and 6 days, 30 and 24 days, and 30 and 27 days. Platelet aggregation occurred within twenty seconds in all samples, independent of storage time. There was no growth of bacteria or yeast in any sample; however, mold growth occurred in the samples stored for 21 days from G1 and G3. It can be concluded that the PRP of rabbits can be stored in 4-6 °C refrigeration for up to18 days and still maintain the number of platelets, with no significant pH alteration or bacterial or fungal contamination.

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

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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.

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

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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

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...

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

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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.

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

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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.

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

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Ayse Balkarli

2016-09-01

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

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

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Gulay Yilmaz

2017-01-01

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

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

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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.

Does platelet mass influence the effectiveness of ibuprofen treatment for patent ductus arteriosus in preterm infants?

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Akar, Selahattin; Karadag, Nilgun; Gokmen Yildirim, Tulin; Toptan, Handan Hakyemez; Dincer, Emre; Tuten, Abdulhamit; Yavuz, Taner; Topcuoglu, Sevilay; Karatepe, Hande Ozgun; Ozalkaya, Elif; Karatekin, Guner; Ovali, Fahri

2016-12-01

The aim of this study is to evaluate whether the platelet mass in the first 24 h of life is effective on closure of patent ductus arteriosus (PDA) or not. Preterm infants with a gestational age of gender and maternal risk factors between the study groups. The mean platelet count in the first postnatal blood count was in Group 1: 211.3 ± 89.2 × 10(3)/mm(3) and in Group 2: 216.5 ± 26 × 10(3)/mm(3), respectively (p = 0.783). The mean platelet volumes (MPV) were similar in both groups (p = 0.535). No statistically significant difference between platelet mass values was detected (Group 1: 1811 ± 884 fl/nl, Group 2: 1868 ± 717 fl/nl) (p = 0.753). Our data suggest that platelet count, MPV and platelet mass did not affect the closure of hsPDA with ibuprofen.

Value of platelet indices in identifying complete resolution of thrombus in deep venous thrombosis patients.

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Sevuk, Utkan; Altindag, Rojhat; Bahadir, Mehmet Veysi; Ay, Nurettin; Demirtas, Ertan; Ayaz, Fırat

2015-03-01

We aimed to evaluate whether mean platelet volume (MPV) and platelet distribution width (PDW) are helpful to identify complete thrombus resolution (CTR) after acute deep venous thrombosis (DVT). Patients who had first-time episode of acute proximal DVT were included in this retrospective study. 100 patients with DVT were divided into two groups according to absence (group 1; n = 68) or presence (group 2; n = 32) of CTR on doppler ultrasonography at month 6. There were no significant difference in admission MPV and PDW levels between group 1 and group 2. MPV (p = 0.03) and PDW (p venous thrombosis in DVT patients. Receiver operating characteristics analysis revealed that a 8.4 % decrease in admission MPV at month 6 provided 62 % sensitivity and 62 % specificity (AUC: 0.64) and a 15.4 % decrease in admission PDW at month 6 provided 87 % sensitivity and 94 % specificity (AUC: 0.89) for prediction of CTR in DVT patients. Percent change in admission MPV and PDW levels at month 6 may be used to identify the patients with CTR after a first episode of acute proximal DVT.

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

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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.

Platelet indices and glucose control in type 1 and type 2 diabetes mellitus: A case-control study.

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Zaccardi, F; Rocca, B; Rizzi, A; Ciminello, A; Teofili, L; Ghirlanda, G; De Stefano, V; Pitocco, D

2017-10-01

The relationship between platelet indices and glucose control may differ in type 1 (T1DM) and type 2 (T2DM) diabetes. We aimed to investigate differences in mean platelet volume (MPV), platelet count, and platelet mass between patients with T1DM, T2DM, and healthy controls and to explore associations between these platelet indices and glucose control. A total of 691 T1DM and 459 T2DM patients and 943 control subjects (blood donors) were included. HbA1c was measured in all subjects with diabetes and 36 T1DM patients further underwent 24 h-continuous glucose monitoring to estimate short-term glucose control (glucose mean and standard deviation). Adjusting for age and sex, platelet count was higher and MPV lower in both T1DM and T2DM patients vs control subjects, while platelet mass (MPV × platelet count) resulted higher only in T2DM. Upon further adjustment for HbA1c, differences in platelet count and mass were respectively 19.5 × 10 9 /L (95%CI: 9.8-29.3; p 1) and 101 fL/nL (12-191; p = 0.027) comparing T2DM vs T1DM patients. MPV and platelet count were significantly and differently related in T2DM patients vs both T1DM and control subjects; this difference was maintained also accounting for HbA1c, age, and sex. Platelet mass and the volume-count relationship were significantly related to HbA1c only in T1DM patients. No associations were found between platelet indices and short-term glucose control. By accounting for confounders and glucose control, our data evidenced higher platelet mass and different volume-count kinetics in subjects with T2DM vs T1DM. Long-term glucose control seemed to influence platelet mass and the volume-count relationship only in T1DM subjects. These findings suggest different mechanisms behind platelet formation in T1DM and T2DM patients with long-term glycaemic control being more relevant in T1DM than T2DM. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian

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

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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.

Conservation and viability of refrigerated platelet-rich plasma from New Zealand rabbits

OpenAIRE

Lucas Vilela Perroni Silva; Duvaldo Eurides; Marina Greco Magalhães Guerra de Andrade; Marcelo Carrijo da Costa; Vinicius Candido Ferreira; Marina de Oliveira Silva; Ednaldo Carvalho Guimarães

2016-01-01

Fifteen male New Zealand rabbits were used in this study, with the aim of storing their platelet-rich plasma (PRP) for 30 days at 4-6 °C to investigate its conservation and viability during this period. Thirty samples of PRP were prepared and sorted into three equal groups (G1, G2, and G3), and every three days a sample was taken out for evaluationof the number of platelets, mean platelet volume (MPV), pH of the plasma, aggregation post addition of calcium thromboplastin, and for the presence...

Can platelet indices be used as predictors of complication in subjects with appendicitis?

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Ceylan, Bahadır; Aslan, Turan; Çınar, Ahmet; Ruhkar Kurt, Ayşe; Akkoyunlu, Yasemin

2016-12-01

We examined the changes of mean platelet volume (MPV) and platelet distribution width (PDW) in subjects with appendicitis and whether MPV and PDW could be used to predict the development of complication due to appendicitis. The healthy control group, the cases of appendicitis with perforation, and the cases of appendicitis without perforation were compared with regard to MPV and PDW. We determined whether MPV and PDW were independent variables predictive of the development of complication in subjects with appendicitis. This retrospective case-control study included a total of 362 patients (249 of which were male (68.8 %) and 113 were female (31.2 %); median age, 30 [range, 18-84 years]). One hundred and ninety-two subjects (53 %) presented with appendicitis and 170 (47 %) comprised the healthy control group. Sixty-six (18.2 %) of the subjects with appendicitis developed complication. MPVs were lower in subjects of appendicitis without complication compared to the subjects of appendicitis with complication and the control group (MPV, 9.78 ± 0.99 vs. 10.20 ± 1.21 and 10.14 ± 1.03, respectively [p = 0.005]). The PDW levels were not different between the three groups. Independent variables predictive of the presence of complication included increased MPV and time from onset of symptoms to hospital presentation (odds ratio[confidence interval], p-value: 1.507[1.064-2.133], 0.021 and 18.887[5.139-69.410], 0.0001, respectively). Our findings suggested these, MPV values in cases of appendicitis without complication were lower than the cases with complication and healthy control and MPV is a predictor of the development of complication in subjects with appendicitis.

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

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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

Blood coagulation parameters and platelet indices: changes in normal and preeclamptic pregnancies and predictive values for preeclampsia.

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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

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

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Hadadi Laszlo

2015-12-01

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

[Optimization on trehalose loading technique as protective conditioning for lyophilization of human platelets].

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Liu, Jing-Han; Zhou, Jun; Ouyang, Xi-Lin; Li, Xi-Jin; Lu, Fa-Qiang

2005-08-01

This study was aimed to further optimize trehalose loading technique including loading temperature, loading time, loading solution and loading concentration of trehalose, based on the established parameters. Loading efficiency in plasma was compared with that in buffer at 37 degrees C; the curves of intracellular trehalose concentration versus loading time at 37 degrees C and 16 degrees C were measured; curves of mean platelet volume (MPV) versus loading time and loading concentration were investigated and compared. According to results obtained, the loaing time, loading temperature, loading solution and trehalose concentration were ascertained for high loading efficiency of trehalose into human platelet. The results showed that the loading efficiency in plasma was markedly higher than that in buffer at 37 degrees C, the loading efficiency in plasma at 37 degrees C was significantly higher than that at 16 degrees C and reached 19.51% after loading for 4 hours, but 6.16% at 16 degrees C. MPV at 16 degrees C was increased by 43.2% than that at 37 degrees C, but had no distinct changes with loading time and loading concentration. In loading at 37 degrees C, MPV increased with loading time and loading concentration positively. Loading time and loading concentration displayed synergetic effect on MPV. MPV increased with loading time and concentration while trehalose loading concentration was above 50 mmol/L. It is concluded that the optimization parameters of trehalose loading technique are 37 degrees C (temperature), 4 hours (leading time), plasma (loading solution), 50 mmol/L (feasible trehalose concentration). The trehalose concentration can be adjusted to meet the requirement of lyophilization.

Mean trombosit volume in patients with retinopathy of prematurity

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Harun Yüksel

2014-06-01

Full Text Available Objective: We aimed to evaluate the mean platelet volume (MPV in patients with retinopathy of prematurity (ROP with respect to development of type 1 ROP Methods: The medical records of the premature infants were evaluated. Babies with a birth weight under 1500 g and a gestational age under 32 weeks were enrolled to the study. Birth weight, gestational age, onset and grade of retinopathy, presence of plus disease were analyzed. At the time of type 1 ROP diagnosis, blood samples were obtained. In the patients without type 1 ROP the blood samples were also obtained at similar gestational age. Hemoglobin, hematocrit, platelet count, and MPV results were recorded. Results: Sixty-three infants were studied. 22 of them had type 1 ROP and 41 had not developed type 1 ROP. The mean gestational age and the mean birth weight between groups were not statistically significant. The mean MPV values in patients with type 1 ROP and without type 1 ROP was 9,1±2,0 fL and 9,4±1,8 fL, respectively (p=0.61. Conclusion: The results demonstrated that MPV values were not associated with severity of ROP in our study population. J Clin Exp Invest 2014; 5 (2: 443-446

Simple tube centrifugation for processing platelet-rich plasma in the horse.

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Fontenot, Robin L; Sink, Carolyn A; Werre, Stephen R; Weinstein, Nicole M; Dahlgren, Linda A

2012-12-01

This study evaluated the quality and bacteriologic safety of platelet-rich plasma (PRP) produced by 3 simple, inexpensive tube centrifugation methods and a commercial system. Citrated equine blood collected from 26 normal horses was processed by 4 methods: blood collection tubes centrifuged at 1200 and 2000 × g, 50-mL conical tube, and a commercial system. White blood cell (WBC), red blood cell (RBC), and platelet counts and mean platelet volume (MPV) were determined for whole blood and PRP, and aerobic and anaerobic cultures were performed. Mean platelet concentrations ranged from 1.55- to 2.58-fold. The conical method yielded the most samples with platelet concentrations greater than 2.5-fold and within the clinically acceptable range of > 250,000 platelets/μL. White blood cell counts were lowest with the commercial system and unacceptably high with the blood collection tubes. The conical tube method may offer an economically feasible and comparatively safe alternative to commercial PRP production systems.

Comparison of different procedures to prepare platelet-rich plasma for studies of platelet aggregation by light transmission aggregometry.

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Femia, Eti Alessandra; Pugliano, Mariateresa; Podda, Gianmarco; Cattaneo, Marco

2012-01-01

Light transmission aggregometry (LTA), the gold standard for the study of patients with defects of platelet function, is a poorly standardized technique. The guidelines that have been produced so far are largely based on consensus of experts, due to the absence of studies directly comparing different procedures. Therefore, ad hoc studies are needed to gather scientific evidence on how to choose the most appropriate procedures for LTA measurement. In this study, we aimed at evaluating the most appropriate conditions for preparing samples of platelet-rich plasma (PRP) for studies of platelet aggregation by LTA. Citrate-anticoagulated blood from 32 individuals was centrifuged at 150, 200, 250 or 300×g at room temperature for 10 min. Red blood cells contamination was highest in PRP prepared at 150×g; mean platelet volume (MPV) was lowest in PRP prepared at 300×g. The extent of platelet aggregation measured by LTA was lower and more variable in PRP prepared at 300×g. Therefore, centrifugation of blood at 200×g or 250×g for 10 min appears to be the best condition for preparing PRP for LTA studies.

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.

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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.

糖尿病视网膜病变患者血小板参数与糖化血红蛋白变化及临床意义%Study on clinical significance of changes in MPV and HbAlc in patients with diabetic retinopathy.

Institute of Scientific and Technical Information of China (English)

徐威; 蔡应木; 王彩霞

2012-01-01

目的 探讨血小板平均体积(MPV)及糖化血红蛋白(HbA1c)在糖尿病视网膜病变时的变化及临床意义.方法采用BEACKMAN COULTER LH750 全自动血细胞分析仪和TOSOH HLC-723G8全自动糖化血红蛋白分析仪检测85例糖尿病患者[单纯糖尿病者45例,糖尿病视网膜病变(DR)者40例]的血小板计数(PLT)、MPV、血小板分布宽度(PDW)、HbA1c并与40例健康成人(对照组)进行对照比较.结果 DR组HbA1c、MPV、PDW明显高于单纯糖尿病组及对照组(P<0.05,P<0.01),而PLT低于单纯糖尿病组及对照组(P<0.05).结论 HbA1c与MPV的联合检测对糖尿病患者视网膜病变的发生及预后判断方面具有重要意义,有助于早期发现DR的存在.%Objective To explore the clinical significance of changes in MPV and glycosylated hemoglobin ( HbAlc ) in patients with diabetic retinopathy. Methods Blood platelet count, mean platelet volume ( MPV ) and platelet distribution width ( PDW ) of 45 diabetics without retinopathy, 40 diabetics with retinopathy and 40 healthy persons were measured by automatic blood cell analyzer BEACKMAN COULTER LH750. Level of HbAlc was measured by automatic glycosylated hemoglobin analyzer TOSOH HLC -723G8. Results Compared with healthy and diabetes groups, levels of HbAlc, MPV and PDW in diabetic retinopathy group were remarkably increased ( P＜0.05, P＜0. 01 ), while platelet count was decreased ( P＜0.05 ). Conclusion Joint detection of level of HbAlc and MPV is helpful for early diagnosis and prognosis judgement of diabetic retinopathy in patients with diabetes.

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

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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.

Effects of sodium citrate and acid citrate dextrose solutions on cell counts and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel.

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Giraldo, Carlos E; Álvarez, María E; Carmona, Jorge U

2015-03-14

There is a lack information on the effects of the most commonly used anticoagulants for equine platelet rich plasmas (PRPs) elaboration on cell counts and growth factor release from platelet rich gels (PRGs). The aims of this study were 1) to compare the effects of the anticoagulants sodium citrate (SC), acid citrate dextrose solution A (ACD-A) and ACD-B on platelet (PLT), leukocyte (WBC) and on some parameters associated to platelet activation including mean platelet volume (MPV) and platelet distribution width (PDW) between whole blood, pure PRP (P-PRP) and platelet-poor plasma (PPP); 2) to compare transforming growth factor beta 1 (TGF-β(1)) and platelet-derived growth factor isoform BB (PDGF-BB) concentrations in supernatants from pure PRG (P-PRG), platelet-poor gel (PPG), P-PRP lysate (positive control) and plasma (negative control); 3) to establish the possible correlations between all the studied cellular and molecular parameters. In all cases the three anticoagulants produced P-PRPs with significantly higher PLT counts compared with whole blood and PPP. The concentrations of WBCs were similar between P-PRP and whole blood, but significantly lower in PPP. The type of anticoagulant did not significantly affect the cell counts for each blood component. The anticoagulants also did not affect the MPV and PDW parameters. Independently of the anticoagulant used, all blood components presented significantly different concentrations of PDGF-BB and TGF-β(1). The highest growth factor (GF) concentrations were observed from P-PRP lysates, followed by PRG supernatants, PPP lysates, PPG supernatants and plasma. Significant correlations were observed between PLT and WBC counts (ρ = 0.80), PLT count and TGF-β(1) concentration (ρ = 0.85), PLT count and PDGF-BB concentration (ρ = 0.80) and PDGF-BB and TGF-β(1) concentrations (ρ = 0.75). The type of anticoagulant was not correlated with any of the variables evaluated. The anticoagulants did not

Detection of hMPV antigen by EIA in clinical specimens.

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Pancer, Katarzyna; Ciaćka, Agnieszka; Gut, Włodzimierz; Lipka, Bozena; Mierzejewska, Justyna; Milewska-Bobula, Bogumiła; Smorczewska-Kiljan, Anna; Jahnz-Rózyk, Karina; Litwińska, Bogumiła

2011-01-01

Human Metapneumovirus (hMPV) is one of the latest discovered viruses. It has been classified to Paramyxoviridae family. It is the second viral etiological agent, after RSV, which causes respiratory tract infections (RTI) in children, especially children below 5 years old. It is estimated that 5-25% of RTI in children is due to hMPV. In adults hMPV reinfections are bounded to upper respiratory tract infections. The aim of the study was to establish usefulness of ELISA test in detecting hMPV antigen and to analyze hMPV infection in connection to clinical diagnosis. 273 nasopharyngeal swabs from children (189 swabs) and adults (84 swabs) with respiratory tract infections collected from 2008 to 2010 were examined. Due to similarity of hMPV and RSV viruses and overlapping of their epidemic season rapid immunochromatographic test for RSV antigen detection was also performed in case of 120 samples, hMPV antigen was detected in 24.5% of all swabs (n = 67): in 0.0% probes in 2008, 29.0% in 2009 and 36.8% in first quarter of 2010. The highest rate ofhMPV infection was detected from summer of 2009 till the end of March 2010 (VIII-IX 2009 - 62.5%, X-XII 2009 - 44.1% and I-III 2010 -36.8%). We analyzed respiratory tract diseases reported in patients with hMPV infection. Infection due to hMPV was found in 26.5% of children and 24.0% of adults with recognized pneumonia, respectively in 28.4 and 17.6% of patients with bronchitis. Bronchiolitis was diagnosed in two children with hMPV. RSV and hMPV coinfections were confirmed in 15 out of 120 examined probes. Cross reaction pattern was excluded thanks to ELISA hMPV antigen test which was performed with suspension of RSV and thanks to statistical analysis. Coinfections were confirmed in 8% of pneumonia, 11% of bronchitis and 24.2% of the rest concomitant diagnoses. We found hMPV infection as the significant agent ofpneumonia not only in children but also in adults. ELISA hMPV antigen test can be used in diagnosis of etiological agent

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

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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.

[Human Metapneumovirus (hMPV) associated to severe bronchial asthmatic crisis].

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López, M A; Kusznierz, G F; Imaz, M S; Cociglio, R; Tedeschi, F A; Zalazar, F E

2006-01-01

Human Metapneumovirus (hMPV) is a recently reported agent of acute infection in the respiratory tract. It has been found in children as well as in young adults and elders. The clinical manifestations produced by hMPV are indistinguishable from those by common respiratory virus, and can evolve from asymptomatic infection into severe pneumonia. On the other hand, some authors have described cases of bronchial asthma exacerbation associated with hMPV infection. In this work we report a case of a child who presented a severe bronchial asthmatic crisis with a suspected viral associated infection. Immunofluorescence tests yielded negative results for sincitial respiratory virus, adenovirus, a-b influenza virus and parainfluenza 1, 2, 3, virus. In an attempt to detect the presence of hMPV, a RT-PCR was carried out to amplify sequences from both N and F genes. Using this approach, a positive result for hMPV was obtained. To our knowledge, this is the first description of a case of asthma exacerbation associated to hMPV in our region. In addition, these results are similar to previous reports where it was hypothesized that, like RSV, hMPV can trigger a respiratory chronic disease as asthma.

Metapneumovirus humano (hMPV asociado con exacerbación de asma aguda bronquial severa Human Metapneumovirus (hMPV associated to severe bronchial asthmatic crisis

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M. A. López

2006-09-01

Full Text Available El metapneumovirus humano (hMPV es un nuevo agente causal de infección aguda del tracto respiratorio, recientemente reportado tras su hallazgo en niños, jóvenes, adultos y ancianos. Las manifestaciones clínicas producidas por el hMPV son indistinguibles de aquellas provocadas por los virus respiratorios clásicamente conocidos, y varían desde infección asintomática hasta neumonía complicada. Por otro lado, se han descrito casos de exacerbación de asma bronquial asociados a la infección con hMPV. En este trabajo se describe el caso de un niño hospitalizado que presentó una crisis asmática bronquial severa con sospecha de una infección viral asociada. Por el test de inmunofluorescencia indirecta no se detectaron virus sincicial respiratorio (VSR, adenovirus, virus influenza a - b ni virus parainfluenza 1, 2 y 3. En un intento por detectar la presencia de hMPV, se realizó una RT-PCR para la amplificación de los genes N y F con resultado positivo. Conforme a nuestro conocimiento, esta sería la primera descripción de un caso de exacerbación de asma asociado a hMPV en nuestra región. Los resultados de este estudio serían similares a los reportados por otros autores, quienes postulan que, a semejanza de lo que ocurre con el VSR, una infección por hMPV puede gatillar una enfermedad respiratoria crónica, como el asma.Human Metapneumovirus (hMPV is a recently reported agent of acute infection in the respiratory tract. It has been found in children as well as in young adults and elders. The clinical manifestations produced by hMPV are indistinguishable from those by common respiratory virus, and can evolve from asymptomatic infection into severe pneumonia. On the other hand, some authors have described cases of bronchial asthma exacerbation associated with hMPV infection. In this work we report a case of a child who presented a severe bronchial asthmatic crisis with a suspected viral associated infection. Immunofluorescence tests

hMPV and RSV: subtle differences but comparable severity

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Nour Akhras

2010-08-01

Full Text Available

 Human metapneumovirus (hMPV is a recently discovered virus that causes respiratory illness in children and can lead to hospitalization.   This study was undertaken to

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

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

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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.

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.

Association of epicardial adipose tissue thickness and inflammation parameters with CHA2DS2-VASc score in patients with nonvalvular atrial fibrillation

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Akdag S

2015-11-01

Full Text Available Serkan Akdag, Hakki Simsek, Musa Sahin, Aytac Akyol, Ramazan Duz, Naci Babat Department of Cardiology, Yuzuncu Yil University Medical Faculty, Van, Turkey Background: Epicardial adipose tissue (EAT, mean platelet volume (MPV, platelet-to- lymphocyte ratio (PLR, and neutrophil-to-lymphocyte ratio (NLR have been shown to be helpful in predicting adverse cardiovascular events. However, to date, in the literature, there have been no studies demonstrating the relationship between EAT, MPV, PLR, NLR, and thromboembolism risk in atrial fibrillation (AF. Therefore, we examined the relationship between EAT, MPV, PLR, NLR, and CHA2DS2-VASc score used for the evaluation of thromboembolism risk in patients with AF.Methods: The study included 96 consecutive patients with AF and 52 age- and sex-matched control subjects. We calculated CHA2DS2-VASc risk score for each patient and measured baseline EAT thickness, MPV, PLR, NLR, left atrial volume index, and left ventricular ejection fraction.Results: The group with high CHA2DS2-VASc score had higher EAT (7.2±1.5 vs 5.9±1.2 mm, P<0.001, MPV (9.1±1.1 vs 8.4±1.0 fL, P=0.004, PLR (152.3±28.4 vs 126.7±25.4, P=0.001, and NLR (4.0±1.6 vs 3.2±1.3, P<0.001 compared to group with low-intermediate CHA2DS2-VASc score. Moreover, CHA2DS2-VASc score was found to be positively correlated with EAT (r=0.623, P<0.001, MPV (r=0.350, P=0.004, PLR (r=0.398, P=0.001, and NLR (r=0.518, P<0.001.Conclusion: Our study results demonstrated that EAT thickness, MPV, PLR, and NLR were associated with the thromboembolic risk exhibited by CHA2DS2-VASc score in patients with nonvalvular AF. Keywords: atrial fibrillation, epicardial adipose tissue, platelet, neutrophil, mean platelet volume

Effects of vitamin C and exercise on lipid profile, platelet and erythrocyte indices in young soccer players.

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Karakilcik, A Z; Halat, R; Zerin, M; Celik, H; Nazligul, Y

2014-10-01

Exercise may increase production of reactive oxygen species (ROS) enhancing oxidative stress. Antioxidants can efficiently scavenge ROS before they initiate oxidative damage of biomolecules such as enzymes, nucleic acids, lipids and lipoproteins in the body. Vitamin C, an important antioxidant, may affect oxidative stress in living organism. Therefore, this study was carried out to investigate the effects of exercise and vitamin C on thiobarbituric acid-reactive substance (TBARS), lipid profile, erythrocyte and platelet indices in young soccer players. This investigation was carried out on twenty two male volunteer players in three groups. The first group was examined as a control. The second group was only exposed to exercise. The third group was exposed to exercise plus vitamin C (500 mg/day) administered per oral. The players were 23.50±0.59 year-old, 67.66±1.52 kg body weight and 1.74±0.03 m height. Blood samples were collected in vacutainer tubes for analysis of biochemical and hematological parameters. While the levels of high density lipoprotein-cholesterol (HDL-C) were significantly increased (PC) were decreased (Pvitamin C treatment. While TBARS levels were increased (Pvitamin C treatment. The platelet counts (PLT), mean platelet volume (MPV), plateletcrit (PCT) and red blood cell distribution width (RDW) were significantly decreased (Pvitamin C. There were significantly correlations (PC and in increasing of HDL-C. In addition, exercise plus vitamin C may diminish TBARS-levels and may affect the values of PLT, MPV, PCT and RDW in young soccer players.

Relationship between insulin resistance and mean platelet volume in gestational diabetes mellitus

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Suleyman Baldane

2015-01-01

Conclusion: We have shown that MPV was significantly elevated in GDM patients when compared to healthy pregnant women. Furthermore, we found that there was a positive correlation between MPV and HOMA-IR.

Report for the MPV Demonstration at New Boston Air Force Base, New Hampshire: UXO Characterization in Challenging Survey Environments Using the MPV

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2017-04-28

EM Electromagnetic EMI Electromagnetic Induction ERDC Engineering Research and Development Center ESTCP Environmental Security Technology... bombs , HE bombs and incendiary bombs . The site hosted demonstrations with the MPV and the 2x2 TEMTADS, both with crews from CH2MHill. Each study...array of five receiver units that measure all three components of the EM field (Figure 2). This second-generation MPV is specifically designed to

Genetics Home Reference: MPV17-related hepatocerebral mitochondrial DNA depletion syndrome

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... DNA depletion syndrome MPV17-related hepatocerebral mitochondrial DNA depletion syndrome Printable PDF Open All Close All Enable ... collapse boxes. Description MPV17 -related hepatocerebral mitochondrial DNA depletion syndrome is an inherited disorder that can cause ...

Demonstration of MPV Sensor at Yuma Proving Ground, AZ

Science.gov (United States)

2011-06-01

test plot in Ashland, OR, where magnetic soils have shown to have a significant effect on EMI sensors ( Pasion et al., 2008). The recorded signal...sensors was also investigated during that survey as part of SERDP MM-1573 (PI: Len Pasion , Sky Research). The MPV offers possibilities to defeat...of magnetic soils (Lhomme et al., 2008; Pasion et al., 2008). The MPV response due to sensor motion and topography over magnetic soil is predicable

ANTI-INFLAMMATORY EFFECT OF CLOPIDOGREL IN ATHEROSCLEROSIS

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L. I. Buriachkovskaia

2011-01-01

Full Text Available Aim. To analyze the literary and own data about clopidogrel influence on platelets during inflammation and to reveal particularities of its usage in ischemic heart disease (IHD patients with active inflammation. Material and methods. The platelet morphology and a number of leukocyte-platelet aggregates (LTA were investigated with scanning electron microscopy in 110 patients with stable angina pectoris of I-III functional class and 18 healthy volunteers. Spontaneous and ADP-induced platelet aggregation were assessed with laser aggregatometre manufactured by LLC “BIOLA”. Mean platelet volume (MPV was estimated with the hematological analyzer . All investigations were performed in IHD patients before and after 2 months of clopidogrel treatment 75 mg a day. Results. IHD patients demonstrated appearance of LTA and big reticular platelets in the blood, increase in MPV and spontaneous aggregation. ADP-induced platelet aggregation was rarely increased probably due to acetylsalicylic acid therapy in all IHD patients. These platelet activity changes are connected with increased risk of thrombotic events and correlated with inflammation markers levels. After 2 months of clopidogrel treatment LTA number reduced in 4 times and big reticular platelets number decreased in 2.5 times as well as MPV and spontaneous aggregation achieved the normal ranges. Conclusion. Clopidogrel has not only antithrombotic effect but also can diminish platelets morphological and functional changes connected with inflammation.

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,.

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

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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.

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

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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

MPV17-related mitochondrial DNA maintenance defect: New cases and review of clinical, biochemical, and molecular aspects.

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El-Hattab, Ayman W; Wang, Julia; Dai, Hongzheng; Almannai, Mohammed; Staufner, Christian; Alfadhel, Majid; Gambello, Michael J; Prasun, Pankaj; Raza, Saleem; Lyons, Hernando J; Afqi, Manal; Saleh, Mohammed A M; Faqeih, Eissa A; Alzaidan, Hamad I; Alshenqiti, Abduljabbar; Flore, Leigh Anne; Hertecant, Jozef; Sacharow, Stephanie; Barbouth, Deborah S; Murayama, Kei; Shah, Amit A; Lin, Henry C; Wong, Lee-Jun C

2018-04-01

Mitochondrial DNA (mtDNA) maintenance defects are a group of diseases caused by deficiency of proteins involved in mtDNA synthesis, mitochondrial nucleotide supply, or mitochondrial dynamics. One of the mtDNA maintenance proteins is MPV17, which is a mitochondrial inner membrane protein involved in importing deoxynucleotides into the mitochondria. In 2006, pathogenic variants in MPV17 were first reported to cause infantile-onset hepatocerebral mtDNA depletion syndrome and Navajo neurohepatopathy. To date, 75 individuals with MPV17-related mtDNA maintenance defect have been reported with 39 different MPV17 pathogenic variants. In this report, we present an additional 25 affected individuals with nine novel MPV17 pathogenic variants. We summarize the clinical features of all 100 affected individuals and review the total 48 MPV17 pathogenic variants. The vast majority of affected individuals presented with an early-onset encephalohepatopathic disease characterized by hepatic and neurological manifestations, failure to thrive, lactic acidemia, and mtDNA depletion detected mainly in liver tissue. Rarely, MPV17 deficiency can cause a late-onset neuromyopathic disease characterized by myopathy and peripheral neuropathy with no or minimal liver involvement. Approximately half of the MPV17 pathogenic variants are missense. A genotype with biallelic missense variants, in particular homozygous p.R50Q, p.P98L, and p.R41Q, can carry a relatively better prognosis. © 2017 Wiley Periodicals, Inc.

Elevated Neutrophil Lymphocyte Ratio in Recurrent Optic Neuritis

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Hande Guclu

2015-01-01

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

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)

Induction of local and systemic immune reactions following infection of turkeys with avian Metapneumovirus (aMPV) subtypes A and B.

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Liman, Martin; Rautenschlein, Silke

2007-02-15

Most of the studies regarding the immunopathogenesis of avian Metapneumovirus (aMPV) have been done with subtype C of aMPV. Not much is known about the immunopathogenesis of aMPV subtypes A and B in turkeys. Specifically, local immune reactions have not been investigated yet. We conducted two experiments in commercial turkeys. We investigated local and systemic humoral and cell mediated immune reactions following infection with an attenuated vaccine strain of aMPV subtype B (Experiment I) and virulent strains of aMPV subtypes A and B (Experiment II). Turkeys infected with virulent aMPV strains developed mild respiratory signs while birds inoculated with the attenuated aMPV did not show any clinical signs. Virus neutralizing antibodies were detected locally in tracheal washes and systemically in serum as soon as 5-7 days post aMPV infection (PI) independent of the strain used. Virus neutralizing antibody titres peaked at 7 days PI and then antibody levels declined. The peak of serum ELISA antibody production varied between infected groups and ranged from 14 and 28 days PI. All aMPV strains induced an increase in the percentage of CD4+ T cell populations in spleen and Harderian gland at days 7 or 14 PI. Furthermore, as shown in Experiment I, infection with the attenuated aMPV-B strain stimulated spleen leukocytes to release significantly higher levels of interferons (IFNs), interleukin-6 and nitric oxide in ex vivo culture in comparison to virus-free controls up to 7 days PI (P<0.05). As detected by quantitative real time RT-PCR in Experiment II, infection with virulent aMPV induced an increased IFNgamma expression in the Harderian gland in comparison to virus-free controls. IFNgamma expression in the spleen varied between aMPV strains and days PI. Overall, our study demonstrates that aMPV subtypes A and B infection induced humoral and cell mediated immune reactions comparable to subtype C infections. We observed only temporary stimulation of serum virus neutralizing

Mpv17 in mitochondria protects podocytes against mitochondrial dysfunction and apoptosis in vivo and in vitro.

Science.gov (United States)

Casalena, Gabriela; Krick, Stefanie; Daehn, Ilse; Yu, Liping; Ju, Wenjun; Shi, Shaolin; Tsai, Su-yi; D'Agati, Vivette; Lindenmeyer, Maja; Cohen, Clemens D; Schlondorff, Detlef; Bottinger, Erwin P

2014-06-01

Mitochondrial dysfunction is increasingly recognized as contributing to glomerular diseases, including those secondary to mitochondrial DNA (mtDNA) mutations and deletions. Mitochondria maintain cellular redox and energy homeostasis and are a major source of intracellular reactive oxygen species (ROS) production. Mitochondrial ROS accumulation may contribute to stress-induced mitochondrial dysfunction and apoptosis and thereby to glomerulosclerosis. In mice, deletion of the gene encoding Mpv17 is associated with glomerulosclerosis, but the underlying mechanism remains poorly defined. Here we report that Mpv17 localizes to mitochondria of podocytes and its expression is reduced in several glomerular injury models and in human focal segmental glomerulosclerosis (FSGS) but not in minimal change disease. Using models of mild or severe nephrotoxic serum nephritis (NTSN) in Mpv17(+/+) wild-type (WT) and Mpv17(-/-) knockout mice, we found that Mpv17 deficiency resulted in increased proteinuria (mild NTSN) and renal insufficiency (severe NTSN) compared with WT. These lesions were associated with increased mitochondrial ROS generation and mitochondrial injury such as oxidative DNA damage. In vitro, podocytes with loss of Mpv17 function were characterized by increased susceptibility to apoptosis and ROS injury including decreased mitochondrial function, loss of mtDNA content, and change in mitochondrial configuration. In summary, the inner mitochondrial membrane protein Mpv17 in podocytes is essential for the maintenance of mitochondrial homeostasis and protects podocytes against oxidative stress-induced injury both in vitro and in vivo. Copyright © 2014 the American Physiological Society.

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

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Yun-Xia Lei

2016-07-01

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

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

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Rauf Oguzhan Kum

2015-12-01

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

Accuracy of tidal volume delivered by home mechanical ventilation during mouthpiece ventilation

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Prigent, Helene; Falaize, Line; Leroux, Karl; Santos, Dante; Vaugier, Isabelle; Orlikowski, David; Lofaso, Frederic

2016-01-01

The aim of our study was to evaluate efficacy and reliability of currently available ventilators for mouthpiece ventilation (MPV). Five life-support home ventilators were assessed in a bench test using different settings simulating the specificities of MPV, such as intermittent circuit disconnection and presence of continuous leaks. The intermittent disconnection of the circuit caused relevant swings in the delivered tidal volume (VT), showing a VT overshoot during the disconnection periods and a VT decrease when the interface was reconnected to the test lung. The five ventilators showed substantial differences in the number of respiratory cycles necessary to reach a stable VT in the volume-controlled setting, ranging from 1.3 ± 0.6 to 7.3 ± 1.2 cycles. These differences were less accentuated in the volume-assisted setting (MPV-dedicated mode, when available). Our data show large differences in the capacity of the different ventilators to deal with the rapidly changing respiratory load features that characterize MPV, which can be further accentuated according to the used ventilator setting. The dedicated MPV modes allow improvement in the performance of ventilators only in some defined situations. This has practical consequences for the choice of the ventilator to be used for MPV in a specific patient. PMID:27146811

Generation and evaluation of recombinant Newcastle disease viruses (NDV) expressing the F and G proteins of avian metapneumovirus subtype C (aMPV-C) as bivalent vaccine against NDV and aMPV challenges in turkeys

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Previously we generated a Newcastle disease virus (NDV) LaSota strain-based recombinant virus expressing the glycoprotein (G) of avian metapneumovirus subgroup C (aMPV-C) as a bivalent vaccine, which provided a partial protection against aMPV-C challenge in turkeys. To improve the vaccine efficacy,...

Effects of cyclosporin A induced T-lymphocyte depletion on the course of avian Metapneumovirus (aMPV) infection in turkeys.

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Rubbenstroth, Dennis; Dalgaard, Tina S; Kothlow, Sonja; Juul-Madsen, Helle R; Rautenschlein, Silke

2010-05-01

The avian Metapneumovirus (aMPV) causes an economically important acute respiratory disease in turkeys (turkey rhinotracheitis, TRT). While antibodies were shown to be insufficient for protection against aMPV-infection, the role of T-lymphocytes in the control of aMPV-infection is not clear. In this study we investigated the role of T-lymphocytes in aMPV-pathogenesis in a T-cell-suppression model in turkeys. T-cell-intact turkeys and turkeys partly depleted of functional CD4(+) and CD8(+) T-lymphocytes by Cyclosporin A (CsA) treatment were inoculated with the virulent aMPV subtype A strain BUT 8544. CsA-treatment resulted in a significant reduction of absolute numbers of circulating CD4(+) and CD8alpha(+) T-lymphocytes by up to 82 and 65%, respectively (P<0.05). Proportions of proliferating T-cells within mitogen-stimulated peripheral blood mononuclear cells were reduced by similar levels in CsA-treated birds compared to untreated controls (P<0.05). CsA-treated turkeys showed delayed recovery from aMPV-induced clinical signs and histopathological lesions and a prolonged detection of aMPV in choanal swabs. The results of this study show that T-lymphocytes play an important role in the control of primary aMPV-infection in turkeys. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Effects of Cyclosporin A induced T-lymphocyte depletion on the course of avian Metapneumovirus (aMPV) infection in turkeys

DEFF Research Database (Denmark)

Rubbenstroth, Dennis; Dalgaard, Tina S; Kothlow, Sonja

2010-01-01

The avian Metapneumovirus (aMPV) causes an economically important acute respiratory disease in turkeys (turkey rhinotracheitis, TRT).While antibodies were shownto be insufficient for protection against a MPV-infection, the role of T-lymphocytes in the control of aMPV-infection is not clear...... to untreated controls (P infection...

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

Storage of Buffy-coat-derived platelets in additive solutions: in vitro effects on platelets prepared by the novel TACSI system and stored in plastic containers with different gas permeability.

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Sandgren, P; Hild, M; Sjödin, A; Gulliksson, H

2010-11-01

The novel TACSI system is designed for automated preparation of platelets (PLTs) from pooled buffy coats (BCs). One TACSI device will handle 6 units at the same time. The aim of our in vitro study is to investigate the effects of using this automated equipment with subsequent storage in two different plastic containers and to compare these results with PLTs prepared by the OrbiSac system. Buffy-coat-derived PLTs (n=8) were prepared by using the TACSI system, including storage in polyvinyl chloride (PVC)-based plastic containers with di, n-decyl phthalate (DnDP) (TACSI R) and BTHC (TACSI T)-based plasticizers. As a reference, the OrbiSac System was used to prepare PLTs (n=8) with subsequent storage in a PVC plastic container with a citrate-based plasticizer (BTHC). In total, 16 TACSI and eight reference units, supplied by approximately 30% plasma and 70% SSP+, were analysed for various in vitro variables during the 7-day storage period. No significant difference in PLT counts, LDH, mean platelet volume (MPV) and adenosine triphosphate between the groups was detected. Glucose was lower (P6·8 (day 7) and swirling remained at the highest level (score=2) for all units throughout storage. Platelets prepared by the TACSI system with subsequent storage in two different PVC-based plastic containers were equivalent to reference PLTs with regard to in vitro characteristics during 7 days of storage. © 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.

Generation and evaluation of a recombinant Newcastle disease virus (NDV) expressing the F and G proteins of avian metapneumovirus subtype C (aMPV-C) as a bivalent vaccine against NDV and aMPV-C challenges in turkeys

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Virulent strains of Newcastle disease virus (NDV) and avian metapneumovirus (aMPV) can cause serious respiratory diseases in poultry. Vaccination combined with strict biosecurity practices has been the recommendation for controlling NDV and aMPV diseases in the field. Previously we generated a NDV r...

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

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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

Demonstration of the MPV at Former Waikoloa Maneuver Area in Hawaii: UXO Characterization in Challenging Survey Environments Using the MPV

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2015-10-01

instantaneous polarization model ( Pasion and Oldenburg, 2001). The target polarizability decay parameters are the main features for the ensuing...Kingdon, John Jackson and Environet crew       Data management Nicolas Lhomme     Technical support Leonard Pasion Laurens Beran   Data analysis and...data, classification of the MPV-3D data, retrospective performance analysis and reporting. Laurens Beran and Len Pasion of Black Tusk Geophysics

In-Vitro Antiviral Activities of Extracts of Plants of The Brazilian Cerrado against the Avian Metapneumovirus (aMPV

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LK Kohn

2015-09-01

Full Text Available ABSTRACTAvian metapneumovirus (aMPV is a negative-sense single-stranded RNA enveloped virus of the Metapneumovirus genus belonging to theParamyxoviridae family. This virus may cause significant economic losses to the poultry industry, despite vaccination, which is the main tool for controlling and preventing aMPV. The aim of this study was to evaluate the antiviral activity of extracts of four different native plants of the Brazilian Cerrado against aMPV. The antiviral activity against aMPV was determined by titration. This technique measures the ability of plant extract dilutions (25 to 2.5 µg mL-1 to inhibit the cytopathic effect (CPE of the virus, expressed as inhibition percentage (IP. The maximum nontoxic concentration (MNTC of the extracts used in antiviral assay was 25 µg mL-1for Aspidosperma tomentosumand Gaylussacia brasiliensis, and 2.5 µg mL-1for Arrabidaea chicaand Virola sebifera. Twelve different extracts derived from four plant species collected from the Brazilian Cerrado were screened for antiviral activity against aMPV. G. brasiliensis, A. chica,and V. sebifera extracts presented inhibition rates of 99% in the early viral replication stages, suggesting that these extracts act during the adsorption phase. On the other hand, A. tomentosum inhibited 99% virus replication after the virus entered the cell. The biomonitored fractioning of extracts active against aMPV may be a tool to identify the active compounds of plant extracts and to determine their precise mode of action.

Subclinical Inflammation and Simple Blood Parameters in Pregnant with Familial Mediterranean Fever

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Korkut Daglar

2016-09-01

Full Text Available Aim: Familial Mediterranean Fever (FMF is the most common hereditary monogenic auto-inflammatory disease. Studies suggest that inflammation persists even in attack-free periods in FMF patients. In this study, we aim to investigate the potential of simple blood parameters including neutrophil to lymphocyte ratio (NLR, platelet to lymphocyte ratio (PLR, lymphocyte/monocyte ratio (LMR, mean platelet volume (MPV, and platelet distributed width (PDW as emerging inflammatory markers to identify chronic inflammations during symptom-free periods in a group of pregnant patients with FMF. Material and Method: A total of consecutive 65 singleton pregnancies, 33 with FMF and the other 32 healthy women, were followed from the first trimester to the end of the pregnancies. Blood samples for biochemical analyses (C-reactive protein, fibrinogen and a complete blood count were obtained at 11-13 weeks and at 16-19 weeks following a detailed examination. Results: While the mean, NLR, PLR, PDW, fibrinogen, and LMR values were comparable between the groups, the mean hs-CRP levels were significantly higher and MPV values were significantly lower in the FMF group compared with the control group at both the first and second trimester. There was a significant negative correlation between hs-CRP levels with MPV at second trimester (r= -0.375 p=0.003. Discussion: Since all of our FMF patients had already been on regular colchicine therapy on admission, we admit, at least theoretically, that the anti-inflammatory and potential effects of colchicine on platelets could have altered our results. Otherwise, MPV may be used as a negative acute-phase reactant in pregnant patients with FMF.

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

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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.

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)

PDW Index - A Simple Model for the Prediction of Liver Fibrosis in Chronic Viral Hepatitis

International Nuclear Information System (INIS)

Ashraf, S.; Ali, N.

2013-01-01

Objectives: To assess the accuracy of platelets, platelet morphological parameters, mean platelet volume(MPV) and platelet distribution width, (PDW) to diagnose advanced fibrosis. Study Design: Validation study. Place and Duration of Study: Combined Military Hospital, Malir, from Jun 2008 to Jun 2009. Patients and Methods: Simple laboratory tests, aspartate aminotransferase (AST) alanine aminotransferase (ALT) platelet count and platelet morphological parameters were measured in 91 chronic viral hepatitis patients. All patients had liver biopsy performed. A new index, PDW index was derived to detect the opposing effects of liver fibrosis on platelet count, MPV, and PDW. The predictive value of the index for advanced fibrosis (F3-F4) was assessed through descriptive statistics and area under the ROC curves. Results: Two cut-offs were chosen to qualify different stages of fibrosis. A value of > 8.00 predicted advanced fibrosis, F3-F4, with a specificity of 94% and positive predictive value of 78%. A value of < 6.00 ruled out advanced fibrosis with a negative predictive value of 93% and a sensitivity of 82%. The area under the ROC curve for advanced fibrosis was 0.840. PDW Index values outside of these cut-offs correctly classified 60% of patients. Conclusion: A simple index comprising platelet as only parameters have high diagnostic value for the advanced stages of fibrosis. (author)

STUDY ON PLATELET INDICES IN PREGNANCY INDUCED HYPERTENSION

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Rabi a Parveen

2015-10-01

Full Text Available INTRODUCTION : Pregnancy induced hypertension includes gestational hypertension, preeclampsia, and eclampsia. In PIH, lower the platelet count, greater are maternal and fetal morbidity and mortality. Recent studies suggest that platele t parameters like platelet indices are most simple and cost effective method for prediction of PIH, way before the appearance of derangements in PT, APTT, TT values so we undertook this study with an aim to see an association between platelet indices and pregnancy induced hypertension. MATERIAL AND METHOD : This was prospective analytical case control study. Study included 125 cases, who were diagnosed as PIH with B.P. > 140/90 mmHg, detected after 20 weeks of pregnancy. Under all aseptic precautions samples were collected randomly in EDTA vials . Samples were analysed for platelet indices . RESULT : Maximum number of cases of Preeclampsia (88.57% & Eclampsia (87.5% were fo und in age group of 21 to 25 . Controls were of same age group i.e. 21 to 25 years. It was observed that platelet count showed gradual decrease in eclampsia (1.44580± 36,210 & pre - e clampsia patients (1.97850± 39,010 as compared to normotensive subjects (2.42620± 40,412. MPV showed gradual increase in eclampsia ( 10.49 ±1.12 & pre - eclampsia ( 9.14 ±0.612 patients as compared to normotensive subjects ( 8.422 ±0.743. PDW value also shows gradual increase in eclampsia ( 18.39 ±2.62 & pre - eclampsia ( 16.29 ±2.34 p atients as compared to normotensive subjects ( 12.09 ±2.53. CONCLUSION : Study showed that platelet indices were important, simple, effortless and cost effective investigations which can be used for early recognition of preventable eclampsia complications.

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

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.

Protection by recombinant Newcastle disease viruses (NDV) expressing the glycoprotein (G) of avian metapneumovirus (aMPV) subtype A or B against challenge with virulent NDV and aMPV

Science.gov (United States)

Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that cause sporadic but serious respiratory diseases in poultry worldwide. Although, vaccination, combined with strict biosecurity practices, has been the recommendation for controlling these diseases in t...

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

KEPERCAYAAN SEBAGAI MEDIASI HUBUNGAN CORPORATE IMAGE TERHADAP LOYALITAS PELANGGAN MOBIL LOW MPV

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Iva Nurdiana Nurfarida

2017-01-01

Full Text Available The program's cost environmentally friendly cars or Low MPV (LCGC issued by the Indonesian government to bring the impact of the availability of consumer choices Indonesia to buy a car at a bargain price. The challenge is whether consumers have confidence that the car MPV although low cost but still quality. Nearly all car manufacturers to get the car with this type so that competition in the automotive business has become very competitive. This study aims to determine causality corporate image to build customer trust and customer loyalty Low MPV car. The study was conducted on customers of Toyota cars, with the number of respondents 150, using accidental sampling and technique using path analysis. The results that the corporate image has a direct influence on the increase in customer loyalty, as well as striving indirectly through increased customer confidence LCGC Toyota. Manufacturer Toyota has the advantage of the corporate image of the customer against Toyota is high, so the products LCGC Toyota produced can be accepted by consumers for consumers / customers have a loyalty to Toyota, meaning that the high corporate image car customers LCGC Toyota lead to customer loyalty. Another result of this study that the corporate image is also able to increase customer confidence LCGC Toyota subsequent impact on improving customer loyalty, meaning that belief becomes a mediation of the causal relationship of corporate image on customer loyalty.

肝癌合并肝硬化患者血小板参数的变化及影响因素

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DING Shengnan

2014-06-01

Full Text Available ObjectiveTo analyze the changes in platelet parameters and their influential factors in cirrhotic patients with hepatocellular carcinoma (HCC. MethodsThe clinical data of 602 cirrhotic patients with HCC who were admitted to the First Hospital of Jilin University from January 2011 to December 2012, as well as 200 cirrhotic patients hospitalized during the same period, were collected. Statistical analysis was performed using SPSS 19.0. Normally distributed continuous data were expressed as mean ± standard deviation; comparison between two groups was made by t test, and comparison between multiple groups was made by analysis of variance. Non-normally distributed data were expressed as median and interquartile range (P25-P75; comparison between groups was made by rank sum test. ResultsCompared with the cirrhotic group, the HCC group had significantly higher platelet count (PLT and plateletcrit (PCT (t=5.019, P=0000; t=5.017, P=0.000 and a significantly lower mean platelet volume (MPV/PLT (t=5.877, P=0.000; there were no significant differences in MPV and platelet distribution width between the two groups (t=-0.942, P=0.347; t=-1.040, P=0.298. The receiver operating characteristic (ROC analysis showed that the area under the ROC curve was 0.636 for PLT, 0.633 for PCT, and 0.639 for MPV/PLT in the diagnosis of HCC in cirrhotic patients. Decreases in PLT and PCT were closely related to hepatitis C virus (HCV infection. Patients with Child-Pugh class A cirrhosis had significantly higher PLT and PCT than those with Child-Pugh class B and C cirrhosis (P＜0.01; patients with a maximum tumor diameter of ≥5 cm had significantly higher PLT and PCT than those with maximum tumor diameters of 2-5 cm and ≤2 cm (P＜0.01. Patients with Child-Pugh class A cirrhosis had a significantly lower MPV/PLT than those with Child-Pugh class B and C cirrhosis (P＜0.01; patients with a maximum tumor diameter of ≥5 cm had a significantly lower MPV/PLT than those

Analytical performance evaluation of a high-volume hematology laboratory utilizing sigma metrics as standard of excellence.

Science.gov (United States)

Shaikh, M S; Moiz, B

2016-04-01

Around two-thirds of important clinical decisions about the management of patients are based on laboratory test results. Clinical laboratories are required to adopt quality control (QC) measures to ensure provision of accurate and precise results. Six sigma is a statistical tool, which provides opportunity to assess performance at the highest level of excellence. The purpose of this study was to assess performance of our hematological parameters on sigma scale in order to identify gaps and hence areas of improvement in patient care. Twelve analytes included in the study were hemoglobin (Hb), hematocrit (Hct), red blood cell count (RBC), mean corpuscular volume (MCV), red cell distribution width (RDW), total leukocyte count (TLC) with percentages of neutrophils (Neutr%) and lymphocytes (Lymph %), platelet count (Plt), mean platelet volume (MPV), prothrombin time (PT), and fibrinogen (Fbg). Internal quality control data and external quality assurance survey results were utilized for the calculation of sigma metrics for each analyte. Acceptable sigma value of ≥3 was obtained for the majority of the analytes included in the analysis. MCV, Plt, and Fbg achieved value of performed poorly on both level 1 and 2 controls with sigma value of <3. Despite acceptable conventional QC tools, application of sigma metrics can identify analytical deficits and hence prospects for the improvement in clinical laboratories. © 2016 John Wiley & Sons Ltd.

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...

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

Platelet activation in pregnancy-induced hypertension.

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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.

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.

SYM1, l’ortologo di lievito del gene umano MPV17, codifica per una proteina indotta da stress che modula lo stato bioenergetico e morfogenetico del mitocondrio

OpenAIRE

Dallabona, Cristina

2010-01-01

Mutazioni nel gene MPV17 causano l’insorgenza di una forma epatocerebrale della sindrome da deplezione del DNA mitocondriale. MPV17 codifica per una piccola proteina idrofobica localizzata nella membrana mitocondriale interna con funzione sconosciuta. Per cercare di chiarire le basi molecolari che causano la patologia, abbiamo utilizzato il lievito S. cerevisiae come organismo modello grazie alla presenza di un ortologo di MPV17: SYM1. Abbiamo dimostrato che la proteina Sym1 è essenziale per ...

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 ...

Evaluation of a LaSota strain-based recombinant Newcastle disease virus (NDV) expressing the glycoprotein (G) of avian metapneumovirus (aMPV) subgroup A or B as a bivalent vaccine in turkeys

Science.gov (United States)

To develop a bivalent vaccine candidate, a LaSota strain-based recombinant Newcastle disease virus (NDV) clone expressing the glycoprotein (G) of avian metapneumovirus (aMPV) subgroup A or B was generated using reverse genetics. Vaccination of turkeys with the NDV/aMPV-A G or NDV/aMPV-B G recombinan...

Estudos experimentais com isolados do metapneumovirus aviário (aMPV) subtipos A e B em frangos de corte

OpenAIRE

Márcia Bianchi dos Santos

2010-01-01

Resumo: O Metapneumovirus aviário (aMPV) pertence à família Paramyxoviridae, subfamília Pneumovirinae, gênero Metapneumovirus. O vírus, relatado pela primeira vez no Brasil em 1995, é o agente etiológico da Rinotraqueíte em perus (TRT) e está associado também à Síndrome da Cabeça Inchada (SHS) em frangos e poedeiras comerciais. O presente estudo foi dividido em três partes. Na primeira foi avaliada a suscetibilidades de oito sistemas celulares para a propagação de amostras virais do aMPV subt...

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.

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

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.

Red cell distribution width in type 2 diabetic patients

Directory of Open Access Journals (Sweden)

Nada AM

2015-10-01

Full Text Available Aml Mohamed Nada Department of Internal Medicine, Unit of Endocrinology, Diabetes and Metabolism, Faculty of Medicine, Mansoura University, Mansoura, Egypt Objective: To study the indices of some elements of the complete blood count, in type 2 diabetic patients, in comparison with nondiabetic healthy controls; and to find out the effects of glycemic control and different medications on these indices. To the best of our knowledge, this study is novel in our environment and will serve as a foundation for other researchers in this field. Methods: This retrospective study included 260 type 2 diabetic patients on treatment and 44 healthy control subjects. Sex, age, weight, height, blood pressure, complete blood count, fasting plasma glucose, hemoglobin A1c (HbA1c, and lipid profile data, were available for all of the study population. For diabetic patients, data on duration of diabetes and all medications were also available. Results: Red cell distribution width (RDW was significantly higher in diabetic patients than in control subjects (P=0.008. It was also higher in patients with uncontrolled glycemia (HbA1c >7% than those with good control (HbA1c ≤7%; P=0.035. Mean platelet volume (MPV was comparable in both diabetic patients and healthy controls (P=0.238. RDW and MPV did not significantly correlate with fasting plasma glucose, HbA1c, or duration of diabetes. Both aspirin and clopidogrel did not show a significant effect on MPV. Both insulin and oral hypoglycemic agents did not show a significant effect on RDW, mean corpuscular volume, MPV, platelet count, or white blood cell count. Diabetic patients treated with indapamide or the combined thiazides and angiotensin receptor blockers showed no significant difference in RDW when compared with the control subjects. Conclusion: RDW, which is recently considered as an inflammatory marker with a significant predictive value of mortality in diseased and healthy populations, is significantly higher in

Role of platelet parameters and haematological indices in myocardial infarction and unstable angina

International Nuclear Information System (INIS)

Yaghoubi, A.; Golmohamadi, Z.; Alizadehasi, A.; Azarfarin, R.

2013-01-01

Objective: To explore the significance of platelet parameters, including mean platelet volume, platelet count and other haematological indices, in patients of acute coronary syndrome. Methods: In this one-year retrospective cross-sectional study in 2010, a total of 631 patients were enrolled at the Cardiovascular Research Institute, Tabriz University of Medical Sciences, Iran, and classified into three groups: myocardial infarction, unstable angina, and Control. Cardiovascular risk factors such as smoking, diabetes mellitus, hyperlipidaemia and hypertension status were compared. Blood samples were collected for the measurement of platelet count, mean platelet volume and other haematological indices, including prothrombin time, partial thromoplastin time, blood group and Rh, haematocrit, haemoglobin, and erythrocyte sedimentation rate. SPSS 18 was used for statistical analysis. Results: Of the total, there were 210 (33.3%; 163 men, 47 women) with myocardial infarction whose mean age was 62.7+-14.2 years; 211 (33.3%; 110 men, 101 women) had unstable angina with a mean age of 63.5+-13.1 years and 210 (33.3%; 117 men, 90 women) health controls with a mean age of 60.6+-12.8 years. The mean platelet volume values of patients in the first two groups were significantly higher than the control group (10.14 +-1.05 fL, 9.82 +- 0.93 fL and 9.34+-1.14 fL, respectively; p< 0.001). The platelet count was detected to be significantly lower in the patients than the controls (207.92+-58.40*109/L, 220.18+-65.81*109/L, 238+-56.10*109/L, respectively, p<0.001). While blood cell count was significantly higher in those with myocardial infarction compared to the unstable angina patients and control group (P<0.001). Differences in mean values of mean platelet volume between the two patient groups was not significant, but mean values of platelet count was statistically significant between these two groups (p<0.04). Conclusion: Mean platelet volume and platelet count may be considered

Determination of vasculopathy-related indexes in patients with type 2 diabetes mellitus and its clinical significance

Directory of Open Access Journals (Sweden)

Xue-bin MA

2013-11-01

Full Text Available Objective　To determined the serum lipid profile, coagulation function and platelet parameters in patients with type 2 diabetes mellitus (T2DM, and provide a basis for the prevention of diabetes related complications. Methods　Two-hundred and forty-six T2DM patients (113 males and 133 females, aged 60.2±15.3 years, disease course 5-22 years hospitalized in the Navy General Hospital of PLA from March to December, 2012, were involved in the present study. The patients were divided into complication group (n=140 and no complication group (n=106 according to whether there were diabetes related complications, and 120 healthy individuals were recruited as control group. The levels of serum total cholesterol (TC, triglyceride (TG, highdensity lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, activated partial thromboplastin time (APTT, prothrombin time (PT, fibrinogen (FIB, platelet count (PLT, and platelet size distribution width (PDW, mean platelet volume (MPV, and platelet large cell ratio (P-LCR were determined and compared among the 3 groups. Results　The levels of TG, TC, LDL-C, MPV, PDW, P-LCR and FIB were significantly higher in complication group than those in no complication group and control group (P<0.05, and PLT, APTT and PT were significantly lower than those in no complication group and control group (P<0.05. No significant difference of HDL-C levels was found among the 3 groups. Conclusions　The blood of patients with T2DM was in hyperviscous and/or hypercoagulable states, and it is prone to induce vascular complications. Monitoring serum lipid profile, coagulation function and platelet parameters should be beneficial for the prevention and treatment of diabetes complications. DOI: 10.11855/j.issn.0577-7402.2013.10.015

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...

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

Establishment of reference intervals for complete blood count parameters during normal pregnancy in Beijing.

Science.gov (United States)

Li, Aiwei; Yang, Shuo; Zhang, Jie; Qiao, Rui

2017-11-01

To observe the changes of complete blood count (CBC) parameters during pregnancy and establish appropriate reference intervals for healthy pregnant women. Healthy pregnant women took the blood tests at all trimesters. All blood samples were processed on Sysmex XE-2100. The following CBC parameters were analyzed: red blood cell count (RBC), hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell distribution width (RDW), platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), white blood cell count (WBC), and leukocyte differential count. Reference intervals were established using the 2.5th and 97.5th percentile of the distribution. Complete blood count parameters showed dynamic changes during trimesters. RBC, Hb, Hct declined at trimester 1, reaching their lowest point at trimester 2, and began to rise again at trimester 3. WBC, neutrophil count (Neut), monocyte count (MONO), RDW, and PDW went up from trimester 1 to trimester 3. On the contrary, MCHC, lymphocyte count (LYMPH), PLT, and MPV gradually descended during pregnancy. There were statistical significances in all CBC parameters between pregnant women and normal women, regardless of the trimesters (Ppregnancy) as follows: RBC 4.50 vs 3.94×10 12 /L, Hb 137 vs 120 g/L, WBC 5.71 vs 9.06×10 9 /L, LYMPH% 32.2 vs 18.0, Neut% 58.7 vs 75.0, and PLT 251 vs 202×10 9 /L. The changes of CBC parameters during pregnancy are described, and reference intervals for Beijing pregnant women are demonstrated in this study. © 2017 Wiley Periodicals, Inc.

Generation and biological assessment of recombinant avian metapneumovirus subgroup C (aMPV-C) viruses containing different length of the G gene.

Science.gov (United States)

Yu, Qingzhong; Estevez, Carlos; Song, Minxun; Kapczynski, Darrell; Zsak, Laszlo

2010-02-01

Genetic variation in length of the G gene among different avian metapneumovirus subgroup C (aMPV-C) isolates has been reported. However, its biological significance in virus replication, pathogenicity and immunity is unknown. In this study, we developed a reverse genetics system for aMPV-C and generated two Colorado (CO) strain-based recombinant viruses containing either the full-length G gene derived from a Canadian goose isolate or a C-terminally truncated G gene of the CO strain. The truncated short G (sG) gene encoded 252 amino acids (aa), which is 333 aa shorter than the full-length G (585 aa). The biological properties of these two recombinant G variants were assessed in Vero cells and in specific-pathogen-free (SPF) turkeys. In Vero cells, the short G variant displayed a similar level of growth dynamics and virus titers as the parental aMPV-CO strain, whereas the full-length G variant replicated less efficiently than the sG variant during the first 72 h post-infection. Both of the G variants induced typical cytopathic effects (CPE) that were indistinguishable from those seen with the parental aMPV-CO infection. In SPF turkeys, both of the G variants were attenuated and caused little or no disease signs, but the full-length G variant appeared to grow more readily in tracheal tissue than the sG variant during the first 5 days post-infection. Both G variants were immunogenic and induced a slightly different level of antibody response. These results demonstrated that the large portion (333 aa) of the extracellular domain of the viral attachment protein is not essential for virus viability in vitro and in vivo, but may play a role in enhancing virus attachment specificity and immunity in a natural host. (c) 2009 Elsevier B.V. All rights reserved.

Generation and evaluation of a LaSota strain-based recombinant Newcastle disease virus (NDV) expressing the glycoprotein (G) of avian metapneumovirus subgroup C (aMPV-C) as a bivalent vaccine

Science.gov (United States)

To develop a bivalent vaccine, a recombinant Newcastle disease virus was generated by using the NDV LaSota strain with insertion of the G gene of aMPV-C. The biological assessments of the recombinant virus, rLS/aMPV-CG, by conducting the mean death time, intracerebral pathogenicity index, and growth...

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.

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.

Estimation of the Hematological Change of Red Blood Cell and Platelet Count of Healthy Pregnant Women in Saudi Arabia

Science.gov (United States)

Hana, M. M.; Ramzun, M. R.; Nabela, Z.; Zahirah, N. A. N.; Razak, Nik Noor Ashikin Nik Abdul; Azhar, A. R.; Iskandar, S. M.; Nursakinah, S.

2018-04-01

Tremendous changes in hematological values were noticed throughout trimesters of pregnancy. This study is aimed to provide a reference for hematological values based on trimesters, focused on the parameter of red blood cell (RBCs) and platelets (PLTs). There were 4075 local Saudi pregnant women were involved, attending the Maternity and Children Hospital in Dammam and King Fahad University Hospital in Al-Khobar, between 2013 to 2015. The statistical analysis, such as frequency and descriptive were performed. Overall, this study revealed a decline in RBCs and PLTs throughout pregnancy. The RBC, HCT, MPV and MCH mean values were found decreases in the 2nd trimester but increased in the 3rd trimester. On the contrary, the MCV, MCHC, and RDW showed increases in the 2nd trimester and decreased in the 3rd trimester. The changes of the RBCs parameters in 3rd trimester compared to 1st trimester shows increased for MCV while the RBC, HCT, MCH and MCHC decreased. Besides that, most of the respondent suffering from anemia. The hematological values after delivery show decreased for RBC, HCT, MCV, MCH and MPV but an increase in the MCHC, RDW and PLT. Thus, it is highly recommended to request for a complete blood cell screening during pregnancy to provide a better healthcare of the maternal and fetus.

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

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

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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.

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

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

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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

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.

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

MPV Blood Test: MedlinePlus Lab Test Information

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... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Platelet Count; p. 419. Important Physician ...

Lead exposure is associated with risk of impaired coagulation in preschool children from an e-waste recycling area.

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Zeng, Zhijun; Huo, Xia; Zhang, Yu; Xiao, Zhehong; Zhang, Yuling; Xu, Xijin

2018-05-12

Environmental lead exposure leads to various deleterious effects on multiple organs and systems, including the hematopoietic system. To explore the effects of lead exposure on platelet indices in preschool children from an informal, lead-contaminated electronic waste (e-waste) recycling area, we collected venous blood samples from 466 preschool children (331 from an e-waste area (Guiyu) and 135 from a non-e-waste area (Haojiang)). Child blood lead levels (BLLs) were determined by graphite furnace atomic absorption spectrophotometry, while platelet indices were quantified using a Sysmex XT-1800i hematology analyzer. Higher blood lead levels are observed in e-waste lead-exposed preschool children. Significant relationships between high blood lead levels (exceeding current health limits) and elevated platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), and platelet large cell ratio (P-LCR) were also uncovered. Furthermore, the median PLT and PCT levels of children from the exposed group both exceeded the respective recommended maximum reference range value, whereas the reference group did not. Location of child residence in Guiyu and BLLs were both risk factors related to platelet indices. These results suggest that high blood lead exposure from e-waste recycling may increase the risk of an amplified coagulation process through the activation of platelets in preschool children.

The hydraulic permeability of blood clots as a function of fibrin and platelet density.

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Wufsus, A R; Macera, N E; Neeves, K B

2013-04-16

Interstitial fluid flow within blood clots is a biophysical mechanism that regulates clot growth and dissolution. Assuming that a clot can be modeled as a porous medium, the physical property that dictates interstitial fluid flow is the hydraulic permeability. The objective of this study was to bound the possible values of the hydraulic permeability in clots formed in vivo and present relationships that can be used to estimate clot permeability as a function of composition. A series of clots with known densities of fibrin and platelets, the two major components of a clot, were formed under static conditions. The permeability was calculated by measuring the interstitial fluid velocity through the clots at a constant pressure gradient. Fibrin gels formed with a fiber volume fraction of 0.02-0.54 had permeabilities of 1.2 × 10(-1)-1.5 × 10(-4)μm(2). Platelet-rich clots with a platelet volume fraction of 0.01-0.61 and a fibrin volume fraction of 0.03 had permeabilities over a range of 1.1 × 10(-2)-1.5 × 10(-5)μm(2). The permeability of fibrin gels and of clots with platelet volume fraction of platelet volume fraction of >0.2 were modeled as a Brinkman medium of coarse solids (platelets) embedded in a mesh of fine fibers (fibrin). Our data suggest that the permeability of clots formed in vivo can vary by up to five orders of magnitude, with pore sizes that range from 4 to 350 nm. These findings have important implications for the transport of coagulation zymogens/enzymes in the interstitial spaces during clot formation, as well as the design of fibrinolytic drug delivery strategies. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

[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.

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...

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

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

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.

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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.

Evaluation value of coronary CTA for coronary plaque features and its correlation with platelet function and serum biochemical indexes

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Jin-Xia Yang

2017-01-01

Full Text Available Objective: To analyze the evaluation value of coronary CT angiography for coronary plaque features and its correlation with platelet function and serum biochemical indexes. Methods: A total of 450 patients with coronary heart disease were divided into calcified plaque group (CT value≥130HU (n=117, soft plaque group (CT value≤60HU (n=150 and mixed plaque group (CT value 60-130HU (n=183 by coronary CT angiography (CTA, and 100 healthy subjects who received physical examination in our hospital during the same period were selected as control group. Differences in platelet function and serum biochemical indexes were compared among four groups of patients, and the judgment value of atheromatous plaque CT value from CTA for the severity of coronary heart disease was analyzed. Results: Platelet function parameters MPV, TEG-MA, P-selectin, PDGF-BB and vWF levels in peripheral blood of soft plaque group were higher than those of the other three groups; inflammatory factors CRP, IL-6, IL-12, IL-18 and IL-23 content in serum were higher than those of the other three groups; chemokines MCP-1, CXCL16, Fractalkine and RANTES content in serum were higher than those of the other three groups; adipocytokines Leptin and RBP4 content in serum were higher than those of the other three groups while SFRP5 content was lower than those of the other three groups. Atheromatous plaque CT value in patients with coronary heart disease was directly correlated with platelet function and the content of serum biochemical indexes. Conclusions: Coronary CTA can accurately assess coronary atheromatous plaque features, and can also be a reliable noninvasive method to judge coronary heart disease severity, treatment prognosis and so on.

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

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

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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

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.

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...

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

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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.

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.

Platelet antiheparin activity. The isolation and characterisation of platelet factor 4 released from thrombin-aggregated washed human platelets and its dissociation into subunits and the isolation of membrane-bound antiheparin activity.

Science.gov (United States)

Moore, S; Pepper, D S; Cash, J D

1975-02-27

Platelet factor 4 was isolated by gel filtration from the soluble release products of thrombin-aggregated washed human platelets as a proteoglycan-platelet factor 4 complex of molecular weight 358 000, Stokes radius (r-s) of 14.0 nm, sedimentation coefficient (s) of 7.1 S and frictional ratio (f/f-o) of 3.04. The complex was dissociated at high ionic strength (I equals 0.75) and the proteoglycan separated from platelet factor 4 by gel filtration. Platelet factor 4 had a molecular weight of 27 100, r-s of 2.52 nm, s of 2.4 S and f/f-o of 1.26, was insoluble under physiological conditions but readily soluble at pH 3. Under these conditions platelet factor 4 dissociated into four subunits with a molecular weight of 6900, r-s of 1.92 nm, s of 0.8 S, and f/f-o of 1.52. Qualitative N-terminal amino acid analysis showed the presence of glutamic acid or glutamine as the major end group. Platelet factor 4 was compared with protamine sulphate, which has similar biological properties, by electrophoresis at pH 2.2, in which both migrated as single bands but with differing mobility, and by amino acid analysis which showed a more normal distribution of residues than occurred in protamine sulphate. Of the basic amino acids platelet factor 4 (molecular weight 27 100) contained 5.97% arginine, 3.18% histidine, and 12.31% lysine compared to protamine sulphate with 64.2% arginine, 0.6% lysine and no histidine. A partial specific volume (v) of 0.747 was calculated for platelet factor 4 from its amino acid analysis. A membrane fraction with antiheparin activity, an isopycnic density of 1.090-1.110 and r-s of 15-35 nm, was also isolated by sucrose density gradient centrifugation from the ultrasonicated insoluble platelet residue remaining after thrombin-induced aggregation of washed human platelets. Trypsin treatment of the membrane fraction neither solubilised nor destroyed the activity.

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

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.

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

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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.

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

Science.gov (United States)

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

1999-08-15

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

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

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.

Clinical Indications and Adverse Reactions of Platelet Apheresis

International Nuclear Information System (INIS)

Amanat, S. T.; Shakoor, H. A.; Raza, M.; Khan, N.; Rauf, A.

2015-01-01

Objective: To determine the clinical indications and adverse reactions of platelet apheresis procedure. Study Design: Cross-sectional, observational study. Place and Duration of Study: Blood Bank of Pakistan Atomic Energy Commission General Hospital, Islamabad, from January 2010 to December 2014. Methodology: Indications and adverse reaction verified for 200 consecutive platelet apheresis donations performed for 125 patients was included in this study. Data was analysed for descriptive variables using SPSS version 16. Results: Donor deferral rate in the study was 63.83 percentage. All the donors were males (100 percentage) and replacement donors. Most prevalent blood type was B-positive (n=63, 31.5 percentage), followed by O-positive (n=59, 29.5 percentage). Rh negative groups constituted 13.5 percentage (n=27) of all the donors. Average age of platelet apheresis donors was 28.56 ± 5.77 years. Maximum numbers of donors were in age range 20 - 30 years. Average weight of the donors was 73.96 ± 11.96 kg. Mean pre-procedure platelet count of donors was 268,000/ micro L. The postprocedure average platelet count was approximately 200,000/ micro L. The mean duration of a platelet apheresis session was 78.27 ± 26.07 minutes. Average volume of the final product was 412.53 ± 45.33 ml. Average volume of anti-coagulant acid citrate dextrose used per procedure was 300 ± 40 ml, 245 ml returned to donor along with returned blood while 55 ml used as anticoagulant in final concentrate. Of total 200, two (1 percentage) final products were contaminated with red cells. Three (1.5 percentage) products were not issued and finally expired. Of the 125 patients for which plateletpheresis procedures were performed, 54 (43.2 percentage) patients were males and 71 (56.8 percentage) were females (M: F=0.76:1). Six donors (3 percentage) had adverse events: three donors (1.5 percentage) had mild reactions, two (1 percentage) moderate reaction, and one donor (0.5 percentage) developing

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.

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.

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.

Alteration of Hemostatic Parameters in Patients with Different Levels of Subclinical Hypothyroidism and the Effect of L-thyroxine Treatment.

Science.gov (United States)

Gao, Fang; Wang, Guangya; Xu, Jinxiu

2017-01-01

Subclinical hypothyroidism (SH) is associated with hypercoagulability and hypofibrinolysis. The objective of this study was to assess the effect of L-thyroxine (L-T4) treatment and to evaluate changes in the hemostatic abnormalities of patients with varying severities of SH. We measured tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), D-dimer (DDI), fibrinogen (FIB), platelet counts (PLT), mean platelet volume (MPV), platelet distribution width (PDW), activated partial thromboplastin time (APTT), and prothrombin time (PT) in 149 female subjects. The prospective study included 54 patients in the control group, 53 patients with 4.2 μIU/mLtreatment, a significant decrease in FIB, PAI-1 and t-PA levels and an increase in APTT and DDI were observed in the severe SH group. In conclusion, SH patients displayed a distinct pattern of alteration of hemostatic parameters that was dependent on the severity of the disease. Patients with TSH levels ≥10 μIU/mL displayed hypercoagulability, which was reversed by 6 months of L-T4 treatment. © 2017 by the Association of Clinical Scientists, Inc.

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

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)

Deletion of the M2-2 Gene from Avian Metapneumovirus Subgroup C (aMPV-C) Impairs Virus Replication and Immunogenicity in Turkeys

Science.gov (United States)

The second matrix (M2) gene of avian metapneumovirus subgroup C (aMPV-C) virus contains two overlapping open reading frames (ORFs), encoding two putative proteins, M2-1 and M2-2. Both proteins are believed to be involved in either viral RNA transcription or replication. To further characterize the f...

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.

Some aspects of rat platelet and serum phospholipase A2 activities

NARCIS (Netherlands)

Aarsman, A.J.; Roosenboom, C.F.P.; Geffen, G.E.W. van; Bosch, H. van den

1985-01-01

Rat platelet lysate contained appreciable phospholipase A2 activity. In agreement with literature data this enzymatic activity eluted in the void volume of a Sephadex G-100 column. When the void volume peak was chromatographed over a Matrex gel blue A column, part of the phospholipase A2 activity

[Experimental research on the effects of different activators on the formation of platelet-rich gel and the release of bioactive substances in human platelet-rich plasma].

Science.gov (United States)

Yang, Y; Zhang, W; Cheng, B

2017-01-20

Objective: To explore the effects of calcium gluconate and thrombin on the formation of platelet-rich gel (PRG) and the release of bioactive substances in human platelet-rich plasma (PRP) and the clinical significance. Methods: Six healthy blood donors who met the inclusion criteria were recruited in our unit from May to August in 2016. Platelet samples of each donor were collected for preparation of PRP. (1) PRP in the volume of 10 mL was collected from each donor and divided into thrombin activation group (TA, added with 0.5 mL thrombin solution in dose of 100 U/mL) and calcium gluconate activation group (CGA, added with 0.5 mL calcium gluconate solution in dose of 100 g/L) according to the random number table, with 5 mL PRP in each group. Then the PRP of the two groups was activated in water bath at 37 ℃ for 1 h. The formation time of PRG was recorded, and the formation situation of PRG was observed within 1 hour of activation. After being activated for 1 h, one part of PRG was collected to observe the distribution of fibrous protein with HE staining, and another part of PRG was collected to observe platelet ultrastructure under transmission electron microscope (TEM). After being activated for 1 h, the supernatant was collected to determine the content of transforming growth factor β(1, )platelet-derived growth factor BB (PDGF-BB), vascular endothelial growth factor, basic fibroblast growth factor (bFGF), epidermal growth factor, and insulin-like growth factorⅠby enzyme-linked immunosorbent assay. (2) Another 10 mL PRP from each donor was collected and grouped as above, and the platelet suspension was obtained after two times of centrifugation and resuspension with phosphate buffered saline, respectively. And then they were treated with corresponding activator for 1 h as that in experiment (1). Nanoparticle tracking analyzer was used to detect the concentrations of microvesicles with different diameters and total microvesicles derived from platelet. Data

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...

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

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.

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

International Nuclear Information System (INIS)

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

1982-01-01

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

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

Science.gov (United States)

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

2011-08-18

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

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.

Platelet Function Tests

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... 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 ...

Evaluation of Complete Blood Count Indices (NLR, PLR, MPV/PLT, and PLCRi) in Healthy Dogs, Dogs With Periodontitis, and Dogs With Oropharyngeal Tumors as Potential Biomarkers of Systemic Inflammatory Response.

Science.gov (United States)

Rejec, Ana; Butinar, Janos; Gawor, Jerzy; Petelin, Milan

2017-12-01

The aim of the study was to retrospectively assess complete blood count (CBC) indices of dogs with periodontitis (PD; n = 73) and dogs with oropharyngeal tumors (OT; n = 92) in comparison to CBC indices of healthy dogs (HD; n = 71). Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, mean platelet volume to platelet ratio, and platelet large cell ratio index (PLCRi) were evaluated as biomarkers of systemic inflammatory response provoked by PD and OT. Results of multivariable polytomous logistic regression analysis indicated no significant associations between CBC indices and PD. Both NLR and PLCRi were significantly higher in dogs with OT when compared to HD and dogs with PD and could, therefore, indicate a tumor-associated systemic inflammatory response. Additional studies of CBC indices, along with other biomarkers of systemic inflammatory response, are recommended to validate them as reliable indicators of clinical disease activity.

Biological assessment of recombinant avian metapneumovirus subgroup C (aMPV-C) viruses containing different length of the G gene in cultured cells and SPF turkeys.

Science.gov (United States)

Genetic variation in length of the glycoprotein (G) gene among different avian metapneumovirus subgroup C (aMPV-C) isolates has been reported. However, its biological significance in virus replication and pathogenicity is unknown. In this study, we generated two Colorado (CO) strain-based recombinan...

Preparation of leukodepleted platelet concentrates from pooled buffy coats: prestorage filtration with Autostop BC

NARCIS (Netherlands)

Pietersz, R. N.; van der Meer, P. F.; Steneker, I.; Hinloopen, B.; Dekker, W. J.; van Zanten, A. P.; Reesink, H. W.

1999-01-01

BACKGROUND AND OBJECTIVES: Our requirements for leukocyte-depleted platelet concentrates (LD-PC) for an adult patient are: platelets >240x10(9), leukocytes <5x10(6), volume of 150-400 ml; and at the end of storage a pH between 6.8 and 7.4 and presence of the swirling effect. Our aim was to develop a

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.

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

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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

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 ...

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

Science.gov (United States)

Zawilska, K; Komarnicki, M; Mańka, B

1978-01-01

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

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

Multicentre standardisation of a clinical grade procedure for the preparation of allogeneic platelet concentrates from umbilical cord blood

Science.gov (United States)

Rebulla, Paolo; Pupella, Simonetta; Santodirocco, Michele; Greppi, Noemi; Villanova, Ida; Buzzi, Marina; De Fazio, Nicola; Grazzini, Giuliano

2016-01-01

Background In addition to a largely prevalent use for bleeding prophylaxis, platelet concentrates from adult blood have also been used for many years to prepare platelet gels for the repair of topical skin ulcers. Platelet gel can be obtained by activation of fresh, cryopreserved, autologous or allogeneic platelet concentrates with calcium gluconate, thrombin and/or batroxobin. The high content of tissue regenerative factors in cord blood platelets and the widespread availability of allogeneic cord blood units generously donated for haematopoietic transplant but unsuitable for this use solely because of low haematopoietic stem cell content prompted us to develop a national programme to standardise the production of allogeneic cryopreserved cord blood platelet concentrates (CBPC) suitable for later preparation of clinical-grade cord blood platelet gel. Materials and methods Cord blood units collected at public banks with total nucleated cell counts 150×109/L and volume >50 mL, underwent soft centrifugation within 48 hours of collection. Platelet-rich plasma was centrifuged at high speed to obtain a CBPC with target platelet concentration of 800–1,200×109/L, which was cryopreserved, without cryoprotectant, below −40 °C. Results During 14 months, 13 banks produced 1,080 CBPC with mean (± standard deviation) volume of 11.4±4.4 mL and platelet concentration of 1,003±229×109/L. Total platelet count per CBPC was 11.3±4.9×109. Platelet recovery from cord blood was 47.7±17.8%. About one-third of cord blood units donated for haematopoietic transplant could meet the requirements for preparation of CBPC. The cost of preparation was € 160.92/CBPC. About 2 hours were needed for one technician to prepare four CBPC. Discussion This study yielded valuable scientific and operational information regarding the development of clinical trials using allogeneic CBPC. PMID:26509822

The effect of Ramadan fasting on hematological parameters

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Jafar Nasiri

2016-12-01

Full Text Available Background: Ramadan fasting is an obligation for many Muslims around the world who abstain from eating and drinking for one month, which has different medical and physiological effects, such as reducing blood pressure, lipid profile, blood glucose, and body weight. It has also been hypothesized that Ramadan fasting may induce some changes in the hematologic parameters. Thus, we aimed to investigate the effect of Ramadan fasting on blood cell count (CBC, and erythrocyte sedimentation rate (ESR. Methods: In the present study, 59 adult healthy individuals, who had completed one month of Ramadan fasting were included. Fasting blood samples were analyzed for ESR, hemoglobin (Hb, hematocrit (Hct, white blood cell (WBC, platelet count (PLT, mean corpuscular Volume (MCV and mean platelet volume (MPV, one day before, on the second and last week of Ramadan and one month after Ramadan (phase I , II, III,  and IV, respectively. Results: 34 men and 25 women with an age range of 15 to 24 years participated in the study. Mean ESR increased significantly (except phase IV, in comparison phase III. Mean Hb and Hct levels were significantly greater in phase III than phase I (P

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

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

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

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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.

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

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Prerna Ashok Karde

2017-01-01

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

Titration of antiplatelet treatment in pregnant women at risk of preeclampsia.

Science.gov (United States)

Sullivan, M H; Clark, N A; de Swiet, M; Nelson-Piercy, C; Elder, M G

1998-04-01

We recruited 111 patients who were considered to be at significantly increased risk of preeclampsia on the basis of previous obstetric history or preexisting medical disorders. All patients were treated with low dose aspirin (75 mg/day) from the first occasion the patient attended the antenatal clinic, regardless of gestational age. If the maternal mean platelet volume (MPV) increased significantly (by > 0.8 fl) from the baseline, antiplatelet treatment was increased. Five pregnancies were lost during the second trimester and 106 of the treated patients had live infants. The incidence of neonatal death (3/106 infants) was much lower than in the previous pregnancies in these patients (32/134 infants). Patients who were treated from the first trimester of pregnancy (group A, 89 patients) did substantially better than those treated from the second trimester (group B, 17 patients) as assessed by the incidence of pre-eclampsia or intrauterine growth restriction (IUGR), gestational age and birthweight at delivery. These data suggest that longitudinal monitoring of the MPV may identify the women who could benefit from increased antiplatelet treatment, and that antiplatelet treatment may be more effective when initiated in the first trimester rather than later in pregnancy.

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

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Sunitha Raja V

2008-01-01

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

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

Science.gov (United States)

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

2015-06-01

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

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.)

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.

Relationship between platelet parameters and sudden ...

African Journals Online (AJOL)

Data synthesis: A total of 9 case-control studies were r found in our search from them 8 studies have reported mean PC, 7 studies have reported mean MPV and 4 studies have reported mean PDW. Our analysis showed that mean PC of patients is 0.03 (-0.14-0.20) unit higher than that of controls with 95% CI which is not ...

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. ...

Selection of donor platelets for alloimmunized patients using a platelet-associated IgG assay

International Nuclear Information System (INIS)

Myers, T.J.; Kim, B.K.; Steiner, M.; Baldini, M.G.

1981-01-01

A quantitative immunofluorescence platelet-associated immunoglobulin-G (PA-IgG) assay was used to detect alloimmunity to platelets in 8/12 multitransfused patients and to perform platelet crossmatching in the 8 alloimmunized patients. The correct separation of multitransfused patients into alloimmune and nonalloimmune groups was substantiated with chromium-51-labeled platelet survival studies. For 5 alloimmunized patients, compatible and incompatible donor platelets were demonstrated by PA-IgG crossmatching and were confirmed by platelet survival studies. With the other 3 alloimmunized patients, only Pa-IgG incompatible donor platelets were found. Survival studies with 5 of these incompatible donor platelets showed markedly reduced survival times on 4 occasions. Pa-IgG compatible donor platelets survived 3.5 to 8.7 days, while Pa-IgG incompatible platelets showed survival times of 0.1 to 2.4 days

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.

Comparison of point-of-care methods for preparation of platelet concentrate (platelet-rich plasma).

Science.gov (United States)

Weibrich, Gernot; Kleis, Wilfried K G; Streckbein, Philipp; Moergel, Maximilian; Hitzler, Walter E; Hafner, Gerd

2012-01-01

This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production. The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay. The principal differences between the analyzed PRP production methods (blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte, and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor β1 (TGF-β1) showed no differences with regard to age or gender. Platelet counts and TGF-β1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies. TGF-β1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i.

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

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.

Application of platelet-rich plasma and platelet-rich fibrin in fat grafting: basic science and literature review.

Science.gov (United States)

Liao, Han-Tsung; Marra, Kacey G; Rubin, J Peter

2014-08-01

Due to the natural properties of fat, fat grafting remains a popular procedure for soft tissue volume augmentation and reconstruction. However, clinical outcome varies and is technique dependent. Platelet-rich plasma (PRP) contains α-granules, from which multiple growth factors such as platelet-derived growth factor, transforming growth factor-β, vascular endothelial growth factor, and epidermal growth factor can be released after activation. In recent years, the scope of PRP therapies has extended from bone regeneration, wound healing, and healing of musculoskeletal injuries, to enhancement of fat graft survival. In this review, we focus on the definition of PRP, the different PRP preparation and activation methods, and growth factor concentrations. In addition, we discuss possible mechanisms for the role of PRP in fat grafting by reviewing in vitro studies with adipose-derived stem cells, preadipocytes, and adipocytes, and preclinical and clinical research. We also review platelet-rich fibrin, a so-called second generation PRP, and its slow-releasing biology and effects on fat grafts compared to PRP in both animal and clinical research. Finally, we provide a general foundation on which to critically evaluate earlier studies, discuss the limitations of previous research, and direct plans for future experiments to improve the optimal effects of PRP in fat grafting.

Apheresis platelet concentrates contain platelet-derived and endothelial cell-derived microparticles

NARCIS (Netherlands)

Rank, A.; Nieuwland, R.; Liebhardt, S.; Iberer, M.; Grützner, S.; Toth, B.; Pihusch, R.

2011-01-01

Background and Objectives Microparticles (MP) are membrane vesicles with thrombogenic and immunomodulatory properties. We determined MP subgroups from resting platelets, activated platelets and endothelial cells in donors and apheresis platelet concentrates (PC). Material and Methods MP were double

Reference intervals for platelet aggregation assessed by multiple electrode platelet aggregometry

DEFF Research Database (Denmark)

Rubak, Peter; Villadsen, Kirsten; Hvas, Anne-Mette

2012-01-01

Abstract Introduction Analyses of platelet aggregation in hirudin whole blood using Multiplate® was validated. Reference intervals for the most commonly used agonists were established, and the association between platelet aggregation, age, gender and haematological values was analysed. Material...... and methods We included 121 healthy individuals to establish reference intervals and six healthy individuals for evaluation of the day-to-day variation. Platelet aggregation was evaluated on hirudin whole blood employing Multiplate® induced by arachidonic acid, ADP, collagen and ristocetin (RISTOlow...... after adjusting for age and gender except for RISTOhigh. A positive significant association was found between platelet count and platelet aggregation (p

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

Evaluation of platelet aggregation in platelet concentrates: storage implications

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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.

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

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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.

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

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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.

Apheresis platelet concentrates contain platelet-derived and endothelial cell-derived microparticles.

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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.

Platelet concentration in platelet concentrates and periodontal regeneration-unscrambling the ambiguity

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A Suchetha

2015-01-01

Full Text Available Context: Platelet-rich-plasma (PRP and Platelet-rich-fibrin (PRF are extensively used autologous platelet concentrates in periodontal regeneration, and PRF has a better efficacy as compared to PRP. The rationale for this difference has often been attributed to the difference in the structure of the fibrin matrix. However, the effect of concentration of platelets on the regenerative potential of these concentrates is obscure. Aims: The study was conducted to evaluate and compare, clinically and radiographically, the efficacy of PRF and PRP in the treatment of periodontal endosseous defects and to assess the effect of platelet concentration on periodontal regeneration. Materials and Methods: Twenty intrabony defects were selected and divided into two groups randomly by the coin toss method. Group I received PRP and Group II subjects were treated with PRF. The platelet counts in PRP and PRF were analyzed. Clinical and radiological parameters were assessed at baseline and 3, 6, and 9 months postoperatively. Statistical Analysis: Kruskal–Wallis Chi-square test, Wilcoxon signed rank test, t-test, and Spearman's rank correlation were used for statistical analysis of data. Results: There was statistically significant improvement in all the parameters in the two groups except in relation to gingival recession. There was a statistically significant difference between the platelet count in Group I and Group II (P = 0.002. Conclusion: PRP and PRF appear to have nearly comparable effects in terms of periodontal regeneration. The concentration of platelets appears to play a paradoxical role in regeneration. The regenerative potential of platelets appears to be optimal within a limited range.

Novel approaches for diagnosing inherited platelet disorders.

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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.

Breaking the mold: transcription factors in the anucleate platelet and platelet-derived microparticles

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Katie L Lannan

2015-02-01

Full Text Available Platelets are small anucleate blood cells derived from megakaryocytes. In addition to their pivotal roles in hemostasis, platelets are the smallest, yet most abundant, immune cell and regulate inflammation, immunity, and disease progression. Although platelets lack DNA, and thus no functional transcriptional activities, they are nonetheless rich sources of RNAs, possess an intact spliceosome, and are thus capable of synthesizing proteins. Previously, it was thought that platelet RNAs and translational machinery were remnants from the megakaryocyte. We now know that the initial description of platelets as cellular fragments is an antiquated notion, as mounting evidence suggests otherwise. Therefore, it is reasonable to hypothesize that platelet transcription factors are not vestigial remnants from megakaryoctes, but have important, if only partly understood functions. Proteins play multiple cellular roles to minimize energy expenditure for maximum cellular function; thus, the same can be expected for transcription factors. In fact, numerous transcription factors have non-genomic roles, both in platelets and in nucleated cells. Our lab and others have discovered the presence and nongenomic roles of transcription factors in platelets, such as the nuclear factor kappa β (NFκB family of proteins and peroxisome proliferator activated receptor gamma (PPARγ. In addition to numerous roles in regulating platelet activation, functional transcription factors can be transferred to vascular and immune cells through platelet microparticles. This method of transcellular delivery of key immune molecules may be a vital mechanism by which platelet transcription factors regulate inflammation and immunity. At the very least, platelets are an ideal model cell to dissect out the nongenomic roles of transcription factors in nucleated cells. There is abundant evidence to suggest that transcription factors in platelets play key roles in regulating inflammatory and

Study of Hematological Parameters in Children Suffering from Iron Deficiency Anaemia in Chattagram Maa-o-Shishu General Hospital, Chittagong, Bangladesh

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Mohammed Mujib, Abu Syed; Halder, Milton; Monirul Hasan, Chowdhury Mohammad

2014-01-01

A total of 150 (30.61%) anemic patients out of 490 patients diagnosed to have iron deficiency anemia (IDA) have been selected for the first time in Bangladesh. For detailed study, blood samples from 150 anemic patients along with 25 controls were analyzed. Analysis of variance showed significant P value between mean platelet volume (MPV) in females (8.08 μm3) and males (7.59 μm3) (P iron deficiency anemia patients. Besides, the value of white blood cells (WBC) in males (10946.08/cmm) was significantly higher than in females (9470.833/cmm) (P anemias with only one of three biochemical parameters decreased and control showed that this group does not have iron deficiency. PMID:25400943

Platelet aggregation and quality control of platelet concentrates produced in the Amazon Blood Bank

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Maria José Dantas Coêlho

2011-01-01

Full Text Available BACKGROUND: The study of platelet aggregation is essential to assess in vitro platelet function by different platelet activation pathways. OBJECTIVE: To assess aggregation and biochemical parameters of random platelet concentrates produced at the Fundação HEMOAM using the quality control tests defined by law. METHODS: Whole blood samples from 80 donors and the respective platelet concentrate units were tested. Platelet concentrates were tested (platelet count, aggregation and pH on days 1, 3 and 5 of storage. Additionally a leukocyte count was done only on day 1 and microbiological tests on day 5 of storage. Collagen and adenosine diphosphate were used as inducing agonists for platelet aggregation testing. RESULTS: Donor whole blood had normal aggregation (aggregation with adenosine diphosphate = 67% and with collagen = 78%. The median aggregation in platelet concentrates with adenosine diphosphate was low throughout storage (18% on day 1, 7% on day 3 and 6% on day 5 and the median aggregation with collagen was normal only on day 1 and low thereafter (54.4% on day 1, 20.5% on day 3 and 9% on day 5. CONCLUSION: Although the results were within the norms required by law, platelet concentrates had low aggregation rates. We suggest the inclusion of a functional assessment test for the quality control of platelet concentrates for a more effective response to platelet replacement therapy.

EXTENDED STORAGE OF BUFFY-COAT PLATELET CONCENTRATES IN PLASMA OR A PLATELET ADDITIVE SOLUTION

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Slichter, Sherrill J.; Bolgiano, Doug; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Bailey, S. Lawrence; Pellham, Esther

2014-01-01

Background Platelet concentrates prepared from whole blood in the U.S. are made using the platelet-rich-plasma (PRP) method. The platelet concentrates must be made within 8 hours of blood collection and stored for only 5 days. In Europe and Canada, platelet concentrates are made using the buffy-coat (BC) method from whole blood held overnight at 22°C and storage times may be up to 7 days. Our studies were designed to determine how long BC platelets can be stored in plasma or Plasmalyte while meeting the FDA’s post-storage viability criteria. Study Design, Materials, And Methods Normal subjects donated whole blood that was stored at 22°C for 22 ± 2 hours prior to preparation of BC platelets. Platelets were stored for 5 to 8 days in either plasma or Plasmalyte concentrations of 65% or 80%. Radiolabeled autologous stored versus fresh platelet recoveries and survivals were assessed as well as post-storage in vitro assays. Results BC platelets stored in either plasma or 65% Plasmalyte met FDA post-storage platelet recovery criteria for 7 days but survivals for only 6 days, while storage in 80% Plasmalyte gave very poor results. Both stored platelet recoveries and survivals correlated with the same donor’s fresh results, but the correlation was much stronger between recoveries than survivals. In vitro measures of extent of shape change, morphology score, and pH best predicted post-storage platelet recoveries, while annexin V binding best predicted platelet survivals. Conclusion BC platelets stored in either plasma or 65% Plasmalyte meet FDA’s post-storage viability criteria for 6 days. PMID:24673482

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

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

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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

In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

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Gupta Ashish

2011-01-01

Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. The present study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, CSM Medical University, Lucknow. Random donor platelets were prepared by platelet rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators, with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7, with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution, whereas platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that platelet viability and aggregation were best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

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Gupta Ashish

2011-01-01

Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. This study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, C S M Medical University, Lucknow. Random donor platelets were prepared by the platelet-rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7 with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution while platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that the platelet viability and aggregation were the best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

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

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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

A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

OpenAIRE

Mustafa Tunalı; Hakan Özdemir; Zafer Küçükodacı; Serhan Akman; Emre Yaprak; Hülya Toker; Erhan Fıratlı

2014-01-01

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn us...

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

Survival of density subpopulations of rabbit platelets: use of 51Cr-or 111In-labeled platelets to measure survival of least dense and most dense platelets concurrently

International Nuclear Information System (INIS)

Rand, M.L.; Packham, M.A.; Mustard, J.F.

1983-01-01

The origin of the density heterogeneity of platelets was studied by measuring the survival of density subpopulations of rabbit platelets separated by discontinuous Stractan density gradient centrifugation. When a total population of 51 Cr-labelled platelets was injected into recipient rabbits, the relative specific radioactivity of the most dense platelets decreased rapidly. In contrast, that of the least dense platelets had not changed 24 hr after injection, and then decreased slowly. To distinguish between the possibilities that most dense platelets are cleared from the circulation more quickly than least dense platelets or that platelets decrease in density as they age in the circulation, the concurrent survival of least dense and most dense platelets, labelled with either 51 Cr or 111 In-labelled total platelet populations, determined concurrently in the same rabbits, are identical, calculated from 1 hr values as 100%. However, the 1-hr recovery of 111 In-labelled platelets was slightly but significantly less than that of 51 Cr-labelled platelets. Therefore, researchers studied the survival of 51 Cr-labelled least dense and 111 In-labelled most dense platelets as well as that of 111 In-labelled least dense and 51 Cr-labelled most dense platelets. Mean 1-hr recovery of least dense platelets, labelled with either isotope (78% +/- 7%, SD) was similar to that of most dense platelets, labelled with either isotope (77% +/- 8%; SD). Mean survival of least dense platelets was 47.3 +/- 18.7 hr (SD), which was significantly less than that of most dense platelets (76.1 +/- 21.6 hr; SD) (p less than 0.0025). These results indicate that platelets decrease in buoyant density as they age in the circulation and that most dense platelets are enriched in young platelets, and least dense in old

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

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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.

Prediction and optimization of the recovery rate in centrifugal separation of platelet-rich plasma (PRP)

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Piao, Linfeng; Park, Hyungmin; Jo, Chris

2016-11-01

We present a theoretical model of the recovery rate of platelet and white blood cell in the process of centrifugal separation of platelet-rich plasma (PRP). For the practically used conditions in the field, the separation process is modeled as a one-dimensional particle sedimentation; a quasi-linear partial differential equation is derived based on the kinematic-wave theory. This is solved to determine the interface positions between supernatant-suspension and suspension-sediment, used to estimate the recovery rate of the plasma. While correcting the Brown's hypothesis (1989) claiming that the platelet recovery is linearly proportional to that of plasma, we propose a new correlation model for prediction of the platelet recovery, which is a function of the volume of whole blood, centrifugal acceleration and time. For a range of practical parameters, such as hematocrit, volume of whole blood and centrifugation (time and acceleration), the predicted recovery rate shows a good agreement with available clinical data. We propose that this model is further used to optimize the preparation method of PRP that satisfies the customized case. Supported by a Grant (MPSS-CG-2016-02) through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

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

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

2016-01-01

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

Platelet count

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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 ...

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...

Comparative Effects of Platelet-Rich Plasma, Platelet Lysate, and Fetal Calf Serum on Mesenchymal Stem Cells.

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Lykov, A P; Bondarenko, N A; Surovtseva, M A; Kim, I I; Poveshchenko, O V; Pokushalov, E A; Konenkov, V I

2017-10-01

We studied the effects of human platelet-rich plasma and platelet lysate on proliferation, migration, and colony-forming properties of rat mesenchymal stem cells. Platelet-rich plasma and platelet lysate stimulated the proliferation, migration, and colony formation of mesenchymal stem cells. A real-time study showed that platelet-rich plasma produces the most potent stimulatory effect, while both platelet-rich plasma and platelet lysate stimulated migration of cells.

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

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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.

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

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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

Congenital platelet function defects

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... 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 ...

Flavanols and Platelet Reactivity

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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.

Biological variation of platelet parameters determined by the Sysmex XN hematology analyzer.

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Buoro, Sabrina; Seghezzi, Michela; Manenti, Barbara; Pacioni, Aurelio; Carobene, Anna; Ceriotti, Ferruccio; Ottomano, Cosimo; Lippi, Giuseppe

2017-07-01

This study was aimed to define the short- and medium-term biological variation (BV) estimates, the index of individuality and the reference change value (RCV) of platelet count, platelet distribution width, mean platelet volume, platelet larger cell ratio, plateletcrit and immature platelet fraction. The study population consisted of 43 health subjects, who participated to the assessment of medium-term (21 subjects; blood sampling once a week for 5 consecutive weeks) and short-term (22 subjects; blood sampling once a day for 5 consecutive days) BV study, using Sysmex XN-module. Eight subjects were also scheduled to participate to both phases. The data were subject to outlier analysis prior to CV-ANOVA, to determine the BV estimates with the relative confidence intervals. The medium-term and short-term within-subject BV (CV I ) was comprised between 2.3 and 7.0% and 1.1-8.6%, whereas the medium-term and short-term between-subjects BV (CV G ) was comprised between 7.1 and 20.7% and 6.8-48.6%. The index of individuality and index of heterogeneity were always respectively 0.63 for all the parameters, in both arms of the study. The RCVs were similar for all parameters, in both arms of the study. This study allowed to define the BV estimates of many platelet parameters, some of them unavailable in literature. The kinetics of platelet turnover suggests the use of short-term BV data for calculating analytical goals and RCV. The correct clinical interpretation of platelet parameters also necessitates that each laboratory estimates local RCV values. Copyright © 2017 Elsevier B.V. All rights reserved.

Alternatives to allogeneic platelet transfusion.

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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.

Collagen induced aggregation of platelets and release of 14C serotonin from platelets depending on temperature and pH during in vitro storage of platelets

International Nuclear Information System (INIS)

Krause, J.

1978-01-01

The paper investigates collagen-induced platelet aggregation and 14 C serotonin release in dependence of age, temperature, and pH value during the storage of the conserved platelets. The optimum pH (with adjusted CO 2 /air mixture) for platelet storage is found to be pH 6.9. The optimum temperature for platelet storage is 4-8 0 C. After 12, 24, or 48 hours of storage at pH 6.9 and 4-8 0 C and subsequent heating of the platelet-rich plasma to 37 0 C for 30 minutes, the values determined for collagen-induced platelet aggregation and 14 C serotonin release rarely differed from the initial values before storage. Cold-induced spontaneous platelet aggregation and serotonin release of the platelets stored at 4-8 0 C can be avoided by 30-60 minutes pre-incubation of the platelets at 37 0 C before transfusions. The in vitro findings for collagen-induced platelet aggregation and 14 C serotonin release indicate that platelet storage for 24-48 hours at pH 6.9 and 4-8 0 C may be permissible also for clinical purposes. The problem remains open whether the clinical effect of these platelets is still sufficient after 48 hours of storage, but literature findings suggest that this may well be the case. (orig.) [de

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

Indium-111 platelet imaging for detection of platelet deposition in abdominal aneurysms and prosthetic arterial grafts

International Nuclear Information System (INIS)

Ritchie, J.L.; Stratton, J.R.; Thiele, B.; Haminton, G.W.; Warrick, L.N.; Huang, T.W.; Harker, L.A.

1981-01-01

Thirty-four platelet imaging studies were performed in 23 patients to determine whether platelet deposition could be detected in patients with vascular aneurysms (18 patients) or in patients in whom Dacron prosthetic grafts had been placed (5 patients). In patients in whom abnormal platelet deposition was detected, the effect of administration of platelet-active drugs on platelet deposition was examined. Of the 18 patients with an aneurysm, 12 had equivocally positive studies on initial imaging and 2 had equivocally positive images. Of five patients with Dacron arterial grafts in place, four had diffuse platelet deposition in the grafts; the fifth patient had a platelet deposition only in a pseudoaneurysm. Eight patients with an abdominal aneurysm and positive or equivocally positive baseline images were restudied during platelet-active drug therapy either with aspirin plus dipyridamole (seven patients) or with sulfinpyrazone (four patients). No patient studied during treatment with aspirin plus dipyridamole had detectably decreased platelet deposition compared with baseline determinations. In contrast, two of four patients studied while receiving sulfinpyrazone showed decreased platelet deposition. Thus, platelet imaging may be of value for studying platelet physiology in vivo and for assessing platelet-active drugs and the thrombogenicity of prosthetic graft materials in human beings

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

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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

Diagnostic significance of haematological testing in patients presenting at the Emergency Department

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Giuseppe Lippi

2012-03-01

Full Text Available The use of simple and economic tests to rule out diseases of sufficient clinical severity is appealing in emergency department (ED, since it would be effective for contrasting ED overcrowding and decreasing healthcare costs. The aim of this study was to assess the diagnostic performance of simple and economic haematological testing in a large sample of adult patients presenting at the ED of the Academic Hospital of Parma during the year 2010 with the five most frequent acute pathologies (i.e., acute myocardial infarction, renal colic, pneumonia, trauma and pancreatitis. Both leukocyte count and hemoglobin showed a good diagnostic performance (Area Under the Curve [AUC] of 0.85 for leukocyte count and 0.76 for hemoglobin; both p < 0.01. Although the platelet count was significantly increased in all patients groups except pancreatitis, the diagnostic performance did not achieve statistical significance (AUC 0.53; p = 0.07. We also observed an increased RDW in all groups, except in those with trauma and the diagnostic performance was acceptable (AUC 0.705; p < 0.01. The mean platelet volume (MPV was consistently lower in all patients groups and also characterized by an efficient diagnostic performance (AUC 0.76; p < 0.01. This evidence led us to design an arbitrary formula, whereby MPV and hemoglobin were multiplied, and further divided by the leukocyte count, obtaining a remarkable AUC (0.91; p < 0.01. We conclude that simple, rapid and cheap hematological tests might provide relevant clinical information for decision making to busy emergency physicians, and the their combination into an arbitrary formula might further increase the specific diagnostic potential of each of them.

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

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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.

Effects of hormones on platelet aggregation.

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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.

Platelets and the innate immune system: Mechanisms of bacterial-induced platelet activation.

OpenAIRE

Cox, Dermot; Kerrigan, Steven W; Watson, Steve

2011-01-01

It has become clear that platelets are not simply cell fragments that can plug the leak in a damaged blood vessel, they are in fact key components in the innate immune system which is supported by the presence of Toll-like receptors (TLRs) on platelets. As the first responding cell to a site of injury they are well placed to direct the immune response to deal with any resulting exposure to pathogens. The response is triggered by bacteria binding to platelets which usually triggers platelet ac...

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

OpenAIRE

Södergren, Anna; Tynngård, Nahreen; Berlin, Gösta; Ramström, Sofia

2016-01-01

Background and ObjectivesStorage lesions may prevent transfused platelets to respond to agonists and arrest bleeding. The aim of this study was to evaluate and quantify the capacity of platelet activation during storage using flow cytometry and new markers of platelet activation. Materials and MethodsActivation responses of platelets prepared by apheresis were measured on days 1, 5, 7 and 12. In addition, comparisons were made for platelet concentrates stored until swirling was affected. Lyso...

Comparative clinical and haematological investigations in lactating cows with subclinical and clinical ketosis

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Vania Marutsova

2015-10-01

Full Text Available Ketosis of lactating cows is among the most common metabolic diseases in modern dairy farms. The economic importance of the disease is caused by the reduced milk yield and body weight loss, poor feed conversion, lower conception rates, culling and increased mortality of affected animals. In the present study, a total of 47 high-yielding dairy cows up to 45 days in milk (DIM are included. All animals were submitted to physical examination wich included checking the rectal body temperature, heart rate, respiratory and rumen contraction rates, and inspection of visible mucous coats. The body condition was scored, and blood β-hydroxybutyrate (BHBA concentrations were assayed. The cows were divided into 3 groups: first group (control (n=24 with blood β-hydroxybutyrate level 2.6 mmol/l (clinical ketosis. Whole blood samples were obtained and analyzed for Red Blood Cell (RBC, 1012/l, Hemoglobin (HGB, g/l, Hematocrit (HCT, %, Mean Corpuscular Volume (MCV, fl, Mean Corpuscular Hemoglobin (MCH, pg, Mean Corpuscular Hemoglobin Concentration (MCHC, g/l, White Blood Cell (WBC, 109/l, Lymphocytes (LYM, 109/l, Monocytes (MON, 109/l, Granulocytes (GRA, 109/l, Red Blood Distribution Width (RDW, %, Red Blood Cell Distribution Width Absolute (RDWa, fl, Platelets (PLT, 109/l and Mean Platelet Volume (MPV, fl. In this study, deviations in the clinical parameters in the control group and in those with subclinical ketosis were not identified. The cows from the third group (clinical ketosis exhibited hypotonia, anorexia and body weight loss vs. control group. Hematological analysis showed leukocytosis and lymphocytosis in cows with subclinical ketosis vs. control group. In cows with clinical ketosis WBC counts decreased (leukopenia, while hemoglobin content and hematocrit values are higher vs. control group. Blood BHBA values are higher in both groups of ketotic cows vs. the control group. The other analyzed parameters (RBC, MCH, MCHC, MCV, RDW, RDWa, MON, GRA, PLT

Platelets and the innate immune system: mechanisms of bacterial-induced platelet activation.

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Cox, D; Kerrigan, S W; Watson, S P

2011-06-01

It has become clear that platelets are not simply cell fragments that plug the leak in a damaged blood vessel; they are, in fact, also key components in the innate immune system, which is supported by the presence of Toll-like receptors (TLRs) on platelets. As the cells that respond first to a site of injury, they are well placed to direct the immune response to deal with any resulting exposure to pathogens. The response is triggered by bacteria binding to platelets, which usually triggers platelet activation and the secretion of antimicrobial peptides. The main platelet receptors that mediate these interactions are glycoprotein (GP)IIb-IIIa, GPIbα, FcγRIIa, complement receptors, and TLRs. This process may involve direct interactions between bacterial proteins and the receptors, or can be mediated by plasma proteins such as fibrinogen, von Willebrand factor, complement, and IgG. Here, we review the variety of interactions between platelets and bacteria, and look at the potential for inhibiting these interactions in diseases such as infective endocarditis and sepsis. © 2011 International Society on Thrombosis and Haemostasis.

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

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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.

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

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

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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

Platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro

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van Bladel Esther R

2012-09-01

Full Text Available Abstract Background In patients with chronic kidney disease studies focusing on platelet function and properties often are non-conclusive whereas only few studies use functional platelet tests. In this study we evaluated a recently developed functional flow cytometry based assay for the analysis of platelet function in chronic kidney disease. Methods Platelet reactivity was measured using flow cytometric analysis. Platelets in whole blood were triggered with different concentrations of agonists (TRAP, ADP, CRP. Platelet activation was quantified with staining for P-selectin, measuring the mean fluorescence intensity. Area under the curve and the concentration of half-maximal response were determined. Results We studied 23 patients with chronic kidney disease (9 patients with cardiorenal failure and 14 patients with end stage renal disease and 19 healthy controls. Expression of P-selectin on the platelet surface measured as mean fluorescence intensity was significantly less in chronic kidney disease patients compared to controls after maximal stimulation with TRAP (9.7 (7.9-10.8 vs. 11.4 (9.2-12.2, P = 0.032, ADP (1.6 (1.2-2.1 vs. 2.6 (1.9-3.5, P = 0.002 and CRP (9.2 (8.5-10.8 vs. 11.5 (9.5-12.9, P = 0.004. Also the area under the curve was significantly different. There was no significant difference in half-maximal response between both groups. Conclusion In this study we found that patients with chronic kidney disease show reduced platelet reactivity in response of ADP, TRAP and CRP compared to controls. These results contribute to our understanding of the aberrant platelet function observed in patients with chronic kidney disease and emphasize the significance of using functional whole blood platelet activation assays.

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

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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.

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.

Aspirin inhibition of platelet deposition at angioplasty sites: demonstration by platelet scintigraphy

International Nuclear Information System (INIS)

Cuningham, D.A.; Kumar, B.; Siegel, B.A.; Gilula, L.A.; Totty, W.G.; Welch, M.J.

1984-01-01

In-111 platelet scintigraphy was used to evaluate the effects of prior aspirin administration on the accumulation of In-111-labeled autologous platelets at sites of arterial injury resulting from iliac, femoral, or popliteal transluminal angioplasty in a nonrandomized study of 17 men. The degree of platelet localization at angioplasty sites was significantly less in nine men who had received aspirin in varying doses within the 4 days before angioplasty than in eight men who had not received aspirin for at least two weeks. The results suggest that aspirin treatment before angioplasty limits the early platelet deposition at the angioplasty site in men

Desenvolvimento de adenovírus recombinantes expres-sando as glicoproteínas F e G do metapneumovírus aviário (aMPV) e do vírus respiratório sincicial bo-vino(bRSV)

OpenAIRE

Luciana Helena Antoniassi da Silva

2013-01-01

Resumo: Os membros da família Paramyxoviridae são vírus que causam infecções em humanos e animais de importância econômica global. Entre os membros desta família incluem patógenos de importância mundial para os humanos, como o vírus respiratório sincicial humano (hRSV), o metapneumovírus humano (hMPV) e vírus de importância em Medicina Veterinária, como o vírus respiratório sincicial bovino (bRSV) e o metapnemovírus aviário (aMPV). Os membros da família Paramyxoviridae, subfamília Pneumovirin...

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....

Platelet lysates produced from expired platelet concentrates support growth and osteogenic differentiation of mesenchymal stem cells.

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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.

Accuracy of Platelet Counting by Optical and Impedance Methods in Patients with Thrombocytopaenia and Microcytosis

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Mohamed-Rachid Boulassel

2015-11-01

Full Text Available Objectives: Obtaining accurate platelet counts in microcytic blood samples is challenging, even with the most reliable automated haematology analysers. The CELL-DYN™ Sapphire (Abbott Laboratories, Chicago, Illinois, USA analyser uses both optical density and electronic impedance methods for platelet counting. This study aimed to evaluate the accuracy of optical density and electrical impedance methods in determining true platelet counts in thrombocytopaenic samples with microcytosis as defined by low mean corpuscular volume (MCV of red blood cells. Additionally, the impact of microcytosis on platelet count accuracy was evaluated. Methods: This study was carried out between February and December 2014 at the Haematology Laboratory of the Sultan Qaboos University Hospital in Muscat, Oman. Blood samples were collected and analysed from 189 patients with thrombocytopaenia and MCV values of <76 femtolitres. Platelet counts were tested using both optical and impedance methods. Stained peripheral blood films for each sample were then reviewed as a reference method to confirm platelet counts. Results: The platelet counts estimated by the impedance method were on average 30% higher than those estimated by the optical method (P <0.001. The estimated intraclass correlation coefficient was 0.52 (95% confidence interval: 0.41–0.62, indicating moderate reliability between the methods. The degree of agreement between methods ranged from -85.5 to 24.3 with an estimated bias of -30, suggesting that these methods generate different platelet results. Conclusion: The impedance method significantly overestimated platelet counts in microcytic and thrombocytopaenic blood samples. Further attention is therefore needed to improve the accuracy of platelet counts, particularly for patients with conditions associated with microcytosis.

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)

A novel platelet concentrate: titanium-prepared platelet-rich fibrin.

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Tunalı, Mustafa; Özdemir, Hakan; Küçükodacı, Zafer; Akman, Serhan; Yaprak, Emre; Toker, Hülya; Fıratlı, Erhan

2014-01-01

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF) was processed with a scanning electron microscope (SEM). The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

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Mustafa Tunalı

2014-01-01

Full Text Available We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF. The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun’s leukocyte- and platelet-rich fibrin (L-PRF method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF was processed with a scanning electron microscope (SEM. The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

In vitro quality of apheresis platelets divided into paediatric-sized units and stored in PVC bags plasticised with TOTM, BTHC or DINCH.

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Bashir, S; Meli, A; Cardigan, R

2018-04-11

Two of the predictive factors of the quality of small volumes of platelets suitable for paediatric use are bag size and material. This study evaluated the storage properties of paediatric platelet aliquots in TOTM-, BTHC- or DINCH-PVC bags. (i) Three apheresis platelet concentrates (PC) were pooled and split into three units. One was retained as an adult unit (control; polyolefin bag). The second and third units were split into four MacoPharma TOTM-PVC and BTHC-PVC paediatric bags, respectively. (ii) Two apheresis PC were pooled and split into two units. One PC was retained as an adult unit, and the other was split into four Fresenius DINCH-PVC paediatric bags. Testing was performed on storage for pH, blood gases, hypotonic shock response, soluble CD62P, LDH, glucose and lactate, ATP, CD62P, CD63, platelet-derived microparticles and annexin V. The volumes, platelet yields and pH of all paediatric units met local specifications. The TOTM-PVC bag showed no worse quality than the adult bag up to day 7 for all parameters studied, and it maintained pH higher than BTHC-PVC and DINCH-PVC over storage. The BTHC-PVC bag was shown to be the most gas permeable; however, it had the highest glucose consumption rates and the highest platelet activation. All bags showed an acceptable in vitro quality. Overall, the TOTM-PVC paediatric bag showed better platelet quality compared to the other storage bags, whereas storage in the BTHC-PVC bag resulted in poorer platelet quality. © 2018 British Blood Transfusion Society.

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

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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.

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

OpenAIRE

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

2014-01-01

The interactions of tumor cells with platelets contribute to the progression of tumor malignancy, and the expression levels of platelet aggregation-inducing factors positively correlate with the metastatic potential of osteosarcoma cells. However, it is unclear how tumor-platelet interaction contributes to the proliferation of osteosarcomas. We report here that osteosarcoma-platelet interactions induce the release of platelet-derived growth factor (PDGF) from platelets, which promotes the pro...

Flow cytometric assessment of activation of peripheral blood platelets in dogs with normal platelet count and asymptomatic thrombocytopenia.

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Żmigrodzka, M; Guzera, M; Winnicka, A

2016-01-01

Platelets play a crucial role in hemostasis. Their activation has not yet been evaluated in healthy dogs with a normal and low platelet count. The aim of this study was to determine the influence of activators on platelet activation in dogs with a normal platelet count and asymptomatic thrombocytopenia. 72 clinically healthy dogs were enrolled. Patients were allocated into three groups. Group 1 consisted of 30 dogs with a normal platelet count, group 2 included 22 dogs with a platelet count between 100 and 200×109/l and group 3 consisted of 20 dogs with a platelet count lower than 100×109/l. Platelet rich-plasma (PRP) was obtained from peripheral blood samples using tripotassium ethylenediaminetetraacetic acid (K3-EDTA) as anticoagulant. Next, platelets were stimulated using phorbol-12-myristate-13-acetate or thrombin, stabilized using procaine or left unstimulated. The expression of CD51 and CD41/CD61 was evaluated. Co-expression of CD41/CD61 and Annexin V served as a marker of platelet activation. The expression of CD41/CD61 and CD51 did not differ between the 3 groups. Thrombin-stimulated platelets had a significantly higher activity in dogs with a normal platelet count than in dogs with asymptomatic thrombocytopenia. Procaine inhibited platelet activity in all groups. In conclusion, activation of platelets of healthy dogs in vitro varied depending on the platelet count and platelet activator.

The content of bone morphogenetic proteins in platelets varies greatly between different platelet donors

International Nuclear Information System (INIS)

Kalen, Anders; Wahlstroem, Ola; Linder, Cecilia Halling; Magnusson, Per

2008-01-01

Platelet derivates and platelet rich plasma have been used to stimulate bone formation and wound healing because of the rich content of potent growth factors. However, not all reports have been conclusive since some have not been able to demonstrate a positive effect. We investigated the interindividual variation of bone morphogenetic proteins (BMPs) in platelets from healthy donors, and the pH-dependent effect on the release of BMPs in preparations of lysed platelets in buffer (LPB). Platelet concentrates from 31 healthy donors were prepared in pH 4.3 and pH 7.4 buffers and investigated with respect to BMP-2, -4, -6, and -7. BMP-2 and BMP-4 were significantly more common in acidic LPBs in comparison with neutral preparations. We also observed a considerable variation among platelet donors with respect to the release of BMPs at pH 4.3 and 7.4. In conclusion, a considerable variation was found among platelet donors, which may be of importance considering the ambiguous results previously reported on osteoblast proliferation and differentiation

The role of platelets during reproduction.

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Isermann, Berend; Nawroth, Peter P

2006-01-01

The availability of mice with defined defects within the hemostatic system enabled researchers to identify a role the coagulation system for embryonic and placental development. However, the role of platelets during development has only recently been experimentally addressed, giving some insight into potential functions of platelets during development. Thus, a quantitative embryonic platelet defect (severe thrombopenia secondary to NF-E2 deficiency) is associated with an embryonic growth retardation and reduced vascularisation of the placenta. Maternal platelet deficiency is associated with placental hemorrhage, which, however, does not impair embryonic or maternal survival. In vitro studies established that platelets or platelet conditioned medium regulate the invasive properties of human extravillous trophoblast cells and induce a phenotypical switch of trophoblast cells. These data imply that platelets are of relevance during placentation. Conversely, platelets and the formation of platelet-fibrin aggregates are dispensable for the development of the embryo proper, establishing that the lethal phenotypes observed in some embryo slacking coagulation regulators does not result from an inability to form platelet-fibrin aggregates, but likely reflects altered protease dependent signaling during vascular development.

Clot lysis time in platelet-rich plasma: method assessment, comparison with assays in platelet-free and platelet-poor plasmas, and response to tranexamic acid.

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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

UV-C irradiation disrupts platelet surface disulfide bonds and activates the platelet integrin alphaIIbbeta3

NARCIS (Netherlands)

Verhaar, Robin; Dekkers, David W. C.; de Cuyper, Iris M.; Ginsberg, Mark H.; de Korte, Dirk; Verhoeven, Arthur J.

2008-01-01

UV-C irradiation has been shown to be effective for pathogen reduction in platelet concentrates, but preliminary work indicated that UV-C irradiation of platelets can induce platelet aggregation. In this study, the mechanism underlying this phenomenon was investigated. Irradiation of platelets with

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

International Nuclear Information System (INIS)

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

1989-01-01

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

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

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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.

Platelet concentrates: reducing the risk of transfusion-transmitted bacterial infections

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de Korte D

2014-06-01

Full Text Available Dirk de Korte,1 Jan H Marcelis2 1Department of Product and Process Development, Sanquin Blood Bank, Amsterdam, 2Department of Microbiology, St Elisabeth Hospital, Tilburg, the Netherlands Abstract: The introduction of a combination of interventions during collection of whole-blood or platelet concentrates has been successful in lowering the degree of bacterial contamination in the final product, the platelet concentrate, by 50%–75%. These interventions were improved donor questionnaires, best-practice skin disinfection, and diversion of first blood volume. These interventions have reduced the number of bacteria present in the platelet concentrates. In combination with screening for bacterial contamination of platelet concentrates with a culture method, the degree of transfusion-transmitted bacterial infection has been reduced significantly. Due to the very low initial bacteria counts upon collection of the products, the need for improved sensitivity of early screenings tests or highly selective point-of-issue tests remains. The latter should be rapid and easy to perform. An alternative approach might be the implementation of pathogen-inactivation methods for cellular blood products to reduce the amount of pathogens. However, these methods are costly, and so far not proved to be cost-effective, especially in countries with an already-low incidence of transfusion-transmitted infections by viruses, parasites, or bacteria. Keywords: blood products, bacterial contamination, screening, point of issue, pathogen inactivation

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, ...

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.

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.

Pilot study of novel lab methodology and testing of platelet function in adolescent women with heavy menstrual bleeding.

Science.gov (United States)

Rocheleau, Anne D; Khader, Ayesha; Ngo, Anh T P; Boehnlein, Colin; McDavitt, Cara; Lattimore, Susan; Recht, Michael; McCarty, Owen J T; Haley, Kristina M

2018-03-01

BackgroundApproximately 40% of adolescent women experience heavy menstrual bleeding (HMB), and 10-62% of them have an underlying bleeding disorder (BD). Diagnosing a BD remains challenging because of limitations of available clinical platelet function assays. The aim of this study was to characterize platelet function in a population of adolescent women with HMB using small-volume whole-blood assays.MethodsAnticoagulated whole blood was used to assess platelet GPIIbIIIa activation, α-granule secretion, and aggregation in response to multiple agonists. Platelet adhesion on collagen or von Willebrand Factor (VWF) under static and shear flow was also assessed.ResultsFifteen participants with HMB were included in the study, of which eight were diagnosed with a clinically identifiable BD. Platelet activation was blunted in response to calcium ionophore in participants without a BD diagnosis compared with that in all other participants. Impaired GPIIbIIIa activation was observed in response to all GPCR agonists, except adenosine diphosphate (ADP), in participants with qualitative platelet disorders. Our assays detected platelet aggregation in the majority of participants with a BD in response to ADP, collagen-related peptide (CRP), thrombin receptor activator 6 (TRAP-6), or U46619. Platelet adhesion and aggregation on collagen and VWF was decreased for participants with VWD.ConclusionParticipants with and without BD exhibited aberrant platelet function in several assays in response to select agonists.

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

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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.

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

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

111In-labeled platelet scintigraphy and two-dimensional echocardiography for detection of left atrial appendage thrombi. Studies in a new canine model

International Nuclear Information System (INIS)

Vandenberg, B.F.; Seabold, J.E.; Conrad, G.R.; Kieso, R.; Johnson, J.; Fox-Eastham, K.; Ponto, J.; Bruch, P.; Kerber, R.E.

1988-01-01

111In-labeled platelet scintigraphy and two-dimensional echocardiography were performed in 40 dogs to determine the ability of the two techniques to detect left atrial appendage thrombi. Thrombi were induced in 33 dogs that were classified into two groups, acute or chronic, according to the time of labeled-platelet injection after thrombus induction. In the acute group (17 dogs), platelets were injected 24 hours after thrombus induction. In the chronic group (16 dogs), platelets were injected 4-8 days after thrombus induction. Sham thoracotomies were performed on seven additional control dogs who did not receive thrombin injections. Analog and blood pool-corrected 111In-labeled platelet scintigraphy images were obtained 4-72 hours later. Closed-chest two-dimensional echocardiography was performed before thoracotomy and repeated at the time of scintigraphy. The location and size of each thrombus were verified at autopsy. Two-dimensional echocardiography detected three of 17 acute (mean volume, 1.2 +/- 1.0 cc) and three of 10 chronic (mean volume, 0.4 +/- 0.3 cc; p less than 0.025) left atrial appendage thrombi. 111In-labeled platelet scintigraphy detected all 17 acute thrombi but only two of 10 chronic thrombi. The measured radioactivity levels of the excised thrombi were 1,949 +/- 1,665 cpm/clot/dose in group 1 and 228 +/- 213 cpm/clot/dose in group 2 (p less than 0.005). In this model, 111In-labeled platelet scintigraphy was able to detect acute left atrial appendage thrombi that could not be identified by two-dimensional echocardiography. Both techniques showed poor sensitivity for detection of chronic thrombi. The decline in sensitivity of 111In-labeled platelet scintigraphy for detection of older thrombi is probably due to diminished labeled-platelet incorporation

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

DEFF Research Database (Denmark)

Pleines, Irina; Eckly, Anita; Elvers, Margitta

2010-01-01

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

Chin Symphysis Bone, Allograft, and Platelet-Rich Fibrin: Is the Combination Effective in Repair of Alveolar Cleft?

Science.gov (United States)

Movahedian Attar, Bijan; Naghdi, Navid; Etemadi Sh, Milad; Mehdizadeh, Mojdeh

2017-05-01

Secondary grafting of alveolar defects with iliac crest bone is a common treatment method in cleft patients. The aim of this study was to evaluate the effectiveness of the combination of symphysis bone, allograft, and platelet-rich fibrin in regeneration of alveolar defects compared with iliac bone graft. In this randomized clinical trial, patients with unilateral alveolar defects were divided randomly into two categories. Group A comprised patients in whom the combination of chin symphysis bone plus allogeneic bone material plus leukocyte- and platelet-rich fibrin was considered for treatment. Group B comprised patients in whom iliac bone graft was considered. Cone beam computed tomography before treatment and 1 year postoperatively was used for measurement of bone formation (bone volume in cubic centimeters). The data were analyzed by paired t and χ 2 tests via SPSS software (version 23; IBM, Armonk, NY). P platelet-rich fibrin is a proper combination for bone regeneration in alveolar defects with a small to moderate volume range. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

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

Platelets Inhibit Migration of Canine Osteosarcoma Cells.

Science.gov (United States)

Bulla, S C; Badial, P R; Silva, R C; Lunsford, K; Bulla, C

2017-01-01

The interaction between platelets and tumour cells is important for tumour growth and metastasis. Thrombocytopenia or antiplatelet treatment negatively impact on cancer metastasis, demonstrating potentially important roles for platelets in tumour progression. To our knowledge, there is no information regarding the role of platelets in cancer progression in dogs. This study was designed to test whether canine platelets affected the migratory behaviour of three canine osteosarcoma cell lines and to give insights of molecular mechanisms. Intact platelets, platelet lysate and platelet releasate inhibited the migration of canine osteosarcoma cell lines. Addition of blood leucocytes to the platelet samples did not alter the inhibitory effect on migration. Platelet treatment also significantly downregulated the transcriptional levels of SNAI2 and TWIST1 genes. The interaction between canine platelets or molecules released during platelet activation and these tumour cell lines inhibits their migration, which suggests that canine platelets might antagonize metastasis of canine osteosarcoma. This effect is probably due to, at least in part, downregulation of genes related to epithelial-mesenchymal transition. Copyright © 2016. Published by Elsevier Ltd.

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

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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.

Platelet-rich plasma in otolaryngology.

Science.gov (United States)

Stavrakas, M; Karkos, P D; Markou, K; Grigoriadis, N

2016-12-01

Platelet-rich plasma is a novel material that is being used more frequently in many surgical specialties. A literature review on the current and potential uses of platelet-rich plasma in otolaryngology was performed. There is limited evidence on the use of platelet-rich plasma in otolaryngology compared with other specialties: only 11 studies on various subspecialties (otology, rhinology and laryngology) were included in the final review. Based on the limited number of studies, we cannot draw safe conclusions about the value of platelet-rich plasma in otolaryngology. Nevertheless, the available literature suggests that platelet-rich plasma holds promise for future research and may have a number of clinical applications.

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.

Blood clotting and platelets: a delicate balance

International Nuclear Information System (INIS)

Heyns, A. du P.; Loetter, M.G.; Badenhorst, P.N.

1988-01-01

The Medical Research Council Blood Platelet Research Unit has studied many of the facets of platelets. The research highlights of the Unit include the following: the identification of ADPase, an enzyme found in the blood vessel wall, which breaks down adenosine diphospate (ADP) to adenosine, and which inhibits platelet aggregation; the determination of the relationship between the biochemical activity of the vessel wall with the development of atherosclerosis; the development of a method to label platelets with the compound In-111-oxine; the use of labelled platelets to study platelets in the spleen: an investigation of the life-span of platelets, which revealed how aged platelets are removed from circulation, and recently a study of methods to demonstrate in vivo activation of platelets. 1 fig

Histologic Evidence of New Collagen Formulation Using Platelet Rich Plasma in Skin Rejuvenation: A Prospective Controlled Clinical Study

OpenAIRE

Abuaf, Ozlem Karabudak; Yildiz, Hamza; Baloglu, H?seyin; Bilgili, Memet Ersan; Simsek, Hasan Aktug; Dogan, Bilal

2016-01-01

Background Platelet-rich plasma (PRP) is an autologous concentration of human platelets contained in a small volume of plasma and has recently been shown to accelerate rejuvenate aging skin by various growth factors and cell adhesion molecules. Objective This study was conducted to evaluate the efficacy and safety of intradermal injection of PRP in the human facial rejuvenation. Methods This study was a prospective, single-center, single-dose, open-label, non-randomized controlled clinical st...

Effect of losartan on human platelet activation.

Science.gov (United States)

Guerra-Cuesta, J I; Montón, M; Rodríguez-Feo, J A; Jiménez, A M; González-Fernández, F; Rico, L A; García, R; Gómez, J; Farré, J; Casado, S; López-Farré, A

1999-03-01

Previous studies have demonstrated that losartan can block the thromboxane A2 receptor on the vascular wall. The aim of the present study was to assess the effect of losartan on human platelet activation. Platelets were obtained from 15 healthy men, aged 26-40 years. Platelet activation was measured by changes in the light transmission of platelet-rich plasma stimulated by the thromboxane A2 analog U46619 (5 x 10(-6) mol/l) or ADP (10(-5) mol/l). U46619-stimulated platelet aggregation was significantly inhibited by losartan in a dose-dependent manner. Only a high dose of EXP 3174 (5 x 10(-5) mol/l), the in vivo active metabolite of losartan, was able to attenuate U46619-induced platelet activation. Captopril, an angiotensin I converting inhibitor, failed to modify U46619-induced platelet aggregation. Furthermore, the binding of [3H]-U46619 to platelets was competitively inhibited by losartan, whereas only a high dose of EXP 3174 reduced the binding of [3H]-U46619. Captopril failed to modify the binding of [3H]-U46619 to platelets. Losartan also reduced the platelet activation induced by ADP (10(-5) mol/l), a platelet agonist partially dependent on thromboxane A2. In addition, when thromboxane A2 generation was blocked by aspirin, ADP-induced platelet aggregation was inhibited to a similar degree to the inhibition induced by losartan. Exogenous angiotensin II did not elicit any modification of either U46619- or ADP-stimulated platelet aggregation. Losartan decreased platelet aggregation by a thromboxane A2-dependent mechanism. EXP 3174 was less potent than losartan in reducing thromboxane A2-dependent platelet activation. Captopril and exogenous angiotensin II had no effect on human platelet activation. These results suggest that losartan reduced thromboxane A2-dependent platelet activation independently of its effect on angiotensin II.

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...

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

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Dijkgraaf Marcel G

2010-03-01

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

Platelet storage lesion in interim platelet unit concentrates: A comparison with buffy-coat and apheresis concentrates.

Science.gov (United States)

Singh, Sukhi; Shams Hakimi, Caroline; Jeppsson, Anders; Hesse, Camilla

2017-12-01

Platelet storage lesion is characterized by morphological changes and impaired platelet function. The collection method and storage medium may influence the magnitude of the storage lesion. The aim of this study was to compare the newly introduced interim platelet unit (IPU) platelet concentrates (PCs) (additive solution SSP+, 40% residual plasma content) with the more established buffy-coat PCs (SSP, 20% residual plasma content) and apheresis PCs (autologous plasma) in terms of platelet storage lesions. Thirty PCs (n=10 for each type) were assessed by measuring metabolic parameters (lactate, glucose, and pH), platelet activation markers, and in vitro platelet aggregability on days 1, 4, and 7 after donation. The expression of platelet activation markers CD62p (P-selectin), CD63 (LAMP-3), and phosphatidylserine was measured using flow cytometry and in vitro aggregability was measured with multiple electrode aggregometry. Higher platelet activation and lower in vitro aggregability was observed in IPU than in buffy-coat PCs on day 1 after donation. In contrast, metabolic parameters, expression of platelet activation markers, and in vitro aggregability were better maintained in IPU than in buffy-coat PCs at the end of the storage period. Compared to apheresis PCs, IPU PCs had higher expression of activation markers and lower in vitro aggregability throughout storage. In conclusion, the results indicate that there are significant differences in platelet storage lesions between IPU, buffy-coat, and apheresis PCs. The quality of IPU PCs appears to be at least comparable to buffy-coat preparations. Further studies are required to distinguish the effect of the preparation methods from storage conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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

Oral and intramuscular application of cyanogenic glycoside amygdalin did not induce changes in haematological profile of male rabbits

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Katarína Zbyňovská

2017-01-01

Full Text Available Amygdalin is a cyanogenic glycoside initially obtained from the seeds of bitter almonds. It is composed of one molecule of benzaldehyde, two molecules of glucose and one molecule of hydrocyanic acid. Various ways of amygdalin application play a different role in recipient organism. Intravenous infusion of amygdalin produced neither cyanidemia nor signs of toxicity, but oral administration resulted in significant blood cyanide levels. The present in vivo study was designed to reveal whether amygdalin is able to cause changes in the haematological profile and thus alter the physiological functions, using rabbits as a biological model. Adult male rabbits (n = 20 were randomly divided into five groups: the control group without any amygdalin administration, two experimental groups received a daily intramuscular injection of amygdalin at a dose 0.6 and 3.0 mg.kg-1 b.w. and other two groups were fed by crushed apricot seeds at dose 60 and 300 mg. kg-1 b.w., mixed with commercial feed over the period of 14 days. After two weeks, haematological parameters in whole blood were analysed (WBC - total white blood cell count, LYM - lymphocytes count, MID - medium size cell count, GRA - granulocytes count, RBC - red blood cell count, HGB - haemoglobin, HCT - haematocrit, MCV - mean corpuscular volume, MCH - mean corpuscular hemoglobin, MCHC - mean corpuscular hemoglobin concentration, RDWc - red cell distribution width, PLT - platelet count, PCT - platelet percentage, MPV - mean platelet volume, PDWc - platelet distribution width using haematology analyser Abacus junior VET. Our findings indicate that intramuscular and oral application of amygdalin for two weeks did not significantly affect the haematology parameters in experimental animals. In this study, no obvious beneficial or negative effects of amygdalin administration on the blood of male rabbits were observed.

Decrease in platelet activating factor stimulated phosphoinositide turnover during storage of human platelets in plasma

International Nuclear Information System (INIS)

Carter, M.G.; Shukla, S.D.

1987-01-01

Human platelet concentrate from the American Red Cross Blood Center was stored at 24 degree C in a shaker and aliquots were taken out at time intervals aseptically. Platelet activating factor (PAF) stimulated turnover of phosphoinositide (PPI) was monitored by assaying 32 P incorporation into phosphoinositides using platelet rich plasma (PRP). Platelets in PRP were incubated with 1 x 10 -7 M PAF at 37 degree C with gentle shaking and after 5 min their lipids were extracted and analysed by TLC for 32 P-phosphoinositides. The percent stimulation of 32 P incorporation by PAF (over control) into PPI was approximately 250, 100, 60, 25 and 20 on days 1, 2, 3, 5 and 6, respectively. This indicated a dramatic decrease in PAF responsive turnover of platelet PPI during storage. These findings have important implications in relation to PAF receptor activity and viability of platelets at different periods of storage

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

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Mahnaz Banihashemi

2014-04-01

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

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

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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.

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

Science.gov (United States)

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

2016-01-01

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

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.

Methods for evaluation of platelet function.

Science.gov (United States)

Lindahl, Tomas L; Ramström, Sofia

2009-10-01

There are a multitude of platelet function tests available, reflecting the complex nature of the platelet in haemostasis. No simple single test will ever cover all aspects of platelet function. Some tests focus on the aggregation of platelets, for example aggregometry, other on the swelling in response to hypotonic solutions, i.e. the well-known hypotonic shock response, or adhesion or coagulation and clot retraction, for example thromboelastography. In general there is a lack of clinical studies showing a predictive value of analysis of platelet concentrates.

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

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

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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

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

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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.

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...

Extended Storage of Pathogen-Reduced Platelet Concentrates (PRECON)

Science.gov (United States)

2017-12-01

transfusion. Our project proposes to determine the efficacy of using a pathogen inactivation technique (Mirasol) coupled with a platelet additive solution (PAS...technology, platelet additive solution, platelet recovery and survival, platelet storage, platelet storage solution, platelets, thrombocytopenia, transfusion...Platelets Report to 2017 Military Health System Research Symposium ……………………………………………………………….. 29 Extended Storage of Pathogen-Reduced Platelet Concentrates

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.

Toward the Relevance of Platelet Subpopulations for Transfusion Medicine

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Stefan Handtke

2018-02-01

Full Text Available Circulating platelets consist of subpopulations with different age, maturation state and size. In this review, we address the association between platelet size and platelet function and summarize the current knowledge on platelet subpopulations including reticulated platelets, procoagulant platelets and platelets exposing signals to mediate their clearance. Thereby, we emphasize the impact of platelet turnover as an important condition for platelet production in vivo. Understanding of the features that characterize platelet subpopulations is very relevant for the methods of platelet concentrate production, which may enrich or deplete particular platelet subpopulations. Moreover, the concept of platelet size being associated with platelet function may be attractive for transfusion medicine as it holds the perspective to separate platelet subpopulations with specific functional capabilities.

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.

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.

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

Science.gov (United States)

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

2011-01-01

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

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.

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

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

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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

Platelet-rich fibrin or platelet-rich plasma – which one is better? an opinion

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Shweta Bansal

2017-01-01

Full Text Available The healing of hard and soft tissue in mediated by a wide range of intracellular and extracellular events that are regulated by signaling proteins. Platelets can play a crucial role in periodontal regeneration as they are the reservoirs of growth factors and cytokines which are the key factors for regeneration of bone and maturation of soft tissue. Platelet-rich plasma (PRP is first generation platelet concentrate. However, the short duration of cytokine release and its poor mechanical properties have resulted in search of new material. Platelet-rich fibrin (PRF is a natural fibrin-based biomaterial prepared from an anticoagulant-free blood harvest without any artificial biochemical modification (no bovine thrombin is required that allows obtaining fibrin membranes enriched with platelets and growth factors. The slow polymerization during centrifugation, fibrin-based structure, ease of preparation, minimal expense makes PRF somewhat superior in some aspect to PRP.

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

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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

Platelet function in the postprandial period

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Sinzinger Helmut

2012-09-01

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

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

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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.

Influence of Oxidative Stress on Stored Platelets

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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.

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...

Platelet concentrates for transfusion-metabolic and storage aspects.

Science.gov (United States)

Farrugia, A

1994-01-01

Transfusion of platelets concentrated from donated blood is an established therapeutic modality in clinical medicine. Over the past 25 years much effort has gone into optimising the conditions for the collection, preparation and storage of platelets for transfusion. Despite significant advances, platelet production is still a costly process requiring a dedicated environment and the use of specially formulated plastic storage containers. A progressive lesion over storage limits the shelf life and the availability of donated platelets, while the need to store platelets in the donor's autologous plasma also results in a loss of valuable fresh plasma for fractionation. Recent studies have addressed the issues of platelet quality and plasma economy by examining the possibility of storing platelets in a synthetic medium. Platelets stored in a variety of crystalloid solutions have been shown to retain in vitro and in vivo properties equivalent or superior to platelets stored in autologous donor plasma. Some additional insight has been gained on the metabolic patterns of stored platelets. In particular, studies have shown that, under these conditions, platelets are unable to oxidise dextrose to any significant extent, and that dextrose is invariably broken down to lactate, irrespective of the oxygen tensions in the platelet's environment. This in turn leads to the metabolic lesion of platelet storage, whereby low pH results in loss of platelet viability. Platelets stored in synthetic dextrose-free media are capable of maintaining aerobic ATP generation, and acetate-a component of many media studied-has been shown to be metabolised by platelets. Similarly, platelets prepared from blood collected into a dextrose-free anticoagulant have satisfactory properties both when suspended in autologous plasma or in a dextrose-free synthetic medium. The requirements for storage in special, high gas-permeable, containers, and for constant agitation during storage, were both found to be

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

DEFF Research Database (Denmark)

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...

Gallic Acid Attenuates Platelet Activation and Platelet-Leukocyte Aggregation: Involving Pathways of Akt and GSK3β

Science.gov (United States)

Chang, Shih-Sheng; Lee, Viola S. Y.; Tseng, Yu-Lun; Chang, Kuan-Cheng; Chen, Kuen-Bao; Chen, Yuh-Lien; Li, Chi-Yuan

2012-01-01

Platelet activation and its interaction with leukocytes play an important role in atherothrombosis. Cardiovascular diseases resulted from atherothrombosis remain the major causes of death worldwide. Gallic acid, a major constituent of red wine and tea, has been believed to have properties of cardiovascular protection, which is likely to be related to its antioxidant effects. Nonetheless, there were few and inconsistent data regarding the effects of gallic acid on platelet function. Therefore, we designed this in vitro study to determine whether gallic acid could inhibit platelet activation and the possible mechanisms. From our results, gallic acid could concentration-dependently inhibit platelet aggregation, P-selectin expression, and platelet-leukocyte aggregation. Gallic acid prevented the elevation of intracellular calcium and attenuated phosphorylation of PKCα/p38 MAPK and Akt/GSK3β on platelets stimulated by the stimulants ADP or U46619. This is the first mechanistic explanation for the inhibitory effects on platelets from gallic acid. PMID:22811749

Gallic Acid Attenuates Platelet Activation and Platelet-Leukocyte Aggregation: Involving Pathways of Akt and GSK3β

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Shih-Sheng Chang

2012-01-01

Full Text Available Platelet activation and its interaction with leukocytes play an important role in atherothrombosis. Cardiovascular diseases resulted from atherothrombosis remain the major causes of death worldwide. Gallic acid, a major constituent of red wine and tea, has been believed to have properties of cardiovascular protection, which is likely to be related to its antioxidant effects. Nonetheless, there were few and inconsistent data regarding the effects of gallic acid on platelet function. Therefore, we designed this in vitro study to determine whether gallic acid could inhibit platelet activation and the possible mechanisms. From our results, gallic acid could concentration-dependently inhibit platelet aggregation, P-selectin expression, and platelet-leukocyte aggregation. Gallic acid prevented the elevation of intracellular calcium and attenuated phosphorylation of PKCα/p38 MAPK and Akt/GSK3β on platelets stimulated by the stimulants ADP or U46619. This is the first mechanistic explanation for the inhibitory effects on platelets from gallic acid.

Assessment of platelet function in healthy sedated cats using three whole blood platelet function tests.

Science.gov (United States)

Ho, Kimberly K; Abrams-Ogg, Anthony C G; Wood, R Darren; O'Sullivan, M Lynne; Kirby, Gordon M; Blois, Shauna L

2015-05-01

The objectives of this study were to establish feline references intervals for 3 commercial whole blood platelet function test analyzer systems: Multiplate analyzer (MP; Roche Diagnostics International Ltd., Rotkreuz, Switzerland), Platelet Function Analyzer-100 (PF: Siemens Canada, Mississauga, Ontario, Canada), and Plateletworks Combo-25 kit (PW; Helena Laboratories, Beaumont, TX). Venipuncture was performed on 55 healthy sedated cats, and platelet aggregation in response to adenosine diphosphate (ADP), collagen (COL), and arachidonic acid (AA; MP only) was assessed using citrated blood. For the MP analyzer, median (95% confidence intervals [CIs]) area under curve (Units) for ADP, COL, and AA agonists were 87 (11-176), 81 (32-129), and 91 (59-129), respectively. For the PF analyzer, median (95% CIs) closure time, using COL-ADP cartridges, was 69 (46-89) sec. For the PW assay, median (95% CIs) percent aggregations for ADP and COL agonists were 71 (18-92) and 49 (9-96), respectively, using impedance hematology analyzer platelet counts, and 94 (25-98) and 68 (14-119), respectively, using flow cytometry hematology analyzer platelet counts. There were low correlations between the PF analyzer (COL-ADP cartridge) and MP analyzer (COL agonist; ρ = 0.11), and between the PF analyzer (COL-ADP cartridge) and PW assay (COL agonist using impedance platelet counts; ρ = 0.14). The PW assay percent aggregations using impedance and flow cytometric platelet counts were correlated for both ADP (ρ = 0.64) and COL (ρ = 0.64) agonists. Platelet function testing using these tests are feasible in cats, but 95% CIs are wide, so single results may be difficult to interpret. Platelet counting by impedance or flow cytometry may be used for the PW assay but are not interchangeable. © 2015 The Author(s).

Mapping the coupled role of structure and materials in mechanics of platelet-matrix composites

Science.gov (United States)

Farzanian, Shafee; Shahsavari, Rouzbeh

2018-03-01

Despite significant progresses on understanding and mimicking the delicate nano/microstructure of biomaterials such as nacre, decoding the indistinguishable merger of materials and structures in controlling the tradeoff in mechanical properties has been long an engineering pursuit. Herein, we focus on an archetype platelet-matrix composite and perform ∼400 nonlinear finite element simulations to decode the complex interplay between various structural features and material characteristics in conferring the balance of mechanical properties. We study various combinatorial models expressed by four key dimensionless parameters, i.e. characteristic platelet length, matrix plasticity, platelet dissimilarity, and overlap offset, whose effects are all condensed in a new unifying parameter, defined as the multiplication of strength, toughness, and stiffness over composite volume. This parameter, which maximizes at a critical characteristic length, controls the transition from intrinsic toughening (matrix plasticity driven without crack growths) to extrinsic toughening phenomena involving progressive crack propagations. This finding, combined with various abstract volumetric and radar plots, will not only shed light on decoupling the complex role of structure and materials on mechanical performance and their trends, but provides important guidelines for designing lightweight staggered platelet-matrix composites while ensuring the best (balance) of their mechanical properties.

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...

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Blood platelets in the progression of Alzheimer's disease.

Directory of Open Access Journals (Sweden)

Nina S Gowert

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

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...

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.

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

Peptide-Mediated Platelet Capture at Gold Micropore Arrays.

Science.gov (United States)

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

2016-11-30

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

Stimulus-response coupling in platelets

International Nuclear Information System (INIS)

Huang, E.M.

1986-01-01

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

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...

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.

Effect of ionizing radiation on platelet function in vitro

International Nuclear Information System (INIS)

Kalovidouris, A.E.; Papayannis, A.G.

1981-01-01

The effect of ionizing radiation on platelet function was investigated in vitro. Platelet-rich plasma (300x10 9 /l) was irradiated with doses of 1, 4, 10, 20 and 50 Gy. Platelet function tests were performed on both irradiated and control (non-irradiated) platelet samples. The platelet function tests were (1) platelet aggregation by ADP (1, 2, 4 μmol final concentration), adrenaline and collagen, (2) ADP-release from platelets, (3) clot retraction and (4) platelet factor-3 availability. It was found that roentgen irradiation of platelets in vitro did not affect these platelet function tests. (Auth.)

Platelet associated IgG, platelet mean life span and treatment with intravenous immunoglobulin in idiopathic thrombocytopenic purpura

International Nuclear Information System (INIS)

Nieminen, U.; Syrjaelae, M.; Ikkala, E.; Myllylae, G.

1988-01-01

The clinical significance of platelet associated IgG in ITP detected by direct platelet suspension immunofluorescence test (PSIFT) was studied. The platelet mean life span (MLS) was measured with 111 In-labelled platelets in 17 adult patients. All the patients had shortened platelet MLS. The direct PSIFT was positive in 14 patients. Patients were initially treated with prednisone; 12 patients with poor response to the drug were splenectomised. 8 of these 12 patients were treated with intravenous immunoglobulin (IvIg) before splenectomy. The response to IvIg was as good or better in the 3 patients with negative PSIFT, than in the 5 patients with positive PSIFT. (author)

Platelet activation in outpatients undergoing esophagogastroduodenoscopy

International Nuclear Information System (INIS)

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

1989-01-01

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

Kinetics of short-lived Indium-111 radiolabelled platelets

Energy Technology Data Exchange (ETDEWEB)

Peters, A.M.; Saverymuttu, S.H.; Bell, R.N.; Lavender, J.P. (Hammersmith Hospital, London, U.K.)

1985-01-01

We have studied the kinetics of autologous /sup 111/In-labelled platelets in patients with reduced platelet life span (<4.5 d), most of whom were thrombocytopenic, and of homologous /sup 111/In-labelled platelets in patients with severe thrombocytopenia. Intrasplenic platelet transit time (t) was calculated by compartmental and deconvolution analysis. In patients with a mean platelet life span of less than a few h, compartmental analysis may not be valid and so only deconvolution analysis was applied. There was a close correlation between values of t given by the two approaches (r=0.88, n=18, P<0.001). In some patients with severely reduced mean platelet life span (MPLS), the deconvolved splenic platelet clearance curves appeared to approach an asymptote, the relative magnitude of which was indicative of the irreversible extraction fraction by the spleen of incoming platelets. In other patients with severely reduced MPLS resulting from abnormal intra-hepatic platelet destruction, the deconvolved splenic curves resembled the normal. The intrasplenic platelet transit time showed no clear relationship with other parameters. It was concluded that platelet pooling within the spleen is normal in patients with reduced platelet life span,including idiopathic thrombocytopenic purpura, even when the predominant site of destruction is the spleen, and that platelets are not delayed in transit through the spleen in preparation of their removal from the circulation and ultimate destruction.

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...

Thrombokinetics with In-111-oxine labelled platelets

International Nuclear Information System (INIS)

Uchida, Tatsumi; Yui, Tokuo; Muroi, Shuichi; Matsuda, Shin; Kariyone, Shigeo

1982-01-01

Indium-111-oxine has been employed as a redioactive platelet label for thrombosis imaging and thrombokinetic studies in man. To evaluate it's suitability for platelet survival and turnover, thrombokinetic studies were carried out in hematological normal subjects, in patients with idiopathic thrombocytopenic purpura (ITP) and chronic congestive splenomegaly. For In-111-oxine labelled platelets, platelets were collected by differential centrifugation from 44 ml of whole blood drawn into 6 ml of acid citrate dextrose solution. Platelet suspension was incubated with In-111-oxine, which was extracted before use by the method of Thakur and co-workers. The survival, recovery and turnover of In-111-labeled platelets were 8.6 +- 0.5 days, 63.0 +- 5.4% and 3.9 +- 0.3 x 10 4 / μl/day, respectively, which were similar with those of Cr-51 method. Platelet disappearance curves labelled with In-111 and Cr-51 simultaneously were similar in one case. In patients with ITP, platelet survival shortened in the same degree with Cr-51 method. The two simultaneous labeling studies between In-111 and Cr-51 showed no differences. In the patients with congestive splenomegaly, the same results were obtained. Thrombokinetic studies with In-111-oxine labelled platelets offer the advantages of reduced blood requirements, and the ability to perform external imaging of platelet distribution. (author)