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  1. Platelet count

    Science.gov (United States)

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

  2. 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 ...

  3. Platelet counting using the Coulter electronic counter.

    Science.gov (United States)

    Eggleton, M J; Sharp, A A

    1963-03-01

    A method for counting platelets in dilutions of platelet-rich plasm using the Coulter electronic counter is described.(1) The results obtained show that such platelet counts are at least as accurate as the best methods of visual counting. The various technical difficulties encountered are discussed.

  4. 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...

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

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    Zainab S Al-Hosni

    2016-11-01

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

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

    African Journals Online (AJOL)

    Amira M. Elsayed

    2016-03-30

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

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Platelet count kinetics following interruption of antiretroviral treatment.

    Science.gov (United States)

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

    2013-01-02

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

  9. Poor prognostic role of the pretreatment platelet counts in colorectal cancer: A meta-analysis.

    Science.gov (United States)

    Rao, Xu-Dong; Zhang, Hua; Xu, Zheng-Shui; Cheng, Hua; Shen, Wei; Wang, Xin-Ping

    2018-06-01

    Recently, a wide variety of studies have suggested that elevated platelet counts are associated with survival in patients with colorectal cancer. On one hand several studies suggest a negative connection in colorectal cancer patients with pre-operative thrombocytosis, on the other hand other studies contradicts this. However, it remains unknown whether elevated platelet counts are associated with survival in colorectal cancer patients. We therefore conducted this meta-analysis to evaluate the prognostic role of platelet counts in colorectal cancer. PubMed, Embase, and the Cochrane Library databases were searched from their inception to October 15, 2016 to identify relevant studies that have explored the prognostic role of platelet counts in colorectal cancer. Studies that examined the association between platelet counts and prognoses in colorectal cancer and that provided a hazard ratio (HR) and 95% confidence interval (CI) for overall survival (OS) and/or disease-free survival (DFS) were included. This meta-analysis included 9 retrospective cohort studies involving 3413 patients with colorectal cancer. OS was shorter in patients with elevated platelet counts than in patients with normal counts (HR 2.11, 95% CI: 1.68-2.65). For DFS, an elevated platelet count was also a poor predictor (HR 2.51, 95% CI: 1.84-3.43). In this meta-analysis, we suggest that an elevated platelet count is a negative predictor of survival in both primary colorectal cancer and resectable colorectal liver metastases.

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

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    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.

  11. 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.

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

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    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.

  13. Platelet count is associated with cardiovascular disease, cancer and mortality

    DEFF Research Database (Denmark)

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

    2016-01-01

    count (100-450×10(9)/L) and mortality, development of future cardiovascular disease (myocardial infarction, ischaemic stroke, or peripheral vascular disease), venous thromboembolism, bleeding or cancer in the general population. MATERIAL AND METHODS: We conducted a register-based cohort study of 21......,252 adults (≥20years) from the Danish General Suburban Population Study (GESUS). Laboratory results from GESUS were linked to information from national registers regarding morbidity and death. Cox proportional hazard regression was conducted with adjustment for age, sex, smoking status, haemoglobin......, leukocyte count, C-reactive protein and Charlson comorbidity index. RESULTS: We found a U-shaped relationship between mortality and platelet count. Mortality was significantly increased for platelet count 300×10(9)/L. When categorizing platelet count using the interval 201-250×10(9)/L...

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

    Science.gov (United States)

    Żmigrodzka, M; Guzera, M; Winnicka, A

    2016-01-01

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

  15. Platelet Counts, MPV and PDW in Culture Proven and Probable Neonatal Sepsis and Association of Platelet Counts with Mortality Rate

    International Nuclear Information System (INIS)

    Ahmad, M. S.; Waheed, A.

    2014-01-01

    Objective: To determine frequency of thrombocytopenia and thrombocytosis, the MPV (mean platelet volume) and PDW (platelet distribution width) in patients with probable and culture proven neonatal sepsis and determine any association between platelet counts and mortality rate. Study Design: Descriptive analytical study. Place and Duration of Study: NICU, Fazle Omar Hospital, from January 2011 to December 2012. Methodology: Cases of culture proven and probable neonatal sepsis, admitted in Fazle Omar Hospital, Rabwah, were included in the study. Platelet counts, MPV and PDW of the cases were recorded. Mortality was documented. Frequencies of thrombocytopenia ( 450000/mm3) were ascertained. Mortality rates in different groups according to platelet counts were calculated and compared by chi-square test to check association. Results: Four hundred and sixty nine patients were included; 68 (14.5%) of them died. One hundred and thirty six (29%) had culture proven sepsis, and 333 (71%) were categorized as probable sepsis. Thrombocytopenia was present in 116 (24.7%), and thrombocytosis was present in 36 (7.7%) cases. Median platelet count was 213.0/mm3. Twenty eight (27.7%) patients with thrombocytopenia, and 40 (12.1%) cases with normal or raised platelet counts died (p < 0.001). Median MPV was 9.30, and median PDW was 12.30. MPV and PDW of the patients who died and who were discharged were not significantly different from each other. Conclusion: Thrombocytopenia is a common complication of neonatal sepsis. Those with thrombocytopenia have higher mortality rate. No significant difference was present between PDW and MPV of the cases who survived and died. (author)

  16. Pregnancies with Platelet Count Lower Than 70000 Platelets/μl

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    Semih Mun

    2006-08-01

    CONCLUSION: If thrombocyte count of a pregnant is not less than 70000/μl and her symptoms are not related with thrombocytopenia then only follow up for platelet counts is sufficient in pregnancy. However if it is less than 70000/μl, treatment of thrombocytopenia and strict follow up of patient is necessary.

  17. 21 CFR 864.8175 - Calibrator for platelet counting.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calibrator for platelet counting. 864.8175 Section 864.8175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Reagents § 864.8175 Calibrator for...

  18. Change in platelet count in patients with hypersplenism subjected to liver transplantation

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    Júlio Cezar Uili Coelho

    2011-09-01

    Full Text Available CONTEXT: Most patients subjected to liver transplantation presents hypersplenism, which is reversed after the operation. However, some patients remain with moderate to intense hypersplenism. OBJECTIVES: To study the effect of liver transplantation on platelet count in patients with hypersplenism. METHOD: Of a total of 233 patients who underwent liver transplantation, 162 were excluded from the present study because of occurrence of steroid-resistant rejection, absence of hypersplenism before the transplantation, absence of follow-up for at least 2 years or incomplete exams data. The electronic study protocols of the remaining 71 patients were reviewed to determine the demographics, etiology of cirrhosis, and results of pathologic examination of the explanted liver. Serial platelet count was obtained from the study protocol on the day before liver transplantation and 1, 2, 4, and 6 months and 1 year after liver transplantation. Statistical analysis was performed using the Student's t-test, chi-square test, and Spearman's correlation test. RESULTS: Posttransplant platelet count at all time intervals was significantly higher than the pretransplant value (P100,000/mm³ in 58 patients (81.7% 1 month after liver transplantation. Twelve patients (16.9% remained with thrombocytopenia 1 year after liver transplantation. Three patients (4.2% had recurrence of thrombocytopenia within 1 year after liver transplantation. There was no correlation between pretransplant platelet count and the Child-Pugh class or the MELD score. CONCLUSION: Liver transplantation reverses hypersplenism in most patients.

  19. The use of regression analysis in determining reference intervals for low hematocrit and thrombocyte count in multiple electrode aggregometry and platelet function analyzer 100 testing of platelet function.

    Science.gov (United States)

    Kuiper, Gerhardus J A J M; Houben, Rik; Wetzels, Rick J H; Verhezen, Paul W M; Oerle, Rene van; Ten Cate, Hugo; Henskens, Yvonne M C; Lancé, Marcus D

    2017-11-01

    Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r 2 ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r 2 = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.

  20. 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.

  1. Average sperm count remains unchanged despite reduction in maternal smoking

    DEFF Research Database (Denmark)

    Priskorn, L; Nordkap, L; Bang, A K

    2018-01-01

    STUDY QUESTION: How are temporal trends in lifestyle factors, including exposure to maternal smoking in utero, associated to semen quality in young men from the general population? SUMMARY ANSWER: Exposure to maternal smoking was associated with lower sperm counts but no overall increase in sperm...... temporal trends. Parental age increased, and exposure in utero to maternal smoking declined from 40% among men investigated in 1996-2000 to 18% among men investigated in 2011-2016. Exposure to maternal smoking was associated with lower sperm counts but no overall increase in sperm counts was observed...... counts was observed during the study period despite a decrease in this exposure. WHAT IS KNOWN ALREADY: Meta-analyses suggest a continuous decline in semen quality but few studies have investigated temporal trends in unselected populations recruited and analysed with the same protocol over a long period...

  2. Platelet-rich plasma and chronic wounds: remaining fibronectin may influence matrix remodeling and regeneration success.

    Science.gov (United States)

    Moroz, Andrei; Deffune, Elenice

    2013-11-01

    Platelet-rich plasma has been largely used as a therapeutic option for the treatment of chronic wounds of different etiologies. The enhanced regeneration observed after the use of platelet-rich plasma has been systematically attributed to the growth factors that are present inside platelets' granules. We hypothesize that the remaining plasma and platelet-bound fibronectin may act as a further bioactive protein in platelet-rich plasma preparations. Recent reports were analyzed and presented as direct evidences of this hypotheses. Fibronectin may directly influence the extracellular matrix remodeling during wound repair. This effect is probably through matrix metalloproteinase expression, thus exerting an extra effect on chronic wound regeneration. Physicians should be well aware of the possible fibronectin-induced effects in their future endeavors with PRP in chronic wound treatment. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  3. 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.

  4. EFFECTS OF COMBINATION THERAPY ON PLATELET COUNT IN PATIENTS OF MYOCARDIAL INFARCTION

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    Sadaf Ahmed

    2014-12-01

    Full Text Available Aspirin and clopidogrel are usually used individually to prevent adverse cardiovascular events and stroke. They are used in stabilizing the blood pressure in patients of myocardial infarction while combination therapy of aspirin and Clopidogrel (dual anti-platelet therapy is used for preventing adverse cardiovascular events in myocardial infarction patients. A cross-sectional observational study is conducted through a structured questionnaire from 110 patients of K.I.H.D (Karachi Institute of Heart Disease hospital, Karachi, Pakistan. Indoor/admitted patients with diagnosis of acute coronary syndrome (ACS, non-ST elevation myocardial infarction (NSTE-MI, ST elevation myocardial infarction (STE-MI, supra ventricular tachycardia (SVT were included along with those with previous or current onset of angina pectoris or heart attack. Information from the test reports of these patients was included in the data. Patients without proper test reports were excluded from the study. Combination therapy duration is considered as key tool for evaluation. Out of 100 patients (after exclusion criteria applied almost 18% patients were using the combination therapy for 10 to 25 years while 52% of patients were using the combination therapy for 1 to 10 years. Platelet count of 88% patients was found to be in between 1,50,000–3,50,000/µl. Remaining patients had less than 1,50,000 µl to more than 3,50,000 to 4,50,000 µl. Most frequently reported side effects were chest pain, respiratory issues, headache and depression. On the basis of our data analysis it is concluded that long duration dual anti-platelet therapy will not harm platelet count in human blood but it can create drug dependency in patients. Hypertension is not completely cured with this therapy but can help in stabilizing blood pressure.

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

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    Taisuke Watanabe

    2017-01-01

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

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

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    Ruhuşen Kutlu

    2017-12-01

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

  7. Does platelet count in platelet-rich plasma influence slope, maximal amplitude and lag phase in healthy individuals? Results of light transmission aggregometry.

    Science.gov (United States)

    Chandrashekar, Vani

    2015-01-01

    Light transmission aggregometry lacks in standardisation and normal reference values are not widely available. The aims of our study were to establish reference ranges for aggregation, slope and lag phase in healthy controls with platelet counts between 150 and 450 × 10(9)/l in platelet-rich plasma (PRP) as well as evaluate the influence of platelet count. Ninety-nine subjects were evaluated with four agonists and divided into two groups based on platelet count and the groups were compared by Student's t-test. There was no difference between the means of the two groups for amplitude and slope barring the lag phase for collagen. Platelet counts between 150 and 450 × 10(9)/l have no effects on light transmission aggregometry and hence adjustment of platelet count is not necessary.

  8. Platelet count kinetics following interruption of antiretroviral treatment

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  9. A Comparison of Platelet Count and Enrichment Percentages in the Platelet Rich Plasma (PRP) Obtained Following Preparation by Three Different Methods.

    Science.gov (United States)

    Sabarish, Ram; Lavu, Vamsi; Rao, Suresh Ranga

    2015-02-01

    Platelet rich plasma (PRP) represents an easily accessible and rich source of autologous growth factors. Different manual methods for the preparation of PRP have been suggested. Lacuna in knowledge exists about the efficacy of PRP preparation by these different manual methods. This study was performed to determine the effects of centrifugation rate revolutions per minute (RPM) and time on the platelet count and enrichment percentages in the concentrates obtained following the three different manual methods of PRP preparation. In vitro experimental study. This was an experimental study in which platelet concentration was assessed in the PRP prepared by three different protocols as suggested by Marx R (method 1), Okuda K (method 2) and Landesberg R (method 3). A total of 60 peripheral blood samples, (n=20 per method) were obtained from healthy volunteers. Baseline platelet count was assessed for all the subjects following which PRP was prepared. The platelet count in the PRP was determined using coulter counter (Sysmex XT 2000i). The mean of the platelet count obtained and their enrichment percentage were calculated and intergroup comparison was done (Tukey's HSD test). The number of platelets and enrichment percentage in PRP prepared by method 1 was higher compared to method 2 and method 3; this difference in platelet concentrates was found to be statistically significant (p < 0.05). The centrifugation rate and time appear to be important parameters, which influence the platelet yield. Method 1 which had lower centrifugation rate and time yielded a greater platelet count and enrichment percentage.

  10. Platelet count evolution as a predictor of outcome after splenectomy for immune thrombocytopenic purpura.

    Science.gov (United States)

    Kim, Moonhwan; Park, Keun Myoung; Shin, Woo Young; Choe, Yun-Mee; Lee, Keon-Young; Ahn, Seung-Ik

    2017-04-01

    Splenectomy is the definitive second-line therapy for refractory immune thrombocytopenic purpura (ITP), and has a reported response rate of 50-80%. Medical attention should be reconsidered when there is no evidence of accessory spleen in refractory ITP patients after splenectomy. The purpose of this study was to determine whether platelet count evolution differs between patients with a successful or unsuccessful result after splenectomy for ITP. Archived records of 104 consecutive patients that underwent splenectomy for ITP were reviewed. Patients were divided into two groups (failures and successes) using a final follow-up platelet count of 100,000/μL as a cut-off. Platelet count evolutions in these two groups were compared using the Student's t test. Successes and failures were found to have significantly different platelet counts from two days postoperatively (P = 0.016). The area under the receiver operating characteristic curve was 0.630 (95% confidence interval, 0.518-0.741, P = 0.030), and when a cut-off value of 100,000/μL was used, sensitivity and specificity were 68.2 and 51.2%, respectively. To obtain positive and negative predictive values exceeding 50%, additional platelet counts were required at one week and one month after splenectomy. We propose a protocol for ITP follow-up after splenectomy.

  11. Function and platelet count in thrombocyte concentrate (TC during the storage

    Directory of Open Access Journals (Sweden)

    Elida Marpaung

    2016-01-01

    Full Text Available AbstrakLatar belakang: Evaluasi terhadap pemberian transfusi belum dilakukan secara optimal baik di hulumaupun di hilir. Tujuan penelitian ini untuk mengetahui pengaruh waktu penyimpanan terhadap perubahanpH, jumlah trombosit, dan fungsi agregasi yang terjadi pada trombosit pada beberapa hari penyimpanan.Metode: Disain penelitian potong lintang terhadap sample kantong konsentrat trombosit yang yang telahlolos skrining infeksi penyakit menular melalui transfusi darah. Pengujian yang dilakukan ialah terhadappH, jumlah trombosit dan fungsi agregasi terhadap sampel pada tiga waktu pengujian pada hari ke-0, ketiga, dan ke lima penyimpanan.Hasil: Pada 50 sampel kantong konsentrat trombosit didapatkan kenaikan pH pada hari ke tigapenyimpanan kantong trombosit yang disertai penurunan pada hari ke lima. Hal serupa ditemui pulapada jumlah trombosit. Sementara penurunan fungsi agregasi trombosit ditemukan lebih awal pada harike tiga penyimpanan dan didapatkan nilai rendah pada hampir semua sampel.Kesimpulan: Ketiga parameter yaitu pH, jumlah trombosit, dan fungsi agregasi mengalami penurunanpada hari kelima. (Health Science Journal of Indonesia;2015;6:48-51Kata kunci: thrombocyte, concentrate, pH, agregasi, waktu penyimpanan. AbstractBackground: Evaluation for platelet transfusion is not optimal for this moment even in upstream at theblood center or in downstream at the hospital. The purpose of this study was to determine the effect ofstorage time to changes in pH, platelet count and function that occurs on platelet aggregation duringdifferent time storage.Methods: The study design was cross-sectional on selected bags of platelet concentrates that have passedthe screening for infection transmitted through blood transfusions. The regular assessment in UTDD forPC has been done every month by random sampling with three parameters pH, platelets count and volumein the bag of blood. The testing for pH, platelet count, and aggregation functions for 50 samples

  12. A STUDY OF PAPAYA EXTRACT IN THE TREATMENT OF LOW PLATELET COUNT

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    Sakuntala Putrevu

    2016-09-01

    Full Text Available BACKGROUND Thrombocytopenia is defined as platelet count less than one and half lakh per mm cube of blood. Thrombocytopenia has been documented in patients with infectious mononucleosis, cytomegalovirus, and varicella zoster infections. Hepatitis C, tuberculosis and human immunodeficiency virus also have been reported in the causes list. Thrombocytopenia is a well-known complication of chronic lymphocytic leukaemia, although it may not be encountered as easily as seen in autoimmune haemolytic anaemias in these patients. It has also been reported in patients with other lymphoproliferative disorders including Hodgkin’s disease. Thrombocytopenia in patients with a variety of solid tumours has also been thought to most likely be immune mediated. Thrombocytopenia may accompany Graves’ disease and Hashimoto’s thyroiditis, but it is not certain that it is immunologically mediated or not. In our country, Dengue and malaria remain the predominant cause for Thrombocytopenia. Chymopapain and papain are the two important compound that are present in papaya. Lipase, a hydrolase, which is tightly bonded to the waterinsoluble fraction of crude papain is also seen in papaya. The papaya seeds and fruits have excellent antibiotic properties. The consumption of unripe and semi-ripe papaya fruits could be dangerous during pregnancy as it contains papain which may cause natural uterine contraction and may lead to abortions. It is reported that the plant extracts of papaya have maximum activity against dengue virus. It also has been reported that the methyl gallate of plant origin interacts with herpes simplex virus and causes its destruction. Majority of the papaya plant parts is known to have antimicrobial property. This study puts in a sincere effort to check the effects of papaya extract in the treatment of low platelet count. This study is intended to help the practising physicians to understand the benefits of the use of papaya extract when using in the

  13. 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.

  14. Correlation of platelet count and acute ST-elevation myocardial infarction.

    Science.gov (United States)

    Paul, G K; Sen, B; Rahman, M Z; Ali, M; Rahman, M M; Rokonuzzaman, S M

    2014-10-01

    The study was conducted in the Department of cardiology, NICVD Dhaka during the period January 2006 to December 2007 to assess the impact of platelet on ST-elevation myocardial infarction (STEMI). To perform this prospective study 200 patients with STEMI within 72 hours of chest pain of both sexes were randomly selected and were evaluated by clinical history, physical examination and with the help of ECG, Echocardiography and others cardiac risk factors analysis. Heparin therapy before admission, previously documented thrombocytopenia (1.6mg/dl) and history of PCI & CABG were excluded in this study. Patient of Platelet count (PC) ≤200000/cubic millimeter (cmm) in Group I and patient of Group II, platelet counts were PC >200000/cmm. Follow up period was 3 days to 7 days after hospital admission. Primary outcome heart failure (any Killip class) was significantly more in Group II than Group I (40.0% vs. 23.0%; p=0.009). Though the incidence of Killip class I and cardiogenic shock were not significant between these two groups but Killip class II (18.0% vs. 8.0%; p=0.036) and Killip class III (15.0% vs. 6.0%; p=0.037) heart failure were significantly more among the patient with higher platelet counts. In-hospital mortality, one of the primary outcomes of this study, was significantly higher in Group II (13.0%) than Group I (5.0 %) and p value was 0.048. Re-infarction was more in patient with higher platelet counts group (Group II) than patients with lower platelet count (Group I) but statistically was not significant (16.0% vs.11.0%; p=0.300).

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

    Science.gov (United States)

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

    2018-01-01

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

  16. Influence of platelet count, platelet mass index, and platelet function on the spontaneous closure of ductus arteriosus in the prematurity

    Directory of Open Access Journals (Sweden)

    Dilek Kahvecioglu

    2018-02-01

    Conclusion: This is the first study in the English literature providing evidence of the influence of platelet dysfunction on the spontaneous closure of ductus arteriosus in prematurity. Longer collagen-ADP duration is identified as a risk factor of ductal closure.

  17. Serum Copper Level Significantly Influences Platelet Count, Lymphocyte Count and Mean Cell Hemoglobin in Sickle Cell Anemia

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    Okocha Chide

    2015-12-01

    Full Text Available Background Changes in serum micro nutrients levels affect a number of critically important metabolic processes; these could potentially influence blood counts and ultimately disease presentation in patients with sickle cell anemia (SCA. Objectives To evaluate the influence of serum micro-nutrients levels; zinc, copper, selenium and magnesium on blood counts in steady state SCA patients. Methods A cross sectional study that involved 28 steady state adult SCA subjects. Seven milliliters (mls of blood was collected; 3 mls was for hemoglobin electrophoresis and full blood count determination while 4 mls was for measurement of serum micro nutrients levels, by the atomic absorption spectrophotometry. Correlation between serum micro-nutrient levels and blood counts was done by the Pearson’s linear regression. Ethical approval was obtained from the institutional review board and each participant gave informed consent. All data was analyzed by SPSS software version 20. Results There was a significant correlation between serum copper levels and mean cell hemoglobin (MCH, platelet and lymphocyte counts (r = 0.418; P = 0.02, r = -0.376; P = 0.04 and r = -0.383; P = 0.04, respectively. There were no significant correlations between serum levels of other micro nutrients (selenium, zinc and magnesium and blood counts. Conclusions Copper influences blood count in SCA patients probably by inducing red cell haemolysis, oxidant tissue damage and stimulating the immune system.

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

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    Asli Tanrivermis Sayit

    2014-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Hannes Sallmon

    2018-03-01

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

  20. Platelet count recovery and seroreversion in immune HIT despite continuation of heparin: further observations and literature review.

    Science.gov (United States)

    Shih, Andrew W; Sheppard, Jo-Ann I; Warkentin, Theodore E

    2017-10-05

    One of the standard distinctions between type 1 (non-immune) and type 2 (immune-mediated) heparin-induced thrombocytopenia (HIT) is the transience of thrombocytopenia: type 1 HIT is viewed as early-onset and transient thrombocytopenia, with platelet count recovery despite continuing heparin administration. In contrast, type 2 HIT is viewed as later-onset (i. e., 5 days or later) thrombocytopenia in which it is generally believed that platelet count recovery will not occur unless heparin is discontinued. However, older reports of type 2 HIT sometimes did include the unexpected observation that platelet counts could recover despite continued heparin administration, although without information provided regarding changes in HIT antibody levels in association with platelet count recovery. In recent years, some reports of type 2 HIT have confirmed the observation that platelet count recovery can occur despite continuing heparin administration, with serological evidence of waning levels of HIT antibodies ("seroreversion"). We now report two additional patient cases of type 2 HIT with platelet count recovery despite ongoing therapeutic-dose (1 case) or prophylactic-dose (1 case) heparin administration, in which we demonstrate concomitant waning of HIT antibody levels. We further review the literature describing this phenomenon of HIT antibody seroreversion and platelet count recovery despite continuing heparin administration. Our observations add to the concept that HIT represents a remarkably transient immune response, including sometimes even when heparin is continued.

  1. A prospective cohort study of light transmission platelet aggregometry for bleeding disorders: is testing native platelet-rich plasma non-inferior to testing platelet count adjusted samples?

    Science.gov (United States)

    Castilloux, Jean Francois; Moffat, Karen A; Liu, Yang; Seecharan, Jodi; Pai, Menaka; Hayward, Catherine P M

    2011-10-01

    Light transmission platelet aggregometry (LTA) is important to diagnose bleeding disorders. Experts recommend testing LTA with native (N) rather than platelet count adjusted (A) platelet-rich plasma (PRP), although it is unclear if this provides non-inferior, or superior, detection of bleeding disorders. Our goal was to determine if LTA with NPRP is non-inferior to LTA with APRP for bleeding disorder assessments. A prospective cohort of patients, referred for bleeding disorder testing, and healthy controls, were evaluated by LTA using common agonists, NPRP and APRP (adjusted to 250 x 10⁹ platelets/l). Recruitment continued until 40 controls and 40 patients with definite bleeding disorders were tested. Maximal aggregation (MA) data were assessed for the detection of abnormalities from bleeding disorders (all causes combined to limit bias), using sample-type specific reference intervals. Areas under receiver-operator curves (AUROC) were evaluated using pre-defined criteria (area differences: 0 for superiority). Forty-four controls and 209 patients were evaluated. Chart reviews for 169 patients indicated 67 had bleeding disorders, 28 from inherited platelet secretion defects. Mean MA differences between NPRP and APRP were small for most agonists (ranges, controls: -3.3 to 5.8; patients: -3.0 to 13.7). With both samples, reduced MA with two or more agonists was associated with a bleeding disorder. AUROC differences between NPRP and APRP were small and indicated that NPRP were non-inferior to APRP for detecting bleeding disorders by LTA, whereas APRP met superiority criteria. Our study validates using either NPRP or APRP for LTA assessments of bleeding disorders.

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

    OpenAIRE

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mehmet Demir

    2014-01-01

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

  4. Liver stiffness plus platelet count can be used to exclude high-risk oesophageal varices.

    Science.gov (United States)

    Ding, Nik S; Nguyen, Tin; Iser, David M; Hong, Thai; Flanagan, Emma; Wong, Avelyn; Luiz, Lauren; Tan, Jonathan Y C; Fulforth, James; Holmes, Jacinta; Ryan, Marno; Bell, Sally J; Desmond, Paul V; Roberts, Stuart K; Lubel, John; Kemp, William; Thompson, Alexander J

    2016-02-01

    Endoscopic screening for high-risk gastro-oesophageal varices (GOV) is recommended for compensated cirrhotic patients with transient elastography identifying increasing numbers of patients with cirrhosis without portal hypertension. Using liver stiffness measurement (LSM) ± platelet count, the aim was to develop a simple clinical rule to exclude the presence of high-risk GOV in patients with Child-Pugh A cirrhosis. A retrospective analysis of 71 patients with Child-Pugh A cirrhosis diagnosed by transient elastography (LSM >13.6 kPa) who underwent screening gastroscopy was conducted. A predictive model using LSM ± platelet count was assessed to exclude the presence of high-risk GOV (diameter >5 mm and/or the presence of high-risk stigmata) and validated using a second cohort of 200 patients from two independent centres. High-risk GOV were present in 10 (15%) and 16 (8%) of the training and validation cohorts, respectively, which was associated with LSM and Pl count (P < 0.05). A combined model based on LSM and Pl count was more accurate for excluding the presence of high-risk GOV than either alone (training cohort AUROC: 0.87 [0.77-0.96] vs. 0.78 [0.65-0.92] for LSM and 0.71 [0.52-0.90] for platelets) with the combination of LSM ≤25 kPa and Pl ≥100 having a NPV of 100% in both the training and validation cohorts. A total of 107 (39%) patients meet this criterion. The combination of LSM ≤25 kPa and Pl ≥100 can be used in clinical practice to exclude the presence of high-risk GOV in patients with Child-Pugh A cirrhosis. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Error in laboratory report data for platelet count assessment in patients suspicious for dengue: a note from observation

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    Somsri Wiwanitkit

    2016-08-01

    Full Text Available Dengue is a common tropical infection that is still a global health threat. An important laboratory parameter for the management of dengue is platelet count. Platelet count is an useful test for diagnosis and following up on dengue. However, errors in laboratory reports can occur. This study is a retrospective analysis on laboratory report data of complete blood count in cases with suspicious dengue in a medical center within 1 month period during the outbreak season on October, 2015. According to the studied period, there were 184 requests for complete blood count for cases suspected for dengue. From those 184 laboratory report records, errors can be seen in 12 reports (6.5%. This study demonstrates that there are considerable high rate of post-analytical errors in laboratory reports. Interestingly, the platelet count in those erroneous reports can be unreliable and ineffective or problematic when it is used for the management of dengue suspicious patients.

  6. Use of Platelet Preparations in Facial Rejuvenation and Wound Healing Remains Unproven.

    Science.gov (United States)

    Kenworthy, William; Langridge, Benjamin; Patel, Nakul; Waterhouse, Norman

    2016-04-01

    There is growing interest in the use of platelet derivatives in facial aesthetic surgery and wound healing. Sclafani et al. have concluded from their review of the literature that the vast majority of studies show a significant and measurable effect on facial aesthetic outcomes with the use of these platelet preparations. We suggest that an alternative review of the same literature may well have produced a different set of conclusions. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  8. Thrombocytopenia in malaria: can platelet counts differentiate malaria from other infections

    International Nuclear Information System (INIS)

    Arshad, A.R.

    2015-01-01

    To determine the accuracy of thrombocytopenia as a diagnostic marker for malaria. Study Design: Cross-sectional study. Place and Duration of Study: Department of Medicine, 1 Mountain Medical Battalion (Bagh, Azad Kashmir) from July to September 2013. Methodology: Adult patients presenting with a short history of fever without any localizing symptoms or signs were included. Exclusion criteria included patients with fever of > 7 days duration, those in whom an underlying diagnosis could be easily confirmed on the basis of history and physical examination, those on antibiotics/ antimalarials or antiplatelet agents and patients with Dengue fever. Platelet counts in venous whole blood samples were analysed with Sysmex KX-21 Haematology analyzer. Thick and thin peripheral blood smears were then prepared and examined for malarial parasites. Diagnosis of malaria was established on the basis of smear findings. Results: There were 245 patients in total. Out of the 109 patients with thrombocytopenia, 61 had vivax malaria. Platelets count was normal in 136 patients, including 4 with vivax malaria. Falciparum malaria was not seen in any patient. All cases with malaria were uncomplicated. Various measures of accuracy thus calculated were sensitivity 93.85%, specificity 73.33%, positive predictive value 55.96%, negative predictive value 97.06%, positive likelihood ratio of 3.52, negative likelihood ratio of 0.08, diagnostic odds ratio 41.94 and diagnostic accuracy of 78.78%. Conclusion: Thrombocytopenia has an excellent sensitivity and a very good specificity for vivax malaria. Normal platelet counts provide very strong evidence against malaria as the etiology of fever without a focus. (author)

  9. Ophthalmic manifestations of 107 cases with hemolysis, elevated liver enzymes and low platelet count syndrome

    International Nuclear Information System (INIS)

    Erbagci, I.; Okumus, S.; Bekir, Necdet A.; Karaca, M.; Ugur, Mete G.

    2008-01-01

    Objective was to present various ophthalmologic disorders in a clinical series of hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome cases. This is a prospective clinical study performed between 2002 and 2005. One hundred seven HELLP attended in either Departments of Ophthalmology or Obstetrics and Gynecology, Medical School, Gaziantep University, Gaziantep, Turkey were evaluated. Mean age was 25.5 (22-36 years). Mean levels were 2.5 gravidity, 1.3 parity, 55,200/mm3 platelet counts, 308.7 U/I aspartate transaminase, 255.4 U/I alanine transminase and 1711.6U/I lactate dehydrogenase. Four patients died (3.7%) despite the proper treatments. Cortical blindness was observed in 3 cases (2.7%), serous retinal detachments in 4 (3.7%) and mild hypertension changes in 18 (16%). Ophthalmic complications are possible during and after this syndrome. Almost all ophthalmologic changes recover after delivery by cesarean section, nevertheless, it is essential that ophthalmologists should be aware of retinal disorders when this fatal complication of pregnancy is encountered. (author)

  10. Comparison of platelet counts by sysmex XE 2100 and LH-750 with the international flow reference method in thrombocytopenic patients

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    Tina Dadu

    2013-01-01

    Full Text Available Background: There are several methods for counting platelets, of which the international flow reference method (IRM is considered to be the gold standard. We compared the platelet count given by this method to the count given by automated analyzers using other methods, such as optical fluorescence and impedance. Aims: The aim of this study is to compare the platelet counts obtained by Sysmex XE 2100 by Impedance (Sysmex-I, optical florescence (Sysmex-O and reported (Sysmex-R based on the switching algorithm and LH-750 by Impedance (LH-750 with the IRM in thrombocytopenic blood samples. To calculate the sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of various technologies at the clinically relevant transfusion thresholds of 10 × 10 9 /l and 20 × 10 9 /l. Materials and Methods: A total of 118 blood samples with platelet count of <50 × 10 9 /l were selected for the study. Platelet counts of all samples were analyzed by all methods using the Sysmex analyzer, LH-750 and IRM in parallel within 6 h of collection. Statistical Analysis Used: Pearson correlation, bland Altman analysis, sensitivity and specificity, PPV and NPV. Results and Conclusions: Sysmex-R had the least Bias and 95% limits of agreement (95%LA range and thus correlated best with IRM values. LH-750 had a higher Bias compared to Sysmex-O and Sysmex-R, but a strikingly similar 95% LA ensures similar results in all three methods. In fact, in the oncology subset, it had the narrowest 95% LA, which made it the best performer in this subgroup. Of the three Sysmex results, Sysmex-I had the highest bias, widest 95% LA and highest potential risk of over transfusion. Hence, Sysmex-R and LH-750 were found to be reliable tools for estimation of platelet count in thrombocytopenic patients.

  11. Bone marrow adsorbed dose of rhenium-186-HEDP and the relationship with decreased platelet counts

    International Nuclear Information System (INIS)

    Klerk, J.M.H. de; Dieren, E.B. van; Schip, A.D. van het

    1996-01-01

    Rhenium-186(Sn)-1,1-hydroxyethylidene diphosphonate ( 186 Re-HEDP) has been used for palliation of metastatic bone pain. The purpose of this study was to find a relationship between the bone marrow absorbed dose and the toxicity, expressed as the percentage decrease in the peripheral blood platelet count. The bone marrow absorbed dose was calculated according to the MIRD model using data obtained from ten treatments of patients suffering from metastatic prostate cancer; noninvasive and pharmacokinetic method were used. The bone marrow doses were related to toxicity using the pharmacodynamic sigmoid E max model. The mean bone marrow absorbed doses using the noninvasive and pharmacokinetic methods were in a close range to each other (1.07 mGy/MBq and 1.02 mGy/MBq, respectively). There was a good relationship between the toxicity and the bone marrow absorbed dose (r = 0.80). Furthermore, the EDrm 50 (i.e., the bone marrow absorbed dose producing a 50% platelet decrease) to bone marrow for 186 Re-HEDP was on the order of 2 Gy. Although the function of normal bone marrow is affected by metastases in patients with metastatic bone disease, the MIRD model can be used to relate toxicity to the bone marrow absorbed dose after a therapeutic dosage of 186 Re-HEDP. 33 refs., 1 fig., 1 tab

  12. Comparative seric TGF(β1, β2) levels and platelets count response in total body irradiated baboons

    International Nuclear Information System (INIS)

    Mestries, J.C.; Veyret, J.; Agay, D.; Van Uye, A.; Caterini, R.; Herodin, F.; Mathieu, J.; Chancerelle, Y.

    1994-01-01

    Total body irradiation associated or not with r-hIL-6 treatment a relation between TGF-β1 and TGF-β2 blood levels and platelets count. During radio-induced thrombocytopenia, by decreasing its ability to inhibit proliferation of stem cells and megakaryocytopoiesis, the TGF-β falling induced a favorable condition for hematopoietic recovery. (author)

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

    LENUS (Irish Health Repository)

    McCabe, D J H

    2005-09-01

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

  14. Influence of centrifuge brake on residual platelet count and routine coagulation tests in citrated plasma.

    Science.gov (United States)

    Daves, Massimo; Giacomuzzi, Katia; Tagnin, Enrico; Jani, Erika; Adcock Funk, Dorothy M; Favaloro, Emmanuel J; Lippi, Giuseppe

    2014-04-01

    Sample centrifugation is an essential step in the coagulation laboratory, as clotting tests are typically performed on citrated platelet (PLT) poor plasma (PPP). Nevertheless, no clear indication has been provided as to whether centrifugation of specimens should be performed with the centrifuge brake set to on or off. Fifty consecutive sodium citrate anticoagulated samples were collected and divided into two aliquots. The former was centrifuged as for Clinical Laboratory Standards Institute (CLSI) guidelines with the centrifuge brake set to on, whereas the latter was centrifuged again as for CLSI guidelines, but with the brake set to off. In the PPP of all samples, a PLT count was performed, followed by the analysis of activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FBG). The PLT count after samples centrifugation was substantially reduced, either with centrifuge brake set to on or off (5 ± 1 versus 3 ± 1 × 10/l; P = 0.009). The frequency of samples exceeding a PLT count less than 10 × 10/l was nearly double in samples centrifuged with the brake on than in those with the brake off (14 versus 8%; P centrifuge brake set to on (mean bias 0.2 s; P centrifuge brake set to on (mean bias 0.29 g/l; P centrifugation for routine coagulation testing should be preferably performed with the centrifuge brake set to off for providing a better quality specimen.

  15. The Influence of Low Platelet Count on Whole Blood Aggregometry Assessed by Multiplate

    DEFF Research Database (Denmark)

    Stissing, Trine; Dridi, Nadia P; Ostrowski, Sisse R

    2011-01-01

    in an artificial matrix, platelet-rich plasma (PRP). Heparinized and citrated blood was diluted with autologous plasma to platelet concentrations 200 to 25 × 10(9)/L in WB samples (n = 10) and 200 to 100 × 10(9)/L in PRP samples (n = 7). The platelet aggregation was investigated by the ADP-, ASPI-, COL-, and TRAP...

  16. The Influence of Low Platelet Count on Whole Blood Aggregometry Assessed by Multiplate

    DEFF Research Database (Denmark)

    Stissing, Trine; Dridi, Nadia P; Ostrowski, Sisse R

    2011-01-01

    in an artificial matrix, platelet-rich plasma (PRP). Heparinized and citrated blood was diluted with autologous plasma to platelet concentrations 200 to 25 × 10(9)/L in WB samples (n = 10) and 200 to 100 × 10(9)/L in PRP samples (n = 7). The platelet aggregation was investigated by the ADP-, ASPI-, COL-, and TRAP......-test. The WB responses decreased at platelet concentration of ≤100 × 10(9)/L (all P PRP samples at platelet concentrations 200 to 100 × 10(9)/L (P

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2015-02-01

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

  19. Pneumatic tube system transport does not alter platelet function in optical and whole blood aggregometry, prothrombin time, activated partial thromboplastin time, platelet count and fibrinogen in patients on anti-platelet drug therapy

    Science.gov (United States)

    Enko, Dietmar; Mangge, Harald; Münch, Andreas; Niedrist, Tobias; Mahla, Elisabeth; Metzler, Helfried; Prüller, Florian

    2017-01-01

    Introduction The aim of this study was to assess pneumatic tube system (PTS) alteration on platelet function by the light transmission aggregometry (LTA) and whole blood aggregometry (WBA) method, and on the results of platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen. Materials and methods Venous blood was collected into six 4.5 mL VACUETTE® 9NC coagulation sodium citrate 3.8% tubes (Greiner Bio-One International GmbH, Kremsmünster, Austria) from 49 intensive care unit (ICU) patients on dual anti-platelet therapy and immediately hand carried to the central laboratory. Blood samples were divided into 2 Groups: Group 1 samples (N = 49) underwent PTS (4 m/s) transport from the central laboratory to the distant laboratory and back to the central laboratory, whereas Group 2 samples (N = 49) were excluded from PTS forces. In both groups, LTA and WBA stimulated with collagen, adenosine-5’-diphosphate (ADP), arachidonic acid (AA) and thrombin-receptor-activated-peptide 6 (TRAP-6) as well as platelet count, PT, APTT, and fibrinogen were performed. Results No statistically significant differences were observed between blood samples with (Group 1) and without (Group 2) PTS transport (P values from 0.064 – 0.968). The AA-induced LTA (bias: 68.57%) exceeded the bias acceptance limit of ≤ 25%. Conclusions Blood sample transportation with computer controlled PTS in our hospital had no statistically significant effects on platelet aggregation determined in patients with anti-platelet therapy. Although AA induced LTA showed a significant bias, the diagnostic accuracy was not influenced. PMID:28392742

  20. White blood cell and platelet count as adjuncts to standard clinical evaluation for risk assessment in patients at low probability of acute aortic syndrome.

    Science.gov (United States)

    Morello, Fulvio; Cavalot, Giulia; Giachino, Francesca; Tizzani, Maria; Nazerian, Peiman; Carbone, Federica; Pivetta, Emanuele; Mengozzi, Giulio; Moiraghi, Corrado; Lupia, Enrico

    2017-08-01

    Pre-test probability assessment is key in the approach to suspected acute aortic syndromes (AASs). However, most patients with AAS-compatible symptoms are classified at low probability, warranting further evaluation for decision on aortic imaging. White blood cell count, platelet count and fibrinogen explore pathophysiological pathways mobilized in AASs and are routinely assayed in the workup of AASs. However, the diagnostic performance of these variables for AASs, alone and as a bundle, is unknown. We tested the hypothesis that white blood cell count, platelet count and/or fibrinogen at presentation may be applied as additional tools to standard clinical evaluation for pre-test risk assessment in patients at low probability of AAS. This was a retrospective observational study conducted on consecutive patients managed in our Emergency Department from 2009 to 2014 for suspected AAS. White blood cell count, platelet count and fibrinogen were assayed during evaluation in the Emergency Department. The final diagnosis was obtained by computed tomography angiography. The pre-test probability of AAS was defined according to guidelines. Of 1210 patients with suspected AAS, 1006 (83.1%) were classified at low probability, and 271 (22.4%) were diagnosed with AAS. Within patients at low probability, presence of at least one alteration among white blood cell count >9*10 3 /µl, platelet count probability, white blood cell count >9*10 3 /µl and platelet count probability, the estimated risk of AAS based on the number of alterations amongst white blood cell count >9*10 3 /µl and platelet count probability to fine-tune risk assessment of AAS.

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

    Science.gov (United States)

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

    2018-01-01

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

  2. Correlations of folic acid, vitamin B12, homocysteine, and thrombopoietin to platelet count in HCV infection

    Directory of Open Access Journals (Sweden)

    Somayh S. Eissa

    2012-01-01

    Conclusion This study concluded that TCP in HCV-related chronic liver diseases is multifactorial and decreased FA is involved in its pathogenesis as an independent risk factor. Increased Hcy may cause TCP through platelet activation and endothelial dysfunction.

  3. 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

  4. 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.

  5. Prognostic significance of platelet count changes during hospitalization for community-acquired pneumonia.

    Science.gov (United States)

    Gorelik, Oleg; Izhakian, Shimon; Barchel, Dana; Almoznino-Sarafian, Dorit; Tzur, Irma; Swarka, Muhareb; Beberashvili, Ilia; Feldman, Leonid; Cohen, Natan; Shteinshnaider, Miriam

    2017-06-01

    The prognostic significance of platelet count (PC) changes during hospitalization for community-acquired pneumonia (CAP) has not been investigated. For 976 adults, clinical data during hospitalization for CAP and all-cause mortality following discharge were compared according to ΔPC (PC on discharge minus PC on admission): groups A (declining PC, ΔPC 50 × 10 9 /l), and according to the presence of thrombocytopenia, normal PC, and thrombocytosis on admission/discharge. Groups A, B, and C comprised 7.9%, 46.5%, and 45.6% of patients, respectively. On hospital admission/discharge, thrombocytopenia, normal PC, and thrombocytosis were observed in 12.8%/6.4%, 84.1%/84.4%, and 3.1%/9.2% of patients, respectively. The respective 90-day, 3-year, and total (median follow-up of 54 months) mortality rates were significantly higher: in group A (40.3%, 63.6%, and 72.7%), compared to groups B (12.3%, 31.5%, and 39.0%) and C (4.9%, 17.3%, and 25.4%), p < 0.001; and in patients with thrombocytopenia at discharge (27.4%, 48.4%, and 51.6%), compared to those with normal PC (10.2%, 26.9%, and 35.4%) and thrombocytosis (8.9%, 17.8%, and 24.4%) at discharge (p < 0.001). Mortality rates were comparable among groups with thrombocytopenia, normal PC, and thrombocytosis at admission (p = 0.6). In the entire sample, each 100 × 10 9 /l increment of ΔPC strongly predicted lower mortality (p < 0.001, relative risk 0.73, 95% confidence interval 0.64-0.83). In conclusion, PC changes are common among CAP inpatients. Rising PC throughout hospitalization is a powerful predictor of better survival, while declining PC predicts poor outcome. Evaluation of PC changes during hospitalization for CAP may provide useful prognostic information.

  6. Pseudothrombocytopenia or platelet clumping as a possible cause of low platelet count in patients with viral infection: a case series from single institution focusing on hepatitis A virus infection.

    Science.gov (United States)

    Choe, W-H; Cho, Y-U; Chae, J-D; Kim, S-H

    2013-02-01

    Pseudothrombocytopenia (PTCP) is the phenomenon of ethylenediaminetetraacetic acid anticoagulant-activated platelet clumping, which results in artificially low platelet counts. Other investigators have reported a few cases of PTCP associated with viral infections. The objective of this study was to demonstrate the association of viral infection with PTCP. Medical records of patients with thrombocytopenia who were tested for peripheral blood smear examination between March 2009 and February 2011 were reviewed for platelet clumping and viral infection. Thrombocytopenic patients with viral infection had a higher frequency of platelet clumping than those with other diseases, which was statistically significant (13.8% vs. 6.5%, respectively: P = 0.003). Among the 18 cases where PTCP or platelet clumping was related to viral infection, hepatitis A virus infection (72.2%) was most common, followed by cytomegalovirus (11.1%) and influenza A H1N1 infections (5.6%). A third (33.3%) of the patients had platelet counts viral infection, particularly if the platelet count is unexpectedly low, because failure to recognize PTCP may lead to unnecessary diagnostic tests and patient mismanagement. © 2012 Blackwell Publishing Ltd.

  7. Effect of prewarming EDTA blood samples to 37°C on platelet count measured by Sysmex XT-2000iV in dogs, cats, and horses.

    Science.gov (United States)

    Williams, Tim L; Archer, Joy

    2016-09-01

    Pseudothrombocytopenia secondary to platelet clumping is a common cause of preanalytic error for platelet counts in dogs, cats, and horses. In human beings, it is suggested that prewarming blood samples to 37°C prior to hematology analysis will reduce platelet clumping. The purpose of the study was to evaluate the effect of prewarming EDTA blood samples to 37°C on measured platelet counts and other hematologic variables. The EDTA blood samples from dogs, cats and horses submitted to the clinical pathology laboratory at the University of Cambridge were included. Complete blood cell counts performed using a Sysmex XT-2000iV hematology analyzer were done on samples at room temperature (approximately 22°C) and following warming of the samples to 37°C in a water bath. The Wilcoxon signed rank test was used to compare hematologic variables, including platelet count, before and after sample warming to 37°C. Data are presented as median (25(th) , 75(th) percentile) increase. Blood samples from 39 dogs, 19 cats, and 10 horses were included. Sample warming to 37°C resulted in a statistically significant increase in platelet counts in dogs (11 [-2, 30] ×10(9) /L), cats (36 [14, 84] ×10(9) /L), and horses (42 [31, 79] ×10(9) /L). Sample warming did not significantly affect other hematologic variables. Prewarming EDTA blood samples to 37°C prior to hematologic analysis increased platelet counts overall in canine, feline, and equine blood, but did not abrogate platelet clumping and pseudothrombocytopenia fully in some cases. Furthermore, true pseudothrombocytopenia was not confirmed in these animals. © 2016 American Society for Veterinary Clinical Pathology.

  8. Antithrombin activity, platelet count, hemoglobin concentration and hematocrit value determined immediately before vaginal delivery among healthy women.

    Science.gov (United States)

    Morikawa, Mamoru; Yamada, Takashi; Yamada, Takahiro; Koyama, Takahiro; Akaishi, Rina; Ishikawa, Satoshi; Takeda, Masamitsu; Nishida, Ryutaro; Araki, Naoto; Minakami, Hisanori

    2012-08-01

    To determine the normal reference values for antithrombin (AT) activity, platelet count (Plt), hemoglobin concentration (Hb), and hematocrit value (Ht) immediately before vaginal delivery among healthy pregnant women with singleton pregnancies and to determine association of these blood parameters with fetal growth. A complete blood count was performed and the AT activity was examined in 300 consecutive women admitted to hospital at > or = gestational week 36 for labor pains and/or the rupture of fetal membranes. All the women were normotensive and had singleton pregnancies, and none of the women had proteinuria, a weekly weight gain > or = 0.5 kg, or other specific complications upon admission. All the women attempted a vaginal delivery. The medians (5th-95th percentile) were 90% (71-110%) for AT activity, 234x10(9)/L (150-337x10(9)/L) for Plt, 11.0 g/dL (9.5-12.8 g/dL) for Hb, and 34.0% (30.4-38.6%) for Ht. Women with an Hb value of > or = the median (11.0 g/dL) gave birth to significantly smaller infants than their counterparts. A considerable number of healthy women exhibit a reduced AT activity and/or platelet count immediately before delivery. Hemoconcentration evidenced by a raised Hb value adversely effects on infant growth. Our data may be helpful when considering the normal ranges of these blood parameters for healthy parturient women.

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

    Science.gov (United States)

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

    2015-01-01

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

  10. 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.

    Science.gov (United States)

    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

  11. The effect of the perfluorocarbon emulsion Oxycyte on platelet count and function in the treatment of decompression sickness in a swine model.

    Science.gov (United States)

    Cronin, William A; Senese, Angela L; Arnaud, Francoise G; Regis, David P; Auker, Charles R; Mahon, Richard T

    2016-09-01

    Decompression from elevated ambient pressure is associated with platelet activation and decreased platelet counts. Standard treatment for decompression sickness (DCS) is hyperbaric oxygen therapy. Intravenous perfluorocarbon (PFC) emulsion is a nonrecompressive therapy being examined that improves mortality in animal models of DCS. However, PFC emulsions are associated with a decreased platelet count. We used a swine model of DCS to study the effect of PFC therapy on platelet count, function, and hemostasis. Castrated male swine (n = 50) were fitted with a vascular port, recovered, randomized, and compressed to 180 feet of sea water (fsw) for 31 min followed by decompression at 30 fsw/min. Animals were observed for DCS, administered 100% oxygen, and treated with either emulsified PFC Oxycyte (DCS-PFC) or isotonic saline (DCS-NS). Controls underwent the same procedures, but were not compressed (Sham-PFC and Sham-NS). Measurements of platelet count, thromboelastometry, and coagulation were obtained 1 h before compression and 1, 24, 48, 96, 168 and 192 h after treatment. No significant changes in normalized platelet counts were observed. Prothrombin time was elevated in DCS-PFC from 48 to 192 h compared with DCS-NS, and from 96 to 192 h compared with Sham-PFC. Normalized activated partial thromboplastin time was also elevated in DCS-PFC from 168 to 192 h compared with Sham-PFC. No bleeding events were noted. DCS treated with PFC (Oxycyte) does not impact platelet numbers, whole blood clotting by thromboelastometry, or clinical bleeding. Late changes in prothrombin time and activated partial thromboplastin time associated with PFC use in both DCS therapy and controls warrant further investigation.

  12. The Prognostic Value of Platelet Count in Patients With Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Pang, Qing; Qu, Kai; Zhang, Jing-Yao; Song, Si-Dong; Liu, Su-Shun; Tai, Ming-Hui; Liu, Hao-Chen; Liu, Chang

    2015-09-01

    Thrombocytopenia has been acknowledged to be a crucial risk factor for cirrhosis formation and hepatocarcinogenesis in chronic liver diseases. However, to date, the association between platelet count (PLT) and the prognosis of hepatocellular carcinoma (HCC) remains inconsistent and controversial. The aim of the present study was to determine whether PLT could be used as a useful predictor of survival in patients with HCC. We performed systematic review in online databases, including PubMed, EmBase, and Web of Science, from inception until 2014. Studies were included if a statistical relationship was investigated between PLT and survival for HCC, and hazard ratio (HR) and 95% confidence intervals (CIs) for overall survival (OS) or recurrence-free survival (RFS) were provided. The quality of each included study was assessed by Newcastle-Ottawa scale score. To synthesize these studies, a random-effects model or a fixed-effects model was applied as appropriate. Then, we calculated heterogeneity, performed sensitivity analysis, tested publication bias, and did subgrouped and meta-regression analysis. Finally, we identified 33 eligible articles (published from 1998 to 2014) involved 5545 patients by retrieval. A low level of preoperative PLT was found to be significantly associated with a poor survival of HCC. Irrespective of the therapy used, the pooled HRs for OS and RFS were 1.41 (95% CI, 1.14-1.75) and 1.44 (95% CI, 1.13-1.83), respectively. Specifically, in patients who underwent liver resection, the pooled HRs for OS and RFS were 1.67 (95% CI, 1.22-2.27) and 1.44 (95% CI, 1.04-1.99), respectively. Furthermore, patients with preoperative thrombocytopenia (PLT limitations of this meat-analysis were nonuniform cut-off values of PLT, high between-study heterogeneities, potential confounders, and a bias of publication year. A low preoperative PLT level results in an unfavorable outcome in HCC. PLT is a simple, inexpensive, and useful predictor of survival in patients

  13. 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

  14. Dual effects of adenovirus-mediated thrombopoietin gene transfer on hepatic oval cell proliferation and platelet counts

    International Nuclear Information System (INIS)

    Ichiba, Miho; Shimomura, Takashi; Murai, Rie; Hashiguchi, Koichi; Saeki, Toshiya; Yoshida, Yoko; Kanbe, Takamasa; Tanabe, Naotada; Tsuchiya, Hiroyuki; Miura, Norimasa; Tajima, Fumihito; Kurimasa, Akihiro; Hamada, Hirofumi; Shiota, Goshi

    2005-01-01

    Thrombopoietin (TPO) is the growth factor for megakaryocytes and platelets, however, it also acts as a potent regulator of stem cell proliferation. To examine the significance of TPO expression in proliferation of hepatic oval cells, the effect of adenovirus-mediated TPO gene transfer into livers of the Solt-Farber model, which mimics the condition where liver regeneration is impaired, was examined. Hepatic TPO mRNA peaked its expression at 2 days after gene transduction and then gradually decreased. The peripheral platelet number began to increase at 4 days (P < 0.05) and reached its plateau at 9 days (P < 0.01). Oval cells expressed c-Mpl, a receptor for TPO as well as immature hematopoietic and hepatocytic surface markers such as CD34 and AFP. The proliferating cell nuclear antigen-positive oval cells in rats into which adenovirus-TPO gene was transferred at 7 and 9 days were significantly greater than those in adenovirus-LacZ gene transferred (P < 0.05, each), and the total numbers of oval cells in the adenovirus-TPO gene transferred at 9 and 13 days were also significantly greater than those in adenovirus-LacZ gene transferred (P < 0.05, each). Expression of SCF protein was increased at 4, 7, and 9 days by TPO gene administration and that of c-Kit was increased at 4 and 7 days. These data suggest that adenovirus-mediated TPO gene transfer stimulated oval cell proliferation in liver as well as increasing peripheral platelet counts, emphasizing the significance of the TPO/c-Mpl system in proliferation of hepatic oval cells

  15. Plasma centrifugation does not influence thrombin-antithrombin and plasmin-antiplasmin levels but determines platelet microparticles count.

    Science.gov (United States)

    Stępień, Ewa; Gruszczyński, Krzysztof; Kapusta, Przemysław; Kowalik, Artur; Wybrańska, Iwona

    2015-01-01

    Centrifugation is an essential step for plasma preparation to remove residual elements in plasma, especially platelets and platelet-derived microparticles (PMPs). Our working hypothesis was that centrifugation as a preanalytical step may influence some coagulation parameters. Healthy young men were recruited (N=17). For centrifugation, two protocols were applied: (A) the first centrifugation at 2500xg for 15 min and (B) at 2500xg for 20 min at room temperature with a light brake. In protocol (A), the second centrifugation was carried out at 2500xg for 15 min, whereas in protocol (B), the second centrifugation involved a 10 min spin at 13,000 x g. Thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes concentrations were determined by enzyme-linked immunosorbent assays. PMPs were stained with CD41 antibody and annexin V, and analyzed by flow cytometry method. Procoagulant activity was assayed by the Calibrated Automated Thrombogram method as a slope of thrombin formation (CAT velocity). Median TAT and PAP concentrations did not differ between the centrifugation protocols. The high speed centrifugation reduced the median (IQR) PMP count in plasma from 1291 (841-1975) to 573 (391-1010) PMP/µL (P=0.001), and CAT velocity from 2.01 (1.31-2.88) to 0.97 (0.82-1.73) nM/min (P=0.049). Spearman's rank correlation analysis showed correlation between TAT and PMPs in the protocol A plasma which was (rho=0.52, PCentrifugation protocols do not influence the markers of plasminogen (PAP) and thrombin (TAT) generation but they do affect the PMP count and procoagulant activity.

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

    Science.gov (United States)

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

    2014-10-01

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

  17. Hepatic Rupture Caused by Hemolysis, Elevated Liver Enzyme, and Low Platelet Count Syndrome: A Case Report with Computed Tomographic and Conventional Angiographic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheong Bok; Ahn, Jae Hong; Choi, Soo Jung; Lee, Jong Hyeog; Park, Man Soo; Jung, Seung Mun; Ryu, Dae Sik [Dept. of Radiology, Asan Foundation, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung (Korea, Republic of)

    2013-03-15

    The authors recently obtained successful clinical outcome after embolization of the hepatic artery and right inferior phrenic artery in a pregnant patient with hemolysis, elevated liver enzyme, and low platelet count (HELLP) syndrome causing hepatic rupture. We report the computed tomographic and conventional angiographic findings in a case of HELLP syndrome, resulting in hepatic infarction and rupture with active bleeding.

  18. Bone marrow vascular endothelial growth factor level per platelet count might be a significant predictor for the treatment outcomes of patients with diffuse large B-cell lymphomas.

    Science.gov (United States)

    Kim, Jung Sun; Gang, Ga Won; Lee, Se Ryun; Sung, Hwa Jung; Park, Young; Kim, Dae Sik; Choi, Chul Won; Kim, Byung Soo

    2015-10-01

    Developing a parameter to predict bone marrow invasion by non-Hodgkin's lymphoma is an important unmet medical need for treatment decisions. This study aimed to confirm the validity of the hypothesis that bone marrow plasma vascular endothelial growth factor level might be correlated with the risk of bone marrow involvement and the prognosis of patients with diffuse large B-cell non-Hodgkin's lymphoma. Forty-nine diffuse large B-cell lymphoma patients treated with rituximab, cyclophosphamide, daunorubicin, vincristine and prednisolone regimen were enrolled. Vascular endothelial growth factor level was measured with enzyme-linked immunosorbent assay. The validity of bone marrow plasma vascular endothelial growth factor level and bone marrow vascular endothelial growth factor level per platelet count for predicting treatment response and survival after initial rituximab, cyclophosphamide, daunorubicin, vincristine and prednisolone combined chemotherapy was assessed. Bone marrow plasma vascular endothelial growth factor level per platelet count was significantly associated with old age (≥ 65 years), poor performance score (≥ 2), high International prognosis index (≥ 3) and bone marrow invasion. The patients with high bone marrow plasma vascular endothelial growth factor level per platelet count (≥ 3.01) showed a significantly lower complete response rate than the others. On Kaplan-Meier survival curves, the patients with high bone marrow plasma vascular endothelial growth factor levels (≥ 655 pg/ml) or high bone marrow plasma vascular endothelial growth factor level per platelet count (≥ 3.01) demonstrated a significantly shorter overall survival and progression-free survival than the others. In the patients without bone marrow involvement, bone marrow plasma vascular endothelial growth factor level per platelet count had a significant relationship with overall survival and progression-free survival. Multivariate analysis revealed that the patients without

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

    Directory of Open Access Journals (Sweden)

    Sang Mi Kim

    2015-12-01

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

  20. Effect of number of cigarettes smoked per day on red blood cell, lecocyte and platelet count in adult Indian male smokers – A case control study

    Directory of Open Access Journals (Sweden)

    Bharati Anil Sherke

    2016-02-01

    Full Text Available The effects of cigarette smoking are fatal. Present study was done to compare cell counts of blood in males smoking different number of cigarettes per day and non smokers of Hyderabad city. 150 consenting subjects of which 30 controls (non-smokers and 120 cases (smokers were studied. Smokers were divided into four groups based on number of cigarettes smoked per day. Blood samples processed using Hematology analyser (ABX Micros60®, HORIBA, Kyoto, Japan. The smokers had significantly different red blood cell counts (p<0.0001, white blood cells counts (p<0.0001 including neutrophils, lymphocytes, monocytes and eosinophils. This effect was significant irrespective of the number of cigarettes. There was no significant change in the percentage of basophils and platelet counts. Conclusion: Our findings showed that cigarette smoking has a significant effect on hematological cell counts and these counts changed significantly with increasing number of cigarettes smoked per day.

  1. Pretreatment combination of platelet counts and neutrophil–lymphocyte ratio predicts survival of nasopharyngeal cancer patients receiving intensity-modulated radiotherapy

    Directory of Open Access Journals (Sweden)

    Lin YH

    2017-05-01

    Full Text Available Yu-Hsuan Lin,1 Kuo-Ping Chang,2 Yaoh-Shiang Lin,2,3 Ting-Shou Chang2–4 1Department of Otolaryngology, Head and Neck Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 2Department of Otolaryngology, Head and Neck Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, 3Department of Otolaryngology, Head and Neck Surgery, National Defense Medical Center, Taipei, 4Institute of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China Background: Increased cancer-related inflammation has been associated with unfavorable clinical outcomes. The combination of platelet count and neutrophil–lymphocyte ratio (COP-NLR has related outcomes in several cancers, except for nasopharyngeal carcinoma (NPC. This study evaluated the prognostic value of COP-NLR in predicting outcome in NPC patients treated with intensity-modulated radiotherapy (IMRT.Materials and methods: We analyzed the data collected from 232 NPC patients. Pretreatment total platelet counts, neutrophil–lymphocyte ratio (NLR, and COP-NLR score were evaluated as potential predictors. Optimal cutoff values for NLR and platelets were determined using receiver operating curve. Patients with both elevated NLR (>3 and platelet counts (>300×109/L were assigned a COP-NLR score of 2; those with one elevated or no elevated value were assigned a COP-NLR a score of 1 or 0. Cox proportional hazards model was used to test the association of these factors and relevant 3-year survivals.Results: Patients (COP-NLR scores 1 and 2=85; score 0=147 were followed up for 55.19 months. Univariate analysis showed no association between pretreatment NLR >2.23 and platelet counts >290.5×109/L and worse outcomes. Multivariate analysis revealed that those with COP-NLR scores of 0 had better 3-year disease-specific survival (P=0.02, overall survival (P=0.024, locoregional relapse-free survival (P=0.004, and distant

  2. [Changes and significance of peripheral blood platelet count in tumor shrinkage induced by a low dose of CTX in T739 mice].

    Science.gov (United States)

    Li, Mo-lin; Jia, Yu-jie; Jiang, Miao-na; Shu, Xiao-hong; Li, Chuan-gang

    2008-06-01

    To establish a mouse model for BTT739 tumor-bearing mice cured by a low dose of cyclophosphamide (CTX). And then to observe the dynamic changes and significance of peripheral blood counts especially blood platelet count during tumor shrinkage induced by a low dose of CTX in T739 mice. Mouse bladder carcinoma tissues were inoculated subcutaneously into T739 mice. Seven days later, different doses of CTX or the same volume of NS were administered intraperitoneally to treat these tumor-bearing T739 mice. Tumor sizes were observed and recorded subsequently to find out the minimal dose of CTX that could cure most of these tumor-bearing mice. Then another 12 tumor-bearing mice were randomly divided into 15 mg/kg CTX treatment group and control group. Blood samples were obtained from orbital venous sinus on different times after CTX treatment. Complete blood counts were performed and the relationship between peripheral blood platelet counts and tumor shrinkage was analyzed. Within 2 weeks after CTX treatment, the speed of tumor shrinkage had a positive relationship with the dose of CTX used; but the survival rate of the tumor-bearing mice had a negative relationship with the dose of CTX used in 2 months after CTX treatment. 15 mg/kg CTX could cure most of the tumor bearing mice, while it had no remarkably inhibitive effects on peripheral blood cells. The perpherial platelet count increased to (1483.4+/-184.4)x10(9)/L in mice 6 h after CTX treatment. There was significant difference compared with that in mice of control group (1086.6+/-81.0)x10(9)/L (P0.05). CTX 15 mg/kg could cure most of bladder tumor-bearing T739 mice. The transient increase of the peripheral platelet count in 6 h after CTX treatment may relate to the antitumor effects of CTX.

  3. The value of daily platelet counts for predicting dengue shock syndrome: Results from a prospective observational study of 2301 Vietnamese children with dengue.

    Science.gov (United States)

    Lam, Phung Khanh; Ngoc, Tran Van; Thu Thuy, Truong Thi; Hong Van, Nguyen Thi; Nhu Thuy, Tran Thi; Hoai Tam, Dong Thi; Dung, Nguyen Minh; Hanh Tien, Nguyen Thi; Thanh Kieu, Nguyen Tan; Simmons, Cameron; Wills, Bridget; Wolbers, Marcel

    2017-04-01

    Dengue is the most important mosquito-borne viral infection to affect humans. Although it usually manifests as a self-limited febrile illness, complications may occur as the fever subsides. A systemic vascular leak syndrome that sometimes progresses to life-threatening hypovolaemic shock is the most serious complication seen in children, typically accompanied by haemoconcentration and thrombocytopenia. Robust evidence on risk factors, especially features present early in the illness course, for progression to dengue shock syndrome (DSS) is lacking. Moreover, the potential value of incorporating serial haematocrit and platelet measurements in prediction models has never been assessed. We analyzed data from a prospective observational study of Vietnamese children aged 5-15 years admitted with clinically suspected dengue to the Hospital for Tropical Diseases in Ho Chi Minh City between 2001 and 2009. The analysis population comprised all children with laboratory-confirmed dengue enrolled between days 1-4 of illness. Logistic regression was the main statistical model for all univariate and multivariable analyses. The prognostic value of daily haematocrit levels and platelet counts were assessed using graphs and separate regression models fitted on each day of illness. Among the 2301 children included in the analysis, 143 (6%) progressed to DSS. Significant baseline risk factors for DSS included a history of vomiting, higher temperature, a palpable liver, and a lower platelet count. Prediction models that included serial daily platelet counts demonstrated better ability to discriminate patients who developed DSS from others, than models based on enrolment information only. However inclusion of daily haematocrit values did not improve prediction of DSS. Daily monitoring of platelet counts is important to help identify patients at high risk of DSS. Development of dynamic prediction models that incorporate signs, symptoms, and daily laboratory measurements, could improve

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

    Science.gov (United States)

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

    2009-02-21

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

  5. [Sensitivity, specificity, and predictive values of the level of hemoglobin, hematocrit and platelet count as an activity index in ulcerative colitis].

    Science.gov (United States)

    Ibarra-Rodríguez, J Jesús; Santiago-Luna, Ernesto; Velázquez-Ramírez, Gabriela Abigail; López-Ramírez, María Karina Lizbeth; Fuentes-Orozco, Clotilde; Cortés-Flores, Ana Olivia; González-Ojeda, Alejandro

    2005-01-01

    Ulcerative colitis (UC) is a disease characterized by relapsing and remitting non-infectious inflammation of the colorectal mucosa. Its heterogeneity makes assessment of the disease's activity a prerequisite for a rational choice of therapy. We aimed to determine sensitivity, specificity, positive and negative predictive values of hemoglobin, hematocrit, and platelets to develop a simplified activity index of UC. Sixty patients with UC were included and submitted to measurements of hemoglobin, hematocrit, and platelets, as well as sigmoidoscopy and biopsy. Sensitivity and specificity, positive and negative predictive values were correlated with the reported degree of activity in the biopsy. Kruskal-Wallis test was used to determine differences between groups, and Pearson and Spearman rank tests were used to correlate each parameter with the degree of activity. A p value hemoglobin level was 51% and 100% for hematocrit, respectively, 51% and 100% for hematocrit, and 84% and 100% for platelet counts. Spearman's correlation for hemoglobin was r = -0.866 (p hematocrit r = -0.864 (p Hemoglobin and hematocrit are useful to catalog the degree of activity of UC when it is severe. Platelet count may be a marker of severity at any time, due to its high sensitivity and specificity as a diagnostic test.

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

    Directory of Open Access Journals (Sweden)

    Ji-Feng Feng

    2014-10-01

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

  7. 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.

  8. Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for preventing bleeding in people with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation.

    Science.gov (United States)

    Estcourt, Lise J; Stanworth, Simon J; Doree, Carolyn; Hopewell, Sally; Trivella, Marialena; Murphy, Michael F

    2015-11-18

    Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people who are thrombocytopenic due to bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate, especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.This is an update of a Cochrane review first published in 2004, and previously updated in 2012 that addressed four separate questions: prophylactic versus therapeutic-only platelet transfusion policy; prophylactic platelet transfusion threshold; prophylactic platelet transfusion dose; and platelet transfusions compared to alternative treatments. This review has now been split into four smaller reviews looking at these questions individually; this review compares prophylactic platelet transfusion thresholds. To determine whether different platelet transfusion thresholds for administration of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect the efficacy and safety of prophylactic platelet transfusions in preventing bleeding in people with haematological disorders undergoing myelosuppressive chemotherapy or haematopoietic stem cell transplantation (HSCT). We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library 2015, Issue 6, 23 July 2015), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 23 July 2015. We included RCTs involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people with haematological disorders (receiving myelosuppressive chemotherapy or undergoing HSCT) that compared different thresholds for administration of prophylactic platelet transfusions (low

  9. Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for preventing bleeding in people with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation

    Science.gov (United States)

    Estcourt, Lise J; Stanworth, Simon J; Doree, Carolyn; Hopewell, Sally; Trivella, Marialena; Murphy, Michael F

    2015-01-01

    Background Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people who are thrombocytopenic due to bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate, especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding. This is an update of a Cochrane review first published in 2004, and previously updated in 2012 that addressed four separate questions: prophylactic versus therapeutic-only platelet transfusion policy; prophylactic platelet transfusion threshold; prophylactic platelet transfusion dose; and platelet transfusions compared to alternative treatments. This review has now been split into four smaller reviews looking at these questions individually; this review compares prophylactic platelet transfusion thresholds. Objectives To determine whether different platelet transfusion thresholds for administration of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect the efficacy and safety of prophylactic platelet transfusions in preventing bleeding in people with haematological disorders undergoing myelosuppressive chemotherapy or haematopoietic stem cell transplantation (HSCT). Search methods We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library 2015, Issue 6, 23 July 2015), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 23 July 2015. Selection criteria We included RCTs involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people with haematological disorders (receiving myelosuppressive chemotherapy or undergoing HSCT) that compared different thresholds for

  10. Combination of recombinant factor VIIa and fibrinogen corrects clot formation in primary immune thrombocytopenia at very low platelet counts

    DEFF Research Database (Denmark)

    Larsen, Ole H; Stentoft, Jesper; Radia, Deepti

    2013-01-01

    Haemostatic treatment modalities alternative to platelet transfusion are desirable to control serious acute bleeds in primary immune thrombocytopenia (ITP). This study challenged the hypothesis that recombinant activated factor VII (rFVIIa) combined with fibrinogen concentrate may correct whole b...

  11. Lymphocyte counts and responses to PHA and PPD following radiation therapy for breast cancer in patients who develop recurrent disease and those who remain clinically disease-free

    International Nuclear Information System (INIS)

    Blomgren, H.; Wasserman, J.; Wallgren, A.; Baral, E.; Petrini, B.; Idestroem, K.

    1980-01-01

    Peripheral blood lymphocyte counts and stimulations by PHA and PPD in vitro were examined before and up to four years after local pre- or post-operative radiation therapy of 99 patients with breast cancer. The patient material was divided into those who remained clinically disease-free during a follow up period of 4.5-7 years and those who relapsed. Radiation therapy reduced the lymphocyte counts and PPD response to the same levels in both groups of patients; there were no essential differences in their recoveries, with the exception of a somewhat delayed recovery of the PPD-response in the patients who relapsed. PHA responses of the lymphocytes were not decreased following radiation therapy. The data indicate that these radiation induced changes of the peripheral lymphocyte population were similar both in patients who relapsed and those who remained symptom free. A group of 47 women with breast cancer that was treated by surgery only was examined similarly as a comparison. Patients from this group who developed local recurrences had higher lymphocyte counts than those who remained disease-free; patients who developed distant metastases had somewhat decreased PHA responses

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

    Directory of Open Access Journals (Sweden)

    Munirah Binti Mokhtar

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohammad Mizanur Rahman

    2017-02-01

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

  14. 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.

  15. Association between isolation of Staphylococcus aureus one week after calving and milk yield, somatic cell count, clinical mastitis, and culling through the remaining lactation.

    Science.gov (United States)

    Whist, Anne Cathrine; Osterås, Olav; Sølverød, Liv

    2009-02-01

    Cows with isolation of Staphylococcus aureus approximately 1 week after calving and milk yield, somatic cell count (SCC), clinical mastitis (CM), and culling risk through the remaining lactation were assessed in 178 Norwegian dairy herds. Mixed models with repeated measures were used to compare milk yield and SCC, and survival analyses were used to estimate the hazard ratio for CM and culling. On average, cows with an isolate of Staph. aureus had a significantly higher SCC than culture-negative cows. If no post-milking teat disinfection (PMTD) was used, the mean values of SCC were 42,000, 61,000, 68,000 and 77,000 cells/ml for cows with no Staph. aureus isolate, with Staph. aureus isolated in 1 quarter, in 2 quarters and more than 2 quarters respectively. If iodine PMTD was used, SCC means were 36,000; 63,000; 70,000 and 122,000, respectively. Primiparous cows testing positive for Staph. aureus had the same milk yield curve as culture-negative cows, except for those with Staph. aureus isolated in more than 2 quarters. They produced 229 kg less during a 305-d lactation. Multiparous cows with isolation of Staph. aureus in at least 1 quarter produced 94-161 kg less milk in 2nd and >3rd parity, respectively, and those with isolation in more than 2 quarters produced 303-390 kg less than multiparous culture-negative animals during a 305-d lactation. Compared with culture-negative cows, the hazard ratio for CM and culling in cows with isolation of Staph. aureus in at least 1 quarter was 2.0 (1.6-2.4) and 1.7 (1.5-1.9), respectively. There was a decrease in the SCC and in the CM risk in culture-negative cows where iodine PMTD had been used, indicating that iodine PMTD has a preventive effect on already healthy cows. For cows testing positive for Staph. aureus in more than 2 quarters at calving, iodine PMTD had a negative effect on the CM risk and on the SCC through the remaining lactation.

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

    Science.gov (United States)

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

    2017-06-01

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

  17. Platelet antibody in prolonged remission of childhood idiopathic thrombocytopenic purpura

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    Science.gov (United States)

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

    2018-03-29

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

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

    Directory of Open Access Journals (Sweden)

    Junhui Li

    2018-03-01

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

  20. Impact of initial platelet count on baseline angiographic finding and end-points in ST-elevation myocardial infarction referred for primary percutaneous coronary intervention.

    Science.gov (United States)

    Kaplan, Sahin; Kaplan, Safiye Tuba; Kiris, Abdulkadir; Gedikli, Omer

    2014-01-01

    The baseline platelet count (BPC) in patients with acute ST elevation myocardial infarction (STEMI) may reflect the baseline anjiografic finding and may also predic long-term outcomes after primary percutaneous coronary intervention (PPCI). Available data for the value of BPC in patients with STEMI treated with PPCI are still questionable. Therefore, we sought to determine the prognostic value of BPC for baseline angiographic finding and the impact of BPC on clinical outcomes of patients treating with PPCI. Blood sample for BPC was obtained on admission in 140 consecutive patients undergoing PPCI. Patients were divided 2 groups that group-1 (104 patients): TIMI flow-grade 0 and group-2 (36 patients): TIMI flow-grade 1-3. Follow-up was performed at 1-9 months. Baseline demographics were comparable, but, BPC was significantly higher in group-1 comparing 2 (293.7±59.8x10(9)/L vs. 237.7±50.9x10(9)/L, pmeasuring of a BPC on admission may also provide further practical and therapeutic profits.

  1. A Correlation of the Platelet Count with D-Dimer Levels as an Indicator for Component Therapy in Children with Dengue Hemorrhagic Fever.

    Science.gov (United States)

    Sridhar, Arthi; Sunil Kumar, B M; Rau, Aarathi; Rau, A T K

    2017-06-01

    Dengue Fever (DF) may evolve into two life threatening forms-Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). DHF is associated with increased vascular permeability and plasma leakage causing thrombocytopenia and loss of clotting factors into the third space and may result in bleeding initially due to thrombocytopenia and later due to disseminated intravascular coagulation (DIC), often as a terminal event. Prompt recognition and treatment of minor bleeds in DF children with incipient DIC with component therapy may be associated with improved survival while failure to do so is usually catastrophic. A sensitive marker for early DIC is the presence of D-dimer (DD) in the blood. To determine the correlation between the severity of thrombocytopenia and early DIC in children with DHF. The impact of additional factors like age and shock will also be evaluated. Case control prospective study of 60 DHF sero -positive children (1-15 years) with thrombocytopenia. After clinical evaluation they were divided into two equal groups based on the degree of thrombocytopenia (more than/less than 30,000/mm 3 ). PT/APTT and DD levels were estimated in all children of both groups and statistical correlation was done. There was no significant difference in the DD levels between the two groups. However, children in either group, presenting with clinical features of shock and thrombocytopenia had significantly higher DD levels. Empirical component therapy in children with DHF based purely on their low platelet counts may not be justified. However, in DHF children with thrombocytopenia and features of shock, aggressive component therapy may prevent subsequent bleeding and may be justified.

  2. 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

  3. Effect of the integrated approach of yoga therapy on platelet count and uric acid in pregnancy: A multicenter stratified randomized single-blind study

    Directory of Open Access Journals (Sweden)

    R Jayashree

    2013-01-01

    Conclusion: Antenatal integrated yoga from the twelfth week is safe and effective in promoting a healthy progression of platelets and uric acid in women with high-risk pregnancy, pointing to healthy hemodilution and better physiological adaptation.

  4. Average sperm count remains unchanged despite reduction in maternal smoking: results from a large cross-sectional study with annual investigations over 21 years.

    Science.gov (United States)

    Priskorn, L; Nordkap, L; Bang, A K; Krause, M; Holmboe, S A; Egeberg Palme, D L; Winge, S B; Mørup, N; Carlsen, E; Joensen, U N; Blomberg Jensen, M; Main, K M; Juul, A; Skakkebaek, N E; Jensen, T K; Jørgensen, N

    2018-06-01

    How are temporal trends in lifestyle factors, including exposure to maternal smoking in utero, associated to semen quality in young men from the general population? Exposure to maternal smoking was associated with lower sperm counts but no overall increase in sperm counts was observed during the study period despite a decrease in this exposure. Meta-analyses suggest a continuous decline in semen quality but few studies have investigated temporal trends in unselected populations recruited and analysed with the same protocol over a long period and none have studied simultaneous trends in lifestyle factors. Cross-sectional population-based study including ~300 participants per year (total number = 6386) between 1996 and 2016. The study is based on men from the Greater Copenhagen area, Denmark, with a median age of 19 years, and unselected with regard to fertility status and semen quality. The men delivered a semen sample, had a blood sample drawn and a physical examination performed and answered a comprehensive questionnaire, including information on lifestyle and the mother's pregnancy. Temporal trends in semen quality and lifestyle were illustrated graphically, and trends in semen parameters and the impact of prenatal and current lifestyle factors were explored in multiple regression analyses. Throughout the study period, 35% of the men had low semen quality. Overall, there were no persistent temporal trends in semen quality, testicular volume or levels of follicle-stimulating hormone over the 21 years studied. The men's alcohol intake was lowest between 2011 and 2016, whereas BMI, use of medication and smoking showed no clear temporal trends. Parental age increased, and exposure in utero to maternal smoking declined from 40% among men investigated in 1996-2000 to 18% among men investigated in 2011-2016. Exposure to maternal smoking was associated with lower sperm counts but no overall increase in sperm counts was observed despite the decrease in this exposure

  5. 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.

  6. 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

  7. The clinical significance of changes of platelet count in children with bronchial pneumonia%支气管肺炎患儿血小板计数变化及临床意义

    Institute of Scientific and Technical Information of China (English)

    杨奕辉; 朱瑞芬

    2016-01-01

    目的:探讨支气管肺炎患儿血小板计数变化及在病情中的临床意义。方法对收治的320例支气管肺炎患儿进行回顾性分析,根据入院后的血小板计数,分为血小板增多组(>400×109/L)和血小板正常组(100~400×109/L),对两组患儿的年龄、性别、呼吸困难发生率、治疗时间、白细胞计数、血红蛋白、CRP等临床资料进行统计分析。结果320例患儿中血小板增多62例,血小板正常258例。与血小板正常组比较,血小板增多组患儿年龄更小(年龄<1岁为主占46.77%,前者1~3岁为主占40.70%,Z =2.08)、治疗时间延长[(7.37±1.90)d,前者为(6.79±1.51)d,t =2.56]、血白细胞计数增高[(10.71±3.91)×109/L,前者为(9.37±3.56)×109/L,t =2.61],以上差异均有统计学意义(均 P <0.05);呼吸困难发生率更高(占74.19%,前者占52.33%,χ2=9.73)、血红蛋白降低[(104±14)g/L,前者为(111±13)g/L,t =3.34]、CRP 增高[(24.42±12.73)mg/L,前者为(18.31±8.86)mg/L,t =3.58],以上差异均有统计学意义(均 P <0.01)。两组在性别上差异无统计学意义。结论支气管肺炎患儿发生血小板增多者年龄更小,病情更重。观察血小板计数变化有助于患儿病情的正确判断及有效治疗。%Objective To explore the changes of platelet count in children with bronchial pneumonia and its clinical significance in the disease.Methods 320 cases of bronchial pneumonia were retrospectively analyzed after hospitalization.According to the number of platelet count,the cases were divided into increased platelet count group (>400 ×109 /L)and normal platelet group(100 -400 ×109 /L),and the clinical data of two groups were statistically analyzed,such as age,gender,dyspnea,treatment,white blood cell count,hemoglobin,C -reactive protein

  8. 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.

  9. 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.

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

    Science.gov (United States)

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

    2009-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

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

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

    Science.gov (United States)

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

    2000-10-01

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

  13. 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....

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

    Directory of Open Access Journals (Sweden)

    Hua Zhang

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

  15. 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...

  16. Extended Storage of Pathogen Reduced Platelet Concentrates (PRECON)

    Science.gov (United States)

    2015-10-01

    PROCEDURES Protocol, Cold Apheresis Platelets in Isoplate (CAPI) 09/14/15 5 W81XWH-13-2-0089 Page 23 Screening An abbreviated version of blood donor ...2 mL sample for a complete blood count (CBC) to obtain the hematocrit and platelet count. Only criteria aimed at assuring donor safety will apply...platelets will be infused back into the subject. During each platelet infusion, the subject will be carefully monitored for adverse reactions ; i.e

  17. 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

  18. Advances and controversies in neonatal ICU platelet transfusion practice.

    Science.gov (United States)

    Christensen, Robert D

    2008-01-01

    Some of the platelet transfusions currently given to NICU patients are unnecessary and convey no benefits. Although ordered with good intentions, unnecessary platelet transfusions carry known and unknown risks. Identifying and eliminating any unnecessary platelet transfusions in NICUs would be a step toward better care, lower costs, and more careful preservation of blood component resources. A renewed interest in platelet transfusion studies is needed, if essential data is to be gathered to improve NICU platelet transfusion practice. Retrospective studies can be of value: for instance, seeking associations between bleeding events and platelet counts can suggest the possibility of cause and effect relationships. Such studies might identify approximate platelet count levels that convey high hemorrhagic risk and might help focus future prospective trials. Prospective indirect studies also can be of value, for instance, measuring the template bleeding time and the PFA-100 closure time as a function of platelet count and perhaps as a function of circulating platelet mass, and would provide new information with relevance to platelet transfusion benefits. Such studies might give a better awareness of how low the platelet count can fall before platelet plug formation is impaired. It seems inescapable, however, that new, multicentered, randomized, prospective studies are needed, where NICU patients are assigned different platelet transfusion triggers and then carefully tracked for bleeding events and long-term neurodevelopmental outcomes. Only that type of study is likely to generate the evidence base needed for widespread implementation of improvements in NICU platelet transfusion practice.

  19. Platelet production, clearance and distribution in patients with idiopathic thrombocytopenic purpura

    International Nuclear Information System (INIS)

    Isaka, Yoshinari; Kambayashi, Junichi; Kimura, Kazufumi

    1990-01-01

    We have studied 8 normal subjects, and 12 patients with idiopathic thrombocytopenic purpura whose platelet counts ranged from 9x10 9 /L to 40x10 9 /L. Autologous platelets labeled with 111 In-tropolone were used for evaluation of mean platelet survival, platelet turnover, platelet sequestration sites, and platelet production (turnover) to clearance (sum of platelet uptake in the liver and the spleen) ratio. Platelet survival correlated directly with platelet counts. There was no significant correlation between the platelet sequestration pattern and platelet count, survival, or turnover. Sum of platelet uptake in the liver and the spleen showed a significant inverse correlation with platelet survival. No significant correlation was found between platelet turnover and platelet count. There was a significant correlation between the platelet production and clearance index when all subjects were analyzed. The distribution of platelet turnover showed considerable individual variation; eight of twelve patients showed platelet turnover less than mean minus 2SD of the control value, but others showed normal range. We conclude that although platelet destruction mechanism in RES shows a primary role of thrombocytopenia, impaired rate of effective thrombopoiesis may also contribute to disease severity in ITP. (author)

  20. 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

  1. Gene targeting implicates Cdc42 GTPase in GPVI and non-GPVI mediated platelet filopodia formation, secretion and aggregation.

    Directory of Open Access Journals (Sweden)

    Huzoor Akbar

    Full Text Available Cdc42 and Rac1, members of the Rho family of small GTPases, play critical roles in actin cytoskeleton regulation. We have shown previously that Rac1 is involved in regulation of platelet secretion and aggregation. However, the role of Cdc42 in platelet activation remains controversial. This study was undertaken to better understand the role of Cdc42 in platelet activation.We utilized the Mx-cre;Cdc42(lox/lox inducible mice with transient Cdc42 deletion to investigate the involvement of Cdc42 in platelet function. The Cdc42-deficient mice exhibited a significantly reduced platelet count than the matching Cdc42(+/+ mice. Platelets isolated from Cdc42(-/-, as compared to Cdc42(+/+, mice exhibited (a diminished phosphorylation of PAK1/2, an effector molecule of Cdc42, (b inhibition of filopodia formation on immobilized CRP or fibrinogen, (c inhibition of CRP- or thrombin-induced secretion of ATP and release of P-selectin, (d inhibition of CRP, collagen or thrombin induced platelet aggregation, and (e minimal phosphorylation of Akt upon stimulation with CRP or thrombin. The bleeding times were significantly prolonged in Cdc42(-/- mice compared with Cdc42(+/+ mice.Our data demonstrate that Cdc42 is required for platelet filopodia formation, secretion and aggregation and therefore plays a critical role in platelet mediated hemostasis and thrombosis.

  2. Therapeutic platelet reduction: Use in postsplenectomy thrombocytosis

    Directory of Open Access Journals (Sweden)

    Gita Negi

    2015-01-01

    Full Text Available Therapeutic platelet reduction is an effective modality for the reduction of platelet count in patients with treatment of extreme thrombocytosis resulting from a variety of primary and secondary causes of thrombocytosis, which may be associated with thrombotic or hemorrhagic complications of varying degrees. These cases when symptomatic fall into the ASFA Category II indication for therapeutic platelet apheresis procedure. Here, we report a case of postsplenectomy secondary thrombocytosis presenting with extremely high platelet counts and subsequent thrombosis in the shunt and successful treatment after therapeutic platelet reduction. The case is being presented to bring forth the fact that therapeutic platelet reduction is an easy procedure that gives quick and good results and also to bring to the attention of transfusion specialists an associated but as yet unreported procedural finding.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Maria José Dantas Coêlho

    2011-01-01

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

  5. Changes in platelet parameters in leukocytosis | Ozturk | Pan African ...

    African Journals Online (AJOL)

    Methods: white blood cell counts count and all platelet parameters were evaluated in 341 results of normal complete blood count (of which the white blood cell counts were within reference range, ... Results: there was a significant difference between these two groups in PLT counts and PCT values, being higher in Group 2.

  6. Reference intervals for platelet aggregation assessed by multiple electrode platelet aggregometry

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  7. Platelet Disorders: MedlinePlus Health Topic

    Science.gov (United States)

    ... Thromobocytopenia - drug-induced (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Platelet Disorders updates ... Willebrand disease Show More Show Less Related Health Topics Bleeding Disorders Blood Clots Blood Count Tests Blood ...

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

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

  10. 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

  11. Platelet aggregation following trauma

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  12. Platelet Donation

    Science.gov (United States)

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

  13. Prediction of early death among patients enrolled in phase I trials: development and validation of a new model based on platelet count and albumin.

    Science.gov (United States)

    Ploquin, A; Olmos, D; Lacombe, D; A'Hern, R; Duhamel, A; Twelves, C; Marsoni, S; Morales-Barrera, R; Soria, J-C; Verweij, J; Voest, E E; Schöffski, P; Schellens, J H; Kramar, A; Kristeleit, R S; Arkenau, H-T; Kaye, S B; Penel, N

    2012-09-25

    Selecting patients with 'sufficient life expectancy' for Phase I oncology trials remains challenging. The Royal Marsden Hospital Score (RMS) previously identified high-risk patients as those with ≥ 2 of the following: albumin upper limit of normal; >2 metastatic sites. This study developed an alternative prognostic model, and compared its performance with that of the RMS. The primary end point was the 90-day mortality rate. The new model was developed from the same database as RMS, but it used Chi-squared Automatic Interaction Detection (CHAID). The ROC characteristics of both methods were then validated in an independent database of 324 patients enrolled in European Organization on Research and Treatment of Cancer Phase I trials of cytotoxic agents between 2000 and 2009. The CHAID method identified high-risk patients as those with albumin model and RMS, respectively. The negative predictive values (NPV) were similar for the CHAID model and RMS. The CHAID model and RMS provided a similarly high level of NPV, but the CHAID model gave a better accuracy in the validation set. Both CHAID model and RMS may improve the screening process in phase I trials.

  14. 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

  15. 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)

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

    International Nuclear Information System (INIS)

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

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

  17. platelet counts and mean platelet volume amongst elderly

    African Journals Online (AJOL)

    Dr Ahmed

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

  18. Platelet Function Tests

    Science.gov (United States)

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

  19. 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. ...

  20. 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.

  1. Utility of the immature platelet fraction in pediatric immune thrombocytopenia: Differentiating from bone marrow failure and predicting bleeding risk.

    Science.gov (United States)

    McDonnell, Alicia; Bride, Karen L; Lim, Derick; Paessler, Michele; Witmer, Char M; Lambert, Michele P

    2018-02-01

    Differentiating childhood immune thrombocytopenia (ITP) from other cause of thrombocytopenia remains a diagnosis of exclusion. Additionally factors that predict bleeding risk for those patients with ITP are currently not well understood. Previous small studies have suggested that immature platelet fraction (IPF) may differentiate ITP from other causes of thrombocytopenia and in combination with other factors may predict bleeding risk. We performed a retrospective chart review of thrombocytopenic patients with an IPF measured between November 1, 2013 and July 1, 2015. Patients were between 2 months and 21 years of age with a platelet count bleeding symptoms. A bleeding severity score was retrospectively assigned. Two hundred seventy two patients met inclusion criteria, 97 with ITP, 11 with bone marrow failure (BMF), 126 with malignancy, and 38 with other causes of thrombocytopenia. An IPF > 5.2% differentiated ITP from BMF with 93% sensitivity and 91% specificity. Absolute immature platelet number (AIPN) was significantly lower in ITP patients with severe to life-threatening hemorrhage than those without, despite similar platelet counts. On multivariate analysis, an IPF bleeding risk at platelet counts <10 × 10 9 /l in patients with ITP. IPF measurement alone has utility in both the diagnosis of ITP and identifying patients at increased risk of hemorrhage. Further study is required to understand the pathophysiological differences of ITP patients with lower IPF/AIPN. © 2017 Wiley Periodicals, Inc.

  2. Immature platelet fraction in bacterial sepsis severity assessment

    Science.gov (United States)

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

    2018-03-01

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

  3. Platelet Donation

    Science.gov (United States)

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

  4. 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.

  5. Counting probe

    International Nuclear Information System (INIS)

    Matsumoto, Haruya; Kaya, Nobuyuki; Yuasa, Kazuhiro; Hayashi, Tomoaki

    1976-01-01

    Electron counting method has been devised and experimented for the purpose of measuring electron temperature and density, the most fundamental quantities to represent plasma conditions. Electron counting is a method to count the electrons in plasma directly by equipping a probe with the secondary electron multiplier. It has three advantages of adjustable sensitivity, high sensitivity of the secondary electron multiplier, and directional property. Sensitivity adjustment is performed by changing the size of collecting hole (pin hole) on the incident front of the multiplier. The probe is usable as a direct reading thermometer of electron temperature because it requires to collect very small amount of electrons, thus it doesn't disturb the surrounding plasma, and the narrow sweep width of the probe voltage is enough. Therefore it can measure anisotropy more sensitively than a Langmuir probe, and it can be used for very low density plasma. Though many problems remain on anisotropy, computer simulation has been carried out. Also it is planned to provide a Helmholtz coil in the vacuum chamber to eliminate the effect of earth magnetic field. In practical experiments, the measurement with a Langmuir probe and an emission probe mounted to the movable structure, the comparison with the results obtained in reverse magnetic field by using a Helmholtz coil, and the measurement of ionic sound wave are scheduled. (Wakatsuki, Y.)

  6. Big data modeling to predict platelet usage and minimize wastage in a tertiary care system.

    Science.gov (United States)

    Guan, Leying; Tian, Xiaoying; Gombar, Saurabh; Zemek, Allison J; Krishnan, Gomathi; Scott, Robert; Narasimhan, Balasubramanian; Tibshirani, Robert J; Pham, Tho D

    2017-10-24

    Maintaining a robust blood product supply is an essential requirement to guarantee optimal patient care in modern health care systems. However, daily blood product use is difficult to anticipate. Platelet products are the most variable in daily usage, have short shelf lives, and are also the most expensive to produce, test, and store. Due to the combination of absolute need, uncertain daily demand, and short shelf life, platelet products are frequently wasted due to expiration. Our aim is to build and validate a statistical model to forecast future platelet demand and thereby reduce wastage. We have investigated platelet usage patterns at our institution, and specifically interrogated the relationship between platelet usage and aggregated hospital-wide patient data over a recent consecutive 29-mo period. Using a convex statistical formulation, we have found that platelet usage is highly dependent on weekday/weekend pattern, number of patients with various abnormal complete blood count measurements, and location-specific hospital census data. We incorporated these relationships in a mathematical model to guide collection and ordering strategy. This model minimizes waste due to expiration while avoiding shortages; the number of remaining platelet units at the end of any day stays above 10 in our model during the same period. Compared with historical expiration rates during the same period, our model reduces the expiration rate from 10.5 to 3.2%. Extrapolating our results to the ∼2 million units of platelets transfused annually within the United States, if implemented successfully, our model can potentially save ∼80 million dollars in health care costs.

  7. 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).

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

    Directory of Open Access Journals (Sweden)

    Singh Ravindra

    2009-01-01

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

  9. RBC count

    Science.gov (United States)

    ... by kidney disease) RBC destruction ( hemolysis ) due to transfusion, blood vessel injury, or other cause Leukemia Malnutrition Bone ... slight risk any time the skin is broken) Alternative Names Erythrocyte count; Red blood cell count; Anemia - RBC count Images Blood test ...

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

    Directory of Open Access Journals (Sweden)

    Tulika Chandra

    2014-08-01

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

  11. Platelet cold agglutinins and thrombocytopenia: A diagnostic dilemma in the intensive care unit

    Directory of Open Access Journals (Sweden)

    TV Bharath Kumar

    2014-01-01

    Full Text Available We report a case of pseudo-thrombocytopenia due to cold agglutinins against platelets. These cold agglutinins were the cause for diagnostic confusion and resulted in extensive workup and unnecessary therapeutic precautions. A thirty two year old female with Guillain-Barre syndrome was admitted in the ICU and serial work-up showed markedly low levels of platelets. The patient had no symptoms of bleeding and patient was investigated extensively for deciphering the etiology of low platelet count. In-vitro clumping of platelets was suspected and in-vitro studies showed marked clumping of platelets with ethylene-diamine-tetra-acetic acid, citrate and heparinized samples. The manual platelet count was found to be within normal limits. Thrombocytopenia as a result of platelet cold agglutinins is a rare cause of in-vitro low platelet counts. No clinical problems have been reported due to the same.

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

    Science.gov (United States)

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

    2015-10-01

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

  13. Congenital platelet function defects

    Science.gov (United States)

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

  14. Anestesia regional e trombocitopenia não pré-eclâmptica; hora de repensar o nível seguro de plaquetas Anestesia regional y trombocitopenia no preclámptica; es hora de pensar de nuevo sobre el nivel seguro de plaquetas Regional anesthesia and non-preeclamptic thrombocytopenia: time to re-think the safe platelet count

    Directory of Open Access Journals (Sweden)

    Motoshi Tanaka

    2009-04-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Apesar de a anestesia regional ser amplamente utilizada no controle da dor em obstetrícia, seu uso pode não ser apropriado nas pacientes com trombocitopenia por causa do risco de hematoma no neuroeixo. Não existem fortes evidências sugerindo número mínimo de plaquetas necessário para garantir a segurança na realização da anestesia regional. O objetivo deste estudo foi rever a segurança da anestesia regional em pacientes com trombocitopenia não pré-eclâmptica na instituição durante período de cinco anos. MÉTODO: Foi realizada revisão retrospectiva dos prontuários médicos de todas as pacientes obstétricas não pré-eclâmpticas cujo parto foi realizado na instituição entre abril de 2001 e março de 2006 e que apresentaram contagem de plaquetas JUSTIFICATIVA Y OBJETIVOS: A pesar de que la anestesia regional esté siendo muy utilizada en el control del dolor en obstetricia, su uso puede no ser muy apropiado en las pacientes con trombocitopenia, debido al riesgo de hematoma en el neuro eje. No existen fuertes evidencias que sugieran un número mínimo de plaquetas necesario para garantizar la seguridad en la realización de la anestesia regional. El objetivo de este estudio fue analizar la seguridad de la anestesia regional en pacientes con trombocitopenia no preeclámptica en la institución durante un período de cinco años. MÉTODO: Fue realizada revisión retrospectiva de las historias clínicas médicas de todas las pacientes obstétricas no preeclámpticas cuyo parto fue realizado en la institución entre abril de 2001 y marzo de 2006 y que presentaron BACKGROUND AND OBJECTIVES: Although regional anesthesia is widely used for pain control in obstetrics, it may not be appropriate for patients with thrombocytopenia due to the risk of neuraxial hematoma. There is no strong evidence to suggest the minimum platelet count that is necessary to ensure the safe practice of regional anesthesia. The

  15. The impact of evaluating platelet transfusion need by platelet mass index on reducing the unnecessary transfusions in newborns.

    Science.gov (United States)

    Kahvecioglu, Dilek; Erdeve, Omer; Alan, Serdar; Cakir, Ufuk; Yildiz, Duran; Atasay, Begum; Arsan, Saadet

    2014-11-01

    Almost 95% of the platelet transfusions (PTs) conducted in the neonatal intensive care unit (NICU) are prophylactic transfusions. Guidelines for prophylactic PTs are based on platelet counts, but not on platelet functions. Nowadays, in order to reduce unnecessary transfusions, utilizing platelet mass index (PMI) was investigated. The aim of study is to find out whether PTs performed in our NICU during last 2 years were in accordance with the current guideline and to evaluate whether the frequency of PTs should be reduced if PMI was considered. Forty-three infants who received 96 prophylactic PTs were enrolled in the study. The guideline utilized in our NICU advocate keeping the platelet count: (a) >100 000 in pre/post-operative, (b) >50 000 in unstable and (c) >20 000 in stable patients. According to PMI criteria, PT should be performed if PMI: (a) platelet functions into account may yield lower transfusion rate, lower costs and better conservation of blood bank resources.

  16. Platelet function in the postprandial period

    Directory of Open Access Journals (Sweden)

    Sinzinger Helmut

    2012-09-01

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

  17. 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.

  18. Platelet count/spleen diameter ratio: analysis of its capacity as a predictor of the existence of esophageal varices Índice contagem de plaquetas/diâmetro do baço: análise de sua capacidade como preditor da existência de varizes esofágicas

    Directory of Open Access Journals (Sweden)

    Ângelo Zambam de Mattos

    2010-09-01

    Full Text Available CONTEXT: Upper gastrointestinal bleeding associated to esophageal varices is the most dramatic complication of cirrhosis. It is recommended screening every cirrhotic for esophageal varices with endoscopy. OBJECTIVES: To evaluate the capacity of the platelet count/spleen diameter ratio in non-invasively predicting esophageal varices in a population of cirrhotics originated in an independent center from the one in which it was developed. METHODS: The study included patients from the ambulatory care clinic of cirrhosis of a Brazilian hospital and studied platelet count, spleen diameter and presence of esophageal varices, as well as Child and MELD scores. It used a cutoff value of 909 for the platelet count/spleen diameter ratio, as previously published. A sample of 139 patients was needed to grant results a 95% confidence level. RESULTS: The study included 164 cirrhotics, 56.7% male, with a mean age of 56.6 ± 11.6 years. In the univariate analysis, platelet count, spleen diameter, presence of ascites, Child and MELD scores and the platelet count/spleen diameter ratio were related to esophageal varices (PCONTEXTO: Hemorragia digestiva por varizes esofágicas é a complicação mais dramática da cirrose. É recomendada triagem de varizes esofágicas em todo o cirrótico. OBJETIVO: Avaliar o índice de contagem de plaquetas/diâmetro do baço como predição de varizes esofágicas em uma população distinta daquela em que ele foi desenvolvido. MÉTODOS: O estudo incluiu pacientes do ambulatório de cirrose de um hospital brasileiro quanto ao número de plaquetas, diâmetro ecográfico do baço, presença de varizes esofágicas, Child e MELD. O ponto de corte do índice foi de 909. Amostra de 139 pacientes foi estimada para conferir nível de confiança de 95%. RESULTADOS: Incluíram-se 164 cirróticos, 56,7% homens e com média de idade de 56,6 anos. Na análise univariada, número de plaquetas, diâmetro do baço, ascite, Child, MELD e o

  19. Impaired Platelet Aggregation and Rebalanced Hemostasis in Patients with Chronic Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Nick S. Nielsen

    2017-05-01

    Full Text Available Increased risk of both cardiovascular disease (CVD and bleeding has been found in patients with chronic hepatitis C (CHC infection, and a re-balanced hemostasis has been proposed. The aim of this study was to investigate functional whole blood coagulation and platelet function in CHC infection. The prospective study included 82 patients with CHC infection (39 with advanced liver fibrosis and 43 with no or mild liver fibrosis and 39 healthy controls. A total of 33 patients were treated for CHC infection and achieved sustained virological response (SVR. Baseline and post-treatment blood samples were collected. Hemostasis was assessed by both standard coagulation tests and functional whole blood hemostatic assays (thromboelastograhy (TEG, and platelet aggregation (Multiplate. Patients with CHC and advanced fibrosis had impaired platelet aggregation both compared to patients with no or mild fibrosis and to healthy controls. Patients with CHC and advanced fibrosis also had lower antithrombin, platelet count, and coagulation factors II-VII-X compared to healthy controls. In contrast, TEG did not differ between groups. In treated patients achieving SVR, post-treatment platelet count was higher than pre-treatment counts (p = 0.033 and ADPtest, ASPItest, and RISTOhightest all increased post treatment (all p < 0.05. All Multiplate tests values, however, remained below those in the healthy controls. CHC-infected patients displayed evidence of rebalanced hemostasis with only partly hemostatic normalization in patients achieving SVR. The implications of rebalanced hemostasis and especially the impact on risk of CVD and bleeding warrants further studies.

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

    Directory of Open Access Journals (Sweden)

    Sanne Bøjet Larsen

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

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

    Directory of Open Access Journals (Sweden)

    Sirada Srihirun

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

  2. In vitro model of platelet aggregation in stenotic arteries

    International Nuclear Information System (INIS)

    Morley, D.; Santamore, W.P.

    1988-01-01

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

  3. Platelet Levels and Implications For Pre-Dialysis Chronic Renal ...

    African Journals Online (AJOL)

    Platelet count is assumed to be normal in chronic renal insufficiency. However, the possible effect of loss of platelet function in chronic renal failure (CFR) in relation to occult chronic blood loss, haematuria and overall health of the patient has not been given the desired attention. The aim of this study was to determine the ...

  4. Effect of varying concentrations of orally ingested glucose on platelet ...

    African Journals Online (AJOL)

    The physiologic basis of bleeding is a function of normal platelets and coagulation factors. This study is aimed at ascertaining the effect of varying concentrations of orally ingested glucose on platelet count and hemoglobin concentration during menstruation. Forty menstruating students between the ages of 18 and 25 from ...

  5. Comparison of the platelet-rich plasma and buffy coat protocols for preparation of canine platelet concentrates.

    Science.gov (United States)

    Hoareau, Guillaume L; Jandrey, Karl E; Burges, Julie; Bremer, Daphne; Tablin, Fern

    2014-12-01

    Platelet (PLT) concentrates (PC) can be produced via the buffy coat (BC) or platelet-rich plasma (PRP) protocols. The 2 methods have not been compared with canine blood. The aims of the study were to compare the PLT, WBC, and RBC concentrations, in vitro PLT function, and markers of platelet storage lesion (PSL) in canine PC generated by 2 different protocols, and determine microbial growth throughout storage. PC from 8 healthy donor dogs were produced using 2 standard protocols, PRP and BC. PLT, WBC, and RBC counts, optical aggregometry assays, and PSL markers (pH, pCO2 , HCO3 , lactate and glucose concentrations, and LDH activity) were determined on storage days 0, 1, 3, 5, and 7. Aerobic and anaerobic bacterial cultures were also performed. Mean PLT counts were comparable between protocols and remained stable throughout storage up to day 7, while median WBC and RBC counts on day 0 were significantly higher in the BC-PC group (17,800 WBCs/μL; 195,000 RBCs/μL) than in the PRP-PC group (200 WBCs/μL; 10,000 RBCs/μL) (P = .012). In PRP-PC aggregometry, the median slope and amplitude in response to γ-thrombin and convulxin (+ ADP) were significantly decreased, and virtually absent in BC-PC during storage. PSL markers (lactate, LDH activity) were higher in BC-PC. Aerobic bacterial growth was observed in 2 PRP-PC and 1 BC-PC. This in vitro study suggests that PRP-PC had lesser WBC and RBC contamination and superior PLT function compared with BC-PC. In vivo studies are required to address safety and efficacy of PRP-PC. © 2014 American Society for Veterinary Clinical Pathology.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

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

  8. Extended Storage of Pathogen-Reduced Platelet Concentrates (PRECON)

    Science.gov (United States)

    2016-10-01

    certified in the Protection of Human Research Subjects. XI. STUDY PROCEDURES Screening An abbreviated version of blood donor screening will be...complete blood count (CBC) to obtain the hematocrit and platelet count. Only criteria aimed at assuring donor safety will apply. Recipient safety...platelet infusion, the subject will be carefully monitored for adverse reactions ; i.e., fever, chills, dyspnea, urticaria or pain (infusion site, chest

  9. Effects of irradiation on platelet function

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  10. Counting carbohydrates

    Science.gov (United States)

    Carb counting; Carbohydrate-controlled diet; Diabetic diet; Diabetes-counting carbohydrates ... Many foods contain carbohydrates (carbs), including: Fruit and fruit juice Cereal, bread, pasta, and rice Milk and milk products, soy milk Beans, legumes, ...

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

    Science.gov (United States)

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

    2016-12-01

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

  12. EcoCount

    Directory of Open Access Journals (Sweden)

    Phillip P. Allen

    2014-05-01

    Full Text Available Techniques that analyze biological remains from sediment sequences for environmental reconstructions are well established and widely used. Yet, identifying, counting, and recording biological evidence such as pollen grains remain a highly skilled, demanding, and time-consuming task. Standard procedure requires the classification and recording of between 300 and 500 pollen grains from each representative sample. Recording the data from a pollen count requires significant effort and focused resources from the palynologist. However, when an adaptation to the recording procedure is utilized, efficiency and time economy improve. We describe EcoCount, which represents a development in environmental data recording procedure. EcoCount is a voice activated fully customizable digital count sheet that allows the investigator to continuously interact with a field of view during the data recording. Continuous viewing allows the palynologist the opportunity to remain engaged with the essential task, identification, for longer, making pollen counting more efficient and economical. EcoCount is a versatile software package that can be used to record a variety of environmental evidence and can be installed onto different computer platforms, making the adoption by users and laboratories simple and inexpensive. The user-friendly format of EcoCount allows any novice to be competent and functional in a very short time.

  13. 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

  14. 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

  15. Kinetics of platelets in dogs with thrombocytopenia induced by antiglycoprotein IIb/IIIa receptor monoclonal antibody

    International Nuclear Information System (INIS)

    Hosono, Makoto; Sone, Naoaki; Endo, Keigo; Saga, Tsuneo; Kobayashi, Hisataka; Hosono, Masako N.; Sakahara, Harumi; Yasunaga, Kojiro; Konishi, Junji

    1995-01-01

    To experimentally assess the kinetics of platelets in thrombocytopenia, we constructed a canine model using 111 In-oxine labeled autologous platelets and an intact antiplatelet monoclonal antibody (MAb) NNKY2-11 (IgG2a). With the infusion of radiolabeled autologous platelets into dogs, the peripheral platelet count and blood radioactivity level were examined, and the radioactivity in the liver, spleen and heart was determined with scintigraphic analysis. Thereafter, i.v. injection of 100 μg/kg of NNKY2-11 had no effect on platelet counts or the biodistribution of radiolabeled platelets. However, 200 and 300 μg/kg of MAb reduced the platelets, and the radioactivity of the liver and spleen augmented clearly after injection of MAb. Platelet radioactivity in serum, which had decreased after MAb infusion, did not recover, even when peripheral platelet counts returned to the normal levels, indicating that these new platelets might be derived from the platelet-storage pool or new thrombocytogenesis. This model of antiplatelet MAb induced thrombocytopenia seems to be useful for analyzing the kinetics of platelets in thrombocytopenia

  16. 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...

  17. 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...

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

    Directory of Open Access Journals (Sweden)

    A Suchetha

    2015-01-01

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

  19. The life cycle of platelet granules.

    Science.gov (United States)

    Sharda, Anish; Flaumenhaft, Robert

    2018-01-01

    Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types-dense granules, α-granules, and lysosomes-although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the trans -Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.

  20. 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...

  1. 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...

  2. Lymphocyte-platelet crosstalk in Graves' disease.

    Science.gov (United States)

    Kuznik, Boris I; Vitkovsky, Yuri A; Gvozdeva, Olga V; Solpov, Alexey V; Magen, Eli

    2014-03-01

    Platelets can modulate lymphocytes' role in the pathophysiology of thyroid autoimmune diseases. The present study was performed to clarify the status of platelet-lymphocyte subpopulations aggregation in circulating blood in patients with Graves' disease (GD). One hundred and fifty patients with GD (GD group) and 45 hyperthyroid patients with toxic multinodular goiter (TMG group) were recruited in the study. Control group consisted 150 healthy subjects. Immunophenotyping of lymphocytes was performed by flow cytometry. Detection of lymphocyte-platelet aggregates (LPAs) was done using light microscope after Ficoll-gradient centrifugation. The group of GD patients exhibited reduced CD8 lymphocyte and higher CD19 cell counts compared with TMG group and healthy controls. A greater number of activated CD3, HLA-DR+ lymphocytes were observed in GD than in TMG group and control group. GD group was characterized by lower blood platelet count (232 ± 89 × 10 cells/µL) than TMG group (251 ± 97 × 10 cells/µL; P TMG group (116 ± 67/µL, P < 0.005) and control group (104 ± 58 /µL; P < 0.001). GD is associated with higher levels of activated lymphocytes and lymphocyte-platelet aggregates.

  3. Counting cormorants

    DEFF Research Database (Denmark)

    Bregnballe, Thomas; Carss, David N; Lorentsen, Svein-Håkon

    2013-01-01

    This chapter focuses on Cormorant population counts for both summer (i.e. breeding) and winter (i.e. migration, winter roosts) seasons. It also explains differences in the data collected from undertaking ‘day’ versus ‘roost’ counts, gives some definitions of the term ‘numbers’, and presents two...

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

    Science.gov (United States)

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

    2017-07-13

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

  5. Proliferation-promoting effect of platelet-rich plasma on human adipose-derived stem cells and human dermal fibroblasts.

    Science.gov (United States)

    Kakudo, Natsuko; Minakata, Tatsuya; Mitsui, Toshihito; Kushida, Satoshi; Notodihardjo, Frederik Zefanya; Kusumoto, Kenji

    2008-11-01

    This study evaluated changes in platelet-derived growth factor (PDGF)-AB and transforming growth factor (TGF)-beta1 release from platelets by platelet-rich plasma activation, and the proliferation potential of activated platelet-rich plasma and platelet-poor plasma on human adipose-derived stem cells and human dermal fibroblasts. Platelet-rich plasma was prepared using a double-spin method, with the number of platelets counted in each preparation stage. Platelet-rich and platelet-poor plasma were activated with autologous thrombin and calcium chloride, and levels of platelet-released PDGF-AB and TGF-beta1 were determined by enzyme-linked immunosorbent assay. Cells were cultured for 1, 4, or 7 days in serum-free Dulbecco's Modified Eagle Medium supplemented with 5% whole blood plasma, nonactivated platelet-rich plasma, nonactivated platelet-poor plasma, activated platelet-rich plasma, or activated platelet-poor plasma. In parallel, these cells were cultured for 1, 4, or 7 days in serum-free Dulbecco's Modified Eagle Medium supplemented with 1%, 5%, 10%, or 20% activated platelet-rich plasma. The cultured human adipose-derived stem cells and human dermal fibroblasts were assayed for proliferation. Platelet-rich plasma contained approximately 7.9 times as many platelets as whole blood, and its activation was associated with the release of large amounts of PDGF-AB and TGF-beta1. Adding activated platelet-rich or platelet-poor plasma significantly promoted the proliferation of human adipose-derived stem cells and human dermal fibroblasts. Adding 5% activated platelet-rich plasma to the medium maximally promoted cell proliferation, but activated platelet-rich plasma at 20% did not promote it. Platelet-rich plasma can enhance the proliferation of human adipose-derived stem cells and human dermal fibroblasts. These results support clinical platelet-rich plasma application for cell-based, soft-tissue engineering and wound healing.

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

    Directory of Open Access Journals (Sweden)

    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

  7. Platelet function and activation in Cavalier King Charles Spaniels with subclinical chronic valvular heart disease.

    Science.gov (United States)

    Tong, Linda J; Hosgood, Giselle L; French, Anne T; Irwin, Peter J; Shiel, Robert E

    2016-08-01

    OBJECTIVE To assess platelet closure time (CT), mean platelet component (MPC) concentration, and platelet component distribution width (PCDW) in dogs with subclinical chronic valvular heart disease. ANIMALS 89 Cavalier King Charles Spaniels (CKCSs) and 39 control dogs (not CKCSs). PROCEDURES Platelet count, MPC concentration, PCDW, and Hct were measured by use of a hematology analyzer, and CT was measured by use of a platelet function analyzer. Murmur grade and echocardiographic variables (mitral valve regurgitant jet size relative to left atrial area, left atrial-to-aortic diameter ratio, and left ventricular internal dimensions) were recorded. Associations between explanatory variables (sex, age, murmur grade, echocardiographic variables, platelet count, and Hct) and outcomes (CT, MPC concentration, and PCDW) were examined by use of multivariate regression models. RESULTS A model with 5 variables best explained variation in CT (R(2), 0.74), with > 60% of the variance of CT explained by mitral valve regurgitant jet size. The model of best fit to explain variation in MPC concentration included only platelet count (R(2), 0.24). The model of best fit to explain variation in PCDW included platelet count and sex (R(2), 0.25). CONCLUSIONS AND CLINICAL RELEVANCE In this study, a significant effect of mitral valve regurgitant jet size on CT was consistent with platelet dysfunction. However, platelet activation, as assessed on the basis of the MPC concentration and PCDW, was not a feature of subclinical chronic valvular heart disease in CKCSs.

  8. Thrombocytopenia in leptospirosis and role of platelet transfusion

    Directory of Open Access Journals (Sweden)

    Sharma Jayashree

    2007-01-01

    Full Text Available Aim : The study was designed to find out the incidence of thrombocytopenia in leptospirosis and to correlate thrombocytopenia with other parameters like renal failure, hepatic failure and bleeding manifestation like adult respiratory distress syndrome and to assess the role of platelet transfusion. Materials and Methods : 50 cases of leptospirosis during the month of July and August 2005 were retrospectively analyzed. Criteria for selection were Lepto Tek Dri - dot test positive cases of the clinically suspected cases of Leptospirosis. Degree of thrombocytopenia was categorized as severe, moderate and mild. Presence of thrombocytopenia was clinically correlated with parameters like renal dysfunction, hepatic dysfunction and hemorrhagic manifestations (mainly ARDS. Role of platelet transfusion was assessed with reference to presence and degree of thrombcytopenia and hemorrhagic manifestations. Results : Out of total 50 patients 26 were male and 24 were females. Major bleeding manifestation in the form of ARDS was seen in 15 (30% of patients. 28 (56% patients had thrombocytopenia and 22 (44% patients had normal platelet counts. Total number of patients with renal dysfunction was 24 (48%. Only four (18.18% patients with normal platelet counts had renal dysfunction while 20 (71.42% patients with thrombocytopenia had renal dysfunction. Only two (9.09% patients with normal platelet counts and 48 (46.42% patients with thrombocytopenia had hepatorenal dysfunction. Total number of patients with ARDS was 15 (30%. Of these two (13.33% had normal platelet count while 13 (86.6% patients were thrombocytopenic. Total 47 units of platelets were transfused to 12 patients in our study. Of these seven patients with severe thrombocytopenia required total 28 units, two patients with moderate thrombocytopenia required total seven units and patients with mild thrombocytopenia were transfused total 12 units of platelets. Conclusion : It is important to anticipate and

  9. Next Generation Sequencing Analysis of Human Platelet PolyA+ mRNAs and rRNA-Depleted Total RNA

    Science.gov (United States)

    Kissopoulou, Antheia; Jonasson, Jon; Lindahl, Tomas L.; Osman, Abdimajid

    2013-01-01

    Background Platelets are small anucleate cells circulating in the blood vessels where they play a key role in hemostasis and thrombosis. Here, we compared platelet RNA-Seq results obtained from polyA+ mRNA and rRNA-depleted total RNA. Materials and Methods We used purified, CD45 depleted, human blood platelets collected by apheresis from three male and one female healthy blood donors. The Illumina HiSeq 2000 platform was employed to sequence cDNA converted either from oligo(dT) isolated polyA+ RNA or from rRNA-depleted total RNA. The reads were aligned to the GRCh37 reference assembly with the TopHat/Cufflinks alignment package using Ensembl annotations. A de novo assembly of the platelet transcriptome using the Trinity software package and RSEM was also performed. The bioinformatic tools HTSeq and DESeq from Bioconductor were employed for further statistical analyses of read counts. Results Consistent with previous findings our data suggests that mitochondrially expressed genes comprise a substantial fraction of the platelet transcriptome. We also identified high transcript levels for protein coding genes related to the cytoskeleton function, chemokine signaling, cell adhesion, aggregation, as well as receptor interaction between cells. Certain transcripts were particularly abundant in platelets compared with other cell and tissue types represented by RNA-Seq data from the Illumina Human Body Map 2.0 project. Irrespective of the different library preparation and sequencing protocols, there was good agreement between samples from the 4 individuals. Eighteen differentially expressed genes were identified in the two sexes at 10% false discovery rate using DESeq. Conclusion The present data suggests that platelets may have a unique transcriptome profile characterized by a relative over-expression of mitochondrially encoded genes and also of genomic transcripts related to the cytoskeleton function, chemokine signaling and surface components compared with other cell and

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

    Directory of Open Access Journals (Sweden)

    Hideki Hayashi

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

  11. Platelets release pathogenic serotonin and return to circulation after immune complex-mediated sequestration.

    Science.gov (United States)

    Cloutier, Nathalie; Allaeys, Isabelle; Marcoux, Genevieve; Machlus, Kellie R; Mailhot, Benoit; Zufferey, Anne; Levesque, Tania; Becker, Yann; Tessandier, Nicolas; Melki, Imene; Zhi, Huiying; Poirier, Guy; Rondina, Matthew T; Italiano, Joseph E; Flamand, Louis; McKenzie, Steven E; Cote, Francine; Nieswandt, Bernhard; Khan, Waliul I; Flick, Matthew J; Newman, Peter J; Lacroix, Steve; Fortin, Paul R; Boilard, Eric

    2018-02-13

    There is a growing appreciation for the contribution of platelets to immunity; however, our knowledge mostly relies on platelet functions associated with vascular injury and the prevention of bleeding. Circulating immune complexes (ICs) contribute to both chronic and acute inflammation in a multitude of clinical conditions. Herein, we scrutinized platelet responses to systemic ICs in the absence of tissue and endothelial wall injury. Platelet activation by circulating ICs through a mechanism requiring expression of platelet Fcγ receptor IIA resulted in the induction of systemic shock. IC-driven shock was dependent on release of serotonin from platelet-dense granules secondary to platelet outside-in signaling by αIIbβ3 and its ligand fibrinogen. While activated platelets sequestered in the lungs and leaky vasculature of the blood-brain barrier, platelets also sequestered in the absence of shock in mice lacking peripheral serotonin. Unexpectedly, platelets returned to the blood circulation with emptied granules and were thereby ineffective at promoting subsequent systemic shock, although they still underwent sequestration. We propose that in response to circulating ICs, platelets are a crucial mediator of the inflammatory response highly relevant to sepsis, viremia, and anaphylaxis. In addition, platelets recirculate after degranulation and sequestration, demonstrating that in adaptive immunity implicating antibody responses, activated platelets are longer lived than anticipated and may explain platelet count fluctuations in IC-driven diseases.

  12. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Tower counts

    Science.gov (United States)

    Woody, Carol Ann; Johnson, D.H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

    2007-01-01

    Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers. 

  15. 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.)

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

    DEFF Research Database (Denmark)

    Söderström, Anna Cecilia; Nybo, Mads; Nielsen, Christian

    2016-01-01

    BACKGROUND: 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....... METHODS: 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...... 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%), p...

  17. 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

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

    LENUS (Irish Health Repository)

    Kinsella, Ja

    2013-04-26

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bert Rutten

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

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  2. Platelets and Multi-Organ Failure in Sepsis

    Directory of Open Access Journals (Sweden)

    Elisabetta Greco

    2017-10-01

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

  3. Platelets and Multi-Organ Failure in Sepsis.

    Science.gov (United States)

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

    2017-10-20

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

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

    International Nuclear Information System (INIS)

    Bjoernson, J.; Aursnes, I.

    1977-01-01

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

  5. Platelet transfusion practice in a tertiary care hospital

    International Nuclear Information System (INIS)

    Rehman, Z.; Alam, M.

    2002-01-01

    Objective: Pakistan is a developing country where platelet concentrates are prepared and administered to patients in only a few large centres of the country. A study was designed for appraisal of the current situation and to review the progress made so far. Design: It was a prospective, non-interventional study. Place and duration of study: The study was conducted at PNS Shifa, Karachi from January, 1995 to December, 1998. Subjects and Methods: During this study 588 random donor platelet concentrates were transfused to 66 patients 148 occasions. Random donor platelet concentrates were prepared by fractionation of whole blood using triple blood collecting bags. Pre-transfusion and one hour posttransfusion platelet counts of the patients were done. The efficacy of the platelet transfusion was monitored by noting the clinical response as well as doing one hour posttransfusion corrected counts increment (CCI).Results: On 114 (77%) occasions platelets were transfused prophylactically and 34 (23%) times therapeutically to stop major bleeding episodes. The mean pre-transfusion platelet count varied from 15.5 x 10/sup 9/1 to 28.5 x 10/sup 9/l in different clinical conditions. On average, 4 random donor platelet concentrates were administered on each occasion. The best response was observed in patients of aplastic anaemia and worst in cases of disseminated intravascular coagulation (DIC). Conclusion: Platelet concentrates administration was inappropriate in significant number of patients, therefore, each hospital should form transfusion committee to review transfusion practices guidelines for blood components usage and compliance to these guidelines by the clinicians. (author)

  6. 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

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

    Science.gov (United States)

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

    2015-01-01

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

  8. Determinants of platelet aggregation in 50-70-year-old men from three Japanese communities.

    Science.gov (United States)

    Imano, Hironori; Iso, Hiroyasu; Sato, Shinichi; Kitamura, Akihiko; Okamura, Tomonori; Tanigawa, Takeshi; Ohira, Tetsuya; Kudo, Minako; Naito, Yoshihiko; Iida, Minoru; Shimamoto, Takashi

    2002-12-01

    To investigate the association of lifestyle and constitutional variables with platelet aggregation, we examined the platelet aggregation, serum fatty acid composition, alcohol intake, smoking, and dietary intake of seafood and soybean estimated by a 1-week dietary record in 448 males aged 50-70 in three rural Japanese communities: Ikawa, Akita prefecture (northeast coast), Noichi, Kochi prefecture (southwest coast), and Kyowa, Ibaraki prefecture (central inland). Platelet aggregatory threshold index (PATI) was used to determine the minimum concentration of adenosine 5'-diphosphate (ADP) that caused a non-reversible aggregation of platelets. Intake of seafood and n3-polyunsaturated fatty acid and ingestion of ethanol were higher in the northeast coastal community than in the other two communities. Mean platelet and white blood cell counts were lower in northeast coastal community than in the other two communities. The geometric mean PATI was higher (i.e. platelet aggregation was lower) in the northeast coastal community than the other two communities. Within the entire sample, platelet aggregation correlated inversely with serum level of n3-polyunsaturated fatty acids and gamma-glutamyl transpeptidase, an index of alcohol consumption, and positively with platelet and white blood cell counts. Platelet aggregation tended to correlate positively with serum arachidonic acid. There was no correlation between smoking and platelet aggregation. Our results suggest that seafood intake and moderate alcohol consumption reduce platelet aggregation.

  9. Platelet transfusion therapy in sub-Saharan Africa: bacterial contamination, recipient characteristics and acute transfusion reactions

    Science.gov (United States)

    Hume, Heather A.; Ddungu, Henry; Angom, Racheal; Baluku, Hannington; Kajumbula, Henry; Kyeyune-Byabazaire, Dorothy; Orem, Jackson; Ramirez-Arcos, Sandra; Tobian, Aaron A.R.

    2017-01-01

    Background Little data are available on bacterial contamination (BC) of platelet units or acute transfusion reactions to platelet transfusions (PT) in sub-Saharan Africa (SSA). Methods This prospective observational study evaluated the rate of BC of whole blood derived platelet units (WB-PU), the utility of performing Gram stains (GS) to prevent septic reactions, characteristics of patients receiving PT and the rate of acute reactions associated with PT at the Uganda Cancer Institute in Kampala, Uganda. An aliquot of each WB-PU studied was taken to perform GS and culture using the Bactec™ 9120 instrument. Study participants were monitored for reactions. Results 337 WB-PU were evaluated for BC, of which 323 units were transfused in 151 transfusion episodes to 50 patients. The frequency of BC ranged from 0.3%–2.1% (according to criteria used to define BC). The GS had high specificity (99.1%), but low sensitivity to detect units with BC. The median platelet count prior to PT was 10,900 (IQR 6,000–18,900) cells/μL. 78% of PT were given to patients with no bleeding. Acute reactions occurred in 11 transfusion episodes, involving 13 WB-PU, for a rate of 7.3% (95%CI=3.7–12.7%) per transfusion episode. All recipients of units with positive bacterial cultures were receiving antibiotics at the time of transfusion; none experienced a reaction. Conclusions The rate of BC observed in this study is lower than previously reported in SSA, but still remains a safety issue. As GS appears to be an ineffective screening tool, alternate methods should be explored to prevent transfusing bacterially-contaminated platelets in SSA. PMID:27079627

  10. Administration of platelets to ruptured abdominal aortic aneurysm patients before open surgery

    DEFF Research Database (Denmark)

    Lunen, T B; Johansson, P I; Jensen, L P

    2018-01-01

    BACKGROUND: In patients undergoing open surgery for a ruptured abdominal aortic aneurysm (rAAA), survivors demonstrate a high platelet count, and proactive administration of platelets (and fresh frozen plasma) appears to influence mortality. OBJECTIVES: This trial investigated the effect of plate......BACKGROUND: In patients undergoing open surgery for a ruptured abdominal aortic aneurysm (rAAA), survivors demonstrate a high platelet count, and proactive administration of platelets (and fresh frozen plasma) appears to influence mortality. OBJECTIVES: This trial investigated the effect...... vs 39; P = 0·15) were similar in the two groups of patients. No adverse reactions to platelet administration were observed. In addition, length of stay in the intensive care unit was unaffected by intervention. CONCLUSIONS: For patients planned for open repair of a rAAA, we observed no significant...... effect of early administration of platelets with regard to post-operative complications and stay in the ICU or in hospital and also no significant effect on mortality....

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  12. Dark Matter remains obscure

    CERN Multimedia

    Fabio Capello

    2011-01-01

    It is one of the hidden secrets that literally surround the Universe. Experiments have shown no result so far because trying to capture particles that do not seem to interact with ordinary matter is no trivial exercise. The OSQAR experiment at CERN is dedicated to the search for axions, one of the candidates for Dark Matter. For its difficult challenge, OSQAR counts on one of the world’s most powerful magnets borrowed from the LHC. In a recent publication, the OSQAR collaboration was able to confirm that no axion signal appears out of the background. In other words: the quest is still on.   The OSQAR experiment installed in the SM18 hall. (Photo by F. Capello) The OSQAR “Light Shining Through a Wall” experiment was officially launched in 2007 with the aim of detecting axions, that is, particles that might be the main components of Dark Matter. OSQAR uses the powerful LHC dipole magnet to intensify the predicted photon-axion conversions in the presence of strong m...

  13. Platelet function in brown bear (Ursus arctos compared to man

    Directory of Open Access Journals (Sweden)

    Särndahl Eva

    2010-06-01

    Full Text Available Abstract Background Information on hemostasis and platelet function in brown bear (Ursus arctos is of importance for understanding the physiological, protective changes during hibernation. Objective The study objective was to document platelet activity values in brown bears shortly after leaving the den and compare them to platelet function in healthy humans. Methods Blood was drawn from immobilized wild brown bears 7-10 days after leaving the den in mid April. Blood samples from healthy human adults before and after clopidogrel and acetylsalicylic acid administration served as control. We analyzed blood samples by standard blood testing and platelet aggregation was quantified after stimulation with various agonists using multiple electrode aggregometry within 3 hours of sampling. Results Blood samples were collected from 6 bears (3 females between 1 and 16 years old and from 10 healthy humans. Results of adenosine diphosphate, aspirin, and thrombin receptor activating peptide tests in bears were all half or less of those in humans. Platelet and white blood cell counts did not differ between species but brown bears had more and smaller red blood cells compared with humans. Conclusion Using three different tests, we conclude that platelet function is lower in brown bears compared to humans. Our findings represent the first descriptive study on platelet function in brown bears and may contribute to explain how bears can endure denning without obvious thrombus building. However, the possibility that our findings reflect test-dependent and not true biological variations in platelet reactivity needs further studies.

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  15. The interaction of thrombin with platelet protease nexin

    International Nuclear Information System (INIS)

    Knupp, C.L.

    1989-01-01

    Thrombin interacts with a platelet protein which is immunologically related to fibroblast protease nexin and has been termed platelet protease nexin I (PNI). Conflicting hypotheses about the relationship of the thrombin-PNI complex formation to platelet activation have been proposed. The studies presented here demonstrate that the platelet-associated and supernatant complexes with added 125I-thrombin are formed only under conditions which produce platelet activation in normal and chymotrypsin-modified platelets. The platelet-associated complex is formed prior to the appearance of complexes in supernatants. Appearance of the supernatant complex coincides with the appearance of thrombospondin in the reaction supernatants. Excess native thrombin, dansylarginine N-(3-ethyl-1,5-pentanediyl) amide or hirudin can prevent radiolabeled platelet-associated complex formation if added before 125I-thrombin. DAPA or hirudin can prevent or dissociate complex formation if added up to one minute after thrombin but not at later time points. The surface associated complex is accessible to trypsin although a portion remains with the cytoskeletal proteins when thrombin-activated platelets are solubilized with Triton X 100. The surface-associated complex formation parallels many aspects of the specific measurable thrombin binding, yet it does not appear to involve other identified surface glycoprotein thrombin receptors or substrates. Although the time course of appearance of the complexes in supernatants is consistent with other data which suggest that PNI may be released from platelet granules during platelet activation, other explanations for the appearance of PNI on the platelet surface and in supernatants during platelet activation are possible

  16. [PALEOPATHOLOGY OF HUMAN REMAINS].

    Science.gov (United States)

    Minozzi, Simona; Fornaciari, Gino

    2015-01-01

    Many diseases induce alterations in the human skeleton, leaving traces of their presence in ancient remains. Paleopathological examination of human remains not only allows the study of the history and evolution of the disease, but also the reconstruction of health conditions in the past populations. This paper describes the most interesting diseases observed in skeletal samples from the Roman Imperial Age necropoles found in urban and suburban areas of Rome during archaeological excavations in the last decades. The diseases observed were grouped into the following categories: articular diseases, traumas, infections, metabolic or nutritional diseases, congenital diseases and tumours, and some examples are reported for each group. Although extensive epidemiological investigation in ancient skeletal records is impossible, the palaeopathological study allowed to highlight the spread of numerous illnesses, many of which can be related to the life and health conditions of the Roman population.

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

    Science.gov (United States)

    Riedl, Julia; Ay, Cihan; Pabinger, Ingrid

    2017-07-01

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

  18. Flavanols and Platelet Reactivity

    Directory of Open Access Journals (Sweden)

    Debra A. Pearson

    2005-01-01

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

  19. 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...

  20. 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...

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  2. Inhibition of the plasma SCUBE1, a novel platelet adhesive protein, protects mice against thrombosis.

    Science.gov (United States)

    Wu, Meng-Ying; Lin, Yuh-Charn; Liao, Wei-Ju; Tu, Cheng-Fen; Chen, Ming-Huei; Roffler, Steve R; Yang, Ruey-Bing

    2014-07-01

    Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1), a secreted and surface-exposed glycoprotein on activated platelets, promotes platelet-platelet interaction and supports platelet-matrix adhesion. Its plasma level is a biomarker of platelet activation in acute thrombotic diseases. However, the exact roles of plasma SCUBE1 in vivo remain undefined. We generated new mutant (Δ) mice lacking the soluble but retaining the membrane-bound form of SCUBE1. Plasma SCUBE1-depleted Δ/Δ mice showed normal hematologic and coagulant features and expression of major platelet receptors, but Δ/Δ platelet-rich plasma showed impaired platelet aggregation in response to ADP and collagen treatment. The addition of purified recombinant SCUBE1 protein restored the aggregation of platelets in Δ/Δ platelet-rich plasma and further enhanced platelet aggregation in +/+ platelet-rich plasma. Plasma deficiency of SCUBE1 diminished arterial thrombosis in mice and protected against lethal thromboembolism induced by collagen-epinephrine treatment. Last, antibodies directed against the epidermal growth factor-like repeats of SCUBE1, which are involved in trans-homophilic protein-protein interactions, protected mice against fatal thromboembolism without causing bleeding in vivo. We conclude that plasma SCUBE1 participates in platelet aggregation by bridging adjacent activated platelets in thrombosis. Blockade of soluble SCUBE1 might represent a novel antithrombotic strategy. © 2014 American Heart Association, Inc.

  3. 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

  4. The comparison of thrombocytosis and platelet-lymphocyte ratio as potential prognostic markers in colorectal cancer

    DEFF Research Database (Denmark)

    Baranyai, Zsolt; Krzystanek, Marcin; Josa, Valeria

    2014-01-01

    The aim of the present study was to analyse the preoperative platelet count and the platelet-lymphocyte ratio (PLR) in patients with colorectal cancer (CRC) of different stages and with hepatic metastasis of CRC (mCRC) and to compare these factors as potential prognostic markers. Clinicopathologi...

  5. Decreased mean platelet volume in panic disorder

    Directory of Open Access Journals (Sweden)

    Göğçegöz Gül I

    2014-09-01

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

  6. 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

  7. 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,.

  8. 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

  9. 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

  10. 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

  11. Counting Possibilia

    Directory of Open Access Journals (Sweden)

    Alfredo Tomasetta

    2010-06-01

    Full Text Available Timothy Williamson supports the thesis that every possible entity necessarily exists and so he needs to explain how a possible son of Wittgenstein’s, for example, exists in our world:he exists as a merely possible object (MPO, a pure locus of potential. Williamson presents a short argument for the existence of MPOs: how many knives can be made by fitting together two blades and two handles? Four: at the most two are concrete objects, the others being merely possible knives and merely possible objects. This paper defends the idea that one can avoid reference and ontological commitment to MPOs. My proposal is that MPOs can be dispensed with by using the notion of rules of knife-making. I first present a solution according to which we count lists of instructions - selected by the rules - describing physical combinations between components. This account, however, has its own difficulties and I eventually suggest that one can find a way out by admitting possible worlds, entities which are more commonly accepted - at least by philosophers - than MPOs. I maintain that, in answering Williamson’s questions, we count classes of physically possible worlds in which the same instance of a general rule is applied.

  12. 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

  13. Interindividual variation in platelets and the cardiovascular response to haemorrhage in the pig

    DEFF Research Database (Denmark)

    Zaar, Morten; Secher, Niels H; Gam, Christiane Marie Bourgin

    2011-01-01

    platelet count. After administration of lactated Ringer and hydroxyethyl starch, however, mean arterial pressure (R² = 0.60, P R² = 0.52, P R² = 0.36, P R² = 0.84, P R² = 0.38, P R² = 0.92, P ... to the pretrauma platelet count and at 60 min, that was also the case for standard base excess (R² = 0.37, P R² = 0.44, P R² = 0.51, P

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

    Directory of Open Access Journals (Sweden)

    Mehmet Ünal

    2015-06-01

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

  15. 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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2013-03-15

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

  18. 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.

  19. Effect of 30-Gy irradiation in conjunction with leukocyte reduction filter on platelet and transfusion efficiency

    International Nuclear Information System (INIS)

    Shimojima, Hiromi; Sawada, Umihiko; Horie, Takashi; Itoh, Takeyoshi

    2001-01-01

    To evaluate the effect of 30-Gy irradiation in conjunction with leukocyte reduction filter on platelet and transfusion efficiency, we studied platelet recovery, leukocyte reduction rate, content of platelet factor 4 and β-thromboglobulin in platelet products, platelet functions, and positive rates of platelet surface membranes CD42 and CD62, prior to and after treatment. We also evaluated the efficiency of platelet transfusion by estimating post- transfusion (1 and 24 hour) corrected count increment (CCI), and transfusion side effects. Recovery of platelets was 91.8±6.5% and depletion rate of leukocytes was 1.7±1.1 log. There was no significant difference in platelet activation markers or function tests prior to and after the procedure. The mean post-transfusion CCI and 1 and 24 hours were 16,550 (n=114) and 13,310 (n=93), respectively, with 30-Gy irradiation and leukocyte reduction filter. Those treated solely with leukocyte reduction filter were 14,970 (n=114) and 10,880 (n=118), respectively. There was no increase in transfusion side effects after the treatment of platelet concentrate with 30-Gy irradiation combined with leukocyte reduction filter compared with treatment by leukocyte reduction filter alone. These results indicate that treatment with 30 Gy irradiation in conjunction with leukocyte reduction filter is safe and effective in platelet transfusion. (author)

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

    Science.gov (United States)

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

    2012-02-15

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

  1. Differential Expression Analysis by RNA-Seq Reveals Perturbations in the Platelet mRNA Transcriptome Triggered by Pathogen Reduction Systems

    OpenAIRE

    Osman, Abdimajid; Hitzler, Walter E.; Ameur, Adam; Provost, Patrick

    2015-01-01

    Platelet concentrates (PCs) are prepared at blood banks for transfusion to patients in certain clinical conditions associated with a low platelet count. To prevent transfusion-transmitted infections via PCs, different pathogen reduction (PR) systems have been developed that inactivate the nucleic acids of contaminating pathogens by chemical cross-linking, a mechanism that may also affect platelets' nucleic acids. We previously reported that treatment of stored platelets with the PR system Int...

  2. Lea blood group antigen on human platelets

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    African Journals Online (AJOL)

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

  4. 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

  5. First comparative analysis concerning the plasma platelet contamination during MNC collection.

    Science.gov (United States)

    Pfeiffer, Hella; Achenbach, Susanne; Strobel, Julian; Zimmermann, Robert; Eckstein, Reinhold; Strasser, Erwin F

    2017-08-01

    Monocytes can be cultured into dendritic cells with addition of autologous plasma, which is highly prone to platelet contamination due to the apheresis process. Since platelets affect the maturation process of monocytes into dendritic cells and might even lead to a diminished harvest of dendritic cells, it is very important to reduce the platelet contamination. A new collection device (Spectra Optia) was analyzed, compared to two established devices (COM.TEC, Cobe Spectra) and evaluated regarding the potential generation of source plasma. Concurrent plasma collected during leukapheresis was analyzed for residual cell contamination in a prospective study with the new Spectra Optia apheresis device (n=24) and was compared with COM.TEC and Cobe Spectra data (retrospective analysis, n=72). Donor pre-donation counts of platelets were analyzed for their predictive value of contaminating PLTs in plasma harvests. The newest apheresis device showed the lowest residual platelet count of the collected concurrent plasma (median 3.50×10 9 /l) independent of pre-donation counts. The other two devices and sets had a higher platelet contamination. The contamination of the plasma with leukocytes was very low (only 2.0% were higher than 0.5×10 9 /l). This study showed a significant reduction of platelet contamination of the concurrent plasma collected with the new Spectra Optia device. This plasma product with low residual platelets and leukocytes might also be used as plasma for fractionation. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2017-09-01

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

  7. Categorical counting.

    Science.gov (United States)

    Fetterman, J Gregor; Killeen, P Richard

    2010-09-01

    Pigeons pecked on three keys, responses to one of which could be reinforced after a few pecks, to a second key after a somewhat larger number of pecks, and to a third key after the maximum pecking requirement. The values of the pecking requirements and the proportion of trials ending with reinforcement were varied. Transits among the keys were an orderly function of peck number, and showed approximately proportional changes with changes in the pecking requirements, consistent with Weber's law. Standard deviations of the switch points between successive keys increased more slowly within a condition than across conditions. Changes in reinforcement probability produced changes in the location of the psychometric functions that were consistent with models of timing. Analyses of the number of pecks emitted and the duration of the pecking sequences demonstrated that peck number was the primary determinant of choice, but that passage of time also played some role. We capture the basic results with a standard model of counting, which we qualify to account for the secondary experiments. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Exchangeable splenic platelet pool in response to intravenous infusion of isoprenaline

    Energy Technology Data Exchange (ETDEWEB)

    Freden, K; Olsson, L B; Suurkula, M; Kutti, J

    1978-01-01

    8 healthy volunteers and 4 asplenic subjects, in whom autologous platelets had been labelled with radioactive sodium chromate, received intravenous infusions of isoprenaline in a dose of 0.03 ..mu..g x kg/sup -1/ x min/sup -1/ over a period of 6 min. In the former group these infusions caused a significant decrease in the concentration of labelled as well as unlabelled platelets in the peripheral blood. Body surface countings showed that a significant increase in the count rate over the spleen occurred concomitantly with the decrease in the circulating platelet-bound radioactivity (PBR). In the group of asplenic subjects no change in PBR occurred. It is concluded that adrenergic beta-receptor stimulation causes a transitory trapping of platelets in the exchangeable splenic platelet pool.

  9. Can mean platelet component be used as an index of platelet activity in stable coronary artery disease?

    LENUS (Irish Health Repository)

    Cooke, John

    2012-01-31

    Acute coronary syndrome is associated with intracoronary thrombosis secondary to platelet activation. Previous groups have investigated platelet activation in both stable and unstable vascular disease. Most measures of platelet activation are not routinely available or easily adaptable to large scale clinical use. Recently, measurement of the mean platelet component (MPC) has become part of the routine data provided by an automated full blood count analyser, the Advia 120. MPC measures platelet density which changes on platelet activation. Our objectives were to determine if platelet activation, as measured by MPC, is increased in patients with stable coronary artery disease (CAD) and to determine if MPC could be useful in differentiating people with stable CAD from controls on an everyday clinical basis. Three hundred and forty-five consecutive patients attending for elective coronary angiography had full blood count analysis and MPC measurement performed using an ADVIA-120 analyser. Three hundred and twenty-four were analysed in our final dataset. Two hundred and fifty-three (78%) had CAD. Patients with CAD were significantly (p<0.001) older than those without (63.8 versus 56.0 years). Results failed to demonstrate a difference (p=0.467) in MPC between patients with CAD and those with normal coronary arteries (25.8 versus 26.0). Likewise, there was no correlation between MPC and the severity of CAD (Kendall\\'s tau b=-0.086, p=0.04). MPC is not a useful index of platelet activity in stable CAD when used in everyday clinical practice.

  10. Can mean platelet component be used as an index of platelet activity in stable coronary artery disease?

    LENUS (Irish Health Repository)

    Cooke, John

    2009-04-01

    Acute coronary syndrome is associated with intracoronary thrombosis secondary to platelet activation. Previous groups have investigated platelet activation in both stable and unstable vascular disease. Most measures of platelet activation are not routinely available or easily adaptable to large scale clinical use. Recently, measurement of the mean platelet component (MPC) has become part of the routine data provided by an automated full blood count analyser, the Advia 120. MPC measures platelet density which changes on platelet activation. Our objectives were to determine if platelet activation, as measured by MPC, is increased in patients with stable coronary artery disease (CAD) and to determine if MPC could be useful in differentiating people with stable CAD from controls on an everyday clinical basis. Three hundred and forty-five consecutive patients attending for elective coronary angiography had full blood count analysis and MPC measurement performed using an ADVIA-120 analyser. Three hundred and twenty-four were analysed in our final dataset. Two hundred and fifty-three (78%) had CAD. Patients with CAD were significantly (p<0.001) older than those without (63.8 versus 56.0 years). Results failed to demonstrate a difference (p=0.467) in MPC between patients with CAD and those with normal coronary arteries (25.8 versus 26.0). Likewise, there was no correlation between MPC and the severity of CAD (Kendall\\'s tau b=-0.086, p=0.04). MPC is not a useful index of platelet activity in stable CAD when used in everyday clinical practice.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    Panes, Olga; Padilla, Oslando; Matus, Valeria; Sáez, Claudia G; Berkovits, Alejandro; Pereira, Jaime; Mezzano, Diego

    2012-01-01

    Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma

  13. [Corrected count].

    Science.gov (United States)

    1991-11-27

    The data of the 1991 census indicated that the population count of Brazil fell short of a former estimate by 3 million people. The population reached 150 million people with an annual increase of 2%, while projections in the previous decade expected an increase of 2.48% to 153 million people. This reduction indicates more widespread use of family planning (FP) and control of fertility among families of lower social status as more information is being provided to them. However, the Ministry of Health ordered an investigation of foreign family planning organizations because it was suspected that women were forced to undergo tubal ligation during vaccination campaigns. A strange alliance of left wing politicians and the Roman Catholic Church alleges a conspiracy of international FP organizations receiving foreign funds. The FP strategies of Bemfam and Pro-Pater offer women who have little alternative the opportunity to undergo tubal ligation or to receive oral contraceptives to control fertility. The ongoing government program of distributing booklets on FP is feeble and is not backed up by an education campaign. Charges of foreign interference are leveled while the government hypocritically ignores the grave problem of 4 million abortions a year. The population is expected to continue to grow until the year 2040 and then to stabilize at a low growth rate of .4%. In 1980, the number of children per woman was 4.4 whereas the 1991 census figures indicate this has dropped to 3.5. The excess population is associated with poverty and a forsaken caste in the interior. The population actually has decreased in the interior and in cities with 15,000 people. The phenomenon of the drop of fertility associated with rural exodus is contrasted with cities and villages where the population is 20% less than expected.

  14. 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, ...

  15. The use of indium-111-labeled platelets in the management of renal transplant patients

    International Nuclear Information System (INIS)

    Sinzin ger, H.F.; Leithner, C.W.

    1985-01-01

    The authors begin by explaining the role of pltelets in the pathogenesis of renal transplant rejection. During the sudden and severe immunilogical event that characterizes hyperacute rejection, when the endothelium is damaged, platelets accumulate on its surface. In chronic graft rejection, platelets liberate a growth factor that stimulates proliferation of arterial smooth muscle cells, and therefore might initiate and promote obliterative arteriopathy. In the opinion of these authors, platelet scanning has contributed greatly to the understanding of the role of platelets in the different kinds of graft rejection. The important remaining question is whether platelets deposit before, concomitantly with, or after infiltration by lymphocytes

  16. Relationship of cytokine levels and clinical effect on platelet-rich plasma-treated lateral epicondylitis.

    Science.gov (United States)

    Lim, Wonbong; Park, Sang H; Kim, Bora; Kang, Sin W; Lee, Jung W; Moon, Young L

    2018-03-01

    Lateral epicondylitis (LE) is difficult to manage and can result in significant patient morbidity. Currently, the clinical use of platelet-rich plasma (PRP) for painful tendons has received attention, but its efficacy remains controversial. This study aimed to investigate the clinical effects of PRP and its biological components. A total of 156 patients with LE were randomly divided into group 1, treated with a single injection of 2-ml autologous PRP, and group 2, treated with a control received only physical therapy without injection. Both groups used a tennis elbow strap and performed stretching and strengthening exercises during 24 weeks' follow-up. Pain and functional improvements were assessed using the visual analog scale (VAS), Modified Mayo Clinic Performance Index for the elbow, and magnetic resonance imaging (MRI). White blood cell count, platelet count, and levels of platelet-derived growth factor-AB (PDGF-AB), PDGF-BB, transforming growth factor-β (TGF-β), vascular endothelial growth factor, epithelial growth factor, and interleukin-1 β in PRP were measured and investigated for statistical correlation with the clinical score. At 24 weeks, all pain and functional variables, including VAS score, Mayo Clinic performance scores, and MRI grade, improved significantly in group 1 (p < 0.05). PDGF-AB, PDGF-BB, and TGF-β levels were more significantly increased in PRP than in whole blood. TGF-β level significantly correlated with Mayo Clinic performance score and MRI grade improvement. Thus, TGF-β level in PRP is considered to play a pivotal role in tendon healing. These results may contribute to identifying the best protocol for PRP application in tendinopathies. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:913-920, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. [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.

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

    Science.gov (United States)

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

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mert DG

    2016-08-01

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

  20. Effect of fingolimod on platelet count among multiple sclerosis patients

    Directory of Open Access Journals (Sweden)

    Mehrdad Farrokhi

    2015-01-01

    Conclusions: MS patients taking oral fingolimod treatment may be at risk for side-effects caused by low Plt levels. This may not be a factor for patients with higher or normal Plt levels. However, a patient with naturally low Plt levels may experience a drop below the normal level and be at risk for excessive bleeding. In addition to these possible harmful side-effects, the decreased Plt population may pose positive effects for MS patients.

  1. Platelet size does not correlate with platelet age.

    Science.gov (United States)

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

    1983-08-01

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

  2. 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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Fang Rao

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

  6. 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.

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

    Science.gov (United States)

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

    2015-06-01

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

  8. Potential Harm of Prophylactic Platelet Transfusion in Adult Dengue Patients.

    Science.gov (United States)

    Lee, Tau-Hong; Wong, Joshua G X; Leo, Yee-Sin; Thein, Tun-Linn; Ng, Ee-Ling; Lee, Linda K; Lye, David C

    2016-03-01

    Thrombocytopenia is a hallmark of dengue infection, and bleeding is a dreaded complication of dengue fever. Prophylactic platelet transfusion has been used to prevent bleeding in the management of dengue fever, although the evidence for its benefit is lacking. In adult dengue patients with platelet count Tan Tock Seng Hospital from January 2005 to December 2008. Baseline characteristics and clinical outcomes were compared between the non-transfused vs. transfused groups. Outcomes studied were clinical bleeding, platelet increment, hospital length of stay, intensive care unit admission and death. Of the 788 patients included, 486 received prophylactic platelet transfusion. There was no significant difference in the presence of clinical bleeding in the two groups (18.2% in non-transfused group vs. 23.5% in transfused group; P = 0.08). Patients in the transfused group took a median of 1 day longer than the non-transfused group to increase their platelet count to 50,000/mm3 or more (3 days vs. 2 days, P hospital stay in the non-transfused group was 5 days vs. 6 days in the transfused group (P50,000/mm3 and increasing length of hospitalization.

  9. Evaluation of amotosalem treated platelets over 7 days of storage with an automated cytometry assay panel.

    Science.gov (United States)

    Diquattro, M; De Francisci, G; Bonaccorso, R; Tagliavia, A M; Marcatti, M; Palma, B; Agliastro, R

    2013-12-01

    Pathogen Inactivation allows to overcome microbial contamination and growth related to storage of platelets concentrates (PC) at room temperature. The aim of our study was to evaluate the platelet storage lesion extending the storage period of pathogen inactivated platelet concentrates over 7 days using an automated cytometry assay panel. We analyzed 43 concentrates subjected to pathogen inactivation (CPPI) at 3, 5 and 7 days evaluating: platelet count, mean platelet volume, platelets at low optical density, platelets at high density, GPIIb-IIIa glycoprotein, platelet microparticles, lactate dehydrogenase. The collection bags (Fenwal) and the IBS kit made in PL2410/PL2411 are approved for the conservation of PC up to 7 days. Data analysis was performed with anova test. All the parameters except small platelets and PMP were statistically different among day 7 vs. 3 and day 7 vs. 5. Our study showed a progressive modification of pathogen inactivated platelet concentrates observed up to 7 days. The persistence of the secretory pool and the presence of the platelet membrane fibrinogen receptor suggest the persistence of a potential hemostatic efficacy. Clinical studies are necessary to directly correlate this type of analysis to 24 h recovery or survival of transfused platelets in humans. © 2013 John Wiley & Sons Ltd.

  10. Do your syringes count?

    International Nuclear Information System (INIS)

    Brewster, K.

    2002-01-01

    Full text: This study was designed to investigate anecdotal evidence that residual Sestamibi (MIBI) activity vaned in certain situations. For rest studies different brands of syringes were tested to see if the residuals varied. The period of time MIBI doses remained in the syringe between dispensing and injection was also considered as a possible source of increased residual counts. Stress Mibi syringe residual activities were measured to assess if the method of stress test affected residual activity. MIBI was reconstituted using 13 Gbq of Technetium in 3mls of normal saline then boiled for 10 minutes. Doses were dispensed according to department protocol and injected via cannula. Residual syringes were collected for three syringe types. In each case the barrel and plunger were measured separately. As the syringe is flushed during the exercise stress test and not the pharmacological stress test the chosen method was recorded. No relationship was demonstrated between the time MIBI remained in a syringe prior to injection and residual activity. Residual activity was not affected by method of stress test used. Actual injected activity can be calculated if the amount of activity remaining in the syringe post injection is known. Imaging time can be adjusted for residual activity to optimise count statistics. Preliminary results in this study indicate there is no difference in residual activity between syringe brands.Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  11. Examining platelet-fibrin interactions during traumatic shock in a swine model using platelet contractile force and clot elastic modulus.

    Science.gov (United States)

    White, Nathan J; Martin, Erika J; Brophy, Donald F; Ward, Kevin R

    2011-07-01

    A significant proportion of severely injured patients develop early coagulopathy, characterized by abnormal clot formation, which impairs resuscitation and increases mortality. We have previously demonstrated an isolated decrease in clot strength by thrombelastography in a swine model of nonresuscitated traumatic shock. In order to more closely examine platelet-fibrin interactions in this setting, we define the observed decrease in clot strength in terms of platelet-induced clot contraction and clot elastic modulus using the Hemostasis Analysis System (HAS) (Hemodyne Inc., Richmond, Virginia, USA). Whole blood was sampled for HAS measurements, metabolic measurements, cell counts, and fibrinogen concentration at baseline prior to injury and again at a predetermined level of traumatic shock defined by oxygen debt. Male swine (N=17) received femur fracture and controlled arterial hemorrhage to achieve an oxygen debt of 80 ml/kg. Platelet counts were unchanged, but fibrinogen concentration was reduced significantly during shock (167.6 vs. 66.7 mg/dl, P=0.0007). Platelet contractile force generated during clot formation did not change during shock (11.7 vs. 10.4 kdynes, P=0.41), but clot elastic modulus was dynamically altered, resulting in a lower final value (22.9 vs. 17.3 kdynes/cm, Pshock, platelet function was preserved, whereas terminal clot elastic modulus was reduced during shock in a manner most consistent with early changes in the mechanical properties of the developing fibrin fiber network.

  12. Haemostatic function and biomarkers of endothelial damage before and after platelet transfusion in patients with acute myeloid leukaemia

    DEFF Research Database (Denmark)

    Larsen, A M; Leinøe, E B; Johansson, P I

    2015-01-01

    and after platelet transfusion in patients with acute myeloid leukaemia. MATERIALS AND METHODS: Blood was sampled before, 1 and 24 h after platelet transfusion. Primary and secondary haemostasis was evaluated by whole blood aggregometry (Multiplate) and thromboelastography (TEG). Endothelial biomarkers (s......OBJECTIVES: The beneficial effect of platelet transfusion on haemostasis is well established, but there is emerging evidence that platelet transfusion induces an inflammatory response in vascular endothelial cells. BACKGROUND: We investigated haemostatic function and endothelial biomarkers before......ICAM-1, syndecan-1, sThrombomodulin, sVE-Cadherin) and platelet activation biomarkers (sCD40L, TGF-beta) were investigated along with haematology/biochemistry analyses. RESULTS: Twenty-two patients were included. Despite continued low platelet counts, platelet transfusion normalised the median values...

  13. Human platelet lysate as a promising growth-stimulating additive for culturing of stem cells and other cell types.

    Science.gov (United States)

    Shanskii, Ya D; Sergeeva, N S; Sviridova, I K; Kirakozov, M S; Kirsanova, V A; Akhmedova, S A; Antokhin, A I; Chissov, V I

    2013-11-01

    We compared the composition and biological activity of fetal calf serum and platelet lysate from donor platelet concentrate. In platelet lysate, the concentrations of alkaline phosphatase, lactate dehydrogenase, creatinine, and mineral metabolism parameters were lower, while parameters of lipid and protein metabolism were higher than in fetal calf serum. The concentrations of growth factors (platelet-derived (AA, AB, BB), vascular endothelial, insulin-like, and transforming growth factor β) in platelet lysate 1.7-148.7-fold surpassed the corresponding parameters in fetal calf serum. After replacement of fetal calf serum with platelet lysate in the culture medium (0, 25, 50, 75, and 100%), the count of multipotent mesenchymal stromal cells on day 7 (in comparison with day 1) increased by 154.8, 206.6, 228.2, 367.7, and 396.5%, respectively. Thus, platelet lysate can be an adequate non-xenogenic alternative for fetal calf serum.

  14. A radiolabeled antiglobulin test for crossmatching platelet transfusions

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  15. Assessment of platelet function in healthy cats in response to commonly prescribed antiplatelet drugs using three point-of-care platelet function tests.

    Science.gov (United States)

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

    2017-06-01

    Objectives The objective was to determine if decreased platelet function could be detected after treatment with aspirin and/or clopidogrel in healthy cats using three point-of-care platelet function tests that evaluate platelet function by different methods: Multiplate (by impedance), Platelet Function Analyzer 100 (by mechanical aperture closure) and Plateletworks (by platelet counting). Methods Thirty-six healthy cats were randomly assigned to receive one of three oral treatments over an 8 day period: (1) aspirin 5 mg q72h; (2) aspirin 20.25 mg q72h; or (3) clopidogrel 18.75 mg q24h. Cats treated with 5 and 20.25 mg aspirin also received clopidogrel on days 4-8. Platelet aggregation in response to adenosine diphosphate and collagen ± arachidonic acid was assessed on days 1 (baseline), 4 and 8. Aspirin and clopidogrel metabolites were measured by high-performance liquid chromatography. Platelet function in response to treatment was analyzed by ANCOVA, linear regression and Spearman correlation. Results The only solitary aspirin effect was detected using Plateletworks with collagen in cats treated with 20.25 mg. The only effect detected by Multiplate was using arachidonic acid in cats treated with both aspirin 20.25 mg and clopidogrel. All clopidogrel treatment effects were detected by Platelet Function Analyzer 100, Plateletworks (adenosine diphosphate) and Plateletworks (collagen). Drug metabolites were present in all cats, but concentrations were minimally correlated to platelet function test results. Conclusions and relevance Platelet Function Analyzer 100 and Plateletworks using adenosine diphosphate ± collagen agonists may be used to detect decreased platelet function in response to clopidogrel treatment. Either aspirin is not as effective an antiplatelet drug as clopidogrel, or the tests used were not optimal to measure aspirin effect. Cats with heart disease are commonly prescribed antiplatelet drugs to decrease the risk of aortic thromboembolism

  16. Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair

    DEFF Research Database (Denmark)

    Ågren, Sven Per Magnus; Rasmussen, Karina; Pakkenberg, Bente

    2014-01-01

    . Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme......·001]. MMP-9 was reduced 139-fold (P tissue regenerative applications....

  17. The human endogenous circadian system causes greatest platelet activation during the biological morning independent of behaviors.

    Directory of Open Access Journals (Sweden)

    Frank A J L Scheer

    Full Text Available Platelets are involved in the thromboses that are central to myocardial infarctions and ischemic strokes. Such adverse cardiovascular events have day/night patterns with peaks in the morning (~9 AM, potentially related to endogenous circadian clock control of platelet activation. The objective was to test if the human endogenous circadian system influences (1 platelet function and (2 platelet response to standardized behavioral stressors. We also aimed to compare the magnitude of any effects on platelet function caused by the circadian system with that caused by varied standardized behavioral stressors, including mental arithmetic, passive postural tilt and mild cycling exercise.We studied 12 healthy adults (6 female who lived in individual laboratory suites in dim light for 240 h, with all behaviors scheduled on a 20-h recurring cycle to permit assessment of endogenous circadian function independent from environmental and behavioral effects including the sleep/wake cycle. Circadian phase was assessed from core body temperature. There were highly significant endogenous circadian rhythms in platelet surface activated glycoprotein (GP IIb-IIIa, GPIb and P-selectin (6-17% peak-trough amplitudes; p ≤ 0.01. These circadian peaks occurred at a circadian phase corresponding to 8-9 AM. Platelet count, ATP release, aggregability, and plasma epinephrine also had significant circadian rhythms but with later peaks (corresponding to 3-8 PM. The circadian effects on the platelet activation markers were always larger than that of any of the three behavioral stressors.These data demonstrate robust effects of the endogenous circadian system on platelet activation in humans--independent of the sleep/wake cycle, other behavioral influences and the environment. The 9 AM timing of the circadian peaks of the three platelet surface markers, including platelet surface activated GPIIb-IIIa, the final common pathway of platelet aggregation, suggests that endogenous

  18. Next generation sequencing analysis of human platelet PolyA+ mRNAs and rRNA-depleted total RNA.

    Directory of Open Access Journals (Sweden)

    Antheia Kissopoulou

    Full Text Available BACKGROUND: Platelets are small anucleate cells circulating in the blood vessels where they play a key role in hemostasis and thrombosis. Here, we compared platelet RNA-Seq results obtained from polyA+ mRNA and rRNA-depleted total RNA. MATERIALS AND METHODS: We used purified, CD45 depleted, human blood platelets collected by apheresis from three male and one female healthy blood donors. The Illumina HiSeq 2000 platform was employed to sequence cDNA converted either from oligo(dT isolated polyA+ RNA or from rRNA-depleted total RNA. The reads were aligned to the GRCh37 reference assembly with the TopHat/Cufflinks alignment package using Ensembl annotations. A de novo assembly of the platelet transcriptome using the Trinity software package and RSEM was also performed. The bioinformatic tools HTSeq and DESeq from Bioconductor were employed for further statistical analyses of read counts. RESULTS: Consistent with previous findings our data suggests that mitochondrially expressed genes comprise a substantial fraction of the platelet transcriptome. We also identified high transcript levels for protein coding genes related to the cytoskeleton function, chemokine signaling, cell adhesion, aggregation, as well as receptor interaction between cells. Certain transcripts were particularly abundant in platelets compared with other cell and tissue types represented by RNA-Seq data from the Illumina Human Body Map 2.0 project. Irrespective of the different library preparation and sequencing protocols, there was good agreement between samples from the 4 individuals. Eighteen differentially expressed genes were identified in the two sexes at 10% false discovery rate using DESeq. CONCLUSION: The present data suggests that platelets may have a unique transcriptome profile characterized by a relative over-expression of mitochondrially encoded genes and also of genomic transcripts related to the cytoskeleton function, chemokine signaling and surface components

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

    LENUS (Irish Health Repository)

    McCabe, Dominick J H

    2004-06-01

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

  20. Blood platelet inventory management

    NARCIS (Netherlands)

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

    2017-01-01

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

  1. Alternatives to allogeneic platelet transfusion.

    Science.gov (United States)

    Desborough, Michael J R; Smethurst, Peter A; Estcourt, Lise J; Stanworth, Simon J

    2016-11-01

    Allogeneic platelet transfusions are widely used for the prevention and treatment of bleeding in thrombocytopenia. Recent evidence suggests platelet transfusions have limited efficacy and are associated with uncertain immunomodulatory risks and concerns about viral or bacterial transmission. Alternatives to transfusion are a well-recognised tenet of Patient Blood Management, but there has been less focus on different strategies to reduce bleeding risk by comparison to platelet transfusion. Direct alternatives to platelet transfusion include agents to stimulate endogenous platelet production (thrombopoietin mimetics), optimising platelet adhesion to endothelium by treating anaemia or increasing von Willebrand factor levels (desmopressin), increasing formation of cross-linked fibrinogen (activated recombinant factor VII, fibrinogen concentrate or recombinant factor XIII), decreasing fibrinolysis (tranexamic acid or epsilon aminocaproic acid) or using artificial or modified platelets (cryopreserved platelets, lyophilised platelets, haemostatic particles, liposomes, engineered nanoparticles or infusible platelet membranes). The evidence base to support the use of these alternatives is variable, but an area of active research. Much of the current randomised controlled trial focus is on evaluation of the use of thrombopoietin mimetics and anti-fibrinolytics. It is also recognised that one alternative strategy to platelet transfusion is choosing not to transfuse at all. © 2016 John Wiley & Sons Ltd.

  2. Sports medicine applications of platelet rich plasma.

    Science.gov (United States)

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

    2012-06-01

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

  3. Agonist-induced platelet reactivity correlates with bleeding in haemato-oncological patients.

    Science.gov (United States)

    Batman, B; van Bladel, E R; van Hamersveld, M; Pasker-de Jong, P C M; Korporaal, S J A; Urbanus, R T; Roest, M; Boven, L A; Fijnheer, R

    2017-11-01

    Prophylactic platelet transfusions are administered to prevent bleeding in haemato-oncological patients. However, bleeding still occurs, despite these transfusions. This practice is costly and not without risk. Better predictors of bleeding are needed, and flow cytometric evaluation of platelet function might aid the clinician in identifying patients at risk of bleeding. This evaluation can be performed within the hour and is not hampered by low platelet count. Our objective was to assess a possible correlation between bleeding and platelet function in thrombocytopenic haemato-oncological patients. Inclusion was possible for admitted haemato-oncology patients aged 18 years and above. Furthermore, an expected need for platelet transfusions was necessary. Bleeding was graded according to the WHO bleeding scale. Platelet reactivity to stimulation by either adenosine diphosphate (ADP), cross-linked collagen-related peptide (CRP-xL), PAR1- or PAR4-activating peptide (AP) was measured using flow cytometry. A total of 114 evaluations were available from 21 consecutive patients. Platelet reactivity in response to stimulation by all four studied agonists was inversely correlated with significant bleeding. Odds ratios (OR) for bleeding were 0·28 for every unit increase in median fluorescence intensity (MFI) [95% confidence interval (CI) 0·11-0·73] for ADP; 0·59 [0·40-0·87] for CRP-xL; 0·59 [0·37-0·94] for PAR1-AP; and 0·43 [0·23-0·79] for PAR4-AP. The platelet count was not correlated with bleeding (OR 0·99 [0·96-1·02]). Agonist-induced platelet reactivity was significantly correlated to bleeding. Platelet function testing could provide a basis for a personalized transfusion regimen, in which platelet transfusions are limited to those at risk of bleeding. © 2017 International Society of Blood Transfusion.

  4. 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.

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

    Science.gov (United States)

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

    2012-04-01

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

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Monique Ramos de Oliveira Trugilho

    2017-05-01

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

  8. Rethinking platelet function: thrombocytopenia induced immunodeficiency in critical illness

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Johansson, Per Ingemar

    2011-01-01

    Thrombocytopenia in critical illness predicts a poor clinical outcome. Apart from its role in microvascular thrombus formation, it is widely anticipated that this association is indirect rather than causal. Emerging evidence however indicates that platelets are also immune competent cells. Like...... per se results in immunodeficiency through loss of platelet-mediated immune functions, and propose that thrombocytopenia induced immunodeficiency in critical illness in part explain the negative predictive value of low or declining platelet count. We propose that rethinking the risks...... of thrombocytopenia to include not only bleeding but also immunodeficiency and immune dysregulation along with the conduct of studies investigating mechanisms contributing to thrombocytopenia induced poor non-hemorrhagic outcome in critical illness, may be means to improve outcome in these patients through...

  9. Effects of hormones on platelet aggregation.

    Science.gov (United States)

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

    2014-04-01

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

  10. STUDY ON PLATELET INDICES IN PREGNANCY INDUCED HYPERTENSION

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2017-11-10

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

  12. Methods for genetic modification of megakaryocytes and platelets.

    Science.gov (United States)

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

    2007-09-01

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

  13. Platelet lysate obtained via plateletpheresis performed in standing and awake equine donors.

    Science.gov (United States)

    Sumner, Scarlett M; Naskou, Maria C; Thoresen, Merrilee; Copland, Ian; Peroni, John F

    2017-07-01

    Platelet preparations containing growth factors, attachment factors, and enzymes are appealing to enhance healing of injured tissues and as an alternative to xenogenic serum in cell culture media. Plateletpheresis is commonly used to collect platelets in human medicine but has not been validated in horses. Plateletpheresis to collect platelet concentrate was performed on six female, mixed breed, chemically restrained horses using commercially available apheresis equipment. Before and immediately after plateletpheresis, we performed physical examinations and collected blood for chemistry and coagulation panels and then again at 8, 16, 24, and 48 hours after the procedure. To produce platelet lysate, the platelet concentrate underwent two freeze-thaw cycles followed by centrifugation and filtration processing. The platelet lysate was then analyzed for cellular debris, fibrinogen, and growth factors. The collected platelet concentration contained a mean platelet yield of 390 × 10 3 /μL. Donor platelet count decreased from a mean of 193 × 10 3 /μL to 138 × 10 3 /μL after plateletpheresis, but no individual was at risk for hemorrhage. Pooled platelet lysate had minimal cellular residue and contained growth factor concentrations at 6.1 ng/mL for transforming growth factor-β1, at 3.5 ng/mL for platelet-derived growth factor-BB, and at 13.8 ng/mL for vascular endothelial growth factor-A. Plateletpheresis using commercially available apheresis equipment is a feasible option for collecting platelet concentrate from equine donors. The lysate generated from the apheresis product contains growth factors and has potential to be used as a fetal bovine serum substitute for cell culture. © 2017 AABB.

  14. 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

  15. Human Platelet Senescence Study.

    Science.gov (United States)

    1980-03-01

    ability to measure certain enzymes to their oxidation-reduc other enzymes which can be measured by o phosphatase , acid phosphatase , chymotryp...alkaline sin, trypsin, esterases (17)); M use of n A or wheat germ agglutinin in the second etect specific carbohydrate constituents. We have...Von Willebrand factor. Nurden and Caen also demonstrated that GPI was rich in sialic acid (5) and probably responsible for the platelets’ surface

  16. Platelet-Derived MRP-14 Induces Monocyte Activation in Patients With Symptomatic Peripheral Artery Disease.

    Science.gov (United States)

    Dann, Rebecca; Hadi, Tarik; Montenont, Emilie; Boytard, Ludovic; Alebrahim, Dornaszadat; Feinstein, Jordyn; Allen, Nicole; Simon, Russell; Barone, Krista; Uryu, Kunihiro; Guo, Yu; Rockman, Caron; Ramkhelawon, Bhama; Berger, Jeffrey S

    2018-01-02

    Peripheral artery disease (PAD), a diffuse manifestation of atherothrombosis, is a major cardiovascular threat. Although platelets are primary mediators of atherothrombosis, their role in the pathogenesis of PAD remains unclear. The authors sought to investigate the role of platelets in a cohort of symptomatic PAD. The authors profiled platelet activity, mRNA, and effector roles in patients with symptomatic PAD and in healthy controls. Patients with PAD and carotid artery stenosis were recruited into ongoing studies (NCT02106429 and NCT01897103) investigating platelet activity, platelet RNA, and cardiovascular disease. Platelet RNA sequence profiling mapped a robust up-regulation of myeloid-related protein (MRP)-14 mRNA, a potent calcium binding protein heterodimer, in PAD. Circulating activated platelets were enriched with MRP-14 protein, which augmented the expression of the adhesion mediator, P-selectin, thereby promoting monocyte-platelet aggregates. Electron microscopy confirmed the firm interaction of platelets with monocytes in vitro and colocalization of macrophages with MRP-14 confirmed their cross talk in atherosclerotic manifestations of PAD in vivo. Platelet-derived MRP-14 was channeled to monocytes, thereby fueling their expression of key PAD lesional hallmarks and increasing their directed locomotion, which were both suppressed in the presence of antibody-mediated blockade. Circulating MRP-14 was heightened in the setting of PAD, significantly correlated with PAD severity, and was associated with incident limb events. The authors identified a heightened platelet activity profile and unraveled a novel immunomodulatory effector role of platelet-derived MRP-14 in reprograming monocyte activation in symptomatic PAD. (Platelet Activity in Vascular Surgery and Cardiovascular Events [PACE]; NCT02106429; and Platelet Activity in Vascular Surgery for Thrombosis and Bleeding [PIVOTAL]; NCT01897103). Copyright © 2018 American College of Cardiology Foundation

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

    Directory of Open Access Journals (Sweden)

    Robert eSokolic

    2015-06-01

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

  18. [Single-donor (apheresis) platelets and pooled whole-blood-derived platelets--significance and assessment of both blood products].

    Science.gov (United States)

    Hitzler, Walter E

    2014-01-01

    , considering five (5) donations per year, theoretically, it would mean 100 donors infected and 500 infectious ATK. Considering 15 apheresis donations per donor per year, this would mean that 33 donors are infected, but still 500 infectious ATK would be produced. The prion is an example of a pathogen that, although its existence is well known, cannot be proven or pathogen-reduced. In addition, it has a very long incubation period compared to the donation intervals. Due to the manufacturing process, PTK has a 4-fold higher donor exposure and therefore a 4-fold higher risk for transfusion-transmitted infections compared to ATK. If a patient needs the transfusion of two platelet concentrates, by transfusing a double-ATK from the same donor the risk of transfusion-transmitted infections will remain the same. On the other hand, the risk will increase by 8-fold by transfusing two PTK. The only current possibility to prevent or to minimize the risk of infection with prions is to minimize the donor exposure by transfusing ATK instead of PTK. Hypothetical risk scenarios carry significant weight in law. This can be seen in the constant rulings of the German Federal Supreme Court (Bundesgerichtshofs (BGH)) on the so-called hypothetical risk explanations (BGH, NJW 1996, 776, 777; 2000, 1784, 1787; 2005, 2614, 2616). Therefore, a risk does not need to be confirmed to be subject to compulsory explanation. It is sufficient that serious voices in the medical scientific community point to specific risks, which cannot be set aside as insignificant outside opinions, but must be viewed as serious warnings. According to the rulings, patients must even be informed of rare and often extremely rare risks, which could, should they come true, significantly impact daily life and, despite their rarity, are specific to the treatment and are startling for the ordinary person (BGH, 15.02.2000- VI ZR 48199 -; BGH, 30.11.2004 - VI ZR 209104 -; OLG Hamm, 29.09.2010 - 1-3 V 169109). These conditions have been

  19. Description of a double centrifugation tube method for concentrating canine platelets

    OpenAIRE

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

    2013-01-01

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

  20. 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)

  1. Increased mean platelet volume in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Ezgi Coşkun Yenigün

    2014-03-01

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

  2. Inhibition of Platelet Aggregation by Supernates from Stored Red Blood Cells

    Science.gov (United States)

    2010-04-01

    450 μl of blood or 450 μl of platelet rich plasma (PRP) was mixed with 225 μl of supernate plus 225 μl of Tyrode’s buffer and incubated for ten... platelet counts, prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin split products, and FVIII:Rag also measured 30 minutes...RTO-MP-HFM-182 22 - 1 Inhibition of Platelet Aggregation by Supernates from Stored Red Blood Cells Dr. Steve J. McFaul, LT Frederick A

  3. Description of a double centrifugation tube method for concentrating canine platelets.

    Science.gov (United States)

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

    2013-07-22

    To evaluate the efficiency of platelet-rich plasma preparations by means of a double centrifugation tube method to obtain platelet-rich canine plasma at a concentration at least 4 times higher than the baseline value and a concentration of white blood cells not exceeding twice the reference range. A complete blood count was carried out for each sample and each concentrate. Whole blood samples were collected from 12 clinically healthy dogs (consenting blood donors). Blood was processed by a double centrifugation tube method to obtain platelet concentrates, which were then analyzed by a flow cytometry haematology system for haemogram. Platelet concentration and white blood cell count were determined in all samples. Platelet concentration at least 4 times higher than the baseline value and a white blood cell count not exceeding twice the reference range were obtained respectively in 10 cases out of 12 (83.3%) and 11 cases out of 12 (91.6%). This double centrifugation tube method is a relatively simple and inexpensive method for obtaining platelet-rich canine plasma, potentially available for therapeutic use to improve the healing process.

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

    Science.gov (United States)

    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.

  5. Six hours of resting platelet concentrates stored at 22-24 ºC for 48 hours in permeable bags preserved pH, swirling and lactate dehydrogenase better and caused less platelet activation.

    Science.gov (United States)

    Naghadeh, Hossin T; Badlou, Bahram A; Ferizhandy, Ali S; Mohammadreza, Tabatabai S; Shahram, Vaeli

    2013-07-01

    During transportation, platelet concentrates (PC) usually undergo a long period without agitation. Whether this interruption improves quality and viability or, contrariwise, has deleterious effects on PC stored for 48 hours (h) is unknown. The aim of this study was to investigate the effects of metabolic resting (6 h of interruption of agitation) vs continue agitation of PC stored for 48 h in the blood bank of Tehran. PC were prepared from platelet-rich plasma and stored in permeable bags in a shaker/incubator for 42 h at room temperature (20-24 ºC). Then, simply by stopping the agitator, the PC remained stationary ("resting") without agitation for 6 h (WCA6h), prior to transfusion. In vitro measurements of platelet quality were carried out just after completion of the resting period and the results were compared with those of PC continuously agitated in the same day (designated as the control group, CA6h). The in vitro variables measured were swirling, ristocetin-induced aggregation (GPIb-related function), lactate dehydrogenase (LDH) concentration, platelet factor 4 (PF4) release and P-selectin expression (activation markers). The mean platelet counts of the control group (CA6h) and rested (WCA6h) PC were not statistically different (P =0.548). Likewise, the mean pH values were not significantly different: WCA6h (7.16 ± 0.08) and CA6h (7.22 ± 0.16) (P =0.300). Although ristocetin-induced aggregation did not differ significantly between CA6h (79.2 ± 4.4) and WCA6h (66.65 ± 28.55) (P =0.186), WCA6h showed significantly less PFA release (P =0.015) and lower P-selectin expression (P =0.006). We observed that PC stored under agitation for 42 h at 22-24 ºC in permeable bags and then rested for 6 h had better preserved pH, swirling and LDH and less platelet activation then PC kept under continuous agitation for the whole 48 h storage period.

  6. Determining random counts in liquid scintillation counting

    International Nuclear Information System (INIS)

    Horrocks, D.L.

    1979-01-01

    During measurements involving coincidence counting techniques, errors can arise due to the detection of chance or random coincidences in the multiple detectors used. A method and the electronic circuits necessary are here described for eliminating this source of error in liquid scintillation detectors used in coincidence counting. (UK)

  7. Effect of different aspirin doses on arterial thrombosis after canine carotid endarterectomy: a scanning electron microscope and indium-111-labeled platelet study

    International Nuclear Information System (INIS)

    Ercius, M.S.; Chandler, W.F.; Ford, J.W.; Swanson, D.P.; Burke, J.C.

    1984-01-01

    Although it is widely accepted that aspirin inhibits platelet aggregation in arterial thrombosis, the appropriate dosage of aspirin remains quite controversial. The purpose of this study was to determine the effect of different doses of aspirin (0.5 mg/kg vs. 10 mg/kg) on mural thrombus formation after carotid endarterectomy. Eighteen hours after oral aspirin administration, 20 endarterectomies were performed on mongrel dogs with the use of the operating microscope. Blood flow was then restored for 3 hours and the vessels were prepared for investigation with the scanning electron microscope. Ten endarterectomies were also performed on unmedicated dogs as controls. Five minutes before vessel unclamping, autologous indium-111-labeled platelets were administered intravenously, and the endarterectomized portions of the vessels were studied with a gamma counter system after harvesting. Group 1, the control group, revealed extensive mural thrombus consisting of platelet aggregates, fibrin, red blood cells, and white blood cells. Six of the 10 vessels in Group 2, premedicated with 0.5 mg of aspirin per kg, demonstrated varying amounts of mural thrombus. Group 3 (10 vessels), premedicated with 10 mg of aspirin per kg, revealed a platelet monolayer completely covering the exposed vessel wall media, with scattered white blood cells and infrequent fine fibrin strands overlying the platelet surface. The mean (+/- SD) radioactivity per group expressed as counts/minute/mm2 was: Group 1--2055.3 +/- 1905.5, log . 7.253 +/- 0.926; Group 2--1235.6 +/- 1234.3, log . 6.785 +/- 0.817; Group 3--526 +/- 433.06, log . 5.989 +/- 0.774

  8. 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...

  9. 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.

  10. Use of 8-methoxypsoralen and long-wavelength ultraviolet radiation for decontamination of platelet concentrates

    International Nuclear Information System (INIS)

    Lin, L.; Wiesehahn, G.P.; Morel, P.A.; Corash, L.

    1989-01-01

    Transmission of viral diseases through blood products remains an unsolved problem in transfusion medicine. We have developed a psoralen photochemical system for decontamination of platelet concentrates in which platelets are treated with long wavelength ultraviolet radiation (UVA, 320-400 nm) in the presence of 8-methoxypsoralen (8-MOP). Bacteria, RNA viruses, and DNA viruses ranging in genome size from 1.2 x 10(6) daltons, encompassing the size range of human pathogens, were inoculated into platelet concentrates and subjected to treatment. This system inactivated 25 to 30 logs/h of bacteria Escherichia coli or Staphylococcus aureus, 6 logs/h of bacteriophage fd, 0.9 log/h of bacteriophage R17 and 1.1 logs/h of feline leukemia virus (FeLV) in platelet concentrates maintained in standard storage bags. Platelet integrity and in vitro function before, immediately following photochemical treatment, and during prolonged storage after treatment, were evaluated by measuring: (1) extracellular pH; (2) platelet yields; (3) extracellular lactate dehydrogenase (LDH) levels; (4) platelet morphology; (5) platelet aggregation responsiveness; (6) thromboxane beta-2 (TXB-2) production; (7) dense body secretion; and (8) alpha granule secretion. These assays demonstrated that this photochemical inactivation system inactivated bacteria and viruses in platelet concentrates with minimal adverse effects on the in vitro function of platelets in comparison to untreated control concentrates maintained under current, standard blood bank conditions

  11. Use of 8-methoxypsoralen and long-wavelength ultraviolet radiation for decontamination of platelet concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Lin, L.; Wiesehahn, G.P.; Morel, P.A.; Corash, L. (Diamond Scientific Company, Des Moines, IA (USA))

    1989-07-01

    Transmission of viral diseases through blood products remains an unsolved problem in transfusion medicine. We have developed a psoralen photochemical system for decontamination of platelet concentrates in which platelets are treated with long wavelength ultraviolet radiation (UVA, 320-400 nm) in the presence of 8-methoxypsoralen (8-MOP). Bacteria, RNA viruses, and DNA viruses ranging in genome size from 1.2 x 10(6) daltons, encompassing the size range of human pathogens, were inoculated into platelet concentrates and subjected to treatment. This system inactivated 25 to 30 logs/h of bacteria Escherichia coli or Staphylococcus aureus, 6 logs/h of bacteriophage fd, 0.9 log/h of bacteriophage R17 and 1.1 logs/h of feline leukemia virus (FeLV) in platelet concentrates maintained in standard storage bags. Platelet integrity and in vitro function before, immediately following photochemical treatment, and during prolonged storage after treatment, were evaluated by measuring: (1) extracellular pH; (2) platelet yields; (3) extracellular lactate dehydrogenase (LDH) levels; (4) platelet morphology; (5) platelet aggregation responsiveness; (6) thromboxane beta-2 (TXB-2) production; (7) dense body secretion; and (8) alpha granule secretion. These assays demonstrated that this photochemical inactivation system inactivated bacteria and viruses in platelet concentrates with minimal adverse effects on the in vitro function of platelets in comparison to untreated control concentrates maintained under current, standard blood bank conditions.

  12. Response to platelet-activating factor in human platelets stored and aged in plasma. Decrease in aggregation, phosphoinositide turnover, and receptor affinity

    International Nuclear Information System (INIS)

    Shukla, S.D.; Morrison, W.J.; Klachko, D.M.

    1989-01-01

    Human platelet concentrates were stored in polyolefin bags at 22 to 24 degrees C on a horizontal shaker for up to 8 days. At different intervals, aliquots of platelet-rich plasma (PRP) were removed aseptically and five variables, i.e., platelet counts, morphology, platelet-activating factor (PAF)-stimulated aggregation, phosphoinositide turnover, and [3H]PAF binding to platelet receptors, were studied. The number of platelets did not change during the 8 days of storage. Scanning electron microscopy of the platelets revealed a gradual morphologic change from biconcave flat discs to irregular, crenated forms. The PAF-induced aggregation of platelets declined with time of storage. A decrease to 50 percent of the Day 1 aggregatory response to PAF was evident on Day 2, and there was a further decline to about 20 percent by Day 6. Similarly, PAF receptor-coupled phosphoinositide turnover, as monitored by 32P incorporation into individual phosphoinositides, decreased dramatically with storage. After 2 to 3 days of storage, the phosphoinositide turnover was reduced to 50 percent of the original response, and it continued to decline to about 25 percent of original response by Day 5 or 6. The binding of [3H]PAF to washed human platelets indicated subtle changes between Days 2 and 4, which became more noticeable by Day 6. These results have raised the possibility of changes in the number of the receptors and/or their affinity for the ligand during storage. We conclude that although the number of platelets was maintained during storage for 8 days, a general deterioration of their responses to PAF occurred at the levels of cell surface receptor, transmembrane signaling (phosphoinositide turnover), and response (aggregation)

  13. 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.

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Badimon, L.; Fuster, V.; Chesebro, J.H.; Dewanjee, M.K.

    1983-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  17. The feed gas composition determines the degree of physical plasma-induced platelet activation for blood coagulation

    Science.gov (United States)

    Bekeschus, Sander; Brüggemeier, Janik; Hackbarth, Christine; Weltmann, Klaus-Dieter; von Woedtke, Thomas; Partecke, Lars-Ivo; van der Linde, Julia

    2018-03-01

    Cold atmospheric (physical) plasma has long been suggested to be a useful tool for blood coagulation. However, the clinical applicability of this approach has not been addressed sufficiently. We have previously demonstrated the ability of a clinically accepted atmospheric pressure argon plasma jet (kINPen® MED) to coagulate liver incisions in mice with similar performance compared to the gold standard electrocauterization. We could show that plasma-mediated blood coagulation was dependent on platelet activation. In the present work, we extended on this by investigating kINPen®-mediated platelet activation in anticoagulated human donor blood ex vivo. With focus on establishing high-throughput, multi-parametric platelet activation assays and performing argon feed gas parameter studies we achieved the following results: (i) plasma activated platelets in heparinized but not in EDTA-anticoagulated blood; (ii) plasma decreased total platelet counts but increased numbers of microparticles; (iii) plasma elevated the expression of several surface activation markers on platelets (CD62P, CD63, CD69, and CD41/61); (iv) in platelet activation, wet and dry argon plasma outperformed feed gas admixtures with oxygen and/or nitrogen; (v) plasma-mediated platelet activation was accompanied by platelet aggregation. Platelet aggregation is a necessary requirement for blood clot formation. These findings are important to further elucidate molecular details and clinical feasibility of cold physical plasma-mediated blood coagulation.

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

    Directory of Open Access Journals (Sweden)

    Trevor P. Fidler

    2017-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Daniela eWeth

    2015-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Olga Meltem Akay

    2016-05-01

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

  1. Temporal trends in sperm count

    DEFF Research Database (Denmark)

    Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson

    2017-01-01

    a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years.......006, respectively). WIDER IMPLICATIONS: This comprehensive meta-regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because......BACKGROUND: Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality. OBJECTIVE AND RATIONALE: To provide a systematic review and meta-regression...

  2. Clean Hands Count

    Medline Plus

    Full Text Available ... Like this video? Sign in to make your opinion count. Sign in 131 2 Don't like this video? Sign in to make your opinion count. Sign in 3 Loading... Loading... Transcript The ...

  3. The Big Pumpkin Count.

    Science.gov (United States)

    Coplestone-Loomis, Lenny

    1981-01-01

    Pumpkin seeds are counted after students convert pumpkins to jack-o-lanterns. Among the activities involved, pupils learn to count by 10s, make estimates, and to construct a visual representation of 1,000. (MP)

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

    Directory of Open Access Journals (Sweden)

    Hadadi Laszlo

    2015-12-01

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

  5. 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

  6. The effects of residual platelets in plasma on plasminogen activator inhibitor-1 and plasminogen activator inhibitor-1-related assays.

    Directory of Open Access Journals (Sweden)

    Marlien Pieters

    Full Text Available Due to controversial evidence in the literature pertaining to the activity of plasminogen activator inhibitor-1 in platelets, we examined the effects of residual platelets present in plasma (a potential pre-analytical variable on various plasminogen activator inhibitor-1 and plasminogen activator inhibitor-1-related assays. Blood samples were collected from 151 individuals and centrifuged at 352 and 1500 g to obtain plasma with varying numbers of platelet. In a follow-up study, blood samples were collected from an additional 23 individuals, from whom platelet-poor (2000 g, platelet-containing (352 g and platelet-rich plasma (200 g were prepared and analysed as fresh-frozen and after five defrost-refreeze cycles (to determine the contribution of in vitro platelet degradation. Plasminogen activator inhibitor-1 activity, plasminogen activator inhibitor-1 antigen, tissue plasminogen activator/plasminogen activator inhibitor-1 complex, plasma clot lysis time, β-thromboglobulin and plasma platelet count were analysed. Platelet α-granule release (plasma β-thromboglobulin showed a significant association with plasminogen activator inhibitor-1 antigen levels but weak associations with plasminogen activator inhibitor-1 activity and a functional marker of fibrinolysis, clot lysis time. Upon dividing the study population into quartiles based on β-thromboglobulin levels, plasminogen activator inhibitor-1 antigen increased significantly across the quartiles while plasminogen activator inhibitor-1 activity and clot lysis time tended to increase in the 4th quartile only. In the follow-up study, plasma plasminogen activator inhibitor-1 antigen was also significantly influenced by platelet count in a concentration-dependent manner. Plasma plasminogen activator inhibitor-1 antigen levels increased further after complete platelet degradation. Residual platelets in plasma significantly influence plasma plasminogen activator inhibitor-1 antigen levels mainly

  7. 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.

  8. Standardization of a Protocol for Obtaining Platelet Rich Plasma from blood Donors; a Tool for Tissue Regeneration Procedures.

    Science.gov (United States)

    Gómez, Lina Andrea; Escobar, Magally; Peñuela, Oscar

    2015-01-01

    To develop a protocol for obtaining autologous platelet rich plasma in healthy individuals and to determine the concentration of five major growth factors before platelet activation. This protocol could be integrated into the guidelines of good clinical practice and research in regenerative medicine. Platelet rich plasma was isolated by centrifugation from 38 healthy men and 42 women ranging from 18 to 59 years old. The platelet count and quantification of growth factors were analyzed in eighty samples, stratified for age and gender of the donor. Analyses were performed using parametric the t-test or Pearson's analysis for non-parametric distribution. P platelet counts from 1.6 to 4.9 times (mean = 2.8). There was no correlation between platelet concentration and the level of the following growth factors: VEGF-D (r = 0.009, p = 0.4105), VEGF-A (r = 0.0068, p = 0.953), PDGF subunit AA (p = 0.3618; r = 0.1047), PDGF-BB (p = 0.5936; r = 0.6095). In the same way, there was no correlation between donor gender and growth factor concentrations. Only TGF-β concentration was correlated to platelet concentration (r = 0.3163, p = 0.0175). The procedure used allowed us to make preparations rich in platelets, low in leukocytes and red blood cells, and sterile. Our results showed biological variations in content of growth factors in PRP. The factors influencing these results should be further studied.

  9. Radiation counting statistics

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Jee, K. Y.; Park, K. K.; Park, Y. J.; Kim, W. H

    1999-08-01

    This report is intended to describe the statistical methods necessary to design and conduct radiation counting experiments and evaluate the data from the experiment. The methods are described for the evaluation of the stability of a counting system and the estimation of the precision of counting data by application of probability distribution models. The methods for the determination of the uncertainty of the results calculated from the number of counts, as well as various statistical methods for the reduction of counting error are also described. (Author). 11 refs., 8 tabs., 8 figs.

  10. Radiation counting statistics

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Jee, K. Y.; Park, K. K. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-08-01

    This report is intended to describe the statistical methods necessary to design and conduct radiation counting experiments and evaluate the data from the experiments. The methods are described for the evaluation of the stability of a counting system and the estimation of the precision of counting data by application of probability distribution models. The methods for the determination of the uncertainty of the results calculated from the number of counts, as well as various statistical methods for the reduction of counting error are also described. 11 refs., 6 figs., 8 tabs. (Author)

  11. Radiation counting statistics

    International Nuclear Information System (INIS)

    Suh, M. Y.; Jee, K. Y.; Park, K. K.; Park, Y. J.; Kim, W. H.

    1999-08-01

    This report is intended to describe the statistical methods necessary to design and conduct radiation counting experiments and evaluate the data from the experiment. The methods are described for the evaluation of the stability of a counting system and the estimation of the precision of counting data by application of probability distribution models. The methods for the determination of the uncertainty of the results calculated from the number of counts, as well as various statistical methods for the reduction of counting error are also described. (Author). 11 refs., 8 tabs., 8 figs

  12. 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

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Chitlur M

    2017-04-01

    patients with suspected platelet refractoriness should be referred to such a hematologist as early as possible. A critical unmet need is the development of a definition of an adequate response to platelet transfusion, which would facilitate early recognition of platelet refractoriness in patients with PFDs who exhibit a normal platelet count. Keywords: platelet function disorder, Glanzmann’s thrombasthenia, alloantibodies, antiplatelet antibodies, platelet refractoriness, bleeding management

  15. Platelet crossmatch tests using radiolabelled staphylococcal protein A or peroxidase anti-peroxidase in alloimmunised patients

    International Nuclear Information System (INIS)

    Yam, P.; Petz, L.D.; Scott, E.P.; Santos, S.

    1984-01-01

    Refractoriness to random-donor platelets as a result of alloimmunization remains a major problem in long-term platelet transfusion therapy despite the use of HLA-matched platelets. A study has been made of two methods for detection of platelet associated IgG as platelet crossmatch tests for the selection of platelet donors. These methods use radiolabelled staphylococcal protein A( 125 I-SPA) and peroxidase anti-peroxidase (PAP), respectively. One hundred and ten crossmatch tests using 125 I-SPA were performed retrospectively in 18 alloimmunized patients. The results indicated that the predictive value of a positive or a negative test was 87%; the sensitivity was 73% and the specificity was 95%. Results with the PAP test were similar. The HLA types were known for 48 donor-recipient pairs. With few exceptions, there was a correlation between the results of the platelet crossmatch tests and the effectiveness of platelet transfusion regardless of the degree of HLA match. These results indicate that platelet crossmatch tests may be valuable even when closely HLA matched donors are not available. A large-scale prospective study is warranted, particularly in highly immunized patients. (author)

  16. Impact of local anaesthetics and needle calibres used for painless PRP injections on platelet functionality.

    Science.gov (United States)

    Bausset, Olivier; Magalon, Jeremy; Giraudo, Laurent; Louis, Marie-Laure; Serratrice, Nicolas; Frere, Corrine; Magalon, Guy; Dignat-George, Françoise; Sabatier, Florence

    2014-01-01

    The platelet-rich plasma (PRP) is an autologous biotherapy commonly used for its healing properties. Once activated, platelets released a real "cocktail" of growth factor and cytokines implied in numerous regenerative processes. However the impact of medical practices associated to PRP therapeutic use on platelets functionality remains poorly known. we evaluated the in vitro effects of two commonly used local anesthetics (Xylocaine(*) and Naropin(*)) on PRP functionality. We also investigated the quantity and quality of PRP that passed through the smallest gauge needle commercialized. PRP from 9 healthy volunteers were prepared using our previously described home made purification protocol. Platelet aggregation capacity was evaluated by aggregometry assays and the growth factor release was determined by ELISA after platelet activation. We also evaluated the platelet activation status, reactivity and stability of platelets by flow cytometry using the P-selectin expression marker. the association of local anaesthetics with PRP injections resulted in a significant decrease of platelets functionality, assessed by their capacity of aggregating. Local anaesthetics did not interfere with the growth factor release. The different needle sizes and calibres tested for PRP injections did not influence the platelet functionality. the use of local anaesthetics to prevent pain during PRP injections could compromise the therapeutic potential of PRP. These results suggest using carefully local anaesthetics or limiting their use as often is possible. To minimize injection pain, we recommend using 30 G needles. These data will lead to clinical recommendations for painless and controlled PRP injections.

  17. 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.

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

    Science.gov (United States)

    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.

  19. Valproic acid modulates platelet and coagulation function ex vivo

    DEFF Research Database (Denmark)

    Bambakidis, Ted; Dekker, Simone E; Halaweish, Ihab

    2017-01-01

    of coagulopathy, it remains unknown whether this is a direct effect of the drug, or the establishment of an overall prosurvival phenotype. We thus conducted an ex-vivo experiment to determine if VPA has an effect on coagulation and platelet function. Ten swine were subjected to traumatic brain injury (TBI...

  20. Prophylactic platelets in dengue

    DEFF Research Database (Denmark)

    Whitehorn, James; Rodriguez Roche, Rosmari; Guzman, Maria G

    2012-01-01

    Dengue is the most important arboviral infection of humans. Thrombocytopenia is frequently observed in the course of infection and haemorrhage may occur in severe disease. The degree of thrombocytopenia correlates with the severity of infection, and may contribute to the risk of haemorrhage...... of platelets in dengue. Respondents were all physicians involved with the treatment of patients with dengue. Respondents were asked that their answers reflected what they would do if they were the treating physician. We received responses from 306 physicians from 20 different countries. The heterogeneity...... of the responses highlights the variation in clinical practice and lack of an evidence base in this area and underscores the importance of prospective clinical trials to address this key question in the clinical management of patients with dengue....

  1. 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

  2. A Cdc42/RhoA regulatory circuit downstream of glycoprotein Ib guides transendothelial platelet biogenesis

    DEFF Research Database (Denmark)

    Dütting, Sebastian; Gaits-Iacovoni, Frederique; Stegner, David

    2017-01-01

    Blood platelets are produced by large bone marrow (BM) precursor cells, megakaryocytes (MKs), which extend cytoplasmic protrusions (proplatelets) into BM sinusoids. The molecular cues that control MK polarization towards sinusoids and limit transendothelial crossing to proplatelets remain unknown...

  3. The counting of native blood cells by digital microscopy

    Science.gov (United States)

    Torbin, S. O.; Doubrovski, V. A.; Zabenkov, I. V.; Tsareva, O. E.

    2017-03-01

    An algorithm for photographic images processing of blood samples in its native state was developed to determine the concentration of erythrocytes, leukocytes and platelets without individual separate preparation of cells' samples. Special "photo templates" were suggested to use in order to identify red blood cells. The effect of "highlighting" of leukocytes, which was found by authors, was used to increase the accuracy of this type of cells counting. Finally to raise the resolution of platelets from leukocytes the areas of their photo images were used, but not their sizes. It is shown that the accuracy of cells counting for native blood samples may be comparable with the accuracy of similar studies for smears. At the same time the proposed native blood analysis simplifies greatly the procedure of sample preparation in comparison to smear, permits to move from the detection of blood cells ratio to the determination of their concentrations in the sample.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-12-01

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

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

    International Nuclear Information System (INIS)

    Yamada, Makoto; Onishi, Kenji; Fukunami, Masatake

    1988-01-01

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

  7. 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

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

    Science.gov (United States)

    Meess, A

    2015-01-01

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

  9. Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

    Directory of Open Access Journals (Sweden)

    Dana Védy

    2009-04-01

    Full Text Available Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

  10. 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.

  11. Is the thrombopoietin assay useful for differential diagnosis of thrombocytopenia? Analysis of a cohort of 160 patients with thrombocytopenia and defined platelet life span.

    Science.gov (United States)

    Gouin-Thibault, I; Cassinat, B; Chomienne, C; Rain, J D; Najean, Y; Schlageter, M H

    2001-09-01

    Thrombopoietin (TPO), the major hormone controlling platelet production, has been measured in thrombocytopenias with discordant results. The aim of our work was to assess the value of the TPO assay for differential diagnosis of thrombocytopenias in a large cohort of patients classified according to the results of their platelet isotopic study. We measured TPO (R&D Systems) in serum of 160 thrombocytopenic patients referred to our department for platelet life span isotopic studies. We classified patients as follows: (a) idiopathic or autoimmune thrombocytopenia group (ITP; patients with increased platelet destruction and shortened platelet life span; n = 67); (b) pure genetic thrombocytopenia group (patients with decreased platelet production, normal platelet life span, and without bone marrow aplasia; n = 55); (c) bone marrow aplasia group (BM; patients with decreased platelet production, normal platelet life span, and bone marrow aplasia; n = 13). In patients with pure genetic thrombocytopenia, TPO (median, 55 ng/L) was not different from TPO in patients with ITP (median, 58 ng/L) or controls (n = 54; median, 51 ng/L). Only in patients with bone marrow aplasia was TPO significantly higher (median, 155 ng/L) and negatively correlated to the platelet count (r(2) = 0.5014). Although the median serum TPO is increased in thrombocytopenia with decreased platelet production from bone marrow aplasia, it does not differentiate patients with pure genetic thrombocytopenia from those with ITP.

  12. Predictable efficacy for splenic artery embolization with sites of sequestration using 99mTc labeled platelets in immunogenic idiopathic thrombocytopenic purpura

    International Nuclear Information System (INIS)

    Tian Aiping

    1992-01-01

    28 patients with chronic Immunogenic (Idiopathic) Thrombocytopenic purpura (ITP) were determined of the site of sequestration using 99m Tc labeled platelets. Among them, partial splenic artery embolization were done in 20 patients. 7/8 spleen type cases and 1/6 hepato-spleen hepatic type cases have their platelets counts raised above 100 x 10 9 /L. The separation of platelets and its 99m Tc labelling method were also discussed. Above results suggested that the determination of sequestration site of the 99m Tc labelled platelets have some help for the splenic artery embolization therapy in ITP

  13. Administration of platelet concentrates suspended in bicarbonated Ringer's solution in children who had platelet transfusion reactions.

    Science.gov (United States)

    Kobayashi, J; Yanagisawa, R; Ono, T; Tatsuzawa, Y; Tokutake, Y; Kubota, N; Hidaka, E; Sakashita, K; Kojima, S; Shimodaira, S; Nakamura, T

    2018-02-01

    Adverse reactions to platelet transfusions are a problem. Children with primary haematological and malignant diseases may experience allergic transfusion reactions (ATRs) to platelet concentrates (PCs), which can be prevented by giving washed PCs. A new platelet additive solution, using bicarbonated Ringer's solution and acid-citrate-dextrose formula A (BRS-A), may be better for platelet washing and storage, but clinical data are scarce. A retrospective cohort study for consecutive cases was performed between 2013 and 2017. For 24 months, we transfused washed PCs containing BRS-A to children with primary haematological and malignant diseases and previous adverse reactions. Patients transfused with conventional PCs (containing residual plasma) were assigned as controls, and results were compared in terms of frequency of ATRs, corrected count increment (CCI) and occurrence of bleeding. We also studied children transfused with PCs washed by a different system as historical controls. Thirty-two patients received 377 conventional PC transfusions. ATRs occurred in 12 (37·5%) patients from transfused with 18 (4·8%) bags. Thirteen patients, who experienced reactions to regular PCs in plasma, then received 119 transfusion bags of washed PCs containing BRS-A, and none had ATRs to washed PCs containing BRS-A. Before study period, six patients transfused 137 classical washed PCs with different platelet additive solution, under same indication, ATRs occurred in one (16·7%) patient from transfused with one (0·7%) bags. CCIs (24 h) in were lower with classical washed PCs (1·26 ± 0·54) compared to regular PCs in plasma (2·07 ± 0·76) (P < 0·001), but there was no difference between washed PCs containing BRS-A (2·14 ± 0·77) and regular PCs (2·21 ± 0·79) (P = 0·769), and we saw no post-transfusion bleeding. Washed PCs containing BRS-A appear to prevent ATRs without loss of transfusion efficacy in children with primary haematological and malignant

  14. Platelet Proteome and Tumor Dormancy: Can Platelets Content Serve as Predictive Biomarkers for Exit of Tumors from Dormancy?

    Energy Technology Data Exchange (ETDEWEB)

    Almog, Nava, E-mail: nava.almog@tufts.edu; Klement, Giannoula Lakka, E-mail: nava.almog@tufts.edu [Center of Cancer Systems Biology, Caritas St. Elizabeth' s Medical Center, Tufts University School of Medicine, Boston, MA (United States)

    2010-05-11

    Although tumor dormancy is highly prevalent, the underling mechanisms are still mostly unknown. It is unclear which lesions will progress and become a disseminated cancer, and which will remain dormant and asymptomatic. Yet, an improved ability to predict progression would open the possibility of timely treatment and improvement in outcomes. We have recently described the ability of platelets to selectively uptake angiogenesis regulators very early in tumor growth, and proposed their use as an early marker of malignancy. In this review we will summarize current knowledge about these processes and will discuss the possibility of using platelet content to predict presence of occult tumors.

  15. 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.

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

    Science.gov (United States)

    McBride, J. A.

    1968-01-01

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

  17. Inhibition of Platelet Aggregation by the Leaf Extract of Carica papaya During Dengue Infection: An In Vitro Study.

    Science.gov (United States)

    Chinnappan, Shobia; Ramachandrappa, Vijayakumar Shettikothanuru; Tamilarasu, Kadhiravan; Krishnan, Uma Maheswari; Pillai, Agiesh Kumar Balakrishna; Rajendiran, Soundravally

    2016-04-01

    Dengue cases were reported to undergo platelet activation and thrombocytopenia by a poorly understood mechanism. Recent studies suggested that Carica papaya leaf extract could recover the platelet count in dengue cases. However, no studies have attempted to unravel the mechanism of the plant extract in platelet recovery. Since there are no available drugs to treat dengue and considering the significance of C. papaya in dengue treatment, the current study aimed to evaluate two research questions: First one is to study if the C. papaya leaf extract exerts its action directly on platelets and second one is to understand if the extract can specifically inhibit the platelet aggregation during dengue viral infection. Sixty subjects with dengue positive and 60 healthy subjects were recruited in the study. Platelet-rich plasma (PRP) and platelet-poor plasma were prepared from both the dengue-infected and healthy control blood samples. Effect of the leaf extract obtained from C. papaya leaves was assessed on plasma obtained as well as platelets collected from both healthy and dengue-infected individuals. Platelet aggregation was significantly reduced when leaf extract preincubated with dengue plasma was added into control PRP, whereas no change in aggregation when leaf extract incubated-control plasma was added into control PRP. Upon direct addition of C. papaya leaf extract, both dengue PRP and control PRP showed a significant reduction in platelet aggregation. Within the dengue group, PRP from severe and nonsevere cases showed a significant decrease in aggregation without any difference between them. From the study, it is evident that C. papaya leaf extract can directly act on platelet. The present study, the first of its kind, found that the leaf extract possesses a dengue-specific neutralizing effect on dengue viral-infected plasma that may exert a protective role on platelets.

  18. Mechanical circulatory support is associated with loss of platelet receptors glycoprotein Ibα and glycoprotein VI.

    Science.gov (United States)

    Lukito, P; Wong, A; Jing, J; Arthur, J F; Marasco, S F; Murphy, D A; Bergin, P J; Shaw, J A; Collecutt, M; Andrews, R K; Gardiner, E E; Davis, A K

    2016-11-01

    Essentials Relationship of acquired von Willebrand disease (VWD) and platelet dysfunction is explored. Patients with ventricular assist devices and on extracorporeal membrane oxygenation are investigated. Acquired VWD and platelet receptor shedding is demonstrated in the majority of patients. Loss of platelet adhesion receptors glycoprotein (GP) Ibα and GPVI may increase bleeding risk. Background Ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) are associated with bleeding that is not fully explained by anticoagulant or antiplatelet use. Exposure of platelets to elevated shear in vitro leads to increased shedding. Objectives To investigate whether loss of platelet receptors occurs in vivo, and the relationship with acquired von Willebrand syndrome (AVWS). Methods Platelet counts, coagulation tests and von Willebrand factor (VWF) analyses were performed on samples from 21 continuous flow VAD (CF-VAD), 20 ECMO, 12 heart failure and seven aortic stenosis patients. Levels of platelet receptors were measured by flow cytometry or ELISA. Results The loss of high molecular weight VWF multimers was observed in 18 of 19 CF-VAD and 14 of 20 ECMO patients, consistent with AVWS. Platelet receptor shedding was demonstrated by elevated soluble glycoprotein (GP) VI levels in plasma and significantly reduced surface GPIbα and GPVI levels in CF-VAD and ECMO patients as compared with healthy donors. Platelet receptor levels were also significantly reduced in heart failure patients. Conclusions These data link AVWS and increased platelet receptor shedding in patients with CF-VADs or ECMO for the first time. Loss of the platelet surface receptors GPIbα and GPVI in heart failure, CF-VAD and ECMO patients may contribute to ablated platelet adhesion/activation, and limit thrombus formation under high/pathologic shear conditions. © 2016 International Society on Thrombosis and Haemostasis.

  19. Characteristics of an autologous leukocyte and platelet-rich fibrin patch intended for the treatment of recalcitrant wounds

    DEFF Research Database (Denmark)

    Lundquist, Rasmus; Holmstrøm, Kim; Clausen, Christian

    2012-01-01

    We have investigated the physical, biochemical, and cellular properties of an autologous leukocyte and platelet-rich fibrin patch. This was generated in an automated device from a sample of a patient's blood at the point of care. Using microscopy, cell counting, enzyme-linked immunosorbent assay...... of chronic wound fluid. By comparison with traditional platelet-rich plasma, differences in immune components were found. The relevance of these findings was assessed by showing a mitogenic and migratory effect on cultured human dermal fibroblasts. Further, we showed that fibrocytes, a cell type important......, antibody arrays, and cell culture assays, we show that the patch is a three-layered membrane comprising a fibrin sheet, a layer of platelets, and a layer of leukocytes. Mean recovery of platelets from the donated blood was 98% (±95%CI 0.8%). Mean levels of platelet-derived growth factor AB, human...

  20. Experience of buffy coat pooling of platelets as a supportive care in thrombocytopenic dengue patients: A prospective study

    Directory of Open Access Journals (Sweden)

    Kabita Chatterjee

    2014-01-01

    Full Text Available Random donor platelet (RDP is not sufficient to improve the platelet count in most thrombocytopenic patients. Single donor platelet (SDP or buffy coat pooled platelet (BCPP are the two choices to provide a full therapeutic dose of platelets. However, there are constraints in the preparation of SDP due to stringent donor selection procedure, time required for procedure, and need of special expensive equipments and kits. BCPP is widely practiced, especially in the European countries, since 1995. In India, we decided to adopt the procedure of buffy coat pooling of platelets, especially for economically backward patients and for emergencies. This study was prospectively conducted from September 2009 to September 2010. A total of 129 units of BCPP [tested prior for viral markers by enzyme-linked immunosorbent assay (ELISA and individual donor nucleic acid amplification test (ID-NAT] were issued to 129 patients suffering from dengue and were included in this study. For comparison between efficacy of SDP and BCCP, patients were divided into two groups of 50 each. The post-transfusion platelet counts of the patients were noted after 2 hours of transfusion for each type of component. The platelet yield varied from 2.5 to 4.4 Χ 10ΉΉ in BCPP samples. The samples analyzed were sterile without any contamination. The different biochemical parameters were analyzed in detail. The observed post-transfusion platelet recovery and corrected count increment (CCI at 1 hour and 24 hours after BCPP transfusion were similar to that after SDP transfusion. Hence, we concluded that BCPP can be a low cost alternative to SDP in the times of emergencies like dengue and non-affordability by the patient for SDP.

  1. 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

  2. And the Dead Remain Behind

    Directory of Open Access Journals (Sweden)

    Peter Read

    2013-08-01

    Full Text Available In most cultures the dead and their living relatives are held in a dialogic relationship. The dead have made it clear, while living, what they expect from their descendants. The living, for their part, wish to honour the tombs of their ancestors; at the least, to keep the graves of the recent dead from disrepair. Despite the strictures, the living can fail their responsibilities, for example, by migration to foreign countries. The peripatetic Chinese are one of the few cultures able to overcome the dilemma of the wanderer or the exile. With the help of a priest, an Australian Chinese migrant may summon the soul of an ancestor from an Asian grave to a Melbourne temple, where the spirit, though removed from its earthly vessel, will rest and remain at peace. Amongst cultures in which such practices are not culturally appropriate, to fail to honour the family dead can be exquisitely painful. Violence is the cause of most failure.

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

    Science.gov (United States)

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

    2017-06-01

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

  4. Clean Hands Count

    Medline Plus

    Full Text Available ... starting stop Loading... Watch Queue Queue __count__/__total__ It’s YouTube. Uninterrupted. Loading... Want music and videos with ... ads? Get YouTube Red. Working... Not now Try it free Find out why Close Clean Hands Count ...

  5. Counting It Twice.

    Science.gov (United States)

    Schattschneider, Doris

    1991-01-01

    Provided are examples from many domains of mathematics that illustrate the Fubini Principle in its discrete version: the value of a summation over a rectangular array is independent of the order of summation. Included are: counting using partitions as in proof by pictures, combinatorial arguments, indirect counting as in the inclusion-exclusion…

  6. 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.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2013-10-10

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

  8. Red Assembly: the work remains

    Directory of Open Access Journals (Sweden)

    Leslie Witz

    installed. What to do at this limit, at the transgressive encounter between saying yes and no to history, remains the challenge. It is the very challenge of what insistently remains.

  9. Use of 8-methoxypsoralen and long-wavelength ultraviolet radiation for decontamination of platelet concentrates

    Science.gov (United States)

    Corash, Laurence; Lin, Lily; Wiesehahn, Gary; Cimino, George

    1992-06-01

    Transmission of viral diseases through blood products remains a problem in transfusion medicine. A number of methods have been developed to inactivate viral pathogens in plasma and plasma fractions, including: dry heating, wet heating, solvent-detergent treatment, and immunoaffinity purification. While some of these methods successfully inactivate pathogenic viruses, inactivation may be incomplete or result in damage to labile plasma proteins and cells. We have developed a photochemical decontamination system (PCD) for platelet concentrates (PC) utilizing treatment with long wavelength ultraviolet radiation (UVA, 320 - 400 nm) and 8-methoxypsoralen (8-MOP). This system is capable of inactivating 25 - 30 logs/hr of bacteria E. coli or S. aureus, 6 logs/hr of bacteriophage fd, 0.9 log/hr of bacteriophage R17 and 1.1 logs/hr of feline leukemia virus (FeLV) in PC. Immediately following 6 hrs of PCD treatment, platelet integrity and function of PCD treated and control PC were equivalent. After overnight storage PCD treated and control PC platelet properties were equal, but there was a slight reduction in TXB-2 production of PCD treated PC compared to controls. Following PCD treatment, PC were stored for 48 to 96 hrs. Platelet counts, morphology scores, extracellular LDH levels, aggregation response, dense body (db) content, and alpha granule ((alpha) g) content of PCD treated and control PC were comparable. We assessed the ability of the PCD technique to inactivate intracellular and extracellular virus, quantified the degree of DNA adduct formation in contaminating lymphocytes, and measured the inhibition of polymerase chain reaction (PCR) mediated amplification of intracellular DNA. High titers of cell-free murine cytomegalovirus added to human platelet concentrates (final concentration 106) were inactivated by PCD within 30 min. Cat renal fibroblasts infected at high levels with feline rhinotracheitis virus (FeRTV) were seeded into PC followed by PCD treatment with

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

    Directory of Open Access Journals (Sweden)

    Adalet Arıkanoğlu

    2012-06-01

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

  11. Green business will remain green

    International Nuclear Information System (INIS)

    Marcan, P.

    2008-01-01

    It all started with two words. Climate change. The carbon dioxide trading scheme, which was the politicians' idea on solving the number one global problem, followed. Four years ago, when the project was begun, there was no data for project initiation. Quotas for polluters mainly from energy production and other energy demanding industries were distributed based on spreadsheets, maximum output and expected future development of economies. Slovak companies have had a chance to profit from these arrangements since 2005. Many of them took advantage of the situation and turned the excessive quotas into an extraordinary profit which often reached hundreds of million Sk. The fact that the price of free quotas offered for sale dropped basically to 0 in 2006 only proved that the initial distribution was too generous. And the market reacted to the first official measurements of emissions. Slovak companies also contributed to this development. However, when planning the maximum emission volumes for 2008-2012 period, in spite of the fact that actual data were available, their expectations were not realistic. A glance at the figures in the proposal of the Ministry of Environment is sufficient to realize that there will be no major change in the future. And so for many Slovak companies business with a green future will remain green for the next five years. The state decided to give to selected companies even more free space as far as emissions are concerned. The most privileged companies can expect quotas increased by tens of percent. (author)

  12. The life cycle of platelet granules [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Anish Sharda

    2018-02-01

    Full Text Available Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types—dense granules, α-granules, and lysosomes—although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the trans-Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.

  13. Silicon photonics: some remaining challenges

    Science.gov (United States)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  14. Determination of reference ranges for immature platelet and reticulocyte fractions and reticulocyte hemoglobin equivalent

    Directory of Open Access Journals (Sweden)

    Iuri Vicente Camargo Morkis

    Full Text Available ABSTRACT Introduction: The immature platelet and immature reticulocyte fractions represent the ratios of platelets and reticulocytes recently released into the circulation and thus with higher RNA content. They are considered early indicators of bone marrow recovery. Objective: The aim of this study was to determine the reference ranges for the immature platelet and reticulocyte fractions of hematologically normal individuals in a university hospital. Methods: Venous blood samples collected in ethylenediaminetetraacetic acid K3 were analyzed using a Sysmex XE-5000™ analyzer. Individuals with platelet and reticulocyte counts within the reference ranges, and a blood count within the laboratory's screening criteria were included. Individuals with clinical conditions that could affect hematological results were excluded. The immature platelet fraction, high, medium and low fluorescence reticulocyte fractions and reticulocyte hemoglobin equivalent were evaluated. The reference ranges were determined according to the recommendations of the International Federation of Clinical Chemistry. Results: One hundred and thirty-two outpatients were evaluated. The mean age was 44 years (range: 13-80 years, 72 (54.5% were women treated in a university hospital. The mean platelet count was 250.8 × 109/L and the mean reticulocyte count was 0.052 × 109/L. The following reference ranges were obtained: immature reticulocyte fraction 1.6-12.1%, the high, medium and low fluorescence reticulocyte fractions were 0.0-1.7%, 1.6-11.0% and 87.9-98.4%, respectively, the reticulocyte hemoglobin equivalent was 30.0-37.6% and immature platelet fraction was 0.8-5.6%. There was a statistically significant difference (p-value = 0.006 between genders in respect to the immature platelet fraction with 0.8-4.7% for females and 0.7-6.1% for males. The immature reticulocyte fraction was directly correlated with the reticulocyte count. Conclusion: Determining the reference range is

  15. 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

  16. 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.

  17. Platelet binding and biodistribution of [99mTc]rBitistatin in animal species and humans

    International Nuclear Information System (INIS)

    Knight, Linda C.; Romano, Jan E.; Bright, Lewis T.; Agelan, Alexis; Kantor, Steven; Maurer, Alan H.

    2007-01-01

    Introduction: 99m Tc recombinant bitistatin (rBitistatin) is a radioligand for α IIb β 3 (glycoproteins IIb/IIIa) receptor on platelets and is being developed as a diagnostic radiopharmaceutical for in vivo imaging of acute thrombi and emboli. Prior to the first administration of [ 99m Tc]rBitistatin to human subjects, its biodistribution and effects on platelets were evaluated in animals. This paper reports findings in animal studies in comparison with initial findings in normal human subjects. Methods: [ 99m Tc]rBitistatin was administered to mice, guinea pigs and dogs to assess time-dependent organ distribution, urinary excretion and blood disappearance rates. Blood samples were analyzed to determine radioligand binding to circulating platelets and the extent of plasma protein binding. The effect of [ 99m Tc]rBitistatin on circulating platelet count was determined. These factors were also determined in normal human subjects who received [ 99m Tc]rBitistatin as part of a Phase I clinical trial. Results: The main organs that accumulated [ 99m Tc]rBitistatin were kidneys, liver and spleen in all animal species and humans. The main organs seen on human images were the kidneys and spleen. Liver uptake was fainter, and soft-tissue background was low. [ 99m Tc]rBitistatin bound to circulating platelets in blood, with a higher percentage of binding to platelets in guinea pigs and dogs compared to that in humans. Plasma protein binding was low and of little consequence in view of platelet binding. The main route of excretion was through the urine. [ 99m Tc]rBitistatin did not affect platelet counts in humans or dogs. Conclusions: [ 99m Tc]rBitistatin, when administered at low doses for imaging, has no adverse effects on platelets and has the qualitative biodistribution predicted by animal studies. [ 99m Tc]rBitistatin was found to bind to circulating platelets in humans, suggesting that it will be able to bind to activated platelets in vivo in patients with acute

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

    Directory of Open Access Journals (Sweden)

    Kazım KIRATLI

    2017-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Neiva Teresinha J.C.

    2003-01-01

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

  20. Mean Platelet Volume in Patients with Chronic Venous Insufficiency

    Directory of Open Access Journals (Sweden)

    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

  1. 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...

  2. Encapsulation of Clay Platelets inside Latex Particles

    NARCIS (Netherlands)

    Voorn, D.J.; Ming, W.; Herk, van A.M.; Fernando, R.H.; Sung, Li-Piin

    2009-01-01

    We present our recent attempts in encapsulating clay platelets inside latex particles by emulsion polymerization. Face modification of clay platelets by cationic exchange has been shown to be insufficient for clay encapsulation, leading to armored latex particles. Successful encapsulation of

  3. Prolonged platelet preservation by transient metabolic suppression

    NARCIS (Netherlands)

    Badlou, Bahram Alamdary

    2006-01-01

    Introduction: Different clinical studies have shown that transfusion of stored platelets results in better haemostasis in patients with thrombocytopenia with and without a platelet function defect. Objectives: Current preservation procedures aim to optimally preserve the metabolic status of

  4. Antimicrobial properties of single-donor-derived, platelet-leukocyte fibrin for fistula occlusion: An in vitro study.

    Science.gov (United States)

    Wu, Xiuwen; Ren, Jianan; Yuan, Yujie; Luan, Jianfeng; Yao, Genhong; Li, Jieshou

    2013-01-01

    Fibrin glue is a promising alternative for low-output enterocutaneous fistula closure. Bacterial flora colonizing inside the fistula tract, however, may limit the glue application. Single-donor-derived, platelet-rich materials were hypothesized in this study to have antimicrobial activity against Gram-negative microorganisms. Platelet-leukocyte fibrin (PLF), platelet-rich plasma (PRP), and platelet-poor plasma (PPP) were obtained from healthy volunteers. The amounts of platelet, leukocyte, and complement/antibody were determined. In vitro laboratory susceptibility to PLF and plasmas was determined by the Kirby-Bauer disc-diffusion method. Antimicrobial activity of PLF, PRP, and PPP against three Gram-negative ATCC strains was determined in a bacterial kill assay. Levels of complement and antibody did not significantly differ among PLF, PRP, and PPP (p > 0.05), while platelet and leukocyte counts in platelet-rich biomaterials were significantly higher than those in PPP (p platelets and leukocytes may play an important role in bacterial defense. This is the first study to demonstrate the antibacterial properties of single-unit PLF for fistula closure, presenting a new opportunity for glue sealing.

  5. Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair.

    Science.gov (United States)

    Agren, M S; Rasmussen, K; Pakkenberg, B; Jørgensen, B

    2014-07-01

    Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods. Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays. The number of leucocytes and erythrocytes was reduced (P platelets increased (P fibrin-I versus whole blood. PRF contained 982 ± 206 × 10(9) platelets/l representing 3·9-fold (P platelet-derived growth factor (PDGF)-AB [2·5-fold, P PDGF-BB [1·6-fold, P vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications. © 2013 International Society of Blood Transfusion.

  6. Comparative evaluation of antiplatelet effect of lycopene with aspirin and the effect of their combination on platelet aggregation: An in vitro study.

    Science.gov (United States)

    Sawardekar, Swapna B; Patel, Tejal C; Uchil, Dinesh

    2016-01-01

    The objective was to compare antiplatelet effect of lycopene with aspirin and to study effect of combination of the two on platelet aggregation in vitro, using platelets from healthy volunteers. Platelets were harvested; platelet count of platelet-rich plasma adjusted to 2.5 Χ 10(5)/μL. Aspirin (140 μmol/L) and lycopene (4, 6, 8, 10, and 12 μmol/L) were studied in vitro against adenosine-5'- diphosphate (ADP) (2.5 μM/L) and collagen. All the concentrations of lycopene (4-12 μmol/L) exhibited reduction in maximum platelet aggregation induced by aggregating agents ADP and collagen (P Lycopene at concentration 10 μmol/L showed maximum platelet inhibition (47.05% ± 19.56%) against ADP, whereas lycopene at concentration 8 μmol/L showed maximum platelet inhibition (54.26% ± 30.71%) against collagen. Four μmol/L of lycopene combined with 140 μmol/L and 70 μmol/L aspirin showed greater inhibition of platelets as compared to aspirin 140 μmol/L alone, against both ADP and collagen. The study favorably compares lycopene and aspirin with respect to their antiplatelet activities against ADP and collagen. Lycopene can be considered as a potential target for modifying the thrombotic and pro-inflammatory events associated with platelet activation.

  7. Kinetics and sites of destruction of 111In-oxine-labeled platelets in idiopathic thrombocytopenic purpura: a quantitative study

    International Nuclear Information System (INIS)

    Heyns, A.D.; Loetter, M.G.; Badenhorst, P.N.; de Kock, F.; Pieters, H.; Herbst, C.; van Reenen, O.R.; Kotze, H.; Minnaar, P.C.

    1982-01-01

    Kinetics and quantification of the sites of destruction of 111 In-oxine-labeled autologous platelets were investigated in eight patients with idiopathic thrombocytopenic purpura. The mean platelet count was 17 +/- 9 X 10(9)/liter; platelets were separated by differential centrifugation and labeled with 5.6 +/- 2.5 MBq 111 In. Whole body and organ 111 In-platelet distribution was quantitated with a scintillation camera and a computer-assisted imaging system acquisition matrix. Areas of interest were selected with the computer and organ 111 In-radioactivity expressed as a percentage of whole body activity. Mean platelet survival was 49.5 +/- 29.6 hr and the survival curves were exponential. Equilibrium percentage organ 111 In-radioactivity was (normal values in parentheses): spleen 33.7 +/- 8.8 (31.1 +/- 10.2); liver 16.1 +/- 9.5 (13.1 +/- 1.3); thorax 22.8 +/- 3.7 (28.2 +/- 5.6). Percentage organ 111 In-activity at the time when labeled platelets had disappeared from the circulation was: spleen 44.5 +/- 16.4 (40 +/- 16); liver 16.0 +/- 11.5 (32.4 +/- 7.2); thorax 19.7 +/- 6.0 (17.7 +/- 10.3). Thorax activity corresponds to bone marrow radioactivity. Three patterns of platelet sequestration were evident. Three patients had mainly splenic sequestration, two mainly hepatic sequestration, and three diffuse reticuloendothelial system sequestration with a major component of platelets destroyed in the bone marrow. Splenectomy was performed in two patients. The pattern of 111 In-platelet sequestration was not predictive of response of glucocorticoid therapy or indicative of the necessity for splenectomy. Quantitative 111 In-labeled autologous platelet kinetic studies provide a new tool for the investigation of platelet disorders.U

  8. Platelet-rich plasma as treatment for persistent ocular epithelial defects.

    Science.gov (United States)

    Ronci, Corrado; Ferraro, Angelo Salvatore; Lanti, Alessandro; Missiroli, Filippo; Sinopoli, Silvia; Del Proposto, Gianpaolo; Cipriani, Chiara; De Felici, Cecilia; Ricci, Federico; Ciotti, Marco; Cudillo, Laura; Arcese, William; Adorno, Gaspare

    2015-06-01

    Platelet- rich plasma (PRP) exhibits regenerative proprieties in wound healing but the biochemical mechanisms are unclear. In this study, autologous PRP with a mean value of 338 × 10(3) platelets/µL was used to treat corneal lesions of different aetiology, while homologous PRP with 1 × 10(6) platelets/µL was used to treat cornel lesions induced by a graft versus host disease. The impact of platelet count on the levels of PDGF AA and BB, VEGF, and EGF in the two PRPs was evaluated after a cycle of freezing/thawing. Treated corneal lesions healed or improved. The levels of PDGF AA and BB, VEGF, and EGF in the autologous PRP raised from 296 ± 61; 201.8 ± 24; 53 ± 14 and 8.9 ± 2 to 1017 ± 253; 924.7 ± 222; 101 ± 46.5 and 174 ± 15.5 pg/mL, while in the homologous PRP were 3.4, 4.5, 3.2 and 2 folds higher, respectively. High level of platelet counts seems not required to treat corneal lesions. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Nauder Faraday

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

  10. Platelets retain high levels of active plasminogen activator inhibitor 1.

    Directory of Open Access Journals (Sweden)

    Helén Brogren

    Full Text Available The vascular fibrinolytic system is crucial for spontaneous lysis of blood clots. Plasminogen activator inhibitor 1 (PAI-1, the principal inhibitor of the key fibrinolytic enzyme tissue-type plasminogen activator (tPA, is present in platelets at high concentrations. However, the majority of PAI-1 stored in platelets has been considered to be inactive. Our recent finding (Brogren H, et al. Blood 2004 that PAI-1 de novo synthesized in platelets remained active for over 24 h, suggested that PAI-1 stored in the α-granules might be active to a larger extent than previously reported. To re-evaluate this issue, we performed experiments where the fraction of active PAI-1 was estimated by analyzing the tPA-PAI-1 complex formation. In these experiments platelets were lysed with Triton X-100 in the presence of serial dilutions of tPA and subsequently the tPA-PAI-1 complex was evaluated by Western blot. Also, using a non-immunologic assay, tPA was labeled with (125I, and (125I-tPA and (125I-tPA-PAI-1 was quantified by scintigraphy. Interestingly, both methods demonstrated that the majority (>50% of platelet PAI-1 is active. Further analyses suggested that pre-analytical procedures used in previous studies (sonication or freezing/thawing may have substantially reduced the activity of platelet PAI-1, which has lead to an underestimation of the proportion of active PAI-1. Our in vitro results are more compatible with the role of PAI-1 in clot stabilization as demonstrated in physiological and pathophysiological studies.

  11. Toward the Relevance of Platelet Subpopulations for Transfusion Medicine

    Directory of Open Access Journals (Sweden)

    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.

  12. Potential fluid mechanic pathways of platelet activation

    OpenAIRE

    Shadden, Shawn C.; Hendabadi, Sahar

    2012-01-01

    Platelet activation is a precursor for blood clotting, which plays leading roles in many vascular complications and causes of death. Platelets can be activated by chemical or mechanical stimuli. Mechanically, platelet activation has been shown to be a function of elevated shear stress and exposure time. These contributions can be combined by considering the cumulative stress or strain on a platelet as it is transported. Here we develop a framework for computing a hemodynamic-based activation ...

  13. 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

  14. 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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  16. Clean Hands Count

    Medline Plus

    Full Text Available ... Clean Hands Count Centers for Disease Control and Prevention (CDC) Loading... Unsubscribe from Centers for Disease Control and Prevention (CDC)? Cancel Unsubscribe Working... Subscribe Subscribed Unsubscribe 65K ...

  17. Clean Hands Count

    Medline Plus

    Full Text Available ... Clean Hands Count Centers for Disease Control and Prevention (CDC) Loading... Unsubscribe from Centers for Disease Control and Prevention (CDC)? Cancel Unsubscribe Working... Subscribe Subscribed Unsubscribe 66K ...

  18. Housing Inventory Count

    Data.gov (United States)

    Department of Housing and Urban Development — This report displays the data communities reported to HUD about the nature of their dedicated homeless inventory, referred to as their Housing Inventory Count (HIC)....

  19. Scintillation counting apparatus

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1978-01-01

    Apparatus is described for the accurate measurement of radiation by means of scintillation counters and in particular for the liquid scintillation counting of both soft beta radiation and gamma radiation. Full constructional and operating details are given. (UK)

  20. Allegheny County Traffic Counts

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Traffic sensors at over 1,200 locations in Allegheny County collect vehicle counts for the Pennsylvania Department of Transportation. Data included in the Health...

  1. Counting Knights and Knaves

    Science.gov (United States)

    Levin,Oscar; Roberts, Gerri M.

    2013-01-01

    To understand better some of the classic knights and knaves puzzles, we count them. Doing so reveals a surprising connection between puzzles and solutions, and highlights some beautiful combinatorial identities.

  2. Clean Hands Count

    Medline Plus

    Full Text Available ... why Close Clean Hands Count Centers for Disease Control and Prevention (CDC) Loading... Unsubscribe from Centers for Disease Control and Prevention (CDC)? Cancel Unsubscribe Working... Subscribe Subscribed ...

  3. Clean Hands Count

    Medline Plus

    Full Text Available ... stop Loading... Watch Queue Queue __count__/__total__ It’s YouTube. Uninterrupted. Loading... Want music and videos with zero ads? Get YouTube Red. Working... Not now Try it free Find ...

  4. Quantification of platelets and platelet derived growth factors from platelet-rich-plasma (PRP) prepared at different centrifugal force (g) and time.

    Science.gov (United States)

    Arora, Satyam; Doda, Veena; Kotwal, Urvershi; Dogra, Mitu

    2016-02-01

    Platelet derived biomaterials represent a key source of cytokines and growth factors extensively used for tissue regeneration; wound healing and tissue repair. Our study was to quantify platelets and growth factors released by PRP when prepared at different centrifugal force (g) and time. Our study was approved by the institutional ethical committee. One hundred millilitres of whole blood (WB) was collected in bag with CPDA as the anticoagulant(AC); (14 mL for 100 mL WB ratio). Nine aliquots of 10 mL each were made from the bag and set of three aliquots were made a group. PRP was prepared at varying centrifugal force (group A: -110 g, group B: -208 g & group C: -440 g) & time (1: -5 min, 2: -10 min & 3: -20 min). Contents of each PRP prepared were analysed. Commercial sandwich ELISA kits were used to quantify the concentrations of CD62P (Diaclone SAS; France), Platelet derived growth factors-AB (Qayee-Bio; China), transforming growth factor-β1 (DRG; Germany) and vascular endothelial growth factor (Boster Immuno Leader; USA) released in each PRP prepared. Eight volunteers were enrolled in the study (24-30 years). The baseline blood counts of all the volunteers were comparable (p ≥ 0.05). Mean ± SD of platelet yield of all nine groups ranged from 17.2 ± 4.2% to 78.7 ± 5.7%. Each PRP was activated with calcified thromboplastin to quantify the growth factors released by them. Significantly higher (p < 0.05) transforming growth factor-β1 and vascular endothelial growth factor were released compared to the baseline. Our study highlights the variation in both force (g) and time results in changes at cellular level and growth factor concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. The Kruskal Count

    OpenAIRE

    Lagarias, Jeffrey C.; Rains, Eric; Vanderbei, Robert J.

    2001-01-01

    The Kruskal Count is a card trick invented by Martin J. Kruskal in which a magician "guesses" a card selected by a subject according to a certain counting procedure. With high probability the magician can correctly "guess" the card. The success of the trick is based on a mathematical principle related to coupling methods for Markov chains. This paper analyzes in detail two simplified variants of the trick and estimates the probability of success. The model predictions are compared with simula...

  6. The Prognostic Role of the Platelet-Lymphocytes Ratio in Gastric Cancer: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Zhengshui Xu

    Full Text Available Systemic inflammatory parameters, such as the elevator PLR (platelet-lymphocyte ratio, the NLR (neutrophil-lymphocyte ratio and the platelet count (PLT, have been found to be associated with the prognosis in gastric cancer; however, these results, especially those relating to the PLR, remain inconsistent. So we aimed to evaluate the prognostic role of the PLR in gastric cancer by conducting and presenting the findings of this meta-analysis.We conducted a systematic literature search in PubMed, Embase and the Cochrane Library to evaluate the prognostic value of the PLR in gastric cancer. The quality of the included studies was evaluated using the Newcastle Ottawa Quality Assessment Scale (NOS. The hazard ratio (HR /Odds Ratio (OR and its 95% confidence were pooled using a random effects model. A funnel plot based on overall survival was used to evaluate the publication bias.It total, 8 studies comprising 4513 patients with gastric cancer met the pre-setting inclusion criteria. In comparison to the normal PLR, an elevated PLR was correlated with a higher risk of lymph node metastasis with an OR of 1.50 (95% Cl:1.24-1.82; I2 = 17% and serosal invasion (T3 +T4 risk with an OR of 2.01 (95% Cl: 1.49-2.73; I2 = 55%, and an elevated PLR also increased the advanced stage (III +IV risk with an OR of 1.99 (95% Cl: 1.60-2.46; I2 = 28%. An elevated PLR was not a reliable predictor for OS with an HR of 0.99 (95% CI: 0.9-1.1; I2 = 12%.An elevated PLR was correlated with a higher risk of lymph node metastasis, serosal invasion and advanced stage (III +IV risk in gastric cancer; however, the PLR may not act as a negative predictor for the overall survival of gastric cancer.

  7. 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...

  8. 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.

  9. Platelet kinetics: the state of the art

    International Nuclear Information System (INIS)

    Heyns, A. duP

    1984-01-01

    In this paper an overview of the state of the art of platelet kinetics 1982 is presented. The subjects considered include a discussion of the advantages and disadvantages of some of the many radionuclide platelet labels, viz 51 Cr, 111 In, focussing briefly on models for analysis of platelets survival. (Auth.)

  10. Effects of platelet and plasma transfusion on outcome in traumatic brain injury patients with moderate bleeding diatheses.

    Science.gov (United States)

    Anglin, Catherine O; Spence, Jeffrey S; Warner, Matthew A; Paliotta, Christopher; Harper, Caryn; Moore, Carol; Sarode, Ravi; Madden, Christopher; Diaz-Arrastia, Ramon

    2013-03-01

    Object Coagulopathy and thrombocytopenia are common after traumatic brain injury (TBI), yet transfusion thresholds for mildly to moderately abnormal ranges of international normalized ratio and platelet count remain controversial. This study evaluates associations between fresh frozen plasma (FFP) and platelet transfusions with long-term functional outcome and survival in TBI patients with moderate hemostatic laboratory abnormalities. Methods This study is a retrospective review of prospectively collected data of patients with mild to severe TBI. Data include patient demographics, several initial injury severity metrics, daily laboratory values, Glasgow Outcome Score- Extended (GOSE) scores, Functional Status Examination (FSE) scores, and survival to 6 months. Correlations were evaluated between these variables and transfusion of FFP, platelets, packed red blood cells (RBCs), cryoprecipitate, recombinant factor VIIa, and albumin. Ordinal regression was performed to account for potential confounding variables to further define relationships between transfusion status and long-term outcome. By analyzing collected data, mild to moderate coagulopathy was defined as an international normalized ratio 1.4-2.0, moderate thrombocytopenia as platelet count 50 × 10(9)/L to 107 × 10(9)/L, and moderate anemia as 21%-30% hematocrit. Results In patients with mild to moderate laboratory hematological abnormalities, univariate analysis shows significant correlations between poor outcome scores and FFP, platelet, or packed RBC transfusion; the volume of FFP or packed RBCs transfused also correlated with poor outcome. Several measures of initial injury and laboratory abnormalities also correlated with poor outcome. Patient age, initial Glasgow Coma Scale score, and highest recorded serum sodium were included in the ordinal regression model using backward variable selection. In the moderate coagulopathy subgroup, patients transfused with FFP were more likely to have a lower GOSE

  11. Delayed-onset of procoagulant signalling revealed by kinetic analysis of COAT platelet formation.

    Science.gov (United States)

    Alberio, Lorenzo; Ravanat, Catherine; Hechler, Béatrice; Mangin, Pierre H; Lanza, François; Gachet, Christian

    2017-06-02

    The combined action of collagen and thrombin induces the formation of COAT platelets, which are characterised by a coat of procoagulant and adhesive molecules on their surface. Although recent work has started to highlight their clinical relevance, the exact mechanisms regulating the formation of procoagulant COAT platelets remain unclear. Therefore, we employed flow cytometry in order to visualise in real time surface and intracellular events following simultaneous platelet activation with convulxin and thrombin. After a rapid initial response pattern characterised by the homogenous activation of the fibrinogen receptor glycoprotein IIb/IIIa in all platelets, starting with a delay of about 2 minutes an increasing fraction transforms to procoagulant COAT platelets. Their surface is characterised by progressive loss of PAC-1 binding, expression of negative phospholipids and retention of α-granule von Willebrand factor. Intracellular events in procoagulant COAT platelets are a marked increase of free calcium into the low micromolar range, concomitantly with early depolarisation of the mitochondrial membrane and activation of caspase-3, while non-COAT platelets keep the intracellular free calcium in the nanomolar range and maintain an intact mitochondrial membrane. We show for the first time that the flow-cytometrically distinct fractions of COAT and non-COAT platelets differentially phosphorylate two signalling proteins, PKCα and p38MAPK, which may be involved in the regulation of the different calcium fluxes observed in COAT versus non-COAT platelets. This study demonstrates the utility of concomitant cellular and signalling evaluation using flow cytometry in order to further dissect the mechanisms underlying the dichotomous platelet response observed after collagen/thrombin stimulation.

  12. Indium-111-oxine labeled platelet kinetics in patients with diabetes mellitus

    International Nuclear Information System (INIS)

    Forstrom, L.A.; Luikens, B.; Johnson, T.

    1984-01-01

    The possible role of abnormal platelet function in the pathogenesis of vascular disease in patients with diabetes mellitus remains controversial. In vitro studies have shown variable alterations in platelet function in such patients. Studies of in vivo platelet kinetics in diabetic patients have been inconclusive, although decreased platelet survival has been observed in some cases. Earlier studies were carried out using chromium-51 or selenium-75 for platelet labeling. The authors have performed Indium-111-oxine labeled platelet kinetic and biodistribution studies in 4 patients with diabetes mellitus (ages 49-61 years), and in 4 control subjects (ages 46-60 years). All subjects were male. All diabetic patients were poorly controlled at the time of study, with blood glucose > 140 mg% and hemoglobin A-1c > 10%. Autologous platelets were labeled with Indium-111-oxine in ACD:plasma by previously reported methods, and reinjected in a dose of approximately 50 μCi (range 42-67μCi). Average recovery of the injected platelets was 67% (range 41-85%). Computer analyzed images at 24 hours showed no significant difference in liver uptake between diabetic and control subjects. Mildly increased splenic uptake in diabetic patients was of borderline significance (p=.07). Platelet survival was slightly decreased in diabetic subjects by 3 of 4 models utilized (linear, exponential, multiple hit and weighted mean), although the difference achieved significance only for the weighted man model (p=.05). These data support observations by earlier methods which suggest that platelet survival may be decreased in patients with diabetes mellitus

  13. Dual mechanism of integrin αIIbβ3 closure in procoagulant platelets.

    Science.gov (United States)

    Mattheij, Nadine J A; Gilio, Karen; van Kruchten, Roger; Jobe, Shawn M; Wieschhaus, Adam J; Chishti, Athar H; Collins, Peter; Heemskerk, Johan W M; Cosemans, Judith M E M

    2013-05-10

    Inactivation of integrin αIIbβ3 reverses platelet aggregate formation upon coagulation. Platelets from patient (Scott) and mouse (Capn1(-/-) and Ppif(-/-)) blood reveal a dual mechanism of αIIbβ3 inactivation: by calpain-2 cleavage of integrin-associated proteins and by cyclophilin D/TMEM16F-dependent phospholipid scrambling. These data provide novel insight into the switch mechanisms from aggregating to procoagulant platelets. Aggregation of platelets via activated integrin αIIbβ3 is a prerequisite for thrombus formation. Phosphatidylserine-exposing platelets with a key role in the coagulation process disconnect from a thrombus by integrin inactivation via an unknown mechanism. Here we show that αIIbβ3 inactivation in procoagulant platelets relies on a sustained high intracellular Ca(2+), stimulating intracellular cleavage of the β3 chain, talin, and Src kinase. Inhibition of calpain activity abolished protein cleavage, but only partly suppressed αIIbβ3 inactivation. Integrin αIIbβ3 inactivation was unchanged in platelets from Capn1(-/-) mice, suggesting a role of the calpain-2 isoform. Scott syndrome platelets, lacking the transmembrane protein TMEM16F and having low phosphatidylserine exposure, displayed reduced αIIbβ3 inactivation with the remaining activity fully dependent on calpain. In platelets from Ppif(-/-) mice, lacking mitochondrial permeability transition pore (mPTP) formation, agonist-induced phosphatidylserine exposure and αIIbβ3 inactivation were reduced. Treatment of human platelets with cyclosporin A gave a similar phenotype. Together, these data point to a dual mechanism of αIIbβ3 inactivation via calpain(-2) cleavage of integrin-associated proteins and via TMEM16F-dependent phospholipid scrambling with an assistant role of mPTP formation.

  14. Fenol y niveles plaquetarios por exposición ocupacional a benceno en trabajadores de estaciones de servicio de la parroquía Pedro José Ovalles, Maracay, Venezuela, 2016 | Phenol and platelet levels for exposure to bencen in workers of service stations, parish Pedro José Ovalles, Maracay, Venezuela, 2016

    Directory of Open Access Journals (Sweden)

    Franklin Pacheco

    2017-11-01

    Full Text Available Decreased platelet counts are known to be the most sensitive indicator of benzene exposure. The objective of this investigation was to relate the concentration of mg phenol/g-creat and the decrease of the platelet count, by exposure to benzene. A descriptive, cross-correlation and field study was carried out involving 29 service station workers and a control group of 27 workers without occupational exposure. For the platelet count, the Mindray hematology analyzer was used, while Theis-Benedict method was employed for phenol, and Jaffé modified for creatinine. Significant deference was observed in platelet and urinary phenol levels between both groups. A significant negative association was found between platelet levels and time in service in the study group. It was evidenced that as the level of urinary phenol increases in the workers' organism, platelet levels tend to decrease.

  15. 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.)

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

    Directory of Open Access Journals (Sweden)

    Sevil Alan

    2015-12-01

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

  17. Low White Blood Cell Count

    Science.gov (United States)

    Symptoms Low white blood cell count By Mayo Clinic Staff A low white blood cell count (leukopenia) is a decrease ... of white blood cell (neutrophil). The definition of low white blood cell count varies from one medical ...

  18. Pseudo (Platelet-type von Willebrand disease in pregnancy: a case report

    Directory of Open Access Journals (Sweden)

    Grover Neetu

    2013-01-01

    Full Text Available Abstract Background Pseudo (platelet-type-von Willebrand disease is a rare autosomal dominant bleeding disorder caused by an abnormal function of the glycoprotein lb protein; the receptor for von Willebrand factor. This leads to an increased removal of VWF multimers from the circulation as well as platelets and this results in a bleeding diathesis. Worldwide, less than 50 patients are reported with platelet type von Willebrand disease (PT-VWD. Case presentation We describe the management of platelet type von Willebrand disease in pregnancy of a 26 year old Caucasian primigravida. The initial diagnosis was made earlier following a significant haemorrhage post tonsillectomy several years prior to pregnancy. The patient was managed under a multidisciplinary team which included obstetricians, haematologists, anaesthetists and neonatologists. Care plans were made for the ante- natal, intra-partum and post-partum periods in partnership with the patient. The patient’s platelet count levels dropped significantly during the antenatal period. This necessitated the active exclusion of other causes of thrombocytopenia in pregnancy. A vaginal delivery was desired and plans were made for induction of labour at 38 weeks of gestation with platelet cover in view of the progressive fall of the platelet count. The patient however went into spontaneous labour on the day of induction. She was transfused two units of platelets before delivery. She had an unassisted vaginal delivery of a healthy baby. The successful antenatal counselling has encouraged the diagnosis of the same condition in her mother and sister. We found this to be a particularly interesting case as well as challenging to manage due to its rarity. Psuedo von Willebrand disease in pregnancy can be confused with a number of other differential diagnoses, such as gestational thrombocutopenia, idiopathatic thrombocytopenia, thrombotic thrombocytopenic purpura and pre-eclampsia; all need consideration

  19. 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.

  20. Automated processing of leucocyte-poor platelet concentrates.

    Science.gov (United States)

    Tandy, N P; Seghatchian, M J; Bessos, H

    1992-10-01

    In view of transfusion reactions and alloimmunization associated with leucocyte contamination of platelet concentrates (PC), there is a general move towards the production of leuco-poor PC. This goal is currently pursued by the production of various PC using buffy coat and apheresis techniques. Although there is no overall consensus on the meaning of 'leuco-poor', by assuming that this refers to a level of 5-50 x 10(7) leucocytes per PC, we were able to make comparisons with available systems used in Europe. In addition to platelet and white cell counts, other markers of PC quality were assessed in some cases. These included traditional markers (such as hypotonic stress response, pH, and lactate and beta-thromboglobulin levels) and newer markers (such as glycocalicin and plasma von Willebrand factor levels). Our preliminary results showed appreciable differences in platelet and white cell content of PC prepared by various types of apheresis equipment. Appreciable differences in the quality of stored PC were also observed between routine PC (non-leuco-poor and buffy coat and apheresed PC (leuco-poor).

  1. Defining Platelet Function During Polytrauma

    Science.gov (United States)

    2014-04-01

    scaffold of the clot after its thrombin-induced polymerization to fibrin fibers. Formation of a stiff fibrin fiber network and its contraction by platelet...In another study (PROTEC T) Refused Participat ion (Yes=Y, No=N, W=Unqua lified , Refused further draws (agreed to keep previous data

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

    Science.gov (United States)

    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.

  3. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A new concept is presented explaining changes in spectrometric parameters of proportional counters which occur due to varying count rate. The basic feature of this concept is that the gas gain of the counter remains constant in a wide range of count rate and that the decrease in the pulse amplitude and the detorioration of the energy resolution observed are the results of changes in the shape of original current pulses generated in the active volume of the counter. In order to confirm the validity of this statement, measurements of the gas amplification factor have been made in a wide count rate range. It is shown that above a certain critical value the gas gain depends on both the operating voltage and the count rate. (author)

  4. Alpha scintillation radon counting

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.

    1977-01-01

    Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

  5. Principles of correlation counting

    International Nuclear Information System (INIS)

    Mueller, J.W.

    1975-01-01

    A review is given of the various applications which have been made of correlation techniques in the field of nuclear physics, in particular for absolute counting. Whereas in most cases the usual coincidence method will be preferable for its simplicity, correlation counting may be the only possible approach in such cases where the two radiations of the cascade cannot be well separated or when there is a longliving intermediate state. The measurement of half-lives and of count rates of spurious pulses is also briefly discussed. The various experimental situations lead to different ways the correlation method is best applied (covariance technique with one or with two detectors, application of correlation functions, etc.). Formulae are given for some simple model cases, neglecting dead-time corrections

  6. Interpretation of galaxy counts

    International Nuclear Information System (INIS)

    Tinsely, B.M.

    1980-01-01

    New models are presented for the interpretation of recent counts of galaxies to 24th magnitude, and predictions are shown to 28th magnitude for future comparison with data from the Space Telescope. The results supersede earlier, more schematic models by the author. Tyson and Jarvis found in their counts a ''local'' density enhancement at 17th magnitude, on comparison with the earlier models; the excess is no longer significant when a more realistic mixture of galaxy colors is used. Bruzual and Kron's conclusion that Kron's counts show evidence for evolution at faint magnitudes is confirmed, and it is predicted that some 23d magnitude galaxies have redshifts greater than unity. These may include spheroidal systems, elliptical galaxies, and the bulges of early-type spirals and S0's, seen during their primeval rapid star formation

  7. 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.

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

    Science.gov (United States)

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

    2015-03-01

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

  9. Glycoprotein Ibα receptor instability is associated with loss of quality in platelets produced in culture.

    Science.gov (United States)

    Robert, Amélie; Boyer, Lucie; Pineault, Nicolas

    2011-03-01

    The development of culture processes for hematopoietic progenitors could lead to the development of a complementary source of platelets for therapeutic purposes. However, functional characterization of culture-derived platelets remains limited, which raises some uncertainties about the quality of platelets produced in vitro. The aim of this study was to define the proportion of functional platelets produced in cord blood CD34+ cell cultures. Toward this, the morphological and functional properties of culture-derived platelet-like particles (PLPs) were critically compared to that of blood platelets. Flow cytometry combined with transmission electron microscopy analyses revealed that PLPs formed a more heterogeneous population of platelets at a different stage of maturation than blood platelets. The majority of PLPs harbored the fibrinogen receptor αIIbβ3, but a significant proportion failed to maintain glycoprotein (GP)Ibα surface expression, a component of the vWF receptor essential for platelet functions. Importantly, GPIbα extracellular expression correlated closely with platelet function, as the GPIIb+ GPIbα+ PLP subfraction responded normally to agonist stimulation as evidenced by α-granule release, adhesion, spreading, and aggregation. In contrast, the GPIIb+ GPIbα⁻ subfraction was unresponsive in most functional assays and appeared to be metabolically inactive. The present study confirms that functional platelets can be generated in cord blood CD34+ cell cultures, though these are highly susceptible to ectodomain shedding of receptors associated with loss of function. Optimization of culture conditions to prevent these deleterious effects and to homogenize PLPs is necessary to improve the quality and yields of culture-derived platelets before they can be recognized as a suitable complementary source for therapeutic purposes.

  10. Computerized radioautographic grain counting

    International Nuclear Information System (INIS)

    McKanna, J.A.; Casagrande, V.A.

    1985-01-01

    In recent years, radiolabeling techniques have become fundamental assays in physiology and biochemistry experiments. They also have assumed increasingly important roles in morphologic studies. Characteristically, radioautographic analysis of structure has been qualitative rather than quantitative, however, microcomputers have opened the door to several methods for quantifying grain counts and density. The overall goal of this chapter is to describe grain counting using the Bioquant, an image analysis package based originally on the Apple II+, and now available for several popular microcomputers. The authors discuss their image analysis procedures by applying them to a study of development in the central nervous system

  11. Rainflow counting revisited

    Energy Technology Data Exchange (ETDEWEB)

    Soeker, H [Deutsches Windenergie-Institut (Germany)

    1996-09-01

    As state of the art method the rainflow counting technique is presently applied everywhere in fatigue analysis. However, the author feels that the potential of the technique is not fully recognized in wind energy industries as it is used, most of the times, as a mere data reduction technique disregarding some of the inherent information of the rainflow counting results. The ideas described in the following aim at exploitation of this information and making it available for use in the design and verification process. (au)

  12. Discrimination between platelet-mediated and coagulation-mediated mechanisms in a model of complex thrombus formation in vivo

    International Nuclear Information System (INIS)

    Cadroy, Y.; Horbett, T.A.; Hanson, S.R.

    1989-01-01

    To study mechanisms of complex thrombus formation in vivo, and to compare the relative antithrombotic effects of anticoagulants and antiplatelet agents, a model was developed in baboons. Segments of collagen-coated tubing followed by two sequentially placed expansion chambers exhibiting disturbed flow patterns were exposed to native blood under laminar flow conditions. The device was incorporated for 1 hour into an exteriorized arteriovenous shunt in baboons under controlled blood flow (20 ml/min). Morphologic evaluation by scanning electron microscopy showed that thrombi associated with collagen were relatively rich in platelets but thrombi in the chambers were rich in fibrin and red cells. Deposition of indium 111-labeled platelets was continuously measured with a scintillation camera. Platelet deposition increased in a linear (collagen-coated segment) or exponential (chambers 1 and 2) fashion over time, with values after 40 minutes averaging 24.1 +/- 3.3 x 10(8) platelets (collagen segment), 16.7 +/- 3.4 x 10(8) platelets (chamber 1), and 8.4 +/- 2.4 x 10(8) platelets (chamber 2). Total fibrinogen deposition after 40 minutes was determined by using iodine 125-labeled baboon fibrinogen and averaged 0.58 +/- 0.14 mg in the collagen segment, 1.51 +/- 0.27 mg in chamber 1, and 0.95 +/- 0.25 mg in chamber 2. Plasma levels of beta-thromboglobulin (beta TG), platelet-factor 4 (PF4), and fibrinopeptide A (FPA) increased fourfold to fivefold after 60 minutes of blood exposure to the thrombotic device. Platelet deposition onto the collagen segment, chamber 1, and chamber 2 was linearly dependent on the circulating platelet count. Platelet accumulation in chamber 1 and chamber 2 was also dependent on the presence of the proximal collagen segment

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

    Directory of Open Access Journals (Sweden)

    Serena Valsami

    2015-01-01

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

  14. Bacterial contamination of platelet components not detected by BacT/ALERT®.

    Science.gov (United States)

    Abela, M A; Fenning, S; Maguire, K A; Morris, K G

    2018-02-01

    To investigate the possible causes for false negative results in BacT/ALERT ® 3D Signature System despite bacterial contamination of platelet units. The Northern Ireland Blood Transfusion Service (NIBTS) routinely extends platelet component shelf life to 7 days. Components are sampled and screened for bacterial contamination using an automated microbial detection system, the BacT/ALERT ® 3D Signature System. We report on three platelet components with confirmed bacterial contamination, which represent false negative BacT/ALERT ® results and near-miss serious adverse events. NIBTS protocols for risk reduction of bacterial contamination of platelet components are described. The methodology for bacterial detection using BacT/ALERT ® is outlined. Laboratory tests, relevant patient details and relevant follow-up information are analysed. In all three cases, Staphylococcus aureus was isolated from the platelet residue and confirmed on terminal sub-culture using BacT/ALERT ® . In two cases, S. aureus with similar genetic makeup was isolated from the donors. Risk reduction measures for bacterial contamination of platelet components are not always effective. Automated bacterial culture detection does not eliminate the risk of bacterial contamination. Visual inspection of platelet components prior to release, issue and administration remains an important last line of defence. © 2017 British Blood Transfusion Society.

  15. The use of platelet-rich plasma to treat chronic tendinopathies: A technical analysis.

    Science.gov (United States)

    Kaux, Jean-François; Emonds-Alt, Thibault

    2018-05-01

    Platelet-rich plasma (PRP) is blood plasma with a high concentration of autologous platelets which constitute an immense reservoir of growth factors. The clinical use of PRP is widespread in various medical applications. Although highly popular with athletes, the use of PRP for the treatment of tendinopathies remains scientifically controversial, particularly due to the diversity of products that go by the name of "PRP." To optimize its use, it is important to look at the various stages of obtaining PRP. In this literature review, we take a closer look at eight parameters which may influence the quality of PRP: 1) anticoagulants used to preserve the best platelet function, 2) the speed of centrifugation used to extract the platelets, 3) the platelet concentrations obtained, 4) the impact of the concentration of red and while blood cells on PRP actions, 5) platelet activators encouraging platelet degranulation and, hence, the release of growth factors, and 6) the use or nonuse of local anesthetics when carrying out infiltration. In addition to these parameters, it may be interesting to analyze other variables such as 7) the use of ultrasound guidance during the injection with a view to determining the influence they have on potential recovery.

  16. Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

    Science.gov (United States)

    Corona de la Peña, Norma; Gutiérrez-Aguilar, Manuel; Hernández-Reséndiz, Ileana; Marín-Hernández, Álvaro

    2017-01-01

    Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway i.e., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times vs. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation. PMID:28817667

  17. Comparison of the effects of platelet-rich or growth factor-rich plasma on intestinal anastomosis healing in pigs.

    Science.gov (United States)

    Giusto, Gessica; Vercelli, Cristina; Iussich, Selina; Tursi, Massimiliano; Perona, Giovanni; Gandini, Marco

    2017-06-19

    The use of autologous platelet-rich plasma (PRP) and plasma rich in growth factors (PRGF) has been proposed for the treatment of several acute and chronic syndromes, such as corneal epithelial defects and dry eye syndrome, gum bleeding during oral surgery, and in orthopaedic surgery. We hypothesized that PRGF, rather than PRP, could be more effective because of its intrinsic characteristics in promoting the healing of intestinal anastomosis. The purpose of the present study was to evaluate and compare the effects of PRP and PRGF on various parameters of anastomotic healing in a swine model. Eight female pigs were randomly assigned to two groups and subjected to hand sewn jeujuno-jejunal appositional extramucosal anastomoses. For each animal, a total of six anastomoses were performed: two were considered controls and received no treatment, while the remaining four anastomoses were treated with PRP or PRGF of which both were prepared at a platelet concentration that was respectively 3.4-fold and 2.81-fold higher than the original platelet count. In each animal, either PRP or PRGF was used as a treatment, to avoid interference among products. Animals were euthanized after 8 days and the anastomoses were evaluated and compared for the presence of adhesions, anastomotic leakage, bursting pressure, and histological appearance. The concentration of platelets in PRP was 3.41-fold higher (range, 3.20-4.24) that the concentration in whole blood, while the concentration in PRGF was 2.81-fold higher (range, 2.89-4.88). The results obtained from the present study highlighted that there are no differences between anastomotic samples treated with either PRP or PRGF preparations, except for a significant increase in epithelization of the intestinal mucosa at the anastomotic site in the PRGF group. Both PRP and PRGF suspensions should be considered a safe strategy and represent a relatively low-cost technology that is flexible enough to be applied in several therapeutic fields. No

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

    Science.gov (United States)

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

    2017-10-01

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

  19. 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.

  20. OP9 bone marrow stroma cells differentiate into megakaryocytes and platelets.

    Directory of Open Access Journals (Sweden)

    Yumiko Matsubara

    Full Text Available Platelets are essential for hemostatic plug formation and thrombosis. The mechanisms of megakaryocyte (MK differentiation and subsequent platelet production from stem cells remain only partially understood. The manufacture of megakaryocytes (MKs and platelets from cell sources including hematopoietic stem cells and pluripotent stem cells have been highlighted for studying the platelet production mechanisms as well as for the development of new strategies for platelet transfusion. The mouse bone marrow stroma cell line OP9 has been widely used as feeder cells for the differentiation of stem cells into MK lineages. OP9 cells are reported to be pre-adipocytes. We previously reported that 3T3-L1 pre-adipocytes differentiated into MKs and platelets. In the present study, we examined whether OP9 cells differentiate into MKs and platelets using MK lineage induction (MKLI medium previously established to generate MKs and platelets from hematopoietic stem cells, embryonic stem cells, and pre-adipocytes. OP9 cells cultured in MKLI medium had megakaryocytic features, i.e., positivity for surface markers CD41 and CD42b, polyploidy, and distinct morphology. The OP9-derived platelets had functional characteristics, providing the first evidence for the differentiation of OP9 cells into MKs and platelets. We then analyzed gene expressions of critical factors that regulate megakaryopoiesis and thrombopoiesis. The gene expressions of p45NF-E2, FOG, Fli1, GATA2, RUNX1, thrombopoietin, and c-mpl were observed during the MK differentiation. Among the observed transcription factors of MK lineages, p45NF-E2 expression was increased during differentiation. We further studied MK and platelet generation using p45NF-E2-overexpressing OP9 cells. OP9 cells transfected with p45NF-E2 had enhanced production of MKs and platelets. Our findings revealed that OP9 cells differentiated into MKs and platelets in vitro. OP9 cells have critical factors for megakaryopoiesis and

  1. 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.

  2. Clean Hands Count

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  12. Clean Hands Count

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  13. Detection and counting systems

    International Nuclear Information System (INIS)

    Abreu, M.A.N. de

    1976-01-01

    Detection devices based on gaseous ionization are analysed, such as: electroscopes ionization chambers, proportional counters and Geiger-Mueller counters. Scintillation methods are also commented. A revision of the basic concepts in electronics is done and the main equipment for counting is detailed. In the study of gama spectrometry, scintillation and semiconductor detectors are analysed [pt

  14. Clean Hands Count

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  15. Clean Hands Count

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  16. Clean Hands Count

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  17. Reticulocyte Count Test

    Science.gov (United States)

    ... htm. (2004 Summer). Immature Reticulocyte Fraction(IRF). The Pathology Center Newsletter v9(1). [On-line information]. Available ... Company, Philadelphia, PA [18th Edition]. Levin, M. (2007 March 8, Updated). Reticulocyte Count. MedlinePlus Medical Encyclopedia [On- ...

  18. Clean Hands Count

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  19. Radiation intensity counting system

    International Nuclear Information System (INIS)

    Peterson, R.J.

    1982-01-01

    A method is described of excluding the natural dead time of the radiation detector (or eg Geiger-Mueller counter) in a ratemeter counting circuit, thus eliminating the need for dead time corrections. Using a pulse generator an artificial dead time is introduced which is longer than the natural dead time of the detector. (U.K.)

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  1. Calorie count - fast food

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Calorie count - fast food URL of this page: //medlineplus.gov/ency/patientinstructions/ ...

  2. Fast counting electronics for neutron coincidence counting

    International Nuclear Information System (INIS)

    Swansen, J.E.

    1987-01-01

    This patent describes a high speed circuit for accurate neutron coincidence counting comprising: neutron detecting means for providing an above-threshold signal upon neutron detection; amplifying means inputted by the neutron detecting means for providing a pulse output having a pulse width of about 0.5 microseconds upon the input of each above threshold signal; digital processing means inputted by the pulse output of the amplifying means for generating a pulse responsive to each input pulse from the amplifying means and having a pulse width of about 50 nanoseconds effective for processing an expected neutron event rate of about 1 Mpps: pulse stretching means inputted by the digital processing means for producing a pulse having a pulse width of several milliseconds for each pulse received form the digital processing means; visual indicating means inputted by the pulse stretching means for producing a visual output for each pulse received from the digital processing means; and derandomizing means effective to receive the 50 ns neutron event pulses from the digital processing means for storage at a rate up to the neutron event rate of 1 Mpps and having first counter means for storing the input neutron event pulses

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

    Directory of Open Access Journals (Sweden)

    Jayitri Mazumdar

    2015-07-01

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

  4. 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)

  5. Influence of Oxidative Stress on Stored Platelets

    Directory of Open Access Journals (Sweden)

    K. Manasa

    2016-01-01

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

  6. The role of platelets during reproduction.

    Science.gov (United States)

    Isermann, Berend; Nawroth, Peter P

    2006-01-01

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

  7. Complete Blood Count Reference Intervals for Healthy Han Chinese Adults

    Science.gov (United States)

    Mu, Runqing; Guo, Wei; Qiao, Rui; Chen, Wenxiang; Jiang, Hong; Ma, Yueyun; Shang, Hong

    2015-01-01

    Background Complete blood count (CBC) reference intervals are important to diagnose diseases, screen blood donors, and assess overall health. However, current reference intervals established by older instruments and technologies and those from American and European populations are not suitable for Chinese samples due to ethnic, dietary, and lifestyle differences. The aim of this multicenter collaborative study was to establish CBC reference intervals for healthy Han Chinese adults. Methods A total of 4,642 healthy individuals (2,136 males and 2,506 females) were recruited from six clinical centers in China (Shenyang, Beijing, Shanghai, Guangzhou, Chengdu, and Xi’an). Blood samples collected in K2EDTA anticoagulant tubes were analyzed. Analysis of variance was performed to determine differences in consensus intervals according to the use of data from the combined sample and selected samples. Results Median and mean platelet counts from the Chengdu center were significantly lower than those from other centers. Red blood cell count (RBC), hemoglobin (HGB), and hematocrit (HCT) values were higher in males than in females at all ages. Other CBC parameters showed no significant instrument-, region-, age-, or sex-dependent difference. Thalassemia carriers were found to affect the lower or upper limit of different RBC profiles. Conclusion We were able to establish consensus intervals for CBC parameters in healthy Han Chinese adults. RBC, HGB, and HCT intervals were established for each sex. The reference interval for platelets for the Chengdu center should be established independently. PMID:25769040