Hematologic Nadirs During Chemoradiation for Anal Cancer: Temporal Characterization and Dosimetric Predictors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Andrew Y.; Golden, Daniel W.; Bazan, Jose G.

Purpose: Pelvic bone marrow (BM) constraints may offer a means to reduce the toxicity commonly associated with chemoradiation for anal cancer. We conducted a bi-institutional analysis of dose-volume metrics in a time-sensitive fashion to devise practical metrics to minimize hematologic toxicity. Methods and Materials: Fifty-six anal cancer patients from 2 institutions received definitive radiation therapy (median primary dose of 54 Gy) using intensity modulated radiation therapy (IMRT, n=49) or 3-dimensional (3D) conformal therapy (n=7) with concurrent 5-fluorouracil (5-FU) and mitomycin C. Weekly blood counts were retrospectively plotted to characterize the time course of cytopenias. Dose-volume parameters were correlated with blood countsmore » at a standardized time point to identify predictors of initial blood count nadirs. Results: Leukocytes, neutrophils, and platelets reached a nadir at week 3 of treatment. Smaller volumes of the pelvic BM correlated most strongly with lower week 3 blood counts, more so than age, sex, body mass index (BMI), or dose metrics. Patients who had ≥750 cc of pelvic BM spared from doses of ≥30 Gy had 0% grade 3+ leukopenia or neutropenia at week 3. Higher V40 Gy to the lower pelvic BM (LP V40) also correlated with cytopenia. Patients with an LP V40 >23% had higher rates of grade 3+ leukopenia (29% vs 4%, P=.02), grade 3+ neutropenia (33% vs 8%, P=.04), and grade 2+ thrombocytopenia (32% vs 7%, P=.04) at week 3. On multivariate analysis, pelvic BM volume and LP V40 remained associated with leukocyte count, and all marrow subsite volumes remained associated with neutrophil counts at week 3 (P<.1). Conclusions: Larger pelvic BM volumes correlate with less severe leukocyte and neutrophil nadirs, suggesting that larger total “marrow reserve” can mitigate cytopenias. Sparing a critical marrow reserve and limiting the V40 Gy to the lower pelvis may reduce the risk of hematologic toxicity.« less

Sphingosine 1-phosphate release from platelets during clot formation: close correlation between platelet count and serum sphingosine 1-phosphate concentration

PubMed Central

2013-01-01

Background Sphingosine 1-phosphate (Sph-1-P), abundantly stored in platelets and released extracellularly upon activation, plays important roles as an extracellular mediator by interacting with specific cell surface receptors, especially in the area of vascular biology and immunology/hematology. Although the plasma Sph-1-P level is reportedly determined by red blood cells (RBCs), but not platelets, this may not be true in cases where the platelets have been substantially activated. Methods and results We measured the Sph-1-P and dihydrosphingosine 1-phosphate (DHSph-1-P) levels in serum samples (in which the platelets had been fully activated) from subjects with (n = 21) and without (n = 33) hematological disorders. We found that patients with essential thrombocythemia exhibited higher serum Sph-1-P and DHSph-1-P concentrations. The serum Sph-1-P concentration was closely correlated with the platelet count but was very weakly correlated with the RBC count. Similar results were obtained for DHSph-1-P. The serum Sph-1-P and DHSph-1-P levels were inversely correlated with the level of autotaxin (ATX), a lysophosphatidic acid-producing enzyme. A multiple regression analysis also revealed that the platelet count had the greatest explanatory impact on the serum Sph-1-P level. Conclusions Our present results showed close correlations between both the serum Sph-1-P and DHSph-1-P levels and the platelet count (but not the RBC count); these results suggest that high concentrations of these sphingoid base phosphates may be released from platelets and may mediate cross talk between platelet activation and the formation of atherosclerotic lesions. PMID:23418753

The effect of iron balance on platelet counts in blood donors.

PubMed

Eder, Anne F; Yau, Yu Ying; West, Kamille

2017-02-01

Thrombocytosis (or, less commonly, thrombocytopenia) is associated with iron-deficiency anemia and resolves with iron therapy. Many volunteer blood donors have low iron stores, with or without anemia. Iron balance could affect platelet counts in blood donors. Whole blood donors deferred for finger-stick hemoglobin levels less than 12.5 g/dL were evaluated by complete blood count and serum iron panel before and after oral iron treatment. Group assignment for iron depletion was based on serum ferritin cutoffs of less than 20 µg/L for women and less than 30 µg/L for men or was based on changes in serum ferritin levels after iron replacement. Among 1273 Hb-deferred whole blood donors, 55% (619 of 1128) of the women and 70% (102 of 145) of the men were iron depleted. Iron-depleted donors had higher platelet counts compared with donors who had normal ferritin levels (women: 286 vs. 268 × 10 3 /µL; p < 0.0001; men: 246 vs. 222 × 10 3 /µL; p = 0.0454). Only 4.4% of iron-depleted donors had thrombocytosis (> 400 × 10 3 /µL) compared with 2.0% of donors who had normal ferritin levels (p = 0.017). Iron replacement decreased platelet counts in iron-depleted female donors (mean, -19,800/µL; interquartile range, 8000 to -45,000/μL), but not in donors who had normal or stable ferritin levels. The same trends were observed in male donors. Iron-depleted donors had higher platelet counts than donors who had adequate iron stores. Oral iron replacement decreased platelet counts on average by about 20,000/µL in iron-depleted donors but had no effect on platelet counts in donors who had normal or stable ferritin levels. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Effective estimation of correct platelet counts in pseudothrombocytopenia using an alternative anticoagulant based on magnesium salt

PubMed Central

Schuff-Werner, Peter; Steiner, Michael; Fenger, Sebastian; Gross, Hans-Jürgen; Bierlich, Alexa; Dreissiger, Katrin; Mannuß, Steffen; Siegert, Gabriele; Bachem, Maximilian; Kohlschein, Peter

2013-01-01

Pseudothrombocytopenia remains a challenge in the haematological laboratory. The pre-analytical problem that platelets tend to easily aggregate in vitro, giving rise to lower platelet counts, has been known since ethylenediamine-tetra acetic acid EDTA and automated platelet counting procedures were introduced in the haematological laboratory. Different approaches to avoid the time and temperature dependent in vitro aggregation of platelets in the presence of EDTA were tested, but none of them proved optimal for routine purposes. Patients with unexpectedly low platelet counts or flagged for suspected aggregates, were selected and smears were examined for platelet aggregates. In these cases patients were asked to consent to the drawing of an additional sample of blood anti-coagulated with a magnesium additive. Magnesium was used in the beginning of the last century as anticoagulant for microscopic platelet counts. Using this approach, we documented 44 patients with pseudothrombocytopenia. In all cases, platelet counts were markedly higher in samples anti-coagulated with the magnesium containing anticoagulant when compared to EDTA-anticoagulated blood samples. We conclude that in patients with known or suspected pseudothrombocytopenia the magnesium-anticoagulant blood samples may be recommended for platelet counting. PMID:23808903

Effect of Nadir CD4+ T Cell Count on Clinical Measures of Periodontal Disease in HIV+ Adults before and during Immune Reconstitution on HAART

PubMed Central

Vernon, Lance T.; Demko, Catherine A.; Babineau, Denise C.; Wang, Xuelei; Toossi, Zahra; Weinberg, Aaron; Rodriguez, Benigno

2013-01-01

Background The contribution of HIV-infection to periodontal disease (PD) is poorly understood.  We proposed that immunological markers would be associated with improved clinical measures of PD. Methods We performed a longitudinal cohort study of HIV-infected adults who had started highly active antiretroviral therapy (HAART) <2 years. PD was characterized clinically as the percent of teeth with ≥1 site with periodontal probing depth (PPD) ≥5.0mm, recession (REC) >0mm, clinical attachment level (CAL) ≥4.0mm, and bleeding on probing (BOP) at ≥4 sites/tooth and microbiologically as specific periodontopathogen concentration. Linear mixed-effects models were used to assess the associations between immune function and PD. Results Forty (40) subjects with median 2.7 months on HAART and median nadir CD4+ T-cell count of 212 cells/μl completed a median 3 visits. Over 24 months, CD4+ T-cell count increased by a mean 173 cells/µl (p<0.001) and HIV RNA decreased by 0.5 log10 copies/ml (p<0.001); concurrently, PPD, CAL and BOP decreased by a mean 11.7%, 12.1%, and 14.7% respectively (all p<0.001). Lower nadir CD4+ T-cell count was associated with worse baseline REC (-6.72%; p=0.04) and CAL (9.06%; p<0.001). Further, lower nadir CD4+ T-cell count was associated with a greater relative longitudinal improvement in PPD in subjects with higher baseline levels of Porphyromonas gingivalis (p=0.027), and BOP in subjects with higher baseline levels of Porphyromonas gingivalis or Treponema denticola (p=0.001 and p=0.006 respectively). Longitudinal changes from baseline in CD4+ T-cell count and level of HIV RNA were not independently associated with longitudinal changes in any clinical markers of PD. Conclusion Degree of immunosuppression was associated with baseline gingival recession. After HAART initiation, measures of active PD improved most in those with lower nadir CD4+ T-cell counts and higher baseline levels of specific periodontopathogens. Nadir CD4+ T-cell count

Comparison of Immature Platelet Count to Established Predictors of Platelet Reactivity During Thienopyridine Therapy.

PubMed

Stratz, Christian; Bömicke, Timo; Younas, Iris; Kittel, Anja; Amann, Michael; Valina, Christian M; Nührenberg, Thomas; Trenk, Dietmar; Neumann, Franz-Josef; Hochholzer, Willibald

2016-07-19

Previous data suggest that reticulated platelets significantly affect antiplatelet response to thienopyridines. It is unknown whether parameters describing reticulated platelets can predict antiplatelet response to thienopyridines. The authors sought to determine the extent to which parameters describing reticulated platelets can predict antiplatelet response to thienopyridine loading compared with established predictors. This study randomized 300 patients undergoing elective coronary stenting to loading with clopidogrel 600 mg, prasugrel 30 mg, or prasugrel 60 mg. Adenosine diphosphate (ADP)-induced platelet reactivity was assessed by impedance aggregometry before loading (intrinsic platelet reactivity) and again on day 1 after loading. Multiple parameters of reticulated platelets were assessed by automated whole blood flow cytometry: absolute immature platelet count (IPC), immature platelet fraction, and highly fluorescent immature platelet fraction. Each parameter of reticulated platelets correlated significantly with ADP-induced platelet reactivity (p < 0.01 for all 3 parameters). In a multivariable model including all 3 parameters, only IPC remained a significant predictor of platelet reactivity (p < 0.001). In models adjusting each of the 3 parameters for known predictors of on-treatment platelet reactivity including cytochrome P450 2C19 (CYP2C19) polymorphisms, age, body mass index, diabetes, and intrinsic platelet reactivity, only IPC prevailed as an independent predictor (p = 0.001). In this model, IPC was the strongest predictor of on-treatment platelet reactivity followed by intrinsic platelet reactivity. IPC is the strongest independent platelet count-derived predictor of antiplatelet response to thienopyridine treatment. Given its easy availability, together with its even stronger association with on-treatment platelet reactivity compared with known predictors, including the CYP2C19*2 polymorphism, IPC may become the preferred predictor of

Platelet count and platelet indices in women with preeclampsia.

PubMed

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 <248.010×10 3 /µL were at higher risk of 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 <248.010×10 3 /µL and PC to MPV ratio 31.2 are valid predictors of preeclampsia.

Postoperative Decrease in Platelet Counts Is Associated with Delayed Liver Function Recovery and Complications after Partial Hepatectomy.

PubMed

Takahashi, Kazuhiro; Kurokawa, Tomohiro; Oshiro, Yukio; Fukunaga, Kiyoshi; Sakashita, Shingo; Ohkohchi, Nobuhiro

2016-05-01

Peripheral platelet counts decrease after partial hepatectomy; however, the implications of this phenomenon are unclear. We assessed if the observed decrease in platelet counts was associated with postoperative liver function and morbidity (complications grade ≤ II according to the Clavien-Dindo classification). We enrolled 216 consecutive patients who underwent partial hepatectomy for primary liver cancers, metastatic liver cancers, benign tumors, and donor hepatectomy. We classified patients as either low or high platelet percentage (postoperative platelet count/preoperative platelet count) using the optimal cutoff value calculated by a receiver operating characteristic (ROC) curve analysis, and analyzed risk factors for delayed liver functional recovery and morbidity after hepatectomy. Delayed liver function recovery and morbidity were significantly correlated with the lowest value of platelet percentage based on ROC analysis. Using a cutoff value of 60% acquired by ROC analysis, univariate and multivariate analysis determined that postoperative lowest platelet percentage ≤ 60% was identified as an independent risk factor of delayed liver function recovery (odds ratio (OR) 6.85; P < 0.01) and morbidity (OR, 4.90; P < 0.01). Furthermore, patients with the lowest platelet percentage ≤ 60% had decreased postoperative prothrombin time ratio and serum albumin level and increased serum bilirubin level when compared with patients with platelet percentage ≥ 61%. A greater than 40% decrease in platelet count after partial hepatectomy was an independent risk factor for delayed liver function recovery and postoperative morbidity. In conclusion, the decrease in platelet counts is an early marker to predict the liver function recovery and complications after hepatectomy.

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

PubMed

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.

Can Eosinophil Count, Platelet Count, and Mean Platelet Volume Be a Positive Predictive Factor in Penile Arteriogenic Erectile Dysfunction Etiopathogenesis?

PubMed Central

Sönmez, Mehmet Giray; Göğer, Yunus Emre; Sönmez, Leyla Öztürk; Aydın, Arif; Balasar, Mehmet; Kara, Cengiz

2016-01-01

Blood count parameters of patients referring with erectile dysfunction (ED) were examined in this study and it was investigated whether eosinophil count (EC), platelet count (PC), and mean platelet volume values among the suspected predictive parameters which may play a role in especially penile arteriogenic ED etiopathogenesis had a contribution on pathogenesis. Patients referring with ED complaint were evaluated. Depending on the medical story, ED degree was determined by measuring International Index of Erectile Function. Penile Doppler ultrasonography was taken in patients suspected to have vasculogenic ED. According to penile Doppler ultrasonography result, patients with arterial deficiency were included in the penile arteriogenic ED group and the patients with normal results were included in the nonvasculogenic ED group. A total of 36 patients participated in the study from the penile arteriogenic ED group and 32 patients from the nonvasculogenic ED group. Compared with the nonvasculogenic ED group, the penile arteriogenic ED group’s low International Index of Erectile Function score, high EC, mean platelet volume and PC values were detected to be statistically significant (p < .001, p = .021, p = .018, p = .034, respectively). No statistically significant difference was observed among the two groups when age, white blood cells, red blood cells, and hemoglobin values were considered. Pansystolic volume velocities were detected as statistically significantly low compared with the nonvasculogenic ED group in the measurements made in 5th, 10th, 15th, and 20th minutes on the right and left sides in the penile arteriogenic ED group. High MPV value and PC is a significant predictive factor for penile arteriogenic ED and vasculogenic ED and high EC is specifically predictive of arteriogenic ED. PMID:27895254

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

PubMed

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 [<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. Platelet 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. 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.

Adjusting MtDNA Quantification in Whole Blood for Peripheral Blood Platelet and Leukocyte Counts.

PubMed

Hurtado-Roca, Yamilee; Ledesma, Marta; Gonzalez-Lazaro, Monica; Moreno-Loshuertos, Raquel; Fernandez-Silva, Patricio; Enriquez, Jose Antonio; Laclaustra, Martin

2016-01-01

Alterations of mitochondrial DNA copy number (mtDNAcn) in the blood (mitochondrial to nuclear DNA ratio) appear associated with several systemic diseases, including primary mitochondrial disorders, carcinogenesis, and hematologic diseases. Measuring mtDNAcn in DNA extracted from whole blood (WB) instead of from peripheral blood mononuclear cells or buffy coat may yield different results due to mitochondrial DNA present in platelets. The aim of this work is to quantify the contribution of platelets to mtDNAcn in whole blood [mtDNAcn(WB)] and to propose a correction formula to estimate leukocytes' mtDNAcn [mtDNAcn(L)] from mtDNAcn(WB). Blood samples from 10 healthy adults were combined with platelet-enriched plasma and saline solution to produce artificial blood preparations. Aliquots of each sample were combined with five different platelet concentrations. In 46 of these blood preparations, mtDNAcn was measured by qPCR. MtDNAcn(WB) increased 1.07 (95%CI 0.86, 1.29; p<0.001) per 1000 platelets present in the preparation. We proved that leukocyte count should also be taken into account as mtDNAcn(WB) was inversely associated with leukocyte count; it increased 1.10 (95%CI 0.95, 1.25, p<0.001) per unit increase of the ratio between platelet and leukocyte counts. If hematological measurements are available, subtracting 1.10 the platelets/leukocyte ratio from mtDNAcn(WB) may serve as an estimation for mtDNAcn(L). Both platelet and leukocyte counts in the sample are important sources of variation if comparing mtDNAcn among groups of patients when mtDNAcn is measured in DNA extracted from whole blood. Not taking the platelet/leukocyte ratio into account in whole blood measurements, may lead to overestimation and misclassification if interpreted as leukocytes' mtDNAcn.

Liver stiffness and platelet count for identifying patients with compensated liver disease at low risk of variceal bleeding.

PubMed

Marot, Astrid; Trépo, Eric; Doerig, Christopher; Schoepfer, Alain; Moreno, Christophe; Deltenre, Pierre

2017-05-01

The 2015 Baveno VI guidelines recommend against performing upper gastrointestinal endoscopy in patients with compensated cirrhosis who have a liver stiffness <20 kPa and a platelet count >150 000/mm³ because of a low prevalence of varices at risk of bleeding in this population. The aim was to synthesize the available evidence on the usefulness of the combined use of liver stiffness and platelet count to identify patients without oesophageal varices. Meta-analysis of trials evaluating the usefulness of a given cut-off for liver stiffness and platelet count to rule out the presence of oesophageal varices. Fifteen studies were included. All studies excepting five used the Baveno VI criteria. Compared to patients with either high liver stiffness or low platelet count, those with low liver stiffness and normal platelet count had a lower risk of varices at risk of bleeding (OR=0.22, 95% CI=0.13-0.39, P<.001) with low heterogeneity between studies (I 2 =21%). They also had a lower risk of varices (OR=0.23, 95% CI=0.17-0.32, P<.001) with moderate heterogeneity between studies (I 2 =28%). In patients with low liver stiffness and normal platelet count, the pooled estimate rates for varices at risk of bleeding was 0.040 (95% CI=0.027-0.059) with low heterogeneity between studies (I 2 =3%). Patients with low liver stiffness and normal platelet count have a lower risk of varices than those with either high liver stiffness or low platelet count. Varices at risk of bleeding are found in no more than 4% of patients when liver stiffness is <20 kPa and platelet count is normal. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

21 CFR 864.8175 - Calibrator for platelet counting.

Code of Federal Regulations, 2010 CFR

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...

21 CFR 864.8175 - Calibrator for platelet counting.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

21 CFR 864.8175 - Calibrator for platelet counting.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

21 CFR 864.8175 - Calibrator for platelet counting.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 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...

21 CFR 864.8175 - Calibrator for platelet counting.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

Impact of Helicobacter pylori Eradication Therapy on Platelet Counts in Patients With Chronic Idiopathic Thrombocytopenic Purpura

PubMed Central

Amiri, Mohamadreza

2016-01-01

This study was a before and after clinical evaluation of Helicobacter pylori eradication on platelet counts in a group of 23 patients with chronic Idiopathic (Autoimmune) thrombocytopenic purpura (CITP). H. pylori infection was identified in patients by a 13C-urea breath test and confirmed by an H. pylori stool antigen test. Eradication was conducted in patients testing positive. Infected (n = 10) and uninfected (n = 13) patient groups did not differ with respect to age, gender, history of previous splenectomy, treatment with anti-D, current treatment with corticosteroids, or initial platelet counts. H. pylori eradication was successful in eight infected CITP patients, with two patients not responsive to treatment. Compared to the uninfected group, patients in the infected group who responded to eradication therapy had significantly increased platelet counts after six months (56.2 ± 22.2 vs. 233 ± 85.6 ×103 million cells/L; P < 0.01), whereas platelet counts in the non-responding patients and uninfected group did not differ after this period of time. H. pylori eradication promotes significant platelet count improvement in patients with CITP. Thus, all patients with CITP should be tested and treated for H. pylori infections. PMID:26925898

Platelet transfusions in cancer patients with hypoproliferative thrombocytopenia in the intensive care unit.

PubMed

Habr, Bassem; Charpentier, Julien; Champigneulle, Benoît; Dechartres, Agnès; Daviaud, Fabrice; Geri, Guillaume; Cariou, Alain; Chiche, Jean-Daniel; Mira, Jean-Paul; Pène, Frédéric

2015-12-01

Thrombocytopenia is a frequent finding in critically ill cancer patients for whom indications of platelet transfusions are unclear. We herein addressed the current practices in platelet transfusion and the risk of bleeding in cancer patients with hypoproliferative thrombocytopenia in the intensive care unit (ICU). A retrospective monocenter study over a 7-year period was conducted in a medical ICU. Adult patients with malignancies and hypoproliferative thrombocytopenia, and who received at least one platelet concentrate during their ICU stay, were included. 296 patients were included and received a total of 904 platelet transfusions, for prophylactic indications in 300 (33.2 %) episodes, for securing an invasive procedure in 257 (28.4 %), and for treatment of minor to major bleeding manifestations in 347 (38.4 %). Most prophylactic transfusions (80 %) were performed at platelet count thresholds below 10-20 × 10(9)/L. Platelet increments were generally low in all three indications, 10 (interquartile range 2-25), 11 (2-25), and 8 (0-21) × 10(9)/L, respectively. A total of 97 major ICU-acquired bleeding events occurred in 40 patients. About half of those bleeding episodes (54.7 %) occurred at platelet counts below 20 × 10(9)/L. However, neither low admission platelet count nor low nadir platelet counts were predictive of ICU-acquired bleeding. The in-ICU mortality rate tended to be higher in patients with severe ICU-acquired bleeding events (50 vs. 36 %). Most prophylactic platelet transfusions were given using thresholds of 10-20 × 10(9)/L in critically ill thrombocytopenic cancer patients. The individual risk of ICU-acquired severe bleeding appears hardly predictable with the depth of thrombocytopenia.

Lymphocyte Nadir and Esophageal Cancer Survival Outcomes After Chemoradiation Therapy.

PubMed

Davuluri, Rajayogesh; Jiang, Wen; Fang, Penny; Xu, Cai; Komaki, Ritsuko; Gomez, Daniel R; Welsh, James; Cox, James D; Crane, Christopher H; Hsu, Charles C; Lin, Steven H

2017-09-01

Host immunity may affect the outcome in patients with esophageal cancer. We sought to identify factors that influenced absolute lymphocyte count (ALC) nadir during chemoradiation therapy (CRT) for esophageal cancer (EC) and looked for clinically relevant associations with survival. 504 patients with stage I-III EC (2007-2013) treated with neoadjuvant or definitive CRT with weekly ALC determinations made during treatment were analyzed. Grade of lymphopenia from ALC nadir during CRT was based on Common Terminology Criteria for Adverse Events version 4.0. Associations of ALC nadir with survival were examined using multivariate Cox proportional hazards analysis (MVA) and competing risks regression analysis. The median follow-up time was 36 months. The incidences of grade 1, 2, 3, and 4 ALC nadir during CRT were 2%, 12%, 59%, and 27%, respectively. The impact was lymphocyte-specific because this was not seen for monocyte or neutrophil count. On MVA, grade 4 ALC nadir (G4 nadir) was significantly associated with worse overall and disease-specific survival outcomes. Predictors of G4 nadir included distal tumor location, definitive CRT, taxane/5-fluorouracil chemotherapy, and photon-based radiation type (vs proton-based). Radiation type strongly influenced the mean body dose exposure, which was a strong predictor for G4 nadir (odds ratio 1.22 per Gray, P<.001). G4 nadir during CRT for EC was associated with poor outcomes, suggesting a role of host immunity in disease control. This observation provides a rationale to prospectively test chemotherapeutic and radiation treatment strategies that may have a lower impact on host immunity. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Carica papaya Leaf Extract Capsule on Platelet Count in Patients of Dengue Fever with Thrombocytopenia.

PubMed

Gadhwal, Ajeet Kumar; Ankit, B S; Chahar, Chitresh; Tantia, Pankaj; Sirohi, P; Agrawal, R P

2016-06-01

Thrombocytopenia in dengue fever is a common and serious complication. However, no specific treatment is available for dengue fever induced thrombocytopenia. In few countries (Pakistan, Malaysia, Sri Lanka and other Asian countries) the leaf extract of Carica papaya has been effectively used for thrombocytopenia. So, the study is planned to access effect of Carica papaya leaf extract on platelet count in dengue fever patients. All participants were randomised into two groups, study group and control group; the study group was given papaya leaf extract capsule of 500 mg once daily and routine supportive treatment for consecutive five days. The controls were given only routine supportive treatment. Daily complete blood counts, platelet counts and haematocrit level, liver function test, renal function test of both groups were observed. On the first day platelet count of study group and control group was (59.82±18.63, 61.06±20.03 thousands, p value 0.36). On the 2nd day platelet count of both study and control groups was not significantly different (61.67±19.46 and 59.93±19.52 thousands, p value 0.20) but on 3rd day platelet count of study group was significantly higher than control group (82.96±16.72, 66.45±17.36 thousands, p value < 0.01). On 4th and 5th day platelet count of study group (122.43±19.36 and 112.47±17.49 thousands respectively) was also significantly higher than the control group (88.75±21.65 and 102.59±19.35 thousands) (p value < 0.01). On 7th day platelet count of study group and control group were not significantly different (124.47±12.35 and 122.46±19.76 thousands respectively, p value 0.08). Average hospitalization period of study group v/s control group was 3.65±0.97 v/s 5.42±0.98 days (p value < 0.01). Average platelet transfusion requirement in study group was significantly less than control group (0.685 units per patient v/s 1.19 units per patient) (p value <0.01). It is concluded that Carica papaya leaf extract increases the

Platelet Distribution Width to Platelet Count Ratio as an Index of Severity of Illness.

PubMed

Purbiya, Pragati; Golwala, Zainab Mohammedi; Manchanda, Ayush; Sreenivas, V; Puliyel, Jacob M

2018-01-01

To prospectively validate association between the ratio of platelet distribution width (PDW)/platelet count (PCT) and pediatric intensive care unit (PICU) mortality. The study was done in the pediatric intensive care unit (PICU). Platelet indices in the first sample taken after admission were used. In this case control analysis, cases were the patients who died in PICU and the survivors served as controls. Consecutive 209 eligible patients over a period of 15 mo from January 2014 through March 2015 were included. Exposure was PDW/PC above 0.07. Of them 174 survived and 35 died. The mean PDW for survivors was 16.77 (±0.92) and for those who died it was 17.33 (±1.03) (p 0.0015). Mean platelet count (PC) for survivors was 3,46,000 (±1,64,700) and for those who died it was 1,75,800 (±1,61,500) (p < 0.001). PDW/PC for survivors was 0.12 (±0.46) and for those who died it was 0.336 (±0.53) (p 0.0014). Using the cut-off of 0.07 for PDW/PC described by Golwala et al., 77.14% above the cut-off died, compared to 22.85% below that cut-off. The odds ratio (OR) for death was 10.6 (95% CI: 4.48 to 25.12). The area under the receiver operating curve (ROC) curve for PDW/PC ratio was 0.81. The ratio of PDW/PC, higher than 0.07 in the first sample after admission can be considered as an independent predictor of mortality with sensitivity and specificity of 77.1% and 77.5%, respectively. It may be a useful component for inclusion in composite scores for predicting mortality.

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.

PubMed

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

Long-term exposure to ambient particulate matter (PM2.5) is associated with platelet counts in adults.

PubMed

Zhang, Zilong; Chan, Ta-Chien; Guo, Cui; Chang, Ly-Yun; Lin, Changqing; Chuang, Yuan Chieh; Jiang, Wun Kai; Ho, Kin Fai; Tam, Tony; Woo, Kam S; Lau, Alexis K H; Lao, Xiang Qian

2018-05-09

The prothrombotic effects of particulate matter (PM) may underlie the association of air pollution with increased risks of cardiovascular disease. This study aimed to investigate the association between long-term exposure to PM with an aerodynamic diameter ≤2.5 μm (PM 2.5 ) and platelet counts, a marker of coagulation profiles. The study participants were from a cohort consisting of 362,396 Taiwanese adults who participated in a standard medical examination program between 2001 and 2014. Platelet counts were measured through Complete Blood Count tests. A satellite-based spatio-temporal model was used to estimate 2-year average ambient PM 2.5 concentration at each participant's address. Mixed-effects linear regression models were used to investigate the association between PM 2.5 exposure and platelet counts. This analysis included 175,959 men with 396,248 observations and 186,437 women with 397,877 observations. Every 10-μg/m 3 increment in the 2-year average PM 2.5 was associated with increases of 0.42% (95% CI: 0.38%, 0.47%) and 0.49% (95% CI: 0.44%, 0.54%) in platelet counts in men and women, respectively. A series of sensitivity analyses, including an analysis in participants free of cardiometabolic disorders, confirmed the robustness of the observed associations. Baseline data analyses showed that every 10-μg/m 3 increment in PM 2.5 was associated with higher risk of 17% and 14% of having elevated platelet counts (≥90th percentile) in men and women, respectively. Long-term exposure to PM 2.5 appears to be associated with increased platelet counts, indicating potential adverse effects on blood coagulability. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

PubMed

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.

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.

PubMed

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 <100 × 10⁹/L. Pseudothrombocytopenia or platelet clumping should be considered in patients with acute 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.

Leukocyte Count is Associated with Increased Platelet Reactivity and Diminished Response to Aspirin in Healthy Individuals with a Family History of Coronary Artery Disease

PubMed Central

Faraday, Nauder; Yanek, Lisa R.; Vaidya, Dhananjay; Kral, Brian; Qayyum, Rehan; Herrera-Galeano, J. Enrique; Moy, Taryn F.; Becker, Diane M.; Becker, Lewis C.

2009-01-01

Background Markers of systemic inflammation, including blood leukocyte count, are associated with increased cardiovascular risk, but the mechanisms underlying this association are unclear. Leukocytes may promote platelet reactivity and thrombus formation, providing a basis for increased risk, but a relation between leukocyte count and platelet function has not been studied. Methods We evaluated the relation of blood leukocyte count, C-reactive protein (CRP), and interleukin-6 (IL-6) to platelet aggregation to collagen, ADP and arachidonic acid, and to urinary excretion of 11-dehydro thromboxane B2. Studies were conducted in 1600 individuals (45.0 ± 12.9 years, 42.7% male) at risk for coronary artery disease (CAD) before and after low dose aspirin. Results At baseline, platelet reactivity increased with increasing quartile of leukocyte count (median counts for each quartile were normal) for all measures of platelet function (P<0.0001). These relations were unchanged by aspirin. The relation between leukocyte count and each measure of platelet reactivity remained significant (P<0.05) after multivariable adjustment for CRP, IL-6, cardiac risk factors, hematologic variables, and platelet thromboxane production. CRP and IL-6 were independently associated with few measures of platelet reactivity. Conclusions Increasing quartile of leukocyte count, even within the normal range, is associated with increasing platelet reactivity in individuals at risk for CAD. This relationship is not altered by aspirin and is independent of inflammatory markers and platelet thromboxane production. Additional studies are needed to determine the mechanism(s) for this association and therapies to reduce cardiovascular risk in patients with elevated leukocyte counts. PMID:19185906

Validity of Particle-Counting Method Using Laser-Light Scattering for Detecting Platelet Aggregation in Diabetic Patients

NASA Astrophysics Data System (ADS)

Nakadate, Hiromichi; Sekizuka, Eiichi; Minamitani, Haruyuki

We aimed to study the validity of a new analytical approach that reflected the phase from platelet activation to the formation of small platelet aggregates. We hoped that this new approach would enable us to use the particle-counting method with laser-light scattering to measure platelet aggregation in healthy controls and in diabetic patients without complications. We measured agonist-induced platelet aggregation for 10 min. Agonist was added to the platelet-rich plasma 1 min after measurement started. We compared the total scattered light intensity from small aggregates over a 10-min period (established analytical approach) and that over a 2-min period from 1 to 3 min after measurement started (new analytical approach). Consequently platelet aggregation in diabetics with HbA1c ≥ 6.5% was significantly greater than in healthy controls by both analytical approaches. However, platelet aggregation in diabetics with HbA1c < 6.5%, i.e. patients in the early stages of diabetes, was significantly greater than in healthy controls only by the new analytical approach, not by the established analytical approach. These results suggest that platelet aggregation as detected by the particle-counting method using laser-light scattering could be applied in clinical examinations by our new analytical approach.

Platelet counts on admission affect coronary flow, myocardial perfusion and left ventricular systolic function after primary percutaneous coronary intervention.

PubMed

Sharif, Dawod; Abu-Salem, Mira; Sharif-Rasslan, Amal; Rosenschein, Uri

2017-10-01

Patients with acute ST-elevation myocardial infarction (STEMI) and increased platelet count treated by fibrinolysis have worse outcomes. The aim of this study was to test the hypothesis that platelet blood count at admission in patients with acute STEMI treated by primary percutaneous coronary intervention affects coronary flow, myocardial perfusion and recovery of left ventricular systolic function. A total of 174 patients presenting with acute anterior STEMI and treated with primary percutaneous coronary intervention were included and divided into subgroups of admission platelet blood count of <200 K, 200-300 K, 300-400 K and >400 K. Evaluation of coronary artery flow and myocardial blush grade was performed according to the TIMI criteria. Electrocardiographic ST elevation resolution post-primary percutaneous coronary intervention was evaluated. Doppler echocardiographic evaluation of left anterior descending coronary artery velocities early and late after primary percutaneous coronary intervention and assessment of left ventricular ejection fraction and wall motion score index (WMSI) of left ventricular and left anterior descending coronary artery territory were performed. Post-primary percutaneous coronary intervention TIMI, myocardial blush grade and ST elevation resolution were similar in all groups. Patients with platelet counts <200 K had higher peak diastolic left anterior descending coronary artery velocity both early and late after primary percutaneous coronary intervention, and higher prevalence of left anterior descending coronary artery velocity deceleration time exceeding 600 ms, (45.5% vs. 40%, P<0.05). Patients with platelet counts >400 K presented with worse left ventricular ejection fraction, left ventricular WMSI and left anterior descending coronary artery WMSI, and before discharge this subgroup had worse left ventricular WMSI and left anterior descending coronary artery WMSI, P<0.01. Patients with anterior STEMI treated by primary

Effect of quinine and artesunate combination therapy on platelet count of children with severe malaria.

PubMed

Gupta, Parul; Narang, Manish; Gomber, Sunil; Saha, Rumpa

2017-05-01

There are several case reports of quinine-induced thrombocytopenia but no clinical trials to ascertain its incidence and significance in severe malaria. The primary objective was to assess the effect of quinine on the platelet count in children with severe malaria and to compare it with artesunate combination therapy (ACT), and the secondary objective was to assess outcome of treatment with quinine and ACT. An open-labelled, randomised, controlled trial was undertaken in 100 children aged 6 months to 12 years who were diagnosed with malaria by microscopy and/or rapid diagnostic test kits with at least one WHO clinical or laboratory criterion for severe malaria. All subjects were commenced on either quinine or ACT. Clindamycin was added to artesunate as a combination drug (ACT). It was also given to patients on quinine to avoid its confounding effect on the results. Platelet counts were undertaken every 24 hours for 7 consecutive days, temperature and coma score (Blantyre coma score ≥3 in children <4 years or Glasgow coma score ≥13 in children >4 years) was recorded 6-hourly and peripheral smears were taken 12-hourly until two consecutively negative smears were obtained. The primary outcome was a fall in the platelet count by ≥20% from the time of drug initiation until day 7. The secondary outcome was comparison of the efficacy, parasite clearance time, fever clearance time, coma recovery time and adverse effects of quinine vs ACT. 30.4% patients in the quinine group (n = 48) had ≥20% fall in platelet count and 10.8% of patients in the ACT group (n = 46) (P = 0.02). Despite the fall in platelet count, there was no bleeding. The efficacy of ACT was significantly better than quinine but the other treatment outcomes showed insignificant difference. Quinine should be used with caution in patients with severe malaria because of the potential risk of quinine-induced thrombocytopenia.

Carica papaya Leaves Juice Significantly Accelerates the Rate of Increase in Platelet Count among Patients with Dengue Fever and Dengue Haemorrhagic Fever

PubMed Central

Subenthiran, Soobitha; Choon, Tan Chwee; Cheong, Kee Chee; Thayan, Ravindran; Teck, Mok Boon; Muniandy, Prem Kumar; Afzan, Adlin; Abdullah, Noor Rain; Ismail, Zakiah

2013-01-01

The study was conducted to investigate the platelet increasing property of Carica papaya leaves juice (CPLJ) in patients with dengue fever (DF). An open labeled randomized controlled trial was carried out on 228 patients with DF and dengue haemorrhagic fever (DHF). Approximately half the patients received the juice, for 3 consecutive days while the others remained as controls and received the standard management. Their full blood count was monitored 8 hours for 48 hours. Gene expression studies were conducted on the ALOX 12 and PTAFR genes. The mean increase in platelet counts were compared in both groups using repeated measure ANCOVA. There was a significant increase in mean platelet count observed in the intervention group (P < 0.001) but not in the control group 40 hours since the first dose of CPLJ. Comparison of mean platelet count between intervention and control group showed that mean platelet count in intervention group was significantly higher than control group after 40 and 48 hours of admission (P < 0.01). The ALOX 12 (FC  =  15.00) and PTAFR (FC  =  13.42) genes were highly expressed among those on the juice. It was concluded that CPLJ does significantly increase the platelet count in patients with DF and DHF. PMID:23662145

Corticosteroids compared with intravenous immunoglobulin for the treatment of immune thrombocytopenia in pregnancy.

PubMed

Sun, Dongmei; Shehata, Nadine; Ye, Xiang Y; Gregorovich, Sandra; De France, Bryon; Arnold, Donald M; Shah, Prakesh S; Malinowski, Ann Kinga

2016-09-08

Treatment options for immune thrombocytopenia (ITP) in pregnancy are limited, and evidence to guide management decisions is lacking. This retrospective study of singleton pregnancies from 2 tertiary centers compared the effectiveness of intravenous immunoglobulin (IVIg) and corticosteroids in treatment of ITP. Data from 195 women who had 235 pregnancies were reviewed. Treatment was not required in 137 pregnancies (58%). Of the remaining 98 pregnancies in 91 women, 47 (48%) were treated with IVIg and 51 were treated with corticosteroids as the initial intervention. Mean maternal platelet count at birth did not differ between groups (IVIg 69 × 10(9)/L vs corticosteroids 77 × 10(9)/L; P = .71) nor did the proportion of mothers who achieved a platelet count response (IVIg 38% vs corticosteroids 39%; P = .85). There were no fatal or severe maternal, fetal, or neonatal hemorrhages. Of 203 neonates in whom platelet counts were available, 56 (28%) had a birth platelet count <150 × 10(9)/L and 18 (9%) had platelet counts <50 × 10(9)/L. Nadir platelet counts for most affected neonates occurred at birth, although for some neonates, nadir platelet counts occurred up to 6 days postnatally. Intracranial hemorrhage was noted in 2 neonates (nadir platelet counts were 135 and 18 × 10(9)/L). There were no neonatal deaths. The majority of pregnant women with a history of ITP did not require treatment, and neonatal outcomes were comparable for mothers who received IVIg or corticosteroids for treatment of maternal ITP. © 2016 by The American Society of Hematology.

Evaluation of the platelet counting by Abbott CELL-DYN SAPPHIRE haematology analyser compared with flow cytometry.

PubMed

Grimaldi, E; Del Vecchio, L; Scopacasa, F; Lo Pardo, C; Capone, F; Pariante, S; Scalia, G; De Caterina, M

2009-04-01

The Abbot Cell-Dyn Sapphire is a new generation haematology analyser. The system uses optical/fluorescence flow cytometry in combination with electronic impedance to produce a full blood count. Optical and impedance are the default methods for platelet counting while automated CD61-immunoplatelet analysis can be run as selectable test. The aim of this study was to determine the platelet count performance of the three counting methods available on the instrument and to compare the results with those provided by Becton Dickinson FACSCalibur flow cytometer used as reference method. A lipid interference experiment was also performed. Linearity, carryover and precision were good, and satisfactory agreement with reference method was found for the impedance, optical and CD61-immunoplatelet analysis, although this latter provided the closest results in comparison with flow cytometry. In the lipid interference experiment, a moderate inaccuracy of optical and immunoplatelet counts was observed starting from a very high lipid value.

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

PubMed Central

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

2018-01-01

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 models were compared using: concordance index (CI), bias-corrected concordance index (BCCI), calibration plots, the Grønnesby and Borgan test, Bayesian Information Criterion (BIC), generalized R2, Integrated Discrimination Improvement (IDI), and continuous Net Reclassification Index (cNRI) for individual risk factors and the three risk groups. Results 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 R2, 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 R2, 0.163 vs. 0.123; IDI, 0.045; cNRI, 0.165 for the three risk groups). Conclusion 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. PMID:28253564

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.

PubMed

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.

Influences of red blood cell and platelet counts on the distribution and elimination of crystalloid fluid.

PubMed

Hahn, Robert G

2017-01-01

A high number of blood cells increases the viscosity of the blood. The present study explored whether variations in blood cell counts are relevant to the distribution and elimination of infused crystalloid fluid. On three different occasions, 10 healthy male volunteers received an intravenous infusion of 25mL/kg of Ringer's acetate, Ringer's lactate, and isotonic saline over 30min. Blood hemoglobin and urinary excretion were monitored for 4h and used as input in a two-volume kinetic model, using nonlinear mixed effects software. The covariates used in the kinetic model were red blood cell and platelet counts, the total leukocyte count, the use of isotonic saline, and the arterial pressure. Red blood cell and platelet counts in the upper end of the normal range were associated with a decreased rate of distribution and redistribution of crystalloid fluid. Simulations showed that high counts were correlated with volume expansion of the peripheral (interstitial) fluid space, while the plasma volume was less affected. In contrast, the total leukocyte count had no influence on the distribution, redistribution, or elimination. The use of isotonic saline caused a transient reduction in the systolic arterial pressure (P<0.05) and doubled the half-life of infused fluid in the body when compared to the two Ringer solutions. Isotonic saline did not decrease the serum potassium concentration, despite the fact that saline is potassium-free. High red blood cell and platelet counts are associated with peripheral accumulation of infused crystalloid fluid. Copyright © 2017 The Lithuanian University of Health Sciences. Production and hosting by Elsevier Sp. z o.o. All rights reserved.

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

PubMed

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.

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

PubMed

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 <200*10 3 /µl and fibrinogen <350 mg/dl was associated with a sensitivity of 95.5% (89.7-98.5%) and a specificity of 18.3% (15.6-21.2%). In patients at low probability, white blood cell count >9*10 3 /µl and platelet count <200*10 3 /µl were found as independent predictors of AAS beyond established clinical risk markers. Within patients at low probability, the estimated risk of AAS based on the number of alterations amongst white blood cell count >9*10 3 /µl and platelet count <200*10 3 /µl was 2.7% (1.2-5.7%) with zero alterations, 11.3% (8.8-14.3%) with one alteration and 31.9% (24

The influence of the platelet count on the incidence of thrombotic and haemorrhagic complications in polycythaemia vera

PubMed Central

Dawson, Audrey A.; Ogston, D.

1970-01-01

In polycythaemia vera, those patients who have an elevated platelet count develop more thrombotic and more haemorrhagic complications than those with a normal count, even when the haematocrit is maintained by therapy within the normal range. PMID:5416508

Enhancing the Accuracy of Platelet to Lymphocyte Ratio after Adjustment for Large Platelet Count: A Pilot Study in Breast Cancer Patients

PubMed Central

Seretis, Charalampos; Seretis, Fotios; Lagoudianakis, Emmanuel; Politou, Marianna; Gemenetzis, George; Salemis, Nikolaos S.

2012-01-01

Background. The objective of our study is to investigate the potential effect of adjusting preoperative platelet to lymphocyte ratio, an emerging biomarker of survival in cancer patients, for the fraction of large platelets. Methods. A total of 79 patients with breast neoplasias, 44 with fibroadenomas, and 35 with invasive ductal carcinoma were included in the study. Both conventional platelet to lymphocyte ratio (PLR) and the adjusted marker, large platelet to lymphocyte ratio (LPLR), were correlated with laboratory and histopathological parameters of the study sample. Results. LPLR elevation was significantly correlated with the presence of malignancy, advanced tumor stage, metastatic spread in the axillary nodes and HER2/neu overexpression, while PLR was only correlated with the number of infiltrated lymph nodes. Conclusions. This is the first study evaluating the effect of adjustment for large platelet count on improving PLR accuracy, when correlated with the basic independent markers of survival in a sample of breast cancer patients. Further studies are needed in order to assess the possibility of applying our adjustment as standard in terms of predicting survival rates in cancer. PMID:23304480

Enhancing the accuracy of platelet to lymphocyte ratio after adjustment for large platelet count: a pilot study in breast cancer patients.

PubMed

Seretis, Charalampos; Seretis, Fotios; Lagoudianakis, Emmanuel; Politou, Marianna; Gemenetzis, George; Salemis, Nikolaos S

2012-01-01

Background. The objective of our study is to investigate the potential effect of adjusting preoperative platelet to lymphocyte ratio, an emerging biomarker of survival in cancer patients, for the fraction of large platelets. Methods. A total of 79 patients with breast neoplasias, 44 with fibroadenomas, and 35 with invasive ductal carcinoma were included in the study. Both conventional platelet to lymphocyte ratio (PLR) and the adjusted marker, large platelet to lymphocyte ratio (LPLR), were correlated with laboratory and histopathological parameters of the study sample. Results. LPLR elevation was significantly correlated with the presence of malignancy, advanced tumor stage, metastatic spread in the axillary nodes and HER2/neu overexpression, while PLR was only correlated with the number of infiltrated lymph nodes. Conclusions. This is the first study evaluating the effect of adjustment for large platelet count on improving PLR accuracy, when correlated with the basic independent markers of survival in a sample of breast cancer patients. Further studies are needed in order to assess the possibility of applying our adjustment as standard in terms of predicting survival rates in cancer.

Platelet count recovery after intravenous immunoglobulin predicts a favorable outcome in children with immune thrombocytopenia

PubMed Central

Ji, Mi Hong; Kim, Sung Jin; Ahn, Hyo Seop

2016-01-01

Background Childhood immune thrombocytopenic purpura (ITP) is a common acquired bleeding disorder. Even though most children recover, either spontaneously or with therapy, 10-20% of newly diagnosed ITP cases have a chronic course beyond 12 months. This study evaluated whether clinical and laboratory findings can predict the response to intravenous immunoglobulin (IVIG) and progression to persistent or chronic ITP in children. Methods During the period between March 2003 and June 2015, we retrospectively analyzed 72 children, newly diagnosed with ITP, who received IVIG treatment. Peripheral blood counts were obtained at diagnosis and at 1, 3, 6, and 12 months after IVIG treatment. Results After 6 months of IVIG treatment, 14 of 72 patients (19.4%) had persistent ITP, and after 12 months, 7 of 40 patients (17.5%) had chronic ITP. Age at diagnosis, gender, history of viral infection, or vaccination before disease onset were not statistically correlated with platelet recovery at 6 and 12 months. However, a platelet count recovery of ≥100×103/µL at 1 and 3 months was significantly correlated with platelet recovery at 6 (P<0.001 and P<0.001, respectively) and 12 (P=0.007 and P=0.004, respectively) months. Conclusion This study demonstrated that early platelet count recovery, at 1 and 3 months after IVIG treatment, predicts a short disease duration and a favorable outcome in children with newly diagnosed ITP. Further investigation in a larger group of patients is warranted to validate these findings. PMID:27382553

Ratio of mean platelet volume to platelet count is a potential surrogate marker predicting liver cirrhosis.

PubMed

Iida, Hiroya; Kaibori, Masaki; Matsui, Kosuke; Ishizaki, Morihiko; Kon, Masanori

2018-01-27

To provide a simple surrogate marker predictive of liver cirrhosis (LC). Specimens from 302 patients who underwent resection for hepatocellular carcinoma between January 2006 and December 2012 were retrospectively analyzed. Based on pathologic findings, patients were divided into groups based on whether or not they had LC. Parameters associated with hepatic functional reserve were compared in these two groups using Mann-Whitney U -test for univariate analysis. Factors differing significantly in univariate analyses were entered into multivariate logistic regression analysis. There were significant differences between the LC group ( n = 100) and non-LC group ( n = 202) in prothrombin activity, concentrations of alanine aminotransferase, aspartate aminotransferase, total bilirubin, albumin, cholinesterase, type IV collagen, hyaluronic acid, indocyanine green retention rate at 15 min, maximal removal rate of technitium-99m diethylene triamine penta-acetic acid-galactosyl human serum albumin and ratio of mean platelet volume to platelet count (MPV/PLT). Multivariate analysis showed that prothrombin activity, concentrations of alanine aminotransferase, aspartate aminotransferase, total bilirubin and hyaluronic acid, and MPV/PLT ratio were factors independently predictive of LC. The area under the curve value for MPV/PLT was 0.78, with a 0.8 cutoff value having a sensitivity of 65% and a specificity of 78%. The MPV/PLT ratio, which can be determined simply from the complete blood count, may be a simple surrogate marker predicting LC.

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

PubMed

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.

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

PubMed Central

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

Decline in platelet count and long-term post-PCI ischemic events: implication of the intra-aortic balloon pump.

PubMed

Schiariti, Michele; Saladini, Patrizia; Cuturello, Domenico; Iannetta, Loredana; Torromeo, Concetta; Puddu, Paolo Emilio

2014-01-01

Thrombocytopenia (TC) following a percutaneous coronary intervention (PCI) has been associated not only with hemorrhagic, but also with ischemic outcomes. The purpose of this study was to re-examine the relationship of TC with ischemic events at a 1-year follow-up, and investigate the possible associations. We studied a real-world, unselected population of ischemic patients undergoing PCI, totaling 861 patients-year, and divided into two groups: with TC (delta platelet count ≥25% from baseline to post-PCI during the hospital admission) and without TC. Compared with patients without TC, patients with TC had a higher and earlier incidence of both hemorrhagic and ischemic events. In them, the use of intra-aortic balloon pump (IABP) was ten-fold higher. In Kaplan-Meier curves assessing the contribution of both TC and IABP to outcome, IABP was a univariate detrimental factor additive to the role of TC. In a forced Cox model, the relative decline (delta) in platelet count (p=0.05) and the use of IABP (p=0.0001) were both associated with ischemic outcomes. After excluding all patients with IABP, the delta platelet count was no longer significantly associated with ischemic outcomes (p=0.66). After excluding all patients with shock and all those who undergone thrombolysis, there was still a relationship (p=0.0042) between the delta platelet count and ischemic events. In this patient population the use of IABP, but not thrombocytopenia per se, is a possible primary cause of worse ischemic outcomes. Copyright © 2013 Elsevier Inc. All rights reserved.

Fibrinogen concentrate as first-line therapy in aortic surgery reduces transfusion requirements in patients with platelet counts over or under 100×109/L

PubMed Central

Solomon, Cristina; Rahe-Meyer, Niels

2015-01-01

Background Administration of fibrinogen concentrate, targeting improved maximum clot firmness (MCF) of the thromboelastometric fibrin-based clot quality test (FIBTEM) is effective as first-line haemostatic therapy in aortic surgery. We performed a post-hoc analysis of data from a randomised, placebo-controlled trial of fibrinogen concentrate, to investigate whether fibrinogen concentrate reduced transfusion requirements for patients with platelet counts over or under 100×109/L. Material and methods Aortic surgery patients with coagulopathic bleeding after cardiopulmonary bypass were randomised to receive either fibrinogen concentrate (n=29) or placebo (n=32). Platelet count was measured upon removal of the aortic clamp, and coagulation and haematology parameters were measured peri-operatively. Transfusion of allogeneic blood components was recorded and compared between groups. Results After cardiopulmonary bypass, haemostatic and coagulation parameters worsened in all groups; plasma fibrinogen level (determined by the Clauss method) decreased by 43–58%, platelet count by 53–64%, FIBTEM maximum clot firmness (MCF) by 38–49%, FIBTEM maximum clot elasticity (MCE) by 43–54%, extrinsically activated test (EXTEM) MCF by 11–22%, EXTEM MCE by 25–41% and the platelet component of the clot by 23–39%. Treatment with fibrinogen concentrate (mean dose 7–9 g in the 4 groups) significantly reduced post-operative allogeneic blood component transfusion requirements when compared to placebo both for patients with a platelet count ≥100×109/L and for patients with a platelet count <100×109/L. Discussion FIBTEM-guided administration of fibrinogen concentrate reduced transfusion requirements when used as a first-line haemostatic therapy during aortic surgery in patients with platelet counts over or under 100×109/L. PMID:25369608

Evaluation of mouse red blood cell and platelet counting with an automated hematology analyzer.

PubMed

Fukuda, Teruko; Asou, Eri; Nogi, Kimiko; Goto, Kazuo

2017-10-07

An evaluation of mouse red blood cell (RBC) and platelet (PLT) counting with an automated hematology analyzer was performed with three strains of mice, C57BL/6 (B6), BALB/c (BALB) and DBA/2 (D2). There were no significant differences in RBC and PLT counts between manual and automated optical methods in any of the samples, except for D2 mice. For D2, RBC counts obtained using the manual method were significantly lower than those obtained using the automated optical method (P<0.05), and PLT counts obtained using the manual method were higher than those obtained using the automated optical method (P<0.05). An automated hematology analyzer can be used for RBC and PLT counting; however, an appropriate method should be selected when D2 mice samples are used.

A simple technique to determine thrombopoiesis level using immature platelet fraction (IPF).

PubMed

Abe, Yasunori; Wada, Hideo; Tomatsu, Hiroaki; Sakaguchi, Akane; Nishioka, Junji; Yabu, Yasunori; Onishi, Katsuya; Nakatani, Kaname; Morishita, Yoshitaka; Oguni, Shinichiro; Nobori, Tsutomu

2006-01-01

Immature platelet fraction (IPF) has been measured by fully automated analyzer (XE-2100) as reticulated platelet (RP) which is reflected with thrombopoiesis in bone marrow. IPF value in the healthy volunteers was 3.3% (1.0-10.3) and upper 95% confidential interval (95% CI) of IPF was determined as 7.7%. IPF was significantly high in the patients with idiopathic thrombocytopenic purpura (ITP; 17.4%, 1.2-53.2%) and recovery phase of post-chemotherapy, and significantly low in nadir phase of post-chemotherapy, and within normal range in the patients with ITP in complete remission (CR) and with aplastic anemia (AA). Total count of IPF was significantly low in patients with ITP, AA or post-chemotherapy. Mean platelet volume (MPV) was significantly high in only patients with ITP. IPF 7.7% is best point for highest sensitivity (86.8%) and specificity (92.6%) in diagnosis of ITP and recovery phase of post-chemotherapy. In receiver operating characteristic curve for diagnosis of ITP and recovery phase of post-chemotherapy, IPF was significantly more useful than MPV. These results show that IPF reflects the pathology of thrombocytopenic disorders, and that measurement of IPF is useful for the differential diagnosis and analysis of platelet kinetics.

Does Carica papaya leaf-extract increase the platelet count? An experimental study in a murine model.

PubMed

Dharmarathna, Sinhalagoda Lekamlage Chandi Asoka; Wickramasinghe, Susiji; Waduge, Roshitha Nilmini; Rajapakse, Rajapakse Peramune Veddikkarage Jayanthe; Kularatne, Senanayake Abeysinghe Mudiyanselage

2013-09-01

To investigate the potential role of fresh Carica papaya (C. papaya) leaf extract on haematological and biochemical parameters and toxicological changes in a murine model. In total 36 mice were used for the trial. Fresh C. papaya leaf extract [0.2 mL (2 g)/mouse] was given only to the test group (18 mice). General behavior, clinical signs and feeding patterns were recorded. Blood and tissue samples were collected at intervals. Haematological parameters including platelet, red blood cell (RBC), white blood cell (WBC), packed cell volume (PCV), serum biochemistry including serum creatinine, serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) were determined. Organs for possible histopathological changes were examined. Neither group exhibited alteration of behavior or reduction in food and water intake. Similarly, no significant changes in SGOT, SGPT and serum creatinine levels were detected in the test group. Histopathological organ changes were not observed in either group of mice except in three liver samples of the test group which had a mild focal necrosis. The platelet count (11.33±0.35)×10⁵/µL (P=0.00004) and the RBC count (7.97±0.61)×10⁶/µL (P=0.00003) were significantly increased in the test group compared to that of the controls. However, WBC count and PCV (%) values were not changed significantly in the test group. The platelet count in the test group started to increase significantly from Day 3 (3.4±0.18×10⁵/µL), reaching almost a fourfold higher at Day 21 (11.3×10⁵/µL), while it was 3.8×10⁵/µL and 5.5×10⁵/µL at Day 3 and Day 21 respectively in the control. Likewise, the RBC count in the test group increased from 6×10⁶/µL to 9×10⁶/ µL at Day 21 while it remained near constant in the control group (6×10⁶/µL). Fresh C. papaya leaf extract significantly increased the platelet and RBC counts in the test group as compared to controls. Therefore, it is very important to identify

Does Carica papaya leaf-extract increase the platelet count? An experimental study in a murine model

PubMed Central

Dharmarathna, Sinhalagoda Lekamlage Chandi Asoka; Wickramasinghe, Susiji; Waduge, Roshitha Nilmini; Rajapakse, Rajapakse Peramune Veddikkarage Jayanthe; Kularatne, Senanayake Abeysinghe Mudiyanselage

2013-01-01

Objective To investigate the potential role of fresh Carica papaya (C. papaya) leaf extract on haematological and biochemical parameters and toxicological changes in a murine model. Methods In total 36 mice were used for the trial. Fresh C. papaya leaf extract [0.2 mL (2 g)/mouse] was given only to the test group (18 mice). General behavior, clinical signs and feeding patterns were recorded. Blood and tissue samples were collected at intervals. Haematological parameters including platelet, red blood cell (RBC), white blood cell (WBC), packed cell volume (PCV), serum biochemistry including serum creatinine, serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) were determined. Organs for possible histopathological changes were examined. Results Neither group exhibited alteration of behavior or reduction in food and water intake. Similarly, no significant changes in SGOT, SGPT and serum creatinine levels were detected in the test group. Histopathological organ changes were not observed in either group of mice except in three liver samples of the test group which had a mild focal necrosis. The platelet count (11.33±0.35)×105/µL (P=0.000 04) and the RBC count (7.97±0.61)×106/µL (P=0.000 03) were significantly increased in the test group compared to that of the controls. However, WBC count and PCV (%) values were not changed significantly in the test group. The platelet count in the test group started to increase significantly from Day 3 (3.4±0.18×105/µL), reaching almost a fourfold higher at Day 21 (11.3×105/µL), while it was 3.8×105/µL and 5.5×105/µL at Day 3 and Day 21 respectively in the control. Likewise, the RBC count in the test group increased from 6×106/µL to 9×106/ µL at Day 21 while it remained near constant in the control group (6×106/µL). Conclusions Fresh C. papaya leaf extract significantly increased the platelet and RBC counts in the test group as compared to controls. Therefore, it is very

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

PubMed

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 < 0.01). The skeletal muscle volume measured by InBody720 significantly decreased in the non-BCAA group (P < 0.001). EIS induced protein-energy malnutrition, however, skeletal muscle volume was maintained by taking 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.

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

PubMed

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 (P<0.01). During the 2nd to 14th day after CTX treatment, there was no obvious difference in the platelet count between treatment group and control group (P>0.05). 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.

Comparison of platelet count recovery with use of vincristine and prednisone or prednisone alone for treatment for severe immune-mediated thrombocytopenia in dogs.

PubMed

Rozanski, Elizabeth A; Callan, Mary Beth; Hughes, Dez; Sanders, Nancy; Giger, Urs

2002-02-15

To evaluate the effect of prednisone alone, compared with a combination of prednisone and vincristine, on platelet counts in bleeding dogs with severe primary immune-mediated thrombocytopenia (IMT). Prospective case study. 24 dogs with severe primary IMT PROCEDURE: All dogs received immunosuppressive doses of prednisone (1.5 to 2 mg/kg [0.7 to 0.9 mg/lb] of body weight, PO, q 12 h). In addition, 12 dogs received a single dose of vincristine (0.02 mg/kg [0.01 mg/lb], IV). Platelet count, transfusion requirement, and outcome were monitored. A response was defined as an increase in platelet count to > or = 40,000/microl. Dogs in the prednisone group that failed to respond received 1 dose of vincristine on day 7. Dogs that received prednisone and vincristine had a significantly faster increase in platelet count to > or = 40,000 platelets/microl than dogs that received prednisone alone (mean +/- SD, 4.9 +/- 1.1 vs 6.8 +/- 4.5 days, respectively). A similarly rapid response was observed in dogs that received vincristine on day 7 after treatment with prednisone alone failed. Furthermore, duration of hospitalization was reduced in the vincristine group, compared with the prednisone group (5.4 +/- 0.3 vs 7.3 +/- 0.5 days, respectively). No adverse effects attributable to vincristine were observed in any dog. Administration of combined vincristine and prednisone is associated with more rapid increase in platelet numbers and shortened duration of hospitalization in dogs with IMT, compared with use of prednisone alone. Early use of vincristine seems warranted in dogs with severe primary IMT.

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

PubMed

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]; p<0.0001). Response to eltrombopag compared with placebo was not affected by predefined study stratification variables (baseline platelet counts, concomitant ITP drugs, and splenectomy status) or by the number of previous ITP treatments. Of the 34 patients in the efficacy analysis who increased their dose of eltrombopag, ten (29%) responded. Platelet counts generally returned to baseline values within 2 weeks after the end of treatment. Patients receiving eltrombopag had less bleeding at any time during the study than did those

Reprint of "Decline in platelet count and long-term post-PCI ischemic events: implication of the intra-aortic balloon pump".

PubMed

Schiariti, Michele; Saladini, Patrizia; Cuturello, Domenico; Iannetta, Loredana; Torromeo, Concetta; Puddu, Paolo Emilio

2014-04-01

Thrombocytopenia (TC) following a percutaneous coronary intervention (PCI) has been associated not only with hemorrhagic, but also with ischemic outcomes. The purpose of this study was to re-examine the relationship of TC with ischemic events at a 1-year follow-up, and investigate the possible associations. We studied a real-world, unselected population of ischemic patients undergoing PCI, totaling 861 patients-year, and divided into two groups: with TC (delta platelet count ≥25% from baseline to post-PCI during the hospital admission) and without TC. Compared with patients without TC, patients with TC had a higher and earlier incidence of both hemorrhagic and ischemic events. In them, the use of intra-aortic balloon pump (IABP) was ten-fold higher. In Kaplan-Meier curves assessing the contribution of both TC and IABP to outcome, IABP was a univariate detrimental factor additive to the role of TC. In a forced Cox model, the relative decline (delta) in platelet count (p=0.05) and the use of IABP (p=0.0001) were both associated with ischemic outcomes. After excluding all patients with IABP, the delta platelet count was no longer significantly associated with ischemic outcomes (p=0.66). After excluding all patients with shock and all those who undergone thrombolysis, there was still a relationship (p=0.0042) between the delta platelet count and ischemic events. In this patient population the use of IABP, but not thrombocytopenia per se, is a possible primary cause of worse ischemic outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

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?

PubMed

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: < 0.15 for non-inferiority, > 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.

Frequent plateletpheresis does not clinically significantly decrease platelet counts in donors.

PubMed

Katz, Louis; Palmer, Kim; McDonnell, Emily; Kabat, Andy

2007-09-01

In October 2005, the US Food and Drug Administration (FDA) issued draft guidance on collecting platelets (PLTs) by automated methods. The FDA proposed limiting collections to 24 components, rather than 24 procedures, annually with up to 3 components per procedure. The rationale was from literature suggesting frequent PLT collection resulted in significant declines in donor PLT counts. Additional requirements for minimal interdonation intervals were proposed. Plateletpheresis records at a regional blood center with predonation PLT counts were used to assess the impact of the restriction on PLT collections. They were reviewed to demonstrate the effects of collection frequency, number of products collected, and interdonation interval on donor PLT counts. Total protein and albumin levels were compared in a subset of 24-times-per-year PLT donors and control whole-blood donors. A limit of 24 components would require replacement of approximately 20 percent of the donor base to recover lost components. No clinically important decrease in PLT counts before donation was seen in donors donating multiple PLT components up to 24 times per year, regardless of interdonation interval. No frequent donor was deferred for a PLT count less than 150 x 10(9) per L. Short interdonation intervals were associated with statistically but not clinically important decreases in PLT counts. Protein levels were not distinguishable between PLT donors and controls. The proposed restrictions are not required to prevent thrombocytopenia in frequent PLT donors and would adversely impact the supply of apheresis PLTs. Protein levels are maintained in these high-frequency donors.

Evaluation of the Value of d-Dimer, P-Selectin, and Platelet Count for Prediction of Portal Vein Thrombosis After Devascularization.

PubMed

Fei, Yang; Zong, Guang-Quan; Chen, Jian; Liu, Ren-Min

2016-07-01

To evaluate the value of d-dimer, P-selectin, and platelet count in patients with cirrhotic portal hypertension (PHT) for prediction of portal vein thrombosis (PVT) after devascularization. A total of 137 patients with cirrhotic PHT who undergone devascularization from January 2012 to April 2014 were retrospectively reviewed, all of them were divided into 2 groups (PVT group and non-PVT group) by Doppler ultrasonography (DU) examination. The level of d-dimer, P-selectin, and platelet count was tested during the perioperative period. In all, 38 (27.7%) patients were found to have PVT by DU examination postoperatively. In contrast to the non-PVT group, the level of d-dimer, P-selectin, and platelet count in the PVT group was much higher significantly at 1, 3, and 7 days after devascularization. (P < .05). However, in the 15 days after surgery, the difference in P-selectin between the 2 groups was not significant (P = .260). It was shown that the highest sensitivity of the 3 markers for PVT was d-dimer, the highest specificity belonged to P-selectin. The area under receiver-operating characteristic (ROC) curve of P-selectin was the biggest of the 3 markers. When the 3 markers were combined to be used to diagnose PVT, the sensitivity was increased to 0.907, with a slight drop of specificity to 0.693, the area under the ROC curve was 0.927. The level of d-dimer, P-selectin, and platelet count might be good candidate predictive markers for PVT in patients with cirrhotic PHT after devascularization. The combined test of the 3 markers can increase the value of prediction. © The Author(s) 2015.

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?

PubMed

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.

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

PubMed

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.

Modified combination of platelet count and neutrophil "to" lymphocyte ratio as a prognostic factor in patients with advanced head and neck cancer.

PubMed

Nakayama, Masahiro; Gosho, Masahiko; Hirose, Yuki; Nishimura, Bungo; Tanaka, Shuho; Tabuchi, Keiji; Okubo, Hideki; Wada, Tetsuro; Hara, Akira

2018-06-01

We evaluated the prognostic potential of the combination of platelet count and neutrophil to lymphocyte ratio (COP-NLR) in patients with advanced head and neck cancer. We proposed a modified COP-NLR scoring system defined as follows: score 0 (platelet count level <300 × 10 9 /L and NLR <3); score 1 (platelet count level ≥300 × 10 9 /L and NLR <3); and score 2 (NLR ≥3). We assessed whether the modified scoring system had better performance as an indicator of prognosis than the existing COP-NLR scoring system (original and 4-group scores). A total of 248 patients were enrolled. The Akaike Information Criterion value with the modified COP-NLR score was the smallest among the 3 models. The 3-year survival rates according to the modified COP-NLR scores of 0, 1, and 2 were 80.6%, 59.9%, and 23.8%, respectively. The modified COP-NLR score is a useful prognostic marker in patients with advanced head and neck cancer. © 2018 Wiley Periodicals, Inc.

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

PubMed

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).

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.

PubMed

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

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

PubMed

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

Immature platelet fraction in bacterial sepsis severity assessment

NASA Astrophysics Data System (ADS)

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-value<0.05). Mean Platelet Volume (MPV) and Platelet Distribution Width (PDW) showed a strongpositive correlation with IPF. Higher sepsis severity based on PCT showed larger platelet count, as the result of platelet destructions caused by pro-inflammatory cytokines and endotoxins.

The effect of molar pregnancies on platelet parameters.

PubMed

Soylu Karapınar, Oya; Benk Şilfeler, Dilek; Dolapçıoğlu, Kenan; Keskin Kurt, Raziye; Beyazıt, Ahmet

2016-10-01

The aim of this study was to compare platelet parameters between abortus groups with gestational trophoblastic disease (GTD) (molar pregnancy, invasive mole, choriocarcinoma, etc) and without disease according to pathological result. The study population consisted of patients with GTD (n = 53) and aborted patients without disease as a control group (n = 53) who were seen in our clinic between January 2010 and December 2013. In this retrospective study, age, gravidity, levels of haemoglobin, white blood cell count, platelets, platelet parameters (mean platelet volume (MPV), platelet distrubition width (PDW), platelet crit (PCT), which shows platelet functions were recorded. The pathological diagnosis of GTD was recorded. The mean platelet count, MPV, PDW and PCT levels were similar between the groups. There is no statistically significiant difference between types of GTN in these parameters according to pathological diagnosis. According to our study results, platelet count and levels of MPV, PDW ve PCT in GTD patients were similar to aborted patients without disease.

Genome-wide Association Study of Platelet Count Identifies Ancestry-Specific Loci in Hispanic/Latino Americans

PubMed Central

Schick, Ursula M.; Jain, Deepti; Hodonsky, Chani J.; Morrison, Jean V.; Davis, James P.; Brown, Lisa; Sofer, Tamar; Conomos, Matthew P.; Schurmann, Claudia; McHugh, Caitlin P.; Nelson, Sarah C.; Vadlamudi, Swarooparani; Stilp, Adrienne; Plantinga, Anna; Baier, Leslie; Bien, Stephanie A.; Gogarten, Stephanie M.; Laurie, Cecelia A.; Taylor, Kent D.; Liu, Yongmei; Auer, Paul L.; Franceschini, Nora; Szpiro, Adam; Rice, Ken; Kerr, Kathleen F.; Rotter, Jerome I.; Hanson, Robert L.; Papanicolaou, George; Rich, Stephen S.; Loos, Ruth J.F.; Browning, Brian L.; Browning, Sharon R.; Weir, Bruce S.; Laurie, Cathy C.; Mohlke, Karen L.; North, Kari E.; Thornton, Timothy A.; Reiner, Alex P.

2016-01-01

Platelets play an essential role in hemostasis and thrombosis. We performed a genome-wide association study of platelet count in 12,491 participants of the Hispanic Community Health Study/Study of Latinos by using a mixed-model method that accounts for admixture and family relationships. We discovered and replicated associations with five genes (ACTN1, ETV7, GABBR1-MOG, MEF2C, and ZBTB9-BAK1). Our strongest association was with Amerindian-specific variant rs117672662 (p value = 1.16 × 10−28) in ACTN1, a gene implicated in congenital macrothrombocytopenia. rs117672662 exhibited allelic differences in transcriptional activity and protein binding in hematopoietic cells. Our results underscore the value of diverse populations to extend insights into the allelic architecture of complex traits. PMID:26805783

The clinical significance of platelet counts in the first 24 hours after severe injury.

PubMed

Stansbury, Lynn G; Hess, Aaron S; Thompson, Kwaku; Kramer, Betsy; Scalea, Thomas M; Hess, John R

2013-04-01

Admission platelet (PLT) counts are known to be associated with all-cause mortality for seriously injured patients admitted to a trauma center. The course of subsequent PLT counts, their implications, and the effects of PLT therapy are less well known. Trauma center patients who were directly admitted from the scene of injury, received 1 or more units of uncrossmatched red blood cells in the first hour of care, survived for at least 15 minutes, and had a PLT count measured in the first hour were analyzed for the association of their admission and subsequent PLT counts in the first 24 hours with injury severity and hemorrhagic and central nervous system (CNS) causes of in-hospital mortality. Over an 8.25-year period, 1292 of 45,849 direct trauma admissions met entry criteria. Admission PLT counts averaged 228×10(9) ±90×10(9) /L and decreased by 104×10(9) /L by the second hour and 1×10(9) /L each hour thereafter. The admission count was not related to time to admission. Each 1-point increase in the injury severity score was associated with a 1×10(9) /L decrease in the PLT count at all times in the first 24 hours of care. Admission PLT counts were strongly associated with hemorrhagic and CNS injury mortality and subsequent PLT counts. Effects of PLT therapy could not be ascertained. Admission PLT counts in critically injured trauma patients are usually normal, decreasing after admission. Low PLT counts at admission and during the course of trauma care are strongly associated with mortality. © 2012 American Association of Blood Banks.

Advances and controversies in neonatal ICU platelet transfusion practice.

PubMed

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.

C-reactive protein, platelets, and patent ductus arteriosus.

PubMed

Meinarde, Leonardo; Hillman, Macarena; Rizzotti, Alina; Basquiera, Ana Lisa; Tabares, Aldo; Cuestas, Eduardo

2016-12-01

The association between inflammation, platelets, and patent ductus arteriosus (PDA) has not been studied so far. The purpose of this study was to evaluate whether C-reactive protein (CRP) is related to low platelet count and PDA. This was a retrospective study of 88 infants with a birth weight ≤1500 g and a gestational age ≤30 weeks. Platelet count, CRP, and an echocardiogram were assessed in all infants. The subjects were matched by sex, gestational age, and birth weight. Differences were compared using the χ 2 , t-test, or Mann-Whitney U-test, as appropriate. Significant variables were entered into a logistic regression model. The association between CRP and platelets was evaluated by correlation and regression analysis. Platelet count (167 000 vs. 213 000 µl -1 , p = 0.015) was lower and the CRP (0.45 vs. 0.20 mg/dl, p = 0.002) was higher, and the platelet count correlated inversely with CRP (r = -0.145, p = 0.049) in the infants with vs. without PDA. Only CRP was independently associated with PDA in a logistic regression model (OR 64.1, 95% confidence interval 1.4-2941, p = 0.033).

Cycad Palm Toxicosis in 14 Dogs from Texas.

PubMed

Clarke, Carolyn; Burney, Derek

The goal of this study is to report clinical information, diagnostic findings, and treatment modalities; assess variables that may help distinguish survivors from nonsurvivors; and review the outcome of cycad palm toxicosis in dogs. Fourteen client-owned dogs with confirmed cycad palm ingestion were identified by reviewing the medical record database at Gulf Coast Veterinary Specialists. Information on signalment, time of ingestion to presentation, clinical signs, physical examination findings, initial and peak/nadir laboratory abnormalities, radiographic and ultrasonographic findings, treatment modalities, liver histopathology, and clinical outcome was retrieved. Of the 14 dogs, nine (64%) died as a direct result of cycad palm intoxication, and three survivors had persistently elevated liver enzymes, signifying residual liver damage. Despite decontamination, patients continued to display evidence of illness, indicating rapid absorption of toxins. When evaluating initial and peak/nadir laboratory values, nadir serum albumin levels and nadir platelet counts were significantly lower in nonsurvivors compared to survivors (1.25 g/dL [0.4-2.1 g/dL] versus 2.6 g/dL [1.7-3.4 g/dL] and 21 × 10 3 [0-64 × 10 3 ] versus 62 × 10 3 [6-144 × 10 3 ], respectively). In this cohort of dogs, the case fatality rate was higher than previously reported. Nadir serum albumin levels and nadir platelet counts may help distinguish potential survivors from nonsurvivors.

[Survival is associated with time to reach PSA nadir (DAN) and the ratio DAN/nadir value after androgen deprivation for prostate cancer].

PubMed

Gagnat, A; Larré, S; Fromont, G; Pirès, C; Doré, B; Irani, J

2011-05-01

The objective of this study was to assess the prognostic decrease rate of PSA in patients treated with androgen suppression (AS) for prostate cancer (PCa). We identified in our database CaP patients with histologically documented, treated with SA alone and for whom vital status with a minimum follow-up of 6 months (except death beforehand) was established. Patient characteristics and CaP and PSA at baseline, PSA nadir, time of reaching the nadir PSA (DAN) and the ratio of the DAN/nadir value (ratio DAN/Nadir) were analyzed in relation to progression-free survival, specific and overall survival. One hundred ninety eight patients met the inclusion criteria and the median was 61.5 months (range 4.8 to 233). The median PSA at the start of the SA were 37.1 ng/mL and the median nadir PSA was 0.48 ng/mL. The median time to progression was 23.6 months. The median specific and overall survivals were 94 and 78 months, respectively. In univariate analysis, predictors of progression-free survival were PSA before SA, PSA nadir, DAN, DAN ratio/nadir, Gleason score, the percentage of core positive prostate biopsy and the status of bone scintigraphy. Except for PSA before SA which was no longer significant, predictors of specific and overall survival were similar and added the biochemical response (decrease of more than 50% of PSA) to a second hormonal manipulation during the biological progression. In multivariate analysis, the nadir PSA and the ratio DAN/Nadir remained significant predictors. These results have confirmed in one hand the predictive value of survival in patients DAN SA for CaP: achieving faster nadir PSA was associated with shorter survival. They have introduced in the other hand the new concept of DAN/Nadir PSA which provides independent prognostic information. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

The platelet count in EDTA-anticoagulated blood from patients with thrombocytopenia may be underestimated when measured in routine laboratories.

PubMed

Podda, Gian Marco; Pugliano, Mariateresa; Femia, Eti Alessandra; Mezzasoma, Anna Maria; Gresele, Paolo; Carpani, Giovanni; Cattaneo, Marco

2012-07-01

Spuriously low platelet counts (PCs) can be observed in normal blood samples anticoagulated with ethylenediamine tetra-acetic acid (EDTA)and, much less frequently, with citrate-tris-pyridossalphosphate (CPT),due to time-dependent in vitro platelet agglutination. Accuracy in PC determination is essential as PC is one of the parameters that usually guides treatment for thrombocytopenic patients. PCs of 93 thrombocy to penic patients were measured in EDTA- or CPT-anticoagulated blood samples immediately after sampling (t0) and 90 min (t90) after storage at room temperature. The presence of platelet agglutinates in blood samples was determined by examining blood smears using optical microscopy.PCs decreased at t90 with both anticoagulants. Platelet agglutinates were present at t90 in 27% of EDTA-samples vs. 2% of CPT-samples with decreased PCs (P < 0.001). Based on PCs in EDTA-samples, 15 patients (16%) shifted from a lower bleeding risk at t0 to a higher bleeding risk category at t90 (P 5 0.019), compared to 5 (5%) patients, based on PCs in CPT-samples. Therefore, time-dependent in vitro platelet agglutination in EDTA-blood samples may cause underestimation of PCs in thrombocytopenic patients, possibly leading to improper management.

Platelet Kinetics in Idiopathic Thrombocytopenic Purpura Patients Treated with Thrombopoietin Receptor Agonists

PubMed Central

Meyer, Oliver; Herzig, Eric; Salama, Abdulgabar

2012-01-01

Aim Thrombopoietin receptor agonists (Tpo RA) increase platelet counts in the majority of chronic autoimmune thrombocytopenia (idiopathic thrombocytopenic purpura; ITP) patients. It is unknown whether this treatment may also improve platelet survival (PS) in these patients. Methods In order to determine platelet survival (PS), autologous platelets were labeled with 111In oxine and retransfused in six patients under treatment with Tpo RA (romiplostim n = 3; eltrombopag n = 3). Results Stable platelet counts of greater than 100 × 103/μl were observed in all 6 patients. Platelet survival was decreased in all cases (mean 2.10 days; range 0.13–3.73 days). No correlation was found between platelet count and PS. Similarly, there was no significant relationship between platelet turnover and platelet count. However, a high platelet turnover, exceeding 25 or three times the norm was observed in 2 patients who presented the lowest PS (0.13 or 0.83 days). Two patients had a moderately shortened PS (1.91 or 2.42 days), and, correspondingly, a moderately increased platelet turnover rate (63,072 or 72,872 platelets/μl/day). Conclusion These results indicate that Tpo RA may not only overcompensate platelet destruction in ITP, but may interfere with other mechanisms, which, in some cases, results in a reduced platelet destruction rate. PMID:22896760

Clinical assessment of oral mucositis and candidiasis compare to chemotherapic nadir in transplanted patients.

PubMed

Patussi, Cleverson; Sassi, Laurindo Moacir; Munhoz, Eduardo Ciliao; Zanicotti, Roberta Targa Stramandinoli; Schussel, Juliana Lucena

2014-01-01

Oral mucositis is a chief complication in patients undergoing hematopoietic stem cell transplantation (HSCT). It is considered a toxic inflammatory reaction that interferes with the patient's recuperation and quality of life. Oral candidiasis is a common fungal infection observed in dental practice, particularly in immunocompromised patients. The aim of this study was to evaluate the presence of oral mucositis and oral candidiasis in patients who underwent HSCT and their correlation with the chemotherapeutic nadir (lowest possible outcome). We evaluated patients with different diagnoses who underwent HSCT at the Hospital Erasto Gaertner. No chemotherapeutic nadir curves could be associated with mucositis, and patients had different presentations of mucositis. No patient developed oral candidiasis during hospitalization. Together with cell counts, we collected demographic data including age, oral hygiene, habits harmful to health, and the use of oral prostheses. It was observed that patients who smoked cigarettes before hospitalization showed less mucositis, resulting in no feeding problems or other comorbid conditions due to the effect of mucositis. However, the nadir of the chemotherapy curve, in isolation, is not a predictive tool for the appearance (or no appearance) of oral mucositis.

Association of Hematological Nadirs and Survival in a Nonhuman Primate Model of Hematopoietic Syndrome of Acute Radiation Syndrome.

PubMed

Gluzman-Poltorak, Zoya; Vainstein, Vladimir; Basile, Lena A

2015-08-01

Recombinant human interleukin-12 (rHuIL-12) mitigates the hematopoietic subsyndrome of acute radiation syndrome (HSARS) after total body irradiation (TBI) in a nonhuman primate (NHP) model of HSARS. The mechanism for this effect appears to involve multiple effects of rHuIL-12 on hematopoiesis. We conducted a meta-analysis to examine hematological nadirs and survival across our three NHP completed studies. Animals were irradiated (700 cGy) and treated with a single subcutaneous injection of vehicle (n = 64) or rHuIL-12 (50-500 ng/kg; n = 108) 24-25 h after irradiation, or with daily subcutaneous injections of granulocyte-colony stimulating factor (G-CSF; 10 μg/kg/day) for 18 days starting 24-25 h after exposure (n = 26). Blood samples were obtained at various time points up to day 60 after TBI. Lymphocytes, neutrophils and platelets were significantly lower in nonsurvivors than in survivors in the overall sample and in each treatment group (P < 0.001 for each comparison, Wilcoxon rank-sum test). Lymphocyte nadir was the strongest and most consistent predictor of death by Spearman's rank correlation. Receiver operating characteristic (ROC) curve analysis of death and threshold hematologic nadir values (where nadir values less than or equal the threshold are predictive of death) showed that a threshold of 0.08 × 10(9)/L for lymphocytes had the largest positive predictive value of death (97.2% and 92.5% for the control and rHuIL-12 groups, respectively) and high sensitivity (76.1% and 62.7%, respectively), consistent with human radiation victims data. The current findings suggest that enhanced early bone marrow regeneration resulting in increases in nadir values for all major blood cell types may be the main mechanism of action by which rHuIL-12 mitigates the lethality of HSARS.

[Platelet allo-antibodies identification strategies for preventing and managing platelet refractoriness].

PubMed

Basire, A; Picard, C

2014-11-01

Platelet refractoriness is a serious complication for patients receiving recurrent platelet transfusions, which can be explained by non-immune and immune causes. Human Leukocyte Antigens (HLA) allo-immunization, especially against HLA class I, is the major cause for immune platelet refractoriness. To a lesser extent, allo-antibodies against specific Human Platelet Antigen (HPA) are also involved. Pregnancy, transplantation and previous transfusions can lead to allo-immune reaction against platelet antigens. After transfusion, platelet count is decreased by accelerated platelet destruction related to antibodies fixation on incompatible platelet antigens. New laboratory tests for allo-antibodies identification were developed to improve sensibility and specificity, especially with the LUMINEX(®) technology. The good use and interpretation of these antibodies assays can improve strategies for platelet refractoriness prevention and management with a patient adapted response. Compatible platelets units can be selected according to their identity with recipient typing or immune compatibility regarding HLA or HPA antibodies or HLA epitope compatibility. Prospective studies are needed to further confirm the clinical benefit of new allo-antibodies identification methods and consensus strategies for immune platelet refractoriness management. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Three Adult Cases of HPV-B19 Infection with Concomitant Leukopenia and Low Platelet Counts

PubMed Central

Yaguchi, Daizo; Marui, Nobuyuki; Matsuo, Masaki

2015-01-01

We encountered three adult patients with flu-like symptoms diagnosed with human parvovirus B19 (HPV-B19) infection. Blood serum analysis also revealed leukopenia, with white blood cell counts (WBCs) of 1,000–2,000/mL and low platelet counts of 89–150 × 109/L. Typical skin rash was absent in one patient. Bone marrow examination of another patient showed hypoplastic marrow with <5% blast cells. All patients recovered without administration of granulocyte colony-stimulating factor (G-CSF). Therefore, HPV-B19 infection with leukopenia should be considered in adult patients with leukopenia during erythema infectiosum epidemics, even if typical clinical findings (ie, skin rash) are absent. Further, the fact that three cases were observed over the stated time period at our hospital, which is located in Nagoya city, showed a transition to a slightly higher level of incidence than the annual average. PMID:25780346

Evaluation of a BED-SIDE platelet function assay: performance and clinical utility.

PubMed

Lau, Wei C; Walker, C Ty; Obilby, David; Wash, Mark M; Carville, David G M; Guyer, Kirk E; Bates, Eric R

2002-01-01

Platelets have a pivotal role in the initial defense against insult to the vasculature and are also recognized of critical importance in the acute care settings of percutaneous coronary intervention and cardiopulmonary bypass. In these environments both platelet count and function may be markedly compromised. Unfortunately, current assays to evaluate the parameters of platelet count and function are of limited utility for bed-side testing. Moreover, it is suggested that there may be significant inter patient variation in response to antiplatelet therapy that may be exacerbated by other agents (e.g. heparin) that are routinely administered during cardiac intervention. Here we describe a practical, rapid and user-friendly whole blood platelet function assay that has been developed for use in bed-side settings. Platelet agonists were formulated with an anticoagulant and lyophilized in blood collection tubes standardised to receive a l mL fresh whole blood sample. In the presence of an agonist, platelets are activated and interact (aggregate). Using traditional cell counting principles, non-aggregated platelets are counted whereas aggregated platelets are not. The percentage (%) of functional platelets in reference to a baseline tube may then be determined. Results are available within four minutes. Platelet aggregation in whole blood demonstrated good correlation with turbidometric aggregometry for both ADP (r=0.91) and collagen (r=0.88). Moreover, in clinical settings where antiplatelet agents were administered, this rapid, bed-side, platelet function assay demonstrated utility in monitoring patient response to these therapies. This novel bed-side assay of platelet function is extremely suitable for the clinical environment with a rapid turn-around time. In addition, it provides a full haematology profile, including platelet count, and should permit enhancement of transfusion and interventional decisions.

Potential Harm of Prophylactic Platelet Transfusion in Adult Dengue Patients.

PubMed

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 <20,000/mm3 without bleeding, we aimed to assess if prophylactic platelet transfusion was effective in reducing clinical bleeding and other outcomes. We conducted a retrospective non-randomised observational study of dengue patients with platelet count < 20,000/mm3 without bleeding (except petechiae) admitted to 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 <0.0001). The median duration of hospital stay in the non-transfused group was 5 days vs. 6 days in the transfused group (P< 0.0001). There was no significant difference in the proportion requiring ICU admission (non-transfused 0.66% vs. transfused 1.23%, P = 0.44) and death (non-transfused 0% vs. transfused 0.2%, P = 0.43). Platelet transfusion in absence of bleeding in adult dengue with platelet count <20,000/mm3 did not reduce bleeding or expedite platelet recovery. There was potential harm by slowing recovery of platelet count to >50,000/mm3 and increasing length of hospitalization.

2-O, 3-O desulfated heparin mitigates murine chemotherapy- and radiation-induced thrombocytopenia

PubMed Central

Tkaczynski, Elizabeth; Arulselvan, Abinaya; Tkaczynski, John; Avery, Stephen; Xiao, Liqing; Torok-Storb, Beverly; Abrams, Kraig; Rao, Narayanam V.; Johnson, Gregory; Poncz, Mortimer

2018-01-01

Thrombocytopenia is a significant complication of chemotherapy and radiation therapy. Platelet factor 4 (PF4; CXCL4) is a negative paracrine of megakaryopoiesis. We have shown that PF4 levels are inversely related to steady-state platelet counts, and to the duration and severity of chemotherapy- and radiation-induced thrombocytopenia (CIT and RIT, respectively). Murine studies suggest that blocking the effect of PF4 improves megakaryopoiesis, raising nadir platelet counts and shortening the time to platelet count recovery. We examined the ability of 2-O, 3-O desulfated heparin (ODSH), a heparin variant with little anticoagulant effects, to neutralize PF4’s effects on megakaryopoiesis. Using megakaryocyte colony assays and liquid cultures, we show that ODSH restored megakaryocyte proliferation in PF4-treated Cxcl4−/− murine and human CD34+-derived megakaryocyte cultures (17.4% megakaryocyte colonies, P < .01 compared with PF4). In murine CIT and RIT models, ODSH, started 24 hours after injury, was examined for the effect on hematopoietic recovery demonstrating higher platelet count nadirs (9% ± 5% treated vs 4% ± 4% control) and significantly improved survival in treated animals (73% treated vs 36% control survival). Treatment with ODSH was able to reduce intramedullary free PF4 concentrations by immunohistochemical analysis. In summary, ODSH mitigated CIT and RIT in mice by neutralizing the intramedullary negative paracrine PF4. ODSH, already in clinical trials in humans as an adjuvant to chemotherapy, may be an important, clinically relevant therapeutic for CIT and RIT. PMID:29599195

Regulating billions of blood platelets: glycans and beyond

PubMed Central

Grozovsky, Renata; Giannini, Silvia; Falet, Hervé

2015-01-01

The human body produces and removes 1011 platelets daily to maintain a normal steady state platelet count. Platelet production must be regulated to avoid spontaneous bleeding or arterial occlusion and organ damage. Multifaceted and complex mechanisms control platelet production and removal in physiological and pathological conditions. This review will focus on different mechanisms of platelet senescence and clearance with specific emphasis on the role of posttranslational modifications. It will also briefly address platelet transfusion and the role of glycans in the clearance of stored platelets. PMID:26330242

Time dependent reduction in platelet aggregation using the multiplate analyser and hirudin blood due to platelet clumping.

PubMed

Chapman, Kent; Favaloro, Emmanuel J

2018-05-01

The Multiplate is a popular instrument that measures platelet function using whole blood. Potentially considered a point of care instrument, it is also used by hemostasis laboratories. The instrument is usually utilized to assess antiplatelet medication or as a screen of platelet function. According to the manufacturer, testing should be performed within 0.5-3 hours of blood collection, and preferably using manufacturer provided hirudin tubes. We report time-associated reduction in platelet aggregation using the Multiplate and hirudin blood collection tubes, for all the major employed agonists. Blood for Multiplate analysis was collected into manufacturer supplied hirudin tubes, and 21 consecutive samples assessed using manufacturer supplied agonists (ADP, arachidonic acid, TRAP, collagen and ristocetin), at several time-points post-sample collection within the recommended test time period. Blood was also collected into EDTA as a reference method for platelet counts, with samples collected into sodium citrate and hirudin used for comparative counts. All platelet agonists showed a diminution of response with time. Depending on the agonist, the reduction caused 5-20% and 22-47% of responses initially in the normal reference range to fall below the reference range at 120min and 180min, respectively. Considering any agonist, 35% and 67% of initially "normal" responses became 'abnormal' at 120 min and 180 min, respectively. Platelet counts showed generally minimal changes in EDTA blood, but were markedly reduced over time in both citrate and hirudin blood, with up to 40% and 60% reduction, respectively, at 240 min. The presence of platelet clumping (micro-aggregate formation) was also observed in a time dependent manner, especially for hirudin. In conclusion, considering any platelet agonist, around two-thirds of samples can, within the recommended 0.5-3 hour testing window post-blood collection, yield a reduction in platelet aggregation that may lead to a change in

Autologous Platelet-Rich Plasma Preparations

PubMed Central

Schippinger, Gert; Prüller, Florian; Divjak, Manuela; Mahla, Elisabeth; Fankhauser, Florian; Rackemann, Steve; Raggam, Reinhard Bernd

2015-01-01

Background Autologous platelet-rich plasma (PRP) has been widely used for the treatment of sports injuries. It has been associated with improved healing and regeneration of soft tissues in elite athletes. Athletes are commonly receiving nonsteroidal anti-inflammatory drugs (NSAIDs). As yet, the effect of these drugs on platelet function in PRP formulations has not been taken into consideration. Hypothesis The function of platelets in PRP produced under the influence of NSAIDs is inhibited and may lessen a possible healing effect on the site of injury. Study Design Controlled laboratory study. Methods PRP was collected from patients receiving NSAIDs after elective orthopaedic surgery, and platelet function was evaluated using light transmission aggregometry (LTA). Results were compared with those obtained from healthy volunteers without a history of NSAID intake during the previous 2 weeks. Two different systems for blood collection and PRP production (Arthrex ACP double-syringe system and standard 4.5-mL sodium citrate blood collection tubes) were used and compared regarding the quality of PRP that was produced. Results For both groups, the baseline platelet counts of whole blood and the platelet counts of PRP formulations were found to be in the normal range. Both collection systems for PRP produced comparable results without significant differences between the groups. Platelet function testing with LTA revealed significantly impaired platelet aggregation in both PRP preparations, obtained from patients taking NSAIDs, irrespective of the type of NSAID (P < .001). All subjects from the control group showed normal platelet aggregation patterns when tested with LTA. Conclusion Autologous PRP produced from subjects after NSAID medication shows significantly impaired platelet function and may result in lower quality regarding the content of bioactive compounds. Clinical Relevance If required, the administration of NSAIDs should be performed after blood collection for

The Relationship of Mean Platelet Volume/Platelet Distribution Width and Duodenal Ulcer Perforation.

PubMed

Fan, Zhe; Zhuang, Chengjun

2017-03-01

Duodenal ulcer perforation (DUP) is a severe acute abdominal disease. Mean platelet volume (MPV) and platelet distribution width (PDW) are two platelet parameters, participating in many inflammatory processes. This study aims to investigate the relation of MPV/PDW and DUP. A total of 165 patients were studied retrospectively, including 21 females and 144 males. The study included two groups: 87 normal patients (control group) and 78 duodenal ulcer perforation patients (DUP group). Routine blood parameters were collected for analysis including white blood cell count (WBC), neutrophil ratio (NR), platelet count (PLT), MPV and PDW. Receiver operating curve (ROC) analysis was applied to evaluate the parameters' sensitivity. No significant differences were observed between the control group and DUP group in age and gender. WBC, NR and PDW were significantly increased in the DUP group ( P <0.001, respectively); PLT and MPV were significantly decreased in the DUP group ( P <0.001, respectively) compared to controls. MPV had the high sensitivity. Our results suggested a potential association between MPV/PDW and disease activity in DUP patients, and high sensitivity of MPV. © 2017 by the Association of Clinical Scientists, Inc.

Phosphatidylserine-mediated platelet clearance by endothelium decreases platelet aggregates and procoagulant activity in sepsis.

PubMed

Ma, Ruishuang; Xie, Rui; Yu, Chengyuan; Si, Yu; Wu, Xiaoming; Zhao, Lu; Yao, Zhipeng; Fang, Shaohong; Chen, He; Novakovic, Valerie; Gao, Chunyan; Kou, Junjie; Bi, Yayan; Thatte, Hemant S; Yu, Bo; Yang, Shufen; Zhou, Jin; Shi, Jialan

2017-07-10

The mechanisms that eliminate activated platelets in inflammation-induced disseminated intravascular coagulation (DIC) in micro-capillary circulation are poorly understood. This study explored an alternate pathway for platelet disposal mediated by endothelial cells (ECs) through phosphatidylserine (PS) and examined the effect of platelet clearance on procoagulant activity (PCA) in sepsis. Platelets in septic patients demonstrated increased levels of surface activation markers and apoptotic vesicle formation, and also formed aggregates with leukocytes. Activated platelets adhered were and ultimately digested by ECs in vivo and in vitro. Blocking PS on platelets or αvβ3 integrin on ECs attenuated platelet clearance resulting in increased platelet count in a mouse model of sepsis. Furthermore, platelet removal by ECs resulted in a corresponding decrease in platelet-leukocyte complex formation and markedly reduced generation of factor Xa and thrombin on platelets. Pretreatment with lactadherin significantly increased phagocytosis of platelets by approximately 2-fold, diminished PCA by 70%, prolonged coagulation time, and attenuated fibrin formation by 50%. Our results suggest that PS-mediated clearance of activated platelets by the endothelium results in an anti-inflammatory, anticoagulant, and antithrombotic effect that contribute to maintaining platelet homeostasis during acute inflammation. These results suggest a new therapeutic target for impeding the development of DIC.

Thrombocytopenia after liver transplantation: Should we care?

PubMed Central

Takahashi, Kazuhiro; Nagai, Shunji; Safwan, Mohamed; Liang, Chen; Ohkohchi, Nobuhiro

2018-01-01

Transient thrombocytopenia is a common phenomenon after liver transplantation. After liver transplantation (LT), platelet count decreases and reaches a nadir on postoperative days 3-5, with an average reduction in platelet counts of 60%; platelet count recovers to preoperative levels approximately two weeks after LT. The putative mechanisms include haemodilution, decreased platelet production, increased sequestration, medications, infections, thrombosis, or combination of these processes. However, the precise mechanisms remain unclear. The role of platelets in liver transplantation has been highlighted in recent years, and particular attention has been given to their effects beyond hemostasis and thrombosis. Previous studies have demonstrated that perioperative thrombocytopenia causes poor graft regeneration, increases the incidence of postoperative morbidity, and deteriorates the graft and decreases patient survival in both the short and long term after liver transplantation. Platelet therapies to increase perioperative platelet counts, such as thrombopoietin, thrombopoietin receptor agonist, platelet transfusion, splenectomy, and intravenous immunoglobulin treatment might have a potential for improving graft survival, however clinical trials are lacking. Further studies are warranted to detect direct evidence on whether thrombocytopenia is the cause or result of poor-graft function and postoperative complications, and to determine who needs platelet therapies in order to prevent postoperative complications and thus improve post-transplant outcomes. PMID:29632420

Platelet indices and netrophil to lymphocyte ratio in adults with acute appendicitis.

PubMed

Kostakis, I D; Machairas, N; Damaskos, C; Doula, C; Tsaparas, P; Charalampoudis, P; Spartalis, E; Sotiropoulos, G C; Kouraklis, G

2016-03-01

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. Data were retrospectively collected from a complete blood count test of 155 adult patients (72 men and 83 women) with histologically proven acute appendicitis upon admission, and of 50 healthy adults (20 men and 30 women). The parameters for white blood cells and platelets were compared between the two groups, and for each gender separately. A higher white blood cell count, neutrophil count, neutrophil percentage, neutrophil to lymphocyte ratio and lower lymphocyte percentage was reported in patients with acute appendicitis than that in the healthy controls, with high areas under the curve (AUC), sensitivities, specifi cities, positive predictive values (PPVs) and moderate negative predictive values (NPVs). The lymphocyte count was lower in patients than it was in the healthy controls. The platletcrit was lower in the female patients than that in the female controls, whereas a difference was not detected in the male participants. Differences were not detected with regard to platelet count, mean platelet volume and platelet distribution width for both genders. The neutrophil to lymphocyte ratio increases and lymphocyte percentage decreases in acute appendicitis, and can be used as an additional diagnostic marker. Plateletcrit, and therefore total platelet mass, is reduced in women with acute appendicitis, indicating the involvement of platelets in its pathophysiology. However, it is neither a reliable predictor or excluder of the disease.

Neutrophil, lymphocyte and platelet counts, and risk of prostate cancer outcomes in white and black men: results from the SEARCH database.

PubMed

Vidal, Adriana C; Howard, Lauren E; de Hoedt, Amanda; Cooperberg, Matthew R; Kane, Christopher J; Aronson, William J; Terris, Martha K; Amling, Christopher L; Taioli, Emanuela; Fowke, Jay H; Freedland, Stephen J

2018-06-01

Systemic inflammation, as measured by C-reactive protein, has been linked with poor prostate cancer (PC) outcomes, predominantly in white men. Whether other immune measures like white blood cell counts are correlated with PC progression and whether results vary by race is unknown. We examined whether complete blood count (CBC) parameters were associated with PC outcomes and whether these associations varied by race. Analyses include 1,826 radical prostatectomy patients from six VA hospitals followed through medical record review for biochemical recurrence (BCR). Secondary outcomes included castration-resistant PC (CRPC), metastasis, all-cause mortality (ACM), and PC-specific mortality (PCSM). Cox-proportional hazards were used to assess the associations between pre-operative neutrophils, lymphocytes, platelets, neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) with each outcome. We used a Bonferroni-corrected p-value of 0.05/5 = 0.01 as the threshold for statistical significance. Of 1,826 men, 794 (43%) were black and 1,032 (57%) white. Neutrophil count (p < 0.001), NLR (p < 0.001), and PLR (p < 0.001) were significantly lower, while lymphocyte count (p < 0.001) was significantly higher in black versus white men. After adjusting for clinicopathological features, no CBC measures were significantly associated with BCR. There were no interactions between CBC and race in predicting BCR. Similarly, no CBC values were significantly associated with CRPC, metastases, or PCSM either among all men or when stratified by race. However, higher neutrophil count was associated with higher ACM risk in white men (p = 0.004). Pre-operative CBC measures were not associated with PC outcomes in black or white men undergoing radical prostatectomy, except for neutrophils-positive association with risk of ACM in white men. Whether circulating immune cell markers provide insight to the pathophysiology of PC progression or adverse treatment

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

PubMed

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 (p<0.05). When smokers 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 (p<0.05). Neutrophil/lymphocyte ratio increases in correlation with pack/year while platelet/lymphocyte ratio is not affected 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.

Analysis of Platelet-Rich Plasma Extraction

PubMed Central

Fitzpatrick, Jane; Bulsara, Max K.; McCrory, Paul Robert; Richardson, Martin D.; Zheng, Ming Hao

2017-01-01

Background: Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP. Purpose: To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons. Study Design: Controlled laboratory study. Methods: Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine. Results: Three kits taking samples from the “buffy coat layer” were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples. Conclusion: This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored

Newborn Plasma Glucose Concentration Nadirs by Gestational-Age Group.

PubMed

Kaiser, Jeffrey R; Bai, Shasha; Rozance, Paul J

2018-01-01

The glucose concentrations and times to nadir for newborns of all gestational ages when intrapartum glucose-containing solutions are not routinely provided are unknown. To characterize and compare patterns of initial glucose concentration nadirs by gestational-age groups. A cross-sectional cohort study of 1,366 newborns born in 1998 at the University of Arkansas for Medical Sciences, appropriate for gestational age, nonasphyxiated, nonpolycythemic, and not infants of diabetic mothers, were included. Initial plasma glucose concentrations, before intravenous fluids or feedings, were plotted against time after birth for 4 gestational-age groups (full term [FT], ≥37-42 weeks; late preterm [LPT], ≥34 and < 37 weeks; preterm [PT], ≥28 and < 34 weeks; and extremely low gestational age newborns [ELGAN], 23 and < 28 weeks of gestation). ELGAN had the earliest nadir at 61 ± 4 min, followed by PT newborns (71 ± 2 min), and then LPT and FT newborns at 92-93 min. The time to nadir for ELGAN and PT newborns was significantly earlier than for FT newborns. Glucose nadir concentrations for ELGAN, PT, and LPT newborns were significantly lower than for FT newborns. LPT newborns' pattern of glucose paralleled those of FT newborns, with values approximately 5-6 mg/dL lower during the first 3 h. Plasma glucose nadirs occurred at different times among gestational-age groups during the early postnatal period as follows: ELGAN < PT < LPT ≈ FT. In order to potentially prevent low glucose concentrations at the time of the nadir, exogenous glucose should be provided to all newborns as soon as possible after birth. © 2018 S. Karger AG, Basel.

Comparison of Circulating Endothelial Cell/Platelet Count Ratio to Aspartate Transaminase/Platelet Ratio Index for Identifying Patients with Cirrhosis

PubMed Central

Sethi, Saurabh; Simonetto, Douglas A; Abdelmoneim, Soha S; Campion, Michael B; Kaloiani, Irakli; Clayton, Amy C; Kremers, Walter K; Halling, Kevin C; Kamath, Patrick S; Talwalkar, Jayant; Shah, Vijay H

2012-01-01

Background/Objectives Circulating endothelial cells (CECs) are indicative of vascular injury and correlate with severity of vascular diseases. A pilot study showed that the ratio of CEC to platelet count (CEC/PC) was effective in predicting cirrhosis. Therefore, we evaluated CEC/PC in a larger cohort of patients, correlated it with cirrhosis, and compared its operating characteristics with previously described biomarker for cirrhosis, the AST/platelet ratio index (APRI). Methods Fifty-three patients with cirrhosis, 20 matched healthy controls, and 9 patients with noncirrhotic liver disease were recruited. Peripheral blood sample was collected and analyzed to enumerate nucleated CEC CD146+, CD105+, CD45– using a commercial assay. Results Median CEC counts were significantly higher in patients with cirrhosis (62 cells/4 mL, interquartile range [IQR]: 43.5–121) as compared with controls (31 cells/4 mL, IQR: 22.2–40). The CEC/PC was also significantly elevated in cirrhotics (0.69, IQR: 0.39–1.48) compared with controls (0.12, IQR: 0.09–0.20) and noncirrhotics (0.21, IQR: 0.08–0.43). Receiver operator characteristic (ROC) analysis revealed that CEC cutoff value of ≥37 cells/4 mL showed sensitivity of 81% and specificity of 75% for differentiating cirrhosis from controls (area under the curve [AUC]: 0.80; 95% confidence interval [CI] 0.67–0.91). The CEC/PC ratio cutoff value of ≥0.23 showed sensitivity of 91% and specificity of 82% (AUC: 0.92; 95% CI 0.83–0.99). The APRI cutoff value of ≥0.4 showed sensitivity of 94% and specificity of 85% for differentiating cirrhosis from control patients (AUC: 0.96; 95% CI 0.90–1.0). A product of CEC and APRI, termed CAPRI (CEC-APRI), effectively distinguished patients with cirrhosis from controls; with cutoff value of ≥12.7, showing higher sensitivity of 98% and specificity of 85% (AUC: 0.98; 95% CI 0.96–1.0). Conclusion The CEC/PC ratio is significantly elevated in patients with cirrhosis and demonstrates

The clearance mechanism of chilled blood platelets.

PubMed

Hoffmeister, Karin M; Felbinger, Thomas W; Falet, Hervé; Denis, Cécile V; Bergmeier, Wolfgang; Mayadas, Tanya N; von Andrian, Ulrich H; Wagner, Denisa D; Stossel, Thomas P; Hartwig, John H

2003-01-10

Platelet transfusion is a very common lifesaving medical procedure. Not widely known is the fact that platelets, unlike other blood cells, rapidly leave the circulation if refrigerated prior to transfusion. This peculiarity requires blood services to store platelets at room temperature, limiting platelet supplies for clinical needs. Here, we describe the mechanism of this clearance system, a longstanding mystery. Chilling platelets clusters their von Willebrand (vWf) receptors, eliciting recognition of mouse and human platelets by hepatic macrophage complement type 3 (CR3) receptors. CR3-expressing but not CR3-deficient mice exposed to cold rapidly decrease platelet counts. Cooling primes platelets for activation. We propose that platelets are thermosensors, primed at peripheral sites where most injuries occurred throughout evolution. Clearance prevents pathologic thrombosis by primed platelets. Chilled platelets bind vWf and function normally in vitro and ex vivo after transfusion into CR3-deficient mice. Therefore, GPIb modification might permit cold platelet storage.

[Influence of raising oxygen content on function of platelet concentrate during preservation].

PubMed

Zhan, Tong; Xiao, Jian-Yu; Tao, Jing; Miao, Xi-Feng; Liu, Yan-Cun; Tang, Rong-Cai

2006-08-01

To explore the influence of raising oxygen (dissolved oxygen) content on function of platelet concentrate, the platelet concentrate was prepared by a CS-3000 plus blood cell separator. Experiments were divided into 2 groups: test group and control group. After raising oxygen content in platelet plasma under sterile operation, the platelet samples of two groups were preserved in oscillator with horizontal oscillation at 22 +/- 2 degrees C. The platelet count, platelet aggregation rate, lactic acid content and CD62p expression level of platelet were detected on 0, 1, 2, 3, 4, 5 days of platelet preservation. The results showed that the platelet count and platelet aggregation rate decreased with prolongation of preserved time, while the lactic acid content and CD62p expression level of platelet increased gradually. Compared with control group, there were significant differences in aggregation rate of platelet preserved for 2-3 days, and in CD62p expression level of platelet preserved for 1-3 days, while significant difference was found in lactic acid content of platelet preserved for 1-3 days. It is concluded that raising content of oxygen in platelet plasma can provide more oxygen to compensate oxygen supply deficiency for platelet metabolism and improve the efficiency of platelet oxygenic metabolism and the quality of platelet during preservation.

Thrombocytopenia in Small for Gestational Age Infants

PubMed Central

Christensen, Robert D.; Baer, Vickie L.; Henry, Erick; Snow, Gregory L.; Butler, Allison; Sola-Visner, Martha C.

2016-01-01

BACKGROUND Thrombocytopenia is common among small for gestational age neonates (SGA; birth weight <10th % reference range) but several aspects of this thrombocytopenia are unclear, including the incidence, typical nadir, duration, association with preeclampsia, mechanism, and risk of death. METHODS Using nine years of multihospital records we studied SGA neonates with ≥2 platelet counts <150,000/μL in their first week. RESULTS We found first-week thrombocytopenia in 31% (905 of 2891) of SGA neonates vs. 10% of non-SGA matched-controls (p<0.0001). One hundred-two of the 905 had a recognized cause of thrombocytopenia (DIC, early-onset sepsis, ECMO). This group had a 65% mortality rate. The remaining 803 did not have an obvious cause for their thrombocytopenia. We termed these the “thrombocytopenia of SGA”. They had a mortality rate of 2% (p<0.0001) and a mean nadir count on day 4 of 93,000/μL (standard deviation, 51,580/μL, 10th % 50,000/μL, 90th % 175,000/μL). By day 14, platelet counts were ≥150,000/μL in >half of the patients. Severely SGA neonates (<1st %) had lower counts and longer thrombocytopenia duration (p<0.001). High nucleated red cell counts at birth correlated with low platelets (p<0.0001). Platelet transfusions were given to 23% and counts typically >tripled. Thrombocytopenia was associated with SGA status more so than with the diagnosis of maternal preeclampsia. CONCLUSIONS SGA neonates with clearly recognized varieties of thrombocytopenia have a high mortality rate. In contrast the “thrombocytopenia of SGA” is a hyporegenerative condition of moderate severity and two weeks duration, associated with evidence of intrauterine hypoxia, and associated with a low mortality rate. PMID:26216323

Lymphocyte-platelet crosstalk in Graves' disease.

PubMed

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 < 0.05) and control group (262 ± 95 × 10 cells/µL; P < 0.05). In GD group, more platelet-bound lymphocytes (332 ± 91 /µL) were found than that in 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.

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

PubMed

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 < 0.001) 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

Blood Count Tests

MedlinePlus

... white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in ... helps doctors check on your overall health. The tests can also help to diagnose diseases and conditions ...

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

PubMed

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.

Role of platelet transfusion in children with bleeding in dengue fever.

PubMed

Pothapregada, Sriram; Kamalakannan, Banupriya; Thulasingam, Mahalakshmy

2015-12-01

The indications for platelet transfusion in dengue fever are clearly defined in World Health Organization (WHO) guidelines (2011) for dengue fever, but physicians face practical difficulty in its implementation in an epidemic setting. On one hand there is an intense social pressure created by the panic-struck parents to transfuse platelets in presence of bleeding and on the other hand there is a need for its judicious use as the requirement is more than its availability. The study was aimed to assess the clinico-hematological parameters, and the requirement and need for platelet transfusion in children with dengue fever. All children (0-12 yr of age) diagnosed and confirmed with dengue fever at a tertiary care hospital in Puducherry between 1 August 2012 and 31 January 2015 were reviewed retrospectively from hospital case records as per the revised WHO guidelines for dengue fever. The diagnosis was confirmed by NS1 antigen- based ELISA test or dengue serology for IgM and IgG antibodies and the data were analyzed using SPSS 16.0 statistical software. Out of 261 cases of dengue fever, hemorrhagic manifestations were observed in 52 children (19.9%), which mainly included petechiae (38.5%), gum bleeding (34.6%) and melena (26.9%). Thrombocytopenia was seen in 211 (80.8%) cases. Bleeding manifestations were present in 20(39.2%), 8(15.7%), 13(25.5%) and 11(21.6%) cases with platelet count <50,000/mm3, 50,000-100,000/mm3, 1-1.50,000/mm3, and >1.50,000/mm3 respectively. Bleeding manifestations did not always correlate with platelet count in non-severe dengue infection in comparison to severe dengue infection. The most common mode of presentation of severe dengue infection was shock with 102(39.1%) cases and among them only 22 children (21.6%) had bleeding. About 17 children (6.5%) with severe dengue infection required platelet transfusion and out of them, 12 children (70.6%) had a platelet count <20,000/ mm3 whereas five children (29.4%) had platelet count in the range of

Platelet Transfusion Practices in Critically Ill Children.

PubMed

Nellis, Marianne E; Karam, Oliver; Mauer, Elizabeth; Cushing, Melissa M; Davis, Peter J; Steiner, Marie E; Tucci, Marisa; Stanworth, Simon J; Spinella, Philip C

2018-05-04

Little is known about platelet transfusions in pediatric critical illness. We sought to describe the epidemiology, indications, and outcomes of platelet transfusions among critically ill children. Prospective cohort study. Multicenter (82 PICUs), international (16 countries) from September 2016 to April 2017. Children ages 3 days to 16 years prescribed a platelet transfusion in the ICU during screening days. None. Over 6 weeks, 16,934 patients were eligible, and 559 received at least one platelet transfusion (prevalence, 3.3%). The indications for transfusion included prophylaxis (67%), minor bleeding (21%), and major bleeding (12%). Thirty-four percent of prophylactic platelet transfusions were prescribed when the platelet count was greater than or equal to 50 × 10 cells/L. The median (interquartile range) change in platelet count post transfusion was 48 × 10 cells/L (17-82 × 10 cells/L) for major bleeding, 42 × 10 cells/L (16-80 × 10 cells/L) for prophylactic transfusions to meet a defined threshold, 38 × 10 cells/L (17-72 × 10 cells/L) for minor bleeding, and 25 × 10 cells/L (10-47 × 10 cells/L) for prophylaxis in patients at risk of bleeding from a device. Overall ICU mortality was 25% but varied from 18% to 35% based on indication for transfusion. Upon adjusted analysis, total administered platelet dose was independently associated with increased ICU mortality (odds ratio for each additional 1 mL/kg platelets transfused, 1.002; 95% CI, 1.001-1.003; p = 0.005). The majority of platelet transfusions are given as prophylaxis to nonbleeding children, and significant variation in platelet thresholds exists. Studies are needed to clarify appropriate indications, with focus on prophylactic transfusions.

Platelet Count Mediates the Contribution of a Genetic Variant in LRRC16A to ARDS Risk

PubMed Central

Wei, Yongyue; Wang, Zhaoxi; Su, Li; Chen, Feng; Tejera, Paula; Bajwa, Ednan K.; Wurfel, Mark M.; Lin, Xihong

2015-01-01

BACKGROUND: Platelets are believed to be critical in pulmonary-origin ARDS as mediators of endothelial damage through their interactions with fibrinogen and multiple signal transduction pathways. A prior meta-analysis identified five loci for platelet count (PLT): BAD, LRRC16A, CD36, JMJD1C, and SLMO2. This study aims to validate the quantitative trait loci (QTLs) of PLT within BAD, LRRC16A, CD36, JMJD1C, and SLMO2 among critically ill patients and to investigate the associations of these QTLs with ARDS risk that may be mediated through PLT. METHODS: ARDS cases and at-risk control subjects were recruited from the intensive care unit of the Massachusetts General Hospital. Exome-wide genotyping data of 629 ARDS cases and 1,026 at-risk control subjects and genome-wide gene expression profiles of 18 at-risk control subjects were generated for analysis. RESULTS: Single-nucleotide polymorphism (SNP) rs7766874 within LRRC16A was a significant locus for PLT among at-risk control subjects (β = −13.00; 95% CI, −23.22 to −2.77; P = .013). This association was validated using LRRC16A gene expression data from at-risk control subjects (β = 77.03 per 1 SD increase of log2-transformed expression; 95% CI, 27.26-126.80; P = .005). Further, rs7766874 was associated with ARDS risk conditioned on PLT (OR = 0.68; 95% CI, 0.51-0.90; P = .007), interacting with PLT (OR = 1.15 per effect allele per 100 × 103/μL of PLT; 95% CI, 1.03-1.30; P = .015), and mediated through PLT (indirect OR = 1.045; 95% CI, 1.007-1.085; P = .021). CONCLUSIONS: Our findings support the role of LRRC16A in platelet formation and suggest the importance of LRRC16A in ARDS pathophysiology by interacting with, and being mediated through, platelets. PMID:25254322

Increased circulating blood cell counts in combat-related PTSD: Associations with inflammation and PTSD severity.

PubMed

Lindqvist, Daniel; Mellon, Synthia H; Dhabhar, Firdaus S; Yehuda, Rachel; Grenon, S Marlene; Flory, Janine D; Bierer, Linda M; Abu-Amara, Duna; Coy, Michelle; Makotkine, Iouri; Reus, Victor I; Aschbacher, Kirstin; Bersani, F Saverio; Marmar, Charles R; Wolkowitz, Owen M

2017-12-01

Inflammation is reported in post-traumatic stress disorder (PTSD). Few studies have investigated circulating blood cells that may contribute to inflammation. We assessed circulating platelets, white blood cells (WBC) and red blood cells (RBC) in PTSD and assessed their relationship to inflammation and symptom severity. One-hundred and sixty-three male combat-exposed veterans (82 PTSD, 81 non-PTSD) had blood assessed for platelets, WBC, and RBC. Data were correlated with symptom severity and inflammation. All cell counts were significantly elevated in PTSD. There were small mediation effects of BMI and smoking on these relationships. After adjusting for these, the differences in WBC and RBC remained significant, while platelet count was at trend level. In all subjects, all of the cell counts correlated significantly with inflammation. Platelet count correlated with inflammation only in the PTSD subjects. Platelet count, but none of the other cell counts, was directly correlated with PTSD severity ratings in the PTSD group. Combat PTSD is associated with elevations in RBC, WBC, and platelets. Dysregulation of all three major lineages of hematopoietic cells in PTSD, as well as their significant correlation with inflammation, suggest clinical significance of these changes. Copyright © 2017 Elsevier B.V. All rights reserved.

Platelet antibody in prolonged remission of childhood idiopathic thrombocytopenic purpura

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1985-11-01

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.more » 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 SVI-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.« less

Nadir creatinine in posterior urethral valves: How high is low enough?

PubMed

Coleman, R; King, T; Nicoara, C-D; Bader, M; McCarthy, L; Chandran, H; Parashar, K

2015-12-01

Large retrospective studies of people with posterior urethral valves (PUV) have reported chronic renal insufficiency (CRI) in up to one third of the participants and end-stage renal failure in up to one quarter of them. Nadir creatinine (lowest creatinine during the first year following diagnosis) is the recognised prognostic indicator for renal outcome in PUV, the most commonly used cut-off being 1 mg/dl (88.4 umol/l). To conduct a statistical analysis of nadir creatinine in PUV patients in order to identify the optimal cut-off level as a prognostic indicator for CRI. Patients treated by endoscopic valve ablation at the present institution between 1993 and 2004 were reviewed. Chronic renal insufficiency was defined as CKD2 or higher. Statistical methods included receiver operating characteristic (ROC) curve analysis, Fisher exact test and diagnostic utility tests. Statistical significance was defined as P < 0.05. Nadir creatinine was identified in 96 patients. The median follow-up was 9.4 (IQR 7.0, 13.4) years. A total of 29 (30.2%) patients developed CRI, with nine (9.4%) reaching end-stage renal failure. On ROC analysis, Nadir creatinine was highly prognostic for future CRI, with an Area Under the Curve of 0.887 (P < 0.001). Renal insufficiency occurred in all 10 (100%) patients with nadir creatinine >88.4 umol/l compared with 19 of 86 (22.2%) patients with lower nadir creatinine (P < 0.001). As a test for future CRI, a nadir creatinine cut-off of 88.4 umol/l gave a specificity of 100%, but poor sensitivity of 34.5%. Lowering the cut-off to 75 umol/l resulted in improvement in all diagnostic utility tests (Table). All 14 (100%) patients with nadir creatinine >75 umol/l developed CRI, compared with 15 of 82 (18.3%) patients with lower nadir creatinine (P < 0.001). Sensitivity only approached 95% at 35 umol/l, at which level specificity was low (Table). Two out of 36 (5.6%) patients with nadir creatinine <35 umol/l developed CRI. Multivariate analysis

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

PubMed

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.

Calcium supplementation during pregnancy for preventing hypertensive disorders is not associated with changes in platelet count, urate, and urinary protein: a randomized control trial.

PubMed

Hofmeyr, G J; Mlokoti, Z; Nikodem, V C; Mangesi, L; Ferreira, S; Singata, M; Jafta, Z; Merialdi, M; Hazelden, C; Villar, J

2008-01-01

To test the hypothesis that calcium supplementation inhibits the underlying pathological processes in women with preeclampsia. Seven hundred and eight nulliparous women were enrolled in a WHO randomized double-blind trial, who received 1.5 g of calcium or placebo from 20 weeks of pregnancy or earlier. Platelet count, serum urate, and urinary protein/creatinine ratio were measured at or near 35 gestational weeks. No difference was detected in rates of abnormal platelet count (relative risk [RR] 1.18; 95% confidence interval [CI], 0.63 to 2.18), serum urate level (1.0; 0.64 to 1.57) or urine protein/creatinine ratio (1.01; 0.76 to 1.34). This was consistent with the main trial finding of no difference in the incidence of 'dipstick' proteinuria between women receiving calcium and those receiving placebo (8312 women; RR, 1.01; 95% CI, 0.88 to 1.15). An effect of calcium supplementation in the second half of pregnancy on the rate of abnormal laboratory measures associated with preeclampsia was not demonstrated.

Platelets and Multi-Organ Failure in Sepsis.

PubMed

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.

Platelets and Multi-Organ Failure in Sepsis

PubMed Central

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

2017-01-01

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. PMID:29053592

New gene functions in megakaryopoiesis and platelet formation

PubMed Central

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; Leach, Irene Mateo; 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; Thein, Swee Lay; 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; Zhao, Jing Hua; Zitting, Paavo; Bradley, John R.; Dedoussis, George V.; Gasparini, Paolo; Hazen, Stanley L.; Metspalu, Andres; Pirastu, Mario; Shuldiner, Alan R.; van Pelt, L. Joost; 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

2012-01-01

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 high-powered meta-analysis of genome-wide association studies (GWAS) in up to 66,867 individuals of European ancestry, followed by extensive biological and functional assessment. We identified 68 genomic loci reliably associated with platelet count and volume mapping to established and putative novel regulators of megakaryopoiesis and platelet formation. These genes show megakaryocyte-specific gene expression patterns and extensive network connectivity. Using gene silencing in Danio rerio and Drosophila melanogaster, we identified 11 of the genes as novel regulators of blood cell formation. Taken together, our findings advance understanding of novel gene functions controlling fate-determining events during megakaryopoiesis and platelet formation, providing a new example of successful translation of GWAS to function. PMID:22139419

Dose of Prophylactic Platelet Transfusions and Prevention of Hemorrhage

PubMed Central

Slichter, Sherrill J.; Kaufman, Richard M.; Assmann, Susan F.; McCullough, Jeffrey; Triulzi, Darrell J.; Strauss, Ronald G.; Gernsheimer, Terry B.; Ness, Paul M.; Brecher, Mark E.; Josephson, Cassandra D.; Konkle, Barbara A.; Woodson, Robert D.; Ortel, Thomas L.; Hillyer, Christopher D.; Skerrett, Donna L.; McCrae, Keith R.; Sloan, Steven R.; Uhl, Lynne; George, James N.; Aquino, Victor M.; Manno, Catherine S.; McFarland, Janice G.; Hess, John R.; Leissinger, Cindy; Granger, Suzanne

2010-01-01

BACKGROUND We conducted a trial of prophylactic platelet transfusions to evaluate the effect of platelet dose on bleeding in patients with hypoproliferative thrombocytopenia. METHODS We randomly assigned hospitalized patients undergoing hematopoietic stem-cell transplantation or chemotherapy for hematologic cancers or solid tumors to receive prophylactic platelet transfusions at a low dose, a medium dose, or a high dose (1.1×1011, 2.2×1011, or 4.4×1011 platelets per square meter of body-surface area, respectively), when morning platelet counts were 10,000 per cubic millimeter or lower. Clinical signs of bleeding were assessed daily. The primary end point was bleeding of grade 2 or higher (as defined on the basis of World Health Organization criteria). RESULTS In the 1272 patients who received at least one platelet transfusion, the primary end point was observed in 71%, 69%, and 70% of the patients in the low-dose group, the medium-dose group, and the high-dose group, respectively (differences were not significant). The incidences of higher grades of bleeding, and other adverse events, were similar among the three groups. The median number of platelets transfused was significantly lower in the low-dose group (9.25×1011) than in the medium-dose group (11.25×1011) or the high-dose group (19.63×1011) (P = 0.002 for low vs. medium, P<0.001 for high vs. low and high vs. medium), but the median number of platelet transfusions given was significantly higher in the low-dose group (five, vs. three in the medium-dose and three in the high-dose group; P<0.001 for low vs. medium and low vs. high). Bleeding occurred on 25% of the study days on which morning platelet counts were 5000 per cubic millimeter or lower, as compared with 17% of study days on which platelet counts were 6000 to 80,000 per cubic millimeter (P<0.001). CONCLUSIONS Low doses of platelets administered as a prophylactic transfusion led to a decreased number of platelets transfused per patient but an

Factors influencing platelet clumping during peripheral blood hematopoietic stem cell collection

PubMed Central

Mathur, Gagan; Bell, Sarah L.; Collins, Laura; Nelson, Gail A.; Knudson, C. Michael; Schlueter, Annette J.

2018-01-01

BACKGROUND Platelet clumping is a common occurrence during peripheral blood hematopoietic stem cell (HSC) collection using the Spectra Optia mononuclear cell (MNC) protocol. If clumping persists, it may prevent continuation of the collection and interfere with proper MNC separation. This study is the first to report the incidence of clumping, identify precollection factors associated with platelet clumping, and describe the degree to which platelet clumping interferes with HSC product yield. STUDY DESIGN AND METHODS In total, 258 HSC collections performed on 116 patients using the Optia MNC protocol were reviewed. Collections utilized heparin in anticoagulant citrate dextrose to facilitate large-volume leukapheresis. Linear and logistic regression models were utilized to determine which precollection factors were predictive of platelet clumping and whether clumping was associated with product yield or collection efficiency. RESULTS Platelet clumping was observed in 63% of collections. Multivariable analysis revealed that a lower white blood cell count was an independent predictor of clumping occurrence. Chemotherapy mobilization and a lower peripheral blood CD34+ cell count were predictors of the degree of clumping. Procedures with clumping had higher collection efficiency but lower blood volume processed on average, resulting in no difference in collection yields. Citrate toxicity did not correlate with clumping. CONCLUSION Although platelet clumping is a common technical problem seen during HSC collection, the total CD34+ cell-collection yields were not affected by clumping. WBC count, mobilization approach, and peripheral blood CD34+ cell count can help predict clumping and potentially drive interventions to proactively manage clumping. PMID:28150319

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

PubMed

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.

Improvement of thrombocytopenia following bone marrow transplantation by pegylated recombinant human megakaryocyte growth and development factor in mice.

PubMed

Kabaya, K; Shibuya, K; Torii, Y; Nitta, Y; Ida, M; Akahori, H; Kato, T; Kusaka, M; Miyazaki, H

1996-12-01

We examined whether pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is capable of improving thrombocytopenia and promoting thrombopoietic reconstitution following lethal irradiation and bone marrow transplantation (BMT) in mice. Immediately after receiving 10 Gy whole body irradiation (day 0), male C3H/HeN mice were inoculated with 10(6) bone marrow cells obtained from syngeneic mice. Circulating platelet counts decreased to below 4% of the normal counts with a nadir on day 10, and then returned to the normal level on day 28 in the control mice undergoing BMT. Subcutaneous consecutive treatment with PEG-rHuMGDF at doses from 10 to 300 micrograms/kg/day from day 1 for 13 days significantly improved the platelet nadir and promoted platelet recovery. The white blood cell counts and hemoglobin concentration following BMT were not influenced by the PEG-rHuMGDF. PEG-rHuMGDF-injection starting from day 5 did not improve the platelet nadir following BMT. Furthermore, administration with PEG-rHuMGDF on alternate days at 55.7 micrograms/kg/day for 7 days or at an interval of 3 days at 78 micrograms/kg/day for 4 days (twice a week for 2 weeks) had a significant efficacy, but these administration regimens had less efficacy than consecutive administration at 30 micrograms/kg/day for 13 days. The numbers of megakaryocytes and megakaryocyte progenitor cells decreased to 5 and 0.2% of normal level, respectively, in the control mice. Consecutive administration of PEG-rHuMGDF enhanced the recovery of the mean number of these cells compared to those in vehicle-treated mice, although such effects were not statistically significant except for the number of megakaryocyte progenitors on day 12. These results suggest that consecutive treatment with PEG-rHuMGDF beginning from the day after BMT may be effective in improving thrombocytopenia following BMT.

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

PubMed

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 < 32 weeks, hospitalized at a tertiary neonatal intensive care unit (NICU) and requiring medical treatment (intravenous or oral ibuprofen) for hemodinamically significant PDA (hsPDA) were enrolled in this study. The patients were divided into two groups after first course of pharmacologic treatment according to closure of PDA (Group 1: PDA closure, Group 2: PDA without closure). Groups were compared in terms of demographics findings, morbidities, platelet measurements like counts, mean platelet volume (MPV) and platelet mass (platelet count × mean platelet volume). The study included 77 preterm newborns in Group 1, and 30 preterms in Group 2. There were no differences in birth weight, gestational age, 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.

Origin-Specific Adhesive Interactions of Mesenchymal Stem Cells with Platelets Influence Their Behavior After Infusion.

PubMed

Sheriff, Lozan; Alanazi, Asma; Ward, Lewis S C; Ward, Carl; Munir, Hafsa; Rayes, Julie; Alassiri, Mohammed; Watson, Steve P; Newsome, Phil N; Rainger, G E; Kalia, Neena; Frampton, Jon; McGettrick, Helen M; Nash, Gerard B

2018-02-28

We investigated the adhesive behavior of mesenchymal stem cells (MSC) in blood, which might influence their fate when infused as therapy. Isolated human bone marrow MSC (BMMSC) or umbilical cord MSC (UCMSC) adhered efficiently from flow to the matrix proteins, collagen, or fibronectin, but did not adhere to endothelial selectins. However, when suspended in blood, BMMSC no longer adhered to collagen, while UCMSC adhered along with many aggregated platelets. Neither MSC adhered to fibronectin from flowing blood, although the fibronectin surface did become coated with a platelet monolayer. UCMSC induced platelet aggregation in platelet rich plasma, and caused a marked drop in platelet count when mixed with whole human or mouse blood in vitro, or when infused into mice. In contrast, BMMSC did not activate platelets or induce changes in platelet count. Interestingly, isolated UCMSC and BMMSC both adhered to predeposited platelets. The differences in behavior in blood were attributable to expression of podoplanin (an activating ligand for the platelet receptor CLEC-2), which was detected on UCMSC, but not BMMSC. Thus, platelets were activated when bound to UCMSC, but not BMMSC. Platelet aggregation by UCMSC was inhibited by recombinant soluble CLEC-2, and UCMSC did not cause a reduction in platelet count when mixed with blood from mice deficient in CLEC-2. We predict that both MSC would carry platelets in the blood, but their interaction with vascular endothelium would depend on podoplanin-induced activation of the bound platelets. Such interactions with platelets might target MSC to damaged tissue, but could also be thrombotic. Stem Cells 2018. © 2018 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

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

PubMed

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.

21 CFR 864.6160 - Manual blood cell counting device.

Code of Federal Regulations, 2012 CFR

2012-04-01

... blood cell counting device. (a) Identification. A manual blood cell counting device is a device used to count red blood cells, white blood cells, or blood platelets. (b) Classification. Class I (general... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Manual blood cell counting device. 864.6160...

21 CFR 864.6160 - Manual blood cell counting device.

Code of Federal Regulations, 2013 CFR

2013-04-01

... blood cell counting device. (a) Identification. A manual blood cell counting device is a device used to count red blood cells, white blood cells, or blood platelets. (b) Classification. Class I (general... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Manual blood cell counting device. 864.6160...

21 CFR 864.6160 - Manual blood cell counting device.

Code of Federal Regulations, 2011 CFR

2011-04-01

... blood cell counting device. (a) Identification. A manual blood cell counting device is a device used to count red blood cells, white blood cells, or blood platelets. (b) Classification. Class I (general... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Manual blood cell counting device. 864.6160...

21 CFR 864.6160 - Manual blood cell counting device.

Code of Federal Regulations, 2014 CFR

2014-04-01

... blood cell counting device. (a) Identification. A manual blood cell counting device is a device used to count red blood cells, white blood cells, or blood platelets. (b) Classification. Class I (general... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Manual blood cell counting device. 864.6160...

21 CFR 864.6160 - Manual blood cell counting device.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual blood cell counting device. 864.6160... blood cell counting device. (a) Identification. A manual blood cell counting device is a device used to count red blood cells, white blood cells, or blood platelets. (b) Classification. Class I (general...

Leukocyte and platelet changes following low-dose lipopolysaccharide administration in five dogs.

PubMed

Flatland, B; Fry, M M; LeBlanc, C J; Rohrbach, B W

2011-02-01

Effects of low-dose LPS (0.1 μg/kg i.v.) on leukocyte and platelet parameters measured using an Advia 120 hematology analyzer were investigated. Five dogs received a saline sham treatment prior to LPS, and blood was collected before and 3, 6, and 24 h post-treatment. LPS-treated dogs had mild neutrophil toxic change and increased neutrophil bands at 3 and 6 h. Compared to saline-treated controls, total leukocyte, neutrophil, and monocyte counts of LPS-treated dogs were significantly decreased at 3 h and increased at 24 h. Compared to baseline, total leukocyte counts of LPS-treated dogs were significantly decreased at 3 h and increased at 24 h. Mean platelet volume was significantly increased and mean platelet component concentration was decreased at 3 h compared to baseline. Platelet count was significantly decreased at 3 and 6 h; plateletcrit did not change significantly. High dosage is not required in order to detect LPS-mediated hematologic effects in dogs. Low-dose LPS administration causes significant changes in leukocyte and platelet indices in dogs without causing severe clinical signs or death. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

PubMed

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.

NADIR: A Flexible Archiving System Current Development

NASA Astrophysics Data System (ADS)

Knapic, C.; De Marco, M.; Smareglia, R.; Molinaro, M.

2014-05-01

The New Archiving Distributed InfrastructuRe (NADIR) is under development at the Italian center for Astronomical Archives (IA2) to increase the performances of the current archival software tools at the data center. Traditional softwares usually offer simple and robust solutions to perform data archive and distribution but are awkward to adapt and reuse in projects that have different purposes. Data evolution in terms of data model, format, publication policy, version, and meta-data content are the main threats to re-usage. NADIR, using stable and mature framework features, answers those very challenging issues. Its main characteristics are a configuration database, a multi threading and multi language environment (C++, Java, Python), special features to guarantee high scalability, modularity, robustness, error tracking, and tools to monitor with confidence the status of each project at each archiving site. In this contribution, the development of the core components is presented, commenting also on some performance and innovative features (multi-cast and publisher-subscriber paradigms). NADIR is planned to be developed as simply as possible with default configurations for every project, first of all for LBT and other IA2 projects.

Combination therapy for radiation-induced bone marrow aplasia in nonhuman primates using synthokine SC-55494 and recombinant human granulocyte colony-stimulating factor.

PubMed

MacVittie, T J; Farese, A M; Herodin, F; Grab, L B; Baum, C M; McKearn, J P

1996-05-15

Combination cytokine therapy continues to be evaluated in an effort to stimulate multilineage hematopoietic reconstitution after bone marrow myelosuppression. This study evaluated the efficacy of combination therapy with the synthetic interleukin-3 receptor agonist, Synthokine-SC55494, and recombinant methionyl human granulocyte colony-stimulating factor (rhG-CSF) on platelet and neutrophil recovery in nonhuman primates exposed to total body 700 cGy 60Co gamma radiation. After irradiation on day (d) 0, cohorts of animals subcutaneously received single-agent protocols of either human serum albumin (HSA; every day [QD], 15 micrograms/kg/d, n = 10), Synthokine (twice daily [BID], 100, micrograms/kg/d, n = 15), rhG-CSF (QD, 10 micrograms/kg/d, n = 5), or a combination of Synthokine and rhG-CSF (BID, 100 and 10 micrograms/kg/d, respectively, n = 5) for 23 days beginning on d1. Complete blood counts were monitored for 60 days postirradiation and the durations of neutropenia (absolute neutrophil count < 500/microL) and thrombocytopenia (platelet count < 20,000/microL) were assessed. Animals were provided clinical support in the form of antibiotics, fresh irradiated whole blood, and fluids. All cytokine protocols significantly (P < .05) reduced the duration thrombocytopenia versus the HSA-treated animals. Only the combination protocol of Synthokine + rhG-CSF and rhG-CSF alone significantly shortened the period neutropenia (P < .05). The combined Synthokine/rhG-CSF protocol significantly improved platelet nadir versus Synthokine alone and HSA controls and neutrophil nadir versus rhG-CSF alone and HSA controls. All cytokine protocols decreased the time to recovery to preirradiation neutrophil and platelet values. The Synthokine/rhG-CSF protocol also reduced the transfusion requirements per treatment group to 0 among 5 animals as compared with 2 among 5 animals for Synthokine alone, 8 among 5 animals for rhG-CSF, and 17 among 10 animals for HSA. These data showed that the

Unmanned aerial system nadir reflectance and MODIS nadir BRDF-adjusted surface reflectances intercompared over Greenland

NASA Astrophysics Data System (ADS)

Faulkner Burkhart, John; Kylling, Arve; Schaaf, Crystal B.; Wang, Zhuosen; Bogren, Wiley; Storvold, Rune; Solbø, Stian; Pedersen, Christina A.; Gerland, Sebastian

2017-07-01

Albedo is a fundamental parameter in earth sciences, and many analyses utilize the Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF)/albedo (MCD43) algorithms. While derivative albedo products have been evaluated over Greenland, we present a novel, direct comparison with nadir surface reflectance collected from an unmanned aerial system (UAS). The UAS was flown from Summit, Greenland, on 210 km transects coincident with the MODIS sensor overpass on board the Aqua and Terra satellites on 5 and 6 August 2010. Clear-sky acquisitions were available from the overpasses within 2 h of the UAS flights. The UAS was equipped with upward- and downward-looking spectrometers (300-920 nm) with a spectral resolution of 10 nm, allowing for direct integration into the MODIS bands 1, 3, and 4. The data provide a unique opportunity to directly compare UAS nadir reflectance with the MODIS nadir BRDF-adjusted surface reflectance (NBAR) products. The data show UAS measurements are slightly higher than the MODIS NBARs for all bands but agree within their stated uncertainties. Differences in variability are observed as expected due to different footprints of the platforms. The UAS data demonstrate potentially large sub-pixel variability of MODIS reflectance products and the potential to explore this variability using the UAS as a platform. It is also found that, even at the low elevations flown typically by a UAS, reflectance measurements may be influenced by haze if present at and/or below the flight altitude of the UAS. This impact could explain some differences between data from the two platforms and should be considered in any use of airborne platforms.

Low-level light treatment ameliorates immune thrombocytopenia

NASA Astrophysics Data System (ADS)

Yang, Jingke; Zhang, Qi; Wu, Mei X.

2017-02-01

Immune thrombocytopenia (ITP) is an immune-mediated acquired bleeding disorder characterized by abnormally low platelet counts. We reported here the ability of low-level light treatment (LLLT) to alleviate ITP in mice. The treatment is based on noninvasive whole body illumination 30 min a day for a few consecutive days by near infrared light (830 nm) transmitted by an array of light-emitting diodes (LEDs). LLLT significantly lifted the nadir of platelet counts and restored tail bleeding time when applied to two passive ITP models induced by anti-CD41 antibody. The anti-platelet antibody hindered megakaryocyte differentiation from the progenitors, impaired proplatelet and platelet formation, and induced apoptosis of platelets. These adverse effects of anti-CD41 antibody were all mitigated by LLLT to varying degrees, owing to its ability to enhance mitochondrial biogenesis and activity in megakaryocytes and preserve mitochondrial functions in platelets in the presence of the antibody. The observations argue not only for contribution of mitochondrial stress to the pathology of ITP, but also clinical potentials of LLLT as a safe, simple, and cost-effective modality of ITP.

Relations of Platelet Indices with Endometrial Hyperplasia and Endometrial Cancer.

PubMed

Karateke, Atilla; Kaplanoglu, Mustafa; Baloglu, Ali

2015-01-01

Platelets are blood elements thought to play a role in the immune system and therefore tumor development and metastasis. Platelet activation parameters such as mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) can be easily evaluated with the whole blood count and have been studied as markers of systemic inflammatory responses in various cancer types. Our aim in this study was to evaluate the correlation between endometrial pathologies and MPV, PDW and PCT. A total of 194 patients who presented to our clinic with abnormal vaginal bleeding were included in our study. The patients were divided into 3 groups (endometrial hyperplasia, endometrial cancer, control) according to their pathology results. The groups were compared for MPV, PDW, and PCT values obtained from the blood samples taken on endometrial biopsy day. The endometrial cancer patients were the oldest group (p=0.04). There was no significant difference between the three groups in terms of white blood cell count (WBC), platelet count (PC), and hemoglobin (Hb) level. The highest MPV (p<0.001), PDW (p=0.002), and PCT (p<0.001) levels were in the endometrial cancer group, and the lowest levels were in the control group. The easy evaluation of platelet parameters in patients who are suspected of having endometrial pathology is a significant advantage. We found MPV, PDW, and PCT to be correlated with the severity of endometrial pathology with the highest values in endometrial cancer. Studies to be conducted together with different laboratory parameters will further help evaluate the diagnosis and severity of endometrial cancer and precursor lesions.

Oscillatory haematopoiesis in adults with sickle cell disease treated with hydroxycarbamide.

PubMed

Baird, John H; Minniti, Caterina P; Lee, Jung-Min; Tian, Xin; Wu, Colin; Jackson, Mary; Alam, Shoaib; Taylor, James G; Kato, Gregory J

2015-03-01

Hydroxycarbamide therapy has been associated with significant oscillations in peripheral blood counts from myeloid, lymphoid and erythroid lineages in patients with polycythaemia vera and chronic myeloid leukaemia. We retrospectively evaluated serial blood counts over an 8-year period from 44 adult patients with sickle cell disease receiving hydroxycarbamide. Platelet counts, leucocyte counts, haemoglobin values and reticulocyte counts, apportioned by hydroxycarbamide status, were analysed using a Lomb-Scargle periodogram algorithm. Significant periodicities were present in one or more counts in 38 patients receiving hydroxycarbamide for a mean duration of 4·81 years. Platelet and leucocyte counts oscillated in 56·8% and 52·3% of patients, respectively. These oscillations generally became detectable within days of initiating therapy. During hydroxycarbamide therapy, the predominant periods of oscillation were 27 ± 1 d for platelet counts and 15 ± 1 d for leucocyte counts. Despite an absolute decrease in leucocyte and platelet counts during hydroxycarbamide treatment, the amplitudes between nadirs and zeniths remained similar regardless of exposure. Our observations appear consistent with previously proposed models of cyclic haematopoiesis, and document that hydroxycarbamide-induced oscillations in blood counts are innocuous phenomena not limited to myeloproliferative disorders as described previously. We speculate the known cell cycle inhibitory properties of hydroxycarbamide may accentuate otherwise latent constitutive oscillatory haematopoiesis. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Nonhuman primate model of polytraumatic hemorrhagic shock recapitulates early platelet dysfunction observed following severe injury in humans.

PubMed

Schaub, Leasha J; Moore, Hunter B; Cap, Andrew P; Glaser, Jacob J; Moore, Ernest E; Sheppard, Forest R

2017-03-01

Platelet dysfunction has been described as an early component of trauma-induced coagulopathy. The platelet component of trauma-induced coagulopathy remains to be fully elucidated and translatable animal models are required to facilitate mechanistic investigations. We sought to determine if the early platelet dysfunction described in trauma patients could be recapitulated in a nonhuman primate model of polytraumatic hemorrhagic shock. Twenty-four male rhesus macaques weighting 7 to 14 kg were subjected to 60 minutes (min) of severe pressure-targeted controlled hemorrhagic shock (HS) with and without other injuries. After 60 min, resuscitation with 0.9% NaCl and whole blood was initiated. Platelet counts and platelet aggregation assays were performed at baseline (BSLN), end of shock (EOS; T = 60 min), end of resuscitation (EOR; T = 180 min), and T = 360 min on overall cohort. Results are reported as mean ± standard deviation (SD) or median (interquartile range). Statistical analysis was conducted using Spearmen correlation, one-way analysis of variance, two-way repeated-measures analysis of variance, paired t-test or Wilcoxon nonparametric test, with p < 0.05 considered significant. Platelet count in all injury cohorts decreased over time, but no animals developed thrombocytopenia. Correlations were observed between platelet aggregation and platelet count for all agonists: adenosine diphosphate, thrombin recognition-activating peptide-6, collagen, and arachidonic acid. Overall, compared to BSLN, platelet aggregation decreased for all agonist at EOS, EOR, and T = 360 min. When normalized to platelet count, platelet aggregation in response to agonist thrombin recognition-activating peptide-6 demonstrated no change from BSLN at subsequent time points. Aggregation to adenosine diphosphate was significantly less at EOR but not EOS or T = 360 min compared to BSLN. Platelet aggregation to collagen and arachidonic acid was not significantly different at EOS compared to BSLN

Platelet Dynamics during Natural and Pharmacologically Induced Torpor and Forced Hypothermia

PubMed Central

de Vrij, Edwin L.; Vogelaar, Pieter C.; Goris, Maaike; Houwertjes, Martin C.; Herwig, Annika; Dugbartey, George J.; Boerema, Ate S.; Strijkstra, Arjen M.; Bouma, Hjalmar R.; Henning, Robert H.

2014-01-01

Hibernation is an energy-conserving behavior in winter characterized by two phases: torpor and arousal. During torpor, markedly reduced metabolic activity results in inactivity and decreased body temperature. Arousal periods intersperse the torpor bouts and feature increased metabolism and euthermic body temperature. Alterations in physiological parameters, such as suppression of hemostasis, are thought to allow hibernators to survive periods of torpor and arousal without organ injury. While the state of torpor is potentially procoagulant, due to low blood flow, increased viscosity, immobility, hypoxia, and low body temperature, organ injury due to thromboembolism is absent. To investigate platelet dynamics during hibernation, we measured platelet count and function during and after natural torpor, pharmacologically induced torpor and forced hypothermia. Splenectomies were performed to unravel potential storage sites of platelets during torpor. Here we show that decreasing body temperature drives thrombocytopenia during torpor in hamster with maintained functionality of circulating platelets. Interestingly, hamster platelets during torpor do not express P-selectin, but expression is induced by treatment with ADP. Platelet count rapidly restores during arousal and rewarming. Platelet dynamics in hibernation are not affected by splenectomy before or during torpor. Reversible thrombocytopenia was also induced by forced hypothermia in both hibernating (hamster) and non-hibernating (rat and mouse) species without changing platelet function. Pharmacological torpor induced by injection of 5′-AMP in mice did not induce thrombocytopenia, possibly because 5′-AMP inhibits platelet function. The rapidness of changes in the numbers of circulating platelets, as well as marginal changes in immature platelet fractions upon arousal, strongly suggest that storage-and-release underlies the reversible thrombocytopenia during natural torpor. Possibly, margination of platelets

Elevated Steady State WBC and Platelet Counts Are Associated with Frequent Emergency Room Use in Adults with Sickle Cell Anemia

PubMed Central

Danda, Neeraja; Etzion, Zipora

2015-01-01

Introduction Sickle cell anemia has many sequelae that result in emergency department (ED) use, but a minority of patients with sickle cell disease are frequent utilizers and make up the majority of ED visits. If patients who are likely to be frequent ED can be identified in steady state, they can be treated with disease modifying agents in an attempt to reduce ED use frequency. We sought to identify steady state markers for frequent ED use. Methods We identified all patients with SS/Sβ0 seen at our facilities in 2012. Health care utilization over the entire year was calculated and ED visit numbers categorized as either 0–1, 2–5, or 6 or more visits a year. Steady state and acutely active laboratory parameters were collected and analyzed using analysis of variance models and odds ratios. Results 432 adult sickle cell patients were identified, ages 18–87, 54% female, and 38% had been prescribed hydroxyurea. Of the 432 patients,192 had 0–1 visits in the year, 144 had 2–5 visits in the year, and 96 had >6 visits for a total of 2259 visits. Those who had >6 visits accounted for 1750 (77%) of the total visits for the year. When steady state laboratory markers were examined, each additional 50x109/L platelets was associated with 22% greater risk (p < .001); each 1x109/L of WBC was associated with 11% greater risk (p = .003), and each 1g/dL Hb was associated with 23% lower risk (p = .007) of >6 ED visits/year. We did not observe a relationship between baseline HbF, LDH or reticulocyte count with >6 ED visits. Conclusion Patients with elevated white blood cell counts, elevated platelet counts, and low hemoglobin levels exhibited higher risk for frequent ED utilization and could be candidates for early and aggressive therapy with disease modifying agents. PMID:26248283

Detection of microbial contamination in platelets

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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, P<0.0001). In this model of traumatic shock, 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.

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

PubMed

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 < 0.01). Although no significant difference was found for APTT values, PT was slightly prolonged using the centrifuge brake set to on (mean bias 0.2 s; P < 0.001). FBG values were also significantly higher using the centrifuge brake set to on (mean bias 0.29 g/l; P < 0.001). The results of this study indicate that sample centrifugation for routine coagulation testing should be preferably performed with the centrifuge brake set to off for providing a better quality specimen.

Differential changes in platelet VEGF, Tsp, CXCL12, and CXCL4 in patients with metastatic cancer.

PubMed

Wiesner, Tina; Bugl, Stefanie; Mayer, Frank; Hartmann, Jörg T; Kopp, Hans-Georg

2010-03-01

Data from animal studies indicate that platelets play a key role in tumor dissemination and metastasis. We therefore hypothesized that metastastic cancer patients may display a specific platelet phenotype. Percentage of activated, p-selectin positive platelets as well as platelet contents (i.e., plasma and platelet count-corrected serum levels of VEGF-A, CXCL12, CXCL4, and thrombospondin-1) were analyzed in 43 patients with newly diagnosed metastatic disease prior to treatment. Tumor patients had increased platelet counts and significantly elevated percentages of activated platelets. Moreover, the platelet content of VEGF-A in cancer patients was significantly increased compared to healthy controls, while thrombospondin-1, CXCL12 and CXCL4 were significantly decreased. Our data contain several unexpected results: firstly, CXCL12 was found in minute quantities in the serum as compared with murine studies. Secondly, CXCL4, which was found by mass spectrometry to be the single massively upregulated intraplatelet chemokine in mice after tumor xenotransplantation, was decreased in tumor patient platelets. While increased contents of VEGF-A have been attributed to platelet scavenger activity, the differential decrease of specific platelet contents may be due to differential secretion or altered megakaryopoiesis in metastatic cancer patients.

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

PubMed

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.

Comparison between a new platelet count drop method PL-11, light transmission aggregometry, VerifyNow aspirin system and thromboelastography for monitoring short-term aspirin effects in healthy individuals.

PubMed

Guan, Jie; Cong, Yulong; Ren, Junwei; Zhu, Yuan; Li, Li; Deng, Xinli; Bai, Jie

2015-01-01

Platelet function has been described by many laboratory assays, and PL-11 is a new point-of-care platelet function analyzer based on platelet count drop method, which counts platelet before and after the addition of agonists in the citrated whole blood samples. The present study sought to compare PL-11 with other three major more established assays, light transmission aggregometry (LTA), VerifyNow™ aspirin system and thromboelastography (TEG), for monitoring the short-term aspirin responses in healthy individuals. Ten healthy young men took 100 mg/d aspirin for 3-day treatment. Platelet function was measured via PL-11, LTA, VerifyNow and TEG, respectively. The blood samples were collected at baseline, 2 hour, 1 day during the aspirin treatment and 1 day, 5 ± 1 days, 8 ± 1 days after the aspirin withdrawal. Moreover, 90 additional healthy subjects were recruited to establish a reference range for PL-11. Platelet function of healthy subjects decreased significantly 2 hours after 100 mg/d aspirin intake and began to recover during 4-6 days after the aspirin withdrawal. Correlations between methods were PL-11 vs. LTA (r = 0.614, p < 0.01); PL-11 vs. VerifyNow (r = 0.829, p < 0.01); PL-11 vs. TEG (r = 0.697, p < 0.001). There was no significant bias between PL-11 and LTA at baseline (bias = 1.94%, p = 0.804) using Bland-Altman analysis, while the data of PL-11 were significantly higher than LTA (bias = 24.02%, p < 0.001) during the aspirin therapy. The reference range for PL-11 in healthy young individuals was from 66.8 to 90.5% (95%CI). When aspirin low-responsiveness was defined as LTA > 20%, the cut-off values for each method were, respectively: PL-11 > 50%, VerifyNow > 533 ARU, TEG > 60.2%. The results of different platelet function assays were uninterchangeable for monitoring aspirin response and correlations among them were also varied. Correlations among PL-11 and other three major assays

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

PubMed

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.

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

PubMed

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.

Effects of Nd:YAG laser-heated metal cap on human platelets in vitro

NASA Astrophysics Data System (ADS)

Liu, Xia; Guo, You-chi

1993-03-01

Human platelet-rich plasma (PRP) was irradiated in vitro with a fiberoptic Nd:YAG laser-heated metal cap to study its effects on platelets. The energy of the laser was 5 and 10 watts with an irradiation time of 0, 3, 6, and 9 seconds and 14 watts with an irradiation time of 0, 3, 4, and 5 seconds, respectively. The irradiated PRPs were analyzed for platelet count, aggregation reaction, thromboxane (TX)B2 measurement and electron microscopy. Various degrees of decrease in platelet count were observed in all groups. Except the 5Wx3S group, the other groups showed an increase in the maximum aggregation rate of platelets, which corresponded to the enhancement of TXB2 formation. It was also demonstrated by a transmission electron microscopy in 10Wx3S, 10Wx6S, 10Wx9S, 14Wx3S, 14Wx4S, and 14Wx5S energy groups that alpha- and dense-particles in irradiated platelets became sparse in number or even disappeared, less electron density, irregularity in size and shape, and a tendency for these particles to cluster around platelet membranes and open canalicular systems, which dilated apparently. Furthermore, scanning electron microscopy depicted the appearance of short and thick pseudopods on the surfaces of some irradiated platelets and an increase in the axis rate in most of the irradiated platelets.

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

PubMed

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.

Maximising platelet availability by delaying cold storage.

PubMed

Wood, B; Johnson, L; Hyland, R A; Marks, D C

2018-04-06

Cold-stored platelets may be an alternative to conventional room temperature (RT) storage. However, cold-stored platelets are cleared more rapidly from circulation, reducing their suitability for prophylactic transfusion. To minimise wastage, it may be beneficial to store platelets conventionally until near expiry (4 days) for prophylactic use, transferring them to refrigerated storage to facilitate an extended shelf life, reserving the platelets for the treatment of acute bleeding. Two ABO-matched buffy-coat-derived platelets (30% plasma/70% SSP+) were pooled and split to produce matched pairs (n = 8 pairs). One unit was stored at 2-6°C without agitation (day 1 postcollection; cold); the second unit was stored at 20-24°C with constant agitation until day 4 then stored at 2-6°C thereafter (delayed-cold). All units were tested for in vitro quality periodically over 21 days. During storage, cold and delayed-cold platelets maintained a similar platelet count. While pH and HSR were significantly higher in delayed-cold platelets, other metabolic markers, including lactate production and glucose consumption, did not differ significantly. Furthermore, surface expression of phosphatidylserine and CD62P, release of soluble CD62P and microparticles were not significantly different, suggesting similar activation profiles. Aggregation responses of delayed-cold platelets followed the same trend as cold platelets once transferred to cold storage, gradually declining over the storage period. The metabolic and activation profile of delayed-cold platelets was similar to cold-stored platelets. These data suggest that transferring platelets to refrigerated storage when near expiry may be a viable option for maximising platelet inventories. © 2018 International Society of Blood Transfusion.

Platelet activation suppresses HIV-1 infection of T cells

PubMed Central

2013-01-01

Background Platelets, anucleate cell fragments abundant in human blood, can capture HIV-1 and platelet counts have been associated with viral load and disease progression. However, the impact of platelets on HIV-1 infection of T cells is unclear. Results We found that platelets suppress HIV-1 spread in co-cultured T cells in a concentration-dependent manner. Platelets containing granules inhibited HIV-1 spread in T cells more efficiently than degranulated platelets, indicating that the granule content might exert antiviral activity. Indeed, supernatants from activated and thus degranulated platelets suppressed HIV-1 infection. Infection was inhibited at the stage of host cell entry and inhibition was independent of the viral strain or coreceptor tropism. In contrast, blockade of HIV-2 and SIV entry was less efficient. The chemokine CXCL4, a major component of platelet granules, blocked HIV-1 entry and neutralization of CXCL4 in platelet supernatants largely abrogated their anti-HIV-1 activity. Conclusions Release of CXCL4 by activated platelets inhibits HIV-1 infection of adjacent T cells at the stage of virus entry. The inhibitory activity of platelet-derived CXCL4 suggests a role of platelets in the defense against infection by HIV-1 and potentially other pathogens. PMID:23634812

Platelet activation suppresses HIV-1 infection of T cells.

PubMed

Solomon Tsegaye, Theodros; Gnirß, Kerstin; Rahe-Meyer, Niels; Kiene, Miriam; Krämer-Kühl, Annika; Behrens, Georg; Münch, Jan; Pöhlmann, Stefan

2013-05-01

Platelets, anucleate cell fragments abundant in human blood, can capture HIV-1 and platelet counts have been associated with viral load and disease progression. However, the impact of platelets on HIV-1 infection of T cells is unclear. We found that platelets suppress HIV-1 spread in co-cultured T cells in a concentration-dependent manner. Platelets containing granules inhibited HIV-1 spread in T cells more efficiently than degranulated platelets, indicating that the granule content might exert antiviral activity. Indeed, supernatants from activated and thus degranulated platelets suppressed HIV-1 infection. Infection was inhibited at the stage of host cell entry and inhibition was independent of the viral strain or coreceptor tropism. In contrast, blockade of HIV-2 and SIV entry was less efficient. The chemokine CXCL4, a major component of platelet granules, blocked HIV-1 entry and neutralization of CXCL4 in platelet supernatants largely abrogated their anti-HIV-1 activity. Release of CXCL4 by activated platelets inhibits HIV-1 infection of adjacent T cells at the stage of virus entry. The inhibitory activity of platelet-derived CXCL4 suggests a role of platelets in the defense against infection by HIV-1 and potentially other pathogens.

Characterization of Global Near-Nadir Backscatter for Remote Sensing Radar Design

NASA Technical Reports Server (NTRS)

Spencer, Michael W.; Long, David G.

2000-01-01

In order to evaluate side-lobe contamination from the near-nadir region for Ku-Band radars, a statistical characterization of global near-nadir backscatter is constructed. This characterization is performed for a variety of surface types using data from TRMM, Seasat, and Topex. An assessment of the relative calibration accuracy of these sensors is also presented.

Characterization of Global Near-Nadir Backscatter for Remote Sensing Radar Design

NASA Technical Reports Server (NTRS)

Spencer, Michael W.; Long, David G.

2000-01-01

In order to evaluate side-lobe contamination from the near-nadir region for Ku-Band radars, a statistical characterization of global near-nadir backscatter is constructed. This characterization is performed for a variety of surface types using data from TRMM, Seasat, and Topex. An assessment of the relative calibration accuracy of them sensors is also presented.

[Platelet transfusion role in neonatal immune thrombocytopenia].

PubMed

Petermann, R

2016-11-01

Neonatal immune thrombocytopenia represent less than 5% of cases of early thrombocytopenia (early-onset<72hours post-delivery). As in adults, thrombocytopenia in neonates is defined as a platelet count less than 150G/L. They are either auto- or allo-immune. Thrombocytopenia resulting from transplacental passage of maternal antibodies directed to platelet membrane glycoproteins can be severe. The major complication of severe thrombocytopenia is bleeding and particularly intra-cranial haemorrhage and neurologic sequelea following. However, auto- and allo-immune thrombocytopenia have very different characteristics including the treatment management. In fact, this treatment is based on platelet transfusion associated or not to intravenous immunoglobulin administration. The purpose of this article is to remind platelet transfusion's place in neonatal immune thrombocytopenia in terms of recently published French guidelines and international practices. Copyright © 2016. Published by Elsevier SAS.

Low-level light treatment ameliorates immune thrombocytopenia

PubMed Central

Yang, Jingke; Zhang, Qi; Li, Peiyu; Dong, Tingting; Wu, Mei X.

2016-01-01

Immune thrombocytopenia (ITP) is an immune-mediated acquired bleeding disorder characterized by abnormally low platelet counts. We reported here the ability of low-level light treatment (LLLT) to alleviate ITP in mice. The treatment is based on noninvasive whole body illumination 30 min a day for a few consecutive days by near infrared light (830 nm) transmitted by an array of light-emitting diodes (LEDs). LLLT significantly lifted the nadir of platelet counts and restored tail bleeding time when applied to two passive ITP models induced by anti-CD41 antibody. The anti-platelet antibody hindered megakaryocyte differentiation from the progenitors, impaired proplatelet and platelet formation, and induced apoptosis of platelets. These adverse effects of anti-CD41 antibody were all mitigated by LLLT to varying degrees, owing to its ability to enhance mitochondrial biogenesis and activity in megakaryocytes and preserve mitochondrial functions in platelets in the presence of the antibody. The observations argue not only for contribution of mitochondrial stress to the pathology of ITP, but also clinical potentials of LLLT as a safe, simple, and cost-effective modality of ITP. PMID:27901126

Human plasma platelet-derived exosomes: effects of aspirin.

PubMed

Goetzl, Edward J; Goetzl, Laura; Karliner, Joel S; Tang, Norina; Pulliam, Lynn

2016-05-01

Platelet-derived exosomes mediate platelet atherogenic interactions with endothelial cells and monocytes. A new method for isolation of plasma platelet-derived exosomes is described and used to examine effects of aging and aspirin on exosome cargo proteins. Exosome secretion by purified platelets in vitro did not increase after exposure to thrombin or collagen, as assessed by exosome counts and quantification of the CD81 exosome marker. Thrombin and collagen increased exosome content of α-granule chemokines CXCL4 and CXCL7 and cytoplasmic high-mobility group box 1 (HMGB1) protein, but not membrane platelet glycoprotein VI (GPVI), with dependence on extracellular calcium. Aspirin consumption significantly blocked thrombin- and collagen-induced increases in exosome cargo levels of chemokines and HMGB1, without altering total exosome secretion or GPVI cargo. Plasma platelet-derived exosomes, enriched by absorption with mouse antihuman CD42b [platelet glycoprotein Ib (GPIb)] mAb, had sizes and cargo protein contents similar to those of exosomes from purified platelets. The plasma platelet-derived exosome number is lower and its chemokine and HMGB1 levels higher after age 65 yr. Aspirin consumption significantly suppressed cargo protein levels of plasma platelet-derived exosomes without altering total levels of exosomes. Cargo proteins of human plasma platelet-derived exosomes may biomark platelet abnormalities and in vivo effects of drugs.- Goetzl, E. J., Goetzl, L., Karliner, J. S., Tang, N., Pulliam, L. Human plasma platelet-derived exosomes: effects of aspirin. © FASEB.

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

PubMed

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.

The Mean Platelet Volume in Patients with Retinal Vein Occlusion

PubMed Central

Şahin, Muhammed; Yüksel, Harun; Türkcü, Fatih Mehmet; Çınar, Yasin; Cingü, Abdullah Kürşat; Arı, Şeyhmus; Çaça, İhsan

2013-01-01

Background. The aim of this study was to investigate the mean platelet volume (MPV) of patients with retinal vein occlusion (RVO). Methods. Hundred and ninty-three patients with the diagnosis of RVO and 83 healthy control subjects were included in this retrospective study. Retinal vein occlusion was diagnosed based on clinical examination. All patients and control subjects underwent complete ocular examination. MPV, hematocrit, hemoglobin, and platelet count of the participants were recorded. The data of patients with RVO was compared with the control subjects. Results. Patients with RVO had significantly higher MPV values (8.19 ± 1.22 fL) compared with the control subjects (7.68 ± 1.11 fL) (P = 0.004). No significant difference was found in platelet counts between RVO group and the control group (275.77 ± 70.87 109/L and 261.96 ± 59.40 109/L, resp., P = 0.161), Mean platelet volume was an independent predictor of RVO (odds ratio (OR) = 1.43; 95% confidence interval (CI) = 1.09–1.89; P = 0.011). Conclusion. Our results demonstrated that the MPV values were significantly higher in patients with RVO, suggesting that larger platelets may contribute to the pathogenesis of the RVOs. PMID:23781328

The mean platelet volume in patients with retinal vein occlusion.

PubMed

Sahin, Alparslan; Sahin, Muhammed; Yüksel, Harun; Türkcü, Fatih Mehmet; Cınar, Yasin; Cingü, Abdullah Kürşat; Arı, Seyhmus; Caça, Ihsan

2013-01-01

Background. The aim of this study was to investigate the mean platelet volume (MPV) of patients with retinal vein occlusion (RVO). Methods. Hundred and ninty-three patients with the diagnosis of RVO and 83 healthy control subjects were included in this retrospective study. Retinal vein occlusion was diagnosed based on clinical examination. All patients and control subjects underwent complete ocular examination. MPV, hematocrit, hemoglobin, and platelet count of the participants were recorded. The data of patients with RVO was compared with the control subjects. Results. Patients with RVO had significantly higher MPV values (8.19 ± 1.22 fL) compared with the control subjects (7.68 ± 1.11 fL) (P = 0.004). No significant difference was found in platelet counts between RVO group and the control group (275.77 ± 70.87 10(9)/L and 261.96 ± 59.40 10(9)/L, resp., P = 0.161), Mean platelet volume was an independent predictor of RVO (odds ratio (OR) = 1.43; 95% confidence interval (CI) = 1.09-1.89; P = 0.011). Conclusion. Our results demonstrated that the MPV values were significantly higher in patients with RVO, suggesting that larger platelets may contribute to the pathogenesis of the RVOs.

TES/Aura L2 Atmospheric Temperatures Nadir V6 (TL2ATMTN)

Atmospheric Science Data Center

2018-01-18

TES/Aura L2 Atmospheric Temperatures Nadir (TL2ATMTN) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Atmospheric Temperatures Spatial Coverage:  5.3 x 8.5 km nadir ... Contact User Services Parameters:  Atmospheric Temperature Temperature Precision Vertical Resolution ...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pumphrey, C.W.; Chesebro, J.H.; Dewanjee, M.K.

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 amore » 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.« less

TES/Aura L2 Atmospheric Temperatures Nadir V6 (TL2TNS)

Atmospheric Science Data Center

2018-01-22

TES/Aura L2 Atmospheric Temperatures Nadir (TL2TNS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Atmospheric Temperatures Spatial Coverage:  5.3 x 8.5 km nadir ... Contact ASDC User Services Parameters:  Atmospheric Temperature Temperature Precision Vertical Resolution ...

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

PubMed

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 (< 35 g/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 < .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). COP-NLR is an independent predictive factor in patients with ESCC. We conclude that COP-NLR predicts survival in ESCC similar to GPS.

Influence of calcium salts and bovine thrombin on growth factor release from equine platelet-rich gel supernatants.

PubMed

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

2017-01-16

To compare five activation methods in equine platelet-rich plasma (PRP) by determination of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor beta 1 (TGF-β1) concentrations in platelet-rich gel (PRG) supernatants. Platelet-rich plasma from 20 horses was activated by calcium chloride (CC), calcium gluconate (CG), bovine thrombin (BT), and their combinations, BTCC and BTCG. Both growth factor concentrations in PRG supernatants were measured by ELISA and compared with plasma and platelet lysates (PL) over time. Growth factor concentrations were significantly lower in plasma and higher for all PRG supernatants. Platelet lysates contained a significantly lower concentration of PDGF-BB than PRG supernatants and a significantly higher concentration of TGF-β1 than PRG supernatants. Clots from PRP activated with sodium salts were more stable over time and had significant growth factor release, whereas CC produced gross salt deposition. Significant correlations were noticed for platelet with leukocyte concentrations in PRP (r s : 0.76), platelet counts in PRP with TGF-β1 concentrations in PRG supernatants (r s : 0.86), platelet counts in PRP with PDGF-BB concentrations in PRG supernatants (r s : 0.78), leukocyte counts in PRP with TGF-β1 concentrations in PRG supernatants (r s : 0.76), and PDGF-BB concentrations with activating substances (r s : 0.72). Calcium gluconate was the better substance to induce PRP activation. It induced growth factor release free from calcium precipitates in the clots. Use of BT alone or combined with calcium salts was not advantageous for growth factor release.

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

PubMed

Alan, Sevil; Tuna, Serpil; Türkoğlu, Elif Betül

2015-12-01

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 < 0.001). Lymphocyte counts and MPVs of the BS group were not statistically different from 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. Copyright © 2015. Published by Elsevier Taiwan.

Identification of platelet refractoriness in oncohematologic patients

PubMed Central

Ferreira, Aline Aparecida; Zulli, Roberto; Soares, Sheila; de Castro, Vagner; Moraes-Souza, Helio

2011-01-01

OBJECTIVES: To identify the occurrence and the causes of platelet refractoriness in oncohematologic patients. INTRODUCTION: Platelet refractoriness (unsatisfactory post-transfusion platelet increment) is a severe problem that impairs the treatment of oncohematologic patients and is not routinely investigated in most Brazilian services. METHODS: Forty-four episodes of platelet concentrate transfusion were evaluated in 16 patients according to the following parameters: corrected count increment, clinical conditions and detection of anti-platelet antibodies by the platelet immunofluorescence test (PIFT) and panel reactive antibodies against human leukocyte antigen class I (PRA-HLA). RESULTS: Of the 16 patients evaluated (median age: 53 years), nine (56%) were women, seven of them with a history of pregnancy. An unsatisfactory increment was observed in 43% of the transfusion events, being more frequent in transfusions of random platelet concentrates (54%). Platelet refractoriness was confirmed in three patients (19%), who presented immunologic and non-immunologic causes. Alloantibodies were identified in eight patients (50%) by the PIFT and in three (19%) by the PRA-HLA. Among alloimmunized patients, nine (64%) had a history of transfusion, and three as a result of pregnancy (43%). Of the former, two were refractory (29%). No significant differences were observed, probably as a result of the small sample size. CONCLUSION: The high rate of unsatisfactory platelet increment, refractoriness and alloimmunization observed support the need to set up protocols for the investigation of this complication in all chronically transfused patients, a fundamental requirement for the guarantee of adequate management. PMID:21437433

Platelet participation in the pathogenesis of dermonecrosis induced by Loxosceles gaucho venom.

PubMed

Tavares, F L; Peichoto, M E; Marcelino, J R; Barbaro, K C; Cirillo, M C; Santoro, M L; Sano-Martins, I S

2016-06-01

Loxosceles gaucho spider venom induces in vitro platelet activation and marked thrombocytopenia in rabbits. Herein, we investigated the involvement of platelets in the development of the dermonecrosis induced by L. gaucho venom, using thrombocytopenic rabbits as a model. L. gaucho venom evoked a drop in platelet and neutrophil counts 4 h after venom injection. Ecchymotic areas at the site of venom inoculation were noticed as soon as 4 h in thrombocytopenic animals but not in animals with initial normal platelet counts. After 5 days, areas of scars in thrombocytopenic animals were also larger, evidencing the marked development of lesions in the condition of thrombocytopenia. Histologically, local hemorrhage, collagen fiber disorganization, and edema were more severe in thrombocytopenic animals. Leukocyte infiltration, predominantly due to polymorphonuclears, was observed in the presence or not of thrombocytopenia. Thrombus formation was demonstrated by immunohistochemistry at the microvasculature, and it occurred even under marked thrombocytopenia. Taken together, platelets have an important role in minimizing not only the hemorrhagic phenomena but also the inflammatory and wound-healing processes, suggesting that cutaneous loxoscelism may be aggravated under thrombocytopenic conditions. © The Author(s) 2015.

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

PubMed Central

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

2014-01-01

This is the protocol for a review and there is no abstract. The objectives are as follows: 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 patients with haematological disorders after chemotherapy with or without stem cell transplantation. PMID:25722651

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

PubMed

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 < 0.0001). PFP- and PPP-, but more significantly PRP-CLT, were positively correlated with age and plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p < 0.001). All these CLT assays had no significant correlations with 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

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

PubMed

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

Heterogeneity of antibody response to human platelet transfusion.

PubMed Central

Wu, K K; Thompson, J S; Koepke, J A; Hoak, J C; Flink, R

1976-01-01

To study the antibody response to human platelet transfusions, nine thrombocytopenia patients with bone marrow failure were given 6 U (3X10(11)) of random platelet concentrates twice a week. Before transfusion, none of the patients had preexisting antibodies detectable with lymphocytotoxicity, platelet aggregation, or capillary leukoagglutination techniques. After receiving 18-78 U of platelets, they became refractory to further transfusions of random platelets and alloantibodies were detectable. Two patterns of antibody response could be identified. In three patients, the sera were not lymphocytotoxic with a panel of standard cells in which all the known HLA antigens in the first and second series were represented at least once. Yet, they caused platelet aggregation with 30, 24, and 60%, respectively, of a donor population studied. The aggregating activities were inhibited by antihuman IgG but not by antihuman IgA or antihuman IgM antiserum. The aggregating antibodies could be absorbed out with donor platelets but not lymphocytes or granulocytes. Antibodies from two of these patients aggregated platelets of their respective siblings matched for both HLA haplotypes. Transfusion of platelets from these two siblings did not increase the platelet count while platelets obtained from aggregation-negative donors did. The sera from the remaining six patients were lymphocytotoxic with 15-100% of the panel of standard cells. They also had aggregating antibodies, which could be absorbed out by both platelets and lymphocytes, suggesting that they were HLA antibodies. These data suggest that the development of platelet-specific antibodies may play an important role in the immunological rejection of isologous platelets, and should be considered in the selection of donors for patients who are refractory to platelets from random donors. PMID:956376

Long-term increases in lymphocytes and platelets in human T-lymphotropic virus type II infection

PubMed Central

Bartman, Melissa T.; Kaidarova, Zhanna; Hirschkorn, Dale; Sacher, Ronald A.; Fridey, Joy; Garratty, George; Gibble, Joan; Smith, James W.; Newman, Bruce; Yeo, Anthony E.

2008-01-01

Human T-lymphotropic viruses types I and II (HTLV-I and HTLV-II) cause chronic infections of T lymphocytes that may lead to leukemia and myelopathy. However, their long-term effects on blood counts and hematopoiesis are poorly understood. We followed 151 HTLV-I–seropositive, 387 HTLV-II–seropositive, and 799 HTLV-seronegative former blood donors from 5 U.S. blood centers for a median of 14.0 years. Complete blood counts were performed every 2 years. Multivariable repeated measures analyses were conducted to evaluate the independent effect of HTLV infection and potential confounders on 9 hematologic measurements. Participants with HTLV-II had significant (P < .05) increases in their adjusted lymphocyte counts (+126 cells/mm3; approximately +7%), hemoglobin (+2 g/L [+0.2 g/dL]) and mean corpuscular volume (MCV; 1.0 fL) compared with seronegative participants. Participants with HTLV-I and HTLV-II had higher adjusted platelet counts (+16 544 and +21 657 cells/mm3; P < .05) than seronegatives. Among all participants, time led to decreases in platelet count and lymphocyte counts, and to increases in MCV and monocytes. Sex, race, smoking, and alcohol consumption all had significant effects on blood counts. The HTLV-II effect on lymphocytes is novel and may be related to viral transactivation or immune response. HTLV-I and HTLV-II associations with higher platelet counts suggest viral effects on hematopoietic growth factors or cytokines. PMID:18755983

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

PubMed

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, p<0.001), TGF-β1 (r=0.85, p<0.001), VEGF (r=0.46, p<0.01) and PDGF-bb (r=0.9, p<0.001). Our results demonstrate that selected growth factors are present in the platelet-rich plasma of minipigs which might thus serve as a source of autologous growth factors.

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

PubMed

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.

Growth factor and pro-inflammatory cytokine contents in platelet-rich plasma (PRP), plasma rich in growth factors (PRGF), advanced platelet-rich fibrin (A-PRF), and concentrated growth factors (CGF).

PubMed

Masuki, Hideo; Okudera, Toshimitsu; Watanebe, Taisuke; Suzuki, Masashi; Nishiyama, Kazuhiko; Okudera, Hajime; Nakata, Koh; Uematsu, Kohya; Su, Chen-Yao; Kawase, Tomoyuki

2016-12-01

The development of platelet-rich fibrin (PRF) drastically simplified the preparation procedure of platelet-concentrated biomaterials, such as platelet-rich plasma (PRP), and facilitated their clinical application. PRF's clinical effectiveness has often been demonstrated in pre-clinical and clinical studies; however, it is still controversial whether growth factors are significantly concentrated in PRF preparations to facilitate wound healing and tissue regeneration. To address this matter, we performed a comparative study of growth factor contents in PRP and its derivatives, such as advanced PRF (A-PRF) and concentrated growth factors (CGF). PRP and its derivatives were prepared from the same peripheral blood samples collected from healthy donors. A-PRF and CGF preparations were homogenized and centrifuged to produce extracts. Platelet and white blood cell counts in A-PRF and CGF preparations were determined by subtracting those counts in red blood cell fractions, supernatant acellular serum fractions, and A-PRF/CGF exudate fractions from those counts of whole blood samples. Concentrations of growth factors (TGF-β1, PDGF-BB, VEGF) and pro-inflammatory cytokines (IL-1β, IL-6) were determined using ELISA kits. Compared to PRP preparations, both A-PRF and CGF extracts contained compatible or higher levels of platelets and platelet-derived growth factors. In a cell proliferation assay, both A-PRF and CGF extracts significantly stimulated the proliferation of human periosteal cells without significant reduction at higher doses. These data clearly demonstrate that both A-PRF and CGF preparations contain significant amounts of growth factors capable of stimulating periosteal cell proliferation, suggesting that A-PRF and CGF preparations function not only as a scaffolding material but also as a reservoir to deliver certain growth factors at the site of application.

The association of platelets with failed patent ductus arteriosus closure after a primary course of indomethacin or ibuprofen: a systematic review and meta-analysis.

PubMed

Mitra, Souvik; Chan, Anthony K; Paes, Bosco A

2017-01-01

To conduct a meta-analysis of the association of platelet counts and pharmacotherapeutic failure in preterms with a patent ductus arteriosus (PDA). MEDLINE, Embase, Science Citation Index, abstracts and conference proceedings were searched, and principal authors contacted. Included studies reported indomethacin or ibuprofen use for PDA closure, compared a group which failed treatment versus a group which did not and reported the association between platelet counts and indomethacin or ibuprofen failure. Two reviewers independently screened results and assessed methodological quality using the Newcastle-Ottawa Scale. Results are expressed as mean difference in platelet counts and summary odds ratios (OR) using a random effects model. 1105 relevant studies were identified; eight involving 1087 preterms were included. Platelet counts were significantly lower in infants who failed pharmacotherapy (Meandifference:-30.88 × 10 9 /L; 95% CI:-45.69 × 10 9 ,-16.07 × 10 9 /L; I2 = 24%; p heterogeneity  =   0.24). Similar results were obtained based on either pharmacotherapeutic agent. Treatment failure was also significantly associated with pre-treatment thrombocytopenia (summary OR:1.75; 95% CI:1.23-2.49, I2 = 36%, p heterogeneity  =   0.20). Platelet counts are significantly lower in preterms who fail primary treatment for PDA. Pre-treatment thrombocytopenia is associated with higher odds of failure. Further cohort studies reporting platelet counts in prostaglandin inhibitor failure are needed for meta-analyses to firmly establish or refute a stronger association.

Platelets Cellular and Functional Characteristics in Patients with Atrial Fibrillation: A Comprehensive Meta-Analysis and Systematic Review

PubMed Central

Weymann, Alexander; Ali-Hasan-Al-Saegh, Sadeq; Sabashnikov, Anton; Popov, Aron-Frederik; Mirhosseini, Seyed Jalil; Nombela-Franco, Luis; Testa, Luca; Lotfaliani, Mohammadreza; Zeriouh, Mohamed; Liu, Tong; Dehghan, Hamidreza; Yavuz, Senol; de Oliveira Sá, Michel Pompeu Barros; Baker, William L.; Jang, Jae-Sik; Gong, Mengqi; Benedetto, Umberto; Dohmen, Pascal M.; D’Ascenzo, Fabrizio; Deshmukh, Abhishek J.; Biondi-Zoccai, Giuseppe; Calkins, Hugh; Stone, Gregg W.

2017-01-01

Background This systematic review with meta-analysis aimed to determine the strength of evidence for evaluating the association of platelet cellular and functional characteristics including platelet count (PC), MPV, platelet distribution width (PDW), platelet factor 4, beta thromboglobulin (BTG), and p-selectin with the occurrence of atrial fibrillation (AF) and consequent stroke. Material/Methods We conducted a meta-analysis of observational studies evaluating platelet characteristics in patients with paroxysmal, persistent and permanent atrial fibrillations. A comprehensive subgroup analysis was performed to explore potential sources of heterogeneity. Results Literature search of all major databases retrieved 1,676 studies. After screening, a total of 73 studies were identified. Pooled analysis showed significant differences in PC (weighted mean difference (WMD)=−26.93 and p<0.001), MPV (WMD=0.61 and p<0.001), PDW (WMD=−0.22 and p=0.002), BTG (WMD=24.69 and p<0.001), PF4 (WMD=4.59 and p<0.001), and p-selectin (WMD=4.90 and p<0.001). Conclusions Platelets play a critical and precipitating role in the occurrence of AF. Whereas distribution width of platelets as well as factors of platelet activity was significantly greater in AF patients compared to SR patients, platelet count was significantly lower in AF patients. PMID:28302997

Levofloxacin-Induced Acute Immune-Mediated Thrombocytopenia of Rapid-Onset.

PubMed

Shih, Andrew W; Lam, Andy S; Warkentin, Theodore E

2018-04-01

Drug-induced immune thrombocytopenia (D-ITP) typically occurs after the patient has been receiving the implicated drug for at least 1 week, due to newly forming drug-dependent antibodies ("typical-onset" D-ITP). A "rapid-onset" form of D-ITP can occur when previous sensitization has occurred, where antibodies have thus already been formed, and a precipitous platelet count fall occurs upon reexposure. Typical-onset D-ITP has been reported after levofloxacin, but the rapid-onset form with a well-documented previous exposure has not been described. We report a 76-year-old male treated with levofloxacin for acute exacerbation of chronic obstructive pulmonary disease. After a single 750 mg oral dose of levofloxacin, his platelet count fell from 187 to 5 × 10 9 /L (nadir) over 4 days. Other causes of thrombocytopenia were ruled out. He had received a previous course of levofloxacin 6 months earlier. Discontinuation of levofloxacin and treatment with intravenous immunoglobulin and dexamethasone resulted in platelet count recovery. Levofloxacin-dependent antibodies were not detectable, consistent with the known low sensitivity of laboratory tests for drug-dependent antibodies, presumably indicating antibodies against levofloxacin metabolites, as is indirectly supported by the abrupt but relatively slow platelet count decline observed. This case illustrates a rapid-onset presentation of levofloxacin-induced D-ITP in the setting of previous drug exposure.

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

PubMed

Pieters, Marlien; Barnard, Sunelle A; Loots, Du Toit; Rijken, Dingeman C

2017-01-01

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 through release of

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

PubMed

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 < 0.01), but a higher MPV (p = 0.03) and IPF (p < 0.01). IPC was similar for the two groups (p = 0.74). PRP had significantly lower MPV (p < 0.01) and significantly higher platelet count and IPC (both p-values <0.03) when compared with whole blood. IPF was similar for PRP and whole blood (p = 0.18). COX-1 expression was 10 times higher and COX-2 expression was 50% higher in PRP than in whole blood (p COX-1 < 0.01, p COX-2 < 0.01). Platelet COX-1 expression was higher in ITP patients than healthy individuals using whole blood (p COX-1 < 0.01) and PRP, though this was nonsignificant in PRP (p COX-1 = 0.17). In ITP patients, positive correlations were found between platelet turnover and COX-1 expression (all p-values <0.01, rho = 0.80-0.94), whereas healthy individuals showed significant though weaker

Risk factors for platelet transfusion in glioblastoma surgery.

PubMed

Lagman, Carlito; Sheppard, John P; Romiyo, Prasanth; Nguyen, Thien; Prashant, Giyarpuram N; Nagasawa, Daniel T; Liau, Linda M; Yang, Isaac

2018-04-01

The objectives of this study are to identify risk factors for and to evaluate clinical outcomes of platelet transfusion in glioblastoma surgery. The medical records of adult patients who underwent craniotomy for glioblastoma resection at a single academic medical center were retrospectively reviewed. We stratified patients into 2 groups: those who were transfused at least 1 unit of platelets intraoperatively or postoperatively (no more than 7 days after surgery), and those who were not transfused with platelets. Through the use of a 1:3 matched cohort analysis, we compared complications, length of stay, discharge disposition, and mortality, across groups. One hundred and five consecutive adult patients were included in this study. Thirteen patients (12.38%) received platelet transfusions. Prior antiplatelet therapy (odds ratio [OR] 8.21, 95% confidence interval [CI]: 2.36-28.58), preoperative platelet count less than 200,000 cells/µL (OR 8.46, 95% CI: 2.16-33.22), and longer operative times (OR 1.73, 95% CI: 1.10-2.72) were significant risk factors for platelet transfusion. There were no significant differences in the outcomes of interest in the matched cohort analysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2017-01-01

Background 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. Materials and methods 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). Results 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. Discussion 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. PMID:27177410

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

PubMed

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.

Inhibitory effects of ethyl pyruvate on platelet aggregation and phosphatidylserine exposure.

PubMed

Li, Wenjin; Yang, Xinyu; Peng, Minyuan; Li, Can; Mu, Guangfu; Chen, Fangping

2017-06-03

Ethyl pyruvate (EP) is a stable lipophilic pyruvate derivative. Studies demonstrated that EP shows potent anti-oxidation, anti-inflammatory and anti-coagulant effects. Inflammation and coagulation are closely interacted with platelet activation. However, it is unclear whether EP has anti-platelet effects. Therefore, we investigated the anti-platelet effect of EP in this study in vitro. We found that EP inhibited agonists induced platelets aggregation, ATP release and adhesion to collagen. Flow cytometric analysis revealed that EP inhibited agonist induced platelets PAC-1 binding, as well as P-selectin and CD40L expression. The underlying mechanism of action may involve the inhibition of platelet PI3K/Akt and Protein Kinase C (PKC) signaling pathways. Additionally, EP dose dependently inhibited platelet PS exposure induced by high concentration thrombin. Lactate dehydrogenase (LDH) activity assay and mice platelet count implied that EP may have no toxic effect on platelets. Therefore, we are the first to report that EP has potent anti-platelet activity and attenuates platelet PS exposure in vitro, suggesting that the inhibitory effects of EP on platelets may also play important roles in improvement of inflammation and coagulation disorder in related animal models. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed

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 (p<0.01, Wilcoxon signed-rank test). Aspirin and placebo treatment were associated with elevated P-selectin expression, platelet-monocyte aggregation and reduced CD42b expression (p<0.05, Wilcoxon 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 (p<0.05, Wilcoxon 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.

Improvement in platelet count after 3rd-line and 4th-line eradication therapy for Helicobacter pylori in patients with immune thrombocytopenia.

PubMed

Jomen, Wataru; Sato, Takashi; Maesawa, Chihaya

2017-01-01

Case 1: A 78-year-old woman was diagnosed with H. pylori positive gastritis at a previous hospital in April 2012 and received 3rd-line H. pylori eradication therapy, which ended in failure. She was referred to our department due to oral hemorrhage, petechiae involving all four extremities, and thrombocytopenia in January 2016. She was hospitalized with a diagnosis of ITP and received inpatient treatment. While receiving outpatient prednisolone (PSL) treatment, we administered 4th-line eradication therapy in March. Her platelet levels have since returned to normal, and PSL treatment has been discontinued. She is currently followed without treatment. Case 2: A 65-year-old woman was diagnosed with ITP at a previous hospital in June 2013 and received 2nd-line eradication therapy, which ended in failure. Thereafter, PSL treatment was continued but she was later referred to our department in March 2016. Since 3rd-line eradication therapy was successful, her platelet count normalized and PSL treatment has been discontinued. She is currently followed without treatment. Based on our observations in these two cases, third-line H. pylori eradication therapy is potentially effective in ITP patients.

Ifosfamide, cisplatin, and etoposide (ICE) in the treatment of advanced non-small cell lung cancer.

PubMed

Shepherd, F A; Evans, W K; Goss, P E; Latreille, J; Logan, D; Maroun, J; Stewart, D; Warner, E; Paul, K

1992-02-01

Forty-seven previously untreated patients with histologically or cytologically proven non-small cell lung cancer were treated with ICE (ifosfamide/cisplatin/etoposide). Patients received ifosfamide 4 g/m2 with mesna uroprotection on day 1, and cisplatin 25 mg/m2/d and etoposide 100 mg/m2/d on days 1, 2, and 3; courses were repeated every 28 days. Premedication with prochlorperazine, dexamethasone, and high-dose metoclopramide was given to prevent nausea; lorazepam was added on days 2 and 3 only. Thirty-four men and 13 women (median age, 60 years) received a total of 146 treatment cycles. One patient had stage IIIA disease, seven had IIIB disease, and 39 had hematogenous metastases. Forty-six patients were evaluable for response and toxicity. One patient suffered a myocardial infarction on day 7 that was judged unrelated to treatment. Two patients suffered early death from toxicity and have been classified as nonresponders. Three patients achieved complete response (median, 42+ weeks) and 14 patients achieved partial response (median, 29+ weeks; range, 10 to 82+), for an overall response rate of 37% (95% confidence limits, 23% to 51%). The median survival of the entire group is 26 weeks (1 to 82+). The median nadir granulocyte count was 0.275 x 10(9)/L (range, 0 to 2.3 x 10(9)/L), and there were 14 episodes (in 11 patients) or neutropenia-associated fever, one of which resulted in death. Seven of these patients had not had the required protocol dose reduction for nadir neutrophil count in the preceding cycle. The median nadir platelet count was 120 x 10(9)/L (range, 13 to 385 x 10(9)/L), and three patients required platelet transfusions. Eleven patients had RBC transfusions. Only ten patients had grade 2 gastrointestinal toxicity. Five patients had microscopic hematuria, and one patient had central nervous system toxicity.

Complement Activation on Platelets Correlates with a Decrease in Circulating Immature Platelets in Patients with Immune Thrombocytopenic Purpura

PubMed Central

Peerschke, Ellinor I.B.; Andemariam, Biree; Yin, Wei; Bussel, James B.

2010-01-01

The role of the complement system in immune thrombocytopenic purpura (ITP) is not well defined. We examined plasma from 79 patients with ITP, 50 healthy volunteers, and 25 patients with non-immune mediated thrombocytopenia, to investigate their complement activation/fixation capacity (CAC) on immobilized heterologous platelets. Enhanced CAC was found in 46 plasma samples (59%) from patients with ITP, but no samples from patients with non-immune mediated thrombocytopenia. Plasma from healthy volunteers was used for comparison. In patients with ITP, an enhanced plasma CAC was associated with a decreased circulating absolute immature platelet fraction (A-IPF) (<15 × 109/L) (p = 0.027) and thrombocytopenia (platelet count less than 100K/μl) (p= 0.024). The positive predictive value of an enhanced CAC for a low A-IPF was 93%, with a specificity of 77%. The specificity and positive predictive values increased to 100% when plasma CAC was defined strictly by enhanced C1q and/or C4d deposition on test platelets. Although no statistically significant correlation emerged between CAC and response to different pharmacologic therapies, an enhanced response to splenectomy was noted (p <0.063). Thus, complement fixation may contribute to the thrombocytopenia of ITP by enhancing clearance of opsonized platelets from the circulation, and/or directly damaging platelets and megakaryocytes. PMID:19925495

Effect of Physical Exercise on Platelet Reactivity in Patients with Dual Antiplatelet Therapy.

PubMed

Brunner, Stefan; Rizas, Konstantinos; Hamm, Wolfgang; Mehr, Michael; Lackermair, Korbinian

2018-06-14

It is known that physical exercise may increase platelet activity. However, the effect of exercise on platelet reactivity in patients on dual antiplatelet therapy has not been investigated yet. In our study, 21 patients with coronary artery disease on dual antiplatelet therapy and 10 controls were enrolled. We performed an exercise test using a cycle ergometer and determined the adenosine diphosphate-induced platelet reactivity before and immediately after exercise testing. Additionally, we analysed maximal exercise capacity and an electrocardiogram. Further, we assessed chromogranin A and P-selectin levels and platelet counts. © Georg Thieme Verlag KG Stuttgart · New York.

Life-threatening haematuria caused by vancomycin-induced thrombocytopenia

PubMed Central

Lobo, Niyati; Ejiofor, Kandi; Thurairaja, Ramesh; Khan, Muhammad Shamim

2015-01-01

Thrombocytopenia is a rare side effect of vancomycin, an antibiotic that is often used to treat Gram-positive bacterial infections. A 67-year-old man developed bilateral pulmonary emboli and hospital-acquired pneumonia following left ureteric reimplantation. He was anticoagulated with rivaroxaban and started on intravenous vancomycin and gentamicin for treatment of pneumonia. After five doses of vancomycin, his platelet count dropped to a nadir of 0×109/L (baseline: 314×109/L) manifesting as visible heavy haematuria and haemodynamic instability due to excessive blood loss. Reversal of the thrombocytopenia was achieved with intravenous immunoglobulin, methylprednisolone and continuous platelet transfusions. PMID:25716041

Immature platelet fraction (IPF) as a predictive value for thrombopoietic recovery after allogeneic stem cell transplantation.

PubMed

Sakuragi, Mikiko; Hayashi, Satoru; Maruyama, Miho; Kiyokawa, Tomoko; Nagamine, Keisuke; Fujita, Jiro; Maeda, Tetsuo; Kato, Hisashi; Kashiwagi, Hirokazu; Kanakura, Yuzuru; Tomiyama, Yoshiaki

2018-03-01

We consecutively examined the utility of measurements of percentage of immature platelet fraction (IPF%) and absolute IPF number (A-IPF) in predicting thrombopoietic recovery in 15 adult patients who underwent allogeneic hematopoietic stem cell transplantation (allo-SCT). Four patients were excluded from the evaluation due to insufficient data. Platelet count and IPF were measured by Sysmex XN-1000 (XN), a newer generation analyzer. First, we confirmed that platelet count measured by XN was more accurate than by XE-2100 (XE). IPF measurement was effective to predict the recovery in 7 of the 11 patients examined. Moreover, IPF measurement, especially IPF% measurement, suggested accelerated platelet turnover in two patients who failed to achieve platelet recovery by day 60. In addition to IPF%, A-IPF showed a complementary role on the prediction of thrombopoietic recovery. The increase in IPF% was only transient, while A-IPF values showed lasting increase during platelet recovery. In two patients (cases 6 and 7) an increase in A-IPF, but not in IPF%, was observed during platelet recovery. Our data suggest that IPF% and A-IPF measured by XN are useful for the prediction of thrombopoietic recovery and the assessment of pathogenesis of thrombocytopenia in patients after allo-SCT.

Constraining the physical properties of Titan's empty lake basins using nadir and off-nadir Cassini RADAR backscatter

NASA Astrophysics Data System (ADS)

Michaelides, R. J.; Hayes, A. G.; Mastrogiuseppe, M.; Zebker, H. A.; Farr, T. G.; Malaska, M. J.; Poggiali, V.; Mullen, J. P.

2016-05-01

We use repeat synthetic aperture radar (SAR) observations and complementary altimetry passes acquired by the Cassini spacecraft to study the scattering properties of Titan's empty lake basins. The best-fit coefficients from fitting SAR data to a quasi-specular plus diffuse backscatter model suggest that the bright basin floors have a higher dielectric constant, but similar facet-scale rms surface facet slopes, to surrounding terrain. Waveform analysis of altimetry returns reveals that nadir backscatter returns from basin floors are greater than nadir backscatter returns from basin surroundings and have narrower pulse widths. This suggests that floor deposits are structurally distinct from their surroundings, consistent with the interpretation that some of these basins may be filled with evaporitic and/or sedimentary deposits. Basin floor deposits also express a larger diffuse component to their backscatter, which is likely due to variations in subsurface structure or an increase in roughness at the wavelength scale (Hayes, A.G. et al. [2008]. Geophys. Res. Lett. 35, 9). We generate a high-resolution altimetry radargram of the T30 altimetry pass over an empty lake basin, with which we place geometric constraints on the basin's slopes, rim heights, and depth. Finally, the importance of these backscatter observations and geometric measurements for basin formation mechanisms is briefly discussed.

Evaluation of mean platelet volume in localized scleroderma.

PubMed

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

2017-01-01

Localized scleroderma is a chronic inflammatory skin disease characterized by sclerosis of the dermis and subcutaneous tissue. Platelets play an important role in inflammation. Following activation, platelets rapidly release numerous mediators and cytokines, which contribute to inflammation. To evaluate whether there was any relation between localized scleroderma and platelet parameters. Forty-one patients with localized scleroderma were enrolled in the study. The control group consisted of 30 healthy subjects. The mean platelet volume level in the patient group was 9.9 ± 1.3 fl and in the control group was 7.6 ± 1.1 fl. This difference was statistically significant (p< 0.001). The plateletcrit values are minimally higher in the patient group as compared to the control group. It was statistically significant (p<0.001). There was no significant difference in the platelet counts between the two groups (p= 0.560) In the patient group, there was no significant relation between the mean platelet volume levels and clinical signs of disease (p=0.09). However, plateletcrit values are higher in generalized than localized forms of disease (p=0.01). The limited number of patients and the retrospective nature of the study were our limitations. This study suggests that platelets might play a role in the pathogenesis of scleroderma. Platelet parameters may be used as markers for evaluating disease severity and inflammatory processes. Thus, there is a need for more detailed and prospective studies.

Review of in vivo studies of dimethyl sulfoxide cryopreserved platelets.

PubMed

Slichter, Sherrill J; Jones, Melinh; Ransom, Janet; Gettinger, Irena; Jones, Mary Kay; Christoffel, Todd; Pellham, Esther; Bailey, S Lawrence; Corson, Jill; Bolgiano, Doug

2014-10-01

A literature review was conducted to assess the efficacy and safety of dimethyl sulfoxide (DMSO) cryopreserved platelets for potential military use. In vivo DMSO cryopreserved platelet studies published between 1972 and June of 2013 were reviewed. Assessed were the methods of cryopreservation, posttransfusion platelet responses, prevention or control of bleeding, and adverse events. Using the Department of Defense's preferred 6% DMSO cryopreservation method with centrifugation to remove the DMSO plasma before freezing at -65°C and no postthaw wash, mean radiolabeled platelet recoveries in 32 normal subjects were 33% ± 10% (52% ± 12% of the same subject's fresh platelet recoveries), and survivals were 7.5 ± 1.2 days (89% ± 15% of fresh platelet survivals). Using a variety of methods to freeze autologous platelets from 178 normal subjects, mean radiolabeled platelet recoveries were consistently 39% ± 9%, and survivals, 7.4 ± 1.4 days. More than 3000 cryopreserved platelet transfusions were given to 1334 patients. There were 19 hematology/oncology patient studies, and, in 9, mean 1-hour corrected count increments were 11 100 ± 3600 (range, 5700-15 800) after cryopreserved autologous platelet transfusions. In 5 studies, bleeding times improved after transfusion; in 3, there was either no improvement or a variable response. In 4 studies, there was immediate cessation of bleeding after transfusion; in 3 studies, patients being supported only with cryopreserved platelets had no bleeding. In 1 cardiopulmonary bypass study, cryopreserved platelets resulted in significantly less bleeding vs standard platelets. In 3 trauma studies, cryopreserved platelets were hemostatically effective. No significant adverse events were reported in any study. In summary, cryopreserved platelets have platelet recoveries that are about half of fresh platelets, but survivals are only minimally reduced. The platelets appear hemostatically effective and have no significant adverse events

Abnormal Whole Blood Thrombi in Humans with Inherited Platelet Receptor Defects

PubMed Central

Castellino, Francis J.; Liang, Zhong; Davis, Patrick K.; Balsara, Rashna D.; Musunuru, Harsha; Donahue, Deborah L.; Smith, Denise L.; Sandoval-Cooper, Mayra J.; Ploplis, Victoria A.; Walsh, Mark

2012-01-01

To delineate the critical features of platelets required for formation and stability of thrombi, thromboelastography and platelet aggregation measurements were employed on whole blood of normal patients and of those with Bernard-Soulier Syndrome (BSS) and Glanzmann’s Thrombasthenia (GT). We found that separation of platelet activation, as assessed by platelet aggregation, from that needed to form viscoelastic stable whole blood thrombi, occurred. In normal human blood, ristocetin and collagen aggregated platelets, but did not induce strong viscoelastic thrombi. However, ADP, arachidonic acid, thrombin, and protease-activated-receptor-1 and -4 agonists, stimulated both processes. During this study, we identified the genetic basis of a very rare double heterozygous GP1b deficiency in a BSS patient, along with a new homozygous GP1b inactivating mutation in another BSS patient. In BSS whole blood, ADP responsiveness, as measured by thrombus strength, was diminished, while ADP-induced platelet aggregation was normal. Further, the platelets of 3 additional GT patients showed very weak whole blood platelet aggregation toward the above agonists and provided whole blood thrombi of very low viscoelastic strength. These results indicate that measurements of platelet counts and platelet aggregability do not necessarily correlate with generation of stable thrombi, a potentially significant feature in patient clinical outcomes. PMID:23300803

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

PubMed

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 (P<.001). The median obtained were (normal vs pregnancy) 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.

Platelet abnormalities in adults with severe pulmonary arterial hypertension related to congenital heart defects (Eisenmenger syndrome).

PubMed

Remková, Anna; Šimková, Iveta; Valkovičová, Tatiana; Kaldarárová, Monika

2016-12-01

Patients with severe pulmonary arterial hypertension suffer from life-threatening thrombotic and bleeding complications. The aim of this study was to compare selected platelet, endothelial, and coagulation parameters in healthy volunteers and patients with severe pulmonary arterial hypertension because of congenital heart defects. The study included healthy volunteers (n = 50) and patients with cyanotic congenital heart defects classified as Eisenmenger syndrome (n = 41). We investigated platelet count, mean platelet volume, and platelet aggregation - spontaneous and induced by various concentrations of five agonists. Von Willebrand factor (vWF), fibrinogen, factor VIII and XII, plasminogen activator inhibitor, antithrombin, D-dimer, and antiphospholipid antibodies were also investigated. We found a decreased platelet count [190 (147-225) vs. 248 (205-295) 10 l, P < 0.0001], higher mean platelet volume [10.9 (10.1-12.0) vs. 10.2 (9.4-10.4) fl, P < 0.0001], and significantly decreased platelet aggregation (induced by five agonists, in various concentrations) in patients with Eisenmenger syndrome compared with controls. These changes were accompanied by an increase of plasma vWF antigen [141.6 (108.9-179.1) vs. 117.4 (9.2-140.7) IU/dl, P = 0.022] and serum anti-β2-glycoprotein [2.07 (0.71-3.41) vs. 0.47 (0.18-0.99) U/ml, P < 0.0001]. Eisenmenger syndrome is accompanied by platelet abnormalities. Thrombocytopenia with increased platelet size is probably due to a higher platelet turnover associated with platelet activation. Impaired platelet aggregation can reflect specific platelet behaviour in patients with Eisenmenger syndrome. These changes can be related both to bleeding and to thrombotic events. A higher vWF antigen may be a consequence of endothelial damage in Eisenmenger syndrome, but the cause for an increase of anti-β2-glycoprotein is unknown.

Platelets and their chemokines in atherosclerosis—clinical applications

PubMed Central

von Hundelshausen, Philipp; Schmitt, Martin M. N.

2014-01-01

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 (MPV) 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 and

Does Preoperative Platelet Function Predict Bleeding in Patients Undergoing Off Pump Coronary Artery Bypass Surgery?

PubMed

Berger, Peter B; Kirchner, H Lester; Wagner, Eric S; Ismail-Sayed, Ibrahim; Yahya, Salma; Benoit, Charles; Blankenship, James C; Carter, Russell; Casale, Alfred S; Green, Sandy M; Scott, Thomas D; Skelding, Kimberly A; Woods, Edward; Henry, Yvette M

2015-06-01

We sought to examine the relationship between preoperative platelet function and perioperative bleeding in patients undergoing CABG. There are many ways to measure platelet aggregability. Little is known about their correlations with one another, or with bleeding. We prospectively studied 50 patients undergoing a first isolated off-pump CABG. Thirty-four were exposed to a thienopyridine prior to surgery; 16 were not. Preoperative platelet function was measured by VerifyNow®, TEG®, AggreGuide™, Plateletworks®, vasodilator-stimulated phosphoprotein (VASP) phosphorylation, and light transmission aggregometry. Bleeding was assessed 2 ways: drop from pre- to nadir postoperative hematocrit, and chest tube drainage. Correlation coefficients were calculated using Spearman's rank-order correlation. Mean age was 62 years. Patient characteristics and surgical details were similar between the thienopyridine-exposed and non-exposed patients. The correlation coefficients between the 4 point-of-care platelet function measurements and hematocrit change ranged from -0.2274 to 0.2882. Only Plateletworks® correlated with drop in hematocrit (r = 0.2882, P = 0.0470). The correlation coefficients between each of the 4 point-of-care platelet function tests and the chest tube drainage were also poor, ranging from -0.3073 to 0.2272. Both AggreGuide™ (r = -0.3073, P = 0.0317) and VASP (r = -0.3187, P = 0.0272) were weakly but significantly correlated with chest tube drainage. The correlation among the 4 point-of-care platelet function measurements was poor, with coefficients ranging from -0.2504 to 0.1968. We observed little correlation among 4 platelet function tests, and between those assays and perioperative bleeding defined 2 different ways. Whether any of these assays should be used to guide decision making in individual patients is unclear. © 2015, Wiley Periodicals, Inc.

Integrating Chlorophyll fapar and Nadir Photochemical Reflectance Index from EO-1/Hyperion to Predict Cornfield Daily Gross Primary Production

NASA Technical Reports Server (NTRS)

Zhang, Qingyuan; Middleton, Elizabeth M.; Cheng, Yen-Ben; Huemmrich, K. Fred; Cook, Bruce D.; Corp, Lawrence A.; Kustas, William P.; Russ, Andrew L.; Prueger, John H.; Yao, Tian

2016-01-01

The concept of light use efficiency (Epsilon) and the concept of fraction of photosynthetically active ration (PAR) absorbed for vegetation photosynthesis (PSN), i.e., fAPAR (sub PSN), have been widely utilized to estimate vegetation gross primary productivity (GPP). It has been demonstrated that the photochemical reflectance index (PRI) is empirically related to e. An experimental US Department of Agriculture (USDA) cornfield in Maryland was selected as our study field. We explored the potential of integrating fAPAR(sub chl) (defined as the fraction of PAR absorbed by chlorophyll) and nadir PRI (PRI(sub nadir)) to predict cornfield daily GPP. We acquired nadir or near-nadir EO-1/Hyperion satellite images that covered the cornfield and took nadir in-situ field spectral measurements. Those data were used to derive the PRI(sub nadir) and fAPAR (sub chl). The fAPAR (sub chl) is retrieved with the advanced radiative transfer model PROSAIL2 and the Metropolis approach, a type of Markov Chain Monte Carlo (MCMC) estimation procedure. We define chlorophyll light use efficiency Epsilon (sub chl) as the ratio of vegetation GPP as measured by eddy covariance techniques to PAR absorbed by chlorophyll (Epsilon(sub chl) = GPP/APAR (sub chl). Daily Epsilon (sub chl) retrieved with the EO-1 Hyperion images was regressed with a linear equation of PRI (sub nadir) Epsilon (sub chl) = Alpha × PRI (sub nadir) + Beta). The satellite Epsilon(sub chl- PRI (sub nadir) linear relationship for the cornfield was implemented to develop an integrated daily GPP model [GPP = (Alpha × PRI(sub nadir) + Beta) × fAPAR (sub chl) × PAR], which was evaluated with fAPAR (sub chl) and PRI (sub nadir) retrieved from field measurements. Daily GPP estimated with this fAPAR (sub chl-) PRI (nadir) integration model was strongly correlated with the observed tower in-situ daily GPP (R(sup 2) = 0.93); with a root mean square error (RMSE) of 1.71 g C mol-(sup -1) PPFD and coefficient of variation (CV) of 16

Rapid Evaluation of Platelet Function With T2 Magnetic Resonance

PubMed Central

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

Surfactants reduce platelet-bubble and platelet-platelet binding induced by in vitro air embolism.

PubMed

Eckmann, David M; Armstead, Stephen C; Mardini, Feras

2005-12-01

The effect of gas bubbles on platelet behavior is poorly characterized. The authors assessed platelet-bubble and platelet-platelet binding in platelet-rich plasma in the presence and absence of bubbles and three surface-active compounds. Platelet-rich plasma was prepared from blood drawn from 16 volunteers. Experimental groups were surfactant alone, sparging (microbubble embolization) alone, sparging with surfactant, and neither sparging nor surfactant. The surfactants were Pluronic F-127 (Molecular Probes, Eugene, OR), Perftoran (OJSC SPC Perftoran, Moscow, Russia), and Dow Corning Antifoam 1510US (Dow Corning, Midland, MI). Videomicroscopy images of specimens drawn through rectangular glass microcapillaries on an inverted microscope and Coulter counter measurements were used to assess platelet-bubble and platelet-platelet binding, respectively, in calcium-free and recalcified samples. Histamine-induced and adenosine diphosphate-induced platelet-platelet binding were measured in unsparged samples. Differences between groups were considered significant for P < 0.05 using analysis of variance and the Bonferroni correction. Sixty to 100 platelets adhered to bubbles in sparged, surfactant-free samples. With sparging and surfactant, few platelets adhered to bubbles. Numbers of platelet singlets and multimers not adherent to bubbles were different (P < 0.05) compared both with unsparged samples and sparged samples without surfactant. No significant platelet-platelet binding occurred in uncalcified, sparged samples, although 20-30 platelets adhered to bubbles. Without sparging, histamine and adenosine diphosphate provoked platelet-platelet binding with and without surfactants present. Sparging causes platelets to bind to air bubbles and each other. Surfactants added before sparging attenuate platelet-bubble and platelet-platelet binding. Surfactants may have a clinical role in attenuating gas embolism-induced platelet-bubble and platelet-platelet binding.

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

PubMed Central

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 (p<0.05), and no significant difference was found between sepsis and SIRS groups in terms of MPV and MPV/PLT ratio (p>0.05). 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

The Small GTPase Rif Is Dispensable for Platelet Filopodia Generation in Mice

PubMed Central

Goggs, Robert; Savage, Joshua S.; Mellor, Harry; Poole, Alastair W.

2013-01-01

Background Formation of filopodia and other shape change events are vital for platelet hemostatic function. The mechanisms regulating filopodia formation by platelets are incompletely understood however. In particular the small GTPase responsible for initiating filopodia formation by platelets remains elusive. The canonical pathway involving Cdc42 is not essential for filopodia formation in mouse platelets. The small GTPase Rif (RhoF) provides an alternative route to filopodia generation in other cell types and is expressed in both human and mouse platelets. Hypothesis/Objective We hypothesized that Rif might be responsible for generating filopodia by platelets and generated a novel knockout mouse model to investigate the functional role of Rif in platelets. Methodology/Principal Findings Constitutive RhoF−/− mice are viable and have normal platelet, leukocyte and erythrocyte counts and indices. RhoF−/− platelets form filopodia and spread normally on various agonist surfaces in static conditions and under arterial shear. In addition, RhoF−/− platelets have normal actin dynamics, are able to activate and aggregate normally and secrete from alpha and dense granules in response to collagen related peptide and thrombin stimulation. Conclusions The small GTPase Rif does not appear to be critical for platelet function in mice. Functional overlap between Rif and other small GTPases may be responsible for the non-essential role of Rif in platelets. PMID:23359340

Intratumoral consumption of indium-111-labeled platelets in a child with splenic hemangioma and thrombocytopenia.

PubMed

Pampin, C; Devillers, A; Treguier, C; Fremond, B; Moisan, A; Goasguen, J; Le Gall, E

2000-01-01

The authors report Kasabach-Merritt syndrome (KMS) in a patient with thrombocytopenia and splenic hemangioma. A 13-month-old boy with a history of anemia, thrombocytopenia, and abdominal mass was admitted to the hospital. The scintigraphic studies showed that a large mass contiguous to the spleen was responsible for the platelet uptake. After partial splenectomy, the platelet count returned to normal. This report of KMS in a child with splenic hemangioma suggests that the scintigraphic studies are mandatory to confirm diagnosis. Indium-111-labeled platelets are useful in identifying hemangiomatous sequestration of platelets in patients with thrombocytopenia.

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

PubMed

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.

Large off-nadir scan angle of airborne LiDAR can severely affect the estimates of forest structure metrics

NASA Astrophysics Data System (ADS)

Liu, Jing; Skidmore, Andrew K.; Jones, Simon; Wang, Tiejun; Heurich, Marco; Zhu, Xi; Shi, Yifang

2018-02-01

Gap fraction (Pgap) and vertical gap fraction profile (vertical Pgap profile) are important forest structural metrics. Accurate estimation of Pgap and vertical Pgap profile is therefore critical for many ecological applications, including leaf area index (LAI) mapping, LAI profile estimation and wildlife habitat modelling. Although many studies estimated Pgap and vertical Pgap profile from airborne LiDAR data, the scan angle was often overlooked and a nadir view assumed. However, the scan angle can be off-nadir and highly variable in the same flight strip or across different flight strips. In this research, the impact of off-nadir scan angle on Pgap and vertical Pgap profile was evaluated, for several forest types. Airborne LiDAR data from nadir (0°∼7°), small off-nadir (7°∼23°), and large off-nadir (23°∼38°) directions were used to calculate both Pgap and vertical Pgap profile. Digital hemispherical photographs (DHP) acquired during fieldwork were used as references for validation. Our results show that angular Pgap from airborne LiDAR correlates well with angular Pgap from DHP (R2 = 0.74, 0.87, and 0.67 for nadir, small off-nadir and large off-nadir direction). But underestimation of Pgap from LiDAR amplifies at large off-nadir scan angle. By comparing Pgap and vertical Pgap profiles retrieved from different directions, it is shown that scan angle impact on Pgap and vertical Pgap profile differs amongst different forest types. The difference is likely to be caused by different leaf angle distribution and canopy architecture in these forest types. Statistical results demonstrate that the scan angle impact is more severe for plots with discontinuous or sparse canopies. These include coniferous plots, and deciduous or mixed plots with between-crown gaps. In these discontinuous plots, Pgap and vertical Pgap profiles are maximum when observed from nadir direction, and then rapidly decrease with increasing scan angle. The results of this research have many

Blood platelet kinetics and platelet transfusion.

PubMed

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.

Short-Term Storage of Platelet-Rich Plasma at Room Temperature Does Not Affect Growth Factor or Catabolic Cytokine Concentration.

PubMed

Wilson, Brooke H; Cole, Brian J; Goodale, Margaret B; Fortier, Lisa A

2018-04-01

The aim of this study was to provide clinical recommendations about the use of platelet-rich plasma (PRP) that was subjected to short-term storage at room temperature. We determined bioactive growth factor and cytokine concentrations as indicators of platelet and white blood cell degranulation in blood and PRP. Additionally, this study sought to validate the use of manual, direct smear analysis as an alternative to automated methods for platelet quantification in PRP. Blood was used to generate low-leukocyte PRP (Llo PRP) or high-leukocyte PRP (Lhi PRP). Blood was either processed immediately or kept at room temperature for 2 or 4 hours prior to generation of PRP, which was then held at room temperature for 0, 1, 2, or 4 hours. Subsequently, bioactive transforming growth factor beta-1 and matrix metalloproteinase-9 were measured by ELISA (enzyme-linked immunosorbent assay). Manual and automated platelet counts were performed on all blood and PRP samples. There were no differences in growth factor or cytokine concentration when blood or Llo PRP or Lhi PRP was retained at room temperature for up to 4 hours. Manual, direct smear analysis for platelet quantification was not different from the use of automated machine counting for PRP samples, but in the starting blood samples, manual platelet counts were significantly higher than those generated using automated technology. When there is a delay of up to 4 hours in the generation of PRP from blood or in the application of PRP to the patient, bioactive growth factor and cytokine concentrations remain stable in both blood and PRP. A manual direct counting method is a simple, cost-effective, and valid method to measure the contents of the PRP product being delivered to the patient.

Cholesterol efflux in megakaryocyte progenitors suppresses platelet production and thrombocytosis

PubMed Central

Murphy, Andrew J.; Bijl, Nora; Yvan-Charvet, Laurent; Welch, Carrie B.; Bhagwat, Neha; Reheman, Adili; Wang, Yiming; Shaw, James A.; Levine, Ross L.; Ni, Heyu; Tall, Alan R.; Wang, Nan

2013-01-01

Platelets play a key role in atherogenesis and its complications. Both hypercholesterolemia and increased platelet production promote athero-thrombosis; however, a potential link between altered cholesterol homeostasis and platelet production has not been explored. Transplantation of bone marrow (BM) deficient in ABCG4, a transporter of unknown function, into Ldlr−/− mice resulted in thrombocytosis, accelerated thrombosis and atherosclerosis. While not detected in lesions, Abcg4 was highly expressed in BM megakaryocyte progenitors (MkP). Abcg4−/− MkPs displayed defective cholesterol efflux to HDL, increased cell surface levels of thrombopoietin (TPO) receptor (c-MPL) and enhanced proliferation. This appeared to reflect disruption of the negative feedback regulation of c-MPL levels and signaling by E3 ligase c-CBL and cholesterol-sensing LYN kinase. HDL infusions reduced platelet counts in Ldlr−/− mice and in a mouse model of myeloproliferative neoplasm, in a completely ABCG4-dependent fashion. HDL infusions may offer a novel approach to reducing athero-thrombotic events associated with increased platelet production. PMID:23584088

TES/Aura L2 Ozone (O3) Nadir V6 (TL2O3NS)

Atmospheric Science Data Center

2018-01-22

TES/Aura L2 Ozone (O3) Nadir (TL2O3NS) News:  TES News Join ... Project Title:  TES Discipline:  Tropospheric Composition Version:  V6 Level:  L2 Platform:  TES/Aura L2 Ozone Spatial Coverage:  5.3 x 8.5 km nadir ...

TES/Aura L2 Ozone (O3) Nadir V6 (TL2O3N)

Atmospheric Science Data Center

2018-01-18

TES/Aura L2 Ozone (O3) Nadir (TL2O3N) News:  TES News Join ... Project Title:  TES Discipline:  Tropospheric Composition Version:  V6 Level:  L2 Platform:  TES/Aura L2 Ozone Spatial Coverage:  5.3 x 8.5 km nadir ...

Correlation of pretreatment clinical parameters and PSA nadir after high-intensity focused ultrasound (HIFU) for localised prostate cancer.

PubMed

Ganzer, Roman; Bründl, Johannes; Koch, Daniel; Wieland, Wolf F; Burger, Maximilian; Blana, Andreas

2015-01-01

To determine which pretreatment clinical parameters were predictive of a low prostate-specific antigen (PSA) nadir following high-intensity focused ultrasound (HIFU) treatment. Retrospective study of patients with clinically localised prostate cancer undergoing HIFU at a single centre between December 1997 and September 2009. Whole-gland treatment was applied. Patients also included if they had previously undergone transurethral resection of the prostate (TURP). TURP was also conducted simultaneously to HIFU. Biochemical failure based on Phoenix definition (PSA nadir + 2). Univariate and multivariate analysis of pretreatment clinical parameters conducted to assess those factors predictive of a PSA nadir ≤0.2 and >0.2 ng/ml. Mean (SD) follow-up was 6.2 (2.8) years; median (range) was 6.3 (1.1-12.2) years. Kaplan-Meier estimate of biochemical disease-free survival rate at 8 years was 83 and 48 % for patients achieving a PSA nadir of ≤0.2 and >0.2 ng/ml, respectively. Prostate volume and incidental finding of cancer were significant predictors of low PSA nadir (≤0.2 ng/ml). Prostate volume and incidental finding of cancer could be predictors for oncologic success of HIFU based on post-treatment PSA nadir.

TES/Aura L2 Ammonia (NH3) Nadir V6 (TL2NH3N)

Atmospheric Science Data Center

2018-01-18

TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3N) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 x 8.5 km nadir ... Contact User Services Parameters:  Ammonia Legacy:  Retired data product , click here for ...

TES/Aura L2 Ammonia (NH3) Nadir V6 (TL2NH3NS)

Atmospheric Science Data Center

2018-01-22

TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3NS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 x 8.5 km nadir ... Contact ASDC User Services Parameters:  Ammonia Legacy:  Retired data product , click here for ...

[The oxidative stress in platelets of patients with ovary cancer as observed at chemotherapy].

PubMed

Zubrikhina, G N; Davydova, T V; Kormosh, N G; Gorozhanskaia, E G

2004-12-01

Disorders in the main chains of platelet antioxidant protection were examined in 32 patients with primarily-diagnosed ovary cancer who were postoperatively receiving chemotherapy according to PC. The activity of antioxidant-protection enzymes (superoxide dismutase, catalase, glutation-S-transferase) as well as the content of malonic dialdehyde (MDA) and glutathione were examined after each course of chemotherapy. The data obtained were compared with the aggregation ability of platelets, with the content of fibrinogen and with the count of platelets. The parameters of the antioxidant system in platelets were examined for control in 30 virtually healthy women. The results denote that the oxidant stress progression in the body due to the growing tumor and aggravating because of chemodrugs deregulates the free-radical processes in platelets, which can affect their functional properties or rheological blood properties.

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

PubMed

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

New Archiving Distributed InfrastructuRe (NADIR): Status and Evolution

NASA Astrophysics Data System (ADS)

De Marco, M.; Knapic, C.; Smareglia, R.

2015-09-01

The New Archiving Distributed InfrastructuRe (NADIR) has been developed at INAF-OATs IA2 (Italian National Institute for Astrophysics - Astronomical Observatory of Trieste, Italian center of Astronomical Archives), as an evolution of the previous archiving and distribution system, used on several telescopes (LBT, TNG, Asiago, etc.) to improve performance, efficiency and reliability. At the present, NADIR system is running on LBT telescope and Vespa (Italian telescopes network for outreach) Ramella et al. (2014), and will be used on TNG, Asiago and IRA (Istituto Radio Astronomia) archives of Medicina, Noto and SRT radio telescopes Zanichelli et al. (2014) as the data models for radio data will be ready. This paper will discuss the progress status, the architectural choices and the solutions adopted, during the development and the commissioning phase of the project. A special attention will be given to the LBT case, due to some critical aspect of data flow and policies and standards compliance, adopted by the LBT organization.

Study of a Two-Step Centrifugation Protocol for Concentrating Cells and Growth Factors in Bovine Platelet-Rich Plasma

PubMed Central

Gutiérrez, Claudia M.; López, Catalina

2017-01-01

There is a lack of information about the methods used for bovine platelet-rich plasma (PRP)/platelet-rich gel (PRG) procurement, including information on platelet (PLT), white blood cell (WBC) in PRP, and growth factor release from PRG supernatants. The aims of this study were to compare and to correlate the PLT, WBC, transforming growth factor beta-1 (TGF-β1), and platelet-derived growth factor BB (PDGF-BB) concentrations in bovine whole blood, plasma, and four PRP layers and their respective PRG supernatants: A and B (obtained by a single centrifugation tube method at 720g/5 min) and C and D (obtained by a double centrifugation tube method, by using two centrifugation episodes at 720g/5 min). PLT and WBC counts were significantly higher in PRP-C, followed by whole blood, PRP-A, PRP-B, and PRP-D. TGF-β1 concentrations were significantly higher in PRG-B supernatants and its correspondent PRP-B lysate when compared to the other PRG supernatants and plasma. Supernatants from PRG-A, PRG-B, and PRG-D had equivalent TGF-β1 concentrations. PDGF-BB concentrations were not statistically different between the hemoderivatives. Significant Pearson correlations were noted between PLT counts and WBC counts (0.8) and between PLT counts and PLT distribution width (0.6). Further studies should be performed to assess the potential clinical applications of these PRPs. PMID:29214094

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

PubMed

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.

Cathepsin G-Dependent Modulation of Platelet Thrombus Formation In Vivo by Blood Neutrophils

PubMed Central

Faraday, Nauder; Schunke, Kathryn; Saleem, Sofiyan; Fu, Juan; Wang, Bing; Zhang, Jian; Morrell, Craig; Dore, Sylvain

2013-01-01

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. PMID:23940756

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

PubMed

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 < 0.05 was considered statistically significant. Our centrifugation protocol allowed us to concentrate basal 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.

Retrospective Review of Platelet Transfusion Practices during 2013 Dengue Epidemic of Delhi, India.

PubMed

Chaurasia, Rahul; Zaman, Shamsuz; Chatterjee, Kabita; Das, Bankim

2015-07-01

Dengue infection is a major public health problem. During explosive outbreaks, there is sudden surge in demands of platelet products. The present study was carried out in order to review platelet transfusion practices during the epidemic of dengue. We retrospectively reviewed the clinical details including the platelet counts and haemorrhagic tendencies of dengue patients as well as the transfusion requirements of diagnosed dengue cases admitted at our centre. A total of 1,750 random donor platelet and 114 single donor platelet units were transfused to 531 patients. 23.2% platelet transfusions were found to be inappropriate Mean dosage of platelets transfused was 2 × 10(11) platelets per patient. A total of 347 (65.3%) patients had bleeding diathesis at the time of presentation. Skin and the oropharynx were the most common bleeding sites. Major bleeding was seen in 119 (34.3%) patients, whereas 228 (65.7%) patients had minor bleeding episodes. The study emphasises the need for minimising unnecessary transfusions and for using this scarce resource judiciously, which can be achieved by strict adherence to evidence-based transfusion guidelines and regular review of the on-going transfusion practices.

The lung is a site of platelet biogenesis and a reservoir for hematopoietic progenitors

PubMed Central

Lefrançais, Emma; Ortiz-Muñoz, Guadalupe; Caudrillier, Axelle; Mallavia, Beñat; Liu, Fengchun; Sayah, David M.; Thornton, Emily E.; Headley, Mark B.; David, Tovo; Coughlin, Shaun R.; Krummel, Matthew F.; Leavitt, Andrew D.; Passegué, Emmanuelle; Looney, Mark R.

2017-01-01

Platelets are critical for hemostasis, thrombosis, and inflammatory responses1,2, yet the events leading to mature platelet production remain incompletely understood3. The bone marrow (BM) is proposed to be a major site of platelet production although indirect evidence points towards a potential pulmonary contribution to platelet biogenesis4-7. By directly imaging the lung microcirculation in mice8, we discovered that a large number of megakaryocytes (MKs) circulate through the lungs where they dynamically release platelets. MKs releasing platelets in the lung are of extrapulmonary origin, such as the BM, where we observed large MKs migrating out of the BM space. The lung contribution to platelet biogenesis is substantial with approximately 50% of total platelet production or 10 million platelets per hour. Furthermore, we identified populations of mature and immature MKs along with hematopoietic progenitors that reside in the extravascular spaces of the lung. Under conditions of thrombocytopenia and relative stem cell deficiency in the BM9, these progenitors can migrate out of the lung, repopulate the BM, completely reconstitute blood platelet counts, and contribute to multiple hematopoietic lineages. These results position the lung as a primary site of terminal platelet production and an organ with considerable hematopoietic potential. PMID:28329764

Aging stability of complete blood count and white blood cell differential parameters analyzed by Abbott CELL-DYN Sapphire hematology analyzer.

PubMed

Hedberg, P; Lehto, T

2009-02-01

This study presents the results of an aging stability study of complete blood count (CBC) and leukocyte differential parameters using the Abbott CELL-DYN Sapphire hematology analyzer. Stability studies showed no substantial change in CBC parameters up to 24-48 h at +23 +/- 2 degrees C (room temperature), except for optical platelet count (PLTo). For specimens aged over 24, the value of impedance platelet count yielded more reliable results than the routine PLTo. White blood cell (WBC) differential parameters, except eosinophils, were stable for up to 48 h at +23 +/- 2 degrees C. CBC parameters were stable for 72 h, except mean platelet volume, which slightly increased between 48 and 72 h, at +4 degrees C. WBC differentials were stable 48-72 h, with a slight decrease observed in absolute neutrophils and lymphocytes at +4 degrees C.

Quebec platelet disorder: update on pathogenesis, diagnosis, and treatment.

PubMed

Blavignac, Jessica; Bunimov, Natalia; Rivard, Georges E; Hayward, Catherine P M

2011-09-01

Quebec platelet disorder (QPD) is an autosomal dominant bleeding disorder associated with reduced platelet counts and a unique gain-of-function defect in fibrinolysis due to increased expression and storage of urokinase plasminogen activator (uPA) by megakaryocytes. QPD increases risks for bleeding and its key clinical feature is delayed-onset bleeding, following surgery, dental procedures or trauma, which responds only to treatment with fibrinolytic inhibitors. The genetic cause of the disorder is a tandem duplication mutation of the uPA gene, PLAU, which upregulates uPA expression in megakaryocytes by an unknown mechanism. The increased platelet stores of uPA trigger plasmin-mediated degradation of QPD α-granule proteins. The gain-of-function defect in fibrinolysis is thought to be central to the pathogenesis of QPD bleeding as the activation of QPD platelets leads to release of uPA from α-granules and accelerated clot lysis. The purpose of this review is to summarize current knowledge on QPD pathogenesis and the recommended approaches to QPD diagnosis and treatment. Thieme Medical Publishers.

Calibrating nadir striped artifacts in a multibeam backscatter image using the equal mean-variance fitting model

NASA Astrophysics Data System (ADS)

Yang, Fanlin; Zhao, Chunxia; Zhang, Kai; Feng, Chengkai; Ma, Yue

2017-07-01

Acoustic seafloor classification with multibeam backscatter measurements is an attractive approach for mapping seafloor properties over a large area. However, artifacts in the multibeam backscatter measurements prevent accurate characterization of the seafloor. In particular, the backscatter level is extremely strong and highly variable in the near-nadir region due to the specular echo phenomenon. Consequently, striped artifacts emerge in the backscatter image, which can degrade the classification accuracy. This study focuses on the striped artifacts in multibeam backscatter images. To this end, a calibration algorithm based on equal mean-variance fitting is developed. By fitting the local shape of the angular response curve, the striped artifacts are compressed and moved according to the relations between the mean and variance in the near-nadir and off-nadir region. The algorithm utilized the measured data of near-nadir region and retained the basic shape of the response curve. The experimental results verify the high performance of the proposed method.

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

PubMed Central

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

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.

PubMed

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

The effects of vincristine on platelet aggregation studied by a filter loop technique in the rat.

PubMed Central

Bee, D.; Leach, E.; Martin, J. F.; Suggett, A. J.

1980-01-01

1 A method for measuring aggregation of platelets of adenosine diphosphate (ADP) is described using a filter inserted into the flowing aortic blood in the rat. 2 Repeated infusions of ADP resulted in a fall in the calculated aggregation index without significant changes in the platelet count. 3 Vincristine (0.05 mg/kg) intravenously caused significant inhibition of ADP-induced platelet aggregation. 4 Infusion of ADP caused some peripheral vasodilatation though it is unlikely that this contributed to the effects seen to any great extent. PMID:7437636

Automated processing of leucocyte-poor platelet concentrates.

PubMed

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).

Using Nadir and Directional Emissivity as a Probe of Particle Microphysical Properties

NASA Astrophysics Data System (ADS)

Pitman, Karly M.; Wolff, Michael J.; Bandfield, Joshua L.; Clayton, Geoffrey C.

Real surfaces are not expected to be diffuse emitters, thus observed emissivity values of surface dust deposits are a function of viewing geometry. Attempts to model infrared emission spectral profiles of surface dust deposits at nadir have not yet matured to match the sophistication of astrophysical dust radiative transfer codes. In the absence of strong thermal gradients, directional emissivity may be obtained theoretically via a combination of reciprocity and Kirchhoff's Law. Owing to a lack of laboratory data on directional emissivity for comparison, theorists have not explored the potential utility of directional emissivity as a direct probe of surface dust microphysical properties. Motivated by future analyses of MGS/TES emission phase function (EPF) sequences and the upcoming Mars Exploration Rover mini-TES dataset, we explore the effects of dust particle size and composition on observed radiances at nadir and off-nadir geometries in the TES spectral regime using a combination of multiple scattering radiative transfer and Mie scattering algorithms. Comparisons of these simulated spectra to laboratory spectra of standard mineral assemblages will also be made. This work is supported through NASA grant NAGS-9820 (MJW) and LSU Board of Regents (KMP).

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

PubMed

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.

FlnA-null megakaryocytes prematurely release large and fragile platelets that circulate poorly

PubMed Central

Jurak Begonja, Antonija; Hoffmeister, Karin M.; Hartwig, John H.

2011-01-01

Filamin A (FlnA) is a large cytoplasmic protein that crosslinks actin filaments and anchors membrane receptors and signaling intermediates. FlnAloxP PF4-Cre mice that lack FlnA in the megakaryocyte (MK) lineage have a severe macrothrombocytopenia because of accelerated platelet clearance. Macrophage ablation by injection of clodronate-encapsulated liposomes increases blood platelet counts in FlnAloxP PF4-Cre mice and reveals the desintegration of FlnA-null platelets into microvesicles, a process that occurs spontaneously during storage. FlnAloxP PF4-Cre bone marrows and spleens have a 2.5- to 5-fold increase in MK numbers, indicating increased thrombopoiesis in vivo. Analysis of platelet production in vitro reveals that FlnA-null MKs prematurely convert their cytoplasm into large CD61+ platelet-sized particles, reminiscent of the large platelets observed in vivo. FlnA stabilizes the platelet von Willebrand factor receptor, as surface expression of von Willebrand factor receptor components is normal on FlnA-null MKs but decreased on FlnA-null platelets. Further, FlnA-null platelets contain multiple GPIbα degradation products and have increased expression of the ADAM17 and MMP9 metalloproteinases. Together, the findings indicate that FlnA-null MKs prematurely release large and fragile platelets that are removed rapidly from the circulation by macrophages. PMID:21652675

The counting of native blood cells by digital microscopy

NASA Astrophysics Data System (ADS)

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.

Platelet Storage Lesions: What More Do We Know Now?

PubMed

Ng, Monica Suet Ying; Tung, John-Paul; Fraser, John Francis

2018-04-17

Platelet concentrate (PC) transfusions are a lifesaving adjunct to control and prevent bleeding in cancer, hematologic, surgical, and trauma patients. Platelet concentrate availability and safety are limited by the development of platelet storage lesions (PSLs) and risk of bacterial contamination. Platelet storage lesions are a series of biochemical, structural, and functional changes that occur from blood collection to transfusion. Understanding of PSLs is key for devising interventions that prolong PC shelf life to improve PC access and wastage. This article will review advancements in clinical and mechanistic PSL research. In brief, exposure to artificial surfaces and high centrifugation forces during PC preparation initiate PSLs by causing platelet activation, fragmentation, and biochemical release. During room temperature storage, enhanced glycolysis and reduced mitochondrial function lead to glucose depletion, lactate accumulation, and product acidification. Impaired adenosine triphosphate generation reduces platelet capacity to perform energetically demanding processes such as hypotonic stress responses and activation/aggregation. Storage-induced alterations in platelet surface proteins such as thrombin receptors and glycoproteins decrease platelet aggregation. During storage, there is an accumulation of immunoactive proteins such as leukocyte-derive cytokines (tumor necrosis factor α, interleukin (IL) 1α, IL-6, IL-8) and soluble CD40 ligand which can participate in transfusion-related acute lung injury and nonhemolytic transfusion reactions. Storage-induced microparticles have been linked to enhanced platelet aggregation and immune system modulation. Clinically, stored PCs have been correlated with reduced corrected count increment, posttransfusion platelet recovery, and survival across multiple meta-analyses. Fresh PC transfusions have been associated with superior platelet function in vivo; however, these differences were abrogated after a period of

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

PubMed

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.

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

PubMed

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

Minimal dose interferon suppository treatment suppresses viral replication with platelet counts and serum albumin levels increased in chronically hepatitis C virus-infected patients: a phase 1b, placebo-controlled, randomized study.

PubMed

Haruna, Yoshimichi; Inoue, Atsuo

2014-02-01

Animal studies have shown that rectally administrated interferon (IFN) is transferred into the lymphatic system via the rectal mucous membrane, suggesting that an IFN suppository could serve as another drug delivery method. We developed an IFN suppository and administered it to patients with chronic hepatitis C to evaluate its efficacy and safety. Twenty-eight patients with chronic hepatitis C participated in the study. The low-dose IFN suppository containing 1,000 international units (IU) of lymphoblastoid IFNα was administered to 14 patients daily for 24 weeks. Others had a placebo dosing. In 13 of the 14 IFN suppository-treated patients, viral load decreased at week 4. The serum hepatitis C virus (HCV) RNA levels (Log IU/mL, mean±standard error) were 5.65±0.18 before the treatment and 5.17±0.27 at week 4 (P=0.01). The 2'-5' oligoadenylate synthetase activity increased, while the CD4/CD8 ratio decreased significantly. Interestingly, platelet counts and serum albumin levels were significantly increased during and after the treatment. No serious adverse events were observed. The low-dose IFN suppository treatment suppressed HCV replication, modifying host immunity, with increased platelet counts and serum albumin levels. The IFN suppository could be considered a new drug delivery method to preserve the quality of life of patients.

TES/Aura L2 Ammonia (NH3) Lite Nadir V6 (TL2NH3LN)

Atmospheric Science Data Center

2017-07-20

TES/Aura L2 Ammonia (NH3) Lite Nadir (TL2NH3LN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 km nadir Spatial ... OPeNDAP Access:  OPeNDAP Parameters:  Ammonia Order Data:  Earthdata Search:   Order Data ...

TES/Aura L2 Carbon Dioxide (CO2) Nadir V6 (TL2CO2N)

Atmospheric Science Data Center

2018-01-18

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.2 x 8.5 km nadir ... Contact User Services Parameters:  Carbon Dioxide Legacy:  Retired data product , click here ...

TES/Aura L2 Carbon Dioxide (CO2) Nadir V6 (TL2CO2NS)

Atmospheric Science Data Center

2018-01-22

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.3 x 8.5 km nadir ... Contact ASDC User Services Parameters:  Carbon Dioxide Legacy:  Retired data product , click here ...

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

PubMed

Trugilho, Monique Ramos de Oliveira; Hottz, Eugenio Damaceno; Brunoro, Giselle Villa Flor; Teixeira-Ferreira, André; Carvalho, Paulo Costa; Salazar, Gustavo Adolfo; Zimmerman, Guy A; Bozza, Fernando A; Bozza, Patrícia T; Perales, Jonas

2017-05-01

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 proteome in dengue

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

PubMed Central

Teixeira-Ferreira, André; Carvalho, Paulo Costa; Salazar, Gustavo Adolfo; Zimmerman, Guy A.; Perales, Jonas

2017-01-01

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 proteome in dengue

Pathogen-reduced platelets for the prevention of bleeding

PubMed Central

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

2017-01-01

Background Platelet transfusions are used to prevent and treat bleeding in people who are thrombocytopenic. Despite improvements in donor screening and laboratory testing, a small risk of viral, bacterial, or protozoal contamination of platelets remains. There is also an ongoing risk from newly emerging blood transfusion-transmitted infections for which laboratory tests may not be available at the time of initial outbreak. One solution to reduce the risk of blood transfusion-transmitted infections from platelet transfusion is photochemical pathogen reduction, in which pathogens are either inactivated or significantly depleted in number, thereby reducing the chance of transmission. This process might offer additional benefits, including platelet shelf-life extension, and negate the requirement for gamma-irradiation of platelets. Although current pathogen-reduction technologies have been proven to reduce pathogen load in platelet concentrates, a number of published clinical studies have raised concerns about the effectiveness of pathogen-reduced platelets for post-transfusion platelet count recovery and the prevention of bleeding when compared with standard platelets. This is an update of a Cochrane review first published in 2013. Objectives To assess the effectiveness of pathogen-reduced platelets for the prevention of bleeding in people of any age requiring platelet transfusions. Search methods We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 9), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 24 October 2016. Selection criteria We included RCTs comparing the transfusion of pathogen-reduced platelets with standard platelets, or comparing different types of pathogen-reduced platelets. Data collection and analysis We used the standard methodological procedures expected by

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

PubMed

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.

Can mean platelet volume and neutrophil-to-lymphocyte ratio be biomarkers of acute exacerbation of bronchiectasis in children?

PubMed Central

Erdem, Semiha Bahceci; Karaman, Sait; Yazici, Selcuk; Can, Demet

2017-01-01

Introduction Bronchiectasis (BE) is a parenchymal lung disease evolving as a result of recurrent lung infections and chronic inflammation. Although it has been shown in adult studies that mean platelet volume (MPV) and neutrophil-to-lymphocyte ratio (NLR) can be used as biomarkers of airway inflammation, knowledge is limited in the paediatric age group. The aim of our study is to investigate the potential of MPV and NLR as biomarkers that may indicate acute exacerbations of non-cystic fibrosis BE in children. Material and methods Children with non-cystic fibrosis BE (n = 50), who were followed in the division of Paediatric Pulmonology of our hospital between June 2010 and July 2015, were involved in the present retrospective cross-sectional study. Haemogram values during acute exacerbations and non-exacerbation periods, and a control group were compared. Results In children with bronchiectasis, the average leukocyte count (p < 0.001), platelet count (p = 0.018), absolute neutrophil count (p < 0.001), and NLR (p < 0.001) were higher, as expected, when compared with the control group. NLR values, in the period of acute exacerbation were significantly higher than the values of both the non-exacerbation periods (p = 0.02) and the control group (p < 0.001). In contrast, MPV values in the period of acute exacerbation did not exhibit a significant difference from those of non-exacerbation periods (p = 0.530) and the control group (p = 0.103). Conclusions It was concluded that leukocyte count, platelet count, absolute neutrophil count, and NLR can be used to show chronic inflammation in BE, but only NLR and absolute neutrophil count can be used as biomarkers to show acute exacerbations. PMID:29472813

Platelet closure time in anesthetized Greyhounds with hemorrhagic shock treated with hydroxyethyl starch 130/0.4 or 0.9% sodium chloride infusions.

PubMed

McBride, Duana; Hosgood, Giselle; Raisis, Anthea; Smart, Lisa

2016-07-01

To measure platelet closure time (PCT) in dogs during controlled hemorrhagic shock and after fluid resuscitation with hydroxyethyl starch (HES) 130/0.4 or 0.9% sodium chloride. Experimental interventional study. University veterinary teaching hospital. Eleven healthy Greyhounds. Dogs were anesthetized and had 48 mL/kg of blood removed to induce hemorrhagic shock. Dogs received 20 mL/kg of HES 130/0.4 (n = 6) or 80 mL/kg of 0.9% sodium chloride (NaCl; n = 5) intravenously over 20 minutes. PCT was measured using the Platelet Function Analyzer-100 with collagen and adenosine-diphosphate cartridges at: T0 = 60 minutes after induction of anesthesia prior to hemorrhage, T1 = during hemorrhagic shock, and T2 = 40 minutes after completion of fluid bolus. Packed cell volume and platelet count were concurrently measured. Hemorrhagic shock did not significantly change PCT, with no difference between T0 and T1. Both the HES 130/0.4 and 0.9% NaCl group had a significantly increased mean PCT at T2 of 91.4 seconds (95% CI 69.3-113.4) and 95.5 seconds (95% CI 78.2-112.8), respectively, compared to T1. The magnitude of change was significantly greater for the 0.9% NaCl group than the HES 130/0.4 group. There was no difference in the magnitude of change in PCV and platelet count between the 2 groups. The PCV and platelet count were >25% and >100,000/μL, respectively, in all dogs, except for dogs in the HES 130/0.4 group at T2 where platelet counts were <100,000/μL. Controlled hemorrhagic shock in Greyhounds under anesthesia did not cause a significant change in PCT. Both HES 130/0.4 and 0.9% NaCl administration after induction of shock increased PCT. These results do not support that HES 130/0.4 causes relevant platelet dysfunction beyond hemodilution. © Veterinary Emergency and Critical Care Society 2016.

Platelet parameters (PLT, MPV, P-LCR) in patients with schizophrenia, unipolar depression and bipolar disorder.

PubMed

Wysokiński, Adam; Szczepocka, Ewa

2016-03-30

There are no studies comparing platelet parameters platelet parameters (platelet count (PLT), mean platelet volume (MPV) and platelet large cell ratio (P-LCR)) between patients with schizophrenia, bipolar disorder and unipolar depression. Therefore, the aim of this study was to determine and compare differences in PLT, MPV and P-LCR in patients with schizophrenia, unipolar depression and bipolar disorder. This was a retrospective, cross-sectional, naturalistic study of 2377 patients (schizophrenia n=1243; unipolar depression n=791; bipolar disorder n=343, including bipolar depression n=259 and mania n=84). There were significant differences for PLT, MPV and P-LCR values between study groups. A significant percentage of patients with bipolar disorder had abnormal (too low or too high) number of platelets. Negative correlation between PLT and age was found in all study groups and positive correlation between age and MPV and P-LCR was found in patients with schizophrenia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

PubMed

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), B (stable PC, ΔPC ± 50 × 10 9 /l), and C (rising 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.

In vitro properties of concentrated canine platelets stored in two additive solutions: a comparative study.

PubMed

Hlavac, N; Lasta, C S; Dalmolin, M L; Lacerda, L A; de Korte, D; Marcondes, N A; Terra, S R; Fernandes, F B; González, F H D

2017-11-15

Platelet transfusion therapy poses many challenges in veterinary clinical practice. Lack of readily available blood donors, short shelf-life, and inability to administer a sufficient number of platelets to meet a dog's transfusion need are the major difficulties encountered. Platelet additive solutions are already in use at American and European human blood banks, showing to be a realistic alternative. This study compares the in vitro platelet function in plasma, Composol, or SSP+ during storage for 13 days. Platelet rich plasma-platelet concentrate with 35% plasma and 65% platelet additive solutions (Composol or SSP+) and a control group (100% plasma) were prepared. Swirling, platelet count, blood gases, metabolic variables, platelet activation markers, and apoptosis markers were analyzed on days 1, 5, 9 and 13. Swirling was well preserved and pH was acceptable (> 6.2) during storage for all platelet additive solutions units until day 9. SSP + units showed more stable pH and metabolic variables until day 13. Platelets in plasma showed higher glucose consumption than in Composol or in SSP+. The platelet additive solutions units showed better platelet metabolism maintenance, reduced glucose consumption and lactate production. The apoptotic markers were still low for 9 days in platelet concentrates with platelet additive solutions, suggesting the possibility to extend the shelf life with the use of SSP+ or Composol. Our findings suggest that the uses of Composol and SSP+ in canine platelet concentrates are potential alternatives in veterinary blood banks.

Arterial thrombosis associated with immune thrombocytopenia: presence of a platelet aggregating IgG synergistic with thrombin and adrenalin.

PubMed

Jackson, S P; Jane, S M; Mitchell, C A; Fernando Cortizo, W; Hau, L; Pfueller, S L; Salem, H H

1989-11-24

We report the case of a 50-year-old lady who presented with arterial thrombosis in the setting of thrombocytopenia. Investigations confirmed the diagnosis of idiopathic thrombocytopenic purpura. A spontaneous platelet aggregating factor (SPAF) was isolated from the immunoglobulin fraction of the patient's plasma. The isolated IgG irreversibly aggregated platelet-rich plasma and washed platelets, an effect abolished by pretreating the platelets with aspirin. The activity of the IgG was greatly enhanced by subaggregatory concentrations of thrombin and adrenalin and was localized to the F(ab')2 of the molecule. Plasmapheresis in combination with anti-platelet therapy resulted in an increase in the patient's platelet count, reduced platelet aggregating activity of plasma and significant clinical improvement. We suggest that the presence of this platelet aggregating IgG contributed to the development of thrombosis in our patient and postulate that a similar factor may explain the paradox of thrombosis observed in a select group of thrombocytopenic patients.

Can Platelet and Leukocyte Indicators Give Us an Idea about Distant Metastasis in Nasopharyngeal Cancer?

PubMed

Arıcıgil, Mitat; Dündar, Mehmet Akif; Yücel, Abitter; Arbağ, Hamdi; Aziz, Suhayb Kuria

This study aimes to evaluate platelet and leucocyte indicators, such as the mean platelet volume, platelet distribution width, plateletcrit, white blood cell count, neutrophil to lymphocyte ratio in nasopharyngeal cancer patients and also to evaluate the relationship between these indicators and nasopharyngeal cancer with distant metastasis. The medical records of 118 patients diagnosed with nasopharyngeal cancer in our hospital between January 2006 and August 2015 were reviewed. The nasopharyngeal cancer group was further sub grouped according to the presence or absence of distant metastasis and TNM (tumour - T, node - N, metastasis - M) classification. A control group consisted of 120 healthy patients. The platelet and leucocyte values at the time of the initial diagnosis were recorded. Neutrophil to lymphocyte ratio and platelet distribution width values were significantly higher in the nasopharyngeal cancer group. But only platelet distribution width values were significantly higher in the nasopharyngeal cancer group with distant metastasis compared to the nasopharyngeal cancer group without distant metastasis. Neutrophil to lymphocyte ratio and platelet distribution width values may increase in nasopharyngeal cancer. But only the platelet distribution width values may give us an idea about the distant metastasis in nasopharyngeal cancer.

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

PubMed

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 <50 × 10 9 /l. Each patient chart was reviewed for final diagnosis and 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 < 10.4% was confirmed as an independent predictor of 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.

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

PubMed Central

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

2000-01-01

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. PMID:10947961

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

PubMed

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

2000-09-01

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

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

PubMed

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.

Impact of acute exacerbations on platelet reactivity in chronic obstructive pulmonary disease patients.

PubMed

Muñoz-Esquerre, Mariana; Ferreiro, José Luis; Huertas, Daniel; Marcano, Ana Lucrecia; López-Sánchez, Marta; Roura, Gerard; Gómez-Hospital, Joan Antoni; Dorca, Jordi; Cequier, Angel; Santos, Salud

2018-01-01

A higher risk of atherothrombotic cardiovascular events, which are platelet-driven processes, has been described during acute exacerbations of chronic obstructive pulmonary disease (AECOPD). However, the relevance of platelet reactivity during AECOPD and whether this is affected by antiplatelet agents are not fully elucidated to date. This study aimed to evaluate whether platelet reactivity is augmented during an exacerbation in COPD patients with and without antiplatelet therapy and its association with systemic inflammatory parameters. Prospective, observational, ex vivo investigation was conducted in consecutive patients suffering an exacerbation of COPD. Platelet reactivity was assessed during AECOPD and at stable state. Platelet function assays included: 1) vasodilator-stimulated phosphoprotein assay expressed as P2Y 12 reactivity index (PRI), 2) multiple electrode aggregometry and 3) optical aggregometry. Systemic inflammatory parameters such as leukocyte count, interleukin-6 and fibrinogen were also assessed. Higher platelet reactivity was observed during AECOPD compared to stability measured by vasodilator-stimulated phosphoprotein (PRI: 75.2%±1.9% vs 68.8%±2.4%, p =0.001). This augmented platelet aggregability was also observed in the subset of patients on antiplatelet therapy (PRI: 72.8%±3.1% vs 61.7%±7.5%, p =0.071). Consistent findings were observed with all other platelet function tests. Patients with greater enhancement of inflammatory markers during AECOPD were more likely to present a higher increase in platelet reactivity. Platelet reactivity is increased during AECOPD, which may contribute to the augmented cardiovascular risk of these patients. Additionally, the increase in platelet reactivity might be associated with an increment in inflammatory markers during exacerbations.

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

PubMed

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.

A microfluidic biochip for complete blood cell counts at the point-of-care

PubMed Central

Hassan, U.; Reddy, B.; Damhorst, G.; Sonoiki, O.; Ghonge, T.; Yang, C.; Bashir, R.

2016-01-01

Complete blood cell counts (CBCs) are one of the most commonly ordered and informative blood tests in hospitals. The results from a CBC, which typically include white blood cell (WBC) counts with differentials, red blood cell (RBC) counts, platelet counts and hemoglobin measurements, can have implications for the diagnosis and screening of hundreds of diseases and treatments. Bulky and expensive hematology analyzers are currently used as a gold standard for acquiring CBCs. For nearly all CBCs performed today, the patient must travel to either a hospital with a large laboratory or to a centralized lab testing facility. There is a tremendous need for an automated, portable point-of-care blood cell counter that could yield results in a matter of minutes from a drop of blood without any trained professionals to operate the instrument. We have developed microfluidic biochips capable of a partial CBC using only a drop of whole blood. Total leukocyte and their 3-part differential count are obtained from 10 μL of blood after on-chip lysing of the RBCs and counting of the leukocytes electrically using microfabricated platinum electrodes. For RBCs and platelets, 1 μL of whole blood is diluted with PBS on-chip and the cells are counted electrically. The total time for measurement is under 20 minutes. We demonstrate a high correlation of blood cell counts compared to results acquired with a commercial hematology analyzer. This technology could potentially have tremendous applications in hospitals at the bedside, private clinics, retail clinics and the developing world. PMID:26909365

A microfluidic biochip for complete blood cell counts at the point-of-care.

PubMed

Hassan, U; Reddy, B; Damhorst, G; Sonoiki, O; Ghonge, T; Yang, C; Bashir, R

2015-12-01

Complete blood cell counts (CBCs) are one of the most commonly ordered and informative blood tests in hospitals. The results from a CBC, which typically include white blood cell (WBC) counts with differentials, red blood cell (RBC) counts, platelet counts and hemoglobin measurements, can have implications for the diagnosis and screening of hundreds of diseases and treatments. Bulky and expensive hematology analyzers are currently used as a gold standard for acquiring CBCs. For nearly all CBCs performed today, the patient must travel to either a hospital with a large laboratory or to a centralized lab testing facility. There is a tremendous need for an automated, portable point-of-care blood cell counter that could yield results in a matter of minutes from a drop of blood without any trained professionals to operate the instrument. We have developed microfluidic biochips capable of a partial CBC using only a drop of whole blood. Total leukocyte and their 3-part differential count are obtained from 10 μL of blood after on-chip lysing of the RBCs and counting of the leukocytes electrically using microfabricated platinum electrodes. For RBCs and platelets, 1 μL of whole blood is diluted with PBS on-chip and the cells are counted electrically. The total time for measurement is under 20 minutes. We demonstrate a high correlation of blood cell counts compared to results acquired with a commercial hematology analyzer. This technology could potentially have tremendous applications in hospitals at the bedside, private clinics, retail clinics and the developing world.

Influence of cardiopulmonary bypass on platelet and neutrophil accumulations in internal organs.

PubMed

Bhujle, R; Li, J; Shastri, P; Gaffke, J N; Clift, J E; Ye, Y W; Dollar, M L; Ching, P; Chao, R; Constantinescu, A; Kulkarni, P V; Cheng, Q C; Wians, F; Jessen, M E; Eberhart, R C

1997-01-01

The authors employed gamma scintigraphy to quantify the post bypass accumulations of platelets and neutrophils in the lung, liver, and heart of adult pigs subjected to a standard 90 min regimen of normothermic cardiopulmonary bypass (CPB). Coated and uncoated microporous polypropylene oxygenator circuits were studied for Cobe Duo (Arvada, CO) oxygenators (amphophilic silicone-caprolactone oligomer [SMA] coating, n = 8 each) and Medtronic Maxima (Irvine, CA) oxygenators (Carmeda heparin coating, n = 5 each). Images of cells in the organs (deposited + blood pool) were corrected for tissue absorption and other factors and compared for a 2 hr period post CPB, using repeat measures ANOVA and rank tests. Platelet accumulations in internal organs correlated positively with whole blood platelet counts and negatively with platelet deposits in oxygenators during CPB. In general, uncoated CPB circuits significantly reduced platelet and neutrophil accumulations in lung, liver, and heart versus preCPB controls for the post CPB interval, for both systems. The SMA treatment significantly increased platelet accumulations versus uncoated controls in lung, liver, and heart for the 2 hr period, including the majority of the post CPB sampling intervals; platelet densities did not reach preCPB levels. Neutrophil accumulations were unaffected by the SMA coating. Carmeda heparin treatment significantly increased platelet accumulations in the liver, but not lung or heart. Despite preservation of circulating neutrophils observed with the Carmeda heparin treatment, neutrophil accumulations in internal organs were not elevated post CPB.

Alteration of mean platelet volume in the pathogenesis of acute ischemic stroke: cause or consequence?

PubMed

Ayas, Zeynep Özözen; Can, Ufuk

2018-01-30

Platelets have a crucial role on vascular disease which are involved in pathogenesis of ischemic stroke. Platelet size is measured as mean platelet volume (MPV) and is a marker of platelet activity. Platelets contain more dense granules as the size increases and produce more serotonin and tromboglobulin (b-TG) than small platelets. In this study, the alteration of MPV values were investigated in patients with acute stroke, who had MPV values before stroke, during acute ischemic stroke and 7 days after the stroke. The relationship between this alteration and risk factors, etiology and localization of ischemic stroke were also investigated. Sixty-seven patients with clinically and radiologically established diagnoses of ischemic stroke were enrolled into the study and stroke etiology was classified by modified Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification and, modified Bamford classification was used for localization and stroke risk factors were also evaluated. The platelet counts and MPV values from patient files in patients who had values before stroke (at examination for another diseases), within 24 hours of symptom onset and after 7 further days were analysed. MPV values increased after stroke (10.59±2.26) compared with acute stroke values (9.84±1.64) and the values before stroke (9.59±1.72) (p<0.0001); this alteration of MPV values occured 7 days after stroke (p<0.016). There was a positive correlation between age and MPV values during acute stroke (r=0.270; p<0.05). Patients with atrial fibrillation had higher alteration in the time of MPV compared with patients without atrial fibrillation (p>0.006). We assessed for gender, men (n=38) had a higher alteration in the time of MPV compared with women (n=29) (p=0.013). Although there was no alteration of platelet counts, MPV values were increased 7 days after stroke in patients with acute ischemic stroke.

Impact of Footprint Diameter and Off-Nadir Pointing on the Precision of Canopy Height Estimates from Spaceborne Lidar

NASA Technical Reports Server (NTRS)

Pang, Yong; Lefskky, Michael; Sun, Guoqing; Ranson, Jon

2011-01-01

A spaceborne lidar mission could serve multiple scientific purposes including remote sensing of ecosystem structure, carbon storage, terrestrial topography and ice sheet monitoring. The measurement requirements of these different goals will require compromises in sensor design. Footprint diameters that would be larger than optimal for vegetation studies have been proposed. Some spaceborne lidar mission designs include the possibility that a lidar sensor would share a platform with another sensor, which might require off-nadir pointing at angles of up to 16 . To resolve multiple mission goals and sensor requirements, detailed knowledge of the sensitivity of sensor performance to these aspects of mission design is required. This research used a radiative transfer model to investigate the sensitivity of forest height estimates to footprint diameter, off-nadir pointing and their interaction over a range of forest canopy properties. An individual-based forest model was used to simulate stands of mixed conifer forest in the Tahoe National Forest (Northern California, USA) and stands of deciduous forests in the Bartlett Experimental Forest (New Hampshire, USA). Waveforms were simulated for stands generated by a forest succession model using footprint diameters of 20 m to 70 m. Off-nadir angles of 0 to 16 were considered for a 25 m diameter footprint diameter. Footprint diameters in the range of 25 m to 30 m were optimal for estimates of maximum forest height (R(sup 2) of 0.95 and RMSE of 3 m). As expected, the contribution of vegetation height to the vertical extent of the waveform decreased with larger footprints, while the contribution of terrain slope increased. Precision of estimates decreased with an increasing off-nadir pointing angle, but off-nadir pointing had less impact on height estimates in deciduous forests than in coniferous forests. When pointing off-nadir, the decrease in precision was dependent on local incidence angle (the angle between the off-nadir

Whole blood flow cytometry measurements of in vivo platelet activation in critically-Ill patients are influenced by variability in blood sampling techniques.

PubMed

Rondina, Matthew T; Grissom, Colin K; Men, Shaohua; Harris, Estelle S; Schwertz, Hansjorg; Zimmerman, Guy A; Weyrich, Andrew S

2012-06-01

Flow cytometry is often used to measure in vivo platelet activation in critically-ill patients. Variability in blood sampling techniques, which may confound these measurements, remains poorly characterized. Platelet activation was measured by flow cytometry performed on arterial and venous blood from 116 critically-ill patients. We determined how variability in vascular sampling site, processing times, and platelet counts influenced levels of platelet-monocyte aggregates (PMA), PAC-1 binding (for glycoprotein (GP) IIbIIIa), and P-selectin (P-SEL) expression. Levels of PMA, but not PAC-1 binding or P-SEL expression, were significantly affected by variability in vascular sampling site. Average PMA levels were approximately 60% higher in whole blood drawn from an arterial vessel compared to venous blood (16.2±1.8% vs. 10.7±1.2%, p<0.05). Levels of PMA in both arterial and venous blood increased significantly during ex vivo processing delays (1.7% increase for every 10 minute delay, p<0.05). In contrast, PAC-1 binding and P-SEL expression were unaffected by processing delays. Levels of PMA, but not PAC-1 binding or P-SEL expression, were correlated with platelet count quartiles (9.4±1.6% for the lowest quartile versus 15.4±1.6% for the highest quartile, p<0.05). In critically-ill patients, variability in vascular sampling site, processing times, and platelet counts influence levels of PMA, but not PAC-1 binding or P-SEL expression. These data demonstrate the need for rigorous adherence to blood sampling protocols, particularly when levels of PMA, which are most sensitive to variations in blood collection, are measured for detection of in vivo platelet activation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Clopidogrel (Plavix) and cardiac surgical patients: implications for platelet function monitoring and postoperative bleeding.

PubMed

Tanaka, Kenichi A; Szlam, Fania; Kelly, Andrew B; Vega, J David; Levy, Jerrold H

2004-08-01

The use of clopidogrel (Plavix), an inhibitor of adenosine diphosphate (ADP)-induced platelet aggregation, has been proven to reduce ischemic events in cardiovascular patients, but little information is available for optimal monitoring of platelet function in patients receiving the drug preoperatively. In the first part of the study we compared different testing modalities (thrombelastography (TEG), platelet aggregometry, and whole blood aggregation) to assess platelet ADP receptor inhibition. Because clopidogrel is a pro-drug, we used an in vitro model of ADP inhibition with 5'-p-fluorosulfonylbenzoyladenosine (FSBA). FSBA at final concentration of 80 microM completely inhibited platelet aggregation but had no effect on TEG maximum amplitude (MA). In the second part of the study, antiplatelet effects of clopidogrel were clinically assessed and correlated to postoperative bleeding in 18 coronary bypass surgery patients. Preoperative TEG results were normal or hypercoagulable in clopidogrel-treated patients, although platelet aggregation responses to ADP were inhibited. Clopidogrel-treated patients who underwent cardiopulmonary bypass had a high incidence (84.6%) of platelet transfusion therapy due to increased chest tube drainage. In conclusion, we have demonstrated that normal preoperative TEG-MA does not preclude clopidogrel-induced ADP receptor blockade; however, TEG can be a reliable monitor for CPB-induced platelet dysfunction related to GPIIb/IIIa. For monitoring clopidogrel, it is necessary to perform more specific platelet function tests (aggregometry or platelet count ratio) using ADP as an activator.

The HAT Score-A Simple Risk Stratification Score for Coagulopathic Bleeding During Adult Extracorporeal Membrane Oxygenation.

PubMed

Lonergan, Terence; Herr, Daniel; Kon, Zachary; Menaker, Jay; Rector, Raymond; Tanaka, Kenichi; Mazzeffi, Michael

2017-06-01

The study objective was to create an adult extracorporeal membrane oxygenation (ECMO) coagulopathic bleeding risk score. Secondary analysis was performed on an existing retrospective cohort. Pre-ECMO variables were tested for association with coagulopathic bleeding, and those with the strongest association were included in a multivariable model. Using this model, a risk stratification score was created. The score's utility was validated by comparing bleeding and transfusion rates between score levels. Bleeding also was examined after stratifying by nadir platelet count and overanticoagulation. Predictive power of the score was compared against the risk score for major bleeding during anti-coagulation for atrial fibrillation (HAS-BLED). Tertiary care academic medical center. The study comprised patients who received venoarterial or venovenous ECMO over a 3-year period, excluding those with an identified source of surgical bleeding during exploration. None. Fifty-three (47.3%) of 112 patients experienced coagulopathic bleeding. A 3-variable score-hypertension, age greater than 65, and ECMO type (HAT)-had fair predictive value (area under the receiver operating characteristic curve [AUC] = 0.66) and was superior to HAS-BLED (AUC = 0.64). As the HAT score increased from 0 to 3, bleeding rates also increased as follows: 30.8%, 48.7%, 63.0%, and 71.4%, respectively. Platelet and fresh frozen plasma transfusion tended to increase with the HAT score, but red blood cell transfusion did not. Nadir platelet count less than 50×10 3 /µL and overanticoagulation during ECMO increased the AUC for the model to 0.73, suggesting additive risk. The HAT score may allow for bleeding risk stratification in adult ECMO patients. Future studies in larger cohorts are necessary to confirm these findings. Copyright © 2017 Elsevier Inc. All rights reserved.

Deletion of RUNX1 exons 1 and 2 associated with familial platelet disorder with propensity to acute myeloid leukemia.

PubMed

Cavalcante de Andrade Silva, Marcela; Krepischi, Ana Cristina Victorino; Kulikowski, Leslie Domenici; Zanardo, Evelin Aline; Nardinelli, Luciana; Leal, Aline Medeiros; Costa, Silvia Souza; Muto, Nair Hideki; Rocha, Vanderson; Velloso, Elvira Deolinda Rodrigues Pereira

2018-04-01

Familial platelet disorder with propensity to acute myeloid leukemia (FPD/AML) associated with RUNX1 mutations is an autosomal dominant disorder included in the group of the myeloid neoplasms with germ line predisposition. We describe two brothers who were diagnosed with hematological malignancies (one with AML and the other with T-cell lymphoblastic lymphoma). There was a history of leukemia in the paternal family and two of their siblings presented with low platelet counts and no history of significant bleeding. A microdeletion encompassing exons 1-2 of RUNX1 (outside the cluster region of the Runt Homology domain and the transactivation domain) was detected in six family members using array-CGH and MLPA validation. A low platelet count was not present in all deletion carriers and, therefore, it should not be used as an indication for screening in suspected families and family members. Copyright © 2018 Elsevier Inc. All rights reserved.

Platelet glycoproteins associated with aspirin-treatment upon platelet activation

PubMed Central

Shah, Punit; Yang, Weiming; Sun, Shisheng; Pasay, Jered; Faraday, Nauder; Zhang, Hui

2017-01-01

Platelet glycoproteins are known to play central roles in hemostasis and vascular integrity and have pathologic roles in vascular occlusive diseases such as myocardial infarction and stroke. Characterizing glycoproteins within and secreted by platelets can provide insight into the mechanisms that underlie vascular pathologies and the therapeutic benefits or failure of anti-platelet agents. To study the impact of aspirin, which is commonly prescribed for primary and secondary cardiovascular prevention, on the platelet glycoproteome, we evaluated washed platelets from ten donors. The platelet glycoproteome, was studied using an iTRAQ in resting and stimulated states and with and without aspirin treatment. Using solid phase extraction of glycosite-containing peptides (SPEG), we were able to identify 799 unique N-linked glycosylation sites (glycosites) in platelets, representing the largest and the most comprehensive analysis to date. We were able to identity a number of glycoproteins impacted by aspirin treatment, which we validated using global proteomics analysis of platelets and their secreted proteins. In our analyses, metallopeptidase inhibitor 1 (TIMP1) was the single most significantly affected glycoprotein by aspirin treatment. ELISA assays confirmed proteomic results and validated our strategy. Functional analysis demonstrated that TIMP1 levels were highly correlated with platelet reactivity in vitro, with a correlation coefficient of −0.5. The release of TIMP1 from platelets, which was previously unknown to be affected by aspirin treatment, may play important roles in hemostasis and/or vascular integrity. If validated, our findings may be useful for developing assays that assess platelet response to aspirin or other anti-platelet therapies. PMID:27452734

Retinal detachment in hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome: Color vision abnormality as the first and predominant manifestation.

PubMed

Morisawa, Hiroyuki; Makino, Shinji; Takahashi, Hironori; Sorita, Mari; Matsubara, Shigeki

2015-11-01

Serous retinal detachment is sometimes caused by hypertensive disorders in pregnancy and its associated conditions, in which the predominant eye symptoms are blurred vision, distorted vision, and reduced visual acuity. To our best knowledge, this is the first report of a puerperal woman with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome in whom color vision abnormality was the first and predominant manifestation of serous retinal detachment. At 32 weeks of gestation, the 34-year-old Japanese woman underwent cesarean section due to HELLP syndrome. She complained of color vision abnormality on day 1 post-partum and ophthalmological examination revealed serous retinal detachment of both eyes. The visual acuity was preserved. With supportive therapy, her color vision abnormality gradually ameliorated and retinal detachment completely resolved on day 34 post-partum without any sequelae. Obstetricians should be aware that color vision abnormality can be the first and predominant symptom of HELLP-related serous retinal detachment. © 2015 Japan Society of Obstetrics and Gynecology.

Lnk regulates integrin αIIbβ3 outside-in signaling in mouse platelets, leading to stabilization of thrombus development in vivo

PubMed Central

Takizawa, Hitoshi; Nishimura, Satoshi; Takayama, Naoya; Oda, Atsushi; Nishikii, Hidekazu; Morita, Yohei; Kakinuma, Sei; Yamazaki, Satoshi; Okamura, Satoshi; Tamura, Noriko; Goto, Shinya; Sawaguchi, Akira; Manabe, Ichiro; Takatsu, Kiyoshi; Nakauchi, Hiromitsu; Takaki, Satoshi; Eto, Koji

2009-01-01

The nature of the in vivo cellular events underlying thrombus formation mediated by platelet activation remains unclear because of the absence of a modality for analysis. Lymphocyte adaptor protein (Lnk; also known as Sh2b3) is an adaptor protein that inhibits thrombopoietin-mediated signaling, and as a result, megakaryocyte and platelet counts are elevated in Lnk–/– mice. Here we describe an unanticipated role for Lnk in stabilizing thrombus formation and clarify the activities of Lnk in platelets transduced through integrin αIIbβ3–mediated outside-in signaling. We equalized platelet counts in wild-type and Lnk–/– mice by using genetic depletion of Lnk and BM transplantation. Using FeCl3- or laser-induced injury and in vivo imaging that enabled observation of single platelet behavior and the multiple steps in thrombus formation, we determined that Lnk is an essential contributor to the stabilization of developing thrombi within vessels. Lnk–/– platelets exhibited a reduced ability to fully spread on fibrinogen and mediate clot retraction, reduced tyrosine phosphorylation of the β3 integrin subunit, and reduced binding of Fyn to integrin αIIbβ3. These results provide new insight into the mechanism of αIIbβ3-based outside-in signaling, which appears to be coordinated in platelets by Lnk, Fyn, and integrins. Outside-in signaling modulators could represent new therapeutic targets for the prevention of cardiovascular events. PMID:20038804

Radiation physics and modelling for off-nadir satellite-sensing of non-Lambertian surfaces

NASA Technical Reports Server (NTRS)

Gerstl, S. A.; Simmer, C.

1986-01-01

The primary objective of this paper is to provide a deeper understanding of the physics of satellite remote-sensing when off-nadir observations are considered. Emphasis is placed on the analysis and modeling of atmospheric effects and the radiative transfer of non-Lambertian surface reflectance characteristics from ground-level to satellite locations. The relative importance of spectral, spatial, angular, and temporal reflectance characteristics for satellite-sensed identification of vegetation types in the visible and near-infrared wavelength regions is evaluated. The highest identification value is attributed to angular reflectance signatures. Using radiative transfer calculations to evaluate the atmospheric effects on angular reflectance distributions of vegetation surfaces, atmosphere-invariant angular reflectance features such as the 'hot spot' and the 'persistent valley' are identified. A new atmospheric correction formalism for complete angular reflectance distributions is described. A sample calculation demonstrates that a highly non-Lambertian measured surface reflectance distribution can be retrieved from simulated satellite data in the visible and near infrared to within about 20 percent accuracy for almost all view directions up to 60 deg off-nadir. Thus the high value of angular surface reflectance characteristics (the 'angular signature') for satellite-sensed feature identification is confirmed, which provides a scientific basis for future off-nadir satellite observations.

Development and evaluation of an automatic method for the study of platelet osmotic response.

PubMed

Gigout, T; Blondel, W; Didelon, J; Latger, V; Dumas, D; Schooneman, F; Stoltz, J F

1999-01-01

Study of the osmotic resistance to hypotonic medium of platelets has often been suggested as a global test to assess the viability of these cells in transfusion or to study modification during haematological pathologies. A number of authors have analysed the behaviour of platelets in hypotonic media by a variety of methods (cell count, determinations of substances released, morphology, etc.), but most studies are currently based on the so-called "Hypotonic Shock Response" test (HSR). In this study, the authors describe a new automated and reproducible apparatus, called fragilimeter, using slow dialysis to assess platelet osmotic resistance. The variations in light transmission through a platelet suspension according to ionic strength are linked to the change in cellular volume and lysis and characterise the osmotic behaviour of the cells. The results revealed the good reproducibility and sensibility of the technique. This apparatus allows also the realisation of the "HSR" test.

Postlaunch Performance of the Suomi National Polar-Orbiting Partnership Ozone Mapping and Profiler Suite (OMPS) Nadir Sensors

NASA Technical Reports Server (NTRS)

Seftor, C. J.; Jaross, G.; Kowitt, M.; Haken, M.; Li, J.; Flynn, L. E.

2014-01-01

The prelaunch specifications for nadir sensors of the Ozone Mapping and Profiler Suite (OMPS) were designed to ensure that measurements from them could be used to retrieve total column ozone and nadir ozone profile information both for operational use and for use in long-term ozone data records. In this paper, we will show results from our extensive analysis of the performance of the nadir mapper (NM) and nadir profiler (NP) sensors during the first year and a half of OMPS nadir operations. In most cases, we determined that both sensors meet or exceed their prelaunch specifications. Normalized radiance (radiance divided by irradiance) measurements have been determined to be well within their 2% specification for both sensors. In the case of stray light, the NM sensor is within its 2% specification for all but the shortest wavelengths, while the NP sensor is within its 2% specification for all but the longest wavelengths. Artifacts that negatively impacted the sensor calibration due to diffuser features were reduced to less than 1% through changes made in the solar calibration sequence. Preliminary analysis of the disagreement between measurements made by the NM and NP sensors in the region where their wavelengths overlap indicates that it is due to shifts in the shared dichroic filter after launch and that it can be corrected. In general, our analysis indicates that both the NM and NP sensors are performing well, that they are stable, and that any deviations from nominal performance can be well characterized and corrected.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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

2014-05-01

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

Comparison between human and porcine thromboelastograph parameters in response to ex-vivo changes to platelets, plasma, and red blood cells.

PubMed

Sondeen, Jill L; de Guzman, Rodolfo; Amy Polykratis, Irene; Dale Prince, Malcolm; Hernandez, Orlando; Cap, Andrew P; Dubick, Michael A

2013-12-01

In the acute care setting, both the tracings and numeric outputs (R time, angle, and MA) of thrombelastography (TEG) may be used to inform treatment decisions. The objective was to determine the sensitivity of TEG to isolated changes in platelet count, hematocrit and fibrinogen concentration in human blood. As pigs have a similar coagulation system, we also compared the responses of the pig blood. Eight volunteers (>18 years of age, no anticoagulation or nonsteroidal anti-inflammatory therapy, not pregnant) were enrolled into this study. Four female anesthetized donor pigs were instrumented percutaneously with a catheter for blood collection. All blood was collected into sodium citrate. The concentration of each component (platelets, fibrinogen, and red blood cells) was changed while keeping the other components constant by use of centrifugation or preparation of each individual's plasma into platelet poor plasma, platelet rich plasma, cryoprecipitate, purified washed platelets, and packed red blood cells as appropriate. TEG (Haemoscope) analysis was performed and compared with the patients' whole blood diluted with lactated Ringer's solution. We demonstrated that the major factor affecting the MA and angle was the platelet count. In fact, reducing platelets alone resulted in TEG profiles and parameters that were similar to lactated Ringer's dilution profiles. Swine blood responses were parallel to that of human blood, although there were offsets especially of TEG-R and angle that confirmed that the swine are hypercoagulable compared with humans. Superficially similar TEG tracing patterns can be produced by divergent mechanisms associated with altered concentrations of blood components.

Platelet and not erythrocyte microparticles are procoagulant in transfused thalassaemia major patients.

PubMed

Agouti, Imane; Cointe, Sylvie; Robert, Stéphane; Judicone, Coralie; Loundou, Anderson; Driss, Fathi; Brisson, Alain; Steschenko, Dominique; Rose, Christian; Pondarré, Corinne; Bernit, Emmanuelle; Badens, Catherine; Dignat-George, Françoise; Lacroix, Romaric; Thuret, Isabelle

2015-11-01

The level of circulating platelet-, erythrocyte-, leucocyte- and endothelial-derived microparticles detected by high-sensitivity flow cytometry was investigated in 37 β-thalassaemia major patients receiving a regular transfusion regimen. The phospholipid procoagulant potential of the circulating microparticles and the microparticle-dependent tissue factor activity were evaluated. A high level of circulating erythrocyte- and platelet-microparticles was found. In contrast, the number of endothelial microparticles was within the normal range. Platelet microparticles were significantly higher in splenectomized than in non-splenectomized patients, independent of platelet count (P < 0·001). Multivariate analysis indicated that phospholipid-dependent procoagulant activity was influenced by both splenectomy (P = 0·001) and platelet microparticle level (P < 0·001). Erythrocyte microparticles were not related to splenectomy, appear to be devoid of proper procoagulant activity and no relationship between their production and haemolysis, dyserythropoiesis or oxidative stress markers could be established. Intra-microparticle labelling with anti-HbF antibodies showed that they originate only partially (median of 28%) from thalassaemic erythropoiesis. In conclusion, when β-thalassaemia major patients are intensively transfused, the procoagulant activity associated with thalassaemic erythrocyte microparticles is probably diluted by transfusions. In contrast, platelet microparticles, being both more elevated and more procoagulant, especially after splenectomy, may contribute to the residual thrombotic risk reported in splenectomized multi-transfused β-thalassaemia major patients. © 2015 John Wiley & Sons Ltd.

Cumulative inhibitory effect of low-dose aspirin on vascular prostacyclin and platelet thromboxane production in patients with atherosclerosis.

PubMed

Weksler, B B; Tack-Goldman, K; Subramanian, V A; Gay, W A

1985-02-01

The relationship between the antithrombotic and antiplatelet effects of aspirin is complex, since aspirin influences other systems that protect against thrombosis as well as inhibiting platelet function. We investigated possible cumulative effects of low-dose aspirin on vascular production of prostacyclin in patients with documented atherosclerotic cardiovascular disease. Candidates for coronary artery vein graft bypass ingested 20 mg of aspirin daily during the week before surgery, and platelet aggregation, platelet formation of thromboxane A2 (TXA2), aortic and saphenous vein production of prostacyclin (PGI2), and hemostatic status were measured at the time of the bypass surgery. Low-dose aspirin markedly inhibited platelet aggregation responses and reduced TXA2 generation by greater than 90%, effects similar to those observed with much higher doses of aspirin. Both aortic and saphenous vein production of PGI2 were inhibited by 50% compared with PGI2 produced by vascular tissues of control subjects who received no aspirin preoperatively (51 +/- 10 pg 6-keto-PGF1 alpha/mg aortic wet weight [mean +/- SEM] in aspirin-treated subjects vs 130 +/- 16 pg/mg in control subjects, and 71 +/- 8 pg/mg saphenous vein wet weight vs 131 +/- 17 pg/mg). Blood loss at surgery was not significantly increased by preoperative low-dose aspirin as measured by chest tube drainage (754 +/- 229 ml in aspirin-treated subjects vs 645 +/- 271 ml in control subjects), hematocrit nadir (31.2 +/- 1.9% vs 31.8 +/- 1.7%), or transfusions (2.2 +/- 1.3 units of red blood cells vs 2.2 +/- 1.7 units).(ABSTRACT TRUNCATED AT 250 WORDS)

Haematological values in pregnant women in Port Harcourt, Nigeria II: Serum iron and transferrin, total and unsaturated iron binding capacity and some red cell and platelet indices.

PubMed

Amah-Tariah, F S; Ojeka, S O; Dapper, D V

2011-12-20

Previous studies on the normal values of serum iron, unsaturated iron binding capacity, total iron binding capacity, serum transferrin, percent transferrin saturation, red cell distribution width, and various platelet indices: Platelet count, mean platelet volume, platelet distribution width, plateletcrit and platelet larger cell ratio in pregnant subjects in Nigeria are relatively scanty. Present study aims to determine the values of these parameters in apparently healthy pregnant subjects residing in Port Harcourt south eastern Nigeria; and help establish normal reference ranges of these parameters for the population under reference. Cross sectional prospective study involving 220 female subjects attending for the first time, the ante-natal clinics of a tertiary health care facility in Port Harcourt. Subjects were divided into 73, 75 and 72 subjects in the first, second and third trimester of pregnancy respectively. Serum iron and unsaturated iron binding capacity, red cell distribution width, platelet count and platelet distribution width were determined by automated methods; total iron binding capacity, serum transferrin concentrations, percent transferrin saturation, mean platelet volume and plateletcrit were calculated using appropriate formulas. The values of serum iron, unsaturated iron binding capacity, total iron binding capacity and serum transferrin concentrations were found to show significant variations between the various trimesters of pregnancy. However, while serum iron showed significant decreases during pregnancy; unsaturated iron binding capacity, total iron binding capacity and serum transferrin concentrations were found to show significant increases during pregnancy amongst our subjects (p<0.05). By contrast the values of red cell distribution width, platelet count, mean platelet volume, platelet distribution width, plateletcrit and platelet larger cell ratio did not show any significant differences at the different trimesters of pregnancy in

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

PubMed

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.

Role for Neutrophil Extracellular Traps (NETs) and Platelet Aggregation in Early Sepsis-induced Hepatic Dysfunction.

PubMed

Sakurai, Kentaro; Miyashita, Tomoharu; Okazaki, Mitsuyoshi; Yamaguchi, Takahisa; Ohbatake, Yoshinao; Nakanuma, Shinichi; Okamoto, Koichi; Sakai, Seisho; Kinoshita, Jun; Makino, Isamu; Nakamura, Keishi; Hayashi, Hironori; Oyama, Katsunobu; Tajima, Hidehiro; Takamura, Hiroyuki; Ninomiya, Itasu; Fushida, Sachio; Harada, Kenichi; Harmon, John W; Ohta, Tetsuo

2017-01-01

Severe sepsis is associated with high morbidity and mortality rates. Inflammation and coagulation play pivotal roles in the pathogenesis of sepsis leading to multiple organ failure, especially in the liver. The aim of the present study was to assess the mechanism from sepsis to liver damage in a mouse model. We created a sepsis model by injecting lipopolysaccharide (LPS) intraperitoneally in mice. At 0, 6, 12, and 24 h following intraperitoneal injection of LPS, mice were euthanised and analyzed. Primary antibodies against myeloperoxidase (MPO), hepatic sinusoidal endothelial cells (SE-1), and P-selectin (CD62p) were used. Expression and localization in neutrophil, sinusoidal endothelial, and platelet cells were assessed by immunohistochemistry. Immunohistochemical analyses revealed a positive staining for MPO, most abundantly in neutrophil granulocytes, within the hepatic sinusoids immediately after injection. Neutrophil extracellular trap (NET)-like structures stained for MPO, indicating the presence of neutrophils undergoing NETosis, were confirmed at 6 h after LPS administration. SE-1 staining for liver sinusoidal endothelial cells was significantly reduced at 12 h post-LPS administration through sinusoidal endothelial injury or detachment. Furthermore, the presence of extravasated platelets was confirmed in the space of Disse at 24 h after LPS administration. Blood sample analyses showed that white blood cell counts and platelet counts decreased gradually, while MPO amounts increased until 12 h after LPS administration. We conclude that NET formation and intravasated platelet aggregation are the first steps from sepsis to liver damage, and that extravasated platelet aggregation promoted by NET-facilitated detachment of sinusoidal endothelial cells is the origin of sepsis-induced liver dysfunction. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

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

PubMed

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.

First-day newborn weight loss predicts in-hospital weight nadir for breastfeeding infants.

PubMed

Flaherman, Valerie J; Bokser, Seth; Newman, Thomas B

2010-08-01

Exclusive breastfeeding reduces infant infectious disease. Losing > or =10% birth weight may lead to formula use. The predictive value of first-day weight loss for subsequent weight loss has not been studied. The objective of the present study was to evaluate the relationship between weight loss at <24 hours and subsequent in-hospital weight loss > or =10%. For 1,049 infants, we extracted gestational age, gender, delivery method, feeding type, and weights from medical records. Weight nadir was defined as the lowest weight recorded during birth hospitalization. We used multivariate logistic regression to assess the effect of first-day weight loss on subsequent in-hospital weight loss. Mean in-hospital weight nadir was 6.0 +/- 2.6%, and mean age at in-hospital weight nadir was 38.7 +/- 18.5 hours. While in the hospital 6.4% of infants lost > or =10% of birth weight. Infants losing > or =4.5% birth weight at <24 hours had greater risk of eventual in-hospital weight loss > or =10% (adjusted odds ratio 3.57 [1.75, 7.28]). In this cohort, 798 (76.1%) infants did not have documented weight gain while in the hospital. Early weight loss predicts higher risk of > or =10% in-hospital weight loss. Infants with high first-day weight loss could be targeted for further research into improved interventions to promote breastfeeding.

Limb-Nadir Matching for Tropospheric NO2: A New Algorithm in the SCIAMACHY Operational Level 2 Processor

NASA Astrophysics Data System (ADS)

Meringer, Markus; Gretschany, Sergei; Lichtenberg, Gunter; Hilboll, Andreas; Richter, Andreas; Burrows, John P.

2015-11-01

SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. Limb and nadir geometries were the main operation modes for the retrieval of scientific data. The new version 6 of ESA's level 2 processor now provides for the first time an operational algorithm to combine measurements of these two geometries in order to generate new products. As a first instance the retrieval of tropospheric NO2 has been implemented based on IUP-Bremen's reference algorithm. We will detail the single processing steps performed by the operational limb-nadir matching algorithm and report the results of comparisons with the scientific tropospheric NO2 products of IUP and the Tropospheric Emission Monitoring Internet Service (TEMIS).

IMMUNOREACTIONS INVOLVING PLATELETS

PubMed Central

Shulman, N. Raphael

1958-01-01

Quantitative aspects of platelet agglutination and inhibition of clot retraction by the antibody of quinidine purpura were described. The reactions appeared to depend on formation of types of antibody-quinidine-platelet complexes which could fix complement but complement was not necessary for these reactions. Complement fixation was at least 10 times more sensitive than platelet agglutination or inhibition of clot retraction for measurement and detection of antibody activity. Although it has been considered that antibodies of drug purpura act as platelet lysins in the presence of complement and that direct lysis of platelets accounts for development of thrombocytopenia in drug purpura, the present study suggests that attachment of antibody produces a change in platelets which is manifested in vitro only by increased susceptibility to non-specific factors which can alter the stability of platelets in the absence of antibody. The attachment of antibody to platelets in vivo may only indirectly affect platelet survival. In contrast to human platelets, dog, rabbit, and guinea pig platelets, and normal or trypsin-treated human red cells did not agglutinate, fix complement, or adsorb antibody; and intact human endothelial cells did not fix complement or adsorb antibody. Rhesus monkey platelets were not agglutinated by the antibody but did adsorb antibody and fix complement although their activity in these reactions differed quantitatively from that of human platelets. Cinchonine could be substituted for quinidine in agglutination and inhibition of clot retraction reactions but quinine and cinchonidine could not. Attempts to cause passive anaphylaxis in guinea pigs with the antibody of quinidine purpura were not successful. PMID:13525580

Platelet-Rich Plasma and Platelet Gel: A Review

PubMed Central

Everts, Peter A.M.; Knape, Johannes T.A.; Weibrich, Gernot; Schönberger, Jacques P.A.M.; Hoffmann, Johannes; Overdevest, Eddy P.; Box, Henk A.M.; van Zundert, André

2006-01-01

Abstract: Strategies to reduce blood loss and transfusion of allogeneic blood products during surgical procedures are important in modern times. The most important and well-known autologous techniques are preoperative autologous predonation, hemodilution, perioperative red cell salvage, postoperative wound blood autotransfusion, and pharmacologic modulation of the hemostatic process. At present, new developments in the preparation of preoperative autologous blood component therapy by whole blood platelet-rich plasma (PRP) and platelet-poor plasma (PPP) sequestration have evolved. This technique has been proven to reduce the number of allogeneic blood transfusions during open heart surgery and orthopedic operations. Moreover, platelet gel and fibrin sealant derived from PRP and PPP mixed with thrombin, respectively, can be exogenously applied to tissues to promote wound healing, bone growth, and tissue sealing. However, to our disappointment, not many well-designed scientific studies are available, and many anecdotic stories exist, whereas questions remain to be answered. We therefore decided to study perioperative blood management in more detail with emphasis on the application and production of autologous platelet gel and the use of fibrin sealant. This review addresses a large variety of aspects relevant to platelets, platelet-rich plasma, and the application of platelet gel. In addition, an overview of recent animal and human studies is presented. PMID:16921694

Platelet-, leucocyte- and red cell-derived microparticles in stored whole blood, with and without leucofiltration, with and without ionising radiation

PubMed Central

Saito, Shunnichi; Ngoma, Alain M.; Ono, Takako; Ohto, Hitoshi

2018-01-01

Background Storage lesion, including microparticle formation, has been partially characterised in whole blood, but not in all combinations of pre-storage leucofiltration and/or irradiation. Materials and methods Single-donor whole blood products were processed into four subunits: with and without leucofiltration, with and without X-irradiation (25 Gy). Platelet-, leucocyte-, and erythrocyte-derived microparticles and free haemoglobin were measured periodically throughout 42 days of storage. Results Pre-storage leucofiltration substantially reduced platelet- and leucocyte-derived microparticle counts throughout storage. Irradiation, in contrast, had no significant effect on microparticle counts. A gate for all microparticles showed a substantial time-dependent increase in unfiltered whole blood. A time-dependent increase in free haemoglobin was greatest in unfiltered, irradiated whole blood. Discussion This study indicates that leucofiltration can prevent the formation of leucocyte- and platelet-derived microparticles, and might reduce haemolysis in irradiated whole blood, either by removing factors that provoke haemolysis, or by selective retention of senescent or effete red cells most prone to haemolysis. PMID:27893349

Platelet-, leucocyte- and red cell-derived microparticles in stored whole blood, with and without leucofiltration, with and without ionising radiation.

PubMed

Saito, Shunnichi; Nollet, Kenneth E; Ngoma, Alain M; Ono, Takako; Ohto, Hitoshi

2018-02-01

Storage lesion, including microparticle formation, has been partially characterised in whole blood, but not in all combinations of pre-storage leucofiltration and/or irradiation. Single-donor whole blood products were processed into four subunits: with and without leucofiltration, with and without X-irradiation (25 Gy). Platelet-, leucocyte-, and erythrocyte-derived microparticles and free haemoglobin were measured periodically throughout 42 days of storage. Pre-storage leucofiltration substantially reduced platelet- and leucocyte-derived microparticle counts throughout storage. Irradiation, in contrast, had no significant effect on microparticle counts. A gate for all microparticles showed a substantial time-dependent increase in unfiltered whole blood. A time-dependent increase in free haemoglobin was greatest in unfiltered, irradiated whole blood. This study indicates that leucofiltration can prevent the formation of leucocyte- and platelet-derived microparticles, and might reduce haemolysis in irradiated whole blood, either by removing factors that provoke haemolysis, or by selective retention of senescent or effete red cells most prone to haemolysis.

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

PubMed

Aktürk, Semra; Büyükavcı, Raikan

2017-08-01

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

Using SOURCES to Examine the Nadir of Race Relations (1890-1920)

ERIC Educational Resources Information Center

LaVallee, Carol; Waring, Scott M.

2015-01-01

The "nadir of race relations" is a term used by historians to describe the time period after Reconstruction, 1890-1920. During this time, African Americans were free; some argue, however, that it was a worse time than when these individuals were enslaved (Brundage 1990; Woodward 2002). There is a debate whether this time period…

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

PubMed

Zawilska, K; Komarnicki, M; Mańka, B

1978-01-01

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

Hydroxysafflor yellow A of Carthamus tinctorius attenuates lung injury of aged rats exposed to gasoline engine exhaust by down-regulating platelet activation.

PubMed

Wang, Chaoyun; Wang, Chunhua; Ma, Chunlei; Huang, Qingxian; Sun, Hongliu; Zhang, Xiaomin; Bai, Xianyong

2014-02-15

Long-term inhalation of gasoline engine exhaust (GEE) increases the risk of respiratory disease. Studies have suggested involvement of platelets in the development of some lung diseases. Hydroxysafflor yellow A (HSYA), a flavonoid compound, prevents hemostasis. Therefore, we investigated its effects on GEE-induced lung injury, and role of platelets in injury. Sixty-week-old male Sprague-Dawley rats were exposed to GEE for 4h/day for 6 weeks, and then grouped as follows: control, GEE, GEE+HSYA, GEE+HSYA+GW9662, and GEE+GW9662. Arterial oxygen tension (PaO2), carbon dioxide tension (PaCO2), pH, and the PaO2/fraction of inspired oxygen ratio (PaO2/FiO2) in the blood were detected using a blood gas analyzer. Wet/dry lung weight ratio, total protein in bronchoalveolar lavage fluid (BALF), and cytokine concentrations in serum and BALF were determined. Furthermore, cyclic adenosine monophosphate (cAMP) level and expression levels of target proteins were analyzed. Platelets were counted and their state was evaluated. HSYA attenuated GEE-mediated decreases in PaO2, PaO2/FiO2, platelet cAMP level, protein kinase A (PKA) activity, and peroxisome proliferator-activated receptor γ (PPARγ) expression. HSYA also attenuated GEE-mediated increases in lung permeability, cytokine levels in serum and BALF, plasma platelet count, and ADP-mediated platelet aggregation. Moreover, it suppressed GEE-induced increases in the expression of adhesion molecules and proinflammatory cytokines in platelets and lung tissue. Therefore, HSYA is therapeutically effective for GEE-mediated lung injury and acts by enhancing PKA activity and inhibiting platelet activation. Copyright © 2013 Elsevier GmbH. All rights reserved.

[Assessment study on a set of platelet-rich plasma preparation].

PubMed

Li, Ming; Zhang, Changqing; Yuan, Ting; Chen, Shengbao; Lü, Ruju

2011-01-01

To calculate the recovery rate and enrichment factor and to analyse the correlation by measuring the concentrations of platelets, leukocyte, and growth factors in platelet-rich plasma (PRP) so as to evaluate the feasibility and stability of a set of PRP preparation. The peripheral blood (40 mL) was collected from 30 volunteers accorded with the inclusion criteria, and then 4 mL PRP was prepared using the package produced by Shandong Weigao Group Medical Polymer Company Limited. Automatic hematology analyzer was used to count the concentrations of platelets and leukocyte in whole blood and PRP. The enrichment factor and recovery rate of platelets or leukocyte were calculated; the platelet and leukocyte concentrations of male and female volunteers were measured, respectively. The concentrations of platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-beta), and vascular endothelial growth factor (VEGF) were assayed by ELISA. The platelet concentrations of whole blood and PRP were (131.40 +/- 29.44) x 10(9)/L and (819.47 +/- 136.32) x 10(9)/L, respectively, showing significant difference (t = 27.020, P = 0.000). The recovery rate of platelets was 60.85% +/- 8.97%, and the enrichment factor was 6.40 +/- 1.06. The leukocyte concentrations of whole blood and PRP were (5.57 +/- 1.91) x 10(12)/L and (32.20 +/- 10.42) x 10(12)/L, respectively, showing significant difference (t = 13.780, P = 0.000). The recovery rate of leukocyte was 58.30% +/- 19.24%, and the enrichment factor was 6.10 +/- 1.93. The concentrations of platelets and leukocyte in PRP were positively correlated with the platelet concentration (r = 0.652, P = 0.000) and leukocyte concentration (r = 0.460, P = 0.011) in whole blood. The concentrations of platelet and leukocyte in PRP between male and female were not significantly different (P > 0.05). The concentrations of PDGF, TGF-beta, and VEGF in PRP were (698.15 +/- 64.48), (681.36 +/- 65.90), and (1071.55 +/- 106.04) ng/mL, which were

Antiretroviral therapy suppressed participants with low CD4+ T-cell counts segregate according to opposite immunological phenotypes

PubMed Central

Pérez-Santiago, Josué; Ouchi, Dan; Urrea, Victor; Carrillo, Jorge; Cabrera, Cecilia; Villà-Freixa, Jordi; Puig, Jordi; Paredes, Roger; Negredo, Eugènia; Clotet, Bonaventura; Massanella, Marta; Blanco, Julià

2016-01-01

Background: The failure to increase CD4+ T-cell counts in some antiretroviral therapy suppressed participants (immunodiscordance) has been related to perturbed CD4+ T-cell homeostasis and impacts clinical evolution. Methods: We evaluated different definitions of immunodiscordance based on CD4+ T-cell counts (cutoff) or CD4+ T-cell increases from nadir value (ΔCD4) using supervised random forest classification of 74 immunological and clinical variables from 196 antiretroviral therapy suppressed individuals. Unsupervised clustering was performed using relevant variables identified in the supervised approach from 191 individuals. Results: Cutoff definition of CD4+ cell count 400 cells/μl performed better than any other definition in segregating immunoconcordant and immunodiscordant individuals (85% accuracy), using markers of activation, nadir and death of CD4+ T cells. Unsupervised clustering of relevant variables using this definition revealed large heterogeneity between immunodiscordant individuals and segregated participants into three distinct subgroups with distinct production, programmed cell-death protein-1 (PD-1) expression, activation and death of T cells. Surprisingly, a nonnegligible number of immunodiscordant participants (22%) showed high frequency of recent thymic emigrants and low CD4+ T-cell activation and death, very similar to immunoconcordant participants. Notably, human leukocyte antigen - antigen D related (HLA-DR) PD-1 and CD45RA expression in CD4+ T cells allowed reproducing subgroup segregation (81.4% accuracy). Despite sharp immunological differences, similar and persistently low CD4+ values were maintained in these participants over time. Conclusion: A cutoff value of CD4+ T-cell count 400 cells/μl classified better immunodiscordant and immunoconcordant individuals than any ΔCD4 classification. Immunodiscordance may present several, even opposite, immunological patterns that are identified by a simple immunological follow-up. Subgroup

Disorders of Platelet Function

PubMed Central

Huebsch, Lothar B.; Harker, Laurence A.

1981-01-01

Platelets play an important role in hemostasis, and alterations in platelet function may be the cause of abnormal bleeding in a wide variety of congenital and acquired clinical disorders. Platelet dysfunction may be classified as disorders of (1) substrate connective tissue, (2) adhesion, (3) aggregation and (4) platelet-release reaction. The congenital defects of platelet function, although uncommon, have provided important insights into platelet physiology and pathophysiology and, as a group, are less common, better characterized and more readily classified than the acquired defects. The severity of bleeding resulting from platelet dysfunction varies greatly and is substantially increased when another defect of hemostasis coexists. A disorder of platelet function is suspected on the basis of the history and physical examination and is confirmed by the finding of a prolonged bleeding time in the presence of an adequate number of platelets. A specific diagnosis often requires measurements of the factor VIII and von Willebrand factor complex and other tests of platelet function. Some of these tests may be available only in specialized laboratories. Therapy for bleeding episodes resulting from platelet dysfunction is directed at (1) removing or treating the underlying cause of the platelet disorder; (2) replacing the missing plasma cofactors needed to support normal platelet function (such as by the transfusion of cryoprecipitate in patients with von Willebrand disease, and (3) transfusing functional platelets in the form of platelet concentrates in patients with disorders of intrinsic platelet dysfunction. ImagesFigure 1.Figure 2.Figure 3. PMID:7013276

TES/MLS Aura L2 Carbon Monoxide (CO) Nadir (TML2CO)

Atmospheric Science Data Center

2018-05-06

TES/MLS Aura L2 Carbon Monoxide (CO) Nadir (TML2CO) Atmospheric ... profile estimates and associated errors derived using TES & MLS spectral radiance measurements taken at nearest time and locations. ... a priori constraint vectors. News:  TES News Join TES News List Project Title:  TES ...

TES/MLS Aura L2 Carbon Monoxide (CO) Nadir (TML2CO)

Atmospheric Science Data Center

2018-05-07

TES/MLS Aura L2 Carbon Monoxide (CO) Nadir (TML2CO) ... profile estimates and associated errors derived using TES & MLS spectral radiance measurements taken at nearest time and locations. ... a priori constraint vectors. News:  TES News Join TES News List Project Title:  TES ...

A Novel Automated Slide-Based Technology for Visualization, Counting, and Characterization of the Formed Elements of Blood: A Proof of Concept Study.

PubMed

Winkelman, James W; Tanasijevic, Milenko J; Zahniser, David J

2017-08-01

- A novel automated slide-based approach to the complete blood count and white blood cell differential count is introduced. - To present proof of concept for an image-based approach to complete blood count, based on a new slide preparation technique. A preliminary data comparison with the current flow-based technology is shown. - A prototype instrument uses a proprietary method and technology to deposit a precise volume of undiluted peripheral whole blood in a monolayer onto a glass microscope slide so that every cell can be distinguished, counted, and imaged. The slide is stained, and then multispectral image analysis is used to measure the complete blood count parameters. Images from a 600-cell white blood cell differential count, as well as 5000 red blood cells and a variable number of platelets, that are present in 600 high-power fields are made available for a technologist to view on a computer screen. An initial comparison of the basic complete blood count parameters was performed, comparing 1857 specimens on both the new instrument and a flow-based hematology analyzer. - Excellent correlations were obtained between the prototype instrument and a flow-based system. The primary parameters of white blood cell, red blood cell, and platelet counts resulted in correlation coefficients (r) of 0.99, 0.99, and 0.98, respectively. Other indices included hemoglobin (r = 0.99), hematocrit (r = 0.99), mean cellular volume (r = 0.90), mean corpuscular hemoglobin (r = 0.97), and mean platelet volume (r = 0.87). For the automated white blood cell differential counts, r values were calculated for neutrophils (r = 0.98), lymphocytes (r = 0.97), monocytes (r = 0.76), eosinophils (r = 0.96), and basophils (r = 0.63). - Quantitative results for components of the complete blood count and automated white blood cell differential count can be developed by image analysis of a monolayer preparation of a known volume of peripheral blood.

First-Day Newborn Weight Loss Predicts In-Hospital Weight Nadir for Breastfeeding Infants

PubMed Central

Bokser, Seth; Newman, Thomas B.

2010-01-01

Abstract Background Exclusive breastfeeding reduces infant infectious disease. Losing ≥10% birth weight may lead to formula use. The predictive value of first-day weight loss for subsequent weight loss has not been studied. The objective of the present study was to evaluate the relationship between weight loss at <24 hours and subsequent in-hospital weight loss ≥10%. Methods For 1,049 infants, we extracted gestational age, gender, delivery method, feeding type, and weights from medical records. Weight nadir was defined as the lowest weight recorded during birth hospitalization. We used multivariate logistic regression to assess the effect of first-day weight loss on subsequent in-hospital weight loss. Results Mean in-hospital weight nadir was 6.0 ± 2.6%, and mean age at in-hospital weight nadir was 38.7 ± 18.5 hours. While in the hospital 6.4% of infants lost ≥10% of birth weight. Infants losing ≥4.5% birth weight at <24 hours had greater risk of eventual in-hospital weight loss ≥10% (adjusted odds ratio 3.57 [1.75, 7.28]). In this cohort, 798 (76.1%) infants did not have documented weight gain while in the hospital. Conclusions Early weight loss predicts higher risk of ≥10% in-hospital weight loss. Infants with high first-day weight loss could be targeted for further research into improved interventions to promote breastfeeding. PMID:20113202

Dynamic adhesion of eryptotic erythrocytes to immobilized platelets via platelet phosphatidylserine receptors.

PubMed

Walker, Britta; Towhid, Syeda T; Schmid, Evi; Hoffmann, Sascha M; Abed, Majed; Münzer, Patrick; Vogel, Sebastian; Neis, Felix; Brucker, Sara; Gawaz, Meinrad; Borst, Oliver; Lang, Florian

2014-02-01

Glucose depletion of erythrocytes triggers suicidal erythrocyte death or eryptosis, which leads to cell membrane scrambling with phosphatidylserine exposure at the cell surface. Eryptotic erythrocytes adhere to endothelial cells by a mechanism involving phosphatidylserine at the erythrocyte surface and CXCL16 as well as CD36 at the endothelial cell membrane. Nothing has hitherto been known about an interaction between eryptotic erythrocytes and platelets, the decisive cells in primary hemostasis and major players in thrombotic vascular occlusion. The present study thus explored whether and how glucose-depleted erythrocytes adhere to platelets. To this end, adhesion of phosphatidylserine-exposing erythrocytes to platelets under flow conditions was examined in a flow chamber model at arterial shear rates. Platelets were immobilized on collagen and further stimulated with adenosine diphosphate (ADP, 10 μM) or thrombin (0.1 U/ml). As a result, a 48-h glucose depletion triggered phosphatidylserine translocation to the erythrocyte surface and augmented the adhesion of erythrocytes to immobilized platelets, an effect significantly increased upon platelet stimulation. Adherence of erythrocytes to platelets was blunted by coating of erythrocytic phosphatidylserine with annexin V or by neutralization of platelet phosphatidylserine receptors CXCL16 and CD36 with respective antibodies. In conclusion, glucose-depleted erythrocytes adhere to platelets. The adhesive properties of platelets are augmented by platelet activation. Erythrocyte adhesion to immobilized platelets requires phosphatidylserine at the erythrocyte surface and CXCL16 as well as CD36 expression on platelets. Thus platelet-mediated erythrocyte adhesion may foster thromboocclusive complications in diseases with stimulated phosphatidylserine exposure of erythrocytes.

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

PubMed

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 <2.5 (p = 0.025). The median PFS was 8.1 months for the patients with N/L ratio >2.5 versus 13.5 months for the patients with N/L ratio <2.5 (p = 0.025). At univariate Cox regression 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.

Overview of platelet physiology and laboratory evaluation of platelet function.

PubMed

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

Attenuation of Thrombosis by Crude Rice (Oryza sativa) Bran Policosanol Extract: Ex Vivo Platelet Aggregation and Serum Levels of Arachidonic Acid Metabolites

PubMed Central

Ismail, Maznah; Tohit, Eusni Rahayu Mohd; Abdullah, Rasedee; Zhang, Yi-Da

2016-01-01

Background. Vascular occlusion or thrombosis was often attributed to uncontrolled platelet activation. Influence of sugarcane policosanol extract on platelet was reported but little was known of rice bran policosanol, particularly its mechanisms of actions on platelet activities. Objective. Antiplatelet mechanisms of rice bran policosanol extract (RBE) were studied using hyperlipidemic Sprague Dawley rats. Ex vivo platelet aggregation, platelet count (PC), bleeding time (BT), and coagulation time were assayed. Serum eicosanoids and other aggregation-related metabolites levels were quantified. Design. Rats were divided into 6 groups for comparisons (vehicle control Tween 20/H2O, high dose policosanol 500 mg/kg, middle dose policosanol 250 mg/kg, low dose policosanol 100 mg/kg, and positive control aspirin 30 mg/kg). Results. Low dose 100 mg/kg of RBE inhibited aggregation by 42.32 ± 4.31% and this was comparable with the effect of 30 mg/kg aspirin, 43.91 ± 5.27%. Results showed that there were no significant differences in PC, BT, and coagulation time among various groups after RBE treatment. Serum thromboxane A2 was attenuated while prostacyclin level increased upon RBE treatment. Conclusions. RBE reduced ex vivo ADP-induced platelet aggregation without giving adverse effects. No changes in full blood count suggested that rice bran policosanol did not disturb biological blood cell production and destruction yet it reduced aggregation through different mechanisms. PMID:27800004

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

PubMed

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

2017-04-01

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

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

PubMed

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

Evidence for Radiation-Induced Disseminated Intravascular Coagulation as a Major Cause of Radiation-Induced Death in Ferrets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krigsfeld, Gabriel S.; Savage, Alexandria R.; Billings, Paul C.

Purpose: The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Methods and Materials: Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. Results: The lethal dose of radiation to 50% of the population (LD{sub 50}) of the ferrets was established at ∼1.5 Gy, with 100%more » mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Conclusions: Data presented here provide evidence that death at the LD{sub 50} in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals.« less

Evidence for radiation-induced disseminated intravascular coagulation as a major cause of radiation-induced death in ferrets.

PubMed

Krigsfeld, Gabriel S; Savage, Alexandria R; Billings, Paul C; Lin, Liyong; Kennedy, Ann R

2014-03-15

The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. The lethal dose of radiation to 50% of the population (LD50) of the ferrets was established at ∼ 1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Data presented here provide evidence that death at the LD50 in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals. Copyright © 2014 Elsevier Inc. All rights reserved.

Heparin-independent, PF4-dependent binding of HIT antibodies to platelets: implications for HIT pathogenesis.

PubMed

Padmanabhan, Anand; Jones, Curtis G; Bougie, Daniel W; Curtis, Brian R; McFarland, Janice G; Wang, Demin; Aster, Richard H

2015-01-01

Antibodies specific for platelet factor 4 (PF4)/heparin complexes are the hallmark of heparin-induced thrombocytopenia and thrombosis (HIT), but many antibody-positive patients have normal platelet counts. The basis for this is not fully understood, but it is believed that antibodies testing positive in the serotonin release assay (SRA) are the most likely to cause disease. We addressed this issue by characterizing PF4-dependent binding of HIT antibodies to intact platelets and found that most antibodies testing positive in the SRA, but none of those testing negative, bind to and activate platelets when PF4 is present without any requirement for heparin (P < .0001). Binding of SRA-positive antibodies to platelets was inhibited by chondroitinase ABC digestion (P < .05) and by the addition of chondroitin-4-sulfate (CS) or heparin in excess quantities. The findings suggest that although all HIT antibodies recognize PF4 in a complex with heparin, only a subset of these antibodies recognize more subtle epitopes induced in PF4 when it binds to CS, the major platelet glycosaminoglycan. Antibodies having this property could explain "delayed HIT" seen in some individuals after discontinuation of heparin and the high risk for thrombosis that persists for weeks in patients recovered from HIT. © 2015 by The American Society of Hematology.

Heparin-independent, PF4-dependent binding of HIT antibodies to platelets: implications for HIT pathogenesis

PubMed Central

Jones, Curtis G.; Bougie, Daniel W.; Curtis, Brian R.; McFarland, Janice G.; Wang, Demin; Aster, Richard H.

2015-01-01

Antibodies specific for platelet factor 4 (PF4)/heparin complexes are the hallmark of heparin-induced thrombocytopenia and thrombosis (HIT), but many antibody-positive patients have normal platelet counts. The basis for this is not fully understood, but it is believed that antibodies testing positive in the serotonin release assay (SRA) are the most likely to cause disease. We addressed this issue by characterizing PF4-dependent binding of HIT antibodies to intact platelets and found that most antibodies testing positive in the SRA, but none of those testing negative, bind to and activate platelets when PF4 is present without any requirement for heparin (P < .0001). Binding of SRA-positive antibodies to platelets was inhibited by chondroitinase ABC digestion (P < .05) and by the addition of chondroitin-4-sulfate (CS) or heparin in excess quantities. The findings suggest that although all HIT antibodies recognize PF4 in a complex with heparin, only a subset of these antibodies recognize more subtle epitopes induced in PF4 when it binds to CS, the major platelet glycosaminoglycan. Antibodies having this property could explain “delayed HIT” seen in some individuals after discontinuation of heparin and the high risk for thrombosis that persists for weeks in patients recovered from HIT. PMID:25342714

The practice of platelet transfusion prior to central venous catheterization in presence of coagulopathy: a national survey among clinicians.

PubMed

van de Weerdt, E K; Peters, A L; Goudswaard, E J; Binnekade, J M; van Lienden, K P; Biemond, B J; Vlaar, A P J

2017-05-01

Correction of coagulopathy prior to central venous catheter (CVC) placement is advocated by guidelines, while retrospective studies support restrictive use of transfusion products. We conducted a mixed vignette and questionnaire web survey to investigate current practice and preferences for CVC placement. Clinical vignettes were used to quantify the tendency to administer platelet concentrate. A positive ß-coefficient is in favour of administering platelet concentrate. Ninety-seven physicians answered the survey questions (36 critical care physicians, 14 haematologists, 20 radiologists and 27 anaesthesiologist). Eighty-six physicians subsequently completed the clinical vignettes (response rate 71%). Preferences in favour of correcting thrombocytopenia prior CVC placement were platelet counts of 10 × 10 9 /L and 20 × 10 9 /L (ß = 3·9; ß = 3·2, respectively), the subclavian insertion site (ß = 0·8). An elevated INR (INR = 3; ß = 0·6) and an elevated aPTT (aPTT = 60 s; ß = 0·4) showed a positive trend towards platelet transfusion. Platelet transfusion was less likely in an emergency setting (ß = -0·4). Reported transfusion thresholds for CVC placement varied from <10 × 10 9 /L to 80 × 10 9 /L for platelet count, from 1·0 to 10·0 for INR and from 25 s to 150 s for aPTT. Implementation of ultrasound guidance as standard practice was limited. Current transfusion practice prior to CVC placement is highly variable. Physicians adjust the decision to correct coagulopathy prior CVC placement based on clinical parameters, insertion site and technique applied. © 2017 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.

Mean platelet volume: a potential biomarker of the risk and prognosis of heart disease.

PubMed

Choi, Dong-Hyun; Kang, Seong-Ho; Song, Heesang

2016-11-01

Platelets are essential for progression of atherosclerotic lesions, plaque destabilization, and thrombosis. They secrete and express many substances that are crucial mediators of coagulation, inflammation, and atherosclerosis. Mean platelet volume (MPV) is a precise measure of platelet size, and is routinely reported during complete blood count analysis. Emerging evidence supports the use of MPV as a biomarker predicting the risk of ischemic stroke in patients with atrial fibrillation, and as a guide for prescription of anticoagulation and rhythm-control therapy. In addition, MPV may predict the clinical outcome of percutaneous coronary intervention (PCI) in patients with coronary artery disease and indicate whether additional adjunctive therapy is needed to improve clinical outcomes. This review focuses on the current evidence that MPV may be a biomarker of the risk and prognosis of common heart diseases, particularly atrial fibrillation and coronary artery disease treated via PCI.

FAK regulates platelet extravasation and tumor growth after antiangiogenic therapy withdrawal.

PubMed

Haemmerle, Monika; Bottsford-Miller, Justin; Pradeep, Sunila; Taylor, Morgan L; Choi, Hyun-Jin; Hansen, Jean M; Dalton, Heather J; Stone, Rebecca L; Cho, Min Soon; Nick, Alpa M; Nagaraja, Archana S; Gutschner, Tony; Gharpure, Kshipra M; Mangala, Lingegowda S; Rupaimoole, Rajesha; Han, Hee Dong; Zand, Behrouz; Armaiz-Pena, Guillermo N; Wu, Sherry Y; Pecot, Chad V; Burns, Alan R; Lopez-Berestein, Gabriel; Afshar-Kharghan, Vahid; Sood, Anil K

2016-05-02

Recent studies in patients with ovarian cancer suggest that tumor growth may be accelerated following cessation of antiangiogenesis therapy; however, the underlying mechanisms are not well understood. In this study, we aimed to compare the effects of therapy withdrawal to those of continuous treatment with various antiangiogenic agents. Cessation of therapy with pazopanib, bevacizumab, and the human and murine anti-VEGF antibody B20 was associated with substantial tumor growth in mouse models of ovarian cancer. Increased tumor growth was accompanied by tumor hypoxia, increased tumor angiogenesis, and vascular leakage. Moreover, we found hypoxia-induced ADP production and platelet infiltration into tumors after withdrawal of antiangiogenic therapy, and lowering platelet counts markedly inhibited tumor rebound after withdrawal of antiangiogenic therapy. Focal adhesion kinase (FAK) in platelets regulated their migration into the tumor microenvironment, and FAK-deficient platelets completely prevented the rebound tumor growth. Additionally, combined therapy with a FAK inhibitor and the antiangiogenic agents pazopanib and bevacizumab reduced tumor growth and inhibited negative effects following withdrawal of antiangiogenic therapy. In summary, these results suggest that FAK may be a unique target in situations in which antiangiogenic agents are withdrawn, and dual targeting of FAK and VEGF could have therapeutic implications for ovarian cancer management.

FAK regulates platelet extravasation and tumor growth after antiangiogenic therapy withdrawal

PubMed Central

Haemmerle, Monika; Bottsford-Miller, Justin; Pradeep, Sunila; Taylor, Morgan L.; Hansen, Jean M.; Dalton, Heather J.; Stone, Rebecca L.; Cho, Min Soon; Nick, Alpa M.; Nagaraja, Archana S.; Gutschner, Tony; Gharpure, Kshipra M.; Mangala, Lingegowda S.; Han, Hee Dong; Zand, Behrouz; Armaiz-Pena, Guillermo N.; Wu, Sherry Y.; Pecot, Chad V.; Burns, Alan R.; Lopez-Berestein, Gabriel; Afshar-Kharghan, Vahid; Sood, Anil K.

2016-01-01

Recent studies in patients with ovarian cancer suggest that tumor growth may be accelerated following cessation of antiangiogenesis therapy; however, the underlying mechanisms are not well understood. In this study, we aimed to compare the effects of therapy withdrawal to those of continuous treatment with various antiangiogenic agents. Cessation of therapy with pazopanib, bevacizumab, and the human and murine anti-VEGF antibody B20 was associated with substantial tumor growth in mouse models of ovarian cancer. Increased tumor growth was accompanied by tumor hypoxia, increased tumor angiogenesis, and vascular leakage. Moreover, we found hypoxia-induced ADP production and platelet infiltration into tumors after withdrawal of antiangiogenic therapy, and lowering platelet counts markedly inhibited tumor rebound after withdrawal of antiangiogenic therapy. Focal adhesion kinase (FAK) in platelets regulated their migration into the tumor microenvironment, and FAK-deficient platelets completely prevented the rebound tumor growth. Additionally, combined therapy with a FAK inhibitor and the antiangiogenic agents pazopanib and bevacizumab reduced tumor growth and inhibited negative effects following withdrawal of antiangiogenic therapy. In summary, these results suggest that FAK may be a unique target in situations in which antiangiogenic agents are withdrawn, and dual targeting of FAK and VEGF could have therapeutic implications for ovarian cancer management. PMID:27064283

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

PubMed

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

2014-12-01

Activated platelets and neutrophils exacerbate atherosclerosis. Platelets release the chemokines CXCL4, CXCL4L1 and CCL5, whereas myeloperoxidase (MPO) and azurocidin are neutrophil-derived. We investigated whether plasma levels of these platelet and neutrophil mediators are affected by the acute coronary syndrome (ACS), its medical treatment, concomitant clinical or laboratory parameters, and predictive for the progression of coronary artery disease (CAD). In an observational study, the association of various factors with plasma concentrations of platelet chemokines and neutrophil mediators in 204 patients, either upon admission with ACS and 6 hours later or without ACS or CAD, was determined by multiple linear regression. Mediator release was further analysed after activation of blood with ACS-associated triggers such as plaque material. CXCL4, CXCL4L1, CCL5, MPO and azurocidin levels were elevated in ACS. CXCL4 and CCL5 but not CXCL4L1 or MPO were associated with platelet counts and CRP. CXCL4 (in association with heparin treatment) and MPO declined over 6 hours during ACS. Elevated CCL5 was associated with a progression of CAD. Incubating blood with plaque material, PAR1 and PAR4 activation induced a marked release of CXCL4 and CCL5, whereas CXCL4L1 and MPO were hardly or not altered. Platelet chemokines and neutrophil products are concomitantly elevated in ACS and differentially modulated by heparin treatment. CCL5 levels during ACS predict a progression of preexisting CAD. Platelet-derived products appear to dominate the inflammatory response during ACS, adding to the emerging evidence that ACS per se may promote vascular inflammation.

On the vertical resolution for near-nadir looking spaceborne rain radar

NASA Astrophysics Data System (ADS)

Kozu, Toshiaki

A definition of radar resolution for an arbitrary direction is proposed and used to calculate the vertical resolution for a near-nadir looking spaceborne rain radar. Based on the calculation result, a scanning strategy is proposed which efficiently distributes the measurement time to each angle bin and thus increases the number of independent samples compared with a simple linear scanning.

Pancytopenia after low dose methotrexate therapy in a hemodialysis patient: case report and review of literature.

PubMed

Yang, Ching-Ping; Kuo, Mei-Chuan; Guh, Jinn-Yuh; Chen, Hung-Chun

2006-01-01

Methotrexate (MTX) is widely used in the treatment of rheumatoid arthritis (RA) with a side effect of pancytopenia. However, only a few cases of severe pancytopenia caused by low-dose MTX therapy have been reported, and the condition is rarely reported in uremic patients on dialysis therapy. We thereby report a hemodialysis patient who developed severe pancytopenia after oral treatment with low-dose MTX for RA. A 55-year-old woman who had been on regular hemodialysis treatment for 7 yr suffered from RA for 10 yr. She was regularly treated with celecoxib, prednisolone, and sulfasalazine in the past year. Because of the increasing arthralgia, 7.5 mg per week MTX was prescribed 3 months before admission. Stomatitis, fever, general fatigue, multiple skin carbuncles, and easy bruising developed after a cumulative dose of 90 mg. Pancytopenia was found at admission and the nadir of white blood cell count was 250/microL with 28% neutrophils, hematocrit was 22%, and platelet count was 6000/microL. Eosinophil counts increased from 11.5% initially to 26.1% on the sixth admission day. Transfusion with red blood cells and platelets, and appropriate antibiotics and folic acid were prescribed. She continued receiving regular hemodialysis and eventually recovered within 3 weeks.

Premature aging of cardiovascular/platelet function in polycystic ovarian syndrome.

PubMed

Chan, Wai Ping A; Ngo, Doan T; Sverdlov, Aaron L; Rajendran, Sharmalar; Stafford, Irene; Heresztyn, Tamila; Chirkov, Yuliy Y; Horowitz, John D

2013-07-01

The objective of this study was to compare the impact of aging on nitric oxide (NO) modulation of platelet and vascular function in healthy women and women with polycystic ovary syndrome. A case-control study of women ages 18 to 60 years, comparing women with polycystic ovarian syndrome against age-matched healthy controls, was performed. A total of 242 women, of whom 109 had polycystic ovarian syndrome (based on Rotterdam criteria), participated in the study. Women who were pregnant or on clopidogrel were excluded from the study. Inhibition of platelet aggregation by nitric oxide (primary outcome measure), vascular endothelial function, plasma concentrations of N(G), N(G)-dimethyl-L-arginine (ADMA), endothelial progenitor cell count, and high-sensitivity C-reactive protein (markers of endothelial dysfunction and inflammation) were assessed. With increasing age in control women, there was progressive attenuation of platelet responses to NO, impairment of endothelial function, and elevation of ADMA levels (P ≤.001). Irrespective of age, women with polycystic ovarian syndrome exhibited greater impairment of all these parameters (all P <.05, 2-way analysis of variance) and demonstrated these anomalies earlier in life. Normal aging in women is associated with attenuation of NO-based signaling in platelets and blood vessels. In women with polycystic ovarian syndrome, these changes are present from early adult life and may contribute to premature atherogenesis. Copyright © 2013 Elsevier Inc. All rights reserved.

Increase in mean platelet volume in patients with myocardial bridge.

PubMed

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.

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

PubMed

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

2015-06-01

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

Exploratory studies of extended storage of apheresis platelets in a platelet additive solution (PAS)

PubMed Central

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

2014-01-01

To evaluate the poststorage viability of apheresis platelets stored for up to 18 days in 80% platelet additive solution (PAS)/20% plasma, 117 healthy subjects donated platelets using the Haemonetics MCS+, COBE Spectra (Spectra), or Trima Accel (Trima) systems. Control platelets from the same subjects were compared with their stored test PAS platelets by radiolabeling their stored and control platelets with either 51chromium or 111indium. Trima platelets met Food and Drug Administration poststorage platelet viability criteria for only 7 days vs almost 13 days for Haemonetics platelets; ie, platelet recoveries after these storage times averaged 44 ± 3% vs 49 ± 3% and survivals were 5.4 ± 0.3 vs 4.6 ± 0.3 days, respectively. The differences in storage duration are likely related to both the collection system and the storage bag. The Spectra and Trima platelets were hyperconcentrated during collection, and PAS was added, whereas the Haemonetics platelets were elutriated with PAS, which may have resulted in less collection injury. When Spectra and Trima platelets were stored in Haemonetics’ bags, poststorage viability was significantly improved. Platelet viability is better maintained in vitro than in vivo, allowing substantial increases in platelet storage times. However, implementation will require resolution of potential bacterial overgrowth during storage. PMID:24258816

[Dose-response of aspirin on platelet function in very elderly patients].

PubMed

Feng, X R; Liu, M L; Liu, F; Fan, Y; Tian, Q P

2016-10-18

To assess the consequences of switching aspirin dosage from 100 mg/d to 40 mg/d on cardiovascular benefit, bleeding risk and platelet aggregation in very elderly patients. Arachidonic acid induced platelet aggregation(AA-Ag) was measured in 537 patients aged 80 or older treated with aspirin (100 mg/d). In the study, 100 patients with low on-treatment platelet aggregation and at high risk of bleeding and low risk of cardiovascular events, were switched to aspirin (40 mg/d) and their platelet aggregation was measured again 7 days later.Their bleeding and upper gastrointestinal symptoms were also recorded in following 3 months. The study observed a heterogeneous distributed aspirin 100 mg/d AA-Ag (range: 0.42% to 28.78%)in the 537 very elderly patients.Aspirin 100 mg/d AA-Ag before the switch in aspirin 40 mg/d group was 5.00%±2.32% and the rate of the patients with low on-treatment platelet aggregation was 71.00%. The rates of melena or occult blood positive, other minimal bleeding,upper gastrointestinal symptoms and a history of gastrointestinal bleeding in 40 mg/d group were higher than those in 100 mg/d group. On a regimen of aspirin 40 mg/d, AA-Ag increased to 11.21%±4.95%(range: 2.12% to 28.84%) with 95.00%of the patients with AA-Ag<20% and the rate of the patients with low on-treatment platelet aggregation was 15.00%. Multiple variable analysis revealed that aspirin 40 mg/d AA-Ag was significantly influenced by aspirin 100 mg/d AA-Ag, BMI and platelet counts. The rate of gastrointestinal bleeding decreased from 12.00% to 5.00%,and upper gastrointestinal symptoms decreased from 59.00% to 21.00% after the switch in 40 mg/d group. Switching aspirin dosage from 100 mg/d to 40 mg/d reduces the bleeding events and improves upper gastrointestinal symptoms, thus inhibiting platelet aggregation effectively in very elderly patients.

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

PubMed

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.

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

PubMed

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

2014-11-01

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

Congenital platelet function defects

MedlinePlus

Platelet storage pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... This disorder may also cause severe bleeding. Platelet storage pool disorder (also called platelet secretion disorder) occurs ...

Effects of the breed, sex and age on cellular content and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel.

PubMed

Giraldo, Carlos E; López, Catalina; Álvarez, María E; Samudio, Ismael J; Prades, Marta; Carmona, Jorge U

2013-02-12

There is no information on the effects of the breed, gender and age on the cellular content and growth factor (GF) release from equine pure-platelet rich plasma (P-PRP) and pure-platelet rich gel (P-PRG). The objectives of this study were: 1) to compare the cellular composition of P-PRP with whole blood and platelet poor plasma (PPP); 2) to compare the concentration of transforming GF beta 1 (TGF-β1) and platelet derived GF isoform BB (PDGF-BB) between P-PRP treated with non-ionic detergent (P-PRP+NID), P-PRG (activated with calcium gluconate -CG-), PPP+NID, PPP gel (PPG), and plasma and; 3) to evaluate and to correlate the effect of the breed, gender and age on the cellular and GF concentration for each blood component. Forty adult horses, 20 Argentinean Creole Horses (ACH) and, 20 Colombian Creole Horses (CCH) were included. Data were analyzed by parametric (i.e.: t-test, one way ANOVA) and non parametric (Kruskal-Wallis test, Wilcoxon test) tests. Correlation analysis was also performed by using the Spearman and Pearson tests. A p ≤ 0.05 was set as significant for all tests. All the blood components were compared for platelet (PLT), leukocyte (WBC), TGF-β1 and PDGF-BB concentrations. The effect of the breed, gender and age on these variables was analyzed. A P ≤ 0.05 was accepted as significant for all the tests. PLT counts were 1.8 and 0.6 times higher in P-PRP than in whole blood and PPP, respectively; WBC counts were 0.5 and 0.1 times lower in P-PRP, in comparison with whole blood and PPP, respectively. TGF-β1 and PDGF-BB concentrations were 2.3 and 262 times higher, respectively, in P-PRG than in plasma, and 0.59 and 0.48 times higher, respectively, in P-PRG than in PPG. P-PRG derived from CCH females or young horses presented significantly (P < 0.001) higher PDGF-BB concentrations than P-PRG derived from ACH males or older horses. Our results indicated that P-PRP obtained by a manual method was affected by intrinsic factors such as the breed

NOD2 Receptor is Expressed in Platelets and Enhances Platelet Activation and Thrombosis

PubMed Central

Zhang, Si; Zhang, Shenghui; Hu, Liang; Zhai, Lili; Xue, Ruyi; Ye, Jianqin; Chen, Leilei; Cheng, Guanjun; Mruk, Jozef; Kunapuli, Satya P.; Ding, Zhongren

2015-01-01

Background Pattern recognition receptor NOD2 (nucleotide binding oligomerization domain 2) is well investigated in immunity, its expression and function in platelets has never been explored. Method and Results Using RT-PCR and Western blot we show that both human and mouse platelets express NOD2, and its agonist MDP induced NOD2 activation as evidenced by receptor dimerization. NOD2 activation potentiates platelet aggregation and secretion induced by low concentration of thrombin or collagen, as well as clot retraction. These potentiating effects of MDP were not seen in platelets from NOD2-deficient mice. Plasma from septic patients also potentiates platelet aggregation induced by thrombin or collagen NOD2-dependently. Using intravital microscopy, we found that MDP administration accelerated in vivo thrombosis in FeCl3-injured mesenteric arteriole thrombosis mouse model. Platelet depletion and transfusion experiments confirmed that NOD2 from platelets contributes to the in vivo thrombosis in mice. NOD2 activation also accelerates platelet-dependent hemostasis. We further found that platelets express RIP2 (receptor-interacting protein 2), and provided evidences suggesting that MAPK and NO/sGC/cGMP/PGK pathways downstream of RIP2 mediate the role of NOD2 in platelets. Finally, MDP stimulates proinflammatory cytokine IL-1β maturation and accumulation in human and mouse platelets NOD2-dependently. Conclusions NOD2 is expressed in platelets and functions in platelet activation and arterial thrombosis, possibly during infection. To our knowledge, this is the first study on NOD-like receptors in platelets which links thrombotic events to inflammation. PMID:25825396

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

PubMed

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 < 0.001). The bactericidal effects produced by PLF and PRP were more pronounced than those by PPP in both qualitative and quantitative aspects. No inhibitory zones against three Gram-negative organisms were observed in the Bioseal®. In conclusion, our homemade PLF, as compared with commercial products, had remarkable antimicrobial activity against Gram-negative bacteria relevant to fistula colonization. The presence of 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.

The Effects of 2′-O-Methoxyethyl Containing Antisense Oligonucleotides on Platelets in Human Clinical Trials

PubMed Central

Baker, Brenda F.; Witztum, Joseph L.; Kwoh, T. Jesse; Pham, Nguyen C.; Salgado, Nelson; McEvoy, Bradley W.; Cheng, Wei; Hughes, Steven G.; Bhanot, Sanjay; Geary, Richard S.

2017-01-01

A thorough analysis of clinical trial data in the Ionis integrated safety database (ISDB) was performed to determine if there is a class effect on platelet numbers and function in subjects treated with 2′-O-methoxyethyl (2′MOE)-modified antisense oligonucleotides (ASOs). The Ionis ISDB includes over 2,600 human subjects treated with 16 different 2′MOE ASOs in placebo-controlled and open-label clinical trials over a range of doses up to 624 mg/week and treatment durations as long as 4.6 years. This analysis showed that there is no class generic effect on platelet numbers and no incidence of confirmed platelet levels below 50 K/μL in subjects treated with 2′MOE ASOs. Only 7 of 2,638 (0.3%) subjects treated with a 2′MOE ASO experienced a confirmed postbaseline (BSLN) platelet count between 100 and 50 K/μL. Three of sixteen 2′MOE ASOs had >10% incidence of platelet decreases >30% from BSLN, suggesting that certain sequences may associate with clinically insignificant platelet declines. Further to these results, we found no evidence that 2′MOE ASOs alter platelet function, as measured by the lack of clinically relevant bleeding in the presence or absence of other drugs that alter platelet function and/or number and by the results from trials conducted with the factor XI (FXI) ASO. PMID:28145801

Pharmacological intervention against bubble-induced platelet aggregation in a rat model of decompression sickness

PubMed Central

Vallée, Nicolas; Ignatescu, Mihaela; Bourdon, Lionel

2011-01-01

Decompression sickness (DCS) with alterations in coagulation system and formation of platelet thrombi occurs when a subject is subjected to a reduction in environmental pressure. Blood platelet consumption after decompression is clearly linked to bubble formation in humans and offers an index for evaluating DCS severity in animal models. Previous studies highlighted a predominant involvement of platelet activation and thrombin generation in bubble-induced platelet aggregation (BIPA). To study the mechanism of the BIPA in DCS, we examined the effect of acetylsalicylic acid (ASA), heparin (Hep), and clopidogrel (Clo), with anti-thrombotic dose pretreatment in a rat model of DCS. Male Sprague-Dawley rats (n = 208) were randomly assigned to one experimental group treated before the hyperbaric exposure and decompression protocol either with ASA (3×100 mg·kg−1·day−1, n = 30), Clo (50 mg·kg−1·day−1, n = 60), Hep (500 IU/kg, n = 30), or to untreated group (n = 49). Rats were first compressed to 1,000 kPa (90 msw) for 45 min and then decompressed to surface in 38 min. In a control experiment, rats were treated with ASA (n = 13), Clo (n = 13), or Hep (n = 13) and maintained at atmospheric pressure for an equivalent period of time. Onset of DCS symptoms and death were recorded during a 60-min observation period after surfacing. DCS evaluation included pulmonary and neurological signs. Blood samples for platelet count (PC) were taken 30 min before hyperbaric exposure and 30 min after surfacing. Clo reduces the DCS mortality risk (mortality rate: 3/60 with Clo, 15/30 with ASA, 21/30 with Hep, and 35/49 in the untreated group) and DCS severity (neurological DCS incidence: 9/60 with Clo, 6/30 with ASA, 5/30 with Hep, and 12/49 in the untreated group). Clo reduced fall in platelet count and BIPA (−4,5% with Clo, −19.5% with ASA, −19,9% with Hep, and −29,6% in the untreated group). ASA, which inhibits the thromboxane A2 pathway, and Hep, which inhibits thrombin

Simultaneous overpass off nadir (SOON): a method for unified calibration/validation across IEOS and GEOSS system of systems

NASA Astrophysics Data System (ADS)

Ardanuy, Philip; Bergen, Bill; Huang, Allen; Kratz, Gene; Puschell, Jeff; Schueler, Carl; Walker, Joe

2006-08-01

The US operates a diverse, evolving constellation of research and operational environmental satellites, principally in polar and geosynchronous orbits. Our current and enhanced future domestic remote sensing capability is complemented by the significant capabilities of our current and potential future international partners. In this analysis, we define "success" through the data customers' "eyes": participating in the sufficient and continuously improving satisfaction of their mission responsibilities. To successfully fuse together observations from multiple simultaneous platforms and sensors into a common, self-consistent, operational environment requires that there exist a unified calibration and validation approach. Here, we consider develop a concept for an integrating framework for absolute accuracy; long-term stability; self-consistency among sensors, platforms, techniques, and observing systems; and validation and characterization of performance. Across all systems, this is a non-trivial problem. Simultaneous Nadir Overpasses, or SNO's, provide a proven intercomparison technique: simultaneous, collocated, co-angular measurements. Many systems have off-nadir elements, or effects, that must be calibrated. For these systems, the nadir technique constrains the process. We define the term "SOON," for simultaneous overpass off nadir. We present a target architecture and sensitivity analysis for the affordable, sustainable implementation of a global SOON calibration/validation network that can deliver the much-needed comprehensive, common, self-consistent operational picture in near-real time, at an affordable cost.

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

PubMed

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.

Nadir Ozone Profile Retrieval from SCIAMACHY: application to the Antarctic Ozone Hole

NASA Astrophysics Data System (ADS)

Shah, Sweta; Piet, Stammes; Tuinder, Olaf N. E.; de Laat, Jos

2017-04-01

We present new nadir ozone profile retrievals using SCIAMACHY UV reflectance spectra for the mission period of the Envisat satellite. We have used the most recent Level-1 data version (v8 with degradation correction included) in the UV range (265-330 nm) and have used the OPERA optimal estimation algorithm (van Peet et al., AMT, 2014) developed in KNMI. We first show the comparison of the retrieved satellite profiles to co-located ozone sonde profiles in order to evaluate the accuracy of the retrieved ozone profile dataset. Based on these results, we have further processed the SCIAMCHY nadir dataset, specifically all the southern hemisphere pixels south of 45 degrees latitude for the months of August-November for the complete years 2003-2011. We show the monthly mean profiles, time-series of daily averages and minima of the retrieved stratospheric columns, and finally the ozone profile trend over the years 2003-2011. We also show the comparison of our results with the literature and hence the consistency of this new SCIAMACHY dataset.

Duffy-Null–Associated Low Neutrophil Counts Influence HIV-1 Susceptibility in High-Risk South African Black Women

PubMed Central

Ramsuran, Veron; Kulkarni, Hemant; He, Weijing; Mlisana, Koleka; Wright, Edwina J.; Werner, Lise; Castiblanco, John; Dhanda, Rahul; Le, Tuan; Dolan, Matthew J.; Guan, Weihua; Weiss, Robin A.; Clark, Robert A.; Abdool Karim, Salim S.; Ndung'u, Thumbi

2011-01-01

Background. The Duffy-null trait and ethnic netropenia are both highly prevalent in Africa. The influence of pre-seroconversion levels of peripheral blood cell counts (PBCs) on the risk of acquiring human immunodeficiency virus (HIV)–1 infection among Africans is unknown. Methods. The triangular relationship among pre-seroconversion PBC counts, host genotypes, and risk of HIV acquisition was determined in a prospective cohort of black South African high-risk female sex workers. Twenty-seven women had seroconversion during follow-up, and 115 remained HIV negative for 2 years, despite engaging in high-risk activity. Results. Pre-seroconversion neutrophil counts in women who subsequently had seroconversion were significantly lower, whereas platelet counts were higher, compared with those who remained HIV negative. Comprising 27% of the cohort, subjects with pre-seroconversion neutrophil counts of <2500 cells/mm3 had a ∼3-fold greater risk of acquiring HIV infection. In a genome-wide association analyses, an African-specific polymorphism (rs2814778) in the promoter of Duffy Antigen Receptor for Chemokines (DARC −46T > C) was significantly associated with neutrophil counts (P = 7.9 × 10−11). DARC −46C/C results in loss of DARC expression on erthyrocytes (Duffy-null) and resistance to Plasmodium vivax malaria, and in our cohort, only subjects with this genotype had pre-seroconversion neutrophil counts of <2500 cells/mm3. The risk of acquiring HIV infection was ∼3-fold greater in those with the trait of Duffy-null–associated low neutrophil counts, compared with all other study participants. Conclusions. Pre-seroconversion neutrophil and platelet counts influence risk of HIV infection. The trait of Duffy-null–associated low neutrophil counts influences HIV susceptibility. Because of the high prevalence of this trait among persons of African ancestry, it may contribute to the dynamics of the HIV epidemic in Africa. PMID:21507922

Hemorrhagic fever with renal syndrome in Albania. Focus on predictors of acute kidney injury in HFRS.

PubMed

Rista, Elvana; Pilaca, Arben; Akshija, Ilir; Rama, Ariol; Harja, Endri; Puca, Edmond; Bino, Silvia; Cadri, Vilma; Kota, Majlinda; Nestor, Thereska; Arjan, Harxhi

2017-06-01

Hemorrhagic fever with renal syndrome (HFRS) is a rodent borne zoonosis, caused by the members of the family Bunyaviridae, genus Hantavirus. The main clinical features of the infection by this virus family are fever, thrombocytopenia and acute kidney injury. The aim of our study was to identify, for the first time, characteristic features of HFRS in the Albanian population. The study comprised 33 consecutive patients admitted with suspected HFRS from April 2011-April 2016 at one center. Clinical diagnosis was confirmed by ELISA and real-time PCR. Statistical analysis was performed to identify prognostic markers and indicators of disease severity. The virus strain causing HFRS was Dobrava type in all 33 cases. The disease outbreaks occurred during the period June-July. Mean hospital stay was 15.7±6.9days. 29 (88%) of the patients were male. The mean age was 39.7±14.1. 16 (48.5%) patients were from Northeast Albania. 8 (24.2%) patients required dialysis. The strongest correlation was the inverse relationship of nadir platelet count with urea and creatinine, p<0.0001, p<0.0079 respectively. Creatinine and hyponatremia were inversely correlated p=0.0007, whereas hyponatremia and nadir platelet count had the highest sensitivity and specificity for development of severe AKI, 92.6%, 100%; 88.9%, 83.3% respectively. Mortality rate was 9.09%. HFRS is a severe viral disease in Albania caused by Dobrava strain. It is associated with high mortality, 9.09% in our cohort. In our study, thrombocytopenia, urinary volume, hyponatremia were indicators of more severe disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Plasma Platelet Microparticles in Thrombotic Thrombocytopenic Purpura.

PubMed

Tahmasbi, Leila; Karimi, Mehran; Kafiabadi, Sedigheh Amini; Nikougoftar, Mahin; Haghpanah, Sezaneh; Ranjbaran, Reza; Moghadam, Mohamad

2017-01-01

Platelet microparticles (PMPs) have a procoagulant activity about 50-100 times greater than active platelets due to high expression of negatively charged phospholipids on their surfaces. In this study, we evaluated microparticle immunophenotyping and also plasma PMPs level in patients with Thrombotic Thrombocytopenic Purpura (TTP) in Southern Iran. We had two study groups: 15 TTP patients and 15 healthy control group and PMPs from platelet concentrate (PC) at the 5 th day of storage. Microparticles were prepared in two steps, by low and high centrifugation followed by size confirmation via 'Dynamic Light Scattering (DLS)' Zetasizer. Immunophenotyping of PMPs was done via flow cytometry, using a FACS Calibur flow cytometer (BD, USA). PMPs counts were obtained using Partec-cyflow and Polysciences Microbeads (1 micron in diameter). Results were analyzed using FlowJo 7.6 (Treestar, USA) and Partec FlowMax software. Our results showed that the majority of microparticles in TTP patients and normal individuals were PMPs and also demonstrated that the plasma PMPs level in TTP patients was higher than the normal control group ( P -value<0.001). It seems that elevated PMPs level in TTP patients could be related to thrombotic events. Nevertheless, more studies are needed to confirm these results. © 2017 by the Association of Clinical Scientists, Inc.

Effect of Blood Shear Forces on Platelet Mediated Thrombosis Inside Arterial Stenosis.

NASA Astrophysics Data System (ADS)

Maalej, Nabil

Shear induced activation of platelets plays a major role in the onset of thrombosis in atherosclerotic arteries. Blood hemodynamics and its effect on platelet kinetics has been studied mainly in in vitro and in ex vivo experiments. We designed new in vivo methods to study blood hemodynamic effects on platelet kinetics in canine stenosed carotid arteries. A carotid artery-jugular vein anastomotic shunt was produced. Intimal damage and controlled variations in the degree of stenosis were produced on the artery. An inflatable cuff was placed around the jugular vein to control vascular resistance. An electromagnetic flowmeter was used to measure blood flow. Doppler ultrasound crystals were used to measure the velocity profiles inside and distal to the stenosis. Stenosis geometry was obtained using digital subtraction angiography and quantitative arteriography. Using these measurements we calculated the wall shear stress using the finite difference solution of the Navier-Stokes equations. To study platelet kinetics, autologous platelets were labeled with Indium Oxine and injected IV. A collimated Nal gamma counter was placed over the stenosis to detect radio-labeled platelet accumulation as platelet mediated thrombi formed in the stenosis. The radioactive count rate increased in an inverse parallel fashion to the decline in flow rate during thrombus formation. The platelet accumulation increased with the increase of percent stenosis and was maximal at the narrow portion of the stenosis. Acute thrombus formation leading to arterial occlusion was only observed for stenosis higher than 70 +/- 5%. Platelet accumulation rate was not significant until the pressure gradient across the stenosis exceeded 40 +/- 10 mmHg. Totally occlusive thrombus formation was only observed for shear stresses greater than a critical value of 100 +/- 10 Pa. Beyond this critical value acute platelet thrombus formation increased exponentially with shear. Increased shear stresses were found to

Platelet granule release is associated with reactive oxygen species generation during platelet storage: A direct link between platelet pro-inflammatory and oxidation states.

PubMed

Ghasemzadeh, Mehran; Hosseini, Ehteramolsadat

2017-08-01

Upon platelet stimulation with agonists, reactive oxygen species (ROS) generation enhances platelet activation and granule release. Whether ROS generation during platelet storage could be directly correlated with the expression of proinflammatory molecules and granule release has been investigated in this study. PRP-platelet concentrates were subjected to flowcytometry analysis to assess the expression of platelet activation marker, P-selectin and CD40L during storage. Intracellular ROS generation was also detected in platelet by flowcytometry using dihydrorhodamine (DHR) 123. Through the dual staining, ROS production was analyzed in either P-selectin positive or negative populations. ROS formation in platelet population was significantly increased by either TRAP (a potent agonist that induces granule release) or PMA (a classic inducer of ROS generation), while the effects of each agonists on P-selectin expression and ROS generation in platelets were comparable. Platelet storage was also associated with the increasing levels of ROS (day 0 vs. day 5; p<0.001) while this increasing pattern was directly correlated with the either expressed P-selectin or CD40L. In addition, in 5 day-stored platelets, samples with ROS levels above 40% showed significantly higher levels of P-selectin and CD40L expression. P-selectin negative population of platelet did not show significant amount of ROS. Our data demonstrated decreased levels of important platelet pro-inflammatory molecules in stored platelets with lower levels of intraplatelet ROS. However, whether quenching of ROS generation during platelet storage can attenuate adverse transfusion reactions raised by platelet pro-inflammatory status is required to be further studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of ultrastructural and nanomechanical signature of platelets from acute myocardial infarction and platelet activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Aiqun; Chen, Jianwei; Liang, Zhi-Hong

Acute myocardial infarction (AMI) initiation and progression follow complex molecular and structural changes in the nanoarchitecture of platelets. However, it remains poorly understood how the transformation from health to AMI alters the ultrastructural and biomechanical properties of platelets within the platelet activation microenvironment. Here, we show using an atomic force microscope (AFM) that platelet samples, including living human platelets from the healthy and AMI patient, activated platelets from collagen-stimulated model, show distinct ultrastructural imaging and stiffness profiles. Correlative morphology obtained on AMI platelets and collagen-activated platelets display distinct pseudopodia structure and nanoclusters on membrane. In contrast to normal platelets, AMImore » platelets have a stiffer distribution resulting from complicated pathogenesis, with a prominent high-stiffness peak representative of platelet activation using AFM-based force spectroscopy. Similar findings are seen in specific stages of platelet activation in collagen-stimulated model. Further evidence obtained from different force measurement region with activated platelets shows that platelet migration is correlated to the more elasticity of pseudopodia while high stiffness at the center region. Overall, ultrastructural and nanomechanical profiling by AFM provides quantitative indicators in the clinical diagnostics of AMI with mechanobiological significance.« less

Clinical application of radiolabelled platelets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kessler, C.

1990-01-01

This book presents papers on the clinical applications of radiolabelled platelets. The papers are grouped into six sections on platelet labelling techniques, radiolabelled platelets in cardiology, monitoring of antiplatelet therapy, platelet scintigraphy in stroke patients, platelet scintigraphy in angiology, and platelet scintigraphy in hematology and other clinical applications, including renal transplant rejection.

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

PubMed

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

2018-04-01

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

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

PubMed

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

2013-12-30

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

Splenic release of platelets contributes to increased circulating platelet size and inflammation after myocardial infarction.

PubMed

Gao, Xiao-Ming; Moore, Xiao-Lei; Liu, Yang; Wang, Xin-Yu; Han, Li-Ping; Su, Yidan; Tsai, Alan; Xu, Qi; Zhang, Ming; Lambert, Gavin W; Kiriazis, Helen; Gao, Wei; Dart, Anthony M; Du, Xiao-Jun

2016-07-01

Acute myocardial infarction (AMI) is characterized by a rapid increase in circulating platelet size but the mechanism for this is unclear. Large platelets are hyperactive and associated with adverse clinical outcomes. We determined mean platelet volume (MPV) and platelet-monocyte conjugation (PMC) using blood samples from patients, and blood and the spleen from mice with AMI. We further measured changes in platelet size, PMC, cardiac and splenic contents of platelets and leucocyte infiltration into the mouse heart. In AMI patients, circulating MPV and PMC increased at 1-3 h post-MI and MPV returned to reference levels within 24 h after admission. In mice with MI, increases in platelet size and PMC became evident within 12 h and were sustained up to 72 h. Splenic platelets are bigger than circulating platelets in normal or infarct mice. At 24 h post-MI, splenic platelet storage was halved whereas cardiac platelets increased by 4-fold. Splenectomy attenuated all changes observed in the blood, reduced leucocyte and platelet accumulation in the infarct myocardium, limited infarct size and alleviated cardiac dilatation and dysfunction. AMI-induced elevated circulating levels of adenosine diphosphate and catecholamines in both human and the mouse, which may trigger splenic platelet release. Pharmacological inhibition of angiotensin-converting enzyme, β1-adrenergic receptor or platelet P2Y12 receptor reduced platelet abundance in the murine infarct myocardium albeit having diverse effects on platelet size and PMC. In conclusion, AMI evokes release of splenic platelets, which contributes to the increase in platelet size and PMC and facilitates myocardial accumulation of platelets and leucocytes, thereby promoting post-infarct inflammation. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Platelet adhesion in hypertension: application of a novel assay of platelet adhesion.

PubMed

Nadar, Sunil K; Caine, Graham J; Blann, Andrew D; Lip, Gregory Y H

2005-01-01

The increased risk of thromboembolism in hypertension may be related to a prothrombotic or hypercoagulable state, with abnormalities in haemostasis and platelet function. To investigate the role of platelets in the pathogenesis of thrombosis in hypertension, we applied a novel new assay to detect and quantify the degree of platelet adhesion to a defined coagulation molecule. Platelet-rich plasma (PRP) and citrated plasma (CP) were obtained from 50 patients with hypertension (25 treated, and 25 untreated) and 30 healthy controls. A suspension of 2 x 10(7) platelets were incubated for one hour in microtitre plates pre-coated with 5mg/mL fibrinogen. The supernatant was carefully aspirated, lysed with 5% tween and stored at -70 degrees C as supernatant platelet lysate (SPL). The wells were carefully washed with saline and bound platelets lysed as before, and stored at -70 degrees C as bound-platelet lysate (BPL). Soluble P-selectin (sP-sel) was determined in CP, SPL and BPL by enzyme-linked immunosorbent assay (ELISA). Patients with hypertension (both treated and previously untreated) had increased platelet adhesion, as determined by increased lysate sP-sel (P=0.002) in BPL, with no change in SPL (P=0.5) compared to healthy controls. There was no significant difference between treated and previously untreated hypertensives. Platelets from patients with hypertension display increased adhesion to an important coagulation factor (fibrinogen). This may, in part, account for the increased risk of thrombosis seen in these patients.

Role of Tumor Suppressor P53 in Megakaryopoiesis and Platelet Function

PubMed Central

Apostolidis, Pani A.; Woulfe, Donna S.; Chavez, Massiel; Miller, William M.; Papoutsakis, Eleftherios T.

2011-01-01

The pathobiological role of p53 has been widely studied, however its role in normophysiology is relatively unexplored. We previously showed that p53 knock-down increased ploidy in megakaryocytic cultures. This study aims to examine the effect of p53 loss on in vivo megakaryopoiesis, platelet production and function, and to investigate the basis for greater ploidy in p53−/− megakaryocytic cultures. Here, we used flow cytometry to analyze ploidy, DNA synthesis and apoptosis in murine cultured and bone marrow megakaryocytes following thrombopoietin administration and to analyze fibrinogen binding to platelets in vitro. Culture of p53−/− marrow cells for 6 days with thrombopoietin gave rise to 1.7-fold more megakaryocytes, 26.1±3.6% of which reached ploidy classes ≥64N compared to 8.2±0.9% of p53+/+ megakaryocytes. This was due to 30% greater DNA synthesis in p53−/− megakaryocytes and 31% greater apoptosis in p53+/+ megakaryocytes by day 4 of culture. Although the bone marrow and spleen steady-state megakaryocytic content and ploidy were similar in p53+/+ and p53−/− mice, thrombopoietin administration resulted in increased megakaryocytic polyploidization in p53−/− mice. Although their platelet counts were normal, p53−/− mice exhibited significantly longer bleeding times and p53−/− platelets were less sensitive than p53+/+ platelets to agonist-induced fibrinogen binding and P-selectin secretion. In summary, our in vivo and ex-vivo studies indicate that p53 loss leads to increased polyploidization during megakaryopoiesis. Our findings also suggest for the first time a direct link between p53 loss and the development of fully functional platelets resulting in hemostatic deficiencies. PMID:22024107

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

PubMed

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

2011-02-01

Microparticles (MP) are membrane vesicles with thrombogenic and immunomodulatory properties. We determined MP subgroups from resting platelets, activated platelets and endothelial cells in donors and apheresis platelet concentrates (PC). MP were double stained with annexin V and CD61 (platelet-derived MP; PMP), P-selectin or CD63 (MP from activated platelets) and CD144 plus E-selectin (endothelial cell-derived MP; EMP) and detected by flow cytometry in platelet donors (n=36) and apheresis PC (n=11; Trima™). PC contained MP, mainly from resting platelets [93% (90-95)], and minor fractions of PMP from activated platelets [P-selectin(+) or CD63(+); 4·8% (3·2-7·7) and 2·6% (2·0-4·0)]. Compared to donors, levels of annexin V+ MP, PMP, P-selectin(+) and CD63(+) MP were 1·7-, 2·3-, 8·6- and 3·1-fold higher in PC (all P<0·05). During storage (1-5 days), levels of annexin V+ MP and PMP did not increase, although small increases in the fraction of P-selectin(+) or CD63(+) MP occurred (both P<0·05). PC also contained EMP, which were 2·6- to 3·7-fold enriched in PC compared to donors (P<0·05). Transfusion of apheresis PC also results in transfusion of HLA-carrying PMP and EMP. This might counteract the aim of reducing transfused HLA load by leucodepletion. The increases in PMP exposing P-selectin or CD63 reflect mild platelet activation during storage. We conclude that in leucodepleted platelet apheresis using fluidized particle bed technology, MP are harvested mainly from the donor by apheresis. Improvement in apheresis technology might reduce MP load. © 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.

High on-clopidogrel treatment platelet reactivity in Thai patients with chronic stable angina scheduled for percutaneous coronary intervention.

PubMed