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BACKGROUND: Defects of integrin alpha(IIb)beta(3) are typical of Glanzmann's thrombasthenia, an inherited autosomal recessive bleeding disorder characterized by the failure of platelets to aggregate in response to all physiological agonists, but with no abnormalities in the number or size of platelets. Although large heterogeneity has been described for Glanzmann's thrombasthenia, no family has so far been described as having an autosomal dominant form of this disease. DESIGN AND METHODS: We describe two Italian families with moderate thrombocytopenia with large platelets, defective platelet function and moderate/severe mucocutaneous bleeding, transmitted as an autosomal dominant trait and associated with a novel integrin beta(3)-gene (ITGB3) mutation. RESULTS: The characteristics of our families are moderate macrothrombocytopenia and defective platelet function associated with a mild reduction of surface alpha(Ib) beta(3), impaired platelet aggregation to physiological agonists but not to ristocetin, normal clot retraction, reduced fibrinogen binding and expression of activated alpha(IIb)beta(3) upon stimulation, normal platelet adhesion to immobilized fibrinogen but reduced platelet spreading and tyrosine phosphorylation, indicating defective alpha(IIb)beta(3)-mediated outside-in signaling. Molecular analysis revealed a novel mutation of ITGB3 that determines an in-frame deletion producing the loss of amino acids 647-686 of the betaTD ectodomain of integrin beta(3). Haplotype analysis indicated that the two families inherited the mutation from a common ancestral chromosome. CONCLUSIONS: This novel autosomal dominant macrothrombocytopenia associated with platelet dysfunction raises interesting questions about the role of integrin beta(3), and its betaTD domain, in platelet formation and function.

5-Lipoxygenase (5-LO) catalyzes the first two steps in leukotriene (LT) biosynthesis. Because LTs play pivotal roles in allergy and inflammation, 5-LO represents a valuable target for anti-inflammatory drugs. Here, we investigated the molecular mechanism, the pharmacological profile, and the in vivo effectiveness of the novel 1,2-benzoquinone-featured 5-LO inhibitor RF-22c. Compound RF-22c potently inhibited 5-LO product synthesis in neutrophils and monocytes (IC50 ≥ 22 nM) and in cell-free assays (IC50 ≥ 140 nM) without affecting 12/15-LOs, cyclooxygenase (COX)-1/2, or arachidonic acid release, in a specific and reversible manner, supported by molecular docking data. Antioxidant or iron-chelating properties were not evident for RF-22c and 5-LO-regulatory cofactors like Ca2+ mobilization, ERK-1/2 activation, and 5-LO nuclear membrane translocation and interaction with 5-LO-activating protein (FLAP) were unaffected. RF-22c (0.1 mg/kg; i.p.) impaired (I) bronchoconstriction in ovalbumin-sensitized mice challenged with acetylcholine, (II) exudate formation in carrageenan-induced paw edema, and (III) zymosan-induced leukocyte infiltration in air pouches. Taken together, RF-22c is a highly selective and potent 5-LO inhibitor in intact human leukocytes with pronounced effectiveness in different models of inflammation that warrants further preclinical analysis of this agent as anti-inflammatory drug.

A recent article published in this journal, entitled “The influence of herbal medicine on platelet function and coagulation: a narrative review,” byMcEwen,1 nicely reviewed how herbal medicines can play a role in modifying cardiovascular diseases (CVDs), and also highlighted the interaction of herbal medicines with standard anticoagulant medicinal therapy. Here, we wish to further reflect on the effects of Danshen on the cardiovascular system, and also to report the novel underlying mechanism of its main constituents on platelets function and hemostasis. To our knowledge, these aspects have not been previously fully described. CVDs are the main causes of morbidity and mortality worldwide.2 They include myocardial infarction, stroke, rheumatic heart disease, and also peripheral artery disease and venous thrombosis.3 The underlying mechanisms diverge depending on the disease in question.4 Scientists working on CVDsagree that inmost cases hyper-platelet aggregation seems to be a crucial step in cardiovascular hemostasis and in the development and progression of CVDs. For these reasons, pharmacological therapies with agents that modulate platelet reactivity have proven to be effective in the treatment and/or in the prevention of CVDs.5 Moreover, advancements in technology and better knowledge of both platelet biology and biological functions of natural products have facilitated this process and pushed researchers to search for new and more reliable targets. Finally, but not less important, research into natural compounds founded on their ethnopharmacological information, has provided significant contributions to drug improvement and has paved the way for new pharmacological tools.6 Danshen has beenwidely used in traditional folk medicine in China and, to a lesser extent,within theUnited States and several European countries to treat CVDs and cerebrovascular diseases.7 Its cardiovascular beneficial actions are attributable to “thinning” the blood and reducing blood clotting, as well as to “invigorate” theblood or improve circulation. AlthoughDanshen is officially listed in the Chinese Pharmacopeia, the cardiovascular pharmacology of its active constituents has not yet been fully described. To date, more than 40 lipophilic tanshinones and 50 hydrophilic phenolics-like compounds have been isolated from Danshen root and extensively investigated for their cardiovascular activities.8 If we had to promote an “ideal candidate” from one of these lipophilic/phenolics-like compounds in the context of CVDs, this would be without any doubt tanshinone IIA (TIIA) and cryptotanshinone (CRY). Indeed, the discovery of these derivatives of phenanthrene-quinone isolated from Danshen have completely changed the way we look at many Danshen-mediated pharmacological properties.9 Recently, the pharmacological properties of TIIA andCRY in the cardiovascular systemhave attractedgreat interest. Emerging experimental studies and clinical trials have demonstrated that both the compounds prevent atherosclerosis and atherogenesis, as well as cardiac injury due the pleiotropic inhibition of low-density lipoprotein oxidation, monocyte adhesion to endothelium, smooth muscle cell migration and proliferation, macrophage cholesterol accumulation, and proinflammatory cytokine production.10,11 Moreover, few but representative studies have reported the effects of Danshen and TIIA on human blood platelets, human cardiomyocytes and vascular endothelial cells.12–14 However, no preclinical studies and clinical evidences have as yet underlined the key role of TIIA and CRY on platelet biology. A recent article15 has changed this scenario showing that TIIA in vitro selectively inhibited rat platelet aggregation induced by reversible adenosine diphosphate (ADP) stimuli (3 μM) in a concentration-dependent manner (0.5–50 μM). Nevertheless, TIIA was less active against the irreversible stimuli induced by ADP (10 μM) and collagen (10 μg/mL). Moreover, experiments performed on platelet lysates collected at different time-point after the addition of the stimuli shown that TIIA modulated tubulin acetylation and inhibited Erk-2 phosphorylation. Concomitantly, TIIA administrated intraperitoneally at 10 mg/kg significantly prolonged the Letter to the Editor

Introdução: A doação de plaquetas por aférese é um método de coleta que vem aumentando em relevância. Sabe-se que esta técnica apresenta inúmeras vantagens em comparação à doação de sangue total. Observamos que há uma preocupação na qualidade dos hemocomponentes enviados ao paciente, no entanto, não se observam muitas pesquisas em busca do cuidado com o doador. Órgãos como o Food and Drug Administration (FDA) já publicaram normas mais restritivas em relação à doação de plaquetas por aférese, pois pesquisas apontaram uma diminuição de algumas células e proteínas do sistema imunológico em doadores de repetição. Objetivos: Analisar doadores de plaquetas de repetição quanto a parâmetros hematimétricos e quantificação de subpopulações linfocitárias comparando-os com um grupo controle composto por doadores de sangue total que não doam há no mínimo um ano ou doando pela primeira vez e, ainda avaliar se a frequência de doações, o tempo de procedimento e o número de plaquetas doadas influenciam na contagem de leucócitos totais e nas subpopulações de linfócitos. Metodologia: Foram analisados 88 indivíduos em um estudo caso-controle, sendo que o grupo controle (CO) incluído foi de doadores de sangue total que haviam doado pela primeira vez ou haviam doado sangue total há mais de um ano. Os casos (CA) incluídos foram os doadores de repetição de plaquetaférese (quatro ou mais doações no último ano). O pareamento foi feito por sexo e idade. As amostras de sangue periférico foram coletadas em tubos contendo EDTA e analisadas em até 6 horas por citometria de fluxo, através da utilização de anticorpos monoclonais anti-CD3, CD4, CD8, HLADR, CD19 e CD56. Resultados: Foram avaliados 44 pares de doadores (caso vs controle). Destes, 81,8% eram homens, a média de idade dos grupos foi de 46 ±13 anos nos casos e 47 ±11 nos controles. Comparando os dois grupos, observou-se diferença estatisticamente significativa (p

Background: Regenerative strategies based on the use of platelet concentrates as an autologous source of growth factors (GF) has been proposed to promote the healing of long bone nonunions. However, the relatively high failure rate stimulates interest in growing knowledge and developing solutions to obtain the best results from the regenerative approach. Objective: In this study we evaluated whether a cell-based assay system could be able to recognize patients who will benefit or not from the use of autologous platelet preparations. Method: The autologous serum was used in culture medium to promote the osteogenic differentiation of normal bone-marrow stromal cells (BMSC). Blood samples were collected from 16 patients affected by aseptic long bone nonunion who were candidates to the treatment with autologous platelet-rich fibrin. The osteoinductive effect was detected by measuring the BMSC proliferation, the mineralization activity, and the expression of bone-related genes. Serum level of basic fibroblast growth factor (bFGF) was considered as a representative marker of the delivery of osteogenic GFs from platelets. Laboratory results were related to the characteristics of the disease before the treatment and to the outcome at 12 months. Results: Serum samples from "good responders" showed significantly higher levels of bFGF and were able to induce a significantly higher proliferation of BMSC, while no significant differences were observed in terms of osteoblast differentiation. Conclusion: BMSC-based assay could be a useful tool to recognize patients who have a low probability to benefit from the use of autologous platelet concentrate to promote the healing of long bone nonunion.

To the editor: Immune thrombocytopenia (ITP) is an autoimmune disorder whose primary pathogenesis is mediated by Fc receptor (FcR) clearance of antibody-opsonized platelets by spleen macrophages.[1][1] Recently, however, an Fc-independent mechanism of platelet clearance mediated by antibodies

Background High platelet reactivity (HPR) to clopidogrel is associated with an increased risk of ischaemic complications during and after coronary interventions and concerns up to 50% of patients undergoing PCI. Aim of the study The aim of the study was to identify patients with HPR to clopidogrel using bedside clinical information obtained in the Stent Thrombosis In Belgium (STIB) trial. Methods Data on platelet reactivity using the VerifyNow (R) point-of-care assay were obtained in 844 patients undergoing PCI for stable coronary artery disease 12 to 24 hours after a 600-mg loading dose of clopidogrel was given. Demographic, clinical and baseline routine biological tests were obtained and compared with P2Y12 reaction units (PRU). Patients with PRU >230 (HPR) were considered as non-responders to clopidogrel. Results HPR was observed in 424/844 pts. Age, weight, body mass index (BMI), HPR to aspirin, diabetes, renal failure (MDRD 28 kg/m(2) and presence of diabetes were equally associated to predict HPR and can be added to derive a simple score to predict clopidogrel resistance. Although 38.5% of patients without a single clinical predictor still have HPR, 2/3 patients with 2 or 3 risk factors are resistant to clopidogrel. Conclusions STIB HPR score allows identification of patients with a high probability of resistance to clopidogrel based on diabetes, Hb 28 kg/m(2). This bedside clinical test could be useful for the identification of patients in whom another P2Y12 inhibitor should be recommended before and after PCI.

Many drugs are nowadays available to inhibit platelet activation and aggregation, especially in patients with acute coronary syndromes and undergoing percutaneous coronary intervention with stent implantation. Primary targets are represented by enzymes or receptors involved in platelet activation. Genetic mutations in these targets contribute to the inter-individual variability in platelet responses therefore weakening the efficacy of antiplatelet agents. High on treatment platelet reactivity is a condition characterized by low levels of platelet inhibition despite the use of antiplatelet drugs. This could be responsible for re-infarction, stent-thrombosis and strokes, affecting short and long-term prognosis after coronary revascularization. So far, to test antiplatelet resistance either the assessment of platelet function or the identification of genetic carriers of poly morphisms have been pursued. Although several methods are now available to test platelet reactivity, it is still debated whether its routine assessment gives real benefits in clinical practice. The present review aims at examining current evidences on genetic polymorphisms affecting optimal platelet inhibition.

The contribution of vessel wall-derived tissue factor (TF) to atherothrombosis is well established, whereas the pathophysiological relevance of the blood-borne TF is still a matter of debate, and controversies on the presence of platelet-associated TF still exist. In the past 15 years, several studies have documented the presence of TF in human platelets, the capacity of human platelets to use TF mRNA to make de novo protein synthesis, and the increase in the percentage of TF positive platelets in pathological conditions such as coronary artery disease (CAD). The exposure of vessel wall-derived TF at the site of vascular injury would play its main role in the initiation phase, whereas the blood-borne TF carried by platelets would be involved in the propagation phase of thrombus formation. More recent data indicate that megakaryocytes are committed to release into the bloodstream a well-defined number of TF-carrying platelets, which represents only a fraction of the whole platelet population. These findings are in line with the evidence that platelets are heterogeneous in their functions and only a subset of them is involved in the hemostatic process. In this review we summarize the existing knowledge on platelet associated TF and speculate on its relevance to physiology and to atherothrombosis and CAD.

Patients with Klinefelter syndrome (KS) exhibit an increased cardiovascular risk, but underlying mechanisms are largely unknown. The present cross-sectional study has been conducted to evaluate platelet reactivity and the expression of platelet activation markers (8-iso-prostaglandin F2α[8-iso-PGF2α] and 11-dehydro-thromboxane-B₂[11-dehydro-TXB2]) in KS patients and healthy controls. Twenty-three consecutive KS patients under testosterone replacement therapy have been included as case group and 46 age-matched healthy males recruited among hospital staff served as controls. Light transmission aggregometry was performed in both cases and controls and maximal platelet aggregation (max-A%) was defined as maximal light transmittance reached within 5min after the addition of 0.2 or 0.4mm arachidonic acid (AA). A≥50% irreversible light transmittance (LT-50%) following platelet stimulation defined an adequate platelet aggregation and AC-50% was defined as the minimal agonist concentration needed to achieve LT-50%. The AC-50% was 0.26mm AA for KS and 0.36mm for controls (p&nbsp

Introduction The Leukocyte-PRF (Leukocyte-Platelet Rich Fibrin) belongs to a second generation of platelet concentrates which doesn’t need a biochemical blood manipulation. It is used for tissue healing and regeneration in periodontal and oral-maxillofacial surgery. We report two cases of hyperplastic gingival lesions treated by exeresis and application of PRF membranes in order to improve and accelerate tissue healing. Case Presentation Two patients (one Caucasian female, 78-year-old, and one Caucasian male, 30-year-old) were treated for hyperplastic gingival lesions. They underwent to exeresis of lesions and application of PRF membranes. Tissue healing was clinically evaluated after one, three, seven, fourteen and thirty post-operative days. No recurrences were observed after two years of semiannual follow up. Conclusion We obtained rapid and good healing of soft tissues probably due to the elevated content of leukocytes, platelets and growth factors in the leukocyte-platelet rich fibrin. According to our results we suggest L-PRF employment for wounds covering after exeresis of oral neoformations such as hyperplastic gingival lesions.

SummaryPlatelets carry megakaryocyte-derived mRNAs whose translation efficiency before and during activation is not known, although this can greatly affect platelet functions, both under basal conditions and in response to physiological and pathological stimuli, such as those involved in acute coronary syndromes. Aim of the present study was to determine whether changes in microRNA (miRNA) expression occur in response to activating stimuli and whether this affects activity and composition of platelet transcriptome and proteome. Purified platelet-rich plasmas from healthy volunteers were collected and activated with ADP, collagen, or thrombin receptor activating peptide. Transcriptome analysis by RNA-Seq revealed that platelet transcriptome remained largely unaffected within the first 2 hours of stimulation. In contrast, quantitative proteomics showed that almost half of > 700 proteins quantified were modulated under the same conditions. Global miRNA analysis indicated that reorganisation of platelet proteome occurring during activation reflected changes in mature miRNA expression, which therefore, appears to be the main driver of the observed discrepancy between transcriptome and proteome changes. Platelet functions significantly affected by modulated miRNAs include, among others, the integrin/cytoskeletal, coagulation and inflammatory-immune response pathways. These results demonstrate a significant reprogramming of the platelet miRNome during activation, with consequent significant changes in platelet proteome and provide for the first time substantial evidence that fine-tuning of resident mRNA translation by miRNAs is a key event in platelet pathophysiology.

Submitted by Boris Flegr (boris@uerj.br) on 2021-01-05T18:13:46Z No. of bitstreams: 1 DISSERTACAO_FINAL_PARA_IMPRESSAO_Wanda_Vianna_Mury (1).pdf: 1178321 bytes, checksum: 2a3173229679106fcd65c66410827703 (MD5) Made available in DSpace on 2021-01-05T18:13:46Z (GMT). No. of bitstreams: 1 DISSERTACAO_FINAL_PARA_IMPRESSAO_Wanda_Vianna_Mury (1).pdf: 1178321 bytes, checksum: 2a3173229679106fcd65c66410827703 (MD5) Previous issue date: 2014-07-25 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Cardiovascular risk is exponentially increased in women after menopause compared to women in reproductive age. This may be partially explained by an increased platelet activation and endothelial dysfunction. Platelet derived nitric oxide is essential for the inhibition of its activation and aggregation, and its bioavailability depends both on its synthesis and its scavenging by reactive oxygen species. Thus, our aim was to investigate L-arginine-nitric oxide signaling in platelets from postmenopausal women and its association with oxidative stress and platelet aggregation. Fifteen young women (control group) and 12 postmenopausal women without risk factors for cardiovascular diseases consented to participate in the study. Blood was collected in the fasting state in appropriate anticoagulant tubes for platelet experiments. Platelet aggregation induced by collagen was significantly increased in postmenopausal than in young women. They also showed an increased total L-arginine transport, despite lower plasma L-arginine levels. Platelet nitric oxide synthase activity was impaired in postmenopausal women, but no difference was observed in endothelial and inducible nitric oxide synthase expression between groups. The expression of 1 and 1 subunits of guanilate cyclase and phosphodiesterase V were similar between groups. The expressions of gp91phox and p47phox subunits of NADPH oxidase and glutathione peroxidase were not modified. On the other hand, there was an up-regulation of catalase protein levels. Superoxide dismutase activity, but not catalase nor glutathione peroxidase activities, was increased in climacteric women. It was also reported that sulfhydryl group content was increased in postmenopausal women. There was no difference in protein oxidative damage between groups. These findings may contribute to a better understanding of platelet hyperaggregation in postmenopausal women, which may help to further elucidate the heightened cardiovascular morbidity and mortality in this population. O risco de desenvolver doença cardiovascular aumenta com o avançar da idade, sendo exponencialmente maior em mulheres após a menopausa em relação a mulheres em idade reprodutiva. Esse aumento pode ser, em parte, explicado por uma hiperatividade plaquetária e disfunção endotelial nessas mulheres. Em plaquetas, o óxido nítrico é uma molécula essencial para a inibição da sua ativação e agregação; cuja biodisponibilidade depende de sua síntese e inativação por espécies reativas de oxigênio. Assim, o presente estudo visa determinar os efeitos da menopausa sobre a função plaquetária, biodisponibilidade de óxido nítrico e estresse oxidativo. Para tal, a amostra foi constituída por mulheres sendo elas 15 jovens entre 20 e 40 anos (grupo controle), 12 mulheres entre 45 e 60 anos pós-menopausadas há no mínimo 12 meses que não faziam uso de reposição hormonal e que não possuíam fatores de risco para doença cardiovascular. Os resultados demonstraram que mulheres pós-menopausadas apresentam uma hiperagregação plaquetária induzida por colágeno em relação a mulheres jovens. Essas mulheres também apresentaram o influxo de L-arginina aumentado em relação ao grupo controle. No entanto, a atividade da enzima óxido nítrico sintase estava diminuída nas mulheres após a menopausa, assim como os níveis plasmáticos de L-arginina. A expressão das enzimas iNOS e eNOS não diferiu significativamente entre os grupos. A expressão das subunidades 1 e 1 da enzima guanilato ciclase, e a fosfodiesterase 5 não se apresentaram diferentes entre os grupos. A expressão das enzimas glutationa peroxidase, subunidades gp91phox e p47phox da NADPH oxidase não estavam alteradas em plaquetas de mulheres pós-menopausadas, já a catalase estava mais expressa neste grupo. Em relação à atividade das enzimas antioxidantes, foi observado um aumento na superóxido dismutase em mulheres pós-menopausadas. Esse grupo apresentou ainda níveis mais elevados de grupamentos sulfidrila. Já em relação a danos proteicos não foi possível observar diferença entre os grupos. Dessa forma, esses resultados podem contribuir para uma melhor compreensão da hiperagregação plaquetária observada nas mulheres após a menopausa, o que, por sua vez, pode contribuir para a elucidação de mecanismos envolvidos na morbidade e mortalidade cardiovascular elevada nessa população.

Anna Dietrich-Muszalska, Anna KwiatkowskaDepartment of Biological Psychiatry of the Chair of Experimental and Clinical Physiology, Medical University of Lodz, Lodz, PolandAbstract: Blood platelets are considered to be a peripheral marker in schizophrenia and other psychiatric disorders. Oxidative stress in schizophrenia may be responsible for changes in platelet metabolism and function; therefore, the aim of this study was to examine and compare the generation of superoxide anions and activity of an antioxidant enzyme (glutathione peroxidase [GPx]) in blood platelets in patients with schizophrenia and healthy subjects. The level of superoxide anions generated in platelets after thrombin and platelet-activating factor stimulation and activity of GPx in patients with schizophrenia and healthy volunteers was estimated. The results obtained from the study indicate that the generation of superoxide anions in platelets as a response of platelets in patients with schizophrenia to such activating factors as thrombin or platelet-activating factor is higher than in the response of platelets of healthy subjects. In platelets from schizophrenic patients, suppressed GPx activity of about 67% was observed.Keywords: schizophrenia, blood platelet, superoxide anion, activating factors, glutathione peroxidase

Megakaryocytes release mature platelets in a complex process. Platelets are known to be released from intermediate structures, designated proplatelets, which are long, tubelike extensions of the megakaryocyte cytoplasm. We have resolved the ultrastructure of the megakaryocyte cytoskeleton at specific stages of proplatelet morphogenesis and correlated these structures with cytoplasmic remodeling events defined by video microscopy. Platelet production begins with the extension of large pseudopodia that use unique cortical bundles of microtubules to elongate and form thin proplatelet processes with bulbous ends; these contain a peripheral bundle of microtubules that loops upon itself and forms a teardrop-shaped structure. Contrary to prior observations and assumptions, time-lapse microscopy reveals proplatelet processes to be extremely dynamic structures that interconvert reversibly between spread and tubular forms. Microtubule coils similar to those observed in blood platelets are detected only at the ends of proplatelets and not within the platelet-sized beads found along the length of proplatelet extensions. Growth and extension of proplatelet processes is associated with repeated bending and bifurcation, which results in considerable amplification of free ends. These aspects are inhibited by cytochalasin B and, therefore, are dependent on actin. We propose that mature platelets are assembled de novo and released only at the ends of proplatelets, and that the complex bending and branching observed during proplatelet morphogenesis represents an elegant mechanism to increase the numbers of proplatelet ends.

Previous work has shown that two general processes contribute to hepatocellular cancer (HCC) prognosis: liver damage, monitored by indices such as blood bilirubin, prothrombin time (PT), and aspartate aminostransferase (AST); and tumor biology, monitored by indices such as tumor size, tumor number, presence of portal vein thrombosis (PVT) and blood alpha-fetoprotein (AFP) levels. These processes may affect one another, with prognostically significant interactions between multiple tumor and host parameters. These interactions form a context that provide personalization of the prognostic meaning of these factors for every patient. Thus, a given level of bilirubin or tumor diameter might have a different significance in different personal contexts. We previously applied network phenotyping strategy (NPS) to characterize interactions between liver function indices of Asian HCC patients and recognized two clinical phenotypes, S and L, differing in tumor size and tumor nodule numbers. Our aim was to validate the applicability of the NPS-based HCC S/L classification on an independent European HCC cohort, for which survival information was additionally available. Four sets of peripheral blood parameters, including AFP-platelets, derived from routine blood parameter levels and tumor indices from the ITA.LI.CA database, were analyzed using NPS, a graph-theory-based approach that compares personal patterns of complete relationships between clinical data values to reference patterns with significant association to disease outcomes. Without reference to the actual tumor sizes, patients were classified by NPS into two subgroups with S and L phenotypes. These two phenotypes were recognized using solely the HCC screening test results, consisting of eight common blood parameters, paired by their significant correlations, including an AFP-platelets relationship. These trends were combined with patient age, gender, and self-reported alcoholism into NPS personal patient profiles. We subsequently validated (using actual scan data) that patients in L phenotype group had 1.5× larger mean tumor masses relative to S, P = 6 × 10(-16). Importantly, with the new data, liver test pattern-identified S-phenotype patients had typically 1.7× longer survival compared to L-phenotype patients. NPS integrated the liver, tumor, and basic demographic factors. Cirrhosis-associated thrombocytopenia was typical for smaller S tumors. In L tumor phenotype, typical platelet levels increased with the tumor mass. Hepatic inflammation and tumor factors contributed to more aggressive L tumors, with parenchymal destruction and shorter survival. NPS provides integrative interpretation for HCC behavior, identifying two tumor and survival phenotypes by clinical parameter patterns. The NPS classifier is provided as an Excel tool. The NPS system shows the importance of considering each tumor marker and parameter in the total context of all the other parameters of an individual patient.

Background and objectivesAlthough several studies demonstrated that platelet count is higher in women, decreases with age, and is influenced by genetic background, most clinical laboratories still use the reference interval 150-400×10(9) platelets/L for all subjects. The present study was to identify age- and sex-specific reference intervals for platelet count.MethodsWe analysed electronic records of subjects enrolled in three population-based studies that investigated inhabitants of seven Italian areas including six geographic isolates. After exclusion of patients with malignancies, liver diseases, or inherited thrombocytopenias, which could affect platelet count, reference intervals were estimated from 40,987 subjects with the non parametric method computing the 2.5° and 97.5° percentiles.ResultsPlatelet count was similar in men and women until the age of 14, but subsequently women had steadily more platelets than men. The number of platelets decreases quickly in childhood, stabilizes in adulthood, and further decreases in oldness. The final result of this phenomenon is that platelet count in old age was reduced by 35% in men and by 25% in women compared with early infancy. Based on these findings, we estimated reference intervals for platelet count ×10(9)/L in children (176-452), adult men (141-362), adult women (156-405), old men (122-350) and, old women (140-379). Moreover, we calculated an "extended" reference interval that takes into account the differences in platelet count observed in different geographic areas.ConclusionsThe age-, sex-, and origin-related variability of platelet count is very wide, and the patient-adapted reference intervals we propose change the thresholds for diagnosing both thrombocytopenia and thrombocytosis in Italy.

In the last ten years the contribution of both vessel wall-derived tissue factor (TF) and platelets to atherosclerosis has been revisited. At the beginning of the 2000 a circulating blood-borne TF has been proposed to sustain coagulation activation and propagation on the edge of a growing thrombus. Concomitantly with the observation that platelets not only contribute to thrombus formation, but also take part to the onset of the atherosclerotic lesion, evidences have been provided that they express functionally active TF, making them able to trigger the coagulation cascade.

Aim. The aim of this study was the evaluation of the safety and efficacy of autologous platelet-rich gel for the treatment of non-healing vascular ulcers, not responsive to the conventional wound care techniques. Methods. Sixteen patients with vascular chronic wounds were selected, with peripheral arterial disease, vasculitis and post-thrombotic chronic venous insufficiency. Every patient had non-healing wounds, not responsive to conventional treatment carried on for at least one month. The platelet gel obtained either from whole-blood derived platelet concentrates (PC) or from plateletapheresis concentrates (PAC) was applied and the medication was completed with a soft dressing. Pictures of the lesions were performed at the beginning of the treatment and every time the platelet gel was applied on the wound. The end-points were the healing or the reduction of the lesion area, the improvement of the ulcer features and the reduction of pain. Results. Five patients healed up, in eight patients we registered an early improvement with reduction of the lesion area and growth of the bottom of the ulcer with granulation tissue, without the complete healing. In the great majority of the patients we obtained a decisive reduction of pain. Only in three patients we had the worsening of the ulcer with a consequent amputation. Conclusion. This treatment is effective in the majority of cases, without side effects. The easy application, the almost complete absence of side effects and the low cost of platelet gel make this approach very interesting to treat chronic non-healing ulcers.

Despite advances in neuroimaging, the diagnosis of idiopathic Parkinson's disease (PD) remains clinical. The identification of biological markers for an early diagnosis is of great interest to start a neuroprotective therapy aimed at slowing, blocking or reversing the disease progression. Vesicular monoamine transporter 2 (VMAT2) sequesters cytoplasmic dopamine into synaptic vesicles for storage and release. Thus, VMAT2 impairment can regulate intra- and extracellular dopamine levels, influencing oxidative stress and neuronal death. Because in vivo imaging studies have demonstrated a VMAT2 reduction in PD patients greater than would be explained by neuronal loss alone, as an exploratory study we assessed VMAT2 mRNA and protein levels in platelets from 39 PD patients, 39 healthy subjects and 10 patients with vascular parkinsonism (VP) to identify a possible peripheral biomarker for PD. A significant reduction (p < 0.05) of VMAT2 mRNA levels was demonstrated in PD patients versus healthy controls. Patients with VP showed VMAT2 mRNA levels similar to controls. No difference in VMAT2 mRNA levels was found in untreated versus treated patients. No correlation was observed between mRNA levels and demographic or clinical characteristics. Furthermore, eight SNPs tagging the VMAT2 gene did not show effects on VMAT2 mRNA levels. Western blot analysis did not allow the quantification of VMAT2 protein expression in blood platelets. Although further studies in a greater number of cases are needed to confirm our data, the reduction in VMAT2 mRNA in platelets from PD patients suggests the existence of a systemic impairment of this transporter possibly contributing to PD pathology.

We tested the hypothesis that residual platelet reactivity after clopidogrel correlates with the extent and severity of coronary atherosclerosis in patients undergoing elective percutaneous coronary intervention (PCI).

Blood platelets are emerging as important immunomodulatory cells, but complement interaction with platelets is not well understood. Several platelet structures have been described as complement protein 1q (C1q) binding receptors, such as C1qRp/CD93 and gC1qR. However, there are conflicting results whether these receptors are C1q binding structures, or even at all expressed on the cell surface. Recently, the collagen-binding integrin alphaIIbetaI was reported to bind C1q on mast cells, and this receptor is also present on platelets. The aim of this study was to further characterize the effects of C1q on platelets, by quantifying the platelet surface expression of P-selectin (CD62P) and monitoring the formation of platelet-neutrophil aggregates. Using flow cytometry, we found that C1q dose-dependently triggered a rapid but moderate and transient up-regulation of P-selectin already within 5s of C1q exposure. Pre-incubation with an antibody directed against gC1qR significantly inhibited (with 57% compared to control) the up-regulation, whereas an antibody towards the alphaIIbetaI-integrin showed no effect. Stimulation with C1q did not change the cytosolic calcium-levels, as measured with the fluorescent ratiometric probe Fura-2, however, a protein kinase C inhibitor (GF109203x) blocked the C1q-induced P-selectin expression. Furthermore, pre-incubation of platelets with C1q diminished both the collagen as well as the collagen-related peptide-induced up-regulation of P-selectin, most evident after 90s of stimulation. This indicates that C1q may regulate platelet activation via the GPVI receptor, which is a novel finding. Moreover, C1q antagonized the collagen-induced formation of platelet-neutrophil aggregates, indicating a reduced interaction between platelet P-selectin and neutrophil P-selectin glycoprotein ligand-1(PSGL-1/CD162). In summary, C1q induces a moderate rapid platelet P-selectin expression, modulates subsequent collagen and collagen-related peptide stimulation of platelets, and inhibits the formation of platelet-neutrophil aggregates. These immuno-regulatory effects of C1q may have a crucial role in innate immunity and inflammation. Original Publication:Caroline Skoglund, Jonas Wetterö, Pentti Tengvall and Torbjörn Bengtsson, C1q induces a rapid up-regulation of P-selectin and modulates collagen- and collagen-related peptide-triggered activation in human platelets, 2010, Immunobiology, (215), 12, 987-995.http://dx.doi.org/10.1016/j.imbio.2009.11.004Copyright: Elsevier Science B. V., Amsterdamhttp://www.elsevier.com/

Autologous platelet gel, which is usually prepared by adding thrombin and calcium to a platelet concentrate, is used to accelerate bone repair as a possible alternative to recombinant growth factors (GF), through the osteogenic GF released from a-granules. The advantages of platelet gel lie in its mimicking the GF effects of the physiological bone healing and regenerative processes, in addition to a relatively simple and low cost technique. Moreover, if autologous platelet gel is used, immunological reactions are avoided. In in vitro systems, platelet gel stimulated osteogenic differentiation of bone marrow stromal cells, while it inhibited complete osteoclast differentiation and activation. Moreover, platelet gel favoured endothelial cell proliferation and expression of pro-osteogenic functions. In experimental animals and in clinical application, the efficacy of platelet gel was increased by the combination with bone allografts, acting as scaffolds, and with bone marrow stromal cells. © Springer-Verlag 2009.

In this brief paper we would like to hypothesize that platelets might represent a "peripheral" contributory source for the elevation of plasma glutamate levels in the setting of acute ischemic stroke: available evidence and possible mechanisms will be discussed, especially drawing attention to the possible relevance for the pathophysiology of early neurological deterioration.

Novel synthetic collagen fibers, poly(PHG) made by polycondensation of Pro-Hyp-Gly, spontaneously assume polymeric structure with molecular weights greater than 10(5). Its application for biomaterials has been explored, but that for a platelet agonist has not been investigated. Poly(PHG)-induced platelet aggregation independently of thromboxane A(2) and integrin alpha2beta1. Poly(PHG)-induced tyrosine phosphorylation of glycoprotein VI (GPVI)-related molecules and failed to activate GPVI/FcRgamma-deficient platelets. Binding of GPVI to poly(PHG) was confirmed by a surface plasmon resonance spectroscopy, suggesting that poly(PHG) activates platelets through GPVI. Poly(PHG) is an useful research tool to investigate GPVI-mediated signals and a substitute for collagen in platelet functional assays.

The density of the serotonin transporter in the plasma membranes of blood platelets was evaluated by labelled paroxetine binding in three different groups. These groups were: normal controls, epileptic patients having undergone a recent seizure (less than 4 days before) and patients who equally recently presented psychogenic non-epileptic seizures (pseudoseizures). Real seizures resulted in a significant decrease of membrane serotonin transporter density. In the instances of pseudoseizures, its membrane density was undistinguishable from that of normal controls. These data lend further support to the idea that down regulation of serotonin transporter may play a homeostatic role in the cessation of epileptic seizures.