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- ItemAcesso aberto (Open Access)Altered immunophenotypic features of peripheral blood platelets in myelodysplastic syndromes(Ferrata Storti Foundation, 2012-06-01) Sandes, Alex Freire [UNIFESP]; Yamamoto, Mihoko [UNIFESP]; Matarraz, Sergio; Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Quijano, Sandra; Lopez, Antonio; Oguro, Tsutomu; Kimura, Eliza Yuriko Sugano [UNIFESP]; Orfao, Alberto; Universidade Federal de São Paulo (UNIFESP); Univ Salamanca; Hosp Serv Publ Estadual São PauloBackgroundMultiparameter flow cytometric analysis of bone marrow and peripheral blood cells has proven to be of help in the diagnostic workup of myelodysplastic syndromes. However, the usefulness of flow cytometry for the detection of megakaryocytic and platelet dysplasia has not yet been investigated. the aim of this pilot study was to evaluate by flow cytometry the diagnostic and prognostic value of platelet dysplasia in myelodysplastic syndromes.Design and MethodsWe investigated the pattern of expression of distinct surface glycoproteins on peripheral blood platelets from a series of 44 myelodysplastic syndrome patients, 20 healthy subjects and 19 patients with platelet alterations associated to disease conditions other than myelodysplastic syndromes. Quantitative expression of CD31, CD34, CD36, CD41a, CD41b, CD42a, CD42b and CD61 glycoproteins together with the PAC-1, CD62-P, fibrinogen and CD63 platelet activation-associated markers and platelet light scatter properties were systematically evaluated.ResultsOverall, flow cytometry identified multiple immunophenotypic abnormalities on platelets of myelodysplastic syndrome patients, including altered light scatter characteristics, over-and under expression of specific platelet glycoproteins and asynchronous expression of CD34; decreased expression of CD36 (n=5), CD42a (n=1) and CD61 (n=2), together with reactivity for CD34 (n=1) were only observed among myelodysplastic syndrome cases, while other alterations were also found in other platelet disorders. Based on the overall platelet alterations detected for each patient, an immunophenotypic score was built which identified a subgroup of myelodysplastic syndrome patients with a high rate of moderate to severe alterations (score>1.5; n=16) who more frequently showed thrombocytopenia, megakaryocytic dysplasia and high-risk disease, together with a shorter overall survival.ConclusionsOur results show the presence of altered phenotypes by flow cytometry on platelets from around half of the myelodysplastic syndrome patients studied. If confirmed in larger series of patients, these findings may help refine the diagnostic and prognostic assessment of this group of disorders.
- ItemSomente MetadadadosEffects of Lopap on human endothelial cells and platelets(Karger, 2001-05-01) Chudzinski-Tavassi, Ana Marisa [UNIFESP]; Schattner, M.; Fritzen, Marcio [UNIFESP]; Pozner, R. G.; Reis, C. V.; Lourenco, Dayse Maria [UNIFESP]; Lazzari, M. A.; FAPESP; Natl Acad Med; Consejo Nacl Invest Cient & Tecn; Universidade Federal de São Paulo (UNIFESP)Severe consumption coagulopathy has been detected in rats after Lopap (a prothrombin activator from Lonomia obliqua caterpillar bristles) infusion and in humans after accidental contact with L. obliqua bristles. However, platelet count and antithrombin (AT) levels were only modestly affected, suggesting that a different form of blood coagulation activation may be involved in this hemorrhagic syndrome. Here we describe that Lopap had no effect on aggregation of washed human platelets induced by several agonists, suggesting that it might not impair platelet function in vivo. AT was able to inhibit the amidolytic activity of thrombin generated by incubation of Lopap with prothrombin in a purified system, which maybe different from that generated by the prothrombinase complex in vivo. The surface expression of both ICAM-1 and E-selectin but not of VCAM-1 was upregulated by Lopap in cultured HUVEC, suggesting that it may behave differently from other mediators, such as thrombin and tumor necrosis factor-alpha. Copyright (C) 2002 S. Karger AG, Basel.
- ItemSomente MetadadadosInterface between breast cancer cells and the tumor microenvironment using platelet-rich plasma to promote tumor angiogenesis - influence of platelets and fibrin bundles on the behavior of breast tumor cells(Impact Journals Llc, 2017) Andrade, Sheila Siqueira [UNIFESP]; Sumikawa, Joana Tomomi [UNIFESP]; Castro, Eloisa Dognani [UNIFESP]; Batista, Fabricio Pereira [UNIFESP]; Paredes-Gamero, Edgar [UNIFESP]; Oliveira, Lilian Carolina; Guerra, Izabel Monasterio [UNIFESP]; Peres, Giovani Bravin [UNIFESP]; Cavalheiro, Renan Pelluzzi [UNIFESP]; Juliano, Luiz; Nazario, Afonso Pinto [UNIFESP]; Facina, Gil [UNIFESP]; Tsai, Siu Mui; Vilela Oliva, Maria Luiza [UNIFESP]; Batista Castello Girao, Manoel Joao [UNIFESP]Cancer progression is associated with an evolving tissue interface of direct epithelial-tumor microenvironment interactions. In biopsies of human breast tumors, extensive alterations in molecular pathways are correlated with cancer staging on both sides of the tumor-stroma interface. These interactions provide a pivotal paracrine signaling to induce malignant phenotype transition, the epithelial-mesenchymal transition (EMT). We explored how the direct contact between platelets-fibrin bundles primes metastasis using platelet-rich plasma (PRP) as a source of growth factors and mimics the provisional fibrin matrix between actively growing breast cancer cells and the tumor stroma. We have demonstrated PRP functions, modulating cell proliferation that is tumor-subtype and cancer cell-type-specific. Epithelial and stromal primary cells were prepared from breast cancer biopsies from 21 women with different cancer subtypes. Cells supplemented with PRP were immunoblotted with anti-phospho and total Src-Tyr-416, FAK-Try-925, E-cadherin, N-cadherin, TGF-beta, Smad2, and Snail monoclonal antibodies. Breast tumor cells from luminal B and HER2 subtypes showed the most malignant profiles and the expression of thrombin and other classes of proteases at levels that were detectable through FRET peptide libraries. The angiogenesis process was investigated in the interface obtained between platelet-fibrin-breast tumor cells co-cultured with HUVEC cells. Luminal B and HER2 cells showed robust endothelial cell capillary-like tubes ex vivo. The studied interface contributes to the attachment of endothelial cells, provides a source of growth factors, and is a solid substrate. Thus, replacement of FBS supplementation with PRP supplementation represents an efficient and simple approach for mimicking the real multifactorial tumor microenvironment.
- ItemSomente MetadadadosPrediction of esophageal varices in hepatic cirrhosis by noninvasive markers(Lippincott Williams & Wilkins, 2011-09-01) Tafarel, Jean Rodrigo [UNIFESP]; Lenz Tolentino, Luciano Henrique [UNIFESP]; Correa, Lucianna Motta [UNIFESP]; Bonilha, Danielle Rossana [UNIFESP]; Piauilino, Patricia [UNIFESP]; Martins, Fernanda Prata [UNIFESP]; Rodrigues, Rodrigo Azevedo [UNIFESP]; Nakao, Frank Shigeo [UNIFESP]; Della Libera, Ermelindo [UNIFESP]; Ferrari, Angelo Paulo [UNIFESP]; Silveira Roehr, Maria Rachel da [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objective To determine whether Model for End-stage Liver Disease (MELD) Child-Turcotte-Pugh (CTP) classification, AST to platelet ratio index (APRI), and laboratory tests could predict the presence of esophageal varices (EV) or varices which need prophylactic therapy (medium or large size EV).Methods Three hundred patients with cirrhosis (193 men; mean age 53.1 years; majority with chronic C hepatitis) were prospectively analyzed. the presence of EV (any size and medium or large EV) was correlated with patients' characteristics (MELD, CTP classification, APRI, platelets count, and liver tests).Results One hundred and seventy-one patients (57%) had EV, of whom 35% (105) had varices which need prophylactic therapy (VPT). the distribution of EV according to CTP classification was as follows: A, 49%; B, 75.3% and C, 80%. Independent predictors of EV were: MELD higher than 8 (P = 0.02); APRI higher than 1.64 (P = 0.01); platelet count lower than 93 000/mm(3) (P < 0.01); aspartate aminotransferase higher than 1.34 x UNL (P = 0.01), and total bilirubin higher than 1 mg/dl (P = 0.04). MELD higher than 8 had the highest discriminative value for presence of EV (sensitivity = 80.1%; specificity = 51.2%; area under receiver operating characteristics = 0.68). Factors independently associated with VPT were: thrombocytopenia (< 92 000/mm(3); P < 0.01) and aspartate aminotransferase higher than 1.47 x UNL (P = 0.03). Platelet count lower than 92 000/mm(3) had sensitivity of 65.7%, specificity of 57.9%, and an area under receiver operating characteristics of 0.62 for the presence of VPT.Conclusion High values on MELD are associated with EV and thrombocytopenia, with varices which need prophylactic therapy. As a result of their low sensitivity and specificity, it is suggested to maintain the recommendation of upper gastrointestinal endoscopy for all patients with cirhosis. Eur J Gastroenterol Hepatol 23: 754-758 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.
- ItemSomente MetadadadosThrombocytemia as a predictor of portal hypertension in schistosomiasis(Springer, 2000-10-01) Souza, Marilia Rodrigues Freitas de [UNIFESP]; Toledo, Carlos Fischer de [UNIFESP]; Borges, Durval Rosa [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Sufferers of schistosomiasis mansoni can evolve a clinical form of the disease associated with portal hypertension. To differentiate this form, routine clinical tests and biological indices were evaluated. In all, 54 HBsAg- and HCV-negative patients were studied, 42 with schistosomiasis and 12 normal volunteers. Using clinical criteria, ultrasonography, and endoscopy, the schistosomiasis patients were classified into two groups: mild chronic form (MS, N = 14) and chronic form associated with portal hypertension (PH, N = 28). The laboratory parameters of the MS group did not differ from the controls. The PH group differed from the others in prothrombin index, thrombocytemia, gamma -glutamyltransferase, serum alpha (2)-macroglobulin, and the calculated indices. ROC plot cutoff levels verified that isolated thrombocytemia was the most efficient marker for discrimination of the PH and MS forms. Thrombocytemia of 130 x 10(9) platelets/liter discriminated the groups with an 86% accuracy when all patients were analyzed and 96% when only schistosomiasis patients who did not consume alcohol were included.