We examined the effects of nitric oxide (NO)/endothelium-derived relaxing factor (EDRF) on platelet surface glycoproteins (GP). As determined by flow cytometry, in both a washed platelet system and platelet-rich plasma, the EDRF congener (S-nitroso-N-acetylcysteine) markedly inhibited both the thrombin-induced and the (stable thromboxane A2 analogue) U-46619-induced upregulation of P-selectin (alpha-granule protein), CD63 (lysosomal protein), and the GPIIb-IIIa complex (fibrinogen receptor) but minimally inhibited downregulation of the GPIb-IX complex (von Willebrand factor receptor). The inhibitory effects of EDRF were markedly reduced in whole blood or by the addition of washed erythrocytes. Platelets in whole blood were still responsive to guanosine 3',5'-cyclic monophosphate (cGMP), as shown by complete inhibition of P-selectin upregulation by the stable analogue N6,2'-O dibutyryl cGMP. These data suggests that 1) cGMP negatively regulates the platelet surface expression of P-selectin, CD63, and the GPIIb-IIIa complex but not the platelet surface expression of the GPIb-IX complex and 2) hemoglobin within erythrocytes inhibits the effects of EDRF/NO on platelet surface glycoproteins.
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http://dx.doi.org/10.1152/ajpheart.1996.270.5.H1640 | DOI Listing |
Clin Nephrol Case Stud
January 2025
Department of Medicine.
Minimal change disease (MCD) accounts for 10 - 15% of idiopathic nephrotic syndromes in adults. Chronic hepatitis C virus (HCV) infection is rarely ascribed as a cause of MCD and was previously associated with interferon-based therapy. MCD in treatment-naïve chronic HCV infection is extremely rare, with only 3 cases reported in the literature.
View Article and Find Full Text PDFPlatelets
December 2025
Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA.
Platelet-like particles (PLPs), derived from megakaryocytic cell lines MEG-01 and K-562, are widely used as a surrogate to study platelet formation and function. We demonstrate by RNA-Seq that PLPs are transcriptionally distinct from platelets. Expression of key genes in signaling pathways promoting platelet activation/aggregation, such as the PI3K/AKT, protein kinase A, phospholipase C, and α-adrenergic and GP6 receptor pathways, was missing or under-expressed in PLPs.
View Article and Find Full Text PDFJ Immunother Precis Oncol
February 2025
Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA, USA.
Introduction: Advanced penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy with a poor prognosis and an unmet need for biomarkers. We performed a retrospective evaluation of real-world efficacy, safety outcomes, and baseline inflammatory biomarkers in patients with advanced pSCC treated with immune checkpoint inhibitors (ICIs).
Methods: We performed a retrospective review of patients with advanced pSCC who received ICIs from 2012 to 2023 at the Winship Cancer Institute of Emory University in Atlanta, GA.
Thromb Haemost
January 2025
Hemostasis and Erythropathology Laboratory, Hematopathology, Pathology Department, Centre de Diagnòstic Biomèdic (CDB), Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
Background: V617F-mutated myeloproliferative neoplasms (MPN) exhibit abnormal proliferation of bone marrow progenitors and increased risk of thrombosis, specifically in splanchnic veins (SVT). The contribution of the endothelium to the development of the prothrombotic phenotype was explored.
Material And Methods: Plasma and serum samples from V617F MPN patients with (n=26) or without (n=7) thrombotic debut and different treatments, were obtained (n=33).
Egypt J Immunol
January 2025
Critical Care unit, Department of Internal Medicine, Faculty of Medicine, Assiut University, Assiut, Egypt.
Platelets are hyperactive in patients with type2 diabetes (T2DM), they adhere to vascular endothelium and play a key role in macrovascular complications. Platelets activity can be measured by flow-cytometry (cluster of differentiation (CD) 41, CD 42, CD 62, CD 63), which allows detection of surface antigens in a sensitive and specific manner. This study aimed to describe platelets activity in T2DM in association with cardiovascular and cerebrovascular complications in relation to duration of diabetes (DM).
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