Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-derived microparticles (PMPs) are released from platelets through the platelet activation by high shear stress, collagen, or calcium ionophore (A23187). PMPs are observed in patients with acute myocardial infarction, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, heparin-induced thrombocytopenia and other thrombotic disorders, but the importance of circulating PMPs in the pathogenesis of these diseases is still debated. Numbers of PMPs are usually determined by flowcytometry (FCM), but easier and reproducible PMP assay systems are needed. To develop a better ELISA for PMPs, we used antibodies against the platelet antigens anti-GPIb (NNKY5-5), anti-GPIIb/IIIa (NNKY2-11, anti-CD41), anti-GPIX (KMP-9), and anti-CD9 (NNKY1-19). PMPs were detected with all combinations of these antibodies, but the ELISA having the highest and most specific absorbance was obtained with a combination of KMP-9 (capture antibody) and NNKY5-5 (detecting antibody). PMPs in blood samples were measured by ELISA and FCM. ELISA correlated with PMPs quantitated by FCM. By shaking ELISA plates during incubation, nonspecific binding of platelets was eliminated. The level of PMPs was not increased in diabetes mellitus, thrombotic thrombocytopenic purpura, antiphospholipid syndrome, or sepsis. The concentration of PMP was elevated in hemolytic uremic syndrome. Activated PMPs were absorbed to 0.8 microm filter, but circulating PMPs were not absorbed. These results suggest that activated PMPs are likely to adhere to leukocytes or endothelial cells at the activation site and that the circulating form of PMPs are likely to be a residue of activated PMPs. To detect only the activated form of PMPs, a new ELISA needs to be developed, and it will likely use a combination of antibodies that detect platelet activation markers such as P-selectin (CD62P) or activated GPIIb/IIIa.
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PMID:Development and assessment of enzyme immunoassay for platelet-derived microparticles. 1124 56

Platelet concentrates are routinely manufactured from whole blood by differential centrifugation (random donor platelets-RDP) or by plateletpheresis (single donor platelets-SDP). These platelet concentrates have a storage period of 5 days and many different approaches exist to measure the condition of platelets during their storage. In this study, platelet aggregation testing using adenosine diphosphate (ADP) and collagen and flow cytometric platelet activation analysis using CD41 FITC and CD62 PE before and after ADP was performed on days 1, 3 and 5 of storage of platelet preparations. Thirty three RDPs, stored in Baxter and Kansuk blood bags and 18 SDPs stored in Fresenius blood bags were evaluated. In RDPs and in SDPs; ADP and collagen induced PA responses were decreased significantly on the 3rd and 5th days compared to 1st day. CD62 positive platelet percentage after ADP were decreased significantly on the 3rd and 5th days compared to the 1st day in Kansuk bags. Flow cytometric analysis revealed minor changes in CD41 expression after ADP on the 3rd day compared to 1st day and on the 5th day compared to 3rd day. Differences in CD62 positive platelet percentage were not significant between the RDPs and SDPs. Our results suggest that: (1) ADP and collagen induced PA responses decrease both in RDPs and SDPs during storage. (2) Flow cytometric analysis does not show major significant changes in platelet activation after ADP during storage. (3) Continous shaking on the agitator does not cause a significant change in CD62 positive platelet percentage during storage. (4) Platelet aggregation responses in RDPs stored in Baxter and Kansuk blood bags do not differ during storage.
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PMID:Platelet function testing during 5-day storage of single and random donor plateletpheresis. 1760 71