Introduction
Centrifugation is an essential step for plasma preparation to remove residual elements in plasma, especially platelets and platelet-derived microparticles (PMPs). Our working hypothesis was that centrifugation as a preanalytical step may influence some coagulation parameters.Materials and methods
Healthy young men were recruited (N = 17). For centrifugation, two protocols were applied: (A) the first centrifugation at 2500 x g for 15 min and (B) at 2500 x g for 20 min at room temperature with a light brake. In protocol (A), the second centrifugation was carried out at 2500 x g for 15 min, whereas in protocol (B), the second centrifugation involved a 10 min spin at 13,000 x g. Thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes concentrations were determined by enzyme-linked immunosorbent assays. PMPs were stained with CD41 antibody and annexin V, and analyzed by flow cytometry method. Procoagulant activity was assayed by the Calibrated Automated Thrombogram method as a slope of thrombin formation (CAT velocity).Results
Median TAT and PAP concentrations did not differ between the centrifugation protocols. The high speed centrifugation reduced the median (IQR) PMP count in plasma from 1291 (841-1975) to 573 (391-1010) PMP/µL (P = 0.001), and CAT velocity from 2.01 (1.31-2.88) to 0.97 (0.82-1.73) nM/min (P = 0.049). Spearman’s rank correlation analysis showed correlation between TAT and PMPs in the protocol A plasma which was (rho = 0.52, P < 0.050) and between PMPs and CAT for protocol A (rho = 0.74, P < 0.050) and protocol B (rho = 0.78, P < 0.050).Conclusion
Centrifugation protocols do not influence the markers of plasminogen (PAP) and thrombin (TAT) generation but they do affect the PMP count and procoagulant activity.Key words: cell-derived microparticles, blood coagulation tests, centrifugation, preanalytical phase 相似文献Modern science is moving away from Michael Polanyi’s vision of ‘the Republic of Science’ and gradually becoming subordinate to political and economic social institutions. This process is accompanied by changes in the normative structure of science. Poland provides an interesting case for empirical study of the scientific ethos mostly because in a relatively short time it experienced a significant reform of the science system, especially in terms of evaluating and financing scientific work. In this paper we examine whether different sets of values and norms are embedded into the normative structure of science in contemporary Poland. The results of a representative survey conducted among 801 researchers were examined with the use of confirmatory factor analysis and fuzzy clustering. The statistical analysis revealed a great complexity in the normative structure of science that goes beyond the expectations formulated on the basis of the theories reviewed. We identified three distinctive groups of researchers, guided by different sets of values and norms in their professional conduct (academic science, post-academic science and the industrial science) and a cluster of researchers with an unidentified system of principles. We argue that the complexity of the normative structure of science should be taken into account in the decision-making regarding any future reforms of the science system.
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