PubMed Health⌕ Search

Biomedical subjects

R Poti

Publications and source records attributed to R Poti.

7 recordsLinked to original sources
PubMed1984

Correlation between changes induced by venous occlusion on factor VIII-von Willebrand factor components and fibrinolytic activity.

The effects of standardized venous occlusion (VO) on factor VIII-von Willebrand factor (F VIII-VWF) components (F VIII:C, F VIIIR:AG, F VIIIR:RCof) and on fibrinolytic activity were investigated in 45 healthy subjects, in 28 women on oral contraceptives, and in 78 patients with various chronic diseases (28 with peripheral arterial disease, 19 with liver cirrhosis, 13 with rheumatoid arthritis, and 18 with diabetes). All the three F VIII-VWF components showed highly significant increases, although not of the same magnitude, with consequent variations in the ratios between them. A significant activation of fibrinolysis was also demonstrated with both euglobulin lysis time (ELT) and diluted blood clot lysis time (DBCLT). A strong linear correlation between pre- and post-stasis values was recorded for all the F VIII-VWF components and for the two fibrinolysis tests. No significant relationship was, on the contrary, found between F VIII-VWF and fibrinolytic parameters.

Blood Coagulation Factors↗
PubMed1979

Predictive value of preoperative in vitro and in vivo studies for correct individual heparinization in cardiac surgery.

Heparin administration for operations with extracorporeal circulation (ECC) usually is performed following prefixed, standardized protocols. These regimens secure an adequate level of anticoagulation, but they often involve prolonged periods of overheparinization associated with an undue risk of hemorrhage. The predictive value of preoperative studies in the anticoagulant effect of heparin was investigated in 10 patients. The study was performed both in vitro and in vivo using the Xa inhibitor assay as an index of the anticoagulation induced by heparin. Adding variable amounts of heparin in vitro to patient's plasma resulted in straight (at least up to 7 U. per milliliter) and parallel, but not coincident, dose/response curves, so confirming a different individual sensitivity to heparin. Disappearance curves of the anticoagulant effect in plasma following intravenous administration of a single standard dose of heparin in the same patients showed an even greater patient-to-patient variability, with "half-life" times ranging from 30 to 150 minutes. No relationship was found between the parameters (in vitro sensitivity to heparin and clearance rate from plasma in vivo). Moreover, neither of them could be correlated with the response to heparin, subsequently observed during ECC in the same patients. Preoperative investigations with the methods presently available are not adequate to choose individual heparin administration regimens for cardiac operations.

Adult↗
PubMed1977

Impaired fibrin formation in advanced cirrhosis.

The process of fibrin formation was systematically in 25 patients with severe alcoholic cirrhosis. Results of functional tests are reported. A significant lengthening of the thrombin time was found which could not be completely attributed either to hypofibrinogenaemia or to an increase in physiological anticoagulants or to the presence of pathological antithrombins. A defect in fibrin polymerization was seen in the absence of significant levels of antipolymerizing agents. Indirect evidence pointed to an abnormal fibrinogen function. This was mainly suggested by the "polymerization curves" of mixtures of normal and pathological plasmas and the changes in physico-chemical properties of the clot (optical and elastic properties; tensile strength). Altered synthesis in hepatocytes may lead to an "acquired dysfibrinogenaemia" in the late stages of liver cirrhosis, although alteration of a normal fibrinogen molecule after secretion cannot be definitely excluded.

Adult↗