During the acute phase of myocardial infarction, the generation of thrombin is reflected in the sudden rise of fibrinopeptide A (FPA) and the thrombin-antithrombin III (TAT) complex in blood. We have systematically determined the FPA and TAT plasma concentrations over a period of 14 days after acute myocardial infarction in 100 patients. Mean levels of both thrombin markers were the highest on admission, remained elevated over the following few days, and then gradually declined after day 5. Still, by the end of the first week two thirds of the patients had distinctly elevated TAT and FPA levels, and by the end of the second week such an abnormality was present in half of them. Continuous intravenous heparin infusion at a dose of 20,000 units/day, administered for 1 week to patients who had either received (n=21) or not received (n=17) streptokinase, led to a significant depression (p<0.05) of thrombin markers over the first 48 hours, an effect that did not persist over the subsequent days of treatment In patients not assigned to heparin treatment, those in heart failure had significantly (p<0.05) higher mean TAT and FPA values on days 3,5, and 7 compared with patients in whom heart failure was absent Infarct extension, pulmonary embolism, and death were also associated with a rise in one or both thrombin markers, often preceding the onset of clinical symptoms. Thrombinogenesis was not accompanied by changes in mean plasma concentrations of prothrombin, antithrombin III, or a^-macroglobulin. It is suggested that thrombin was continuously released to the plasma from coronary or extracoronary thrombi undergoing lysis and subsequent rebuilding. Thus, thrombin generation that extends beyond the acute phase of myocardial infarction indicates an increased risk to the patients and might call for more anticoagulation, angioplasty, or the use of new antithrombotic agents.

Bull semen was separated by sedimentation in milk, with egg-yolk and powdered milk added. The sex ratio (SR) of the progeny of 2866 cows inseminated with sedimented spermatozoa was compared to that of 2171 cows inseminated with unsedimented semen from the same sires. After insemination with the more rapidly sedimenting spermatozoa, a statistically significant preponderance of females was born compared to the number born after insemination with the remaining fractions of the sedimented semen. The percentage of males born after insemination with the slower sedimenting spermatozoa, however, was not higher than that in the control series. After insemination of sedimented semen, there was an increase in abortion and a deviation of the SR to the disadvantage of the numbers of males born, probably due to a more frequent abortion of male foetuses. The differentiation in the SR of the progeny, depending on the fraction used for insemination, remained, even allowing for correction as to the supposed sex of the aborted foetuses.

No abstract