The euglobulin lysis time test: an ineffectual monitor of the therapeutic inhibition of fibrinolysis

In two clinical situations associated with hyperfibrinolysis the administration of antifibrinolytic drugs resulted in clinical haemostasis. The dilute clot lysis time and fibrin plate activity test but not the euglobulin lysis time reflected this control of excessive fibrinolysis by the antifibrinolytic drugs. The inhibition by epsilon-amino-caproic acid (EACA) of hyperfibrinolysis induced in vitro was reflected by the dilute clot lysis time but not by the euglobulin lysis time. Paper chromatography of the supernatant and euglobulin fractions as prepared for the euglobulin lysis time test from plasma with added EACA demonstrated that some 85% of the EACA was present in the supernatant, normally discarded during the test. Similarly, cellulose-acetate electrophoresis of the supernatant and euglobulin fractions from plasma containing Trasylol demonstrated the drug in the supernatant only. These findings indicate that when acetic acid is added to plasma containing EACA or Trasylol only a small proportion of the drug is precipitated with the euglobulin fraction. The euglobulin lysis time is thus an inaccurate index of the neutralization of hyperfibrinolysis by antifibrinolytic drugs.

Reduction of incidence of prematurity by folic acid supplementation in pregnancy

Folic acid administered to pregnant Bantu, whose diet is low in folate, was associated with a significant reduction in the incidence of prematurity. No such effect could be demonstrated in White patients subsisting on an average Western diet. This suggests that folate deficiency may contribute to the "pregnancy wastage" in populations whose dietary folate intake is low, and is a further indication for folic acid supplementation during pregnancy in these groups.

Platelet life-span and sites of platelet sequestration in onyalai

With radioactive chromium, platelet kinetic studies were carried out in four patients with onyalai, a form of thrombocytopenic purpura occurring in the African Negro. Results were compared with those of White patients suffering from idiopathic thrombocytopenic purpura. In the onyalai patients platelet life-span was considerably reduced, and this was associated with a definite rise in radioactivity over the spleen in three of the four cases. In two patients remission was associated with steroid therapy, while in the other two remission followed splenectomy after steroids had failed to raise the platelet count. These findings are similar to those in White patients with idiopathic thrombocytopenic purpura.

Pigmentation in megaloblastic anaemia associated with pregnancy and lactation

Generalized skin pigmentation in five African women with megaloblastic anaemia in the postnatal period was associated with low serum folate levels, as distinct from vitamin B(12) deficiency. It is suggested that the occurrence of pigmentation in both folate and vitamin B(12) deficiency may reflect a common abnormality of metabolism.

Defective DNA synthesis in human megaloblastic bone marrow: effects of homocysteine and methionine

In B(12) deficiency, inadequate DNA synthesis seems due in large measure to a block of tetrahydrofolic acid (THFA) regeneration from 5-methyl THFA (via homocysteine transmethylation). In support of the above, homocysteine appears to facilitate and methionine to reduce de novo DNA synthesis. This was measured by the ability of deoxyuridine to suppress thymidine-(3)H uptake into DNA in human bone marrow cultures. The homocysteine effect in B(12)-deficient marrow supports the possibility that there is in man an additional B(12)-independent pathway for regeneration of THFA by methylation of homocysteine to form methionine. Among possible explanations for the methionine effect is end-product inhibition of the homocysteine transmethylase reaction, resulting in further accumulation of 5-methyl THFA. Homocysteine transmethylation may play an important role in the regulation of THFA availability and de novo DNA synthesis. In vitro and in vivo evidence suggests that methionine may be useful to potentiate and homocysteine to reduce methotrexate action.

[The optical beam]

The optical beam emitted by a high power laser has been studied. The beam cross section at various locations is considered, from optical and photometrical points of view. Output wavefront shaping is deduced as well as some ideas about focusing devices.

Significance of tests of iron nutrition in pregnancy

Tests of iron and folate nutrition have been carried out in early pregnancy and at delivery in 63 Bantu females. Accepted normal values for serum iron, and percentage saturation of transferrin, but not for unsaturated iron-binding capacity, for non-pregnant subjects were found to apply equally well in pregnancy. Concomitant folate deficiency in early pregnancy did not render tests of iron deficiency less valid. The unsaturated iron-binding capacity, percentage saturation, and marrow iron stores in early pregnancy all showed a significant correlation with the haemoglobin value at term. Patients with normal marrow iron stores and a percentage saturation of transferrin of 20 or more at or before the 24th week are unlikely to become anaemic from iron deficiency during pregnancy.