A variant of human lactate dehydrogenase is described. The occurrence of lactate dehydrogenase-1, -2, -3, and -4 as five, four, three, and two components, respectively, is interpreted as supporting the hypothesis that LDH isozymes are tetramers formed from various combinations of two types of subunits.

No abstract

Thrombotic thrombocytopenic purpura (TTP), a syndrome of diverse etiology probably related to factors regulating platelet-vessel wall interaction, is predominantly a disorder of women. We report our experience with 14 patients in an 11-year period. Thirteen were female and aged between 25-69 years. Four were postmenopausal, and of the nine premenopausal women three were pregnant, one was immediately postpartum, and three were taking estrogen-containing oral contraceptives. A review of the literature confirms the two to one female/male preponderance and that TTP is reported in 56 women who are pregnant or recently postpartum. While this association with possible hormonal events has been noted, it has previously received little comment. We stress the similarity between TTP and some occurrences of preeclamptic toxemia, and that this may suggest not only a common etiology but that therapeutic attempts should be similar. While no single therapeutic modality is universally successful, our experience is that plasma exchange is the most effective, with five of seven patients so-treated obtaining prolonged remission; four of five patients responded to splenectomy and corticosteroids, but one died of infection postoperatively. Five patients, including two treated exclusively with antiplatelet aggregating agents, died without achieving remission. The frequency of successful therapy is not changed by the concurrent pregnancy, but the fetal loss is high. There does seem to be an increased risk of recurrence of TTP in a subsequent pregnancy, and this might be considered when counseling premenopausal patients who have achieved remission of TTP.

Summary In 12 years (1958–69) 38 patients with homozygous sickle‐cell anaemia (SS) were studied during the course of 61 pregnancies. Maternal prognosis was poor, with 7 deaths. The causes of mortality and morbidity were severe anaemia, acute sequestration, bacterial infections, bone pain crises, and bone marrow embolism. The proportion of these patients requiring operative deliveries was high chiefly because of fetopelvic disproportion from generally contracted pelvis. For obstetric operations various types of anaesthesia were used with excellent results, provided gross anaemia was corrected and hypoxia was avoided. When bone pain crises occurred during late pregnancy, labour and in the early puerperium, heparinization and blood transfusions were freely used. Fertility was reduced in these women, and both the spontaneous abortion rate and fetal wastage were at least twice as high as they were in the general population. The average birthweight of the babies was comparatively low, for no obvious reasons.

Summary: Follow-up