Enzyme activity in paroxysmal nocturnal haemoglobinuria - like red cells

Activities of two membrane enzymes, actylcholinesterase (AChE) and adenosine triphosphatase (ATPase), were studied in a patient with paroxysmal nocturnal haemoglobinuria (PNH), and in PNH-like cells produced by treating normal red cells with 2-aminoethyl isothiouronium bromide. AChE activity was low in the patient with PNH, particularly in the youngest red cells, but ATPase activity of whole blood was normal. AChE activity was decreased in PNH-like red cells, but ATPase activity and the activities of cytoplasmic enzymes were unchanged. These findings indicate that only the superficial part, and not the whole, of the red cell membrane is affected by the PNH lesion (AU)

Glucose-6-phosphate dehydrogenase deficiency and homozygous sickle cell disease in Jamaica

The relationship between D-glucose-6-phosphate: NADP oxide-reductase (E.C.1.1.1.49; glucose-6-phosphate dehydrogenase; G6PD) deficiency and homozygous sickle cell (SS) disease was examined in 120 patients. The proportion of hemizygotes (22.6 percent) was slightly more than that observed, and the combined proportions of heterozygotes and homozygotes (28.3 percent) were slightly less than would be expected, in the general population, but the differences were not significant. However, the proportion of patients of abnormal G6PD status in the 10-19 years age group was 41.7 percent, significantly more than that found in the 20-29 years age group (0.02

Beta-thalassaemia of clinical significance in adult Jamaican negroes

Over a 9-year period, three adult Negro patients with á-thalassaemia of clinical significance were recognized out of approximately 185,000 new adult patients attending the University Hospital. These patients, ages 15-58 years, have clinical and haematological characteristics within the spectrum of á-thalassaemia intermedia; which in this paper refers to phenotypes resulting from defects in á-chain synthesis clinically intermediate between classical Cooley's anaemia and á-thalassaemia trait, genetic classification being dependent on family study. Family studies established the presence of two á-thalassaemia genes conclusively in one case (proposita, family A); presumptively in another(propositus, family C); while in the remaining subject (proposita, famaily B), who has two similarly affected siblings, homozygosity is suspected, but not proven by family study. In simultaneous Fe and Cr studies, estimates of effective erythropoiesis are in reasonable agreement with measurements of red cell destruction.(Summary)