Precipitins in Liberian sera reacting with goat and sheep sera.

Precipitins in nine sera from normal Liberian adults were shown to react with an alpha-globulin in goat and sheep sera. No cross-reaction was demonstrated with bovine sera. Hence these precipitins are different to others previously described.

Cytochemical reactions of human hematopoietic cells in liquid culture.

Growth of human bone marrow in liquid suspension cultures has been used to study normal hematopoietic cell differentiation and abnormalities in blood diseases. A variety of cytochemical stains were applied to human marrow cells cultured in vitro for up to 14 days. AS-D- CHLOROACETATE ESTERASE AND ALPHA-NAPHYHYL BUTYrate esterase were most useful in distinguishing different cell lines in culture.

Heterotypic antibodies in Liberian sera causing anomalous reactions when using a commercial haemagglutination test for hepatitis-B surface antigen.

Agglutinins reacting with normal and tanned sheep erythrocytes were the probable cause of false positive reactions given by 51 of 214 Liberian sera when using a commercial passive-haemagglutination test for hepatitis-B surface antigen. Absorption showed these agglutinins to be identical to those described earlier in Nigerian sera. Rheumatoid factor and anti-sheep-serum antibodies although present in 12 and five per cent respectively of all sera were not responsible for any false positive reactions.

Homozygous beta thalassaemia in Liberia.

The clinical and haematological findings in 19 Liberians probably homozygous for beta thalassaemia are described. The haemoglobin patterns were similar with Hb F levels in the 30-50% range and a raised level of Hb A2 and, although the clinical severity varied widely, over half the cases were symptomless and even the more severely affected ones showed a milder picture than that found in Mediterranean races. Haemoglobin-synthesis studies carried out on three homozygotes and two heterozygotes indicated a variable degree of globin-chain imbalance.

Thalassaemia in northern Liberia. A survey in the Mount Nimba area.

A population survey in northern Liberia showed an average incidence of 9 percent of beta-thalassaemia trait. There was considerable tribal variation, the highest rates being mainly found in tribes having a low incidence of Hb S. A single example of deltabeta-thalassaemia trait was also found; the incidence of delta-chain variants was 1.