Summary. An example of persistent mixed‐field polyagglutination of the Tn‐type is described, with particular reference to the value of plant seed agglutinins in the elucidation of polyagglutinable states. Extracts of the seeds of Dolichos biflorus, Bauhinia variegata and Wistaria sinensis strongly agglutinate Tn‐polyagglutinable cells. Inhibition studies indicate that N‐acetylgalactosamine may be an important determinant of Tn‐specificity. Positively charged polymers such as polybrene aggregate normal erythrocytes but not those appreciably deficient in sialic acid such as T‐ or Tn‐polyagglutinable cells. This observation forms the basis of a simple method of separating polyagglutinable from non‐agglutinating cells in a mixed‐field Tn‐polyagglutination. There are indications that Tn‐polyagglutinability, haemolytic anaemia, leucopenia and thrombocytopenia may constitute a distinct haematological syndrome.

Community-based surveys of a representative sample of 53 3 subjects aged 65 yr and over were conducted in a mining valley and a seaside town in South Wales. Haemoglobin level, PCV, serum vitamin B,, , plasma and red-cell folate were measured and several simple tests of learning and memory were applied. The results give no evidence to suggest that anaemia is common and although low levels of vitamin B,, and folate occurred no evidence of an associated impairment of health was detected.

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Summary: A clinical trial of the effect of vitamin B12 therapy was conducted in 39 elderly subjects who had been found, in a community screening survey, to have low levels of serum B12 without a macrocytic anaemia or neuropathy. The study produced no evidence which suggests that in such subjects B12 is superior to placebo in effecting an improvement in psychiatric state or general well-being. There was a clear tendency for all the subjects to show an improvement during the trial, but this probably represents the therapeutic effect of involvement in a research exercise of this kind.