Auto-Antibodies to Leukemic Cells Detected by Immune Adherence

Sixteen Long-Evans rats with leukemias induced by 7,12-dimethylbenz(a)-anthracene were studied for evidence of naturally occurring immunologic responses to their own leukemic cells using an immune adherence hemagglutination technique which was designed to detect fresh serum auto-antibodies to the membrane of the leukemic cells. Auto-antibodies to the cell membranes were found in 14 out of 16 rats, but were not demonstrable in the other two rats. Autochthonous thymus cells used as controls did not show positive immune adherence hemagglutination reactions with their own sera, nor did the leukemic cells show positive reactions with the pooled normal rat serum. These findings suggest a possibility that the leukemic rats are able to produce humoral antibodies against membrane-specific antigens of autochthonous leukemic cells.

The demonstration of auto-antibody to human leukemic cells was attempted in 23 patients with leukemia using the immune adherence hemagglutination technique.

Pyruvate Kinase Activity of Wheat Plants Grown under Potassium Deficient Conditions

The activity of pyruvate kinase was determined in the first leaves of wheat plants grown under K(+)-deficient conditions. An enhancement of the enzyme activity compared with the normal plants was found to start from eighth day of growth, and about 4-fold increase in the enzyme activity was observed in 14-day wheat leaves. The addition of K(2)SO(4) to the nutrient solution given to the K(+)-deficient plants at tenth day resulted in the restoration of the enzyme activity to the normal level after 3 days. The levels of K(+) as well as carbohydrates and chlorophyll were found to return normal over the same period. These findings are discussed in relation to the metabolic pattern of plants at the early stages of K(+)-deficiency.

Chromosome abnormality in rat leukemia induced by 7,12-dimethylbenz[a]anthracene

A high percentage of consistent chromosome abnormality, trisomy of the longest telocentric chromosome, was found in leukemias induced in rats of the Long-Evans strain by pulse doses of 7,12-dimethylbenz[a]anthracene. Cells with this abnormality were large, immature, and mononuclear and tended toward erythroblastic maturation.