Centrosomes are reduced to their cores in sperm. Emerging molecular explanations for centrosome construction have now helped to elucidate the mechanism of their destruction in sperm. Since centrosome inaccuracies cause aneuploidies responsible for cancers, birth defects and infertility, this new insight into centrosome behavior has broad implications.

Tissue culture cells of Drosophila melanogaster were given various doses of ultraviolet light. The results indicate that Drosophila cells do have a dark-repair excision mechanism which is not sensitive to caffeine. Pyrimidine dimers were destroyed by photoreactivating illumination in these cells and this destruction probably represents monomerization of the pyrimidine dimers.

On the Occurrence, Sites and Modes of Origin and Discussion: Destruction, of Principles Affecting the CompensaBiology in the Premedical Curriculum: PROFESSoR tory Vascular Mechanism in Experimental Shock: VIKToR HAMBURGER. Suppression of Vital Data: DR. EPHRAIM SHORR, DR. BENJAMIN W. ZWEIPACH PRoFESSoR D. L. THOMSON and PROFESSOR H. E. and DR. ROBERT F. FuICHGoTT .......................... .......

It is established that mutations in viral antigenic epitopes, or antigenic drifts, allow viruses to escape recognition by both Ab's and T lymphocytes. It is unclear, however, whether tumor cells can escape immune recognition via antigenic drift. Here we show that adoptive therapy with both monoclonal and polyclonal transgenic CTLs, specific for a natural tumor antigen, P1A, selects for multiple...

The destruction of large pinosomes was examined with phase-contrast microscopy in cultured mouse fibroblasts. In areas of rapid pinosome breakdown, lysosomes were observed to repeatedly collide with pinosomes without fusing, tearing off small pieces until the pinosomes became smaller and denser. This segmentation of pinosomes by lysosomal collision has been named "piranhalysis."

Staphylococci which have been allowed to grow rapidly in a favorable environment and subsequently have been maintained in a resting state characteristically produce a sharp rise in [phage] (activity) titre when added to phage. This capacity is quickly lost when the cells are suspended in distilled water and are exposed to 44 degrees C. for a period of 15 minutes; at the same time the viable cou...