Cytotoxicity of ethyl methanesulfonate in mice spermatogonia.

Enumeration of different types of spermatogonia, following a single i.p. administration of different doses of ethyl methanesulfonate in mice, showed a survival of A1-A4 and in spermatogonia is markedly reduced due to cell killing while the remaining types of spermatogonia were affected marginally. The cell killing effect was dose-dependent, and replenishment of these cells was observed by the end of one cycle of the seminiferous epithelium comprising of 8.5 days.     

Relationship between the pentose phosphate shunt and methemoglobin reductase activity in human erythrocytes: Effect of aging on methemoglobin reductase activity.

The increase in methemoglobin reductase activity in human erythrocytes upon incubation with inosine, phosphate, pyruvate occurs only in the presence of methylene blue. No difference in activity of the methemoglobin reductases was observed between enzyme extracts of fresh cells and aged cells.     

Water compartments in the myelinated nerve. III. Pulsed NMR results.

3 experimentally distinct transverse relaxation components of the water in frog sciatic nerve are obtained by Carr-Purcell-Meiboom-Gill technique. The relative weights of these components: approximately 29%; approximately 50%; approximately 21% fit well with water compartments in this tissue as revealed by previous methods.     

Effects of the antiprotease Trasylol on peripheral blood leucocytes.

Binding of the antiprotease Trasylol to human peripheral blood lymphocytes and polymorphonuclear leucocytes (PMNs) was demonstrated at the ultrastructural level using an indirect immunoperoxidase technique. This also revealed endocytosis of membrane bound Trasylol by PMNs. Trasylol inhibited PHA- and ConA-induced lymphocyte stimulation, and was cytotoxic to unstimulated cells.     

Toxicity of Phytophthora infestans and Alternaria solani to chick embryos

None of the extracts and culture filtrates from growth of 9 races of Phytophthora infestans on living potato tissue and potato dextrose broth are toxic to chick embryos. Chloroform extracts of 4 out of 10 isolates of Alternaria solani grown on potato dextrose broth showed some toxicity to chick embryos.     

GABAergic inhibition of neurons in the ventral tegmental area.

Stimulation of the nucleus accumbens evokes a potent inhibition in neurons of the ventral tegmental area. GABA is likely to act as a transmitter in this descending inhibitory system.     

Permeability coefficients of the egg-case membrane of Scyliorhinus canicula L

The cleidoic egg-case of the dogfish appears to have a highly porous and permeable outer membrane, the pore radius being computed to be 13.6 A. It does not present any physiological barrier to small molecules and therefore constitutes an open ionic and osmotic system for the embryo. Being a porous protein membrane it may be of value as a model for molecular transport mechanisms.