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Biomedical subjects

J Padawer

Publications and source records attributed to J Padawer.

34 records · Page 2Linked to original sources

Uptake of colloidal thorium dioxide by mast cells.

Mast cells from the peritoneal cavity of the rat were obtained at various times following in situ injection of a colloidal thorium dioxide preparation (Thorotrast). They were prepared for electron microscopy by aldehyde fixation, osmium tetroxide postfixation, and embedding in Epon. Thorotrast was rapidly taken up by mast cells through enhanced or newly elicited surface specializations. It was confined at first to large vesicles which moved to the Golgi area. Subsequently, in a matter of a few hours only, it became associated with progressively more mature granules, including "fully" mature ones. In addition to demonstrating a further phagocytic or pinocytotic activity of mast cells, the findings suggest that mast cell granules share a common membranous investment, and that substances from the tissue environment may theoretically percolate over and interact with the granules. Mast cell function could thus be served primarily by absorptive rather than secretory processes.

Animals↗

Supplemental arginine increases thymic cellularity in normal and murine sarcoma virus-inoculated mice and increases the resistance to murine sarcoma virus tumor.

Arginine supplements were given to 6 week old CBA mice beginning 3 days prior to inoculation with a murine sarcoma virus, the Moloney Sarcoma Virus (MSV). Although the basal diet contained 1.8% arginine and was therefore not arginine-deficient, supplementation of the diet and the drinking water with 0.5% arginine HCl reduced tumor incidence, lengthened the latency period, decreased tumor size, and hastened tumor regression. Arginine also increased thymic weight and cellularity in normal and in MSV-inoculated mice. The antitumor action of arginine may be related to its effect on the thymus.

Adrenal Glands↗