The modulating influence of vitamin A deficiency on carcinogenesis induced by two potent carcinogens, diethylnitrosamine (DEN) and acetoxymethyl methylnitrosamine (AMMN), was studied in BALB/c mice. DEN was administered intragastrically every 30 days at a total dose of 200 mg/kg body weight, split into four doses. AMMN was applied continuously every 14 days on the tongue, at a dose of 2 mg/kg body weight. AMMN and DEN treated animals fed the vitamin A deficient diet had a significantly higher tumor incidence that mice fed the normal diet (p less than 0.05). Studies on the levels of vitamins A, C, B2 and folic acid in the liver and plasma of mice treated with the two carcinogens revealed that both the carcinogens increased vitamin C in both tissues, decreased folic acid and had no effect on vitamin A, while hepatic vitamin B2 was lowered by treatment with AMMN by not by DEN.

Animals↗

PubMedDate not supplied

Culture and phagocytic characteristics of Schwann cells in vitro. A possible model substrate for cultivation of M. leprae.

Tissue cultures of five acoustic and four spinal schwannomas demonstrated good growth and migration of Schwann cells within two to four days. Two types of cells corresponding to Antoni type A tissue and Antoni type B tissue were clearly recognized. Both these cell types showed avid phagocytosis when the cultures were inoculated with mycobacteria, either ICRC bacilli or M. leprae. The phagocytic index was 95% at the end of two hours. The Schwann cells grown in vitro also showed intense acid phosphatase reaction with Gomori's stain, suggesting lysosomal activity. Neither this nor any phagocytosis was evidenced by fetal fibroblasts cultured similarly. Cells from two spinal neurofibromas grew and migrated slowly in vitro and were mainly fibroblasts.

Cells, Cultured↗

PubMedDate not supplied

A case of muscular dystrophy with probable lipoma of the corpus callosum.

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Adolescent↗