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Biomedical subjects

B Halpern

Publications and source records attributed to B Halpern.

192 records · Page 11Linked to original sources
PubMedDate not supplied

Monocytosis-inducing activity (MIA) of serum in Corynebacterium parvum treated mice.

Intravenous injection of 548 microgram of C. parvum (Lot 0407, Mérieux Laboratories, France) into C57Bl mice produced rapidly appearing monocytopenia which was followed by marked and prolonged monocytosis after the third day. The serum of these animals, collected during the monocytopenic but not the monocytosis phase, showed monocytosis inducing activity (MIA) as was demonstrated by the intravenous injection of the serum into normal test mice. Serum from normal untreated mice or from mice given an intravenous injection of sterile pyrogen-free saline did not cause monocytosis in the test mice. Monocytosis induced in the test animals presented two interesting peaks. The first was observed 2 h after the injection of serum and the second 5 days later. The former was accompanied by a decrease and the latter by an increase in the number of bone marrow monocytes, suggesting that MIA probably represents a releasing activity. The late increase in marrow monocytes is considered as a phenomenon secondary to the initial reduction.

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PubMedDate not supplied

In vitro anti-tumour properties of peritoneal exudate cells of conventional germ-free and stimulated mice.

Adherent cells of peritoneal exudates were obtained from conventional, or from germ-free mice or from mice having received in intraperitoneal infection of a variety of phlogogenic substances such as Corynebacterium parvum (C. parvum) (Mérieux) 500 microgram, thioglycolate (Difco) 3 ml, Bayol (Esso) 0.50 ml + 0.50 ml culture medium, glycogene 1.2 ml. The cytotoxic properties adherent cells were studied in vitro by the chromium release technique (CRT) and their cytostatic properties by the inhibition of the incorporation of tritiated thymidine by YC8 lymphoma cells. C. parvum was found to be the most active agent in enhancing the cytotoxic properties of adherent cells, followed by BCG and Bayol. Glycogen peptone and other substrates were without effect. The unstimulated peritoneal macrophages of conventional mice were found to inhibit thymidine incorporation by tumour cells, whereas those of germ-free mice could not do so. C. parvum markedly increased the cytostatic property adhered cells from both germ-free and conventional mice.

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