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Biomedical subjects

J Hamburger

Publications and source records attributed to J Hamburger.

At least 127 records · Page 7Linked to original sources
PubMed1975

Macrophage arming factor release by allografted mouse lymphocytes stimulated by phytohermgglutinin.

Spleen cells from a C57BL/6 mouse allografted with DBA/2 skin may release a macrophage arming factor when stimulated with phytohemagglutinin. This in vitro nonspecific release is observed only when the recipient cells are collected during a limited period preceding or coinciding with graft rejection. The phenomenon disappears if the skin allograft has been removed before cell collection. It appears if an i.v. injection of donor cells is given to the recipient after graft removal, on the day preceding cell collection. These data suggest that this in vitro apparently nonspecific macrophage arming factor release by phytohemagglutinin-stimulated recipient cells may in fact disclose a previous specific in vivo immune cell triggering by graft antigens.

Animals↗
PubMed1975

Antibody-mediated elimination of malaria parasites (plasmodium berghei) in vivo.

An infective preparation of extracellular blood forms (FP) of Plasmodium berghei was used to study some aspects of the interaction between protective antibodies and malaria parasites. FP but not infected erythrocytes (IRBC) were shown by the fluorescent antibody technique to be coated by antibodies after in vitro incubation with immune serum. Preincubation of both FP and IRBC with immune serum followed by their washing did not result in enhanced elimination of the parasites in vivo. However, FP preincubated with immune serum and subsequently washed were eliminated more efficiently than FP preincubated with normal serum if the preparations were injected with some immune serum. Such an increase in the efficiency of elimination was not detected with similarly pretreated IRBC. It is thus probable that protective antibodies acted in vivo against extracellular parasites rather than against parasites in erythrocytes. The interaction between parasites and antibodies may be of a highly reversible nature, and washing of the in vitro-treated parasites may cause elution of antibody from the sensitized parasites so that the amount of antibody on the parasite falls below the critical level required for in vivo elimination.

Animals↗
PubMed1975

Macrophage cytotoxicity in the mouse immune response against a skin allograft.

Macrophage-rich peritoneal cell populations from C57BL/6 mice grafted with DBA/2 skin were found to be cytotoxic against 51Cr-labeled target cells from the donor strain. Normal peritoneal macrophages were also rendered cytotoxic by incubation with acellular supernatants of mixed lymphocyte cultures (MLC) between an allograft recipient and a donor mouse. Supernatants alone were not cytotoxic. The macrophage arming factor(s) was found in supernatants when the MLC was performed after more than 6 to 9 days following grafting. In order to produce MAF, sensitized lymphocytes must usually be stimulated in a specific way by donor type cells. The armed macrophage cytotoxicity was, however, not found to be specific in these experiments.

Animals↗