A SYNTHETIC GLYCOLIPID WITH B-CELL MITOGENIC ACTIVITY

A synthetic glycolipid, N-palmitoyl-D-glucosamine, (NPG) was found to be a potent B-cell mitogen, that stimulated spleen cells from nu/nu as well as from normal mice. The proper dispersion of the water insoluble preparation is critical for the elicitation of this mitogenic effect. Limulus lysate clotting assay indicated that the NPG preparation either contains only 0.001% endotoxin contamination, or that NPG itself is 10–5 times less active in this assay than purified endotoxic LPS. Since such low levels of endotoxin concentration are not mitogenic, it is concluded that synthetic N-palmitoyl-D-glucosamine, when properly dispersed, is itself a B-cell mitogen

Failure of Endotoxin to Protect C3H/HeJ Mice Against Lethal X-Irradiation

C3H/HeJ mice are more sensitive to lethal X-irradiation and cannot be protected by pretreatment with endotoxin, compared to the C3HeB/FeJ strain. Lack of a granulopoietic response in C3H/HeJ mice is evident

BIOLOGICAL ACTIVITY OF COMPLEMENT IN VIVO ROLE OF C5 IN THE ACCUMULATION OF POLYMORPHONUCLEAR LEUKOCYTES IN INFLAMMATORY EXUDATES

The development of quantitative in vitro methods for the analysis of various mediators of the inflammatory response has led to a greater understanding of the functions of such mediators. Indeed, recent investigations have suggested that the complement (C) ~ system plays a central role as an effector of a number of events in the inflammatory process (1, 2). A point which has emerged from various in vitro studies, however, is that there are a multiplicity of mediators for any given biological function. For example, fragmentation products from each of the complement, clotting, and kinin systems have been reported to increase vascular permeability, contract smooth muscle, and chemotactically attract polymorphonuclear leukocytes (PMN) (3). Important questions for future investigations will be aimed at determining the relative quantitative and qualitative importance in vivo of each of the known biological effectors in mediating any given aspect of the inflammatory process. A cardinal event in the acute inflammatory response is the accumulation of PMN at the inflammatory site. While we have previously discussed the importance of the fifth component of C (C5) in the generation of PMN, as well as mononuclear leukocyt