86 Burns (1992) Vol. M/No. I

TNF alpha inhibits lipoprotein lipase activity Tumour necrosis factor (TNF) is implicated in the increased pro- duction of triglycerides by the action of lipoprotein lipase after severe bums following studies in two strains of mice that differed genetically in their susceptibility to lipopolysaccharides (LPS).

In the LPS + burned mice there was a 26 per cent increase in plasma triglyceride levels 24 h after the bum compared with no rise in the levels in the LPS - mice. Sera taken from LPS + mice l-2 h postbum was injected into non-burned LPS+ mice and induced a 62 per cent increase in plasma triglyceride levels 24 h after injection. An injection of anti TNF alpha 1 h postbum into LPS + mice prevented the rise in plasma triglyceride levels at any time between I and 3 days. This lack of increase was associated with a depressed hepatic secretion of triglycerides,

Vega G. L. and Baxter C. R. (1991) Tumor necrosis factor medi- ates hypertriglyceridemia during thermal injury in mice geneti- cally susceptible to lipopolysaccharides. 1. Btim Care Rehabil. 12, (5) 463-467.

Lipid peroxides stimulate IgM antibody formation Extracts of lipid peroxides (conjugated dienes) obtained from burned and non-burned control rats were dissolved in ethanol and injected intraperitoneally into normal rats. Fifteen minutes after the diene injection the rats were immunized with sheep Jed cells. Five days later serum and spleen cells obtained from these immu- nized rats were tested for IgM immunity against sheep red cells. Both plaque-forming cells from the spleen and haemagglutination titres in serum were significantly enhanced in the rats receiving the dienes taken from the burned rats.

Thomson P. D., Till G. 0. and Smith D. J. (1991) Modulation of IgM antibody formation by lipid peroxidation products from bum plasma. Arch. Surg. 126, (B), 973-976.

Energy metabolism following ablation of the hypothalamus Ablation of the preoptic anterior hypothalamus in rats with deep bums covering about 23 per cent TBSA impaired the hyper- metabolic response to the injury. When kept at 22°C the rats became hypothermic. However, the plasma levels and urinary excretion of catecholamines were not decreased, indeed they showed an inverse relationship with heat production. Burned lesioned rats kept at an ambient temperature of 28°C were able to maintain body temperature.

Caldwell F. T., Graves D. B., Mullis R. J. et al. (1991) The effect of ablation of the preoptic anterior hypothalamus on energy metabolism and plasma catecholamines after burn injury in the rat. 1. Burn Care Rehabil. 12, (5),446-453.

LABORATORY STUDIES

Effective use of sodium hypochlorite The bactericidal activity and possible deleterious effects on wound healing of varying concentrations of sodium hypochlorite were measured using both Gram-positive and Gram-negative bacterial isolates, in vitro assays using fibroblasts and an in vivo incisional wound model to determine its effects on wound healing.

It was found that a solution of sodium hypochlorite at a concen- tration of 0.025 per cent is therapeutically effective since at this concentration it is bactericidal without any detrimental effects on wound healing.

Heggers J. P., Sazy J. A., Stenberg B. D. et al. (1991) Bactericidal and wound healing properties of sodium hypochlorite solutions. The 1991 Lindberg Award. J. Burn Care Rehabil. 12, (5) 420-424.