216 Burns Vol. 5/No. 2

Oedema formation Studies to determine the relationship between increased vascular permeability (water content and protein leakage) and time post injury were performed in rats. Three small (0"2 per cent of the body surface) burns were inflicted to the left of the spine. The animals were killed at either 0-5, 1 '5, 3, 6, 12, 18, 24, 36 or 48 h after burning. Radioiodinated human serum albumin (131I) (200 gCi per kg body weight) was injected intravenously 30 min before death. Segments of skin were taken, weighed, counted for radioactivity, dried at 60 °C for 96 h and then reweighed. The distribution of radioactivity in the skin was deter- mined by autoradiography. The water content was maximal at 3 h post burn and had returned to normal by 24 h. Albumin leakage was maximal at 30 min and had returned to normal by 12h after burning. In another series of experiments in which the radioactive albumin was injected at the time of the burn a high tissue content of radioactivity persisted for as long as 48 h. These studies suggested that abnormal extra- vasation of albumin occurs only during the first 6 to 12 h after burning. Once in the interstitium however, albumin may remain trapped for up to 48 h.

Brouhard B. H., Carvajal H. F. and Linares H. A. (1978) Burn edema and protein leakage in the rat. I. Relationship to time of injury. Microvasc. Res. 15, 221.

Phosphorus burns The efficacy of a suspension of copper sulphate in a mixture of hydroxy-ethyl-cellulose and sodium lauryl sulphate for treating phosphorus burns has been tested in two monkeys. Each animal received a burn from the ignition of 600rag of phosphorus, one animal was then treated with the copper sulphate complex 4 rain after burning. The untreated animal was killed 5 days after burning for humane reasons, the treated animal survived. Biochemical studies of blood and urine samples from both monkeys taken during the study showed marked changes in kidney and liver function, disturbed electrolyte balance and a high concentration of phosphorus ions in the blood of the untreated monkey. The corresponding values in the treated monkey were normal and no incorpora- tion of phosphorus or copper ions into the blood was observed. Histopathological studies of tissues from the untreated monkey confirmed the biochemical observations and suggested severe morphological aberrations in the kidney, liver, spleen and heart. The results indicate that therapy with the copper sulphate completely alleviates the effects of phosphorus burns and is non-toxic.

Ben-hur N., Shani J. and Appelbaum J. (1978) Phosphorus burn in primates: a conclusive experi- mental study of a new specific therapy. Burns 4, 246.

Oedema formation The potential disadvantages of extensive oedema were studied using dichromatic absorptiometry. With this accurate and precise technique involving scanning oedematous tissue with dual photon sources (l~Siodine and Z41americium) the variable attenuation of the two photon energies permits selective measurements of the mass of fluid, protein, lipid and bone content of the tissue. Studies were made in 11 adult sheep with burns produced by immersion of one hind leg in water at 85 °C for 10 s or in water at 95 °C for 10 s producing, partial-thickness and full-thickness skin loss burns respectively. The correlation between the volume of oedema estimated with dichromate absorptiometry and the change in the circumference of the limb was high (r = 0.97) but the absorptiometry method was more sensitive. The results showed that in deep partial-thickness and full-thickness skin loss burns, oedema formation was maximal between 12 and 18 h after burning and that 80 per cent of the maximum was already present at 4 h. Resorption of the oedema was complete by 1 week after burning in partial- thickness skin loss burns, but significantly delayed in full-thickness skin loss burns. Superimposed infection was associated with persistent oedema.

Demling R. H., Mazess R. B., Witt R. M. et al. (1978) The study of burn wound oedema using dichromatic absorptiometry. Y. Trauma 18, 124.

Cerium sulphadiazine Cerium sulphadiazine has been synthesized and compared with silver and zinc sulphadiazine. All three of these metal sulphadiazines are effective, both in vitro and in the prevention of bacterial infection and mortality in burned mice and rats. Animals treated with zinc sulphadiazine show superior wound healing and longer survival. Cerium sulphadiazine, unlike silver and zinc sulphadiazine, binds to DNA instan- taneously, forming an insoluble cerium-DNA complex. The toxicity of cerium sulphadiazine is much lower than that of silver or zinc sulphadiazine. The efficacy of silver sulphadiazine, the wound healing potential of zinc sulphadiazine and the low toxicity of cerium sulphadiazine can be combined to give a superior form of topical therapy.

Fox C. L., Modak S. M. and Stanford J. W. (1978) Cerium sulphadiazine as a topical agent for burn wound infections: a comparison with silver sulpha- diazine and zinc sulphadiazine. Burns 4, 233.

Abstracts compiled by John W. L. Davies, DSc, MRC Industrial Injuries and Burns Unit, Birmingham Accident Hospital, Bath Row, Birmingham, B15 1NA.