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To establish a standardised reproducible animal model of intraperitoneal sepsis, and to investigate early immunoserological responses to find a mediator-based system for evaluation and grading of diffuse peritonitis in patientsProspective experimental study4 Teaching hospitals, Germany and Austria42 LEW. 1W rats, 12 of which acted as controlsGram negative sepsis was induced by intraperitoneal injection of 6 ml of a mixture of Escherichia coli (K1:H+) 10(10) organisms/ml, autogenous haemoglobin 2.9 ml (haemoglobin concentration 3%), 0.9% sodium chloride 3 ml, and suspension 0.1 ml. Control rats were given physiological saline 6 ml alone.Concentrations of endotoxin, interferon gamma (IFN-gamma), and biopterin, and serum phospholipase A2 (PLA2) activity.There were significant differences between the septic and control rats in concentrations of endotoxin (EU/ml) (median (interquartile range) 21.85 (2.02-159.5) compared with 0, p0.0001; IFN-gamma (pg/ml) 1263.0 (271.0-7575.0) compared with 101.0 (89.0-141.0), p0.0001; biopterin (nmol/L) 111.0 (66.4-156.3) compared with 53.7 (38.3-67.6), p0.001; and PLA2 (U/L) 163.0 (125.8-209.0) compared with 112.5 (88.5-126.5) p0.01.Measurements of concentrations of endotoxin, IFN-gamma, pteridines, and PLA2 activity may well be adequate markers for early recognition of sepsis, and perhaps for grading it during the first 6 hours after induction. The allow a clear distinction to be made between septic and non-septic disorders in 87% of cases.

Among the proteins that comprise the albumin family, alpha-fetoprotein (AFP) is the only member which exhibits immunoregulatory properties. However, some investigations have argued that AFP-mediated immunosuppression is not an inherent property of the molecule itself, but is instead, hypothesized to be either a function of a low molecular weight inhibitor bound to AFP or to a post-translational modification of the protein. AFP cannot be isolated from natural sources in quantities sufficient for the detailed biochemical and functional analyses required to resolve these issues. We have therefore produced recombinant forms of the protein (rAFP) by cloning the cDNA's for mouse and human AFP in both eukaryotic and prokaryotic expression systems. As described in this report, we were able to abundantly express rAFP's in bacterial, baculovirus and yeast expression systems. Recombinant proteins derived from each expression system were recognized by polyclonal and monoclonal anti-AFP antibodies as determined by immunoblot analysis. Pure recombinant protein samples, as characterized by polyacrylamide gel analyses, N-terminal sequencing and FPLC and HPLC chromatography, were evaluated for their immunoregulatory properties in murine and human in vitro immunological assays. The results of these studies establish that rAFP is functionally equivalent to natural fetal derived AFP molecules. Importantly, the data reported here demonstrate that AFP-mediated immunoregulation is an activity intrinsic to the molecule itself and cannot be attributed to either putative non-covalently bound moieties or to post-translational modifications such as glycosylation and sialylation. These studies provide a basis for initiating detailed investigations into the potential clinical usefulness of AFP as an immunotherapeutic agent.

The catabolism of glucose and amino acids has been studied in the normal, the fasted, and the fasted septic dog. The fasted septic dog oxidized more glucose and alanine, and had more gluconeogenesis from alanine and the five tritiated amino acids--glutamate, threonine, phenylalanine, leucine, and valine--as compared to the normal and equally fasted dog. Thus the total body protein catabolic state was characterized in biochemical terms. In contrast, following glucose infusion, the fasted septic animal responded much like the fasted animal in terms of decreased animo acid gluconeogenesis and decreased plasma concentrations of amino acids, fats and fat products, but considerably increased the oxidation of alanine. The increased alanine oxidation appeared to be primarily related to increased tissue clearance and increased plasma concentration. There was some suggestive evidence for enhanced oxidation of the tritiated amino acids including leucine and valine during glucose infusion. The protein catabolic state secondary to this sort of sepsis in dogs only on per os fluid support appears to be best characterized as a glucose catabolic state with alanine being oxidized directly. Such states are known to be ones of enhanced metabolic rate secondary to enhanced synthetic processes generally. This is probably related to enhanced sympathetic nervous system release of glucagon with insulin being normally responsive to glucose because of a normal plasma epinephrine.

A canine hind-limb exercise model is described that permits study of pressure and flow changes through an area of arterial stenosis before, during, and after exercise. Following creation of a critical stenosis in the external iliac artery (50% reduction in flow), exercise alone resulted in an increase in flow over the stenosis related to the degree of exercise produced, accompanied by a widening of the arteriovenous oxygen difference and an increase in oxygen consumption. Infusion of an intra-arterial vasodilator (tolazoline hydrochloride) during the exercise period resulted in only a negligible change in flow over the stenosis, but a marked narrowing of the arteriovenous difference (30%) with a resulting reduction in limb oxygen consumption. These findings suggest that this intraarterial vasodilator opens arteriovenous shunts, apparently bypassing the capillary bed.