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Biomedical subjects

R W Worthington

Publications and source records attributed to R W Worthington.

17 recordsLinked to original sources
PubMed1979

Catecholamine and cyclic nucleotide response of sheep to the injection of Clostridium welchii type D epsilon toxin.

Injection of Clostridium welchii (C. perfringens) type D epsilon toxin into sheep caused large increases in catecholamine and cyclic adenosine 3',5'-monophosphate levels and moderate increases in cyclic guanosine 3',5'-monophosphate levels. Haemoconcentration also occurred. It is suggested that a rapidly developing brain oedema is the stimulus for a release of catecholamines which in turn activates adenyl cyclase. The resulting rise in cAMP causes glycogenolysis and hyperglycaemia.

Animals↗
PubMed1979

Isolation and partial characterization of two different heat-stable enterotoxins produced by bovine and porcine strains of enterotoxigenic Escherichia coli.

Heat-stable enterotoxins (ST-124 and ST-1261) have been isolated from two different enterotoxigenic Escherichia coli of bovine (124) and porcine (1261) origin. The enterotoxin preparations were isolated by ultrafiltration and ion-exchange chromatography and were both active in the suckling mouse test and pig ligated loop test in the nanogram range. The bovine (ST-124) enterotoxin was not stable to heating in its isolated form, and significant differences in amino acid composition were observed between the two enterotoxins. Although both toxins were active at similar levels in the suckling mouse and pig ligated loop tests, ST-124 lacked the ability to cause the profound secretory responses seen with ST-1261 in the weanling pig ligated loop.

Amino Acids↗
PubMed1979

Isolation and characterization of antibodies to Clostridium perfringens epsilon toxin from hyperimmune horse serum.

Antibodies against epsilon toxin were isolated from hyperimmune horse serum by affinity chromatography. Purified epsilon prototoxin covalently bound to Affigel 202 was used as immunosorbent, and antibodies were eluted with 6.0 M guanidine chloride. In a single run 80 mg of antibody could be recovered from a 20 microliter column of immunosorbent. The antibody was shown to belong to the IgG(T) class of immunoglobulins.

Animals↗
PubMed1975

Effect of Clostridium perfringens epsilon toxin on the blood brain barrier of mice.

It was shown that Clostridium perfringens epsilon toxin has the effect of allowing the passage of 125I polyvinyl-pyrrolidone and 125I human serum albumin into mouse brain. These substances did not enter the brains of normal control mice. The passage of albumin into the brains of mice poisoned with epsilon toxin was extremely rapid. When large doses of toxin (+/-4 000 MLD) were given death ensued within 2-3 min at which stage 1,5% of the injected albumin had already entered the brain. In cases where smaller doses were given and the time interval between injection and death was longer the figure was increased to 2-2 1/2% of the injected plasma albumin.

Animals↗
PubMed1975

The partial purification of Clostridium perfringens beta toxin.

An attempt was made to purify Clostridium perfringens Beta toxin. Crude toxin prepared by ammonium sulphate precipitation of culture supernatants was purified by chromatography on Sephadex G50, Sephadex G100 and DEAE cellulose. This material, although highly purified was not homogeneous on polyacrylamide gel electrophoresis. It had a toxicity of 800 000 mouse MLDs/mg N, a typical protein absorption spectrum in the UV region, an iso-electric point of 5, 6 and the main component had a molecular mass of 42 000 +/- 2 000 (estimated by electrophoresis in sodium dodecyl sulphate containing polyacrylamide gels).

Chromatography, DEAE-Cellulose↗