The 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 2-2½% of the injected plasma albumin.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acroabt XI was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

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 mℓ column of immunosorbent. The antibody was shown to belong to the IgG(T) class of immunoglobulins.This article has been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-Format.University of Pretoria Research Fun

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)The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acroabt XI was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Antigenic relationship of Brucella ovis to Brucella abortus and Brucella melitensis using the complement fixation test

The CF test was used to investigate the serological relationship of Br. ovis to Br. abortus and Br. melitensis. A definite antigenic relationship between Br. ovis and Br. abortus could be demonstrated. Definitive results were obtained by absorbing sera with Br. ovis, Br. melitensis and Br. abortus before testing.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Further physiopathological features of experimental Homeria glauca (Wood and Evans) N.E.Br. poisoning in Merino sheep

Three Merino sheep were given 3 g/kg of dried, finely-milled Homeria glauca (Natal yellow tulp) plant material intraruminally. Plasma glucose, cortisol, catecholarnines and lactate were measured hourly and also at the moment of death. Rising plasma glucose was shown to be associated with rising plasma cortisol and catecholamines, and the metabolic component of tulp-associated acidosis was shown to be the result of lactate accumulation.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Department of Agriculture.am201

Clostridium perfringens type D epsilon prototoxin. Some chemical, immunological and biological properties of a highly purified prototoxin

Highly purified Cl. perfringens type D epsilon prototoxin was prepared by ammonium sulphate precipitation and DEAE cellulose chromatography of culture filtrate of cultures of Cl. perfringens type D (Strain ET 468). Preparations of prototoxin were electrophoretically heterogeneous. The protein bands demonstrable in polyacrylamide gel electrophoresis were, however, all immunologically identical and toxic. The faster moving bands were shown to be degradation products of the main prototoxin band which was the slowest moving of the major bands. There was an inverse relationship between electrophoretic mobility and the activation ratio of these degradation products. The unde- graded prototoxin could be separated from its degradation products by CM cellulose chromatography but degradation appears to be a continual process and isolation of an absolutely pure product was not achieved.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Enzymatic activation of Clostridium perfringens epsilon prototoxin and some biological properties of activated toxin

Maximal activation of Clostridium perfringens epsilon toxin was only achieved by the combined action of trypsin and chymotrypsin. Impure preparations of trypsin, presumably containing small amounts of chymotrypsin were more efficient in activating prototoxin than pure trypsin. Activated toxin was readily absorbed by brain tissue and smaller amounts were possibly absorbed by kidney tissue. Other tissues absorbed only very small amounts of toxin. Injection of mice with toxoid 3 h prior to challenge with toxin increased their resistance 32 times.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Serological titres following vaccination of sheep and goats with Brucella melitensis Rev I vaccine

Rev 1 vaccination of sheep induced complement fixation titres to both Brucella abortus and Brucella ovis antigens, the complement fixing antibody titres were, however, higher with the B. abortus antigen. These titres generally fell to negative levels (below 1/20) within 5 to 6 months of vaccination. In goats Rev 1 vaccination induced complement fixation titres against B. abortus antigen which fell to negative levels within 5 to 6 months. Agglutination at 37°C or 56°C, agglutination in 5% NaCl, and Coombs tests are less useful in vaccinated animals as titres remain at positive levels for much longer periods after vaccination.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A serological investigation on adult cattle vaccinated with Brucella abortus strain 19

Serum antibody titres were followed for a period of two years in 99 beef and 29 dairy cows which had been vaccinated as adults with B. abortus strain 19. Agglutination titres remained above diagnostic levels throughout but complement fixation, mercaptoethanol agglutination and rivanol agglutination titres generally returned to negative levels within 6 months. Coombs tests and agglutination at 56° proved to be of limited value for recognising antibody titres caused by vaccination.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Stability and partitioning of closantel and rafoxanide in ruminal fluid of sheep

The stability and the partitioning of closantel and rafoxanide in ruminal fluid (RF) was examined in vitro. Stability was evaluated in two studies in a ruminal fluid-artificial saliva (RF-AS) mixture containing either drug. Drug concentrations were measured in samples collected sequentially from four batches of RF-AS fortified with either closantel or rafoxanide in one study and in four separately incubated aliquots of a RF-AS mixture of each drug in the second study at the start and at various intervals during a 24 h incubation period. The viability of the in vitro RF-AS incubation model was validated by the presence of digoxin degradation (T1/2 of 39.1±13 h) and by the absence of significant time related differences (P>0.5) in volume of gas produced, pH and methylene blue reduction time of the RF-AS drug mixture. Partitioning of closantel and rafoxanide was determined by measuring the relative drug concentration of the fluid and particulate phases in RF fortified with either drug at different concentrations. Closantel and rafoxanide were shown to be stable in a RF-AS mixture and were not subjected to any significant biodegradation. An initial marked reduction in drug concentration measured in the RF-AS mixture during the first 2 h of incubation was attributed to the attachment of both drugs onto particulate matter. This was subsequently confirmed in the partitioning study. More than 80% of closantel and rafoxanide was shown to be associated with the particulate phase of RF.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Faculty of Veterinary Science, University of Pretoria.mn2012ab201