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Biomedical subjects

A H Corner

Publications and source records attributed to A H Corner.

At least 37 records · Page 2Linked to original sources
PubMed1977

Myocardial lesions in rats fed rapeseed oil. I. Influence of strain of rats.

The influence of strain of rat on the development of myocardial lesions was investigated in an experiment which included two factors: strain (Wistar, Sherman, Chester Beatty (Hooded), and Sprague-Dawley from two sources designated Sprague-Dawley A, Sprague-Dawley C) and diet (5% corn oil, 20% corn oil, and 20% Brassica napus var. Zephyr rapeseed oil). Groups of 30 rats, housed 2 per cage, from each of three different strains of rats and groups of 10 rats, housed 2 per cage, from one strain of rats (Hooded) were fed semisynthetic diets containing the test oils for 16 weeks on an ad libitum basis. Rats of the Hooded strain consumed considerably less feed and grew at a significantly (P less than 0.01) slower rate than did rats of the Sprague-Dawley C strain, which in turn ate less and grew significantly (P less than 0.01) slower than rats of the other three strains. No marked differences were observed in the fatty acid composition of total cardiac lipids among strains. Rats from all strains except Hooded fed the diet containing 20% Zephyr RSO had a significantly (P less than 0.001) higher incidence of myocardial lesions than rats fed the 20% corn oil diet which in turn had a significantly (P less than 0.001) higher incidence than rats fed 5% corn oil. Similarly, significantly (P less than 0.05) more Sprague-Dawley C rats had myocardial lesions than Sprague-Dawley A rats regardless of diet. None of the Hooded rats fed the diet containing 20% Zephyr RSO developed myocardial lesions whereas all other strains fed this diet developed a high incidence of myocardial lesions.

Animals↗
PubMed1977

Myocardial lesions in rats fed rapeseed oil. II. Effects of castration.

The effects of castration on the incidence of myocardial lesions in rats were investigated in an experiment which included two factors: sex (entire males, castrated males, entire females and castrated (ovariohysterectomized) females) and diets (5% corn oil, 20% corn oil, and 20% Brassica napus var. Zephyr rapeseed oil). For 16 weeks, each of the 12 groups of 30 Sprague-Dawley rats, housed 2 per cage, were fed ad libitum the test oils incorporated in a semisynthetic diet. At each weighing, the mean body weights for each diet were highest in entire males followed by castrated males, castrated females, and entire females with all differences significant (P less than 0.05). The results indicated that castration did not influence cardiac fatty acid composition. The incidence of myocardial lesions in entire and castrated females and in castrated males was similar while significantly more entire males developed lesions (P less than 0.001). Rats fed a diet containing 20% Zephyr rapeseed oil showed a significantly (P less than 0.001) higher incidence of heart lesions than did rats fed diets containing 5% or 20% corn oil. Similarly, significantly (P less than 0.05) more rats fed the 20% corn oil diet had lesions than rats fed the 5% corn oil diet. The involvement of androgens in the formation of myocardial lesions is suggested, since castration significantly lowered the incidence in males but not in females.

Animals↗
PubMed1976

Effect of cold stress on rapeseed oil fed rats.

No mortality was observed in 6 week old male Sprague-Dawley rats subjected to cold at 4 C for 3 weeks and fed either a control diet (Chow) or a semisynthetic diet containing 20% by wt rapeseed oil high in erucic acid (23.6%). All rats fed the Chow diet and 17 of 20 rats fed the rapeseed oil-containing diet survived 4 weeks in the same environment. Three rats on the latter diet died of self-mutilation. Marked myocardial lipidosis as well as a large acumulation of 20:1 and 22:1 was observed in the hearts of rats fed the rapeseed oil-containing diet. Five of 20 rats on the Chow diet and 2 of 20 rats on the rapeseed oil-containing diet had focal necrotic areas in the myocardium.

Animals↗
PubMed1976

Meningoencephalomyelitis in horses associated with equine herpesvirus 1 infection.

During an outbreak of abortion caused by equine herpesvirus 1, a neurologic disease characterized clinically by dullness and ataxia occurred in several mares. Equine herpesvirus 1 was isolated from brain and lung of two severely affected mares. Histologically, both mares had disseminated meningoencephalomyelitis characterized by necrotizing arteritis, focal malacia in grey and white matter of brain and spinal cord, and accumulation of lymphocytes and neutrophils in paravertebral ganglia. Eosinophilic intranuclear inclusion bodies occurred in foci of necrosis in thyroid adenomas of both mares.

Abortion, Veterinary↗
PubMed1975

Cardiac lesions in rats fed rapeseed oils.

Fully refined rapeseed oils containing different amounts of erucic acid (1.6%, 4.3% and 22.3%) were fed, at 20% by weight of diet, to weanling male and female Sprague-Dawley rats for periods up to 112 days. Transient myocardial lipidosis characterized by accumulation of fat droplets in myocardial fibers was marked in male and female rats fed oxidized and unoxidized rapeseed oil containing 22.3% erucic acid, moderate with rapeseed oil containing 4.3% erucic acid and very slight in rats fed rapeseed oil containing 1.6% erucic acid. Peak intensity of myocardial lipidosis occurred at three to seven days and regressed thereafter. Focal myocardial necrosis and fibrosis occurred in male rats fed rapeseed oils containing different levels of erucic acid for 112 days. The incidence of myocardial necrosis and fibrosis was markedly lower in female rats, and the incidence of these lesions in either sex was not affected by the state of oxidation of these oils. In a second experiment, male rats were fed diets containing crude, partially refined or fully refined rapeseed oils. There was no correlation between the number of foci of myocardial necrosis and fibrosis and the state of refinement of the oils, but there were generally fewer lesions in rats fed those oils having the lowest levels of erucic acid.

Animals↗
PubMed1972

The fluorescent antibody technique in the diagnosis of equine rhinopneumonitis virus abortion.

Using two known positive equine viral rhinopneumonitis (EVR) sera, conjugates were prepared with fluorescein isothiocyanate and tested for specificity using EVR infected tissue culture cells. The conjugate was then applied to selected tissues from 32 aborted fetuses and foals submitted during a natural outbreak of EVR. Antigen was detected in various tissues by immunofluorescence in 20 cases (62.5%). In 24 cases bovine fetal kidney cell monolayers were inoculated with a pool of lung and liver and EVR virus was isolated from 15 (62.5%). Histological examination of various tissues from 29 cases resulted in the diagnosis of EVR in 19 (65.5%), based upon the presence of focal areas of necrosis and intranuclear inclusion bodies. Correlation of results was not obtained in two cases. One was diagnosed positive histologically and negative on fluorescence, the other was negative histologically and by virus isolation but showed fluorescence. The distribution of fluorescence in various infected fetal tissues indicated that the combined examination of lung and thymus gland was most likely to provide a positive diagnosis.

Abortion, Veterinary↗
PubMed1969

Glasser's disease of swine produced by the intracheal inoculation of haemophilus suis.

The intracheal inoculation of pigs with Haemophilus suis led to the production of Glasser's disease at every attempt without significant pulmonary involvement. Isolation of this organism from the experimental animals was possible only in the acute phase of the disease. The indirect fluorescent antibody technique when applied to frozen sections of tissues obtained from the experimentally infected pigs at autopsy, revealed a few rod forms but mostly "round bodies" of H. suis in animals from which the organism was isolated, and "round bodies" only in the pigs from which the organism was not isolated. Attention is drawn to the similarities between the lesions caused by H. suis and Mycoplasma hyorhinis, and to the confusion which may result therefrom. It is stressed that the laboratory diagnosis of these two diseases is complicated by the fact that both agents may not be isolated on the media commonly used in diagnostic laboratories. Both organisms necessitate the use of special media where the clinical and autopsy results indicate polyserositis and arthritis.

Animals↗
PubMed1969

Equine infectious anemia: preliminary investigation of the complement-fixation test for the demonstration of antibodies and antigen.

Clinical field cases of equine infectious anemia were studied and the disease was reproduced experimentally in horses. Attempts were made to adapt the complement-fixation test to the detection of antibodies in the serum of infected animals and to the demonstration of antigens in tissue extracts.A moderate complement-fixing antibody response was demonstrated in the serum of horses shortly after primary exposure to the infectious agent. However, this reactivity was of short duration and occurred with normal as well as with infected saline tissue extracts. It was therefore concluded that this reaction was not specific for equine infectious anemia. Possibly it is due to the appearance of auto-tissue antibodies. The value of this reaction in the diagnosis of the infection was limited because of its short duration and absence in chronic infection and following re-exposure to the infectious agent.

Animals↗
PubMed1968

A histological study of the effects of enzootic abortion of ewes virus in the lactating bovine mammary gland.

Inoculation of the udders of cows with the virus of enzootic abortion of ewes resulted in a severe acute mastitis. The mastitis was characterized clinically by pyrexia, anorexia, decreased milk production, swelling and marked alteration in the physical quality of the milk. The basic lesion was necrosis of alveolar and duct epithelial cells. Virus particles were demonstrated in all levels of the mammary gland three days after inoculation illustrating the rapid spread of the agent. Cells resembling Reed-Sternberg cells and similar to those seen in experimental mastitis produced by the virus of infectious bovine rhinotracheitis were seen in tissues collected six and nine days after inoculation.

Abortion, Veterinary↗
PubMed1967

A histological study of the effects of the herpesvirus of infectious bovine rhinotracheitis in the lactating bovine mammary gland.

Mastitis was produced in three first calf heifers by inoculation of the udder with the virus of infectious bovine rhinotracheitis. These animals were killed at different times during the course of the disease and tissues were harvested and examined histologically. The basic lesion resulted from the necrotizing effect of the virus upon the epithelial cells of the alveoli and ducts. Eosinophilic intranuclear inclusion bodies were demonstrated in tissues from animals killed at three and six days postinoculation, but not at nine days. Of interest was the presence of a large Reed-Sternberglike cell in tissues of the last two animals killed.

Animals↗
PubMed1966

Induced tolerance in turkeys to aflatoxin poisoning.

The consumption of moderately poisonous levels of toxic groundnut meal by turkey poults induced a degree of tolerance to aflatoxin Poults thus ;conditioned' gained more than ;unconditioned' birds on successively higher levels of aflatoxin and were enabled to survive and gain on rations which killed mature turkeys. Ingestion of aflatoxin led to marked alterations in the serum electrophoretic patterns followed in a few weeks by a return to nearly normal patterns. Subsequent increases in aflatoxin intake induced only minimal alternations in the serum patterns but the tolerance appeared unrelated to the hepatotoxic effect because extensive pathological changes developed in the liver.

Animal Feed↗
PubMed1966

Some observations on the diagnosis and epidemiology of leptospirosis in swine.

The results of combined epidemiological, clinical, serological, bacteriological and histopathological studies following an outbreak of disease caused by L. pomona on a farm stocked with cattle, sheep, pigs, goats and horses maintained for experimental purposes, are reported.The incidence of infection was high in horses, cattle and pigs. A few low titres were seen in sheep. The goats were not infected. Apart from a single bovine abortion all the clinical symptoms observed occurred in pregnant sows. Seven of these aborted or gave birth to stillborn pigs within a six week period. Fifteen species of wildlife were trapped or shot on the farm during the year following the outbreak. L. pomona was isolated from four skunks and a porcupine. Epidemiological studies indicated that wildlife reservoir hosts were the primary source of infection for the domestic livestock. Leptospiruria and the serological response were studied in a group of eight infected sows. Microscopic agglutination titres of 10(2) or less could not be associated with leptospiruria and the duration of leptospiruria was found to range from a few weeks to over two years in individual sows. Direct dark-field examination of urine proved superior to guinea-pig inoculation as a method of detecting leptospiruria and it is suggested that the former technique could be adopted with advantage as a routine aid to diagnosis.

Agglutination Tests↗