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Biomedical subjects

B N Gupta

Publications and source records attributed to B N Gupta.

At least 127 records · Page 7Linked to original sources
PubMed1978

Isolation of Pasteurella aerogenes from the uterus of a rabbit following abortion.

Pasteurella aerogenes was isolated from the uterus and peritoneal cavity of a rabbit which died 4 days after abortion. Histopathologic observations confirmed a bacterial infection. Mouse pathogenicity tests indicated that this organism was an opportunistic pathogen that might have been responsible for the stillbirths. The cultural and biochemical characteristics of this isolate were similar to those of the Pasteurella aerogenes isolated from swine. This is the first report describing the isolation of Pasteurella aerogenes from a rabbit.

Abortion, Veterinary↗
PubMed1977

The location and distribution of type A and type B atrial endings in cats.

In the attempt to explain the difference in discharge pattern of atrial endings, 131 endings were localized by punctate stimulation, 44 were type A, 77 type B and 10 of an intermediate type. All were located on the dorsal wall of the atria with none on the ventral wall or in the appendage. On the right side, 74% of type A were located in the atria and 63% of type B in or near the veins. On the left side, 67% of type A and 94% of type B were located in or near the veins. Thus, there appeared to be some difference in the location of type A and type B endings on the right side, but on the left side both types of endings were for the most part confined to the venous region. Further, on both right and left sides, these endings were present both in the central part of the atria and in or adjacent to veins. This leads to the suggestion that the difference in discharge patterns is not caused by the location but may be due to some other reasons, e.g. difference of arrangement in the atrial wall with respect to the contractile elements.

Animals↗
PubMed1977

Studies on the adaptation rate and frequency distribution of type A and type B atrial endings in cats.

Since from the study of location no clue could be found regarding the difference in discharge patterns of type A and type B endings in cats, two separate series of experiments were performed. In the first series, the responses obtained from types A, B and intermediate endings on stretching the isolated atrial chamber were identical. From the second series directed to the frequency distribution of atrial endings and performed by recording of the neural activity in single fibres of the whole vagus, a ratio of 1:1 between type A and type B endings was found. Endings with an intermediate pattern of discharge were rare. Out of 71 atrial endings recorded from 4 vagus nerves, only 7 were of this type. These studies showed that: (1) the types A, B and intermediate endings are slowly adapting, (2) the intermediate type is a variant of type B and (3) type A and type B endings belong to different types. It is speculated that the difference in discharge patterns of type A and type B endings may be due to their arrangements in the atria.

Adaptation, Physiological↗
PubMed1976

The effect of aerosol hair spray inhalation in the hamster.

Hamsters were exposed to a commercially available aerosol hair spray actuated for a total of 8 minutes over a 4-hour-period, 5 days/week. They were examined after 1, 2, 3, 4, and 6-week exposures, and 2,4 and 8 weeks after a 6-week exposure. There was a significant increase in the lung weight of exposed hamsters at every time point except 8 weeks after the 6-week exposure. Microscopic changes in the lung were characterized by the presence of a few to a moderate number of macrophages and neutrophils in the alveolar lumina. The number of macrophages and neutrophils appeared directly related to the duration of exposure. Lung changes were minimal during the first 2-weeks of exposure, and 8 weeks after the 6-week exposure (recovery period). Pathologic changes in the lungs of hamsters were reversible after cessation of the hair spray inhalation exposure.

Aerosols↗
PubMed1976

Primary isolation of Mycobacterium avium complex-serotype 6 on blood agar.

Mycobacterium avium complex-serotype 6 was isolated in pure culture on blood agar plates from inocula taken from the heart blood, lungs, liver, kidneys, and spleen of a naturally infected captive female opossum (Didelphis marsupialis virginiana). Repeat cultures from stored tissues and transfer of colonies from original blood agar plates revealed that the mycobacterium grew on tryptose, brilliant green, eosin-methylene blue. Sabouraud glucose, and mycobiotic agar plates and in Fletcher leptospira medium. The cultural, biochemical, and serological characteristics of the test isolate were compared with other mycobacteria. This is the first report to describe the primary isolation of a serotype from the M. avium complex from an animal species on blood agar or in Fletcher broth. In addition, this is the second documented report describing the isolation and identification of a mycobacterial species from the American opossum.

Agar↗
PubMed1976

Histopathologic changes in laboratory animals resulting from various methods of euthanasia.

The histopathologic changes caused by various methods of euthanosia were studied in rats, mice, guinea pigs, and rabbits. Lesions resulting from a particular methods of euthanasia were consistent from species to species. Each method studied affected the lungs to some degree, ranging from mild congestion of alveolar capillaries to marked intramural edema of pulmonary arteries and alteration of vascular permeability. Euthanasia of experimental animals by overexposure to CO2, or ip injection of concentrated sodium pentobarbital seemed most suitable for pulmonary studies. Decapitation (mice, rats, guinea pigs), cervical dislocation (mice), CO2, and intracardial injection of sodium pentobarbital were more suitable for examination of abdominal viscera.

Anesthesia↗
PubMed1976

Lymphosarcoma in a rabbit.

Generalized lymphosarcoma was observed in a 7-month-old New Zealand White rabbit. Numerous grayish white nodules were found in the kidney and liver. The mucosal surface of the stomach was hemorrhagic and ulcerated. Virus-like particles were observed in neoplastic tissue from the kidney on electron microscopic examination. Significance of the presence of virus-like particles was not determined.

Animals↗
PubMed1975

Opossums as a reservoir for Salmonellae.

Approximately 200 opossums, trapped during the fall of 1973 in the vicinity of Raleigh, NC, were maintained in the Institute's breeding colony in individual cages until the breeding season. Clinically normal, dead, and moribund opossums were examined for Salmonella. Six serotypes of Salmonella were identified in both clinically normal and diseased opossums. Positive culture results were obtained on 39 of 56 (70%) rectal swab specimens collected in the fall from incoming opossums, and on 30 of 50 (60%) rectal swab specimens collected during midwinter from an additional group of clinically normal opossums, which were maintained in isolation for approximately 3 months before testing. At necropsy, 87 of 108 (81%) diseased opossums were culture positive for Salmonella. Salmonellae in serogroups B and R were isolated from the spleen, liver, kidneys, or heart blood as well as the ileum of 57 diseased opossums. In 23 cases, S typhimurium or S bern was isolated in pure culture from the visceral organs. These findings indicated bacterial septicemia. In contrast, salmonellae in serogroups C1, E1, and F were routinely isolated from the feces of clinically normal and diseased opossums, suggesting a habitat restricted to the intestinal tract and probably the mesenteric lymph nodes. It was concluded that the opossum serves as a reservoir for a number of serotypes of Salmonella and may have an important role in the epizootiology of wildlife salmonellosis.

Animals↗
PubMed1975

Effects of vinyl chloride exposures to rats pretreated with phenobarbital.

Male rats were exposed to 10 consecutive days, 6 hr/day, to vinyl chloride vapors at an average concentration of 13,500 ppm. The exposed rats were divided into three groups of eight rats each: one group was pretreated with 3-methylcholanthrene, one group was pretreated with phenobarbital, and the third group received no treatment. Half the animals in each group were sacrificed 18 hr after the last exposure and half were sacrificed 4 days later. In a second experiment, four rats pretreated with phenobarbital were exposed to vinyl chloride vapors at a concentration of 17,300 ppm for 2 days and sacrificed about 9 A.M. on the third day. In both experiments control animals, also treated with phenobarbital or 3-methylcholanthrene, were exposed to air only. At the time of sacrifice, lungs, kidneys, spleen, heart, and a small piece of liver from each animal were preserved for histological examination. The remainder of the liver was processed for assay of microsomal enzyme activity. The following parameters were investigated: growth rate, organ weights, morphological changes, and both benzphetamine-N-demethylase activity and cytochrome P-450 content of microsomes prepared from the livers. In both experiments the only marked difference noted in any group was a decrease in the growth rate of the animals exposed to vinyl chloride and treated with phenobarbital. This decreased growth rate was particularly apparent on the third day of the vinyl chloride exposures. Occasional morphological changes were also seen in the livers of the animals treated with phenobarbital and exposed to vinyl chloride.

Animals↗
PubMed1975

Tissue-washing tank for histologic preparations.

A small tank made of plexiglass was designed to wash tissues for histologic preparations. The tank was divided into 16 compartments in 2 rows to wash 16 tissue samples at one time. The compartments in the same row alternately intercommunicated by rows of holes in the upper or lower halves. The arrangement of holes at 2 water levels in the partition appeared to create silent water waves, making the tank more efficient for washing tissues.

Histological Techniques↗