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Biomedical subjects

J M Cummins

Publications and source records attributed to J M Cummins.

At least 91 records · Page 5Linked to original sources
PubMed1986

Nitrogen metabolism of calves inoculated with bovine adenovirus-3 or with infectious bovine rhinotracheitis virus.

Beef calves were inoculated with bovine adenovirus-3 or infectious bovine rhinotracheitis virus. After inoculation, plasma fibrinogen increased, serum phosphorus decreased, and nitrogen and phosphorus digestibility decreased compared with preinoculation values. Urinary N excretion increased when calves developed rectal temperatures greater than 39.7 C. Results indicated that clinical infection of calves with infectious bovine rhinotracheitis virus increases urinary N excretion and reduces N and phosphorus balance, and that clinical and subclinical infections with either virus reduce dietary N digestibility.

Adenoviridae Infections↗
PubMed1985

On mammalian sperm dimensions.

Data on linear sperm dimensions in mammals are presented. There is information on a total of 284 species, representing 6.2% of all species; 17.2% of all genera and 49.2% of all families have some representation, with quantitative information missing only from the orders Dermoptera, Pholidota, Sirenia and Tubulidentata. In general, sperm size is inverse to body mass (except for the Chiroptera), so that the smallest known spermatozoa are amongst those of artiodactyls and the largest are amongst those of marsupials. Most variations are due to differences in the lengths of midpiece and principal piece, with head lengths relatively uniform throughout the mammals.

Animals↗
PubMed1984

Antiviral effects of bovine interferons on bovine respiratory tract viruses.

The antiviral effects of bovine interferons on the replication of bovine respiratory tract viruses were studied. Bovine turbinate monolayer cultures were treated with bovine interferons and challenged with several bovine herpesvirus 1 strains, bovine viral diarrhea virus, parainfluenza type 3 virus, goat respiratory syncytial virus, bovine respiratory syncytial virus, bovine adenovirus type 7, or vesicular stomatitis virus. Treatment with bovine interferons reduced viral yield for each of these viruses as compared with that of control cultures.

Adenoviridae↗
PubMed1983

Use of a fluorometric immunoassay to determine antibody response to Pasteurella haemolytica in vaccinated and nonvaccinated feedlot cattle.

A retrospective study of the antibody response to Pasteurella haemolytica was conducted by using sera from 368 feedlot cattle divided among five experiments. In three experiments, live vaccines or a bacterin were administered to some of the cattle and others were left as nonvaccinated controls. In two experiments, cattle were not vaccinated. Clinical signs of disease with subsequent recovery developed in 48.0% of the cattle, and 10.3% of the cattle died. Vaccination had no apparent effect on morbidity or mortality. At the time of purchase, 78% of the cattle had low antibody titers (less than 25) as measured by a quantitative fluorometric immunoassay. In most groups of cattle (both vaccinated and nonvaccinated), there was a significant rise in mean antibody titers between the time of purchase and days 28 to 32 in the feedlot. The antibody titers at the time of shipment and health status of cattle. The antibody ratios were significantly greater for cattle that became sick and then recovered compared with those of cattle that remained healthy. Although significance could not be established, antibody titers at the time of shipment were higher for cattle that remained healthy compared with cattle that became sick and then recovered.

Animals↗
PubMed1979

Leukocyte changes and interferon production in calves injected with hydrocortisone and infected with infectious bovine rhinotracheitis virus.

Correlations between leukocyte counts and serum interferon titers were determined in calves given hydrocortisone (HC) and infectious bovine rhinotracheitis (IBR) virus. Calves were injected with either 1 mg or 3 mg of HC/kg of body weight every 8 hours for a total of 9 injections each. Control calves were given placebo injections. Viral inoculation was given IV 10 hours after the 1st dose of HC or placebo was given. By the time of viral inoculation, all calves injected with HC had developed neutrophilia, and the calves injected with 3 mg of HC also developed leukocytosis, lymphopenia, and eosinopenia; total leukocyte counts in calves injected with 1 mg of HC were increased, but not as much as in other HC-treated calves. Leukocyte counts in calves given placebo remained essentially unchanged before viral inoculation. At 1 day after IBR virus was inoculated, the number of circulating lymphocytes in HC-treated calves and control calves was decreased by more than 50%, on the average, of the counts taken before the HC injections or inoculation of virus. A significant negative correlation existed between the numbers of circulating lymphocytes and serum interferon titers at 1, 2, and 3 days after inoculation with IBR virus. The interferon response of calves undergoing lymphocyte suppression due to HC was not impaired, but was enhanced.

Animals↗
PubMed1976

Effects of epididymal occlusion on sperm maturation in the hamster.

Hamster epididymal spermatozoa were isolated in the caput, corpus and cauda regions for one, two and three days. Sperm suspensions from these regions were assessed for morphology, motility, viability; and for fertility by A.I. The ability to capacitate was tested by checking for acrosome reactions when the sperm were cultured under defined capacitating conditions at 37 degrees C in vitro. Normal, mature cauda sperm were highly fertile (overall 77% of ova fertilized) and showed 50-80% incidence of acrosome reactions after six hours in culture. Isolation for up to three days had no effect. Immature sperm from the caput and corpus were poorly motile, infertile, and did not manifest an acrosome reaction. Isolation for one and two days produced improvements in motility, and distal migration of the cytoplasmic droplet skin to normal maturation, however the sperm remained infertile and did not capacitate in vitro. Survival after three days isolation was poor. Thus the development of fertilizing ability in hamster epididymal spermatozoa is closely related to the ability to manifest an acrosome reaction in vitro; however it is only poorly correlated with motility and morphology. Completion of sperm maturation in this species appears to require the environment of the cauda epididymidis.

Animals↗
PubMed1975

Immersion fixation of rapidly frozen, untreated tissues and suspensions of cells including spermatozoa.

Small pieces of tissue, and cell suspensions in plastic artificial insemination (AI) 'straws', were frozen rapidly in Freon-12 at -155 degrees C, without pre-treatment. Peripheral fragments were thawed directly in 2% glutaraldehyde at 0 degrees C, and processed for transmission electron microscopy (TEM) studies. Preservation of ultrastructure was satisfactory, and freezing artifacts were minimal.

Animals↗