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Biomedical subjects

J F Evermann

Publications and source records attributed to J F Evermann.

At least 109 records · Page 6Linked to original sources
PubMed1984

Pathogenesis of experimental bovine respiratory syncytial virus infection in sheep.

Conventionally reared lambs, seronegative to bovine respiratory syncytial virus (RSV), were inoculated with bovine RSV by an aerosol route. A mild clinical response, characterized by transient fever at postinoculation day (PID) 4, occurred and was accompanied by serous oculonasal secretions in less than 50% of the infected lambs. A decrease in total WBC was observed on PID 6 and 11, with a reduction in the total numbers of lymphocytes. Bovine RSV was recovered from nasal secretions of inoculated lambs from PID 2 to 6. The lambs were euthanatized, and at necropsy, the virus was only isolated from lambs killed between PID 2 and 4. Serum neutralizing antibodies were noticed as early as PID 6 and peaked at PID 13 to 15. Neutralizing antibodies were also detected at low concentration in pulmonary washings. Viral antigen was mainly located in alveolar walls and occasionally in bronchiolar epithelium and alveolar macrophages in lambs killed between PID 2 to 4. Later, specific fluorescence was only present in alveolar walls and was not observed in tissue from lambs killed after PID 22. Budding and free virus-like particles were observed by electron microscopy in type I and type II alveolar epithelial cells. Outstanding macroscopic lesions were not seen. Histologically, mild bronchiolitis and alveolitis were observed.

Aerosols↗
PubMed1984

Interaction of bovine respiratory syncytial virus and Pasteurella haemolytica in the ovine lung.

The potential synergistic effect of bovine respiratory syncytial virus (RSV) and Pasteurella haemolytica in the production of pneumonia after aerosol/intranasal infection of conventionally reared lambs was evaluated. A mild clinical response was observed in lambs given virus and/or bacteria. Gross pulmonary lesions were seen in 3 of 6 lambs given RSV and then P haemolytica 3 or 6 days later, respectively (groups D and E), and in 1 lamb of 5 given virus and bacteria simultaneously (group G). Gross lesions were not seen in control sheep (group A), in lambs given virus or bacteria alone (groups B and C), or in lambs exposed to bacteria and then virus 3 days later (group F). Bovine RSV and P haemolytica were recovered from the lungs of 5 of 7 lambs with macroscopic lesions. Gross pulmonary lesions were cranioventral firm areas of red consolidation. Microscopically, the predominant lesion was a suppurative bronchopneumonia. Bovine RSV was recovered from the nasal cavity of 8 of 27 (30%) lambs given RSV during days 3 to 6 after viral inoculation, including 1 lamb in group B, 2 in groups D, E, and F, and 1 in group G. Pasteurella haemolytica was recovered from the nasal cavity of 9 of 28 (32%) inoculated lambs, including 2 lambs from groups C and E, 3 in group D, and 1 in groups F and G. Viral antigen, as determined by immunofluorescence, was concentrated mainly in individual cells in alveolar walls, some alveolar macrophages, and a few bronchiolar epithelial cells. In vitro alveolar macrophage assays indicated decreased numbers of Fc receptors on those macrophages collected from lambs given RSV 6 days before P haemolytica infection, as compared with that in the other groups. These cellular defects disappeared after 24 hours of culture. Seemingly, bovine RSV does facilitate P haemolytica pulmonary infection in conventional, immuno-competent lambs and provides evidence for decreased Fc receptors on alveolar macrophages.

Aerosols↗
PubMed1984

Pathogenesis of feline gastric chlamydial infection.

Studies were conducted to determine whether the gastric chlamydiae that have been observed recently in cats are of pathologic significance. Chlamydiae were isolated in mouse L cell cultures from the homogenized pooled gastric mucosa of 3 cats that had been identified, by histopathologic examination, to have gastric chlamydiosis. Ten specific-pathogen-free kittens were exposed by aerosol and oral inoculation to the harvested feline gastric chlamydiae cell-culture media. In general, the clinical signs and lesions were conjunctivitis, rhinitis, and mild gastritis. The clinical signs and lesions were most severe in 2 chlamydia-infected kittens that had received methylprednisolone acetate (50 mg/kg of body weight). Chlamydiae were demonstrated in epithelial cells of conjunctival and nasal smears in 10 of 10 infected kittens from postexposure days 7 through 35. In addition, chlamydiae were isolated in L cell cultures from a variety of antemortem and postmortem specimens from infected kittens. The present study provided evidence that feline gastric chlamydiae, under appropriate conditions, were capable of inducing, in cats, clinical signs and lesions similar to those induced by the feline pneumonitis agent.

Animals↗
PubMed1983

Ultrastructure of newly recognized caliciviruses of the dog and mink.

Two recently recognized viruses obtained from a dog with glossitis and from mink with hemorrhagic pneumonia were characterized by electron microscopy. The results of the negative-stained preparations indicated that the viruses were structurally compatible with the calicivirus group.

Animals↗
PubMed1983

Hematologic, serum chemistry and serologic values of Dall's sheep (Ovis dalli dalli) in Alaska.

In June 1979, 73 Dall's sheep were captured near Tok, Alaska to determine selected hematologic and serum metabolite parameters and to determine the presence of antibodies to selected pathogens. Hematology and serum metabolite values were compared with values for domestic sheep and bighorn sheep (Ovis canadensis). Antibodies were detected against Brucella sp. (4%), Campylobacter feti (30%), contagious ecthyma virus (23%) and bovine parainfluenza type 3 virus (1%). Antibodies were not detected against Anaplasma sp., Leptospira sp., bovine virus diarrhea virus, bluetongue virus, infectious bovine rhinotracheitis virus, ovine progressive pneumonia, and Toxoplasma sp.

Alaska↗
PubMed1982

Infectious agents associated with neonatal calf disease in southwestern Idaho and eastern Oregon.

Over a 2-year period, 296 episodes of disease involving 226 1-to-60-day-old calves were referred to the Caldwell Veterinary Teaching Center. Infectious disease agents were found in 96% of the cases. Salmonella spp were the most frequently isolated agents from dairy calves, whereas coronavirus was the agent most commonly associated with diarrhea in beef calves. Multiple agents were found in 20% of the dairy calves and in 12% of the beef calves. Salmonella dublin, which is associated with severe disease in man, made up a large percentage of the Salmonella spp isolated (40%). In vitro drug sensitivities indicated that a high percentage of Salmonella and Escherichia coli were resistant to drugs, especially to the drugs commonly used to treat calf diarrhea.

Animals↗
PubMed1982

Effects of chronic heat and cold stressors on plasma immunoglobulin and mitogen-induced blastogenesis in calves.

Fifty-six Holstein calves were used to investigate effects of heat and cold stressors on mitogen-induced blastogenesis of isolated peripheral blood mononuclear cells and immunoglobulins G1 and M in blood plasma. Calves were exposed to constant hot (35 degrees C), constant cold (-5 degrees C), or thermoneutral (23 degrees C) ambient conditions in environmentally-controlled chambers. Immune responses were measured soon after introduction into environmental chambers (3 days) and after various degrees of adaptation (7 and 14 days). Mortality was greater among heat- and cold-exposed calves than among thermoneutral calves. Neither heat nor cold exposure had a direct effect on blastogenesis of peripheral blood mononuclear cells by phytohemagglutinin or concanavalin A. Plasma from heat- and cold-exposed calves then was incorporated into the culture medium at a final concentration of 5% and tested in a mitogenesis assay on peripheral blood mononuclear cells from a single healthy donor. Plasma from heat-exposed calves consistently enhanced tritiated thymidine incorporation into normal peripheral blood mononuclear cells by phytohemagglutinin and concanavalin A as compared to plasma from cold-exposed calves. After heat exposure for 3 to 14 days, immunoglobulin G1 averaged 27% less in heat-exposed calves than in calves that were held at thermoneutrality, but M was unaffected. Cold exposure did not have a consistent effect on G1 or M. These data demonstrate that chronic heat and cold stressors affect calves by altering both antibody- and cell-mediated immunity.

Animals↗
PubMed1982

Border disease virus isolation from postpartum ewes.

The prevalence of border disease virus in a flock of Targhee sheep in southern Idaho was determined by serologic and virologic techniques. Of 249 ewes, 73 (29%) were seropositive to the antigenically related togavirus, bovine seropositive to the antigenically related togavirus, bovine viral diarrhea virus (BVDV). Concurrent testing of sera from 337 neonatal lambs indicated that 172 (51%) were seropositive for BVDV. It was observed that a high percentage (35%) of the BVDV-seropositive lambs were derived from seronegative ewes. Immunotolerance of the ewe was considered as the explanation for the lack of serologic relationship between seropositive lambs and their seronegative dams. Eleven cytopathogenic viruses were isolated from nasal and vaginal specimens obtained from 80 clinically healthy ewes within 24 hours of parturition. The viral isolates were demonstrated to be antigenically related to BVDV by direct immunofluorescence. Six of the 11 isolates were obtained from BVDV-seronegative ewes.

Animals↗
PubMed1982

Diarrheal condition in dogs associated with viruses antigenically related to feline herpesvirus.

Viruses with properties consistent with herpesvirus were isolated from dogs with diarrhea. The viruses were shown to be antigenically related to feline herpesvirus-1 (FHV-1) by virus neutralization tests. It was also observed that a canine herpesvirus (CHV) prototype, D004, and two field isolates from fatal CHV infections in 2-week-old and 6-week-old puppies were neutralized at a low level by antiserum to FHV-1. Reciprocal neutralization tests with CHV antiserum against FHV-1 were negative. These results indicated that viruses related to FHV-1 can infect the dog and that there appears to be uni-directional virus neutralization of CHV by FHV-1 antibody.

Animals↗
PubMed1982

Delayed-type hypersensitivity, contact sensitivity, and phytohemagglutinin skin-test responses of heat- and cold-stressed calves.

Three-week-old Holstein bull calves were used to investigate the effect of a 2-week chronic heat (35 C) or cold (-5 C) exposure on delayed-type hypersensitivity (DTH) reactions to purified protein derivative after sensitization with heat-killed Mycobacterium tuberculosis, contact sensitivity (CS) reactions to 1-fluoro-2,4-dinitrobenzene, and phytohemagglutinin (PHA) skin tests. Heat exposure reduced expression of DTH reactions by 42% and CS reactions by 38% at 24 hours after elicitation of the responses. The PHA-induced skin tests were not affected after 1 week of heat exposure, but this reaction was reduced by 20% after 2 weeks of heat exposure. The immune response of calves exposed to cold air temperatures was more complex. Cold exposure suppressed CS reactions by 39% at the end of both the 1st and 2nd weeks. The PHA response was reduced by 39% after 2 weeks of cold exposure. The DTH response depended on duration of cold exposure. The DTH reaction was increased by 42% after 1 week, but was reduced by 14% after 2 weeks. These data are consistent with the hypothesis that environmental stressors alter host resistance by affecting the immune system. Furthermore, these stress-induced changes in immune events depend on the type of immune response, the nature of the environmental stressor, and the length of time that calves are exposed to the stressor.

Animals↗
PubMed1981

Properties of an encephalitogenic canine parainfluenza virus.

An isolate of canine parainfluenza (CPI) virus from the cerebrospinal fluid of a dog with neurological dysfunction was characterized in vitro in comparison to a prototype strain of CPI virus, D008. The virus, designated 78-238 was found to be antigenically related to CPI virus (Manhatten strain) and simian virus 5 (SV5), but not to mumps virus (Enders strain). Ultrastructural observation of gradient-purified 78-238 virus revealed enveloped pleomorphic virions with helical nucleocapsid symmetry. Preliminary pathological studies indicated that 78-238 virus was encephalitogenic for gnotobiotic dogs when inoculated by the intracerebral route.

Animals↗
PubMed1981

Characterization of a feline infectious peritonitis virus isolate.

A virus isolated in cell culture from the spleen of a cat with feline infectious peritonitis was identified by physicochemical, morphological and antigenic criteria as a coronavirus. The feline infectious peritonitis virus was compared in vitro with canine coronavirus, a reported enteric pathogen of dogs. The feline isolate was characterized, by chloroform sensitivity and resistance to 5-iododeoxyuridine, respectively, as containing essential lipid and an RNA genome. Other traits of the isolate included resistance to acidic conditions, heat lability, and resistance to trypsin. Electron microscopy showed viral particles with a structure consistent with that of the prototype of the coronavirus group, infectious bronchitis virus. Indirect immunofluorescence with canine coronavirus monospecific antiserum showed the viral isolate to be antigenically related to canine coronavirus. Specific-pathogen-free cats inoculated by various routes with cell-culture-propagated virus had both clinical symptoms and lesions consistent with feline infectious peritonitis.

Animals↗
PubMed1981

Bovine leukemia virus infection in a large Holstein herd: prospective comparison of production and reproductive performance in antibody-negative and antibody-positive cows.

Serum samples from lactating cows in a purebred Holstein herd were tested annually (from 1977 to 1980) for antibodies to bovine leukemia virus (BLV), using the agargel immunodiffusion test. Production and reproductive variables were obtained from Dairy Herd Improvement Association records. All milk and fat production values were converted to 3.5% fat-corrected milk (FCM). Variables examined included: FCM, 305-day actual; FCM, 305-day mature-equivalent; FCM, total lactation; FCM per day, 305-day actual; total days milked during lactation; days nonlactating; age at calving; calving interval; days open, and number of times bred. Lactations were stratified from 1 to greater than 5 for comparison of variables. A matched case-control analysis was performed to assess the risk of clinical mastitis in BLV-infected cows. The retention of BLV antibody-negative and antibody-positive cows in the herd was compared. There were no significant trends in the means of production and reproductive variables between BLV antibody-negative and antibody-positive cows. The relative risk of clinical mastitis in BLV antibody-positive cows was 1.3, which was not significant (P greater than 0.05). Survivorship analysis over 3 years demonstrated no significant difference in the retention of BLV antibody-negative and antibody-positive cows in the herd. The BLV-infected cows did not have lower milk production, poorer reproductive efficiency, increased prevalence of mastitis, or lesser longevity in the herd than did noninfected cows.

Animals↗
PubMed1981

Whole blood leukocyte vs. separated mononuclear cell blastogenesis in calves: time-dependent changes after shipping.

The blastogenic response of peripheral blood mononuclear cells to mitogenic stimulation by concanavalin A was lower (P less than 0.01) after transporting 60 dairy calves 480 km than it was either one or two weeks later. The response was similar for phytohemagglutinin. There was a decrease (P less than 0.05) in the number of peripheral blood monocytes and neutrophils two weeks after shipping. The transportation of calves did not affect plasma IgG1 or IgM level. The mitogenic stimulation of peripheral blood leukocytes by both phytohemagglutinin and concanavalin A in whole blood cultures was more variable than with the culture of peripheral blood mononuclear cells. Technique variation, which was defined as the coefficient of variation among quadruplicate cultures, was greater than 20% for while blood assays and less than 10% for cultures of peripheral blood mononuclear cells. The variation among different calves tested at the same time and the variation within single calves tested at different times were also lower in peripheral blood mononuclear cell cultures than in whole blood mononuclear cell cultures than in whole blood assays. It is suggested that the variation among replicate cultures be reported in blastogenesis studies.

Animals↗