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Biomedical subjects

J F Evermann

Publications and source records attributed to J F Evermann.

118 records · Page 7Linked to original sources
PubMed1980

Isolation of a paramyxovirus from the cerebrospinal fluid of a dog with posterior paresis.

A paramyxovirus was isolated from cerebrospinal fluid of a dog with a history of incoordination and posterior paresis. The virus apparently was not related to canine distemper virus (CDV), considering the lack of virus neutralization with CDV-specific antibody, negative immunofluorescence with CDV-specific conjugate, and avirulence for ferrets. The virus was antigenically related to a prototype strain of canine parainfluenza virus, as determined by positive immunofluorescence with canine parainfluenza virus-specific conjugate and virus neutralization tests.

Animals↗
PubMed1980

Prevalence of bovine leukemia virus antibody in seven herds of Holstein-Friesian cattle.

Sera from 959 Holstein-Friesian cattle in 7 herds were tested for antibody to bovine leukemia virus, using the agar gel immunodiffusion test with glycoprotein antigen. Seropositive cattle were found in 6 herds; 120 (12.5%) were reactors. In 1 of the herds, the prevalence of seropositive cattle was significantly greater in purebred than in grade cows. Purebred cows raised on the premises and an overall antibody prevalence similar to purchased purebred cows. Purebred cattle more than 2 years old had a significantly greater prevalence of reactors than younger cattle. There was no difference in prevalence by sex.

Age Factors↗
PubMed1980

Naturally occurring picornavirus infection of domestic mink.

The isolation and preliminary characterization of a virus from domestic mink- are reported. The virus was tentatively classified as a member of the family Picornaviridae on the basis of its physicochemical properties. The mink virus was not neutralized by antiserum to some known members of the calicivirus genus, which included the nine serotypes of vesicular exanthema of swine virus, ten serotypes of San Miguel sea lion virus and feline calicivirus. Seroepidemiological studies indicated that the incidence of mink virus infection was widespread in domestic mink populations. Although the virus was isolated from mink on ranches with a history of hemorrhagic pneumonia (pseudomonas pneumonia), no specific disease process could be attributed to the virus infection.

Animals↗
PubMed1977

Hamster brain tumor cells persistently infected with measles-subacute sclerosing panencephalitis virus.

A persistent infection was established in a cell line derived from a hamster brain tumor (HBT) with the HBS strain of measles-subacute sclerosing panencephalitis (SSPE) virus. The persistently infected cells (HBT-M) were studied with regard to their growth in vitro and their transplantability in vivo. Although the growth of the HBT-M cells paralleled that of the HBT cells in vitro their transplantability was decreased in weanling hamsters. Hydrocortisone treatment of the hamsters abrogated the lowered transplantability restoring the tumor-producing capacity to levels comparable to the HBT cells. The decreased cell growth of the HBT-M cells in vivo was attributed to the acquisition of measles virus (MV) antigens and the host immune response directed against these new antigens.

Animals↗
PubMed1977

Temperature-sensitive mutants of measles virus produced from persistently infected HeLa cells.

A persistent infection with the Edmonston strain of measles virus was established in HeLa cells in the absence of measles virus antibody (HeLaPI cells). By hemadsorption or immunofluoresnce virtually 100 per cent of the cells possessed measles virus components. HeLaPI cells produced no interferon and were not resistant to superinfection with Newcastle disease virus. HeLaPI cells contained both smooth (15--18 nm) and rought (20--35 nm) nucleocapsids as detected by electron microscopy. The virus produced from the HeLaPI cells (MVPI) varied in titer between 1.5 X 10(2) and 5.5 X10(4) PFU/ml, had a smaller plque size and was more heat resistant than wild-type measles virus. MVPI was also found to be temperature-sensitive. The temperature-sensitivity of MVPI was determined by the efficiency of plaquing at 33 degrees and 39 degrees C in Vero cell monolayers. When HeLaPI cells were incubated at 33 degrees C, there was a 50-fold increase in virus production as well as a slight increase in the percentage of cells forming infectious centers compared to HeLaPI cells grown at 37 degrees C. MVPI readily established a persistent infection in HeLa cells which also rleased temperature-sensitive virus.

Antigens, Viral↗
PubMed1975

Immune enhancement of the tumorigenicity of hamster brain tumor cells persistently infected with measles virus.

Studies were conducted on the tumorigenicity of a hamster brain tumor (HBT) cell line persistently infected with measles virus (MV). This cell population, termed HBT-M, exhibited decreased tumorigenicity in weanling hamsters when implanted intracutaneously. The lowered tumorigenicity of the HBT-M cells could be counteracted by concurrent hydrocortisone treatment restoring the tumor-producing capacity to levels comparable to those of the highly tumorigenic HBT cells. It was also determined that prior immunization of hamsters with MV resulted in enhancement of tumor formation from usually subtumorigenic doses of HBT-M cells. This increase in tumorigenicity appeared to correlate with high titers of MV antibody. Treatment of hamsters with cyclophosphamide resulted in a reduction of MV antibody titers and effected a decrease of HBT-M cell tumorigenicity to control levels. Preliminary studies with passive immunizations indicated that the enhancing factor could be transferred in the sera from hamsters hyperimmunized with MV. These data suggested that MV antibody may potentiate the development of neoplasia of cells persistently infected with MV in a manner similar to the enhancement of tumor growth by blocking antibody.

Animals↗
PubMedDate not supplied

Comparative pathogenicity and serogrouping of three Washington isolates of infectious bursal disease virus.

The pathology of three infectious bursal disease virus (IBDV) isolates of Washington poultry origin (WA-678, WA-770, and WA-994) and seven other known IBDV strains (SAL, D-78, MO, OH, Var-A, 2512, and IM) was studied in 3-week-old specific-pathogen-free chickens. Inoculation with IM and 2512 strains resulted in illness and death. No clinical signs or mortality were present with WA-678, WA-770, and WA-994. Macroscopically, bursae were swollen and gelatinous with occasional hemorrhages. Isolate WA-994 caused marked bursal atrophy. Isolate WA-678 elicited moderate bursal pathology. Isolate WA-770 resulted in minimal atrophy. Strains IM and 2512 caused severe bursal atrophy, and strains Var-A and D-78 caused moderate atrophy. Strains SAL, MO, and OH caused no demonstrable bursal atrophy. Results of the cross-neutralization study showed that the three isolates were more closely related to serotype 1 than to serotype 2 IBDV.

Animals↗