Search PubMed⌕ Search

Biomedical subjects

G C Dulac

Publications and source records attributed to G C Dulac.

At least 37 records · Page 2Linked to original sources
PubMed1989

Porcine circovirus antigens in PK-15 cell line (ATCC CCL-33) and evidence of antibodies to circovirus in Canadian pigs.

Permanent infection of a PK-15 (ATCC CCL-33) cell line by the porcine circovirus was demonstrated. This virus appears to be common in the Canadian swine population as indicated by the presence of antibodies detected by indirect immunofluorescence or immunoperoxidase tests in the serum of culled sows and sows in commercial herds. One source of the PK-15 cell line was found to be free of circovirus antigen.

Animals↗
PubMed1988

Experimental peste des petits ruminants (goat plague) in goats and sheep.

In order to study the pathomorphology and immunohistochemistry of peste des petits ruminants, four goats and two sheep were inoculated intranasally with the Malig-Yemen strain of peste des petits ruminants virus. The animals developed fever, nasal discharge, oral erosions, cough and diarrhea. One goat and one sheep died and one moribund goat was killed. Three animals survived the infection. At necropsy, erosive stomatitis, pneumonia and gastroenteritis were found. Histopathologically the pneumonocytes and epithelial cells of the ileum had eosinophilic cytoplasmic and nuclear inclusions. By an indirect immunoperoxidase method, the nuclei and cytoplasm of the ileal epithelial cells of one goat contained positively (brown) stained antigen, which corresponded to viral nucleocapsids by electron microscopy. Virus appeared to be released through the microvilli of the epithelial cells. We also confirmed the formation of giant cells due to peste des petits ruminants virus.

Animals↗
PubMed1987

Specificity of the indirect enzyme-linked immunosorbent assay for detection of pseudorabies virus antibodies in pigs exposed to bovine herpesvirus-1.

Six 5-week-old pigs were inoculated intranasally (IN) with 10(7.6) TCID50 of bovine herpesvirus-1 (BHV-1). Three of the pigs also were inoculated IV with a similar dose of BHV-1. Clinical responses were not observed in these 6 pigs before oronasal challenge exposure with 10(7.8) TCID50 of virulent pseudorabies virus (PRV) at postinoculation day 42. Two pigs inoculated IN with BHV-1 and challenge exposed with PRV remained healthy, whereas the remaining 4 pigs developed severe clinical signs of pseudorabies and were moribund at postinoculation day 50 (8 days after challenge exposure). Anti-BHV-1 antibodies were demonstrable by ELISA in all 6 pigs and by serum neutralization (SN) in 5 pigs before challenge exposure with PRV. Anti-PRV antibody was not detected by ELISA or SN before challenge exposure to PRV. After challenge exposure to PRV, pigs with humoral antibody to BHV-1 responded anamnestically, and anti-PRV antibody activity was demonstrable by ELISA and SN in the 2 surviving pigs.

Animals↗
PubMed1987

Evaluation of an enzyme immunoassay for detection of antibodies to pseudorabies virus in porcine field sera.

The performance of an indirect enzyme-linked immunosorbent assay and the standard serum neutralization test for detection of antibodies to pseudorabies virus in porcine field sera were compared, using 304 sera from pseudorabies-free pigs in Canada, and 1082 and 580 swine sera from the USA and England, respectively. The sensitivity and specificity of the ELISA relative to the serum neutralization test were in the order of 97 to 98%, with the higher agreement between the tests when a 1:40 dilution of serum samples was used for the ELISA. The indirect ELISA was considered to be a rapid and convenient procedure, offering many advantages over the serum neutralization test for routine serodiagnostic use.

Animals↗
PubMed1986

Dot-enzyme immunoassay for visual detection of antibodies to pseudorabies virus in swine serum.

A modified solid-phase enzyme immunoassay (EIA) is described for the visual detection of anti-pseudorabies virus (anti-PRV) antibody in porcine serum. Dots of PRV antigens were adsorbed to nitrocellulose paper (hence the name dot-EIA), and the remaining nonspecifically reactive sites were blocked with bovine serum albumin or skim milk powder. After immersion in test serum, bound antibodies were reacted with a peroxidase-conjugated anti-porcine immunoglobulin G (H & L). Positive reactions were easily visualized as brown dots after enzyme degradation of a substrate containing hydrogen peroxide and diaminobenzidine. The dot-EIA was comparable to the serum neutralization test and the standard microtiter EIA in its ability to detect antibody in the sera of pigs 9 days after experimental infection and 12 days after contact with infected pigs. The sensitivity and specificity of the dot-EIA relative to the serum neutralization test and the standard EIA were determined from the testing of 856 field sera from the United Kingdom, the United States, and Canada. In all comparisons, both the relative sensitivity and specificity of the dot-EIA were in the order of 98 to 99%. The dot EIA appears to have potential application as a rapid and economical field test in the diagnosis of PRV infection.

Animals↗
PubMed1986

Immunoperoxidase plaque staining for the detection of pseudorabies virus.

A quantitative indirect immunoperoxidase plaque staining method was developed for the detection of pseudorabies virus infection in a pig kidney cell line (PK-15). The method is rapid and specific and foci of infection, represented by stained plaques, are easily counted by the unaided eye. Possible modification of this technique in a plaque reduction assay for the detection of antipseudorabies virus antibody is also discussed.

Animals↗
PubMed1986

Development and evaluation of an indirect enzyme immunoassay for detection of porcine antibodies to pseudorabies virus.

An indirect enzyme immunoassay is described for detection of porcine serum antibody to pseudorabies virus. The analytical sensitivity of the enzyme immunoassay was found to be approximately 4.5 log 4 X 10 (5120 times) greater than the serum neutralization test, based on parallel end point titrations. The diagnostic sensitivity of the enzyme immunoassay was comparable or superior to that of the serum neutralization, based on the earliest detectable antibody after infection of swine with pseudorabies virus by intranasal or intrauterine routes or by contact with infected pigs. The enzyme immunoassay, at a screening dilution of 1:20, gave 100% agreement with ELISA results provided with a U.S. Department of Agriculture-Animal and Plant Health Inspection Service proficiency panel of 40 sera. One serum having demonstrable antibody by the enzyme immunoassay was seronegative by the serum neutralization test.

Animals↗
PubMed1981

Gamma ray inactivation of some animal viruses.

Twenty samples of animal viruses comprising 14 different viruses in 12 families were subjected to varying doses of gamma irradiation from a 60Co source in a Gamma Cell 220 (Atomic Energy of Canada Limited) to determine lethal dose levels. The dose responses appeared linear throughout inactivation. The D10 values, that is the dose necessary to reduce infectivity by one log10, ranged from less than 0.20 Megarads to approximately 0.55 Megarads. There was not a complete inverse correlation between the target size (virion core) and the D10 value.

Dose-Response Relationship, Radiation↗
PubMed1979

Pseudorabies: adaptation of the countercurrent immunoelectrophoresis for the detection of antibodies in porcine serum.

A countercurrent immunoelectrophoresis test was developed for the detection of precipitating antibodies to pseudorabies virus in pig serum. The precipitation reaction occurred only between the pseudorables antigen and the homologous porcine antiserum. The sensitivity of the method was compared to that of the serum neutralization test. On the basis of its sensitivity, its specificity and the rapidity with which the results were obtained, the countercurrent immunoelectrophoresis may become a potentially valuable screening method to test large numbers of porcine serum.

Animals↗
PubMed1978

Demonstration of parvovirus in Canadian swine and antigenic relationships with isolates from other countries.

A Canadian isolate of porcine parvovirus, isolated from cultured pig thyroid cells, was shown to be antigenically indistinguishable from a British (59e/63) and a German (G10/1) strain when treated by the modified direct complement-fixation, the hemagglutination-inhibition and the fluorescent antibody tests. These tests also revealed that antibodies to parvoviruses were detectable in a large proportion of the conventionally raised pigs in the provinces of Quebec and Ontario. Cell cultures, prepared from tissues collected in a slaughterhouse, were often found to be infected with parvovirus. In cell cultures the infection was demonstrated more effectively by immunofluorescence than by the hemagglutination test.

Animals↗
PubMed1977

Transmissible gastroenteritis: demonstration of the virus from field specimens by means of cell culture and pig inoculation.

Isolation of transmissible gastroenteritis virus was attempted from segments of jejunum collected from piglets submitted for diagnosis of transmissible gastroenteritis. The virus was isolated more frequently in susceptible piglets than in pig kidney or pig thyroid cells. Practically, both cell systems were equally capable of demonstrating the virus when the tissue suspensions were sonicated. The pig thyroid cells prepared with glands collected from minimal disease pigs were preferred to the pig kidney cells for initial virus isolation because of their ability to respond to transmissible gastroenteritis virus with a progressive cytopathic effect. However, the pig thyroid cells, prepared from pool of glands collected in abattoirs, were often contaminated with parvoviruses and could not be used for diagnostic work. Controlled ultrasound treatments of the inoculum increased the frequency of virus isolation in both cell systems.

Animals↗
PubMed1977

Necrotizing encephalitis in skunks caused by Herpes simplex virus.

Herpes simplex virus was isolated from the brain of a wild skunk (Mephitis mephitis) which had clinical neurological disease. In the brain of this skunk and in brain of skunks inoculated intracerebrally, there were areas of necrosis in the grey matter of the cerebral cortex and to a lesser extent in the brain stem. Intranuclear inclusions occurred in neurons and glial cells with vascular cuffing by mononuclear cells and a few neutrophils. Skunks inoculated intravenously had extensive focal necrosis in the liver and adrenal glands.

Adrenal Glands↗
PubMed1976

Transmissible gastroenteritis virus: plaques and a plaque neutralization test.

A plaquing system and plaque neutralization test in porcine thyroid cells were used to study different transmissible gastroenteritis isolates and hemagglutinating encephalomyelitis virus. Among transmissible gastroenteritis virus isolates, plaque size varied considerably and mixed size ranges sometimes occurred. The most recently isolated viruses produced smaller plaques than the laboratory viruses or hemagglutinating encephalomyelitis virus. All transmissible gastroenteritis virus isolates reacted in the plaque neutralization test with a transmissible gastroenteritis virus antiserum which showed no activity against hemagglutinating encephalomyelitis virus. Plaque neutralization results both from experimentally infected pigs and following a field outbreak demonstrated the reliability of this test and its greater sensitivity than the conventional tube test.

Animals↗
PubMed1975

Viral susceptibility of a cell line derived from the pig oviduct.

Seventeen of 24 RNA viruses and eight of nine DNA viruses replicated in a cell line derived from a pig fallopian tube. The following RNA viruses grew poorly in it: the virus of transmissible gastroenteritis of pig and the swine-influenza, Sendai and bovine para-influenza type 3 viruses. Among other RNA viruses an untyped swine para-myxovirus and some picornaviruses, rhabdoviruses and togaviruses attained high titers and produced an extensive cytopathic effect. Among the DNA viruses a porcine adeno, equine rhinopneumonitis, infectious bovine rhinotraceheitis, pseudorabies and porcine cytomegalo viruses replicated in pig fallopian tube cells as well as in other cells generally used to grow them.

Adenoviridae↗