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Biomedical subjects

G M Allan

Publications and source records attributed to G M Allan.

79 records · Page 5Linked to original sources

Reovirus-like agent (rotavirus) from lambs.

Rotavirus particles were demonstrated by electron microscopy in the feces of lambs with diarrhea. Rotavirus antigen was synthesized in cell cultures infected with filtrates of the diarrheic feces, but the virus was not adapted to grow serially in cell cultures. An antigenic relationship between rotaviruses from lambs, pigs, and calves was demonstrated by immunofluorescence. Colostrum-deprived lambs were infected with the lamb rotavirus, and the virus was passaged in lambs. Viral replication occurred in the villous epithelial cells of the small intestine, and the virus was excreted in the feces up to 78 h postinfection. Diarrhea was not observed in the experimentally infected lambs.

Animals↗

In situ hybridization: an optimised detection protocol for a biotinylated DNA probe renders it more sensitive than a comparable 35S-labelled probe.

The development of a highly sensitive biotinylated in situ hybridization protocol using egg drop syndrome virus infection of domestic fowl as a model is described. This protocol incorporates the use of a monoclonal antibody to biotin as the initial step in a peroxidase-based detection system. The detection of viral nucleic acid in formalin-fixed, paraffin-embedded sections using biotinylated and 35S-labelled probes is compared to the detection of viral antigen by immunocytochemistry. Biotinylated probes detected more positive cells than 35S-labelled probes and were more specific. Biotinylated probes detected more positive cells than immunocytochemistry.

Adenoviridae↗

In situ hybridization for the detection of chicken anemia virus in formalin-fixed, paraffin-embedded sections.

The development of a biotinylated in situ hybridization procedure for the detection of chicken anemia virus (CAV) is described. A double-stranded DNA probe was prepared using polymerase chain reaction and was biotinylated by nick translation. Hybridization conditions included the use of a microwave oven to denature target and probe nucleic acids and a five-step protocol for detection of biotinylated hybrids. In situ hybridization detected CAV nucleic acid in thymus tissue from experimentally infected birds after 6 hours, 3 days, and 7 days fixation time in formalin. However, immunocytochemical detection of CAV antigen was severely impaired if tissue was fixed in formalin for more than 6 hours.

Anemia↗

A sequential histopathologic and immunocytochemical study of chickens, turkey poults, and broiler breeders experimentally infected with turkey rhinotracheitis virus.

The histopathologic changes and the distribution of turkey rhinotracheitis virus (TRTV) antigen in the respiratory and reproductive tracts of experimentally infected chickens, turkey poults, and broiler breeders is described. TRTV antigen was detected using both immunofluorescent staining of cryostat sections and immunoperoxidase staining of formalin-fixed tissues. Viral antigen was observed associated with the cilia of the epithelial cells of turbinates, trachea, and lung. No TRTV antigen and no histopathologic changes were detected in the conjunctiva of any of the sacrificed birds, or in the reproductive tract and central nervous system of broiler breeders. The main histopathologic lesions and sites of TRTV replication were observed in the ciliated epithelial cells of turbinates and lung. These findings bring forward new information about pathologic changes and TRTV antigen distribution in tissues of experimentally infected birds.

Animals↗