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Biomedical subjects

R Duff

Publications and source records attributed to R Duff.

7 recordsLinked to original sources
PubMed1978

Effects of experimental excision arthroplasty of the hip joint.

The experimental results are reported on a series of sheep in which unilateral hip excision arthroplasty was performed. These sheep were slaughtered at regular postoperative intervals. Radiography and histology were performed on the normal and excised hip joints of the experimental sheep to provide information of the formation of the pseudarthrosis that develops following excision arthroplasty. The efficiency of the false joint that develops is good, judged on a clinical basis. Continuous remodelling of the acetabulum and resected face was noted throughout the experimental period. A sequence of degenerative changes in the acetabular cartilage was observed followed by filling in of the acetabular favity with new bone. New bone also developed on the cemoral component of the pseudarthrosis in the form of osteophytes situated around the perimeter of the resected surface. Growth deformities of the contralateral, nonoperated limb were induced.

Acetabulum↗
PubMed1975

Chromosome aberrations in Syrian hamster embryo cells transformed after exposure to ultraviolet-irradiated herpes simplex virus type 1 or 2.

Six Syrian hamster embryo cell lines (14-012-8-1, KOS-6-1, 333-8-9, 333-2-29, MS-4-1, FR-6-1), developed after exposure of primary cultures to different strains of UV-irradiated herpes simplex virus (HSV) type 1 or 2, were analyzed for chromosome aberrations. All the cell lines showed chromosome stability (number of chromosomes were maintained within a narrow range of variation in the diploid region) and a low incidence of polyploids, endoreduplications, and metaphases with pulveration or extensively fragmented chromosomes. The cell lines, passaged over long periods of time in vitro, developed marker chromosomes that suggested a clonal-type evolution of the cell populations. Two cell lines, 333-8-9 and 14-012-8-1, showed two different marker chromosomes with large heterochromatic regions. Chromosomes with abnormal heterochromatic regions, which often appeared like prominent secondary constrictions, were found in all the cell lines we examined. The level of chromosome breakage was low in all the cell lines except the highly tumorigenic cell line 333-2-29, which had a high incidence of cells with single or double chromatinic bodies. The abnormal heterochromatic regions that occurred on marker chromosomes and prominent secondary constrictions were interpreted as a possible chromosomal effect of the HSV. The karyotypic stability and low incidence of open breaks might have been the result of UV irradiation of the HSV.

Animals↗
PubMed1975

Quantitative assay for transformation of 3T3 cells by herpes simplex virus type 2.

The interaction of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) with Swiss/3T3 cells was investigated. Virus-induced cytopathic effects developed in the absence of production of infectious virus. HSV-2 inactivated with UV light (2, 4, 6, and 8 min) also induced cell death in the absence of virus replication. Cell death was not detectable after infection by HSV-2 that had been inactivated by UV irradiation for 10, 12, and 14 min. 3T3 cells infected with UV-inactivated virus (10 and 12 min) continued to replicate past the contact-inhibited monolayer normally associated with these cells. Infection of 3T3 cells with UV-irradiated USV-2 also induced the development of transformed foci. Transformed cells with an epithelioid of fibroblastoid morphology were identified and isolated. All HSV-2-transformed cell lines contained HSV-2-specific antigens detectable by immunofluorescence techniques. The maximum frequency of HSV-2-induced transformation was 3 times 105 PFU per transformed focus, and the observed transformation could be inhibited by pretreatment of the virus with specific antiserum. No type C particles were detected within five cell culture passages after transformation by HSV-2. Type C virus particles were detected after 10 cell culture passages of the HSV-2-transformed cell lines.

Animals↗
PubMed1975

Isolation and preliminary characterization of temperature-sensitive mutants of measles virus.

Twenty-four genetically stable temperature-sensitive mutants of measles virus were isolated after mutangenesis by 5-azacytidine, 5 fluorouracil, or proflavine. The restricted replication of all mutants at 39 C was blocked subsequent to cell penetration and could not be attributed to heat inactivation of virus infectivity. Complementation analysis was made possible through the use of poly-L-ornithine. The members of one complementation group exhibited wild-type RNA synthesis at the nonpermissive temperature and induced the synthesis of virus antigens. These mutants were found defective in both hemolysin antigen synthesis and cell fusion "from within," supporting the unitary hypothesis for these functions. The members of the other two complementation groups synthesized neither virion RNA nor detectable virus antigens at the nonpermissive temperature.

Antigens, Viral↗