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Biomedical subjects

D G Harnden

Publications and source records attributed to D G Harnden.

At least 37 records · Page 2Linked to original sources

Subpopulations of cytogenetically abnormal cells in fibroblast cultures derived from workers exposed to mineral oil.

Fibroblast cultures were grown from skin biopsy specimens from individuals with a high risk of cancer due to occupational exposure to mineral oil. A high frequency of chromosomally abnormal fibroblast subpopulations was found in cultures derived from tissue that had been exposed to the carcinogen, but these aberrant clonal populations were also present in control lines from the same individuals. Abnormal clones formed a greater proportion of the total cell population in the lines derived from the oil-exposed tissue compared with the control lines after a comparable time in culture. This difference in clone size may be a consequence of the in vivo exposure to mineral oil or other environmental agents.

Aged↗

Relevance of short-term carcinogenicity tests to the study of the carcinogenic potential of urban air.

It is now accepted that screening for carcinogens in animals is expensive and demonstrates carcinogenic potential rather than actual carcinogenicity in man. A number of short-term tests which depend on mutagenicity, stimulation of DNA repair, ability to produce chromosome damage or other actions, and which correlate at least to some extent with carcinogenic potential, have been devised. These have the advantages of being rapid and cheap. Some can be carried out by using human cells. They may have advantages in the context of air pollution since they are sensitive down to very low dose levels and since they can deal with complex mixtures. Combinations of such tests may be of more value than any single test. Their particular value may be as a preliminary screening procedure in a tiered testing programme which may have high predictive efficiency.

Air Pollutants↗

The chromosome analysis and susceptibility to transformation by Simian Virus 40 of fibroblasts from ataxia-telangiectasia.

Chromosome analyses are reported for 14 lines of fibro-blasts derived from 8 ataxia-telangiectasia (ATT) patients and for 14 lines of control cells. An elevated incidence of chromosome damage including gaps and breaks, rings, dicentrics and fragments, and chromosome figures has been found to occur in ATT cells. Similar abnormalities present in different cell lines suggest that common break points occur in ATT fibroblast chromosomes. The SV40 virus transformation rates found for ATT cells lie within the range found for normal cells, and there is no direct correlation between the degree of chromosome damage exhibited by any ATT cell line and its transformation rate with SV40.

Ataxia Telangiectasia↗

Cytogenetically marked clones in human fibroblasts cultured from normal subjects.

Clones of cytogenetically abnormal cells have been recognized in fibroblasts cultured from normal human adult skin. No such clones have been observed in human embryo skin fibroblasts cultured in the same way. Although the culture conditions may have played some part in the emergence of these clones, it is possible that the abnormal cells from which the clones were derived were present in vivo.

Adult↗

The transformation by simian virus 40 of cells from patients with mucopolysaccharidosis and from normal controls.

Fibroblasts derived from individuals with mucopolysaccharidosis, an inborn error of metabolism, have been found to be more easily transformed by simian virus 40 than are cells derived from normal individuals. The increased susceptibility does not seem to depend upon changes in glycoprotein at the cell surface. Repeated observations were necessary to demonstrate these differences, and we do not believe that this test is suitable for routine screening for cancer susceptibility.

Adsorption↗