Biomedical subjects

D G Harnden

Publications and source records attributed to D G Harnden.

At least 55 records · Page 3Linked to original sources

PubMed1975

Proceedings: Tests of two hair colourants for carcinogenicity by repeated application to mouse skin.

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Animals↗

PubMed1975

Somatic rearrangement of chromosome 14 in human lymphocytes.

Ataxia-telangiectasia is a rare genetic disorder associated with immune deficiency, chromosome instability, and a predisposition to lymphoid malignancy. We have detected chromosomally anomalous clones of lymphocytes in eight patients with this disorder. Chromosome banding disclosed that the clones are consistently marked by structural rearrangement of the long arm (q) of chromosome 14. A translocation involving 14q was found in clones obtained from seven of the eight patients whereas a ring 14 chromosome was found in a clone obtained from the other. These findings as well as data obtained by others for patients with ataxia-telangiectasia suggest that structural rearrangement of 14q is the initial chromosomal change in lymphocyte clones of patients with this disorder. Chromosomes of lymphocytes from one of the patients were studied before and after the onset of chronic lymphocytic leukemia. Before leukemia was diagnosed, the patient had a lymphocyte clone with a 14q translocation. This clone appears to have given rise to the leukemic cells. We hypothesize that structural rearrangement of 14q is directly related to abnormal growth of lymphocytes and that it may be a step toward the development of lymphoid malignancies. Increasing evidence, provided by others, for the nonrandom involvement of 14q in African-type Burkitt's lymphoma and other lymphoid neoplasms further strengthens this hypothesis.

Adolescent↗

PubMed1975

Specific chromosome aberrations in ataxia telangiectasia.

Cytogenetic observations on seven cases of ataxia telangiectasia are presented. The aberration frequency was found to be increased in all of them with a specificity for the involvement of the D-group chromosomes in rearrangements. Clones of cytogenetically abnormal cells were observed in the lymphocytes of three cases and in the cultured skin fibroblasts of two cases, again with a specificity for D-group involvement. G-banding shows that chromosome 14 is frequently involved in rearrangements in clone cells and that the band 14q12 may be a highly specific exchange point. The significance of lymphocyte clones with a proliferative advantage in vivo is discussed. Cytogenetic studies of the parents and sibs of these cases are also reported.

Adolescent↗

PubMed1974