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Biomedical subjects

J H Robbins

Publications and source records attributed to J H Robbins.

At least 73 records · Page 4Linked to original sources
PubMed1975

Genetic heterogeneity in xeroderma pigmentosum: complementation groups and their relationship to DNA repair rates.

Fibroblast strains from 12 patients with xeroderma pigmentosum had lower than normal rates of DNA repair, as determined by autoradiographic studies of ultraviolet-induced unscheduled nuclear DNA synthesis. The nuclei in binuclear cells, obtained by fusing fibroblasts from certain pairs of these strains, had a greater rate of DNA repair than the nuclei of either strain's unfused mononuclear cells. These results indicate that complementary corrections of the strains' repair defects had occurred in the fused cells. Four complementation groups were found, indicating that at least four mutations caused decreased DNA repair among these 12 strains. The unfused mononuclear cells of each group had a characteristic rate of repair that differed from the rates of the other groups.

Autoradiography↗
PubMed1975

DNA repair in tumor cells from the variant form of xeroderma pigmentosum.

Cells from most patients with xeroderma pigmentosum (XP) can be shown to be defective in repairing ultraviolet (UV) light-induced damage to their DNA, for they have a reduced rate of UV-induced thymidine incorporation. XP variants, however, have clinical manifestations of XP, but all their tissues tested to date have a normal rate of UV-induced 3H-thymidine incorporation. We have now tested tumor cells from an XP variant and from a typical XP patient. The variant's tumor cells, in contrast to those of the typical patient, had no detectable defect in their UV-induced thymidine corporation. We conclude, therefore, that the cells that formed tumors in this XP variant resemble his other cells in DNA repair capacity, and do not represent a minor cell population with the kind of DNA repair defect that is reflected in reduced UV-induced thymidine incorporation.

Autoradiography↗
PubMed1972

Measurement of DNA synthesis in leucocyte microcultures.

A microculture technique is described in which human peripheral blood leucocytes undergo DNA synthesis in response to specific and non-specific blastogenic factors. A sensitive Millipore filter assay technique is shown to be suitable for determining the incorporation of radioactive thymidine into the DNA of the stimulated cells in these microcultures. With these methods it is possible to measure the DNA synthesis in a 50-mul culture containing an innoculum of only 10(5) leucocytes. This small culture volume, with its low number of leucocytes, therefore makes it possible to perform experiments when either the available leucocytes or blastogenic factors are in limited supply.

Culture Techniques↗