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Biomedical subjects

J D Pitts

Publications and source records attributed to J D Pitts.

At least 55 records · Page 3Linked to original sources
PubMed1983

Inhibition and recovery of DNA synthesis in PHA-stimulated u.v.-irradiated lymphocytes from patients with actinic keratosis.

The recovery, after inhibition by u.v.-irradiation, of phytohaemagglutinin-stimulated DNA synthesis is impaired in lymphocytes from patients with multiple actinic keratoses (AK) compared to the recovery in lymphocytes from age-matched, control individuals. This shows that the reduced level (50%) of DNA repair activity in AK cells is sufficiently different from that in normal cells to significantly affect cellular activity.

DNA Repair↗
PubMed1983

DNA repair in cells from patients with actinic keratosis.

UV-induced DNA repair was studied in peripheral blood lymphocytes from patients with multiple actinic keratoses (AK) requiring surgical therapy and from age-matched normal control individuals. The DNA repair activity in lymphocytes from AK patients at 4 h after UV-irradiation was 50% of that in control lymphocytes, but at 21 h the extent of DNA repair synthesis was similar to that in control cells.

DNA Repair↗
PubMed1982

The gap junctional channel.

Two distinct forms of intercellular communication have been found in animal tissues, one using the familiar, trans-membrane, extracellular route and the other using an entirely intracellular route. The intracellular route depends on specialized, permeable (gap) junctions which form at areas of contact between adjacent cells. The junctions contain aqueous channels which directly link the cytoplasms of the coupled cells. Small ions and molecules pass through these channels and move freely between all cells in coupled populations. The structural protein which forms the gap junctional channel has been isolated and characterized. It has an apparent M.Wt. of 16,000 and readily forms multimeric structures. In the membrane, six protein subunits surround the central aqueous pore. Addition of retinoic acid to cells appears to close the junctional channels. This effect of retinoic acid on the junctional pathway of intercellular communication may explain some of its biological activities.

Animals↗
PubMed1981

Non-selective junctional communication between some different mammalian cell types in primary culture.

Intercellular transfer of tritium-labelled uridine nucleotides has been used to detect junctional communication between various cell types in primary culture. Epidermal keratinocytes, melanocytes and dermal fibroblasts from new-born-mouse skin, and epithelial cells from baby mouse kidney form communicating junctions in all possible homologous and heterologous combinations. This lack of detectable communication specificity between cells in primary culture contrasts with the specificity shown by some established cell lines.

Animals↗
PubMed1980

The role of junctional communication in animal tissues.

Permeable intercellular junctions are a common feature of most animal tissues. These junctions allow the free exchange of small ions and molecules between all the cells in coupled populations. Such limited syncytial interaction contributes to the integration of individual cells into organized tissues.

Animals↗
PubMed1978

DNA repair deficiency in lymphocytes from patients with actinic keratosis.

DNA repair activity was measured in peripheral blood lymphocytes from 18 patients with Actinic Keratosis and 18 age-matched control subjects, by comparing the incorporation of 3H-thymidine into cells after irradiation with ultraviolet light with that into unirradiated cells. The incorporation was followed autoradiographically or by measuring acid insoluble radioactivity in cells labelled in the presence of hydroxyurea. The repair activity in lymphocytes from Actinic keratosis patients was only 47.1 percent (+/- 6.5%) of that in cells from the control subjects.

Aged↗