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Biomedical subjects

R N Butler

Publications and source records attributed to R N Butler.

At least 217 records · Page 12Linked to original sources
PubMed1989

An assessment of proliferative and enzyme activity in transitional mucosa adjacent to colonic cancer.

The mucosa within 2 cm of cancers of the large bowel (transitional mucosa) shows histologic and histochemical changes which may indicate premalignant change. In this study, the authors used specimens from resected colonic tissue to compare morphometric, proliferative, and enzyme markers in transitional mucosa with those in cancer tissue and with those in uninvolved mucosa at least 10 cm from the cancer. Proliferative activity was assessed using the Ki 67 monoclonal antibody technique whereas a variety of methods were used to determine enzyme activities in mucosal homogenates. When compared to uninvolved mucosa, crypts in transitional mucosa contained greater number of cells, were significantly deeper and wider and were more likely to be branched. However, crypts in transitional mucosa had a significantly lower labelling index using the Ki 67 technique and there was no evidence of a shift in the proliferative zone towards the bowel lumen. The activities of ornithine decarboxylase, thymidine kinase, alkaline phosphatase, and lactate dehydrogenase were similar in transitional and uninvolved mucosa. Cancer tissue showed significantly higher levels of activity for ornithine decarboxylase and lactate dehydrogenase. Transitional mucosa showed morphometric changes but there were no proliferative or enzyme markers to suggest a higher than expected risk for malignant change.

Alkaline Phosphatase↗
PubMed1988

Zinc deficiency is associated with suppression of colonocyte proliferation in the distal large bowel of rats.

As zinc status may influence susceptibility to colon cancer, we examined the effect of dietary zinc deficiency on the proliferation of epithelial cells (colonocytes) in the large bowel of rats. When compared to feed-restricted rats, those with zinc deficiency showed a significant reduction in proliferation in the distal colon as assessed by accumulated metaphase arrest and crypt cell production rates in vivo. Zinc deficiency had no apparent effect on thymidine kinase activity in colonocytes but was accompanied by minor changes in fecal mass and fecal pH. In rats, zinc deficiency is associated with a reduction in the rate of proliferation of colonocytes in the distal colon.

Animals↗