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Biomedical subjects

D C Williams

Publications and source records attributed to D C Williams.

At least 199 records · Page 11Linked to original sources
PubMed1978

The effect of ascorbic acid (vitamin C) on two tumor cell lines in culture.

The effect of vitamin C on cell proliferation and DNA synthesis was investigated using two tumor cell lines Hep2 and KB. The results show that there was an increase in the ratio of dead to live cells and a decrease in the rate of DNA synthesis. The results also agree with other work carried out on animal experimental models which claimed that vitamin C may be involved in the arrest of neoplastic cell proliferation.

Ascorbic Acid↗
PubMed1978

The effect of chronic alcohol intake upon the hepatic microsomal carcinogen-activation system.

Ethanol was administered to mice either by repeated intraperitoneal injection, or orally in the drinking water over an extended period of time. Following intraperitoneal ethanol pre-treatment further groups of mice received an injection of benzo(a)pyrene. Alcohol intake decreased the level of microsomal aryl hydrocarbon hydroxylase which corresponded to the observed decrease in DNA binding of benzo(a)pyrene. In contrast, the number of tumors which developed in the alcohol pre-treated mice exceeded those of the control animals.

Administration, Oral↗
PubMed1978

The effect of chronic ethanol intake on the growth and spread of some murine tumors.

The effect of chronic ethanol intake on the growth and spread of some murine tumors has been investigated. The treatment had no effect on the B 16 melanoma but tended to decrease the number of Ehrlich ascites cells. In the case of the Lewis lung carcinoma, administration of ethanol for two weeks tended to lower the number of metastases to the lung without significantly affecting the primary tumor size, whereas more prolonged ethanol intake decreased the weight of the primary tumor in addition to decreasing its dissemination.

Alcoholism↗
PubMed1978

Bleomycin (review).

Since the original observation and description of the various forms of Bleomycin (BLM), numerous articles have appeared dealing with the activity on mammalian cells and its possible clinical use. The present review on this very important compound, although not very comprehensive, deals with the important characteristics; such as the action of DNA and cells, and its chromosome breaking effects. The manner in which the minute detail of the action of BLM on cells has helped to implement in vivo chemotherapeutic regimes, is also discussed.

Animals↗
PubMed1978

Ascorbic acid therapy for the relief of bone pain in Paget's disease.

Sixteen patients with painful Paget's disease of the bone were treated with high doses of ascorbic acid. Of these patients, 8 experienced lessening of pain within a period of 5 to 7 days after commencing the vitamin therapy. In 3 of these patients pain was completely abolished. Subsequent treatment with calcitonin caused improvement in most cases. There was little change in plasma alkaline phosphatase levels but the excretion of hydroxyproline was elevated following administration of the vitamin. The highest excretions were found in those patients who experienced complete relief of pain. In patients treated with calcitonin alone, the excretion of hydroxyproline was reduced and urinary levels of ascorbic acid dropped in parallel. It seems clear that ascorbic acid and calcitonin have different effects upon bone metabolism.

Aged↗
PubMed1978

Normative beliefs about tobacco smoking on campus in relation to an exposititon of the viewpoint of the nonsmokers' rights movement.

A 147-item questionnaire on the effects of tobacco smoking on campus was administered to 307 University of New Hampshire undergraduates. Questions were asked in relation to an exposition of the viewpoint of the nonsmokers' rights movement. A group of 21 items, dealing with attitudes and normative beliefs related to issues of smokers' and nonsmokers' rights, were selected for analysis in this paper. Descriptive statistics and t tests contrasting the smokers and nonsmokers were presented. A majority of both groups agreed that smoking on campus should be limited to special areas and agreed that the right to breathe smoke-free air is the primary right. Nonsmokers in particular affirmed that nonsmokers who find smoke aversive often hide their true feelings and do not request that smokers abstain. Interpretation of results focused upon the normative structure of our society as the key element involved in perpetuating smoking in shared areas. At the present time it appears that smoking in these areas without permission is defined as normative (i.e., appropriate), whereas objecting is implicitly characterized as a norm violation.

Female↗
PubMed1978

The effect of bleomycin on rat bone marrow cells.

Experiments were carried out to determine the cytogenetic effects of the antibiotic bleomycin (BLM) in rats using the bone marrow system. A total of eighteen male and eighteen female Sprague-Dawley rats were injected with varying concentration of BLM, over varying periods of time. The results revealed that at low concentrations BLM showed no alteration in the ploidy or the morphology of rat chromosomes. This however, was not the case when the dose or administration period was increased.

Animals↗
PubMed1977

Carcinogenic and possible mutagenic effects of stilboestrol in offspring exposed in utero.

The relevant literature has been reviewed and it appears that there is no doubt that in utero exposure to stilboestrol is related to the eventual development of vaginal adenocarcinoma in young females. Although cancer of other types are also prevalent, the incidence is not great and may be related to other types of drugs taken during pregnancy. The review attempts to correlate the genetic effects with the abnormal development, but on account of the scarcity of data such correlation is not possible. Further work on the genetic effects and the development of the lower genital tract in the female needs to be carried out.

Abnormalities, Drug-Induced↗
PubMed1977

Substrate retention of fractured retraction fibres during detachment of trypsinized BHK21 fibroblasts.

When BHK21 fibroblasts adhering to glass were incubated in trypsin they became spherical within a few minutes. They did not, however, respond simultaneously; the most trypsin-resistant cells in an unsynchronized population were of greater length, had more processes projecting from the cell body, and were more spread out than the most trypsin sensitive cells. In no instance did trypsin detach cells from their substrate, even when the incubation period was prolonged to 5 h in trypsin concentrations almost sufficient to cause cell lysis. Scanning electron-microscope observations showed that initially flat cells rounded up in trypsin to reveal persistent adhesion sites joined to the cell body by retraction fibres. Such cell could be dislodged only by agitation; when this occurred parts of the cell remained attached to the substrate in the form of small spheres and fibres; these were remnants of the retraction fibres and adhesion sites. We propose that the adhesion sites are not susceptible to proteolytic degradation, presumably because of steric hindrance, and that this causes detachment to be dependent upon mechanical dislocation. We suggest that some of the descriptions of substrate-associated 'cell exudates' in the literature may refer to these cell remnants on the substrate which consist of membrane-bound fragments of cytoplasm rather than secreted products.

Animals↗