PubMed Health⌕ Search

Biomedical subjects

D M Conning

Publications and source records attributed to D M Conning.

At least 19 recordsLinked to original sources
PubMed1989

Studies on the induction of cholangiofibrosis by coumarin in the rat.

The histogenesis of coumarin-induced cholangiofibrosis in the rat has been determined. Proliferation of ductal structures was preceded by extensive damage to hepatocytes in the centrilobular region. Focal proliferation of ducts and fibrous tissue was present at 3 months and typical areas of cholangiofibrosis at 6 months. By 18 months the lesion was extensive and contained areas showing bizarre histological features suggestive of malignancy although no evidence of extra-hepatic metastasis was found. The lesion in animals returned to standard diet showed varying degrees of involution with extensive atrophy and fibrosis. A number of parameters of hepatic mixed function oxidase activity were reduced during the initial treatment period, at later times there was recovery of some microsomal enzyme activities. The activity of gamma-glutamyltransferase and the hepatic content of non-protein sulphydryl groups, in contrast, were raised throughout the treatment period.

Animals↗
PubMed1979

Quantitative comparisons of the pulmonary toxicity of tobacco and NSM smoke.

Smoking elicits a panacinar rise in pulmonary alveolar lysosomal activity that is thought to correlate with the irritancy of the smoke. Quantitative image analysis of lung sections stained histochemically for acid phosphatase indicates that tobacco smoke is significantly more irritant than NSM smoke.

Acid Phosphatase↗
PubMed1978

Effect of glycerol on local and systemic carcinogenicity of topically applied tobacco condensate.

When glycerol was added to tobacco smoke condensate in acetone solvent, the topical carcinogenicity and the ability to produce epithelial hyperplasia in mice was reduced. Two doses of condensate were applied, combined with 2 concentrations of added glycerol. Age-standardized results show that glycerol reduced the incidence of tumours and malignant tumours and of hyperplasia in animals not developing skin tumours. The relative incidences of malignant tumours, benign tumours, hyperplasia and unaffected skin suggest that there is a sequential relationship (i.e. normal skin to hyperplasia to benign neoplasia to malignant neoplasia) which is impeded by glycerol. There was no systemic effect attributable to the condensate.

Administration, Topical↗
PubMed1977

Studies on the local and systemic carcinogenicity of topically applied smoke condensate from a substitute smoking material.

The topical carcinogenicity to mouse skin of smoke condensates obtained from a tobacco substitute (NSM), alone or in combination with tobacco, has been compared with condensate from tobacco and with acetone, the solvent used. Sixteen different types of cigarette were used to make the condensates, and the age-standardized results have been analysed according to the Weibull distribution model. The results show that NSM condensate has less than 25% of the potency of tobacco condensate (37% at 95% upper confidence limit), and that condensates from blends of NSM and tobacco are similarly reduced in activity. General pathology analysis failed to reveal abnormalities due to NSM.

Animals↗