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Biomedical subjects

J H Main

Publications and source records attributed to J H Main.

At least 37 records · Page 2Linked to original sources
PubMed1980

The effect of DMBA on hamster cheek pouch mucosa in vitro.

Neonatal hamster cheek pouch mucosa was treated with DMBA for three h either before being explanted or after 7 days in vitro. The epithelium of the treated cultures exhibited dysplasic changes, most marked at 21 to 28 days in vitro. These changes were not seen in the explants maintained for 35 to 49 days in vitro indicating a return to an apparently normal morphology. Examination of the ultrastructure of DMBA treated and untreated explants showed changes consistent with those described in similar tissues in vivo. The epithelium of the carcinogen treated tissue exhibited widened intercellular spaces, tortuous cell membranes, an irregular and discontinuous basal lamina and pseudopodia of the basal cells extending into the underlying mesenchyme. Similar changes have been described in inflamed epithelium, in some other experimental preparations, and in premalignant lesions in vitro, both in animals and man.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

The effect of vitamin A on hamster cheek pouch mucosa in organ culture.

Vitamin A was added to the medium of neonatal hamster cheek pouch mucosa maintained in organ culture. The epithelium of the treated explants showed a reduction in keratinization and down-growth into the underlying connective tissue. The cytological and morphological changes in the epithelium were consistent with glandular metaplasia.

Animals↗
PubMed1978

The diagnosis of melanotic and other pigmented lesions of the lips and oral mucosa (dark spots in the mouth).

Pigmented lesions of the oral mucosa may be due to collections of blood, metallic particles of melanin. Any of these substances will appear of a blue tinge if at any depth in the tissues, while superficial collections may be red, black or brown respectively. Lesions associated with blood will be hematomas, dilated veins, hemangiomas or telangiectases. Metallic particles are found in amalgam tattoos. Melanotic pigmentation may occur as a normal variation, following hormonal disturbance and inflammation, and sometimes iatrogenically. Benign and malignant melanoma of the oral cavity is highly lethal. 25% of malignant melanomas in this site present as nondescript brown spots, and isolated broid overlooking an early malignant melanoma.

Dental Amalgam↗
PubMed1976

Long-term organ culture of hamster cheek pouch mucosa.

Explants of cheek pouch mucosa from 12- to 48-hour-old hamsters have been maintained in organ culture for up to 49 days with excellent preservation of tissue integrity and relationships. The technique uses gelatin sponge matrix in Leighton tubes with Eagle's Minimum Essential Medium (M.E.M.) supplemented with 10% calf serum and antibiotics.

Animals↗
PubMed1976

Salivary gland tumors: review of 643 cases.

643 cases of salivary gland tumors constitute two series of histological sections that were studied from hospitals and dental schools in Southeast Scotland and Southern Ontario. The Scottish series represented epithelial tumors of the parotid and intra-oral salivary glands, but the Canadian series also included tumors of the submandibular and sublingual glands. Classification was based on that recommended by the World Health Organisation (Thackray 1972). While direct statiscal comparisons between the two series are not appropriate, the differences between them suggest that malignant tumors are more common in Canada. The Scottish series contains the largest proportion of benign salivary tumors so far reported. In the Scottish series, 88.7% of parotid tumors were benign compared with 51.9% of Canadian series. In the Canadian series from the submandibular glands, 21.2% only were benign. Of the intra-oral salivary tumors, 62.2% from the Scottish series were benign compared with only 34.7% from the Canadian series.

Adenocarcinoma↗
PubMed1975

Investigation of possible oncogenic action of zinc polycarboxylate cement by implantation in mice and hamsters.

Powdered, sterilized zinc polycarboxylate was implanted subcutaneously in 56 young hamsters and 54 mice, using equal numbers of each sex, with 24 sham operated hamsters and 26 mice as controls. The hamsters were sacrificed after 15 months and the mice after 12. Implant material was recovered from one of 42 surviving mice and from 16 of 43 surviving hamsters. Benign adenomas of the gut, thyroid, sebaceous glands and ovary were found in 3 experimental mice and in one control. Benign adrenal adenomas were found in 3 experimental hamsters and in one control. One control hamster developed a rhabdomyosarcoma in a limb. One experimental hamster developed a leiomysarcoma in close relation to an implant.

Acrylates↗