Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new GC-TEA method for the analysis of tobacco-specific N-nitrosamines (TSNA) has been developed. Four TSNA have thus far been identified; these are N'-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N'-nitrosoanatabine (NAT) and N'-nitrosoanabasine (NAB). The method is currently being applied to the development of cigarette filter-tips which will selectively remove these carcinogens from cigarette smoke. Since recent epidemiological studies have established a correlation between snuff dipping and oral cancer, we have analysed leading snuff brands for TSNA. Snuff products from Sweden, Denmark, Bavaria and the USA contained 5-106 mg/kg of the TSNA and the saliva of snuff dippers had TSNA levels of 20-890 micrograms/kg. NNN, NNK and NAB induce benign and malignant tumours of the respiratory tract of mice and rats. We have shown that NNN and NNK induce tumours in the upper respiratory tract of hamsters and that NNK is the most active carcinogen of the TSNA, also inducing adenoma and adenocarcinoma in the hamster lung. The reported chemical analyses and bioassay results support the epidemiological findings on the causal association of tobacco use and cancer in man.
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PMID:Tobacco specific N-nitrosamines: occurrence and bioassays. 689 May 26

Cancer cells from five oral cancer patients and pleomorphic adenoma cells from one individual were inoculated as single cell suspension into subcutis of 30 Swiss nude mice and tail vein of additional 30 mice. Further, tumor tissue pieces from three oral cancer patients were xenografted s.c. in 18 nude mice, and 10 mice were kept as controls. In animals implanted with tumor pieces, 7/18 (39%) mice, developed squamous cell carcinoma at the site of inoculation within 8-15 days, while tumors were not observed in mice inoculated with single cell suspension, up to 60/90 days. In 8/68 (12%) mice, white foci were observed in several tissues, with hepatomegaly and splenomegaly noted in 27/68 (39%) mice. Histopathological examination of various tissues revealed presence of large cell lymphoma in several organs in 14/68 (21%) mice. No regional or distant metastasis of the implanted oral tumor cells was detected. Mice injected with cells from pleomorphic adenoma, also demonstrated large cell lymphoma in 2/10 (20%) mice, whereas none of the 10 control animals showed any gross abnormalities or microscopic abnormalities in several organs. 2/16 (12%) lymphomas exhibited positive reaction with mouse B cell antibodies illustrating the murine origin of the lymphomas, and these were immunophenotyed as B cell lymphomas. The lymphomas were also examined with mouse T cell antibodies and none reacted positively with the mouse T cell antibodies. The lymphomas also failed to react with human T cell, B cell and human Leucocyte common antigen (LCA) antibodies, indicating that the induced lymphomas were not of human origin. The tumor specimens from seven of eight oral cancer patients and the pleomorphic adenoma patient induced lymphomas in nude mice. Thus it appears that xenografting oral tumor cells into nude mice may cause induction of the murine lymphomas, and this needs further investigation.
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PMID:Induction of lymphomas on implantation of human oral squamous cell carcinomas in nude mice. 1148 Feb 6

Application of case-cohort design to multi-state disease progression in epidemiological studies has been barely addressed. To estimate multi-state disease natural history, we proposed non-homogeneous exponential regression stochastic model to accommodate the data requiring a non-standard case-cohort design. We allowed transition rates to vary with time by modelling the time of transitions between two states with Weibull distribution. The exponential regression model was used to assess the effect of patient-specific covariates on multi-state disease progressions. This method was successfully applied to two epidemiological applications. The first application was to elucidate the effect of betel quids, smoking and alcohol on three-state disease progression, from normal, through leukoplakia and finally to oral cancer. The second application was to extend the three-state to a five-state model to estimate transition rates from normal to diminutive adenoma to small adenoma to large adenoma and finally to invasive carcinoma of the colon and rectum. Finally, an index for assessing the treatment efficacy for pre-cancerous lesion was developed by comparing transition probabilities derived from the proposed model with the probabilities of malignant transformation after a medical regime.
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PMID:Stochastic model for non-standard case-cohort design. 1475 94

A 69-year-old Hispanic woman presented for the evaluation of nodules on the head and back. In the past, she had been treated for basal cell carcinoma (BCC) of the face; the referring physician was concerned that the new lesions might also be BCC. The patient had an extensive past medical history. In addition to BCC, she had been treated for breast cancer, colon cancer, and cervical cancer prior to emigrating to the USA. Her colonic malignancy had been localized proximal to the splenic flexure. She also had a history of colonic polyps and distal colonic villous adenoma. She denied ever being treated with radiation. Further details of her medical history and cancer staging were not available. Her family history was significant for a sister with colon cancer and transitional cell carcinoma of the urinary bladder. In addition, she had a great aunt with oral cancer and a great uncle with lung cancer. Neither the patient or her relatives had any history of tobacco use. On physical examination, in addition to scars from a radical mastectomy and midline abdominal laparotomy, four skin lesions were noted: two on the scalp, one on the tragus, and one on the mid-back. The first lesion on the vertex of the scalp was a yellow-brown waxy papule measuring 0.6 x 0.5 cm. This lesion was similar to that on the mid-back, except in size. The lesion on the back measured 1.2 x 1.0 cm. The second lesion on the frontal scalp measured 0.8 x 0.6 cm and was red-brown with a pearly appearance and some central hyperkeratosis. The tragus lesion was similar in appearance to that on the frontal scalp. Shave biopsies of all lesions were obtained. The lesions on the scalp and mid-back revealed lobules of sebaceous cells in the dermis with a minority of surrounding basaloid cells, consistent with a diagnosis of sebaceous adenoma (Fig. 1). Although the lesion on the frontal scalp also showed sebaceous differentiation, there were a greater number of basaloid cells, some with hyperchromatic nuclei and mitotic figures; this was consistent with a diagnosis of sebaceous epithelioma (Fig. 2). The final lesion (tragus) was histologically consistent with a keratotic BCC. No further treatment was required for these benign sebaceous tumors, but their presence defined our patient's condition as Muir-Torre syndrome. Mohs' micrographic surgery was performed on the tragus BCC and the margins were tumor free in one stage. The patient returned 1 year later with a lesion anterior to the left axilla which was biopsied to rule out BCC (Fig. 3). Histologically, this lesion was also consistent with sebaceous epithelioma.
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PMID:Muir-Torre syndrome: a case of this uncommon entity. 1653 37