Indução da carcinogênese mamária experimental em ratas com 7,12-dimetilbenz(a)antraceno

PURPOSE: To test an experimental model of chemical mammary carcinogenesis induction in rats. METHODS: Twenty young virgin Sprague-Dawley female rats, aged 47 days, received 20 mg of 7,12-dimethylbenz(a)anthracene (DMBA) intragastrically by gavage. Afterwards, at 8 and 13 weeks, their mammary glands were examined. At the end of the experiment, the animals were sacrificed, and the mammary tumors were measured and weighed. Tumor fragments were analyzed using light microscopy. RESULTS: Eight weeks after DMBA injection, 16 rats presented at least 1 breast tumor (80%). After 13 weeks, all of them (100%) developed breast carcinomas that were confirmed by histopathological analysis. CONCLUSION: This experimental animal model of chemical mammary induced carcinogenesis is feasible and can be used in further experiments on the role of tumorigenic biomodulator substances.OBJETIVO: Testar um modelo experimental de indução química de carcinogênese mamária em ratas. MATERIAL E MÉTODOS: Com 47 dias de vida, 20 ratas Sprague-Dawley, jovens e virgens, receberam por gavagem intragástrica 20 mg de 7,12-dimetilbenz(a)antraceno (DMBA). Oito e 13 semanas depois da injeção de droga as mamas das ratas foram examinadas. Ao final os animais foram sacrificados e fragmentos dos tumores foram estudados ao microscópio. RESULTADO: Oito semanas depois da injeção de DMBA 16 ratas apresentavam tumor nas mamas (80%). Com 13 semanas todas desenvolveram carcinomas de mama (100%), que foram confirmados por análise histopatológica. CONCLUSÃO: Este modelo experimental de indução química de carcinogênese mamária é factível e pode ser empregado em futuras pesquisas para avaliar o papel de substâncias biomoduladoras da tumorigênese

Gastric stump mucosa: is there a risk for carcinoma?

Background - Patients who underwent partial gastric resections are at an increased risk for the development of cancer in the gastric remnant. Aim - To assess the long-term patients who underwent surgical treatment for peptic ulcer disease through endoscopic and pathologic evaluation of the gastric stump mucosal alterations. Patients and Methods - Between 1987 and 1990, 154 patients (mean = 20.4 years after gastrectomy) were evaluated by upper digestive endoscopy with multiple biopsies and pathological examination. Results - Endoscopic alterations were present in 111 patients (72.1%). The commonest pathologic alterations were foveolar hyperplasia, intestinal metaplasia and cystic dilation. Severe dysplasia was noted in two (1.25%) and carcinoma in 13 (8.4%) of the cases. In four patients (3.8%) the endoscopic findings did not show any evidence of tumors, however they were detected due to multiple biopsies and histologic studies. Conclusions - Surveillance of these patients with endoscopy and multiple biopsies may provide the means to diagnose tumors at an early stage, but the cost benefit ratio of surveillance requires further study

Induction of experimental mammary carcinogenesis in rats with 7,12-dimethylbenz(a)anthracene Indução da carcinogênese mamária experimental em ratas com 7,12-dimetilbenz(a)antraceno

PURPOSE: To test an experimental model of chemical mammary carcinogenesis induction in rats. METHODS: Twenty young virgin Sprague-Dawley female rats, aged 47 days, received 20 mg of 7,12-dimethylbenz(a)anthracene (DMBA) intragastrically by gavage. Afterwards, at 8 and 13 weeks, their mammary glands were examined. At the end of the experiment, the animals were sacrificed, and the mammary tumors were measured and weighed. Tumor fragments were analyzed using light microscopy. RESULTS: Eight weeks after DMBA injection, 16 rats presented at least 1 breast tumor (80%). After 13 weeks, all of them (100%) developed breast carcinomas that were confirmed by histopathological analysis. CONCLUSION: This experimental animal model of chemical mammary induced carcinogenesis is feasible and can be used in further experiments on the role of tumorigenic biomodulator substances.<br>OBJETIVO: Testar um modelo experimental de indução química de carcinogênese mamária em ratas. MATERIAL E MÉTODOS: Com 47 dias de vida, 20 ratas Sprague-Dawley, jovens e virgens, receberam por gavagem intragástrica 20 mg de 7,12-dimetilbenz(a)antraceno (DMBA). Oito e 13 semanas depois da injeção de droga as mamas das ratas foram examinadas. Ao final os animais foram sacrificados e fragmentos dos tumores foram estudados ao microscópio. RESULTADO: Oito semanas depois da injeção de DMBA 16 ratas apresentavam tumor nas mamas (80%). Com 13 semanas todas desenvolveram carcinomas de mama (100%), que foram confirmados por análise histopatológica. CONCLUSÃO: Este modelo experimental de indução química de carcinogênese mamária é factível e pode ser empregado em futuras pesquisas para avaliar o papel de substâncias biomoduladoras da tumorigênese