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1.
Rev. gastroenterol. Perú ; 37(2): 129-136, abr.-jun. 2017. ilus, tab
Article Dans Espagnol | LILACS | ID: biblio-991239

Résumé

Objetivos: Evaluar el efecto protector del aceite de Sacha Inchi (ASI) sobre el desarrollo de cáncer de colon (CC) inducido con 1,2–dimetilhidrazina (DMH) en ratas Holtzman. Materiales y métodos: Estudio experimental con 28 ratas albinas machos de la cepa Holtzman distribuidas al azar en 4 grupos: un grupo control positivo expuesto a DMH (C1), un grupo control negativo expuesto a ASI a 150 μL/kg/día (C2), y dos grupos experimentales expuestos a DMH con ASI a 150 μL/kg/día (E1) y ASI a 300 μL/kg/día (E2). La DMH se aplicó por 8 semanas y con un tiempo total de inducción de 22 semanas. Luego se realizó el análisis patológico mediante la identificación de lesiones tumorales cancerosas en los intestinos. El efecto protector se evaluó en base a las proporciones de ausencia de lesión en los grupos expuestos a DMH. Resultados: Se identificaron lesiones tumorales cancerosas en: dos especímenes del grupo C1, un espécimen del grupo E1 y dos especímenes del grupo E2. No se identificaron lesiones intestinales en el grupo C2. Las proporciones de ausencia de lesión fueron: en el grupo C1 de 75%, en el grupo E1 de 87,5% y en el grupo E2 de 75%. No se encontraron diferencias significativas (p>0,05). Conclusiones: No se evidenció un efecto protector significativo del ASI sobre el desarrollo de CC inducido con DMH en ratas Holtzman, respecto al grupo control.


Objectives: To evaluate the preventive effect of Sacha Inchi oil (SIO) on 1,2–dimethylhydrazine (DMH)-induced colon carcinogenesis (CC) in Holtzman rats. Materials and methods: Experimental study with 28 Holtzman male albino rats randomly distributed into 4 groups: a positive control group exposed to DMH (C1), a negative control group exposed to SIO at 150 uL/kg/ day (C2), and two experimental groups exposed to DMH with SIO at 150 uL/kg/day (E1) and SIO at 300 uL/kg/day (E2). The DMH was applied for 8 weeks and the total induction time was 22 weeks. Pathological examination was performed by identifying cancerous tumor lesions in the guts. The preventive effect was evaluated based on proportions of lack of lesion in the groups exposed to DMH. Results: Cancerous tumor lesions were identified in: two specimens of group C1, one specimen of group E1 and two specimens of group E2. No intestinal lesions were identified in group C2. The proportions of lack of lesion were: in group C1 of 75%, in group E1 of 87.5% and group E2 of 75%. No significant differences were found (p>0.05). Conclusions: It was not found a significant protective effect of SIO on DMH-induced CC in Holtzman rats, compared to control group.


Sujets)
Animaux , Mâle , Rats , Huiles végétales/usage thérapeutique , Adénocarcinome/prévention et contrôle , Tumeurs du côlon/prévention et contrôle , Euphorbiaceae , Phytothérapie , Adénocarcinome/induit chimiquement , Adénocarcinome/anatomopathologie , Répartition aléatoire , Résultat thérapeutique , Rat Sprague-Dawley , Tumeurs du côlon/induit chimiquement , Tumeurs du côlon/anatomopathologie , 1,2-Diméthyl-hydrazine
2.
Indian J Med Sci ; 2010 July; 64(7) 315-319
Article Dans Anglais | IMSEAR | ID: sea-145545

Résumé

Background: There is scarcity of data on asbestos fiber burden in lung and pleural malignancies. Aim: To evaluate asbestos fiber burden in biopsy samples of suspected lung and pleural malignancies. Study Design: This was a single-centre, observational study. Study Period: From August 2010 to July 2010. Setting: Department of Pulmonary Medicine, CSMMU, UP, Lucknow, a tertiary care hospital in India. Study Population: Suspected cases of lung and pleural malignancy. Materials and Methods: Biopsy tissues taken by computed tomography (CT)-guided biopsy, bronchoscopic biopsy, and pleural biopsy by Cope's needle were analyzed for histopathology and asbestos burden by Haq et al.'s method. Results: 20 patients were studied. Mean fiber burden was 9.25 × 10 4 fibers/g. Average burden in lung malignancies (11 patients) was 9.178 × 10 4 fibers/g and in pleural tissue (9 patients) was 9.332 × 10 4fibers/g. Among the different cell types, mean fiber burden in squamous cell carcinoma was 8.99 × 10 4 fibers/g, in adenocarcinoma was 9.71 × 10 4 fibers/g, and in small cell carcinoma was 7.54 × 10 4 fibers/g. Mean fiber burden in bronchoscopic endobronchial biopsy tissue was 10.69 × 10 4 fibers/g, while in CT-guided biopsy was 8.60× 10 4fibers/g. Conclusion: Maximum number of fibers was found in adenocarcinoma.


Sujets)
Adénocarcinome/induit chimiquement , Adénocarcinome/épidémiologie , Amiante/analyse , Amiante/isolement et purification , Biopsie/méthodes , Humains , Inde/épidémiologie , Biopsie guidée par l'image/méthodes , Tumeurs du poumon/induit chimiquement , Tumeurs du poumon/diagnostic , Patients , Tumeurs de la plèvre/induit chimiquement , Tumeurs de la plèvre/épidémiologie , Centres de soins tertiaires , Tomodensitométrie
3.
Braz. j. med. biol. res ; 42(12): 1167-1172, Dec. 2009. tab
Article Dans Anglais | LILACS | ID: lil-532289

Résumé

We determined the effect of fish oil (FO) ingestion on colonic carcinogenesis in rats. Male Wistar rats received 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethylhydrazine (DMH) at 3-day intervals and were fed a diet containing 18 percent by weight FO (N = 10) or soybean oil (SO, N = 10) for 36 weeks. At sacrifice, the colon was removed, aberrant crypt foci were counted and the fatty acid profile was determined. Intestinal tumors were removed and classified as adenoma or carcinoma. Liver and feces were collected and analyzed for fatty acid profile. FO reduced the mean (± SEM) number of aberrant crypt foci compared to SO (113.55 ± 6.97 vs 214.60 ± 18.61; P < 0.05) and the incidence of adenoma (FO: 20 percent vs SO: 100 percent), but carcinoma occurred equally in FO and SO rats (2 animals per group). The polyunsaturated fatty acid (PUFA) profile of the colon was affected by diet (P < 0.05): total ù-3 (FO: 8.18 ± 0.97 vs SO: 1.71 ± 0.54 percent) and total ù-6 (FO: 3.83 ± 0.59 vs SO: 10.43 ± 1.28 percent). The same occurred in the liver (P < 0.05): total ù-3 (FO: 34.41 ± 2.6 vs SO: 6.46 ± 0.59 percent) and total ù-6 (FO: 8.73 ± 1.37 vs SO: 42.12 ± 2.33 percent). The PUFA profile of the feces and liver polyamine levels did not differ between groups (P > 0.05). In conclusion, our findings indicate that chronic FO ingestion protected against the DMH-induced preneoplastic colon lesions and adenoma development, but not against carcinoma in rats.


Sujets)
Animaux , Mâle , Rats , Adénocarcinome/prévention et contrôle , Carcinomes/prévention et contrôle , Tumeurs du côlon/prévention et contrôle , Huiles de poisson/administration et posologie , États précancéreux/prévention et contrôle , Adénocarcinome/induit chimiquement , Adénocarcinome/anatomopathologie , Cancérogènes , Carcinomes/induit chimiquement , Carcinomes/anatomopathologie , Tumeurs du côlon/induit chimiquement , Tumeurs du côlon/anatomopathologie , Acides gras insaturés , États précancéreux/induit chimiquement , États précancéreux/anatomopathologie , Rat Wistar
5.
Acta cir. bras ; 22(supl.1): 16-20, 2007. ilus
Article Dans Anglais | LILACS | ID: lil-449609

Résumé

PURPOSE: To elaborate an experimental model of pulmonary carcinogenesis in Wistar rats. METHODS: Male Rattus norvegicus albinus, Wistar lineage was carried through an intra-pulmonary instillation of the Benzo[a]pyrene (B[a]P) dilution in alcohol 70 percent, a polycyclic aromatic hydrocarbon widely known by its power of tumoral induction. Three experimental groups had been formed with 08 animals each: Control Group (Alcohol 70 percent); B[a]P Group 10 mg/kg; e B[a]P Group 20mg/kg, submitted to euthanasia 08, 10, 12 and 14 weeks after the experimental procedure. The pulmonary sections had been colored by hematoxilin-eosin (HE) and submitted to the morphometrical analysis to describe the tissue alterations. RESULTS: The presence of diffuse inflammatory alterations was observed in all groups, however, at the analysis of the pulmonary tissue of the experimental groups, it had been observed hyperplasic alterations (BALT hyperplasia), and in one of the animals of the experimental group 20mg/kg (12 weeks), it was noticed the presence of cellular epithelial tracheal pleomorphism, suggesting the adenocarcinoma formation in situ. CONCLUSION: The main secondary alterations to the intra-pulmonary instillation of B[a]P in Wistar rats were: cellular proliferation, inflammatory alterations of several degrees and nodular lymphoid hyperplasias. The association of an activator agent of the pulmonary metabolic reply is necessary to establish the ideal reply-dose to the development of the lung cancer.


OBJETIVO: Elaborar um modelo experimental de carcinogênese pulmonar em ratos wistar. MÉTODOS: Rattus norvegicus albinus, linhagem Wistar foram submetidos a instilação intra-pulmonar da diluição em álcool 70 por cento de Benzo[a]pireno (B[a]P), um hidrocarboneto aromático policíclico amplamente conhecido por seu poder de indução tumoral. Foram formados três grupos experimentais com 08 animais cada: Grupo Controle (álcool 70 por cento); Grupo B[a]P 10 mg/kg; e Grupo B[a]P 20mg/kg, submetidos a eutanásia 08, 10, 12 e 14 semanas após o procedimento experimental. As secções pulmonares foram coradas por HE e submetidas a análise morfométrica para descrição das alterações teciduais. RESULTADOS: em todos os grupos observou-se a presença de alterações inflamatórias difusas, porém na análise do tecido pulmonar dos grupos experimentais, observou-se alterações hiperplásicas (hiperplasia de BALT), e em um dos animais do grupo experimental 20mg/kg (12 semanas) notou-se a presença de pleomorfismo celular epitelial traqueal, sugerindo a formação de adenocarcinoma in situ. CONCLUSÃO: as principais alterações secundárias à instilação intra-pulmonar de B[a]P em ratos Wistar foram: proliferação celular, alterações inflamatórias de diversos graus e hiperplasias nodulares linfóides. A associação de um agente ativador da resposta metabólica pulmonar pode ser necessária para estabelecimento da dose-resposta ideal ao desenvolvimento do câncer de pulmão.


Sujets)
Animaux , Mâle , Rats , Adénocarcinome/anatomopathologie , Benzo[a]pyrène/toxicité , Cocancérogenèse , Cancérogènes/toxicité , Modèles animaux de maladie humaine , Tumeurs du poumon/anatomopathologie , Adénocarcinome/induit chimiquement , Tumeurs du poumon/induit chimiquement , Rat Wistar
6.
Article Dans Anglais | IMSEAR | ID: sea-37910

Résumé

We examined the modifying effect of freeze-dried whole-leaf Aloe arborescens Miller var. natalensis Berger (Kidachi aloe in Japan; designated as 'ALOE') on azoxymethane (AOM)-induced intestinal carcinogenesis in rats. Male F344 rats (4 weeks old) were fed basal diet or experimental diet containing 0.2% or 1% ALOE for 28 weeks. Starting two weeks later, the animals received subcutaneous injections of AOM once weekly for 10 weeks. The incidence of colorectal adenocarcinomas in the 0.2% (but not 1%) ALOE group showed a strong tendency for decrease (p = 0.056) from the control group. Further, the adenocarcinoma incidence in the entire intestine (small and large intestines) in the 0.2% ALOE group was significantly (p = 0.024) decreased compared to the control value. However, there were no significant differences in tumor multiplicities of colorectal or entire intestines among the 3 groups. In addition, we also studied the safety of long-term ingestion of ALOE as a health food or natural thickening stabilizer. Rats were fed the basal diet or 1% ALOE diet for 35 weeks without AOM treatment. Feeding with 1% ALOE did not affect most hematological and serum biochemical parameters in the rats. These results indicate that a low level of ALOE ingestion might have a mild suppressive effect on intestinal tumor growth without harmful side effects.


Sujets)
Adénocarcinome/induit chimiquement , Administration par voie orale , Aloe/composition chimique , Analyse de variance , Animaux , Oxyde de diméthyl-diazène , Chromatographie en phase liquide à haute performance , Incidence , Tumeurs de l'intestin/induit chimiquement , Mâle , Phytothérapie/méthodes , Rats , Rats de lignée F344
7.
Article Dans Anglais | IMSEAR | ID: sea-39089

Résumé

Breast cancer is among the commonest malignancies in women and tamoxifen has been widely used for more than two decades for treatment of breast cancer. It has been known that long term use of tamoxifen significantly increases the risk of endometrial cancer but there is no generally accepted recommendation regarding the surveillance of endometrial pathologies in breast cancer patients taking tamoxifen. Although the incidence of endometrial cancer associated with tamoxifen use is not high, the risk is true and these patients could be helped by screening methods such as transvaginal ultrasonogrphy. We report here a case of endometrial cancer detected by transvaginal 2D scan in an asymptomatic postmenopausal woman taking tamoxifen.


Sujets)
Adénocarcinome/induit chimiquement , Antinéoplasiques hormonaux/effets indésirables , Tumeurs du sein/traitement médicamenteux , Tumeurs de l'endomètre/induit chimiquement , Issue fatale , Femelle , Humains , Adulte d'âge moyen , Métastase tumorale , Post-ménopause , Tamoxifène/effets indésirables
8.
Journal of Korean Medical Science ; : S42-S53, 2001.
Article Dans Anglais | WPRIM | ID: wpr-147187

Résumé

The anticarcinogenic effects and mechanisms of the biotechnological drugs of Panax ginseng C.A. Meyer cultivated in Russia, bioginseng, panaxel and panaxel- 5, were studied. Bioginseng was produced from a tissue culture of ginseng root cultured on standard medium, whereas panaxel and panaxel-5 were produced from ginseng tissue root cultures using standard mediums enriched with 2-carboxyethylgermanium sesquioxide and 1-hydroxygermatran-monohydrate respectively. All three ginseng drugs inhibited the development of mammary tumors induced by intramammary injections of N-methyl-N-nitrosourea (MNU) in rats, the development of the brain and spinal cord tumors induced by transplacental administration of N-ethyl-N-nitrosourea (ENU) in rats, and the development of uterine, cervical and vaginal tumors induced by intravaginal applications of 7,12-dimethylbenz(a)anthracene (DMBA) in mice. The ginseng drugs induced the cytotoxic activity of macrophages in mice, enhanced T-lymphocyte rosette formation in guinea pigs exposed to cyclophosphamide, and stimulated the production of thyroid hormones in rats. These mechanisms may contribute to the anticarcinogenic action of the ginseng drugs. The organic germanium compounds present in panaxel and panaxel-5 did not potentiate the anticarcinogenic or immuno- stimulatory effects as much as biogeinseng. Preliminary clinical trials with panaxel and bioginseng were carried out in patients with precancerous lesions of the esophagus and endometrium. Panaxel was found to have a strong therapeutic effect in patients suffering from chronic erosive esophagitis. Bioginseng induced the regression of adenomatous-cystic hyperplasia of the endometrium in some patients. Thus, we conclude that the drugs of ginseng appear to hold considerable promise for future cancer chemoprevention.


Sujets)
Adulte , Femelle , Humains , Mâle , Souris , Rats , Adénocarcinome/induit chimiquement , Animaux , Antinéoplasiques d'origine végétale/usage thérapeutique , Cellules cultivées , Tumeurs du col de l'utérus/induit chimiquement , Essais cliniques comme sujet , Tests de cytotoxicité immunologique , Modèles animaux de maladie humaine , Tumeurs de l'endomètre/anatomopathologie , Endomètre/anatomopathologie , Tumeurs de l'oesophage/anatomopathologie , Oesophage/anatomopathologie , Oestradiol/sang , Fibroadénome/induit chimiquement , Macrophages péritonéaux/cytologie , Tumeurs expérimentales de la mamelle/induit chimiquement , Souris de lignée C57BL , Tumeurs expérimentales/induit chimiquement , Tumeurs du système nerveux/induit chimiquement , Panax/métabolisme , États précancéreux/anatomopathologie , Techniques de culture , Tumeurs de l'utérus/induit chimiquement , Tumeurs du vagin/induit chimiquement
9.
Acta cir. bras ; 15(3): 137-141, set. 2000. ilus, tab
Article Dans Anglais | LILACS | ID: lil-265752

Résumé

This study demonstrates the tumor promoting effect at a distant site of skin wounding, in a model of colon carcinogenesis induced by 1,2 dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH, 20mg/kg, or saline, once a week, for eight weeks. One week after the last DMH injection the animals received a full thickness skin wound in their dorsal skin and the wound was left open to heal by second intention. Control and DMH-treated rats, with or without skin wounds were killed at the 12th week, just after healing of the skin wound was complete. The colons were removed and divided into proximal and distal parts. Each segment was rolled as "Swiss roll"and processed for histology. The incidence, distribution and morphology of the colon tumors was recorded. The total number of tumors in the colonic mucosa and the number of tumors per rat was significantly higher in the skin-wounding DMH- treated group than in the unwounded group. In the histopathological analysis of the colon the number of poorly differentiated mucin-secreting carcinomas was 6-fold in the skin-wounding DMH-treated group than in the unwounded group and the majority of tumors were located near to lymphoid aggregates. The present results suggest that wound healing enhances tumor development at a distant site, such as the colon, and this effect seems to be related to tumor histology.


Sujets)
Animaux , Mâle , Rats , 1,2-Diméthyl-hydrazine/effets indésirables , Adénocarcinome/induit chimiquement , Adénocarcinome/physiopathologie , Cancérogènes/effets indésirables , Cicatrisation de plaie/physiologie , Côlon/anatomopathologie , Tumeurs du côlon/physiopathologie , Tumeurs du côlon/induit chimiquement , Rat Wistar , Lambeaux chirurgicaux
10.
Rev. argent. cir ; 78(1/2): 24-34, ene.-feb. 2000.
Article Dans Espagnol | LILACS | ID: lil-258526

Résumé

La manipulación traumática del colon portador de una neoplasia, durante la ejecución de una colectomía laparoscópica podría aumentar la exfoliación de células malignas dentro de la cavidad peritoneal, y por consiguiente ser una de las causas de los implantes cutáneos. Objetivo: Desarrollar un modelo de cáncer colónico experimental con similitud al del hombre y determinar si la manipulación laparoscópica instrumental del carcinoma de colon y recto comparada con la laparotomía, aumenta la exfoliación de células malignas en la cavidad peritoneal, instrumental y trócares. Material y Métodos: Se desarrolló un protocolo de cáncer colorrectal experimental con inyección subcutánea de 1-2 Dimethylhydrazina a una dosis de 20 mg/kg de peso, semanalmente y durante 20 semanas, en 40 ratas Wistar, sexo masculino. Se operaron a la semana 21º, dividiéndolas en 2 grupos (1 y 2). Grupo 1 (n 23) sometidas a laparotomía y manipulación instrumental del colon. Grupo 2 (n 17) se efectuó neumoperitoneo con CO2 hasta una presión de 12 mm Hg, laparoscopia y manipulación instrumental del colon y recto. Un tercer grupo lo constituyeron las ratas controles (n 5). Se realizó citología de: líquido de lavado peritoneal pre y post manipulación intestinal, del instrumental convencional y laparoscópico, de la aguja de Verres y de los trócares. Se efectuó el estudio histológico del colon y recto, ganglios mesentéricos, hígado y peritoneo. Resultados: El 80 por ciento de las ratas desarrollaron adenocarcinomas de colon. No existió diferencia significativa entre la exfoliación celular de ambos grupos de animales. Conclusiones: El carcinoma colorrectal inducido por la 1-2 Dimethylhydrazina tiene características muy similares al del ser humano y es un modelo válido para la investigación. La manipulación instrumental con una prolija técnica durante los procedimientos laparoscópicos no aumenta la exfoliación celular


Sujets)
Humains , Animaux , Rats , Adénocarcinome/induit chimiquement , Bronchoscopie/effets indésirables , Tumeurs colorectales/anatomopathologie , Métastase tumorale/physiopathologie , Essaimage tumoral , Tumeurs expérimentales/anatomopathologie , Tumeurs colorectales/induit chimiquement , Diméthylhydrazines/effets indésirables , Modèles animaux de maladie humaine , Récidive tumorale locale , Lavage péritonéal , Pneumopéritoine artificiel/effets indésirables , Rat Wistar , Tumeurs cutanées/secondaire
11.
Journal of Veterinary Science ; : 121-126, 2000.
Article Dans Anglais | WPRIM | ID: wpr-128396

Résumé

Deregulation of G1 cyclins has been reported in several human and rodent tumors including colon cancer. To investigate the expression pattern of G1 cyclins in 1,2- dimethyl-hydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis, we studied the expression of cyclin D1 and cyclin E by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry (IHC). The mRNA level of cyclin D1 was increased 1.2-fold in adenocarcinomas but not significantly in adenomas, when compared with normal rat colonic mucosa (p<0.05). The cyclin E mRNA level was increased 2.7-fold in adenomas and 3.3-fold in adenocarcinomas (p<0.05). The PCNA mRNA level was also increased 1.9-fold in adenomas and 1.8-fold in adenocarcinomas (p<0.05). Immunohistochemical staining revealed exclusive nuclear staining of the neoplastic cells for cyclin D1, cyclin E and PCNA. Cyclin D1 expression was detected in 56.3% of the adenomas and in 61.5% of the adenocarcinomas examined, whereas cyclin E expression was detected in 87.5% of the adenomas and in 92.3% of the adenocarcinomas. Overall, cyclin D1, cyclin E and PCNA expression was significantly increased at both the mRNA and protein levels in normal colonic mucosa, adenomas and adenocarcinomas, but there was no significant difference in the degree of expression of these genes in adenomas and adenocarcinomas. Our results indicate that the overexpression of cyclin D1 and cyclin E may play an important role during the multistage process of rat colon carcinogenesis, at a relatively early stage, and may disturb cell-cycle control in benign adenomas, and thereafter, participate in tumor progression.


Sujets)
Animaux , Mâle , Rats , 1,2-Diméthyl-hydrazine/toxicité , Adénocarcinome/induit chimiquement , Adénomes/induit chimiquement , Cancérogènes/toxicité , Cycle cellulaire/effets des médicaments et des substances chimiques , Côlon/métabolisme , Tumeurs du côlon/induit chimiquement , Cycline D1/biosynthèse , Cycline E/biosynthèse , Régulation de l'expression des gènes tumoraux , Immunohistochimie , Antigène nucléaire de prolifération cellulaire/biosynthèse , ARN messager/métabolisme , Rat Sprague-Dawley , RT-PCR
12.
Bol. Asoc. Méd. P. R ; 84(2): 74-7, feb. 1992.
Article Dans Anglais | LILACS | ID: lil-176708

Résumé

A case report of a 70 years old female, on tamoxifen for over five (5) years after a left mastectomy and with lymphadenectomy and radiotherapy in whom an asymptomatic adenocarcinoma of the endometrium is reported. Review of the literature suggests this association, however, definitive proof that tamoxifen causes cancer of endometrium has not been fully accepted. The best study in this regards is the one from Radiohemmet Oncologic Centre from Stockholm, Sweden. Patients with cancer of the breast that have been over two (2) years on tamoxifen should be screened with endovaginal sonograms for thickness of endometrium, thickness over 9mm and possibly over 5mm should be investigated with hysteroscopy and fractional uterine curetage


Sujets)
Sujet âgé , Femelle , Humains , Adénocarcinome/induit chimiquement , Tumeurs du sein/traitement médicamenteux , Tumeurs de l'endomètre/induit chimiquement , Seconde tumeur primitive/induit chimiquement , Tamoxifène/effets indésirables , Tamoxifène/usage thérapeutique
13.
Bol. Acad. Nac. Med. B.Aires ; 69(2): 483-92, jul.-dic. 1991. ilus
Article Dans Espagnol | LILACS | ID: lil-157615

Résumé

En nuestro modelo experimental el acetato de medroxiprogesterona induce adenocarcinomas de mama en hembras vírgenes de la cepa BALB/c. Estos tumores, con receptores para progesterona y estrógenos, originaron líneas de crecimiento hormono-dependientes (HD) o independiente (HI)..La progesterona y el MPA estímulan el crecimiento de las HD y los estrógenos inhiben el crecimiento de las HD y HI. En este trabajo demostramos que cultivos primarios de tumores HD conservan la misma sensibilidad hormonal que los tumores parenterales: la proliferación celular aumenta con concentraciones de MPA 10-9-10-7 M y es inhibida con estrógenos 10-9 o 10-7 M aun en presencia de MPA. Estos resultados sugerirían que las hormonas actúan directamente sobre las células tumorales. En experimentos "in vivo" demostraron que animales tratados con progesterona también desarrollaron adenocarcinomas de mama aunque la incidencia fue menor que en los tratados con MPA. Curiosamente se observó que la mayoría de los adenocarcinomas de mama inducidos por progesterona eran lobulillares y III mientras que en los tratados con MPA la mayoría fue ductal y HD. También se demostró que la ovariectomía y la sialoadenectomía disminuyen el poder carcinogénico del MPA sin alterar el patrón morfológico: 70 por ciento ductal y HD


Sujets)
Animaux , Rats , Adénocarcinome/induit chimiquement , Tumeurs expérimentales de la mamelle/induit chimiquement , Médroxyprogestérone/effets indésirables , Progestérone/effets indésirables , Récepteur STH , Oestrogènes , Ovariectomie
14.
Journal of Korean Medical Science ; : 308-312, 1991.
Article Dans Anglais | WPRIM | ID: wpr-186741

Résumé

Eighty rats out of 233 developed malignant tumors in the stomach and small intestine by administration of 100 micrograms/ml N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in drinking water for 28 weeks. Fifteen lesions (30%) among the 50 small intestinal carcinomas showed ossification in the tumor, while none in the sarcomas (12 lesions) or gastric adenocarcinomas (59 lesions) showed ossification. Multifocal heterotopic bone formation was found within stroma in close approximation to the neoplastic glands. The islands of bone trabeculae were covered by osteoblast-like cells, and abundant fibroblasts in loose stroma gathered around the bony islands which enclosed osteocytes in lacunae. Neither osteoclast nor cartilage was identified. In 5 cases, ossification was extensive, which comprised the major portion of the stroma. In contrast, intraluminal calcification without ossified foci were occasionally seen in the gastric carcinoma. Ossification of the intestinal tumors correlated to the degree of mucin content (p<0.05, chi square with Yates' correction), degree of neutrophilic infiltration (p<0.05), and size of the tumor (p<0.1). (The average size of the ossified tumor was 21.5 +/- 4.0 mm, while that of nonossified tumors was 12.5 +/- 1.9 mm). The degree of tumoral necrosis, desmoplasia or depth of invasion did not seem to be related to the ossification of the tumor. The ossification rate of this experimental model was much higher than in human cases. Various histologic alterations, such as mucin leakage, inflammatory cell infiltration, necrosis and/or fibrosis, which might be caused by continuous stimulation of the strong carcinogen, may play some role in the ossification of experimental tumors.


Sujets)
Animaux , Rats , Adénocarcinome/induit chimiquement , Tumeurs de l'intestin/induit chimiquement , Intestin grêle/anatomopathologie , 1-Méthyl-3-nitro-1-nitroso-guanidine , Ossification hétérotopique/anatomopathologie , Rat Sprague-Dawley , Coloration et marquage , Tumeurs de l'estomac/induit chimiquement
15.
Journal of Korean Medical Science ; : 197-203, 1990.
Article Dans Anglais | WPRIM | ID: wpr-165970

Résumé

The purpose of this study is to elucidate the participation of Paneth cells in experimentally induced adenocarcinoma of the intestine. The rats were fed with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) dissolved in drinking water ad libitum at a concentration of 100 micrograms/ml for 28 weeks. They were sacrificed 12 weeks after the last MNNG administration. A number of tumor cells containing large eosinophilic granules in their supranuclear cytoplasm (Paneth cells) were observed in about 20% of the experimentally induced adenocarcinoma of the small intestine. The granules were stained positively with Lendrum, periodic acid-Schiff, Masson's trichrome, and Mallory's phosphotungstic acid hematoxylin. Ultrastructurally, the granules were round, osmiophilic, and relatively even in size. We compared the morphologic features of the Paneth cell-containing small intestinal adenocarcinomas (Group I) with those without Paneth cells (Group II). Group I was distinguished from Group II by its better differentiation, larger tumor size and lower incidence of calcification. Although Paneth cells are extremely rare in human gastrointestinal carcinomas, twenty percent of MNNG-induced intestinal carcinomas harbor Paneth cells. The neoplastic Paneth cells in experimental carcinomas may differentiate from uncommitted cells in the deeper portion of the crypt.


Sujets)
Animaux , Rats , Adénocarcinome/induit chimiquement , Transformation cellulaire néoplasique/induit chimiquement , Tumeurs de l'intestin/induit chimiquement , 1-Méthyl-3-nitro-1-nitroso-guanidine , Lignées consanguines de rats
16.
Article Dans Portugais | LILACS | ID: lil-33782

Résumé

O adenocarcinoma de células claras de vagina e cérvice é um câncer raro. Aproximadamente 2/3 destas pacientes têm história positiva de exposiçäo intra-uterina ao dietilestilbestrol. A maioria das pacientes säo jovens e têm estágios iniciais e säo tratados com sucesso pela cirurgia pélvica radical. Um cuidadoso programa de investigaçäo e tratamento é proposto pelos autores


Sujets)
Enfant , Adolescent , Humains , Femelle , Adénocarcinome/induit chimiquement , Tumeurs du col de l'utérus/induit chimiquement , Tumeurs du vagin/induit chimiquement , Diéthylstilbestrol/effets indésirables
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