Olá a todos!
Esta semana vou postar sobre um artigo que li há uns 10 dias. É da publicação dedicada à Medicina por parte da revista Nature, e fala sobre os mecanismos envolvidos no desenvolvimento do tumor de cólon. Sabemos que a flora local tem participação importante neste processo, porém os autores investigaram mecanismos imunológicos que podem ajudar na compreensão da carcinogênese nestes casos, evidenciando a participação do Bacteroides fragilis enterotoxigênico.
A seguir, reproduzo o abstract deste artigo:
Article abstract
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Nature Medicine 15, 1016 - 1022 (2009)
Published online: 23 August 2009 | doi:10.1038/nm.2015
A human colonic commensal promotes colon tumorigenesis via activation of T helper type 17 T cell responses
Shaoguang Wu1,8, Ki-Jong Rhee1,7,8, Emilia Albesiano2, Shervin Rabizadeh3,8, Xinqun Wu1,2, Hung-Rong Yen2,4, David L Huso5, Frederick L Brancati1, Elizabeth Wick6, Florencia McAllister1,2, Franck Housseau2, Drew M Pardoll1,2 & Cynthia L Sears1,2
________________________________________
Abstract
The intestinal flora may promote colon tumor formation. Here we explore immunologic mechanisms of colonic carcinogenesis by a human colonic bacterium, enterotoxigenic Bacteroides fragilis (ETBF). ETBF that secretes B. fragilis toxin (BFT) causes human inflammatory diarrhea but also asymptomatically colonizes a proportion of the human population. Our results indicate that whereas both ETBF and nontoxigenic B. fragilis (NTBF) chronically colonize mice, only ETBF triggers colitis and strongly induces colonic tumors in multiple intestinal neoplasia (Min) mice. ETBF induces robust, selective colonic signal transducer and activator of transcription-3 (Stat3) activation with colitis characterized by a selective T helper type 17 (TH17) response distributed between CD4+ T cell receptor- (TCR )+ and CD4–8–TCR + T cells. Antibody-mediated blockade of interleukin-17 (IL-17) as well as the receptor for IL-23, a key cytokine amplifying TH17 responses, inhibits ETBF-induced colitis, colonic hyperplasia and tumor formation. These results show a Stat3- and TH17-dependent pathway for inflammation-induced cancer by a common human commensal bacterium, providing new mechanistic insight into human colon carcinogenesis.
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Até o próximo!
segunda-feira, 30 de novembro de 2009
quarta-feira, 18 de novembro de 2009
ARTIGO PRIMEIRO
Accuracy of Surgical Diagnosis in Detecting Early Gastric Cancer and Lymph Node Metastasis
and Its Role in Determining Limited Surgery
Vol. 209, No. 3, September 2009 Jeong et al. Journal of the American College of Surgeons
ABSTRACT
BACKGROUND: The aim of this study was to evaluate the accuracy of surgical diagnosis of early gastric cancer (EGC) and lymph node metastasis, and elucidate its role in determining limited surgery for EGC.
STUDY DESIGN: We reviewed 369 patients undergoing gastrectomy for primary gastric carcinoma. Surgical diagnosis was evaluated by determining its sensitivity, specificity, and accuracy, and was compared with preoperative examinations.
RESULTS: Sensitivity, specificity, and accuracy of intraoperative diagnosis for EGC were 74.5%, 95.7%, and 83.7%, respectively. The predictive value for EGC by intraoperative diagnosis was 95.7%.
Surgical diagnosis of EGC showed higher specificity and predictive value than preoperative
examinations did, which significantly reduced the risk of underestimating advanced gastric
cancer (AGC) to EGC. The sensitivity, specificity, and accuracy for lymph node metastasis by
surgical diagnosis were 73.2%, 78.1%, and 76.4%, respectively. In 70 patients with a discrepancy
in the diagnosis of EGC between pre- and intraoperative diagnoses, surgical diagnosis was
correct in 63 (90%) patients, but preoperative examination was correct in only 7 (10%)
patients.
CONCLUSIONS: Surgical diagnosis shows better accuracy than preoperative examinations do in detecting EGC and lymph node metastasis. Our results suggest that the decision to perform limited surgery based on surgical diagnosis might reduce the risk of undertreatment of AGCtoEGCbetter than preoperative examinations.
Os autores realizaram um estudo retrospectivo quanto à qualidade do diagnóstico intra-operatório do câncer gástrico em relação à seu estágio de desenvolvimento(principalmente entre câncer gástrico precoce - EGC no artigo e câncer gástrico avançado - AGC). É muito interessante o estudo individual feito apenas com aqueles casos em que houve discrepância entre os exames pré-operatórios e avaliação intra-operatóio, pois nestes casos o diagnóstico intra-operatório mostrou-se indubitavelmente superior à avaliação pré-op, mesmo utlizando USG endoscópico e
reconstrução do estômago por tomografia.
O artigo enfatiza que nos casos em que se detectou um tumor menos avançado do que mostravam os exames pré-op, foram realizadas cirurgias menos agressivas, com vantagens para a qualidade de vida do paciente. Considero isto primordial, pois estamos considerando pacientes com uma sobrevida prolongada e chances reais de cura.
and Its Role in Determining Limited Surgery
Vol. 209, No. 3, September 2009 Jeong et al. Journal of the American College of Surgeons
ABSTRACT
BACKGROUND: The aim of this study was to evaluate the accuracy of surgical diagnosis of early gastric cancer (EGC) and lymph node metastasis, and elucidate its role in determining limited surgery for EGC.
STUDY DESIGN: We reviewed 369 patients undergoing gastrectomy for primary gastric carcinoma. Surgical diagnosis was evaluated by determining its sensitivity, specificity, and accuracy, and was compared with preoperative examinations.
RESULTS: Sensitivity, specificity, and accuracy of intraoperative diagnosis for EGC were 74.5%, 95.7%, and 83.7%, respectively. The predictive value for EGC by intraoperative diagnosis was 95.7%.
Surgical diagnosis of EGC showed higher specificity and predictive value than preoperative
examinations did, which significantly reduced the risk of underestimating advanced gastric
cancer (AGC) to EGC. The sensitivity, specificity, and accuracy for lymph node metastasis by
surgical diagnosis were 73.2%, 78.1%, and 76.4%, respectively. In 70 patients with a discrepancy
in the diagnosis of EGC between pre- and intraoperative diagnoses, surgical diagnosis was
correct in 63 (90%) patients, but preoperative examination was correct in only 7 (10%)
patients.
CONCLUSIONS: Surgical diagnosis shows better accuracy than preoperative examinations do in detecting EGC and lymph node metastasis. Our results suggest that the decision to perform limited surgery based on surgical diagnosis might reduce the risk of undertreatment of AGCtoEGCbetter than preoperative examinations.
Os autores realizaram um estudo retrospectivo quanto à qualidade do diagnóstico intra-operatório do câncer gástrico em relação à seu estágio de desenvolvimento(principalmente entre câncer gástrico precoce - EGC no artigo e câncer gástrico avançado - AGC). É muito interessante o estudo individual feito apenas com aqueles casos em que houve discrepância entre os exames pré-operatórios e avaliação intra-operatóio, pois nestes casos o diagnóstico intra-operatório mostrou-se indubitavelmente superior à avaliação pré-op, mesmo utlizando USG endoscópico e
reconstrução do estômago por tomografia.
O artigo enfatiza que nos casos em que se detectou um tumor menos avançado do que mostravam os exames pré-op, foram realizadas cirurgias menos agressivas, com vantagens para a qualidade de vida do paciente. Considero isto primordial, pois estamos considerando pacientes com uma sobrevida prolongada e chances reais de cura.
PRIMEIRA INCISÃO
BLOG DA CIRURGIA
Bem Vindos! Este é o 1º post de uma idéia que venho nutrindo há algum tempo. Para começar, vou me apresentar: meu nome é João Vicente, tenho 27 anos, cursei a faculdade de Medicina na UNESC e residência em Cirugia Geral Hospital São José, ambos em Criciúma - S.C. Atualmente sou residente (R3) de Cirurgia do Aparelho Digestivo no Hospital Universitario da UFSC, em Florianópolis.
A idéia aqui é trazer aos colegas uma breve análise dos principais artigos e notícias relacionados à cirurgia geral e do aparelho digestivo, publicados recentemente.
Também vou tomar a liberdade de comentar - se me parecer prudente - os artigos em variados aspectos, pois considero importante além de lermos os artigos, analisarmos as informações e sua qualidade. Este exercício já potencializa o benefício de nossos estudos.
Bom, chega de conversa, vamos aos trabalho!
João Vicente.
Figura: A Aula de Patologia do Dr. Nicolaes Tulp - Rembrandt, 1632.
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