A comparative study of structure and function of the longitudinal muscle of the anal canal and the internal anal sphincter in pigs.

PURPOSE: This study aims to compare the physiology of the longitudinal muscle of the anal canal with the internal anal sphincter in pigs. METHODS: Histology and in vitro studies were performed to compare the effect of neural responses induced by electric stimulation and through nicotinic, purinergic, and serotoninergic receptors. RESULTS: The longitudinal muscle and the internal anal sphincter are constituted exclusively by smooth muscle. Strips from the internal anal sphincter a) developed myogenic tone; b) responded to electric stimulation with an "on" relaxation antagonized by nitric oxide synthase inhibitors and purinergic P2Y1 antagonists, and with an "off" contraction antagonized by atropine and phentolamine; and c) responded to stimulation of nicotinic receptors with a relaxation antagonized by nitrergic and purinergic P2Y1 antagonists, responded to stimulation of serotoninergic 5-hydroxytryptamine 3 receptors with a contraction, and relaxed to carbachol and purinergic P2X agonists. Strips from the longitudinal muscle a) did not develop tone, b) responded to electric stimulation with an "on" contraction antagonized by atropine, and c) did not respond to stimulation of nicotinic or serotoninergic 5-hydroxytryptamine 3 receptors, and carbachol and purinergic P2X agonists induced a contraction. CONCLUSIONS: The motility of the internal anal sphincter includes myogenic tone, relaxation mediated by nitric oxide and purinergic P2Y1 receptors, and contraction mediated by cholinergic motor neurons and sympathetic fibers. The motility of the longitudinal muscle is limited to a contraction mediated by cholinergic neurons, suggesting that longitudinal muscle contracts during relaxation of the internal sphincter, shortening the anal canal. Nicotinic, muscarinic, and serotoninergic receptors might be therapeutic targets for anal motor disorders.

Adenocarcinoma de vesícula biliar: estadio tumoral, factores pronósticos histológicos y supervivencia / Gallbladder adenocarcinoma: tumoral staging, histological prognostic factors and survival

Introducción. El adenocarcinoma de vesícula biliar, debido a su comportamiento biológico sumamente agresivo, es uno de los tumores digestivos de peor pronóstico. En muchas ocasiones, debido a la afección locorregional y al retardo del diagnóstico, la resecabilidad con intención curativa es imposible. Presentamos, desde el punto de vista histopatológico, un estudio retrospectivo de los adenocarcinomas de vesícula biliar diagnosticados en nuestra área de influencia y evaluamos, según el estadio tumoral, los factores pronósticos histológicos y la supervivencia. Pacientes y método. Se considera a un total de 62 casos de adenocarcinoma de vesícula biliar en un período de 15 años. Realizamos la colecistectomía por vía laparoscópica, por laparotomía o tratamiento paliativo en los casos irresecables. Se comparan para cada estadio tumoral la edad, el sexo, el grado de diferenciación celular, el tamaño tumoral, la presencia de adenopatías metastásicas, los factores de mal pronóstico histológico y la supervivencia. Resultados. Predomina el número de mujeres respecto al de varones (45/17). La edad media del grupo es de 75 años. No hallamos diferencias significativas respecto a la edad y el sexo entre los diferentes grupos. El grado de diferenciación celular y la supervivencia van empeorando a medida que progresa el estadio tumoral. Hay un predominio significativo de los factores de mal pronóstico histológico en los estadios T2 y T3. Conclusiones. Es difícil diagnosticar el adenocarcinoma de la vesícula biliar de forma preoperatoria, excepto en los casos avanzados. Suelen ser hallazgos incidentales en el estudio histológico postoperatorio, localmente poco avanzados y con buen grado de diferenciación celular. La etiología es desconocida, aunque con un gran predominio en las mujeres. La clínica se superpone a la patología de la vesícula habitada. En nuestro estudio, la edad y el sexo no se relacionan con el estadio tumoral. En estadios tumorales avanzados predomina la mala diferenciación celular, junto con factores de mal pronóstico histológico. Se describe una alta supervivencia para los tumores en estadio T3, posiblemente por la buena diferenciación celular. No hemos reintervenido a ningún paciente, dada la elevada comorbilidad asociada (AU)

Introduction. Gallbladder adenocarcinoma is an aggressive tumor and is one of the digestive tract malignancies with the poorest prognosis. Because of loco-regional extension and delayed diagnosis, curative resection is often impossible. To determine histological prognostic factors and survival in relation to tumoral stage at diagnosis, we performed a retrospective study of our patients with gallbladder carcinoma. Patients and method. Sixty-two patients with gallbladder adenocarcinoma diagnosed over a 15-year period were retrospectively included in this study. The surgical procedures performed in this group of patients were laparoscopic cholecystectomy, open cholecystectomy and palliative surgery in patients with unresectable tumors. For each tumoral stage, age, sex, cellular differentiation, tumor size, the presence of metastatic nodes, histological variables linked to poor prognosis, and survival were compared. Results. Of the 62 patients included, 45 were women and 17 were men. The mean age was 75 years. No significant differences were found in relation to age or sex among the different tumoral stages. Cellular differentiation and survival were poorer with advanced tumoral stage. A significant predominance of histological factors of poor prognosis was found in T2 and T3 tumors. Conclusions. Preoperative diagnosis of gallbladder adenocarcinoma is difficult except in advanced cases. It is often incidentally diagnosed at histological examination of gallbladders, and shows little local advancement and a good degree of cellular differentiation. The etiology of this tumor is unknown but its prevalence is greater among women. Clinical symptoms are similar to those caused by gallstones. In this study no relationship was found between age and sex and tumoral stage. In advanced tumoral stages poor cellular differentiation is predominant as well as other histological markers of poor prognosis. Good survival was found in T3 tumors, possibly linked to good cellular differentiation. Due to high associated comorbidity, none of the patients underwent reintervention (AU)

[Gallbladder adenocarcinoma: tumoral staging, histological prognostic factors and survival]. / Adenocarcinoma de vesícula biliar: estadio tumoral, factores pronósticos histológicos y supervivencia.

INTRODUCTION: Gallbladder adenocarcinoma is an aggressive tumor and is one of the digestive tract malignancies with the poorest prognosis. Because of loco-regional extension and delayed diagnosis, curative resection is often impossible. To determine histological prognostic factors and survival in relation to tumoral stage at diagnosis, we performed a retrospective study of our patients with gallbladder carcinoma. PATIENTS AND METHOD: Sixty-two patients with gallbladder adenocarcinoma diagnosed over a 15-year period were retrospectively included in this study. The surgical procedures performed in this group of patients were laparoscopic cholecystectomy, open cholecystectomy and palliative surgery in patients with unresectable tumors. For each tumoral stage, age, sex, cellular differentiation, tumor size, the presence of metastatic nodes, histological variables linked to poor prognosis, and survival were compared. RESULTS: Of the 62 patients included, 45 were women and 17 were men. The mean age was 75 years. No significant differences were found in relation to age or sex among the different tumoral stages. Cellular differentiation and survival were poorer with advanced tumoral stage. A significant predominance of histological factors of poor prognosis was found in T2 and T3 tumors. CONCLUSIONS: Preoperative diagnosis of gallbladder adenocarcinoma is difficult except in advanced cases. It is often incidentally diagnosed at histological examination of gallbladders, and shows little local advancement and a good degree of cellular differentiation. The etiology of this tumor is unknown but its prevalence is greater among women. Clinical symptoms are similar to those caused by gallstones. In this study no relationship was found between age and sex and tumoral stage. In advanced tumoral stages poor cellular differentiation is predominant as well as other histological markers of poor prognosis. Good survival was found in T3 tumors, possibly linked to good cellular differentiation. Due to high associated comorbidity, none of the patients underwent reintervention.