[Splanchnic remodeling secondary to experimental prehepatic portal hypertension]. / Remodelación esplácnica secundaria a hipertensión portal prehepática experimental.

OBJECTIVE: Portal hypertension as an inducer of intestinal inflammatory response would cause epithelial and splanchnic vascular remodeling in the long-term. This experimental study was carried out to verify this hypothesis. METHOD: Structural alterations characteristic of intestinal epithelial and mesenteric vascular remodeling, the density of goblet cells and the diameter of mesenteric vein branches were studied, respectively, in rats with partial portal vein ligation in the short (1 month) and long-term (1 year). RESULTS: Hyperplasia of goblet cells in the small intestine (duodenum, jejunum, ileum) is maximum after 1 year of evolution of the portal hypertension and is associated with dilatation of the distal branches (3rd and 4th order) of the superior mesenteric vein. CONCLUSION: Long-term splanchnic remodeling in experimental portal hypertension suggests the existence of a chronic inflammatory process in this clinical condition.

[Development of pre-hepatic portal hypertension of the rat]. / Tipos evolutivos de hipertensión portal prehepática en la rata.

OBJECTIVE: A long-term study of the prehepatic portal hypertension model by triple stenosing ligation of the portal vein in the rat. METHOD: A cluster analysis of the animals in the different evolutive stages of portal hypertension (1 1/2, 6, 12 and 14 months) has been carried out. This analysis has made it possible to identify three homogeneous groups (A, B and C) in relationship to the liver weight. RESULTS: The animals with liver atrophy (group C) show a decrease of body, splenic and testicular weights as well as a higher development of the portosystemic collateral circulation in relation to the A and B groups. CONCLUSION: The percentage of animals belonging to the group C decrease progressively during the evolution of portal hypertension and those animals corresponding to the group A, in which is superior the liver weight, increase, while the B group does not change.

[Sepsis and septic shock: a turmoil of inflammatory mediators with difficult therapeutic management]. / Sepsis y shock séptico: un torbellino de mediadores inflamatorios de difícil manejo terapéutico.

Sepsis and septic shock continue being a topic of enormous interest for their high frequency, and for not existing a decrease in the figures of mortality in spite of the new acquired knowledges relation with their physiopathology and the advances arisen in the diverse applied treatments. The purpose of the present study is to update the present notions in the specialized literature, trying to summarize the complex existent interaction among different mediators of double character: exogenous and endogenous, and to enunciate the possible causes for those that the novel treatments applied in the sepsis continue not to be very promising.

Sepsis y shock séptico: un torbellino de mediadores inflamatorios de difícil manejo terapéutico / Sepsis and septic shock: a turmoil of inflammatory mediators with a difficult therapeutic management

La sepsis y el shock séptico continúan siendo un capítulo de enorme interés por su elevada frecuencia, y por no existir una disminución en las cifras de mortalidad a pesar de los nuevos conocimientos adquiridos en su fisiopatología y los avances surgidos en los diversos tratamientos aplicados. El propósito de la presente revisión es actualizar los conceptos presentes en la literatura especializada, tratando de resumir la compleja interacción existente entre diferentes mediadores de doble carácter: exógenos y endógenos, y enunciar las posibles causas por las que los tratamientos novedosos aplicados en la sepsis siguen siendo poco prometedores (AU)

[Long-term portal hypertension in the rat by means of triple stenotic ligation of the portal vein]. / Hipertensión portal a largo plazo en la rata por triple ligadura estenosante de la vena porta.

OBJECTIVE: To improve the technique of stenosing ligation of the portal vein, frequently used to obtain a prehepatic portal hypertension model in the rat, by increase the initial resistance to the blood flow. METHODS: In this experimental work portal stenosis by three equidistant stenosing ligatures which are fixed in a plastic guide is proposed as an alternative technique. RESULTS: Triple stenosing ligation of the portal vein does not produce mortality and causes splenomegaly as well as a larger degree of collateral venous circulation, particularly of splenorenal type, in relation to rats with a simple stenosing ligation. CONCLUSION: Increase of the stenosed tract length of the portal vein in the rats with triple ligation increases the initial resistance to the portal flow and then the posterior evolution would be impaired and this mechanism could be involved in a larger degree of collateral venous circulation.

Hipertensión portal a largo plazo en la rata por triple ligadura estenosante de la vena porta / Long-term portal hypertension in the rat by means of triple stenotic ligation of the portal vein

Objetivo: Mejorar la técnica de la ligadura estenosante portal, habitualmente utilizada como modelo experimental de hipertensión portal prehepática en la rata, aumentando la resistencia inicial al flujo sanguíneo. Método: Para ello se propone como alternativa la estenosis portal por tres ligaduras estenosantes equidistantes que se mantienen en posición mediante su fijación a una guía plástica. Resultados: La triple ligadura estenosante de la vena porta no produce mortalidad en la rata y a los 45 días del postoperatorio causa esplenomegalia y mayor desarrollo de circulación colateral, en particular de tipo esplenorenal, respecto de la ligadura simple. Conclusión: El aumento de la longitud del trayecto portal estenosado en las ratas con triple ligadura podría aumentar la resistencia inicial al flujo y así agravar la evolución posterior, causando mayor desarrollo de circulación colateral (AU)

Principios de la investigación clínica / Principles of clinical research

Objetivo. Se exponen las normas éticas que debe cumplir la investigación en la clínica humana. Destacan la Declaración de Helsinki de 1964, revisada posteriormente en Tokio (1975), Venecia (1983), en Hong Kong (1989). El informe Belmont (1979), base de la bioética estadounidense y el Convenio para la protección de los Derechos Humanos y la dignidad del ser humano con respecto a las aplicaciones de la Biología y la Medicina, aprobado por los miembros del Consejo de Europa en 1996.Conclusión. En esencia, la investigación y la práctica de la medicina deben estar regidas por tres principios éticos fundamentales: autonomía, beneficio y justicia. El principio de autonomía se basa en el respecto por las personas. El principio de beneficio o de hacer el bien obliga a asegurar el bienestar de los individuos. El principio de justicia determina que los pacientes deben ser seleccionados sin tener en cuenta el grupo social al que pertenecen y se fundamentan en la distribución equitativa de los medios que se disponen (AU)

Normas éticas para el cuidado y utilización de los animales de experimentación / Ethical norms for the care and use of experimental animals

Introducción. La experimentación animal y la investigación con animales es una parte integral de la investigación clínica quirúrgica cuyo objetivo es resolver los problemas que se plantean en la clínica humana. Objetivo. La exposición de las normas éticas que deben regir la investigación con animales de experimentación. Métodos. Se describen los principios de un Código de Ética sobre el animal de laboratorio de ámbito internacional, las condiciones que deben cumplir el cuidado y utilización de los animales en investigación, recogidas en el Real Decreto 223/1988 de la Legislación Española y basadas en la Normativa de la Comunidad Europea 86/609. Se recogen los principios éticos y las responsabilidades del investigador en la experimentación animal, se exponen las condiciones de alojamiento en estabularios y su control, los cuidados que han de recibir los animales y el empleo de técnicas anestésicas. Conclusión. Los animales de laboratorio pueden y deben ser utilizados en beneficio de la ciencia y la salud pública ya que la experimentación animal ha contribuido al progreso de la ciencia quirúrgica al permitir la docencia, la investigación y el ensayo de nuevas técnicas e ideas. Su utilización siempre se regirá por principios éticos y se debe evitar su uso indiscriminado combinándolo con técnicas alternativa (AU)

Protagonism of the arterial circulation in the preservation of the pig's liver by simple perfusion and hypothermic storage.

A modified technique to perform the successive perfusions of the liver that are necessary for its preservation by the simple perfusion method and hypothermic storage is presented. This technical variety has been tested on Large White pig's livers and consists in doing the successive perfusions of cooling, preservation and washout, first through the hepatic artery and there after through the portal vein. The macroscopic and biochemical characteristics of the effluents obtained through the infrahepatic inferior vena cava during the perfusion-washout of the livers at the end of the period cold ischemia shows its effectiveness. Likewise, the hepatic perfusion-washout begun via the arterial vein and finished via the portal one avoids post-revascularization hyperpotassemia in the receptor animals. It is hypothesized that the arterial protoganism of perfusions, when the simple perfusion and hypothermic storage method of hepatic preservation is used, could be a prophylaxis against complications of a post-transplant biliary origin.

[Effect of verapamil on hepatorenal toxicity induced by cyclosporin]. / Efecto de verapamil sobre la toxicidad hepatorrenal inducida por ciclosporina.

The immunosuppressive and nephrotoxic effects of cyclosporine A (CsA) have been ascribed to a calcium-dependent mechanism of action. However, verapamil, a slow-calcium-channel blocking agent, enhances the immunosuppressive action of CsA and reduces its nephrotoxicity. The present experimental study performed in Wistar rats demonstrates that 0.1 mg..24 h.-1 IM verapamil prevents reduction of liver weight caused by treatment with 20 mg..kg.-1..24 h.-1 IM, as well as a rise in SGOT, SGPT, serum LDH and creatinine. The nephro-protective effects of verapamil in rats treated with CsA could be ascribable to the increased plasma clearance of the immunosuppressive agent.

[Segmental portal hypertension caused by aneurysm of the distal splenic artery]. / Hipertensión portal segmentaria por aneurisma de la arteria esplénica distal.

A case is reported of segmental portal hypertension secondary to compression of the splenic vein by an aneurysm of the distal splenic artery. Splenectomy was used to treat the aneurysm and segmental portal hypertension, as well as the hypersplenism existent. Collateral circulation through the short gastric veins originated grade V gastroesophageal varices, which makes this mechanism of production equivalent to that described in cases of thrombosis of the splenic vein.

[Ductal adenocarcinoma of the head of the pancreas: associated pathology of body and tail]. / Adenocarcinoma ductal de la cabeza del páncreas: patología asociada de cuerpo y cola.

Histologic study of the body and tail of the pancreas in a patient in whom total duodenopancreatectomy was carried out for ductal adenocarcinoma of the head (ADC) demonstrates the existence of dysplasia of the pancreatic duct in its entire length associated with intente parenchymal atrophy. It is considered that cephalic duodenopancreatectomy in ductal adenocarcinoma of the head of the pancreas should be based on an adequate anatomic, histologic and functional evaluation of the residual pancreas.