Jaume Fernández-Llamazares

Endotoxin contamination may be responsible for the unexplained failure of human pancreatic islet transplantation.

Clinical transplantation of human islets has a disappointingly low rate of success. We report here the identification of a possible causative factor: endotoxin present in the collagenase preparations used to disperse the pancreatic tissue before islet purification and transplantation. Supporting evidence includes (1) detection of unexpectedly high levels of endotoxin in most collagenase solutions currently used to digest human pancreases; (2) demonstration that supernatants generated during islet separation are able to induce the inflammatory cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in macrophages; and (3) induction of IL-1, IL-6, and TNF-alpha in the islets during the separation procedure. Cytokine expression was assessed by reverse transcription-polymerase chain reaction and, for TNF-alpha, confirmed by enzyme-linked immunoabsorbent assay. It is proposed that endotoxin and locally induced cytokines carried over with the graft activate the endothelium and promote lymphomonocytic infiltration of grafted islets and surrounding liver tissue favoring primary nonfunction and early rejection. These results also have implications for the numerous experimental procedures that use collagenase, and they point to possible ways to improve islet preparation and transplantation protocols.

Advantages of using a cell separator and metrizamide gradients for human islet purification.

Human islet transplantation has a high rate of failure, often due to primary nonfunction, which suggests that islets are damaged during the processing of the pancreas. The preparation of human islets for transplantation is still a complex process that requires large teams of surgical and laboratory personnel. To overcome this problem, we have adopted the use of the IBM 2991 COBE cell separator and a metrizamide/Ficoll density medium that is easy to prepare. Twenty-seven pancreatic glands have been processed using the COBE cell separator, 23 of which were purified in metrizamide/Ficoll gradients and 4 in bovine serum albumin gradients. The results show an improvement of recovery and viability in these preparations when compared retrospectively with manual gradients. More importantly, the time required for purification was shortened to one fourth the usual time and total processing time is about half as long. Moreover, a team of two laboratory staff was regularly able to prepare islets for transplantation, reducing the separation time from 7 hr to 3.5 hr. We conclude that the automatic cell separator and metrizamide-based separation medium are useful modifications of current islet purification methods.

Valoración de la función esplénica mediante gammagrafía dinámica y estudio de «pits» de la membrana eritrocitaria y de vacuolas submembranarias en los pacientes con traumatismo leve y grave de bazo tratados de forma conservadora o mediante esplenectomía

Fundamento y objetivo Cuantificar la funcion esplenica de los pacientes controlados en el Servicio de Cirugia General y Digestiva del Hospital Universitari Germans Trias i Pujol (HUGTiP) desde 1985 hasta 2003 tras haber sufrido diferentes grados de lesion traumatica del bazo segun la clasificacion de la American Association for the Surgery of Trauma (AAST) del ano 1994 y relacionarla con el tratamiento recibido (no operatorio, esplenectomia total con o sin esplenosis y esplenectomia mas autotrasplante), con la finalidad de detectar disfunciones esplenicas que predispongan al desarrollo de la sepsis tras la esplenectomia. Pacientes y metodo Se ha realizado a 43 pacientes un estudio isotopico con gammagrafia esplenica «dinamica », estudio de «pits» de la membrana eritrocitaria (optica de Nomarsky) y de vacuolas submembranarias (microscopia electronica de transmision). Resultados El grupo de no operados presenta una funcion normal de fagocitosis y filtracion, con una mediana de velocidad de captacion esplenica de 3,46 Kcts/s2 (intervalo, 0,8-6,98). El porcentaje mediano de «pits» de membrana fue del 2% (intervalo, 0-8,8%); el numero de «pits» por hematies, de 0,03 (intervalo, 0-0,12), y el porcentaje de hematies con 1, 2, 3 y 4 «pits», del 1,6, el 0,4, el 0 y el 0%, respectivamente. El porcentaje mediano de hematies con vacuolas submembranarias fue el 2,55% (intervalo, 0-5,6%); el numero de vacuolas por hematie, de 0,03 (intervalo, 0-0,06), y el porcentaje de hematies con 1, 2, 3 y 4 vacuolas, del 2, el 0,2, el 0 y el 0%, respectivamente. En el grupo operado, la velocidad mediana de captacion esplenica fue de 0,08 Kcts/s2 (intervalo, 0-1,75; p Conclusiones La funcion esplenica de los pacientes con antecedentes de traumatismo esplenico tratados de forma conservadora es normal, independientemente del grado de la lesion. Ello refuerza la conveniencia de aplicar de entrada esta actitud a todos los protocolos para intentar evitar la sepsis tras la esplenectomia. En los casos tratados con esplenectomia, con o sin esplenosis, la funcion esplenica esta ausente o muy alterada, mientras que en los casos tratados con esplenectomia y autotrasplante esta parcialmente conservada.

Clinical Outcome in Patients With Peripheral Artery Disease and Renal Artery Stenosis

Background: There is controversy on the influence of renal artery stenosis on outcome in patients with peripheral artery disease. Patients and Methods: The 12-month impact of renal artery stenosis on declining renal function, control of hypertension, and incidence of major cardiovascular events in 100 consecutive patients undergoing angiography for peripheral artery disease was evaluated. Results: A total of 60 patients had renal artery stenosis: 32 mild, 16 moderate, and 12 severe stenosis. There were no significant differences in either the decline of renal function (2.7 ± 18% vs 0.9 ± 16%), control of hypertension (139 ± 16 vs 139 ± 22 mm Hg) or number of antihypertensive drugs (1.8 ± 1.0 vs 1.6 ± 0.8). Patients with renal artery stenosis had an increased incidence of major cardiovascular events (odds ratio: 2.3; 95% confidence interval: 1.03-5.4), but on multivariate analysis its influence disappeared. Conclusions: Patients with peripheral artery disease having renal artery stenosis had similar decline of renal function and control of hypertension. They had an increased incidence of major cardiovascular events, but it may be explained by the confounding effect of additional variables.

Long-Term Results of Serial Transverse Enteroplasty with Neovalve Creation for Extreme Short Bowel Syndrome: Report of Two Cases

Objective: The aim of this article was to determine whether serial transverse enteroplasty (STEP) and the creation of a new ileocecal valve in extreme short bowel syndrome (SBS) cases (<45 cm) is effective in intestinal adaptation and improvement of nutritional parameters and serum citrulline levels. Patients and Methods: We present 2 cases of SBS treated with STEP. Enterectomy was performed for massive intestinal ischemia secondary to a gastrointestinal stromal tumor in the first case and to catastrophic antiphospholipid syndrome in the second. After enterectomy, the short residual bowel measured 34 cm in the first patient and 45 cm in the second. In both cases STEP, cholecystectomy, and gastrostomy were performed. In the first case a Brooke neovalve was created, and in the other the ileocecal valve was preserved. Results: Both patients could finally be weaned off total parenteral nutrition (TPN) and gastrostomy feeding, maintaining a good nutritional status 1 year after surgery. Conclusions: In extreme SBS, a minimum length of 80–90 cm of functioning small bowel and an intact ileocecal valve are necessary. We plead for the use of STEP with preservation of the ileocecal valve or creation of a neovalve using the Brooke technique in order to achieve the ultimate goal, which is to wean patients off TPN. After a critical review of different surgical techniques, a treatment algorithm is proposed.