El Campus Virtual de Salud Pública: seis años de formar recursos humanos en México / Virtual Campus of Public Health: six years of human resources education in Mexico

Este trabajo muestra, desde el punto de vista de la normatividad de la Organización Panamericana de la Salud (OPS), el proceso de gestación, la metodología de implementación y los resultados obtenidos de la iniciativa de formación de recursos humanos en salud vía e-learning a través del Campus Virtual de Salud Pública de la Universidad de Guadalajara, México, a seis años de su inicio. Se trata de un informe especial del trabajo realizado por el comité institucional del campus virtual en la región occidental de México para generar un portal de Internet que se ajustara a los lineamientos del Modelo Estratégico establecido por el Nodo México y la OPS para la Región de las Américas. Este Campus Virtual inició sus actividades en el año 2007. Su filosofía es el uso de software libre y la colaboración entre instituciones. El nodo fue implementado en un año y ha logrado capacitar a más de 500 profesionales de la salud a través de cursos virtuales, su plataforma educativa y un repositorio de recursos virtuales de aprendizaje con interoperabilidad con los repositorios de México y de la Región de las Américas. El comité del Campus Virtual de la Universidad de Guadalajara ha intentado respetar lo más posible al modelo propuesto, lo que ha permitido cumplir la mayoría de los objetivos fijados en el plan de trabajo inicial, aunque ha enfrentado una serie de dificultades administrativas y de motivación de sus integrantes.

This paper discusses the gestation process, implementation methodology, and results obtained from the initiative to use e-learning to train human resources for health, six years after the launch of the Virtual Campus of Public Health of the University of Guadalajara (Mexico); the discussion is framed by Pan American Health Organization (PAHO) standards and practices. This is a special report on the work done by the institutional committee of the Virtual Campus in western Mexico to create an Internet portal that follows the guidelines of the strategic model established by Nodo México and PAHO for the Region of the Americas. This Virtual Campus began its activities in 2007, on the basis of the use of free software and institutional collaboration. Since the initial year of implementation of the node, over 500 health professionals have been trained using virtual courses, the node's educational platform, and a repository of virtual learning resources that are interoperable with other repositories in Mexico and the Region of the Americas. The University of Guadalajara Virtual Campus committee has followed the proposed model as much as possible, thereby achieving most of the goals set in the initial work plan, despite a number of administrative challenges and the difficulty of motivating committee members.

Función renal en cirugía cardíaca con circulación extracorpórea: Pacientes valvulares y coronarios / Renal function during cardiac surgery with extracorporeal circulation

Background: Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation. Aim: To describe changes in renal function parameters during surgery with extracorporeal circulation in patients with valvular heart disease and compare them with those found in patients undergoing elective coronary surgery Material and Methods: Two groups of patients were studied. Group 1 was composed by twelve patients undergoing elective coronary surgery and group 2 was composed by eleven patients undergoing surgery for heart valve replacement. Glomerular filtration rate and effective renal plasma now were estimated from inulin and the 131 I-hippuran clearance respectively, at five different times, during surgery and the postoperative period. Sodium filtration fraction and fractional excretion were calculated. Alpha and pi-glutathione s-transferase in urine were measured as markers of tubular damage in the pre and postoperative periods. Results: Effective renal plasma flow was reduced in both groups before induction of anesthesia, did not change during surgery and decreased significantly in patients with valvular disease in the postoperative period. Glomerular filtration rates were normal during all the study period. There was a non significant reduction of filtration fraction during extracorporeal circulation. Alpha and pi glutathione s-transferases were normal and did not change. Fractional excretion of sodium increased significantly postoperatively Conclusions: In patients with valvular disease undergoing surgery with extracorporeal circulation, renal function does not deteriorate. No significant difference was found when compared with patients undergoing coronary surgery. No evidence of functional and cellular renal disfunction or damage was found in both study groups.

BTCI enhances guanylin-induced natriuresis and promotes renal glomerular and tubular effects

Guanylin and uroguanylin are small cysteine-rich peptides involved in the regulation of fluid and electrolyte homeostasis through binding and activation of guanylyl cyclases signaling molecules expressed in intestine and kidney. Guanylin is less potent than uroguanylin as a natriuretic agent and is degraded in vitro by chymotrypsin due to unique structural features in the bioactive moiety of the peptide. Thus, the aim of this study was to verify whether or not guanylin is degraded by chymotrypsin-like proteases present in the kidney brush-border membranes. The isolated perfused rat kidney assay was used in this regard. Guanylin (0.2 µM) induced no changes in kidney function. However, when pretreated by the black-eyed pea trypsin and chymotrypsin inhibitor (BTCI - 1.0 µM; guanylin - 0.2 µM) it promoted increases in urine flow (deltaUF of 0.25 ± 0.09 mL.g-1/min, P < 0.05) and Na+ excretion ( percent delta ENa+ of 18.20 ± 2.17, P < 0.05). BTCI (1.0 µM) also increased percentENa+ (from 22.8 ± 1.30 to 34.4 ± 3.48, P < 0.05, 90 minutes). Furthermore, BTCI (3.0 µM) induced increases in glomerular filtration rate (GFR; from 0.96 ± 0.02 to 1.28 0.02 mL.g-1/min, P < 0.05, 60 minutes). The present paper strongly suggests that chymotrypsin-like proteases play a role in renal metabolism of guanylin and describes for the first time renal effects induced by a member of the Bowman-Birk family of protease inhibitors.

Guanilina e uroguanilina são peptídeos pequenos, ricos em cisteína, envolvidos na regulação da homeostase de fluidos e eletrólitos através da ligação e ativação da guanilato ciclase expressa no intestino e nos rins. A guanilina é menos potente do que a uroguanilina como agente natriurético e é degradada in vitro pela quimiotripsina devido a características estruturais únicas no domínio bioativo do peptídeo. Portanto o objetivo deste trabalho foi verificar se a guanilina é degradada por proteases tipo quimiotripsina, presentes na membrana da borda em escova dos rins. Para esta investigação, foi usado o modelo do rim isolado de rato perfundido. A Guanilina (0,2 µM) não induziu mudanças na função renal. Entretanto, quando pré-tratada com inibidor de tripsina e de quimiotripsina de black-eyed pea (BTCI - 1,0 µM; guanilina - 0,2 µM) promoveu um aumento no fluxo urinário (deltaUF de 0,25 ± 0,09 mL.g-1/min, P < 0,05) e na excreção de Na+ ( por centoDENa+ de 18,20 ± 2,17, P < 0,05). BTCI (1,0 µM) também aumenta por centoENa+ (de 22,8 ± 1,30 a 34,4 ± 3,48, P < 0,0590 minutos). Além disto, BTCI (3,0 µM) induziu um aumento da taxa de filtração glomerular (GFR; de 0,96 ± 0,02 para 1,28 ± 0,02 mL.g-1/min, P < 0,05, 60 minutos). O presente trabalho sugere fortemente que proteases semelhantes à quimiotripsina desempenham um papel no metabolismo renal de guanilinas e descreve, pela primeira vez, os efeitos renais induzidos por um membro da família de inibidores de proteases do tipo Bowman-Birk.

A computer program for single-injection tracer clearance from one, two, or many blood samples

A computer program based on a Bayesian statistical model has been developed for calculating tracer clearance from any number of plasma samples drawn at arbitrary time intervals. Bayesian prior parameters were calculated from clinical data for Tc99m-MAG3, Tc99m-EC, I131-OIH, Tc99m-DTPA, and Yb169-DTPA and then used to calculate clearance from prospective data. Clearance estimates using only one or two plasma samples were found to closely approximate the results of using multiple samples. When only one or a few samples are available, the program supplements the observed data by a Bayesian prior probability distribution (based on prior clinical measurements) to achieve agreement with multisample clearance. When many points are available, the observed data overwhelm the prior probability, and results approach those of conventional curve fitting but with less sensitivity to bad data points and less risk of fitting failure.

Vascular and glomerular effects of Clostridium difficile toxin A peptide on the isolated rat kidney

Toxin A peptide from Clostridium difficile caused damage and secretion in the intestinal mucosa. These effects are mediated in part by pro-inflammatory substances. In order to evaluate and compare the biologic effect of toxin A on renal vascular, glomerular and tubular functions, we studied this toxin in isolated rat kidneys. Isolated kidneys from adult male Wistar rats (260-320 g) were perfused with Krebs-Henseleit solution containing 60 mg/ml dialyzed bovine serum albumin. We studied the effect of toxin A peptide (3.2 x 10(-6) M, injected into perfusate) on glomerular filtration rate (GFR), urinary flow rate (UF) and total sodium reabsorption (TNa+, per cent ). All experiments were preceded by a 30-min basal period, and in another group of kidneys the time course of the variables was followed without toxin infusion for unpaired control. Toxin A (TxA) reduced the perfusion pressure (PP), from PPcontrol/30min = 124.89 +/- 1.91 to PPTxA/120min = 88.13 +/- 5.1 mmHg (N = 6, P < 0.01) with a maximal effect at 120 min after toxin infusion. TxA also caused a significant decrease in GFR with maximal effect at 90 min after toxin infusion (GFRcontrol/30min = 0.53 +/- 0.05 to GFRTxA/90min = 0.30 + 0.05 ml min-1g-1; N = 6, P < 0.01). TxA did not alter renal tubular sodium transport when compared with a control without toxin infusion. In addition, toxin-treated kidneys caused a time-dependent increase in urinary flow from UFcontrol/30min = 0.16 +/- 0.08 to UFTxA/120min = 0.35 +/- 0.1 ml min-1g-1 (N = 6, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulacao renal da excrecao de sodio na insuficiencia cardiaca experimental: estudo da hemodinamica e da funcao tubular renal / Renal regulation of sodium excretion in experimental heart failure: study of hemodynamics and renal tubular function

O objetivo do presente trabalho foi estudar o papel desempenhado pelo rim na retencao de sodio e agua na insuficiencia cardiaca em caes com fistulas arterio-venosas femorais atraves de medidas de clearance e hemodinamica. Vinte e sete caes foram estudados em hidropenia e em diurese aquosa, 96 horas apos a realizacao de fistulas arterio-venosas femorais bilaterais, em 3 periodos: 1) fistulas abertas; 2) fistulas fechadas e 3) fistulas reabertas. Os animais retinham sal e agua e desenvolveram edema no periodo em que as fistulas estavam abertas. Quando as mesmas foram fechadas ocorreu uma maior diurese, natriurese, com aumento da excrecao urinaria de fosfato e do aporte distal de solutos, sugerindo uma diminuicao da reabsorcao proximal de sodio e agua. Apos a reabertura das fistulas, observou-se um aumento da reabsorcao de sodio pelos segmentos distais do nefron, sugerido pela elevacao da excrecao de agua livre por unidade de aporte de solutos. Estes achados nao foram acompanhados por alteracoes da distribuicao do fluxo sanguineo renal cortical. Em conclusao, a retencao de sodio e agua na insuficiencia cardiaca congestiva produzida por fistulas arterio-venosas se deve a um aumento da reabsorcao de sodio pelos segmentos distais do nefron e nao e devida a uma redistribuicao do fluxo sanguineo renal cortical.

Estudo da funçäo de rins transplantados no pós-operatótio imediato / Function of transplanted kidneys in the immediate post-operative period

Com a finalidade de melhor caracterizar as funçöes glomerular, e tubular de rins transplantados no pós-operatório imediato, foram estudados dez receptores e seus respectivos doadores 48 e 72 horas após o transplante, em período em que a volemia e a osmolalidade plasmática já eram normais nos receptores e semelhante a dos doadores. Nenhum receptor apresentou insuficiência renal aguda ou rejeiçäo durante o período da observaçäo, mas eram hipertenso. A filtraçäo glomerular, medida pelas depuraçöes de uréia e creatinina, foram comparáveis nos dois grupos e normais para indivíduos com um só rim. A funçäo tubular foi avaliada pela excreçäo de sódio, potássio, cálcio e fósforo e pela depuraçäo osmolar e da água livre. A depuraçäo e excreçäo fracional de cálcio foi semelhante nos dois grupos. Os receptores apresentaram depuraçäo e excreçäo fracional de potássio semelhante a dos doadores de depuraçäo de água livre positiva. Esses dados foram interpretados como evidência de funçäo tubular distal intacta receptores. Ao contrário, a excreçäo fracional de sódio (p < 0,05) e de fósforo (p < 0,01) foi significativamente mais elevada nos receptores. Esses resultados sugerem a existência de disfunçäo tubular proximal independente de fatores osmóticos e volêmicos. Esta disfunçäo pode ser intrínseca ou secundária a alteraçöes hemodinâmicas específicas do rim transplantado ou a agentes hormonais

Atropine enhancement of aldosterone induced renal sodium reabsorption in dogs

El objetivo del presente trabajo fue investigar el efecto de la atropina sobre la membrana de los túbulos renales, como hemos sugerido en un trabajo previo. Se anestesiaron perros mestizos a los que se les infundió una solución de ClNa isotónica por vía endovenosa. Se cateterizaron ambos uréteres y se recogieron muestras de orina en períodos de diez minutos. Diferentes grupos de perros recibieron una dosis única de aldosterona ev (2 y 4 ug/kg de peso corporal); atropina (1 ug/kg de peso corporal); atropina previa a la dosis menor de aldosterona y solución salina en volúmenes de 1 ml. La administración de atropina previa a la dosis menor de aldosterona aumentó el efecto antinatriurético de la hormona y, además, produjo una anticipación en la aparición del efecto. Los resultados obtenidos parecen compatibles con cambios de la permeabilidad o de la capacidad de transporte de las membranas tubulares inducidos por atropina

Channels for water flow in epithelia: characteristics and regulation

Pos y Pd, los coeficientes de permeabilidad osmótica y difusiva al agua, de túbulos proximales (TP) de conejo (por cm**2 de membrana celular real, micronm/s) son Pos, 396; Pd, 22; Pos/Pd, 18 (controles). Con paracloromercuribencenosulfonato son Pos, 32; Pd, 10; Pos/Pd, 3. El reactivo de grupos sulfhidrilos ditiotreitol (DTT) revierte la acción del pCMBS. Las energías de activación (Kcal/mol) son Pos, 3.2 (controles); 9.2 (pCMBS); Pd, 5.2 (controles, 9.1 (pCMBS). Por lo tanto, canales acuosos atraviesan la membrana celular control y son cerrados por pCMBS. Las altas permeabilidades de TP (controles) son similares a las de la vejiga urinaria de anfibio (un análogo del túbulo colector, TC), estimulada con hormona antidiurética (ADH) y los valores bajos con pCMBS en TP recuerdan los de TC en reposo (sin ADH). La permeabilidad transcelular puede ser regulada por el estado de grupos sulfhidrilo en TP y por la adición de canales acuosos por la HAD (o su supresión, reposo). En T.P.(a) no-electrólitos extracelulares son arrastrados por el flujo de agua indicando interacción extracelular aguasoluto; (b) la Pos transepitelial es mucho mayor que la transcelualr. Por consiguiente, en adición al flujo transcelular hay flujo paracelular de agua. La permeabilidad en TP se incrementa si la urea luminal es mayor que la sanguínea (en 15-50 mM) y se reduce en la situación inversa. En TD (control) la permeabilidad paracelular es cero. Se incrementa con urea en condición control en TP y muy pequeña en TC...