Actin cytoskeletal and functional studies of the proximal convoluted tubules after preservation.

BACKGROUND: Proximal tubule cells have specialized apical membranes with microvilli that provide an extensive surface area for unidirectional transport of solute from lumen to blood. The major structural solute component is F-actin, which interacts with transmembrane proteins, including ion transport molecules related to normal absorptive and secretory functions. Our study was to evaluate F-actin and fluid absorption (Jv) in proximal tubules after exposure to preservation solutions. METHODS: In vitro microperfusion technique and immunohistochemistry analysis. RESULTS: 1. Absorptions were similar in 1- and 24-hour-preserved tubules, as well as in fresh tubules. The exception was tubules for 24 hours in Euro-Collins solution, which did not show absorption, suggesting that it was affected. 2. Fluorescence intensity of actin tubules preserved for 1 hour in both solutions showed similar values to each other and to the control group; tubules preserved for 24 hours in both solutions were similar to each other, although statistically different than the control group and those preserved for 1 hour in Belzer (UW) solution. CONCLUSION: There were differences among groups in the distribution of F-actin; Jv values were different for 24-hour preservation in each solution, whereas fluorescence intensity was similar in both 24-hour solutions. Thus, actin cytoskeleton was not responsible for it, because 24-hour preservation in UW showed Jv results comparable to the control group.

Permeability of ovine primordial follicles to different cryoprotectants.

OBJECTIVE: To determine the behavior of isolated primordial follicles that were exposed to different concentrations of dimethyl sulfoxide (DMSO), ethylene glycol (EG), propylene glycol (PROH), and glycerol (GLY). DESIGN: Isolated primordial follicles were exposed to the cryoprotectant (CPA) solution and photographed to calculate their volume at different periods of exposure. SETTING: Laboratorio Renzo Giuliani, University of Florence, Italy. ANIMAL(S): Lambs, 30-40 days old. INTERVENTION(S): Isolation of primordial follicles and subsequent exposure to CPA. MAIN OUTCOME MEASURE(S): Follicular volume. RESULT(S): At 2 minutes of CPA exposure, all follicles appeared to be shrunken. At approximately 5 minutes, shrinkage ceased, and follicles started to swell, absorbing the CPA and water to maintain osmotic equilibrium. When DMSO was tested, follicular dehydration in all concentrations did not exceed 17%; with PROH and EG, it reached 33% and 27%, respectively. The highest degree of dehydration (48%) was seen with GLY. In almost all tested concentrations, follicular shrinkage occurred up to 5 minutes. CONCLUSION(S): Volume changes in isolated primordial follicles can fluctuate according to the CPA used and its concentration.

Distribuiçäo da soluçäo Euro-Collins em pulmöes de porcos ministrada por diferentes vias de perfusäo rápida: estudo comparativo / Distribution of Euro-Collins solution in lung of pigs

O transplante pulmonar tem sido realizado com sucesso no tratamento de pacientes selecionados com doenças pulmonares no seu estágio final, apesar de ainda muito limitado quanto ao seu uso, pela escassez de doadoes adequados.A aquisiçäo à distância de órgäos adequados, poderá aumentar consideravelmente o número de transplantes pulmonares e esforços se concentram na possibilidade de proteçäo dos pulmöes por tempos maiores de isquemia e de reduçäo das lesöes nas fases iniciais de reperfusäo. As técnicas de preservaçäo atualmente utilizadas para a aquisiçäo à distância de pulmöes, incluem a auto-perfusäo isolada, o bypass cardio-pulmonar com hipotermia profunda e a preservaçäo estática com várias formas de perfusäo rápida via artéria pulmonar.As complicaçöes nas anastomoses brônquicas, continuam sendo importante fator de morbidade e de mortalidade em transplantes. Entre outros fatores, a qualidade de proteçäo das vias aéreas parece contribuir para melhor cicatrizaçäo brônquica.Na maioria dos centros de transplante, a técnica de preservaçäo pulmonar mais utilizada é a perfusäo rápida via artéria pulmonar, seguida por armazenamento hipotérmico dos pulmöes. Com esta técnica, a soluçäo de preservaçäo parece atingir a circulaçäo tráqueo-brônquica por meio de anastomoses, talvez nem sempre suficientes, ocasionando complicaçöes isquêmicas nas anastomoses das vias aéreas superiores. Vias de perfusäo rápida alternativas säo representadas pela retrógrada, via átrio esquerdo e veias pulmonares e pela anterógrada simultânea, via artéria pulmonar e segmento de aorta contendo as artérias brônquicas. No presente trabalho, foi feito um estudo comparativo sobre a distribuiçäo da soluçäo Euro-Collins em pulmöes de porcos através de diferentes vias de perfusäo rápida e foi utilizada a técnica de micro-esferas coloridas, näo-radioativas, para a mensuraçäo de fluxo ao parênquima pulmonar e às vias aéreas. Os animais foram divididos em 4 grupos: grupo controle (n=6); grupo AP (artéria pulmonar (n=6); grupo AP + AB (artéria pulmonar e artérias brônquicas contidas em seguimento de aorta) (n=8) e grupo VP (veias pulmonares) (n=6). Após preparaçäo cirúrgica, canulaçöes e cardioplegia, iniciava-se infusäo rápida de Euro-Collins através de uma das diferentes vias descritas, conforme o grupo a que pertencia o animal. Removia-se entäo o coraçäo e, após, o bloco contendo os dois pulmöes...