Involvement of energetic metabolism in the effects of ischemic postconditioning on the ischemic-reperfused heart of fed and fasted rats.

The effects of ischemic-postconditioning (IPOC) on functional recovery and cell viability of ischemic-reperfused hearts from fed and fasted rats were studied in relation to triacylglycerol and glycogen mobilization, ATP content, glucose-6-phosphate dehydrogenase activity and reduced/oxidized glutathione (GSH/GSSG). Oxidative damage was estimated by measuring thiobarbituric acid reactive substances (TBARS). IPOC improved contractile recovery and cell viability in the fed but attenuated them in the fasted hearts. In both groups ischemia lowered glycogen. IPOC further reduced it. Triacylglycerol remained unchanged during ischemia-reperfusion in both groups, but triacylglycerol mobilization was activated by IPOC in the fasted group. ATP was increased by IPOC in the fed hearts, but lowered in the fasted ones, which appeared to be associated with the rates of ATP synthesis in isolated mitochondria. In the fed hearts IPOC raised glucose-6-phosphate dehydrogenase activity and GSH/GSSG, and lowered TBARS. These results suggest that IPOC effects are associated with changes in the ATP supply, mobilization of energy sources and glutathione antioxidant ratio.

Mitochondrial dysfunction as a mediator of hippocampal apoptosis in a model of hepatic encephalopathy.

In this study, we describe the presence of apoptosis, associated with a mitochondrial dysfunction in the hippocampus of animals in an experimental model defined as minimal hepatic encephalopathy (MHE). This experimental model was studied after 10 days of induced portal vein calibrated stricture, leading to portal hypertension and to a moderate hyperammonemia, without the presence of other evident central nervous system changes. The molecular mechanisms here proposed indicate the presence of apoptotic intrinsic pathways that point to hippocampal mitochondria as an important mediator of apoptosis in this experimental model. In this model of MHE, the presence of DNA fragmentation is documented by 2.3-times increased number of TUNEL-positive cells. These findings together with a higher ratio of the Bcl-2 family members Bax/Bcl-xL in the outer mitochondrial membrane of the MHE animals together with 11% of cytochrome c release indicate the presence of apoptosis in this experimental model. A detailed analysis of the hippocampal mitochondrial physiology was performed after mitochondrial isolation. The determination of the respiratory rate in the presence of malate plus glutamate and ADP showed a 45% decrease in respiratory control in MHE animals as compared with the sham group. A marked decrease of cytochrome oxidase (complex IV of the electron transport chain) was also observed, showing 46% less activity in hippocampal mitochondria from MHE animals. In addition, mitochondria from these animals showed less ability to maintain membrane potential (ΔΨ (m)) which was 13% lower than the sham group. Light scattering experiments showed that mitochondria from MHE animals were more sensitive to swell in the presence of increased calcium concentrations as compared with the sham group. In addition, in vitro studies performed in mitochondria from sham animals showed that mitochondrial permeability transition (MPT) could be a mitochondrial mediator of the apoptotic signaling in the presence of NH(4) (+) and calcium.

Desinfección ecológica de aguas para envasar

Se refiere a los tratamientos o métodos usados para conservar el agua envasada durante el mayor tiempo posible. Describe, en orden cronológico los tratamientos que perduran actualmente: plata, cloro, ozono. Considera en cada caso su efectividad y la influencia de cada uno en el agua luego del envasado. Concluye que el ozono es la alternativa más efectiva para la desinfección del agua, en la medida en que no altera su composición físico-química (a excepción del hierro y manganeso que deben ser eliminados si estuvieran presentes), ni agrega al agua sustancias extrañas ni nocivas para la salud humana. Recomienda el ozono para la desinfección de envases, lo que permite eliminar el cloro que presenta dificultades en el control de su dosificación, riesgos de manipulación y posibilidades cancerígenas y mutagénicas

Desinfección ecológica de aguas para envasar

Se refiere a los tratamientos o métodos usados para conservar el agua envasada durante el mayor tiempo posible. Describe, en orden cronológico los tratamientos que perduran actualmente: plata, cloro, ozono. Considera en cada caso su efectividad y la influencia de cada uno en el agua luego del envasado. Concluye que el ozono es la alternativa más efectiva para la desinfección del agua, en la medida en que no altera su composición físico-química (a excepción del hierro y manganeso que deben ser eliminados si estuvieran presentes), ni agrega al agua sustancias extrañas ni nocivas para la salud humana. Recomienda el ozono para la desinfección de envases, lo que permite eliminar el cloro que presenta dificultades en el control de su dosificación, riesgos de manipulación y posibilidades cancerígenas y mutagénicas