Activated polymorphonuclear leukocytes generate a cascade of reduced oxygen metabolites. In addition to their antimicrobial role, hydrogen peroxide (H 2 O 2) and hypochlorous acid (HOCl) function as inflammatory mediators and increase the protein permeability of the vascular endothelium. The objectives of the present study were to compare the effects of H 2 O 2 and HOCl with respect to relative potencies and the time course and magnitude of changes in cell shape and permeability of endothelial cell monolayers derived from bovine pulmonary artery, to determine if HOCl produced by conversion of H 2 O 2 with myeloperoxidase and Cl Ϫ produces comparable results as the direct administration of HOCl, and to show that adenosine 3 Ј ,5 Ј-cyclic monophosphate (cAMP)-enhancing agents can prevent the increased endothelial permeability induced by HOCl and H 2 O 2. HOCl given directly or produced by myeloperoxidase, H 2 O 2 , and Cl Ϫ caused faster and greater changes in cell shape (cell retraction), electrical resistance, and protein permeability (125 I-labeled albumin clearance) of endothelial cell monolayers than induced by H 2 O 2. HOCl (10 to 100 M) induced these changes within 1 to 3 min, whereas H 2 O 2 (50 to 400 M) required ‫ف‬ 30 min. 8-Bromo-cAMP prevented the increased endothelial protein permeability induced by HOCl or H 2 O 2 , but isoproterenol only prevented the H 2 O 2 response. Thus, HOCl at a much lower concentration caused a faster and greater increase in endothelial permeability in vitro than H 2 O 2 , and an increased intracellular level of cAMP prevented the increased permeability induced by either oxidant. Ochoa L, Waypa G, Mahoney JR, Jr., Rodriguez L, Minnear FL. Contrasting effects of hypochlorous acid and hydrogen peroxide on endothelial permeability: prevention with cAMP drugs.

The aim of the study was to analyze the impact of melatonin on brain oxidative stress in experimental biliary obstruction. Cholestasis was done by a double ligature and section of the extrahepatic biliary duct. Melatonin was injected intraperitoneally (500 microg/kg/day). Malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) contents were determined in the brain tissue. Biliary obstruction raised MDA and reduced GSH contents in the cortex, cerebellum, and hypothalamus areas. Moreover, the scavenger enzyme activity significantly dropped in all areas of the brain. Melatonin drastically reduced MDA concentration and enhanced GSH concentration, as well as all antioxidant enzyme activity in all brain areas obtained from the bile duct-ligated animals. In conclusion, the treatment with melatonin decreased lipid peroxidation and recovered the antioxidant status in the brain from cholestatic animals.

Water is a fundamental nutrient in the life of any living being. Therefore, it is necessary to estimate its quality, because it is an issue of increasing concern countries around the world for reasons such as the health of the population, regional, national and international economic development, and the environmental quality of the ecosystems. One tool that has been used to know the state of the water is the water quality indexes (WQI). The objective of this research was to develop a WQI based on fuzzy logic, which allows for the estimation of water quality in the Utcubamba River. The methodology used was proposed by Icaga in 2007. To evaluate the proposed WQI called "Diffuse Water Quality Index" (DWQI), sixteen points from the sampling conducted by the Research Institute for Sustainable Development during October 2014 on the Utcubamba River and its tributaries were used. To validate the index, it was necessary to estimate the correlation coefficient R2 between the results obtained and those of the NSF WQI wáter quality index reported by the Water Research Center. This new index presented results and reasonable correlation, R2 = 0.81. It is concluded that DWQI can be used as a tool for decision making in the water management of the Utcubamba River.

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