Differential Effects of Buffer pH On Ca\u3csup\u3e2+\u3c/sup\u3e-Induced ROS Emission with Inhibited Mitochondrial Complexes I and III

Excessive mitochondrial reactive oxygen species (ROS) emission is a critical component in the etiology of ischemic injury. Complex I and complex III of the electron transport chain are considered the primary sources of ROS emission during cardiac ischemia and reperfusion (IR) injury. Several factors modulate ischemic ROS emission, such as an increase in extra-matrix Ca2+, a decrease in extra-matrix pH, and a change in substrate utilization. Here we examined the combined effects of these factors on ROS emission from respiratory complexes I and III under conditions of simulated IR injury. Guinea pig heart mitochondria were suspended in experimental buffer at a given pH and incubated with or without CaCl2. Mitochondria were then treated with either pyruvate, a complex I substrate, followed by rotenone, a complex I inhibitor, or succinate, a complex II substrate, followed by antimycin A, a complex III inhibitor. H2O2 release rate and matrix volume were compared with and without adding CaCl2 and at pH 7.15, 6.9, or 6.5 with pyruvate + rotenone or succinate + antimycin A to simulate conditions that may occur during in vivo cardiac IR injury. We found a large increase in H2O2 release with high [CaCl2] and pyruvate + rotenone at pH 6.9, but not at pHs 7.15 or 6.5. Large increases in H2O2 release rate also occurred at each pH with high [CaCl2] and succinate + antimycin A, with the highest levels observed at pH 7.15. The increases in H2O2 release were associated with significant mitochondrial swelling, and both H2O2 release and swelling were abolished by cyclosporine A, a desensitizer of the mitochondrial permeability transition pore (mPTP). These results indicate that ROS production by complex I and by complex III is differently affected by buffer pH and Ca2+ loading with mPTP opening. The study suggests that changes in the levels of cytosolic Ca2+ and pH during IR alter the relative amounts of ROS produced at mitochondrial respiratory complex I and complex III

Briófitos de Cáceres, Pantanal de Matogrosso, Brasil, con nuevos registros para el estado y el país

The Pantanal Ecosystem is still poorly known in its bryoflora, with almost no literature and very few collections. This paper represents a contribution to better understand the bryophyte diversity in the brazilian Pantanal. With a population around 85,857 and 27,462.38 Km2 and located at 16º11’42" S and 57º40’51" W, the Cáceres county is totally inserted in the Pantanal ecosystem. Its bryoflora has never been studied before. Here are presented 5 liverworts and 21 mosses, of which Barbula indica (Hook.) Spreng., Calymperes palisoti Schwägr., Fabronia ciliaris var polycarpa (Hook) W.R.Buck, Taxiphyllum taxirameum (Mitt.) M. Fleisch. are cited for the first time for Mato Grosso. Fissidens dissitifolius Sull. is cited for the first time to Brazil and Tortella lilliputana (Müll. Hal. ex G. Roth) R.H. Zander, is cited for the second time to Brazil. The data suggest how poorly known the area still remains and more studies are in need for the Pantanal and Mato Grosso state.O ecossistema Pantanal ainda permanece pouco conhecido do ponto de vista briológico, com poucas coleções e quase nenhuma literatura. Neste contexto, este trabalho apresenta uma inédita contribuição para o conhecimento da diversidade briológica Pantaneira. Com uma população de 85.857 habitantes em 27.462,38 quilômetros quadrados, entre as coordenadas 16º11’42" S e 57º40’51" W, o municípo de Cáceres, está totalmente inserido no ecossistema Pantanal. Sua brioflora nunca foi estudada anteriormente. Neste trabalho apresentamos a ocorrência de 5 hepáticas e 21 musgos, entre os quais: Barbula indica (Hook.) Spreng., Calymperes palisoti Schwägr., Fabronia ciliaris var polycarpa (Hook) W.R.Buck, Taxiphyllum taxirameum (Mitt.) M. Fleisch. e Tortella lilliputana (Müll. Hal. ex G. Roth) R.H. Zander, são citadas pela primeira vez para o estado do Mato Grosso. Fissidens dissitifolius Sull. está sendo citado pela primeira vez para o Brasil e Tortella lilliputana (Müll. Hal. ex G. Roth) R.H. Zander é citada pela segunda vez. Os dados sugerem o quão pouco conhecida é a brioflora do ecossistema Pantanal e do Estado do Mato Grosso, sendo necessárias mais coletas e estudos na região

Attitudes of dental implantologists in Spain to prescribing antibiotics, analgesics and anti-inflammatories in healthy patients

The implantologists frequently prescribe antibiotics, analgesics and anti-inflammatories in dental implant surgery. The aims of this study were to evaluate the attitudes of implantologists in Murcia (Spain) to prescribing antibiotics, analgesics and anti-inflammatories in healthy patients during different implant dentistry procedures, and to see how these are influenced by individual dentist?s academic level, professional experience, and ongoing training (attending courses or reading scientific literature on medication use) This cross-sectional study included a total of 200 implantologists from the Murcia area (Spain), who each completed a two-page questionnaire consisting of 26 questions. The implant procedure in which most dentists (n=97) prescribed antibiotics was multiple implant surgery with flap raising, in which 55.6% of these 97 respondents used a prophylactic antibiotic regime for 7 days after implant placement. All subjects (n=200) prescribed analgesics for eight out of the eleven procedures included in the survey and anti-inflammatories in six. Dentists with higher academic levels or longer professional experience prescribed more antibiotics, but those who underwent continuous training (attending courses or reading scientific literature) reduced antibiotic prescription. Dentists often prescribed antibiotics, analgesics and anti-inflammatories in almost all implant procedures in healthy patients, but ongoing training reduced the frequency of antibiotic prescription in some procedures