The role of mitochondrial DNA damage in the citotoxicity of reactive oxygen species

Mitochondria contain their own genome, a small circular molecule of around 16.5 kbases. The mitochondrial DNA (mtDNA) encodes for only 13 polypeptides, but its integrity is essential for mitochondrial function, as all 13 proteins are regulatory subunits of the oxidative phosphorylation complexes. Nonetheless, the mtDNA is physically associated with the inner mitochondrial membrane, where the majority of the cellular reactive oxygen species are generated. In fact, the mitochondrial DNA accumulates high levels of oxidized lesions, which have been associated with several pathological and degenerative processes. The cellular responses to nuclear DNA damage have been extensively studied, but so far little is known about the functional outcome and cellular responses to mtDNA damage. In this review we will discuss the mechanisms that lead to damage accumulation and the in vitro models we are establishing to dissect the cellular responses to oxidative damage in the mtDNA and to sort out the differential cellular consequences of accumulation of damage in each cellular genome, the nuclear and the mitochondrial genome.

Organotellurides as precursors of reactive organometallics

Reaction of organotellurides with easily available organometallics leads to a fast and clean tellurium/metal exchange reaction, allowing the preparation of a range of functionalized organometallics with C-sp(3), C-sp(2), and C-sp hybridization carbanionic centers. Some synthetic applications of the tellurium/metal exchange reactions are discussed.

Effects of a high fat diet on liver mitochondria: increased ATP-sensitive K(+) channel activity and reactive oxygen species generation

High fat diets are extensively associated with health complications within the spectrum of the metabolic syndrome. Some of the most prevalent of these pathologies, often observed early in the development of high-fat dietary complications, are non-alcoholic fatty liver diseases. Mitochondrial bioenergetics and redox state changes are also widely associated with alterations within the metabolic syndrome. We investigated the mitochondrial effects of a high fat diet leading to non-alcoholic fatty liver disease in mice. We found that the diet does not substantially alter respiratory rates, ADP/O ratios or membrane potentials of isolated liver mitochondria. However, H(2)O(2) release using different substrates and ATP-sensitive K(+) transport activities are increased in mitochondria from animals on high fat diets. The increase in H(2)O(2) release rates was observed with different respiratory substrates and was not altered by modulators of mitochondrial ATP-sensitive K(+) channels, indicating it was not related to an observed increase in K(+) transport. Altogether, we demonstrate that mitochondria from animals with diet-induced steatosis do not present significant bioenergetic changes, but display altered ion transport and increased oxidant generation. This is the first evidence, to our knowledge, that ATP-sensitive K(+) transport in mitochondria can be modulated by diet.

Pt film electrodes prepared by the Pechini method for electrochemical decolourisation of Reactive Orange 16

Electrochemical decolourisation of Reactive Orange 16 was carried out in an electrochemical flow-cell, using as working electrodes a Pt thin film deposited on a Ti substrate (Pt/Ti) prepared by the Pechini method and a pure platinum (Pt) foil. Using the Pt/Ti electrodes better results for dye decolourisation were obtained under milder conditions than those used for pure Pt. For the Pt electrode, colour removal of 93 % (lambda = 493 nm) was obtained after 60 min, at 2.2 V vs. RHE, using 0.017 mol L(-1) NaCl + 0.5 mol L(-1) H(2)SO(4) solution. For the Pt/Ti electrode there was better colour removal, 98%, than for the Pt electrode. Moreover, we used 0.017 mol L(-1) NaCl solution and the applied potential was 1.8 V. Under this condition after 15 min of electrolysis, more than 80% of colour was removed. The rate reaction constant, assuming a first order reaction, was 0.024 min(-1) and 0.069 min(-1), for Pt and Pt/Ti electrodes, respectively.

Anodic oxidation of wastewater containing the Reactive Orange 16 Dye using heavily boron-doped diamond electrodes

Boron-doped diamond (BDD) films grown on the titanium substrate were used to study the electrochemical degradation of Reactive Orange (RO) 16 Dye. The films were produced by hot filament chemical vapor deposition (HFCVD) technique using two different boron concentrations. The growth parameters were controlled to obtain heavily doped diamond films. They were named as E1 and E2 electrodes, with acceptor concentrations of 4.0 and 8.0 x 10(21) atoms cm(-3), respectively. The boron levels were evaluated from Mott-Schottky plots also corroborated by Raman`s spectra, which characterized the film quality as well as its physical property. Scanning Electron Microscopy showed well-defined microcrystalline grain morphologies with crystal orientation mixtures of (1 1 1) and (1 00). The electrode efficiencies were studied from the advanced oxidation process (AOP) to degrade electrochemically the Reactive Orange 16 azo-dye (RO16). The results were analyzed by UV/VIS spectroscopy, total organic carbon (TOC) and high-performance liquid chromatography (HPLC) techniques. From UV/VIS spectra the highest doped electrode (E2) showed the best efficiency for both, the aromaticity reduction and the azo group fracture. These tendencies were confirmed by the TOC and chromatographic measurements. Besides, the results showed a direct relationship among the BDD morphology, physical property, and its performance during the degradation process. (C) 2011 Elsevier B.V. All rights reserved.

Heterogeneous photocatalytic degradation of reactive dyes in aqueous TiO(2) suspensions: Decolorization kinetics

This work assesses the photocatalytic (TiO(2)/UV) degradation of a simulated reactive dye bath (Black 5, Red 239, Yellow 17, and auxiliary chemicals). Color removal was monitored by spectrophotometry. Mineralization was determined by DOC analyses. Photocatalytic, photolytic, and adsorption experiments were performed, showing that adsorption was negligible. After 30 min of irradiation, it was achieved 97% and 40% of color removal with photocatalysis and photolysis, respectively. No mineralization occurred within 30 min. A kinetic model composed of two, first-order in-series reactions was used. The first photocatalytic decolorization rate constant was k(1) = 2.6 min(-1) and the second k(2) = 0.011 min(-1). The fast decolorization of Reactive Black 5 dye is an indication that the number of azo and vinylsulfone groups in the dye molecule maybe a determining factor for the increased photolytic and photocatalytic color removal and degradation rates. (C) 2008 Elsevier B.V. All rights reserved.

Modelo experimental de lesões intra-epiteliais e de adenocarcinoma ductal pancreático induzidos por 7,12-dimetilbenzantraceno em camundongos

INTRODUÇÃO: O adenocarcinoma de pâncreas apresenta um mau prognóstico. A utilização de modelos experimentais é necessária para a compreensão do comportamento biológico tumoral, principalmente das lesões precoces (neoplasias intra-epiteliais pancreáticas - NIPan) e para o desenvolvimento de opções terapêuticas. OBJETIVO: Avaliar a carcinogênese pancreática induzida por 7,12-dimetilbenzantraceno (DMBA), em camundongos, aplicando a classificação das neoplasias intra-epiteliais pancreáticas. MÉTODOS: 90 camundongos machos, mus musculus, da cepa CF1, foram submetidos à laparotomia mediana e 1 mg de DMBA foi implantado na porção cefálica do pâncreas. Os animais foram divididos em dois grupos, com eutanásia em 30 e 60 dias. Em seguida, o pâncreas foi retirado, fixado em formalina e foram confeccionadas lâminas coradas com hematoxilina eosina. Os cortes histológicos foram avaliados por dois patologistas de acordo com os seguintes critérios: pâncreas normal, hiperplasia reacional, NIPan 1A, NIPan 1B, NIPan 2, NIPan 3 e carcinoma. As alterações inflamatórias também foram analisadas. RESULTADOS: A avaliação patológica evidenciou, no grupo de 30 dias: 4 (16,7%) animais com hiperplasia reativa, 16 (66,6%) com NIPan e 4 (16,7%) com adenocarcinoma. No grupo de 60 dias: 10 (27,1%) animais com hiperplasia reativa, 13 (35,1%) com NIPan e 14 (37,8%) com adenocarcinoma. A diferença entre os grupos apresentou significância estatistística (P < 0,05 – teste exato de Fisher). A prevalência de alterações inflamatórias em 30 dias foi: pancreatite aguda (n=11), pancreatite crônica (n=5) e inflamação dependente da bolsa (n=8). No grupo de 60 dias 11 espécimes apresentavam pancreatite aguda e 26 pancreatite crônica. CONCLUSÕES: O modelo experimental com DMBA em camundongos, induz neoplasia intra-epitelial pancreática e adenocarcinoma ductal histologicamente semelhantes ao carcinoma pancreático em humanos. Este modelo pode ser utilizado na investigação da carcinogênese com enfoque na progressão molecular das lesões precursoras até o adenocarcinoma.

Avaliação histológica da próstata de cães adultos sexualmente intactos

Avaliou-se histologicamente a próstata de 30 cães adultos e idosos sexualmente intactos que apresentavam ou não sintomatologia clínica de doença prostática, e verificou-se a incidência de possíveis alterações da glândula. Dentre as alterações encontradas, a hiperplasia prostática benigna constituiu o diagnóstico mais comum, 85,6% (n=24), seguida por prostatite crônica, 64,3% (n=18), displasia do epitélio glandular, 42,8% (n=12), atrofia do epitélio glandular, 39,3% (n=11), infiltrado inflamatório focal, 25% (n=7), dilatação glandular focal, 21,4% (n=6), prostatite aguda, 7,1% (n=2), metaplasia escamosa, 3,6%, (n=1), metástase de neoplasia sistêmica, 3,6% (n=1) e abscesso prostático, 3,6% (n=1). Como em muitos casos os cães são assintomáticos, ressalta-se a importância da realização rotineira de exames clínicos específicos, como o toque retal e a ultrassonografia, para o diagnóstico precoce e o tratamento das afecções prostáticas.

Punção aspirativa com agulha fina guiada por ultrassom e biópsia por videolaparoscopia em próstata de cães

Onze cães, sem raça definida, machos, adultos, não castrados e hígidos foram submetidos à punção aspirativa com agulha fina da próstata guiada por ultrassom para avaliação citológica e, após um período mínimo de sete dias, à videolaparoscopia para obtenção de fragmento prostático para avaliação histológica. Nos exames citológicos, dois animais apresentaram alterações celulares compatíveis com hiperplasia prostática benigna. Durante a videolaparoscopia, a colheita do fragmento prostático foi realizada de maneira rápida, não sendo observada hemorragia significativa após o procedimento. Os animais não apresentaram nenhuma complicação no período pós-operatório. Verificaram-se, ao exame histológico, morfologia e estrutura celulares e teciduais nos padrões normais do parênquima prostático em 10 animais; um único cão apresentou alterações celulares e teciduais sugestivas de hiperplasia prostática benigna.

Detection of Leptospira spp. in the semen and urine of bulls serologically reactive to Leptospira interrogans serovar hardjo

O presente trabalho avaliou a PCR na detecção de leptospiras em sêmen e urina de dez touros sorologicamente reagentes, comparando seus resultados com aqueles obtidos por outras técnicas de diagnóstico. Foram realizadas duas colheitas de materiais em dias alternados. As amostras de sêmen e de urina foram separadas em alíquotas para visualização direta em microscopia de campo escuro, inoculação em hamsters (apenas para o sêmen), isolamento em meio de cultura e PCR. Nenhum hamster apresentou positividade na prova de soroaglutinação microscópica (SAM); fragmentos de rins e fígado desses animais foram utilizados para a tentativa de isolamento em meio de cultura, sendo positivo o cultivo a partir do rim de hamster inoculado com semen de um touro, e do fígado de hamsters inoculados com o semen de três touros. O isolamento em meio de cultura foi negativo para todas as amostras de sêmen, mas foi positivo para cinco amostras de urina. Na PCR não houve resultado positivo para as amostras de sêmen, e apenas uma amostra de urina apresentou resultado positivo, sendo coincidente com uma das culturas positivas. Não foi possível visualizar leptospiras em nenhuma das amostras por exame direto em microscopia de campo escuro.

Immune response pattern of the popliteal lymph nodes of dogs with visceral leishmaniasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diagnósticos de enfermagem em pacientes no pós-operatório imediato de prostatectomia de um Hospital Universitário de Natal-RN

The characterization of the nursing diagnoses in prostatectomized patients is important to provide an unique nursing language, facilitating the communication between professionals and patients. The objective of this study was to analyze the nursing diagnoses of patients in the immediate prostatectomy postoperative period. This is a cross-sectional and descriptive study, developed at the surgical-clinic of Onofre Lopes University Hospital, in the Natal City RN - Brazil. The sample was composed of 50 patients included by the criteria: have presented a diagnosis of a benign prostatic hyperplasia or a prostate cancer, have been subjected to a prostate surgery at the mentioned hospital, and have been in the immediate postoperative period at the moment of the data collection. The exclusion criteria were: haven t been in an appropriate physical and mental condition, have presented a brain vascular disease, a lung disease, an advanced liver disease, a heart disease or a extensive coronary artery disease. The data collection instruments were: the script of an interview and physical examination. The data collection period was between November 2010 and April 2011. The data were organized in two phases: the diagnostic process and the construction of the database. The project was approved by the Ethics Committee of the Federal University of Rio Grande do Norte The results showed that most patients came from the countryside, was living with partners, had an average of 67.78 years, was pensionerthose with low schooling, Catholic and often did not perform preventive examinations of prostatic disease. The patients showed an average of 9.48 nursing diagnoses, defining characteristics 21.70 and 20.72 related or risk factors per patient. We identified 30 nursing diagnoses, of which 7 were above the 75 percentile: Risk of falls, Impaired ambulation, Risk of infection, Self-care deficit bath / hygiene and dress up and Risk for deficient fluid volume. The top six nursing diagnoses were in all patients, and therefore could not apply any statistical test. The others ND were associated with their defining characteristics and related or risk factors. We conclude that the nursing diagnoses identified in this study contribute to the progress of the nursing care to the prostatectomized patients in post-surgery period, allowing the deployment of nursing actions for the effective resolution of identified problems