Diazoxide protects against methylmalonate-induced neuronal toxicity

Methylmalonic acidemia is an inherited metabolic disorder that leads to brain damage associated to the accumulation of methylmalonic acid (MMA) and impairment of energy metabolism. We demonstrate here that treatment with diazoxide, an agonist of mitochondrial ATP-sensitive K+ channels (mitoK(ATP)), can prevent death promoted by treatment with MMA in PC12 cells and freshly prepared rat brain slices. This diazoxide effect was reversed by 5-hydroxydecanoate, a mitoK(ATP) antagonist, confirming it occurs due to the activity of this channel. Diazoxide was not capable of preventing inner membrane potential loss promoted by MMA and Ca2+ in isolated mitochondria, indicating it does not directly prevent mitochondrial damage. Furthermore, diazoxide did not prevent respiratory inhibition in cells treated with MMA. Interestingly, we found that the mitochondrial inner membrane potential within intact cells treated with MMA was maintained in part by the reverse activity of ATP synthase (ATP hydrolysis) and that diazoxide prevented the formation of the membrane potential in the presence of MMA, in a manner sensitive to 5-hydroxydecanoate. Furthermore, the effects of diazoxide on cell survival after treatment with MMA were similar to those of ATP synthase inhibitor oligomycin and adenine nucleotide translocator inhibitor atractyloside. These results indicate that diazoxide prevents PC12 cell death promoted by MMA by decreasing mitochondrial ATP hydrolysis. These results uncover new potential neuroprotective effects of mitoK(ATP) agonists under situations in which oxidative phosphorylation is inhibited. (c) 2006 Elsevier Inc. All rights reserved.201116517

Comparative assessment of the organization of the colors of the Vita Classical color pallet by digital images and visual analysis for dental bleaching

New formularizations, techniques and devices have become the dental whitening most safe and with better results. Although this, the verification of the levels whitening is being continued for visual comparison, that is an empirical, subjective method, subject to errors and dependent of the individual interpretation. Normally the result of the whitening is express for the amplitude of displacement between the initial and the final color, being take like reference the tonalities of a scale of color commanded of darkest for more clearly. Although to be the most used scale, the ordinance of the Vita Classical (R) - Vita, according to recommendations of the manufacturer, reveals inadequate for the evaluation of the whitening. From digital images and of algorithm OER (ordinance of the reference scale), especially developed for the ScanWhite (C), the ordinance of the tonalities of the scale Vita Classical (R) was made. For such, the values of the canals of color R, G, and B of medium part average of the crowns was adopted as reference for evaluation. The images had been taken with the camera Sony Cybershoot DSC F828. The results of the computational ordinance had been compared with the sequence proposal for the manufacturer and with the earned one for the visual evaluation, carried through by 10 volunteers, under standardized conditions of illumination. It statistics analyzes demonstrated significant differences between the ordinances

Temperament, behaviour and physiology of sheep trained with tactile stimulation and halter walking

This study aimed to evaluate the influence of tactile stimulation and halter walking trainings in the temperament, physiology, behavior and body weight of sheep. A total of 80 sheep, males and females, of the Morada Nova (MN) and Santa Ines (SI) breeds, with initial ages of six to eight months, were trained with tactile stimulation (TS), halter walking (HW) or tactile stimulation and halter walking (TS+HW). The control (C) animals were not submitted to any kind of training. The behavioral aspects were measured by application of a open-field test, to quantify the traits movement, vocalization, escape attempt and digging, and the temperament test, with assignment of a temperament score for each animal. The animals were weighed and rectal temperature, heart rate and respiratory rate were measured. Males were more reactive than females to human. Animals trained with TS were the least reactive in the temperament test, while the most reactive animals were SI male from C and TS+HW treatments. Males of treatments C and HW were the heaviest during the study. The animals in the control group showed higher averages for heart rate and rectal temperature, while animals trained with TS and HW showed the lowest values. Females MN trained with TS and TS+HW moved more during the open-field test, while the SI females of the control group moved less. The SI animals vocalized more during the open-field test, both from treatment C and from TS+HW. The MN animals from C treatment vocalized less. Sheep trained with tactile stimulation were more docile. The training with tactile stimulation and halter walking in Santa Ines and Morada Nova sheep influenced the heart rate, rectal temperature, moviment, vocalization, escape attempt and body weight

Comparison of infection by Brucella spp. in free-ranging and captive wild animals from São Paulo State, Brazil

The aim of the current study was to evaluate the infection rate by Brucella spp. in wild and in captive animals. Serum samples from 121 animals (94 free-ranging and 27 captive) of different mammal species were evaluated. Sera were submitted to rose Bengal test (RBT) for screening and serum agglutination tests (SAT) and 2-mercaptoethanol test (2-ME) for confirmatory results. Nine animals (five free-ranging and four captive) tested positive in RBT, but negative in the confirmatory tests. Several domestic animal diseases that have control programs are not focused on wild reservoirs, such as brucellosis in Brazil. The study of new reservoirs in wildlife is essential to prevent emerging diseases