Melatonin improves behavioral parameters and oxidative stress in zebrafish submitted to a leucine-induced MSUD protocol.

Maple syrup urine disease (MSUD) is an inherited metabolic disorder caused by a deficiency in branched-chain alpha-ketoacid dehydrogenase complex (BCKAC). The treatment is a standard therapy based on a protein-restricted diet with low branched-chain amino acids (BCAA) content to reduce plasma levels and, consequently, the effects of accumulating their metabolites, mainly in the central nervous system. Although the benefits of dietary therapy for MSUD are undeniable, natural protein restriction may increase the risk of nutritional deficiencies, resulting in a low total antioxidant status that can predispose and contribute to oxidative stress. As MSUD is related to redox and energy imbalance, melatonin can be an important adjuvant treatment. Melatonin directly scavenges the hydroxy radical, peroxyl radical, nitrite anion, and singlet oxygen and indirectly induces antioxidant enzyme production. Therefore, this study assesses the role of melatonin treatment on oxidative stress in brain tissue and behavior parameters of zebrafish (Danio rerio) exposed to two concentrations of leucine-induced MSUD: leucine 2 mM and 5mM; and treated with 100 nM of melatonin. Oxidative stress was assessed through oxidative damage (TBARS, DCF, and sulfhydryl content) and antioxidant enzyme activity (SOD and CAT). Melatonin treatment improved redox imbalance with reduced TBARS levels, increased SOD activity, and normalized CAT activity to baseline. Behavior was analyzed with novel object recognition test. Animals exposed to leucine improved object recognition due to melatonin treatment. With the above, we can suggest that melatonin supplementation can protect neurologic oxidative stress, protecting leucine-induced behavior alterations such as memory impairment.

Exposure to leucine induces oxidative stress in the brain of zebrafish.

Maple Syrup Urine Disease (MSUD) is an autosomal recessive inherited disorder caused by a deficiency in the activity of the branched-chain alpha-ketoacid dehydrogenase complex leading to the accumulation of branched-chain amino acids (BCAA) leucine, isoleucine, and valine and their respective branched-chain α-ketoacids and corresponding hydroxy acids. Considering that Danio rerio, known as zebrafish, has been widely used as an experimental model in several research areas because it has favorable characteristics that complement other experimental models, this study aimed to evaluate oxidative stress parameters in zebrafish exposed to high levels of leucine (2 mM and 5 mM), in a model similar of MSUD. Twenty-four hours after exposure, the animals were euthanized, and the brain content dissected for analysis of oxidative stress parameters: thiobarbituric acid reactive substances (TBARS), 2',7'-dichlorofluorescein oxidation assay (DCF); content of sulfhydryl, and superoxide dismutase (SOD) and catalase (CAT) activities. Animals exposed to 2 mM and 5 mM leucine showed an increase in the measurement of TBARS and decreased sulfhydryl content. There were no significant changes in DCF oxidation. In addition, animals exposed to 2 mM and 5 mM leucine were found to have decreased SOD activity and increased CAT activity. Based on these results, exposure of zebrafish to high doses of leucine can act as a promising animal model for MSUD, providing a better understanding of the toxicity profile of leucine exposure and its use in future investigations and strategies related to the pathophysiology of MSUD.

Reabilita‡Æo est‚tica de diastema m£ltiplo anterior com resina composta – controle cl¡nico de sete meses / Aesthetic rehabilitation of multiple anterior diastemas using composite resin – seven months recall

A busca por padrães est‚ticos ideais contribuiu para o advento de procedimentos restauradores que possibilitam a mimetiza‡Æo do natural e a introdu‡Æo do conceito de harmonia do sorriso atendendo …s exigˆncias dos pacientes. A presen‡a de diastemas anteriores m£ltiplos constitui um desafio … Odontologia, tendo em vista o aspecto negativo que agrega a despropor‡Æo do sorriso e a est‚tica facial. Sendo assim, o presente caso objetiva descrever a t‚cnica operat¢ria do fechamento de diastemas em resina composta atrav‚s de embasamento te¢rico cient¡fico para a resolu‡Æo do caso. O caso descrito relata a reabilita‡Æo est‚tica de diastemas anteriores por meio de procedimentos restauradores diretos em resina composta promovendo a preserva‡Æo da estrutura dent ria, mimetiza‡Æo do natural, restabelecimento das corretas propor‡ães dentais e redu‡Æo do tempo cl¡nico necess rio, alcan‡ando resultados est‚ticos de excelˆncia. A realiza‡Æo de uma t‚cnica padronizada e bem fundamentada em resina composta para o fechamento de diastemas proporciona resultados cl¡nicos est‚ticos satisfat¢rios e previs¡veis.

The indreasing serach for aesthetic standards has collaborated for the advent of restorative procedures that allow a natural apearence and has lauched concept of harmonic smile, meeting patients’ expectations. Considered as a negative aspect of smile and facial aesthetics the presence of multiple anterior diastemas is very chalenging. This case report aims to describe the technique of the diastema closure with composite resin considering the scientific literature for the resolution of the case. In this study the is described the aesthetic rehabilitation of anterior distaemas through of direct restorative procedures with composite resin and preservation of tooth structure, mimicking natural teeth, reestablishment of dental proportions and reduced clinical time, achieving excellent aesthetic results. The implementation of a standardized and wellgrounded technique using composite for diastema closure provides clinical and aesthetic satisfactory and predictable results.

O significado da participação em visitas domiciliares pelo acadêmico de odontologia / The meaning of participation in visit home by academic dentistry

Este estudo teve por finalidade analisar a percepção do estudante de odontologia quanto à necessidade da inclusão das visitas domiciliares realizadas na estratégia de promoção da saúde da família durante o curso de graduação. Para a coleta das informações, foram utilizados questionários fechados aplicados aos alunos da disciplina de Estágio Supervisionado I (AU).

The aim of this study was to evaluate the student's perception of dentistry, as the need for inclusion in home visits conducted in the strategy of family health. For the collection of information were used closed questionnaires applied to students of the discipline of supervised probation I (AU).