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.

Zebrafish as a potential model for stroke: A comparative study with standardized models.

Animal models of cerebral ischemia have improved our understanding of the pathophysiology and mechanisms involved in stroke, as well as the investigation of potential therapies. The potential of zebrafish to model human diseases has become increasingly evident. The availability of these models allows for an increased understanding of the role of chemical exposure in human conditions and provides essential tools for mechanistic studies of disease. To evaluate the potential neuroprotective properties of minocycline against ischemia and reperfusion injury in zebrafish and compare them with other standardized models. In vitro studies with BV-2 cells were performed, and mammalian transient middle cerebral artery occlusion (tMCAO) was used as a comparative standard with the zebrafish stroke model. Animals were subjected to ischemia and reperfusion injury protocols and treated with minocycline. Infarction size, cytokine levels, oxidative stress, glutamate toxicity, and immunofluorescence for microglial activation, and behavioral test results were determined and compared. Administration of minocycline provided significant protection in the three stroke models in different parameters analyzed. Both experimental models complement each other in their particularities. The proposal also strengthens the findings in the literature in rodent models and allows the validation of alternative models so that they can be used in further research involving diseases with ischemia and reperfusion injury.

Gallic acid modulates purine metabolism and oxidative stress induced by ethanol exposure in zebrafish brain.

Gallic acid (GA) is a secondary metabolite found in plants. It has the ability to cross the blood-brain barrier and, through scavenging properties, has a protective effect in a brain insult model. Alcohol metabolism generates reactive oxygen species (ROS); thus, alcohol abuse has a deleterious effect on the brain. The zebrafish is a vertebrate often used for screening toxic substances and in acute ethanol exposure models. The aim of this study was to evaluate whether GA pretreatment (24 h) prevents the changes induced by acute ethanol exposure (1 h) in the purinergic signaling pathway in the zebrafish brain via degradation of extracellular nucleotides and oxidative stress. The nucleotide cascade promoted by the nucleoside triphosphate diphosphohydrolase (NTPDase) and 5'-nucleotidase was assessed by quantifying nucleotide metabolism. The effect of GA alone at 5 and 10 mg L-1 did not change the nucleotide levels. Pretreatment with 10 mg L-1 GA prevented an ethanol-induced increase in ATP and ADP levels. No significant difference was found between the AMP levels of the two pretreatment groups. Pretreatment with 10 mg L-1 GA prevented ethanol-enhanced lipid peroxidation and dichlorodihydrofluorescein (DCFH) levels. The higher GA concentration was also shown to positively modulate against ethanol-induced effects on superoxide dismutase (SOD), but not on catalase (CAT). This study demonstrated that GA prevents the inhibitory effect of ethanol on NTPDase activity and oxidative stress parameters, thus consequently modulating nucleotide levels that may contribute to the possible protective effects induced by alcohol and purinergic signaling.

Prolonged fluoride exposure alters neurotransmission and oxidative stress in the zebrafish brain.

Fluoride is an essential chemical found in dental preparations, pesticides and drinking water. Excessive fluoride exposure is related to toxicological and neurological disruption. Zebrafish are used in translational approaches to understand neurotoxicity in both biomedical and environmental areas. However, there is no complete knowledge about the cumulative effects of fluoride on neurotransmission systems. Therefore, the aim of this study was to evaluate whether prolonged exposure to sodium fluoride (NaF) alters cholinergic and glutamatergic systems and oxidative stress homeostasis in the zebrafish brain. Adult zebrafish were used, divided into four experimental groups, one control group and three groups exposed to NaF at 30, 50 and 100 mg.L-1 for a period of 30 days. After NaF at 30 mg.L-1 exposure, there were significant decreases in acetylcholinesterase (29.8 %) and glutamate uptake (39.3 %). Furthermore, thiobarbituric acid-reactive species were decreased at NaF 50 mg.L-1 (32.7 %), while the group treated with NaF at 30 mg.L-1 showed an increase in dichlorodihydrofluorescein oxidation (41.4 %). NaF at 30 mg.L-1 decreased both superoxide dismutase (55.3 %) and catalase activities (26.1 %). The inhibitory effect observed on cholinergic and glutamatergic signalling mechanisms could contribute to the neurodegenerative events promoted by NaF in the zebrafish brain.

Melatonin Pretreatment Protects Against Status epilepticus, Glutamate Transport, and Oxidative Stress Induced by Kainic Acid in Zebrafish.

Status epilepticus (SE) develops from abnormal electrical discharges, resulting in neuronal damage. Current treatments include antiepileptic drugs. However, the most common drugs used to treat seizures may sometimes be ineffective and have many side effects. Melatonin is an endogenous physiological hormone that is considered an alternative treatment for neurological disorders because of its free radical scavenging property. Thus, this study aimed to determine the effects of melatonin pretreatment on SE by inducing glutamatergic hyperstimulation in zebrafish. Seizures were induced in zebrafish using kainic acid (KA), a glutamate analog, and the seizure intensity was recorded for 60 min. Melatonin treatment for 7 days showed a decrease in seizure intensity (28%), latency to reach score 5 (14 min), and duration of SE (29%). In addition, melatonin treatment attenuated glutamate transporter levels, which significantly decreased in the zebrafish brain after 12 h of KA-induced seizures. Melatonin treatment reduced the increase in oxidative stress by reactive oxygen species formation through thiobarbituric acid reactive substances and 2',7'-dichiorofluorescin, induced by KA-seizure. An imbalance of antioxidant enzyme activities such as superoxide dismutase and catalase was influenced by melatonin and KA-induced seizures. Our study indicates that melatonin promotes a neuroprotective response against the epileptic profile in zebrafish. These effects could be related to the modulation of glutamatergic neurotransmission, recovery of glutamate uptake, and oxidative stress parameters in the zebrafish brain.

Association Between Epicardial Adipose Tissue and Stroke.

Epicardial adipose tissue (EAT) is correlated with endothelial dysfunction, metabolic syndrome, increased mortality and recent studies showed a possible association with the increased risk of stroke. We performed a systematic review of studies evaluating the association between EAT and stroke. Eighty studies met the inclusion criteria and were consequently analyzed. The review had Five main findings. First, the increased epicardial fat thickness (EFT) may be associated with the stroke episode. Second, regardless of the imaging method (echocardiography, MRI, and CT) this association remains. Third, the association of metabolic syndrome and atrial fibrillation seems to increase the risk of stroke. Fourth, this systematic review was considered as low risk of bias. Despite being unable to establish a clear association between EAT and stroke, we have organized and assessed all the research papers on this topic, analyzing their limitations, suggesting improvements in future pieces of research and pointing out gaps in the literature. Furthermore, the mechanistic links between increased EAT and stroke incidence remains unclear, thus, further research is warranted.

Evaluation of the dopaminergic system with positron-emission tomography in alcohol abuse: A systematic review.

OBJECTIVE: Performed a systematic review to evaluated the dopaminergic system in alcohol abuse in a systematic review in humans. METHOD: A search of the electronic databases was proceeded, on MEDLINE, EMBASE, Cochrane Library, Insight and Gray literature (Google Scholar and the British Library) for studies published until August 2018. A search strategy was developed using the terms: "dopamine" and "ethanol" or ""alcohol"," and "positron-emission tomography" as text words and Medical Subject Headings (i.e., MeSH and EMTREE) and searched. RESULTS: We found 293 studies. After reading titles and abstracts 235 were considered irrelevant, as they did not meet the inclusion criteria. For the reading of the full text, 50 studies were analyzed. Of these 41 were excluded with reasons by study design, patient population, intervention and outcomes. Nine studies were included in our qualitative synthesis. Four studies have resulted in a reduction in availability only at the D2 receptor in different brain regions. Concerning the D3 receptor alone only one study reported this finding and four studies reported a decrease in both receptors. CONCLUSION: Changes in D2 receptors in several brain regions in human alcoholics were found in a systematic review.

Accuracy of Anal Cytology for Diagnostic of Precursor Lesions of Anal Cancer: Systematic Review and Meta-analysis.

BACKGROUND: Anal canal carcinoma is relevant because it commonly occurs in high-risk groups, and its incidence has been increasing. OBJECTIVE: This study evaluated the accuracy of anal cytology in the screening of precursor lesions of anal cancer, compared with histopathologic examination as the reference, in all subjects and in men who have sex with men, HIV-infected men and women, and men who have sex with men and HIV-infected subgroups. DATA SOURCES: The data included studies identified in the MEDLINE, Latin American and Caribbean Health Sciences, Cochrane Library, and Embase electronic databases, as well as in the grey literature. The search terms included anal cancer, anal dysplasia, anal intraepithelial neoplasia, screening, and anal cytology. STUDY SELECTION: After excluding studies with no histopathological data and those with duplicate and missing data, 34 primary studies were included. INTERVENTION: Cytology of anal smears was studied. MAIN OUTCOME MEASURES: Sensitivity, specificity, diagnostic OR, and area under the curve were measured. RESULTS: A total of 5093 patients were included. The pooled sensitivity of anal cytology was 85.0% (95% CI, 82.0%-87.0%) and pooled specificity was 43.2% (95% CI, 41.4%-45.1%) for the detection of anal intraepithelial neoplasia grade 2 or worse versus anal intraepithelial neoplasia grade 1 and normal when measuring all subjects. The accuracy of anal cytology was higher in the men who have sex with men and HIV-infected and men who have sex with men only subgroups. LIMITATIONS: This study was limited by its specificity. CONCLUSIONS: The study results support the hypothesis that cytology is a good test for the screening of anal cancer.

Urinary EN-2 to predict prostate cancer: Systematic review and meta-analysis.

INTRODUCTION: Prostate cancer is the second type of cancer diagnosed and the fifth cause of death in men worldwide. Early diagnosis helps to control disease progression. Currently, prostate specific antigen is the standard biomarker, as it has a broad scope of identification and, thus, new and more specific biomarkers must be studied. OBJECTIVE: To evaluate the accuracy of engrailed-2 protein (EN2) in urine as a prostate cancer biomarker. METHOD: A comprehensive search was conducted in the period from January 2005 to July 2016 using the following electronic databases: Medline (PubMed), Embase, Cochrane Library and Lilacs. The keywords used in the databases were: "engrailed-2," "EN2," "prostatic neoplasms." The search was limited to humans and there was no language restriction. Critical appraisal of the included studies was performed according to Quadas-2. Statistical analysis was performed using Meta-DiSc® and RevMan 5.3 softwares. RESULTS: A total of 248 studies were identified. After title and abstract screening, 231 studies were removed. A total of 17 studies were read in full and two studies were included in the meta-analysis. The pooled sensitivity was 66% (95CI 0.56-0.75) and specificity was 89% (95CI 0.86-0.92). The DOR was 15.08 (95CI 8.43-26.97). CONCLUSION: The EN2 test showed high specificity (89%) and low sensitivity (66%).

Urinary EN-2 to predict prostate cancer: Systematic review and meta-analysis / Proteína EN2 urinária no diagnóstico do câncer de próstata: revisão sistemática e metanálise

Summary Introduction: Prostate cancer is the second type of cancer diagnosed and the fifth cause of death in men worldwide. Early diagnosis helps to control disease progression. Currently, prostate specific antigen is the standard biomarker, as it has a broad scope of identification and, thus, new and more specific biomarkers must be studied. Objective: To evaluate the accuracy of engrailed-2 protein (EN2) in urine as a prostate cancer biomarker. Method: A comprehensive search was conducted in the period from January 2005 to July 2016 using the following electronic databases: Medline (PubMed), Embase, Cochrane Library and Lilacs. The keywords used in the databases were: "engrailed-2," "EN2," "prostatic neoplasms." The search was limited to humans and there was no language restriction. Critical appraisal of the included studies was performed according to Quadas-2. Statistical analysis was performed using Meta-DiSc® and RevMan 5.3 softwares. Results: A total of 248 studies were identified. After title and abstract screening, 231 studies were removed. A total of 17 studies were read in full and two studies were included in the meta-analysis. The pooled sensitivity was 66% (95CI 0.56-0.75) and specificity was 89% (95CI 0.86-0.92). The DOR was 15.08 (95CI 8.43-26.97). Conclusion: The EN2 test showed high specificity (89%) and low sensitivity (66%).

Resumo Introdução: O câncer de próstata é o segundo tipo de câncer diagnosticado e a quinta causa de morte em homens em todo o mundo. O diagnóstico precoce é fundamental para o prognóstico da doença. Atualmente, o antígeno específico da próstata (PSA) é o biomarcador mais utilizado; porém, biomarcadores mais específicos devem ser estudados. Objetivo: Avaliar a acurácia da proteína engrenada-2 (EN2) na urina como biomarcador de câncer de próstata. Método: Foi realizada uma busca abrangente no período de janeiro de 2005 a julho de 2016, utilizando as seguintes bases de dados eletrônicas: Medline (PubMed), Embase, Cochrane Library e Lilacs. As palavras-chave utilizadas foram: "engrailed-2", "EN2", "prostatic neoplasms". A busca foi limitada a humanos e não houve restrição de idioma. A avaliação da qualidade dos estudos incluídos foi realizada de acordo com Quadas-2. A análise estatística foi realizada usando o software Meta-DiSc® e RevMan 5.3. Resultados: Foram identificados 248 estudos. Após a triagem dos títulos e resumos, foram excluídos 231. Um total de 17 foram lidos na íntegra e dois, incluídos na metanálise. A sensibilidade combinada foi de 66% (IC95% 0,56-0,75). A especificidade foi de 89% (IC95% 0,86-0,92). O DOR foi de 15,08 (IC95% 8,43-26,97). Conclusão: O teste EN2 mostrou alta especificidade (89%) e baixa sensibilidade (66%).

Increased BDNF levels after electroconvulsive therapy in patients with major depressive disorder: A meta-analysis study.

OBJECTIVE: We performed a systematic review and meta-analysis to estimate brain-derived neurotrophic factor (BDNF) level in patients with major depressive disorder (MDD) after electroconvulsive therapy (ECT). METHOD: A comprehensive search of the Cochrane Library, MEDLINE, LILACS, Grey literature, and EMBASE was performed for papers published from January 1990 to April 2016. The following key terms were searched: "major depressive disorder", "unipolar depression", "brain-derived neurotrophic factor", and "electroconvulsive therapy". RESULTS: A total of 252 citations were identified by the search strategy, and nine studies met the inclusion criteria of the meta-analysis. BDNF levels were increased among patients with MDD after ECT (P value = 0.006). The standardized mean difference was 0.56 (95% CI: 0.17-0.96). Additionally, we found significant heterogeneity between studies (I2 = 73%). CONCLUSION: Our findings suggest a potential role of BDNF as a marker of treatment response after ECT in patients with MDD.

Accuracy of magnetic resonance in deeply infiltrating endometriosis: a systematic review and meta-analysis.

OBJECTIVE: To estimate the accuracy of pelvic magnetic resonance imaging (MRI) in the diagnosis of deeply infiltrating endometriosis (DIE). METHODS: A comprehensive search of the Medline, Pubmed, Lilacs, Scopus, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Biomed Central, and ISI Web of Science databases was conducted from January 1990 to December 2013. The medical subject headings (MeSHs) and text words "deep endometriosis", "deeply infiltrating endometriosis", "DIE", "magnetic resonance", and "MRI" were searched. Studies that compared the parameters of pelvic MRIs with those of paraffin-embedded sections for the diagnosis of DIE were included. RESULTS: Twenty studies were analyzed, which included 1,819 women. Pooled sensitivity and specificity were calculated across eight subgroups: for all sites, these were 0.83 and 0.90, respectively; for the bladder, 0.64 and 0.98, respectively; for the intestine, 0.84 and 0.97, respectively; for the pouch of Douglas, 0.89 and 0.94, respectively; for the rectosigmoid, 0.83 and 0.88, respectively; for the rectovaginal, 0.77 and 0.95, respectively; for the uterosacral ligaments, 0.85 and 0.80, respectively; and for the vagina and the posterior vaginal fornix, 0.82 and 0.82, respectively. CONCLUSION: In summary, pelvic MRI is a useful preoperative test for predicting the diagnosis of multiple sites of deep infiltrating endometriosis.