The effect of light regime and time of slaughter in broiler on broiler performance, liver antioxidant status, and expression of genes related to peptide absorption in the jejunum and melatonin synthesis in the brain.

This study aimed to assess the effects of light regime and time of slaughter on primal cut and organ weights, peptide transporter 1 (PEPT1) gene expression in the jejunum, arylalkylamine N-acetyltransferase (AANAT) gene expression in the brain, and liver oxidant/antioxidant status in broilers aged 37 days. The experiment was conducted in a factorial completely randomized design, with two light regimes (intermittent light varying according to bird age and continuous light under an 18 h light/6 h dark photoperiod) and four times of slaughter (2:00, 8:00, 14:00 and 20:00 h). There was an interaction effect on PEPT1 and AANAT expression, lipid and protein oxidation and superoxide dismutase (SOD) activity. In both light regimes, PEPT1 expression responded cubically to slaughter time. In the continuous light group, PEPT1 expression was highest in birds slaughtered at 2:00 and 14:00 h, whereas, in the intermittent light treatment, expression was highest at 8:00 h. In the continuous light regime, AANAT expression had a cubic relationship with time of slaughter, with the greatest values recorded at 20:00 h. In the intermittent light regime, slaughter time showed a cubic effect on lipid oxidation, which was highest at 8:00 h. In the continuous light group, there was a cubic effect on nitrite concentration, lipid oxidation, protein oxidation, and SOD activity; nitrite levels, lipid oxidation, and protein oxidation were highest and SOD activity was lowest in birds slaughtered at 14:00 h. Time of slaughter influenced catalase activity, which responded cubically; catalase activity was lowest at 8:00 and 14:00 h. This study is the first to demonstrate that PEPT1 expression in the jejunum of broilers follows a diurnal rhythm and varies according to light regime. The results also suggest that mainly continuous lighting and slaughter at 14:00 h when the animals are possibly more active may be more stressful to broilers.

Effects of methionine supplementation on the expression of protein deposition-related genes in acute heat stress-exposed broilers.

The objective of this study was to evaluate the effect of heat stress and methionine supplementation on the gene expression of insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), phosphatidylinositol 3-kinase, and regulatory 1 (PI3KR1) in the liver, as well as the expression of the atrogin 1 and cathepsin L2 (CTSL2) genes in the breast muscle of broilers. Broilers from 1-21 and 22-42 days of age were divided into three treatments related to methionine supplementation as follows: without methionine supplementation (MD), recommended level of methionine (DL1), and excess supplementation of methionine (DL2). The animals were either maintained at a thermal comfort temperature or exposed to heat stress (HS) (38°C for 24 hours, starting on day 20 or day 41 for experiments 1 and 2, respectively). The heat stress increased the body temperature at both ages. Starter period: The HS animals presented increased plasma creatinine content (P<0.0001) and the highest CTSL2 gene expression (P<0.0001). The methionine supplementation increased the IGF-I (P = 0.0144) and GHR (P = 0.0011) gene expression and decreased the CTSL2 (P = 0.0004) and atrogin 1 (P = 0.0012) gene expression. Grower period: Significant effects for the interaction between supplementation and environment were observed for GHR (P = 0.0252) and CTSL2 (P = 0.0011) gene expression. The highest GHR expression was observed in animals that remained in thermal comfort on the DL2 diet, and the lowest expression occurred in the HS animals fed the MD diet. For CTSL2, the HS animals fed the MD diet presented the highest CTSL2 gene expression, and the lowest expression was observed in the animals maintained at thermal comfort on DL1 and DL2 diets. Only methionine supplementation had effect on atrogin-1 gene expression (P<0.0001), with higher methionine content in the diet lower atrogin-1 gene expression was observed. Our results suggest that heat stress induces greater protein degradation and that methionine supplementation could induce protein deposition because methionine increased the expression of genes related to protein synthesis and decreased the expression of genes related to protein breakdown.

Effects of methionine supplementation on the expression of oxidative stress-related genes in acute heat stress-exposed broilers.

The aim of the present study was to evaluate the effects of heat stress (HS) and methionine supplementation on the markers of stress and on the gene expression levels of uncoupling proteins (UCP), betaine-homocysteine methyltransferase (BHMT), cystathionine ß-synthase (CBS), glutathione synthetase (GSS) and glutathione peroxidase 7 (GPx7). Broilers from 1 to 21 d and from 22 to 42 d of age were divided into three treatment groups related to methionine supplementation: without methionine supplementation (MD); recommended level of methionine supplementation (DL1); excess methionine supplementation (DL2). The broilers were either kept at a comfortable thermal temperature or exposed to HS (38°C for 24 h). During the starter period, we observed the effects of the interaction between diet and environment on the gene expression levels of UCP, BHMT and GSS. Higher gene expression levels of UCP and BHMT were observed in broilers that were maintained at thermal comfort conditions and received the MD diet. HS broilers fed the DL1 and DL2 diets had the highest expression level of GSS. The expression levels of the CBS and GPx7 genes were influenced by both the environment and methionine supplementation. During the grower period, the gene expression levels of BHMT, CBS, GSS and GPx7 were affected by the diet × environment interaction. A higher expression level of BHMT was observed in broilers maintained at thermal comfort conditions and on the MD diet. HS induced higher expression levels of CBS, GSS and GPx7 in broilers that received the DL1 and DL2 diets. The present results suggest that under HS conditions, methionine supplementation could mitigate the effects of stress, since methionine contributed to the increased expression levels of genes related to antioxidant activity.

Uso da bioinformática na diferenciação molecular da Entamoeba histolytica e Entamoeba díspar / Molecular discrimination of Entamoeba histolytica and Entamoeba disparby bioinformatics resources

Amebíase invasiva, causada por Entamoeba histolytica, é microscopicamente indistinguível da espécie não-patogênica Entamoeba dispar. Com auxílio de ferramentas debioinformática, objetivou-se diferenciar Entamoeba histolytica e Entamoeba dispar por técnicas moleculares. A análise foi realizada a partir do banco de dados da National Center for Biotechnology Information; pela pesquisa de similaridade de sequências, elegeu-se o gene da cisteína sintase. Um par de primer foi desenhado (programa Web Primer) e foi selecionada a enzima de restrição TaqI (programa Web Cutter). Após a atuação da enzima, o fragmento foi dividido em dois, um com 255 pb e outro com 554 pb, padrão característico da E. histolytica.Na ausência de corte, o fragmento apresentou o tamanho de 809 pb, referente à E. dispar.

Under microscopic conditions, the invasive Entamoeba histolytica is indistinguishable from the non-pathogenic species Entamoeba dispar. In this way, the present study was carried out to determine a molecular strategy for discriminating both species by the mechanisms of bioinformatics. The gene cysteine synthetase was consideredfor such a purpose by using the resources of the National Center for BiotechnologyInformation data bank in the search for similarities in the gene sequence. In this way, a primer pair was designed by the Web Primer program and the restriction enzyme TaqI was selected by the Web Cutter software program. The DNA fragment had a size of 809 bp before cutting, which is consistent with E. dispar. The gene fragment was partitioned in a first fragment with 255 bp and a second one with 554 bp, which is similar to the genetic characteristics of E. histolytica.

Estudo do alelo g do gene da alphas1-caseína em uma população de cabras leiteiras / Estudio del alelo g del gen de la alphas1- caseína en una población de cabras lecheras / Study on the g allele of the alphas1-casein gene in dairy goats

Devido ao diminuído potencial alergênico do leite de cabra, em relação ao leite de vaca, as proteínas do primeiro têm sido investigadas e mostram um amplo polimorfismos da ?S1-caseína, variando de produção nula até 7 g/L. No lócus gênico da ?S1-caseína já foram encontrados 18 alelos, sendo o alelo G relacionado a baixos níveis de ?s1-caseína (0,6 g/L), decorrente de uma transição G?A (guanina por adenina) no sítio doador de splice do intron 4, levando à perda do exon 4 durante o processamento do RNA mensageiro. No Brasil existem poucos relatos de estudos sobre o polimorfismo genético desta proteína. Assim, este trabalho teve como objetivo estabelecer um protocolo para detecção do alelo G do gene da ?S1- caseína e verificar sua existência em um grupo de animais caprinos. Para isto, leucócitos foram utilizados para isolamento de DNA com o reagente CTAB e um par de primer, desenhado com base na seqüência do GenBank (AJ504710), possibilitou a amplificação da região gênica de interesse, gerando produtos de PCR com tamanho de 550 pb. Após a digestão com a enzima AciI, foram observados dois fragmentos com tamanhos de 308 e 242 pb, indicando a presença da guanina no sítio doador de splice. Alguns animais, suspeitos de portarem o alelo G, tiveram amostras de DNA seqüenciadas. Os resultados mostraram inexistência da transição de base e, conseqüentemente, a inexistência do alelo G nos 80 animais estudados, indicando a necessidade de investigação de um número maior de animais, por se tratar de um alelo raro

Study on optic microscope of the collagen component of the aorto-iliac bifurcation septum and initial segment of the middle sacral artery

Estudiamos la disposición de las fibras colágenas en el septo de la bifurcación aortoilíaca y en la porción inicial de la arteria sacra mediana a través de técnicas de microscopía óptica. Utilizamos muestras anatómicas de individuos de ambos sexos con edades entre 20 a 33 años. Para la detección de estas fibras colágenas, se utilizaron las tinciones Azan Picrofucsina de van Gieson, Verhoeff y Weigert modificado por van Gieson. Se observó engrosamiento de la túnica íntima en el septo de la bifurcación aortoilíaca con predominio de fibras colágenas. A través de cortes seriados fue posible analizar el comportamiento de estas fibras desde el origen de la arteria sacra mediana, en la pared posterior de la aorta, hasta su completa individualización. El objetivo de este trabajo ha sido dar una base anatómica para la mejor comprensión de las alteraciones fisiopatológicas que frecuentemente afectan esta región

Estudo dos componentes fibrocelulares das granulaçöes aracnóides humanas / Fibrocellular components study of human arachnoid granulations

O estudo microscópico dos elementos fibrocelulares da granulaçao aracnóide de seres humanos revela uma concentraçao de canalículos que cruzam a regiao medular, em direçao a luz do seio sagital superior. As células aracnóides acompanham a disposiçao espacial dos elementos fibrosos, através de seus processos citoplasmáticos alongados. Os feixes de fibras elásticas formam condensaçoes em torno dos espaços extracelulares e ao redor da granulaçao, isto, segundo os autores, forneceria grande maleabilidade a estrutura, capacitando-a a responder a diferentes estados funcionais, quer retraindo quer distendendo.