Effects of bovine enterovirus and type 1 diabetes on liver and kidney pyruvate kinase activity in an animal model

Type 1 diabetes (T1D) is an autoimmune disease characterized by the selective destruction of pancreatic beta cells. In addition to genetic factors, enteroviruses have been considered the main environmental factor involved in this pathology. Therefore, the objective of this study was to evaluate the effects of streptozotocin-induced diabetes and bovine enterovirus (BEV) on liver and kidney pyruvate kinase activity in rats. Fourteen male Wistar rats were divided in three groups: control, diabetes and a third group, which was fed with water experimentally contaminated by BEV. Increased blood glucose levels were found in both diabetes and enterovirus groups, whereas there were no alterations in the lipid profile. A reduced pyruvate kinase activity was observed in the liver and kidney of animals from diabetes and enterovirus groups. Under our experimental conditions, the ingestion of water experimentally contaminated by BEV induced alterations in glycaemia, and also interfered in the pyruvate kinase activity in liver and kidney of the rats, which might be one of the possible mechanisms involved in the T1D development.

Effects of chronic exposure to hexavalent chromium in water on oxidative stress parameters in Wistar rats

Hexavalent chromium [Cr (VI)] is a metal utilized in different industries and consequently disposed in the environment. It is a toxic substance and its reduction to trivalent Cr [Cr (III)] generates intermediates, which are responsible for the oxidation of molecules, and cause the oxidative stress. Therefore, the aim of this study was to evaluate if Cr (VI) could induce oxidative stress in Wistar rats. In this study, Wistar rats were chronically exposed to 25 and 50 ppm of potassium dichromate in drinking water for 30 days. The levels of Cr were evaluated in the blood and tissues (liver, kidneys, and lungs). Oxidative stress was determined in the liver, kidneys, and lungs and was evaluated by DFCH, TBA-RS and carbonyl test. Antioxidant enzymes were evaluated through catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Regarding the results, Cr concentration was significantly elevated in all tissues, however, it was lower in the lungs. In relation to the oxidative stress parameters, there was a significant increase of DCFH levels in the kidneys and carbonyls in liver and kidneys. Regarding the antioxidant enzymes, SOD was decreased in all organs and GPx was diminished in the kidneys. These data indicated that Cr (VI) could induce oxidative stress in the kidneys and liver due to an imbalance between oxidative and antioxidant parameters. The lungs were little affected, possibly by the lowest chromium accumulation.

Oxidative damage to DNA in independent-living elderly persons and their correlations with sociodemographic, anthropometric, and functional parameters / Dano oxidativo ao DNA em idosos com vida independente e suas correlações com parâmetros sociodemográficos, antropométricos e funcionais

Abstract Objective: To evaluate the correlations between oxidative DNA damage among elderly persons aged between 60 and 79 years and sociodemographic, anthropometric and functional parameters. Method: The present study has a descriptive, quantitative and cross-sectional design. A group of 195 independent-living elderly persons of both genders underwent blood collection and the subsequent measurement of serum concentrations of 8-OHdG, a residue generated by the attack of reactive oxygen species to DNA. The same subjects also underwent evaluation for body mass index (BMI), body fat percentage, the Short Physical Performance Battery (SPPB), and the education level of the participants was analyzed. Statistical analysis was performed using the Spearman correlation test, adopting a 5% significance level. Result: Higher fat percentage and BMI are directly correlated with higher concentrations of 8-OHdG, while SPPB and education were inversely correlated with the concentration of this molecule in the sample. Conclusion: These results suggest factors such as lifestyle and educational level influenced oxidative DNA damage in these elderly persons and had an impact on their functional capacity.

Resumo Objetivo: avaliar a ocorrência de correlações entre danos oxidativos ao DNA em idosos entre 60 e 79 anos de idade e parâmetros sociodemográficos, antropométricos e funcionais. Método: delineamento descritivo, quantitativo e transversal. Um grupo de 195 idosos independentes, de ambos os sexos, submetidos à coleta de sangue e subsequente medição das concentrações séricas de 8-OHdG, resíduo gerado pelo ataque de espécies reativas de oxigênio ao DNA. Os mesmos sujeitos avaliados formam o índice de massa corporal (IMC), porcentagem de gordura corporal, o Short Physical Performance Balance (SPPB) e o nível de escolaridade dos participantes. A análise estatística dos dados foi realizada através dos testes de correlação de Spearman, adotando um nível de significância de 5%. Resultado: a percentagem de gordura e maior IMC estão diretamente correlacionados com maiores concentrações de 8-OHdG, enquanto que a educação e o SPPB foram inversamente correlacionados com uma concentração dessa molécula na amostra. Conclusão: esses resultados sugerem que o dano oxidativo ao DNA nesses idosos é fortemente condicionado por fatores como o estilo de vida e o nível educacional, que apresentam impacto sobre a capacidade funcional dos mesmos.

Relationship between depression and diabetes Mellitus / Relação entre depressão e diabetes Mellitus

Objective: To review studies examining the possible relationship between depression and diabetes Mellitus.Methods: Articles were searched in the following databases: the Latin-American and Caribbean Center on Health Sciences, the Scientific Library Online, Base in Nursing and Pubmed. The search was limited to articles published between January 2000 and October 2010. Search terms included: ?diabetes?, ?depression?, ?chronic diseases? and ?psychiatric disorders? Results: A total of 21 articles which examined the relationship between diabetes and depression were included in the present paper. There is a bidirectional relationship between these two chronic diseases. Diabetes could lead to depression due its effects on the quality life of patients, its complications and the difficulty in treatment adhesion. Depression could lead to diabetes on account of alterations in glucose transport function and increased immunoninflamatory activation, which could contribute to insulin resistance and beta islet cell dysfunction. Conclusion: There is a bidirectional relation between diabetes and depression and the nature of this relation is still unclear. However, this research contributes to the comprehension of this relation and possible mechanisms involved, since both diseases should be monitored and deserve attention from health professionals.

Objetivo: Revisar estudos que avaliaram a possível existência da relação entre depressão e diabetes Mellitus.Métodos: Artigos foram pesquisados nas seguintes bases de dados: Literatura Latino-Americana e do Caribe em Ciências da Saúde, Scientific Electronic Library Online, Bases de Dados em Enfermagem e Pubmed. A busca foi limitada aos artigos publicados de janeiro de 2000 a outubro de 2010. Os termos de busca utilizados foram ?diabetes?, ?depressão?, ?doenças crônicas? e ?distúrbios psiquiátricos? Resultados: Um total de 21 artigos que avaliaram a relação entre diabetes e depressão foi incluído e analisado no presente trabalho. Há uma relação bidirecional entre essas duas doenças crônicas. O diabetes poderia levar à depressão por afetar a qualidade de vida dos pacientes, dadas suas complicações e a dificuldade de adesão ao tratamento. A depressão poderia ocasionar o diabetes devido às alterações na função do transporte de glicose e ao aumento da ativação da resposta imunoinflamatória, o que poderia contribuir para a resistência à insulina e para a disfunção da célula betapancreática. Conclusão: Existe uma relação bidiretional entre diabetes e depressão, e a natureza dessa relação permanece desconhecida. Esta revisão contribui para a compreensão dessa relação e dos possíveis mecanismos envolvidos, visto que ambas as doenças devem ser monitoradas e merecem atenção dos profissionais da saúde.

Vivência das mães na amamentação do recém-nascido pré-termo / Mothers' Experience of Breastfeeding Preterm Infants

O presente estudo teve por objetivo conhecer a vivência das mães em relação à amamentação do recém-nascido pré-termo internado na Unidade de Tratamento Intensivo Neonatal. O estudo de natureza descritiva, de caráter qualitativo teve a participação de quatro (04) mães que tiveram seusfilhos pré-termos internados na Unidade de Terapia Intensiva Neonatal (UTIN) no início do ano de 2013 e, que vivenciaram a prática da amamentação nesta unidade. A coleta das informações foi realizada por meio de entrevista semi estruturada, que utiliza para a análise dos resultados a técnica de análise de conteúdo temática. A análise permitiu a estruturação de quatro categorias. Após conhecer a vivência das mães em relação à amamentação do recém-nascido pré-termo, pode-seinferir que as mães experimentam sentimentos negativos e positivos em relação à amamentação. Os momentos mais significativos em relação à amamentação são marcados pela pega do seio. As mães relatam como principal dificuldade na amamentação de seus bebês a pega, devido à imaturidade do sistema estomatognático de seus filhos, bem como o ambiente da UTIN. As mãesinvestigadas relataram ser de extrema importância as orientações sobre a amamentação recebidas pela equipe de enfermagem, porém algumas vezes as orientações não são seguidas após a altahospitalar pelo fato de serem realizadas somente na UTIN.

This study aimed to get to know the experiences of mothers in breastfeeding newborn preterm infants admitted to the Neonatal Intensive Care Unit. The descriptive study of qualitative character observed four (04) mothers who had their preterm children hospitalized in a Neonatal IntensiveCare Unit (NICU) at the beginning of the year 2013, and so experienced breastfeeding in this unit. Data collection was conducted through semi-structured interview, which uses the thematic content analysis technique to analyze the results. The analysis allowed the structuring of four categories. After knowing mothers’ experience on breastfeeding preterm newborn it was possible to infer thatthey experience negative and positive feelings about breastfeeding. The most significant moments regarding breastfeeding are marked by latch-on. Mothers report latching-on as the main difficulty in breastfeeding, due to the immaturity of their babies’ stomatognathic system, as well as theenvironment of the NICU. Mothers surveyed reported that the guidelines about breastfeeding provided by the nursing staff are extremely important, but sometimes the directions are not followed after hospital discharge because they are performed only in the NICU.

Pyruvate kinase activity and δ-aminolevulinic acid dehydratase activity as biomarkers of toxicity in workers exposed to lead.

Lead (Pb(2+)) is a heavy metal that has long been used by humans for a wide range of technological purposes, which is the main reason for its current widespread distribution. Pb(2+) is thought to enter erythrocytes through anion exchange and to remain in the cell by binding to thiol groups. Pyruvate kinase (PK) is a thiol-containing enzyme that plays a key role in erythrocyte cellular energy homeostasis. δ-aminolevulinic acid dehydratase (δ-ALAD) is the second enzyme in the heme biosynthetic pathway and plays a role in the pathogenesis of Pb poisoning. Our primary objective was to investigate the effect of Pb(2+) on the activity of the thiolenzymes δ-ALAD and PK and on the concentration of glutathione (GSH), a nonenzymatic antioxidant defense, in erythrocytes from Pb-exposed workers. The study sample comprised 22 male Pb workers and 21 normal volunteers (15 men and 6 women). The Pb-exposed workers were employed in manufacturing and recycling of automotive batteries. Basic red-cell parameters were assayed and total white blood cell counts performed. PK and δ-ALAD activity and blood Pb (BPb) concentrations were determined in all subjects. Pb-exposed individuals had significantly greater BPb levels than controls. Both PK and δ-ALAD activity levels were significantly lower in Pb-exposed individuals than in controls. Pb significantly inhibited PK and δ-ALAD activity in a dose-dependent manner. We found that erythrocyte GSH levels were lower in Pb-exposed individuals than normal volunteers. Pb-exposed individuals had lower values than controls for several red cell parameters (hemoglobin, hematocrit, red blood cell count, mean corpuscular volume). These results suggest that Pb inhibits δ-ALAD and PK activity by interacting with their thiol groups. It is therefore possible that Pb disrupts energy homeostasis and may be linked with decreased glucose metabolism because it affects the heme synthesis pathway in erythrocytes, contributing to the cell dysfunction observed in these in Pb-exposed individuals. These results indicate an apparent dose-effect relationship between PK activity and BPb. PK activity in human erythrocytes can be used for biological monitoring of Pb exposure. Study of the mechanisms by which Pb acts may contribute to greater understanding of the symptoms caused by Pb.

Frequency of the anti-glutamic acid decarboxylase immunological marker in patients with diabetes duration longer than three years in southern Brazil.

CONTEXT AND OBJECTIVE: The anti-GAD (glutamic acid decarboxylase) antibody is considered to be an important marker for type 1 diabetes mellitus (DM1), with frequency that varies depending on the population studied and the duration of the disease. Therefore, the aim of this study was to determine the frequency of this autoantibody in a group of patients in southern Brazil with DM1 that had been diagnosed more than three years previously. DESIGN AND SETTING: Analytical cross-sectional study with a control group conducted at the Biomedicine Laboratory of Universidade Feevale. METHODS: This study was conducted between June 2007 and December 2008, and 109 individuals were enrolled during this period. Fifty-eight were DM1 patients and 51 were individuals free from DM1 and without any history of diabetes, who constituted the control group. RESULTS: In the DM1 group, the mean age was 27 ± 1.7 years and 50% were men. The mean fasting blood glucose in the DM1 group was 208 ± 15 mg/dl and mean HbA1c (glycosylated hemoglobin) was 8.7 ± 0.25%. In the control group, the mean fasting blood glucose and HbA1c were 82 mg/dl and 5.0% respectively. Thirty-seven individuals with DM1 (63.8%) were positive for anti-GAD, and this proportion was significantly larger than in the control group. CONCLUSIONS: These results show the high prevalence of anti-GAD in the population of diabetic patients in southern Brazil, thus indicating that the antibody was still present a long time after the disease had been diagnosed.

Frequency of the anti-glutamic acid decarboxylase immunological marker in patients with diabetes duration longer than three years in southern Brazil / Frequência do marcador imunológico de anti-decarboxilase do ácido glutâmico em pacientes com diabetes há mais de três anos no Sul do Brasil

CONTEXT AND OBJECTIVE: The anti-GAD (glutamic acid decarboxylase) antibody is considered to be an important marker for type 1 diabetes mellitus (DM1), with frequency that varies depending on the population studied and the duration of the disease. Therefore, the aim of this study was to determine the frequency of this autoantibody in a group of patients in southern Brazil with DM1 that had been diagnosed more than three years previously. DESIGN AND SETTING: Analytical cross-sectional study with a control group conducted at the Biomedicine Laboratory of Universidade Feevale. METHODS: This study was conducted between June 2007 and December 2008, and 109 individuals were enrolled during this period. Fifty-eight were DM1 patients and 51 were individuals free from DM1 and without any history of diabetes, who constituted the control group. RESULTS: In the DM1 group, the mean age was 27 ± 1.7 years and 50 percent were men. The mean fasting blood glucose in the DM1 group was 208 ± 15 mg/dl and mean HbA1c (glycosylated hemoglobin) was 8.7 ± 0.25 percent. In the control group, the mean fasting blood glucose and HbA1c were 82 mg/dl and 5.0 percent respectively. Thirty-seven individuals with DM1 (63.8 percent) were positive for anti-GAD, and this proportion was significantly larger than in the control group. CONCLUSIONS: These results show the high prevalence of anti-GAD in the population of diabetic patients in southern Brazil, thus indicating that the antibody was still present a long time after the disease had been diagnosed.

CONTEXTO E OBJETIVO: O anticorpo anti-decarboxilase do ácido glutâmico (anti-GAD) é considerado um importante marcador no diabetes mellitus tipo 1 (DM1), cuja frequência varia segundo a população estudada e o tempo de duração da doença. Assim, o objetivo deste estudo foi determinar a frequência deste auto-anticorpo em um grupo de pacientes localizados no Sul do Brasil com mais de três anos de diagnóstico de DM1. TIPO DE ESTUDO E LOCAL: Estudo transversal analítico com grupo controle, realizado no Laboratório de Biomedicina da Universidade Feevale. MÉTODOS: Este estudo foi realizado no período de Junho de 2007 a Dezembro de 2008, em que 109 indivíduos foram incluídos, sendo 58 destes com DM1 e 51 indivíduos sem DM1 e sem antecedentes de diabetes, que constituíram o grupo controle. RESULTADOS: No grupo DM1, a idade média foi 27 ± 1,7 anos e 50 por cento eram homens. A média da glicemia de jejum no grupo DM1 foi 208 ± 15 mg/dL e a HbA1c média foi 8,7 ± 0.25 por cento. No grupo controle a glicemia de jejum média e a HbA1c (hemoglobina glicosilada) foram 82 mg/dL e 5,0 por cento, respectivamente. O anti-GAD foi positivo em 37 (63,8 por cento) indivíduos com DM1, valores significativamente maiores quando comparados com os do grupo controle. CONCLUSÕES: Estes resultados mostram a alta prevalência do anti-GAD na população de pacientes diabéticos da região Sul do Brasil, indicando que o anticorpo está presente após um longo período de diagnóstico da doença.

Lead inhibits in vitro creatine kinase and pyruvate kinase activity in brain cortex of rats.

Lead intoxication is a serious occupational disease that constitutes a major public health problem. Lead, a heavy metal, has been used by humans for many technological purposes, which is the main reason for its widespread distribution. The toxic mechanisms of lead on the molecular machinery of living organisms include metal transport, energy metabolism, diverse enzymatic processes, genetic regulation, and membrane ionic channels and signaling molecules. Since lead is able to cross the blood-brain barrier it may cause neurotoxicity. Creatine kinase and pyruvate kinase are two thiol-containing enzymes that exert a key role for cellular energy homeostasis in brain. Our main objective was to investigate the in vitro effect of lead on pyruvate kinase and creatine kinase activities of extracts and subcellular fractions from the brain cortex of rats in the presence or not of thiol-protecting substances such as glutathione and cysteamine. The results showed that lead inhibited the two enzyme activities and the thiol-protecting substances prevented their inhibition. These results suggest that lead inhibits creatine kinase and pyruvate kinase activity by interaction with their thiol groups. Therefore, lead may disrupt energy homeostasis and this effect may contribute to the neurological dysfunction found in lead exposed individuals.

Nitric oxide is involved in the memory facilitation induced by spermidine in rats.

RATIONALE: Spermidine (SPD) is an endogenous polyamine that modulates N-methyl-D: -aspartate receptor functions, which has been reported to facilitate memory formation. OBJECTIVES: In the current study, we investigated the involvement of nitric oxide in the facilitatory effect of SPD on the memory of adult male Wistar rats in the inhibitory avoidance task. RESULTS: The coadministration of the nonspecific NOS inhibitor N (G) nitro-L: -arginine methyl ester (L: -NAME) (0.1 nmol, intrahippocampus) with spermidine (0.2 nmol), immediately after training, prevented the memory improvement caused by spermidine in the avoidance inhibitory task. Spermidine increased nitrite and nitrate levels (NO(X)) in the hippocampus 30 min after its administration, and L: -NAME coinjection prevented the stimulatory effect of spermidine on NO(X) levels. The systemic injection of 7-nitroindazole (30 mg/kg, i.p.), 30 min before training, impaired memory and did not prevent spermidine-induced increase of NO(X) levels in the hippocampus. CONCLUSIONS: These results suggest that memory enhancement by spermidine is prevented by the nonspecific nitric oxide synthase inhibitor L: -NAME.

Time-dependent modulation of inhibitory avoidance memory by spermidine in rats.

The polyamines, spermine, spermidine, and putrescine, are a group of aliphatic amines that may act as physiological modulators of N-methyl-D-aspartate (NMDA) receptors. Although the modulatory role of polyamines in NMDA receptor function has long been known, the effects of polyamines on learning and memory only recently began to be unraveled. In the present study, we investigated the effect of bilateral infusions of spermidine (0.02-2 nmol), a polyamine agonist, into the CA1 region of the rat dorsal hippocampus on inhibitory avoidance learning 30 min pre-training, immediately post-training, 6 h post-training, or 10 min pre-test. Bilateral microinjections of 0.2 nmol spermidine prolonged step-down latencies compared to the respective control group when administered 30 min pre-training or immediately post-training. These results provide evidence that the modulatory effects of spermidine on the acquisition and/or early consolidation of memory of inhibitory avoidance tasks in the hippocampus occur within a limited time window.