Influence of gestational diabetes on the activity of δ-aminolevulinate dehydratase and oxidative stress biomarkers.

OBJECTIVES: This study aimed to evaluate the activity of delta-aminolevulinate dehydratase (δ-ALA-D) and oxidative stress biomarkers in pregnant women with gestational diabetes mellitus (GDM), in order to demonstrate the involvement of oxidative stress in this condition, which presents pathophysiology still undetermined. METHODS: δ-ALA-D activity, lipid peroxidation estimated as the levels of thiobarbituric acid reactive substances (TBARS), protein (P-SH) and non-protein thiol (NP-SH) content, catalase (CAT) activity and concentration of vitamin C (VIT C) in samples of pregnant women with GDM (n = 48) and in healthy pregnant women (n = 30), who constituted the control group. RESULTS: The δ-ALA-D activity was significantly lower in pregnant women with GDM compared to controls, as well as levels of thiols, VIT C and CAT activity. Lipid peroxidation was higher in GDM group. DISCUSSION: The results suggest that the main factor for the increase in oxidative stress and reduced δ-ALA-D activity in diabetic pregnant women is gestational hyperglycemic environment, which changed the redox balance and interfered on mechanism of the δ-ALA-D activity in relation to normoglycemic pregnant women.

Concepções sobre mediação da aprendizagem e relações com indicadores de estresse ocupacional / Conceptions on mediated learning and relations with indicators of occupational stress / Concepciones sobre mediación del aprendizaje y relaciones con indicadores de estrés ocupacional

A mediação da aprendizagem é um processo importante para a alfabetização. Assim, este estudo analisou as relações entre concepções sobre mediação, variáveis pessoais e indicadores de estresse em 36 professores da região metropolitana de Vitória, ES. A partir de um protocolo e de um conjunto de escalas, houve tratamento quantitativo e qualitativo dos dados. Os participantes apresentaram conhecimentos básicos sobre mediação, mas desconheciam a teoria da Experiência de Aprendizagem Mediada - EAM. Cerca de 40% apresentaram alto nível de estresse. Os principais estressores relacionaram-se ao envolvimento dos alunos e às relações com a comunidade ou instituição. Houve correlação negativa entre estresse e satisfação no trabalho e positiva entre satisfação e evocações ligadas às ações do professor como responsáveis pela mediação de qualidade. Sugere-se acesso a teorias sobre mediação da aprendizagem e investimento em políticas públicas visando à satisfação no trabalho, uma possível variável mediadora entre concepções e estresse percebido.

The mediation of learning is an important process for literacy. Thus, this study analyzed the relationships between conceptions about mediation, personal variables and stress indicators in 36 teachers from the metropolitan region of Vitória, ES. From a protocol and a set of scales, there was quantitative and qualitative treatment of the data. Participants presented basic knowledge about mediation but did not know the theory of the Mediated Learning Experience (MLE). About 40% had a high level of stress. The main stressors were related to the students' involvement and the relationships with the community or institution. There was a negative correlation between stress and satisfaction at work and positive correlation between satisfaction and evocations related to teacher actions as responsible for quality mediation. It is suggested access to theories about mediation of learning and investment in public policies aiming at job satisfaction, a possible mediating variable between conceptions and perceived stress.

La mediación del aprendizaje es un proceso importante para la alfabetización. Así, este estudio analizó relaciones entre concepciones sobre mediación, variables personales e indicadores de estrés en 36 profesores de la región metropolitana de Vitória, ES. A partir de un protocolo y de un conjunto de escalas, hubo tratamiento cuantitativo y cualitativo de los datos. Los participantes presentaron conocimientos básicos sobre mediación, pero desconocían la teoría de la Experiencia del Aprendizaje Mediada - EAM. Cerca del 40% presentó alto nivel de estrés. Los principales estresores se relacionaron y al involucramiento de los alumnos y a las relaciones con la comunidad o institución. Hubo correlación negativa entre estrés y satisfacción en el trabajo y positiva entre satisfacción y evocaciones enlazadas a las acciones del profesor como responsables por mediación de calidad. Se sugiere acceso a teorías sobre mediación del aprendizaje e investimento en políticas públicas visando a la satisfacción en el trabajo, una posible variable mediadora entre concepciones y estrés percibido.

Delta-aminolevulinate dehydratase activity and oxidative stress markers in preeclampsia.

Preeclampsia is an important pregnancy-specific multisystem disorder characterized by the onset of hypertension and proteinuria. It is of unknown etiology and involves serious risks for the pregnant women and fetus. One of the main factors involved in the pathophysiology of preeclampsia is oxidative stress, where excess free radicals produce harmful effects, including damage to macromolecules such as lipids, proteins and DNA. In addition, the sulfhydryl delta-aminolevulinate dehydratase enzyme (δ-ALA-D) that is part of the heme biosynthetic pathway in pro-oxidant conditions can be inhibited, which may result in the accumulation of 5-aminolevulinic acid (ALA), associated with the overproduction of free radicals, suggesting it to be an indirect marker of oxidative stress. As hypertensive pregnancy complications are a major cause of morbidity and mortality maternal and fetal where oxidative stress appears to be an important factor involved in preeclampsia, the aim of this study was to evaluate the activity of δ-ALA-D and classic oxidative stress markers in the blood of pregnant women with mild and severe preeclampsia. The analysis and quantification of the following oxidative stress markers were performed: thiobarbituric acid-reactive species (TBARS); presence of protein and non-protein thiol group; quantification of vitamin C; Catalase and δ-ALA--D activities in samples of blood of pregnant women with mild preeclampsia (n=25), with severe preeclampsia (n=30) and in a control group of healthy pregnant women (n=30). TBARS was significantly higher in women with preeclampsia, while the presence of thiol groups, levels of vitamin C, catalase and δ-ALA-D activity were significantly lower in groups of pregnant women with preeclampsia compared with healthy women. In addition, the results showed no significant difference between groups of pregnant women with mild and severe preeclampsia. The data suggest a state of increased oxidative stress in pregnant women with preeclampsia compared to healthy pregnant women, which may be related to the complications of this disease.

Oxidative Profile and δ-Aminolevulinate Dehydratase Activity in Healthy Pregnant Women with Iron Supplementation.

An oxidative burst occurs during pregnancy due to the large consumption of oxygen in the tissues and an increase in metabolic demands in response to maternal physiological changes and fetal growth. This study aimed to determine the oxidative profile and activity of δ-aminolevulinate dehydratase (δ-ALA-D) in pregnant women who received iron supplementation. Oxidative stress parameters were evaluated in 25 pregnant women with iron supplementation, 25 pregnant women without supplementation and 25 non-pregnant women. The following oxidative stress parameters were evaluated: thiobarbituric acid reactive substances (TBARS), protein thiol groups (P-SH), non-protein thiol levels (NP-SH), vitamin C levels, catalase and δ-ALA-D activity. Markers of oxidative stress and cell damage, such as TBARS in plasma were significantly higher in pregnant women without supplementation. Levels of P-SH, NP-SH and δ-ALA-D activity were significantly lower in pregnant women without supplementation compared to non-pregnant and pregnant women with supplementation, while vitamin C levels were significantly lower in pregnant women without supplementation when compared to non-pregnant women. The increase in the generation of oxidative species and decrease of antioxidants suggest the loss of physiological oxidative balance during normal pregnancy, which was not observed in pregnant women with iron supplementation, suggesting a protective effect of iron against oxidative damage.

A methodological model for collecting high-quality data on physical activity in developing settings-the experience of the 1993 Pelotas (Brazil) Birth Cohort study.

BACKGROUND: Prospective studies on physical activity (PA), diet, and body composition in adolescents are lacking, particularly outside high-income countries. GOALS: To describe the methods used to assess these variables in the 1993 Pelotas (Brazil) Birth Cohort and to discuss the fieldwork challenges faced and alternatives to overcome them. METHODS: In 2006-07 a subsample of the 1993 Pelotas cohort was revisited. PA was estimated using questionnaires, a combined heart-rate and motion sensor (Acti-Heart), and the ActiGraph GT1M accelerometer. Diet was investigated by questionnaire. Total body water was determined by stable isotopes. Thirty individuals had their total energy expenditure assessed by doubly labeled water. All data were collected at participants' home. RESULTS: The logistics of the fieldwork and the difficulties in undertaking the study and alternatives to overcome them are presented. Preliminary analyses show that 511 individuals were traced (response rate = 90.0%). Compliance of both adolescents and their families for the motion sensors and body-composition measurements was excellent. CONCLUSIONS: The authors conclude that it is feasible to carry out high-quality studies on PA in developing countries. They hope the article will be useful to other researchers interested in carrying out similar studies.