Daiane Bolzan Berlese

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.

Pyruvate Kinase Activity and δ-Aminolevulinic Acid Dehydratase Activity as Biomarkers of Toxicity in Workers Exposed to Lead

Lead (Pb2+) 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. Pb2+ 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 Pb2+ 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.

Enterovirus infections and type 1 diabetes mellitus: is there any relationship?

Several health organizations have classified diabetes mellitus, a metabolic syndrome, as the epidemic of the century, since it affects millions of people worldwide and is one of the top ten causes of death. Type 1 diabetes is considered to be an autoimmune disease, in which autoaggressive T cells infiltrate the islets of Langerhans in the pancreas, leading to the destruction of insulin producing beta cells. The risk of the disease is modulated by genetic factors, mainly genes coding for human leukocyte antigens (HLA). However, the incidence of this disease has increased significantly during the recent decades, which cannot be explained only by genetic factors. Environmental perturbations have also been associated to the development of diabetes. Among these factors, viral triggers have been implicated; particularly enteroviruses, which have been associated to the induction of the disease. Supporting the hypothesis, numerous lines of evidence coming from mouse models and patients with this type of diabetes have shown the association. The present review aims to provide some understanding of how type 1 diabetes occurs and the possible role of enterovirus in this pathology.

Oxidative damage to DNA in independent-living elderly persons and their correlations with sociodemographic, anthropometric, and functional parameters

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, Palavras-chave: Idoso.

PERFIL DEMOGRÁFICO Y CLÍNICO DE PACIENTES PORTADORES DE ENFERMEDAD PULMONAR OBSTRUCTIVA CRÓNICA EN EL SUR DE BRASIL

Objective: To characterize a population of Chronic Obstructive Pulmonary Disease (COPD) patients followed through a Pulmonary Rehabilitation Program (PRP). Methods: the study was observational, descriptive, with 83 patients with a diagnosis of COPD. All patients underwent spirometry and biochemical laboratory tests. Results: 47 men (56.6%) and 36 women (43.4%) were included. The most relevant comorbidity was Hyperten* Fisioterapeuta, Doutora em Ciências Pneumológicas. Professora do curso de fisioterapia da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: cassiac@feevale.br ** Química, Doutora em Bioquímica Toxicológica. Professora do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: daianeb@feevale.br *** Educador Físico, Mestrado em Qualidade Ambiental. Professor do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: rafaelms@feevale.br **** Enfermeira, aluna de Aperfeiçoamento Científico da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: samynh@ hotmail.com ***** Médico, Doutor em Medicina. Professor do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: paulojzt@feevale.br

PERFIL DEMOGRÁFICO E CLÍNICO DE PORTADORES DE DOENÇA PULMONAR OBSTRUTIVA CRÓNICA NO SUL DO BRASIL

Objective: To characterize a population of Chronic Obstructive Pulmonary Disease (COPD) patients followed through a Pulmonary Rehabilitation Program (PRP). Methods: the study was observational, descriptive, with 83 patients with a diagnosis of COPD. All patients underwent spirometry and biochemical laboratory tests. Results: 47 men (56.6%) and 36 women (43.4%) were included. The most relevant comorbidity was Hyperten* Fisioterapeuta, Doutora em Ciências Pneumológicas. Professora do curso de fisioterapia da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: cassiac@feevale.br ** Química, Doutora em Bioquímica Toxicológica. Professora do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: daianeb@feevale.br *** Educador Físico, Mestrado em Qualidade Ambiental. Professor do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: rafaelms@feevale.br **** Enfermeira, aluna de Aperfeiçoamento Científico da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: samynh@ hotmail.com ***** Médico, Doutor em Medicina. Professor do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: paulojzt@feevale.br

DEMOGRAPHIC AND CLINICAL PROFILE OF PATIENTS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE IN SOUTHERN BRAZIL

Objective: To characterize a population of Chronic Obstructive Pulmonary Disease (COPD) patients followed through a Pulmonary Rehabilitation Program (PRP). Methods: the study was observational, descriptive, with 83 patients with a diagnosis of COPD. All patients underwent spirometry and biochemical laboratory tests. Results: 47 men (56.6%) and 36 women (43.4%) were included. The most relevant comorbidity was Hyperten* Fisioterapeuta, Doutora em Ciências Pneumológicas. Professora do curso de fisioterapia da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: cassiac@feevale.br ** Química, Doutora em Bioquímica Toxicológica. Professora do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: daianeb@feevale.br *** Educador Físico, Mestrado em Qualidade Ambiental. Professor do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: rafaelms@feevale.br **** Enfermeira, aluna de Aperfeiçoamento Científico da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: samynh@ hotmail.com ***** Médico, Doutor em Medicina. Professor do Instituto de Ciências da Saúde da Universidade Feevale. Novo Hamburgo, Brasil. E-mail: paulojzt@feevale.br