Marcadores sorológicos de hepatite B em indivíduos submetidos a exames de sangue em unidades de saúde

OBJECTIVE: To study some of the epidemiological aspects of hepatitis B in a non-representative sample of patients seen in health care clinics. METHODS: The study population comprised 632 patients who were seen at health care clinics in the city of Ribeirão Preto, Brazil, for the purpose of blood testing, regardless the reason. After signing a written consent, an additional amount of blood was drawn from the same venous puncture site used to collect the original sample for the testing assigned to the patient at the health care clinic. A questionnaire was applied to each participant, looking for the presence of risk factors for hepatitis B. The blood samples were tested for HBV markers, using immunoenzimatic techniques. RESULTS: The prevalences of HBsAg and anti-HBcAg were 0.3% and 13.9%, respectively. By a logistic regression model, the following variables were significantly associated with the infection: age, time of residency in the city (higher risk among those living for a period less than one year), past history of hepatitis, incarceration and sexual behavior (higher risk among homosexual and bisexual males). CONCLUSIONS: The growing difficulties in obtaining blood samples from a representative group of patients, as done in classic surveys, make it necessary to look for alternative methodologies which can provide information concerning the presence of infectious agents in a community. Though the results cannot be generalized to the population as a whole, the methodology used conveyed some knowledge regarding the circulation of hepatitis B virus. In addition, it makes much easier to obtain agreement from the participants, since it does not add any invasive procedure. Despite the limitations, this methodology may be helpful in epidemiological surveillance of infectious agents known as producing asymptomatic infections in much of the population.OBJETIVO: Estudar aspectos da epidemiologia da hepatite B em pessoas submetidas à coleta de sangue em unidades de saúde. MÉTODOS: Indivíduos dos quais se coletou sangue em unidades de saúde de Ribeirão Preto, independentemente do motivo, foram solicitados a fornecer uma quantidade adicional de material, obtida no momento da coleta e submetida à detecção de marcadores de hepatite B. Simultaneamente, por meio de questionário padronizado, foram obtidas informações de possíveis fatores de risco para a doença. Os dados foram analisados por meio de um modelo de regressão logística. RESULTADOS: As prevalências de HBsAg e de anti-HBcAg foram de 0,3% e 13,9%, respectivamente. Os fatores de risco associados à infecção foram: idade, residência na cidade há menos de um ano, antecedente de hepatite, exposição prévia a casas de correção e homo/bissexualismo masculino. CONCLUSÕES: Devido a dificuldades crescentes de obtenção de sangue de indivíduos sadios, essa pode ser uma alternativa para estudos que objetivem fornecer informações sobre a circulação de agentes infecciosos na população. Embora não se possa generalizar os dados obtidos pela metodologia usada, ela traz conhecimento referente à circulação do vírus de hepatite B

Oxidation of SQSTM1/p62 mediates the link between redox state and protein homeostasis

Cellular homoeostatic pathways such as macroautophagy (hereinafter autophagy) are regulated by basic mechanisms that are conserved throughout the eukaryotic kingdom. However, it remains poorly understood how these mechanisms further evolved in higher organisms. Here we describe a modification in the autophagy pathway in vertebrates, which promotes its activity in response to oxidative stress. We have identified two oxidation-sensitive cysteine residues in a prototypic autophagy receptor SQSTM1/p62, which allow activation of pro-survival autophagy in stress conditions. The Drosophila p62 homologue, Ref(2)P, lacks these oxidation-sensitive cysteine residues and their introduction into the protein increases protein turnover and stress resistance of flies, whereas perturbation of p62 oxidation in humans may result in age-related pathology. We propose that the redox-sensitivity of p62 may have evolved in vertebrates as a mechanism that allows activation of autophagy in response to oxidative stress to maintain cellular homoeostasis and increase cell survival.Peer reviewe

Oxidation of SQSTM1/p62 mediates the link between redox state and protein homeostasis

Cellular homoeostatic pathways such as macroautophagy (hereinafter autophagy) are regulated by basic mechanisms that are conserved throughout the eukaryotic kingdom. However, it remains poorly understood how these mechanisms further evolved in higher organisms. Here we describe a modification in the autophagy pathway in vertebrates, which promotes its activity in response to oxidative stress. We have identified two oxidation-sensitive cysteine residues in a prototypic autophagy receptor SQSTM1/p62, which allow activation of pro-survival autophagy in stress conditions. The Drosophila p62 homologue, Ref(2)P, lacks these oxidation-sensitive cysteine residues and their introduction into the protein increases protein turnover and stress resistance of flies, whereas perturbation of p62 oxidation in humans may result in age-related pathology. We propose that the redox-sensitivity of p62 may have evolved in vertebrates as a mechanism that allows activation of autophagy in response to oxidative stress to maintain cellular homoeostasis and increase cell survival

No contribution of GSTM1 and GSTT1 null genotypes to the risk of neutropenia due to benzene exposure in Southeastern Brazil

Exposure to benzene has been associated with haematological diseases such as neutropenia (NEB) and acute myeloid leukaemia (AML). We tested whether the null genotypes of the GSTM1 and GSTT1 genes, involved in benzene inactivation, altered the risk for NEB in southeastern Brazil. Genomic DNA from 55 NEB patients and 330 controls was analysed by multiplex-polymerase chain reaction. The frequency of the GSTM1, GSTT1 and combined null genotypes was similar in patients and controls (GSTM1, 27.3% vs. 38.8%, p = 0.16; GSTT1, 25.5% vs. 19.7%, p = 0.24; GSTM1/GSTT1, 12.7% vs. 6.7%, p = 0.26; respectively). The distribution of genotype classes in NEB patients was similar to normal controls, suggesting that GSTM1 and GSTT1 null genotypes make no specific contribution to the risk of NEB. As the GSTM1 and GSTT1 null genotypes were previously associated with increased risk for AML in Brazil and elsewhere, we hypothesise that different thresholds of chemical exposure relative to distinct GSTM1 and GSTT1 genotypes may determine whether AML or NEB manifests in benzene exposed individuals from southeastern Brazil. Although indicative, our results still require support by prospective and large scale epidemiological studies, with rigorous assessment of daily chemical exposures and control of the possible contribution of other polymorphic genes involved in benzene metabolism

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

Self-reported diabetes in older people: comparison of prevalences and control measures

OBJECTIVE The objective of this study was to analyze the prevalence of diabetes in older people and the adopted control measures. METHODS Data regarding older diabetic individuals who participated in the Health Surveys conducted in the Municipality of Sao Paulo, SP, ISA-Capital, in 2003 and 2008, which were cross-sectional studies, were analyzed. Prevalences and confidence intervals were compared between 2003 and 2008, according to sociodemographic variables. The combination of the databases was performed when the confidence intervals overlapped. The Chi-square (level of significance of 5%) and the Pearson’s Chi-square (Rao-Scott) tests were performed. The variables without overlap between the confidence intervals were not tested. RESULTS The age of the older adults was 60-69 years. The majority were women, Caucasian, with an income of between > 0.5 and 2.5 times the minimum salary and low levels of schooling. The prevalence of diabetes was 17.6% (95%CI 14.9;20.6) in 2003 and 20.1% (95%CI 17.3;23.1) in 2008, which indicates a growth over this period (p at the limit of significance). The most prevalent measure adopted by the older adults to control diabetes was hypoglycemic agents, followed by diet. Physical activity was not frequent, despite the significant differences observed between 2003 and 2008 results. The use of public health services to control diabetes was significantly higher in older individuals with lower income and lower levels of education. CONCLUSIONS Diabetes is a complex and challenging disease for patients and the health systems. Measures that encourage health promotion practices are necessary because they presented a smaller proportion than the use of hypoglycemic agents. Public health policies should be implemented, and aimed mainly at older individuals with low income and schooling levels. These changes are essential to improve the health condition of older diabetic patients