Variability in baseline laboratory measurements of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Multi-center epidemiological studies must ascertain that their measurements are accurate and reliable. For laboratory measurements, reliability can be assessed through investigation of reproducibility of measurements in the same individual. In this paper, we present results from the quality control analysis of the baseline laboratory measurements from the ELSA-Brasil study. The study enrolled 15,105 civil servants at 6 research centers in 3 regions of Brazil between 2008-2010, with multiple biochemical analytes being measured at a central laboratory. Quality control was ascertained through standard laboratory evaluation of intra- and inter-assay variability and test-retest analysis in a subset of randomly chosen participants. An additional sample of urine or blood was collected from these participants, and these samples were handled in the same manner as the original ones, locally and at the central laboratory. Reliability was assessed with the intraclass correlation coefficient (ICC), estimated through a random effects model. Coefficients of variation (CV) and Bland-Altman plots were additionally used to assess measurement variability. Laboratory intra and inter-assay CVs varied from 0.86% to 7.77%. From test-retest analyses, the ICCs were high for the majority of the analytes. Notably lower ICCs were observed for serum sodium (ICC=0.50; 95%CI=0.31-0.65) and serum potassium (ICC=0.73; 95%CI=0.60-0.83), due to the small biological range of these analytes. The CVs ranged from 1 to 14%. The Bland-Altman plots confirmed these results. The quality control analyses showed that the collection, processing and measurement protocols utilized in the ELSA-Brasil produced reliable biochemical measurements.

Variability in baseline laboratory measurements of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Multi-center epidemiological studies must ascertain that their measurements are accurate and reliable. For laboratory measurements, reliability can be assessed through investigation of reproducibility of measurements in the same individual. In this paper, we present results from the quality control analysis of the baseline laboratory measurements from the ELSA-Brasil study. The study enrolled 15,105 civil servants at 6 research centers in 3 regions of Brazil between 2008–2010, with multiple biochemical analytes being measured at a central laboratory. Quality control was ascertained through standard laboratory evaluation of intra- and inter-assay variability and test-retest analysis in a subset of randomly chosen participants. An additional sample of urine or blood was collected from these participants, and these samples were handled in the same manner as the original ones, locally and at the central laboratory. Reliability was assessed with the intraclass correlation coefficient (ICC), estimated through a random effects model. Coefficients of variation (CV) and Bland-Altman plots were additionally used to assess measurement variability. Laboratory intra and inter-assay CVs varied from 0.86% to 7.77%. From test-retest analyses, the ICCs were high for the majority of the analytes. Notably lower ICCs were observed for serum sodium (ICC=0.50; 95%CI=0.31–0.65) and serum potassium (ICC=0.73; 95%CI=0.60–0.83), due to the small biological range of these analytes. The CVs ranged from 1 to 14%. The Bland-Altman plots confirmed these results. The quality control analyses showed that the collection, processing and measurement protocols utilized in the ELSA-Brasil produced reliable biochemical measurements.

LAMP2 as a marker of EBV-mediated B lymphocyte transformation in the study of lysosomal storage diseases.

Following the degradative pathway, vesicles loaded with extracellular material, eventually, dock and fuse with lysosomes, acquiring specific membrane markers of these organelles and acid hydrolases responsible for digest their content. The lysosomal-associated membrane protein 2 (LAMP-2), the best characterized lysosomal membrane protein, is found in late stages of endosome maturation and may be used as a marker of lysosome-associated membranes. Lysosomal storage disorders (LSDs) are described by the absence or deficiency in hydrolase activity leading to substrate accumulation within lysosomal components and to the onset of several diseases. It is known that lymphocytes infected by Epstein-Barr virus (EBV) are able to form cytoplasmic vacuoles, which work as a storage compartment for lysosomal acidic hydrolases. At the present study, we validate the EBV as a transforming agent of B lymphocytes in stability studies of long-term stored samples, since the methods used to keep samples in liquid nitrogen and thaw them have all proven to be efficient in samples frozen for up to 2 years. To confirm and investigate some of the most prevalent LSDs in the South of Brazil-Pompe, Fabry and Gaucher diseases-we first measured the enzymatic activity of α-glicosidase, α-galactosidase, and ß-glicosidase in those cytoplasmic-formed vacuoles and then looked to LAMP-2 immunoreactivity by employing confocal microscopy techniques.

Newborn screening for biotinidase deficiency in Brazil: biochemical and molecular characterizations.

Biotinidase deficiency is an inherited metabolic disorder characterized by neurological and cutaneous symptoms. Fortunately, it can be treated and the symptoms prevented by oral administration of the vitamin biotin. Using dried blood-soaked filter paper cards, biotinidase activity was determined in the sera of 225,136 newborns in Brazil. Mutation analysis performed on DNA from 21 babies with low serum biotinidase activity confirmed that 3 had profound biotinidase deficiency (less than 10% of mean normal sera biotinidase activity), 10 had partial biotinidase deficiency (10 to 30% of mean normal serum activity), 1 was homozygous for partial biotinidase deficiency, 4 were heterozygous for either profound or partial deficiency, and 3 were normal. Variability in serum enzyme activities and discrepancies with mutation analyses were probably due to inappropriate handling and storage of samples sent to the laboratory. Obtaining an appropriate control serum at the same time as that of the suspected child will undoubtedly decrease the false-positive rate (0.09%). Mutation analysis can be used to confirm the genotype of these children. The estimated incidence of biotinidase deficiency in Brazil is about 1 in 9,000, higher than in most other countries. Screening and treatment of biotinidase deficiency are effective and warranted. These results strongly suggest that biotinidase deficiency should be included in the newborn mass screening program of Brazil.

Newborn screening for biotinidase deficiency in Brazil: biochemical and molecular characterizations

Biotinidase deficiency is an inherited metabolic disorder characterized by neurological and cutaneous symptoms. Fortunately, it can be treated and the symptoms prevented by oral administration of the vitamin biotin. Using dried blood-soaked filter paper cards, biotinidase activity was determined in the sera of 225,136 newborns in Brazil. Mutation analysis performed on DNA from 21 babies with low serum biotinidase activity confirmed that 3 had profound biotinidase deficiency (less than 10 percent of mean normal sera biotinidase activity), 10 had partial biotinidase deficiency (10 to 30 percent of mean normal serum activity), 1 was homozygous for partial biotinidase deficiency, 4 were heterozygous for either profound or partial deficiency, and 3 were normal. Variability in serum enzyme activities and discrepancies with mutation analyses were probably due to inappropriate handling and storage of samples sent to the laboratory. Obtaining an appropriate control serum at the same time as that of the suspected child will undoubtedly decrease the false-positive rate (0.09 percent). Mutation analysis can be used to confirm the genotype of these children. The estimated incidence of biotinidase deficiency in Brazil is about 1 in 9,000, higher than in most other countries. Screening and treatment of biotinidase deficiency are effective and warranted. These results strongly suggest that biotinidase deficiency should be included in the newborn mass screening program of Brazil.

[Public figures on trial: an assessment of the use of the "jury court" technique for city officials in Santa Catarina, Brazil]. / O homem público em julgamento: avaliação da aplicação da téchnica "tribunal do júri" para dirigentes municipais em Santa Catarina.

This study describes the 'Law Court' technique as applied to City Health Departments in the State of Santa Catarina, in dealing with the issue of obligations on the part of public officials. The project was the first part of a training course for public administrators held in 1997. The article presents the technique's components and results. Some 98% of the 156 participants had a positive opinion of the training course, considering it dynamic/participatory (31%), educational/stimulating reflection (27%), and realistic (24%). The technique fostered the discussion of the main subjects pertaining to the country's Unified Health System (SUS). Although all five juries acquitted the defendants, the issue of ethics was reported by 58% of the participants as the main prerequisite for a public administrator.