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Firacative C.,University of Sydney | Firacative C.,Instituto Nacional Of Salud | Trilles L.,University of Sydney | Trilles L.,Institute Pesquisa Clinica Evandro Chagas | Meyer W.,University of Sydney
PLoS ONE | Year: 2012

Background: The Cryptococcus neoformans/C. gattii species complex comprises two sibling species that are divided into eight major molecular types, C. neoformans VNI to VNIV and C. gattii VGI to VGIV. These genotypes differ in host range, epidemiology, virulence, antifungal susceptibility and geographic distribution. The currently used phenotypic and molecular identification methods for the species/molecular types are time consuming and expensive. As Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) offers an effective alternative for the rapid identification of microorganisms, the objective of this study was to examine its potential for the identification of C. neoformans and C. gattii strains at the intra- and inter-species level. Methodology: Protein extracts obtained via the formic acid extraction method of 164 C. neoformans/C. gattii isolates, including four inter-species hybrids, were studied. Results: The obtained mass spectra correctly identified 100% of all studied isolates, grouped each isolate according to the currently recognized species, C. neoformans and C. gattii, and detected potential hybrids. In addition, all isolates were clearly separated according to their major molecular type, generating greater spectral differences among the C. neoformans molecular types than the C. gattii molecular types, most likely reflecting a closer phylogenetic relationship between the latter. The number of colonies used and the incubation length did not affect the results. No spectra were obtained from intact yeast cells. An extended validated spectral library containing spectra of all eight major molecular types was established. Conclusions: MALDI-TOF MS is a rapid identification tool for the correct recognition of the two currently recognized human pathogenic Cryptococcus species and offers a simple method for the separation of the eight major molecular types and the detection of hybrid strains within this species complex in the clinical laboratory. The obtained mass spectra provide further evidence that the major molecular types warrant variety or even species status. © 2012 Firacative et al. Source


Hirschfeld G.,German Pediatric Pain Center | Hirschfeld G.,Witten/Herdecke University | Do Brasil P.E.A.A.,Institute Pesquisa Clinica Evandro Chagas
Journal of Clinical Epidemiology | Year: 2014

Objectives: Many diagnostic studies are aimed at defining "optimal" thresholds. Here, we evaluate the performance of empirically defined optimal thresholds (1) in the sample in which they were defined and (2) in the population from which the sample was drawn. Study Design and Setting: We simulated test results for 120,000 samples varying the number of people without a disease (n between 20 and 500), number of people with a disease (m between 20 and 500), the magnitude of the difference between group means [effect size (ES) between 0.5 and 4], and distributions (normal and log-normal). The thresholds associated with the maximal Youden index were defined as optimal. Performance was defined as the percentage of correct classifications in the sample and when applied to the whole population. Results: At the population level, the thresholds defined for the four ESs (0.5, 0.8, 2, and 4) yielded a median of 59%, 65%, 83%, and 97% correct classifications, respectively. At the sample level, the samples with similar characteristics yielded widely varying estimates of the performance that were systematically higher than at the population level. Conclusion: Researchers need to be careful defining cut points for mean differences that are traditionally considered "large" (ES = 0.8). The diagnostic utility of optimal thresholds needs to be assessed in prospective studies. © 2014 Elsevier Inc. All rights reserved. Source


Lima M.A.,Institute Pesquisa Clinica Evandro Chagas
Arquivos de Neuro-Psiquiatria | Year: 2013

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the CNS caused by reactivation of JC virus (JCV) in a setting of cellular immunosuppression. Originally, PML was observed in patients with advanced HIV infection, lymphoproliferative disorders and transplant recipients. However, the widespread use of HIV antiretroviral drugs and the new selective immunomodulatory and immunosuppressive medications, such as Rituximab and Natalizumab, has recently modified the epidemiology, clinical presentation and prognosis of PML. Herein, we discuss the new concepts on PML, emphasizing the recent modification in the epidemiology; the impact of new immunomodulatory treatments in the disease, PML-IRIS (Immune reconstitution inflammatory síndrome), new treatment strategies and other JCV related CNS diseases. Source


Alves M.G.M.,Federal University of Fluminense | Hokerberg Y.H.M.,Institute Pesquisa Clinica Evandro Chagas | Faerstein E.,State University of Rio de Janeiro
Revista Brasileira de Epidemiologia | Year: 2013

Introduction: Karasek's demand-control model has been used to investigate association between job strain and health outcomes. However, different instruments and definitions have been utilized to assess the exposure 'high strain at work', which makes difficult the comparison of results across studies. Objective: To describe the measurement instruments and the definitions adopted for the exposure variable 'job strain', according to the demand-control model, by observational studies published until 2010. Methods: Systematic review of observational studies published until December 2010, addressing the exposure 'job strain', measured according to the demand-control model and used the JCQ or its derivatives, since explicit. Results: Among 877 selected abstracts, 496 (57%) met the inclusion criteria. It identified a trend towards the increasing production literature on the subject. Most studies were sectional; found no relevant differences among study populations of men and women. Sweden, USA, Japan and Canada accounted for 57% of publications, mostly including more than 1000 participants and diverse occupations. Cardiovascular outcomes and their risk factors were the most studied (45%), followed by those related to mental health (25%). In 71% of the studies used the Job Content Questionnaire (from 2 to 49 items) and 19% of the total, the Swedish version (Demand-Control Questionnaire Swedish). Quadrants of the demand-control exposure were used in 51% of the work, but with different cutoff points; scores of the two dimensions were analyzed separately in 27%, and its ratio in 14% of the total. Social support at work was assessed in 44% of the studies. Conclusion: Karasek's model should continue to raise epidemiological studies and we hope that researchers face these theoretical and methodological issues outstanding. Source


Domingues R.M.S.M.,Institute Pesquisa Clinica Evandro Chagas | Hartz Z.M.A.,New University of Lisbon | Dias A.B.M.,Instituto Fernandes Figueira | Leal M.C.,Escola Nacional de Saude Publica Sergio Arouca
Cadernos de Saude Publica | Year: 2012

The persistence of negative perinatal outcomes in Rio de Janeiro suggests problems in the quality of prenatal care. The most recent study in the city showed that only 38% of prenatal care was adequate. This study aimed to evaluate the adequacy of prenatal care under the Brazilian Unified National Health System in the city of Rio de Janeiro. A cross-sectional study in 2007-2008 interviewed2,422 women receiving prenatal care for low-risk pregnancy. Evaluation of care used the PHPN index, based on guidelines from the Program for Humanization of Prenatal Care and Childbirth (Brazilian Ministry of Health) and an expanded PHPN index, which included clinical-obstetric procedures, prescription of supplementary ferrous sulfate, and educational activities. According to the PHPN index, 38.5% of prenatal care was adequate, as compared to 33.3% based on the expanded PHPN index. Strategies to expand early entry of pregnant women into prenatal care and better use of their contact with the health services in order to promote healthcare measures are essential to correct this situation. Source

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