Objective: Obstructive sleep apnea syndrome is mainly characterized by intermittent hypoxia (IH) during sleep, being associated with several complications. Exposure to IH is the most widely used animal model of sleep apnea, short-term IH exposure resulting in cognitive and neuronal impairment. Pigment epithelium-derived factor (PEDF) is a hypoxia-sensitive factor acting as a neurotrophic, neuroprotective, and antiangiogenic agent. Our study analyzed performance on learning and cognitive tasks, as well as PEDF gene expression and PEDF protein expression in specific brain structures, in rats exposed to long-term IH. Methods: Male Wistar rats were exposed to IH (oxygen concentrations of 21-5%) for 6 weeks-the chronic IH (CIH) group-or normoxia for 6 weeks-the control group. After CIH exposure, a group of rats were allowed to recover under normoxic conditions for 2 weeks (the CIH+N group). All rats underwent the Morris water maze test for learning and memory, PEDF gene expression and PEDF protein expression in the hippocampus, frontal cortex, and temporal cortex being subsequently assessed. Results: The CIH and CIH+N groups showed increased PEDF gene expression in the temporal cortex, PEDF protein expression remaining unaltered. PEDF gene expression and PEDF protein expression remained unaltered in the frontal cortex and hippocampus. Long-term exposure to IH did not affect cognitive function. Conclusions: Long-term exposure to IH selectively increases PEDF gene expression at the transcriptional level, although only in the temporal cortex. This increase is probably a protective mechanism against IH-induced injury.

Keywords: Sleep apnea, central; Disease models, animal; Cognition; Sleep; Sleep apnea, obstructive.

Background: Although the prevalence of smoking among medical students declined steadily between the 1960s and 1980s, it seems to have stabilized in recent years. Objectives: To evaluate temporal trends, over the last 17 years, in the smoking habits of medical students at the Universidade Federal de Pelotas, in the state of Rio Grande do Sul, Brazil, and to identify some possible risk factors for smoking. Method: Cross-sectional surveys with comparable methodologies were conducted in 1986, 1991, 1996 and 2002. Self-administered questionnaires were used. Smokers were defined as those who were smoking at least one cigarette per day for at least one month. Descriptive analyses were carried out, as well as crude evaluations using chi-square tests for heterogeneity and linear trend. In addition, Poisson regression, adjusted for age, was used in order to evaluate the effect of medical school class year on the incidence of smoking. Results: The prevalence of smoking among UFPel medical students was 10.1%, statistically similar to values found in 1991 and 1996. No differences in smoking frequency were found relating to sex, age, or parental smoking. The prevalence of smoking was found to increase progressively over the course of medical school. Conclusions: The downward trend in smoking prevalence among UFPel medical students is being replaced by a stable rate of approximately 10-15%. Anti-smoking campaigns are still necessary in university environments, especially in medical schools.

Keywords: Smoking/trends. Smoking/epidemiology. Medical students/tobacco use cessation. Cross-sectional studies. Questionnaires.

Objective: To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers. Methods: The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic. Results: Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV1 (% of predicted) and relative serum vWF activity (r2 = −0.13; p = 0.009). Conclusions: Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients.

Keywords: von Willebrand factor; Pulmonary disease, chronic obstructive; Endothelial cells.

Objective: To analyze the temporal trends of the incidence and prevalence of tuberculosis, with and without HIV co-infection, as well as of the associated mortality, in Brazil, the Americas, and worldwide. Methods: We collected data related to tuberculosis, with and without HIV co-infection, between 1990 and 2010, in Brazil, the Americas, and worldwide. Temporal trends were estimated by linear regression. Results: We identified a trend toward a decrease in tuberculosis prevalence and mortality, and that trend was more pronounced in Brazil and the Americas than worldwide. There was also a trend toward an increase in the incidence of tuberculosis/HIV co-infection, as well as in the rates of detection of new cases of active and latent tuberculosis. The incidence of tuberculosis was found to trend downward in Brazil, whereas it trended upward worldwide. Tuberculosis incidence rates correlated positively with poverty rates and with HIV incidence rates. Conclusions: Social inequality and the advent of AIDS are the major factors that aggravate the current situation of tuberculosis. In this context, methodical approaches to the assessment of surveillance activities are welcome, because they will identify situations in which the reported tuberculosis data do not reflect the true incidence of this disease.

Keywords: Tuberculosis/epidemiology; HIV; Socioeconomic factors.

Objective: To describe the prevalences of asthma and rhinitis in adolescents (13-14 years of age) in the city of Fortaleza, Brazil, in 2010, comparing the results with those obtained in a prevalence survey conducted in 2006-2007. Methods: This was a cross-sectional study involving probabilistic samples of 3,015 and 3,020 adolescents in surveys conducted in 2006-2007 and 2010, respectively. The International Study of Asthma and Allergies in Childhood protocol was used on both occasions. Results: Comparing the two periods, there were no significant differences regarding cumulative wheezing, active asthma, four or more wheezing attacks within the last year, sleep disturbed by wheezing more than one night per week, and speech-limiting wheezing. The prevalences of exercise-induced wheezing, dry cough at night, and physician-diagnosed asthma were significantly higher in 2010 than in the 2006-2007 period (p < 0.01 for all). The prevalence of physician-diagnosed rhinitis was significantly lower in 2010 (p = 0.01), whereas there were no significant differences between the two periods regarding cumulative rhinitis, current rhinitis, and rhinoconjunctivitis. In both periods, dry cough at night, current rhinitis, and rhinoconjunctivitis were significantly more prevalent in females than in males (p < 0.01 for all). Also in both periods, active asthma, current rhinitis, and rhinoconjunctivitis were more prevalent in private school students than in public school students (p < 0.01 for all). Conclusions: Our data show that the prevalences of asthma and rhinitis symptoms remain high among 13- and 14-year-olds in Fortaleza, predominantly among females and private school students.

Keywords: Asthma/epidemiology; Rhinitis/epidemiology; Adolescent.

Objective: To estimate the evolution of the prevalence of asthma and wheezing among schoolchildren in Brazil from 2012 to 2015, as well as to identify factors associated with both conditions. Methods: This was a cross-sectional study using data from the Brazilian National School-Based Adolescent Health Survey for 2012 and 2015. To characterize the evolution of the prevalence of asthma and wheezing, we used linear regression with weighted-least-squares estimation and presented the annual percent change (APC). Results: During the study period, there was a reduction in the prevalence of wheezing, from 23.2% in 2012 to 22.4% in 2015 (APC, −0.27). The prevalence of asthma increased from 12.4% in 2012 to 16.0% in 2015 (APC, 1.20). The increase in the prevalence of asthma was greatest in the southern region of the country (APC, 2.17). Having any history of smoking and having consumed alcohol in the last 30 days were factors that influenced the prevalence of wheezing and the prevalence of a self-reported diagnosis of asthma during the two years evaluated. Conclusions: There has been an increase in the prevalence of asthma in recent years in Brazil. Our data underscore the importance of improving health strategies and policies aimed at the control of asthma.

Keywords: Asthma/epidemiology; Respiratory sounds; Students.

Objective: To analyze mortality from idiopathic pulmonary fibrosis (IPF) in Brazil over the period 1979-2014. Methods: Microdata were extracted from the Brazilian National Ministry of Health Mortality Database. Only deaths for which the underlying cause was coded as International Classification of Diseases version 9 (ICD-9) 515 or 516.3 (until 1995) or as ICD version 10 (ICD-10) J84.1 (from 1996 onward) were included in our analysis. Standardized mortality rates were calculated for the 2010 Brazilian population. The annual trend in mortality rates was analyzed by joinpoint regression. We calculated risk ratios (RRs) by age group, time period of death, and gender, using a person-years denominator. Results: A total of 32,092 deaths were recorded in the study period. Standardized mortality rates trended upward, rising from 0.24/100,000 population in 1979 to 1.10/100,000 population in 2014. The annual upward trend in mortality rates had two inflection points, in 1992 and 2008, separating three distinct time segments with an annual growth of 2.2%, 6.8%, and 2.4%, respectively. The comparison of RRs for the age groups, using the 50- to 54-year age group as a reference, and for the study period, using 1979-1984 as a reference, were 16.14 (14.44-16.36) and 6.71 (6.34-7.12), respectively. Men compared with women had higher standardized mortality rates (per 100,000 person-years) in all age groups. Conclusion: Brazilian IPF mortality rates are lower than those of other countries, suggesting underdiagnosis or underreporting. The temporal trend is similar to those reported in the literature and is not explained solely by population aging.

Keywords: Idiopathic pulmonary fibrosis/epidemiology; Idiopathic pulmonary fibrosis/mortality; Population dynamics.

Objective: Virulent strains of the Mycobacterium tuberculosis complex, under certain appropriate conditions, grow as characteristic ropes, bundles or serpentine cords known as cord factor or growth in cords. The objective of the present study was to evaluate cord factor detection as a method of achieving presumptive identification of the M. tuberculosis complex, comparing it to conventional typing tests. Methods: A total of 743 strains were analyzed from January of 2002 to December of 2005 in the Mycobacteria Sector of the Adolfo Lutz Institute, located in the city of Santos, Brazil. Samples were obtained from clinical specimens collected from patients with respiratory symptoms treated at basic health clinics in the greater metropolitan area of Santos. Ziehl-Neelsen-stained smears were prepared, 301 (40.5%) in MB/BacT broth and 442 (59.5%) on solid media, either Lowenstein-Jensen or Ogawa-Kudoh. Results: The sensitivity, specificity, positive predictive value and negative predictive value obtained during the performance comparison of the two methods (cord factor detection and conventional typing) using both isolation media were, respectively, 98.5, 88, 97 and 93%. The method was more sensitive on solid medium (100%), and the difference in sensitivity between the two media types was only 2.7%. Conclusions: Taking into consideration the results obtained, we conclude that, in laboratories with a high incidence of M. tuberculosis complex isolation and limited economic resources, cord factor detection is a fast and valid criterion for identifying these mycobacteria using liquid or solid medium. It also enables subsequent conclusive identification tests, as well as additional sensitivity tests when necessary.

Keywords: Laboratory techniques and procedures; Mycobacterium tuberculosis; Cord factors

BACKGROUND: In agreement with other reported studies, wehad previously found a possible association between gender and prognosis in stage I non-small cell lung cancer (NSCLC), showing a higher survival rate among females. OBJECTIVES: The purpose of this study was to further clarify the role of gender as a possible prognostic factor in NSCLC. METHOD: In a retrospective cohort study, we examined the survival of 163 NSCLC patients who underwent curative surgical treatment at the Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) Hospital between 1990 and 1997. Data was analyzed using Kaplan-Meier plots. Additionally, we used the Mann-Whitney test for comparing group survival rates and the Cox regression model to adjust for potential confounding factors. RESULTS: Were included 124 (76.07%) males and 39 (23.93%) females, whose median survival was of 32.3 and 60.6 months, respectively. The 5-year survival was 38.0% for men and 55.4% for women (P=0.030). Considering only stage I patients, survival rates were 44.4% and 81.8% for men and women, respectively (P=0.009). Effect of gender continued after adjustment for several factors (age, hemoglobin, histology, tumor size, type of surgery and postoperative complications). CONCLUSION: This study confirms our previous findings that women live longer after NSCLC surgery when compared to men. This result is only observed at an early stage and persists after adjustment of several factorsP

Keywords: Carcinoma, bronchogenic [surgery]; Carcinoma, bronchogenic [epidemiolgy]; Prognosis; Sex distribution; Disease - free survival.

Objective: To derive reference values from white race adults, for DCO in a sample from different sites in Brazil, through the same equipment model (Sensormedics), and compare the results with the derivatives from Crapo, Miller, Neder equations and from the Global Lung Initiative (GLI) proposal. Methods: The tests were performed according to the norms suggested by ATS/ERS in 2005 in six Brazilian cities, with 120 adult volunteers of each gender, non-smokers, without referred anemia and without lung or cardio diseases. The expected values were derived from linear regressions and the differences between the values forecasted by some authors and the ones observed in the current study were calculated. Results: Among men, the age varied between 25 and 88 years old, and the height varied between 140 and 176 cm. DCO was correlated significantly and positively with the height and negatively with the age. The values forecasted by Crapo, Neder, and Miller equations were higher in comparison with the ones obtained by the current study (p<0.01) in both genders. Among men, the values did not differ when compared to the ones calculated by GLI (p=0.29); among women, the values derived by GLI were slightly higher: 0.99 ml/min/mmHg (p<0.01). Conclusion: new values forecasted for DCO were derived in a sample of white adults in Brazil. The forecasted values are similar to the ones complied by GLI equations and differ from the previously proposed equations.

Keywords: Transfer factor; Pulmonary diffusing capacity; Diffusion; Carbon monoxide; Reference values; Lung function tests.

Objective: To determine the spatial distribution of tuberculosis in the city of Ribeirão Preto, located in the state of São Paulo, Brazil, between 1998 and 2002, with a focus on the potential spatially-dependent nature of its occurrence. Methods: The secondary Epi-Tb database of the Ribeirão Preto Municipal Secretary of Health. Georeferencing of tuberculosis cases was performed using MapInfo 6.5 software, and the Spring program was used for statistical analysis of spatial data. Results: Through analysis of the existing spatial pattern and those of the previous years analyzed, we found a consistent pattern of spatial distribution of tuberculosis in Ribeirão Preto. Although there are areas that were homogeneous in terms of risk, the highest concentrations of cases were found in one zone, consisting of middle- to lower middle-class neighborhoods, located in the northeast part of the city. Conclusion: These results add to the store of knowledge regarding the spatial distribution of tuberculosis in Ribeirão Preto in various periods, emphasizing the importance of space as a methodological alternative to aid the planning, monitoring and evaluation of health care programs, allowing interventions to be more appropriately directed in order to decrease inequalities in the allocation of health care resources.

Keywords: Tuberculosis/epidemiology; Health status indicators; Residence characteristics; Urban health/ statistics & numerical data; Topography, medical

The objective of this study was to describe temporal trends in tuberculosis morbidity and mortality in the state of Santa Catarina, Brazil, between 2002 and 2009. Data regarding mortality and incidence were obtained from the Brazilian Mortality Database and National Case Registry Database, respectively. Crude rates were calculated and standardized by age using the direct method. We estimated annual variation by joinpoint regression, identifying the points at which there were changes in the trends. There was a significant (3.7%) annual decrease in the mortality rate. In the study period, two distinct temporal trends were identified: one between 2002 and 2007, showing a significant (5.9%) annual decrease in the mortality rate; and one between 2007 and 2009, showing an insignificant (2.0%) annual increase. There was also a significant (0.9%) annual reduction in tuberculosis incidence.

Keywords: Tuberculosis/epidemiology; Tuberculosis/mortality; Brazil.

Objective: To investigate the reported cases of tuberculosis and of tuberculosis-HIV co-infection in Brazil between 2002 and 2012. Methods: This was an observational study based on secondary time series data collected from the Brazilian Case Registry Database for the 2002-2012 period. The incidence of tuberculosis was stratified by gender, age group, geographical region, and outcome, as was that of tuberculosis-HIV co-infection. Results: Nationally, the incidence of tuberculosis declined by 18%, whereas that of tuberculosis-HIV co-infection increased by 3.8%. There was an overall decrease in the incidence of tuberculosis, despite a significant increase in that of tuberculosis-HIV co-infection in women. The incidence of tuberculosis decreased only in the 0- to 9-year age bracket, remaining stable or increasing in the other age groups. The incidence of tuberculosis-HIV co-infection increased by 209% in the ≥ 60-year age bracket. The incidence of tuberculosis decreased in all geographical regions except the south, whereas that of tuberculosis-HIV co-infection increased by over 150% in the north and northeast. Regarding the outcomes, patients with tuberculosis-HIV co-infection, in comparison with patients infected with tuberculosis only, had a 48% lower chance of cure, a 50% greater risk of treatment nonadherence, and a 94% greater risk of death from tuberculosis. Conclusions: Our study shows that tuberculosis continues to be a relevant public health issue in Brazil, because the goals for the control and cure of the disease have yet to be achieved. In addition, the sharp increase in the incidence of tuberculosis-HIV co-infection in women, in the elderly, and in the northern/northeastern region reveals that the population of HIV-infected individuals is rapidly becoming more female, older, and more impoverished.

Keywords: Tuberculosis/epidemiology; HIV infections/epidemiology; Comorbidity.

Objective: To analyze the role that low income plays in the development of asthma in children and adolescents. Methods: A case-control study using a questionnaire. Results: A total of 687 participants were studied at a tertiary hospital via the Brazilian Unified Health System. Ages ranged from 5 to 15 years, and 54.7% of the participants were male. Nearly half of the individuals (49.1%) lived in the metropolitan area of the city of Recife, and the remainder lived in the countryside. Most (98.1%) lived in concrete houses or apartments, with a mean of 5.7 rooms and 4.8 occupants per residence. Mean maternal level of education was 6.8 years of schooling. The median monthly per capita income was R$ 103.75 (Brazilian reals). The sample was stratified according to cut-off points related to the national minimum wage (R$ 350.00): <25% of minimum wage = very low income (39% of the sample); <50% of minimum wage = low income (37.3% of the sample); and ≥50% of minimum wage = satisfactory income (23.7% of the sample). There was no association between poverty and development of asthma. Conclusions: Poverty is not protective against asthma in children and adolescents treated via the Brazilian Unified Health System, as we might suppose based on the hygiene hypothesis. However, cohort studies are needed in order to confirm these findings.

Keywords: Asthma; Poverty; National health programs/Brazil; Child; Adolescent; Case-control studies.