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p.2251-2262 Submitted by Rigaud Andréa (andrearigaud16@yahoo.com.br) on 2011-08-30T17:51:30Z No. of bitstreams: 1 repos2010.6.pdf: 243023 bytes, checksum: 98333b427337cc113309ce2af6cc4729 (MD5) Made available in DSpace on 2011-08-30T17:51:30Z (GMT). No. of bitstreams: 1 repos2010.6.pdf: 243023 bytes, checksum: 98333b427337cc113309ce2af6cc4729 (MD5) Previous issue date: 2010-12 Structural equation modeling (SEM) is an important statistical tool for evaluating complex relations in several research areas. In epidemiology, the use and discussion of SEM have been limited thus far. This article presents basic principles and concepts in SEM, including an application using epidemiological data analysis from a study on the determinants of cognitive development in young children, considering constructs related to organization of the child’s home environment, parenting style, and the child’s health status. The relations between the constructs and cognitive development were measured. The results showed a positive association between psychosocial stimulus at home and cognitive development in young children. The article presents the contributions by SEM to epidemiology, highlighting the need for an a priori theoretical model for improving the study of epidemiological questions from a new perspective. Rio de Janeiro

Background The causation of asthma is poorly understood. Risk factors for atopic and non-atopic asthma may be different. This study aimed to analyze the associations between markers of poverty, dirt and infections and wheezing in atopic and non-atopic children. Methods 1445 children were recruited from a population-based cohort in Salvador, Brazil. Wheezing was assessed using the ISAAC questionnaire and atopy defined as allergen-specific IgE ≥0.70 kU/L. Relevant social factors, environmental exposures and serological markers for childhood infections were investigated as risk factors using multivariate multinomial logistic regression. Results Common risk factors for wheezing in atopic and non-atopic children, respectively, were parental asthma and respiratory infection in early childhood. No other factor was associated with wheezing in atopic children. Factors associated with wheezing in non-atopics were low maternal educational level (OR 1.49, 95% CI 0.98-2.38), low frequency of room cleaning (OR 2.49, 95% CI 1.27-4.90), presence of rodents in the house (OR 1.48, 95% CI 1.06-2.09), and day care attendance (OR 1.52, 95% CI 1.01-2.29). Conclusions Non-atopic wheezing was associated with risk factors indicative of poverty, dirt and infections. Further research is required to more precisely define the mediating exposures and the mechanisms by which they may cause non-atopic wheeze.

Helminth infections have been associated with protection against allergy and autoimmune diseases. We investigated the effects of chronic infections with Ascaris lumbricoides and Trichuris trichiura (measured twice over a 5-year period) on cytokine and antibody responses. We collected blood from 1,060 children aged 4 to 11 years living in a poor urban area of Brazil and measured Th1 (gamma interferon [IFN-γ]) and Th2 (interleukin-5 [IL-5] and IL-13) cytokines and the regulatory cytokine IL-10 in unstimulated and stimulated (with mitogen or A . lumbricoides antigens) cultures of peripheral blood leukocytes and levels of total IgE and anti- A . lumbricoides IgG4 and IgE in serum. Intestinal helminth infections were associated with an increased proportion of children producing IL-5 in response to A . lumbricoides and producing IL-10 spontaneously, especially among coinfected and chronically infected children. Helminth infections were associated with a generalized suppression of cytokine responses to mitogen. Levels of total IgE and anti- A . lumbricoides IgG4 and IgE were especially elevated in chronically infected children. In conclusion, intestinal helminth infections were associated with a typical Th2 immune response profile and with the induction of immune hyporesponsiveness that was associated with greater frequencies of the production of spontaneous IL-10.

Texto completo: acesso restrito. p.3160-3167 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-08-26T15:11:27Z No. of bitstreams: 1 Infect. Immun.-2010-Figueiredo-3160-7.pdf: 764823 bytes, checksum: a9219f8d20410b441614a8a8ad700c26 (MD5) Made available in DSpace on 2013-08-26T15:11:27Z (GMT). No. of bitstreams: 1 Infect. Immun.-2010-Figueiredo-3160-7.pdf: 764823 bytes, checksum: a9219f8d20410b441614a8a8ad700c26 (MD5) Previous issue date: 2010 Helminth infections have been associated with protection against allergy and autoimmune diseases. We investigated the effects of chronic infections with Ascaris lumbricoides and Trichuris trichiura (measured twice over a 5-year period) on cytokine and antibody responses. We collected blood from 1,060 children aged 4 to 11 years living in a poor urban area of Brazil and measured Th1 (gamma interferon [IFN-γ]) and Th2 (interleukin-5 [IL-5] and IL-13) cytokines and the regulatory cytokine IL-10 in unstimulated and stimulated (with mitogen or A. lumbricoides antigens) cultures of peripheral blood leukocytes and levels of total IgE and anti-A. lumbricoides IgG4 and IgE in serum. Intestinal helminth infections were associated with an increased proportion of children producing IL-5 in response to A. lumbricoides and producing IL-10 spontaneously, especially among coinfected and chronically infected children. Helminth infections were associated with a generalized suppression of cytokine responses to mitogen. Levels of total IgE and anti-A. lumbricoides IgG4 and IgE were especially elevated in chronically infected children. In conclusion, intestinal helminth infections were associated with a typical Th2 immune response profile and with the induction of immune hyporesponsiveness that was associated with greater frequencies of the production of spontaneous IL-10.

10 p. Submitted by Ana Valéria de Jesus Moura (anavaleria_131@hotmail.com) on 2011-12-11T17:24:14Z No. of bitstreams: 1 1465-9921-11-167.pdf: 308598 bytes, checksum: b19e8980ad52664002f3f839c7513596 (MD5) Made available in DSpace on 2011-12-11T17:24:14Z (GMT). No. of bitstreams: 1 1465-9921-11-167.pdf: 308598 bytes, checksum: b19e8980ad52664002f3f839c7513596 (MD5) Previous issue date: 2010 Background: The causation of asthma is poorly understood. Risk factors for atopic and non-atopic asthma may be different. This study aimed to analyze the associations between markers of poverty, dirt and infections and wheezing in atopic and non-atopic children. Methods: 1445 children were recruited from a population-based cohort in Salvador, Brazil. Wheezing was assessed using the ISAAC questionnaire and atopy defined as allergen-specific IgE ≥0.70 kU/L. Relevant social factors, environmental exposures and serological markers for childhood infections were investigated as risk factors using multivariate multinomial logistic regression. Results: Common risk factors for wheezing in atopic and non-atopic children, respectively, were parental asthma and respiratory infection in early childhood. No other factor was associated with wheezing in atopic children. Factors associated with wheezing in non-atopics were low maternal educational level (OR 1.49, 95% CI 0.98-2.38), low frequency of room cleaning (OR 2.49, 95% CI 1.27-4.90), presence of rodents in the house (OR 1.48, 95% CI 1.06-2.09), and day care attendance (OR 1.52, 95% CI 1.01-2.29). Conclusions: Non-atopic wheezing was associated with risk factors indicative of poverty, dirt and infections. Further research is required to more precisely define the mediating exposures and the mechanisms by which they may cause non-atopic wheeze.

Texto completo: acesso restrito. p.3160-3167 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-08-26T15:11:27Z No. of bitstreams: 1 Infect. Immun.-2010-Figueiredo-3160-7.pdf: 764823 bytes, checksum: a9219f8d20410b441614a8a8ad700c26 (MD5) Made available in DSpace on 2013-08-26T15:11:27Z (GMT). No. of bitstreams: 1 Infect. Immun.-2010-Figueiredo-3160-7.pdf: 764823 bytes, checksum: a9219f8d20410b441614a8a8ad700c26 (MD5) Previous issue date: 2010 Helminth infections have been associated with protection against allergy and autoimmune diseases. We investigated the effects of chronic infections with Ascaris lumbricoides and Trichuris trichiura (measured twice over a 5-year period) on cytokine and antibody responses. We collected blood from 1,060 children aged 4 to 11 years living in a poor urban area of Brazil and measured Th1 (gamma interferon [IFN-γ]) and Th2 (interleukin-5 [IL-5] and IL-13) cytokines and the regulatory cytokine IL-10 in unstimulated and stimulated (with mitogen or A. lumbricoides antigens) cultures of peripheral blood leukocytes and levels of total IgE and anti-A. lumbricoides IgG4 and IgE in serum. Intestinal helminth infections were associated with an increased proportion of children producing IL-5 in response to A. lumbricoides and producing IL-10 spontaneously, especially among coinfected and chronically infected children. Helminth infections were associated with a generalized suppression of cytokine responses to mitogen. Levels of total IgE and anti-A. lumbricoides IgG4 and IgE were especially elevated in chronically infected children. In conclusion, intestinal helminth infections were associated with a typical Th2 immune response profile and with the induction of immune hyporesponsiveness that was associated with greater frequencies of the production of spontaneous IL-10.

The droplet size distribution of 50 batches of multi-chamber bags containing the parenteral nutrition emulsions Intralipid (Kabiven and Kabiven Peripheral) or Structolipid (StructoKabiven and StructoKabiven Peripheral), respectively, has been investigated. The results show that the non-compounded lipid emulsions analysed are in compliance with the United States Pharmacopeia (USP) chapter 729, Method II limit for the droplet size distribution, PFAT(5)

Texto completo: acesso restrito. p. 416-420 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-11-04T15:17:54Z No. of bitstreams: 1 art%3A10.1007%2Fs00127-008-0450-x.pdf: 197553 bytes, checksum: 1b2900205f094fa673b5bb0da5188d42 (MD5) Made available in DSpace on 2013-11-04T15:17:54Z (GMT). No. of bitstreams: 1 art%3A10.1007%2Fs00127-008-0450-x.pdf: 197553 bytes, checksum: 1b2900205f094fa673b5bb0da5188d42 (MD5) Previous issue date: 2009 Objective: Recent studies have shown that asthma represents a major health issue not only in children of developed countries but also in urban centers in some middle-income countries. Brazil has one of the highest prevalences of asthma worldwide. Recently, interest has grown in the relationship between psychosocial factors and asthma. This article examines the relationship between maternal mental disorders and the prevalence of asthma in low-income children from an inner city area of Salvador in the state of Bahia, Brazil, and is part of the SCAALA program (Social Change, Allergy and Asthma in Latin America). Patients and methods: A total of 1,087 children between the ages of 5 and 12 were investigated, together with their mothers. The mothers’ mental health was evaluated using the SRQ-20, an instrument for the psychiatric screening of minor psychiatric disorders (depression, anxiety and somatic complaints). The prevalence of asthma was investigated using the ISAAC survey, a standardized, validated questionnaire for asthma and other allergic diseases. Cases were defined as asthma if the patient reported having had wheezing in the previous 12 months in addition to at least one of the following: having asthma, wheezing while exercising, waking during the night because of wheezing, or having had at least four episodes of wheezing in the previous 12 months. Atopy was defined as a positive skin prick test to allergens. Results and conclusion: The presence of minor psychiatric disorders in the mothers was significantly associated with the presence of asthma in the children, and this association was consistent with all forms of asthma, irrespective of whether it was atopic or nonatopic. Future studies should be carried out to further investigate this association and the potential biological mechanisms involved. Programs for asthma control should include strategies for stress reduction and psychological support for the families of asthmatic children.

Many epidemiologic studies involve the occurrence of recurrent events and much attention has been given for the development of modeling techniques that take into account the dependence structure of multiple event data. This paper presents a time-dependent coefficient rates model that incorporates regression splines in its estimation procedure. Such methods would be appropriate in situations where the effect of an exposure or covariates changes over time in recurrent event data settings. The finite sample properties of the estimators are studied via simulation. Using data from a randomized community trial that was designed to evaluate the effect of vitamin A supplementation on recurrent diarrheal episodes in small children, we model the functional form of the treatment effect on the time to the occurrence of diarrhea. The results describe how this effect varies over time. In summary, we observed a major impact of the vitamin A supplementation on diarrhea after 2 months of the dosage, with the effect diminishing after the third dosage. The proposed method can be viewed as a flexible alternative to the marginal rates model with constant effect in situations where the effect of interest may vary over time.

Background Control of soil-transmitted helminth (STH) infections relies on the periodic and long-term administration of anthelmintic drugs to high-risk groups, particularly school-age children living in endemic areas. There is limited data on the effectiveness of long-term periodic anthelmintic treatment on the prevalence of STHs, particularly from operational programmes. The current study investigated the impact of 15 to 17 years of treatment with the broad-spectrum anthelmintic ivermectin, used for the control of onchocerciasis, on STH prevalence and intensity in school-age and pre-school children. Methods and Findings A cross-sectional study was conducted in communities that had received annual or twice-annual ivermectin treatments and geographically adjacent communities that had not received treatment in two districts of Esmeraldas Province in Ecuador. Stool samples were collected from school-age children and examined for STH infection using the Kato-Katz and formol-ether concentration methods. Samples were collected also from pre-school children and examined by the formol-ether concentration method. Data on risk factors for STH infection were collected by parental questionnaire. We sampled a total of 3,705 school-age children (6–16 years) from 31 treated and 27 non-treated communities, and 1,701 pre-school children aged 0–5 years from 18 treated and 18 non-treated communities. Among school-age children, ivermectin treatment had significant effects on the prevalence (adjusted OR = 0.06, 95% CI 0.03–0.14) and intensity of Trichuris trichiura infection (adjusted RR = 0.28, 95% CI 0.11–0.70), but appeared to have no impact on Ascaris lumbricoides or hookworm infection. Reduced prevalence and intensities of T. trichiura infection were observed among children not eligible to receive ivermectina, providing some evidence of reduced transmission of T. trichiura infection in communities receiving mass ivermectin treatments. Conclusion Annual and twice-annual treatments with ivermectin over a period of up to 17 years may have had a significant impact on T. trichiura infection. The present data indicate that the long-term control of onchocerciasis with ivermectin may provide additional health benefits by reducing infections with trichuriasis. The addition of a second anthelmintic drug such as albendazole may be useful for a long-term effect on A. lumbricoides infection., Author Summary Soil-transmitted helminth (intestinal worm) infections are very common in developing countries and are an important cause of illness. Mass de-worming treatments of school children are an important strategy to reduce illness caused by these infections in communities without access to clean water and sanitation. Few studies have examined the effect of repeated mass treatments in the long-term in controlling these infections. The objective of the present study was to assess the impact of the drug ivermectin used for the control of onchocerciasis (river blindness), that has important effects against intestinal worms, on the epidemiology of intestinal worms in children when administered repeatedly for 15–17 years. We compared the epidemiology of infections between children living in communities that received ivermectin with communities that never received the drug. The data suggest that ivermectin has important differential effects on intestinal worms with a greater impact on infections with Trichuris trichiura and little impact on Ascaris lumbricoides and hookworms infections. Our data suggest that long-term ivermectin treatments may provide health benefits through effects on T. trichiura infections but that the addition of second de-worming drug such as albendazole may be required for the control of other intestinal worm infections.

Purpose: Metabolic syndrome (MS) is a clustering of cardiovascular disease risk factors that identifies individuals with the highest risk for heart disease. Two factors that may influence the MS are physical activity and aerobic fitness. This study determined if adolescent with the MS had low levels of aerobic fitness and physical activity as children. Methods: This longitudinal, exploratory study had 389 participants: 51% girls, 84% Caucasian, 12% African American, 1% Hispanic, and 3% other races, from the State of North Carolina. Habitual physical activity (PA survey), aerobic fitness (VO2max), body mass index (BMI), blood pressure, and lipids obtained at 7–10 y of age were compared to their results obtained 7 y later at ages 14–17 y. Results: Eighteen adolescents (4.6%) developed 3 or more characteristics of the MS. Logistic regression, adjusting for BMI percentile, blood pressure, and cholesterol levels, found that adolescents with the MS were 6.08 (95%CI = 1.18–60.08) times more likely to have low aerobic fitness as children and 5.16 (95%CI = 1.06–49.66) times more likely to have low PA levels. Conclusion: Low levels of childhood physical activity and aerobic fitness are associated with the presence of the metabolic syndrome in adolescents. Thus, efforts need to begin early in childhood to increase exercise.

Recent studies have shown that asthma represents a major health issue not only in children of developed countries but also in urban centers in some middle-income countries. Brazil has one of the highest prevalences of asthma worldwide. Recently, interest has grown in the relationship between psychosocial factors and asthma. This article examines the relationship between maternal mental disorders and the prevalence of asthma in low-income children from an inner city area of Salvador in the state of Bahia, Brazil, and is part of the SCAALA program (Social Change, Allergy and Asthma in Latin America).A total of 1,087 children between the ages of 5 and 12 were investigated, together with their mothers. The mothers' mental health was evaluated using the SRQ-20, an instrument for the psychiatric screening of minor psychiatric disorders (depression, anxiety and somatic complaints). The prevalence of asthma was investigated using the ISAAC survey, a standardized, validated questionnaire for asthma and other allergic diseases. Cases were defined as asthma if the patient reported having had wheezing in the previous 12 months in addition to at least one of the following: having asthma, wheezing while exercising, waking during the night because of wheezing, or having had at least four episodes of wheezing in the previous 12 months. Atopy was defined as a positive skin prick test to allergens.The presence of minor psychiatric disorders in the mothers was significantly associated with the presence of asthma in the children, and this association was consistent with all forms of asthma, irrespective of whether it was atopic or nonatopic. Future studies should be carried out to further investigate this association and the potential biological mechanisms involved. Programs for asthma control should include strategies for stress reduction and psychological support for the families of asthmatic children.

Background Many epidemiologic studies report the odds ratio as a measure of association for cross-sectional studies with common outcomes. In such cases, the prevalence ratios may not be inferred from the estimated odds ratios. This paper overviews the most commonly used procedures to obtain adjusted prevalence ratios and extends the discussion to the analysis of clustered cross-sectional studies. Methods Prevalence ratios(PR) were estimated using logistic models with random effects. Their 95% confidence intervals were obtained using delta method and clustered bootstrap. The performance of these approaches was evaluated through simulation studies. Using data from two studies with health-related outcomes in children, we discuss the interpretation of the measures of association and their implications. Results The results from data analysis highlighted major differences between estimated OR and PR. Results from simulation studies indicate an improved performance of delta method compared to bootstrap when there are small number of clusters. Conclusion We recommend the use of logistic model with random effects for analysis of clustered data. The choice of method to estimate confidence intervals for PR (delta or bootstrap method) should be based on study design.

p. 1-10 Submitted by JURANDI DE SOUZA SILVA (jssufba@hotmail.com) on 2012-05-24T12:58:38Z No. of bitstreams: 1 C__Documents and Settings_rep...t.default_Cache_9_6C_C324Bd01.pdf: 221014 bytes, checksum: 8ba8e2e7cacdcee671615b8ec3e84504 (MD5) Made available in DSpace on 2012-05-24T12:58:38Z (GMT). No. of bitstreams: 1 C__Documents and Settings_rep...t.default_Cache_9_6C_C324Bd01.pdf: 221014 bytes, checksum: 8ba8e2e7cacdcee671615b8ec3e84504 (MD5) Previous issue date: 2008 Background: Many epidemiologic studies report the odds ratio as a measure of association for cross-sectional studies with common outcomes. In such cases, the prevalence ratios may not be inferred from the estimated odds ratios. This paper overviews the most commonly used procedures to obtain adjusted prevalence ratios and extends the discussion to the analysis of clustered cross-sectional studies. Methods: Prevalence ratios(PR) were estimated using logistic models with random effects. Their 95% confidence intervals were obtained using delta method and clustered bootstrap. The performance of these approaches was evaluated through simulation studies. Using data from two studies with health-related outcomes in children, we discuss the interpretation of the measures of association and their implications. Results: The results from data analysis highlighted major differences between estimated OR and PR. Results from simulation studies indicate an improved performance of delta method compared to bootstrap when there are small number of clusters.Conclusion: We recommend the use of logistic model with random effects for analysis of clustered data. The choice of method to estimate confidence intervals for PR (delta or bootstrap method) should be based on study design.

p. 1-9 Submitted by JURANDI DE SOUZA SILVA (jssufba@hotmail.com) on 2012-06-04T20:11:53Z No. of bitstreams: 1 journal.pntd.0000293-1.pdf: 175772 bytes, checksum: 010d100a4fcc236ec4ba8c2d29443105 (MD5) Made available in DSpace on 2012-06-04T20:11:53Z (GMT). No. of bitstreams: 1 journal.pntd.0000293-1.pdf: 175772 bytes, checksum: 010d100a4fcc236ec4ba8c2d29443105 (MD5) Previous issue date: 2008 Background: Control of soil-transmitted helminth (STH) infections relies on the periodic and long-term administration of anthelmintic drugs to high-risk groups, particularly school-age children living in endemic areas. There is limited data on the effectiveness of long-term periodic anthelmintic treatment on the prevalence of STHs, particularly from operational programmes. The current study investigated the impact of 15 to 17 years of treatment with the broad-spectrum anthelmintic ivermectin, used for the control of onchocerciasis, on STH prevalence and intensity in school-age and preschool children. Methods and Findings: A cross-sectional study was conducted in communities that had received annual or twice-annual ivermectin treatments and geographically adjacent communities that had not received treatment in two districts of Esmeraldas Province in Ecuador. Stool samples were collected from school-age children and examined for STH infection using the Kato-Katz and formol-ether concentration methods. Samples were collected also from pre-school children and examined by the formol-ether concentration method. Data on risk factors for STH infection were collected by parental questionnaire. We sampled a total of 3,705 school-age children (6–16 years) from 31 treated and 27 non-treated communities, and 1,701 pre-school children aged 0–5 years from 18 treated and 18 non-treated communities. Among school-age children, ivermectin treatment had significant effects on the prevalence (adjusted OR = 0.06, 95% CI 0.03–0.14) and intensity of Trichuris trichiura infection (adjusted RR = 0.28, 95% CI 0.11–0.70), but appeared to have no impact on Ascaris lumbricoides or hookworm infection. Reduced prevalence and intensities of T. trichiura infection were observed among children not eligible to receive ivermectina, providing some evidence of reduced transmission of T. trichiura infection in communities receiving mass ivermectin treatments. Conclusion: Annual and twice-annual treatments with ivermectin over a period of up to 17 years may have had a significant impact on T. trichiura infection. The present data indicate that the long-term control of onchocerciasis with ivermectin may provide additional health benefits by reducing infections with trichuriasis. The addition of a second anthelmintic drug such as albendazole may be useful for a long-term effect on A. lumbricoides infection.

Texto completo: acesso restrito. p. 5890-5906 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-11-19T14:13:15Z No. of bitstreams: 1 10.1002-sim.3400.pdf: 181138 bytes, checksum: 0e846ea7fb1f49fc09b2499df09fb226 (MD5) Made available in DSpace on 2013-11-19T14:13:15Z (GMT). No. of bitstreams: 1 10.1002-sim.3400.pdf: 181138 bytes, checksum: 0e846ea7fb1f49fc09b2499df09fb226 (MD5) Previous issue date: 2008 Many epidemiologic studies involve the occurrence of recurrent events and much attention has been given for the development of modeling techniques that take into account the dependence structure of multiple event data. This paper presents a time-dependent coefficient rates model that incorporates regression splines in its estimation procedure. Such methods would be appropriate in situations where the effect of an exposure or covariates changes over time in recurrent event data settings. The finite sample properties of the estimators are studied via simulation. Using data from a randomized community trial that was designed to evaluate the effect of vitamin A supplementation on recurrent diarrheal episodes in small children, we model the functional form of the treatment effect on the time to the occurrence of diarrhea. The results describe how this effect varies over time. In summary, we observed a major impact of the vitamin A supplementation on diarrhea after 2 months of the dosage, with the effect diminishing after the third dosage. The proposed method can be viewed as a flexible alternative to the marginal rates model with constant effect in situations where the effect of interest may vary over time.

Background Cluster designs have become increasingly popular in many research areas. Adopting these designs requires special considerations because individuals within the same cluster may be correlated. Therefore, appropriate sample size calculations in these settings require the incorporation of additional information regarding intraclass or intracluster correlations (ICCs), which measure the degree of similarity between individuals within the same cluster or class. Objectives To discuss the importance of the ICC in cluster-designed studies and present ICC estimates for selected physiologic characteristics in children and adolescents. Method The ICCs for body mass index (BMI), sum of skinfolds (SSF), blood pressure, glucose, insulin, and lipids were determined using baseline data from the Cardiovascular Health in Children and Youth Studies (CHIC II and III). The ICC estimates presented were obtained through the use of mixed models for the entire data set and separately by age groups, gender, and ethnicity. Results The estimated ICCs ranged from .0104 for BMI to .1657 for glucose. The differences in the estimated ICCs among the three age groups were most marked for blood pressure, SSF, and glucose and were small for aerobic power, insulin, and lipids. The greatest difference in ICC by gender was in BMI and SSF: The ICC for SSF in girls was 8.2 times larger than that for boys. Caucasians had higher ICC estimates for insulin than did African Americans and other ethnic groups. Discussion The magnitude of the ICC varied by the outcome of interest, and factors such as age, gender, and ethnicity also influenced the magnitude of the ICC. The presence of ICCs should be assumed when using cluster designs, and ICCs should be considered when conducting sample size calculations for such studies.

Cryo-transmission electron microscopy (cryo-TEM) was used to image the microstructure in dilute sonicated dispersions of monoolein and oleic acid. The aim of the study was to explore how different experimental parameters, such as sample composition, total lipid concentration, pH, and ageing affect the phase behaviour and aggregate structure. Our investigations show that a rich variety of lamellar and non-lamellar structures, including liposomes and particles of cubic and inverted hexagonal phase, may form depending on the experimental conditions. The results are analyzed and discussed in relation to existing phase diagrams and earlier investigations concerning phase- and structural behaviour in monoolein/oleic acid/water systems.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:41:04Z No. of bitstreams: 1 S1516-93322004000100008.pdf: 336776 bytes, checksum: 04b10d8b1f345d8646c4b0d2f54551f3 (MD5) Made available in DSpace on 2013-08-22T18:41:04Z (GMT). No. of bitstreams: 1 S1516-93322004000100008.pdf: 336776 bytes, checksum: 04b10d8b1f345d8646c4b0d2f54551f3 (MD5) Previous issue date: 2004-03-01 Made available in DSpace on 2013-09-30T18:07:24Z (GMT). No. of bitstreams: 2 S1516-93322004000100008.pdf: 336776 bytes, checksum: 04b10d8b1f345d8646c4b0d2f54551f3 (MD5) S1516-93322004000100008.pdf.txt: 25775 bytes, checksum: 0644b0f8000196c70640c726038679a5 (MD5) Previous issue date: 2004-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:25:17Z No. of bitstreams: 2 S1516-93322004000100008.pdf: 336776 bytes, checksum: 04b10d8b1f345d8646c4b0d2f54551f3 (MD5) S1516-93322004000100008.pdf.txt: 25775 bytes, checksum: 0644b0f8000196c70640c726038679a5 (MD5) Made available in DSpace on 2014-05-20T13:25:17Z (GMT). No. of bitstreams: 2 S1516-93322004000100008.pdf: 336776 bytes, checksum: 04b10d8b1f345d8646c4b0d2f54551f3 (MD5) S1516-93322004000100008.pdf.txt: 25775 bytes, checksum: 0644b0f8000196c70640c726038679a5 (MD5) Previous issue date: 2004-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Foram preparados complexos de inclusão de rifampicina (RP) com hidroxipropil-²-ciclodextrina (HP²CD). A solubilidade da RP em água aumentou linearmente com a concentração de ciclodextrina na faixa de concentração utilizada no diagrama de solubilidade. Os resultados foram analisados quantitativamente através do modelo de Higuchi e Connors. Os valores da constante de estabilidade (K) para o complexo RP/HP²CD em pH 6,9 foram 18 e 120-125 M-1 para as forças iônicas 0,01 e 0,18 M, respectivamente. A análise dos dados de deslocamento químico de ¹H e 15N-NMR para a RP livre e do complexo de inclusão RP/HP²CD revelou que somente os picos da cadeia lateral relacionada com o anel piperazina modificaram substancialmente, provavelmente devido à interação desta região da molécula da RP com a cavidade hidrofóbica da HP²CD. Com base no estudo de modelagem molecular foi proposta a estrutura otimizada para o complexo de inclusão RP/HP²CD. A estrutura proposta está de acordo com os resultados dos espectros de ¹H e 13C-NMR e 15N-NMR . Inclusion complexes of rifampicin (RP) were prepared with hydroxypropyl-²-cyclodextrin (HP²CD). The aqueous solubility of RP increased linearly with cyclodextrin concentration in all range of the solubility diagram. The data was analyzed using the framework of Higuchi and Connors. The stability constant (K) values for RP/HP²CD complex at pH 6.9 were 18 and 120-125 M-1 for ionic strength 0.01 and 0.18M, respectively. The analysis of the chemical shift data of ¹H and 15N for free RP and RP/HP²CD inclusion complex reveal that only peaks of the side chain related to the piperazine ring of RP change substantially, probably due to interaction of this region of RP molecule with the hydrophobic core of HP²CD. We also postulated the optimized structure of RP/HP²CD inclusion complex using molecular modelling study. We found that the postulated structure was in agreement with ¹H and 13C-NMR and 15N-NMR spectra. Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Farmacêuticas Departamento de Fármacos e Medicamentos Universidade Federal de São Carlos (UFSCar) Departamento de Química Laboratório de RMN Universidade de São Paulo Faculdade de Ciências Farmacêuticas de Ribeirão Preto Laboratório de Química Farmacêutica Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Farmacêuticas Departamento de Fármacos e Medicamentos

Serotypes of dengue DEN-1 and DEN-2 have been reported in much of Brazil over the last 15 years, and DEN-3 serotype was only recently detected. This prospective study was conducted in Salvador, a large city in north-east Brazil, where two epidemics were previously recorded (DEN-1 and DEN-2). We obtained the seroprevalence and 1-year incidence of dengue infections in the population of 30 sampling areas of Salvador and analysed the relationship between intensity of viral circulation, standard of living and vector density. High seroprevalence (68.7%) and annual incidence (70.6%) of infection for one or both circulating serotypes (DEN-1 and DEN-2) were found. High rates of transmission were observed in all studied areas, from the highest to the lowest socio-economic status. The mean PI (Premise Index) for Aedes aegypti was 7.4% (range 0.27-25.6%). Even in the areas with the lowest PI (

No atual estágio do conhecimento científico, a única medida de controle disponível para as infecções causadas pelo vírus da dengue é a eliminação do seu principal vetor urbano, o Aedes aegypti. O Brasil há muitas décadas desenvolve programas de combate a este mosquito; entretanto, observa-se desde o início dos anos oitenta uma expansão geográfica da infestação do seu território e circulação progressiva e intensa deste vírus, com registro de grandes epidemias e de transmissão endêmica em diferentes centros urbanos. Esta situação epidemiológica evidencia a existência de dificuldades para o controle destas infecções, razão pela qual o Ministério da Saúde solicitou uma avaliação da efetividade das ações que vinham sendo implementadas na cidade de Salvador pelo atual programa de combate vetorial, sendo o objetivo deste artigo apresentar os resultados deste estudo. Foi utilizado um desenho prospectivo, procedendo-se a inquéritos sorológicos de uma população amostral de indivíduos residentes em 30 distintos espaços da cidade - "áreas sentinelas". Os resultados revelaram elevadas soroprevalência (67,7%) e soroincidência (70,6%) para os sorotipos circulantes (DEN-1 e DEN-2), com grande variabilidade nos valores entre as 30 áreas estudadas. Verificou-se que a efetividade das medidas de combate vetorial é muito reduzida e, embora tenha sido encontrada uma Fração Prevenível de 29,7 %, mesmo em áreas sentinelas com Índices de Infestação Predial

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2012-11-03T06:01:41Z No. of bitstreams: 1 A Community Per Intern 2012.pdf: 90901 bytes, checksum: dca7626ce35c4b879267f9290a9a26bd (MD5) Made available in DSpace on 2012-11-03T06:01:41Z (GMT). No. of bitstreams: 1 A Community Per Intern 2012.pdf: 90901 bytes, checksum: dca7626ce35c4b879267f9290a9a26bd (MD5) Previous issue date: 2012-05 Background: Asthma constitutes a serious public health problem in many regions of the world, including the city of Salvador, State of Bahia – Brazil. The purpose of this study was to analyse the factors associated with poor asthma control. Methodology/Principal Findings: Two definitions were used for asthma: 1) wheezing in the last 12 months; 2) wheezing in the last 12 months plus other asthma symptoms or asthma diagnosis ever. The definition of poorly controlled asthma was: at least one reported hospitalisation due to asthma and/or high frequency of symptoms, in the last year. Children with poorly controlled asthma (N = 187/374) were compared with wheezing children with controlled asthma regarding age, gender, atopy, parental asthma, rhinitis, eczema, exposure to second hand tobacco smoke, presence of moulds, pets and pests in the house, helminth infections and body mass index. Crude and logistic regression adjusted odds ratios were used as measures of association. There was a higher proportion of poorly controlled asthma among children with eczema (OR = 1.55; 95% CI 1.02; 2.37). The strength of the association was greater among children with eczema and rhinitis (42.6%,53.4% and 57.7%, respectively, in children who had no rhinitis nor eczema, had only one of those, and had both (p = 0.02 for trend test). The presence of mould in the houses was inversely associated with poorly controlled asthma (OR = 0.54; 95% CI 0.34; 0.87). Conclusions/Significance: Our results indicate an association between eczema and poor asthma control in this environment, but emphasize the role of various other individual and environmental factors as determinants of poor control. San Francisco

Summary Background Allergic diseases cause a large and increasing burden in developed countries and in urban centres in middle-income countries. The causes of this increase are unknown and, currently, there are no interventions to prevent the development of allergic diseases. The ‘hygiene hypothesis’ has tried to explain the increase through a reduction in the frequency of childhood infections causing a failure to program the immune system for adequate immune regulation. Intestinal helminth parasites are prevalent in childhood in developing countries and are associated with a lower prevalence of allergen skin test reactivity and asthma. Objectives To investigate whether children who had intestinal helminth infections during early childhood have a lower prevalence of allergen skin test reactivity later in childhood. Methods We re-visited a population of 1055 children from whom stool samples had been collected for detection of intestinal helminth infections for another study, and collected new stool samples and performed allergen skin prick testing. Information on potential confounding variables was collected. Results Children with heavy infections with Trichuris trichiura in early childhood had a significantly reduced prevalence of allergen skin test reactivity in later childhood, even in the absence of T. trichiura infection at the time of skin testing in later childhood. Conclusion Early heavy infections with T. trichiura may protect against the development of allergen skin test reactivity in later childhood. Novel treatments to program immune-regulation in early childhood in a way that mimics the effects of early infections with T. trichiura may offer new strategies for the prevention of allergic disease.

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2017-05-26T17:49:04Z No. of bitstreams: 1 Ines Dourado 3. 2016.pdf: 277312 bytes, checksum: ea4d3b8eab90f5797178f0722643e857 (MD5) Made available in DSpace on 2017-05-26T17:49:04Z (GMT). No. of bitstreams: 1 Ines Dourado 3. 2016.pdf: 277312 bytes, checksum: ea4d3b8eab90f5797178f0722643e857 (MD5) Diante das evidências de que os homens que fazem sexo com homens são afetados de forma desproporcional pelas infecções por HIV, investigamos os fatores de risco sociodemográficos, biológicos e de comportamentos sexuais associados à infecção por HIV, na cidade de Salvador, Bahia. Este trabalho é um recorte da pesquisa nacional "Comportamento, atitudes, práticas e prevalência de HIV e Sífilis entre homens que fazem sexo com homens em 10 cidades brasileiras", que foi do tipo corte transversal e selecionou participantes via técnica Respondent Driven Sampling . Devido à prevalência do HIV ser menor do que 10% e ao reduzido tamanho da amostra (383), utilizamos regressão logística exata nas análises para medir associação entre os fatores de risco e a infecção por HIV. A prevalência do HIV foi de 6,3% (IC95% 3,9 - 8,8), e após o ajuste do modelo final, os fatores de vulnerabilidade que se associaram à infecção por HIV foram: não fez teste de sífilis na vida (OR = 3,1: IC95% 1,3 - 7,3), ter mais de 8 parceiros sexuais (OR = 3,3; IC95% 1,4 - 8,1). Este estudo mostrou a alta prevalência do HIV na amostra, em comparação a população geral, bem como confirmou a importância da realização do teste de sífilis na vida no contexto da epidemia do HIV, sendo que essa detecção precoce permite uma aproximação das ações de prevenção para DST. São Paulo

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2021-08-17T20:12:55Z No. of bitstreams: 1 DISSERTAÇÃO-ACACIA-MAYRA-PEREIRA-LIMA.pdf: 2861650 bytes, checksum: 91ce6caeb16599e1e4c0945f9a51ffc1 (MD5) Approved for entry into archive by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2021-08-19T17:59:48Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO-ACACIA-MAYRA-PEREIRA-LIMA.pdf: 2861650 bytes, checksum: 91ce6caeb16599e1e4c0945f9a51ffc1 (MD5) Made available in DSpace on 2021-08-19T17:59:48Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO-ACACIA-MAYRA-PEREIRA-LIMA.pdf: 2861650 bytes, checksum: 91ce6caeb16599e1e4c0945f9a51ffc1 (MD5) Introdução: O uso de profilaxia pós-exposição ao HIV (PEP) é fundamental para as mulheres e especialmente para mulheres trabalhadoras do sexo (MTS) como um método de prevenção da transmissão do HIV. No entanto, as MTS ainda enfrentam barreiras ao acesso a PEP em muitos lugares, inclusive no Brasil. Nosso objetivo foi analisar os fatores associados ao uso de PEP entre MTS após agressão sexual no Brasil. Metodologia: Estudo transversal de 4.245 MTS recrutadas em 12 cidades brasileiras por amostra respondente (RDS) em 2016. As participantes foram entrevistadas e as associações de variáveis comportamentais, sociodemográficas, relacionadas aos serviços de saúde, apoio social e histórico de violência e discriminação com o uso da PEP após a agressão sexual foram analisadas. Para cada cidade, os indivíduos foram ponderados usando o estimador RDSII. Os dados combinados foram analisados pelo procedimento de amostra complexa do STATA 14, usando cada cidade como um estrato e cada grupo de mulheres recrutadas pela mesma TS como um cluster. Odds ratios e IC95% foram estimados por meio de regressão logística. Resultados: Das 4245 MTS 1174 relataram ter sido vítima de violência sexual alguma vez na vida (26,3%). A maioria delas apresentavam idade abaixo dos 30 anos e 19,6% não concluíram o ensino médio. 18% se autodeclararam pretas; com baixo nível socioeconômico e 8,2% afirmaram conhecer a PEP. Após a violência sexual, 7,5% afirmaram ter utilizado PEP, 18,7% procuraram um serviço de saúde, mas não tiveram acesso à PEP e 73,8% não procuraram assistência em saúde. Os fatores associados ao uso da PEP após a agressão sexual foram: conhecimento de PEP (OR: 3,71); participação em atividades educativas sobre HIV (OR: 1,53); revelar ser trabalhadora do sexo nos serviços de saúde (OR: 1,80) e o número de clientes por dia (1-9 versus 10 ou mais) (OR: 6,67). Conclusões: Apesar da política existente para vítimas de violência sexual no Brasil que inclui o serviço de PEP, o uso da tecnologia de prevenção após violência sexual foi extremamente baixo entre MTS, mesmo para aquelas que procuraram assistência de saúde, indicando iniquidade no acesso. Triagem, documentação e cuidados para vítimas de violência sexual, como aconselhamento e engajamento em cuidados adequados são essenciais para promover o acesso a serviços preventivos para HIV. Os serviços de saúde devem estar melhor qualificados para cuidar de vítimas de violência sexual.

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2018-07-06T12:44:40Z No. of bitstreams: 1 Tese Final. Caroline Feitosa. 2017.pdf: 1907972 bytes, checksum: af3cb94a7dd03e4d4533a0c25a96e61f (MD5) Approved for entry into archive by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2018-07-11T17:42:23Z (GMT) No. of bitstreams: 1 Tese Final. Caroline Feitosa. 2017.pdf: 1907972 bytes, checksum: af3cb94a7dd03e4d4533a0c25a96e61f (MD5) Made available in DSpace on 2018-07-11T17:42:23Z (GMT). No. of bitstreams: 1 Tese Final. Caroline Feitosa. 2017.pdf: 1907972 bytes, checksum: af3cb94a7dd03e4d4533a0c25a96e61f (MD5) A investigação da asma implica em importantes desafios, particularmente devido à ausência de consenso sobre sua definição fenotípica, etiologia e fatores que influenciam no seu curso. Embora as primeiras descrições da doença já relatassem a importância dos fatores psicológicos e psicossociais para ocorrência e prognóstico dos sintomas asmáticos, apenas recentemente foram identificadas evidências epidemiológicas dessa associação, sendo sua causalidade ainda controversa. Além disso, sugere-se que esses fenômenos ocorrem em conjunto por compartilharem exposições de fonte comum, particularmente estressores ambientais, como a violência comunitária. A identificação dos mecanismos associados à asma na adolescência pode contribuir substancialmente para formulação de políticas de prevenção e cuidado, num país caracterizado por elevadas prevalências desse fenômeno. O objetivo da presente tese foi identificar a contribuição dos problemas internalizantes e de outros fatores psicossociais no surgimento e evolução dos sintomas de asma, assim como investigar os potenciais mecanismos imunológicos e de alergia envolvidos nessa relação. Especificamente, buscou-se: (1) descrever o panorama geral das pesquisas sobre o curso da asma, buscando identificar os principais fatores de risco para remissão descritos na literatura; (2) avaliar o efeito dos sintomas de ansiedade e depressão, expressos através dos problemas internalizantes sobre a incidência, remissão e curso dos sintomas de asma em adolescentes; (3) identificar os possíveis mecanismos imunológicos e alérgicos mediadores da associação entre violência comunitária, sintomas internalizantes e a ocorrência de asma em adolescentes. Visando responder à lacuna sobre a escassez de informações sobre o curso da asma da infância para a adolescência, foi realizada uma revisão sistemática da literatura, a qual identificou elevada variabilidade no tamanho amostral dos estudos, nos fatores de risco avaliados e nas metodologias empregadas, particularmente nas estratégias de definição de remissão. A severidade dos sintomas foi o mais importante preditor da remissão da asma da infância para a adolescência, e não foram identificadas investigações sobre o efeito dos fatores emocionais/psicossociais sobre o curso da asma. Seguiu-se então com a análise dos dados da coorte SCAALA (Social Changes Asthma and Allergies in Latin America), composta por aproximadamente 1.200 adolescentes de 12 a 19 anos, avaliados através de entrevistas domiciliares e coleta de material biológico em dois momentos distintos: durante a infância, na linha de base, em 2005, e posteriormente em 2013. Questionário adaptado do International Study of Asthma and Allergies in Childhood (ISAAC) foi utilizado para avaliação dos desfechos asmáticos. O Child Behavior Checklist (CBCL) e Youth Self-report (YSR) foram aplicados na linha de base e no acompanhamento para avaliação dos sintomas internalizantes. Foram utilizados modelos de regressão logística multivariada com efeitos aleatórios e modelo de análise de caminhos (Path analysis) para identificar as associações entre exposições e desfechos. Identificou-se forte evidência do efeito dos sintomas internalizantes, particularmente na infância, na remissão da asma na adolescência, mesmo levando em consideração o efeito de potenciais confundidores (OR: 0,29; IC95%: 0,12-0,53). As associações com a incidência foram limítrofes (OR:2,7 IC95%: 0,94-7,63). Os sintomas internalizantes também estiveram associadas à ocorrência de asma na adolescência (p=0,009), particularmente asma não-atópica e sem envolvimento das variáveis imunológicas ou marcadores de alergia (p>0,05). Identificou-se evidência de um possível efeito mediador dos problemas internalizantes na relação entre violência comunitária e ocorrência de sintomas de asma em adolescentes. Os achados sugerem que os problemas internalizantes contribuem significativamente para a ocorrência e curso dos sintomas de asma, sem envolvimento de mecanismos alérgicos e imunológicos nessa relação. Reforça-se a necessidade de implementação de estratégias para redução da violência e promoção de saúde mental em crianças e adolescentes, assim como de estudos que abordem modelos alternativos para investigação dos mecanismos envolvidos na relação entre fatores psicossociais e asma.

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2015-07-14T19:35:02Z No. of bitstreams: 1 TESE GISEL FATORE. 2015.pdf: 3095009 bytes, checksum: becebe9f8956330c8c568ff335a8e172 (MD5) Approved for entry into archive by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2015-07-14T20:45:28Z (GMT) No. of bitstreams: 1 TESE GISEL FATORE. 2015.pdf: 3095009 bytes, checksum: becebe9f8956330c8c568ff335a8e172 (MD5) Made available in DSpace on 2015-07-14T20:45:28Z (GMT). No. of bitstreams: 1 TESE GISEL FATORE. 2015.pdf: 3095009 bytes, checksum: becebe9f8956330c8c568ff335a8e172 (MD5) A asma é uma doença urbana complexa com múltiplos fatores associados ao seu desenvolvimento e remissão. Muitos fatores de risco para a doença foram identificados, e existe um debate sobre a contribuição dos fatores psicossociais na gênese da asma. A discriminação racial configura-se como um importante estressor psicossocial com efeitos negativos sobre a saúde. No entanto, os efeitos da discriminação sobre a asma infantil não tem sido investigados. Este estudo teve como objetivo analisar o efeito da exposição à discriminação em mulheres sobre a prevalência de asma nas crianças. Trata-se de um estudo transversal sobre a população integrante do programa Social Changes Asthma and Allergy in Latin America (SCAALA) em Salvador. A tese foi desenvolvida sob a forma de quatro artigos, tendo o primeiro como objetivo avaliar a confiabilidade e estrutura dimensional do “Experiência de Discriminação” (Experience of Discrimination - EOD), um instrumento de mensuração das experiências de discriminação desenvolvido nos Estados Unidos. Identificaram-se dois indicadores de discriminação: a experiência de discriminação e a preocupação com discriminação, com parâmetros aceitáveis de ajuste para o EOD no contexto brasileiro. O segundo artigo mensurou a prevalência de discriminação auto relatada utilizando analise de classes latentes. Os indivíduos foram classificados perfis de discriminação alto e baixo. A frequência das classes expostas à discriminação ou preocupadas com discriminação mostraram-se altas, principalmente no que respeita ao emprego e trabalho, com a cor da pele como um importante preditor das experiências relatadas. Já o terceiro artigo analisou o efeito da discriminação sobre a prevalência de transtornos mentais comuns nas mulheres participantes do estudo, evidenciando maiores prevalências de TMC entre aquelas mulheres que referiram alto grau de exposição à discriminação ou preocupação com discriminação. O suporte social moderou a associação entre preocupação com discriminação e sofrimento mental. Finalmente, o quarto artigo estimou o efeito da discriminação referida pelas mães sobre a prevalência de asma nos filhos. Os resultados corroboraram a hipótese de que a exposição à discriminação racial nas mães se associa com sintomas asmáticos nas crianças, e com o fenótipo atópico. Em acordo com nossa hipótese de estudo, mães com sintomas psicológicos foram mais propensas a ter filhos com sintomas asmáticos quando expostas a discriminação que àquelas sem sintomas. Os achados deste estudo destacam a importância de estudar a discriminação racial no contexto brasileiro. Embora esses resultados necessitem ser confirmados em estudos longitudinais, contribuirão com a compreensão de uma doença complexa como a asma em crianças.

CAPES A modelagem para dados de contagem é bastante utilizada em diversas áreas do conhecimento, como nas ciências biológicas, educação e saúde pública. O modelo comumente utilizado para analisar dados de contagem é o modelo Poisson. Contudo, quando os dados apresentam superdispersão o modelo Poisson não é mais indicado. Existem extensões do modelo Poisson que podem ser usados nesta situação, como o modelo Poisson in acionado de zeros (ZIP, em inglês). Porém, neste trabalho, é considerado o modelo Binomial Negativo, que é adequado para esta situação, além de ser um modelo simples e bastante conhecido. Uma suposição do modelo de regressão tradicional é a independência entre as observações. Contudo, quando as unidades amostrais são medidas repetidamente ao longo do tempo, os estudos longitudinais permite a veri cação das taxas de mudança que ocorrem ao longo do tempo e os fatores que podem motivar tal variação. Estes estudos são de particular interesse quando o objetivo é avaliar variações globais ou individuais da resposta ao longo do tempo. Este tipo de estudo considera a correlação entre as respostas dentro das unidades amostrais e a ordenação cronológica das respostas. Duas abordagens de regressão comumente utilizadas para analisar dados longitudinais são os modelos condicionais e os marginais. O modelo condicional assume a existência de efeitos aleatórios que descrevem o comportamento de um indivíduo especí co, sendo este modelo também chamado de multinível. No modelo marginal a variável resposta é modelada independentemente da correlação existente entre as medidas de cada unidade amostral (denotada por correlação intra-indivíduo), modelando a expectativa marginal como uma função das variáveis explicativas. Neste trabalho as duas abordagens foram aplicadas à análise de dados de contagem longitudinais. Estudos de simulação foram realizados para avaliar a performance dos estimadores provenientes destas metodologias. Aplicações com bases de dados reais são apresentadas.

Estudos que envolvem respostas binárias com estruturas hierárquicas de agrupamento são frequentemente encontrados nas diversas áreas do conhecimento. Em modelos de regressão essas estruturas de agrupamento devem ser devidamente tratadas, uma vez que violam o pressuposto básico de independência das observações. Quando o foco principal do estudo está na estrutura da média, os Modelos Marginais de primeira ordem, ajustados pelo método GEE1, propostos por Liang e Zeger (1986), oferecem uma solução elegante por sua facilidade na interpretação e ausência de suposições distribucionais. Entretanto com o método GEE1, não é possível acomodar satisfatoriamente estruturas hierárquicas ou múltiplas estruturas de agrupamento, podendo ocasionar perda de eficiência na estrutura da média. Para acomodar de forma satisfatória estruturas hierárquicas de agrupamento, o GEE1 foi estendido para o GEE2 (Prentice, 1988) com a introdução de uma segunda equação de estimação, o que possibilitou estimar e realizar inferências para os parâmetros de associação a partir de covariáveis. Quando o foco principal do estudo está na estrutura da associação e se tem estruturas hierárquicas de agrupamento, é muito comum à presença de um grande número de observações nos grupos. Os métodos numéricos para GEE2 podem ser inviáveis computacionalmente se a quantidade de observações dentro dos grupos for grande, além de não permitir utilizar a razão de chances para interpretação da estrutura de associação, sendo possível utilizar somente o coeficiente de correlação. Com adequadas modificações na segunda equação de estimação, Carey, Zeger e Diggle (1993) desenvolveram o ALR e Zink (2003) o ORTH, que além de permitir utilizar a razão de chances para interpretação da estrutura de associação, exigem um menor esforço computacional quando comparados aos métodos já propostos. Neste trabalho apresentamos e comparamos os modelos marginais (GEE2, ALR e ORTH) em simulações e aplicações reais com estruturas hierárquicas de agrupamento em respostas binárias, com o foco da pesquisa não somente nos coeficientes da média, mas também nas medidas de associação. Nossos resultados indicaram que os métodos ALR e ORTH se mostraram eficazes para aplicações com respostas binárias na presença de múltiplas estruturas hierárquicas, especialmente nos casos com um grande número de observações nos grupos. Nossos resultados também indicaram que quando o objetivo principal da pesquisa estiver na estrutura de associação, deve-se ter um cuidado especial na modelagem da estrutura da média, pois sua mal especificação pode induzir uma falta de consistência nas medidas de associação. Studies involving binary responses with hierarchical clustering are often found in different areas of knowledge. In regression models clustering structures should be properly handled, once they violate basic assumption of independence of observations. When the main focus of the study lies in the mean structure, first order Marginal Models , known as GEE1 proposed by Liang and Zeger (1986), has no distributional assumptions and offers an ease interpretation solution. However with GEE1 method, it is not possible satisfactorily accommodate hierarchical structures or multiple clustering structures, which may cause loss of efficiency in the mean structure. In order to satisfactorily accommodate hierarchical clustering, GEE1 been extended to the GEE2 (Prentice, 1988) by introducing a second estimation equation, allowing to estimate and make inferences for association parameters starting from covariates. When the main focus of the study lies in association structure and there is a hierarchical clustering structures, it is very common the presence of alarge number of observations in the clusters. Numerical methods for GEE2 can be computationally infeasible if the number of observations within the clusters is large, and do not allow use of odds ratio for interpretation of association structure, being possible only the of correlation coefficient. With appropriate modification in the second equation estimation, Carey, Zeger and Diggle (1993) developed the ALR and Zink (2003) the ORTH, that requires less computational effort when compared with existing methods allows the use of odds ratio for interpretation of association structure. Here we report the comparison of marginal models (GEE2, ALR and ORTH) in simulations and real applications cases with hierarchical clustering in binary responses,with the research focus not only on the coefficients of the mean, but also in the association measures. Our results indicate that the methods ALR and ORTH proved to be effective for studies with binary responsesin the presence of multiple hierarchical structures, especially in cases with a large number of observations in the clusters. Our results also indicate that when the primary purpose of the research is associationstructure, one should take special care in modeling the structure of the mean, because its misspecification may inconsistency of the association measures.

A modelagem de respostas politômicas, em especial as ordinais, tem sido alvo de crescente interesse nos últimos anos, e vem ganhando espaço em pesquisas sobre qualidade de vida, indicadores de condição de saúde, avaliação da proficiência dos alunos em determinadas disciplinas, dentre outras. A sua utilização vai desde os estudos transversais, onde se assume independência entre as observações, até os estudos longitudinais, em que mais de uma resposta do mesmo indivíduo é observada ao longo do tempo. Existem na literatura várias metodologias propostas para modelar dados desta natureza em estudos transversais, sendo a mais usual na prática a que utiliza o modelo de logitos cumulativos, também conhecido como modelo de odds proporcionais devido ao pressuposto do modelo que assume proporcionalidade nas odds, ou seja, o modelo assume que há um crescimento aproximadamente linear das razões de chances para os coeficientes da regressão. Em muitas situações práticas o referido pressuposto pode não ser verificado, tornando desaconselhável a utilização do modelo. Há, contudo, outro modelo que generaliza o de odds proporcionais, conhecido por odds proporcionais parciais, que permite a não proporcionalidade para um subconjunto de covariáveis que violaram o pressuposto de proporcionalidade. Em estudos longitudinais, os modelos usuais - modelos marginais, modelos lineares generalizados mistos e modelos de transição - para análise de dados correlacionados também podem ser utilizados para modelar respostas politômicas. Nesse trabalho a modelagem de respostas politômicas ordinais em estudos longitudinais é discutida sob a ótica dos modelos marginais, modelos lineares generalizados mistos e de transição. A especificação e interpretação dos modelos é ilustrada e discutida através da análise de dois conjuntos de dados reais. The modeling of polytomous responses, especially ordinal, has been the subject of increasing interest in recent years, and has been gaining ground in research on quality of life, health status indicators, assessment of student proficiency, among others. Its use goes from cross-sectional studies, which assume independence among the observations, to longitudinal studies, where more than one response from the same individual is observed over time. There are several methods proposed in the literature for modeling polytomous responses in transversal studies, being the most commonly used the cumulative logits model, also known as proportional odds model due to the assumption of proportionality in odds, i.e., the model assumes that there is an approximately linear increase in odds ratios for the regression coefficients. In many practical situations this assumption is violated. There is, however, another model that generalizes the proportional odds, known as partial proportional odds, which allows no odds proportionality to a subset of covariates that violated that assumption. In longitudinal studies, the conventional models - marginal models, generalized linear mixed models and transition models - for analysis of correlated data can also be used to model polytomous responses. In this work modeling of ordinal polytomous responses in longitudinal studies is discussed from the perspective of marginal, generalized linear mixed models and transition models. The specification and interpretation of the models is illustrated and discussed by analyzing two real data sets.

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2013. Introdução – No Brasil estima-se que 0,6% da população de 15 a 49 anos vive com o HIV/aids. Nas capitais estima-se que 0,4% e 1,4% da população de 10 a 69 anos apresentam marcadores de infecção pelos vírus das hepatites B e C, respectivamente. A interação entre os vírus das hepatites B e C com o HIV aumenta a chance de progressão para doença hepática grave e consequentemente ao óbito. Objetivos – Estimar a prevalência, descrever o perfil epidemiológico e estimar o tempo de sobrevida dos casos de aids coinfectados por HBV HCV no Brasil. Métodos – Os registros de aids foram obtidos do Sistema de Informação de Agravos de Notificação e do Sistema de Controle de Exames Laboratoriais. A coinfecção com as hepatites virais (B e C) foi obtida pelo relacionamento dos casos de aids com os casos de hepatites virais. A informação dos óbitos foi extraída pelo Sistema de Informação de Mortalidade, onde estes registros foram relacionados com a base de dados dos coinfectados. Todos os relacionamentos das bases de dados foram realizados no RecLink III, utilizando o método probabilístico e, tendo como campos de comparação as variáveis referentes ao nome do paciente, nome da mãe e data de nascimento. Os modelos de regressão logístico e de Cox foram utilizados para identificar fatores associados aos desfechos coinfecção e óbito, respectivamente. Resultados – Entre 1999 e 2010 foram notificados 370.672 casos de aids, desses 3.724 (1,0%) foram identificados como coinfectados com HBV e 5.932 (1,6%) como coinfectados com HCV. A chance de coinfecção aumenta com a idade, chegando a ser 3 vezes maior entre coinfectados com HBV com 45 anos ou mais, quando comparados com pacientes com até 24 anos de idade; entre os coinfectados com HCV a chance é 12 vezes maior. A categoria "usuário de drogas injetáveis" apresentou chance de coinfecção aumentada de duas a seis vezes para HBV e HCV, respectivamente, quando comparada com a categoria sexual; e o risco de morte aumentado em 70,8% quando comparada com outras categorias. Os pacientes de aids da raça “pretos e pardos” apresentam o risco de morte elevado, sendo aumentado em 13,8% e 28,1% para os coinfectados com HBV e HCV, respectivamente. Conclusões – A categoria "usuário de drogas injetáveis" é uma das principais formas de exposição para infecção pelo HCV e HIV, o que ajuda explicar a elevada chance de coinfecção por estes vírus entre indivíduos expostos por esta categoria. Entre os coinfectados com aids e HBV o uso de drogas injetáveis não representa a principal categoria de exposição, no entanto, apresenta menor probabilidade de sobrevivência e elevado risco de morte quando comparada com outras categorias. Estratégias probabilísticas de relacionamento de bases de dados são úteis quando o interesse é obter informações unificadas de diferentes fontes e não se dispõe de campos unívocos. Neste estudo foi possível avaliar um importante do quadro de coinfecção dos casos de aids com HBV e HCV no Brasil utilizando notificações desses agravos, sem a necessidade de realizar pesquisa de soroprevalência e coorte de sobrevida. _______________________________________________________________________________________ ABSTRACT Introduction – In Brazil it is estimated that 0.6% of the population aged 15 to 49 years is living with HIV/AIDS. In major cities in Brazil it is estimated that 0.4% and 1.4% of the population aged 10 a 69 years have the infection marker for hepatitis B and C, respectively. The interaction between the hepatitis B and C viruses with HIV amplifies the chance of developing severe liver diseases and consequently to death. Objectives – To estimate the prevalence, to describe the epidemiological profile and to estimate the survival time of individuals with AIDS coinfected with HBV and HCV in Brazil. Methods – AIDS cases were obtained from the "Sistema de Informação de Agravos de Notificação" and the "Sistema de Controle de Exames Laboratoriais". Coinfection was identified through probabilistic record linkage of the AIDS cases with hepatitis viral (B and C) from Sinan’s notifications. Death's information was obtained from "Sistema de Informação de Mortalidade" and was linked to coinfection data. All probabilistic records linkages were performed using the RecLink III software. Logistic and Cox regression models were used to identify factors associated to coinfection and death, respectively. Results – Between 1999 and 2010, 370,672 AIDS cases were reported, of which 3,724 (1.0%) were identified as HBV coinfections and 5,932 (1.6%) as HCV coinfections. The chance of coinfection increases with age, it is 3 times higher in aged 45 and older individuals coinfected with HBV than patients aged 24 and younger; the chance is 12 times higher among those coinfected with HCV. The chance for coinfections increases 2- to 6-fold for HBV and HCV, respectively, for the "injecting drugs users" (IDU) category compared to sexual exposure; and the IDU have 70.8% higher a risk of dying when compared to other exposure categories. Individuals with AIDS referring skin color "black and brown" have higher risk of dying, and also increased chance of coinfection; i.e. about 13.8% and 28.1% higher chances to HBV and HCV coinfections, respectively. Conclusions – The IDU category is one of the main forms of HCV and HIV transmissions, which help explain the higher chance of coinfection in patients of this category. On the other hand, among individuals with AIDS coinfected with HBV, the IDU category isn't the main form of transmission, although this group presents higher risk of death compared to other exposure categories. Strategies of probabilistic record linkage applied to databases are useful when the purpose is to obtain unified information from various data sources. This study permitted an important evaluation of cases of AIDS with HBV and HCV coinfected in Brazil by the use of reported cases, without the need to conduct seroprevalence research and survival cohort.