781 research outputs found

    Uso de contracepção por adolescentes de escolas públicas na Bahia

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    OBJECTIVE: There has been a growing interest in patterns of contraceptive use among adolescents, due, in particular, to the social relevance attached to pregnancy in this age group. Therefore, the objective of the study was to investigate factors associated with the use of contraceptive methods among female and male adolescent students. METHOD: A cross-sectional study was conducted, by means of self-applied questionnaires, among 4,774 students ranging from 11 to 19 years of age. Prevalence with respect to the use of contraceptive methods during the first experience of sexual intercourse as well as the most recent one was calculated both separately, that is, for each of these events, and in conjunction as a measure of consistent use. Logistic regression was carried out for simultaneous analysis of factors associated with the use of contraceptive methods and in order to calculate adjusted measures. RESULTS: Among the 1,664 students who reported being sexually active, the factors positively associated with the consistent use of contraceptive methods among male students included a) postponing their first experience of sexual intercourse and interaction with a stable partner, b) the family as a potential supplier of contraceptive methods, and c) access to health services. On the other hand, among female students factors positively associated with the consistent use of contraceptive methods included a) recent sexual initiation, and b) having a father as their source of information regarding sexuality, contraception and STD/Aids prevention. Pregnancy was reported by 6.4% of the boys and 18.1% of the girls, its absence was associated with the consistent use of contraceptives by them (the girls) (Odds Ratio=3.83; 2.06-7.15). CONCLUSIONS: The results confirm the complexity of determining contraceptive behavior among adolescents and therefore reinforce the need to include multi-dimensional aspects of this theme in order to ensure the efficacy of sex education programs.OBJETIVO: O interesse sobre o comportamento contraceptivo de adolescentes vem crescendo, especialmente pela relevância social conferida à gravidez nessa faixa etária. Assim, realizou-se estudo para investigar fatores associados ao uso de métodos anticoncepcionais entre adolescentes escolares. MÉTODOS: Estudo transversal que utilizou um questionário auto-aplicado em 4.774 alunos de ambos os sexos, entre 11 e 19 anos. Calcularam-se as prevalências de uso de contraceptivos na primeira e na última relação sexual e em ambas as situações (uso consistente). A regressão logística foi utilizada para a análise simultânea dos fatores e cálculo de medidas ajustadas. RESULTADOS: Entre 1.664 estudantes com iniciação sexual, os fatores associados positivamente ao uso consistente de contraceptivos pelos rapazes incluíram a iniciação sexual mais tardia, com parceria estável, contar com a família como fonte potencial de contraceptivos e acesso a serviços de saúde; entre as moças, ter iniciado a vida sexual há pouco tempo e ter o pai como fonte de informação sobre sexualidade, contracepção e prevenção DST/Aids. A gravidez foi relatada por 6,4% dos rapazes e 18,1% das moças, sendo sua ausência associada ao uso consistente de contraceptivos por elas (OR=3,83; 2,06-7,15). CONCLUSÕES: Os resultados confirmam a complexidade da determinação do comportamento contraceptivo entre adolescentes e a necessidade de que os programas educativos incorporem as múltiplas dimensões da questão para que tenham efetividade

    Electronic sculpting of ligand-GPCR subtype selectivity:the case of angiotensin II

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    GPCR subtypes possess distinct functional and pharmacological profiles, and thus development of subtype-selective ligands has immense therapeutic potential. This is especially the case for the angiotensin receptor subtypes AT1R and AT2R, where a functional negative control has been described and AT2R activation highlighted as an important cancer drug target. We describe a strategy to fine-tune ligand selectivity for the AT2R/AT1R subtypes through electronic control of ligand aromatic-prolyl interactions. Through this strategy an AT2R high affinity (<i>K</i><sub>i</sub> = 3 nM) agonist analogue that exerted 18,000-fold higher selectivity for AT2R versus AT1R was obtained. We show that this compound is a negative regulator of AT1R signaling since it is able to inhibit MCF-7 breast carcinoma cellular proliferation in the low nanomolar range

    iPSC-derived myelinoids to study myelin biology of humans

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    Myelination is essential for central nervous system (CNS) formation, health, and function. Emerging evidence of oligodendrocyte heterogeneity in health and disease and divergent CNS gene expression profiles between mice and humans supports the development of experimentally tractable human myelination systems. Here, we developed human iPSC-derived myelinating organoids (“myelinoids”) and quantitative tools to study myelination from oligodendrogenesis through to compact myelin formation and myelinated axon organization. Using patient-derived cells, we modeled a monogenetic disease of myelinated axons (Nfasc155 deficiency), recapitulating impaired paranodal axo-glial junction formation. We also validated the use of myelinoids for pharmacological assessment of myelination—both at the level of individual oligodendrocytes and globally across whole myelinoids—and demonstrated reduced myelination in response to suppressed synaptic vesicle release. Our study provides a platform to investigate human myelin development, disease, and adaptive myelination

    Metabolomic Profiling in Relation to New-Onset Atrial Fibrillation (from the Framingham Heart Study)

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    Previous studies have shown several metabolic biomarkers to be associated with prevalent and incident atrial fibrillation (AF), but the results have not been replicated. We investigated metabolite profiles of 2,458 European ancestry participants from the Framingham Heart Study without AF at the index examination and followed them for 10 years for new-onset AF. Amino acids, organic acids, lipids, and other plasma metabolites were profiled by liquid chromatography–tandem mass spectrometry using fasting plasma samples. We conducted Cox proportional hazard analyses for association between metabolites and new-onset AF. We performed hypothesis-generating analysis to identify novel metabolites and hypothesis-testing analysis to confirm the previously reported associations between metabolites and AF. Mean age was 55.1 ± 9.9 years, and 53% were women. Incident AF developed in 156 participants (6.3%) in 10 years of follow-up. A total of 217 metabolites were examined, consisting of 54 positively charged metabolites, 59 negatively charged metabolites, and 104 lipids. None of the 217 metabolites met our a priori specified Bonferroni corrected level of significance in the multivariate analyses. We were unable to replicate previous results demonstrating associations between metabolites that we had measured and AF. In conclusion, in our metabolomics approach, none of the metabolites we tested were significantly associated with the risk of future AF

    Infectious diseases in the first year of life, perinatal characteristics and childhood acute leukaemia

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    The objective of the present study was to investigate the role of early common infections and perinatal characteristics in the aetiology of childhood common leukaemia. A case-control study was conducted from 1995 to 1998 in France, and included 473 incident cases of acute leukaemia (AL) (408 acute lymphoblastic leukaemia (ALL), 65 acute myeloid leukaemia (AML) age-, sex- and region-matched with 567 population-based controls. Data on the medical history of the child and his/her environment were collected using self-administered questionnaires. Analyses were conducted using nonconditional logistic regression. A slight negative association with early infections was observed (OR=0.8; 95% CI (0.6-1.0)). The association was stronger for early gastrointestinal infections. Early day-care was found to be associated with a decreased risk of AL (OR=0.6; 95% CI (0.4-0.8) and OR=0.8; 95% CI (0.5-1.2) for day-care starting before age 3 months and between 3 and 6 months, respectively). No association with breast-feeding was observed, irrespective of its duration. A birth order of 4 or more was associated with a significantly increased risk of AL (OR=2.0; 95% CI (1.1-3.7) with ALL). A history of asthma was associated with a decreased risk of ALL (OR 0.5; 95% CI (0.3-0.90). Although the results regarding birth order and breast-feeding do not fit with Greaves' hypothesis, the study supports the hypothesis that early common infections may play a protective role in the aetiology of childhood leukaemia, although this effect was not more marked for common ALL

    Evaluation of a Peer Network-Based Sexual Risk Reduction Intervention for Men in Beer Halls in Zimbabwe: Results from a Randomized Controlled Trial

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    While much emphasis has been placed on involving men in AIDS prevention in sub-Saharan Africa, there remain few rigorously evaluated interventions in this area. A particularly appealing point of intervention is the sexual risk behavior associated with men’s alcohol consumption. This article reports the outcomes of The Sahwira HIV Prevention Program, a male-focused, peer-based intervention promoting the idea that men can assist their friends in avoiding high-risk sexual encounters associated with alcohol drinking. The intervention was evaluated in a randomized, controlled trial (RCT) implemented in 24 beer halls in Harare, Zimbabwe. A cadre of 413 male beer hall patrons (~20% of the patronage) was trained to assist their male peers within their friendship networks. Activities included one-on-one interactions, small group discussions, and educational events centering on the theme of men helping their male friends avoid risk. Venues were randomized into 12 control versus 12 intervention beer halls with little cross-contamination between study arms. The penetration and impact of the intervention were assessed by pre- and post-intervention cross-sectional surveys of the beer hall patronage. The intervention was implemented with a high degree of fidelity to the protocol, with exposure to the intervention activities significantly higher among intervention patrons compared to control. While we found generally declining levels of risk behavior in both study arms from baseline to post-intervention, we found no evidence of an impact of the intervention on our primary outcome measure: episodes of unprotected sex with non-wife partners in the preceding 6 months (median 5.4 episodes for men at intervention beer halls vs. 5.1 among controls, P = 0.98). There was also no evidence that the intervention reduced other risks for HIV. It remains an imperative to find ways to productively engage men in AIDS prevention, especially in those venues where male bonding, alcohol consumption, and sexual risk behavior are intertwined

    Fetal Demise and Failed Antibody Therapy During Zika Virus Infection of Pregnant Macaques

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    Zika virus (ZIKV) infection of pregnant women is associated with pathologic complications of fetal development. Here, we infect pregnant rhesus macaques (Macaca mulatta) with a minimally passaged ZIKV isolate from Rio de Janeiro, where a high rate of fetal development complications was observed. The infection of pregnant macaques with this virus results in maternal viremia, virus crossing into the amniotic fluid (AF), and in utero fetal deaths. We also treated three additional ZIKV-infected pregnant macaques with a cocktail of ZIKV-neutralizing human monoclonal antibodies (nmAbs) at peak viremia. While the nmAbs can be effective in clearing the virus from the maternal sera of treated monkeys, it is not sufficient to clear ZIKV from AF. Our report suggests that ZIKV from Brazil causes fetal demise in non-human primates (NHPs) without additional mutations or confounding co-factors. Treatment with a neutralizing anti-ZIKV nmAb cocktail is insufficient to fully stop vertical transmission

    Sexual behavior and drug consumption among young adults in a shantytown in Lima, Peru

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    <p>Abstract</p> <p>Background</p> <p>Risky sexual behaviors of young adults have received increasing attention during the last decades. However, few studies have focused on the sexual behavior of young adults in shantytowns of Latin America. Specifically, studies on the association between sexual behaviors and other risk factors for sexually transmitted infections (STI) and HIV/AIDS transmission, such as the consumption of illicit drugs or alcohol are scarce in this specific context.</p> <p>Methods</p> <p>The study participants were 393 men and 400 women between 18 and 30 years of age, from a shantytown in Lima, Peru. Data were obtained via survey: one section applied by a trained research assistant, and a self-reporting section. Logistic regression was used to estimate associations between use of any illicit drug, high-risk sexual behaviors and reported STI symptoms, adjusting for alcohol consumption level and various socio-demographic characteristics.</p> <p>Results</p> <p>Among men, age of sexual debut was lower, number of lifetime sexual partners was higher, and there were higher risk types of sexual partners, compared to women. Though consistent condom use with casual partners was low in both groups, reported condom use at last intercourse was higher among men than women. Also, a lifetime history of illicit drug consumption decreased the probability of condom use at last sexual intercourse by half. Among men, the use of illicit drugs doubled the probability of intercourse with a casual partner during the last year and tripled the probability of reported STI symptoms.</p> <p>Conclusion</p> <p>Drug consumption is associated with high-risk sexual behaviors and reported STI symptoms in a Lima shantytown after controlling for alcohol consumption level. Development of prevention programs for risky sexual behaviors, considering gender differences, is discussed.</p

    Unions, Dynamism and economic performance

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    This paper explores the relationship between economic performance and US unionism, focusing first on what we do and do not know based on empirical research handicapped by limited data on establishment and firm level collective bargaining coverage. Evidence on the relationship of unions with wages, productivity, profitability, investment, debt, employment growth, and business failures are all relevant in assessing the future of unions and public policy with respect to unions. A reasonably coherent story emerges from the empirical literature, albeit one that rests heavily on evidence that is dated and (arguably) unable to identify truly causal effects. The paper's principal thesis is that union decline has been tied fundamentally to competitive forces and economic dynamism. Implications of these findings for labor law policy and the future of worker voice institutions is discussed briefly in a final section
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