Urbanization and kidney dysfunction in Brazilian indigenous people: a burden for the youth

SUMMARY OBJECTIVE: The aim of this study was to investigate whether the degree of urbanization influences the prevalence of chronic kidney disease in Brazilian indigenous people. METHODS: This is a cross-sectional study conducted between 2016 and 2017 in northeastern Brazil and includes individuals aged between 30 and 70 years from two specific indigenous groups who volunteered to participate in the study: the Fulni-ô people (lowest degree of urbanization) and the Truká group (greater degree of urbanization). Cultural and geographical parameters were used to characterize and measure the magnitude of urbanization. We excluded individuals with known cardiovascular disease or renal failure who required hemodialysis. Chronic kidney disease was defined as a single measurement of an estimated glomerular filtration rate <60 mL/min/1.73 m2 using the Chronic Kidney Disease Epidemiology Collaboration creatinine equation. RESULTS: A total of 184 indigenous people from the Fulni-ô group and 96 from the Truká group with a median age of 46 years (interquartile range: 15.2) were included. We found a chronic kidney disease rate of 4.3% in the total indigenous population, generally affecting an older population: 41.7% over 60 years old (p<0.001). The Truká people had a chronic kidney disease prevalence of 6.2%, with no differences in kidney dysfunction across age groups. The Fulni-ô participants had a chronic kidney disease prevalence of 3.3%, with a higher proportion of kidney dysfunction in older participants (of the six Fulni-ô indigenous people with chronic kidney disease, five were older). CONCLUSION: Our results suggest that a higher degree of urbanization seems to negatively influence the prevalence of chronic kidney disease in Brazilian indigenous people.

Métodos para avaliação da efetividade de vacinas para COVID-19 com ênfase em abordagens quase-experimentais / Methods to evaluate COVID-19 vaccine effectiveness, with an emphasis on quasi-experimental approaches

Resumo A avalição da efetividade de vacinas é feita com dados do mundo real e é essencial para monitorar o desempenho dos programas de vacinação ao longo do tempo bem como frente a novas variantes. Até o momento, a avaliação da efetividade das vacinas para COVID-19 tem sido baseada em métodos clássicos como estudos de coorte e caso controle teste-negativo, que muitas vezes podem não permitir o adequado controle dos vieses intrínsecos da alocação das campanhas de vacinação. O objetivo dessa revisão foi discutir os desenhos de estudo disponíveis para avaliação de efetividade das vacinas, enfatizando os estudos quase-experimentais, que buscam mimetizar os estudos aleatorizados ao introduzir um componente exógeno para atribuição ao tratamento, bem como suas vantagens, limitações e aplicabilidade no contexto dos dados brasileiros. O emprego de métodos quase-experimentais, incluindo as séries temporais interrompidas, o método de diferença em diferenças, escore de propensão, variáveis instrumentais e regressão descontínua, são relevantes pela possibilidade de gerar estimativas mais acuradas da efetividade de vacinas para COVID-19 em cenários como o brasileiro, que se caracteriza pelo uso de várias vacinas, com respectivos número e intervalos entre doses, aplicadas em diferentes faixas etárias e em diferentes momentos da pandemia.

Abstract The evaluation of vaccine effectiveness is conducted with real-world data. They are essential to monitor the performance of vaccination programmes over time, and in the context of the emergence of new variants. Until now, the effectiveness of COVID-19 vaccines has been assessed based on classic methods, such as cohort and test-negative case-control studies, which may often not allow for adequate control of inherent biases in the assignment of vaccination campaigns. The aim of this review was to discuss the study designs available to evaluate vaccine effectiveness, highlighting quasi-experimental studies, which seek to mimic randomized trials, by introducing an exogenous component to allocate to treatment, in addition to the advantages, limitations, and applicability in the context of Brazilian data. The use of quasi-experimental approaches, such as interrupted time series, difference-in-differences, propensity scores, instrumental variables, and regression discontinuity design, are relevant due to the possibility of providing more accurate estimates of COVID-19 vaccine effectiveness. This is especially important in scenarios such as the Brazilian, which characterized by the use of various vaccines, with the respective numbers and intervals between doses, applied to different age groups, and introduced at different times during the pandemic.

Ecocardiografia e Análise de Doenças Cardiovasculares Subclínicas em Povos Indígenas que Vivem em Diferentes Graus de Urbanização: Projeto de Aterosclerose nas Populações Indígenas (Pai) / Echocardiography and Analysis of Subclinical Cardiovascular Diseases in Indigenous People Living in Different Degrees of Urbanization: Project of Atherosclerosis Among Indigenous Populations (Pai

Fundamento: O processo de urbanização tem impacto na carga de doenças cardiovasculares. As populações indígenas podem sofrer uma transição epidemiológica devastadora. Objetivos: Descrever o protocolo de estudo do Projeto de Aterosclerose nas Populações Indígenas (PAI) para avaliar a análise ecocardiográfica e as doenças cardiovasculares (CV) subclínicas em populações indígenas de acordo com o grau de urbanização e mostrar resultados preliminares do estudo piloto. Métodos: O PAI é um estudo transversal, com voluntários com idade entre 30 e 70 anos, em grupos indígenas brasileiros expostos a estágios baixos e avançados de urbanização (Fulni-ô e Truká, respectivamente) e um grupo controle urbano, excluindo indivíduos com doenças CV conhecidas ou em hemodiálise. O estudo piloto começou no território de Fulni-ô em setembro de 2016. Os participantes foram submetidos a avaliação clínica e laboratorial, eletrocardiograma (ECG), ultrassonografia de carótidas e um protocolo ecocardiográfico abrangente, incluindo strain longitudinal global (SLG) avaliado por speckle tracking. Os resultados preliminares são descritos de acordo com o sexo em uma análise univariada. Resultados: O estudo piloto avaliou o protocolo descrito em 55 indivíduos do grupo indígena Fulni-ô (48,7 ± 12,0 anos, 80% mulheres). Foram encontrados fatores de risco tradicionais como hipertensão, diabetes e dislipidemia em 40%, 36% e 54%, respectivamente, sem diferenças estatísticas significativas entre os sexos. O uso de tabaco mostrou-se extremamente prevalente, referido em 91% dos participantes. Os parâmetros derivados da ecocardiografia estavam, em média, dentro da faixa normal. No entanto, a média do SLG foi de 17,3 ± 3,4% (p 0,73 por sexo). Conclusão: Descrevemos o protocolo do estudo PAI para avaliar doenças cardiovasculares subclínicas e fatores de risco em populações indígenas de acordo com o estágio de urbanização. Resultados preliminares sugerem alta prevalência desses na população indígena em menor grau de urbanização.

Background: The urbanization process impacts the burden of cardiovascular disease (CVD). Indigenous populations can undergo a devastating epidemiological transition. Objective: The present study aimed to describe the Project of Atherosclerosis among Indigenous Populations (PAI) study protocol for assessing echocardiographic images and subclinical CVD in indigenous populations according to the degree of urbanization and report its preliminary results. Methods: The PAI is a cross-sectional study that includes volunteers aged 30­70 years among Brazilian indigenous groups exposed to low and advanced stages of urbanization (Fulni-ô and Truká, respectively) and an urban control group. Individuals with known CVD or who were on hemodialysis were excluded. The pilot study began in Fulni-ô territory in September 2016. The participants underwent clinical and laboratory

Investigating associations between intestinal alterations and parasite load according to Bifidobacterium spp. and Lactobacillus spp. abundance in the gut microbiota of hamsters infected by Leishmania infantum

BACKGROUND Visceral leishmaniasis (VL) is a tropical neglected disease with high associated rates of mortality. Several studies have highlighted the importance of the intestinal tract (IT) and gut microbiota (GM) in the host immunological defense. Data in the literature on parasite life cycle and host immune defense against VL are scarce regarding the effects of infection on the IT and GM. OBJECTIVES This study aimed to investigate changes observed in the colon of Leishmania infantum-infected hamsters, including alterations in the enteric nervous system (ENS) and GM (specifically, levels of bifidobacteria and lactobacilli). METHODS Male hamsters were inoculated with L. infantum and euthanised at four or eight months post-infection. Intestines were processed for histological analysis and GM analysis. Quantitative polymerase chain reaction (qPCR) was performed to quantify each group of bacteria: Bifidobacterium spp. (Bf) and Lactobacillus spp (LacB). FINDINGS Infected hamsters showed histoarchitectural loss in the colon wall, with increased thickness in the submucosa and the mucosa layer, as well as greater numbers of intraepithelial lymphocytes. Forms suggestive of amastigotes were seen inside mononuclear cells. L. infantum infection induced changes in ENS, as evidenced by increases in the area of colonic enteric ganglia. Despite the absence of changes in the levels of Bf and LacB during the course of infection, the relative abundance of these bacteria was associated with parasite load and histological alterations. MAIN CONCLUSIONS Our results indicate that L. infantum infection leads to important changes in the colon and suggest that bacteria in the GM play a protective role.

Preservação da privacidade no enfrentamento da COVID-19: dados pessoais e a pandemia global / Personal data usage and privacy considerations in the COVID-19 global pandemic

Resumo Dados ganham cada vez mais importância e valor na busca de respostas para enfrentar a COVID-19 tanto para a ciência quanto para as autoridades sanitárias. Em virtude da dificuldade de realizar diagnóstico da infecção na população em geral, iniciativas apoiadas em tecnologias digitais vêm sendo desenvolvidas por governos ou empresas privadas para possibilitar rastreamentos de sintomas, contatos e deslocamentos de modo a apoiar estratégias de acompanhamento e avaliação na vigilância de contágios. A despeito da importância e necessidade dessas iniciativas, questionamentos acerca da quantidade e tipos de dados pessoais coletados, processados, compartilhados e utilizados em nome da saúde pública, bem como os concomitantes ou posteriores usos desses dados, suscitam questionamentos éticos, legais e técnicos. Desafios que apontam para a necessidade de novos modelos de governança de dados e de tecnologias, responsáveis e transparentes, para controlar o Sars-Cov2 e as futuras emergências de saúde pública.

Abstract Data has become increasingly important and valuable for both scientists and health authorities searching for answers to the COVID-19 crisis. Due to difficulties in diagnosing this infection in populations around the world, initiatives supported by digital technologies are being developed by governments and private companies to enable the tracking of the public's symptoms, contacts and movements. Considering the current scenario, initiatives designed to support infection surveillance and monitoring are essential and necessary. Nonetheless, ethical, legal and technical questions abound regarding the amount and types of personal data being collected, processed, shared and used in the name of public health, as well as the concomitant or posterior use of this data. These challenges demonstrate the need for new models of responsible and transparent data and technology governance in efforts to control SARS-COV2, as well as in future public health emergencies.

Urbanization is Associated with Increased Trends in Cardiovascular Mortality Among Indigenous Populations: the PAI Study / Urbanização Associa-se com Tendência a Maior Mortalidade Cardiovascular em Populações Indígenas: o Estudo PAI

Abstract Background: The cardiovascular risk burden among diverse indigenous populations is not totally known and may be influenced by lifestyle changes related to the urbanization process. Objectives: To investigate the cardiovascular (CV) mortality profile of indigenous populations during a rapid urbanization process largely influenced by governmental infrastructure interventions in Northeast Brazil. Methods: We assessed the mortality of indigenous populations (≥ 30 y/o) from 2007 to 2011 in Northeast Brazil (Bahia and Pernambuco states). Cardiovascular mortality was considered if the cause of death was in the ICD-10 CV disease group or if registered as sudden death. The indigenous populations were then divided into two groups according to the degree of urbanization based on anthropological criteria:9,10 Group 1 - less urbanized tribes (Funi-ô, Pankararu, Kiriri, and Pankararé); and Group 2 - more urbanized tribes (Tuxá, Truká, and Tumbalalá). Mortality rates of highly urbanized cities (Petrolina and Juazeiro) in the proximity of indigenous areas were also evaluated. The analysis explored trends in the percentage of CV mortality for each studied population. Statistical significance was established for p value < 0.05. Results: There were 1,333 indigenous deaths in tribes of Bahia and Pernambuco (2007-2011): 281 in Group 1 (1.8% of the 2012 group population) and 73 in Group 2 (3.7% of the 2012 group population), CV mortality of 24% and 37%, respectively (p = 0.02). In 2007-2009, there were 133 deaths in Group 1 and 44 in Group 2, CV mortality of 23% and 34%, respectively. In 2009-2010, there were 148 deaths in Group 1 and 29 in Group 2, CV mortality of 25% and 41%, respectively. Conclusions: Urbanization appears to influence increases in CV mortality of indigenous peoples living in traditional tribes. Lifestyle and environmental changes due to urbanization added to suboptimal health care may increase CV risk in this population.

Resumo Fundamento: O risco cardiovascular das diversas comunidades indígenas não está bem estabelecido e pode ser influenciado pelo processo de urbanização a que se submetem esses povos. Objetivos: Investigar o perfil da mortalidade cardiovascular (CV) das populações indígenas durante o rápido processo de urbanização altamente influenciado por intervenções governamentais de infraestrutura no Nordeste do Brasil. Métodos: Avaliamos a mortalidade de populações indígenas (≥ 30 anos) do Vale do São Francisco (Bahia e Pernambuco) no período de 2007-2011. Considerou-se mortalidade CV se a causa de morte constasse no grupo de doenças CV do CID-10 ou se tivesse sido registrada como morte súbita. As populações indígenas foram divididas em dois grupos conforme o grau de urbanização baseado em critérios antropológicos: Grupo 1 - menos urbanizadas (Funi-ô, Pankararu, Kiriri e Pankararé); e Grupo 2 - mais urbanizadas (Tuxá, Truká e Tumbalalá). Taxas de mortalidade de cidades altamente urbanizadas (Petrolina e Juazeiro) nas proximidades das áreas indígenas foram também avaliadas. A análise explorou tendências na porcentagem de mortalidade CV para cada população estudada. Adotou-se o valor de p < 0,05 como significância estatística. Resultados: Houve 1.333 mortes indígenas nas tribos da Bahia e de Pernambuco (2007-2011): 281 no Grupo 1 (1,8% da população de 2012) e 73 no Grupo 2 (3,7% da população de 2012), mortalidade CV de 24% e 37%, respectivamente (p = 0,02). Entre 2007 e 2009, houve 133 mortes no Grupo 1 e 44 no Grupo 2, mortalidade CV de 23% e 34%, respectivamente. Entre 2009 e 2010, houve 148 mortes no Grupo 1 e 29 no Grupo 2, mortalidade CV de 25% e 41%, respectivamente. Conclusões: A urbanização parece influenciar os aumentos de mortalidade CV dos povos indígenas vivendo de modo tradicional. Mudanças no estilo de vida e ambientais devidas à urbanização somadas à subótima atenção à saúde podem estar implicadas no aumento do risco CV nos povos indígenas.

Scoring clinical signs can help diagnose canine visceral leishmaniasis in a highly endemic area in Brazil

Canine visceral leishmaniasis (CVL) diagnosis is still a challenge in endemic areas with limited diagnostic resources. This study proposes a score with the potential to distinguish positive CVL cases from negative ones. We studied 265 dogs that tested positive for CVL on ELISA and parasitological tests. A score ranging between 0 and 19 was recorded on the basis of clinical signs. Dogs with CVL had an overall higher positivity of the majority of clinical signs than did dogs without CVL or with ehrlichiosis. Clinical signs such as enlarged lymph nodes (83.93%), muzzle/ear lesions (55.36%), nutritional status (51.79%), bristle condition (57.14%), pale mucosal colour (48.21%), onychogryphosis (58.93%), skin lesion (39.28%), bleeding (12.50%), muzzle depigmentation (41.07%), alopecia (39.29%), blepharitis (21.43%), and keratoconjunctivitis (42.86%) were more frequent in dogs with CVL than in dogs with ehrlichiosis or without CVL. Moreover, the clinical score increased according to the positivity of all diagnostic tests (ELISA, p < 0.001; parasite culture, p = 0.0021; and smear, p = 0.0003). Onychogryphosis (long nails) [odds ratio (OR): 3.529; 95% confidence interval (CI): 1.832-6.796; p < 0.001], muzzle depigmentation (OR: 4.651; 95% CI: 2.218-9.750; p < 0.001), and keratoconjunctivitis (OR: 5.400; 95% CI: 2.549-11.441; p < 0.001) were highly associated with CVL. Interestingly, a score cut-off value ≥ 6 had an area under the curve of 0.717 (p < 0.0001), sensitivity of 60.71%, and specificity of 73.64% for CVL diagnosis. The clinical sign-based score for CVL diagnosis suggested herein can help veterinarians reliably identify dogs with CVL in endemic areas with limited diagnostic resources.

The microbiological signature of human cutaneous leishmaniasis lesions exhibits restricted bacterial diversity compared to healthy skin

Localised cutaneous leishmaniasis (LCL) is the most common form of cutaneous leishmaniasis characterised by single or multiple painless chronic ulcers, which commonly presents with secondary bacterial infection. Previous culture-based studies have found staphylococci, streptococci, and opportunistic pathogenic bacteria in LCL lesions, but there have been no comparisons to normal skin. In addition, this approach has strong bias for determining bacterial composition. The present study tested the hypothesis that bacterial communities in LCL lesions differ from those found on healthy skin (HS). Using a high throughput amplicon sequencing approach, which allows for better populational evaluation due to greater depth coverage and the Quantitative Insights Into Microbial Ecology pipeline, we compared the microbiological signature of LCL lesions with that of contralateral HS from the same individuals.Streptococcus, Staphylococcus,Fusobacterium and other strict or facultative anaerobic bacteria composed the LCL microbiome. Aerobic and facultative anaerobic bacteria found in HS, including environmental bacteria, were significantly decreased in LCL lesions (p < 0.01). This paper presents the first comprehensive microbiome identification from LCL lesions with next generation sequence methodology and shows a marked reduction of bacterial diversity in the lesions.

Immunoregulation in human malaria: the challenge of understanding asymptomatic infection

Asymptomatic Plasmodium infection carriers represent a major threat to malaria control worldwide as they are silent natural reservoirs and do not seek medical care. There are no standard criteria for asymptomaticPlasmodium infection; therefore, its diagnosis relies on the presence of the parasite during a specific period of symptomless infection. The antiparasitic immune response can result in reducedPlasmodium sp. load with control of disease manifestations, which leads to asymptomatic infection. Both the innate and adaptive immune responses seem to play major roles in asymptomatic Plasmodiuminfection; T regulatory cell activity (through the production of interleukin-10 and transforming growth factor-β) and B-cells (with a broad antibody response) both play prominent roles. Furthermore, molecules involved in the haem detoxification pathway (such as haptoglobin and haeme oxygenase-1) and iron metabolism (ferritin and activated c-Jun N-terminal kinase) have emerged in recent years as potential biomarkers and thus are helping to unravel the immune response underlying asymptomatic Plasmodium infection. The acquisition of large data sets and the use of robust statistical tools, including network analysis, associated with well-designed malaria studies will likely help elucidate the immune mechanisms responsible for asymptomatic infection.

Análise do conhecimento teórico e prática científica entre otorrinolaringologistas brasileiros / Analysis of theoretical knowledge and the practice of science among Brazilian otorhinolaryngologists

A compreensão dos princípios científicos e a interpretação de artigos é necessária em qualquer especialidade médica. Entretanto, inexistem publicações sobre o conhecimento teórico e prático dos otorrinolaringologistas brasileiros. OBJETIVO: Avaliar a formação e o conhecimento científico de médicos da área de Otorrinolaringologia. MÉTODO: Durante dois congressos nacionais da especialidade, os participantes foram convidados a preencher questionário sobre prática e conhecimento científico para residentes e especialistas dessa área. RESULTADOS E CONCLUSÃO: Participaram do estudo 73 médicos (52% otorrinolaringologistas e 38% residentes), com idade entre 18 e 65 anos. Cerca de dois terços envolveram-se em alguma atividade científica durante a graduação e/ou referiram já ter escrito um artigo científico. Os médicos que já participaram de projetos de pesquisa sentem-se mais preparados para interpretar um artigo científico e conduzir um projeto de pesquisa (p = 0,0103 e p = 0,0240, respectivamente). Aqueles que participaram de projetos de pesquisa ou já escreveram um artigo tiveram melhor desempenho nos conceitos científicos teóricos (p = 0,0101 e p = 0,0103, respectivamente). Entretanto, o índice geral de acertos nas questões referentes ao conhecimento científico foi de 46,1%. Dessa forma, identificamos que há deficiências na formação científica dos otorrinolaringologistas brasileiros que podem ser atenuadas pela participação em projetos de pesquisa.

Physicians from all medical specialties are required to understand the principles of science and to interpret medical literature. Yet, the levels of theoretical and practical knowledge held by Brazilian otorhinolaryngologists has not been evaluated to date. OBJECTIVE: To assess the background and level of scientific knowledge of Brazilian otorhinolaryngologists. METHOD: Participants of two national ENT meetings were invited to answer a questionnaire to assess scientific practice and knowledge. RESULTS AND CONCLUSION: This study included 73 medical doctors (52% otorhinolaryngologists and 38% residents) aged between 18 and 65 years. About two-thirds have been involved in some form of scientific activity during undergraduate education and/or reported to have written at least one scientific paper. Physicians who took part in research projects felt better prepared to interpret scientific papers and carry out research projects (p = 0.0103 and p = 0.0240, respectively). Respondents who claimed to have participated in research or to have written papers had higher scores on theoretical scientific concepts (p = 0.0101 and p = 0.0103, respectively). However, the overall rate of right answers on questions regarding scientific knowledge was 46.1%. Therefore, a deficiency was observed in the scientific education of Brazilian otorhinolaryngologists. Such deficiency may be mitigated through participation in research.

Cytokines and visceral leishmaniasis: a comparison of plasma cytokine profiles between the clinical forms of visceral leishmaniasis

It is not well established whether cytokine production differs in response to different clinical forms of visceral leishmaniasis (VL). In this work, we performed a cross-sectional study to investigate the plasma levels of cytokines [interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-10 and IL-12] involved in the pathogenesis of VL in 80 subjects from VL endemic areas, including subjects with active VL, subjects with asymptomatic infection, subjects with cured VL and uninfected controls. The patients were recruited by sampling from a referral hospital and by random selection from a population-based cohort study. The results showed significant differences in the plasma concentration of all cytokines between the groups (p < 0.05). Patients with the active disease had higher plasma levels of IL-10, IL-4, INF-γ and TNF-α relative to the other groups and they produced more IL-12 than asymptomatic and cured subjects. Only the IL-2 concentration was higher in the asymptomatic and cured subjects relative to the patients with active disease (p < 0.05). Our results suggest that these cytokines can be used as markers in epidemiological studies conducted in endemic areas to distinguish between different clinical forms of VL. However, their usefulness should be confirmed in investigations conducted in other endemic areas.

Biomarkers for susceptibility to infection and disease severity in human malaria

Malaria remains a major infectious disease that affects millions of people. Once infected with Plasmodium parasites, a host can develop a broad range of clinical presentations, which result from complex interactions between factors derived from the host, the parasite and the environment. Intense research has focused on the identification of reliable predictors for exposure, susceptibility to infection and the development of severe complications during malaria. Although most promising markers are based on the current understanding of malaria immunopathogenesis, some are also focused more broadly on mechanisms of tissue damage and inflammation. Taken together, these markers can help optimise therapeutic strategies and reduce disease burden. Here, we review the recent advances in the identification of malarial biomarkers, focusing on those related to parasite exposure and disease susceptibility. We also discuss priorities for research in biomarkers for severe malaria.

In vitro initial immune response against Leishmania amazonensis infection is characterized by an increased production of IL-10 and IL-13

The initial encounter of Leishmania with its host's immune system is important in the outcome of infection. Previous studies have shown that PBMCs from healthy volunteers (HV) exposed to Leishmania differ in IFN-γ production. We have expanded such observations evaluating the profile and kinetics of cytokines (IFN-γ, IL-12p70, IL-10, IL-13), chemokines (CCL5, CCL3, CCL4, CXCL10), and chemokine receptors (CCR1,CCR5, CXCR3, CCR4) in vitro L. amazonensis-stimulated of HV's PBMCs. HVs were divided in groups of high (HR) or low (LR) IFN-γ responders. In both groups, HR and LR, after L. amazonensis infection there was a predominance of IL-10 and IL-13 over IFN-γ production, while IL-12 was produced in similar amount. Regarding chemokines, a more striking difference was observed for CCL3 expression that was lower at 12 hours and 48 hours post infection in LR than in HR. Interestingly, a downregulation of CCR5 and a greater expression of CCR4 were found in low IFN-γ responders. These data suggest that early after L. amazonensis infection there is a cytokine milieu dominated by IL-13 and IL-10, and despite of this environment, IFN-γ is produced, supporting the complexity of the response. It is noteworthy that the pattern of immune response is mounted in first hours after Leishmania stimulation, with the definition of the differentiation of Th1 versus Th2 cells. It remains to be determined if such an in vitro difference has an in vivo counterpart in terms of susceptibility to infection.

Research knowledge in undergraduate school in Brazil: a comparison between medical and law students / Conhecimento científico na graduação do Brasil: comparação entre estudantes de Medicina e Direito

Objective: Exposure to science education during college may affect a students profile, and research experience may be associated with better professional performance. We hypothesized that the impact of research experience obtained during graduate study differs among professional curricula and among graduate courses. Methods: A validated multiple-choice questionnaire concerning scientific concepts was given to students in the first and fourth years of medical and law school at a public Brazilian educational institution. Results: Medical students participated more frequently in introductory scientific programs than law students, and this trend increased from the first to the fourth years of study. In both curricula, fourth-year students displayed a higher percentage of correct answers than first-year students. A higher proportion of fourth-year students correctly defined the concepts of scientific hypothesis and scientific theory. In the areas of interpretation and writing of scientific papers, fourth-year students, in both curricula, felt more confident than first-year students. Although medical students felt less confident in planning and conducting research projects than law students, they were more involved in research activities. Conclusion: Medical graduation seems to favor the development of critical scientific maturity than law graduation. Specific policy in medical schools is a reasonable explanation for medical students participation in more scientific activities.

Objetivo: A exposição à educação científica durante a faculdade pode afetar o perfil do estudante, e a experiência na pesquisa pode estar associada com um melhor desempenho profissional. Hipotetizamos que o impacto da experiência na pesquisa obtida durante a graduação varia entre os currículos profissionais e entre os cursos de graduação. Métodos: Um questionário validado de múltipla escolha sobre conceitos científicos foi dado aos alunos do primeiro e quarto anos das faculdades de Medicina e Direito em uma instituição pública brasileira de ensino. Resultados: Os estudantes de Medicina participaram com mais frequência de programas de iniciação científica em relação aos estudantes de Direito, e essa tendência aumentou do primeiro ao quarto ano de faculdade. Em ambos os currículos, os alunos do quarto ano apresentaram uma maior porcentagem de acertos que os alunos do primeiro ano. A maior proporção de alunos do quarto ano definiu corretamente os conceitos de hipótese científica e teoria científica. Nas áreas de interpretação e escrita de artigos científicos, os alunos do quarto ano, em ambos os currículos, se sentiram mais confiantes do que os estudantes do primeiro ano. Embora os estudantes de Medicina tenham se sentido menos confiantes no planejamento e na realização de projetos de pesquisa que os estudantes de Direito, eles estavam mais envolvidos em atividades de pesquisa. Conclusão: A graduação em Medicina parece favorecer o desenvolvimento da maturidade crítica científica do que a graduação em Direito. A existência de políticas específicas nas escolas médicas é uma explicação razoável para a participação de estudantes de Medicina em mais atividades científicas.

Haematophagous arthropod saliva and host defense system: a tale of tear and blood

A saliva de artrópodes hematófagos é rica em moléculas com funções diversas que mediam uma alimentação sangüínea bem sucedida. Estas moléculas agem não apenas como armas contra a resposta hemostática, inflamatória e imunológica do hospedeiro funcionando também como ferramentas para o estabelecimento de patógenos. Parasitas, vírus e bactérias aproveitando-se deste arsenal dos vetores adaptaram-se facilitando seu estabelecimento no hospedeiro. Hoje, várias moléculas salivares foram identificadas e caracterizadas como novos alvos para o desenvolvimento de vacinas futuras. Neste trabalho, centramos em informação recente sobre a saliva de vetores e as moléculas responsáveis por modificar a resposta hemostática e imunológica assim como seu papel na transmissão de doenças.

Frequency of Infection of Lutzomyia Phlebotomines with Leishmania braziliensis in a Brazilian endemic area as assessed by pinpoint capture and polymerase chain reaction

Leishmania infected of Lutzomyia spp. are rare in endemic areas. We tested the hypothesis that there is clustering of infected vectors by combining pinpoint capture with sensitive L. braziliensis kDNA minicircle specific PCR/dot blot in an endemic area in the State of Bahia. Thirty out of 335 samples (10 to 20 sand flies/sample; total of 4,027 female sand flies) were positive by PCR analysis and dot blot leading to a underestimated overall rate of 0.4 percent positive phlebotomines. However, 83.3 percent of the positive samples were contributed by a single sector out of four sectors of the whole studied area. This resulted in a rate of 1.5 percent Leishmania positive phlebotomines for this sector, far above rates of other sectors. Incidence of American cutaneous leishmaniasis cases for this sector was about twice that for other sectors. Our results show that there is a non-homogeneous distribution of Leishmania-infected vectors. Such a clustering may have implications in control strategies against leishmaniasis, and reinforces the necessity of understanding the ecological and geographical factors involved in leishmanial transmission

In vivo lymphocyte activation and apoptosis by lectins of the Diocleinae subtribe

This paper reports the overall effects of three lectins, extracted from Canavalia brasiliensis, Dioclea violacea, and D. grandiflora, on BALB/c mice popliteal draining lymph nodes. These lectins have presented high stimulatory capacity on lymph node T cells. Additionally, they were able to induce apoptosis and inflammation (frequently associated with high endothelial venule necrosis). The data presented here suggest that the Diocleinae lectins studied can stimulate in vivo T cell activation and apoptosis, as well as present important side effects

Impacto de múltiplas biópsias em dois pontos distintos da superfície pleural no diagnóstico de tuberculose / Impact of multiple biopsies in two different sites of the pleural surface for the diagnosis of tuberculosis

Com o objetivo de avaliar se a retirada de maior número de fragmentos pleurais em um único sítio (A), bem como se a biópsia em um segundo sítio (B) da sua superfície, através do mesmo orifício cutâneo, acrescenta em rendimento diagnóstico aos três fragmentos habitualmente retirados, conduzimos um estudo prospectivo no Hospital Octávio Mangabeira, envolvendo 115 pacientes com indicação de biópsia pleural. Os fragmentos pleurais foram colocados em três frascos distintos: FRA1-3 = 3 primeiros fragmentos, FRA4-8 = 5 fragmentos subseqüentes e FRB1-5 = 5 fragmentos em segundo sítio da superfície pleural. Era retirada a agulha até o subcutâneo, feitas inclinação lateral e reintrodução no espaço pleural. A análise dos fragmentos provindos do FRA1-3 evidenciou granuloma em 72/92 casos de tuberculose (78,3 por cento) e no FRA4-8 e FRB1-5, em 74/92 casos (80,5 por cento). Em 6/92 pacientes foram encontrados pleurite inespecífica no FRA1-3 e granuloma no FRA4-8, resultando em acréscimo diagnóstico de 8,3 por cento (6 aos 72 pacientes). Em 7/92 pacientes (7,6 por cento) a HP foi inespecífica no sítio A e mostrou granuloma no sítio B, resultando em acréscimo diagnóstico de 9,0 por cento (7 aos 78 pacientes). A concordância histológica intra-observador teve um índice kappa de 0,62 (0,54 a 0,70) e interobservador de 0,64 (0,56 a 0,72). Concluímos que a realização de múltiplas biópsias em dois sítios diferentes da superfície pleural diagnosticou 13 pacientes que não obteriam diagnóstico definitivo se fossem retirados apenas três fragmentos pleurais, resultando em incremento diagnóstico de 18,0 por cento (13 aos 72 diagnosticados no FRA1-3), sendo considerado significativo do ponto de vista médico e social.