Hygiene habits and carriers in families with a child who has had typhoid fever

The relationship between asymptomatic shedding of bacterial enteropathogens and the hygiene habits of families who have had a child with typhoid fever (TF) are investigated. The sample was made up of 80 families: 40 families in which one child had had TF (Group A) and 40 in which no children or either of the parents had had a history of TF (Group B). In each group 20 families belonged to a low socieconomic status (SES) and 20 to a high SES. A structured interview was used to evaluate the SES and the hygiene habits of the child; observations were made to measure the hygiene habits of the family (toilet, kitchen and food preparation) and bacteriological studies (fecal samples and hand markers). Results show that carriers were more frequent in Group A than in Group B. The bacterial species found were significantly more numerous in Group A than in Group B (fecal samples: E. coli, the classic serotypes, Shigella ssp, and hand markers: E. coli). Families of Group A had higher carriage rates than those of Group B. Finally there exists a significantly higher association between inadequate hygiene habits and carrier families. These results show the need to teach specific habits of proper hygiene to the entire population, because the fact of belonging to the high SES does not in itself preclude inadequate hygiene habits.

Long-term monitoring across elevational gradients to assess ecological hypothesis : a description of standardized sampling methods in oceanic islands and first results

We are launching a long-term study to characterize the biodiversity at different elevations in several Azorean Islands. Our aim is to use the Azores as a model archipelago to answer the fundamental question of what generates and maintains the global spatial heterogeneity of diversity in islands and to be able to understand the dynamics of change across time. An extensive, standardized sampling protocol was applied in most of the remnant forest fragments of five Azorean Islands. Fieldwork followed BRYOLAT methodology for the collection of bryophytes, ferns and other vascular plant species. A modified version of the BALA protocol was used for arthropods. A total of 70 plots (10 m x 10 m) are already established in five islands (Flores, Pico, São Jorge, Terceira and São Miguel), all respecting an elevation step of 200 m, resulting in 24 stations examined in Pico, 12 in Terceira, 10 in Flores, 12 in São Miguel and 12 in São Jorge. The first results regarding the vascular plants inventory include 138 vascular species including taxa from Lycopodiophyta (N=2), Pteridophyta (N=27), Pinophyta (N=2) and Magnoliophyta (N=107). In this contribution we also present the main research question for the next six years within the 2020 Horizon.

Oral health, hygiene practices and oral cancer

OBJECTIVE: To assess the association between oral health and hygiene practices and oral cancer. METHODS: Hospital-based case-control study in the metropolitan area of São Paulo, southeastern Brazil, from 1998 to 2002. A total 309 patients with squamous cell carcinoma of the mouth and the pharynx and 468 controls matched by sex and age were included in the study. Cases were recruited in seven reference hospitals and controls were selected in five out of the seven participating hospitals. Detailed information on smoking, alcohol consumption, schooling, oral health status and hygiene practices were obtained through interviews. Odds ratios (OR) and 95% confidence intervals (95% CI), adjusted by sex, age, schooling, smoking, alcohol consumption as well as the variables oral health status and hygiene practices were estimated using unconditional logistic regression analyses. RESULTS: The use of complete dental prosthesis was not associated with oral cancer but regular gum bleeding showed a strong association (OR 3.1; 95% CI 1.2-7.9). Those who never attended a dental visit were more likely to have oral cancer (OR 2.5; 95% CI 1.3-4.8). Daily mouthwash use showed a stronger association to pharynx (OR 4.7; 95% CI 1.8-12.5) than mouth cancer (OR 3.2; 95% CI 1.6-6.3). CONCLUSIONS: Gum bleeding, no dental care, and daily mouthwash use were factors associated with oral cancer regardless of tobacco and alcohol consumption.

Beyond the income inequality hypothesis and human health: a worldwide exploration

OBJECTIVE: To analyze whether the relationship between income inequality and human health is mediated through social capital, and whether political regime determines differences in income inequality and social capital among countries. METHODS: Path analysis of cross sectional ecological data from 110 countries. Life expectancy at birth was the outcome variable, and income inequality (measured by the Gini coefficient), social capital (measured by the Corruption Perceptions Index or generalized trust), and political regime (measured by the Index of Freedom) were the predictor variables. Corruption Perceptions Index (an indirect indicator of social capital) was used to include more developing countries in the analysis. The correlation between Gini coefficient and predictor variables was calculated using Spearman's coefficients. The path analysis was designed to assess the effect of income inequality, social capital proxies and political regime on life expectancy. RESULTS: The path coefficients suggest that income inequality has a greater direct effect on life expectancy at birth than through social capital. Political regime acts on life expectancy at birth through income inequality. CONCLUSIONS: Income inequality and social capital have direct effects on life expectancy at birth. The "class/welfare regime model" can be useful for understanding social and health inequalities between countries, whereas the "income inequality hypothesis" which is only a partial approach is especially useful for analyzing differences within countries.

Estimation and hypothesis testing in mixed linear models

Dissertação apresentada para obtenção do Grau de Doutor em Matemática, Estatística, pela Universidade Nova de Lisboa, faculdade de Ciências e Tecnologia

The experimental granuloma: a hypothesis to explain the persistence of the lesion

Granulomatous inflammation is the morphological substrate of a variety of important infectious diseases such as tuberculosis, leprosy, schistosomiasis and others. Nevertheless, although many aspects of this special type of inflammation are known, fundamental questions concerning granuloma formation, persistence, fate and significance for host-parasite relationships still remain to be elucidated. In this brief review, the basic and more relevant literature related to experimental investigations on granuloma physiopathology is presented. Based on recent investigations performed in our laboratory showing that MDF (Macrophage Deactivating Fator) secreted by epithelioid cells and characterized as the calcium-binding protein protein MRP-14 deactivates activated macrophages, a hypothesis to explain the persistence of granulomatous inflammation is put forward

MICROCIRCULATION AND CHAGAS' DISEASE: HYPOTHESIS AND RECENT RESULTS

This review focuses on studies that support the microvascular hypothesis, as well as on immunological and neurogenic mechanisms, and the role of the parasite itself, to explain further the pathology and clinical course of myocardial involvement in chagasic cardiomyopathy. The salient features of coronary microcirculation and Chagas' disease are discussed.

On the unknown ecological niche of Paracoccidioides brasiliensis: our hypothesis of 1989: present status and perspectives

In 1989, CONTI DÍAZ & RILLA published a hypothesis concerning the as yet unknown ecological niche of Paracoccidioides brasiliensis. The hypothesis proposed a highly efficient paracoccidioidal ecological strategy based on an important natural reservoir of the parasite, probably in heterothermic animals from fresh water environments. Further, the hypothesis proposed, a transient and variable residence in the soil with a wide aleuriospore dispersion throughout the environment together with an elevated capability of infecting humans, and domestic and wild animals. This paper analyzes scientific publications from the IX International Meeting on Paracoccidioidomycosis held in Águas de Lindoia, São Paulo, Brazil from 2-5 October 2005, providing a comparative study among this articles and with other recently published papers and the hypothesis' postulates. Since various findings and observations appear to agree with the postulates, the pursuit of novel, specific research projects in the supposed reservoirs is recommended partially or fully to confirm the hypothesis using classical laboratorial methods and modern molecular biology techniques.

Chagas disease as a mechanistic model for testing a novel hypothesis

The association between depression and cardiovascular disease is well documented. Nevertheless, the process through which they are linked remains unknown, as does the direction of this relationship. Studies have suggested both that depression is a risk factor for heart disease and that heart disease is a risk factor for depression. A number of studies have established that a relationship exists between depression and inflammation, with alterations in the levels of inflammatory markers (IL-1, IL-6, TNF-alpha and others). Depressive symptoms have also been identified in many diseases characterized by inflammatory processes e.g. rheumatoid arthritis, bronchial asthma, diabetes, tuberculosis and cardiovascular diseases. In this brief viewpoint, we explain and propose how to use Chagas disease, a disorder characterized by inflammatory processes and leading to cardiovascular and autonomic problems, as a model for studying the directionality of the relationship between heart disease and depression.

Exposição profissional ao chumbo : análise da indução de efeitos genotóxicos

RESUMO - A exposição contínua a substâncias químicas tem consequências para a saúde humana, algumas das quais não estão ainda totalmente estabelecidas. A toxicologia ocupacional é uma área interdisciplinar que envolve conhecimentos de higiene e de medicina ocupacional, de epidemiologia e de toxicologia e que tem por principal objectivo prevenir a ocorrência de efeitos adversos decorrentes do ambiente ocupacional sendo um dos seus principais papéis fornecer o máximo de dados que possam contribuir para o conhecimento dos potenciais efeitos na saúde. O chumbo é um tóxico de características cumulativas que provoca na saúde efeitos principalmente sistémicos, ou seja, o efeito tóxico manifesta-se em locais afastados do contacto inicial que resultam essencialmente de exposições crónicas, resultantes de períodos de exposição mais ou menos longos ao metal (entre meses e anos). Pode interagir com diferentes órgãos e tecidos, ligando-se a moléculas e constituintes celulares. Uma vez que não possui qualquer função fisiológica, a presença do chumbo no organismo humano resulta numa série de efeitos prejudiciais que afectam diversos órgãos e sistemas. A toxicidade do chumbo manifesta-se em diversos órgãos e tecidos, nomeadamente no sistema hematopoiético, no sistema nervoso, no rim, no aparelho reprodutor, no sistema cardiovascular, no sistema endócrino e no sistema imunitário. Da interferência do chumbo com o funcionamento de alguns sistemas biológicos resultam um conjunto de alterações fundamentais ao nível dos processos de transporte através das membranas, da integridade estrutural e funcional das enzimas e de várias vias metabólicas, em especial da fosforilação oxidativa e da síntese do heme sendo os primeiros efeitos bioquímicos do chumbo detectados a partir de valores de plumbémia inferiores a 10 μg/dL. As medidas de higiene e segurança actualmente em vigor nos países desenvolvidos asseguram que os casos de intoxicação grave são cada vez menos frequentes. No entanto, o risco de exposição a nível ocupacional existe em todas as actividades que envolvem materiais que o contenham como as explorações mineiras, as fundições primária e secundária, a produção de baterias de chumbo ácido, a produção de vidro com pigmentos de chumbo, as soldaduras de reparação automóvel e a instrução de tiro. Desde 2006 o chumbo é considerado pela International Agency for Research on Cancer (IARC) uma substância carcinogénica do grupo 2A (provável carcinogénio para o ser humano). Considera-se, assim, que o chumbo tem, inequivocamente, capacidade de induzir cancro em animais experimentais mas que, embora haja fortes indícios de que os mecanismos que medeiam a carcinogénese desses compostos ocorrem no ser humano, os dados disponíveis ainda não podem assegurar essa relação. Com este estudo pretendeu-se contribuir para o conhecimento da toxicidade do chumbo através do estudo da exposição ao chumbo e da influência da susceptibilidade individual (em industrias sem co-exposição significativa a outros agentes conhecidos ou suspeitos de serem carcinogénicos). Pretendeu-se estudar o caso através de uma abordagem múltipla que permitisse relacionar diferentes tipos de marcadores biológicos uma vez que a monitorização biológica integra todas as possíveis vias de entrada no organismo (para além da via respiratória), eventuais exposições fora do contexto estritamente profissional assim como uma série de factores intrínsecos individuais (relacionados com modos de via, de natureza fisiológica e comportamentais). Sendo a co-exposição a outros compostos com propriedades genotóxicas e carcinogénicas uma questão difícil de tornear quando se quer avaliar o potencial genotóxico do chumbo em populações expostas, ocupacional ou ambientalmente este estudo tem a vantagem de ter sido efectuado em populações sem co-exposição conhecida a outras substâncias deste tipo, permitindo concluir sobre os efeitos resultantes apenas da exposição a chumbo na população humana, contribuindo para explicar algumas das aparentes inconsistências e contradições entre diferentes estudos sobre este tema. Os indicadores de exposição usados foram: indicadores de dose interna (doseamento de chumbo e de PPZ no sangue), indicadores de efeitos adversos no heme e genotóxicos (actividade da ALAD, teste do cometa e mutação em TCR) e indicadores de susceptibilidade (polimorfismos genéticos de ALAD e VDR) através de uma abordagem estatística de comparação directa de sub-grupos previamente definidos na população e da aplicação de um modelo de regressão múltipla. Este estudo revelou que os níveis de plumbémia na população portuguesa baixaram significativamente nos últimos 10 anos, tanto na população ocupacionalmente exposta como na população em geral e que a presença do genótipo B-B (do gene VDR) é preditiva das variações de plumbémia, quando comparada com o genótipo mais frequente na população, B-b; ao contrário, o genótipo b-b não aparenta ter influência em nenhum dos marcadores estudados. No que diz respeito a efeitos genotóxicos concluiu-se que estes não se manifestaram na população estudada, levando a concluir que nos níveis de exposição estudados, o chumbo não tem capacidade de induzir este tipo de efeitos per si levando ao reforço da hipótese, já levantada por outros autores, de que o mecanismo de genotoxicidade do chumbo seja essencialmente de promoção de processos de genotoxicidade desencadeados por outros agentes. A realização de estudos de efeitos genotóxicos e de stress oxidativo desenhados de forma a comparar grupos de trabalhadores expostos apenas a chumbo com grupos de trabalhadores com o mesmo nível de exposição a chumbo, mas com co-exposição a outros agentes reconhecidamente carcinogénicos poderá ajudar a aumentar o conhecimento deste efeito do chumbo na saúde humana.

Hepatitis C: sexual or intrafamilial transmission? Epidemiological and phylogenetic analysis of hepatitis C virus in 24 infected couples

The role of sexual or intrafamilial transmission of hepatitis C is controversial. A phylogenetic analysis was performed on the non-structural region 5B of the hepatitis C virus (NS5B-HCV). High percentages of homology (mean of 98.3%) were shown between the couples. Twenty (83.3%) of the 24 men but only two of the women (8.3%) reported having had sexually transmitted diseases during their lives. The risk factors for HCV acquisition were blood transfusion (10 couples), use of illegal injected drugs (17), use of inhalants (15), acupuncture (5) and tattoos (5). The shared use of personal hygiene items included toothbrushes between six couples (25%), razor blades between 16 (66.7%), nail clippers between 21 (87.5%) and manicure pliers between 14 (58.3%). The high degree of similarity of the hepatitis C virus genome supports the hypothesis of hepatitis C virus transmission between these couples. The shared use of personal hygiene items suggests the possibility of intrafamilial transmission of infection.