Macromolecular Transport Through Porous Arterial Walls

Arteries are heterogeneous, composite structures that undergo large cyclic deformations during blood transport. Presence, build-up and consequent rupture of blockages in blood vessels, called atherosclerotic plaques, lead to disruption in the blood flow that can eventually be fatal. Abnormal lipid profile and hypertension are the main risk factors for plaque progression. Treatments span from pharmacological methods, to minimally invasive balloon angioplasty and stent procedures, and finally to surgical alternatives. There is a need to understand arterial disease progression and devise methods to detect, control, treat and manage arterial disease through early intervention. Local delivery through drug eluting stents also provide an attractive option for maintaining vessel integrity and restoring blood flow while releasing controlled amount of drug to reduce and alleviate symptoms. Development of drug eluting stents is hence interesting albeit challenging because it requires an integration of knowledge of mechanical properties with material transport of drug through the arterial wall to produce a desired biochemical effect. Although experimental models are useful in studying such complex multivariate phenomena, numerical models of mass transport in the vessel have proved immensely useful to understand and delineate complex interactions between chemical species, physical parameters and biological variables. The goals of this review are to summarize literature based on studies of mass transport involving low density lipoproteins in the arterial wall. We also discuss numerical models of drug elution from stents in layered and porous arterial walls that provide a unique platform that can be exploited for the design of novel drug eluting stents.

Mathematical Model of Viral Kinetics In Vitro Estimates the Number of E2-CD81 Complexes Necessary for Hepatitis C Virus Entry

Interaction between the hepatitis C virus (HCV) envelope protein E2 and the host receptor CD81 is essential for HCV entry into target cells. The number of E2-CD81 complexes necessary for HCV entry has remained difficult to estimate experimentally. Using the recently developed cell culture systems that allow persistent HCV infection in vitro, the dependence of HCV entry and kinetics on CD81 expression has been measured. We reasoned that analysis of the latter experiments using a mathematical model of viral kinetics may yield estimates of the number of E2-CD81 complexes necessary for HCV entry. Here, we constructed a mathematical model of HCV viral kinetics in vitro, in which we accounted explicitly for the dependence of HCV entry on CD81 expression. Model predictions of viral kinetics are in quantitative agreement with experimental observations. Specifically, our model predicts triphasic viral kinetics in vitro, where the first phase is characterized by cell proliferation, the second by the infection of susceptible cells and the third by the growth of cells refractory to infection. By fitting model predictions to the above data, we were able to estimate the threshold number of E2-CD81 complexes necessary for HCV entry into human hepatoma-derived cells. We found that depending on the E2-CD81 binding affinity, between 1 and 13 E2-CD81 complexes are necessary for HCV entry. With this estimate, our model captured data from independent experiments that employed different HCV clones and cells with distinct CD81 expression levels, indicating that the estimate is robust. Our study thus quantifies the molecular requirements of HCV entry and suggests guidelines for intervention strategies that target the E2-CD81 interaction. Further, our model presents a framework for quantitative analyses of cell culture studies now extensively employed to investigate HCV infection.

Current trends in modeling hostpathogen interactions

The rapid emergence of infectious diseases calls for immediate attention to determine practical solutions for intervention strategies. To this end, it becomes necessary to obtain a holistic view of the complex hostpathogen interactome. Advances in omics and related technology have resulted in massive generation of data for the interacting systems at unprecedented levels of detail. Systems-level studies with the aid of mathematical tools contribute to a deeper understanding of biological systems, where intuitive reasoning alone does not suffice. In this review, we discuss different aspects of hostpathogen interactions (HPIs) and the available data resources and tools used to study them. We discuss in detail models of HPIs at various levels of abstraction, along with their applications and limitations. We also enlist a few case studies, which incorporate different modeling approaches, providing significant insights into disease. (c) 2013 Wiley Periodicals, Inc.

Current trends in modeling hostpathogen interactions

The rapid emergence of infectious diseases calls for immediate attention to determine practical solutions for intervention strategies. To this end, it becomes necessary to obtain a holistic view of the complex hostpathogen interactome. Advances in omics and related technology have resulted in massive generation of data for the interacting systems at unprecedented levels of detail. Systems-level studies with the aid of mathematical tools contribute to a deeper understanding of biological systems, where intuitive reasoning alone does not suffice. In this review, we discuss different aspects of hostpathogen interactions (HPIs) and the available data resources and tools used to study them. We discuss in detail models of HPIs at various levels of abstraction, along with their applications and limitations. We also enlist a few case studies, which incorporate different modeling approaches, providing significant insights into disease. (c) 2013 Wiley Periodicals, Inc.

Phase-variable surface structures are required for infection of Campylobacter jejuni by bacteriophages.

This study characterizes the interaction between Campylobacter jejuni and the 16 phages used in the United Kingdom typing scheme by screening spontaneous mutants of the phage-type strains and transposon mutants of the sequenced strain NCTC 11168. We show that the 16 typing phages fall into four groups based on their patterns of activity against spontaneous mutants. Screens of transposon and defined mutants indicate that the phage-bacterium interaction for one of these groups appears to involve the capsular polysaccharide (CPS), while two of the other three groups consist of flagellatropic phages. The expression of CPS and flagella is potentially phase variable in C. jejuni, and the implications of these findings for typing and intervention strategies are discussed.

Avaliação do impacto de uma intervenção de promoção de frutas e hortaliças sobre o consumo desses alimentos por alunos e professores de escolas públicas

O consumo de frutas e hortaliças (F&H) tem sido incentivado em vários países como medida de prevenção de doenças crônicas não transmissíveis, sendo a escola um espaço privilegiado para a promoção do consumo desses alimentos. Este estudo tem como objetivo avaliar o impacto de uma intervenção de promoção de F&H sobre o consumo desses alimentos por alunos e professores de escolas públicas do município do Rio de Janeiro. Trata-se de estudo de avaliação do tipo antes e depois, realizado com turmas de primeiro ciclo do ensino fundamental em oito unidades públicas municipais situadas em territórios cobertos pela Estratégia da Saúde da Família. No diagnóstico pré-intervenção foram registradas as atividades de promoção da alimentação saudável desenvolvidas nas escolas e o consumo usual de F&H pelos professores. Foram também observados o ambiente escolar e o consumo, pelos alunos, das F&H oferecidas pelo Programa de Alimentação Escolar. A intervenção abarcou um curso de formação para professores e merendeiras sobre promoção da alimentação saudável, com ênfase na promoção de F&H; distribuição de materiais educativos e realização de eventos de mobilização. No diagnóstico pós-intervenção, foram incluídas questões referentes às estratégias da intervenção. Foram criados indicadores de cobertura da atividade e intensidade de exposição à intervenção, de síntese do nível de implementação da intervenção, de adesão à alimentação escolar, aceitação e consumo de F&H pelos alunos e do consumo de F&H pelos professores, e, também, indicadores de variação da aceitação (alunos) e do consumo (alunos e professores) de F&H. As variações observadas foram testadas estatisticamente por meio do teste t-Student pareado (no caso de médias) ou do Qui Quadrado de McNemar (no caso de proporções). A eventual influência do nível de implementação da intervenção sobre a variação do consumo e aceitação de F&H foi examinada por meio de modelos de regressão linear ou logística, dependendo do tipo de desfecho. Foram observados índices altos de aceitação de F&H entre alunos e de consumo de F&H entre alunos e professores no diagnóstico inicial. A intervenção alcançou 52,7% de implementação, tendo sido bem avaliada entre os professores. Nenhuma variação estatisticamente significativa foi observada após a intervenção tanto em relação à aceitação quanto em relação ao consumo de F&H. Foram observados resultados estatisticamente significativos somente para a associação positiva entre o nível de exposição à intervenção e a aceitação de hortaliças pelos alunos. A intervenção proposta alcançou nível intermediário de implementação e os resultados alcançados foram modestos em termos de variação do consumo de F&H por alunos e professores.

Prevalência do medo de quedas em idosos e sua associação com fatores clínicos,funcionais e psicossociais: Estudo FIBRA-RJ

Introdução: Com o expressivo aumento da população idosa, as quedas são eventos comuns e levam a desfechos adversos à saúde. As consequências do medo de quedas podem ser tão incapacitantes como as quedas. Objetivo: O presente estudo teve como objetivo estimar a prevalência do medo de quedas em idosos e sua associação com fatores clínicos, funcionais e psicossociais. Métodos: Utilizaram-se os dados do Estudo FIBRA-RJ, que avaliou clientes de uma operadora de saúde, residentes na Zona Norte do município do Rio de Janeiro. A seleção desta amostra foi realizada através de amostragem aleatória inversa, de acordo com estratos de faixa etária e sexo do cadastro oferecido pela operadora. As entrevistas foram realizadas face a face no domicilio. O medo de quedas, variável dependente, foi avaliado através da FES-I-BR. As seguintes variáveis clínicas, funcionais e psicossociais foram avaliadas como variáveis independentes: histórico de quedas, fratura pós-queda, número de comorbidades, número de medicamentos, internação no último ano, uso de dispositivo de auxílio à marcha, dependência funcional nas atividades básicas e instrumentais de vida diária, dificuldade visual e auditiva, força de preensão palmar, velocidade de marcha, autopercepção de saúde, sintomas depressivos, alteração cognitiva, morar só, apoio social instrumental e nível de atividade. As associações foram avaliadas através de regressão logística. Resultados: Dentre os 742 idosos avaliados, 51,9% apresentaram medo de quedas, sendo esta prevalência maior no sexo feminino e nos mais idosos. Na análise logística multivariada, houve associação com histórico de 1 ou 2 quedas (OR=2,18; IC95%1,42-3,36), 3 ou mais quedas (OR=2,72; IC95% 1,10-6,70), usar 7 ou mais medicamentos (OR=1,70; IC95%1,04-2,80), dificuldade auditiva (OR=1,66; IC95% 1,10-2,49), ter dependência funcional nas atividades de vida diária (AVDs) (OR=1,73; IC95%1,07-2,79), velocidade de marcha diminuída (OR=1,64; IC95%1,04-2,58), autopercepção de saúde regular (OR=1,89; IC95%1,30-2,74) e ruim/muito ruim (OR=4,92; IC95%1,49-16,27) e sintomas depressivos (OR=1,68; IC95%1,07-2,63). Conclusão: Os resultados obtidos mostram a prevalência elevada de medo de quedas. Destaca-se a necessidade de avaliação desta condição nos idosos. Identificar os fatores associados é útil para desenvolver estratégias efetivas de intervenção dos possíveis fatores modificáveis.

Consórcio em saúde mental: uma análise da experiência de Quatis e Porto Real/RJ

A conjuntura atual referente à política de saúde mental Brasileira tem suas ações, serviços e estratégias de intervenção direcionadas pelos princípios do projeto da Reforma Psiquiátrica. Logo, há no Brasil uma série de serviços substitutivos ao hospício que foram criados ao longo dos últimos trinta anos para substituir em sua totalidade a perspectiva da psiquiatria clássica, que pensa ser o isolamento social a única maneira de cuidar e tratar o sujeito em sofrimento psíquico. O presente trabalho tem por objetivo realizar uma reflexão acerca de uma experiência política no campo da Reforma Psiquiátrica Brasileira. O objeto de estudo se designa ao conhecimento do consórcio em saúde mental existente entre os municípios de Quatis e Porto Real situados na região Médio-Paraíba interior do Estado do Rio de Janeiro. Utilizamos uma abordagem qualitativa, pois acreditamos que a mesma pode nos oferecer instrumentos de conhecimento da realidade que desejamos alcançar que são mais apropriados para desvendar os significados das ações em saúde mental e seus impactos na vida dos sujeitos envolvidos nesse processo. Para tal optamos por realizar uma observação participante no campo de pesquisa que se dá no CAPS Sonho Real e também a realização de dois grupos focais, um com usuários e outro com profissionais. Acreditamos que conhecer essa experiência se constitui como tarefa de sua importância para o fortalecimento e consolidação do compromisso político assumido por esses dois municípios no que tange a modalidade de consórcio de serviços de saúde, sendo dois territórios que se referenciam a um único dispositivo de saúde.

中老年危机热线来电者的应激源与自杀危险性

Objective: Psychosocial crisis and psychiatric disorders are two stressors for suicide action. This study will explore the differences on demographic characteristics, severity of depression, and suicidality of middle-aged and elder crisis line callers under the influences of psychosocial crisis or psychiatric disorders or two simultaneously-mixed stressors, in order to develop effective intervention strategies for crisis line. Methods: Analysis data of 1,092 cases selected from national crisis line callers aged 45 and over who were assessed with “Suicide risk assessment” during the period from December, 2002 to December, 2008. The sample were divided into three groups of psychosocial crisis, mental health problems, and mixed-stressors of three types of general callers (48.2%, 32.3%, 19.5%), callers with current suicide ideation (43.7%, 33.0%, 23.3%) and callers attempted suicide 2 weeks prior to the call (33.6%, 42.3%, 24.1%) respectively according to the operators’ judgments of the callers’ claimed difficult situations and classification system of crisis line database. X2 test and Tukey-type and Multinomial Logistic Regression multiple comparison methods are applied to analysis the differences of the three groups. Results: In agreement with previous studies, more females (71.3%, X2=13.45, P<0.001), especially females influenced by relationship stressors (76.8%, X2=25.12, P<0.001) made the call for crisis. Among general callers, the check-out rates of Major Depression Episode of mixed-stressor callers (78.5%, P<0.001) and problem callers (68.7%, P<0.05) were significantly higher than that of crisis callers (57.1%). The check-out rates of suicide ideation of mixed-stressor callers (71.4%) were significantly higher than that in crisis callers (53.8%, P<0.001) and problem callers (60.9%, P<0.05). The check-out rates of prior suicide attempts of mixed-stressor (16.6%, P<0.05) and problem callers (18.5%, P<0.01) were significantly higher than that of crisis callers (9.8%). More than half of the mixed-stressor callers (51.8%) reported over 50% degree of hopelessness, which was significantly higher than that of crisis callers (35.6%, P<0.01) and problem callers (38.2%, P<0.05). Fewer crisis callers sought medical help than problem and mixed-stressor callers among three types of callers (X2=241.35, 146.56, 50.87; P<0.001). Compare to non-compound crisis callers, the proportion of minor, severe depression and prior depression diagnosis (14.0% vs. 17.4%; 54.9% vs. 65.2%; 0 vs. 2.2%; X2=14.35，P<0.01), suicide ideation (51.1% vs. 64.0%, P<0.05) and prior suicide attempts (8.4% vs. 15.0%, P<0.05) in compound crisis callers were significantly higher. There were more compound crisis callers with over 50% hopelessness (51.9% vs. 31.0%，X2=11.96，P<0.01). Conclusion: As predicted, among middle-aged and elderly participants, mixed-stressor and compound crisis callers were higher in degree of severity of depression and suicidality. Intervention strategies should be developed addressing to specific stressor or stressors. The promotions of crisis callers’ medical help seeking behavior need to be emphasized.

Workplace sedentary health risks and exercise interventions

Sedentary lifestyle and physical inactivity are causes of major health risks including cardiovascular disease (CVD), diabetes and cancer. Workplace is an ideal setting to understand both the prevalence of these risks and for devising and implementing effective intervention strategies. It is now possible to perform direct workplace assessments to identify the sedentary prevalence and assess the sedentary related health risks, which can include assessing the risks of atherosclerosis, hypertension, hypercholesterolemia, hyperglyaemia and reduced cardiorespiratory capacity. Based on evaluating the workplace health risks, it is possible to identify individuals who may be at higher CVD risk so they can be targeted with a risk-reduction intervention that can also be tailored towards improving healthy behaviours, especially towards physical activity activity and exercise. This chapter explains workplace sedentary risks, and provides examples of CVD risk prevalence, particularly within the university campus workplace, and presents examples of an exercise based targeted interventions aimed at reducing CVD risks amongst high risk sedentary employees.

Estádios de motivação para o tratamento na dependência alcoólica – percursos individuais e género

Dissertação de Mestrado apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia Clínica e da Saúde.

Os moinhos da Abelheira

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Arquitetura e Urbanismo

Understanding student stress: a qualitative study of the stress experienced by third level students

Stress can be understood in terms of the meaning of stressful experiences for individuals. The meaning of stressful experiences involves threats to self-adequacy, where self-adequacy is considered a basic human need. Appropriate research methods are required to explore this aspect of stress. The present study is a qualitative exploration of the stress experienced by a group of 27 students at the National Institute of Higher Education, Limerick (since renamed the University of Limerick). The study was carried out by the resident student counsellor at the college. A model of student stress was explored, based on student developmental needs. The data consist of a series of interviews recorded with each of the 27 students over a 3 month period. These interviews were transcribed and the resulting transcripts are the subject of detailed analysis. The analysis of the data is an account of the sense-making process by the student counsellor of the students' reported experiences. The aim of the analysis was to reduce the large amounts of data to their most salient aspects in an ordered fashion, so as to examine the application of a developmental model of stress with this group of students. There were two key elements to the analysis. First, the raw data were edited to identify the key statements contained in the interviews. Second, the statements were categorised, as a means of summarising the data. The results of the qualitative dataanalysis were then applied to the developmental model. The analysis of data revealed a number of patterns of stress amongst the sample of students. Patterns of academic over-identification, parental conflict and social inadequacy were particularly noteworthy. These patterns consisted of an integration of academic, family and social stresses within a developmental framework. Gender differences with regard to the need for separateness and belonging are highlighted. Appropriate student stress intervention strategies are discussed. Based on the present results, the relationship between stress and development has been highlighted and is recommended as a firm basis for future studies of stress in general and student stress in particular.

Factors influencing malaria control policy-making in Kenya, Uganda and Tanzania.

BACKGROUND: Policy decisions for malaria control are often difficult to make as decision-makers have to carefully consider an array of options and respond to the needs of a large number of stakeholders. This study assessed the factors and specific objectives that influence malaria control policy decisions, as a crucial first step towards developing an inclusive malaria decision analysis support tool (MDAST). METHODS: Country-specific stakeholder engagement activities using structured questionnaires were carried out in Kenya, Uganda and Tanzania. The survey respondents were drawn from a non-random purposeful sample of stakeholders, targeting individuals in ministries and non-governmental organizations whose policy decisions and actions are likely to have an impact on the status of malaria. Summary statistics across the three countries are presented in aggregate. RESULTS: Important findings aggregated across countries included a belief that donor preferences and agendas were exerting too much influence on malaria policies in the countries. Respondents on average also thought that some relevant objectives such as engaging members of parliament by the agency responsible for malaria control in a particular country were not being given enough consideration in malaria decision-making. Factors found to influence decisions regarding specific malaria control strategies included donor agendas, costs, effectiveness of interventions, health and environmental impacts, compliance and/acceptance, financial sustainability, and vector resistance to insecticides. CONCLUSION: Malaria control decision-makers in Kenya, Uganda and Tanzania take into account health and environmental impacts as well as cost implications of different intervention strategies. Further engagement of government legislators and other policy makers is needed in order to increase funding from domestic sources, reduce donor dependence, sustain interventions and consolidate current gains in malaria.