1,597 research outputs found

    Huntington disease: natural history, biomarkers and prospects for therapeutics

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    Huntington disease (HD) can be seen as a model neurodegenerative disorder, in that it is caused by a single genetic mutation and is amenable to predictive genetic testing, with estimation of years to predicted onset, enabling the entire range of disease natural history to be studied. Structural neuroimaging biomarkers show that progressive regional brain atrophy begins many years before the emergence of diagnosable signs and symptoms of HD, and continues steadily during the symptomatic or 'manifest' period. The continued development of functional, neurochemical and other biomarkers raises hopes that these biomarkers might be useful for future trials of disease-modifying therapeutics to delay the onset and slow the progression of HD. Such advances could herald a new era of personalized preventive therapeutics. We describe the natural history of HD, including the timing of emergence of motor, cognitive and emotional impairments, and the techniques that are used to assess these features. Building on this information, we review recent progress in the development of biomarkers for HD, and potential future roles of these biomarkers in clinical trials

    Monsoon mixing cycles in the Bay of Bengal: A year-long subsurface mixing record

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    Based on the first year-long record of mixing collected in the eastern central Bay of Bengal, we quantify the role that subsurface turbulent heat fluxes play in upper-ocean cooling brought on by southwest (SW) and northeast (NE) monsoons. During the NE (dry, or winter) monsoon, atmospheric and subsurface turbulent heat fluxes each contribute about 50% of the net sea surface cooling. During the SW (wet, or summer) monsoon, the atmospheric heat flux varied widely due to “active” and “break” cycles of the monsoon intraseasonal oscillations, but had a net positive seasonal average. The subsurface turbulent heat flux during the SW monsoon led to surface cooling at rates more than three times greater than those measured during the NE monsoon. Since the seasonally averaged atmospheric heat flux was positive, subsurface mixing accounted for nearly all of the cooling during the SW monsoon. During the transition between the NE and SW monsoons, subsurface heat flux was near zero, and atmospheric heating rapidly warmed the sea surface. Following the SW monsoon, passage of Tropical Storm Hudhud led to O(1) m2 s–1 rates of turbulence diffusivity and strong subsurface heat flux, accounting for roughly half of the 1.4°C surface cooling that occurred over a 60-hour period

    Oportunidades perdidas na prevenção da sífilis congênita e da transmissão vertical do HIV

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    OBJECTIVE: To estimate the prevalence of missed opportunities for congenital syphilis and HIV prevention in pregnant women who had access to prenatal care and to assess factors associated to non-testing of these infections. METHODS: Cross-sectional study comprising a randomly selected sample of 2,145 puerperal women who were admitted in maternity hospitals for delivery or curettage and had attended at least one prenatal care visit, in Brazil between 1999 and 2000. No syphilis and/or anti-HIV testing during pregnancy was a marker for missed prevention opportunity. Women who were not tested for either or both were compared to those who had at least one syphilis and one anti-HIV testing performed during pregnancy (reference category). The prevalence of missed prevention opportunity was estimated for each category with 95% confidence intervals. Factors independently associated with missed prevention opportunity were assessed through multinomial logistic regression. RESULTS: The prevalence of missed prevention opportunity for syphilis or anti-HIV was 41.2% and 56.0%, respectively. The multivariate analysis showed that race/skin color (non-white), schooling (OBJETIVO: Estimar la prevalencia de oportunidad de pérdida de prevención de la sífilis y el HIV entre gestantes que tuvieron acceso al pre-natal y factores asociados con la no evaluación de estos agravios. MÉTODOS: Se realizó estudio transversal con muestra aleatoria de 2.145 puérperas de Brasil, 1999 y 2000 admitidas en maternidades para parto o curetaje y que habían realizado al menos una consulta de pre-natal. La no realización del examen de prueba para sífilis y/o anti-HIV durante el embarazo fue usada como marcador para oportunidad de pérdida de prevención. Las mujeres que realizaron sólo examen de sífilis o sólo examen de anti-HIV, o que no realizaron ninguno, fueron comparadas con las que realizaron los dos (categoría de referencia). La prevalencia de oportunidad de pérdida de prevención fue estimada para cada categoría, con intervalo de confianza de 95%. Los factores asociados con la oportunidad de pérdida de prevención fueron analizados por medio de regresión logística multinomial. RESULTADOS: La prevalencia de oportunidad de pérdida de prevención para la realización de la prueba de sífilis o anti-HIV fue de 41,2% e 56,0%, respectivamente. El análisis multivariado indicó que raza/color (no blanca), escolaridad (< 8 años de estudio), estado civil (soltera), renta < 3 salarios mínimos, relación sexual durante el embarazo, no haber tenido sífilis anterior al embarazo actual, realización de seis o mas consultas de pre-natal y la realización de la última visita antes del tercer trimestre de embarazo, estaban asociados con mayor riesgo de tener oportunidad de pérdida de prevención. Se observó una asociación negativa entre estado civil (soltera), lugar de realización de pre-natal (hospital) y la realización de la primera consulta pre-natal en el tercer trimestre con oportunidad de pérdida de prevención. CONCLUSIONES: Altos porcentajes de gestantes no evaluadas señalan fallas en la prevención y control de la infección por HIV y de la sífilis congénita en los servicios de salud. Las gestantes continúan interrumpiendo el cuidado pre-natal precozmente y no logran realizar los procedimientos de selección para HIV y sífilis.OBJETIVO: Estimar a prevalência de oportunidade perdida de prevenção a sífilis e HIV entre gestantes que tiveram acesso ao pré-natal e fatores associados a não-testagem para esses agravos. MÉTODOS: Estudo transversal com amostra aleatória de 2.145 puérperas do Brasil, 1999 e 2000 admitidas em maternidades para parto ou curetagem e que haviam realizado pelo menos uma consulta de pré-natal. A não-realização de exame de teste para sífilis e/ou anti-HIV durante a gravidez foi usada como marcador para oportunidade perdida de prevenção. Mulheres que realizaram apenas exame de sífilis ou apenas o anti-HIV, ou não realizaram nenhum, foram comparadas àquelas que realizaram os dois (categoria de referência). A prevalência de oportunidade perdida de prevenção foi estimada para cada categoria, com intervalo de confiança de 95%. Os fatores associados com oportunidade perdida de prevenção foram analisados por meio de regressão logística multinomial. RESULTADOS: A prevalência de oportunidade perdida de prevenção para a realização do teste de sífilis ou anti-HIV foi de 41,2% e 56,0%, respectivamente. A análise multivariada indicou que raça/cor (não branca), escolaridade (< 8 anos de estudo), estado civil (solteira), rend

    New Strategies for Research in Clinical Practice: A focus on self–harm.

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    This article suggests new ways of approaching clinical-based research in an era of evidence-based practice. Using the example of self-harm, we identify three distinct problems with current dominant approaches to research in this area. These include insufficient clarity about target issues, an overreliance on predetermined outcomes which prioritise behavioural measures (such as self-harm cessation) and an undue focus on treatment techniques. We argue that clinical research requires flexible, user-centred and practice-based methods, informed by a focus on principles instead of techniques. Therefore, we outline key practice-based principles that we argue need to be embedded within clinical research strategies. We then demonstrate how traditional behavioural approaches to research can be enriched with more qualitative cognitive and emotionally based data. We conclude that such strategies provide thickened, meaningful and context-specific research which is more relevant for service commissioners, clinicians and service users

    Over 1200 drugs-related deaths and 190,000 opiate-user-years of follow-up : relative risks by sex and age-group

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    Heroin users/injectors' risk of drugs-related death by sex and current age is weakly estimated both in individual cohorts of under 1000 clients, 5000 person-years or 50 drugs-related deaths and when using cross-sectional data. A workshop in Cambridge analysed six cohorts who were recruited according to a common European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) protocol from drug treatment agencies in Barcelona, Denmark, Dublin, Lisbon, Rome and Vienna in the 1990s; and, as external reference, opiate-user arrestees in France and hepatitis C diagnosed ever-injectors in Scotland in 1993-2001, both followed by database linkage to December 2001. EMCDDA cohorts recorded approximately equal numbers of drugs-related deaths (864) and deaths from other non-HIV causes (865) during 106,152 person-years of follow-up. External cohorts contributed 376 drugs-related deaths (Scotland 195, France 181) and 418 deaths from non-HIV causes (Scotland 221, France 197) during 86,417 person-years of follow-up (Scotland 22,670, France 63,747). EMCDDA cohorts reported 707 drugs-related deaths in 81,367 man-years {8.7 per 1000 person-years, 95% CI: 8.1 to 9.4} but only 157 in 24,785 person-years for females {6.3 per 1000 person-years, 95% CI: 5.4 to 7.4}. Except in external cohorts, relative risks by current age-group were not particularly strong, and more modest in Poisson regression than in cross-sectional analyses: relative risk was 1.2 (95% CI: 1.0-1.4) for 35-44 year olds compared to 15-24 year 3 olds, but 1.4 for males (95%CI: 1.2-1.6), and dramatically lower at 0.44 after the first year of follow-up (95% CI: 0.37-0.52)

    Connexin-mimetic peptide Gap 27 decreases osteoclastic activity

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    BACKGROUND: Bone remodelling is dependent on the balance between bone resorbing osteoclasts and bone forming osteoblasts. We have shown previously that osteoclasts contain gap-junctional protein connexin-43 and that a commonly used gap-junctional inhibitor, heptanol, can inhibit osteoclastic bone resorption. Since heptanol may also have some unspecific effect unrelated to gap-junctional inhibition we wanted to test the importance of gap-junctional communication to osteoclasts using a more specific inhibitor. METHODS: A synthetic connexin-mimetic peptide, Gap 27, was used to evaluate the contribution of gap-junctional communication to osteoclastic bone resorption. We utilised the well-characterised pit-formation assay to study the effects of the specific gap-junctional inhibitor to the survival and activity of osteoclasts. RESULTS: Gap 27 caused a remarked decrease in the number of both TRAP-positive mononuclear and multinucleated rat osteoclasts cultured on bovine bone slices. The decrease in the cell survival seemed to be restricted to TRAP-positive cells, whereas the other cells of the culture model seemed unaffected. The activity of the remaining osteoclasts was found to be diminished by measuring the percentage of osteoclasts with actin rings of all TRAP-positive cells. In addition, the resorbed area in the treated cultures was greatly diminished. CONCLUSIONS: On the basis of these results we conclude that gap-junctional communication is essential for the action of bone resorbing osteoclasts and for proper remodelling for bone
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