83 research outputs found

    Shape description and matching using integral invariants on eccentricity transformed images

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    Matching occluded and noisy shapes is a problem frequently encountered in medical image analysis and more generally in computer vision. To keep track of changes inside the breast, for example, it is important for a computer aided detection system to establish correspondences between regions of interest. Shape transformations, computed both with integral invariants (II) and with geodesic distance, yield signatures that are invariant to isometric deformations, such as bending and articulations. Integral invariants describe the boundaries of planar shapes. However, they provide no information about where a particular feature lies on the boundary with regard to the overall shape structure. Conversely, eccentricity transforms (Ecc) can match shapes by signatures of geodesic distance histograms based on information from inside the shape; but they ignore the boundary information. We describe a method that combines the boundary signature of a shape obtained from II and structural information from the Ecc to yield results that improve on them separately

    The Effect of Multidomain Interventions on Global Cognition, Symptoms of Depression and Apathy - A Pooled Analysis of Two Randomized Controlled Trials.

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    BACKGROUND: Cardiovascular risk factors and lifestyle factors are associated with an increased risk of cognitive decline and dementia in observational studies, and have been targeted by multidomain interventions. OBJECTIVES: We pooled individual participant data from two multi-domain intervention trials on cognitive function and symptoms of depression to increase power and facilitate subgroup analyses. DESIGN: Pooled analysis of individual participant data. SETTING: Prevention of Dementia by Intensive Vascular Care trial (preDIVA) and Multidomain Alzheimer Preventive Trial (MAPT). PARTICIPANTS: Community-dwelling individuals, free from dementia at baseline. INTERVENTION: Multidomain interventions focused on cardiovascular and lifestyle related risk factors. MEASUREMENTS: Data on cognitive functioning, depressive symptoms and apathy were collected at baseline, 2 years and 3-4 years of follow-up as available per study. We analyzed crude scores with linear mixed models for overall cognitive function (Mini Mental State Examination [MMSE]), and symptoms of depression and apathy (15-item Geriatric Depression Scale). Prespecified subgroup analyses were performed for sex, educational level, baseline MMSE <26, history of hypertension, and history of stroke, myocardial infarction and/or diabetes mellitus. RESULTS: We included 4162 individuals (median age 74 years, IQR 72, 76) with a median follow-up duration of 3.7 years (IQR 3.0 to 4.1 years). No differences between intervention and control groups were observed on change in cognitive functioning scores and symptoms of depression and apathy scores in the pooled study population. The MMSE declined less in the intervention groups in those with MMSE <26 at baseline (N=250; MD: 0.84; 95%CI: 0.15 to 1.54; p<0.001). CONCLUSIONS: We found no conclusive evidence that multidomain interventions reduce the risk of global cognitive decline, symptoms of depression or apathy in a mixed older population. Our results suggest that these interventions may be more effective in those with lower baseline cognitive functioning. Extended follow-up for dementia occurrence is important to inform on the potential long-term effects of multidomain interventions

    Travel-related schistosomiasis, strongyloidiasis, filariasis, and toxocariasis: the risk of infection and the diagnostic relevance of blood eosinophilia

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    <p>Abstract</p> <p>Background</p> <p>This study prospectively assessed the occurrence of clinical and subclinical schistosomiasis, strongyloidiasis, filariasis, and toxocariasis, and the screening value of eosinophilia in adult short-term travelers to helminth-endemic countries.</p> <p>Methods</p> <p>Visitors of a pre-travel health advice centre donated blood samples for serology and blood cell count before and after travel. Samples were tested for eosinophilia, and for antibodies against schistosomiasis, strongyloidiasis, filariasis, and toxocariasis. Previous infection was defined as seropositivity in pre- and post-travel samples. Recent infection was defined as a seroconversion. Symptoms of parasitic disease were recorded in a structured diary.</p> <p>Results</p> <p>Previous infection was found in 112 of 1207 subjects: schistosomiasis in 2.7%, strongyloidiasis in 2.4%, filariasis in 3.4%, and toxocariasis in 1.8%. Recent schistosomiasis was found in 0.51% of susceptible subjects at risk, strongyloidiasis in 0.25%, filariasis in 0.09%, and toxocariasis in 0.08%. The incidence rate per 1000 person-months was 6.4, 3.2, 1.1, and 1.1, respectively. Recent infections were largely contracted in Asia. The positive predictive value of eosinophilia for diagnosis was 15% for previous infection and 0% for recent infection. None of the symptoms studied had any positive predictive value.</p> <p>Conclusion</p> <p>The chance of infection with schistosomiasis, strongyloidiasis, filariasis, and toxocariasis during one short-term journey to an endemic area is low. However, previous stay leads to a cumulative risk of infection. Testing for eosinophilia appeared to be of no value in routine screening of asymptomatic travelers for the four helminthic infections. Findings need to be replicated in larger prospective studies.</p

    Early Onset Prion Disease from Octarepeat Expansion Correlates with Copper Binding Properties

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    Insertional mutations leading to expansion of the octarepeat domain of the prion protein (PrP) are directly linked to prion disease. While normal PrP has four PHGGGWGQ octapeptide segments in its flexible N-terminal domain, expanded forms may have up to nine additional octapeptide inserts. The type of prion disease segregates with the degree of expansion. With up to four extra octarepeats, the average onset age is above 60 years, whereas five to nine extra octarepeats results in an average onset age between 30 and 40 years, a difference of almost three decades. In wild-type PrP, the octarepeat domain takes up copper (Cu2+) and is considered essential for in vivo function. Work from our lab demonstrates that the copper coordination mode depends on the precise ratio of Cu2+ to protein. At low Cu2+ levels, coordination involves histidine side chains from adjacent octarepeats, whereas at high levels each repeat takes up a single copper ion through interactions with the histidine side chain and neighboring backbone amides. Here we use both octarepeat constructs and recombinant PrP to examine how copper coordination modes are influenced by octarepeat expansion. We find that there is little change in affinity or coordination mode populations for octarepeat domains with up to seven segments (three inserts). However, domains with eight or nine total repeats (four or five inserts) become energetically arrested in the multi-histidine coordination mode, as dictated by higher copper uptake capacity and also by increased binding affinity. We next pooled all published cases of human prion disease resulting from octarepeat expansion and find remarkable agreement between the sudden length-dependent change in copper coordination and onset age. Together, these findings suggest that either loss of PrP copper-dependent function or loss of copper-mediated protection against PrP polymerization makes a significant contribution to early onset prion disease

    Joseph Franz Barwirsch levele Lukács Györgynek

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    _Background:_ Acute kidney injury (AKI) is a frequently encountered complication of imported Plasmodium falciparum infection. Markers of structural kidney damage have been found to detect AKI earlier than serum creatinine-based prediction models but have not yet been evaluated in imported malaria. This pilot study aims to explore the predictive performance of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) for AKI in travellers with imported P. falciparum infection. _Methods:_ Thirty-nine patients with imported falciparum malaria from the Rotterdam Malaria Cohort with available serum and urine samples at presentation were included. Ten of these patients met the criteria for severe malaria. The predictive performance of NGAL and KIM-1 as markers for AKI was compared with that of serum creatinine. _Results:_ Six of the 39 patients (15 %) developed AKI. Serum and urine NGAL and urine KIM-1 were all found to have large areas under the receiver operating characteristics curves (AUROC) for predicting AKI. Urine NGAL was found to have an excellent performance with positive predictive value (PPV) of 1.00 (95 % CI 0.54-1.00), a negative predictive value (NPV) of 1.00 (95 % CI 0.89-1.00) and an AUROC of 1.00 (95 % CI 1.00-1.00). _Conclusion:_ A good diagnostic performance of NGAL and KIM-1 for AKI was found. Particularly, urine NGAL was found to have an excellent predictive performance. Larger studies are needed to demonstrate whether these biomarkers are superior to serum creatinine as predictors for AKI in P. falciparum malaria

    Factors associated with the prevalence of hypertension and control practices among elderly residents of São Paulo city, Brazil

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    The aim of this study was to analyze the prevalence of hypertension and control practices among the elderly. The survey analyzed data from 872 elderly people in São Paulo, Brazil, through a cluster sampling, stratified according to education and income. A Poisson multiple regression model checked for the existence of factors associated with hypertension. The prevalence of self-reported hypertension among the elderly was 46.9%. Variables associated with hypertension were self-rated health, alcohol consumption, gender, and hospitalization in the last year, regardless of age. The three most common measures taken to control hypertension, but only rarely, are oral medication, routine salt-free diet and physical activity. Lifestyle and socioeconomic status did not affect the practice of control, but knowledge about the importance of physical activity was higher among those older people with higher education and greater income. The research suggests that health policies that focus on primary care to encourage lifestyle changes among the elderly are necessary.O objetivo deste estudo foi analisar a prevalência de hipertensão e práticas de controle em idosos. Inquérito transversal analisou dados de 872 idosos de São Paulo, Brasil, por meio de uma amostra por conglomerados, estratificada segundo escolaridade e renda. O modelo de regressão múltiplo de Poisson verificou a existência de fatores associados à hipertensão. A prevalência de hipertensão referida entre os idosos foi de 46,9%. As variáveis associadas à hipertensão foram autopercepção de saúde, consumo de álcool, sexo e hospitalização no último ano, independentemente da idade. As três medidas mais adotadas para o controle da hipertensão, embora pouco praticadas, são tomar medicação oral de rotina, dieta sem sal e atividade física. O estilo de vida e a condição socioeconômica não influenciaram a prática de controle, mas o conhecimento sobre a importância da atividade física foi maior entre os idosos com mais escolaridade e renda. Fazem-se necessárias políticas de saúde com foco na atenção primária que incentivem mudanças no estilo de vida dos idosos.El objetivo de este estudio fue analizar la prevalencia de hipertensión y prácticas de control en ancianos. Un estudio transversal analizó los datos de 872 ancianos de São Paulo, Brasil, mediante una muestra por conglomerados, estratificada según la escolaridad y renta. El modelo de regresión múltiple de Poisson verificó la existencia de factores asociados a la hipertensión. La prevalencia de hipertensión referida a los ancianos fue de un 46,9%. Las variables asociadas a la hipertensión fueron: autopercepción de salud, consumo de alcohol, sexo y hospitalización durante el último año, independientemente de la edad. Las tres medidas más adoptadas para el control de la hipertensión, aunque poco practicadas, son: tomar medicación oral de rutina, dieta sin sal, y actividad física. El estilo de vida y la condición socioeconómica no influenciaron la práctica de control, sin embargo, el conocimiento sobre la importancia de la actividad física fue mayor entre los ancianos con mayor escolaridad y renta. Se necesitan políticas de salud enfocadas a la atención primaria que incentiven cambios en el estilo de vida de los ancianos.Universidade de São Paulo Faculdade de MedicinaUniversidade de São Paulo Faculdade de Saúde PúblicaUniversidade Estadual de Campinas Faculdade de Ciências MédicasUniversidade Estadual Paulista Faculdade de Medicina de BotucatuUniversidade Estadual Paulista Faculdade de Medicina de Botucat
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