665 research outputs found

    A lower body mass index is associated with cardiomyopathy in people with HIV infection: Evidence from a case comparison study

    Get PDF
    The cause of cardiomyopathy in patients infected with the human immunodeficiency virus (HIV) remains largely unknown, although a number of predisposing factors have been identified. Malnutrition has been postulated to be a contributory factor, but the association of anthropometric measures of nutritional status with HIV-associated cardiomyopathy has not been established. Method. We investigated the association between anthropometric measures of nutritional status and cardiomyopathy in HIV-positive individuals in a cross-sectional case comparison study. Results. Seventeen cases of HIV-associated cardiomyopathy and a comparison group of 18 HIV-positive individuals without cardiomyopathy were studied. There was no significant difference between the two groups in age, gender, CD4 cell count, HIV RNA viral load or World Health Organization (WHO) clinical stage of HIV disease. Patients with HIV-associated cardiomyopathy had evidence of undernutrition compared with HIV-infected people without cardiomyopathy, as evidenced by a significantly lower body mass index (BMI) (20.9 kg/m2 v. 27.0 kg/m2, p=0.02), mid-upper arm circumference (26.2 cm v. 27.3 cm, p=0.02), and bone-free arm muscle area (26.7 cm2 v. 32.8 cm2, p=0.02). However, in a multivariate stepwise logistic regression model, a lower BMI was the only independent anthropometric risk factor for cardiomyopathy (odds ratio 0.76, 95% confidence interval 0.64 - 0.97, p=0.02). Conclusion. A lower BMI is associated with cardiomyopathy in people who are living with HIV

    A 'short walk' is longer before radiotherapy than afterwards: a qualitative study questioning the baseline and follow-up design

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Numerous studies have indirectly demonstrated changes in the content of respondents' QoL appraisal process over time by revealing response-shift effects. This is the first known study to qualitatively examine the assumption of consistency in the content of the cognitive processes underlying QoL appraisal over time. Specific objectives are to examine whether the content of each distinct cognitive process underlying QoL appraisal is (dis)similar over time and whether patterns of (dis)similarity can be discerned across and within patients and/or items.</p> <p>Methods</p> <p>We conducted cognitive think-aloud interviews with 50 cancer patients prior to and following radiotherapy to elicit cognitive processes underlying the assessment of 7 EORTC QLQ-C30 items. Qualitative analysis of patients' responses at baseline and follow-up was independently carried out by 2 researchers by means of an analysis scheme based on the cognitive process models of Tourangeau et al. and Rapkin & Schwartz.</p> <p>Results</p> <p>The interviews yielded 342 comparisons of baseline and follow-up responses, which were analyzed according to the five cognitive processes underlying QoL appraisal. The content of comprehension/frame of reference changed in 188 comparisons; retrieval/sampling strategy in 246; standards of comparison in 152; judgment/combinatory algorithm in 113; and reporting and response selection in 141 comparisons. Overall, in 322 comparisons of responses (94%) the content of at least one cognitive component changed over time. We could not discern patterns of (dis)similarity since the content of each of the cognitive processes differed across and within patients and/or items. Additionally, differences found in the content of a cognitive process for one item was not found to influence dissimilarity in the content of that same cognitive process for the subsequent item.</p> <p>Conclusions</p> <p>The assumption of consistency in the content of the cognitive processes underlying QoL appraisal over time was not found to be in line with the cognitive processes described by the respondents. Additionally, we could not discern patterns of (dis)similarity across and within patients and/or items. In building on cognitive process models and the response shift literature, this study contributes to a better understanding of patient-reported QoL appraisal over time.</p

    Latent cluster analysis of ALS phenotypes identifies prognostically differing groups

    Get PDF
    BACKGROUND Amyotrophic lateral sclerosis (ALS) is a degenerative disease predominantly affecting motor neurons and manifesting as several different phenotypes. Whether these phenotypes correspond to different underlying disease processes is unknown. We used latent cluster analysis to identify groupings of clinical variables in an objective and unbiased way to improve phenotyping for clinical and research purposes. METHODS Latent class cluster analysis was applied to a large database consisting of 1467 records of people with ALS, using discrete variables which can be readily determined at the first clinic appointment. The model was tested for clinical relevance by survival analysis of the phenotypic groupings using the Kaplan-Meier method. RESULTS The best model generated five distinct phenotypic classes that strongly predicted survival (p<0.0001). Eight variables were used for the latent class analysis, but a good estimate of the classification could be obtained using just two variables: site of first symptoms (bulbar or limb) and time from symptom onset to diagnosis (p<0.00001). CONCLUSION The five phenotypic classes identified using latent cluster analysis can predict prognosis. They could be used to stratify patients recruited into clinical trials and generating more homogeneous disease groups for genetic, proteomic and risk factor research

    Nutritional status and structural brain changes in Alzheimer's disease: The NUDAD project

    Get PDF
    INTRODUCTION: Weight loss is associated with higher mortality and progression of cognitive decline, but its associations with magnetic resonance imaging (MRI) changes related to Alzheimer's disease (AD) are unknown. METHODS: We included 412 patients from the NUDAD project, comprising 129 with AD dementia, 107 with mild cognitive impairment (MCI), and 176 controls. Associations between nutritional status and MRI measures were analyzed using linear regression, adjusted for age, sex, education, cognitive functioning, and cardiovascular risk factors. RESULTS: Lower body mass index (BMI), fat mass (FM), and fat free mass index were associated with higher medial temporal atrophy (MTA) scores. Lower BMI, FM, and waist circumference were associated with more microbleeds. Stratification by diagnosis showed that the observed associations with microbleeds were only significant in MCI. DISCUSSION: Lower indicators of nutritional status were associated with more MTA and microbleeds, with largest effect sizes in MCI

    An Experimental Investigation of Electrical Conductivities in Biopolymers

    Get PDF
    Tuberculosis is a devastating infectious disease causing many deaths worldwide. Recent investigations have implicated neutrophil extracellular traps (NETs) in the host response to tuberculosis. The aim of the current study was to obtain evidence for NETs release in the circulation during human tuberculosis. For this we measured the plasma concentrations of nucleosomes in conjunction with neutrophil elastase, in 64 patients with active pulmonary tuberculosis and 32 healthy controls. Patients with active tuberculosis had elevated plasma levels of nucleosomes and elastase when compared with local healthy blood donors. Furthermore nucleosome and elastase levels showed a positive correlation. These findings provide the first evidence for the release of NETs in the circulation of patients with active pulmonary tuberculosis

    The distribution of genetic diversity in a Brassica oleracea gene bank collection related to the effects on diversity of regeneration, as measured with AFLPs

    Get PDF
    The ex situ conservation of plant genetic resources in gene banks involves the selection of accessions to be conserved and the maintenance of these accessions for current and future users. Decisions concerning both these issues require knowledge about the distribution of genetic diversity within and between accessions sampled from the gene pool, but also about the changes in variation of these samples as a result of regenerations. These issues were studied in an existing gene bank collection of a cross-pollinating crop using a selection of groups of very similar Dutch white cabbage accessions, and additional groups of reference material representing the Dutch, and the global white cabbage gene pool. Six accessions were sampled both before and after a standard regeneration. 30 plants of each of 50 accessions plus 6 regeneration populations included in the study were characterised with AFLPs, using scores for 103 polymorphic bands. It was shown that the genetic changes as a result of standard gene bank regenerations, as measured by AFLPs, are of a comparable magnitude as the differences between some of the more similar accessions. The observed changes are mainly due to highly significant changes in allele frequencies for a few fragments, whereas for the majority of fragments the alleles occur in similar frequencies before and after regeneration. It is argued that, given the changes of accessions over generations, accessions that display similar levels of differentiation may be combined safely

    Amyloid-driven disruption of default mode network connectivity in cognitively healthy individuals

    Get PDF
    Cortical accumulation of amyloid beta is one of the first events of Alzheimer's disease pathophysiology, and has been suggested to follow a consistent spatiotemporal ordering, starting in the posterior cingulate cortex, precuneus and medio-orbitofrontal cortex. These regions overlap with those of the default mode network, a brain network also involved in memory functions. Aberrant default mode network functional connectivity and higher network sparsity have been reported in prodromal and clinical Alzheimer's disease. We investigated the association between amyloid burden and default mode network connectivity in the preclinical stage of Alzheimer's disease and its association with longitudinal memory decline. We included 173 participants, in which amyloid burden was assessed both in CSF by the amyloid beta 42/40 ratio, capturing the soluble part of amyloid pathology, and in dynamic PET scans calculating the non-displaceable binding potential in early-stage regions. The default mode network was identified with resting-state functional MRI. Then, we calculated functional connectivity in the default mode network, derived from independent component analysis, and eigenvector centrality, a graph measure recursively defining important nodes on the base of their connection with other important nodes. Memory was tested at baseline, 2- and 4-year follow-up. We demonstrated that higher amyloid burden as measured by both CSF amyloid beta 42/40 ratio and non-displaceable binding potential in the posterior cingulate cortex was associated with lower functional connectivity in the default mode network. The association between amyloid burden (CSF and non-displaceable binding potential in the posterior cingulate cortex) and aberrant default mode network connectivity was confirmed at the voxel level with both functional connectivity and eigenvector centrality measures, and it was driven by voxel clusters localized in the precuneus, cingulate, angular and left middle temporal gyri. Moreover, we demonstrated that functional connectivity in the default mode network predicts longitudinal memory decline synergistically with regional amyloid burden, as measured by non-displaceable binding potential in the posterior cingulate cortex. Taken together, these results suggest that early amyloid beta deposition is associated with aberrant default mode network connectivity in cognitively healthy individuals and that default mode network connectivity markers can be used to identify subjects at risk of memory decline

    Current Welfare Problems Facing Horses in Great Britain as Identified by Equine Stakeholders

    Get PDF
    Despite growing concerns about the welfare of horses in Great Britain (GB) there has been little surveillance of the welfare status of the horse population. Consequently we have limited knowledge of the range of welfare problems experienced by horses in GB and the situations in which poor welfare occurs. Thirty-one in-depth interviews were conducted with a cross -section of equine stakeholders, in order to explore their perceptions of the welfare problems faced by horses in GB. Welfare problems relating to health, management and riding and training were identified, including horses being under or over weight, stabling 24 hours a day and the inappropriate use of training aids. The interviewees also discussed broader contexts in which they perceived that welfare was compromised. The most commonly discussed context was where horses are kept in unsuitable environments, for example environments with poor grazing. The racing industry and travellers horses were identified as areas of the industry where horse welfare was particularly vulnerable to compromise. Lack of knowledge and financial constraints were perceived to be the root cause of poor welfare by many interviewees. The findings give insight into the range of welfare problems that may be faced by horses in GB, the contexts in which these may occur and their possible causes. Many of the problems identified by the interviewees have undergone limited scientific investigation pointing to areas where further research is likely to be necessary for welfare improvement. The large number of issues identified suggests that some form of prioritisation may be necessary to target research and resources effectively

    Protein disulfide isomerases as CSF biomarkers for the neuronal response to tau pathology

    Get PDF
    Introduction: Cerebrospinal fluid (CSF) biomarkers for specific cellular disease processes are lacking for tauopathies. In this translational study we aimed to identify CSF biomarkers reflecting early tau pathology-associated unfolded protein response (UPR) activation. Methods: We employed mass spectrometry proteomics and targeted immunoanalysis in a combination of biomarker discovery in primary mouse neurons in vitro and validation in patient CSF from two independent large multicentre cohorts (EMIF-AD MBD, n = 310; PRIDE, n = 771). Results: First, we identify members of the protein disulfide isomerase (PDI) family in the neuronal UPR-activated secretome and validate secretion upon tau aggregation in vitro. Next, we demonstrate that PDIA1 and PDIA3 levels correlate with total- and phosphorylated-tau levels in CSF. PDIA1 levels are increased in CSF from AD patients compared to controls and patients with tau-unrelated frontotemporal and Lewy body dementia (LBD). Highlights: Neuronal unfolded protein response (UPR) activation induces the secretion of protein disulfide isomerases (PDIs) in vitro. PDIA1 is secreted upon tau aggregation in neurons in vitro. PDIA1 and PDIA3 levels correlate with total and phosphorylated tau levels in CSF. PDIA1 levels are increased in CSF from Alzheimer's disease (AD) patients compared to controls. PDIA1 levels are not increased in CSF from tau-unrelated frontotemporal dementia (FTD) and Lewy body dementia (LBD) patients

    Reliability and validity of three questionnaires measuring context-specific sedentary behaviour and associated correlates in adolescents, adults and older adults

    Get PDF
    BACKGROUND: Reliable and valid measures of total sedentary time, context-specific sedentary behaviour (SB) and its potential correlates are useful for the development of future interventions. The purpose was to examine test-retest reliability and criterion validity of three newly developed questionnaires on total sedentary time, context-specific SB and its potential correlates in adolescents, adults and older adults. METHODS: Reliability and validity was tested in six different samples of Flemish (Belgium) residents. For the reliability study, 20 adolescents, 22 adults and 20 older adults filled out the age-specific SB questionnaire twice. Test-retest reliability was analysed using Kappa coefficients, Intraclass Correlation Coefficients and/or percentage agreement, separately for the three age groups. For the validity study, data were retrieved from 62 adolescents, 33 adults and 33 older adults, with activPAL as criterion measure. Spearman correlations and Bland-Altman plots (or non-parametric approach) were used to analyse criterion validity, separately for the three age groups and for weekday, weekend day and average day. RESULTS: The test-retest reliability for self-reported total sedentary time indicated following values: ICC = 0.37-0.67 in adolescents; ICC = 0.73-0.77 in adults; ICC = 0.68-0.80 in older adults. Item-specific reliability results (e.g. context-specific SB and its potential correlates) showed good-to-excellent reliability in 67.94%, 68.90% and 66.38% of the items in adolescents, adults and older adults respectively. All items belonging to sedentary-related equipment and simultaneous SB showed good reliability. The sections of the questionnaire with lowest reliability were: context-specific SB (adolescents), potential correlates of computer use (adults) and potential correlates of motorized transport (older adults). Spearman correlations between self-reported total sedentary time and the activPAL were different for each age group: rho = 0.02-0.42 (adolescents), rho = 0.06-0.52 (adults), rho = 0.38-0.50 (older adults). Participants over-reported total sedentary time (except for weekend day in older adults) compared to the activPAL, for weekday, weekend day and average day respectively by +57.05%, +46.29%, +53.34% in adolescents; +40.40%, +19.15%, +32.89% in adults; +10.10%, -6.24%, +4.11% in older adults. CONCLUSIONS: The questionnaires showed acceptable test-retest reliability and criterion validity. However, over-reporting of total SB was noticeable in adolescents and adults. Nevertheless, these questionnaires will be useful in getting context-specific information on SB
    corecore