775 research outputs found

    The diagnosis of dengue in patients presenting with acute febrile illness using supervised machine learning and impact of seasonality

    Get PDF
    Background: Symptomatic dengue infection can result in a life-threatening shock syndrome and timely diagnosis is essential. Point-of-care tests for non-structural protein 1 and IgM are used widely but performance can be limited. We developed a supervised machine learning model to predict whether patients with acute febrile illnesses had a diagnosis of dengue or other febrile illnesses (OFI). The impact of seasonality on model performance over time was examined. Methods: We analysed data from a prospective observational clinical study in Vietnam. Enrolled patients presented with an acute febrile illness of 90%). Conclusion: Supervised machine learning models are able to discriminate between dengue and OFI diagnoses in patients presenting with an early undifferentiated febrile illness. These models could be of clinical utility in supporting healthcare decision-making and provide passive surveillance across dengue endemic regions. Effects of seasonality and changing disease prevalence must however be taken into account—this is of significant importance given unpredictable effects of human-induced climate change and the impact on health

    Cortical thickness, surface area and volume measures in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy

    Get PDF
    OBJECTIVE Parkinson's disease (PD), Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) are neurodegenerative diseases that can be difficult to distinguish clinically. The objective of the current study was to use surface-based analysis techniques to assess cortical thickness, surface area and grey matter volume to identify unique morphological patterns of cortical atrophy in PD, MSA and PSP and to relate these patterns of change to disease duration and clinical features. METHODS High resolution 3D T1-weighted MRI volumes were acquired from 14 PD patients, 18 MSA, 14 PSP and 19 healthy control participants. Cortical thickness, surface area and volume analyses were carried out using the automated surface-based analysis package FreeSurfer (version 5.1.0). Measures of disease severity and duration were assessed for correlation with cortical morphometric changes in each clinical group. RESULTS Results show that in PSP, widespread cortical thinning and volume loss occurs within the frontal lobe, particularly the superior frontal gyrus. In addition, PSP patients also displayed increased surface area in the pericalcarine. In comparison, PD and MSA did not display significant changes in cortical morphology. CONCLUSION These results demonstrate that patients with clinically established PSP exhibit distinct patterns of cortical atrophy, particularly affecting the frontal lobe. These results could be used in the future to develop a useful clinical application of MRI to distinguish PSP patients from PD and MSA patients

    Crisis Visits and Psychiatric Hospitalizations Among Patients Attending a Community Clinic in Rural Southern California

    Get PDF
    Ethnic minorities from disadvantaged socioeconomic backgrounds report increased utilization of mental health emergency services; however findings have been inconsistent across ethnic/racial groups. In this study we describe patients who present to a rural crisis unit in Southern California, examine rates of psychiatric hospitalizations across ethnic/racial groups, and investigate factors that are associated with increased psychiatric hospitalizations in this sample. This is a retrospective study of 451 racially and ethnically diverse patients attending a crisis unit in Imperial County, California. Chart review and data abstraction methods were used to characterize the sample and identify factors associated with psychiatric crises and subsequent hospitalizations. The sample was predominantly Latino/Hispanic (58.5%). Based on chart review, common psychosocial stressors which prompted a crisis center visit were: (a) financial problems; (b) homelessness; (c) partner or family conflict; (d) physical and health problems; (e) problems at school/work; (f) medication compliance; (g) aggressive behavior; (h) delusional behavior; (i) addiction and (j) anxiety/depression. Bivariate analyses revealed that Hispanics had a disproportionately lower rate of psychiatric hospitalizations while African Americans had a higher rate. Multivariate analyses which included demographic, clinical and psychosocial stressor variables revealed that being African American, having a psychotic disorder, and presenting as gravely disabled were associated with a higher likelihood of hospitalization while partner/family conflict was associated with a lesser likelihood in this rural community. These data elucidate the need for longitudinal studies to understand the interactions between psychosocial stressors, ethnicity and social support as determinants of psychiatric hospitalizations

    Study circles improve the precision in nutritional care in special accommodations

    Get PDF
    Background: Disease-related malnutrition is a major health problem in the elderly population, but it has until recently received very little attention, especially are management issues under-explored. By identifying residents at the risk of undernutrition, appropriate nutritional care can be provided. Objectives: Do study circles and policy documents improve the precision in nutritional care and decrease the prevalence of low or high BMI? Design: Pre and post intervention study. Setting: Special accommodations (nursing homes) within six municipalities were involved. Participants: In 2005, 1726 (90.4%) out of 1910 residents agreed to participate and in 2007, 1526 (81.8%) out of 1866 residents participated. Intervention: Study circles in one municipality, having a policy document in one municipality and no intervention in four municipalities. Measurements: Risk of undernutrition was defined as involving any of: involuntary weight loss, low BMI, and/or eating difficulties. Overweight was defined as high BMI. Results: In 2005 and 2007, 64% of 1726 and 66% of 1526 residents respectively were at the risk of undernutrition. In 2007 significantly more patients in the study circle municipality were accurately provided protein and energy enriched food compared to in the no intervention municipalities. There was a decrease in the prevalence of low BMI in the study circle municipality and the prevalence of overweight increased in the policy document municipality between 2005 and 2007

    On the effects of mechanical stress of biological membranes in modeling of swelling dynamics of biological systems

    Get PDF
    We highlight mechanical stretching and bending of membranes and the importance of membrane deformations in the analysis of swelling dynamics of biological systems, including cells and subcellular organelles. Membrane deformation upon swelling generates tensile stress and internal pressure, contributing to volume changes in biological systems. Therefore, in addition to physical (internal/external) and chemical factors, mechanical properties of the membranes should be considered in modeling analysis of cellular swelling. Here we describe an approach that considers mechanical properties of the membranes in the analysis of swelling dynamics of biological systems. This approach includes membrane bending and stretching deformations into the model, producing a more realistic description of swelling. We also discuss the effects of membrane stretching on swelling dynamics. We report that additional pressure generated by membrane bending is negligible, compared to pressures generated by membrane stretching, when both membrane surface area and volume are variable parameters. Note that bending deformations are reversible, while stretching deformation may be irreversible, leading to membrane disruption when they exceed a certain threshold level. Therefore, bending deformations need only be considered in reversible physiological swelling, whereas stretching deformations should also be considered in pathological irreversible swelling. Thus, the currently proposed approach may be used to develop a detailed biophysical model describing the transition from physiological to pathological swelling mode.National Aeronautics & Space Administration (NASA):80NSSC19M0049; PR Space Grant (NASA):NNX15AI11Hinfo:eu-repo/semantics/publishedVersio

    Air–liquid interface cultures enhance the oxygen supply and trigger the structural and functional differentiation of intestinal porcine epithelial cells (IPEC)

    Get PDF
    The specific function of the epithelium as critical barrier between the intestinal lumen and the organism’s internal microenvironment is reflected by permanent maintenance of intercellular junctions and cellular polarity. The intestinal epithelial cells are responsible for absorption of nutritional components, facing mechanical stress and a changing oxygen supplementation via blood stream. Oxygen itself can regulate the barrier and the absorptive function of the epithelium. Therefore, we compared the dish cell culture, the transwell-like membrane culture and the oxygen enriched air–liquid interface (ALI) culture. We demonstrated strong influence of the different culture conditions on morphology and function of intestinal porcine epithelial cell lines in vitro. ALI culture resulted in a significant increase in cell number, epithelial cell layer thickness and expression as well as apical localisation of the microvilli-associated protein villin. Remarkable similarities regarding the morphological parameters were observed between ALI cultures and intestinal epithelial cells in vivo. Furthermore, the functional analysis of protein uptake and degradation by the epithelial cells demonstrated the necessity of sufficient oxygen supply as achieved in ALI cultures. Our study is the first report providing marked evidence that optimised oxygen supply using ALI cultures directly affects the morphological differentiation and functional properties of intestinal epithelial cells in vitro

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

    Get PDF
    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
    corecore