129 research outputs found

    Is there a role for vitamin C in preventing osteoporosis and fractures?:A review of the potential underlying mechanisms and current epidemiological evidence

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    Osteoporosis and related fractures are a major global health issue, but there are few preventative strategies. Previously reported associations between higher intakes of fruits and vegetables and skeletal health have been suggested to be partly attributable to vitamin C. To date, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention but an overall consensus of published studies has not yet been drawn. The present review aims to provide a summary of the proposed underlying mechanisms of vitamin C on bone and reviews the current evidence in the literature, examining a potential link between vitamin C intake and status with osteoporosis and fractures. The Bradford Hill criteria were used to assess reported associations. Recent animal studies have provided insights into the involvement of vitamin C in osteoclastogenesis and osteoblastogenesis, and its role as a mediator of bone matrix deposition, affecting both the quantity and quality of bone collagen. Observational studies have provided some evidence for this in the general population, showing positive associations between dietary vitamin C intake and supplements and higher bone mineral density or reduced fracture risk. However, previous intervention studies were not sufficiently well designed to evaluate these associations. Epidemiological data are particularly limited for vitamin C status and for fracture risk and good-quality randomised controlled trials are needed to confirm previous epidemiological findings. The present review also highlights that associations between vitamin C and bone health may be non-linear and further research is needed to ascertain optimal intakes for osteoporosis and fracture prevention

    RABIES SURVEILLANCE AMONG BATS IN TENNESSEE, USA, 1996–2010

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    Rabies virus (RABV) infects multiple bat species in the Americas, and enzootic foci perpetuate in bats principally via intraspecific transmission. In recent years, bats have been implicated in over 90% of human rabies cases in the US. In Tennessee, two human cases of rabies have occurred since 1960: one case in 1994 associated with a tricolored bat (Perimyotis subflavus) RABV variant and another in 2002 associated with the tricolored/silver-haired bat (P. subflavus/ Lasionycteris noctivagans) RABV variant. From 1996 to 2010, 2,039 bats were submitted for rabies testing in Tennessee. Among 1,943 bats in satisfactory condition for testing and with a reported diagnostic result, 96% (1,870 of 1,943) were identified to species and 10% (196 of 1,943) were rabid. Big brown (Eptesicus fuscus), tricolored, and eastern red (Lasiurus borealis) bats comprised 77% of testable bat submissions and 84% of rabid bats. For species with five or more submissions during 1996–2010, the highest proportion of rabid bats occurred in hoary (Lasiurus cinereus; 46%), unspecified Myotis spp. (22%), and eastern red (17%) bats. The best model to predict rabid bats included month of submission, exposure history of submission, species, and sex of bat

    RABIES SURVEILLANCE AMONG BATS IN TENNESSEE, USA, 1996–2010

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    Rabies virus (RABV) infects multiple bat species in the Americas, and enzootic foci perpetuate in bats principally via intraspecific transmission. In recent years, bats have been implicated in over 90% of human rabies cases in the US. In Tennessee, two human cases of rabies have occurred since 1960: one case in 1994 associated with a tricolored bat (Perimyotis subflavus) RABV variant and another in 2002 associated with the tricolored/silver-haired bat (P. subflavus/ Lasionycteris noctivagans) RABV variant. From 1996 to 2010, 2,039 bats were submitted for rabies testing in Tennessee. Among 1,943 bats in satisfactory condition for testing and with a reported diagnostic result, 96% (1,870 of 1,943) were identified to species and 10% (196 of 1,943) were rabid. Big brown (Eptesicus fuscus), tricolored, and eastern red (Lasiurus borealis) bats comprised 77% of testable bat submissions and 84% of rabid bats. For species with five or more submissions during 1996–2010, the highest proportion of rabid bats occurred in hoary (Lasiurus cinereus; 46%), unspecified Myotis spp. (22%), and eastern red (17%) bats. The best model to predict rabid bats included month of submission, exposure history of submission, species, and sex of bat

    Effort and Fatigue-Related Functional Connectivity in Mild Traumatic Brain Injury

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    Mental fatigue in healthy individuals is typically observed under conditions of high cognitive demand, particularly when effort is required to perform a task for a long period of time—thus the concepts of fatigue and effort are closely related. In brain injured individuals, mental fatigue can be a persistent and debilitating symptom. Presence of fatigue after brain injury is prognostic for return to work/school and engagement in activities of daily life. As such, it should be a high priority for treatment in this population, but because there is little understanding of its behavioral and neural underpinnings, the target for such treatment is unknown. Here, the neural underpinnings of fatigue and effort are investigated in active duty military service members with mild traumatic brain injury (mTBI) and demographically-matched orthopedic controls. Participants performed a Constant Effort task for which they were to hold a pre-defined effort level constant for long durations during fMRI scanning. The task allowed for investigation of the neural systems underlying fatigue and their relationship with sense of effort. While brain activation associated with effort and fatigue did not differentiate the mTBI and controls, functional connectivity amongst active brain regions did. The mTBI group demonstrated immediate hyper-connectivity that increased with effort level but diminished quickly when there was a need to maintain effort. Controls, in contrast, demonstrated a similar pattern of hyper-connectivity, but only when maintaining effort over time. Connectivity, particularly between the left anterior insula, rostral anterior cingulate cortex, and right-sided inferior frontal regions, correlated with effort-level and state fatigue in mTBI participants. These connections also correlated with effort level in the Control group, but only the connection between the left insula and superior medial frontal gyrus correlated with fatigue, suggesting a differing pattern of connectivity. These findings align, in part, with the dopamine imbalance, and neural efficiency hypotheses that pose key roles for medial frontal connections with insular or striatal regions in motivating or optimizing performance. Sense of effort and fatigue are closely related. As people fatigue, sense of effort increases systematically. The data propose a complex link between sense of effort, fatigue, and mTBI that is centered in what may be an inefficient neural system due to brain trauma that warrants further investigation

    Designing a complex intervention for dementia case management in primary care

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    Background: Community-based support will become increasingly important for people with dementia, but currently services are fragmented and the quality of care is variable. Case management is a popular approach to care co-ordination, but evidence to date on its effectiveness in dementia has been equivocal. Case management interventions need to be designed to overcome obstacles to care co-ordination and maximise benefit. A successful case management methodology was adapted from the United States (US) version for use in English primary care, with a view to a definitive trial. Medical Research Council guidance on the development of complex interventions was implemented in the adaptation process, to capture the skill sets, person characteristics and learning needs of primary care based case managers. Methods: Co-design of the case manager role in a single NHS provider organisation, with external peer review by professionals and carers, in an iterative technology development process. Results: The generic skills and personal attributes were described for practice nurses taking up the case manager role in their workplaces, and for social workers seconded to general practice teams, together with a method of assessing their learning needs. A manual of information material for people with dementia and their family carers was also created using the US intervention as its source. Conclusions: Co-design produces rich products that have face validity and map onto the complexities of dementia and of health and care services. The feasibility of the case manager role, as described and defined by this process, needs evaluation in ‘real life’ settings

    Extensive acute and sustained changes to neutrophil proteomes post-SARS-CoV-2 infection

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    Background Neutrophils are important in the pathophysiology of coronavirus disease 2019 (COVID-19), but the molecular changes contributing to altered neutrophil phenotypes following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are not fully understood. We used quantitative mass spectrometry-based proteomics to explore neutrophil phenotypes immediately following acute SARS-CoV-2 infection and during recovery. Methods Prospective observational study of hospitalised patients with PCR-confirmed SARS-CoV-2 infection (May to December 2020). Patients were enrolled within 96 h of admission, with longitudinal sampling up to 29 days. Control groups comprised non-COVID-19 acute lower respiratory tract infection (LRTI) and age-matched noninfected controls. Neutrophils were isolated from peripheral blood and analysed using mass spectrometry. COVID-19 severity and recovery were defined using the World Health Organization ordinal scale. Results Neutrophil proteomes from 84 COVID-19 patients were compared to those from 91 LRTI and 42 control participants. 5800 neutrophil proteins were identified, with &gt;1700 proteins significantly changed in neutrophils from COVID-19 patients compared to noninfected controls. Neutrophils from COVID-19 patients initially all demonstrated a strong interferon signature, but this signature rapidly declined in patients with severe disease. Severe disease was associated with increased abundance of proteins involved in metabolism, immunosuppression and pattern recognition, while delayed recovery from COVID-19 was associated with decreased granule components and reduced abundance of metabolic proteins, chemokine and leukotriene receptors, integrins and inhibitory receptors. Conclusions SARS-CoV-2 infection results in the sustained presence of circulating neutrophils with distinct proteomes suggesting altered metabolic and immunosuppressive profiles and altered capacities to respond to migratory signals and cues from other immune cells, pathogens or cytokines.</p

    Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status

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    Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research

    SFX-01 in hospitalised patients with community-acquired pneumonia during the COVID-19 pandemic : a double-blind, randomised, placebo-controlled trial

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    We acknowledge the members of the STAR-COVID data monitoring committee: Aran Singanayagam (Imperial College, London, UK), Timothy Hinks (University of Oxford, Oxford, UK), Oriol Sibila (Hospital Clinic, Barcelona, Spain), Alex McConnachie (University of Glasgow, Glasgow, UK) and Petra Rauchhaus (University of Dundee, Dundee, UK). This trial was delivered by Tayside Clinical Trials Unit, a UKCRC registered clinical trials unit. Thanks to Clare Clarke, Jennifer Taylor, Angela Strachan, Heather Loftus and Jodie Strachan (Ninewells Hospital and Medical School, Dundee, UK) and Diane Cassidy (University of Dundee). We thank all study participants and their families.Peer reviewe

    Examination of the Cytotoxic and Embryotoxic Potential and Underlying Mechanisms of Next-Generation Synthetic Trioxolane and Tetraoxane Antimalarials

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    Semisynthetic artemisinin-based therapies are the first-line treatment for P. falciparum malaria, but next-generation synthetic drug candidates are urgently required to improve availability and respond to the emergence of artemisinin-resistant parasites. Artemisinins are embryotoxic in animal models and induce apoptosis in sensitive mammalian cells. Understanding the cytotoxic propensities of antimalarial drug candidates is crucial to their successful development and utilization. Here, we demonstrate that, similarly to the model artemisinin artesunate (ARS), a synthetic tetraoxane drug candidate (RKA182) and a trioxolane equivalent (FBEG100) induce embryotoxicity and depletion of primitive erythroblasts in a rodent model. We also show that RKA182, FBEG100 and ARS are cytotoxic toward a panel of established and primary human cell lines, with caspase-dependent apoptosis and caspase-independent necrosis underlying the induction of cell death. Although the toxic effects of RKA182 and FBEG100 proceed more rapidly and are relatively less cell-selective than that of ARS, all three compounds are shown to be dependent upon heme, iron and oxidative stress for their ability to induce cell death. However, in contrast to previously studied artemisinins, the toxicity of RKA182 and FBEG100 is shown to be independent of general chemical decomposition. Although tetraoxanes and trioxolanes have shown promise as next-generation antimalarials, the data described here indicate that adverse effects associated with artemisinins, including embryotoxicity, cannot be ruled out with these novel compounds, and a full understanding of their toxicological actions will be central to the continuing design and development of safe and effective drug candidates which could prove important in the fight against malaria
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