347 research outputs found

    INvestigational Vertebroplasty Efficacy and Safety Trial (INVEST): a randomized controlled trial of percutaneous vertebroplasty

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    Background: The treatment of painful osteoporotic vertebral compression fractures has historically been limited to several weeks of bed rest, anti-inflammatory and analgesic medications, calcitonin injections, or external bracing. Percutaneous vertebroplasty (the injection of bone cement into the fractured vertebral body) is a relatively new procedure used to treat these fractures. There is increasing interest to examine the efficacy and safety of percutaneous vertebroplasty and to study the possibility of a placebo effect or whether the pain relief is from local anesthetics placed directly on the bone during the vertebroplasty procedure. Methods/Designs: Our goal is to test the hypothesis that patients with painful osteoporotic vertebral compression fractures who undergo vertebroplasty have less disability and pain at 1 month than patients who undergo a control intervention. The control intervention is placement of local anesthesia near the fracture, without placement of cement. One hundred sixty-six patients with painful osteoporotic vertebral compression fractures will be recruited over 5 years from US and foreign sites performing the vertebroplasty procedure. We will exclude patients with malignant tumor deposit (multiple myeloma), tumor mass or tumor extension into the epidural space at the level of the fracture. We will randomly assign participants to receive either vertebroplasty or the control intervention. Subjects will complete a battery of validated, standardized measures of pain, functional disability, and health related quality of life at baseline and at post-randomization time points (days 1, 2, 3, and 14, and months 1, 3, 6, and 12). Both subjects and research interviewers performing the follow-up assessments will be blinded to the randomization assignment. Subjects will have a clinic visit at months 1 and 12. Spine X-rays will be obtained at the end of the study (month 12) to determine subsequent fracture rates. Our co-primary outcomes are the modified Roland score and pain numerical rating scale at 1 month. Discussion: Although extensively utilized throughout North America for palliation of pain, vertebroplasty still has not undergone rigorous study. The study outlined above represents the first randomized, controlled study that can account for a placebo effect in the setting of vertebroplasty. Trial Registration: Current Controlled Trials ISRCTN81871888.The source of funding for the study and all authors for this publication was National Institutes of Health (NIH)/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

    Impact of a silver layer on the membrane of tap water filters on the microbiological quality of filtered water

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    <p>Abstract</p> <p>Background</p> <p>Bacteria in the hospital's drinking water system represent a risk for the acquisition of a nosocomial infection in the severely immunocompromised host. Terminal tap water filters may be used to prevent nosocomial Legionnaires' disease. We present data from water samples using an improved kind of tap water filters.</p> <p>Methods</p> <p>In a blinded study on an intermediate care unit of the thoracic surgery department, a modified type of the Germlyser water filter (Aqua-Free Membrane Technology) with a newly-introduced silver layer on the filtration membrane was compared to its preceding type without such a layer on 15 water outlets. We determined growth of <it>Legionella</it>, other pathogenic bacteria, and the total heterotrophic plate count in unfiltered water and filtered water samples after filter usage intervals of 1 through 4 weeks.</p> <p>Results</p> <p>A total of 299 water samples were tested. Twenty-nine of the 60 unfiltered water samples contained <it>Legionella </it>of various serogroups (baseline value). In contrast, all samples filtered by the original water filter and all but one of the water samples filtered by the modified filter type remained <it>Legionella</it>-free. No other pathogenic bacteria were detected in any filtered sample. The total plate count in water samples increased during use of both kinds of filters over time. However, for the first 7 days of use, there were significantly fewer water samples containing >100 CFU per mL when using the new filter device compared with the older filters or taps with no filter. No advantage was seen thereafter.</p> <p>Conclusion</p> <p>The use of this type of terminal water filter is an appropriate method to protect immunocompromised patients from water-borne pathogens such as <it>Legionella</it>.</p

    Quantitative Historical Change in Bumblebee (Bombus spp.) Assemblages of Red Clover Fields

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    Flower visiting insects provide a vitally important pollination service for many crops and wild plants. Recent decline of pollinating insects due to anthropogenic modification of habitats and climate, in particular from 1950's onwards, is a major and widespread concern. However, few studies document the extent of declines in species diversity, and no studies have previously quantified local abundance declines. We here make a quantitative assessment of recent historical changes in bumblebee assemblages by comparing contemporary and historical survey data. species observed in the 1930's, five species were not observed at present. The latter were all long-tongued, late-emerging species.Because bumblebees are important pollinators, historical changes in local bumblebee assemblages are expected to severely affect plant reproduction, in particular long-tubed species, which are pollinated by long-tongued bumblebees

    Childhood asthma and indoor allergens in Native Americans in New York

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    BACKGROUND: The objective of this study was to assess the correlation between childhood asthma and potential risk factors, especially exposure to indoor allergens, in a Native American population. METHODS: A case-control study of St. Regis Mohawk tribe children ages 2–14 years, 25 diagnosed with asthma and 25 controls was conducted. Exposure was assessed based on a personal interview and measurement of mite and cat allergens (Der p 1, Fel d 1) in indoor dust. RESULTS: A non-significant increased risk of childhood asthma was associated with self-reported family history of asthma, childhood environmental tobacco smoke exposure, and air pollution. There was a significant protective effect of breastfeeding against current asthma in children less than 14 years (5.2 fold lower risk). About 80% of dust mite and 15% of cat allergen samples were above the threshold values for sensitization of 2 and 1 μg/g, respectively. The association between current asthma and exposure to dust mite and cat allergens was positive but not statistically significant. CONCLUSION: This research identified several potential indoor and outdoor risk factors for asthma in Mohawks homes, of which avoidance may reduce or delay the development of asthma in susceptible individuals

    Extrapulmonary tuberculosis, human immunodeficiency virus, and foreign birth in North Carolina, 1993 – 2006

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    <p>Abstract</p> <p>Background</p> <p>The proportion of extrapulmonary tuberculosis (EPTB) reported in the United States has been gradually increasing. HIV infection and foreign birth are increasingly associated with tuberculosis and understanding their effect on the clinical presentation of tuberculosis is important.</p> <p>Methods</p> <p>Case-control study of 6,124 persons with tuberculosis reported to the North Carolina Division of Public health from January 1, 1993 to December 31, 2006. Multivariate logistic regression was used to obtain adjusted odds ratios measuring the associations of foreign birth region and US born race/ethnicity, by HIV status, with EPTB.</p> <p>Results</p> <p>Among all patients with tuberculosis, 1,366 (22.3%) had EPTB, 563 (9.2%) were HIV co-infected, and 1,299 (21.2%) were foreign born. Among HIV negative patients, EPTB was associated with being foreign born (adjusted ORs 1.36 to 5.09, depending on region of birth) and with being US born, Black/African American (OR 1.84; 95% CI 1.42, 2.39). Among HIV infected patients, EPTB was associated with being US born, Black/African American (OR 2.60; 95% CI 1.83, 3.71) and with foreign birth in the Americas (OR 5.12; 95% CI 2.84, 9.23).</p> <p>Conclusion</p> <p>Foreign born tuberculosis cases were more likely to have EPTB than US born tuberculosis cases, even in the absence of HIV infection. Increasing proportions of foreign born and HIV-attributable tuberculosis cases in the United States will likely result in a sustained burden of EPTB. Further research is needed to explore why the occurrence and type of EPTB differs by region of birth and whether host genetic and/or bacterial variation can explain these differences in EPTB.</p

    High Visual Working Memory Capacity in Trait Social Anxiety

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    Working memory capacity is one of the most important cognitive functions influencing individual traits, such as attentional control, fluid intelligence, and also psychopathological traits. Previous research suggests that anxiety is associated with impaired cognitive function, and studies have shown low verbal working memory capacity in individuals with high trait anxiety. However, the relationship between trait anxiety and visual working memory capacity is still unclear. Considering that people allocate visual attention more widely to detect danger under threat, visual working memory capacity might be higher in anxious people. In the present study, we show that visual working memory capacity increases as trait social anxiety increases by using a change detection task. When the demand to inhibit distractors increased, however, high visual working memory capacity diminished in individuals with social anxiety, and instead, impaired filtering of distractors was predicted by trait social anxiety. State anxiety was not correlated with visual working memory capacity. These results indicate that socially anxious people could potentially hold a large amount of information in working memory. However, because of an impaired cognitive function, they could not inhibit goal-irrelevant distractors and their performance decreased under highly demanding conditions

    Creatine Protects against Excitoxicity in an In Vitro Model of Neurodegeneration

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    Creatine has been shown to be neuroprotective in aging, neurodegenerative conditions and brain injury. As a common molecular background, oxidative stress and disturbed cellular energy homeostasis are key aspects in these conditions. Moreover, in a recent report we could demonstrate a life-enhancing and health-promoting potential of creatine in rodents, mainly due to its neuroprotective action. In order to investigate the underlying pharmacology mediating these mainly neuroprotective properties of creatine, cultured primary embryonal hippocampal and cortical cells were challenged with glutamate or H2O2. In good agreement with our in vivo data, creatine mediated a direct effect on the bioenergetic balance, leading to an enhanced cellular energy charge, thereby acting as a neuroprotectant. Moreover, creatine effectively antagonized the H2O2-induced ATP depletion and the excitotoxic response towards glutamate, while not directly acting as an antioxidant. Additionally, creatine mediated a direct inhibitory action on the NMDA receptor-mediated calcium response, which initiates the excitotoxic cascade. Even excessive concentrations of creatine had no neurotoxic effects, so that high-dose creatine supplementation as a health-promoting agent in specific pathological situations or as a primary prophylactic compound in risk populations seems feasible. In conclusion, we were able to demonstrate that the protective potential of creatine was primarily mediated by its impact on cellular energy metabolism and NMDA receptor function, along with reduced glutamate spillover, oxidative stress and subsequent excitotoxicity

    Correlations of behavioral deficits with brain pathology assessed through longitudinal MRI and histopathology in the R6/1 mouse model of huntington's disease

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    Huntington's disease (HD) is caused by the expansion of a CAG repeat in the huntingtin (HTT) gene. The R6 mouse models of HD express a mutant version of exon 1 HTT and typically develop motor and cognitive impairments, a widespread huntingtin (HTT) aggregate pathology and brain atrophy. Unlike the more commonly used R6/2 mouse line, R6/1 mice have fewer CAG repeats and, subsequently, a less rapid pathological decline. Compared to the R6/2 line, fewer descriptions of the progressive pathologies exhibited by R6/1 mice exist. The association between the molecular and cellular neuropathology with brain atrophy, and with the development of behavioral phenotypes remains poorly understood in many models of HD. In attempt to link these factors in the R6/1 mouse line, we have performed detailed assessments of behavior and of regional brain abnormalities determined through longitudinal, in vivo magnetic resonance imaging (MRI), as well as an end-stage, ex vivo MRI study and histological assessment. We found progressive decline in both motor and non-motor related behavioral tasks in R6/1 mice, first evident at 11 weeks of age. Regional brain volumes were generally unaffected at 9 weeks, but by 17 weeks there was significant grey matter atrophy. This age-related brain volume loss was validated using a more precise, semi-automated Tensor Based morphometry assessment. As well as these clear progressive phenotypes, mutant HTT (mHTT) protein, the hallmark of HD molecular pathology, was widely distributed throughout the R6/1 brain and was accompanied by neuronal loss. Despite these seemingly concomitant, robust pathological phenotypes, there appeared to be little correlation between the three main outcome measures: behavioral performance, MRI-detected brain atrophy and histopathology. In conclusion, R6/1 mice exhibit many features of HD, but the underlying mechanisms driving these clear behavioral disturbances and the brain volume loss, still remain unclear. © 2013 Rattray et al

    Mitochondrial calcium uniporter Mcu controls excitotoxicity and is transcriptionally repressed by neuroprotective nuclear calcium signals

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    The recent identification of the mitochondrial Ca(2+) uniporter gene (Mcu/Ccdc109a) has enabled us to address its role, and that of mitochondrial Ca(2+) uptake, in neuronal excitotoxicity. Here we show that exogenously expressed Mcu is mitochondrially localized and increases mitochondrial Ca(2+) levels following NMDA receptor activation, leading to increased mitochondrial membrane depolarization and excitotoxic cell death. Knockdown of endogenous Mcu expression reduces NMDA-induced increases in mitochondrial Ca(2+), resulting in lower levels of mitochondrial depolarization and resistance to excitotoxicity. Mcu is subject to dynamic regulation as part of an activity-dependent adaptive mechanism that limits mitochondrial Ca(2+) overload when cytoplasmic Ca(2+) levels are high. Specifically, synaptic activity transcriptionally represses Mcu, via a mechanism involving the nuclear Ca(2+) and CaM kinase-mediated induction of Npas4, resulting in the inhibition of NMDA receptor-induced mitochondrial Ca(2+) uptake and preventing excitotoxic death. This establishes Mcu and the pathways regulating its expression as important determinants of excitotoxicity, which may represent therapeutic targets for excitotoxic disorders
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