190 research outputs found

    The Effects of Isokinetic Contraction Velocity on the Concentric to Eccentric Strength Relationship of the Biceps Brachii

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    The purpose of this investigation was to determine the influence of contraction velocity on the eccentric (ECC) and concentric (CON) torque production of the biceps brachii. After performing warm-up procedures, each male subject (n = 11) completed 3 sets of 5 maximal bilateral CON and ECC isokinetic contractions of the biceps at three different speeds on a Biodex System 3 dynamometer. The men received a 3-minute rest between sets and the order of exercises was randomized. Peak torque (Nm) values were obtained for CON and ECC contractions at each speed. Peak torque scores (ECC vs. CON) were compared using a t-test at each speed. A repeated measures analysis of variance was used to determine differences between speeds. ECC peak torque scores were greater than CON peak torque scores at each given speed. No differences were found between the ECC peak torque scores (p = 0.62) at any of the speeds. Differences were found among the CON scores (p = 0.004). Post hoc analysis revealed differences. The data suggests that ECC contractions of the biceps brachii were somewhat resistant to a force decrement as the result of an increase in velocity, whereas CON muscular actions of the biceps brachii were unable to maintain force as velocity increased

    Increased risk of incident dementia following use of anticholinergic agents: A systematic literature review and meta-analysis

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    Background/rationale: Long-term treatment with anticholinergic agents may increase the risk of cognitive impairment or dementia. This systematic literature review and meta-analysis aimed to assess the impact of ≥3 months of exposure to anticholinergics as a class on the risk of dementia, mild cognitive impairment, and change in cognitive function. The impact of anticholinergic agents specifically used to treat overactive bladder was also evaluated. Materials and Methods: A systematic literature review was conducted to identify English language articles evaluating the impact of anticholinergic use for ≥3 months on dementia or cognitive function in adult patients. Databases searched included PubMed, Embase, and the Cochrane Library. Meta-analyses were conducted using random-effects models; 95% confidence intervals (CIs) and 95% prediction intervals (PIs) were reported. Results: A total of 2122 records were identified. Out of those, 21 studies underwent qualitative synthesis and 6 reported endpoints relevant for inclusion in a meta-analysis assessing the risk of incident dementia. The overall rate ratio for incident dementia was 1.46 (95% CI: 1.17–1.81; 95% PI: 0.70–3.04; n = 6). The risk of incident dementia increased with increasing exposure (n = 3). In addition, two studies from the meta-analysis reported an increased risk of dementia with ≥3 months of use of bladder antimuscarinics (adjusted odds ratios ranged from 1.21 to 1.65, depending on exposure category). Conclusion: Anticholinergic use for ≥3 months increased the risk of dementia on average by an estimated 46% versus nonuse. This relationship was consistent in studies assessing overactive bladder medications. The risk of developing dementia should be carefully considered in the context of potential benefit before prescribing anticholinergics

    Evaluation of the modified FINDRISC to identify individuals at high risk for diabetes among middle-aged white and black ARIC study participants

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    Objective: To evaluate a modified Finnish Diabetes Risk Score (FINDRISC) for predicting the risk of incident diabetes among white and black middle-aged participants from the Atherosclerosis Risk in Communities (ARIC) study. Research design and methods: We assessed 9754 ARIC cohort participants who were free of diabetes at baseline. Logistic regression and receiver operator characteristic (ROC) curves were used to evaluate a modified FINDRISC for predicting incident diabetes after 9 years of follow-up, overall and by race/gender group. The modified FINDRISC used comprised age, body mass index, waist circumference, blood pressure medication and family history. Results: The mean FINDRISC (range, 2 [lowest risk] to 17 [highest risk]) for black women was higher (9.9 ± 3.6) than that for black men (7.6 ± 3.9), white women (8.0 ± 3.6) and white men (7.6 ± 3.5). The incidence of diabetes increased generally across deciles of FINDRISC for all 4 race/gender groups. ROC curve statistics for the FINDRISC showed the highest area under the curve for white women (0.77) and the lowest for black men (0.70). Conclusions: We used a modified FINDRISC to predict the 9-year risk of incident diabetes in a biracial US population. The modified risk score can be useful for early screening of incident diabetes in biracial populations, which may be helpful for early interventions to delay or prevent diabetes

    Stem cell transplantation for type 1 diabetes mellitus

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    <p>Abstract</p> <p>Background</p> <p>The use of stem cells to treat type 1 diabetes mellitus has been proposed for many years, both to downregulate the immune system and to provide β cell regeneration.</p> <p>Conclusion</p> <p>High dose immunosuppression followed by autologous hematopoietic stem cell transplantation is able to induce complete remission (insulin independence) in most patients with early onset type 1 diabetes mellitus.</p

    Responsiveness of the Acne-Specific Quality of Life Questionnaire (Acne-QoL) to treatment for acne vulgaris in placebo-controlled clinical trials

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    The Acne-Specific Quality of Life Questionnaire (Acne-QoL) was developed to measure the impact of facial acne across four dimensions of patient quality of life. The main objective of the current study was to evaluate the responsiveness of this instrument. Secondarily, this study provided an opportunity to extend the developer's psychometric validation. The Acne-QoL was utilized in two randomized, double-blind, placebo-controlled studies of the efficacy of Estrostep ® (norethindrone acetate/ethinyl estradiol) in the treatment of facial acne; a total of 296 Estrostep ® and 295 placebo patients were evaluated. The Acne-QoL was completed at the beginning, middle (cycle 3), and end (cycle 6) of the 6-month treatment period. The responsiveness of the Acne-QoL was demonstrated through its ability to detect both small (baseline to mid-study) and moderate (baseline to study end) treatment advantages for Estrostep ® patients. Confirmatory factor analysis supported the subscale structure, and internal consistency estimates were excellent. Convergent and discriminant validity were supported by correlations between Acne-QoL scores and clinical measures that were both in the direction and relative magnitude hypothesized. Finally, item response theory analyses confirmed that each item is highly related to its subscale's latent construct and that each subscale is sensitive across a broad range of the underlying continuum. The results of this evaluation confirm that the Acne-QoL is responsive, internally consistent, and valid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43563/1/11136_2004_Article_5089801.pd

    Protection of Visual Functions by Human Neural Progenitors in a Rat Model of Retinal Disease

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    BACKGROUND: A promising clinical application for stem and progenitor cell transplantation is in rescue therapy for degenerative diseases. This strategy seeks to preserve rather than restore host tissue function by taking advantage of unique properties often displayed by these versatile cells. In studies using different neurodegenerative disease models, transplanted human neural progenitor cells (hNPC) protected dying host neurons within both the brain and spinal cord. Based on these reports, we explored the potential of hNPC transplantation to rescue visual function in an animal model of retinal degeneration, the Royal College of Surgeons rat. METHODOLOGY/PRINCIPAL FINDINGS: Animals received unilateral subretinal injections of hNPC or medium alone at an age preceding major photoreceptor loss. Principal outcomes were quantified using electroretinography, visual acuity measurements and luminance threshold recordings from the superior colliculus. At 90–100 days postnatal, a time point when untreated rats exhibit little or no retinal or visual function, hNPC-treated eyes retained substantial retinal electrical activity and visual field with near-normal visual acuity. Functional efficacy was further enhanced when hNPC were genetically engineered to secrete glial cell line-derived neurotrophic factor. Histological examination at 150 days postnatal showed hNPC had formed a nearly continuous pigmented layer between the neural retina and retinal pigment epithelium, as well as distributed within the inner retina. A concomitant preservation of host cone photoreceptors was also observed. CONCLUSIONS/SIGNIFICANCE: Wild type and genetically modified human neural progenitor cells survive for prolonged periods, migrate extensively, secrete growth factors and rescue visual functions following subretinal transplantation in the Royal College of Surgeons rat. These results underscore the potential therapeutic utility of hNPC in the treatment of retinal degenerative diseases and suggest potential mechanisms underlying their effect in vivo

    Enumeration of islets by nuclei counting and light microscopic analysis

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    Author Manuscript 2011 May 1.Islet enumeration in impure preparations by conventional dithizone staining and visual counting is inaccurate and operator dependent. We examined nuclei counting for measuring the total number of cells in islet preparations, and we combined it with morphological analysis by light microscopy (LM) for estimating the volume fraction of islets in impure preparations. Cells and islets were disrupted with lysis solution and shear, and accuracy of counting successively diluted nuclei suspensions was verified with (1) visual counting in a hemocytometer after staining with crystal violet, and automatic counting by (2) aperture electrical resistance measurement and (3) flow cytometer measurement after staining with 7-aminoactinomycin-D. DNA content averaged 6.5 and 6.9 pg of DNA per cell for rat and human islets, respectively, in agreement with literature estimates. With pure rat islet preparations, precision improved with increasing counts, and samples with about greater than or equal to 160 islets provided a coefficient of variation of about 6%. Aliquots of human islet preparations were processed for LM analysis by stereological point counting. Total nuclei counts and islet volume fraction from LM analysis were combined to obtain the number of islet equivalents (IEs). Total number of IE by the standard method of dithizone staining/manual counting was overestimated by about 90% compared with LM/nuclei counting for 12 freshly isolated human islet research preparations. Nuclei counting combined with islet volume fraction measurements from LM is a novel method for achieving accurate islet enumeration.National Institutes of Health (U.S.) (Grant NCRR ICR U4Z 16606)National Institutes of Health (U.S.) (Grant R01-DK063108-01A1)National Institutes of Health (U.S.) (Grant NCRR ICR U42 RR0023244-01)Joslin Diabetes and Endocrinology Research Center (Grant DK36836)Diabetes Research & Wellness FoundationJuvenile Diabetes Research Foundation International (Islet Transplantation, Harvard Medical School

    TReatIng Urinary symptoms in Men in Primary Healthcare using non-pharmacological and non-surgical interventions (TRIUMPH) compared with usual care: Study protocol for a cluster randomised controlled trial

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    Background: Lower urinary tract symptoms (LUTS) can relate to urinary storage or voiding. In men, the prevalence and severity of LUTS increases with age, with a significant impact on quality of life. The majority of men presenting with LUTS are managed by their general practitioner (GP) in the first instance, with conservative therapies recommended as the initial treatment. However, the provision of conservative therapies in primary care is variable and can be time and resource limited. GPs require practical resources to enhance patient engagement with such interventions. TRIUMPH aims to determine whether a standardised and manualised care intervention delivered in primary care achieves superior symptomatic outcome for LUTS versus usual care.Methods/design: TRIUMPH is a two-arm, cluster randomised controlled trial (RCT) being conducted in 30 National Health Service (NHS) general practices in England. The TRIUMPH intervention comprises a standardised LUTS advice booklet developed for the trial with patient and healthcare professional (HCP) consultation. The booklet is delivered to patients by nurses/healthcare assistants following assessment of their urinary symptoms. Patients are directed to relevant sections of the booklet, providing the manualised element of the intervention. To encourage adherence, HCPs provide follow-up contacts over 12 weeks. Practices are randomised 1:1 to either deliver the TRIUMPH intervention or a usual care pathway. The patient-reported International Prostate Symptom Score (IPSS) at 12 months post consent is the primary outcome. Secondary outcomes include cost-effectiveness, patient-reported outcomes on LUTS, quality of life, and patient and HCP acceptability and experience of the intervention. Primary analyses will be conducted on an intention-to-treat basis.Discussion: It is unclear whether conservative therapies for male LUTS are effectively delivered in primary care using current approaches. This can lead to men being inappropriately referred to secondary care or experiencing persistent symptoms. Primary care, therefore, holds the key to effective treatment for these men. The TRIUMPH intervention, through its standardised and manualised approach, has been developed to support GP practices in delivering effective conservative care. This pragmatic, cluster RCT should provide robust evidence in a primary-care setting to inform future guidelines

    Modeling Boundary Vector Cell Firing Given Optic Flow as a Cue

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    Boundary vector cells in entorhinal cortex fire when a rat is in locations at a specific distance from walls of an environment. This firing may originate from memory of the barrier location combined with path integration, or the firing may depend upon the apparent visual input image stream. The modeling work presented here investigates the role of optic flow, the apparent change of patterns of light on the retina, as input for boundary vector cell firing. Analytical spherical flow is used by a template model to segment walls from the ground, to estimate self-motion and the distance and allocentric direction of walls, and to detect drop-offs. Distance estimates of walls in an empty circular or rectangular box have a mean error of less than or equal to two centimeters. Integrating these estimates into a visually driven boundary vector cell model leads to the firing patterns characteristic for boundary vector cells. This suggests that optic flow can influence the firing of boundary vector cells
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