512 research outputs found

    Physical and physiologic determinants of rock climbing

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    Purpose: Rock climbing performance relies on many characteristics. Here, we identified the physical and physiologic determinants of peak performance in rock climbing across the range from lower-grade to elite. Methods: 44 male and 33 female climbers with onsight maximal climbing grades 5a-8a and 5a-7b+, respectively, were tested for physical, physiologic and psychologic characteristics (independent variables) that were correlated and modelled by multiple regression and principal component analysis to identify the determinants of rock climbing ability. Results: In males, 23 of 47 variables correlated with climbing ability (p<0.05, Pearson’s correlation coefficients 0.773-0.340), including shoulder endurance, hand and finger strength, shoulder power-endurance, hip flexibility, lower-arm grip strength, shoulder power, upper-arm strength, core-body endurance, upper-body aerobic endurance, hamstrings and lower-back flexibility, aerobic endurance, and open-hand finger strength. In females, 10 of 47 variables correlated with climbing ability (p<0.05, Pearson’s correlation coefficients 0.742-0.482): shoulder endurance and power, lower-arm grip strength, balance, aerobic endurance, and arm span. Principal component analysis and univariate multiple regression identified the main explanatory variables. In both sexes, shoulder power and endurance measured as maximum pull-ups, average arm crank power, and bent-arm hang, emerged as the main determinants (p<0.01; adjusted R2=0.77 in males and 0.62 in females). In males, finger pincer (p=0.07) and grip strength also had trends (p=0.09) toward significant effects. Finally, in test-of-principle training studies, we trained to increase main determinants 42-67%; this improved climbing ability 2-3 grades. Conclusions: Shoulder power and endurance majorly determines maximal climbing. Finger, hand and arm strength, core-body endurance, aerobic endurance, flexibility and balance are important secondary determinants

    Dynamic changes in lung microRNA profiles during the development of pulmonary hypertension due to chronic hypoxia and monocrotaline

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    <b>Objective</b>: MicroRNAs (miRNAs) are small noncoding RNAs that have the capacity to control protein production through binding "seed" sequences within a target mRNA. Each miRNA is capable of potentially controlling hundreds of genes. The regulation of miRNAs in the lung during the development of pulmonary arterial hypertension (PAH) is unknown.<p></p> <b>Methods and Results</b>: We screened lung miRNA profiles in a longitudinal and crossover design during the development of PAH caused by chronic hypoxia or monocrotaline in rats. We identified reduced expression of Dicer, involved in miRNA processing, during the onset of PAH after hypoxia. MiR-22, miR-30, and let-7f were downregulated, whereas miR-322 and miR-451 were upregulated significantly during the development of PAH in both models. Differences were observed between monocrotaline and chronic hypoxia. For example, miR-21 and let-7a were significantly reduced only in monocrotaline-treated rats. MiRNAs that were significantly regulated were validated by quantitative polymerase chain reaction. By using in vitro studies, we demonstrated that hypoxia and growth factors implicated in PAH induced similar changes in miRNA expression. Furthermore, we confirmed miR-21 downregulation in human lung tissue and serum from patients with idiopathic PAH.<p></p> <b>Conclusion</b>: Defined miRNAs are regulated during the development of PAH in rats. Therefore, miRNAs may contribute to the pathogenesis of PAH and represent a novel opportunity for therapeutic intervention.<p></p&gt

    The men's health center: Disparities in gender specific health services among the top 50 “best hospitals” in America

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    AbstractObjectiveGender-specific integrated health services have long existed in the arena of women's health care, but men's health centers (MHCs) have only recently emerged as a novel practice model. Here, we seek to evaluate the prevalence and format of MHCs found in the leading academic medical centers in the United States.MethodsThe US News & World Report's Top 50 Ranked Hospitals for Urology was used as our cohort. Data were gathered on the presence of MHCs and types of providers and conditions treated. An equivalent search was performed for women's health centers (WHCs).ResultsSixteen of 50 (32%) promoted some type of MHC, compared to 49 of 50 (98%) offering a WHC. Eight of the top 15 ranked institutions (53%) had an MHC compared to eight of 35 (23%) remaining programs. Six of 16 MHCs incorporated providers from a variety of medical disciplines, including urologists, internists, endocrinologists, cardiologists, and psychologists, while another six of 16 MHCs were staffed solely by urologists. Eight of 16 provided services for exclusively urologic issues, four of 16 offered additional services in treatment of other medical conditions, and four of 16 did not specify.ConclusionA considerable disparity exists between the prevalence of gender-specific health services, with WHCs being much more numerous than MHCs. All but one leading institution had WHCs compared to less than one-third having MHCs. Our findings also highlight the heterogeneous nature of men's health programs, as they exhibit great variability in program type and focus, yet are all being marketed under the “Men's Health” banner

    C-Reactive Protein in Heart Failure

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    Background— The role of C-reactive protein (CRP) in heart failure is not well studied. We assessed the prognostic value of CRP in patients randomized in Val-HeFT (Valsartan Heart Failure Trial) and studied changes in CRP that were associated with valsartan. Methods and Results— Characteristics of patients with baseline CRP levels above and below the median value were compared. Univariable and multivariable Cox proportional hazards regression models were used to examine the relationship of CRP to mortality and morbidity. Interactions were tested to determine whether differences in CRP changes from baseline to 4 and 12 months between groups randomly assigned to valsartan or placebo depended on baseline ACE inhibitor use. Median plasma CRP was 3.23 mg/L (interquartile range 1.42 to 7.56 mg/L), which is higher than in the general population. Patients with CRP above the median had features of more severe heart failure than those with CRP levels below the median. The cumulative likelihood of death and first morbid event increased with increasing quartile of CRP. Relative to the lowest CRP quartile, the risk of mortality (hazard ratio 1.51, 95% CI 1.2 to 1.9) and first morbid event (hazard ratio 1.53, 95% CI 1.28 to 1.84) was increased in the highest CRP quartile in multivariable models. CRP added incremental prognostic information to that provided by brain natriuretic peptide alone. CRP did not change significantly over time in the placebo group; however, after 12 months, valsartan was associated with a decrease in CRP in patients not receiving ACE inhibitors but not in those receiving ACE inhibitors at 12 months. Conclusions— CRP is increased in heart failure. Higher levels are associated with features of more severe heart failure and are independently associated with mortality and morbidity. The ability of treatments to reduce CRP levels and the prognostic importance of reducing CRP require further study

    Treatment for lupus nephritis

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    BackgroundCyclophosphamide, in combination with corticosteroids has been used to induce remission in proliferative lupus nephritis, the most common kidney manifestation of the multisystem disease, systemic lupus erythematosus. Cyclophosphamide therapy has reduced mortality from over 70% in the 1950s and 1960s to less than 10% in recent years. Cyclophosphamide combined with corticosteroids preserves kidney function but is only partially effective and may cause ovarian failure, infection and bladder toxicity. Several new agents, including mycophenolate mofetil (MMF), suggest reduced toxicity with equivalent rates of remission. This is an update of a Cochrane review first published in 2004.ObjectivesTo assess the benefits and harms of different immunosuppressive treatments in biopsy-proven proliferative lupus nephritis.Search methodsFor this update, we searched the Cochrane Renal Group's Specialised Register (up to 15 April 2012) through contact with the Trials' Search Coordinator using search terms relevant to this review.Selection criteriaRandomised controlled trials (RCTs) and quasi-RCTs comparing any treatments for biopsy-proven lupus nephritis in both adult and paediatric patients with class III, IV, V + III and V + IV lupus nephritis were included. All immunosuppressive treatments were considered.Data collection and analysisData were abstracted and quality assessed independently by two authors, with differences resolved by discussion. Dichotomous outcomes were reported as risk ratio (RR) and measurements on continuous scales reported as mean differences (MD) with 95% confidence intervals (CI).Main resultsWe identified 50 RCTs involving 2846 participants. Of these, 45 studies (2559 participants) investigated induction therapy, and six studies (514 participants), considered maintenance therapy.Compared with intravenous (IV) cyclophosphamide, MMF was as effective in achieving stable kidney function (5 studies, 523 participants: RR 1.05, 95% CI 0.94 to 1.18) and complete remission of proteinuria (6 studies, 686 participants: RR 1.16, 95% CI 0.85 to 1.58). No differences in mortality (7 studies, 710 participants: RR 1.02, 95% CI 0.52 to 1.98) or major infection (6 studies, 683 participants: RR 1.11, 95% CI 0.74 to 1.68) were observed. A significant reduction in ovarian failure (2 studies, 498 participants: RR 0.15, 95% CI 0.03 to 0.80) and alopecia (2 studies, 522 participants: RR 0.22, 95% CI 0.06 to 0.86) was observed with MMF. In maintenance therapy, the risk of renal relapse (3 studies, 371 participants: RR 1.83, 95% CI 1.24 to 2.71) was significantly higher with azathioprine compared with MMF. Multiple other interventions were compared but outcome data were relatively sparse. Overall study quality was variable. The internal validity of the design, conduct and analysis of the included RCTs was difficult to assess in some studies because of the omission of important methodological details. No study adequately reported all domains of the risk of bias assessment so that elements of internal bias may be present.Authors' conclusionsMMF is as effective as cyclophosphamide in inducing remission in lupus nephritis, but is safer with a lower risk of ovarian failure. MMF is more effective than azathioprine in maintenance therapy for preventing relapse with no increase in clinically important side effects. Adequately powered trials with long term follow-up are required to more accurately define the risks and eventual harms of specific treatment regimens

    Radio source calibration for the VSA and other CMB instruments at around 30 GHz

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    Accurate calibration of data is essential for the current generation of CMB experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 percent or better for experiments such as the VSA and CBI. Particular attention is paid to the stability of the receiver systems, the quality of the site and frequent observations of reference sources. At 30 GHz the careful correction for atmospheric emission and absorption is shown to be essential for achieving 1 percent precision. The sources for which a 1 percent relative flux density calibration was achieved included Cas A, Cyg A, Tau A and NGC7027 and the planets Venus, Jupiter and Saturn. A flux density, or brightness temperature in the case of the planets, was derived at 33 GHz relative to Jupiter which was adopted as the fundamental calibrator. A spectral index at ~30 GHz is given for each. Cas A,Tau A, NGC7027 and Venus were examined for variability. Cas A was found to be decreasing at 0.394±0.0190.394 \pm 0.019 percent per year over the period March 2001 to August 2004. In the same period Tau A was decreasing at 0.22±0.070.22\pm 0.07 percent per year. A survey of the published data showed that the planetary nebula NGC7027 decreased at 0.16±0.040.16\pm 0.04 percent per year over the period 1967 to 2003. Venus showed an insignificant (1.5±1.31.5 \pm 1.3 percent) variation with Venusian illumination. The integrated polarization of Tau A at 33 GHz was found to be 7.8±0.67.8\pm 0.6 percent at pa =148∘±3∘ = 148^\circ \pm 3^\circ.}Comment: 13 pages, 15 figures, submitted to MNRA
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