788 research outputs found

    Testosterone reactivity to competition and competitive endurance in men and women

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    Transient shifts in testosterone occur during competition and are thought to positively influence dominance behavior aimed at enhancing social status. However, individual differences in testosterone reactivity to status contests have not been well-studied in relation to real-time expressions of competitive behavior among men and women. This research tests the association between changes in endogenous testosterone levels during competition and performance in terms of competitive endurance. Participant sex, social presence, and relative status outcomes (e.g., winning vs. losing) are tested as moderators of this relationship. In two studies, men and women (total N = 398) competed in the competitive will task (timed weight-holding) either individually or in the presence of an opponent (Study 1) or as a team with and without the presence of a competitor team (Study 2). Results showed a positive relationship between testosterone reactivity and performance for men, particularly those who won or ranked highest among their group - with increasing testosterone predicting better performance and decreasing testosterone predicting worse performance. For women, the effect only emerged among individuals who competed in dyads and lost. In Study 2, an exploratory mediation analysis revealed that individual differences in trait dominance predicted both testosterone reactivity to competition and task performance, with testosterone reactivity (moderated by sex and status outcome) partially explaining the direct relationship between dominance-related traits and behavior. Our goal was to examine testosterone reactivity in relation to real-time competitive effort and highlight the potential role of this relationship in explaining how individual differences in trait dominance produce competitive behavior

    Comparative efficacy of topical tetraVisc versus lidocaine gel in cataract surgery

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    <p>Abstract</p> <p>Background</p> <p>To compare the clinical efficacy of lidocaine 2% with tetracaine 0.5% for cataract surgery.</p> <p>Methods</p> <p>In a randomized, multi-surgeon, controlled clinical trial,122 consecutive cataract cases eligible for topical anesthesia, were randomly assigned to receive lidocaine 2% gel (1 ml) or tetracaine solution 0.5% (TetraVisc, 0.5 ml) before clear corneal phacoemulsification. Main outcome measure was visual analog scale (0 to 10), which was used to measure intra-operative pain. Secondary outcome measures included patients' discomfort due to tissue manipulation and surgeon graded patients' cooperation. Duration of surgery and intra-operative complications were also recorded.</p> <p>Results</p> <p>The mean age in TetraVisc (TV) group was 70.4 years and in the lidocaine gel group (LG) it was 70.6 years (p = 0.89). Patient reported mean intra-operative pain scores by visual analog scale were 0.70 ± 0.31 in TV group and 1.8 ± 0.4 in LG group (<it>P </it>< 0.001). Mean patient cooperation was also marginally better in the TV group (8.3 ± 0.3) compared to LG group (8.4 ± 0.6) (P = 0.25). 96% of patients in TV group showed intra-operative corneal clarity compared to 91% in LG group. TV group had less (1 out of 61 patients, 1.6%) intra-operative complications than LG group (3 out of 61 patients, 4.8%). No anesthesia related complications were noted in either group</p> <p>Conclusion</p> <p>Topical TetraVisc solution was superior to lidocaine 2% gel for pain control in patients undergoing clear corneal phacoemulsification. Lidocaine 2% gel is similar to TetraVisc in patient comfort and surgeon satisfaction.</p> <p>Trial Registration</p> <p><b>Clinical trials number</b>: ISRCTN78374774</p

    Interactions between Naïve and Infected Macrophages Reduce Mycobacterium tuberculosis Viability

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    A high intracellular bacillary load of Mycobacterium tuberculosis in macrophages induces an atypical lysosomal cell death with early features of apoptosis that progress to necrosis within hours. Unlike classical apoptosis, this cell death mode does not appear to diminish M. tuberculosis viability. We previously reported that culturing heavily infected macrophages with naïve macrophages produced an antimicrobial effect, but only if naïve macrophages were added during the pre-necrotic phase of M. tuberculosis-induced cell death. In the present study we investigated the mechanism of antimicrobial activity in co-cultures, anticipating that efferocytosis of bacilli in apoptotic bodies would be required. Confocal microscopy revealed frustrated phagocytosis of M. tuberculosis-infected macrophages with no evidence that significant numbers of bacilli were transferred to the naïve macrophages. The antimicrobial effect of naïve macrophages was retained when they were separated from infected macrophages in transwells, and conditioned co-culture supernatants transferred antimicrobial activity to cultures of infected macrophages alone. Antimicrobial activity in macrophage co-cultures was abrogated when the naïve population was deficient in IL-1 receptor or when the infected population was deficient in inducible nitric oxide synthase. The participation of nitric oxide suggested a conventional antimicrobial mechanism requiring delivery of bacilli to a late endosomal compartment. Using macrophages expressing GFP-LC3 we observed the induction of autophagy specifically by a high intracellular load of M. tuberculosis. Bacilli were identified in LC3-positive compartments and LC3-positive compartments were confirmed to be acidified and LAMP1 positive. Thus, the antimicrobial effect of naïve macrophages acting on M. tuberculosis in heavily-infected macrophages is contact-independent. Interleukin-1 provides an afferent signal that induces an as yet unidentified small molecule which promotes nitric oxide-dependent antimicrobial activity against bacilli in autolysosomes of heavily infected macrophages. This cooperative, innate antimicrobial interaction may limit the maximal growth rate of M. tuberculosis prior to the expression of adaptive immunity in pulmonary tuberculosis

    CAG Repeat Variants in the POLG1 Gene Encoding mtDNA Polymerase-Gamma and Risk of Breast Cancer in African-American Women

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    The DNA polymerase-gamma (POLG) gene, which encodes the catalytic subunit of enzyme responsible for directing mitochondrial DNA replication in humans, contains a polyglutamine tract encoded by CAG repeats of varying length. The length of the CAG repeat has been associated with the risk of testicular cancer, and other genomic variants that impact mitochondrial function have been linked to breast cancer risk in African-American (AA) women. We evaluated the potential role of germline POLG-CAG repeat variants in breast cancer risk in a sample of AA women (100 cases and 100 age-matched controls) who participated in the Women's Circle of Health Study, an ongoing multi-institutional, case-control study of breast cancer. Genotyping was done by fragment analysis in a blinded manner. Results from this small study suggest the possibility of an increased risk of breast cancer in women with minor CAG repeat variants of POLG, but no statistically significant differences in CAG repeat length were observed between cases and controls (multivariate-adjusted odds ratio 1.74; 95% CI, 0.49–6.21). Our study suggests that POLG-CAG repeat length is a potential risk factor for breast cancer that needs to be explored in larger population-based studies

    Neurotrophin receptors expression and JNK pathway activation in human astrocytomas

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    <p>Abstract</p> <p>Background</p> <p>Neurotrophins are growth factors that regulate cell growth, differentiation and apoptosis in the nervous system. Their diverse actions are mediated through two different transmembrane – receptor signaling systems: Trk receptor tyrosine kinases (TrkA, TrkB, TrkC) and p75<sup>NTR </sup>neurotrophin receptor. Trk receptors promote cell survival and differentiation while p75<sup>NTR </sup>induces, in most cases, the activity of JNK-p53-Bax apoptosis pathway or suppresses intracellular survival signaling cascades. Robust Trk activation blocks p75<sup>NTR </sup>-induced apoptosis by suppressing the JNK-p53-Bax pathway. The aim of this exploratory study was to investigate the expression levels of neurotrophin receptors, Trks and p75<sup>NTR</sup>, and the activation of JNK pathway in human astrocytomas and in adjacent non-neoplastic brain tissue.</p> <p>Methods</p> <p>Formalin-fixed paraffin-embedded serial sections from 33 supratentorial astrocytomas (5 diffuse fibrillary astrocytomas, WHO grade II; 6 anaplastic astrocytomas, WHO grade III; 22 glioblastomas multiforme, WHO grade IV) were immunostained following microwave pretreatment. Polyclonal antibodies against TrkA, TrkB, TrkC and monoclonal antibodies against p75<sup>NTR </sup>and phosphorylated forms of JNK (pJNK) and c-Jun (pc-Jun) were used. The labeling index (LI), defined as the percentage of positive (labeled) cells out of the total number of tumor cells counted, was determined.</p> <p>Results</p> <p>Moderate to strong, granular cytoplasmic immunoreactivity for TrkA, TrkB and TrkC receptors was detected in greater than or equal to 10% of tumor cells in the majority of tumors independently of grade; on the contrary, p75<sup>NTR </sup>receptor expression was found in a small percentage of tumor cells (~1%) in some tumors. The endothelium of tumor capillaries showed conspicuous immunoreactivity for TrkB receptor. Trk immunoreactivity seemed to be localized in some neurons and astrocytes in non-neoplastic tissue. Phosphorylated forms of JNK (pJNK) and c-Jun (pc-Jun) were significantly co-expressed in a tumor grade-dependent manner (p < 0.05). Interestingly, a statistically significant (p < 0.05) reverse relationship between Trk receptors LIs and pc-Jun/pJNK LIs was noted in some glioblastomas multiforme.</p> <p>Conclusion</p> <p>In the context of astrocytomas, Trk receptors (TrkA, TrkB, TrkC) expression may promote tumor growth independently of grade. Furthermore, activation of JNK pathway may contribute to progression towards malignancy. Considering the fact that regional tumor heterogeneity may be a limiting factor for immunohistochemical studies, the significance of the reverse relationship between Trk receptors and pc-Jun/pJNK LIs with respect to biological behavior of human astrocytomas requires further evaluation.</p

    Comparing composite likelihood methods based on pairs for spatial Gaussian random fields

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    In the last years there has been a growing interest in proposing methods for estimating covariance functions for geostatistical data. Among these, maximum likelihood estimators have nice features when we deal with a Gaussian model. However maximum likelihood becomes impractical when the number of observations is very large. In this work we review some solutions and we contrast them in terms of loss of statistical efficiency and computational burden. Specifically we focus on three types of weighted composite likelihood functions based on pairs and we compare them with the method of covariance tapering. Asymptotic properties of the three estimation methods are derived. We illustrate the effectiveness of the methods through theoretical examples, simulation experiments and by analyzing a data set on yearly total precipitation anomalies at weather stations in the United States.In the last years there has been a growing interest in proposing methods for estimating covariance functions for geostatistical data. Among these, maximum likelihood estimators have nice features when we deal with a Gaussian model. However maximum likelihood becomes impractical when the number of observations is very large. In this work we review some solutions and we contrast them in terms of loss of statistical efficiency and computational burden. Specifically we focus on three types of weighted composite likelihood functions based on pairs and we compare them with the method of covariance tapering. Asymptotic properties of the three estimation methods are derived. We illustrate the effectiveness of the methods through theoretical examples, simulation experiments and by analyzing a data set on yearly total precipitation anomalies at weather stations in the United States

    Effectiveness of an evidence-based chiropractic continuing education workshop on participant knowledge of evidence-based health care

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    BACKGROUND: Chiropractors must continue to learn, develop themselves professionally throughout their careers, and become self-directed and lifelong learners. Using an evidence-based approach increases the probability of optimal patient outcomes. But most chiropractors lack knowledge and interest in evidence-based approaches. The purpose of this study was to develop and measure the effectiveness of evidence-based training for chiropractic practitioners in a continuing education setting. METHODS: We developed and evaluated a continuing education workshop on evidence-based principles and methods for chiropractic practitioners. Forty-seven chiropractors participated in the training and testing. The course consisted of 12.5 hours of training in which practitioners learned to develop focused questions, search electronic data bases, critically review articles and apply information from the literature to specific clinical questions. Following the workshop, we assessed the program performance through the use of knowledge testing and anonymous presentation quality surveys. RESULTS: Eighty-five percent of the participants completed all of the test, survey and data collection items. Pretest knowledge scores (15-item test) were low (47%). Post intervention scores (15-item test) improved with an effect size of 2.0. A 59-item knowledge posttest yielded very good results (mean score 88%). The quality of presentation was rated very good, and most participants (90%) would "definitely recommend" or "recommend" the workshop to a colleague. CONCLUSION: The results of the study suggest that the continuing education course was effective in enhancing knowledge in the evidence-based approach and that the presentation was well accepted

    Results from the translation and adaptation of the Iranian Short-Form McGill Pain Questionnaire (I-SF-MPQ): preliminary evidence of its reliability, construct validity and sensitivity in an Iranian pain population

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    <p>Abstract</p> <p>Background</p> <p>The Short Form McGill Pain Questionnaire (SF-MPQ) is one of the most widely used instruments to assess pain. The aim of this study was to translate and culturally adapt the questionnaire for Farsi (the official language of Iran) speakers in order to test its reliability and sensitivity.</p> <p>Methods</p> <p>We followed Guillemin's guidelines for cross-cultural adaption of health-related measures, which include forward-backward translations, expert committee meetings, and face validity testing in a pilot group. Subsequently, the questionnaire was administered to a sample of 100 diverse chronic pain patients attending a tertiary pain and rehabilitation clinic. In order to evaluate test-retest reliability, patients completed the questionnaire in the morning and early evening of their first visit. Finally, patients were asked to complete the questionnaire for the third time after completing a standardized treatment protocol three weeks later. Intraclass correlation coefficient (ICC) was used to evaluate reliability. We used principle component analysis to assess construct validity.</p> <p>Results</p> <p>Ninety-two subjects completed the questionnaire both in the morning and in the evening of the first visit (test-retest reliability), and after three weeks (sensitivity to change). Eight patients who did not finish treatment protocol were excluded from the study. Internal consistency was found by Cronbach's alpha to be 0.951, 0.832 and 0.840 for sensory, affective and total scores respectively. ICC resulted in 0.906 for sensory, 0.712 for affective and 0.912 for total pain score. Item to subscale score correlations supported the convergent validity of each item to its hypothesized subscale. Correlations were observed to range from r<sup>2 </sup>= 0.202 to r<sup>2 </sup>= 0.739. Sensitivity or responsiveness was evaluated by pair t-test, which exhibited a significant difference between pre- and post-treatment scores (p < 0.001).</p> <p>Conclusion</p> <p>The results of this study indicate that the Iranian version of the SF-MPQ is a reliable questionnaire and responsive to changes in the subscale and total pain scores in Persian chronic pain patients over time.</p

    Identification of mutations in the PYRIN-containing NLR genes (NLRP) in head and neck squamous cell carcinoma

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    Head and Neck Squamous Cell Carcinoma (HNSCC) encompasses malignancies that arise in the mucosa of the upper aerodigestive tract. Recent high throughput DNA sequencing revealed HNSCC genes mutations that contribute to several cancer cell characteristics, including dysregulation of cell proliferation and death, intracellular proinflammatory signaling, and autophagy. The PYRIN-domain containing NLR (Nucleotide-binding domain, Leucine rich Repeats - containing) proteins have recently emerged as pivotal modulators of cell death, autophagy, inflammation, and metabolism. Their close physiologic association with cancer development prompted us to determine whether mutations within the NLRP (PYRIN-containing NLR ) gene family were associated with HNSCC genome instability and their clinicopathologic correlations. Catastrophic mutational events underlie cancer cell genome instability and mark a point-of-no-return in cancer cell development and generation of heterogeneity. The mutation profiles of 62 patients with primary conventional type HNSCC excluding other histologic variants were analyzed. Associations were tested using Fisher's Exact test or Mann-Whitney U test. Mutations in NLRP were associated with elevated genome instability as characterized by higher mutation rates. Clinically, NLRP mutations were more frequently found in HNSCC arising in the floor of mouth (50.0%) in comparison with HNSCC at other head and neck locations (14.8%). These mutations were clustered at the leucine rich repeats region of NLRP proteins, and affected NLRP genes were mostly localized at chromosomes 11p15.4 and 19q13.42-19q13.43. Twenty novel NLRP mutations were identified in HNSCC, and mutations in this group of genes were correlated with increased cancer cell genome mutation rates, and such features could be a potential molecular biomarker of HNSCC genome instability. © 2014 Lei et al
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