1,977 research outputs found

    The androgen receptor and signal-transduction pathways in hormone-refractory prostate cancer. Part 1: modifications to the androgen receptor

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    Prostate cancer is the second most common male malignancy in the western world an increasing incidence in an ageing population. Treatment of advanced prostate cancer relies on androgen deprivation. Although the majority of patients initially respond favourably to androgen deprivation therapy, the mean time to relapse is 12-18 months. Currently there are few treatments available for men who have developed resistance to hormone therapy, due to the lack of understanding of the molecular mechanisms underlying development of this disease. Recently, however, major advances have been made in understanding both androgen receptor (AR) dependent and independent pathways which promote development of hormone resistant prostate cancer. This review will focus on modifications to the AR and associated pathways. Molecular modifications to the androgen receptor itself, e.g. mutations and/or amplification, although involved in the development of hormone resistance cannot explain all cases. Phosphorylation of AR, via either Ras/MAP kinase or PI3K/Akt signal transduction pathways, have been shown to activate AR in both a ligand (androgen) dependent and independent fashion. During this review we will discuss the clinical evidence to support AR dependent pathways as mediators of hormone resistance

    Perforin gene transfer into hematopoietic stem cells improves immune dysregulation in murine models of perforin deficiency

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    Defects in perforin lead to the failure of T and NK cell cytotoxicity, hypercytokinemia, and the immune dysregulatory condition known as familial hemophagocytic lymphohistiocytosis (FHL). The only curative treatment is allogeneic hematopoietic stem cell transplantation which carries substantial risks. We used lentiviral vectors (LV) expressing the human perforin gene, under the transcriptional control of the ubiquitous phosphoglycerate kinase promoter or a lineage-specific perforin promoter, to correct the defect in different murine models. Following LV-mediated gene transfer into progenitor cells from perforin-deficient mice, we observed perforin expression in mature T and NK cells, and there was no evidence of progenitor cell toxicity when transplanted into irradiated recipients. The resulting perforin-reconstituted NK cells showed partial recovery of cytotoxicity, and we observed full recovery of cytotoxicity in polyclonal CD8 + T cells. Furthermore, reconstituted T cells with defined antigen specificity displayed normal cytotoxic function against peptide-loaded targets. Reconstituted CD8 + lymphoblasts had reduced interferon-γ secretion following stimulation in vitro, suggesting restoration of normal immune regulation. Finally, upon viral challenge, mice with >30% engraftment of gene-modified cells exhibited reduction of cytokine hypersecretion and cytopenias. This study demonstrates the potential of hematopoietic stem cell gene therapy as a curative treatment for perforin-deficient FHL

    Heart Rate and Heart Rate Variability Changes Are Not Related to Future Cardiovascular Disease and Death in People With and Without Dysglycemia: A Downfall of Risk Markers? The Whitehall II Cohort Study

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    OBJECTIVE: Higher resting heart rate (rHR) and lower heart rate variability (HRV) are associated with increased risk of cardiovascular disease (CVD) and all-cause mortality in people with and without diabetes. It is unknown whether temporal changes in rHR and HRV may contribute to this risk. We investigated associations between 5-year changes in rHR and HRV and risk of future CVD and death, taking into account participants' baseline glycemic state. RESEARCH DESIGN AND METHODS: In this prospective, population-based cohort study we investigated 4,611 CVD-free civil servants (mean [SD] age, 60 [5.9] years; 70% men). We measured rHR and/or six indices of HRV. Associations of 5-year change in 5-min rHR and HRV with fatal and nonfatal CVD and all-cause mortality or the composite of the two were assessed, with adjustments made for relevant confounders. Effect modification by glycemic state was tested. RESULTS: At baseline, 63% of participants were normoglycemic, 29% had prediabetes, and 8% had diabetes. During a median (interquartile range) follow-up of 11.9 (11.4; 12.3) years, 298 participants (6.5%) experienced a CVD event and 279 (6.1%) died of non-CVD-related causes. We found no association between 5-year changes in rHR and HRV and future events. Only baseline rHR was associated with all-cause mortality. A 10 bpm-higher baseline HR level was associated with a 11.4% higher rate of all-cause mortality (95% CI 1.0-22.9%; P = 0.032). Glycemic state did not modify associations. CONCLUSIONS: Changes in rHR and HRV and possibly also baseline values of these measures are not associated with future CVD or death in people with or without dysglycemia

    Determinants of Health Care Renunciation among Women in Ivory Coast: Case of the District of Abobo Anonkoi-3

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    Background: Health care renunciation aims to identify unmet care needs that a health con­dition would have justified. This behavior appears to be more common in women than in men. The objective of this work was to analyze the determinants of the health care renuncia­tion among women in the city of Abidjan.Subjects and Method: We carried out a cross-sectional study from March to May 2019 in Anonkoi-3, a peri-urban district of the muni­cipality of Abobo, in the north of the city of Abidjan. Questionnaires served to collect infor­mations. Bivariate analyzes and a multiple logistic regression were used to measure the association between the different types of renunciation and the characteristics of women. Dependant variable was healthcare renuncia­tion. Independent variables were socio-demo­graphic, economic, health status characte­ristics and reasons for renouncing to health care.Results: The population sample consisted of 423 women (with mean age= 32; SD= 12 years). The renunciation on consultations with the general practitioner concerned, 72.34% of women. Regarding consultation with the spe­cialist, the ophthalmologist (25.05%), the dentist (21.99%), and the gynecologist (14.89%) were those mostly renounced by the women. After consultation, 31.2% of them renounced to pursuing other treatment. They most often renounced to buying drugs from conventional medicine (19.62%) and preferred to use street drugs and traditional drugs (87.71%). All things being equal, women aged 28 to 38 (OR= 2.45; 95% CI= 1.31 to 4.68; p= 0.013), artisans and traders (OR= 3.22; 95% CI= 1.48 to 7.38; p= 0.004) and those in trade learning (OR= 2.42; 95% CI= 1.12 to 5.49; p= 0.028) significantly renouncing more on health care.Conclusion: In addition to financial reasons, the renunciation on health care can be explained by individual and social behaviors specific to individuals.Keywords: women, healthcare renunciation, precariousness, social inequalities, ivory coastCorrespondence: Jérôme Kouame, Faculty of Pharmaceutical and Biological Sciences, Department of Public Health, Hydrology and Toxicology, University Félix Houphouët Boigny, BPV 34 Abidjan 01, Ivory Coast. Email: jerome.kouamejj­@­gmail.­com. Mobile: 0022565237900.Journal of Health Policy and Management (2021), 06(02): 116-129https://doi.org/10.26911/thejhpm.2021.06.02.0

    Evaluation of range of motion restriction within the hip joint

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    In Total Hip Arthroplasty, determining the impingement free range of motion requirement is a complex task. This is because in the native hip, motion is restricted by both impingement as well as soft tissue restraint. The aim of this study is to determine a range of motion benchmark which can identify motions which are at risk from impingement and those which are constrained due to soft tissue. Two experimental methodologies were used to determine motions which were limited by impingement and those motions which were limited by both impingement and soft tissue restraint. By comparing these two experimental results, motions which were limited by impingement were able to be separated from those motions which were limited by soft tissue restraint. The results show motions in extension as well as flexion combined with adduction are limited by soft tissue restraint. Motions in flexion, flexion combined with abduction and adduction are at risk from osseous impingement. Consequently, these motions represent where the maximum likely damage will occur in femoroacetabular impingement or at most risk of prosthetic impingement in Total Hip Arthroplasty

    A phase III trial of tirasemtiv as a potential treatment for amyotrophic lateral sclerosis

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    Objective: To assess the efficacy of tirasemtiv, a fast skeletal muscle troponin activator, vs. placebo in patients with amyotrophic lateral sclerosis. Methods: VITALITY-ALS (NCT02496767) was a multinational, double-blind, randomized, placebo-controlled clinical trial. Participants tolerating 2 weeks of open-label tirasemtiv (125?mg twice daily) were randomized 3:2:2:2 to placebo or one of three target tirasemtiv dose levels, using an escalating dosage protocol lasting 28 days. The primary outcome measure was changed in slow vital capacity (SVC) at 24 weeks. Secondary endpoints included a change in muscle strength and time to respiratory milestones of disease progression. Results: Of 744 participants, 565 tolerated open-label tirasemtiv and received randomized treatment. By 24 weeks, 23 (12.2%) placebo-treated participants discontinued study treatment vs. 129 (34.2%) randomized to tirasemtiv. SVC declined by 14.4% (95% CI: ?16.8, ?11.9) in the placebo group and 13.4% (95% CI: ?15.3, ?11.6) in the tirasemtiv group (p?=?0.56). Secondary endpoints did not show significant differences. However, participants who tolerated tirasemtiv at their randomized dose showed a numeric trend toward a dose-related slowing of decline in SVC (p?=?0.11). Dizziness, fatigue, nausea, weight loss, and insomnia occurred more frequently on tirasemtiv. Serious adverse events were similar across groups. Conclusions: Tirasemtiv did not alter the decline of SVC or significantly impact secondary outcome measures. Poor tolerability of tirasemtiv may have contributed to this result. However, participants tolerating their intended dose exhibited a trend toward treatment benefit on SVC, suggesting the underlying mechanism of action may still hold promise, as is being tested with a different fast skeletal muscle troponin activator (NCT03160898)

    Local Difference Measures between Complex Networks for Dynamical System Model Evaluation

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    Acknowledgments We thank Reik V. Donner for inspiring suggestions that initialized the work presented herein. Jan H. Feldhoff is credited for providing us with the STARS simulation data and for his contributions to fruitful discussions. Comments by the anonymous reviewers are gratefully acknowledged as they led to substantial improvements of the manuscript.Peer reviewedPublisher PD

    Impact of Circulating Cholesterol Levels on Growth and Intratumoral Androgen Concentration of Prostate Tumors

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    Prostate cancer (PCa) is the second most common cancer in men. Androgen deprivation therapy (ADT) leads to tumor involution and reduction of tumor burden. However, tumors eventually reemerge that have overcome the absence of gonadal androgens, termed castration resistant PCa (CRPC). Theories underlying the development of CRPC include androgen receptor (AR) mutation allowing for promiscuous activation by non-androgens, AR amplification and overexpression leading to hypersensitivity to low androgen levels, and/or tumoral uptake and conversion of adrenally derived androgens. More recently it has been proposed that prostate tumor cells synthesize their own androgens through de novo steroidogenesis, which involves the step-wise synthesis of androgens from cholesterol. Using the in vivo LNCaP PCa xenograft model, previous data from our group demonstrated that a hypercholesterolemia diet potentiates prostatic tumor growth via induction of angiogenesis. Using this same model we now demonstrate that circulating cholesterol levels are significantly associated with tumor size (R = 0.3957, p = 0.0049) and intratumoral levels of testosterone (R = 0.41, p = 0.0023) in LNCaP tumors grown in hormonally intact mice. We demonstrate tumoral expression of cholesterol uptake genes as well as the spectrum of steroidogenic enzymes necessary for androgen biosynthesis from cholesterol. Moreover, we show that circulating cholesterol levels are directly correlated with tumoral expression of CYP17A, the critical enzyme required for de novo synthesis of androgens from cholesterol (R = 0.4073, p = 0.025) Since hypercholesterolemia does not raise circulating androgen levels and the adrenal gland of the mouse synthesizes minimal androgens, this study provides evidence that hypercholesterolemia increases intratumoral de novo steroidogenesis. Our results are consistent with the hypothesis that cholesterol-fueled intratumoral androgen synthesis may accelerate the growth of prostate tumors, and suggest that treatment of CRPC may be optimized by inclusion of cholesterol reduction therapies in conjunction with therapies targeting androgen synthesis and the AR

    Pulsed radiofrequency treatment in interventional pain management: mechanisms and potential indications—a review

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    Item does not contain fulltextBACKGROUND: The objective of this review is to evaluate the efficacy of Pulsed Radiofrequency (PRF) treatment in chronic pain management in randomized clinical trials (RCTs) and well-designed observational studies. The physics, mechanisms of action, and biological effects are discussed to provide the scientific basis for this promising modality. METHODS: We systematically searched for clinical studies on PRF. We searched the MEDLINE (PubMed) and EMBASE database, using the free text terms: pulsed radiofrequency, radio frequency, radiation, isothermal radiofrequency, and combination of these. We classified the information in two tables, one focusing only on RCTs, and another, containing prospective studies. Date of last electronic search was 30 May 2010. The methodological quality of the presented reports was scored using the original criteria proposed by Jadad et al. FINDINGS: We found six RCTs that evaluated the efficacy of PRF, one against corticosteroid injection, one against sham intervention, and the rest against conventional RF thermocoagulation. Two trials were conducted in patients with lower back pain due to lumbar zygapophyseal joint pain, one in cervical radicular pain, one in lumbosacral radicular pain, one in trigeminal neuralgia, and another in chronic shoulder pain. CONCLUSION: From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regards to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the methodological quality of the included study. PRF application to the supracapular nerve was found to be as efficacious as intra-articular corticosteroid in patients with chronic shoulder pain. The use of PRF in lumbar facet arthropathy and trigeminal neuralgia was found to be less effective than conventional RF thermocoagulation techniques
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