535 research outputs found

    Single-nucleotide polymorphism-based genetic risk score and patient age at prostate cancer diagnosis

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    Importance: Few studies have evaluated the association between a single-nucleotide polymorphism-based genetic risk score (GRS) and patient age at prostate cancer (PCa) diagnosis. Objectives: To test the association between a GRS and patient age at PCa diagnosis and to compare the performance of a GRS with that of family history (FH) in PCa risk stratification. Design, Setting, and Participants: A cohort study of 3225 white men was conducted as a secondary analysis of the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) chemoprevention trial, a 4-year, randomized, double-blind, placebo-controlled multicenter study conducted from March 2003 to April 2009 to evaluate the safety and efficacy of dutasteride in reducing PCa events. Participants were confirmed to be cancer free by prostate biopsy (6-12 cores) within 6 months prior to the study and underwent 10 core biopsies every 2 years per protocol. The dates for performing data analysis were from July 2016 to October 2019. Interventions: A well-established, population-standardized GRS was calculated for each participant based on 110 known PCa risk-associated single-nucleotide polymorphisms, which is a relative risk compared with the general population. Men were classified into 3 GRS risk groups based on predetermined cutoff values: low (\u3c0.50), average (0.50-1.49), and high (≥1.50). Main Outcomes and Measures: Prostate cancer diagnosis-free survival among men of different risk groups. Results: Among 3225 men (median age, 63 years [interquartile range, 58-67 years]) in the study, 683 (21%) were classified as low risk, 1937 (60%) as average risk, and 605 (19%) as high risk based on GRS alone. In comparison, 2789 (86%) were classified as low or average risk and 436 (14%) as high risk based on FH alone. Men in higher GRS risk groups had a PCa diagnosis-free survival rate that was worse than that of those in the lower GRS risk group (χ2 = 53.3; P \u3c .001 for trend) and in participants with a negative FH of PCa (χ2 = 45.5; P \u3c .001 for trend). Combining GRS and FH further stratified overall genetic risk, indicating that 957 men (30%) were at high genetic risk (either high GRS or positive FH), 1667 men (52%) were at average genetic risk (average GRS and negative FH), and 601 men (19%) were at low genetic risk (low GRS and negative FH). The median PCa diagnosis-free survival was 74 years (95% CI, 73-75 years) for men at high genetic risk, 77 years (95% CI, 75 to \u3e80 years) for men at average genetic risk, and more than 80 years (95% CI, \u3e80 to \u3e80 years) for men at low genetic risk. In contrast, the median PCa diagnosis-free survival was 73 years (95% CI, 71-76 years) for men with a positive FH and 77 years (95% CI, 76-79 years) for men with a negative FH. Conclusions and Relevance: This study suggests that a GRS is significantly associated with patient age at PCa diagnosis. Combining FH and GRS may better stratify inherited risk than FH alone for developing personalized PCa screening strategies

    Rosiglitazone Prevents High Glucose-Induced Vascular Endothelial Growth Factor and Collagen IV Expression in Cultured Mesangial Cells

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    Peroxisome proliferator-activated receptor (PPARγ), a ligand-dependent transcription factor, negatively modulates high glucose effects. We postulated that rosiglitazone (RSG), an activator of PPARγ prevents the upregulation of vascular endothelial growth factor (VEGF) and collagen IV by mesangial cells exposed to high glucose. Primary cultured rat mesangial cells were growth-arrested in 5.6 mM (NG) or 25 mM D-glucose (HG) for up to 48 hours. In HG, PPARγ mRNA and protein were reduced within 3 h, and enhanced ROS generation, expression of p22phox, VEGF and collagen IV, and PKC-ζ membrane association were prevented by RSG. In NG, inhibition of PPARγ caused ROS generation and VEGF expression that were unchanged by RSG. Reduced AMP-activated protein kinase (AMPK) phosphorylation in HG was unchanged with RSG, and VEGF expression was unaffected by AMPK inhibition. Hence, PPARγ is a negative modulator of HG-induced signaling that acts through PKC-ζ but not AMPK and regulates VEGF and collagen IV expression by mesangial cells

    Active sensing coating for early detection of corrosion processes

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    A corrosion sensing coating based on specially developed polymeric microcapsules with a pH-indicator is reported. The synthesis of the microcapsules is designed in a way to ensure their optimal compatibility with the polyurethane protective coatings and to allow release of the indicator at higher pH values. The obtained polyurea microcapsules have a regular and microsized morphology and a loading content of 12 wt%. The developed sensing coating applied on aluminium and magnesium alloys is able to indicate initiation of corrosion processes through a pink coating coloration, as a result of local pH increase in the cathodic areas

    Molecular Mechanism of Insulin Resistance in Obesity and Type 2 Diabetes

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    Insulin resistance is a major risk factor for developing type 2 diabetes caused by the inability of insulin-target tissues to respond properly to insulin, and contributes to the morbidity of obesity. Insulin action involves a series of signaling cascades initiated by insulin binding to its receptor, eliciting receptor autophosphorylation and activation of the receptor tyrosine kinase, resulting in tyrosine phosphorylation of insulin receptor substrates (IRSs). Phosphorylation of IRSs leads to activation of phosphatidylinositol 3-kinase (PI3K) and, subsequently, to activation of Akt and its downstream mediator AS160, all of which are important steps for stimulating glucose transport induced by insulin. Although the mechanisms underlying insulin resistance are not completely understood in skeletal muscle, it is thought to result, at least in part, from impaired insulin-dependent PI3K activation and downstream signaling. This review focuses on the molecular basis of skeletal muscle insulin resistance in obesity and type 2 diabetes. In addition, the effects of insulin-sensitizing agent treatment and lifestyle intervention of human insulin-resistant subjects on insulin signaling cascade are discussed. Furthermore, the role of Rho-kinase, a newly identified regulator of insulin action in insulin control of metabolism, is addressed

    Curcumin Prevents High Fat Diet Induced Insulin Resistance and Obesity via Attenuating Lipogenesis in Liver and Inflammatory Pathway in Adipocytes

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    Background: Mechanisms underlying the attenuation of body weight gain and insulin resistance in response to high fat diet (HFD) by the curry compound curcumin need to be further explored. Although the attenuation of the inflammatory pathway is an accepted mechanism, a recent study suggested that curcumin stimulates Wnt signaling pathway and hence suppresses adipogenic differentiation. This is in contrast with the known repressive effect of curcumin on Wnt signaling in other cell lineages. Methodology and Principal Findings: We conducted the examination on low fat diet, or HFD fed C57BL/6J mice with or without curcumin intervention for 28 weeks. Curcumin significantly attenuated the effect of HFD on glucose disposal, body weight/fat gain, as well as the development of insulin resistance. No stimulatory effect on Wnt activation was observed in the mature fat tissue. In addition, curcumin did not stimulate Wnt signaling in vitro in primary rat adipocytes. Furthermore, curcumin inhibited lipogenic gene expression in the liver and blocked the effects of HFD on macrophage infiltration and the inflammatory pathway in the adipose tissue. Conclusions and Significance: We conclude that the beneficial effect of curcumin during HFD consumption is mediated by attenuating lipogenic gene expression in the liver and the inflammatory response in the adipose tissue, in the absence o

    Metformin treatment in diabetes and heart failure: when academic equipoise meets clinical reality

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    <p>Abstract</p> <p>Objective</p> <p>Metformin has had a 'black box' contraindication in diabetic patients with heart failure (HF), but many believe it to be the treatment of choice in this setting. Therefore, we attempted to conduct a pilot study to evaluate the feasibility of undertaking a large randomized controlled trial with clinical endpoints.</p> <p>Study Design</p> <p>The pilot study was a randomized double blinded placebo controlled trial. Patients with HF and type 2 diabetes were screened in hospitals and HF clinics in Edmonton, Alberta, Canada (population ~1 million). Major exclusion criteria included the current use of insulin or high dose metformin, decreased renal function, or a glycosylated hemoglobin <7%. Patients were to be randomized to 1500 mg of metformin daily or matching placebo and followed for 6 months for a variety of functional outcomes, as well as clinical events.</p> <p>Results</p> <p>Fifty-eight patients were screened over a six month period and all were excluded. Because of futility with respect to enrollment, the pilot study was abandoned. The mean age of screened patients was 77 (SD 9) years and 57% were male. The main reasons for exclusion were: use of insulin therapy (n = 23; 40%), glycosylated hemoglobin <7% (n = 17; 29%) and current use of high dose metformin (n = 12; 21%). Overall, contraindicated metformin therapy was the most commonly prescribed oral antihyperglycemic agent (n = 27; 51%). On average, patients were receiving 1,706 mg (SD 488 mg) of metformin daily and 12 (44%) used only metformin.</p> <p>Conclusion</p> <p>Despite uncertainty in the scientific literature, there does not appear to be clinical uncertainty with regards to the safety or effectiveness of metformin in HF making a definitive randomized trial virtually impossible.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier: NCT00325910</p

    Characterising brown dwarf companions with IRDIS long-slit spectroscopy: HD 1160 B and HD 19467 B

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    The determination of the fundamental properties (mass, separation, age, gravity and atmospheric properties) of brown dwarf companions allows us to infer crucial informations on their formation and evolution mechanisms. Spectroscopy of substellar companions is available to date only for a limited number of objects (and mostly at very low resolution, R<50) because of technical limitations, i.e., contrast and angular resolution. We present medium resolution (R=350), coronagraphic long-slit spectroscopic observations with SPHERE of two substellar companions, HD 1160 B and HD 19467 B. We found that HD 1160 B has a peculiar spectrum that cannot be fitted by spectra in current spectral libraries. A good fit is possible only considering separately the Y+J and the H spectral band. The spectral type is between M5 and M7. We also estimated a T_eff of 2800-2900 K and a log(g) of 3.5-4.0 dex. The low surface gravity seems to favour young age (10-20 Myr) and low mass (~20 M Jup ) for this object. HD 19467 B is instead a fully evolved object with a T_eff of ~1000 K and log g of ~5.0 dex. Its spectral type is T6+/-1.Comment: 14 pages, 14 Figures. Accepted for publication on MNRA
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