195 research outputs found

    Association of selenium, tocopherols, carotenoids, retinol, and 15-isoprostane F(2t) in serum or urine with prostate cancer risk: the multiethnic cohort.

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    We examine the association of antioxidants and 15-isoprostane F(2t) with risk of prostate cancer.We conducted a nested case-control study of serum antioxidant biomarkers (selenium, tocopherols, carotenoids, and retinol) and a urinary oxidation biomarker (15-isoprostane F(2t)) with risk of prostate cancer within the Multiethnic Cohort. Demographic, dietary, and other exposure information was collected by self-administered questionnaire in 1993-1996. We compared prediagnostic biomarker levels from 467 prostate cancer cases and 936 cancer free controls that were matched on several variables. Multivariate conditional logistic regression models were used to compute adjusted odds ratios (ORs) and 95% confidence intervals (CIs).We observed that there was no overall association of serum concentrations of antioxidants and urinary concentrations of 15-isoprostane F(2t) with risk of prostate cancer or risk of advanced prostate cancer. However, we did observe an inverse association for serum selenium only among African-American men (p trend = 0.02); men in the third tertile of selenium concentrations had a 41% lower risk (95% CI: 0.38-0.93) of prostate cancer when compared to men in the first tertile.Overall, our study found no association of serum antioxidants or 15-isoprostane F(2t) with the risk of prostate cancer. The observed inverse association of selenium with prostate cancer in African-Americans needs to be validated in other studies

    Association of Serum Îł-Tocopherol Levels with Mortality: The Multiethnic Cohort Study

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    Background/Objectives—γ-Tocopherol has unique properties that protect against nitrogen oxide-mediated cellular damage. To elucidate the potential role of Îł-tocopherol in the aging process, we examined the associations of serum Îł-tocopherol levels with all-cause and cause-specific mortality. Subjects/Methods—Among participants in the biorepository subcohort of the Multiethnic Cohort Study, pre-cancer diagnostic serum Îł-tocopherol levels were measured in a subset of 3904 men and 4461 women. Of these, 22.7% of men and 13.5% of women died during a mean follow- up time of 9.6±2.6 years. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) for mortality associated with Îł-tocopherol were estimated by Cox proportional hazards regression. Results—Positive associations of serum Îł-tocopherol with all-cause, cancer and cardiovascular disease mortality (CVD) (Ptrend\u3c0.05) were detected after adjusting for age, race-ethnicity and serum cholesterol levels. The respective HRs (95%CIs) for the highest versus the lowest sex- specific Îł-tocopherol quartile were 1.43 (1.17–1.74), 1.79 (1.22–2.64), and 1.52 (1.10–2.11) for men and 1.58 (1.25–2.00), 1.59 (1.05–2.41), and 1.59 (1.07–2.37) for women. Associations remained significant for all-cause mortality among women after further adjusting for smoking variables and history of cancer, CVD, diabetes, and hypertension at cohort entry (highest vs. lowest Îł-tocopherol quartile: HR=1.38; 95%CI=1.08–1.75; Ptrend= 0.005). Overall, associations with all-cause mortality were consistent across race/ethnicity and were significant in three of ten sex-specific racial/ethnic groups in the fully adjusted models with no interactions between ethnicity and Îł-tocopherol. Conclusions—The positive association between Îł-tocopherol and mortality suggests a potential physiological role for Îł-tocopherol in response to pathological conditions

    Predicting total, abdominal, visceral and hepatic adiposity with circulating biomarkers in Caucasian and Japanese American women.

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    Characterization of abdominal and intra-abdominal fat requires imaging, and thus is not feasible in large epidemiologic studies.We investigated whether biomarkers may complement anthropometry (body mass index [BMI], waist circumference [WC], and waist-hip ratio [WHR]) in predicting the size of the body fat compartments by analyzing blood biomarkers, including adipocytokines, insulin resistance markers, sex steroid hormones, lipids, liver enzymes and gastro-neuropeptides.Fasting levels of 58 blood markers were analyzed in 60 healthy, Caucasian or Japanese American postmenopausal women who underwent anthropometric measurements, dual energy X-ray absorptiometry (DXA), and abdominal magnetic resonance imaging. Total, abdominal, visceral and hepatic adiposity were predicted based on anthropometry and the biomarkers using Random Forest models.Total body fat was well predicted by anthropometry alone (R(2) = 0.85), by the 5 best predictors from the biomarker model alone (leptin, leptin-adiponectin ratio [LAR], free estradiol, plasminogen activator inhibitor-1 [PAI1], alanine transaminase [ALT]; R(2) = 0.69), or by combining these 5 biomarkers with anthropometry (R(2) = 0.91). Abdominal adiposity (DXA trunk-to-periphery fat ratio) was better predicted by combining the two types of predictors (R(2) = 0.58) than by anthropometry alone (R(2) = 0.53) or the 5 best biomarkers alone (25(OH)-vitamin D(3), insulin-like growth factor binding protein-1 [IGFBP1], uric acid, soluble leptin receptor [sLEPR], Coenzyme Q10; R(2) = 0.35). Similarly, visceral fat was slightly better predicted by combining the predictors (R(2) = 0.68) than by anthropometry alone (R(2) = 0.65) or the 5 best biomarker predictors alone (leptin, C-reactive protein [CRP], LAR, lycopene, vitamin D(3); R(2) = 0.58). Percent liver fat was predicted better by the 5 best biomarker predictors (insulin, sex hormone binding globulin [SHBG], LAR, alpha-tocopherol, PAI1; R(2) = 0.42) or by combining the predictors (R(2) = 0.44) than by anthropometry alone (R(2) = 0.29).The predictive ability of anthropometry for body fat distribution may be enhanced by measuring a small number of biomarkers. Studies to replicate these data in men and other ethnic groups are warranted

    Plasma carotenoids, retinol, and tocopherols and postmenopausal breast cancer risk in the Multiethnic Cohort Study: a nested case-control study

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    Assessments by the handful of prospective studies of the association of serum antioxidants and breast cancer risk have yielded inconsistent results. This multiethnic nested case-control study sought to examine the association of plasma carotenoids, retinol, and tocopherols with postmenopausal breast cancer risk.From the biospecimen subcohort of the Multiethnic Cohort Study, 286 incident postmenopausal breast cancer cases were matched to 535 controls on age, sex, ethnicity, study location (Hawaii or California), smoking status, date/time of collection and hours of fasting. We measured prediagnostic circulating levels of individual carotenoids, retinol, and tocopherols. Conditional logistic regression was used to compute odds ratios and 95% confidence intervals.Women with breast cancer tended to have lower levels of plasma carotenoids and tocopherols than matched controls, but the differences were not large or statistically significant and the trends were not monotonic. No association was seen with retinol. A sensitivity analysis excluding cases diagnosed within 1 year after blood draw did not alter the findings.The lack of significant associations in this multiethnic population is consistent with previously observed results from less racially-diverse cohorts and serves as further evidence against a causal link between plasma micronutrient concentrations and postmenopausal breast cancer risk

    miRNA Regulatory Circuits in ES Cells Differentiation: A Chemical Kinetics Modeling Approach

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    MicroRNAs (miRNAs) play an important role in gene regulation for Embryonic Stem cells (ES cells), where they either down-regulate target mRNA genes by degradation or repress protein expression of these mRNA genes by inhibiting translation. Well known tables TargetScan and miRanda may predict quite long lists of potential miRNAs inhibitors for each mRNA gene, and one of our goals was to strongly narrow down the list of mRNA targets potentially repressed by a known large list of 400 miRNAs. Our paper focuses on algorithmic analysis of ES cells microarray data to reliably detect repressive interactions between miRNAs and mRNAs. We model, by chemical kinetics equations, the interaction architectures implementing the two basic silencing processes of miRNAs, namely “direct degradation” or “translation inhibition” of targeted mRNAs. For each pair (M,G) of potentially interacting miRMA gene M and mRNA gene G, we parameterize our associated kinetic equations by optimizing their fit with microarray data. When this fit is high enough, we validate the pair (M,G) as a highly probable repressive interaction. This approach leads to the computation of a highly selective and drastically reduced list of repressive pairs (M,G) involved in ES cells differentiation

    An analysis of consumer protection for gamblers across different online gambling operators in Ireland: a descriptive study

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    The aim of the present study was to evaluate the responsible gambling tools which are available to online gamblers at Irish online gambling websites. The present study used a similar methodology to a recent study carried out on the world’s most popular websites (Bonello and Griffiths Gaming Law Review and Economics, 21, 278–285, 2017), where 50 of the most advertised online gambling websites were evaluated in relation to their responsible gambling (RG) practices. The present study evaluated 39 gambling websites with either a “.ie” or “.com/ie” domain. Each website was evaluated by checking for a number of RG practices, including presence of a dedicated RG page; age verification; access to gambling account history; the availability of RG tools, such as limit setting facilities and exclusion settings; and links to limit-setting options on the deposit page. Descriptive statistics were then performed on the results from each website. Of the 39 online gambling operators identified, 22 redirected gamblers to a “.com” domain, while 17 operators remained as a “.ie” domain. Thirty-five websites (89.7%) visited had a dedicated RG page. Responsible gambling features were evaluated and demonstrated to be available in an inconsistent manner across online gambling websites. Irish websites were shown to perform poorly in comparison with non-Irish counterparts in the provision of RG tools. The researchers of the present study are not aware of any similar studies conducted to date in Ireland

    Post hoc Analysis for Detecting Individual Rare Variant Risk Associations Using Probit Regression Bayesian Variable Selection Methods in Case-Control Sequencing Studies

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    Rare variants (RVs) have been shown to be significant contributors to complex disease risk. By definition, these variants have very low minor allele frequencies and traditional single-marker methods for statistical analysis are underpowered for typical sequencing study sample sizes. Multimarker burden-type approaches attempt to identify aggregation of RVs across case-control status by analyzing relatively small partitions of the genome, such as genes. However, it is generally the case that the aggregative measure would be a mixture of causal and neutral variants, and these omnibus tests do not directly provide any indication of which RVs may be driving a given association. Recently, Bayesian variable selection approaches have been proposed to identify RV associations from a large set of RVs under consideration. Although these approaches have been shown to be powerful at detecting associations at the RV level, there are often computational limitations on the total quantity of RVs under consideration and compromises are necessary for large-scale application. Here, we propose a computationally efficient alternative formulation of this method using a probit regression approach specifically capable of simultaneously analyzing hundreds to thousands of RVs. We evaluate our approach to detect causal variation on simulated data and examine sensitivity and specificity in instances of high RV dimensionality as well as apply it to pathway-level RV analysis results from a prostate cancer (PC) risk case-control sequencing study. Finally, we discuss potential extensions and future directions of this work
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