259 research outputs found

    Is Household Air Pollution a Risk Factor for Eye Disease?

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    In developing countries, household air pollution (HAP) resulting from the inefficient burning of coal and biomass (wood, charcoal, animal dung and crop residues) for cooking and heating has been linked to a number of negative health outcomes, mostly notably respiratory diseases and cancers. While ocular irritation has been associated with HAP, there are sparse data on adverse ocular outcomes that may result from acute and chronic exposures. We consider that there is suggestive evidence, and biological plausibility, to hypothesize that HAP is associated with some of the major blinding, and painful, eye conditions seen worldwide. Further research on this environmental risk factor for eye diseases is warranted

    Circulating markers of arterial thrombosis and late-stage age-related macular degeneration: a case-control study.

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    PURPOSE: The aim of this study was to examine the relation of late-stage age-related macular degeneration (AMD) with markers of systemic atherothrombosis. METHODS: A hospital-based case-control study of AMD was undertaken in London, UK. Cases of AMD (n=81) and controls (n=77) were group matched for age and sex. Standard protocols were used for colour fundus photography and to classify AMD; physical examination included height, weight, history of or treatment for vascular-related diseases and smoking status. Blood samples were taken for measurement of fibrinogen, factor VIIc (FVIIc), factor VIIIc, prothrombin fragment F1.2 (F1.2), tissue plasminogen activator, and von Willebrand factor. Odds ratios from logistic regression analyses of each atherothrombotic marker with AMD were adjusted for age, sex, and established cardiovascular disease risk factors, including smoking, blood pressure, body mass index, and total cholesterol. RESULTS: After adjustment FVIIc and possibly F1.2 were inversely associated with the risk of AMD; per 1 standard deviation increase in these markers the odds ratio were, respectively, 0.62 (95% confidence interval 0.40, 0.95) and 0.71 (0.46, 1.09). None of the other atherothrombotic risk factors appeared to be related to AMD status. There was weak evidence that aspirin is associated with a lower risk of AMD. CONCLUSIONS: This study does not provide strong evidence of associations between AMD and systematic markers of arterial thrombosis, but the potential effects of FVIIc, and F1.2 are worthy of further investigation

    Patterns of diagnostic transition in eating disorders: A longitudinal population study in Sweden

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    Background Transition across eating disorder diagnoses is common, reflecting instability of specific eating disorder presentations. Previous studies have examined temporal stability of diagnoses in adult treatment-seeking samples but have not uniformly captured initial presentation for treatment. The current study examines transitions across eating disorder diagnostic categories in a large, treatment-seeking sample of individuals born in Sweden and compares these transitions across two birth cohorts and from initial diagnosis.Methods Data from Swedish eating disorders quality registers were extracted in 2013, including 9622 individuals who were seen at least twice from 1999 to 2013. Patterns of remission were examined in the entire sample and subsequently compared across initial diagnoses. An older (born prior to 1990) and younger birth cohort were also identified, and analyses compared these cohorts on patterns of diagnostic transition.Results Although diagnostic instability was common, transition between threshold eating disorder diagnoses was infrequent. For all diagnoses, transition to remission was likely to occur following a diagnosis state that matched initial diagnosis, or through a subthreshold diagnostic state. Individuals in the younger cohort were more likely to transition to a state of remission than those in the older cohort.Conclusions Results indicate more temporal continuity in eating disorder presentations than suggested by previous research and highlight the importance of early detection and intervention in achieving remission

    Comparing Internalization of Appearance Ideals and Appearance-Related Pressures Among Women from the United States, Italy, England, and Australia

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    Researchers have observed variation in levels of body image disturbance and eating pathology among women from different Western countries. Examination of cross-cultural differences in the established risk factors (i.e., thin-ideal internalization, muscular-ideal internalization, and appearance pressures from family, peers, and media) for negative outcomes may help to elucidate the prominence of specific risk factors within a given Western society and guide associated interventions. Women from the United States (US), Italy, England, and Australia completed the Sociocultural Attitudes Towards Appearance Questionnaire-4 (SATAQ-4). Analysis of covariance controlling for age and BMI indicated significant cross-country differences for all SATAQ-4 subscales. Results typically indicated higher levels of appearance-ideal internalization and appearance pressures in the US and lower levels in Italy; however, associated effect sizes were generally small. A medium effect of country was observed for peer-appearance pressures, which were highest in the US compared with all other countries. Repeated-measures analysis of variance and paired samples t tests conducted within each country identified thin-ideal internalization and media appearance pressures as the predominant risk factors for all four countries. Overall, findings suggest more cross-country similarities than differences, and highlight the importance of delivering interventions to address thin-ideal internalization and media appearance pressures among women from Western backgrounds

    Regression analysis with categorized regression calibrated exposure: some interesting findings

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    BACKGROUND: Regression calibration as a method for handling measurement error is becoming increasingly well-known and used in epidemiologic research. However, the standard version of the method is not appropriate for exposure analyzed on a categorical (e.g. quintile) scale, an approach commonly used in epidemiologic studies. A tempting solution could then be to use the predicted continuous exposure obtained through the regression calibration method and treat it as an approximation to the true exposure, that is, include the categorized calibrated exposure in the main regression analysis. METHODS: We use semi-analytical calculations and simulations to evaluate the performance of the proposed approach compared to the naive approach of not correcting for measurement error, in situations where analyses are performed on quintile scale and when incorporating the original scale into the categorical variables, respectively. We also present analyses of real data, containing measures of folate intake and depression, from the Norwegian Women and Cancer study (NOWAC). RESULTS: In cases where extra information is available through replicated measurements and not validation data, regression calibration does not maintain important qualities of the true exposure distribution, thus estimates of variance and percentiles can be severely biased. We show that the outlined approach maintains much, in some cases all, of the misclassification found in the observed exposure. For that reason, regression analysis with the corrected variable included on a categorical scale is still biased. In some cases the corrected estimates are analytically equal to those obtained by the naive approach. Regression calibration is however vastly superior to the naive method when applying the medians of each category in the analysis. CONCLUSION: Regression calibration in its most well-known form is not appropriate for measurement error correction when the exposure is analyzed on a percentile scale. Relating back to the original scale of the exposure solves the problem. The conclusion regards all regression models

    Clinical disorders affecting mesopic vision

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    Vision in the mesopic range is affected by a number of inherited and acquired clinical disorders. We review these conditions and summarize the historical background, describing the clinical characteristics alongside the genetic basis and molecular biological mechanisms giving rise to rod and cone dysfunction relevant to twilight vision. The current diagnostic gold standards for each disease are discussed and curative and symptomatic treatment strategies are summarized

    Myths and Methodologies: Reducing scientific design ambiguity in studies comparing sexes and/or menstrual cycle phases

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    In recent years, the increase in scientific literature exploring sex differences has been beneficial to both clinicians and allied health science professionals, although female athletes are still significantly under‐represented in sport and exercise science research. Women have faced exclusion throughout history though the complexities of sociocultural marginalization and biomedical disinterest in women's health. These complexities have contributed to challenges of studying women and examining sex differences. One underlying complexity to methodological design may be hormonal perturbations of the menstrual cycle. The biphasic responses of oestrogen and progesterone across the menstrual cycle significantly influence physiological responses, which contribute to exercise capacity and adaptation in women. Moreover, oral contraceptives add complexity through the introduction of varying concentrations of circulating exogenous oestrogen and progesterone, which may moderate physiological adaptations to exercise in a different manner to endogenous ovarian hormones. Thus, applied sport and exercise science research focusing on women remains limited, in part, by poor methodological design that does not define reproductive status. By highlighting specific differences between phases with regard to hormone perturbations and the systems that are affected, methodological inconsistencies can be reduced, thereby improving scientific design that will enable focused research on female athletes in sports science and evaluation of sex differences in responses to exercise. The aims of this review are to highlight the differences between endogenous and exogenous hormone profiles across a standard 28–32 day menstrual cycle, with the goal to improve methodological design for studies exploring sex differences, menstrual cycle phase differences and/or endogenous versus exogenous female sex hormones

    Perturbation of hyaluronan metabolism predisposes patients with type 1 diabetes mellitus to atherosclerosis

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    AIMS/HYPOTHESIS: Cardiovascular disease contributes to mortality in type 1 diabetes mellitus, but the specific pathophysiological mechanisms remain to be established. We recently showed that the endothelial glycocalyx, a protective layer of proteoglycans covering the endothelium, is severely perturbed in type 1 diabetes, with concomitantly increased plasma levels of hyaluronan and hyaluronidase. In the present study, we evaluated the relationship between hyaluronan and hyaluronidase with carotid intima-media thickness (cIMT), an established surrogate marker for cardiovascular disease. SUBJECTS AND METHODS: Non-smoking type 1 diabetes patients without micro- or macrovascular complications and matched controls were recruited and cIMT of both carotid arteries was measured. To evaluate the relationship between cIMT and hyaluronan and hyaluronidase as well as other parameters, uni- or multivariate regression analyses were performed. RESULTS: We included 99 type 1 diabetes patients (age 10-72 years) and 99 age- and sex-matched controls. Mean cIMT, HbA(1c), high sensitivity C-reactive protein, hyaluronan and hyaluronidase were significantly increased in type 1 diabetes vs controls. Plasma hyaluronan and hyaluronidase were correlated in type 1 diabetes. In univariate regression analyses, mean IMT was associated with plasma hyaluronan, age and male sex, whereas after multivariate analysis only age and sex remained statistically significant. CONCLUSIONS/INTERPRETATION: We conclude that type 1 diabetes patients show structural changes of the arterial wall associated with increased hyaluronan metabolism. These data may lend further support to altered glycosaminoglycan metabolism in type 1 diabetes as a potential mechanism involved in accelerated atherogenesi

    C2 and CFB Genes in Age-Related Maculopathy and Joint Action with CFH and LOC387715 Genes

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    Background: Age-related maculopathy (ARM) is a common cause of visual impairment in the elderly populations of industrialized countries and significantly affects the quality of life of those suffering from the disease. Variants within two genes, the complement factor H (CFH) and the poorly characterized LOC387715 (ARMS2), are widely recognized as ARM risk factors. CFH is important in regulation of the alternative complement pathway suggesting this pathway is involved in ARM pathogenesis. Two other complement pathway genes, the closely linked complement component receptor (C2) and complement factor B (CFB), were recently shown to harbor variants associated with ARM. Methods/Principal Findings: We investigated two SNPs in C2 and two in CFB in independent case-control and family cohorts of white subjects and found rs547154, an intronic SNP in C2, to be significantly associated with ARM in both our case-control (P-value 0.00007) and family data (P-value 0.00001). Logistic regression analysis suggested that accounting for the effect at this locus significantly (P-value 0.002) improves the fit of a genetic risk model of CFH and LOC387715 effects only. Modeling with the generalized multifactor dimensionality reduction method showed that adding C2 to the two-factor model of CFH and LOC387715 increases the sensitivity (from 63% to 73%). However, the balanced accuracy increases only from 71% to 72%, and the specificity decreases from 80% to 72%. Conclusions/Significance: C2/CFB significantly influences AMD susceptibility and although accounting for effects at this locus does not dramatically increase the overall accuracy of the genetic risk model, the improvement over the CFH-LOC387715 model is statistically significant. © 2008 Jakobsdottir et al
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