1,454 research outputs found

    Visual-spatial cognition in women with polycystic ovarian syndrome: the role of androgens

    Get PDF
    STUDY QUESTION: Are women with polycystic ovary syndrome (PCOS) better at three-dimensional mental rotation than other women? SUMMARY ANSWER: Women with PCOS scored significantly higher on a mental rotation task than a female control group. WHAT IS KNOWN ALREADY: PCOS is a condition characterized by elevated testosterone levels. Some researches have found that three-dimensional mental rotation task performance is positively correlated with testosterone levels. STUDY DESIGN, SIZE, DURATION: This cross-sectional study was conducted between June 2006 and January 2009. The participants were 69 women with PCOS and 41 controls recruited from five gynaecology clinics in London. The control group consisted of non-PCOS women of comparable subfertility to PCOS group. These groups sizes gave roughly 80% power to detect moderate effect sizes for the main statistical test. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were recruited at London gynaecology clinics. The women were aged between 18 and 43. PCOS was diagnosed based on the Rotterdam criteria. Controls were women who experienced some degree of subfertility. Blood samples from participants were frozen for up to 4 months until being assayed by direct electrochemiluminescence. The mental rotation task was undertaken electronically. Some questionnaires and other tasks were completed as control measures. MAIN RESULTS AND THE ROLE OF CHANCE: Women with PCOS scored significantly higher than controls: median (range) 3.00 (0-9) and 2.00 (0-8), respectively (U = 1147.500, N1 = 69, N2 = 41, P < 0.047). Within the PCOS group, circulating levels of testosterone were significantly positively correlated with three-dimensional scoring (rs = 0.376, n = 56, P < 0.002), whereas estradiol was significantly negatively correlated with three-dimensional scoring (rs = -0.473, n = 29, P < 0.010). In the control group, the relationship between sex hormones and mental rotation was non-significant. Other factors, including general intelligence and social class, did not account for these findings. A subgroup analysis comparing hyperandrogenic PCOS cases, non-hyperandrogenic PCOS cases and controls, in which age and body mass index were controlled for using ANCOVA, found a non-significant difference in three-dimensional scoring between the three groups (F = 1.062, d.f. = 1, 73, P < 0.351). LIMITATIONS, REASONS FOR CAUTION: The small number of women in the control group meant that correlations were underpowered in this group. WIDER IMPLICATIONS OF THE FINDINGS: This study is the first to find a benefit of PCOS in visuospatial cognition, and the first to find a link between visuospatial cognition and sex hormones in PCOS. The fact that the correlations went in the opposite direction in the PCOS group compared with the controls might suggest the influence of increased prenatal exposure to androgen in PCOS. STUDY FUNDING/COMPETING INTEREST(S): The assays for this study were funded by the Department of Psychology, City University London. All authors report no conflicts of interest

    Meta-analysis of sex difference in testosterone levels in umbilical cord blood

    Get PDF
    This meta-analysis reviewed published literature comparing human male and female umbilical cord total testosterone (T) levels. A total of 18 studies using 1,229 samples from 602 male and 627 female newborns were analysed using the RevMan 5 statistical package. Analysis using the inverse variance method based on a random-effects model revealed significantly higher cord T in boys than girls at a moderate effect size (Hedges' g = 0.57). There was significant heterogeneity between the 18 studies, although the five studies using direct assays showed no heterogeneity. For studies using extraction and chromatography, those that combined T from arterial and venous cord blood found a larger sex difference than those using only cord venous samples (Hedges' g = 0.94 vs 0.32); this suggests umbilical cord venous T is of maternal/placental origin and arterial T is of fetal origin. The wide range of T values between studies suggests high cross-reactivity in the assay methods reviewed

    Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas

    Get PDF
    Neglected tropical diseases (NTDs) have\ud been recently identified as significant public\ud health problems in Texas and elsewhere in\ud the American South. A one-day forum on the\ud landscape of research and development and\ud the hidden burden of NTDs in Texas\ud explored the next steps to coordinate advocacy,\ud public health, and research into a\ud cogent health policy framework for the\ud American NTDs. It also highlighted how\ud U.S.-funded global health research can serve\ud to combat these health disparities in the\ud United States, in addition to benefiting\ud communities abroad

    An exploration of the hypothesis that testosterone is implicated in the psychological functioning of women with polycystic ovary syndrome (PCOS)

    Get PDF
    One of the diagnostic features of polycystic ovary syndrome (PCOS) is elevation of the androgen, testosterone. It is known that women with PCOS are more likely to suffer from psychological problems, especially anxiety and depression, than other women. However, little is known of how much of this is due to testosterone, and if so, what the mechanism(s) might be. This study explores the hypothesis that testosterone impacts women with PCOS both directly and indirectly, via testosterone currently in the bloodstream and through prenatal exposure. It is hypothesised that direct effects occur when testosterone acts directly upon receptors; indirect effects occur where the impact of testosterone is mediated via another variable; activational effects are ephemeral and are caused by testosterone in the bloodstream; organizational effects occur prenatally and cause permanent changes. Four pathways are hypothesised in this paper: 1/ a direct and activational pathway which improves mental rotation ability; 2/ an indirect and activational pathway, whereby distress is caused when the physiological symptoms of testosterone are experienced as embarrassing or otherwise disturbing; 3/ an indirect and organizational effect on mood, where elevated prenatal testosterone predisposes women with PCOS to low blood sugar levels and thus low mood; 4/ and finally, it is suggested that the pathway from biology to psychology can be travelled in reverse, with a direct activational effect of relaxation training on the reduction of adrenal androgens. Testing these hypotheses has important implications for our understanding of PCOS, and our ability to treat this condition more effectively

    Urban agriculture : evaluating informal and formal practices

    Get PDF
    Urban agriculture (UA) is a fast-increasing element in many settlements in the Global North. This paper reviews the diversity of UA activity, ranging from legal to illegal, formal to informal. Focusing particularly on current research on UA projects in England, including small-scale guerrilla gardening and large community projects supported by community and government funding, we look at the realities of UA. We suggest that it is under-theorised as previous research has focused on practicalities and activism. In particular, we highlight the problematic contribution of UA to food production, the wider value in terms of community development, health and wellbeing, and warn of the danger of the ‘local trap’

    Risk of endometrial, ovarian and breast cancer in women with polycystic ovary syndrome: a systematic review and meta-analysis

    Get PDF
    BACKGROUND Polycystic ovary syndrome (PCOS) is a common condition affecting ∼8% of women. The objective of the present study was to quantify separately the risk of endometrial cancer, ovarian cancer and breast cancer in women with PCOS compared with non-PCOS controls, and quantify separately the risk to women of all ages as well as the risk to premenopausal women. METHODS We conducted a systematic review and meta-analysis of observational studies. Studies were eligible for inclusion if they compared women with PCOS to non-PCOS groups for fatal or non-fatal gynaecological cancers. Studies listed in MEDLINE and EMBASE published up to 7 October 2013 in any language were identified, and relevant papers were also searched by hand. Relevant data (for example, study design, source of control data, diagnostic criteria) were extracted and tabulated. RESULTS From 698 references, 11 studies (5 of endometrial cancer and 3 each of ovarian and breast cancer) met the inclusion criteria for the meta-analysis (919 women with PCOS and 72054 non-PCOS controls). Using the Mantel–Haenszel method, with fixed or random effects model as appropriate, women with PCOS were at a significantly increased risk of endometrial cancer (odds ratio (OR), 2.79; 95% confidence interval (CI), 1.31–5.95, P < 0.008), but the risk of ovarian and breast cancers was not significantly increased (OR, 1.41; 95% CI, 0.93–2.15, P < 0.11 and OR, 0.95; 95% CI, 0.64–1.39, P < 0.78, respectively). However when studies which included women aged over 54 years were excluded from the analysis, the risk for women with PCOS increased further for endometrial cancer (OR, 4.05; 95% CI, 2.42–6.76, P < 0.00001), became significantly increased for ovarian cancer (OR, 2.52; 95% CI, 1.08–5.89, P < 0.03), but remained non-significant for breast cancer (OR, 0.78; 95% CI, 0.46–1.32, P < 0.35). CONCLUSIONS This is the first meta-analysis to examine gynaecological cancers in women with PCOS younger than 54 years of age compared with controls of similar age. Current data suggest that women of all ages with PCOS are at an increased risk of endometrial cancer but the risk of ovarian and breast cancer was not significantly increased overall. These results highlight the potential risk of gynaecological cancer morbidities associated with PCOS. However, the available evidence is far from robust and variation in diagnostic criteria for PCOS, associated risk factors (particularly obesity), and selection bias in the studies may have resulted in an exaggeration of the increased risk. Furthermore, women who have PCOS should also be made aware that any increased risk for endometrial cancer must be judged in the context of its relatively low incidence in the general population. A large well-controlled prospective study is required in order to gain a more accurate estimate of the risk of gynaecological cancers in women with PCOS. PROSPERO CRD REGISTRATION NUMBER CRD42012003500

    Are routinely collected NHS administrative records suitable for endpoint identification in clinical trials? Evidence from the West of Scotland coronary prevention study

    Get PDF
    Background: Routinely collected electronic patient records are already widely used in epidemiological research. In this work we investigated the potential for using them to identify endpoints in clinical trials.&lt;p&gt;&lt;/p&gt; Methods: The events recorded in the West of Scotland Coronary Prevention Study (WOSCOPS), a large clinical trial of pravastatin in middle-aged hypercholesterolaemic men in the 1990s, were compared with those in the record-linked deaths and hospitalisations records routinely collected in Scotland.&lt;p&gt;&lt;/p&gt; Results: We matched 99% of fatal study events by date. We showed excellent matching (97%) of the causes of fatal endpoint events and good matching (.80% for first events) of the causes of nonfatal endpoint events with a slightly lower rate of mismatching of record linkage than study events (19% of first study myocardial infarctions (MI) and 4% of first record linkage MIs not matched as MI). We also investigated the matching of non-endpoint events and showed a good level of matching, with .78% of first stroke/TIA events being matched as stroke/TIA. The primary reasons for mismatches were record linkage data recording readmissions for procedures or previous events, differences between the diagnoses in the routinely collected data and the conclusions of the clinical trial expert adjudication committee, events occurring outside Scotland and therefore being missed by record linkage data, miscoding of cardiac events in hospitalisations data as ‘unspecified chest pain’, some general miscoding in the record linkage data and some record linkage errors.&lt;p&gt;&lt;/p&gt; Conclusions: We conclude that routinely collected data could be used for recording cardiovascular endpoints in clinical trials and would give very similar results to rigorously collected clinical trial data, in countries with unified health systems such as Scotland. The endpoint types would need to be carefully thought through and an expert endpoint adjudication committee should be involved.&lt;p&gt;&lt;/p&gt

    Plot-scale agroforestry modeling explores tree pruning and fertilizer interactions for maize production in a Faidherbia parkland

    Get PDF
    Poor agricultural productivity has led to food shortages for smallholder farmers in Ethiopia. Agroforestry may improve food security by increasing soil fertility, crop production, and livelihoods. Agroforestry simulation models can be useful for predicting the effects of tree management on crop growth when designing modifications to these systems. The Agricultural Production Systems sIMulator (APSIM) agroforestry tree-proxy model was used to simulate the response of maize yield to N fertilizer applications and tree pruning practices in the parkland agroforestry system in the Central Rift Valley, Ethiopia. The model was parameterized and tested using data collected from an experiment conducted under trees and in crop-only plots during the 2015 and 2016 growing seasons. The treatments contained three levels of tree pruning (100% pruned, 50% pruned, and unpruned) as the main plots, and N fertilizers were applied to maize at two rates (9 or 78 kg N ha−1) as sub-plots. Maize yield predictions across two years in response to tree pruning and N applications under tree canopies were satisfactorily simulated (NSE = 0.72, RSR = 0.51, R2 = 0.8). Virtual experiments for different rates of N, pruning levels, sowing dates, and cultivars suggest that maize yield could be improved by applying fertilizers (particularly on crop-only plots) and by at least 50% pruning of trees. Optimal maize yield can be obtained at a higher rate of fertilization under trees than away from them due to better water relations, and there is scope for improving the sowing date and cultivar. Across a 34-year range of recent climate, small increases in yields due to optimum N-fertilizing and pruning were probably limited by nutrient limitations other than N, but the highest yields were consistently in the 2–4 m zone under trees. These virtual experiments helped to form hypotheses regarding fertilizers, pruning, and the effects of trees on soil that warrant further field evaluation
    • …
    corecore