138 research outputs found
Prevalence, sources, and predictors of soy consumption in breast cancer
<p>Abstract</p> <p>Background</p> <p>A number of components in soy appear to have anticancer properties, including the isoflavones, genistein and daidzein. The use of soy by women with breast cancer is now being questioned because of the estrogen-like effects of isoflavones and possible interactions with tamoxifen. Clinicians providing nutrition counseling to these women are concerned because the availability of soy foods has increased dramatically in the past few years. The goal of this study was to quantify the intake of isoflavones in women with breast cancer.</p> <p>Methods</p> <p>A cross-sectional study of 100 women with breast cancer treated at Cancer Treatment Centers of America<sup>® </sup>between 09/03 and 02/04. Each patient completed a soy food frequency questionnaire (FFQ) that was scored by Fred Hutchinson Cancer Research Center. Demographic and clinical predictors of soy intake were evaluated using one-way non-parametric Mann Whitney test and non-parametric spearman's rank correlation.</p> <p>Results</p> <p>Mean age was 50.5 years (std. dev. = 9.4; range 31–70) and mean BMI was 27.3 kg/m<sup>2 </sup>(std. dev. = 6.75; range 17–59). Genistein and Daidzein consumption was limited to 65 patients with a mean intake of 11.6 mg/day (std. dev. = 21.9; range 0–97.4) and 7.6 mg/day (std. dev. = 14.1; range 0–68.9) respectively. Soy milk (37%) and pills containing soy, isoflavones, or "natural" estrogen (24%) were the two biggest contributors to isoflavone intake.</p> <p>Conclusion</p> <p>Our study suggests that the isoflavone intake of breast cancer patients at our hospital was quite variable. Thirty-five patients reported no soy intake. The mean daily intake of 11.6 mg genistein and 7.4 mg daidzein, is the equivalent of less than 1/4 cup of tofu per day. This amount is higher than what has been previously reported in non-Asian American women.</p
Effective Long-Distance Pollen Dispersal in Centaurea jacea
BACKGROUND: Agri-environment schemes play an increasingly important role for the conservation of rare plants in intensively managed agricultural landscapes. However, little is known about their effects on gene flow via pollen dispersal between populations of these species. METHODOLOGY/PRINCIPAL FINDINGS: In a 2-year experiment, we observed effective pollen dispersal from source populations of Centaurea jacea in restored meadows, the most widespread Swiss agri-environment scheme, to potted plants in adjacent intensively managed meadows without other individuals of this species. Potted plants were put in replicated source populations at 25, 50, 100 m and where possible 200 m distance from these source populations. Pollen transfer among isolated plants was prevented by temporary bagging, such that only one isolated plant was accessible for flower visitors at any one time. Because C. jacea is self-incompatible, seed set in single-plant isolates indicated insect mediated effective pollen dispersal from the source population. Seed set was higher in source populations (35.7+/-4.4) than in isolates (4.8+/-1.0). Seed set declined from 18.9% of that in source populations at a distance of 25 m to 7.4% at 200 m. At a distance of 200 m seed set was still significantly higher in selfed plants, indicating long-distance effective pollen dispersal up to 200 m. Analyses of covariance suggested that bees contributed more than flies to this long-distance pollen dispersal. We found evidence that pollen dispersal to single-plant isolates was positively affected by the diversity and flower abundance of neighboring plant species in the intensively managed meadow. Furthermore, the decline of the dispersal was less steep when the source population of C. jacea was large. CONCLUSIONS: We conclude that insect pollinators can effectively transfer pollen from source populations of C. jacea over at least 200 m, even when "recipient populations" consisted of single-plant isolates, suggesting that gene flow by pollen over this distance is very likely. Source population size and flowering environment surrounding recipient plants appear to be important factors affecting pollen dispersal in C. jacea. It is conceivable that most insect-pollinated plants in a network of restored sites within intensively managed grassland can form metapopulations, if distances between sites are of similar magnitude as tested here
Variants in Neuropeptide Y Receptor 1 and 5 Are Associated with Nutrient-Specific Food Intake and Are Under Recent Selection in Europeans
There is a large variation in caloric intake and macronutrient preference between individuals and between ethnic groups, and these food intake patterns show a strong heritability. The transition to new food sources during the agriculture revolution around 11,000 years ago probably created selective pressure and shaped the genome of modern humans. One major player in energy homeostasis is the appetite-stimulating hormone neuropeptide Y, in which the stimulatory capacity may be mediated by the neuropeptide Y receptors 1, 2 and 5 (NPY1R, NPY2R and NPY5R). We assess association between variants in the NPY1R, NPY2R and NPY5R genes and nutrient intake in a cross-sectional, single-center study of 400 men aged 40 to 80 years, and we examine whether genomic regions containing these genes show signatures of recent selection in 270 HapMap individuals (90 Africans, 90 Asians, and 90 Caucasians) and in 846 Dutch bloodbank controls. Our results show that derived alleles in NPY1R and NPY5R are associated with lower carbohydrate intake, mainly because of a lower consumption of mono- and disaccharides. We also show that carriers of these derived alleles, on average, consume meals with a lower glycemic index and glycemic load and have higher alcohol consumption. One of these variants shows the hallmark of recent selection in Europe. Our data suggest that lower carbohydrate intake, consuming meals with a low glycemic index and glycemic load, and/or higher alcohol consumption, gave a survival advantage in Europeans since the agricultural revolution. This advantage could lie in overall health benefits, because lower carbohydrate intake, consuming meals with a low GI and GL, and/or higher alcohol consumption, are known to be associated with a lower risk of chronic diseases
Red clover-derived isoflavones and mammographic breast density: a double-blind, randomized, placebo-controlled trial [ISRCTN42940165]
INTRODUCTION: Isoflavones are hypothesized to protect against breast cancer, but it is not clear whether they act as oestrogens or anti-oestrogens in breast tissue. Our aim was to determine the effects of taking a red clover-derived isoflavone supplement daily for 1 year on mammographic breast density. Effects on oestradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), lymphocyte tyrosine kinase activity and menopausal symptoms were also assessed. METHODS: A total of 205 women (age range 49–65 years) with Wolfe P2 or DY mammographic breast patterns were randomly assigned to receive either a red clover-derived isoflavone tablet (26 mg biochanin A, 16 mg formononetin, 1 mg genistein and 0.5 mg daidzein) or placebo. Change in mammographic breast density, serum oestradiol, FSH, LH, menopausal symptoms and lymphocyte tyrosine kinase activity from baseline to 12 months were assessed. RESULTS: A total of 177 women completed the trial. Mammographic breast density decreased in both groups but the difference between the treatment and placebo was not statistically significant. There was a significant interaction between treatment group and oestrogen receptor (ESR1) PvuII polymorphism for the change in estimated percentage breast density (mean ± standard deviation): TT isoflavone 1.4 ± 12.3% and TT placebo -9.6 ± 14.2%; CT isoflavone -5.2 ± 12.0% and CT placebo -2.8 ± 10.3%; and CC isoflavone -3.4 ± 9.7% and CC placebo -1.1 ± 9.5%. There were no statistically significant treatment effects on oestradiol, FSH, or LH (assessed only in postmenopausal women), or on lymphocyte tyrosine kinase activity. Baseline levels of menopausal symptoms were low, and there were no statistically significant treatment effects on frequency of hot flushes or other menopausal symptoms. CONCLUSION: In contrast to studies showing that conventional hormone replacement therapies increase mammographic breast density, the isoflavone supplement did not increase mammographic breast density in this population of women. Furthermore, there were no effects on oestradiol, gonadotrophins, lymphocyte tyrosine kinase activity, or menopausal symptoms
Preliminary clinical study of left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy by three-dimensional speckle tracking imaging
<p>Abstract</p> <p>Background</p> <p>Non-ischemic dilated cardiomyopathy (DCM) is the most common cardiomyopathy worldwide, with significant mortality. Correct evaluation of the patient's myocardial function has important clinical significance in the diagnosis, therapeutic effect assessment and prognosis in non-ischemic DCM patients. This study evaluated the feasibility of three-dimensional speckle tracking imaging (3D-STE) for assessment of the left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy (DCM).</p> <p>Methods</p> <p>Apical full-volume images were acquired from 65 patients with non-ischemic DCM (DCM group) and 59 age-matched normal controls (NC group), respectively. The following parameters were measured by 3D-STE: the peak systolic radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of each segment. Then all the parameters were compared between the two groups.</p> <p>Results</p> <p>The peak systolic strain in different planes had certain regularities in normal groups, radial strain (RS) was the largest in the mid region, the smallest in the apical region, while circumferential strain (CS) and longitudinal strain (LS) increased from the basal to the apical region. In contrast, the regularity could not be applied to the DCM group. RS, CS, LS were significantly decreased in DCM group as compared with NC group (<it>P </it>< 0.001 for all). The interobserver, intraobserver and test-retest reliability were acceptable.</p> <p>Conclusions</p> <p>3D-STE is a reliable tool for evaluation of left ventricular myocardial strain in patients with non-ischemic DCM, with huge advantage in clinical application.</p
Age at Menarche and Its Association with the Metabolic Syndrome and Its Components: Results from the KORA F4 Study
OBJECTIVE: The metabolic syndrome is a major public health challenge and identifies persons at risk for diabetes and cardiovascular disease. The aim of this study was to examine the association between age at menarche and the metabolic syndrome (IDF and NCEP ATP III classification) and its components. DESIGN: 1536 women aged 32 to 81 years of the German population based KORA F4 study were investigated. Data was collected by standardized interviews, physical examinations, and whole blood and serum measurements. RESULTS: Young age at menarche was significantly associated with elevated body mass index (BMI), greater waist circumference, higher fasting glucose levels, and 2 hour glucose (oral glucose tolerance test), even after adjusting for the difference between current BMI and BMI at age 25. The significant effect on elevated triglycerides and systolic blood pressure was attenuated after adjustment for the BMI change. Age at menarche was inversely associated with the metabolic syndrome adjusting for age (p-values: <0.001 IDF, 0.003 NCEP classification) and additional potential confounders including lifestyle and reproductive history factors (p-values: 0.001, 0.005). Associations remain significant when additionally controlling for recollected BMI at age 25 (p-values: 0.008, 0.033) or the BMI change since age 25 (p-values: 0.005, 0.022). CONCLUSION: Young age at menarche might play a role in the development of the metabolic syndrome. This association is only partially mediated by weight gain and increased BMI. A history of early menarche may help to identify women at risk for the metabolic syndrome
Deletion of transketolase triggers a stringent metabolic response in promastigotes and loss of virulence in amastigotes of Leishmania mexicana
Transketolase (TKT) is part of the non-oxidative branch of the pentose phosphate pathway (PPP). Here we describe the impact of removing this enzyme from the pathogenic protozoan Leishmania mexicana. Whereas the deletion had no obvious effect on cultured promastigote forms of the parasite, the Δtkt cells were not infective to mice. Δtkt promastigotes were more susceptible to oxidative stress and various leishmanicidal drugs than wild-type, and metabolomics analysis revealed profound changes to metabolism in these cells. In addition to changes consistent with those directly related to the role of TKT in the PPP, central carbon metabolism was substantially decreased, the cells consumed significantly less glucose, flux through glycolysis diminished, and production of the main end products of metabolism was decreased. Only minor changes in RNA abundance from genes encoding enzymes in central carbon metabolism, however, were detected although fructose-1,6-bisphosphate aldolase activity was decreased two-fold in the knock-out cell line. We also showed that the dual localisation of TKT between cytosol and glycosomes is determined by the C-terminus of the enzyme and by engineering different variants of the enzyme we could alter its sub-cellular localisation. However, no effect on the overall flux of glucose was noted irrespective of whether the enzyme was found uniquely in either compartment, or in both
Macular thickness measurements in healthy Norwegian volunteers: an optical coherence tomography study
<p>Abstract</p> <p>Background</p> <p>Ethnic, intersubject, interoperator and intermachine differences in measured macular thickness seem to exist. Our purpose was to collect normative macular thickness data in Norwegians and to evaluate the association between macular thickness and age, gender, parity, and contraception status.</p> <p>Methods</p> <p>Retinal thickness was measured by Stratus Optical Coherence Tomography in healthy subjects. Mean macular thickness (MMT) was analyzed by repeated measures ANOVA with three dependent regional MMT-variables for interaction with age, gender, parity and oral contraception use. Exploratory correlation with age by the Pearson correlation test, both before and after stratification by gender was performed. Differences in MMT between older and younger subjects, between oral contraception users and non-users, as well as parous and nulliparous women were studied by post-hoc Student's t-tests.</p> <p>Results</p> <p>Central MMT in Norwegians was similar to values earlier reported in whites. MMT in central areas of 1 and 2.25 mm in diameter were higher in males than in females. In younger subjects (≤43 years) differences in MMT between genders were larger than in the mixed age group, whereas in older subjects (>43 years) the small differences did not reach the set significance level. No differences were found in minimal foveolar thickness (MMFT) between the genders in any age group.</p> <p>Mean foveal thickness (1 mm in diameter) was positively associated with age in females (r = 0.28, p = 0.03). MMFT was positively associated with age in all groups and reached significance both in females and in mixed gender group (r = 0.20, p = 0.041 and r = 0.26, p = 0.044 respectively).</p> <p>Mean foveal thickness and MMFT were significantly higher in parous than in nulliparous women, and age-adjusted ANOVA for MMFT revealed a borderline effect of parity.</p> <p>Conclusions</p> <p>Age and gender should be taken into consideration when establishing normal ranges for MMT in younger subjects. The gender difference in retinal thickness in young, but not older adults suggests a gonadal hormonal influence. The possible association between parity and retinal structure and its clinical relevance, should be studied further.</p
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