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Reproductive Variables (reproductive + variable)
Selected AbstractsEffects of the estrogen agonist 17,-estradiol and antagonist tamoxifen in a partial life-cycle assay with zebrafish (Danio rerio)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2007Leo T. M. van der Ven Abstract A partial life-cycle assay (PLC) with zebrafish (Danio rerio) was conducted to identify endocrine-disrupting effects of 17,-estradiol (E2) and tamoxifen (TMX) as reference for estrogen agonist and antagonist activity. Adult zebrafish were exposed for 21 d and offspring for another 42 d, allowing differentiation of gonads in control animals. The assessed end points included reproductive variables (egg production, fertilization, and hatching), gonad differentiation of juveniles, histopathology, and vitellogenin (VTG) expression. With E2, the most sensitive end points were feminization of offspring (at 0.1 nM) and increased VTG production in males (at 0.32 nM). At 1 nM, decreased F1 survival, increased F1 body length and weight, VTG-related edema and kidney lesions, and inhibited spermatogenesis were observed. Oocyte atresia occurred at even higher concentrations. Exposure to TMX resulted in specific effects at an intermediate test concentration (87 nM), including oocyte atresia with granulosa cell transformation and disturbed spermatogenesis (asynchrony within cysts). In F1, decreased hatching, survival, and body weight and length as well as decreased feminization were observed. Decreased vitellogenesis and egg production in females and clustering of Leydig cells in males occurred at higher concentrations. Toxicological profiles of estrogen agonists and antagonists are complex and specific; a valid and refined characterization of endocrine activity of field samples therefore can be obtained only by using a varied set of end points, including histology, as applied in the presented PLC. Evaluation of only a single end point can easily produce under- or overestimation of the actual hazard. [source] Using the composite variables of reproductive morphology, histology and steroid hormones to determine age and size at sexual maturity for the thorny skate Amblyraja radiata in the western Gulf of MaineJOURNAL OF FISH BIOLOGY, Issue 5 2006J. A. Sulikowski Age at size was linked to sexual maturity in 77 male and 93 female thorny skates Amblyraja radiata from the western Gulf of Maine using three criteria: 1) gross reproductive morphology, 2) histology and 3) steroid hormone concentrations. Age-bias plots and the coefficient of variation from vertebral band counts suggested that the ageing method represented a non-biased and precise approach to the age assessment of A. radiata. Maturity ogives for males, based on data gathered for clasper length, circulating testosterone concentrations and proportion of mature spermatocysts within the testes, predicted that 50% maturity occurred at a total length (LT) of 865 mm and c. 10·90 years of age. For females, maturity ogives, based on data gathered for ovary mass, shell gland mass, follicle size and circulating oestradiol concentrations, predicted that 50% maturity occurred at 875 mm LT and c. 11·00 years of age. Collectively, the results suggest that analysis of several contemporaneous reproductive variables offers an accurate determination of sexual maturity in the thorny skate. [source] The impact of developmental conditions on adult salivary estradiol levels: Why this differs from progesterone?AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2008Alejandra Núñez-De La Mora Women living in energetically stressful conditions have significantly lower baseline salivary steroid levels compared to those in affluent environments. Developmental hypotheses suggest that interpopulation variation in ovarian function results from contrasting environments experienced during growth. We use a migrant study of Bangladeshi women to test this hypothesis. We compared middle-class women (19,39 years) who migrated to London, UK, at different life-stages (pre and postmenarche), with Bangladeshi sedentees, second-generation British-Bangladeshis, and white British women living in similar London neighborhoods (total n = 227). We analyzed levels of salivary estradiol for one menstrual cycle, together with data on anthropometry, diet, lifestyle, and migration and reproductive histories. Results from multiple linear regression models, controlling for anthropometric and reproductive variables, show no significant differences in baseline estradiol levels between groups whether all cycles or just ovulatory cycles are analyzed. We also found no correlation between age at migration or time since migration on estradiol levels, nor between adult estradiol levels and age at menarche. Our results differ from previous reports of significantly lower salivary estradiol levels in populations living in more extreme ecological settings. They also contrast with our previous findings of significant intergroup differences in baseline levels of salivary progesterone. However, women who spent their childhood in Sylhet have a lower proportion of ovulatory cycles compared to women who developed in Britain. These group differences in ovulation frequency indicate more qualitative effects of contrasting developmental environments. We discuss possible explanations for differences in response between progesterone and estradiol, as well as broader implications of our findings. Am. J. Hum. Biol., 2008. © 2007 Wiley-Liss, Inc. [source] Prevalence and Potential Risk Factors of Female Sexual Difficulties: An Urban Iranian Population-Based StudyTHE JOURNAL OF SEXUAL MEDICINE, Issue 11 2009Azita Goshtasebi MD ABTSRACT Introduction., Female sexual dysfunction is common, a multifactorial phenomenon with a potential to cause marital strain, impaired fertility, and poor quality of life. Epidemiologic data are scarce and little is known about the prevalence of sexual difficulties and the exact role of putative risk factors in Iran. Aim., To determine the prevalence of female sexual difficulties and the potential risk factors in an urban Iranian population. Methods., A cross-sectional study was performed in the province of Kohgilooyeh,Boyerahmad (KB) in the southwest of Iran and involved sexually active urban women aged 15 years and over, selected via a quota-based cluster sampling method. The study used an ad hoc questionnaire covering the demographic and reproductive variables as well as the data related to sexual difficulties. Data were analyzed using multiple logistic regression models. The main outcome measures were the prevalence rates and the predictors of sexual difficulties. Main Outcome Measures., The prevalence of female sexual difficulties and the associated risk factors. Results., One thousand four hundred fifty-six sexually active women living in the urban areas of KB province in 2005 were selected. The mean age of the sample was 34.04 ± 9.2 (16,71) years and the mean number of completed grades was 7.18 (±4.8). More than 52% of the participants had experienced at least one type of sexual difficulty. The greatest and smallest frequencies were observed for orgasm difficulty (21.3%, confidence interval[CI]0.95 = 19.2,23.4%) and lubrication difficulty (11.9%, CI0.95 = 10.2,13.6%). Age, education, contraceptive modality, and obstetric/gynecologic procedures were all associated with at least one type of sexual dysfunction. Conclusion., Similar to previous studies, we found a relatively high prevalence of sexual difficulties in this urban population of low socioeconomic status. However, our results concerning the role of some demographic and reproductive variables in producing sexual difficulties were different from those reported by other researchers. Goshtasebi A, Vahdaninia M, and Rahimi Foroshani A. Prevalence and potential risk factors of female sexual difficulties: An urban Iranian population-based study. J Sex Med 2009;6:2988,2996. [source] | ||||||||||