The interaction of phytoestrogens with the most important binding sites of steroid hormones, i.e. sex hormone-binding globulin and estrogen receptors, was investigated. Relative binding affinities and association constants for 21 compounds among them isoflavones, flavones, flavonols, flavanones, chalcones and lignans were determined. The lignan nordihydroguaiaretic acid weakly displaced 17beta-...

BackgroundSolar ultraviolet radiation (UVR) affects the body through pathways that exhibit positive as well negative health effects such immunoregulation and vitamin D production. Different metabolites are associated with higher or lower concentrations of estrogens may thus alter female sex hormone balance.ObjectiveTo study whether exposure to UVR, a modifiable lifestyle factor, is levels hormo...

Background: Estrogens include estoril (E3), estradiol and estrone (E1). These chemicals are produced in human and animal bodies as well as in synthetic chemicals (drugs). Estrogens can enter water sources in different ways. When these chemicals enter the human body through water and wastewater, they have the ability to mimic or disrupt the normal estrogen activities in humans and animals. Estro...

The steroid hormone estradiol, and the glycoprotein hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are known to be essential for the growth and differentiation of follicles in the ovary. The present study was conducted to determine quantitatively the effects of estradiol, FSH and LH on proliferation of different ovarian cell types (granulosa and theca cells). The imma...

The influence of 17beta-estradiol and 17alpha-estradiol on adult human omental adipocyte precursors grown in a propagating culture system was studied. Cells were grown in subculture in the presence or absence of hormone. 17beta-estradiol resulted in significant promotion of adipocyte precursor replication, as determined by cell counting and incorporation of radioactive thymidine into DNA. The h...

OBJECTIVE To correlate circulating hormone levels with the clinical and biological features of the tumors in menopausal breast cancer patients. DESIGN Circulating hormone levels were measured in 161 previously untreated menopausal breast cancer patients within 72 h of their planned surgery. The obtained hormone levels were correlated with tumor size, histological and nuclear grade, histologic...

The use of progesterone for luteal support in stimulated cycles for in-vitro fertilization is well established. However, the benefits of the addition of estradiol are still controversial. The aim of this study was to compare ongoing pregnancy rates in patients stimulated with recombinant follicle stimulating hormone and gonadotrophin releasing hormone antagonist for in vitro fertilization, who ...

OBJECTIVE It has been suggested that the high prevalence of subnormal free testosterone concentrations, along with low or inappropriately normal gonadotropins in men with type 2 diabetes, may be the result of an increase in plasma estradiol concentrations secondary to an increase in aromatase activity in the adipose tissue that leads to the suppression of the hypothalamo-hypophyseal-gonadal axi...

OBJECTIVE Our purpose was to confirm the elevation of vaginal pH expected in patients with bacterial pathogens in premenopausal women and to examine the relationship of serum follicle-stimulating hormone and estradiol levels to vaginal pH in menopausal patients without and with hormone replacement therapy. STUDY DESIGN Vaginal pH was determined by phenaphthazine (Nitrazine) pH paper in 253 pa...