Estrogens (Total 99638 Papers Found)

A stage critical in mammalian development is embryo implantation. At this point, the blastocyst establishes a close interaction with the uterine tissues, a step necessary for its continued embryonic development. In many mammalian species, including man, uterine expression of the cytokine, leukemia inhibitory factor (LIF) is coincident with the onset of implantation and in mice LIF is essential to this process. The reasons for implantation failure have not been established. Here we show in LIF-de ...
There has been increasing concern about the impact of environmental compounds with hormone-like action on human development and reproductive health over the past decades. An alternative but neglected source of hormone action that may be considered in this connection is hormone residues in meat from husbandry animals treated with sex steroid hormones for growth promotion. Treatment of cattle with naturally occurring or synthetic sex hormones may enhance lean muscle growth and improve feed efficie ...
Little is known about the neural control of female responses to male courtship. Female European starlings in breeding condition with high concentrations of estrogen select mates based on variation in song and approach nest boxes broadcasting male song. In contrast, outside of the breeding season (when estrogen is low) females do not display the same response to male song. The catecholamines dopamine and norepinephrine regulate behaviors important for mate choice such as arousal, attention, sexua ...
Postmenopausal patients with metastatic breast cancer were treated with medroxyprogesterone acetate (MPA) (Clinovir) in dosages between 500 and 1500 mg orally per day. The relation of MPA plasma concentrations and endocrine effects were studied in a longitudinal fashion. MPA exerted suppressive effects on the basal and gonadotropin-releasing hormone (GnRH) stimulated gonadotropin secretion, cortisol, dehydroepiandrosterone (DHEA), and estradiol (E2) in a dose-dependent manner leading to a comple ...
Mutations in BRCA1 and BRCA2 confer high risks of breast cancer and ovarian cancer. The risk prediction algorithm BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) may be used to compute the probabilities of carrying mutations in BRCA1 and BRCA2 and help to target mutation screening. Tumours from BRCA1 and BRCA2 mutation carriers display distinctive pathological features that could be used to better discriminate between BRCA1 mutation carriers, BRCA2 mu ...
The diagnosis of premature ovarian failure was made in 35 women (ages 17 to 40) with increased concentrations of follicle-stimulating hormone and luteinizing hormone. Three had primary amenorrhea, 29 had secondary amenorrhea (less than one to 15 years), and three had irregular menstrual intervals of less than six months. Symptoms and signs of estrogen deficiency were present in fewer than 50% of these women and were not helpful in distinguishing the different causes of ovarian failure. Six of th ...
Recent studies using a mouse model of weight-drop-induced "diffuse" traumatic brain injury (TBI) have demonstrated a substantial gender difference in the time course and magnitude of post-traumatic neurodegeneration following a severe level of injury. The time of maximal damage, as assessed by the de Olmos aminocupric silver staining method, occurred at 72 h in male mice, whereas the peak of neurodegeneration was not observed until 14 days in females and was less in magnitude compared to males. ...
Expression of the new 17beta-hydroxysteroid dehydrogenase (HSD), type 10 (17beta-HSD-10), formerly known as endoplasmic reticulum-associated amyloid-binding protein, has been investigated in the testes of various mammals under normal and perturbed conditions. Results show that 17beta-HSD-10 is a major product of both fetal and adult-type Leydig cells. In the former, protein persists until late in postnatal development; and in the short-day hamster model, it does not disappear when Leydig cells i ...
X-box binding protein 1 (XBP-1) is stimulated by endoplasmic reticulum stress as part of the unfolded protein response (UPR), which can promote apoptosis or cell survival. Non-conventional splicing, stimulated during the UPR, converts mRNA for "unspliced" XBP-1U to "spliced" XBP-1S mRNA. XBP-1 mRNA is oestrogen-responsive, but XBP-1S confers oestrogen independence and anti-oestrogen resistance to breast cancer cell lines. We therefore evaluated XBP-1 mRNA splicing as a factor in response of brea ...
OBJECTIVE Evidence indicates that estrogen depresses hepatic lipid oxidation. We tested the hypothesis that estradiol (E(2)) treatment depresses transcription of carnitine palmitoyltransferase-1 (Cpt 1) mRNA and increases adiposity. RESEARCH METHODS AND PROCEDURES Six ovariectomized female rats were given a subcutaneous pellet of E(2) (5 mg/d), and six were given placebo. Rats were pair-fed by group for 18 days. Body composition was assessed chemically: mRNA for liver Cpt 1, adipose tissue unc ...
In a retrospective immunohistochemical study, the expression of oestrogen receptors has been investigated in paraffin-embedded transitional cell carcinomas of the urinary bladder with antibody 6F11, using both a conventional immunohistochemical detection system and the highly sensitive tyramide staining amplification (TSA) technique. The study comprised 88 invasive and 97 non-invasive carcinomas of 101 female (mean age 68.4 years) and 84 male (mean age 68.2 years) patients. Oestrogen receptors w ...
Steroids regulate alternative splicing of RUSH/SMARCA3. The full-length, progesterone-dependent alpha-isoform and the 3'-truncated, estrogen-dependent beta-isoform have identical DNA-binding domains, nuclear localization signals, and RING fingers. Transcription of RUSH/SMARCA3 is mediated by a bipartite progesterone receptor half-site/overlapping Y-box combination (-38/-26), where progesterone activation is attenuated by nuclear factor Y binding. Regulation also involves two GC-rich sequences in ...
OBJECTIVE To support the practitioner in the diagnosis of vaginal atrophy and in the management of the related symptoms. OPTIONS The modalities of evaluation range from basic pelvic examination, examination of the vulva, and laboratory tests. OUTCOMES A comprehensive approach to the detection of vaginal atrophy and a discussion of available therapeutic and nontherapeutic options. EVIDENCE Published opinions of experts, supplemented by evidence from clinical trials, where appropriate. VAL ...
OBJECTIVE This trial was a therapeutic and pharmacokinetic dose-finding study with subdermal implants that showed a constant in vitro daily release rate of estradiol. The aim was to find the daily release rate of estradiol that produces serum estradiol concentrations comparable with those obtained with transdermal estradiol at 0.05 mg/day. STUDY DESIGN The study was an open crossover comparison of transdermal and subcutaneous delivery systems. Thirty-six postmenopausal (serum follicle-stimulat ...
The identification of the proximal causes of coronary heart disease (CHD) during the second half of the 20th century contributed to the prevention of premature CHD and the extension of life expectancy in middle-aged and older people in many wealthy countries. These major CHD risk factors-high blood cholesterol, high blood pressure, cigarette smoking and physical inactivity-satisfy public health criteria of causality. Strong epidemiological evidence suggests that they explain at least 75% of new ...
Maternal obesity is linked with increased adverse pregnancy outcomes for both mother and child. The metabolic impact of excessive fat within the context of pregnancy is not fully understood. We used a mouse model of high fat (HF) feeding to induce maternal obesity to identify adipose tissue-mediated mechanisms driving metabolic dysfunction in pregnant and non-pregnant obese mice. As expected, chronic HF-feeding for 12 weeks preceding pregnancy increased peripheral (subcutaneous) and visceral (me ...
OBJECTIVE To determine the effects of maternal undernutrition (MUN) on the reproductive axis of aging offspring. DESIGN Animal (rat) study. SETTING Research laboratory. ANIMAL(S) Female Sprague-Dawley rats. INTERVENTION(S) Food restriction during the second half of pregnancy in rats. MAIN OUTCOME MEASURE(S) Circulating gonadotropins, antimüllerian hormone (AMH), ovarian morphology, estrous cyclicity, and gene expression studies in the hypothalamus and ovary in 1-day-old (P1) and aging ...
We have previously shown that transforming growth factor beta (TGF beta) is a hormonally regulated negative growth factor in estrogen responsive MCF-7 human breast cancer cells. We have now compared the antiestrogens tamoxifen, droloxifene (3-hydroxytamoxifen), and toremifene in their ability to induce the secretion of autoinhibitory TGF beta by MCF-7 cells. The main results are as follows: induction of TGF beta secretion by droloxifene is about two to three times higher than by identical concen ...
BACKGROUND The origin and the contribution of breast tumor heterogeneity to its progression are not clear. We investigated the effect of a growing orthotopic tumor formed by an aggressive estrogen receptor (ER)-negative breast cancer cell line on the metastatic potential of a less aggressive ER-positive breast cancer cell line for the elucidation of how the presence of heterogeneous cancer cells might affect each other's metastatic behavior. METHODS ER positive ZR-75-1/GFP/puro cells, resistan ...
[F-18] 16 alpha-Fluoroestradiol (FES) has been shown to be a tracer of estrogen receptor content in breast tumors; however, quantitative analysis of FES images is complicated by the rapid metabolism of the tracer in vivo. To optimize FES PET imaging studies and to provide an input function for the quantitative analysis of the tracer FES uptake in breast tumors, we studied the clearance and metabolism of FES in 15 breast cancer patients. FES clearance, protein binding, and metabolite production a ...
Breast cancer survivors (BCSs) often suffer from menopausal symptoms induced by systemic treatments, with a consequent negative effect on quality of life. Since the introduction of aromatase inhibitors as the standard therapy for hormone-dependent tumors, genitourinary syndrome of menopause (GSM) has become a main problem for BCSs. This new terminology refers to the wide range of vaginal and urinary symptoms related to menopause, which can be relieved by estrogen therapy. Unfortunately, systemic ...
Five catechol estrogens and two 2-methoxyestrogens were compared for their relative affinity of binding to hypothalamic, pituitary, and uterine cytosol estrogen receptors; and for the kinetics of the catechols' methylation by hepatic catechol-0-methyltransferase. All of the catechol estrogens tested have similar Km's for 0-methylation (9-14 muM). Estrogen receptor affinities, however, differ widely. In hypothalamus, for example, where estradiol-17 beta has a Kd of 0.039 +/- 0.008 nanomolar, 4-hy ...
Aromatase is a particularly attractive target in the treatment of estrogen receptor positive breast cancer. Aromatase levels in breast cancer cells are enhanced by prostaglandins and reduced by COX inhibitors. The synthesis and biological evaluation of a novel series of sulfonanilide analogues derived from the COX-2 selective inhibitor NS-398 are described. The compounds suppress aromatase enzyme activity in SK-BR-3 breast cancer cells in a dose- and time-dependent manner. The effect of these co ...
Longitudinal bone growth occurs in the growth plate through a process called endochondral bone formation, a process where resting zone chondrocytes are recruited to start active proliferation and then undergo differentiation, followed by apoptosis and later mineralization. The balance between proliferation and differentiation is a crucial regulatory step controlled by various growth factors/hormones acting in both endocrine and paracrine/autocrine ways. From studies of individuals with aromatase ...
Pituitary and corpus luteum hormone patterns throughout the elephant estrous cycle have been well characterized. By contrast, analysis of follicular maturation by measurement of circulating estrogens has been uninformative. This study tested the ability of a urinary estradiol-3-glucuronide radioimmunoassay to noninvasively assess follicular development during the nonluteal phase of the elephant estrous cycle, and to determine the relationship between estrogen production and the ‘‘double LH s ...
Twenty-six patients, meeting strict criteria for primary peritoneal serous papillary carcinoma (PPSPC), were matched to 22 patients with ovarian serous papillary cancer (OSPC) for age and stage. Immunohistochemistry was used to determine the status of estrogen receptors (ER), progesterone receptors (PR), the expression of cell proliferation marker Ki-67, and the overexpression of HER-2/neu and p53 protein. Of the PPSPCs, 53.8% were poorly differentiated, as were 18.2% of the OSPCs (p = 0.012). P ...
OBJECTIVE To identify those women who might benefit from oestrogen replacement after hysterectomy. DESIGN Targeted health screening. SETTING Large group practice. SUBJECTS All women aged under 50 who had had a hysterectomy. MAIN OUTCOME MEASURES Concentration of follicle stimulating hormone, symptom profile, uptake of oestrogen replacement therapy. RESULTS 145 of 1953 women aged 32-49 had had a hysterectomy. 35 of the 41 with bilateral oophorectomy and 27 of 104 with one or more ovarie ...
Following menopause, body fat is redistributed from peripheral to central depots. This may be linked to the age related decrease in estrogen levels. We hypothesized that estrogen supplementation could counteract this fat redistribution through tissue-specific modulation of glucocorticoid exposure. We measured fat depot masses and the expression and activity of the glucocorticoid-activating enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) in fat and liver of ovariectomized female ra ...
To understand the changes of serum levels of sex steroids in the wild Japanese eel Anguilla japonica during silvering process, eels collected from the Kaoping River of Taiwan from August 2000 through June 2001 were examined. The maturational stages of female eels before and during silvering were divided into four stages: juvenile, sub-adult, pre-silver and silver stages based on skin coloration and oocyte diameter. Male eels were investigated only in the silver stage. Radioimmunoassays were empl ...
Gonadal steroids modulate CNS plasticity, including phrenic long-term facilitation (pLTF), a form of spinal respiratory neuroplasticity resulting in increased phrenic nerve motor output following exposure to acute intermittent hypoxia (aIH; three 5 min episodes, 10.5% O2). Despite the importance of respiratory system neuroplasticity, and its dependence on estrogen in males, little is known about pLTF expression or mechanisms of estrogen signaling in females. Here, we tested the hypotheses that ( ...
The action of aminoglutethimide in alleviating bone pain in women with metastatic breast cancer may be due to either an inherent analgesic effect or an interaction with other analgesic drugs. These possibilities have been investigated in mice by conventional antinociceptive tests. In the abdominal constriction test, aminoglutethimide alone had a dose-related antinociceptive activity. A low dose (which had no pharmacological activity) when co-administered with an effective sub-maximal dose of the ...
LNCaP cells represent a useful tool to explore the mechanism of sex hormone action on cell proliferation in an "in culture-in animal" model. Results indicated that: (a) these cells were inhibited from proliferating for extended periods (up to 30 days) when placed in charcoal-dextranstripped sera; they remained, however, viable because they proliferated when sex hormones were added to this medium; (b) the inhibitory effect of sera was reversed by the addition of Sa-dihydrotestosterone at 3 x I0~" ...
BACKGROUND Functional hypothalamic amenorrhea (FHA) refers to a functional menstrual disorder with various causes and presentations. Recovery of menstrual cyclicity is common in long-term follow-up but the affecting factors remain unknown. AIM To explore factors affecting the menstrual resumption and to evaluate the pituitary response to gonadotropin-releasing hormone (GnRH) in FHA. MATERIALS AND METHODS Thirty cases with FHA were recruited. All subjects were put on continuous 1 mg/day estra ...
At the moment, there is no clear molecular explanation for the steeper decline in muscle performance after menopause or the mechanisms of counteractive treatments. The goal of this genome-wide study was to identify the genes and gene clusters through which power training (PT) comprising jumping activities or estrogen containing hormone replacement therapy (HRT) may affect skeletal muscle properties after menopause. We used musculus vastus lateralis samples from early stage postmenopausal (50–5 ...
The direct role of estradiol and progesterone in sensitizing the adenohypophysis to the releasing action of LHRH (luteinizing hormone-releasing hormone) has been examined in rats bearing pituitary homografts. Groups (10-14/group) of virgin female rats (CDF) strain) were hypophysectomized, ovariectomized, and pituitaries obtained from long-term ovariectomized donors were implanted under the kidney capsule. The animals were treated on the sixth day after transplantation with sesame oil vehicle, es ...
Pachychoroid pigment epitheliopathy (PPE) is considered to be a forme fruste of central serous chorioretinopathy. Tamoxifen (Soltamax; Midatech Pharma, Raleigh, NC) has an anti-estrogenic effect on cytoplasmic estrogen receptors. Serum total testosterone, cortisol, and cortisone levels increase during tamoxifen therapy. Tamoxifen may cause hormone disturbance leading to the development of disorders in the pachychoroid spectrum. The authors present two cases of PPE associated with tamoxifen thera ...
The effects of percutaneous estradiol-17 beta 3 mg daily on the postmenopausal endometrium were quantified by morphometric analysis during 6 months of cyclic replacement therapy. A marked cellular response was recorded, together with increased serum levels of estradiol-17 beta and a satisfactory therapeutic effect. Glandular epithelial cells and nuclei proved to be the most sensitive markers for the estrogenic effect, with profile areas increasing 80% and 65% respectively, whereas stromal cell n ...
The present study aimed to investigate the potential role of leptin in the progression of breast cancer and the associated cell proliferation signalling pathway(s). A total of 44 female patients diagnosed with breast cancer and 24 healthy donors from Ain Shams University Hospitals (Cairo, Egypt) were enrolled in the present study. The present study assessed leptin expression in breast cancer tissues at the gene and protein level using reverse transcription-quantitative polymerase chain reaction ...
Estrogens act in brain to profoundly influence neurogenesis, sexual differentiation, neuroprotection, cognition, energy homeostasis, and female reproductive behavior and physiology through a variety of mechanisms, including the induction of progestin receptors (PRs). PRs are expressed as two isoforms, PR-A and PR-B, that have distinct functions in physiology and behavior. Because these PR isoforms cannot be distinguished using cellular resolution techniques, the present study used isoform-specif ...
We have recently identified nip-2 as a gene target for 17beta-oestradiol activity in the neuroblastoma SK-ER3 cells expressing the oestrogen receptor (ER) alpha. Here we show 17beta-oestradiol treatment of neuroblastoma and rat embryo neurones in culture blocks the increase in nip-2 mRNA induced by apoptotic stimuli and prevents cell death as indicated by cell counting, 3,(4,5-dimethylthiazol-2-yl)2,5-diphenil-tetrazoliumbromi de and DNA fragmentation assays. Neither of these effects are observe ...
In the purpose of establishing if the antiestrogens may inhib the protective effects of the estrogens during an experimental infection with Schistosoma mansoni in golden female hamster, we have studied the following estrogen-anti-estrogen associations: 17 beta-estradiol + trans-tamoxifène, 17 beta-estradiol + trans-clomifène, hexestrol + trans-tamoxifène. The decrease of the number of worms in the animals under experiment shows that these associations still give a protective effect. This prot ...
Osteoporosis is an age-related disorder that affects both women and men, although estrogen deficiency induced by menopause accelerates bone loss in older women. As the demographic shifts to a more aged population, a growing number of men and women will be afflicted with osteoporosis. Since the current drug therapies available have multiple side effects, including increased risk of developing certain types of cancer or complications, a search for potential nonpharmacologic alternative therapies f ...
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  • Nature Clinical Practice Endocrinology &Metabolism
  • 2007
Most cortisol that circulates in the blood is bound to proteins such as cortisol-binding globulin (CBG). Direct measurement of the ‘free’ (biologically active) form in the serum is difficult, but salivary cortisol levels are relatively easy to determine and are a marker of blood free cortisol levels. Oral estrogen preparations are known to increase CBG levels, thereby increasing total blood cortisol levels. As well as the potential physiological consequences of this, the increased cortisol a ...