Temporal changes in cervical mucus after insertion of the levonorgestrel-releasing intrauterine system.

Background: The major contraceptive action of the levonorgestrel-releasing intrauterine system (LNG-IUS) is cervical mucus (CM) thickening, which prevents sperm penetration. No study to date has examined the temporal relationship between the insertion of the LNG-IUS and changes in CM quality and sperm penetration.

Study Design: Participants were enrolled in a clinically descriptive study to compare the quality of CM and three parameters of sperm penetration prior to insertion of the LNG-IUS and on Days 1, 3 and 5 after insertion.

Sex steroid hormone levels in breast adipose tissue and serum in postmenopausal women.

Elevated levels of circulating estrogens and androgens are linked to higher breast cancer risk among postmenopausal women; however, little is known about hormone levels within the breast. Hormone concentrations within the breast may not be reflected in the blood and are likely important contributors to breast carcinogenesis. We used a previously validated method to measure levels of estrone, estradiol, androstenedione, and testosterone in adipose tissue removed as part of breast excisions performed for cancer in 100 postmenopausal women (69 ER/PR +/+ and 31 ER/PR -/-) participating in a breast cancer case-control study.

Estrogen levels in nipple aspirate fluid and serum during a randomized soy trial.

Background: On the basis of hypothesized protective effect, we examined the effect of soy foods on estrogens in nipple aspirate fluid (NAF) and serum, possible indicators of breast cancer risk.

Methods: In a crossover design, we randomized 96 women who produced 10 μL or more NAF to a high- or low-soy diet for 6 months. During the high-soy diet, participants consumed 2 soy servings of soy milk, tofu, or soy nuts (∼50 mg of isoflavones per day); during the low-soy diet, they maintained their usual diet.

Sex differences in β-amyloid accumulation in 3xTg-AD mice: role of neonatal sex steroid hormone exposure.

The risk of Alzheimer's disease (AD) is higher in women than in men, a sex difference that likely results from the effects of sex steroid hormones. To investigate this relationship, we first compared progression of β-amyloid (Aβ) pathology in male and female triple transgenic (3xTg-AD) mice. We found that female 3xTg-AD mice exhibit significantly greater Aβ burden and larger behavioral deficits than age-matched males.

Measurement of sex steroid hormones in breast adipocytes: methods and implications.

Background: The lack of validated methods for measuring sex steroid hormones in breast tissue has limited our knowledge of their role in the development of breast cancer. We explored the feasibility of measuring hormones in breast adipocytes for epidemiologic and clinical studies by refining an existing assay procedure and assessing the reliability of hormone measurements using the modified assay. This report presents the reproducibility of measurements of androstenedione (A), testosterone (T), estrone (E(1)), and estradiol (E(2)), using breast adipose tissue samples obtained from women undergoing surgical resection for a variety of pathologic conditions.

Formation of ethinyl estradiol in women during treatment with norethindrone acetate.

Context: The significance of the conversion of norethindrone acetate (NET-A), a commonly prescribed, synthetic, oral progestogen, to ethinyl estradiol (EE(2)) is controversial.

Objective: We sought to determine accurately the extent to which NET-A may be converted to EE(2), and if so, whether circulating levels of EE(2) would be of clinical significance. DESIGN, SUBJECTS, AND INTERVENTIONS: We administered NET-A 10, 20, or 40 mg once daily for 7 d to 20 regularly menstruating premenopausal women and measured NET-A and EE(2) levels before drug intake; at 1, 2, 4, 8, and 24 h after the first dose; and 2 h after the seventh dose.

Locus-wide chromatin remodeling and enhanced androgen receptor-mediated transcription in recurrent prostate tumor cells.

Prostate cancers (PCas) become resistant to hormone withdrawal through increased androgen receptor (AR) signaling. Here we show increased AR-mediated transcription efficiency in PCa cells that have acquired the ability to grow in low concentrations of androgen. Compared to androgen-dependent PCa cells, these cells showed increased activity of transiently transfected reporters and increased mRNA synthesis relative to levels of AR occupancy of the prostate-specific antigen (PSA) gene.

Long-term, low-dose lead exposure alters the gonadotropin-releasing hormone system in the male rat.

Lead is a male reproductive toxicant. Data suggest that rats dosed with relatively high levels of lead acetate for short periods of time induced changes in the hypothalamic gonadotropin-releasing hormone (GnRH) at the molecular level, but these changes were attenuated with increased concentration of exposure. The current study evaluated whether exposure to low levels of lead acetate over longer periods of time would produce a similar pattern of adaptation to toxicity at the molecular and biologic levels.

Urinary 2-hydroxyestrone/16alpha-hydroxyestrone ratio and family history of breast cancer in premenopausal women.

It has been hypothesized that the ratio of urinary 2-hydroxyestrone to 16alpha-hydroxyestrone (2-OHE1/16alpha-OHE1 represents a biomarker for breast cancer risk; the lower the ratio the higher the risk. We obtained early morning urine samples from 70 'high risk' premenopausal women who had a first degree family history of breast cancer and 27 'low risk' women with no such history. Five estrogen metabolites in urine were determined: 2-OHE1, 16alpha-OHE1, estrone (E1), estradiol (E2), and estriol (E3) conjugates.