Steroid hormones affect sex determination in a variety of vertebrates. The feminizing effects of exposure to estradiol and the masculinizing effects of aromatase inhibition during development are well established in a broad range of vertebrate taxa, but paradoxical findings are occasionally reported. Four independent experiments were conducted on two turtle species with temperature-dependent se...

The effect of exemestane (6-methylenandrosta-1,4-diene-3,17-dione) 25 mg p.o. once daily on in vivo aromatization was studied in 10 postmenopausal women with advanced breast cancer. Aromatization was determined before treatment and after 6-8 weeks on therapy by administering a bolus injection of [3H]androstenedione (500 microCi) and [14C]estrone (5 microCi) followed by measurement of the isotop...

Though aromatase inhibitors (AIs) are an essential part of estrogen receptor-positive (ER+) breast cancer therapy, many patients discontinue the medicine before their adjuvant therapy is completed because of the arthralgia which often accompanies the medicine. Up to half of women on AI therapy experience joint pain, and up to 20% will become non-compliant with the medicine because of the joint ...

Stroke risk and outcome are strongly modified by estrogen. In addition to ovaries, estrogen is produced locally in peripheral tissue by the enzyme aromatase, and extragonadal synthesis becomes the major source of estrogen after menopause. Aromatase gene deletion in female mice exacerbates ischemic brain damage after stroke. However, it is not clear which cell type is responsible for this effect...

PURPOSE To optimize treatment strategies for postmenopausal breast cancer patients, we investigated the efficacy of the steroidal aromatase inhibitor exemestane alone or in combination with the antiestrogen tamoxifen in a xenograft model of postmenopausal breast cancer. We also determined the effects of these agents in sequential second-line therapy and the effect of the nonsteroidal aromatase ...

INTRODUCTION Eruptive keloids are rarely described in the literature and are typically reported in association with a systemic disease. Because reports of eruptive keloids are sparse, the pathophysiology of eruptive keloids remains to be clearly explained. We report a case of a 77-year-old woman who had extensive eruptive keloids while taking letrozole for hormone receptorepositive infiltrating...

The murine Leydig cell tumor (M5480A) possesses high levels of estrogen receptor and is known to produce estrogens. In these studies we examined the effects of the potent aromatase inhibitor 4-hydroxyandrostenedione (4-OHA) on Leydig tumor cell steroidogenesis both in vitro and in vivo. The addition of 4-OHA to Leydig tumor cells in primary culture resulted in a dose- and a time-dependent decre...

Aromatase, catalyzing final step of estrogen biosynthesis, is considered a key target for the development of drug against estrogen-dependent breast cancer (EDBC). Identification and development of naturally occurring compounds, such as flavonoids, as drugs against EDBC is in demand due to their lesser toxicity when compared to those of synthetic ones. Thus, a three-dimensional quantitative stru...

4-Hydroxyandrostenedione (4-OHA) is a more potent and specific inhibitor of aromatase (estrogen synthetase) than aminoglutethimide (AG). The two inhibitors were compared in rats with 7,12-dimethylbenz(a)anthracene-induced, hormone-dependent tumors and in normal cyclic rats treated for 4 and 2 weeks, respectively. Ovarian estradiol levels and aromatase activities were not consistently reduced, a...