Evidence that disease due to the thermally dimorphic fungus Paracoccidioides brasiliensis occurs post-puberty predominantly in males led us to hypothesize that hormonal factors critically affect its pathogenesis. We show here that estrogens inhibit mycelial- to yeast-form transformation of P. brasiliensis in vitro. Transformation of three isolates was inhibited to 71, 33, and 19% of the control...

The therapeutic use of estrogens has been associated with an increased risk of some of the most predominant, as well as less prevalent, cancers in women. The estrogen-induced renal tumor is one of the primary animal models to evaluate the carcinogenic properties of estrogens. Correlations were made with various estrogens by using parameters of estrogenicity end points such as competitive bindin...

We previously reported that 17 beta-estradiol inhibits cytokine-stimulated bioassayable IL-6 and the steady-state level of IL-6 mRNA. To determine the molecular basis of this effect, the transient expression of chloramphenicol acetyltransferase (CAT) reporter plasmid driven by the human IL-6 promoter was studied here in HeLa or murine bone marrow stromal cells (MBA 13.2). 17 beta-estradiol (10(...

A time-resolved fluoroimmunoassay (TR-FIA) for unconjugated estrogens in human urine is described. 6-Keto-17 beta-estradiol-6-(O-carboxymethyl)oxime:bovine serum albumin is immobilized onto microtiter strip wells and the coated wells are incubated with 17 beta-estradiol standard preparations or unknowns with a polyclonal antiserum to 17 beta-estradiol-16,17-monosuccinyl:albumin. The antiserum-b...

A single transient dose of estradiol-17 beta is sufficient to elicit the permanent induction of hepatic estrogen receptor mRNA, which is induced 18-fold (from 0.13 to 2.4 molecules per cell) and then remains fully induced for at least 125 days. In primary liver cultures, extremely low concentrations of estradiol-17 beta, which are below the Kd of the Xenopus laevis estrogen receptor, maintain p...

One minute after instillation of 14C-estradiol-17 beta (14C-E2 17 beta) into selected sections of the gastrointestinal tract of swine, radioactive estradiol metabolites were present in blood collected from the portal and jugular veins. Ether was used to extract free but not conjugated estrogens. The percentage of plasma radioactivity that was ether extractable (EE) was low in portal plasma and ...

Mammary carcinoma induced in male Sprague-Dawley rats by multiple intragastric intubations of 7,12-dimethylbenz-(a)anthracene showed ovary-independent growth but contained estrogen receptors (ER) and progesterone receptors (Yoshida, Yoshida. Fukunishi, Sato, Okamoto, and Matsumoto, Cancer Res., 42: 2434-2439, 1982). Transplantable carcinoma (MT6) was obtained from dimethylbenz(a)anthracene-indu...

Natural estrogens and their derivatives comprising 30 compounds in total were tested for their ability to induce microtubule disruption in Chinese hamster V79 cells. The cytoplasmic microtubule networks were examined by the indirect immunofluorescence method using anti-beta-tubulin antibody. The effective concentrations of 17 beta-estradiol (E2-17 beta) and 17 alpha-estradiol required for the i...