Search results for "Antiestrogen"
showing 10 items of 18 documents
Treatment of idiopathic oligozoospermia with tamoxifen--a randomized controlled study.
1992
There is no conclusive evidence of the usefulness of tamoxifen in the treatment of idiopathic oligozoospermia (OAT-syndrome), as it has been used mostly in uncontrolled studies. We herein report on the controlled treatment of OAT-syndrome with tamoxifen versus placebo following a randomized design. Seventy-six men with sperm counts of 2-20 x 10(6) ml-1, sperm motility of 20-50%, and sperm morphology (abnormal cells) between 50 and 80% were involved in the study. Patients with varicocele, a history of testicular maldescent or genital inflammation were excluded. Thirty-nine patients received tamoxifen (30 mg daily), 37 patients placebo. There was a statistically significant increase in the me…
Pharmacokinetics of Droloxifene and Its Metabolites in Breast Cancer Patients
1991
Pharmacokinetics and metabolism of droloxifene, a new antiestrogenic drug, have been investigated by single- and multiple-dose studies in postmenopausal patients with advanced breast cancer. Short terminal elimination half-life, low accumulation, and improved drug tolerability are the most striking features of this safe and effective new antiestrogen. Bioequivalence of film-coated tablet, tablet, and standard solution of droloxifene has been shown. The concentrations of droloxifene and its metabolites have been determined by a highly selective HPLC method.
Acute abdomen due to endometriosis in a premenopausal woman taking tamoxifen.
2003
Tamoxifen exhibits agonistic properties on the uterus. We describe a premenopausal woman who, while having tamoxifen due to a diagnosis of in situ ductal carcinoma, developed endometriosis requiring surgery.
CtIP silencing as a novel mechanism of tamoxifen resistance in breast cancer.
2007
AbstractAcquired resistance to the antiestrogen tamoxifen constitutes a major clinical challenge in breast cancer therapy. However, the mechanisms involved are still poorly understood. Using serial analysis of gene expression, we identified CtIP, a BRCA1- and CtBP-interacting protein, as one of the most significantly down-regulated transcripts in estrogen receptor α–positive (ER+) MCF-7 tamoxifen-resistant breast cancer cells. We further confirmed the association of CtIP down-regulation with tamoxifen resistance in an additional ER+ breast cancer line (T47D), strengthening the relevance of the phenomenon observed. In additional studies, we found CtIP protein expression in a majority of ER+ …
Does tamoxifen change oestrogen and progesterone receptor expression in the endometrium and breast?
2000
We studied the expression of oestrogen and progesterone receptors (ER, PR) in postmenopausal women receiving tamoxifen for breast cancer. In addition the literature addressing the question of ER and PR expression in breast tissue during treatment with tamoxifen was reviewed. We demonstrated consistent expression of ER and PR in endometria from patients receiving tamoxifen, with a trend towards a higher proportion of receptor positive specimens during tamoxifen. In breast cancer tissue, the ER content seemed to be reduced following tamoxifen treatment. After short time exposure to tamoxifen, the PR appeared to be increased, longer treatment caused the PR to go down to pretreatment levels or …
Nuclear insulin receptor substrate 1 interacts with estrogen receptor alpha at ERE promoters.
2004
Insulin receptor substrate 1 (IRS-1) is a major signaling molecule activated by the insulin and insulin-like growth factor I receptors. Recent data obtained in different cell models suggested that in addition to its conventional role as a cytoplasmic signal transducer, IRS-1 has a function in the nuclear compartment. However, the role of nuclear IRS-1 in breast cancer has never been addressed. Here we report that in estrogen receptor alpha (ERalpha)-positive MCF-7 cells, (1) a fraction of IRS-1 was translocated to the nucleus upon 17-beta-estradiol (E2) treatment; (2) E2-dependent nuclear translocation of IRS-1 was blocked with the antiestrogen ICI 182,780; (3) nuclear IRS-1 colocalized and…
Droloxifene-Induced Spikes of Tumor Markers Predict Benefit of Therapy
1991
In the clinical monitoring of cancer, tumor marker proteins may reflect the status of the disease. In cases with radio- and chemotherapy, spikes of tumor markers were found shortly after starting the therapy. These spikes were interpreted as a sign of tumor lysis. Recently during therapy of breast cancer with the new antiestrogen droloxifene, spikes of CA 125 and CA 15-3 were also found in about one-third of patients responding to therapy. The peaks of these initial increases were recorded between 14 and 60 days after the onset of treatment, with maximum concentrations up to 1,890% of the initial value. Marker concentrations decreased thereafter, to new baselines at or below the initial val…
Solid lipid nanoparticles containing tamoxifen characterization and in vitro antitumoral activity.
2005
Solid lipid nanoparticles (SLNs) containing tamoxifen, a nons- teroidal antiestrogen used in breast cancer therapy, were prepared by microemulsion and precipitation techniques. Tamoxifen loaded SLNs seem to have dimensional properties useful for parenteral administration, and in vitro plasmatic drug release studies demon- strated that these systems are able to give a prolonged release of the drug in the intact form. Preliminary study of antiproliferative ac- tivity in vitro, carried out on MCF-7 cell line (human breast cancer cells), demonstrated that SLNs, containing tamoxifen showed an antitumoral activity comparable to free drug. The results of char- acterization studies and of in vitro …
Interspecies differences in cancer susceptibility and toxicity.
1999
One of the most complex challenges to the toxicologist represents extrapolation from laboratory animals to humans. In this article, we review interspecies differences in metabolism and toxicity of heterocyclic amines, aflatoxin B1, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and related compounds, endocrine disrupters, polycyclic aromatic hydrocarbons, tamoxifen, and digitoxin. As far as possible, extrapolations to human toxicity and carcinogenicity are performed. Humans may be more susceptible to the carcinogenic effect of heterocyclic amines than monkeys, rats, and mice. Especially, individuals with high CYP1A2 and 3A4 activities and the rapid acetylator phenotype may be expected to have …
Studies on effects of tamoxifen (ICI 46474) on agonistic encounters between pairs of intact mice.
1988
The anti-estrogen tamoxifen (Tam), which has been shown to dramatically suppress offensive behavior in male rats without markedly influencing other aspects of the social encounter, was tested for its effectiveness in mice. TO strain albino mice were given control injections or 50 or 100 micrograms of Tam for 4 or 8 days. Subsequently, mice were tested in pairs (for a particular dose and treatment duration) in which both animals received Tam, one animal received Tam and one saline, or both animals received saline control injections. Ten-minute videotaped encounters were analyzed in terms of total times allocated to nonsocial investigation, social investigation, offense, defense, sexual activ…