Sample records for auger-electron emitting estrogen

  1. Therapy of estrogen receptor-positive micrometastases in the peritoneal cavity with Auger electron-emitting estrogens--Theoretical and practical considerations

    Energy Technology Data Exchange (ETDEWEB)

    DeSombre, E.R.; Hughes, A.; Hanson, R.N.; Kearney, T. [Univ. of Chicago, IL (United States). Ben May Inst. for Cancer Research


    Previous studies have demonstrated that Auger electron-emitting estrogens, when associated with the estrogen receptor (ER), can effect breaks in DNA and ER-dependent radiotoxicity. To evaluate the potential of {sup 123}I-iodoestrogens, ({sup 123}I-IE) to treat ER-positive human cancer cells, we have studied the effect of incubation of {sup 123}I-IE with ER-positive MCF-7 breast cancer cells on cell survival in vitro and found that subnanomolar concentrations of {sup 123}I-IE effectively reduce survival, with a mean lethal dose of about 800 decays per cell. MCF-7 cells incubated 30 min with 2 nM {sup 123}I-IE (13 MBq/ml) showed a 2 log reduction in the ability to form tumors in immunodeficient mice. Evaluation of a mathematical model for {sup 123}I-IE therapy for intraperitoneal micrometastases in vivo in the mouse, based on variables related to the (a) specific activity of {sup 123}I-IE; (b) its affinity for ER; (c) the characteristics of the uptake and retention of {sup 123}I-IE by the target cells; (d) the concentration of ER in the tumor cells and (e) the tumor weight suggest that such therapy may be feasible.

  2. Accelerator based production of auger-electron-emitting isotopes for radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thisgaard, H.


    In this research project the focus has been on the identification and production of new, unconventional Auger-electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry calculations on the subcellular level, the Auger-emitter 119Sb has been identified as a potent candidate for therapy. The corresponding imaging analogue 117Sb has been shown from planar scintigraphy and single-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb-labeled radiopharmaceutical. The production method of these radioisotopes has been developed using a low-energy cyclotron via the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function for the former reaction. Moreover, a new high-yield radiochemical separation method has been developed to allow the subsequent separation of the produced 119Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron, two new 'High Power' cyclotron targets were developed in this study. The target development was primarily based on theoretical thermal modeling calculations using finite-element-analysis software. With these targets, I have shown that it will be possible to produce several tens of GBq of therapeutics isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able to experimentally evaluate and compare the potency of the new and unconventional Auger-emitters (e.g. 119Sb). However, due to experimental complications, the development

  3. Investigation of production routes for the 161Ho Auger-electron emitting radiolanthanide, a candidate for therapy

    CERN Document Server

    Tárkányi, F; Hermanne, A; Takács, S; Ignatyuk, A V


    The radiolanthanide 161Ho (2.48 h) is a promising Auger-electron emitter for internal radiotherapy that can be produced with particle accelerators. The excitation functions of the natDy(p,xn)161Ho and natDy(d,x)161Ho reactions were measured up to 40 and 50 MeV respectively by using the stacked foil activation method and gamma-ray spectrometry. The experimental data were compared with results of the TALYS code available in the TENDL 2011 library [1]. The main parameters of different production routes are discussed.

  4. ¹¹¹In-Bn-DTPA-nimotuzumab with/without modification with nuclear translocation sequence (NLS) peptides: an Auger electron-emitting radioimmunotherapeutic agent for EGFR-positive and trastuzumab (Herceptin)-resistant breast cancer. (United States)

    Fasih, Aisha; Fonge, Humphrey; Cai, Zhongli; Leyton, Jeffrey V; Tikhomirov, Ilia; Done, Susan J; Reilly, Raymond M


    Increased expression of epidermal growth factor receptors (EGFR) in breast cancer (BC) is often associated with trastuzumab (Herceptin)-resistant forms of the disease and represents an attractive target for novel therapies. Nimotuzumab is a humanized IgG(1) monoclonal antibody that is in clinical trials for treatment of EGFR-overexpressing malignancies. We show here that nimotuzumab derivatized with benzylisothiocyanate diethylenetriaminepentaacetic acid for labelling with the subcellular range Auger electron-emitter, (111)In and modified with nuclear translocation sequence (NLS) peptides ((111)In-NLS-Bn-DTPA-nimotuzumab) was bound, internalized and transported to the nucleus of EGFR-positive BC cells. Emission of Auger electrons in close proximity to the nucleus caused multiple DNA double-strand breaks which diminished the clonogenic survival (CS) of MDA-MB-468 cells that have high EGFR density (2.4 × 10(6) receptors/cell) to less than 3 %. (111)In-Bn-DTPA-nimotuzumab without NLS peptide modification was sevenfold less effective for killing MDA-MB-468 cells. (111)In-Bn-DTPA-nimotuzumab with/without NLS peptide modification were equivalently cytotoxic to MDA-MB-231 and TrR1 BC cells that have moderate EGFR density (5.4 × 10(5) or 4.2 × 10(5) receptors/cell, respectively) reducing their CS by twofold. MDA-MB-231 cells have intrinsic trastuzumab resistance due to low HER2 density, whereas TrR1 cells have acquired resistance despite HER2 overexpression. Biodistribution and microSPECT/CT imaging revealed that (111)In-NLS-Bn-DTPA-nimotuzumab exhibited more rapid elimination from the blood and lower tumour uptake than (111)In-Bn-DTPA-nimotuzumab. Tumour uptake of the radioimmunoconjugates in mice with MDA-MB-468 xenografts was high (8-16 % injected dose/g) and was blocked by administration of an excess of unlabelled nimotuzumab, demonstrating EGFR specificity. We conclude that (111)In-Bn-DTPA-nimotuzumab with/without NLS peptide modification are promising Auger

  5. Validation of 64Cu-ATSM damaging DNA via high-LET Auger electron emission (United States)

    McMillan, Dayton D.; Maeda, Junko; Bell, Justin J.; Genet, Matthew D.; Phoonswadi, Garrett; Mann, Kelly A.; Kraft, Susan L.; Kitamura, Hisashi; Fujimori, Akira; Yoshii, Yukie; Furukawa, Takako; Fujibayashi, Yasuhisa; Kato, Takamitsu A.


    Radioactive copper (II) (diacetyl-bis N4-methylthiosemicarbazone) (Cu-ATSM) isotopes were originally developed for the imaging of hypoxia in tumors. Because the decay of a 64Cu atom is emitting not only positrons but also Auger electrons, this radionuclide has great potential as a theranostic agent. However, the success of 64Cu-ATSM internal radiation therapy would depend on the contribution of Auger electrons to tumor cell killing. Therefore, we designed a cell culture system to define the contributions to cell death from Auger electrons to support or refute our hypothesis that the majority of cell death from 64Cu-ATSM is a result of high-LET Auger electrons and not positrons or other low-LET radiation. Chinese hamster ovary (CHO) wild type and DNA repair–deficient xrs5 cells were exposed to 64Cu-ATSM during hypoxic conditions. Surviving fractions were compared with those surviving gamma-radiation, low-LET hadron radiation, and high-LET heavy ion exposure. The ratio of the D10 values (doses required to achieve 10% cell survival) between CHO wild type and xrs5 cells suggested that 64Cu-ATSM toxicity is similar to that of high-LET Carbon ion radiation (70 keV/μm). γH2AX foci assays confirmed DNA double-strand breaks and cluster damage by high-LET Auger electrons from 64Cu decay, and complex types of chromosomal aberrations typical of high-LET radiation were observed after 64Cu-ATSM exposure. The majority of cell death was caused by high-LET radiation. This work provides strong evidence that 64Cu-ATSM damages DNA via high-LET Auger electrons, supporting further study and consideration of 64Cu-ATSM as a cancer treatment modality for hypoxic tumors. PMID:26251463

  6. Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Rezaee, Mohammad, E-mail:; Hunting, Darel J.; Sanche, Léon [Groupe en Sciences des Radiations, Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4 (Canada)


    Purpose: The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods: Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by{sup 125}I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results: For a single decay of{sup 125}I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm{sup 3} volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions: Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should

  7. Production of no carrier added 80mBr for investigation of Auger electron toxicity. (United States)

    Mease, R C; DeJesus, O T; Gatley, S J; Harper, P V; Desombre, E R; Friedman, A M


    80mBr (half-life = 4.43 h) is an Auger electron emitting nuclide with convenient properties for investigating Auger electron cytotoxicity and with potential for labeling in vivo radiotherapeutic agents. We have investigated three cyclotron target systems capable of generating 80mBr of sufficiently high specific radioactivity (no carrier added) for biomedical experiments. A 83Kr gas target irradiated with 21.5 MeV deuterons made 80mBr at a production yield of 1.6 +/- 0.2 mCi/muAh at saturation. A five-fold increase in 80mBr yield was obtained from 15 MeV proton irradiation of thin elemental Se enriched in 80Se targets although technical improvements are expected to further raise this production yield. This route is therefore superior for current medical cyclotrons. Irradiation of a reusable 80Se copper selenide target also yielded multi-millicurie amounts of 80mBr, and recovery of radiobromine by dry distillation is faster and more convenient than in the elemental Se target, but an optimum copper selenide target for 80mBr production has not yet been built.

  8. Kinetic energies to analyze the experimental auger electron spectra by density functional theory calculations (United States)

    Endo, Kazunaka


    In the Auger electron spectra (AES) simulations, we define theoretical modified kinetic energies of AES in the density functional theory (DFT) calculations. The modified kinetic energies correspond to two final-state holes at the ground state and at the transition-state in DFT calculations, respectively. This method is applied to simulate Auger electron spectra (AES) of 2nd periodic atom (Li, Be, B, C, N, O, F)-involving substances (LiF, beryllium, boron, graphite, GaN, SiO2, PTFE) by deMon DFT calculations using the model molecules of the unit cell. Experimental KVV (valence band electrons can fill K-shell core holes or be emitted during KVV-type transitions) AES of the (Li, O) atoms in the substances agree considerably well with simulation of AES obtained with the maximum kinetic energies of the atoms, while, for AES of LiF, and PTFE substance, the experimental F KVV AES is almost in accordance with the spectra from the transitionstate kinetic energy calculations.

  9. Block copolymer micelles target Auger electron radiotherapy to the nucleus of HER2-positive breast cancer cells. (United States)

    Hoang, Bryan; Reilly, Raymond M; Allen, Christine


    Intracellular trafficking of Auger electron emitting radionuclides to perinuclear and nuclear regions of cells is critical to realizing their full therapeutic potential. In the present study, block copolymer micelles (BCMs) were labeled with the Auger electron emitter indium-111 ((111)In) and loaded with the radiosensitizer methotrexate. HER2 specific antibodies (trastuzumab fab) and nuclear localization signal (NLS; CGYGPKKKRKVGG) peptides were conjugated to the surface of the BCMs to direct uptake in HER2 expressing cells and subsequent localization in the cell nucleus. Cell uptake and intracellular distribution of the multifunctional BCMs were evaluated in a panel of breast cancer cell lines with different levels of HER2 expression. Indeed cell uptake was found to be HER2 density dependent, confirming receptor-mediated internalization of the BCMs. Importantly, conjugation of NLS peptides to the surface of BCMs was found to result in a significant increase in nuclear uptake of the radionuclide (111)In. Successful nuclear targeting was shown to improve the antipoliferative effect of the Auger electrons as measured by clonogenic assays. In addition, a significant radiation enhancement effect was observed by concurrent delivery of low-dose MTX and (111)In in all breast cancer cell lines evaluated.

  10. Inner-shell ionization of rotating linear molecules in the presence of spin-dependent interactions: Entanglement between a photoelectron and an auger electron (United States)

    Ghosh, R.; Chandra, N.; Parida, S.


    This paper reports results of a theoretical study of angle- and spin-resolved photo-Auger electron coincident spectroscopy in the form of entanglement between these two particles emitted from a linear molecule. First, we develop an expression for a density matrix needed for studying spin-entanglement between a photoelectron and an Auger electron. In order to properly represent the molecular symmetries, nuclear rotation, and the spin-dependent interactions (SDIs), we have used symmetry adapted wavefunctions in Hund’s coupling scheme (a) for all the species participating in this two-step process. This expression shows that spin-entanglement in a photo-Auger electron pair in the presence of SDIs very strongly depends upon, among other things, polarization of the ionizing radia- tion, directions of motion and of spin polarization of two ejected electrons, and the dynamics of photoionization and of Auger decay. We have applied this expression, as an example, to a generic linear molecule in its J0, M0 = 0 state. This model calculation clearly brings out the salient features of the spin-entanglement of a photo-Auger electron pair in the presence of the SDIs.

  11. Inner-shell ionization of rotating linear molecules in the presence of spin-dependent interactions: Entanglement between a photoelectron and an Auger electron

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, R.; Chandra, N.; Parida, S. [Indian Institute of Technology, Dept. of Physics and Meteorology, Kharagpur (India)


    This paper reports results of a theoretical study of angle- and spin-resolved photo-Auger electron coincident spectroscopy in the form of entanglement between these two particles emitted from a linear molecule. First, we develop an expression for a density matrix needed for studying spin-entanglement between a photoelectron and an Auger electron. In order to properly represent the molecular symmetries, nuclear rotation, and the spin-dependent interactions (SDIs), we have used symmetry adapted wavefunctions in Hund's coupling scheme (a) for all the species participating in this two-step process. This expression shows that spin-entanglement in a photo-Auger electron pair in the presence of SDIs very strongly depends upon, among other things, polarization of the ionizing radiation, directions of motion and of spin polarization of two ejected electrons, and the dynamics of photoionization and of Auger decay. We have applied this expression, as an example, to a generic linear molecule in its J{sub 0}, M{sub 0} = 0 state. This model calculation clearly brings out the salient features of the spin-entanglement of a photo-Auger electron pair in the presence of the SDIs. (authors)

  12. DNA and chromosome breaks induced by {sup 123}I-estrogen in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, J.L. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology]|[Univ. of Chicago, IL (United States). Dept. of Radiation and Cellular Oncology; Mustafi, R.; Hughes, A.; DeSombre, E.R. [Univ. of Chicago, IL (United States)


    The effects of the Auger electron-emitting isotope I-123, covalently bound to estrogen, on DNA single- and double-strand breakage and on chromosome breakage was determined in estrogen positive Chinese hamster ovary (CHO-ER) cells. Exposure to the {sup 123}I-estrogen induced both single- and double-strand breaks with a ratio of single- to double-strand breaks of 2.2. The corresponding ratio with {sup 60}Co gamma rays was 15.6. The dose-response was biphasic suggesting that either receptor sites are saturated at high does, or that there is a nonrandom distribution of breaks induced by the {sup 123}I-estrogen. The {sup 123}I-estrogen treatment induced chromosome aberrations with an efficiency of about 1 aberration for each 1,000 disintegrations per cell. This corresponds to the mean lethal dose of {sup 123}I-estrogen for these cells suggesting that the lethal event induced by the Auger electron emitter bound to estrogen is a chromosome aberration. Most of the chromosome-type aberrations were dicentrics and rings, suggesting that {sup 123}I-estrogen-induced chromosome breaks are rejoined. The F-ratio, the ratio of dicentrics to centric rings, was 5.8 {plus_minus} 1.7, which is similar to that seen with high LET radiations. Their results suggest that I-123 bound to estrogen is an efficient clastogenic agent, that the cytotoxic damage produced by I-123 bound to estrogen is very like high LET-induced damage, and the I-123 in the estrogen-receptor-DNA complex is probably in close proximity to the sugar-phosphate backbone of the DNA.

  13. Photoelectron spectroscopy and Auger electron spectroscopy of solids and surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, S.P.


    The use of photoelectron spectroscopy, primarily x-ray photoelectron spectroscopy, to obtain information on the electronic structure of a wide variety of solids (especially the bulk electronic structure of solids) is covered. Both valence band and core-level spectra, as well as a few cases of photon excited Auger electron spectroscopy, are employed in the investigations to derive information on N(E). The effect of several modulations inherent in the measured I(E)'s, such as final state band structure, cross section, and relaxation, is discussed. Examples of many-electron interactions in PES are given. Some experimental aspects of PES and AES studies are given with emphasis on sample preparation techniques. Multiple splitting of core levels is examined using the Mn levels in MnF/sub 2/ as a detailed case study. Core level splittings in transition metals, rare earth metals, transition metal halides and several alloys are also reported. The application of PES to the study of the chemical bond in some crystalline semiconductors and insulators, A/sup N/B/sup 8-N/ and A/sup N/B/sup 10-N/ compounds is treated, and a spectroscopic scale of ionicity for these compounds is developed from the measured ''s-band'' splitting in the valence band density of states. (GHT)

  14. Monte-Carlo simulation of backscattered electrons in Auger electron spectroscopy. Part 1: Backscattering factor calculation

    Energy Technology Data Exchange (ETDEWEB)

    Tholomier, M.; Vicario, E.; Doghmane, N.


    The contribution of backscattered electrons to Auger electrons yield was studied with a multiple scattering Monte-Carlo simulation. The Auger backscattering factor has been calculated in the 5 keV-60 keV energy range. The dependence of the Auger backscattering factor on the primary energy and the beam incidence angle were determined. Spatial distributions of backscattered electrons and Auger electrons are presented for a point incident beam. Correlations between these distributions are briefly investigated.

  15. Localized Irradiation of Cell Membrane by Auger Electrons Is Cytotoxic Through Oxidative Stress-Mediated Nontargeted Effects (United States)

    Paillas, Salomé; Ladjohounlou, Riad; Lozza, Catherine; Pichard, Alexandre; Boudousq, Vincent; Jarlier, Marta; Sevestre, Samuel; Le Blay, Marion; Deshayes, Emmanuel; Sosabowski, Jane; Chardès, Thierry; Navarro-Teulon, Isabelle; Mairs, Robert J.


    Abstract Aims: We investigated whether radiation-induced nontargeted effects are involved in the cytotoxic effects of anticell surface monoclonal antibodies labeled with Auger electron emitters, such as iodine 125 (monoclonal antibodies labeled with 125I [125I-mAbs]). Results: We showed that the cytotoxicity of 125I-mAbs targeting the cell membrane of p53+/+ HCT116 colon cancer cells is mainly due to nontargeted effects. Targeted and nontargeted cytotoxicities were inhibited in vitro following lipid raft disruption with Methyl-β-cyclodextrin (MBCD) or filipin or use of radical oxygen species scavengers. 125I-mAb efficacy was associated with acid sphingomyelinase activation and modulated through activation of the AKT, extracellular signal-related kinase ½ (ERK1/2), p38 kinase, c-Jun N-terminal kinase (JNK) signaling pathways, and also of phospholipase C-γ (PLC-γ), proline-rich tyrosine kinase 2 (PYK-2), and paxillin, involved in Ca2+ fluxes. Moreover, the nontargeted response induced by directing 5-[(125)I]iodo-2′-deoxyuridine to the nucleus was comparable to that of 125I-mAb against cell surface receptors. In vivo, we found that the statistical significance of tumor growth delay induced by 125I-mAb was removed after MBCD treatment and observed oxidative DNA damage beyond the expected Auger electron range. These results suggest the involvement of nontargeted effects in vivo also. Innovation: Low-energy Auger electrons, such as those emitted by 125I, have a short tissue range and are usually targeted to the nucleus to maximize their cytotoxicity. In this study, we show that targeting the cancer cell surface with 125I-mAbs produces a lipid raft-mediated nontargeted response that compensates for the inferior efficacy of non-nuclear targeting. Conclusion: Our findings describe the mechanisms involved in the efficacy of 125I-mAbs targeting the cancer cell surface. Antioxid. Redox Signal. 25, 467–484. PMID:27224059

  16. New approach for correction of distortions in spectral line profiles in Auger electron spectroscopy

    NARCIS (Netherlands)

    Sasse, A.G.B.M.; Wormeester, H.; Silfhout, van A.


    A new deconvolution method for Auger electron spectroscopy is presented. This method is based on a non-linear least squares minimizing routine (Levenberg-Marquardt) and global approximation using splines, solving many of the drawbacks inherent to the Van Cittert and Fourier transform based deconvolu

  17. Chemical-state imaging of Li using scanning Auger electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Nobuyuki, E-mail: [Global Research Center for Environment and Energy based on Nanomaterials Science (GREEN), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Fujita, Daisuke [Global Research Center for Environment and Energy based on Nanomaterials Science (GREEN), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Advanced Nanocharacterization Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)


    Highlights: •Scanning Auger electron microscopy is used to image chemical states of Li. •The combined use of AES and EELS signals for the elemental mapping is powerful. •Distribution corresponding to metallic and oxidized states of Li can be imaged. -- Abstract: The demand for measurement tools to detect Li with high spatial resolution and precise chemical sensitivity is increasing with the spread of lithium-ion batteries (LIBs) for use in a wide range of applications. In this work, scanning Auger electron microscopy (SAM) is used to image chemical states of a partially oxidized Li surface on the basis of the Auger electron spectroscopy (AES) and electron energy loss spectroscopy (EELS) data obtained during an oxidation process of a metal Li. We show that distribution of metallic and oxidized states of Li is clearly imaged by mapping the intensity of the corresponding AES and EELS peaks. Furthermore, a tiny difference in the extent of oxidation can be distinguished by comparing the elemental map of an AES peak with that of an EELS peak owing to the different behaviors of those signals to the chemical states of Li.

  18. Accelerator based Production of Auger-Electron-emitting Isotopes for Radionuclide Therapy

    DEFF Research Database (Denmark)

    Thisgaard, Helge

    Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron...... isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able...

  19. Evaluation of new iodinated acridine derivatives for targeted radionuclide therapy of melanoma using 125I, an Auger electron emitter. (United States)

    Gardette, Maryline; Papon, Janine; Bonnet, Mathilde; Desbois, Nicolas; Labarre, Pierre; Wu, Ting-Dee; Miot-Noirault, Elisabeth; Madelmont, Jean-Claude; Guerquin-Kern, Jean-Luc; Chezal, Jean-Michel; Moins, Nicole


    The increasing incidence of melanoma and the lack of effective therapy on the disseminated form have led to an urgent need for new specific therapies. Several iodobenzamides or analogs are known to possess specific affinity for melanoma tissue. New heteroaromatic derivatives have been designed with a cytotoxic moiety and termed DNA intercalating agents. These compounds could be applied in targeted radionuclide therapy using (125)I, which emits Auger electrons and gives high-energy, localized irradiation. Two iodinated acridine derivatives have been reported to present an in vivo kinetic profile conducive to application in targeted radionuclide therapy. The aim of the present study was to perform a preclinical evaluation of these compounds. The DNA intercalating property was confirmed for both compounds. After radiolabeling with (125)I, the two compounds induced in vitro a significant radiotoxicity to B16F0 melanoma cells. Nevertheless, the acridine compound appeared more radiotoxic than the acridone compound. While cellular uptake was similar for both compounds, SIMS analysis and in vitro protocol showed a stronger affinity for melanin with acridone derivative, which was able to induce a predominant scavenging process in the melanosome and restrict access to the nucleus. In conclusion, the acridine derivative with a higher nuclear localization appeared a better candidate for application in targeted radionuclide therapy using (125)I.

  20. Sliding of poly(vinyl chloride) on metals studied by Auger electron spectroscopy (United States)

    Pepper, S. V.


    The sliding of polyvinyl chloride on nickel, iron and S-Monel has been studied by Auger electron spectroscopy. Polymer was not transferred to the metals, rather shear appeared to take place at the interface. The metal was progressively chlorinated as the polymer made multiple passes on the surface. The thickness of this chlorine film was the order of one atomic layer. Electron-induced desorption studies indicate that the chlorine is chemisorbed to the metal. These results are interpreted as evidence for mechanically induced and/or thermal degradation of the polymer during sliding. Degradation products of HCl and Cl2 which chemisorb to the metal are evolved near the interface.

  1. Chirped Auger electron emission due to field-assisted post-collision interaction

    Directory of Open Access Journals (Sweden)

    Bonitz M.


    Full Text Available We have investigated the Auger decay in the temporal domain by applying a terahertz streaking light field. Xenon and krypton atoms were studied by implementing the free-electron laser in Hamburg (FLASH as well as a source of high-order harmonic radiation combined with terahertz pulses from an optical rectification source. The observed linewidth asymmetries in the streaked spectra suggest a chirped Auger electron emission which is understood in terms of field-assisted post-collision interaction. The experimentally obtained results agree well with model calculations.

  2. Radiotoxicity induced by Auger electron emitters in human osteosarcoma cell line using comet assay

    Institute of Scientific and Technical Information of China (English)

    XU Yu-Jie; LI Qing-Nuan; ZHU Ran; ZHU Ben-Xing; ZHANG Yong-Ping; ZHANG Xiao-Dong; FAN Wo; HONG Cheng-Jiao; LI Wen-Xin


    The comet assay (single cell gel electrophoresis assay) was used to evaluate the radiotoxicity of Augerelectron emitters in the human osteosarcoma cell line (HOS-8603). After internal exposure to 67Ga-EDTMP, the sar-coma cell has been injured severely. The comet length was longer along with the increase of dose, the appearance ofcomet tail was different from that with respect to the 60Co γ-ray irradiation. DNA damage of cell was mainly due tothe radiation effect of Auger electrons. The 67Ga may be a therapeutic radionuclide with good prospect for tumortreatment and palliation of bone pain induced by metastasis.

  3. The characterisation of non-evaporable getters by Auger electron spectroscopy Analytical potential and artefacts

    CERN Document Server

    Scheuerlein, C; Taborelli, M


    The surfaces of getter materials are particularly difficult to analyse because of their high chemical reactivity. The results obtained can be strongly influenced by the experimental set-up and procedures. In this paper the experimental influence on the Auger electron spectroscopy results is discussed, based on the measurements of more than 100 different non-evaporable getter (NEG) materials. There are four typical changes in the Auger electron spectra when a NEG becomes activated. The oxygen peak intensity decreases, the shape of the metal peaks changes, the carbon peak shape changes shape and intensity and a chlorine peak occurs. All these changes are affected by instrumental artefacts. The Zr-MNV peak shape changes occurring during the reduction of ZrO2 are well suited to determine the onset of NEG activation, while the slope with which the O-KLL peak intensity decreases in a certain temperature range is a better criterion for the determination of the temperature at which activation is complete. The O-KLL i...

  4. Calculations of energies and absolute intensities of Auger electrons and X-rays arising from electron capture decay

    Institute of Scientific and Technical Information of China (English)

    ZHOU Chun-Mei; WU Zhen-Dong; HUANG Xiao-Long


    Calculations of energies and absolute intensities of Auger electron and X-ray arising from electron capture are introduced briefly. The calculation codes and main process are also presented. The application is also given by taking 55Fe ε decay as an example.

  5. Auger Emitting Radiopharmaceuticals for Cancer Therapy (United States)

    Falzone, Nadia; Cornelissen, Bart; Vallis, Katherine A.

    Radionuclides that emit Auger electrons have been of particular interest as therapeutic agents. This is primarily due to the short range in tissue, controlled linear paths and high linear energy transfer of these particles. Taking into consideration that ionizations are clustered within several cubic nanometers around the point of decay the possibility of incorporating an Auger emitter in close proximity to the cancer cell DNA has immense therapeutic potential thus making nuclear targeted Auger-electron emitters ideal for precise targeting of cancer cells. Furthermore, many Auger-electron emitters also emit γ-radiation, this property makes Auger emitting radionuclides a very attractive option as therapeutic and diagnostic agents in the molecular imaging and management of tumors. The first requirement for the delivery of Auger emitting nuclides is the definition of suitable tumor-selective delivery vehicles to avoid normal tissue toxicity. One of the main challenges of targeted radionuclide therapy remains in matching the physical and chemical characteristics of the radionuclide and targeting moiety with the clinical character of the tumor. Molecules and molecular targets that have been used in the past can be classified according to the carrier molecule used to deliver the Auger-electron-emitting radionuclide. These include (1) antibodies, (2) peptides, (3) small molecules, (4) oligonucleotides and peptide nucleic acids (PNAs), (5) proteins, and (6) nanoparticles. The efficacy of targeted radionuclide therapy depends greatly on the ability to increase intranuclear incorporation of the radiopharmaceutical without compromising toxicity. Several strategies to achieve this goal have been proposed in literature. The possibility of transferring tumor therapy based on the emission of Auger electrons from experimental models to patients has vast therapeutic potential, and remains a field of intense research.

  6. Positron Annihilation Induced Auger Electron Spectroscopy of Inner Shell Transitions Using Time-Of Technique (United States)

    Xie, Shuping; Jiang, Neng; Weiss, A. H.


    Positron annihilation induced Auger electron spectroscopy (PAES) has been shown to have unique advantages over conventional electron collision induced Auger techniques, including the ability to eliminate the secondary electron background and selectively probe the top-most atomic layer on the sample surface. Here we report on the development of a new time-of-flight (TOF) spectrometer which combines features high efficiency magnetic transport and parrallel energy measurment with high resolution by using an innovative timing method. The new TOF-PAES system, was used to make the first quantitative comparative measurements of the Auger intensities associated with the annihilation of positrons with the deep core levels (1s) of S KLL (180eV), C KLL (270eV), N KLL (360eV), and O KLL (510eV). Experimental results of Auger probabilities at outer core level (3s, 3P) of Cu M2,3VV (60eV), M1VV (105eV) are compared with the theoretical value of Jensen and Weiss. Quantitatively study the surface adsorbate process on Cu is performed and concentration changes of surface components are obtained. These results demonstrate that TOF-PAES can be used to obtain quantitative,top-layer specific, information from chemically important elements including those with relatively deep core levels (e.g. C and O).

  7. Auger electron spectroscopic study of CO{sub 2} adsorption on Zircaloy-4 surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stojilovic, N.; Farkas, N. [Institute for Teaching and Learning and Departments of Physics and Chemistry, University of Akron, Akron, OH 44325-6236 (United States); Ramsier, R.D. [Institute for Teaching and Learning and Departments of Physics and Chemistry, University of Akron, Akron, OH 44325-6236 (United States)], E-mail:


    We investigate the adsorption of CO{sub 2} onto Zircaloy-4 (Zry-4) surfaces at 150, 300 and 600 K using Auger electron spectroscopy (AES). Following CO{sub 2} adsorption at 150 K the graphitic form of carbon is detected, whereas upon chemisorption at 300 and 600 K we detect the carbidic phase. As the adsorption temperature is increased, the carbon Auger signal increases, whereas the oxygen signal decreases. Adsorption at all three temperatures results in a shift of the Zr Auger features, indicating surface oxidation. The effect of adsorbed CO{sub 2} on the Zr(MVV) and Zr(MNV) transitions depends on adsorption temperature and is less pronounced at higher temperatures. On the other hand, changes in the Zr(MNN) feature are similar for all three adsorption temperatures. The changes in the Zr Auger peak shapes and positions are attributed to oxygen from dissociated CO{sub 2}, with the differences observed at various temperatures indicative of the diffusion of oxygen into the subsurface region.

  8. Electron stimulated carbon adsorption in ultra high vacuum monitored by Auger Electron Spectroscopy (AES)

    CERN Document Server

    Scheuerlein, C


    Electron stimulated carbon adsorption at room temperature (RT) has been studied in the context of radiation induced surface modifications in the vacuum system of particle accelerators. The stimulated carbon adsorption was monitored by AES during continuous irradiation by 2.5 keV electrons and simultaneous exposure of the sample surface to CO, CO2 or CH4. The amount of adsorbed carbon was estimated by measuring the carbon Auger peak intensity as a function of the electron irradiation time. Investigated substrate materials are technical OFE copper and TiZrV non-evaporable getter (NEG) thin film coatings, which are saturated either in air or by CO exposure inside the Auger electron spectrometer. On the copper substrate electron induced carbon adsorption from gas phase CO and CO2 is below the detection limit of AES. During electron irradiation of the non-activated TiZrV getter thin films, electron stimulated carbon adsorption from gas phase molecules is detected when either CO or CO2 is injected, whereas the CH4 ...

  9. Atomic and Molecular Photoelectron and Auger Electron SpectroscopyStudies Using Synchrotron Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Stephen H.


    Electron spectroscopy, combined with synchrotron radiation, was used to measure the angular distributions of photoelectrons and Auger electrons from atoms and molecules as functions of photon energy. The branching ratios and partial cross sections were a 130 measured in certain cases. By comparison with theoretical calculations, the experimental results are interpreted in terms of the characteristic electronic structure and ionization dynamics of the atomic or molecular sample. The time structure of the synchrotron radiation source was used to record time-of-flight (TOF) spectra o f the ejected electrons. The ''a double-angle-TOF'' method for the measurement of photoelectron angular distributions is discussed. This technique offers the advantages of increased electron collect ion efficiency and the elimination of certain systematic errors. Several results were obtained for Xe using photon energies in the range hv {approx_equal} 60-190 eV, where excitation and ionization of the inner-subshell 4d electrons dominates. The 4d asymmetry parameter {beta} exhibits strong oscillations with energy, in agreement with several theoretical calculations. As predicted, the 5p asymmetry parameter was observed to deviate strongly from that calculated using the independent-electron model, due to intershell correlation with the 4d electrons.

  10. Channel-resolved photo- and Auger-electron spectroscopy of halogenated hydrocarbons (United States)

    Ablikim, Utuq; Kaderiya, B.; Kumarapan, V.; Kushawaha, R.; Rudenko, A.; Rolles, D.; Xiong, H.; Berrah, N.; Bomme, C.; Savelyev, E.; Kilcoyne, D.


    Inner-shell photoelectron and Auger electron spectra of polyatomic molecules such as halogenated hydrocarbons are typically hard to interpret and assign due to many overlapping states that form broad bands even in high-resolution measurements. With the help of electron-ion-ion coincidence measurements performed using the velocity map imaging technique, we are able to detect high-energy (assigning individual components of the electron spectra to specific potential surfaces and final states. In this work, we present measurements on CH3 I, CH2 IBr, and CH2 ICl molecules in the gas-phase using soft x-ray light provided by the Advanced Light Source at LBNL. This project is supported by the DOE, Office of Science, BES, Division of Chemical, Geological and Biological Sciences under Award Number DE-FG02-86ER13491 (U.A., B.K., V.K., A.R., D.R.) and Award Number DE-SC0012376 (H.X., N.B.).

  11. Features of atomic images reconstructed from photoelectron, Auger electron, and internal detector electron holography using SPEA-MEM

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, Tomohiro, E-mail: [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198 (Japan); Matsui, Fumihiko [Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192 (Japan)


    Highlights: • We develop a 3D atomic image reconstruction algorithm for photoelectron, Auger electron, and internal detector holography. • We examine the shapes of the atomic images reconstructed by using a developed kernel function. • We examine refraction effect at surface, limitation effect of the hologram data, energy resolution effect, and angular resolution effect. • These discussions indicate the experimental requirements to obtain the clear 3D atomic image. - Abstract: Three-dimensional atomic images can be reconstructed from photoelectron, Auger electron, and internal detector electron holograms using a scattering pattern extraction algorithm using the maximum entropy method (SPEA-MEM) that utilizes an integral transform. An integral kernel function for the integral transform is the key to clear atomic image reconstruction. We composed the kernel function using a scattering pattern function and estimated its ability. Image distortion caused by multiple scattering was also evaluated. Four types of Auger electron wave functions were investigated, and the effect of these wave function types was estimated. In addition, we addressed refraction at the surface, the effects of data limitation, and energy and angular resolutions.



    Halle, Bo; Thisgaard, Helge; Aaberg-Jessen, Charlotte; Olsen, Birgitte; Dam, Johan; Langkjær, Niels; Munthe, Sune; Någren, Kjell; Høilund-Carlsen, Poul Flemming; Kristensen, Bjarne


    BACKGROUND: Glioblastomas (GBMs), the most common and malignant primary brain tumors, always recur after standard treatment. In order to develop more efficient therapies, we tested a novel therapeutic approach using the radioactive Auger-electron-emitter (AEE) [125I]5-Iodo-2'-deoxyuridine (125I-UdR). This drug incorporates into DNA of dividing cells and upon decay emission of Auger-electrons causes clusters of double strand breaks leading to cell death. METHODS: In vitro, cells from two GBM s...

  13. Theory of Auger-electron and appearance-potential spectroscopy for interacting valence-band electrons (United States)

    Nolting, W.; Geipel, G.; Ertl, K.


    A theory of Auger-electron spectroscopy (AES) and appearance-potential spectroscopy (APS) is presented for interacting electrons in a nondegenerate energy band, described within the framework of the Hubbard model. Both types of spectroscopy are based on the same two-particle spectral density. A diagrammatic vertex-correction method (Matsubara formalism) is used to express this function in terms of the one-particle spectral density. The latter is approximately determined for arbitrary temperature T, arbitrary coupling strength U/W (U, the intra-atomic Coulomb matrix element; W, the width of the ``free'' Bloch band), and arbitrary band occupations n (0QDOS) in relation to the Bloch density of states (BDOS), where, however, spontaneous magnetic order is excluded, irrespective of the band filling n. The AE (AP) spectra consist of only one structure a few eV wide (``bandlike'') which is strongly n dependent, but only slightly T dependent, being rather well approximated by a simple self-convolution of the occupied (unoccupied) QDOS. For strongly correlated electrons the Bloch band splits into two quasiparticle subbands. This leads for n1. For sufficiently strong correlations U/W additional satellites appear that refer to situations where the two excited quasiparticles (quasiholes) propagate as tightly bound pairs through the lattice without being scattered by other charge carriers. As soon as the satellite splits off from the bandlike part of the spectrum, it takes almost the full spectral weight, conveying the impression of an ``atomiclike'' AE (AP) line shape. The satellite has almost exactly the structure of the free BDOS. If the particle density n as well as the hole density 2-n exceed certain critical values determined by U/W and the BDOS ρ0(E), spontaneous ferromagnetism becomes possible in the strongly correlated electron band. The magnetic phase transition gives rise to a distinctive T dependence for the QDOS and hence also for the AE and AP line shapes

  14. Studies of films and heterostructures on Pbsub(1-x)Snsub(x)Te base by Auger electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gas' kov, A.M.; Alenberg, V.B.; Lisina, N.G.; Drozd, I.A.; Zlomanov, V.P.; Novoselova, A.V. (Moskovskij Gosudarstvennyj Univ. (USSR))


    The Auger electron spectroscopy method has been used to determine the composition of films and heterostructures on the base of Pbsub(1-x)Snsub(x)Te grown by the molecular-radiation epitaxy method on BaF/sub 2/ substrates. The excess tin concentration in a near-surface layer is revealed, the fact which is associated with oxidation of the film surface in the process of conservation. The transitional layer in PbTe-Pbsub(0.8)Snsub(0.2)Te heterostructures constitutes 300 A and it is characterized by excess tellurium concentration, which is connected with high dislocation density on the interface.

  15. Auger electron and X-ray photoelectron spectroscopic study of the biocorrosion of copper by alginic acid polysaccharide (United States)

    Jolley, John G.; Geesey, Gill G.; Hankins, Michael R.; Wright, Randy B.; Wichlacz, Paul L.


    Thin films (3.4 nm) of copper on germanium substrates were exposed to 2% alginic acid polysaccharide aqueous solution. Pre- and post-exposure characterization were done by Auger electron spectroscopy and X-ray photoelectron spectroscopy. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium substrate. Results indicate that some of the copper was oxidized by the alginic acid solution. Some of the copper was removed from the Cu/Ge interface and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the alginic acid polysaccharide.

  16. High energy resolution and first time-dependent positron annihilation induced Auger electron spectroscopty

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Jakob


    It was the aim of this thesis to improve the existing positron annihilation induced Auger spectrometer at the highly intense positron source NEPOMUC (NEutron induced POsitron source MUniCh) in several ways: Firstly, the measurement time for a single spectrum should be reduced from typically 12 h to roughly 1 h or even less. Secondly, the energy resolution, which amounted to {delta}E/E{approx}10%, should be increased by at least one order of magnitude in order to make high resolution positron annihilation induced Auger spectroscopy (PAES)-measurements of Auger transitions possible and thus deliver more information about the nature of the Auger process. In order to achieve these objectives, the PAES spectrometer was equipped with a new electron energy analyzer. For its ideal operation all other components of the Auger analysis chamber had to be adapted. Particularly the sample manipulation and the positron beam guidance had to be renewed. Simulations with SIMION {sup registered} ensured the optimal positron lens parameters. After the adjustment of the new analyzer and its components, first measurements illustrated the improved performance of the PAES setup: Firstly, the measurement time for short overview measurements was reduced from 3 h to 420 s. The measurement time for more detailed Auger spectra was shortened from 12 h to 80 min. Secondly, even with the reduced measurement time, the signal to noise ratio was also enhanced by one order of magnitude. Finally, the energy resolution was improved to {delta}E/E < 1. The exceptional surface sensitivity and elemental selectivity of PAES was demonstrated in measurements of Pd and Fe, both coated with Cu layers of varying thickness. PAES showed that with 0.96 monolayer of Cu on Fe, more than 55% of the detected Auger electrons stem from Cu. In the case of the Cu coated Pd sample 0.96 monolayer of Cu resulted in a Cu Auger fraction of more than 30% with PAES and less than 5% with electron induced Auger spectroscopy

  17. Auger electron spectroscopy study of initial stages of oxidation in a copper - 19.6-atomic-percent-aluminum alloy (United States)

    Ferrante, J.


    Auger electron spectroscopy was used to examine the initial stages of oxidation of a polycrystalline copper - 19.6 a/o-aluminum alloy. The growth of the 55-eV aluminum oxide peak and the decay of the 59-, 62-, and 937-eV copper peaks were examined as functions of temperature, exposure, and pressure. Pressures ranged from 1x10 to the minus 7th power to 0.0005 torr of O2. Temperatures ranged from room temperature to 700 C. A completely aluminum oxide surface layer was obtained in all cases. Complete disappearance of the underlying 937-eV copper peak was obtained by heating at 700 C in O2 at 0.0005 torr for 1 hr. Temperature studies indicated that thermally activated diffusion was important to the oxidation studies. The initial stages of oxidation followed a logarithmic growth curve.

  18. Thermal effects in equilibrium surface segregation in a copper/10-atomic-percent-aluminum alloy using Auger electron spectroscopy (United States)

    Ferrante, J.


    Equilibrium surface segregation of aluminum in a copper-10-atomic-percent-aluminum single crystal alloy oriented in the /111/ direction was demonstrated by using Auger electron spectroscopy. This crystal was in the solid solution range of composition. Equilibrium surface segregation was verified by observing that the aluminum surface concentration varied reversibly with temperature in the range 550 to 850 K. These results were curve fitted to an expression for equilibrium grain boundary segregation and gave a retrieval energy of 5780 J/mole (1380 cal/mole) and a maximum frozen-in surface coverage three times the bulk layer concentration. Analyses concerning the relative merits of sputtering calibration and the effects of evaporation are also included.

  19. Auger electron spectroscopy study of oxidation of a PdCr alloy used for high-temperature sensors (United States)

    Boyd, Darwin L.; Zeller, Mary V.; Vargas-Aburto, Carlos


    A Pd-13 wt. percent Cr solid solution is a promising high-temperature strain gage alloy. In bulk form it has a number of properties that are desirable in a resistance strain gage material, such as a linear electrical resistance versus temperature curve to 1000 C and stable electrical resistance in air at 1000 C. However, unprotected fine wire gages fabricated from this alloy perform well only to 600 C. At higher temperatures severe oxidation degrades their electrical performance. In this work Auger electron spectroscopy was used to study the oxidation chemistry of the alloy wires and ribbons. Results indicate that the oxidation is caused by a complex mechanism that is not yet fully understood. As expected, during oxidation, a layer of chromium oxide is formed. This layer, however, forms beneath a layer of metallic palladium. The results of this study have increased the understanding of the oxidation mechanism of Pd-13 wt. percent Cr.

  20. Auger electron spectroscopy, secondary ion mass spectroscopy and optical characterization of a-C-H and BN films (United States)

    Pouch, J. J.; Alterovitz, S. A.; Warner, J. D.


    The amorphous dielectrics a-C:H and BN were deposited on III-V semiconductors. Optical band gaps as high as 3 eV were measured for a-C:H generated by C4H10 plasmas; a comparison was made with bad gaps obtained from films prepared by CH4 glow discharges. The ion beam deposited BN films exhibited amorphous behavior with band gaps on the order of 5 eV. Film compositions were studied by Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The optical properties were characterized by ellipsometry, UV/VIS absorption, and IR reflection and transmission. Etching rates of a-C:H subjected to O2 dicharges were determined.

  1. Silicidation in Ni/Si thin film system investigated by X-ray diffraction and Auger electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Abhaya, S. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Amarendra, G. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)]. E-mail:; Kalavathi, S. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Gopalan, Padma [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Kamruddin, M. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Tyagi, A.K. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Sastry, V.S. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Sundar, C.S. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)


    Silicide formation induced by thermal annealing in Ni/Si thin film system has been investigated using glancing incidence X-ray diffraction (GIXRD) and Auger electron spectroscopy (AES). Silicide formation takes place at 870 K with Ni{sub 2}Si, NiSi and NiSi{sub 2} phases co-existing with Ni. Complete conversion of intermediate silicide phases to the final NiSi{sub 2} phase takes place at 1170 K. Atomic force microscopy measurements have revealed the coalescence of pillar-like structures to ridge-like structures upon silicidation. A comparison of the experimental results in terms of the evolution of various silicide phases is presented.

  2. Auger electron emitter against multiple myeloma - targeted endo-radio-therapy with {sup 125}I-labeled thymidine analogue 5-iodo-4'-thio-2'-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Morgenroth, Agnieszka, E-mail: [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Dinger, Cornelia; Zlatopolskiy, Boris D.; Al-Momani, Ehab; Glatting, Gerhard [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Mottaghy, Felix M. [Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Reske, Sven N. [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany)


    Introduction: Multiple myeloma (MM) is a plasma cell malignancy characterized by accumulation of malignant, terminally differentiated B cells in the bone marrow. Despite advances in therapy, MM remains an incurable disease. Novel therapeutic approaches are, therefore, urgently needed. Auger electron-emitting radiopharmaceuticals are attractive for targeted nano-irradiation therapy, given that DNA of malignant cells is selectively addressed. Here we evaluated the antimyeloma potential of the Auger electron-emitting thymidine analogue {sup 125}I-labeled 5-iodo-4'-thio-2'-deoxyuridine ([{sup 125}I]ITdU). Methods: Cellular uptake and DNA incorporation of [{sup 125}I]ITdU were determined in fluorodeoxyuridine-pretreated KMS12BM, U266, dexamethasone-sensitive MM1.S and -resistant MM1.R cell lines. The effect of stimulation with interleukin 6 (IL6) or insulin-like growth factor 1 (IGF1) on the intracellular incorporation of [{sup 125}I]ITdU was investigated in cytokine-sensitive MM1.S and MM1.R cell lines. Apoptotic cells were identified using Annexin V. Cleavage of caspase 3 and PARP was visualized by Western blot. DNA fragmentation was investigated using laddering assay. Therapeutic efficiency of [{sup 125}I]ITdU was proven by clonogenic assay. Results: [{sup 125}I]ITdU was shown to be efficiently incorporated into DNA of malignant cells, providing a promising mechanism for delivering highly toxic Auger radiation emitters into tumor DNA. [{sup 125}I]ITdU had a potent antimyeloma effect in cell lines representing distinct disease stages and, importantly, in cell lines sensitive or resistant to the conventional therapeutic agent, but was not toxic for normal plasma and bone marrow stromal cells. Furthermore, [{sup 125}I]ITdU abrogated the protective actions of IL6 and IGF1 on MM cells. [{sup 125}I]ITdU induced massive damage in the DNA of malignant plasma cells, which resulted in efficient inhibition of clonogenic growth. Conclusion: These studies may provide a

  3. Auger electron spectroscopic study of mechanism of sulfide-accelerated corrosion of copper-nickel alloy in seawater (United States)

    Schrader, Malcolm E.

    The mechanism of sulfide-induced accelerated corrosion of 90-10 copper-nickel(iron) alloy is investigated. Samples of the alloy are exposed to flowing (2.4 m/s) seawater, with and without 0 01 mg/l sulfide, for various periods of time. The resulting surfaces are examined by means of Auger electron spectroscopy coupled with inert-ion-homoardment. A detailed depth profile is thereby obtained of concentrations in the surface region of a total of nine elements. The results are consistent with the hypothesis that iron hydroxide segregates at the surface to form a protective gelatinous layer against the normal chloride-induced corrosion process. Trace sulfide interferes with formation of a good protective layer and leaves the iron hydroxide vulnerable to ultimate partial or complete debonding. When the alloy is first exposed to "pure" seawater for a prolonged period of time, however, subsequent exposure to sulfide is no longer deleterious. This is apparently due to a layer of copper-nickel salt that slowly forms over the iron hydroxide.

  4. Segregation Study of the β phase on the Al-Li Alloy Surface using Auger Electron Spectroscopy (United States)

    Belkhiat, S.; Keraghel, F.


    Auger Electron spectroscopy (AES) has been used to study lithium segregation on Al-3.49wt%-Li alloy surface. In this work, the surface atomic composition as a function of temperature was followed. In our previous works, the activation energy of Li segregation has been determined experimentally being in agreement with the resulted theoretical value. In this paper, one showed that the segregation energy of Li on the surface depends of the crystalline structure and of the Li content in the Al-Li alloy matrix. β-AlLi phase on the alloy surface, used in the power sources for the propulsion of electrical vehicles and for stocking energy, is obtained by progressive heating. We showed that the segregated lithium on the alloy surface is reversible as a function of decreasing temperature and consequently β-AlLi phase is converted in α-AlLi phase. On the other hand, the brutal heating of the sample drives to the conversion of the α-AlLi phase to β-AlLi phase and stabilizes the surface towards other segregation; therefore the conversion of β-AlLi phase to α-AlLi phase is irreversible.

  5. Auger-electron spectra of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} obtained by using monochromatized synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, Shin-ichi, E-mail: [Department of Chemistry, Faculty of Science, Ehime University, Matsuyama 790-8577 (Japan); Nitta, Akiko [Department of Chemistry, Faculty of Science, Ehime University, Matsuyama 790-8577 (Japan); Tamenori, Yusuke [Japan Synchrotron Radiation Research Institute/SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun 679-5198 (Japan); Fukuzawa, Hironobu; Ueda, Kiyoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Takahashi, Osamu [Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Kakiuchi, Takuhiro [Department of Chemistry, Faculty of Science, Ehime University, Matsuyama 790-8577 (Japan); Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Kitajima, Yoshinori; Mase, Kazuhiko; Suzuki, Isao H. [Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan)


    A study on Auger-electron spectra of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} was performed by using monochromatized synchrotron radiation. The normal Si:L{sub 23}VV Auger-electron spectrum was measured in the vapor phase and characterized through the ab initio molecular orbital calculation. The cascade Si:L{sub 23}VV Auger-electron spectra were also obtained by L{sub 23}-holes creation through Si:KL{sub 23}L{sub 23} Auger transitions after Si:1s photoexcitation in the vapor phase or its photoelectron emission in the condensed phase. Further the C:KVV and F:KVV Auger-electron spectra were measured and discussed in comparison with those of some related molecules.

  6. Direct and Auger Electron-Induced, Single- and Double-Strand Breaks on Plasmid DNA Caused by 99mTc-Labeled Pyrene Derivatives and the Effect of Bonding Distance (United States)

    Reissig, Falco; Mamat, Constantin; Steinbach, Joerg; Pietzsch, Hans-Juergen; Freudenberg, Robert; Navarro-Retamal, Carlos; Caballero, Julio; Kotzerke, Joerg; Wunderlich, Gerd


    It is evident that 99mTc causes radical-mediated DNA damage due to Auger electrons, which were emitted simultaneously with the known γ-emission of 99mTc. We have synthesized a series of new 99mTc-labeled pyrene derivatives with varied distances between the pyrene moiety and the radionuclide. The pyrene motif is a common DNA intercalator and allowed us to test the influence of the radionuclide distance on damages of the DNA helix. In general, pUC 19 plasmid DNA enables the investigation of the unprotected interactions between the radiotracers and DNA that results in single-strand breaks (SSB) or double-strand breaks (DSB). The resulting DNA fragments were separated by gel electrophoresis and quantified by fluorescent staining. Direct DNA damage and radical-induced indirect DNA damage by radiolysis products of water were evaluated in the presence or absence of the radical scavenger DMSO. We demonstrated that Auger electrons directly induced both SSB and DSB in high efficiency when 99mTc was tightly bound to the plasmid DNA and this damage could not be completely prevented by DMSO, a free radical scavenger. For the first time, we were able to minimize this effect by increasing the carbon chain lengths between the pyrene moiety and the 99mTc nuclide. However, a critical distance between the 99mTc atom and the DNA helix could not be determined due to the significantly lowered DSB generation resulting from the interaction which is dependent on the type of the 99mTc binding motif. The effect of variable DNA damage caused by the different chain length between the pyrene residue and the Tc-core as well as the possible conformations of the applied Tc-complexes was supplemented with molecular dynamics (MD) calculations. The effectiveness of the DNA-binding 99mTc-labeled pyrene derivatives was demonstrated by comparison to non-DNA-binding 99mTcO4–, since nearly all DNA damage caused by 99mTcO4– was prevented by incubating with DMSO. PMID:27583677

  7. Scanning Auger Electron Microscope (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope. Specifications / Capabilities: Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  8. Scanning Auger Electron Microscope (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  9. Making use of x-ray optical effects in photoelectron-, Auger electron-, and x-ray emission spectroscopies: Total reflection, standing-wave excitation, and resonant effects

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.-H. [IBM Almaden Research Center, San Jose, California 95120 (United States); Gray, A. X. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States); Stanford Institute for Materials and Energy Science, Stanford University and SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kaiser, A. M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States); Peter Grunberg Institute, PGI-6, Forschungszentrum Juelich, 52425 Juelich (Germany); Mun, B. S. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Applied Physics, Hanyang University, Ansan, Gyeonggi 426-791 (Korea, Republic of); Sell, B. C. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States); Department of Physics, Otterbein College, Westerville, Ohio 43081 (United States); Kortright, J. B. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Fadley, C. S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States)


    We present a general theoretical methodology and related open-access computer program for carrying out the calculation of photoelectron, Auger electron, and x-ray emission intensities in the presence of several x-ray optical effects, including total reflection at grazing incidence, excitation with standing-waves produced by reflection from synthetic multilayers and at core-level resonance conditions, and the use of variable polarization to produce magnetic circular dichroism. Calculations illustrating all of these effects are presented, including in some cases comparisons to experimental results. Sample types include both semi-infinite flat surfaces and arbitrary multilayer configurations, with interdiffusion/roughness at their interfaces. These x-ray optical effects can significantly alter observed photoelectron, Auger, and x-ray intensities, and in fact lead to several generally useful techniques for enhancing surface and buried-layer sensitivity, including layer-resolved densities of states and depth profiles of element-specific magnetization. The computer program used in this study should thus be useful for a broad range of studies in which x-ray optical effects are involved or are to be exploited in next-generation surface and interface studies of nanoscale systems.

  10. X-ray photoelectron and Auger electron spectroscopic analysis of surface treatments and electrochemical decomposition of CuInSe2 photoelectrodes (United States)

    Cahen, David; Ireland, P. J.; Kazmerski, L. L.; Thiel, F. A.


    CuInSe2 photoanodes can be optimized for use in electrochemical photovoltaic cells, containing aqueous polyiodide as the electrolyte, by wet chemical etching in Br2MeOH and subsequent thermal treatment (air oxidation). Surface analyses show the formation of a rather clean, Cu-depleted surface with some adsorbed oxygen after Br2/MeOH etch, and the formation of indium-oxygen bonds after thermal treatment, in accordance with previous studies that show indium oxides to be the native ones on this semiconductor. Samples that underwent photoanodic decomposition in the iodide electrolyte and those that were purposely decomposed in acetonitrile showed severe to near-total Cu depletion near their surface and the presence of lower valent Se. These data complement those from solution analyses and from electrochemical studies, to characterize the preferred decomposition path of CuInSe2 sufficiently to stabilize this type of photoelectrochemical cell. Our conclusions are based on the use of Auger parameters and, to a lesser extent, on empirical comparison of x-ray induced Auger electron line shapes, because of the difficulty in extracting unambiguous conclusions from x-ray photoelectron binding energies only.

  11. Investigation of Sn surface segregation during GeSn epitaxial growth by Auger electron spectroscopy and energy dispersive x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Takahiro; Suda, Yoshiyuki [Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Hirose, Nobumitsu; Kasamatsu, Akifumi; Mimura, Takashi; Matsui, Toshiaki [National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)


    The mechanism of Sn surface segregation during the epitaxial growth of GeSn on Si (001) substrates was investigated by Auger electron spectroscopy and energy dispersive X-ray spectroscopy. Sn surface segregation depends on the growth temperature and Sn content of GeSn layers. During Sn surface segregation, Sn-rich nanoparticles form and move on the surface during the deposition, which results in a rough surface owing to facet formation. The Sn-rich nanoparticles moving on the surface during the deposition absorb Sn from the periphery and yield a lower Sn content, not on the surface but within the layer, because the Sn surface segregation and the GeSn deposition occur simultaneously. Sn surface segregation can occur at a lower temperature during the deposition compared with that during postannealing. This suggests that the Sn surface segregation during the deposition is strongly promoted by the migration of deposited Ge and Sn adatoms on the surface originating from the thermal effect of substrate temperature, which also suggests that limiting the migration of deposited Ge and Sn adatoms can reduce the Sn surface segregation and improve the crystallinity of GeSn layers.

  12. Determination of the surface composition of binary alloys by Auger electron spectroscopy: the gold--silver and gold--tin systems

    Energy Technology Data Exchange (ETDEWEB)

    Overbury, S.H.


    Auger electron spectroscopy was exploited as a means of determining the surface phase diagram of Au--Ag and Au--Sn alloys. Polycrystalline Au--Ag alloy foils of a wide range of composition (atom fractions of 0.15 to 0.97) were cleaned. The intensities of the Auger emission from transitions at several energies were measured and normalized to those of pure Au and Ag. The surface monolayer compositions of the alloys were determined. The Auger data was consistent with enrichment of Ag in the surface monolayer. Ingots of Au--Sn with bulk composition between 50 and 99 at % Au were prepared. The bulk structure and composition of these complex alloys were characterized by electron microprobe, x-ray diffraction, x-ray fluorescence and optical microscopy. The samples were cleaned and equilibrated in ultra high vacuum and the intensities of the Auger emission from transitions at several energies were measured and normalized to those of pure Au and pure Sn. Using the intensity model, the normalized Auger intensity ratios were used to determine the surface monolayer composition. Enrichment of Sn was found in the surface monolayer for disordered zeta and ..cap alpha.. phase alloys. The highly ordered delta (50.0 at % Au) phase alloy was found to exhibit no surface segregation. The surfaces of two phase alloys (delta and zeta) were found to be describable by the lever rule. The results were interpreted in terms of the bulk structures, ordering properties, and driving force for segregation of the alloys. The effects of ion sputtering upon the surface of Au--Ag and Au--Sn alloys were also investigated.

  13. Estrogen Injection (United States)

    The estradiol cypionate and estradiol valerate forms of estrogen injection are used to treat hot flushes (hot ... should consider a different treatment. These forms of estrogen injection are also sometimes used to treat the ...

  14. Trastuzumab Labeled to High Specific Activity with (111)In by Site-Specific Conjugation to a Metal-Chelating Polymer Exhibits Amplified Auger Electron-Mediated Cytotoxicity on HER2-Positive Breast Cancer Cells. (United States)

    Ngo Ndjock Mbong, Ghislaine; Lu, Yijie; Chan, Conrad; Cai, Zhongli; Liu, Peng; Boyle, Amanda J; Winnik, Mitchell A; Reilly, Raymond M


    Our objective was to evaluate the cytotoxicity toward HER2-positive human breast cancer (BC) cells of trastuzumab modified site-specifically with a metal-chelating polymer (MCP) that presents multiple DTPA chelators for complexing (111)In. (111)In emits subcellular range Auger electrons that induce multiple lethal DNA double-strand breaks (DSBs) in cells. MCPs were synthesized with a polyglutamide backbone with 24 or 29 pendant DTPA groups, with or without nuclear translocation sequence (NLS) peptide modification and a terminal hydrazide group for reaction with aldehydes generated by sodium periodate (NaIO4)-oxidation of glycans on the Fc-domain of trastuzumab. Trastuzumab was site-specifically modified with two DTPA and labeled with (111)In for comparison (trastuzumab-NH-Bn-DTPA-(111)In). The maximum specific activity (SA) for labeling trastuzumab-Hy-MCP with (111)In was 90-fold greater than for trastuzumab-NH-Bn-DTPA-(111)In [8.9 MBq/μg (1.5 × 10(6) MBq/μmol) vs 0.1 MBq/μg (1.2 × 10(4) MBq/μmol)]. Trastuzumab-Hy-MCP-(111)In was bound, internalized, and imported into the nucleus of SK-BR-3 cells. NLS peptide modification of MCPs did not increase nuclear importation. A greater density of DNA DSBs was found for BC cells exposed to high SA (5.5 MBq/μg) than low SA (0.37 MBq/μg) radioimmunoconjugates. At 20 nmol/L, high SA trastuzumab-Hy-MCP-(111)In was 6-fold more effective at reducing the clonogenic survival (CS) of HER2 overexpressed and HER2 gene-amplified SK-BR-3 cells (1.3 × 10(6) receptors/cell) than low SA MCP-radioimmunoconjugates (CS = 1.8 ± 1.3 vs 10.9 ± 0.7%; P = 0.001). Low SA trastuzumab-NH-Bn-DTPA-(111)In (20 nmol/L) reduced the CS of SK-BR-3 cells to 15.8 ± 2.1%. The CS of ZR-75-1 cells with intermediate HER2 density (4 × 10(5) receptors/cell) but without HER2 gene amplification was reduced to 20.5 ± 4.3% by high SA trastuzumab-Hy-MCP-(111)In (20 nmol/L). The CS of HER2-overexpressed (5 × 10(5) HER2/cell) but trastuzumab-resistant TrR1

  15. X-ray photoelectron spectroscopy and Auger electron spectroscopy analyses of the initial growth mechanism of CdTe layers on (100) GaAs by metalorganic vapor phase epitaxy



    X‐ray photoelectron spectroscopy and Auger electron spectroscopy measurements were performed to investigate the initial growth mechanism and the selection of growth orientations of CdTe layers grown on (100) GaAs by metalorganic vapor phase epitaxy (MOVPE). The surface stoichiometry of the GaAs substrate was found to recover when annealed in a H2 flow atmosphere (500°C, 5 min), although the surface was initially in an As‐rich condition after chemical etching by H2SO4@B:H2O2@B:H2O=5@B:1@B:1. N...

  16. Investigation of inhomogeneities in Ga, Cd and Zn - doped Pbsub(1-x)Snsub(x)Te (x=0,00 and 0,20) crystals by the method of Auger electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gas' kov, A.M.; Lisina, N.G.; Zlomanov, V.P.; NovoseloVa, A.V. (Moskovskij Gosudarstvennyj Univ. (USSR))

    An Auger electron microanalysis of doped crystal Pbsub(1-x)Snsub(x)Te is made using the Jamp-10 Jeol device with an analyser of cycindric mirror type. The crystals have been doped with Ga, Cd and Zn both in the process of growing from vapour and by means of diffusion annealing. Auger electron spectra have been studied in high vacuum (10/sup -9/ - 10/sup -10/ mm Hg) in the range of 70-1200 eV under the following conditions: the energy of electron beam is 5 keV, the current across the sample is 10/sup -8/ - 10/sup -9/ A. A conclusion is made that PbTe and Pbsub(0,8)Snsub(0,2)Te crystals doped by Ga, Cd and Zn both in the process of growing and by means of the diffusion annealing are characterized by inhomogeneous distribution of impurities. Gallium segregations in the vicinity of low-angle boundaries and dislocations in PbTe (Ga) tin- and lead-enriched inclusions in Pbsub(0,8)Snsub(0,2)Te (Cd), and ZnTe inclusions in Pbsub(0,8)Snsub(0,2)Te (Zn) samples are found.

  17. AES (auger electron spectroscopy) and EELS (electron energy loss spectroscopy) analysis of TlBaCaCuO/sub x/ thin films at 300 K and at 100 K

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A.J.; Swartzlander, A.; Kazmerski, L.L.; Kang, J.H.; Kampwirth, R.T.; Gray, K.E.


    Auger electron spectroscopy line-shape analysis of the Tl(NOO), Ba(MNN), Ca(LMM), Cu(LMM) and O(KLL) peaks has been performed in conjunction with electron energy loss spectroscopy (EELS) on magnetron sputter deposited TlBaCaCuO/sub x/ thin films exhibiting a superconducting onset at 110K with zero resistance at 96K. AES and EELS analyses were performed at 300K and at 100K. Changes in the Auger line shapes and in the EELS spectra as the temperature is lowered below the critical point are related to changes in the electronic structure of states in the valence band (VB). Bulk and surface plasmon peaks are identified in the EELS spectra along with features due to core level transitions. Electron beam and ion beam induced effects are also addressed. 13 refs., 3 figs., 1 tab.

  18. Mg diffusion in K(Ta{sub 0.65}Nb{sub 0.35})O{sub 3} thin films grown on MgO evidenced by Auger electron spectroscopy investigation

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Q.; Bouquet, V.; Demange, V.; Deputier, S. [Sciences Chimiques de Rennes, UMR 6226 CNRS/Universite de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Universite Europeenne de Bretagne (France); Wyczisk, F.; Garry, G.; Ziaie, A. [Thales Research and Technology, rd. 128, 91767 Palaiseau Cedex (France); Guilloux-Viry, M., E-mail: [Sciences Chimiques de Rennes, UMR 6226 CNRS/Universite de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Universite Europeenne de Bretagne (France)


    The diffusion of Mg in pulsed laser deposited K(Ta{sub 0.65}Nb{sub 0.35})O{sub 3} thin films epitaxially grown on (1 0 0) MgO single crystal substrate were investigated by Auger electron spectroscopy (AES). A diffusion of Mg from the substrate into the whole thickness (400 nm) of the as-deposited K(Ta{sub 0.65}Nb{sub 0.35})O{sub 3} films was observed with an accumulation of Mg at the surface. Ex situ post-annealing (750 deg. C/2 h) has led to a homogeneous distribution of Mg in all the ferroelectric coating. This strong reaction between film and substrate promotes a doping effect, responsible for the reduction of K(Ta{sub 0.65}Nb{sub 0.35})O{sub 3} dielectric losses in comparison with films grown on other substrates.

  19. Bioluminescent bioreporter integrated circuit devices and methods for detecting estrogen

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Michael L.; Paulus, Michael J.; Sayler, Gary S.; Applegate, Bruce M.; Ripp, Steven A.


    Bioelectronic devices for the detection of estrogen include a collection of eukaryotic cells which harbor a recombinant lux gene from a high temperature microorganism wherein the gene is operably linked with a heterologous promoter gene. A detectable light-emitting lux gene product is expressed in the presence of the estrogen and detected by the device.

  20. WE-E-BRE-08: Impact of IUdR in Rat 9L Glioma Cell Survival for 25–35 KeV Photo-Activated Auger Electron Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, D; Hogstrom, K [Louisiana State University, Baton Rouge, LA (United States); Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Brown, T; Dugas, J; Varnes, M [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Matthews, K [Louisiana State University, Baton Rouge, LA (United States)


    Purpose: To determine the biological effect from Auger electrons with 9% and 18% iododeoxyuridine (IUdR) incorporated into the DNA of rat 9L glioma cells at photon energies above and below the K-edge of iodine (33.2 keV). Methods: Rat 9L glioma cell survival versus dose curves with 0%, 9%, and 18% thymidine replacement with IUdR were measured using four irradiation energies (4 MV x-rays; monochromatic 35, 30, and 25 keV synchrotron photons). For each of 11 conditions (Energy, %IUdR) survival curves were fit to the data (826 cell cultures) using the linear-quadratic model. The ratio of doses resulting in 10% survival gave sensitization enhancement ratios (SER10) from which contributions due to linear-energy transfer (LET), radiosensitization (RS), and Auger effect (AE) were extracted. Results: At 35, 30, and 25 keV, SER10,LET values were 1.08±0.03, 1.22±0.02, and 1.37±0.02, respectively. At 4 MV SER10,RS values for 9% and 18% IUdR were 1.28±0.02 and 1.40±0.02, respectively. Assuming LET effects are independent of %IUdR and radiosensitization effects are independent of energy, SER10,AE values for 18% IUdR at 35, 30, and 25 keV were 1.35±0.05, 1.06±0.03, and 0.98±0.03, respectively; values for 9% IUdR at 35 and 25 keV were 1.01±0.04 and 0.82±0.02, respectively. Conclusion: For 18% IUdR the radiosensitization effect of 1.40 and the Auger effect of 1.35 at 35 keV are equally important to the combined effect of 1.90. No measureable Auger effect was observed for energies below the K-edge at 20 and 25 keV, as expected. The insignificant Auger effect at 9% IUdR was not expected. Additional data (40–70 keV) and radiobiological modeling are being acquired to better understand the energy dependence of Auger electron therapy with IUdR. Funding support in part by the National Science Foundation Graduate Research Fellowship Program and in part by Contract No. W81XWH-10-1-0005 awarded by the U.S. Army Research Acquisition Activity. This paper does not necessarily

  1. Auger electron spectroscopy study of surface segregation in the binary alloys copper-1 atomic percent indium, copper-2 atomic percent tin, and iron-6.55 atomic percent silicon (United States)

    Ferrante, J.


    Auger electron spectroscopy was used to examine surface segregation in the binary alloys copper-1 at. % indium, copper-2 at. % tin and iron-6.55 at. % silicon. The copper-tin and copper-indium alloys were single crystals oriented with the /111/ direction normal to the surface. An iron-6.5 at. % silicon alloy was studied (a single crystal oriented in the /100/ direction for study of a (100) surface). It was found that surface segregation occurred following sputtering in all cases. Only the iron-silicon single crystal alloy exhibited equilibrium segregation (i.e., reversibility of surface concentration with temperature) for which at present we have no explanation. McLean's analysis for equilibrium segregation at grain boundaries did not apply to the present results, despite the successful application to dilute copper-aluminum alloys. The relation of solute atomic size and solubility to surface segregation is discussed. Estimates of the depth of segregation in the copper-tin alloy indicate that it is of the order of a monolayer surface film.

  2. Positron lifetime measurements and positron-annihilation induced auger electron spectroscpy using slow positron beams; Teisoku yodenshi bimu wo mochiita yodenshi jumyo sokutei oyobi yodenshi shometsu reiki oje denshi bunko

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, R. [Electrotechnical Lab., Tsukuba (Japan)


    Slow positron beam with less than several eV can be controlled freely such as accelerating, throttling the beam size, shortening the pulse or making pulse with short time width and so forth. These low positron beams are applied to various measurements like Doppler broadening measurement of annihilation {gamma} rays or lifetime measurement of positron, and secondary particle measurements using positron microscope, positron electron ray diffraction, flight time method and so forth. In particular, these recent years, high intensity slow positron beams were possible using accelerators like electron linac and its application is increasing. In this report, pulse shortening method for high intensity slow positron beam, and incidence energy variable positron lifetime measurement method using this slow pulsed beam and flight time type positron-annihilation-induced auger electron spectroscopy are outlined. In future, these measurements can be possible to carry out with high resolution and also with high counting rate if higher intensity monochromatic excellent positron beam than present one is produced. 31 refs., 5 figs.

  3. Surface and subsurface oxidation of Mo2C/Mo(100): low-energy ion-scattering, auger electron, angle-resolved X-ray photoelectron, and mass spectroscopy studies. (United States)

    Ovári, László; Kiss, János; Farkas, Arnold P; Solymosi, Frigyes


    The interaction of oxygen with a carburized Mo(100) surface was investigated at different temperatures (300-1000 K). The different information depths of low-energy ion-scattering (LEIS) spectroscopy, with topmost layer sensitivity, Auger electron spectroscopy (AES), and angle-resolved X-ray photoelectron spectroscopy (ARXPS) allowed us to discriminate between reactions on the topmost layer and subsurface transformations. According to ARXPS measurements, a carbide overlayer was prepared by the high-temperature decomposition of C(2)H(4) on Mo(100), and the carbon distribution proved to be homogeneous with a Mo(2)C stoichiometry down to the information depth of XPS. O(2) adsorbs dissociatively on the carbide layer at room temperature. One part of the chemisorbed oxygen is bound to both C and Mo sites, indicated by LEIS. Another fraction of oxygen atoms probably resides in the hollow sites not occupied by C. The removal of C from the outermost layer by O(2), in the form of CO, detected by mass spectroscopy (MS), was observed at 500-600 K. The carbon-depleted first layer is able to adsorb more oxygen compared to the Mo(2)C/Mo(100) surface. Applying higher doses of O(2) at 800 K results in the inward diffusion of O and the partial oxidation of Mo atoms. This process, however, is not accompanied by the removal of C from subsurface sites. The depletion of C from the bulk starts only at 900 K (as shown by MS, AES, and XPS), very probably by the diffusion of C to the surface followed by its reaction with oxygen. At T(ads) = 1000 K, the carbon content of the sample, down to the information depth of XPS, decreased further, accompanied by the attenuation of the C concentration gradient and a substantially decreased amount of oxygen.

  4. Uptake and dosimetry of Auger emitting diagnostic radionuclides (in particular indium-111) in human male germ cells

    Energy Technology Data Exchange (ETDEWEB)

    Nettleton, J.S. [Health and Safety Executive, Quay House, Manchester (United Kingdom); Lawson, R.S.; Prescott, M.C. [Department of Nuclear Medicine, Manchester Royal Infirmary, Manchester (United Kingdom); Hoyes, K.P.; Morris, I.D. [School of Biological Sciences, University of Manchester, Manchester (United Kingdom)


    This paper concerns the uptake and dosimetry of Auger electron emitting radionuclides which are used during routine diagnostic nuclear medicine procedures, in human testes and spermatozoa (sperm). A computer model was developed to calculate the doses to sperm heads from cellular localisation of the Auger electron emitting radionuclides {sup 99m}Tc, {sup 111}In, {sup 123}I and {sup 201}Tl. An assumption of ellipsoidal geometry was made to approximate the sperm head. S Factors were determined for differing sub-cellular localisations of radionuclide. The S-Factors determined were then combined with in-vitro data for quantification of radionuclide uptake for {sup 99m}Tc pertechnetate, {sup 111}In chloride and {sup 201}Tl chloride, to estimate in-vivo doses to sperm heads following intravenous administration of radionuclide in typical diagnostic quantities. The uptake and resulting cellular radiation dose of {sup 111}In (from the chloride) was significantly larger than the other radionuclides in the chemical forms investigated. Further investigations were carried out to determine localisation of {sup 111}In on sperm. The results of these experiments indicate that the radiation dose to mature sperm following administration of {sup 111}In pharmaceuticals for diagnostic purposes might be large enough to result in DNA damage which is not expressed until after fertilisation of an oocyte. Consideration should therefore be given to providing some contraceptive advice following diagnostic administrations of this radionuclide. In order to consider the possible effects of these radionuclides on other spermatogenic cells, further studies were undertaken to obtain in-vivo data for quantification of {sup 111}In chloride and {sup 201}Tl chloride uptake into the human testis following intravenous administration. Conventional dosimetry was then used to estimate testicular radiation dose using our values of percentage uptake. The results obtained indicate that the values of testicular

  5. Estrogen and Osteoporosis. (United States)

    Lindsay, Robert


    This article reviews the use of estrogen in the prevention and treatment of osteoporosis. Dosage levels, interactions with other factors, side effects, and the mechanism of estrogen action are discussed. (Author/MT)

  6. Estrogens, inflammation and cognition. (United States)

    Au, April; Feher, Anita; McPhee, Lucy; Jessa, Ailya; Oh, Soojin; Einstein, Gillian


    The effects of estrogens are pleiotropic, affecting multiple bodily systems. Changes from the body's natural fluctuating levels of estrogens, through surgical removal of the ovaries, natural menopause, or the administration of exogenous estrogens to menopausal women have been independently linked to an altered immune profile, and changes to cognitive processes. Here, we propose that inflammation may mediate the relationship between low levels of estrogens and cognitive decline. In order to determine what is known about this connection, we review the literature on the cognitive effects of decreased estrogens due to oophorectomy or natural menopause, decreased estrogens' role on inflammation--both peripherally and in the brain--and the relationship between inflammation and cognition. While this review demonstrates that much is unknown about the intersection between estrogens, cognition, inflammation, we propose that there is an important interaction between these literatures.

  7. Enzymatic treatment of estrogens and estrogen glucuronide

    Institute of Scientific and Technical Information of China (English)

    Takaaki Tanaka; Toshiyuki Tamura; Yuuichi Ishizaki; Akito Kawasaki; Tomokazu Kawase; Masahiro Teraguchi; Masayuki Taniguchi


    Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers.In this article we investigated the enzymatic treatment of three estrogens (estrone,17β-estradiol,and 17α-ethynyletstradiol) by a fungal laccase which oxidize phenolic compounds with dissolved oxygen.The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay.In addition,we developed an enzymatic treatment system comprised of β-D-glucuronidase and the laccase for 17β-estradiol 3-(β-D-glucuronide) degradation.The two enzymes eliminated 17β-estradiol 3-(β-D-glucuronide) and the intermediate,17β-estradiol,efficiently.

  8. Surface photovoltage and Auger electron spectromicroscopy studies of HfO{sub 2}/SiO{sub 2}/4H-SiC and HfO{sub 2}/Al{sub 2}O{sub 3}/4H-SiC structures

    Energy Technology Data Exchange (ETDEWEB)

    Domanowska, A., E-mail: [Department of Surface Physics and Nanostructures, Institute of Physics - Centre for Science and Education, Silesian University of Technology, Krzywoustego 2, 44-100 Gliwice (Poland); Miczek, M.; Ucka, R.; Matys, M.; Adamowicz, B. [Department of Surface Physics and Nanostructures, Institute of Physics - Centre for Science and Education, Silesian University of Technology, Krzywoustego 2, 44-100 Gliwice (Poland); Zywicki, J. [High-Tech International Services, Rome (Italy); Taube, A. [Institute of Electron Technology, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Korwin-Mikke, K. [Institute of Electron Technology, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Gieraltowska, S. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Sochacki, M. [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland)


    The electronic and chemical properties of the interface region in the structures obtained by the passivation of epitaxial n-type 4H-SiC layers with bilayers consisting of a 5 nm-thick SiO{sub 2} or Al{sub 2}O{sub 3} buffer film and high-{kappa} HfO{sub 2} layer were investigated. The main aim was to estimate the influence of the passivation approach on the interface effective charge density (Q{sub eff}) from the surface photovoltage (SPV) method and, in addition to determine the in-depth element distribution in the interface region from the Auger electron spectroscopy (AES) combined with Ar{sup +} ion profiling. The structure HfO{sub 2}/SiO{sub 2}/4H-SiC exhibited slightly superior electronic properties in terms of Q{sub eff} (in the range of -10{sup 11} q cm{sup -2}).

  9. Estrogen and Bazedoxifene (United States)

    ... frequent and stop and women may experience other symptoms and body changes). Estrogen and bazedoxifene tablets are also used to prevent osteoporosis (condition in which the bones become thin and ...

  10. Estrogen supplements in menopause. (United States)

    Booher, D L


    The number of women aged 65 and older is expected to double by the year 2000, increasing the need for effective management of symptoms related to menopause. Contemporary management of menopause addresses the continuum of events associated with the effects of estrogen deprivation on quality and duration of life, including neuroendocrine changes, urogenital atrophy, sexual dysfunction, skin and hair changes, osteoporosis, and cardiovascular disease. The risks and benefits of management strategies, including hormone replacement therapy, must be weighted carefully by both physician and patient. The use of estrogens and progestins, alterative compounds, dosages, routes of administration, and their advantages and disadvantages must be analyzed.

  11. Exercise, Eating, Estrogen, and Osteoporosis. (United States)

    Brown, Jim


    Osteoporosis affects millions of people, especially women. Three methods for preventing or managing osteoporosis are recommended: (1) exercise; (2) increased calcium intake; and (3) estrogen replacement therapy. (CB)

  12. Estrogenic effects from household stoves. (United States)

    Wu, W Z; Chen, J; Rehmann, K; Schramm, K W; Kettrup


    With the application of a genetically modified yeast, estrogen receptor-activating compounds were detected in the soot and emission gas of a wood-burning household stove. The EC50 value of 17beta-estradiol was divided by the EC50 value of soot, and the obtained relative estrogenic value for raw soot was 2.37E-5, indicating that soot was about 100,000 times less estrogenic than 17beta-estradiol. Chemical analysis revealed that alkyl phenol, benzonic acid, and PAHs represented the major constituents in the most potent fractions of the soot. Along with PAHs, other constituents might also contribute to the estrogenicity of soot.

  13. Presence of estrogenic activity from emission of fossil fuel combustion as detected by a recombinant yeast bioassay (United States)

    Wang, Jingxian; Wu, Wenzhong; Henkelmann, Bernhard; You, Li; Kettrup, Antonius; Schramm, Karl-Werner

    Estrogenic activities of emission samples generated by fossil fuel combustion were investigated with human estrogen receptor (ER) recombinant yeast bioassay. The results showed that there were weak but clear estrogenic activities in combustion emissions of fossil fuels including coal, petroleum, and diesel. The estrogenic relative potency (RP) of fossil fuel combustion was the highest in petroleum-fired car, followed by coal-fired stove, diesel-fired agrimotor, coal-fired electric power station. On the other hand, the estrogenic relative inductive efficiency (RIE) was the highest in coal-fired stove and coal-fired electric power station, followed by petroleum-fired car and diesel-fired agrimotor. The estrogenic activities in the sub-fractions from chromatographic separation of emitted materials were also determined. The results indicated that different chemical fractions in these complex systems have different estrogenic potencies. The GC/MS analysis of the emission showed that there were many aromatic carbonyls, big molecular alcohol, PAHs and derivatives, and substituted phenolic compounds and derivatives which have been reported as environmental estrogens. The existence of estrogenic substances in fossil fuel combustion demands further investigation of their potential adverse effects on human and on the ecosystem. The magnitude of pollution due to global usage of fossil fuels makes it imperative to understand the issue of fossil fuel-derived endocrine activities and the associated health risks, particularly the aggregated risks stemmed from exposure to toxicants of multiple sources.

  14. Presence of estrogenic activity from emission of fossil fuel combustion as detected by a recombinant yeast bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.X.; Wu, W.Z.; Henkelmann, B.; You, L.; Kettrup, A.; Schramm, K.W. [GSF, Neuherberg (Germany). National Research Center for Environmental & Health


    Estrogenic activities of emission samples generated by fossil fuel combustion were investigated with human estrogen receptor recombinant yeast bioassay. The results showed that there were weak but clear estrogenic activities in combustion emissions of fossil fuels including coal, petroleum, and diesel. The estrogenic relative potency of fossil fuel combustion was the highest in petroleum-fired car, followed by coal-fired stove, diesel-fired agrimotor, coal-fired electric power station. On the other hand, the estrogenic relative inductive efficiency was the highest in coal-fired stove and coal-fired electric power station, followed by petroleum-fired car and diesel-fired agrimotor. The estrogenic activities in the sub-fractions from chromatographic separation of emitted materials measured. The results indicated that different chemical fractions in these complex systems have different estrogenic potencies. The GC/MS analysis of the emission showed that there were many aromatic carbonyls, big molecular alcohol, PAHs and derivatives, and substituted phenolic compounds and derivatives which have been reported as environmental estrogens. The existence of estrogenic substances in fossil fuel combustion demands further investigation of their potential adverse effects on human and on the ecosystem.

  15. Estrogen receptors in breast carcinoma. (United States)

    Huaman, A


    On the basis of estrogen receptor assays, breast carcinomas are presently classified as estrogen-dependent tumors, which respond to endocrine therapy, and autonomous tumors, for which endocrine therapy is useless. This paper presents a short review of the biochemical principles of estrogen dependence, the procedures used to determine estrogen receptors, and the clinical applications of the findings of these assay procedures. Biobhemically, the estroogen dependence of normal breast cells is explained as a biochemical reaction occurring between the circulating estradiol and the breast cell, which occurs in 3 steps: 1) circulating estradiol penetrates the cellular membrane by passive diffusion, followed by 2) combining of estradiol with the estrogen-binding protein (estrophilin) and formation of an estrogen receptor complex which undergoes activation and translocation into the nucleus, to result in 3) the activated steroid receptor which combines with the nuclear charomatin and stimulates ribonucleic acid synthesis for the formation of estradiol binding proteins or estradiol receptors. The cytosol method of Wittliff et al. is described in brief and entails radioactive competitive analysis; the other available laboratory procedure is immunofluorescence of tumor sections. Quantification of estrogen receptor content can be used clinically to decide on ablative endocrine therapy, to determine the effectiveness of anti-estrogen administration, to determine the primary site of metastatic carcinoma, and as a screenng device.


    NARCIS (Netherlands)

    ter Horst, Gert J.; Litwack, G


    Estrogens are a group of steroid hormones that function as the primary female sex hormone. Estrogens not only have an important role in the regulation of the estrous or menstrual cycle but also control, for example, bone formation, the cardiovascular system, and cognitive functions. Estradiol (E2),

  17. Estrogenic compounds -endocrine disruptors

    Directory of Open Access Journals (Sweden)

    Munteanu Constantin


    Full Text Available Endocrine disruptors (polychlorinated biphenyls, dichlorodiphenyl-trichloroethane [DDT], dioxin, and some pesticides are estrogen-like and anti-androgenic chemicals in the environment. They mimic natural hormones, inhibit the action of hormones, or alter the normal regulatory function of the endocrine system and have potential hazardous effects on male reproductive axis causing infertility. Although testicular and prostate cancers, abnormal sexual development, undescended testis, chronic inflammation, Sertoli-cell-only pattern, hypospadias, altered pituitary and thyroid gland functions are also observed, the available data are insufficient to deduce worldwide conclusions.

  18. Estrogen Receptor Agonists and Antagonists in the Yeast Estrogen Bioassay. (United States)

    Wang, Si; Bovee, Toine F H


    Cell-based bioassays can be used to predict the eventual biological activity of a substance on a living organism. In vitro reporter gene bioassays are based on recombinant vertebrate cell lines or yeast strains and especially the latter are easy-to-handle, cheap, and fast. Moreover, yeast cells do not express estrogen, androgen, progesterone or glucocorticoid receptors, and are thus powerful tools in the development of specific reporter gene systems that are devoid of crosstalk from other hormone pathways. This chapter describes our experience with an in-house developed RIKILT yeast estrogen bioassay for testing estrogen receptor agonists and antagonists, focusing on the applicability of the latter.

  19. Some strategies for quantitative scanning Auger electron microscopy (United States)

    Browning, R.; Peacock, D. C.; Prutton, M.


    The general applicability of power law forms of the background in electron spectra is pointed out and exploited for background removal from under Auger peaks. This form of B(E) is found to be extremely sensitive to instrumental alignment and to fault-free construction - an observation which can be used to set up analyser configurations in an accurate way. Also, differences between N(E) and B(E) can be used to derive a spectrometer transmission function T(E). The questions of information density in an energy-analysing spatially-resolving instrument are addressed after reliable instrumental characterization has been established. Strategies involving ratio histograms, showing the population distribution of the ratio of a pair of Auger peak heights, composition scatter diagrams and windowed imaging are discussed and illustrated.

  20. Photoelectron-Auger electron coincidence study for condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Stefani, G. [Department of Physics and Unita' INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy)]. E-mail:; Gotter, R. [National Laboratory TASC-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy); Ruocco, A. [Department of Physics and Unita INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Offi, F. [Department of Physics and Unita INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Pieve, F. Da [Department of Physics and Unita INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Iacobucci, S. [IMIP-CNR Area della Ricerca di Roma, via Salaria Km 29, 3 Montelibretti (Italy); Morgante, A. [National Laboratory TASC-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy); Verdini, A. [National Laboratory TASC-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy); Liscio, A. [IMIP-CNR Area della Ricerca di Roma, via Salaria Km 29, 3 Montelibretti (Italy); Yao, H. [Department of Physics and Astronomy and Laboratory of Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 (United States); Bartynski, R.A. [Department of Physics and Astronomy and Laboratory of Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 (United States)


    Advances in materials science have produced a wide array of new solid-state systems with tunable properties and previously unattainable combinations of phenomena that hold the promise of entirely new approaches to technological applications. Invariably, these new materials are increasingly complex and include a large number of constituents in a variety of chemical states. Entirely new theoretical and experimental approaches are needed to gain the insights necessary for intelligent engineering of these materials. In the past 20 years, a steadily increasing number of electron-electron coincidence experiments on atoms and molecules have demonstrated the capability of investigating complicated systems with sensitivity and specificity well beyond the limits imposed by conventional electron spectroscopies. Over the past decade or so, Auger-photoelectron coincidence spectroscopy (APECS) has emerged as a powerful technique for obtaining detailed information about complex materials systems. Moreover, the recent advent of angle-resolved (AR)-APECS has introduced a new level of discrimination in studying the distribution of electrons photoemitted from complex systems. In this review, we describe the basic ideas behind APECS and discuss a study of the SiO{sub 2} system as an example of the unique information this technique can provide. We then introduce the concept of AR-APECS, explain its novel state and angular momentum selectivity that can be used to disentangle information about complex systems that is hidden to conventional spectroscopies. Examples of AR-APECS measurements from Cu, Ge, and graphite that exemplify the capabilities of this technique are presented.

  1. Estrogen and gastrointestinal malignancy.

    LENUS (Irish Health Repository)

    Hogan, A M


    The concept that E2 exerts an effect on the gastrointestinal tract is not new and its actions on intestinal mucosa have been investigated for at least three decades. An attempt to consolidate results of these investigations generates more questions than answers, thus suggesting that many unexplored avenues remain and that the full capabilities of this steroid hormone are far from understood. Evidence of its role in esophageal, gastric and gallbladder cancers is confusing and often equivocal. The most compelling evidence regards the protective role conferred by estrogen (or perhaps ERbeta) against the development and proliferation of colon cancer. Not only has the effect been described but also many mechanisms of action have been explored. It is likely that, along with surgery, chemotherapy and radiotherapy, hormonal manipulation will play an integral role in colon cancer management in the very near future.

  2. Red Emitting VCSEL (United States)

    Jetter, Michael; Roßbach, Robert; Michler, Peter

    This chapter describes the progress in development of vertical-cavity surface-emitting lasers (VCSEL) emitting in the red spectral region around 650 nm for data transmission over polymer optical fibers (POF). First, growth issues of red VCSEL using two different material systems, namely AlGaAs and AlGaInP, are introduced. In particular, the optical and electrical state-of-the-art characteristics as low threshold currents ({≤} 1 mA) and high output powers (several mW) are presented with a special focus on emission wavelength. Also the thermal budget and heat removal in the devices are pointed out with regard to the geometry of the VCSEL. Small-signal modulation response in terms of maximum resonance frequency in dependance on temperature behavior are discussed. Applications of these devices in optical interconnects are described and digital data transmission at data rates up to 2.1 Gbit/s over step-index POF is reported. These properties make red emitting VCSEL perfectly suited for high-speed low power consuming light sources for optical data communication via POF. By introducing InP quantum dots as gain material in red emitting VCSEL nearly temperature independent record low threshold current densities of around 10 A/cm2 could be observed.

  3. Light-Emitting Pickles (United States)

    Vollmer, M.; Mollmann, K-P.


    We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

  4. Fish populations surviving estrogen pollution. (United States)

    Wedekind, Claus


    Among the most common pollutants that enter the environment after passing municipal wastewater treatment are estrogens, especially the synthetic 17α-ethinylestradiol that is used in oral contraceptives. Estrogens are potent endocrine disruptors at concentrations frequently observed in surface waters. However, new genetic analyses suggest that some fish populations can be self-sustaining even in heavily polluted waters. We now need to understand the basis of this tolerance.

  5. The Relationship between Periodontopathy and Estrogen

    Institute of Scientific and Technical Information of China (English)

    YAN Shiguang; LI Dexiang


    Objecitve To discuss the relationship between peridontopathy and estrogen. Method We discussed the relationship between periodontopathy and increasing of estrogen, the relationship between peridontopoathy and deficiency of estrogen and the relationship between osteoprotegerin in osteoblasts and estrogen. Results When estrogen increased or decreased abnormally, osteoporosis could occur, which induced alveolar ridge resorption and alveolar bone atrophy. Then the teeth exfoliated.Teeth uncleanness facilitated periodontopathy. Conclusion No matter how young or old, keeping the relative balance of estrogen can protect gingiva and alveolar bone. At the same time, keeping teeth clean is also essential to prevent periodontopathy.

  6. Estrogenic flavonoids: structural requirements for biological activity. (United States)

    Miksicek, R J


    A systematic survey of polycyclic phenols has been performed to identify members of this chemical group with estrogenic activity. Twelve compounds were found to be able to stimulate the transcriptional activity of the human estrogen receptor expressed in cultured cells by transient transfection. These natural estrogens belong to several distinct, but chemically related classes including chalcones, flavanones, flavones, flavonols, and isoflavones. Selected examples of estrogenic flavonoids were further analyzed to determine their biological potencies and their relative affinities for binding to the estrogen receptor. These data are interpreted with respect to the molecular structure of polycyclic phenols required for hormonal activity as nonsteroidal estrogens.

  7. Estrogenic endocrine disruptors: Molecular mechanisms of action. (United States)

    Kiyama, Ryoiti; Wada-Kiyama, Yuko


    A comprehensive summary of more than 450 estrogenic chemicals including estrogenic endocrine disruptors is provided here to understand the complex and profound impact of estrogen action. First, estrogenic chemicals are categorized by structure as well as their applications, usage and effects. Second, estrogenic signaling is examined by the molecular mechanism based on the receptors, signaling pathways, crosstalk/bypassing and autocrine/paracrine/homeostatic networks involved in the signaling. Third, evaluation of estrogen action is discussed by focusing on the technologies and protocols of the assays for assessing estrogenicity. Understanding the molecular mechanisms of estrogen action is important to assess the action of endocrine disruptors and will be used for risk management based on pathway-based toxicity testing.

  8. Breast Cancer and Estrogen-Alone Update (United States)

    ... Issues Research News From NIH Breast Cancer and Estrogen-Alone Update Past Issues / Summer 2006 Table of ... version of this page please turn Javascript on. Estrogen-alone hormone therapy does not increase the risk ...

  9. Light Emitting Porous Silicon (United States)


    ml - mm m lm m ~ m m ThO report Page 14 preparation method which has been originally described by Wohler [23] leads to a bright yellow substance with...Solid State Commun. 81, 307 (1992). [221 H. Kautsky, and H. Zocher, Z. Phys. 9,267 (1992). L TNO report Page 28 [231 F. Wohler , Lieb. Ann. 127, 275 (1863...Netherlands Fax + 31 70 328 09 61 Phone + 31 70 326 42 21 TNO- report copy no. e FEL-93eo047r Lh Emitting Porous Silicon sitho(s): DTICHMi.P.Th

  10. Selectively targeting estrogen receptors for cancer treatment

    NARCIS (Netherlands)

    Shanle, Erin K.; Xu, Wei


    Estrogens regulate growth and development through the action of two distinct estrogen receptors (ERs), ER alpha and ER beta, which mediate proliferation and differentiation of cells. For decades, ER alpha mediated estrogen signaling has been therapeutically targeted to treat breast cancer, most nota

  11. Estrogenic activity of natural and synthetic estrogens in human breast cancer cells in culture.


    Zava, D T; Blen, M; Duwe, G


    We investigated the estrogenic activity of various environmental pollutants (xenobiotics), in particular the xenoestrogen o,p-DDT, and compared their effects with those of endogenous estrogens, phytoestrogens, and mycoestrogens on estrogen receptor binding capacity, induction of estrogen end products, and activation of cell proliferation in estrogen-sensitive human breast cancer cells in monolayer culture. We also quantified the levels of phytoestrogens in extracts of some common foods, herbs...

  12. In Vivo Imaging of Activated Estrogen Receptors in Utero by Estrogens and Bisphenol A


    Lemmen, Josephine G.; Arends, Roel J.; van der Saag, Paul T.; van der Burg, Bart


    Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that...

  13. Fabrication of Metal-Deposited Indium Tin Oxides: Its Applications to 385 nm Light-Emitting Diodes. (United States)

    Kim, Min Ju; Kim, Tae Geun


    We report performance improvements in near-ultraviolet (NUV) light-emitting diodes (LEDs) using various metal-doped indium tin oxide (ITO/metals). Metals with an orbital energy gap greater than that of an In atom (e.g., Ti, Ga, Ge, and Al) are deposited on ITO, and subsequent annealing is performed to improve optical transmittance of ITO due to effective bandgap increase via the linear combination of atomic orbitals, as well as electrical conductivity; thus, current spreading via metal-doping effect at the surface of ITO. As a result, the ITO/metals (annealed at 550 °C, 1 min) exhibit 90.5-94.7% transmittance at 385 nm and a specific contact resistance of 2.1-3.0 × 10(-3) Ω cm(2), whereas the reference ITOs exhibit 76.5-89.5% and 3.2-4.5 × 10(-3) Ω cm(2), respectively. Compared to NUV LEDs using conventional ITO (60 nm), the InGaN/AlGaInN NUV LED using ITO (110 nm)/metal (3 nm) on average exhibits a 70% increase in light output power at 100 mA and a 2% decrease in forward voltage at 20 mA, with more uniform and brighter emission images. We also identified the origin for the improvement by analyzing the surface of ITO/metals using X-ray photoelectron spectroscopy and Auger electron spectroscopy. This approach could offer a simple, effective way to enhance the overall efficiency of conventional NUV LEDs using ITO.

  14. Estrogen and estrogen receptors in cardiovascular oxidative stress. (United States)

    Arias-Loza, Paula-Anahi; Muehlfelder, Melanie; Pelzer, Theo


    The cardiovascular system of a premenopausal woman is prepared to adapt to the challenges of increased cardiac output and work load that accompany pregnancy. Thus, it is tempting to speculate whether enhanced adaptability of the female cardiovascular system might be advantageous under conditions that promote cardiovascular disease. In support of this concept, 17β-estradiol as the major female sex hormone has been shown to confer protective cardiovascular effects in experimental studies. Mechanistically, these have been partially linked to the prevention and protection against oxidative stress. Current evidence indicates that estrogens attenuate oxidative stress at two levels: first, by preventing generation of reactive oxygen species (ROS) and, second, by scavenging ROS in the myocardium and in the vasculature. The purpose of this review is to give an overview on current concepts on conditions and mechanisms by which estrogens protect the cardiovascular system against ROS-mediated cellular injury.

  15. The role of environmental estrogens and autoimmunity. (United States)

    Chighizola, Cecilia; Meroni, Pier Luigi


    The prevalence of autoimmune diseases has significantly increased over the recent years. It has been proposed that this epidemiological evidence could be in part attributable to environmental estrogens, compounds that display estrogen-like activity and are ubiquitously present in the environment. Environmental estrogens can be found in a wide variety of foods: phytoestrogens occur in plants such as clover and soy, while mycoestrogens are food contaminants produced by fungi. Meat, eggs and dairy products from animals given exogenous hormones contain relatively high concentration of estrogens. Among xenoestrogens, industrial estrogens are synthetic chemicals produced for specific purposes (pesticides, plastics, surfactants and detergents) while metalloestrogens are found in heavy metals. Estrogens can be also administered through medications (contraceptive pill, hormone replacement therapy, genistein, cimetidine, creams). There is a considerable burden of evidence in vitro and in animal models that these compounds may exert immunotoxic effects. However, to date there is no convincing data that exposure to environmental estrogens can be regarded as a risk for human health. In particular, there is no consensus whether prolonged exposure to relatively low concentrations of different estrogenic chemicals can affect the human immune system and induce clinically evident diseases in real-life scenario. Moreover, the effects on human health of the synergistic interactions between natural, medical, dietary and environmental estrogens have not been fully elucidated yet. Here we provide an extensive review of the in vivo and in vitro effects of environmental estrogens on the immune system, focusing on the evidences of association between exposure and autoimmune disorders.

  16. Estrogen Therapy Rescues Advanced Heart Failure via Estrogen Receptor Beta


    Iorga, Andrea


    Cardiac hypertrophy, defined as an enlargement of the ventricles, is often triggered when the heart is subjected to hemodynamic stress from physiological stimuli such as pregnancy, or from pathological stimuli such as pressure overload-induced left ventricular hypertrophy or pulmonary hypertension-induced right ventricular hypertrophy. Physiological hypertrophy is beneficial and adaptive, while pathological hypertrophy is maladaptive and detrimental. Estrogen treatment prior to the onset of p...

  17. Targeted Radiotherapy of Estrogen Receptor Positive Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan Rajagopalan


    The overall objectives of the proposal were to develop estrogen receptor (ER) binding small molecule radiopharmaceuticals for targeted radiotherapy of ER positive (ER+) tumors. In particular, this proposal focused on embedding a {sup 186,188}Re or a {sup 32}P radionuclide into an estrogen steroidal framework by isosteric substitution such that the resulting structure is topologically similar to the estrogen (estrogen mimic). The estrogen mimic molecules expected to bind to the ER and exhibit biodistribution akin to that of native estrogen due to structural mimicry. It is anticipated that the {sup 186,188}Re- or a {sup 32}P-containing estrogen mimics will be useful for targeted molecular radiotherapy of ER+ tumors. It is well established that the in vivo target tissue uptake of estrogen like steroidal molecules is related to the binding of the steroids to sex hormone binding globulin (SHBG). SHBG is important in the uptake of estrogens and testosterone in target tissues by SHBG receptors on the cell surface. However, hitherto the design of estrogen like small molecule radiopharmaceuticals was focused on optimizing ER binding characteristics without emphasis on SHBG binding properties. Consequently, even the molecules with good ER affinity in vitro, performed poorly in biodistribution studies. Based on molecular modeling studies the proposal focused on developing estrogen mimics 1-3 which were topologically similar to native estrogens, and form hydrogen bonds in ER and SHBG in the same manner as those of native estrogens. To this end the technical objectives of the proposal focused on synthesizing the rhenium-estrone and estradiol mimics 1 and 2 respectively, and phosphorous estradiol mimic 3 and to assess their stability and in vitro binding characteristics to ER and SHBG.

  18. Holographic QSAR of environmental estrogens

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaodong; XIAO; Qianfen; CUI; Shihai; LIU; Shushen


    Experimental and epidemiological studies suggest that some man-made and naturally occurring chemicals related to the environment have the potential to interrupt normal functioning of the endocrine systems of humans and wildlife. These chemicals, termed EDCs (Endocrine disrupting Chemicals), pose serious threats to the reproductive capability of humans and wildlife. Because of the structural diversity and various types, development of structure-based rapid screening methodologies is important and necessary for the assessment of the environmental pollutants. In this paper molecular hologram based QSAR models were developed with the combinatory application of partial least square (PLS) regression for a large diverse set of 105 environmental estrogens. Quantitatively predictive models were developed based on only molecular structures, which can be used for the accurate prediction of estrogenicity to rapidly screen potential environmental endocrine disrupting chemicals.

  19. Binding of Estrogenic Compounds to Recombinant Estrogen Receptor-α: Application to Environmental Analysis


    Pillon, Arnaud; Boussioux, Anne-Marie; Escande, Aurélie; Aït-Aïssa, Sélim; Gomez, Elena; Fenet, Hélène; Ruff, Marc; Moras, Dino; Vignon, Françoise; Duchesne, Marie-Josèphe; Casellas, Claude; Nicolas, Jean-Claude; Balaguer, Patrick


    Estrogenic activity in environmental samples could be mediated through a wide variety of compounds and by various mechanisms. High-affinity compounds for estrogen receptors (ERs), such as natural or synthetic estrogens, as well as low-affinity compounds such as alkylphenols, phthalates, and polychlorinated biphenyls are present in water and sediment samples. Furthermore, compounds such as polycyclic aromatic hydrocarbons, which do not bind ERs, modulate estrogen activity by means of the aryl ...

  20. Binding of estrogenic compounds to recombinant estrogen receptor-alpha: application to environmental analysis.


    Pillon, Arnaud; Boussioux, Anne-Marie; Escande, Aurélie; Aït-Aïssa, Sélim; Gomez, Elena; Fenet, Hélène; Ruff, Marc; Moras, Dino; Vignon, Françoise; Duchesne, Marie-Josèphe; Casellas, Claude; Nicolas, Jean-Claude; Balaguer, Patrick


    International audience; Estrogenic activity in environmental samples could be mediated through a wide variety of compounds and by various mechanisms. High-affinity compounds for estrogen receptors (ERs), such as natural or synthetic estrogens, as well as low-affinity compounds such as alkylphenols, phthalates, and polychlorinated biphenyls are present in water and sediment samples. Furthermore, compounds such as polycyclic aromatic hydrocarbons, which do not bind ERs, modulate estrogen activi...

  1. Distinct Effects of Estrogen on Mouse Maternal Behavior: The Contribution of Estrogen Synthesis in the Brain. (United States)

    Murakami, Gen


    Estrogen surge following progesterone withdrawal at parturition plays an important role in initiating maternal behavior in various rodent species. Systemic estrogen treatment shortens the latency to onset of maternal behavior in nulliparous female rats that have not experienced parturition. In contrast, nulliparous laboratory mice show rapid onset of maternal behavior without estrogen treatment, and the role of estrogen still remains unclear. Here the effect of systemic estrogen treatment (for 2 h, 1 day, 3 days, and 7 days) after progesterone withdrawal was examined on maternal behavior of C57BL/6 mice. This estrogen regimen led to different effects on nursing, pup retrieval, and nest building behaviors. Latency to nursing was shortened by estrogen treatment within 2 h. Moreover, pup retrieval and nest building were decreased. mRNA expression was also investigated for estrogen receptor α (ERα) and for genes involved in regulating maternal behavior, specifically, the oxytocin receptor (OTR) and vasopressin receptor in the medial amygdala (MeA) and medial preoptic area (MPOA). Estrogen treatment led to decreased ERα mRNA in both regions. Although OTR mRNA was increased in the MeA, OTR and vasopressin receptor mRNA were reduced in the MPOA, showing region-dependent transcription regulation. To determine the mechanisms for the actions of estrogen treatment, the contribution of estrogen synthesis in the brain was examined. Blockade of estrogen synthesis in the brain by systemic letrozole treatment in ovariectomized mice interfered with pup retrieval and nest building but not nursing behavior, indicating different contributions of estrogen synthesis to maternal behavior. Furthermore, letrozole treatment led to an increase in ERα mRNA in the MeA but not in the MPOA, suggesting that involvement of estrogen synthesis is brain region dependent. Altogether, these results suggest that region-dependent estrogen synthesis leads to differential transcriptional activation due

  2. CERAPP: Collaborative Estrogen Receptor Activity Prediction Project (United States)

    U.S. Environmental Protection Agency — Data from a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) demonstrating using predictive computational...

  3. Emissive Ion Thruster -EMIT Project (United States)

    National Aeronautics and Space Administration — A propulsion system is proposed that is based on acceleration of ions emitted from a thin, solid-state electrochemical ceramic membrane. This technology would...

  4. Electrochemical Light-Emitting Gel

    Directory of Open Access Journals (Sweden)

    Nobuyuki Itoh


    Full Text Available Light-emitting gel, a gel state electroluminescence material, is reported. It is composed of a ruthenium complex as the emitter, an ionic liquid as the electrolyte, and oxide nanoparticles as the gelation filler. Emitted light was produced via electrogenerated chemiluminescence. The light-emitting gel operated at low voltage when an alternating current was passed through it, regardless of its structure, which is quite thick. The luminescence property of the gel is strongly affected by nanoparticle materials. TiO2 nanoparticles were a better gelation filler than silica or ZnO was, with respect to luminescence stability, thus indicating a catalytic effect. It is demonstrated that the light-emitting gel device, with quite a simple fabrication process, flashes with the application of voltage.

  5. Parabens inhibit human skin estrogen sulfotransferase activity: possible link to paraben estrogenic effects. (United States)

    Prusakiewicz, Jeffery J; Harville, Heather M; Zhang, Yanhua; Ackermann, Chrisita; Voorman, Richard L


    Parabens (p-hydroxybenzoate esters) are a group of widely used preservatives in topically applied cosmetic and pharmaceutical products. Parabens display weak associations with the estrogen receptors in vitro or in cell based models, but do exhibit estrogenic effects in animal models. It is our hypothesis that parabens exert their estrogenic effects, in part, by elevating levels of estrogens through inhibition of estrogen sulfotransferases (SULTs) in skin. We report here the results of a structure-activity-relationship of parabens as inhibitors of estrogen sulfation in human skin cytosolic fractions and normal human epidermal keratinocytes. Similar to reports of paraben estrogenicity and estrogen receptor affinity, the potency of SULT inhibition increased as the paraben ester chain length increased. Butylparaben was found to be the most potent of the parabens in skin cytosol, yielding an IC(50) value of 37+/-5 microM. Butylparaben blocked the skin cytosol sulfation of estradiol and estrone, but not the androgen dehydroepiandrosterone. The parabens were also tested as inhibitors of SULT activity in a cellular system, with normal human epidermal keratinocytes. The potency of butylparaben increased three-fold in these cells relative to the IC(50) value from skin cytosol. Overall, these results suggest chronic topical application of parabens may lead to prolonged estrogenic effects in skin as a result of inhibition of estrogen sulfotransferase activity. Accordingly, the skin anti-aging benefits of many topical cosmetics and pharmaceuticals could be derived, in part, from the estrogenicity of parabens.

  6. Identification of estrogenic/anti-estrogenic compounds in diesel exhaust particulate extract. (United States)

    Noguchi, Keiko; Toriba, Akira; Chung, Sang Woon; Kizu, Ryoichi; Hayakawa, Kazuichi


    Diesel exhaust particulate extract (DEPE) was obtained from diesel exhaust particulates with Soxhlet extraction using dichloromethane. After separating DEPE into 11 fractions by liquid-liquid extraction, the neutral fraction (N) showed anti-estrogenic activity and the weak acid (phenol) fraction (WA(P)) showed estrogenic and anti-estrogenic activities by a yeast two-hybrid assay system expressing human estrogen receptor alpha. Both fractions were thoroughly fractionated by silica gel column chromatography and reversed-phase HPLC. In the WA(P) fraction, 3-methyl-4-nitrophenol and 2,6-dimethyl-4-nitrophenol were identified by LC-MS/MS as estrogenic compounds. This is the first study to identify 2,6-dimethyl-4-nitrophenol in DEPE and the first study to show that it is an estrogenic compound. In the N fraction, 1-hydroxypyrene was also identified by LC-MS/MS as an anti-estrogenic compound.

  7. Quantum chemical studies of estrogenic compounds (United States)

    Quantum chemical methods are potent tools to provide information on the chemical structure and electronic properties of organic molecules. Modern computational chemistry methods have provided a great deal of insight into the binding of estrogenic compounds to estrogenic receptors (ER), an important ...

  8. Estrogenic activity of naturally occurring anthocyanidins. (United States)

    Schmitt, E; Stopper, H


    Anthocyanins, which are natural plant pigments from the flavonoid family, represent substantial constituents of the human diet. Because some other bioflavonoids are known to have estrogenic activity, the aim of this study was to determine the estrogenic activity of the anthocyanine aglycones. Binding affinity to the estrogen receptor-alpha was 10,000- to 20,000-fold lower than that of the endogenous estrogen estradiol. In the estrogen receptor-positive cell line MCF-7, the anthocyanidins induced expression of a reporter gene. The tested anthocyanidins showed estrogen-inducible cell proliferation in two cell lines (MCF-7 and BG-1), but not in the receptor-negative human breast cancer cell line MDA-MB-231. The phytoestrogen-induced cell proliferation could be blocked by addition of the receptor antagonist 4-hydroxytamoxifen. Combination treatments with the endogenous estrogen estradiol resulted in a reduction of estradiol-induced cell proliferation. Overall, the tested anthocyanidins exert estrogenic activity, which might play a role in altering the development of hormone-dependent adverse effects.

  9. Use of vaginal estrogen in Danish women

    DEFF Research Database (Denmark)

    Meaidi, Amani; Goukasian, Irina; Lidegaard, Oejvind


    INTRODUCTION: We know little about the use of vaginal estrogen in perimenopausal and postmenopausal women. We aimed to assess the prevalence of vaginal estrogen use in Denmark. MATERIAL AND METHODS: The study was designed as a nationwide cross-sectional study of all Danish women aged 40-79 years,...

  10. Estrogen potency of oral contraceptive pills. (United States)

    Chihal, H J; Peppler, R D; Dickey, R P


    The estrogen potencies of 9 oral contraceptive pills, Enovid-E, Enovid-5, Ovulen, Demulen, Norinyl+80, Norinyl+50, Ovral, Norlestrin 1 mg. and Norlestrin 2.5 mg., were determined by bioassay. Relative estrogen potency was determined by analysis of variance. Enovid-5, the most estrogenic compound, had a potency of 4.88 compared to ethinyl estradiol, 50 mcg. equal 1.00; Ovral, the least estrogenic compound, had a potency of 0.81, a sixfold difference. Estrogen potencies at a fractional dose of 0.00155 correlate with reports of the incidence of minor side effects and thromboembolic disease. The effect of progestins on estrogen potency was purely additive (norgestrel and norethynodrel), purely antagonistic, or additive at low concentrations and antagonistic at high concentrations (norethindrone, norethindrone acetate, and ethynodiol diacetate). These results suggest that pills with a greater margin of safety might be developed by utilizing greater ratios of progestin to estrogen. In addition, differences in relative estrogen potency of oral contraceptive pills may be used as a basis for better clinical selection.

  11. Minireview: osteoprotective action of estrogens is mediated by osteoclastic estrogen receptor-alpha. (United States)

    Imai, Yuuki; Kondoh, Shino; Kouzmenko, Alexander; Kato, Shigeaki


    The osteoprotective action of estrogen in women has drawn considerable attention because estrogen deficiency-induced osteoporosis became one of the most widely spread diseases in developed countries. In men, the significance of estrogen action for bone health maintenance is also apparent from the osteoporotic phenotype seen in male patients with genetically impaired estrogen signaling. Severe bone loss and high bone turnover, including typical osteofeatures seen in postmenopausal women, can also be recapitulated in rodents after ovariectomy. However, the expected osteoporotic phenotype is not observed in female mice deficient in estrogen receptor (ER)-alpha or -beta or both, even though the degenerative defects are clearly seen in other estrogen target tissues together with up-regulated levels of circulating testosterone. It has also been reported that estrogens may attenuate bone remodeling by cell autonomous suppressive effects on osteoblastogenesis and osteoclastogenesis. Hence, the effects of estrogens in bone appear to be complex, and the molecular role of bone estrogen receptors in osteoprotective estrogen action remains unclear. Instead, it has been proposed that estrogens indirectly control bone remodeling. For example, the enhanced production of cytokines under estrogen deficiency induces bone resorption through stimulation of osteoclastogenesis. However, the osteoporotic phenotype without systemic defects has been recapitulated in female (but not in male) mice by osteoclast-specific ablation of the ERalpha, proving that bone cells represent direct targets for estrogen action. An aberrant accumulation of mature osteoclasts in these female mutants indicates that in females, the inhibitory action of estrogens on bone resorption is mediated by the osteoclastic ERalpha through the shortened lifespan of osteoclasts.

  12. Raloxifene: a selective estrogen receptor modulator. (United States)

    Scott, J A; Da Camara, C C; Early, J E


    Raloxifene is a selective estrogen receptor modulator that produces both estrogen-agonistic effects on bone and lipid metabolism and estrogen-antagonistic effects on uterine endometrium and breast tissue. Because of its tissue selectivity, raloxifene may have fewer side effects than are typically observed with estrogen therapy. The most common adverse effects of raloxifene are hot flushes and leg cramps. The drug is also associated with an increased risk of thromboembolic events. The beneficial estrogenic activities of raloxifene include a lowering of total and low-density lipoprotein cholesterol levels and an augmentation of bone mineral density. Raloxifene has been labeled by the U.S. Food and Drug Administration for the prevention of osteoporosis. However, its effects on fracture risk and its ability to protect against cardiovascular disease have yet to be determined. Studies are also being conducted to determine its impact on breast and endometrial cancer reduction.

  13. The effects of estrogen in ischemic stroke. (United States)

    Koellhoffer, Edward C; McCullough, Louise D


    Stroke is a leading cause of death and the most common cause of long-term disability in the USA. Women have a lower incidence of stroke compared with men throughout most of the lifespan which has been ascribed to protective effects of gonadal steroids, most notably estrogen. Due to the lower stroke incidence observed in pre-menopausal women and robust preclinical evidence of neuroprotective and anti-inflammatory properties of estrogen, researchers have focused on the potential benefits of hormones to reduce ischemic brain injury. However, as women age, they are disproportionately affected by stroke, coincident with the loss of estrogen with menopause. The risk of stroke in elderly women exceeds that of men and it is clear that in some settings estrogen can have pro-inflammatory effects. This review will focus on estrogen and inflammation and its interaction with aging.

  14. Mass spectrometry evidence for formation of estrogen-homocysteine conjugates: estrogens can regulate homocysteine levels. (United States)

    Gaikwad, Nilesh W


    Homocysteine (HCys), a sulfur-containing amino acid, is formed during the metabolism of methionine. An imbalance between the rate of production and the use of HCys during methionine metabolism can result in an increase in the plasma and urinary levels of HCys. HCys has been shown to be toxic to vascular endothelial cells through several pathways. Many earlier clinical studies have revealed an association between plasma HCys and cardiovascular and other diseases. In contrast, estrogens are suggested to lower the risk of cardiovascular disease. Several studies indicate that estrogen metabolites could be responsible for cardiovascular protection. It has been demonstrated that electrophilic estrogen quinones, E1(E2)-2,3-Q and E1(E2)-3,4-Q, can alkylate DNA as well as form conjugates with glutathione. I hypothesize that estrogen quinones generated in situ by oxidative enzymes, metal ions, or molecular oxygen can interact with HCys to form conjugates. This in turn could lower the levels of toxic HCys as well as quenching the reactive estrogen quinones, resulting in cardiovascular protective effects. To test the feasibility of a protective estrogen-HCys pathway, estrogen quinones were treated with HCys. Tandem mass spectrometry analysis of the assay mixture shows the formation of estrogen-HCys conjugates. Furthermore, incubation of catechol estrogens with myeloperoxidase (MPO) in the presence of HCys resulted in the formation of respective estrogen-HCys conjugates. The identities of estrogen-HCys conjugates in MPO assay extracts were confirmed by comparing them to pure synthesized estrogen-HCys standards. I propose that through conjugation estrogens could chemically regulate HCys levels; moreover these conjugates could be used as potential biomarkers in determining health.


    Directory of Open Access Journals (Sweden)

    Aririguzo Marvis Ijeaku


    Full Text Available An Organic Light Emitting Diode (OLED is a device composed of an organic layer that emits lights in response to an electrical current. Organic light emitting diodes have advanced tremendously over the past decades. The different manufacturing processes of the OLED itself to several advantages over flat panel displays made with LCD technology which includes its light weight and flexible plastic substrates, wider viewing angles, improved brightness, better power efficiency and quicker response time. However, its drawbacks include shorter life span, poor color balance, poor outdoor performance, susceptibility to water damage etc.The application of OLEDs in electronics is on the increase on daily basics from cameras to cell phones to OLED televisions, etc. Although OLEDs provides prospects for thinner, smarter, lighter and ultraflexible electronics displays, however, due to high cost of manufacturing, it is not yet widely used.

  16. Estrogen and ischemic heart disease in females

    Directory of Open Access Journals (Sweden)

    Stević-Gajić Vesna


    Full Text Available Introduction: Although ischemic heart disease (IHD develops in both genders under the influence of the same risk factors, it is much less frequent among female population, which is mostly assigned to favorable effects of estrogen. Objective: Since latest investigations have pointed to higher incidence of disease in female population, the objective of our study was to examine the relation between estrogen and other clinical and biochemical parameters significant for its manifestation. Method: The relation between estrogen levels and frequency of obesity, diabetes, hypertension as well as the levels of total, HDL, LDL i VLDL cholesterol, triglycerides, Lp(a, apoprotein A i B i PAI-1 was analyzed in 50 (25 pre- and postmenopausal patients, treated due to IHD in the Health Center, Krusevac, in 2002 year. Results: Low concentration of estrogen was found in 22 (44% patients. In addition, frequency of diabetes, obesity and risky levels of high atherogenic lipid fractions (total and LDL cholesterol, Lp(a, apoprotein B was insignificantly higher, whereas the concentrations of PAI 1, triglycerides and HDL cholesterol were lower, with significant correlation between estrogen level and PAI-1 (T=0.32, p<0.05. Conclusion: Despite all past investigations, numerous questions related to high incidence of IHD among premenopausal women, have remained open - whether it occurs as a consequence of reduced estrogen synthesis, lower expression of estrogen receptors, their modified function or maybe concomitant influence of other risk factors, not necessarily connected with sex, that eliminate protective effects of this hormone.

  17. Estrogen receptor beta treats Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    Zhu Tian; Jia Fan; Yang Zhao; Sheng Bi; Lihui Si; Qun Liu


    In vitro studies have shown that estrogen receptor β can attenuate the cytotoxic effect of amyloid β protein on PC12 cells through the Akt pathway without estrogen stimulation. In this study, we aimed to observe the effect of estrogen receptor β in Alzheimer's disease rat models established by intraventricular injection of amyloid β protein. Estrogen receptor β lentiviral particles delivered via intraventricular injection increased Akt content in the hippocampus, decreased interleukin-1β mRNA, tumor necrosis factor α mRNA and amyloid β protein levels in the hippocampus, and improved the learning and memory capacities in Alzheimer's disease rats. Estrogen receptor β short hairpin RNA lentiviral particles delivered via intraventricular injection had none of the above impacts on Alzheimer's disease rats. These experimental findings indicate that estrogen receptor β, independent from estrogen, can reduce inflammatory reactions and amyloid β deposition in the hippocampus of Alzheimer's disease rats, and improve learning and memory capacities. This effect may be mediated through activation of the Akt pathway.

  18. Estrogen (United States)

    ... you are allergic to aspirin or tartrazine (a food color additive). Ask your pharmacist or check the manufacturer's patient ... this medication.If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting ...

  19. Estrogenic and anti-estrogenic activity of 23 commercial textile dyes.


    Bazin, Ingrid; Ibn Hadj Hassine, Aziza; Haj Hamouda, Yosra; Mnif, Wissem; Bartegi, Ahgleb; Lopez-Ferber, Miguel; De Waard, Michel; Gonzalez, Catherine


    International audience; The presence of dyes in wastewater effluent of textile industry is well documented. In contrast, the endocrine disrupting effects of these dyes and wastewater effluent have been poorly investigated. Herein, we studied twenty-three commercial dyes, usually used in the textile industry, and extracts of blue jean textile wastewater samples were evaluated for their agonistic and antagonistic estrogen activity. Total estrogenic and anti-estrogenic activities were measured u...

  20. Effects of Estrogens and Estrogenic Disrupting Compounds on Fish Mineralized Tissues


    Patricia I. S. Pinto; Estêvão, Maria D.; Power, Deborah M.


    Estrogens play well-recognized roles in reproduction across vertebrates, but also intervene in a wide range of other physiological processes, including mineral homeostasis. Classical actions are triggered when estrogens bind and activate intracellular estrogen receptors (ERs), regulating the transcription of responsive genes, but rapid non-genomic actions initiated by binding to plasma membrane receptors were recently described. A wide range of structurally diverse compounds from natural and ...

  1. Effects of estrogen and tibolone on bladder histology and estrogen receptors in rats

    Institute of Scientific and Technical Information of China (English)

    YANG Xin; LI Ya-zhen; MAO Zhuo; GU Pei; SHANG Ming


    Background Estrogen deficiency causes atrophic changes within the urogenital tract, and is associated with urinary symptoms. The purpose of this study was to investigate the effects of estrogen and tibolone on bladder histology, and the changes of estrogen receptor α and β (ERα and β) protein expression in the detrusor muscle.Methods Forty female rats were separated into four groups of ten each. They received a sham operation (Sham), ovariectomy (Ovx), ovariectomy plus estrogen replacement (Ovx+E), or ovariectomy plus tibolone treatment (Ovx+T). After 12 weeks each rat was anesthetized and the bladders were removed. The bladders' ultra structure, collagen fiber (CF) to smooth muscle(SM) ratio and ER subtypes were studied. Statistical analyses were performed using the one-way analysis of variance test.Results Ovx resulted in significant degeneration in bladder ultra structure; however, estrogen and tibolone reversed those changes. Ovx increased the CF/SM ratio, estrogen and tibolone resulted in an increase. Two estrogen receptors (ERs) were expressed in the bladder detrusor, with ERβ the main subtype. Ovx resulted in up-regulation of ERα and down-regulation of ERβ. With estrogen and tibolone treatment, ERβ showed a significant increase but ERα showed no significant difference compared with Ovx.Conclusions Estrogen deficiency deteriorates bladder ultra structure and histology. Supplementary estrogen can improve bladder function which may be due to inhibition of collagen hyperplasia and increased SM density. ERβ has an important role in mediating estrogen function in the bladder. Tibolone has a mild estrogenic action and has an effect on bladder function and structure to some degree.

  2. Impact of environmental estrogens on Yfish considering the diversity of estrogen signaling. (United States)

    Segner, Helmut; Casanova-Nakayama, Ayako; Kase, Robert; Tyler, Charles R


    Research on endocrine disruption in fish has been dominated by studies on estrogen-active compounds which act as mimics of the natural estrogen, 17β-estradiol (E2), and generally exert their biological actions by binding to and activation of estrogen receptors (ERs). Estrogens play central roles in reproductive physiology and regulate (female) sexual differentiation. In line with this, most adverse effects reported for fish exposed to environmental estrogens relate to sexual differentiation and reproduction. E2, however, utilizes a variety of signaling mechanisms, has multifaceted functions and targets, and therefore the toxicological and ecological effects of environmental estrogens in fish will extend beyond those associated with the reproduction. This review first describes the diversity of estrogen receptor signaling in fish, including both genomic and non-genomic mechanisms, and receptor crosstalk. It then considers the range of non-reproductive physiological processes in fish that are known to be responsive to estrogens, including sensory systems, the brain, the immune system, growth, specifically through the growth hormone/insulin-like growth factor system, and osmoregulation. The diversity in estrogen responses between fish species is then addressed, framed within evolutionary and ecological contexts, and we make assessments on their relevance for toxicological sensitivity as well as ecological vulnerability. The diversity of estrogen actions raises questions whether current risk assessment strategies, which focus on reproductive endpoints, and a few model fish species only, are protective of the wider potential health effects of estrogens. Available - although limited - evidence nevertheless suggests that quantitative environmental threshold concentrations for environmental protection derived from reproductive tests with model fish species are protective for non-reproductive effects as well. The diversity of actions of estrogens across divergent

  3. Effects of environmental estrogenic chemicals on AP1 mediated transcription with estrogen receptors alpha and beta. (United States)

    Fujimoto, Nariaki; Honda, Hiroaki; Kitamura, Shigeyuki


    There has been much discussion concerning endocrine disrupting chemicals suspected of exerting adverse effects in both wildlife and humans. Since the majority of these compounds are estrogenic, a large number of in vitro tests for estrogenic characteristics have been developed for screening purpose. One reliable and widely used method is the reporter gene assay employing estrogen receptors (ERs) and a reporter gene with a cis-acting estrogen responsive element (ERE). Other elements such as AP1 also mediate estrogenic signals and the manner of response could be quite different from that of ERE. Since this has yet to be explored, the ER mediated AP1 activity in response to a series of environmental estrogens was investigated in comparison with ERE findings. All the compounds exhibited estrogenic properties with ERE-luc and their AP1 responses were quite similar. These was one exception, however, p,p'-DDT (1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane) did not exert any AP1-luc activity, while it appeared to be estrogenic at 10(-7) to 10(-5)M with the ERE action. None of the compounds demonstrated ER beta:AP1 activity. These data suggest that significant differences can occur in responses through the two estrogen pathways depending on environmental chemicals.

  4. In vivo imaging of activated estrogen receptors in utero by estrogens and bisphenol A. (United States)

    Lemmen, Josephine G; Arends, Roel J; van der Saag, Paul T; van der Burg, Bart


    Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that, using this in vivo model in combination with the IVIS imaging system, activation of estrogen receptors (ERs) by maternally applied BPA and other estrogens can be detected in living embryos in utero. Eight hours after exposure to 1 mg/kg BPA, ER transactivation could be significantly induced in the embryos. This was more potent than would be estimated from in vitro assays, although its intrinsic activity is still lower than that of diethylstilbestrol and 17beta-estradiol dipropionate. On the basis of these results, we conclude that the estrogenic potency of BPA estimated using in vitro assays might underestimate its estrogenic potential in embryos.

  5. Construction of a Bacterial Assay for Estrogen Detection Based on an Estrogen-Sensitive Intein ▿ †


    Liang, Rubing; Zhou, Jing; Liu, Jianhua


    Escherichia coli strain DIER was constructed for estrogen detection by inserting an estrogen-sensitive intein (VMAER intein) into the specific site of the constitutively expressed chromosomal lacZ gene. This VMAER intein was generated by replacing the endonuclease region of the Saccharomyces cerevisiae VMA intein with the estrogen binding region of the human estrogen receptor α (hERα). When there were estrogens or analogs, the splicing of the VMAER intein was induced to produce the mature Lac...

  6. Bioinformatics analysis of estrogen-responsive genes (United States)

    Handel, Adam E.


    Estrogen is a steroid hormone that plays critical roles in a myriad of intracellular pathways. The expression of many genes is regulated through the steroid hormone receptors ESR1 and ESR2. These bind to DNA and modulate the expression of target genes. Identification of estrogen target genes is greatly facilitated by the use of transcriptomic methods, such as RNA-seq and expression microarrays, and chromatin immunoprecipitation with massively parallel sequencing (ChIP-seq). Combining transcriptomic and ChIP-seq data enables a distinction to be drawn between direct and indirect estrogen target genes. This chapter will discuss some methods of identifying estrogen target genes that do not require any expertise in programming languages or complex bioinformatics. PMID:26585125

  7. Sulfation of thyroid hormone by estrogen sulfotransferase

    NARCIS (Netherlands)

    M.H.A. Kester (Monique); T.J. Visser (Theo); C.H. van Dijk (Caren); D. Tibboel (Dick); A.M. Hood (Margaret); N.J. Rose; W. Meinl; U. Pabel; H. Glatt; C.N. Falany; M.W. Coughtrie


    textabstractSulfation is one of the pathways by which thyroid hormone is inactivated. Iodothyronine sulfate concentrations are very high in human fetal blood and amniotic fluid, suggesting important production of these conjugates in utero. Human estrogen sulfotransferas

  8. Phenolics from Phaleria nisidai with Estrogenic Activity

    Directory of Open Access Journals (Sweden)

    Christopher Kitalong


    Full Text Available The methanol extract of P. nisidai leaves yielded a benzophenone rhamnoside , iriflophenone 2-O-α-L-rhamnopyranoside (1 in addition to g enkwanin 5-O-β-D-primeveroside (2 and mangiferin (3. The isolated compounds as well as the derived aglycones of 1 and 2 assigned as compounds 4 and 5, respectively, were tested for their estrogenic activity on ERα using an estrogen receptor competitive binding screen. Compounds 1 , 4 and 5 showed almost the same binding ability to ERα with IC 50 of 630 µM, 700 µM and 800 µM, respectively. Virtual docking with ERα revealed that compound 1, 4 and 5 strongly hydrogen bond with amino acids Glu353, Arg349, Gly521 and His524, in the estrogen receptor ligand binding domain, similar to that of mammalian estrogen 17β-estradiol.

  9. Estrogen and Progestin (Hormone Replacement Therapy) (United States)

    ... made by the body. Estrogen reduces feelings of warmth in the upper body and periods of sweating ... and the laboratory. You should have a complete physical exam, including blood pressure measurements, breast and pelvic ...

  10. Estrogen Metabolism and Prostate Cancer Risk (United States)


    fat and low vegetables , in particular low in cruciferous , and obesity may increase estrogen metabolism towards 16a hydroxylation. This preferential...and Prostate Cancer Risk PRINCIPAL INVESTIGATOR: Paola C. Muti, M.D., M.S. CONTRACTING ORGANIZATION: State University of New York Amherst, New York...DATES COVERED October 1999 Annual (I Oct 98 - 30 Sep 99) 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Estrogen Metabolism and Prostate Cancer Risk DAMD17-98-l

  11. Urinary estrogens and estrogen metabolites and subsequent risk of breast cancer among premenopausal women. (United States)

    Eliassen, A Heather; Spiegelman, Donna; Xu, Xia; Keefer, Larry K; Veenstra, Timothy D; Barbieri, Robert L; Willett, Walter C; Hankinson, Susan E; Ziegler, Regina G


    Endogenous estrogens and estrogen metabolism are hypothesized to be associated with premenopausal breast cancer risk but evidence is limited. We examined 15 urinary estrogens/estrogen metabolites and breast cancer risk among premenopausal women in a case-control study nested within the Nurses' Health Study II (NHSII). From 1996 to 1999, urine was collected from 18,521 women during the mid-luteal menstrual phase. Breast cancer cases (N = 247) diagnosed between collection and June 2005 were matched to two controls each (N = 485). Urinary estrogen metabolites were measured by liquid chromatography-tandem mass spectrometry and adjusted for creatinine level. Relative risks (RR) and 95% confidence intervals (CI) were estimated by multivariate conditional logistic regression. Higher urinary estrone and estradiol levels were strongly significantly associated with lower risk (top vs. bottom quartile RR: estrone = 0.52; 95% CI, 0.30-0.88; estradiol = 0.51; 95% CI, 0.30-0.86). Generally inverse, although nonsignificant, patterns also were observed with 2- and 4-hydroxylation pathway estrogen metabolites. Inverse associations generally were not observed with 16-pathway estrogen metabolites and a significant positive association was observed with 17-epiestriol (top vs. bottom quartile RR = 1.74; 95% CI, 1.08-2.81; P(trend) = 0.01). In addition, there was a significant increased risk with higher 16-pathway/parent estrogen metabolite ratio (comparable RR = 1.61; 95% CI, 0.99-2.62; P(trend) = 0.04). Other pathway ratios were not significantly associated with risk except parent estrogen metabolites/non-parent estrogen metabolites (comparable RR = 0.58; 95% CI, 0.35-0.96; P(trend) = 0.03). These data suggest that most mid-luteal urinary estrogen metabolite concentrations are not positively associated with breast cancer risk among premenopausal women. The inverse associations with parent estrogen metabolites and the parent estrogen metabolite/non-parent estrogen metabolite ratio

  12. The molecular, cellular and clinical consequences of targeting the estrogen receptor following estrogen deprivation therapy. (United States)

    Fan, Ping; Maximov, Philipp Y; Curpan, Ramona F; Abderrahman, Balkees; Jordan, V Craig


    During the past 20 years our understanding of the control of breast tumor development, growth and survival has changed dramatically. The once long forgotten application of high dose synthetic estrogen therapy as the first chemical therapy to treat any cancer has been resurrected, refined and reinvented as the new biology of estrogen-induced apoptosis. High dose estrogen therapy was cast aside once tamoxifen, from its origins as a failed "morning after pill", was reinvented as the first targeted therapy to treat any cancer. The current understanding of the mechanism of estrogen-induced apoptosis is described as a consequence of acquired resistance to long term antihormone therapy in estrogen receptor (ER) positive breast cancer. The ER signal transduction pathway remains a target for therapy in breast cancer despite "antiestrogen" resistance, but becomes a regulator of resistance. Multiple mechanisms of resistance come into play: Selective ER modulator (SERM) stimulated growth, growth factor/ER crosstalk, estrogen-induced apoptosis and mutations of ER. But it is with the science of estrogen-induced apoptosis that the next innovation in women's health will be developed. Recent evidence suggests that the glucocorticoid properties of medroxyprogesterone acetate blunt estrogen-induced apoptosis in estrogen deprived breast cancer cell populations. As a result breast cancer develops during long-term hormone replacement therapy (HRT). A new synthetic progestin with estrogen-like properties, such as the 19 nortestosterone derivatives used in oral contraceptives, will continue to protect the uterus from unopposed estrogen stimulation but at the same time, reinforce apoptosis in vulnerable populations of nascent breast cancer cells.

  13. Estrogen biosynthesis and action in ovarian cancer

    Directory of Open Access Journals (Sweden)

    Theresia eThalhammer


    Full Text Available Ovarian cancer is still the deadliest of all gynecologic malignancies in women worldwide. This is attributed to two main features of these tumors, namely, i a diagnosis at an advanced tumor stage, and, ii the rapid onset of resistance to standard chemotherapy after an initial successful therapy with platin- and taxol-derivatives. Therefore, novel targets for an early diagnosis and better treatment options for these tumors are urgently needed. Epidemiological data show that induction and biology of ovarian cancer is related to life-time estrogen exposure. Also experimental data reveal that ovarian cancer cells share a number of estrogen regulated pathways with other hormone-dependent cancers, e.g. breast and endometrial cancer. However, ovarian cancer is a heterogeneous disease and the subtypes are quite different with respect to mutations, origins, behaviours, markers and prognosis and respond differently to standard chemotherapy. Therefore, a characterization of ovarian cancer subtypes may lead to better treatment options for the various subtypes and in particular for the most frequently observed high-grade serous ovarian carcinoma. For this intention, further studies on estrogen-related pathways and estrogen formation in ovarian cancer cells are warranted. The review gives an overview on ovarian cancer subtypes and explains the role of estrogen in ovarian cancer. Furthermore, enzymes active to synthesize and metabolize estrogens are described and strategies to target these pathways are discussed.

  14. Effects of estrogens and estrogenic disrupting compounds on fish mineralized tissues. (United States)

    Pinto, Patricia I S; Estêvão, Maria D; Power, Deborah M


    Estrogens play well-recognized roles in reproduction across vertebrates, but also intervene in a wide range of other physiological processes, including mineral homeostasis. Classical actions are triggered when estrogens bind and activate intracellular estrogen receptors (ERs), regulating the transcription of responsive genes, but rapid non-genomic actions initiated by binding to plasma membrane receptors were recently described. A wide range of structurally diverse compounds from natural and anthropogenic sources have been shown to interact with and disrupt the normal functions of the estrogen system, and fish are particularly vulnerable to endocrine disruption, as these compounds are frequently discharged or run-off into waterways. The effect of estrogen disruptors in fish has mainly been assessed in relation to reproductive endpoints, and relatively little attention has been given to other disruptive actions. This review will overview the actions of estrogens in fish, including ER isoforms, their expression, structure and mechanisms of action. The estrogen functions will be considered in relation to mineral homeostasis and actions on mineralized tissues. The impact of estrogenic endocrine disrupting compounds on fish mineralized tissues will be reviewed, and the potential adverse outcomes of exposure to such compounds will be discussed. Current lacunae in knowledge are highlighted along with future research priorities.

  15. Estrogenic effect of the MEK1 inhibitor PD98059 on endogenous estrogen receptor alpha and beta. (United States)

    Cotrim, Cândida Z; Amado, Francisco L; Helguero, Luisa A


    Estrogens are key regulators in mammary development and breast cancer and their effects are mediated by estrogen receptors alpha (ERα) and beta (ERβ). These two receptors are ligand activated transcription factors that bind to regulatory regions in the DNA known as estrogen responsive elements (EREs). ERα and ERβ activation is subject to modulation by phosphorylation and p42/p44 MAP kinases are the best characterized ER modifying kinases. Using a reporter gene (3X-ERE-TATA-luciferase) to measure activation of endogenous ERs, we found that MEK1 inhibitor PD98059, used in concentrations insufficient to inhibit MEK1 activation of p42/p44 MAP kinases, exerted estrogenic effects on the reporter gene and on the ERE-regulated RIP 140 protein. Such estrogenic effects were observed in mammary epithelial HC11 cells and occur on unliganded ERα and ligand activated ERβ. Additionally, concentrations of PD98059 able to inhibit p42/p44 phosphorylation were not estrogenic. Further, inhibition of p42 MAP kinase expression with siRNAs also resulted in loss of PD98059 estrogenic effect. In summary, PD98059 in concentrations below the inhibitory for MEK1, exerts estrogenic effects in HC11 mammary epithelial cells.

  16. Effects of Estrogens and Estrogenic Disrupting Compounds on Fish Mineralized Tissues

    Directory of Open Access Journals (Sweden)

    Patricia I. S. Pinto


    Full Text Available Estrogens play well-recognized roles in reproduction across vertebrates, but also intervene in a wide range of other physiological processes, including mineral homeostasis. Classical actions are triggered when estrogens bind and activate intracellular estrogen receptors (ERs, regulating the transcription of responsive genes, but rapid non-genomic actions initiated by binding to plasma membrane receptors were recently described. A wide range of structurally diverse compounds from natural and anthropogenic sources have been shown to interact with and disrupt the normal functions of the estrogen system, and fish are particularly vulnerable to endocrine disruption, as these compounds are frequently discharged or run-off into waterways. The effect of estrogen disruptors in fish has mainly been assessed in relation to reproductive endpoints, and relatively little attention has been given to other disruptive actions. This review will overview the actions of estrogens in fish, including ER isoforms, their expression, structure and mechanisms of action. The estrogen functions will be considered in relation to mineral homeostasis and actions on mineralized tissues. The impact of estrogenic endocrine disrupting compounds on fish mineralized tissues will be reviewed, and the potential adverse outcomes of exposure to such compounds will be discussed. Current lacunae in knowledge are highlighted along with future research priorities.

  17. Estrogens and selective estrogen receptor modulators regulate gene and protein expression in the mesenteric arteries. (United States)

    Mark-Kappeler, Connie J; Martin, Douglas S; Eyster, Kathleen M


    Estrogen has both beneficial and detrimental effects on the cardiovascular system. Selective estrogen receptor modulators (SERMs) exhibit partial estrogen agonist/antagonist activity in estrogen target tissues. Gene targets of estrogen and SERMs in the vasculature are not well-known. Thus, the present study tested the hypothesis that estrogens (ethinyl estradiol, estradiol benzoate, and equilin) and SERMs (tamoxifen and raloxifene) cause differential gene and protein expression in the vasculature. DNA microarray and real-time RT-PCR were used to investigate gene expression in the mesenteric arteries of estrogen and SERM treated ovariectomized rats. The genes shown to be differentially expressed included stearoyl-CoA desaturase (SCD), soluble epoxide hydrolase (sEH), secreted frizzled related protein-4 (SFRP-4), insulin-like growth factor-1 (IGF-1), phospholipase A2 group 1B (PLA2-G1B), and fatty acid synthase (FAS). Western blot further confirmed the differential expression of sEH, SFRP-4, FAS, and SCD protein. These results reveal that estrogens and SERMs cause differential gene and protein expression in the mesenteric artery. Consequently, the use of these agents may be associated with a unique profile of functional and structural changes in the mesenteric arterial circulation.

  18. Fecal microbial determinants of fecal and systemic estrogens and estrogen metabolites: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Flores Roberto


    Full Text Available Abstract Background High systemic estrogen levels contribute to breast cancer risk for postmenopausal women, whereas low levels contribute to osteoporosis risk. Except for obesity, determinants of non-ovarian systemic estrogen levels are undefined. We sought to identify members and functions of the intestinal microbial community associated with estrogen levels via enterohepatic recirculation. Methods Fifty-one epidemiologists at the National Institutes of Health, including 25 men, 7 postmenopausal women, and 19 premenopausal women, provided urine and aliquots of feces, using methods proven to yield accurate and reproducible results. Estradiol, estrone, 13 estrogen metabolites (EM, and their sum (total estrogens were quantified in urine and feces by liquid chromatography/tandem mass spectrometry. In feces, β-glucuronidase and β-glucosidase activities were determined by realtime kinetics, and microbiome diversity and taxonomy were estimated by pyrosequencing 16S rRNA amplicons. Pearson correlations were computed for each loge estrogen level, loge enzymatic activity level, and microbiome alpha diversity estimate. For the 55 taxa with mean relative abundance of at least 0.1%, ordinal levels were created [zero, low (below median of detected sequences, high] and compared to loge estrogens, β-glucuronidase and β-glucosidase enzymatic activity levels by linear regression. Significance was based on two-sided tests with α=0.05. Results In men and postmenopausal women, levels of total urinary estrogens (as well as most individual EM were very strongly and directly associated with all measures of fecal microbiome richness and alpha diversity (R≥0.50, P≤0.003. These non-ovarian systemic estrogens also were strongly and significantly associated with fecal Clostridia taxa, including non-Clostridiales and three genera in the Ruminococcaceae family (R=0.57−0.70, P=0.03−0.002. Estrone, but not other EM, in urine correlated significantly with

  19. The estrogen receptor of the gastropod Nucella lapillus: Modulation following exposure to an estrogenic effluent?

    Energy Technology Data Exchange (ETDEWEB)

    Castro, L. Filipe C. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Cellular and Molecular Studies, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal)], E-mail:; Melo, C. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Cellular and Molecular Studies, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Guillot, R.; Mendes, I.; Queiros, S.; Lima, D. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Environmental Toxicology, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Reis-Henriques, M.A. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Environmental Toxicology, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); ICBAS, Instituto Ciencias Biomedicas Abel Salazar, University of Porto, Largo Professor Abel Salazar 2, 4099-003 Porto (Portugal); Santos, M.M. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Environmental Toxicology, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal)], E-mail:


    The molecular targets of estrogenic endocrine disrupting chemicals have been studied in detail in vertebrates. The lack of basic endocrine knowledge impairs similar approaches for invertebrates. Evidence indicates that the signalling pathways of invertebrates may also be a target of estrogenic chemicals (ECs). In fact, the exposure to effluents containing ECs has been reported to impact mollusc reproduction. Despite the reported estrogen independence of the mollusc nuclear estrogen receptor (ER), its role in EC-induced toxicity has not been investigated in vivo. Therefore, we have cloned the ER of the gastropod Nucella lapillus and evaluated the effects of a mixture of estrogenic chemicals (sewage effluent) on its expression in the ovary. Here, we show that the exposure to a raw domestic/industrial effluent, impact ER expression with a simultaneous reproductive maturation. These results highlight the need to further investigate the role of ER on the reproductive process in prosobranch gastropods and whether this signalling pathway is prone to disruption by ECs.

  20. Effect of vaginal estrogen on pessary use (United States)

    Dessie, Sybil G.; Armstrong, Katherine; Modest, Anna M.; Hacker, Michele R.


    Introduction and hypothesis Many providers recommend concurrent estrogen therapy with pessary use to limit complications; however, limited data exist to support this practice. We hypothesized that vaginal estrogen supplementation decreases incidence of pessary-related complications and discontinuation. Methods We performed a retrospective cohort study of women who underwent a pessary fitting from 1 January 2007 through 1 September 2013 at one institution; participants were identified by billing code and were eligible if they were post-menopausal and had at least 3 months of pessary use and 6 months of follow-up. All tests were two sided, and P values < 0.05 were considered statistically significant. Results Data from 199 women were included; 134 used vaginal estrogen and 65 did not. Women who used vaginal estrogen had a longer median follow-up time (29.5 months) compared with women who did not (15.4 months) and were more likely to have at least one pessary check (98.5 % vs 86.2 %, P < 0.001). Those in the estrogen group were less likely to discontinue using their pessary (30.6 % vs 58.5 %, P < 0.001) and less likely to develop increased vaginal discharge than women who did not [hazard ratio (HR) 0.31, 95 % confidence interval (CI) 0.17–0.58]. Vaginal estrogen was not protective against erosions (HR 0.93, 95 % CI 0.54–1.6) or vaginal bleeding (HR 0.78, 95 % CI 0.36–1.7). Conclusions Women who used vaginal estrogen exhibited a higher incidence of continued pessary use and lower incidence of increased vaginal discharge than women who did not. PMID:26992727

  1. The role of estrogens at men. Part 1. General and developmental endocrinology, physiology and pathophysiology of estrogens at men

    Directory of Open Access Journals (Sweden)

    I. A. Tyuzikov


    Full Text Available Estrogens (female sex hormones are important sex hormones for women and men, although traditionally the problems associated with impaired synthesis and metabolism of estrogens are considered, especially in relation to the female population. However, presented an overview allows for a different look at the role and significance of estrogens for men. In the first part of the literature review highlights issues of general endocrinology and age of estrogens and the results of clinical and experimental studies, reflecting the physiological functionsof estrogens and pathophysiologic consequences of violations of the synthesis and metabolism of estrogens in male organism.

  2. Bioassays for estrogenic activity: development and validation of estrogen receptor (ERalpha/ERbeta) and breast cancer proliferation bioassays to measure serum estrogenic activity in clinical studies. (United States)

    Li, J; Lee, L; Gong, Y; Shen, P; Wong, S P; Wise, Stephen D; Yong, E L


    Standard estrogenic prodrugs such as estradiol valerate (E2V) and increasingly popular phytoestrogen formulations are commonly prescribed to improve menopausal health. These drugs are metabolized to numerous bioactive compounds, known or unknown, which may exert combinatorial estrogenic effects in vivo. The aim of this study is to develop and validate estrogen receptor (ER) alpha/ERbeta reporter gene and MCF-7 breast cancer cell proliferation bioassays to quantify serum estrogenic activities in a clinical trial setting. We measured changes in serum estrogenicity following ingestion of E2V and compared this to mass spectrometric measurements of its bioactive metabolites, estrone and 17beta-stradiol. ERalpha bioactivity of the 192 serum samples correlated well (R = 79%) with 17beta-estradiol levels, and adding estrone improved R to 0.83 (likelihood ratio test, P estrogenic activity and that these assays suggest that the Epimedium formulation tested is unlikely to exert significant estrogenic effects in humans.

  3. Estrogenicity of glabridin in Ishikawa cells.

    Directory of Open Access Journals (Sweden)

    Melissa Su Wei Poh

    Full Text Available Glabridin is an isoflavan from licorice root, which is a common component of herbal remedies used for treatment of menopausal symptoms. Past studies have shown that glabridin resulted in favorable outcome similar to 17β-estradiol (17β-E2, suggesting a possible role as an estrogen replacement therapy (ERT. This study aims to evaluate the estrogenic effect of glabridin in an in-vitro endometrial cell line -Ishikawa cells via alkaline phosphatase (ALP assay and ER-α-SRC-1-co-activator assay. Its effect on cell proliferation was also evaluated using Thiazoyl blue tetrazolium bromide (MTT assay. The results showed that glabridin activated the ER-α-SRC-1-co-activator complex and displayed a dose-dependent increase in estrogenic activity supporting its use as an ERT. However, glabridin also induced an increase in cell proliferation. When glabridin was treated together with 17β-E2, synergistic estrogenic effect was observed with a slight decrease in cell proliferation as compared to treatment by 17β-E2 alone. This suggest that the combination might be better suited for providing high estrogenic effects with lower incidences of endometrial cancer that is associated with 17β-E2.

  4. Survey of estrogenic activity in fish feed by yeast estrogen-screen assay. (United States)

    Matsumoto, Takeru; Kobayashi, Makito; Moriwaki, Toshihisa; Kawai, Shin'ichiro; Watabe, Shugo


    Fishes have been used as laboratory animal for research of estrogenic endocrine disrupters by many researchers. However, much less attention was paid to the possibility that compounds with estrogenic activity are present in fish diets. In order to examine this possibility, we measured the estrogenic activity in commercial fish feed by in vitro yeast estrogen-screen (YES) assay based on the binding ability of tested compounds to estrogen receptors. Estrogenic activity was detected in all the commercial fish feed examined (0.2-6.2 ng estradiol equivalent/g fish feed), some phytoestrogens (genistein, formononetin, equol and coumestrol; relative activity to estradiol, 8.6 x 10(-6)-1.1 x 10(-4) by giving a value of 1.0 to estradiol) and some androgens (testosterone, 11-ketotestosterone and 5 alpha-dihydrotestosterone; relative activity to estradiol, 3.0 x 10(-6)-1.2 x 10(-4)). Therefore, it is possible that these compounds could affect the results of in vivo estrogen assay, such as vitellogenin production in male fish, especially when fish are fed commercial feed.

  5. Novel Promising Estrogenic Receptor Modulators: Cytotoxic and Estrogenic Activity of Benzanilides and Dithiobenzanilides. (United States)

    Kucinska, Malgorzata; Giron, Maria-Dolores; Piotrowska, Hanna; Lisiak, Natalia; Granig, Walter H; Lopez-Jaramillo, Francisco-Javier; Salto, Rafael; Murias, Marek; Erker, Thomas


    The cytotoxicity of 27 benzanilides and dithiobenzanilides built on a stilbene scaffold and possessing various functional groups in aromatic rings previously described for their spasmolytic properties was assayed on three human cancer cell lines (A549 -lung adenocarcinoma, MCF-7 estrogen dependent breast adenocarcinoma and MDA-MB-231 estrogen independent breast adenocarcinoma) and 2 non-tumorigenic cell lines (CCD39Lu-lung fibroblasts, MCF-12A - breast epithelial). Three compounds (6, 15 and 18) showed selective antiproliferative activity against estrogen dependent MCF-7 cancer cells and their estrogenic activity was further confirmed in MCF-7 transfected with an estrogen receptor reporter plasmid and in HEK239 cells over-expressing the estrogen receptor alpha (ERα). Compound 18 is especially interesting as a potential candidate for therapy since it is highly toxic and selective towards estrogen dependent MCF7 cell lines (IC50 = 5.07 μM versus more than 100 μM for MDA-MB-231) and almost innocuous for normal breast cells (IC50 = 91.46 μM for MCF-12A). Docking studies have shown that compound 18 interacts with the receptor in the same cavity as estradiol although the extra aromatic ring is involved in additional binding interactions with residue W383. The role of W383 and the extended binding mode were confirmed by site-directed mutagenesis.

  6. Functional associations between two estrogen receptors, environmental estrogens, and sexual disruption in the roach (Rutilus rutilus). (United States)

    Katsu, Yoshinao; Lange, Anke; Urushitani, Hiroshi; Ichikawa, Rie; Paull, Gregory C; Cahill, Laura L; Jobling, Susan; Tyler, Charles R; Iguchi, Taisen


    Wild male roach (Rutilus rutilus) living in U.K. rivers contaminated with estrogenic effluents from wastewater treatment works show feminized responses and have a reduced reproductive capability, but the chemical causation of sexual disruption in the roach has not been established. Feminized responses were induced in male roach exposed to environmentally relevant concentrations of the pharmaceutical estrogen 17alpha-ethinylestradiol, EE2 (up to 4 ng/ L), during early life (from fertilization to 84 days posthatch, dph), and these effects were signaled by altered patterns of expression of two cloned roach estrogen receptor (ER) subtypes, ERalpha. and ERbeta, in the brain and gonad/ liver. Transactivation assays were developed for both roach ER subtypes and the estrogenic potencies of steroidal estrogens differed markedly at the different ER subtypes. EE2 was by far the most potent chemical, and estrone (E1, the most prevalent environmental steroid in wastewater discharges) was equipotent with estradiol (E2) in activating the ERs. Comparison of the EC50 values for the compounds tested showed that ERbeta was 3-21-fold more sensitive to natural steroidal estrogens and 54-fold more sensitive to EE2 as compared to ERalpha. These findings add substantial support to the hypothesis that steroidal estrogens play a significant role in the induction of intersex in roach populations in U.K. rivers and that the molecular approach described could be usefully applied to understand interspecies sensitivity to xenoestrogens.

  7. Determination of estrogens and estrogenic activities in water from three rivers in Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    Kaifeng Rao; Bingli Lei; Na Li; Mei Ma; Zijian Wang


    Studies on estrogenic disrupting compounds (EDCs) occurrence and identification of main responsible compounds in river water discharged into the sea are of significance.In the present research,we screened estrogenic activities of 10 river water samples from 3 main rivers discharged into Bohai Sea in Tianjin using a recombinant two-hybrid yeast assay and chemical analysis by gas chromatography-mass spectrometry.All sample extracts induced significant estrogenic activity,with 17β-estradiol equivalents (EEQ)of raw water ranging from 5.72 to 59.06 ng/L.Six most concerned EDCs in the river water samples including estrone,17β-estradiol,17α-ethinylestradiol,estriol,diethylstilbestrol and estradiol valerate were determined,with their concentrations up to 50.70,31.40,24.40,37.20,2.56,and 8.47 ng/L,respectively.Through causality analysis by comparing the EEQ values of yeast assay and chemical analysis,17α-ethinylestradiol and 17ββ-estradiol were identified as the main contributors to the estrogenic effects of the river samples,accounting for the whole estrogenic activities (62.99% to 185.66%),and estrogen antagonistic compounds might presented in the heavy polluted water samples.The proposed approach using both chemical analysis and bioassay could be used for identification and evaluation of the estrogenic activity of EDCs in river water.

  8. Estrogen receptors and function in the male reproductive system


    Lazari, Maria de Fatima Magalhaes [UNIFESP; Lucas, Thais Fabiana Gameiro [UNIFESP; Yasuhara, Fabiana [UNIFESP; Gomes, Gisele Renata de Oliveira [UNIFESP; Siu, Erica Rosanna; Royer, Carine [UNIFESP; Fernandes, Sheilla Alessandra Ferreira [UNIFESP; Porto, Catarina Segreti [UNIFESP


    A substantial advance in our understanding on the estrogen signaling occurred in the last decade. Estrogens interact with two receptors, ESR1 and ESR2, also known as ERα and ERβ, respectively. ESR1 and ESR2 belong to the nuclear receptor family of transcription factors. In addition to the well established transcriptional effects, estrogens can mediate rapid signaling, triggered within seconds or minutes. These rapid effects can be mediated by ESRs or the G protein-coupled estrogen receptor GP...

  9. Estrogenic and anti-estrogenic activity of 23 commercial textile dyes. (United States)

    Bazin, Ingrid; Ibn Hadj Hassine, Aziza; Haj Hamouda, Yosra; Mnif, Wissem; Bartegi, Ahgleb; Lopez-Ferber, Miguel; De Waard, Michel; Gonzalez, Catherine


    The presence of dyes in wastewater effluent of textile industry is well documented. In contrast, the endocrine disrupting effects of these dyes and wastewater effluent have been poorly investigated. Herein, we studied twenty-three commercial dyes, usually used in the textile industry, and extracts of blue jean textile wastewater samples were evaluated for their agonistic and antagonistic estrogen activity. Total estrogenic and anti-estrogenic activities were measured using the Yeast Estrogen Screen bioassay (YES) that evaluates estrogen receptor binding-dependent transcriptional and translational activities. The estrogenic potencies of the dyes and wastewater samples were evaluated by dose-response curves and compared to the dose-response curve of 17β-estradiol (E2), the reference compound. The dose-dependent anti-estrogenic activities of the dyes and wastewater samples were normalized to the known antagonistic effect of 4-hydroxytamoxifen (4-OHT) on the induction of the lac Z reporter gene by E2. About half azo textile dyes have anti-estrogenic activity with the most active being Blue HFRL. Most azo dyes however have no or weak estrogenic activity. E2/dye or E2/waste water ER competitive binding assays show activity of Blue HFRL, benzopurpurine 4B, Everzol Navy Blue FBN, direct red 89 BNL 200% and waste water samples indicating a mechanism of action common to E2. Our results indicate that several textile dyes are potential endocrine disrupting agents. The presence of some of these dyes in textile industry wastewater may thus impact the aquatic ecosystem.

  10. Phytoestrogens: Plant-derived Estrogenic Compounds

    Directory of Open Access Journals (Sweden)

    Nevzat Konar


    Full Text Available Estrogen is a hormone, which is produced in ovary and testis; however, it has many biological effects besides the reproductive system. Phytoestrogens are the compounds, which have estrogen-like structure and activities, taking place in structure of various edible plants at different levels and in different compositions. These compounds attracted notice after the first quarter of 20th century upon they had been associated with infertility seen in some of animals fed with alfalfa, and these compounds have been identified in human-derived biological samples and its effects on health have been taken under study in the recent 30 years. These materials have especially antioxidant role in plants while they have activities in animals and humans as estrogen agonist and antagonists. Based on their chemical structure, they may be gathered under especially isoflavon and lignan groups while some of members of coumestan and stilbene groups are also identified as phytoestrogenic compound.

  11. The immunologic effects of estrogen on psoriasis: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Melissa Danesh, B.S.


    Conclusions: Increased estrogen production in pregnancy is associated with decreased Th1 and Th17 cytokine production. While estrogen may be responsible for some of these immune shifts resulting in disease improvement, there remains no definitive evidence to prove the hypothesis that estrogen is responsible for such improvement.

  12. Estrogen receptor alpha polymorphisms and postmenopausal breast cancer risk.

    NARCIS (Netherlands)

    Ladd, AM Gonzalez-Zuloet; Vasquez, A.A.; Rivadeneira, F.; Siemes, C.; Hofman, A.; Stricker, B.H.; Pols, H.A.; Uitterlinden, A.G.; Duijn, C.M. van


    BACKGROUND: The estrogen receptor alpha (ESR1) is a mediator of estrogen response in the breast. The most studied variants in this gene are the PvuII and XbaI polymorphisms, which have been associated to lower sensitivity to estrogen. We evaluated whether these polymorphisms were associated with bre

  13. Estrogen receptor α polymorphisms and postmenopausal breast cancer risk

    NARCIS (Netherlands)

    A.M. González-Zuloeta Ladd (Angela); A.A. Vásquez (Arias); F. Rivadeneira Ramirez (Fernando); C. Siemes (Claire); A. Hofman (Albert); B.H.Ch. Stricker (Bruno); H.A.P. Pols (Huib); A.G. Uitterlinden (André); P. Tikka-Kleemola (Päivi)


    textabstractBackground: The estrogen receptor alpha (ESR1) is a mediator of estrogen response in the breast. The most studied variants in this gene are the PvuII and XbaI polymorphisms, which have been associated to lower sensitivity to estrogen. We evaluated whether these polymorphisms were associa

  14. Cumulative Estrogen Exposure and Prospective Memory in Older Women (United States)

    Hesson, Jacqueline


    This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to…

  15. Estrogen Abolishes Latent Inhibition in Ovariectomized Female Rats (United States)

    Nofrey, Barbara S.; Ben-Shahar, Osnat M.; Brake, Wayne G.


    Estrogen is frequently prescribed as a method of birth control and as hormone replacement therapy for post-menopausal women with varied effects on cognition. Here the effects of estrogen on attention were examined using the latent inhibition (LI) behavioral paradigm. Ovariectomized (OVX) female rats were given either estrogen benzoate (EB, 10 or…

  16. Estrogen inhibits Dlk1/FA1 production: A potential mechanism for estrogen effects on bone turnover

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Bay-Jensen, Anne-Christine; Srinivasan, Bhuma;


    We have recently identified delta-like 1/fetal antigen 1 (Dlk1/FA1) as a novel regulator of bone mass that functions to mediate bone loss under estrogen deficiency in mice. In this report, we investigated the effects of estrogen (E) deficiency and E replacement on serum (s) levels of Dlk1/FA1 (s...... estrogen-replacement therapy (ERT, n = 166). s-Dlk1/FA1 and s-CTX were elevated in postmenopausal E-deficient women compared with premenopausal E-replete women (both p ...

  17. CERAPP: Collaborative estrogen receptor activity prediction project

    DEFF Research Database (Denmark)

    Mansouri, Kamel; Abdelaziz, Ahmed; Rybacka, Aleksandra


    Background: Humans are exposed to thousands of man-made chemicals in the environment. Some chemicals mimic natural endocrine hormones and, thus, have the potential to be endocrine disruptors. Most of these chemicals have never been tested for their ability to interact with the estrogen receptor (ER......). Risk assessors need tools to prioritize chemicals for evaluation in costly in vivo tests, for instance, within the U.S. EPA Endocrine Disruptor Screening Program. oBjectives: We describe a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project...

  18. Estrogens in the daily diet: in vitro analysis indicates that estrogenic activity is omnipresent in foodstuff and infant formula. (United States)

    Behr, Maximilian; Oehlmann, Jörg; Wagner, Martin


    Food is a main source of exposure to endocrine active compounds, many of which have been linked to adverse health effects. Phytoestrogens, especially from soy, are the major dietary source of estrogenicity. However, foodstuff contains a variety of estrogen-like compounds that might not be detected analytically. To assess the total estrogenic activity of foodstuff, we employed the Yeast Estrogen Screen (YES). We analyzed 18 food samples and five milk-based infant formulas. Soy-based products contained potent estrogenicity of 100-1500ng estradiol equivalents per kilogram (EEQ/kg). The estrogenicity in soy-free products was far lower (10-40ng EEQ/kg). We also detected significant estrogenic activity in three infant formulas (14-22ng EEQ/kg). Furthermore, we found soy lecithin to be strongly estrogenic. It might, therefore, be a major contributor to total estrogenicity. We conclude that dietary estrogens are omnipresent and not limited to soy-based food. In an exposure assessment we calculated a total dietary intake of 27.5 and 34.0ng EEQ/d for adults and 1.46ng EEQ/d for infants. While the dietary exposure to estrogenic activity is lower than previously estimated, our results demonstrate that many food types are a source of unidentified estrogen-like compounds still awaiting toxicological evaluation.

  19. Molecular analysis of human endometrium: Short-term tibolone signaling differs significantly from estrogen and estrogen + progestagen signaling

    NARCIS (Netherlands)

    P. Hanifi-Moghaddam (Payman); B. Boers-Sijmons (Bianca); A.H.A. Klaassens (Anet); F.H. van Wijk (Heidy); M.A. den Bakker (Michael); M.C. Ott; G.L. Shipley; H.A.M. Verheul (Herman); H.J. Kloosterboer (Helenius); C.W. Burger (Curt); L.J. Blok (Leen)


    textabstractTibolone, a tissue-selective compound with a combination of estrogenic, progestagenic, and androgenic properties, is used as an alternative for estrogen or estrogen plus progesterone hormone therapy for the treatment of symptoms associated with menopause and osteoporosis. The current stu

  20. Estrogenic pyrethroid pesticides regulate expression of estrogen receptor transcripts in mouse Sertoli cells differently from 17beta-estradiol. (United States)

    Taylor, J S; Thomson, B M; Lang, C N; Sin, F Y T; Podivinsky, E


    Studies suggested that exposure to agricultural pesticides may affect male fertility. Pyrethroids are widely used pesticides due to their insecticidal potency and low mammalian toxicity. A recombinant yeast assay system incorporating the human alpha-estrogen receptor was used to analyze the estrogenicity of a range of readily available pyrethroid pesticides. The commercial product Ripcord Plus showed estrogenic activity by this assay. To determine whether pyrethroid compounds might exert an effect on male fertility, mouse Sertoli cells were exposed in vitro to the endogenous estrogen, 17beta-estradiol, and selected estrogenic pyrethroids. Following exposure, transcript levels of the alpha- and beta-estrogen receptors were assessed. Exposure of Sertoli cells to the pyrethroid compounds, both at high and at low published serum concentrations, affected the expression of the two estrogen receptors; however, the influence on estrogen receptor gene expression was different from the effect from exposure to 17beta-estradiol. These results from our model systems suggest that (1) estrogenic pyrethroid pesticides affect the estrogen receptors, and therefore potentially the endocrine system, in a different manner from that of endogenous estrogen, and (2) should cells in the male testes be exposed to pyrethroid pesticides, male fertility may be affected through molecular mechanisms involving estrogen receptors.

  1. Effect of combining in vitro estrogenicity data with kinetic characteristics of estrogenic compounds on the in vivo predictive value

    NARCIS (Netherlands)

    Punt, A.; Brand, W.; Murk, A.J.; van Wezel, Annemarie; Schriks, M.; Heringa, M.B.


    With the ultimate aim of increasing the utility of in vitro assays for toxicological risk assessment, a method was developed to calculate in vivo estrogenic potencies from in vitro estrogenic potencies of compounds by taking into account systemic availability. In vitro estrogenic potencies of three

  2. Effect of combining in vitro estrogenicity data with kinetic characteristics of estrogenic compounds on the invivo predictive value

    NARCIS (Netherlands)

    Punt, A.; Brand, W.; Murk, A.J.; Wezel, van A.P.; Schriks, M.; Heringa, M.B.


    With the ultimate aim of increasing the utility of in vitro assays for toxicological risk assessment, a method was developed to calculate in vivo estrogenic potencies from in vitro estrogenic potencies of compounds by taking into account systemic availability. In vitro estrogenic potencies of three

  3. Estrogenic activity of flavonoids in mice. The importance of estrogen receptor distribution, metabolism and bioavailability

    DEFF Research Database (Denmark)

    Breinholt, Vibeke; Hossaini, A.; Svendsen, Gitte W.


    to subsequently encountered estrogens. Oral administration of equol, genistein, biochanin A and daidzein to 6-week-old female mice revealed a great variation in their systemic bioavailability. The urinary recovery of equol was thus over 90% of a single gavage administered dose, whereas the urinary recoveries...... of biochanin A, genistein and daidzein were 16, 11 and 3%, respectively. Most of the metabolites were either hydroxylated or dehydrogenated forms of the parent compounds. The in vitro estrogenic potency of some of the metabolites was greater than that of the parent compounds, whereas others were of similar...... or lower potency. Bioavailability, metabolism, the ability to alter ER alpha distribution in the uterus and the estrogenic potential of parent compound and metabolites may thus contribute to the differences in in vivo estrogenicity of dietary flavonoids....

  4. Role of Estrogens on Human Male Reproductive System

    Institute of Scientific and Technical Information of China (English)

    Vincenzo Rochira; Lucia Zirilli; Bruno Madeo; Antonio Balestrieri; Cesare Carani; Antonio R. M. Granata


    This review focuses on estrogen role on human male physiology. Biological estrogen actions on male reproductive system are summarized with particular regard to the effects of congenital estrogen deprivation in men. The effects of estrogen on spermatogenesis, hormonal secretion and gonadotropin feedback and on sexual behavior are discussed. It is remarked that the role of estrogens in male reproduction is a very recent acquisition in reproductive endocrinology, but it promises new future fields of research to be investigated as well as the possible disclosure of new strategies in clinical practice.

  5. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity (United States)


    These data are presented in Hill, L., Venkatesh, J., Chinnasamy, P., Grimaldi , C and Diamond. B Differential roles of estrogen receptors α and β...Yoshifuji, H., Kawabata, D., Chinnasamy, P., Stanevsky, A., Grimaldi , C., and Diamond, B. Antigen is required for maturation and activation of...Venkatesh, J., Chinnasamy, P., Grimaldi , C and Diamond. B Differential roles of estrogen receptors α and β in control of B cell maturation and

  6. Estrogenicity profile and estrogenic compounds determined in river sediments by chemical analysis, ELISA and yeast assays. (United States)

    Viganò, Luigi; Benfenati, Emilio; van Cauwenberge, Anne; Eidem, Janne K; Erratico, Claudio; Goksøyr, Anders; Kloas, Werner; Maggioni, Silvia; Mandich, Alberta; Urbatzka, Ralph


    An effects-directed strategy was applied to bed sediments of a polluted tributary in order to isolate and identify the major estrogenic chemicals it discharges into the River Po, the principal Italian watercourse. Sediment extract was concentrated by solid phase extraction and then fractioned into 10 fractions by reversed phase high performance liquid chromatography (RP-HPLC). Estrogenic activity of whole extract and fractions were determined using a recombinant yeast assay containing the human estrogen receptor (YES). The 10 fractions and whole extract were analysed for target compounds, e.g. estrone (E1), 17beta-estradiol (E2), estriol (E3), 4-nonylphenol (NP), 4-tert-octylphenol (t-OP), bisphenol A (BPA), using both liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-competitive enzyme-linked immunosorbent assays (ELISA). The YES assay determined high estrogenic activity in whole sediment (15.6 ng/g EE2 equivalents), and positive results for fractions nr 1, 2, 6, 7 and 8. E1, E3 and NP were the main estrogenic chemicals, however, other unidentified compounds contributed to sediment estrogenicity, particularly for polar fractions nr 1 and 2. A GC-MS screening performed in scan mode identified other potential contributors such as phthalates (DBP, BBP), and OP isomers. A next sampling campaign extended to other tributaries and receiving stretches of the River Po confirmed E1, E3 and NP as major estrogenic chemicals potentially threatening other sites of the main river. In general, target compound ELISAs have been shown to be suitable tools for a rapid screening of wide areas or large numbers of environmental samples for estrogenic risk. The potential for interferences suggests however to use cautiously the concentration values obtained from some of the immunoassays.

  7. Assaying estrogenicity by quantitating the expression levels of endogenous estrogen-regulated genes.


    Jørgensen, M.; Vendelbo, B; Skakkebaek, N. E.; Leffers, H


    Scientific evidence suggests that humans and wildlife species may experience adverse health consequences from exposure to environmental chemicals that interact with the endocrine system. Reliable short-term assays are needed to identify hormone-disrupting chemicals. In this study we demonstrate that the estrogenic activity of a chemical can be evaluated by assaying induction or repression of endogenous estrogen-regulated "marker genes" in human breast cancer MCF-7 cells. We included four mark...

  8. Combining docking and comparative molecular similarity indices analysis (COMSIA) to predict estrogen activity and probe molecular mechanisms of estrogen activity for estrogen compounds

    Institute of Scientific and Technical Information of China (English)

    YANG XuShu; WANG XiaoDong; JI Li; LI Rong; SUN Cheng; WANG LianSheng


    Estrogen compounds are suspected of disrupting endocrine functions by mimicking natural hormones,and such compounds may pose a serious threat to the health of humans and wildlife. Close attention has been paid to the prediction and molecular mechanisms of estrogen activity for estrogen compounds. In this article, estrogen receptor a subtype (Era) -based comparative molecular similarity indices analysis (COMSIA) was performed on 44 estrogen compounds with structural diversity to find out the structural relationship with the activity and to predict the activity. The model with the significant correlation and the best predictive power (R2 = 0.965, (Q2LOO = 0.599, R2pred = 0.825) was achieved. The COMSIA and docking results revealed the structural features for estrogen activity and key amino acid residues in binding pocket, and provided an insight into the interaction between the ligands and these amino acid residues.

  9. Light-Emitting Devices with Conjugated Polymers

    Directory of Open Access Journals (Sweden)

    Xian-Yu Deng


    Full Text Available This article introduces a previous study and tremendous progress in basic theoretical modeling, material developments and device engineering for polymer light-emitting devices (PLEDs.

  10. Hierarchical Non-Emitting Markov Models

    CERN Document Server

    Ristad, E S; Ristad, Eric Sven; Thomas, Robert G.


    We describe a simple variant of the interpolated Markov model with non-emitting state transitions and prove that it is strictly more powerful than any Markov model. More importantly, the non-emitting model outperforms the classic interpolated model on the natural language texts under a wide range of experimental conditions, with only a modest increase in computational requirements. The non-emitting model is also much less prone to overfitting. Keywords: Markov model, interpolated Markov model, hidden Markov model, mixture modeling, non-emitting state transitions, state-conditional interpolation, statistical language model, discrete time series, Brown corpus, Wall Street Journal.

  11. Estrogen and its role in gastrointestinal health and disease.

    LENUS (Irish Health Repository)

    Hogan, Aisling M


    INTRODUCTION: While the concept of a role of estrogen in gastrointestinal (in particular, colonic) malignancy has generated excitement in recent years, no review has examined the role of this potent and omnipresent steroid hormone in physiological states or its contribution to the development of benign pathological processes. Understanding these effects (and mechanisms therein) may provide a platform for a deeper understanding of more complex disease processes. METHODS: A literature search was conducted using the PubMed database and the search terms were "estrogen," "estrogen AND gastrointestinal tract," "estrogen AND colon," "estrogen AND esophagus," "estrogen AND small intestine," "estrogen AND stomach," "estrogen AND gallbladder," and "estrogen AND motility." Bibliographies of extracted studies were further cross-referenced. In all, 136 full-text articles were selected for review. A logical organ-based approach was taken to enable extraction of data of clinical relevance and meaningful interpretation thereof. Insight is provided into the hypotheses, theories, controversies, and contradictions generated over the last five decades by extensive investigation of estrogen in human, animal, and cell models using techniques as diverse as autoradiographic studies of baboons to human population analysis. CONCLUSIONS: Effects from esophagus through to the colon and rectum are summarized in this first concise collection of data pertaining to estrogenic actions in gastrointestinal health and disease. Mechanisms of these actions are discussed where possible. Undoubtedly, this hormone exerts many actions yet to be elucidated, and its potential therapeutic applications remain, as yet, largely unexplored.

  12. Xeno-estrogenic compounds in precipitation

    NARCIS (Netherlands)

    Peters, R.J.B.; Beeltje, H.; Delft, R.J.


    The exposure to some chemicals can lead to hormone disrupting effects. Presently, much attention is focused on so-called xeno-estrogens, synthetic compounds that interact with hormone receptors causing a number of reactions that eventually lead to effects related to reproduction and development. The

  13. Urinary estrogen metabolites and breast cancer

    DEFF Research Database (Denmark)

    Dallal, Cher M; Stone, Roslyn A; Cauley, Jane A


    Background: Circulating estrogens are associated with increased breast cancer risk, yet the role of estrogen metabolites in breast carcinogenesis remains unclear. This combined analysis of 5 published studies evaluates urinary 2-hydroxyestrone (2-OHE1), 16a-hydroxyestrone (16a-OHE1......), and their ratio (2:16a-OHE1) in relation to breast cancer risk. ¿Methods: Primary data on 726 premenopausal women (183 invasive breast cancer cases and 543 controls) and 1,108 postmenopausal women (385 invasive breast cancer cases and 723 controls) were analyzed. Urinary estrogen metabolites were measured using...... premenopausal 2:16a-OHE1 was suggestive of reduced breast cancer risk overall (study-adjusted ORIIIvsI=0.80; 95% CI: 0.49-1.32) and for estrogen receptor negative (ER-) subtype (ORIIIvsI=0.33; 95% CI: 0.13-0.84). Among postmenopausal women, 2:16a-OHE1 was unrelated to breast cancer risk (study-adjusted ORIIIvs...

  14. [Experimental sialadenitis in castrated rats administered estrogens]. (United States)

    Fonseca, M M; Rins de David, M L; Gendelman, H


    Salivary glands are dependent on sexual hormones. The aim of the present work is to study the behavior of inflammatory response induced in animals that were castrated and injected with estrogens. Male adult wistar castrated rats (60-90 days) were used. A phlogogen pellet (zinc-oxide-turpentine essence) was placed between their sublingual and submaxillary glands and they were daily injected with 5 units of estrogen. The rats were killed after 8 and 12 days of treatment; submandibular pack was weighed, dissected and fixed in phormol Ph7 for its morphohistochemical study. Phlogogen pellet breaks out an acute inflammatory response that appears attenuated in castrated animals. Such character is enhanced when estrogens are used, disappearing ductal ectasis, becoming evident a granulation tissue of strange body in phagocytic activity and in contact with the pellet. As a consequence its follows that estrogen administration in castrated animals attenuates acute inflammatory response broken out by phlogogen pellet, determining characters with tendency to chronicity and giant cells differentiation of strange body.

  15. [Pharmacodynamics of synthetic estrogens. Review article]. (United States)

    Sojo-Aranda, I; Cortés-Gallegos, V


    Some details about the function of natural and synthetical hormonas are reviewed, particularly estrogens as ethynyl estradiol and its 3, Methyl ether (mestranol); its peripheral concentration vs tissular hormonal contents, a relationship of biological importance as the first step in its hormonal action and the cummulative local effects that could explain some intra and extracellular phenomena.

  16. [Pharmacodynamics of synthetic estrogens. A review]. (United States)

    Sojo-Aranda, I; Cortés-Gallegos, V


    Some details about the function of natural and synthetical hormonas are reviewed, particularly estrogens as ethynyl estradiol and its 3, Methyl ether (mestranol); its peripheral concentration vs tissular hormonal contents, a relationship of biological importance as the first step in its hormonal action and the cumulative local effects that could explain some intra and extracellular phenomena.

  17. Estrogen receptors in human vaginal tissue

    NARCIS (Netherlands)

    Wiegerinck, M.A.H.M.; Poortman, J.; Agema, A.R.; Thijssen, J.H.H.


    The presence of specific estrogen receptors could be demonstrated in vaginal tissue, obtained during operation from 38 women, age 27–75 yr. In 23 premenopausal women the receptor concentration in the vaginal tissue varied between 12 and 91 fmol/mg protein, no significant difference in the receptor

  18. 3D-QSAR and docking studies of estrogen compounds based on estrogen receptor β

    Institute of Scientific and Technical Information of China (English)

    YANG XuShu; WANG XiaoDong; LUO Si; JI Li; QIN Liang; LI Rong; SUN Cheng; WANG LianSheng


    Close attention has been paid to estrogen compounds because these chemicals may pose a serious threat to the health of humans and wildlife.Estrogen receptor (ER) exists as two subtypes,ERo and ERβ.The difference in amino acids sequence of the binding sites of ERo and ERβ might lead to a result that some synthetic estrogens and naturally occurring steroidal ligands have different relative affinities and binding modes for ERa and ERβ.In this investigation,comparative molecular similarity indices analysis (CoMSIA) was performed on 50 estrogen compounds binding ERβ to find out the structural relationship with the activities.We also compared two alignment schemes employed in CoMSIA analysis,namely,atom-fit and receptor-based alignment,with respect to the predictive capability of their respective models for structurally diverse data sets.The model with the significant correlation and the best predictive power (R2=0.961,q2LOO=0.671,Rp2red=0.722) was achieved.The CoMSIA and docking results revealed the structural features related to an activity and provided an insight into molecular mechanisms of estrogenic activities for estrogen compounds.

  19. 3D-QSAR and docking studies of estrogen compounds based on estrogen receptor β

    Institute of Scientific and Technical Information of China (English)


    Close attention has been paid to estrogen compounds because these chemicals may pose a serious threat to the health of humans and wildlife. Estrogen receptor (ER) exists as two subtypes, ERα and ERβ. The difference in amino acids sequence of the binding sites of ERα and ERβ might lead to a result that some synthetic estrogens and naturally occurring steroidal ligands have different relative affinities and binding modes for ERα and ERβ. In this investigation, comparative molecular similarity indices analysis (CoMSIA) was performed on 50 estrogen compounds binding ERβ to find out the structural relationship with the activities. We also compared two alignment schemes employed in CoMSIA analy-sis, namely, atom-fit and receptor-based alignment, with respect to the predictive capability of their respective models for structurally diverse data sets. The model with the significant correlation and the best predictive power (R2=0.961, qL 2OO=0.671, RP 2red=0.722) was achieved. The CoMSIA and docking results revealed the structural features related to an activity and provided an insight into molecular mechanisms of estrogenic activities for estrogen compounds.

  20. Estrogens, estrogen receptors, and female cognitive aging: the impact of timing. (United States)

    Daniel, Jill M


    Estrogens have been shown to be protective agents against neurodegeneration and associated cognitive decline in aging females. However, clinical data have been equivocal as to the benefits to the brain and cognition of estrogen therapy in postmenopausal women. One factor that is proposed to be critical in determining the efficacy of hormone therapy is the timing of its initiation. The critical period or window of opportunity hypothesis proposes that following long-term ovarian hormone deprivation, the brain and cognition become insensitive to exogenously administered estrogens. In contrast, if estrogens are administered during a critical period near the time of cessation of ovarian function, they will exert beneficial effects. The focus of the current review is the examination of evidence from rodent models investigating the critical period hypothesis. A growing body of experimental data indicates that beneficial effects of 17β-estradiol (estradiol) on cognition and on cholinergic function and hippocampal plasticity, both of which have been linked to the ability of estradiol to exert beneficial effects on cognition, are attenuated if estradiol is administered following a period of long-term ovarian hormone deprivation. Further, emerging data implicate loss of estrogen receptor alpha (ERα) in the brain resulting from long-term hormone deprivation as a basis for the existence of the critical period. A unifying model is proposed by which the presence or absence of estrogens during a critical period following the cessation of ovarian function permanently alters the system resulting in decreased or increased risk, respectively, of neurodegeneration and cognitive decline.

  1. Estrogen and Growth Hormone and their Roles in Reproductive Function

    Directory of Open Access Journals (Sweden)

    Hüseyin Baki ÇİFTCİ


    Full Text Available The aim of this study was to review the effect of estrogen on growth hormone secretion and the roles of estrogen and growth hormone in reproductive function. Estrogen is the main hormone affecting growth, development, maturation and functioning of reproductive tract as well as the sexual differentiation and the behavior. Growth hormone is also important factor in sexual maturation and attainment of puberty. The impact of estrogen on growth hormone secretion has been reported in rodents and primates. However, the precise mechanism for the alterations in growth hormone secretion is not clearly known. Estrogen may possibility have a direct affect on growth hormone secretion via the binding to estrogen receptor-α due to its co-expression in growth hormone neurons in the medial preoptic area and arcuate nucleus. Estrogen may also have an indirect effect via the reducing insulin-like growth factor-1 feedback inhibition resulting with increased growth hormone secretion.

  2. Estrogen receptors and cell proliferation in breast cancer. (United States)

    Ciocca, D R; Fanelli, M A


    Most of the actions of estrogens on the normal and abnormal mammary cells are mediated via estrogen receptors (ERs), including control of cell proliferation; however, there are also alternative pathways of estrogen action not involving ERs. Estrogens control several genes and proteins that induce the cells to enter the cell cycle (protooncogenes, growth factors); estrogens also act on proteins directly involved in the control of the cell cycle (cyclins), and moreover, estrogens stimulate the response of negative cell cycle regulators (p53, BRCA1). The next challenge for researchers is elucidating the integration of the interrelationships of the complex pathways involved in the control of cell proliferation. This brief review focuses on the mechanisms of estrogen action to control cell proliferation and the clinical implications in breast cancer. (Trends Endocrinol Metab 1997;8:313-321). (c) 1997, Elsevier Science Inc.

  3. Estrogen, male dominance and esophageal adenocarcinoma: Is there a link?

    Institute of Scientific and Technical Information of China (English)

    Huiqi Yang; Olga A Sukocheva; Damian J Hussey; David I Watson


    Esophageal adenocarcinoma is a cancer with poor prognosis, and its incidence has risen sharply over recent decades. Obesity is a major risk factor for developing this cancer and there is a clear male gender bias in the incidence that cannot be fully explained by known risk factors. It is possible that a difference in the expression of estrogen, or its signaling axes, may contribute to this gender bias. We undertook a comprehensive literature search and analyzed the available data regarding estrogen and estrogen receptor expression, and the possible sex-specific links with esophageal adenocarcinoma development. Potentially relevant associations between visceral vs subcutaneous fat deposition and estrogen expression, and the effect of crosstalk between estrogen and leptin signaling were identified. We also found limited studies suggesting a role for estrogen receptor β expression in esophageal adenocarcinoma development. The current literature supports speculation on an etiological role for estrogen in the male gender bias in esophageal adenocarcinoma, but further studies are required.


    Directory of Open Access Journals (Sweden)

    H. Laswati


    Full Text Available Background: Aging is termed as same as degenerative process, in which all part of tissue organs retarted the microstructure either macrostructure, forming and function even the colour, including black hair change to white hair. Several researchers have been recommended that estrogen hormone be able ease black to white hair, but hormone without any presenting of receptor won’t be work properly. The main aim of this study were to determine amount of estrogen receptor contents in famales and males black and white hairs included the microscopically structure. Method: Twelve females and males there were 50 -56 years old each pairs black and white head hairs were plucked along with follicles. This estrogen receptors analyzed using radioreceptor binding assay there were 5mm eah hair follices including the root cutted and each pair put its in 2 ml glass tube already filled in with 500 µl 125I-estradiol and incubated in 37oC for 3 hrs. Following times were over the tube flushed twice carefully the hair won’t be flushed. Then count by putting in the gamma counter chamber for 1 minute each. The values that shown in the monitor as CPM (count per minute, recorded as receptor of estradiol. Results: Mean (±SD sum estrogen receptor in females black and white hairs were 479.3 ± 37.5 and 387.7 ± 33.0, but significantly decreased in male black hair was 316.9±17.8 and 274.0 ± 19.8. All those pairs significantly different either female black and white hairs or male black and white hair and also significantly different among groups. Conclusion: The lowest estrogen receptors recorded in male white hairs and microstructure decreasing of melanin contents.

  5. Estrogens and male reproduction: a new concept

    Directory of Open Access Journals (Sweden)

    S. Carreau


    Full Text Available The mammalian testis serves two main functions: production of spermatozoa and synthesis of steroids; among them estrogens are the end products obtained from the irreversible transformation of androgens by a microsomal enzymatic complex named aromatase. The aromatase is encoded by a single gene (cyp19 in humans which contains 18 exons, 9 of them being translated. In rats, the aromatase activity is mainly located in Sertoli cells of immature rats and then in Leydig cells of adult rats. We have demonstrated that germ cells represent an important source of estrogens: the amount of P450arom transcript is 3-fold higher in pachytene spermatocytes compared to gonocytes or round spermatids; conversely, aromatase activity is more intense in haploid cells. Male germ cells of mice, bank voles, bears, and monkeys express aromatase. In humans, we have shown the presence of a biologically active aromatase and of estrogen receptors (alpha and ß in ejaculated spermatozoa and in immature germ cells in addition to Leydig cells. Moreover, we have demonstrated that the amount of P450arom transcripts is 30% lower in immotile than in motile spermatozoa. Alterations of spermatogenesis in terms of number and motility of spermatozoa have been described in men genetically deficient in aromatase. These last observations, together with our data showing a significant decrease of aromatase in immotile spermatozoa, suggest that aromatase could be involved in the acquisition of sperm motility. Thus, taking into account the widespread localization of aromatase and estrogen receptors in testicular cells, it is obvious that, besides gonadotrophins and androgens, estrogens produced locally should be considered to be physiologically relevant hormones involved in the regulation of spermatogenesis and spermiogenesis.

  6. Activation of estrogen response elements is mediated both via estrogen and muscle contractions in rat skeletal muscle myotubes

    DEFF Research Database (Denmark)

    Wiik, A.; Hellsten, Ylva; Berthelson, P.


    The aim of the present study was to investigate the activation of estrogen response elements (EREs) by estrogen and muscle contractions in rat myotubes in culture and to assess whether the activation is dependent on the estrogen receptors (ERs). In addition, the effect of estrogen and contraction...... then differentiated into myotubes and subjected to either estrogen or electrical stimulation. Activation of the ERE sequence was determined by measurement of luciferase activity. The results show that both ERalpha and ERbeta are expressed in myotubes from rats. Both estrogen stimulation and muscle contraction...... increased (P muscle contraction. Use of ER antagonists showed that, whereas the estrogen-induced transactivation is mediated via ERs, the effect of muscle contraction...

  7. Estrogen receptor-alpha mediates estrogen facilitation of baroreflex heart rate responses in conscious mice. (United States)

    Pamidimukkala, Jaya; Xue, Baojian; Newton, Leslie G; Lubahn, Dennis B; Hay, Meredith


    Estrogen facilitates baroreflex heart rate responses evoked by intravenous infusion of ANG II and phenylephrine (PE) in ovariectomized female mice. The present study aims to identify the estrogen receptor subtype involved in mediating these effects of estrogen. Baroreflex responses to PE, ANG II, and sodium nitroprusside (SNP) were tested in intact and ovariectomized estrogen receptor-alpha knockout (ERalphaKO) with (OvxE+) or without (OvxE-) estrogen replacement. Wild-type (WT) females homozygous for the ERalpha(+/+) were used as controls. Basal mean arterial pressures (MAP) and heart rates were comparable in all the groups except the ERalphaKO-OvxE+ mice. This group had significantly smaller resting MAP, suggesting an effect of estrogen on resting vascular tone possibly mediated by the ERbeta subtype. Unlike the WT females, estrogen did not facilitate baroreflex heart rate responses to either PE or ANG II in the ERalphaKO-OvxE+ mice. The slope of the line relating baroreflex heart rate decreases with increases in MAP evoked by PE was comparable in ERalphaKO-OvxE- (-6.97 +/- 1.4 beats.min(-1).mmHg(-1)) and ERalphaKO-OvxE+ (-6.18 +/- 1.3) mice. Likewise, the slope of the baroreflex bradycardic responses to ANG II was similar in ERalphaKO-OvxE- (-3.87 +/- 0.5) and ERalphaKO-OvxE+(-2.60 +/- 0.5) females. Data suggest that estrogen facilitation of baroreflex responses to PE and ANG II is predominantly mediated by ERalpha subtype. A second important observation in the present study is that the slope of ANG II-induced baroreflex bradycardia is significantly blunted compared with PE in the intact as well as the ERalphaKO-OvxE+ females. We have previously reported that this ANG II-mediated blunting of cardiac baroreflexes is observed only in WT males and not in ovariectomized WT females independent of their estrogen replacement status. The present data suggest that in females lacking ERalpha, ANG II causes blunting of cardiac baroreflexes similar to males and may be

  8. Fast spatial atomic layer deposition of Al{sub 2}O{sub 3} at low temperature (<100 °C) as a gas permeation barrier for flexible organic light-emitting diode displays

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hagyoung; Shin, Seokyoon; Jeon, Hyeongtag, E-mail: [Department of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Choi, Yeongtae; Kim, Junghun; Kim, Sanghun; Chung, Seog Chul; Oh, Kiyoung [LIG INVENIA Co., Ltd., Seongnam, Gyeonggi 462-807 (Korea, Republic of)


    The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures (<100 °C). In this paper, the authors report the excellent moisture barrier properties of Al{sub 2}O{sub 3} films deposited on 2G glass substrates of an industrially relevant size (370 × 470 mm{sup 2}) using the newly developed ALD system. This new ALD system reduced the ALD cycle time to less than 1 s. A growth rate of 0.9 Å/cycle was achieved using trimethylaluminum as an Al source and O{sub 3} as an O reactant. The morphological features and step coverage of the Al{sub 2}O{sub 3} films were investigated using field emission scanning electron microscopy. The chemical composition was analyzed using Auger electron spectroscopy. These deposited Al{sub 2}O{sub 3} films demonstrated a good optical transmittance higher than 95% in the visible region based on the ultraviolet visible spectrometer measurements. Water vapor transmission rate lower than the detection limit of the MOCON test (less than 3.0 × 10{sup −3} g/m{sup 2} day) were obtained for the flexible substrates. Based on these results, Al{sub 2}O{sub 3} deposited using our new high-throughput and scalable spatial ALD is considered a good candidate for preparation of TFE films of flexible OLEDs.

  9. Phosphorescent Nanocluster Light-Emitting Diodes. (United States)

    Kuttipillai, Padmanaban S; Zhao, Yimu; Traverse, Christopher J; Staples, Richard J; Levine, Benjamin G; Lunt, Richard R


    Devices utilizing an entirely new class of earth abundant, inexpensive phosphorescent emitters based on metal-halide nanoclusters are reported. Light-emitting diodes with tunable performance are demonstrated by varying cation substitution to these nanoclusters. Theoretical calculations provide insight about the nature of the phosphorescent emitting states, which involves a strong pseudo-Jahn-Teller distortion.

  10. Light emitting device having peripheral emissive region (United States)

    Forrest, Stephen R


    Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.

  11. Physiological and pharmacological effects of estrogens in breast cancer. (United States)

    Leclercq, G; Heuson, J C


    Focus here is on the mechanism of action of both estrogens and antiestrogens at the tumor cell levels in breast cancer. The interactions of estrogens and their antagonists are emphasized and analyzed in terms of current and potential clinical applications to breast cancer treatment. This review deals with these interrelationships at the molecular levels, not just with general aspects of endocrine interrelationships. The article is divided into 8 main parts: 1) an introduction, which reviews historical understanding of receptor technology and significances; 2) main properties of estrogens and estrogen receptors; 3) the influence of estrogens and antiestrogens on growth of experimental mammary tumor systems; 4) the suppression of or administration of estrogens for treatment of advanced human breast cancer; 5) estrogen receptivity of mammary tumors; 6) progress in treatment of advanced breast cancer derived from studies on the mode of action of estrogens; 7) the prognostic significance of estrogens and estrogenic receptivity (the estriol theory); and 8) concluding remarks on the future paths of receptor research.

  12. Estrogen Deficiency and the Origin of Obesity during Menopause

    Directory of Open Access Journals (Sweden)

    Fernando Lizcano


    Full Text Available Sex hormones strongly influence body fat distribution and adipocyte differentiation. Estrogens and testosterone differentially affect adipocyte physiology, but the importance of estrogens in the development of metabolic diseases during menopause is disputed. Estrogens and estrogen receptors regulate various aspects of glucose and lipid metabolism. Disturbances of this metabolic signal lead to the development of metabolic syndrome and a higher cardiovascular risk in women. The absence of estrogens is a clue factor in the onset of cardiovascular disease during the menopausal period, which is characterized by lipid profile variations and predominant abdominal fat accumulation. However, influence of the absence of these hormones and its relationship to higher obesity in women during menopause are not clear. This systematic review discusses of the role of estrogens and estrogen receptors in adipocyte differentiation, and its control by the central nervous systemn and the possible role of estrogen-like compounds and endocrine disruptors chemicals are discussed. Finally, the interaction between the decrease in estrogen secretion and the prevalence of obesity in menopausal women is examined. We will consider if the absence of estrogens have a significant effect of obesity in menopausal women.

  13. Estrogen replacement therapy and cardioprotection: mechanisms and controversies

    Directory of Open Access Journals (Sweden)

    M.T.R. Subbiah


    Full Text Available Epidemiological and case-controlled studies suggest that estrogen replacement therapy might be beneficial in terms of primary prevention of coronary heart disease (CHD. This beneficial effect of estrogens was initially considered to be due to the reduction of low density lipoproteins (LDL and to increases in high density lipoproteins (HDL. Recent studies have shown that estrogens protect against oxidative stress and decrease LDL oxidation. Estrogens have direct effects on the arterial tissue and modulate vascular reactivity through nitric oxide and prostaglandin synthesis. While many of the effects of estrogen on vascular tissue are believed to be mediated by estrogen receptors alpha and ß, there is evidence for `immediate non-genomic' effects. The role of HDL in interacting with 17ß-estradiol including its esterification and transfer of esterified estrogens to LDL is beginning to be elucidated. Despite the suggested positive effects of estrogens, two recent placebo-controlled clinical trials in women with CHD did not detect any beneficial effects on overall coronary events with estrogen therapy. In fact, there was an increase in CHD events in some women. Mutations in thrombogenic genes (factor V Leiden, prothrombin mutation, etc. in a subset of women may play a role in this unexpected finding. Thus, the cardioprotective effect of estrogens appears to be more complicated than originally thought and requires more research.

  14. Extra-gonadal sites of estrogen biosynthesis and function. (United States)

    Barakat, Radwa; Oakley, Oliver; Kim, Heehyen; Jin, Jooyoung; Ko, CheMyong Jay


    Estrogens are the key hormones regulating the development and function of reproductive organs in all vertebrates. Recent evidence indicates that estrogens play important roles in the immune system, cancer development, and other critical biological processes related to human well-being. Obviously, the gonads (ovary and testis) are the primary sites of estrogen synthesis, but estrogens synthesized in extra- gonadal sites play an equally important role in controlling biological activities. Understanding non-gonadal sites of estrogen synthesis and function is crucial and will lead to therapeutic interventions targeting estrogen signaling in disease prevention and treatment. Developing a rationale targeting strategy remains challenging because knowledge of extra-gonadal biosynthesis of estrogens, and the mechanism by which estrogen activity is exerted, is very limited. In this review, we will summarize recent discoveries of extra-gonadal sites of estrogen biosynthesis and their local functions and discuss the significance of the most recent novel discovery of intestinal estrogen biosynthesis. [BMB Reports 2016; 49(9): 488-496].

  15. Sensing Estrogen with Electrochemical Impedance Spectroscopy (United States)

    Li, Jing; Kim, Byung Kun; Im, Ji-Eun; Choi, Han Nim; Kim, Dong-Hwan; Cho, Seong In


    This study demonstrates the application feasibility of electrochemical impedance spectroscopy (EIS) in measuring estrogen (17β-estradiol) in gas phase. The present biosensor gives a linear response (R2 = 0.999) for 17β-estradiol vapor concentration from 3.7 ng/L to 3.7 × 10−4 ng/L with a limit of detection (3.7 × 10−4 ng/L). The results show that the fabricated biosensor demonstrates better detection limit of 17β-estradiol in gas phase than the previous report with GC-MS method. This estrogen biosensor has many potential applications for on-site detection of a variety of endocrine disrupting compounds (EDCs) in the gas phase.

  16. Sensing Estrogen with Electrochemical Impedance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Jing Li


    Full Text Available This study demonstrates the application feasibility of electrochemical impedance spectroscopy (EIS in measuring estrogen (17β-estradiol in gas phase. The present biosensor gives a linear response (R2=0.999 for 17β-estradiol vapor concentration from 3.7 ng/L to 3.7 × 10−4 ng/L with a limit of detection (3.7 × 10−4 ng/L. The results show that the fabricated biosensor demonstrates better detection limit of 17β-estradiol in gas phase than the previous report with GC-MS method. This estrogen biosensor has many potential applications for on-site detection of a variety of endocrine disrupting compounds (EDCs in the gas phase.

  17. Autoradiographic localization of estrogen binding sites in human mammary lesions

    Energy Technology Data Exchange (ETDEWEB)

    Buell, R.H.


    The biochemical assay of human mammary carcinomas for estrogen receptors is of proven clinical utility, but the cellular localization of estrogen binding sites within these lesions is less certain. The author describes the identification of estrogen binding sites as visualized by thaw-mount autoradiography after in vitro incubation in a series of 17 benign and 40 malignant human female mammary lesions. The results on the in vitro incubation method compared favorably with data from in vivo studies in mouse uterus, a well-characterized estrogen target organ. In noncancerous breast biopsies, a variable proportion of epithelial cells contained specific estrogen binding sites. Histologically identifiable myoepithelial and stromal cells were, in general, unlabeled. In human mammary carcinomas, biochemically estrogen receptor-positive, labeled and unlabeled neoplastic epithelial cells were identified by autoradiography. Quantitative results from the autoradiographic method compared favorably with biochemical data.

  18. Computational method for discovery of estrogen responsive genes

    DEFF Research Database (Denmark)

    Tang, Suisheng; Tan, Sin Lam; Ramadoss, Suresh Kumar;


    Estrogen has a profound impact on human physiology and affects numerous genes. The classical estrogen reaction is mediated by its receptors (ERs), which bind to the estrogen response elements (EREs) in target gene's promoter region. Due to tedious and expensive experiments, a limited number...... of human genes are functionally well characterized. It is still unclear how many and which human genes respond to estrogen treatment. We propose a simple, economic, yet effective computational method to predict a subclass of estrogen responsive genes. Our method relies on the similarity of ERE frames...... across different promoters in the human genome. Matching ERE frames of a test set of 60 known estrogen responsive genes to the collection of over 18,000 human promoters, we obtained 604 candidate genes. Evaluating our result by comparison with the published microarray data and literature, we found...

  19. The role of estrogen in bipolar disorder, a review

    DEFF Research Database (Denmark)

    Meinhard, Ninja; Kessing, Lars Vedel; Vinberg, Maj


    BACKGROUND: It appears that the female reproductive events and hormonal treatments may impact the course of bipolar disorder in women. In particular, childbirth is known to be associated with onset of affective episodes in women with bipolar disorder. During the female reproductive events the sex...... hormones, e.g. estrogen, are fluctuating and particularly postpartum there is a steep fall in the levels of serum estrogen. The role of estrogen in women with bipolar disorder is, however, not fully understood. AIM: The main objective of this review is to evaluate the possible relation between serum...... estrogen levels and women with bipolar disorder including studies of the anti manic effects of the selective estrogen receptor modulator tamoxifen. METHOD: A systematically literature search on PubMed was conducted: two studies regarding the connection between serum estrogen levels and women with bipolar...

  20. Estrogen, Progesterone and Epithelial Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Ho Shuk-Mei


    Full Text Available Abstract Ovarian carcinoma (OCa continues to be the leading cause of death due to gynecologic malignancies and the vast majority of OCa is derived from the ovarian surface epithelium (OSE and its cystic derivatives. Epidemiological evidence strongly suggests that steroid hormones, primarily estrogens and progesterone, are implicated in ovarian carcinogenesis. However, it has proved difficult to fully understand their mechanisms of action on the tumorigenic process. New convincing data have indicated that estrogens favor neoplastic transformation of the OSE while progesterone offers protection against OCa development. Specifically, estrogens, particularly those present in ovulatory follicles, are both genotoxic and mitogenic to OSE cells. In contrast, pregnancy-equivalent levels progesterone are highly effective as apoptosis inducers for OSE and OCa cells. In this regard, high-dose progestin may exert an exfoliation effect and rid an aged OSE of pre-malignant cells. A limited number of clinical studies has demonstrated efficacies of antiestrogens, aromatase inhibitors, and progestins alone or in combination with chemotherapeutic drugs in the treatment of OCa. As a result of increased life expectancy in most countries, the number of women taking hormone replacement therapies (HRT continues to grow. Thus, knowledge of the mechanism of action of steroid hormones on the OSE and OCa is of paramount significance to HRT risk assessment and to the development of novel therapies for the prevention and treatment of OCa.

  1. The role of estrogen in intrusive memories. (United States)

    Cheung, Jessica; Chervonsky, Liza; Felmingham, Kim L; Bryant, Richard A


    Intrusive memories are highly vivid, emotional and involuntary recollections which cause significant distress across psychological disorders including posttraumatic disorder (PTSD). Recent evidence has potentially extended our understanding of the development of intrusive memories by identifying biological factors which significantly impact on memories for emotionally arousing stimuli. This study investigated the role of stress on the development of intrusions for negative and neutral images, and indexed the potential contributions of sex (estrogen and progesterone) and stress (noradrenaline and cortisol) hormones. Whilst viewing the images, half the participants underwent a cold pressor stress (CPS) procedure to induce stress while the control participants immersed their hands in warm water. Saliva samples were collected to index estrogen, progesterone and noradrenergic and cortisol response. Participants (55 university students, 26 men, 29 women) viewed a series of negatively arousing and neutral images. Participants completed recall and intrusions measures 2 days later. Negative images resulted in greater recall and more intrusions than neutral images. In the cold water condition females recalled fewer neutral memories than males. Cortisol increase predicted decreased recall of negative memories in males, and estrogen predicted increased intrusions of negative images in women. These findings are consistent with evidence that circulating levels of ovarian hormones influence memory for emotionally arousing events, and provides the first evidence of the influence of sex hormones on intrusive memories. These results provide one possible explanation for the higher incidence of anxiety disorders in women.

  2. Estrogenic activity of isoflavonoids from Onobrychis ebenoides. (United States)

    Halabalaki, Maria; Alexi, Xanthippi; Aligiannis, Nektarios; Lambrinidis, George; Pratsinis, Harris; Florentin, Ida; Mitakou, Sofia; Mikros, Emmanuel; Skaltsounis, Alexios-Leandros; Alexis, Michael N


    Fractionation of the neutral extract of Onobrychis ebenoides (Leguminosae) yielded a new isoflavone, named ebenosin (1), in addition to the known ones, afrormosin (2), formononetin (3) and daidzein (4). Although the relative binding affinities of 1 - 4 for estrogen receptor alpha (ERalpha) were nearly comparable and matched those of 1-3 for ERbeta, that of 4 for the latter receptor was significantly higher than any of the other. Compounds 1 - 4 induced cell proliferation and gene expression in breast and endometrial cancer cells in an ER-dependent manner. Nonetheless, the rank order of induction potencies ( 4 > 3 >or= 2 >or= 1) matched better that of affinities for ERbeta ( 4 > 3 >or= 2 >or= 1) rather than ERalpha ( 4 >or= 3 >or= 2 >or= 1). While the antiestrogen ICI 182,780 could inhibit the induction of proliferation of ER-positive breast cancer cells by 1-4, it could not prevent 1 from exhibiting significant ER-independent cytotoxicity at 10 microM. By contrast, 1 was much less cytotoxic and only weakly estrogenic for ER-positive endometrial adenocarcinoma cells. In conclusion, our data suggest that the C-8 isoprenyl substituent of 1 renders it cytotoxic and/or estrogenic in a cell-dependent manner.

  3. The estrogenic activity of phthalate esters in vitro.


    Harris, CA; Henttu, P; Parker, MG; Sumpter, JP


    A large number of phthalate esters were screened for estrogenic activity using a recombinant yeast screen. a selection of these was also tested for mitogenic effect on estrogen-responsive human breast cancer cells. A small number of the commercially available phthalates tested showed extremely weak estrogenic activity. The relative potencies of these descended in the order butyl benzyl phthalate (BBP) > dibutyl phthalate (DBP) > diisobutyl phthalate (DIBP) > diethyl phthalate (DEP) > diisiono...

  4. Neonatal oxytocin alters subsequent estrogen receptor alpha protein expression and estrogen sensitivity in the female rat. (United States)

    Perry, Adam N; Paramadilok, Auratip; Cushing, Bruce S


    In most species, the effects of oxytocin (OT) on female reproductive behavior are dependent upon estrogen, which increases both OT and OT receptor expression. It is also becoming apparent that OT neurotransmission can influence estrogen signaling, especially during development, as neonatal OT manipulations in prairie voles alter ERalpha expression and estrogen-dependent behaviors. We tested the hypothesis that OT developmentally programs ERalpha expression and estrogen sensitivity in female Sprague-Dawley rats, a species previously used to establish the estrogen-dependence of OT signaling in adulthood. OT treatment for the first postnatal week significantly increased ERalpha-immunoreactivity in the ventromedial nucleus of the hypothalamus (VMH), but not in the medial preoptic area (MPOA). Conversely, neonatal OT antagonist (OTA) treatment significantly reduced ERalpha-immunoreactivity in the MPOA, but not in the VMH. Both treatments increased OT-immunoreactivity in the paraventricular nucleus of the hypothalamus (PVN) and reduced estrogen sensitivity, indicated by reduced sexual receptivity following chronic estradiol benzoate (EB) administration. Behavioral deficits in OTA-treated females were apparent during both paced and non-paced tests with 0.5 microg EB (but not 5.0 or 10.0 microg EB), whereas deficits in OT-treated females were only observed during the initial paced test with 0.5 and 5.0 microg EB (but not 10.0 microg EB). The current results demonstrate that OT can positively regulate ERalpha expression within the MPOA and VMH during development; however, endogenous OT selectively programs ERalpha expression within the MPOA. Thus, exogenous OT or OTA exposure during development may have long-term consequences on behavior through stable changes in ERalpha and OT expression.

  5. Melatonin affects the dynamic steady-state equilibrium of estrogen sulfates in human umbilical vein endothelial cells by regulating the balance between estrogen sulfatase and sulfotransferase. (United States)

    González, Alicia; Martínez-Campa, Carlos; Alonso-González, Carolina; Cos, Samuel


    Melatonin is known to reduce the growth of endocrine-responsive breast cancers by interacting with estrogen signaling pathways. Estrogens play an important role in breast cancer, but also in various types of tissues, including vascular tissue. Estrogen sulfatase (STS) converts inactive estrogen sulfates into active estrogens, whereas estrogen sulfotransferase (EST) sulfonates estrogens to estrogen sulfates. Therefore, STS and EST are considered to be involved in the regulation of local estrogen levels in hormone‑dependent tumors and in non-pathologic tissues, such as those of the vascular system. Estrogens have a major impact on the vasculature, influencing vascular function, the expression of adhesion proteins, angiogenesis and the inflammatory state. In this study, we investigated the status of STS and EST in human umbilical vein endothelial cells (HUVECs) and the modulatory effects of melatonin. Both STS and EST were highly expressed in the HUVECs. The enzymatic activity correlated with the expression levels in these cells. Our findings also demonstrated that melatonin, at physiological concentrations, modulated the synthesis and transformation of biologically active estrogens in HUVECs through the inhibition of STS activity and expression, and the stimulation of EST activity and expression. Since melatonin decreased the STS levels and increased the EST levels, it modified the dynamic steady‑state equilibrium of estrogen sulfates by increasing the inactive estrogen levels and decreasing the active estrogen levels. Therefore, melatonin may modulate the known different biological actions of estrogens in endothelial cells, as well as in estrogen-dependent tumors and non-pathologic tissues.

  6. Ozonation of estrogenic chemicals in biologically treated sewage

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Andersen, Henrik Rasmus; Ledin, Anna


    The present study shows that ozonation of effluents from municipal wastewater treatment plants (WWTPs) is likely to be a future treatment solution to remove estrogens and xeno-estrogens. The required ozone dose and electrical energy for producing the ozone were determined in two WWTP effluents....... It is furthermore suggested that UV-absorbance is a useful parameter for online control of the ozone dose in a full scale application since the absorbance of the WWTP effluents and the remaining concentration of the estrogens and xeno-estrogens correlated well with the applied ozone dose....

  7. Regulation of Activation Induced Deaminase (AID) by Estrogen. (United States)

    Pauklin, Siim


    Regulation of Activation Induced Deaminase (AID) by the hormone estrogen has important implications for understanding adaptive immune responses as well as the involvement of AID in autoimmune diseases and tumorigenesis. This chapter describes the general laboratory techniques for analyzing AID expression and activity induced by estrogen, focusing on the isolation and preparation of cells for hormone treatment and the subsequent analysis of AID responsiveness to estrogen at the RNA level and for determining the regulation of AID activity via estrogen by analyzing Ig switch circle transcripts and mutations in switch region loci.

  8. Estrogens and the pathophysiology of the biliary tree

    Institute of Scientific and Technical Information of China (English)

    Domenico Alvaro; Maria Grazia Mancino; Paolo Onori; Antonio Franchitto; Gianfranco Alpini; Heather Francis; Shannon Glaser; Eugenio Gaudio


    The scientific framework concerning estrogen effects on different tissues has expanded enormously during the last decades, when estrogen receptor (ER) subtypes were identified. Estrogens are not only essential for the female reproductive system, but they also control fundamental functions in other tissues including the cardiovascular system, bone, brain and liver. Recently,estrogens have been shown to target the biliary tree,where they modulate the proliferative and secretory activities of cholangiocytes, the epithelial cells lining bile ducts. By acting on both estrogen receptors (ER-α) and (ER-β) subtypes, and by activating either genomic or non-genomic pathways, estrogens play a key role in the complex loop of growth factors and cytokines, which modulates the proliferative response of cholangiocytes to damage. Specifically, estrogens activate intracellular signalling cascades [ERK1/2 (extracellular regulated kinases 1/2, PI3- kinase/AKT (phosphatidylinositol-3'kinase/AKT)] typical of growth factors such as insulin like growth factor (IGF1), nerve growth factor (NGF)and vascular endothelial growth factor (VEGF), thus potentiating their action. In addition, estrogens stimulate the secretion of different growth factors in proliferating cholangiocytes. This review specifically deals with the recent advances related to the role and mechanisms by which estrogens modulate cholangiocyte functions in normal and pathological conditions.

  9. Estrogen regulates pulmonary alveolar formation, loss, and regeneration in mice. (United States)

    Massaro, Donald; Massaro, Gloria Decarlo


    Lung tissue elastic recoil and the dimension and number of pulmonary gas-exchange units (alveoli) are major determinants of gas-exchange function. Loss of gas-exchange function accelerates after menopause in the healthy aged and is progressively lost in individuals with chronic obstructive pulmonary disease (COPD). The latter, a disease of midlife and later, though more common in men than in women, is a disease to which women smokers and never smokers may be more susceptible than men; it is characterized by diminished lung tissue elastic recoil and presently irremediable alveolar loss. Ovariectomy in sexually immature rats diminishes the formation of alveoli, and estrogen prevents the diminution. In the present work, we found that estrogen receptor-alpha and estrogen receptor-beta, the only recognized mammalian estrogen receptors, are required for the formation of a full complement of alveoli in female mice. However, only the absence of estrogen receptor-beta diminishes lung elastic tissue recoil. Furthermore, ovariectomy in adult mice results, within 3 wk, in loss of alveoli and of alveolar surface area without a change of lung volume. Estrogen replacement, after alveolar loss, induces alveolar regeneration, reversing the architectural effects of ovariectomy. These studies 1) reveal estrogen receptors regulate alveolar size and number in a nonredundant manner, 2) show estrogen is required for maintenance of already formed alveoli and induces alveolar regeneration after their loss in adult ovariectomized mice, and 3) offer the possibility estrogen can slow alveolar loss and induce alveolar regeneration in women with COPD.

  10. Estrogen signaling in the proliferative endometrium: implications in endometriosis

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Pereira da Costa e Silva


    Full Text Available SUMMARY Even though the physiological role of estrogen in the female reproductive cycle and endometrial proliferative phase is well established, the signaling pathways by which estrogen exerts its action in the endometrial tissue are still little known. In this regard, advancements in cell culture techniques and maintenance of endometrial cells in cultures enabled the discovery of new signaling mechanisms activated by estrogen in the normal endometrium and in endometriosis. This review aims to present the recent findings in the genomic and non-genomic estrogen signaling pathways in the proliferative human endometrium specifically associated with the pathogenesis and development of endometriosis.

  11. Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Caroline [Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5056 (United States); Grimaldi, Marina; Boulahtouf, Abdelhay [Institut de Recherche en Cancérologie de Montpellier, Institut National de la Santé de la Recherche Médicale U896, Institut Régional de Cancérologie de Montpellier, Université Montpellier 1, 34298 Montpellier (France); Pakdel, Farzad [Institut de Recherche sur la Santé, Environnement et Travail (IRSET), INSERM U1085, Université de Rennes 1, Rennes (France); Brion, François; Aït-Aïssa, Sélim [Unité Écotoxicologie In Vitro et In Vivo, INERIS, Parc ALATA, 60550 Verneuil-en-Halatte (France); Cavaillès, Vincent [Institut de Recherche en Cancérologie de Montpellier, Institut National de la Santé de la Recherche Médicale U896, Institut Régional de Cancérologie de Montpellier, Université Montpellier 1, 34298 Montpellier (France); Bourguet, William [U1054, Centre de Biochimie Structurale, CNRS UMR5048, Université Montpellier 1 et 2, 34290 Montpellier (France); Gustafsson, Jan-Ake [Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5056 (United States); Department of Biosciences and Nutrition, Karolinska Institutet, 14183 Huddinge (Sweden); and others


    Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28 °C as compared to 37 °C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology. - Highlights: • Zebrafish is increasingly used to study the effects of estrogens. • We assessed the activity of pharmaceutical and environmental estrogens on zfERs. • Environmental estrogens displayed greater potency for zfERα compared to zfERβs. • hERβ selective agonists displayed greater potency for zf

  12. Regulation of Estrogen Receptor Nuclear Export by Ligand-Induced and p38-Mediated Receptor Phosphorylation


    Lee, Heehyoung; Bai, Wenlong


    Estrogen receptors are phosphoproteins which can be activated by ligands, kinase activators, or phosphatase inhibitors. Our previous study showed that p38 mitogen-activated protein kinase was involved in estrogen receptor activation by estrogens and MEKK1. Here, we report estrogen receptor-dependent p38 activation by estrogens in endometrial adenocarcinoma cells and in vitro and in vivo phosphorylation of the estrogen receptor α mediated through p38. The phosphorylation site was identified as...

  13. Bioluminescent yeast estrogen assay (BLYES) as a sensitive tool to monitor surface and drinking water for estrogenicity


    Bergamasco, AMD; Eldridge, M; Sanseverino, J; Sodre, FF; Montagner, CC; Pescara, IC; Jardim, WF; Umbuzeiro, GD


    dEstrogenic Endocrine Disrupting Chemicals (EDCs) are a concern due to their ubiquity and recognized adverse effects to humans and wildlife. Methods to assess exposure to and associated risks of their presence in aquatic environment are still under development. The aim of this work is to assess estrogenicity of raw and treated waters with different degrees of pollution. Chemical analyses of selected EDCs were performed by liquid chromatography-tandem mass spectrometry, and estrogenic activity...

  14. Rapid signaling actions of environmental estrogens in developing granule cell neurons are mediated by estrogen receptor ß. (United States)

    Le, Hoa H; Belcher, Scott M


    Estrogenic endocrine disrupting chemicals (EDCs) constitute a diverse group of man-made chemicals and natural compounds derived from plants and microbial metabolism. Estrogen-like actions are mediated via the nuclear hormone receptor activity of estrogen receptor (ER)α and ERβ and rapid regulation of intracellular signaling cascades. Previous study defined cerebellar granule cell neurons as estrogen responsive and that granule cell precursor viability was developmentally sensitive to estrogens. In this study experiments using Western blot analysis and pharmacological approaches have characterized the receptor and signaling modes of action of selective and nonselective estrogen ligands in developing cerebellar granule cells. Estrogen treatments were found to briefly increase ERK1/2-phosphorylation and then cause prolonged depression of ERK1/2 activity. The sensitivity of granule cell precursors to estrogen-induced cell death was found to require the integrated activation of membrane and intracellular ER signaling pathways. The sensitivity of granule cells to selective and nonselective ER agonists and a variety of estrogenic and nonestrogenic EDCs was also examined. The ERβ selective agonist DPN, but not the ERα selective agonist 4,4',4'-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol or other ERα-specific ligands, stimulated cell death. Only EDCs with selective or nonselective ERβ activities like daidzein, equol, diethylstilbestrol, and bisphenol A were observed to induce E2-like neurotoxicity supporting the conclusion that estrogen sensitivity in granule cells is mediated via ERβ. The presented results also demonstrate the utility of estrogen sensitive developing granule cells as an in vitro assay for elucidating rapid estrogen-signaling mechanisms and to detect EDCs that act at ERβ to rapidly regulate intracellular signaling.

  15. Radiation Emitting Product Corrective Actions and Recalls (United States)

    U.S. Department of Health & Human Services — This database provides descriptions of radiation-emitting products that have been recalled under an approved corrective action plan to remove defective and...

  16. Radiation-emitting Electronic Product Codes (United States)

    U.S. Department of Health & Human Services — This database contains product names and associated information developed by the Center for all products, both medical and non-medical, which emit radiation. It...

  17. Bioluminescent yeast estrogen assay (BLYES) as a sensitive tool to monitor surface and drinking water for estrogenicity. (United States)

    Bergamasco, Ana Marcela Di Dea; Eldridge, Melanie; Sanseverino, John; Sodré, Fernando Fabriz; Montagner, Cassiana Carolina; Pescara, Igor Cardoso; Jardim, Wilson Figueiredo; Umbuzeiro, Gisela de Aragão


    Estrogenic Endocrine Disrupting Chemicals (EDCs) are a concern due to their ubiquity and recognized adverse effects to humans and wildlife. Methods to assess exposure to and associated risks of their presence in aquatic environment are still under development. The aim of this work is to assess estrogenicity of raw and treated waters with different degrees of pollution. Chemical analyses of selected EDCs were performed by liquid chromatography-tandem mass spectrometry, and estrogenic activity was evaluated using in vitro bioluminescent yeast estrogen assay (BLYES). Most raw water samples (18/20) presented at least one EDC and 16 rendered positive in BLYES. When EDCs were detected, the bioassay usually provided a positive response, except when only bisphenol A was detected at low concentrations. The highest values of estrogenic activity were detected in the most polluted sites. The maximum estrogenic activity observed was 8.7 ng equiv. of E2 L(-1). We compared potencies observed in the bioassay to the relative potency of target compounds and their concentrations failed to fully explain the biological response. This indicates that bioassay is more sensitive than the chemical approach either detecting estrogenic target compounds at lower concentrations, other non-target compounds or even synergistic effects, which should be considered on further investigations. We have not detected either estrogenic activity or estrogenic compounds in drinking water. BLYES showed good sensitivity with a detection limit of 0.1 ng equiv. E2 L(-1) and it seems to be a suitable tool for water monitoring.

  18. Effect of estrogens on boar sperm capacitation in vitro

    Directory of Open Access Journals (Sweden)

    Ded Lukas


    Full Text Available Abstract Background Mammalian sperm must undergo a series of controlled molecular processes in the female reproductive tract called capacitation before they are capable of penetrating and fertilizing the egg. Capacitation, as a complex biological process, is influenced by many molecular factors, among which steroidal hormone estrogens play their role. Estrogens, present in a high concentration in the female reproductive tract are generally considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive parameters. The purpose of this study is to investigate the effect of three natural estrogens such as estrone (E1, 17beta-estradiol (E2 and estriol (E3 as well as the synthetical one, 17alpha-ethynylestradiol (EE2 on boar sperm capacitation in vitro. Methods Boar sperm were capacitated in vitro in presence of estrogens. Capacitation progress in control and experimental samples was analyzed by flow cytometry with the anti-acrosin monoclonal antibody (ACR.2 at selected times of incubation. Sperm samples were analyzed at 120 min of capacitation by CTC (chlortetracycline assay, immunocytochemistry and flow cytometry with anti-acrosin ACR.2 antibody. Furthermore, sperm samples and capacitating media were analyzed by immunocytochemistry, ELISA with the ACR.2 antibody, and the acrosin activity assay after induced acrosomal reaction (AR. Results Estrogens stimulate sperm capacitation of boar sperm collected from different individuals. The stimulatory effect depends on capacitation time and is highly influenced by differences in the response to estrogens such as E2 by individual animals. Individual estrogens have relatively same effect on capacitation progress. In the boar samples with high estrogen responsiveness, estrogens stimulate the capacitation progress in a concentration-dependent manner. Furthermore, estrogens significantly increase the number of acrosome-reacted sperm after zona

  19. Estrogenic followed by anti-estrogenic effects of PCBs exposure in juvenil fish (Spaurus aurata). (United States)

    Calò, M; Alberghina, D; Bitto, A; Lauriano, E R; Lo Cascio, P


    Vitellogenin (Vtg) is a phospho-lipo-glycoprotein produced by oviparous animals in response to estrogen receptor (ER) binding. The presence of Vtg in juvenile and male fish liver and plasma has been used as biomarker to evaluate levels of environmental contaminants as dioxin and PCBs. Interaction of dioxins and PCBs with aryl hydrocarbon receptor (AhR) may affect reproduction by recruitment of estrogen receptor alpha (ERalpha). The aim of this study was to investigate the effects of PCB-126, a co-planar PCB prototypical AhR agonist, and of PCB-153, a non-coplanar PCB lacking dioxine-like activity, on Vtg expression in young fish (Spaurus aurata) after a 12 or 24h exposure to PCBs as well as 48h following PCBs removal. Vtg expression was evaluated by immunohistochemistry and by Western-blot analysis. Our results showed an increased Vtg expression following PCBs administration, with a maximum level after 12h of exposure to either PCB-126, PCB-153 or a mixture of both PCBs. Following this estrogenic activity, an anti-estrogenic activity was detected after 24h of incubation with PCB-126 (alone or mixed with PCB-153), suggested by a decrease in Vtg expression likely through AhR, as a consequence of a hypothetic defence mechanism to endogenous or exogenous ligands.

  20. Do estrogen or selective estrogen receptor modulators improve quality of life for women with postmenopausal osteoporosis? (United States)

    Gold, Deborah T; Silverman, Stuart L


    Osteoporotic fractures result in significant deficits in health-related quality of life (HRQOL). The accumulation of deficits resulting from osteoporosis and fractures is now recognized as a major cause of reduced HRQOL in women after the menopause and in later life. Some of these same postmenopausal women may also have deficits in HRQOL related to vasomotor symptoms during the menopausal transition. Although estrogen therapy has not been shown to improve overall HRQOL in late postmenopausal women in randomized, controlled trials, it may improve menopausal symptoms. In contrast, selective estrogen receptor modulators (SERMs) such as raloxifene may increase vasomotor symptoms. Although estrogen is not indicated for the primary prevention of osteoporosis, estrogen therapy may be considered for the postmenopausal woman at risk of osteoporotic fracture who is symptomatic and who is not at high risk of breast cancer or cardiovascular events. Raloxifene decreases risk of invasive breast cancer and may be considered in women at high risk of breast cancer. Decision making about osteoporosis treatment should also consider the impact of the treatment on HRQOL.

  1. Estrogen receptor genes in gastropods: phylogenetic divergence and gene expression responses to a synthetic estrogen. (United States)

    Hultin, Cecilia L; Hallgren, Per; Hansson, Maria C


    Endocrine disrupting chemicals (EDCs) have the potential to affect development and reproduction in gastropods. However, one is today lacking basic understanding of the Molluscan endocrine system and one can therefore not fully explain these EDC-induced affects. Furthermore, only a few genes that potentially may be connected to the endocrine system have been sequenced in gastropods. An example is the estrogen receptor gene (er) that have been identified in a restricted number of freshwater and marine gastropods. Here, we have identified a new partial coding sequence of an estrogen receptor gene (er) in the European common heterobranch Radix balthica. The following phylogenetic analysis divided the ers of heterobranchs and ceanogastropods in two branches. Furthermore, exposure to the synthetic estrogen 17α-ethinylestradiol (EE2) showed that exposure could significantly affect er expression level in the heterobranch R. balthica. This paper is the first that phylogenetically compares gastropods' er, basal er expression profiles, and transcriptional estrogenic responses in gastropods from two different evolutionary groups.

  2. Bisphenol-A acts as a potent estrogen via non-classical estrogen triggered pathways. (United States)

    Alonso-Magdalena, Paloma; Ropero, Ana Belén; Soriano, Sergi; García-Arévalo, Marta; Ripoll, Cristina; Fuentes, Esther; Quesada, Iván; Nadal, Ángel


    Bisphenol-A (BPA) is an estrogenic monomer commonly used in the manufacture of numerous consumer products such as food and beverage containers. Widespread human exposure to significant doses of this compound has been reported. Traditionally, BPA has been considered a weak estrogen, based on its lower binding affinity to the nuclear estrogen receptors (ERs) compared to 17-β estradiol (E2) as well as its low transcriptional activity after ERs activation. However, in vivo animal studies have demonstrated that it can interfere with endocrine signaling pathways at low doses during fetal, neonatal or perinatal periods as well as in adulthood. In addition, mounting evidence suggests a variety of pathways through which BPA can elicit cellular responses at very low concentrations with the same or even higher efficiency than E2. Thus, the purpose of the present review is to analyze with substantiated scientific evidence the strong estrogenic activity of BPA when it acts through alternative mechanisms of action at least in certain cell types.

  3. The in vivo estrogenic and in vitro anti-estrogenic activity of permethrin and bifenthrin. (United States)

    Brander, Susanne M; He, Guochun; Smalling, Kelly L; Denison, Michael S; Cherr, Gary N


    Pyrethroids are highly toxic to fish at parts per billion or parts per trillion concentrations. Their intended mechanism is prolonged sodium channel opening, but recent studies reveal that pyrethroids such as permethrin and bifenthrin also have endocrine activity. Additionally, metabolites may have greater endocrine activity than parent compounds. The authors evaluated the in vivo concentration-dependent ability of bifenthrin and permethrin to induce choriogenin (an estrogen-responsive protein) in Menidia beryllina, a fish species known to reside in pyrethroid-contaminated aquatic habitats. The authors then compared the in vivo response with an in vitro assay--chemical activated luciferase gene expression (CALUX). Juvenile M. beryllina exposed to bifenthrin (1, 10, 100 ng/L), permethrin (0.1, 1, 10 µg/L), and ethinylestradiol (1, 10, 50 ng/L) had significantly higher ng/mL choriogenin (Chg) measured in whole body homogenate than controls. Though Chg expression in fish exposed to ethinylestradiol (EE2) exhibited a traditional sigmoidal concentration response, curves fit to Chg expressed in fish exposed to pyrethroids suggest a unimodal response, decreasing slightly as concentration increases. Whereas the in vivo response indicated that bifenthrin and permethrin or their metabolites act as estrogen agonists, the CALUX assay demonstrated estrogen antagonism by the pyrethroids. The results, supported by evidence from previous studies, suggest that bifenthrin and permethrin, or their metabolites, appear to act as estrogen receptor (ER) agonists in vivo, and that the unmetabolized pyrethroids, particularly bifenthrin, act as an ER antagonists in cultured mammalian cells.

  4. Techniques for the correction of topographical effects in scanning Auger electron microscopy (United States)

    Prutton, M.; Larson, L. A.; Poppa, H.


    A number of ratioing methods for correcting Auger images and linescans for topographical contrast are tested using anisotropically etched silicon substrates covered with Au or Ag. Thirteen well-defined angles of incidence are present on each polyhedron produced on the Si by this etching. If N1 electrons are counted at the energy of an Auger peak and N2 are counted in the background above the peak, then N1, N1 - N2, (N1 - N2)/(N1 + N2) are measured and compared as methods of eliminating topographical contrast. The latter method gives the best compensation but can be further improved by using a measurement of the sample absorption current. Various other improvements are discussed.

  5. Epidermal Growth Factor Receptor Overexpression as a Target for Auger Electron Radiotherapy of Breast Cancer (United States)


    buffer containing 200 mM sucrose/3 mM calcium chloride/50 mM Tris hydrochloride pH 7.6, followed by a wash step in 140 mM sodium chloride/10 mM the sheep . J Endocrinol 1989; 123:121-130. 24. Duncan JR and Welch MJ. Intracellular metabolism of indium-111-DTPA labeled receptor the potential of glycosylated albumin in targeting intraperitoneal (i.p.) tu- bohydrate ligands (glucarate and gluconate ) for tumors and sites of

  6. Epidermal Growth Factor Receptor Overexpression as a Target for Auger Electron Radiotherapy of Breast Cancer (United States)


    radiotherapeutic agent for breast cancer. © 2001 Elsevier Science Inc . All rights reserved. Keywords: Breast cancer; Indium-111; Epidermal growth factor receptor... Science Inc . All rights reserved. PII: S0969-8051(01)00262-1 896 .1. Wang et al. / Nuclear Medicine and Biology 28 (2001) 895-902 A NW3 rn- NH, + (R.M. Reilly). (cDTPAA) with an E-amino group on a lysine residue or the 0969-8051/01/$ - see front matter © 2001 Elsevier

  7. Isoflavones: estrogenic activity, biological effect and bioavailability. (United States)

    Vitale, Daniela Cristina; Piazza, Cateno; Melilli, Barbara; Drago, Filippo; Salomone, Salvatore


    Isoflavones are phytoestrogens with potent estrogenic activity; genistein, daidzein and glycitein are the most active isoflavones found in soy beans. Phytoestrogens have similarity in structure with the human female hormone 17-β-estradiol, which can bind to both alpha and beta estrogen receptors, and mimic the action of estrogens on target organs, thereby exerting many health benefits when used in some hormone-dependent diseases. Numerous clinical studies claim benefits of genistein and daidzein in chemoprevention of breast and prostate cancer, cardiovascular disease and osteoporosis as well as in relieving postmenopausal symptoms. The ability of isoflavones to prevent cancer and other chronic diseases largely depends on pharmacokinetic properties of these compounds, in particular absorption and distribution to the target tissue. The chemical form in which isoflavones occur is important because it influences their bioavailability and, therefore, their biological activity. Glucose-conjugated isoflavones are highly polar, water-soluble compounds. They are hardly absorbed by the intestinal epithelium and have weaker biological activities than the corresponding aglycone. Different microbial families of colon can transform glycosylated isoflavones into aglycones. Clinical studies show important differences between the aglycone and conjugated forms of genistein and daidzein. The evaluation of isoflavone metabolism and bioavailability is crucial to understanding their biological effects. Lipid-based formulations such as drug incorporation into oils, emulsions and self-microemulsifying formulations have been introduced to increase bioavailability. Complexation with cyclodextrin also represent a valid method to improve the physicochemical characteristics of these substances in order to be absorbed and distributed to target tissues. We review and discuss pharmacokinetic issues that critically influence the biological activity of isoflavones.

  8. The Endocrine Role of Estrogens on Human Male Skeleton

    Directory of Open Access Journals (Sweden)

    Vincenzo Rochira


    Full Text Available Before the characterization of human and animal models of estrogen deficiency, estrogen action was confined in the context of the female bone. These interesting models uncovered a wide spectrum of unexpected estrogen actions on bone in males, allowing the formulation of an estrogen-centric theory useful to explain how sex steroids act on bone in men. Most of the principal physiological events that take place in the developing and mature male bone are now considered to be under the control of estrogen. Estrogen determines the acceleration of bone elongation at puberty, epiphyseal closure, harmonic skeletal proportions, the achievement of peak bone mass, and the maintenance of bone mass. Furthermore, it seems to crosstalk with androgen even in the determination of bone size, a more androgen-dependent phenomenon. At puberty, epiphyseal closure and growth arrest occur when a critical number of estrogens is reached. The same mechanism based on a critical threshold of serum estradiol seems to operate in men during adulthood for bone mass maintenance via the modulation of bone formation and resorption in men. This threshold should be better identified in-between the ranges of 15 and 25 pg/mL. Future basic and clinical research will optimize strategies for the management of bone diseases related to estrogen deficiency in men.

  9. Estrogen-related and other disease diagnoses preceding Parkinson's disease

    DEFF Research Database (Denmark)

    Latourelle, Jeanne C; Dybdal, Merete; Destefano, Anita L;


    Estrogen exposure has been associated with the occurrence of Parkinson's disease (PD), as well as many other disorders, and yet the mechanisms underlying these relations are often unknown. While it is likely that estrogen exposure modifies the risk of various diseases through many different...

  10. Bioassay- versus analytically-derived estrogen equivalents: Ramifications for monitoring (United States)

    Due to concern for possible endocrine-related effects on aquatic vertebrates, environmental estrogens (EEs) are a growing focus of surface water contaminant monitoring programs. Some efforts utilize measurement of a targeted set of chemicals known to act as estrogen receptor (ER)...

  11. Estrogen receptor polymorphisms: significance to human physiology, disease and therapy. (United States)

    Figtree, Gemma A; Noonan, Jonathon E; Bhindi, Ravinay; Collins, Peter


    Other than its well-recognized effects on reproductive physiology, estrogen has important actions in a wide variety of other body systems with important examples including bone, blood vessels and the heart. These effects are seen in both females and males. Investigators have hypothesized those genetic variants in the genes coding for estrogen signaling proteins may cause variable sensitivity to the hormone and influence an individual's estrogen-sensitive phenotypes. The most obvious candidate genes are the estrogen receptors alpha and (ERalpha and beta). However, the regulation of these genes is complex and not well understood. Furthermore, their coding exons, and regulatory sequences are dispersed across large segments of the genome. A number of common polymorphisms have been identified in both ERalpha and ERbeta, with variable degrees of evidence of their direct biological significance and their association with human disease. The identification of genetic variations associated with altered estrogen response is of potential public health importance. Insights may be gained into the pathogenesis of estrogen sensitive diseases such as osteoporosis, breast cancer and cardiovascular disease contributing to the development and application of newer therapies for these disorders. Furthermore, genetic variants that alter sensitivity to estrogen may affect both therapeutic and harmful responses to exogenous estrogen administered in the form of the oral contraceptive pill or hormone replacement therapy. This clinical significance has led to the publication of a number of patents which will be reviewed.

  12. Effect of estrogenic binary mixtures in the yeast estrogen screen (YES). (United States)

    Ramirez, Tzutzuy; Buechse, Andreas; Dammann, Martina; Melching-Kollmuß, Stephanie; Woitkowiak, Claudia; van Ravenzwaay, Bennard


    Endocrine disrupting compounds (EDCs) of natural or synthetic origin can interfere with the balance of the hormonal system, either by altering hormone production, secretion, transport, or their binding and consequently lead to an adverse outcome in intact animals. An important aspect is the prediction of effects of combined exposure to two or more EDCs at the same time. The yeast estrogen assay (YES) is a broadly used method to assess estrogenic potential of chemicals. Besides exhibiting good predictivity to identify compounds which interfere with the estrogen receptor, it is easy to handle, rapid and therefore allows screening of a large number of single compounds and varying mixtures. Herein, we applied the YES assay to determine the potential combination effects of binary mixtures of two estrogenic compounds, bisphenol A and genistein, as well as one classical androgen that in vitro also exhibits estrogenic activity, trenbolone. In addition to generating data from combined exposure, we fitted these to a four-parametric logistic dose-response model. As all compounds tested share the same mode of action dose additivity was expected. To assess this, the Loewe model was utilized. Deviations between the Loewe additivity model and the observed responses were always small and global tests based on the whole dose-response data set indicated in general a good fit of the Loewe additivity model. At low concentrations concentration additivity was observed, while at high concentrations, the observed effect was lower than additivity, most likely reflecting receptor saturation. In conclusion, our results suggest that binary combinations of genistein, bisphenol A and trenbolone in the YES assay do not deviate from expected additivity.

  13. Caffeine, coffee and tea intake and urinary estrogens and estrogen metabolites in premenopausal women (United States)

    Sisti, Julia S.; Hankinson, Susan E.; Caporaso, Neil E.; Gu, Fangyi; Tamimi, Rulla M.; Rosner, Bernard; Xu, Xia; Ziegler, Regina; Eliassen, A. Heather


    Background Prior studies have found weak inverse associations between breast cancer and caffeine and coffee intake, possibly mediated through their effects on sex hormones. Methods High-performance liquid chromatography/tandem mass spectrometry was used to quantify levels of 15 individual estrogens and estrogen metabolites (EM) among 587 premenopausal women in the Nurses’ Health Study II with mid-luteal phase urine samples and caffeine, coffee and/or tea intakes from self-reported food frequency questionnaires. Multivariate linear mixed models were used to estimate geometric means of individual EM, pathways and ratios by intake categories, and P-values for tests of linear trend. Results Compared to women in the lowest quartile of caffeine consumption, those in the top quartile had higher urinary concentrations of 16α-hydroxyestrone (28% difference; P-trend=0.01) and 16-epiestriol (13% difference; P-trend=0.04), and a decreased parent estrogens/2-, 4-, 16-pathway ratio (P-trend=0.03). Coffee intake was associated with higher 2-catechols, including 2-hydroxyestradiol (57% difference, ≥4 cups/day vs. ≤6 cups/week; P-trend=0.001) and 2-hydroxyestrone (52% difference; P-trend=0.001), and several ratio measures. Decaffeinated coffee was not associated with 2-pathway metabolism, but women in the highest (vs. lowest) category of intake (≥2 cups/day vs. ≤1–3 cups/month) had significantly lower levels of two 16-pathway metabolites, estriol (25% difference; P-trend=0.01) and 17-epiestriol (48% difference; Ptrend=0.0004). Tea intake was positively associated with 17-epiestriol (52% difference; Ptrend=0.01). Conclusion Caffeine and coffee intake were both associated with profiles of estrogen metabolism in premenopausal women. Impact Consumption of caffeine and coffee may alter patterns of premenopausal estrogen metabolism. PMID:26063478

  14. Signaling from the membrane via membrane estrogen receptor-alpha: estrogens, xenoestrogens, and phytoestrogens. (United States)

    Watson, Cheryl S; Bulayeva, Nataliya N; Wozniak, Ann L; Finnerty, Celeste C


    Estrogen mimetics in the environment and in foods can have important consequences for endocrine functions. When previously examined for action via genomic steroid signaling mechanisms, most of these compounds were found to be very weak agonists. We have instead tested their actions via several membrane-initiated signaling mechanisms in GH3/B6 pituitary tumor cells extensively selected for high (responsive) or low (nonresponsive) expression of the membrane version of estrogen receptor-alpha (mERalpha). We found many estrogen mimetic compounds to be potently active in our quantitative extracellular-regulated kinase (ERK) activation assays, to increase cellular Ca++ levels, and to cause rapid prolactin release. However, these compounds may activate one or both mechanisms with different potencies. For instance, some compounds activate ERKs in both pM and nM concentration ranges, while others are only active at nM and higher concentrations. Compounds also show great differences in their temporal activation patterns. While estradiol causes a bimodal time-dependent ERK activation (peaking at both 3 and 30 min), most estrogen mimetics cause either an early phase activation, a late phase activation, or an early sustained activation. One xenoestrogen known to be a relatively potent activator of estrogen response element-mediated actions (bisphenol A) is inactive as an ERK activator, and only a modest inducer of Ca++ levels and prolactin release. Many different signaling machineries culminate in ERK activation, and xenoestrogens differentially affect various pathways. Clearly individual xenoestrogens must be individually investigated for their differing abilities to activate distinct membrane-initiated signal cascades that lead to a variety of cellular functions.

  15. Evolution of estrogen receptors in ray-finned fish and their comparative responses to estrogenic substances. (United States)

    Tohyama, Saki; Miyagawa, Shinichi; Lange, Anke; Ogino, Yukiko; Mizutani, Takeshi; Ihara, Masaru; Tanaka, Hiroaki; Tatarazako, Norihisa; Kobayashi, Tohru; Tyler, Charles R; Iguchi, Taisen


    In vertebrates, estrogens play fundamental roles in regulating reproductive activities through estrogen receptors (ESRs), and disruption of estrogen signaling is now of global concern for both wildlife and human health. To date, ESRs of only a limited number of species have been characterized. We investigated the functional diversity and molecular basis or ligand sensitivity of ESRs among ray-finned fish species (Actinopterygii), the most variable group within vertebrates. We cloned and characterized ESRs from several key species in the evolution of ray-finned fish including bichir (Polypteriformes, ESR1 and ESR2) at the basal lineage of ray-finned fish, and arowana (Osteoglossiformes, ESR1 and ESR2b) and eel (Anguilliformes, ESR1, ESR2a and ESR2b) both belonging to ancient early-branching lineages of teleosts, and suggest that ESR2a and ESR2b emerged through teleost-specific whole genome duplication, but an ESR1 paralogue has been lost in the early lineage of euteleost fish species. All cloned ESR isoforms showed similar responses to endogenous and synthetic steroidal estrogens, but they responded differently to non-steroidal estrogenic endocrine disrupting chemicals (EDCs) (e.g., ESR2a exhibits a weaker reporter activity compared with ESR2b). We show that variation in ligand sensitivity of ESRs can be attributed to phylogeny among species of different taxonomic groups in ray-finned fish. The molecular information provided contributes both to understanding of the comparative role of ESRs in the reproductive biology of fish and their comparative responses to EDCs.

  16. Assaying estrogenicity by quantitating the expression levels of endogenous estrogen-regulated genes. (United States)

    Jørgensen, M; Vendelbo, B; Skakkebaek, N E; Leffers, H


    Scientific evidence suggests that humans and wildlife species may experience adverse health consequences from exposure to environmental chemicals that interact with the endocrine system. Reliable short-term assays are needed to identify hormone-disrupting chemicals. In this study we demonstrate that the estrogenic activity of a chemical can be evaluated by assaying induction or repression of endogenous estrogen-regulated "marker genes" in human breast cancer MCF-7 cells. We included four marker genes in the assay--pS2, transforming growth factor beta3 (TGFbeta3), monoamine oxidase A, and [alpha]1-antichymotrypsin--and we evaluated estrogenic activity for 17beta-estradiol (E(2)), diethylstilbestrol, [alpha]-zearalanol, nonylphenol, genistein, methoxychlor, endosulphan, o,p-DDE, bisphenol A, dibutylphthalate, 4-hydroxy tamoxifen, and ICI 182.780. All four marker genes responded strongly to the three high-potency estrogens (E(2), diethylstilbestrol, and [alpha]-zearalanol), whereas the potency of the other chemicals was 10(3)- to 10(6)-fold lower than that of E(2). There were some marker gene-dependent differences in the relative potencies of the tested chemicals. TGFbeta3 was equally sensitive to the three high-potency estrogens, whereas the sensitivity to [alpha]-zearalanol was approximately 10-fold lower than the sensitivity to E(2) and diethylstilbestrol when assayed with the other three marker genes. The potency of nonylphenol was equal to that of genistein when assayed with pS2 and TGFbeta3, but 10- to 100-fold higher/lower with monoamine oxidase A and [alpha]1-antichymotrypsin, respectively. The results are in agreement with results obtained by other methods and suggest that an assay based on endogenous gene expression may offer an attractive alternative to other E-SCREEN methods.

  17. Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors. (United States)

    Pinto, Caroline; Grimaldi, Marina; Boulahtouf, Abdelhay; Pakdel, Farzad; Brion, François; Aït-Aïssa, Sélim; Cavaillès, Vincent; Bourguet, William; Gustafsson, Jan-Ake; Bondesson, Maria; Balaguer, Patrick


    Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28°C as compared to 37°C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology.

  18. The Antidepressant-like Effects of Estrogen-mediated Ghrelin (United States)

    Wang, Pu; Liu, Changhong; Liu, Lei; Zhang, Xingyi; Ren, Bingzhong; Li, Bingjin


    Ghrelin, one of the brain-gut peptides, stimulates food-intake. Recently, ghrelin has also shown to play an important role in depression treatment. However, the mechanism of ghrelin’s antidepressant-like actions is unknown. On the other hand, sex differences in depression, and the fluctuation of estrogens secretion have been proved to play a key role in depression. It has been reported that women have higher level of ghrelin expression, and ghrelin can stimulate estrogen secretion while estrogen acts as a positive feedback mechanism to up-regulate ghrelin level. Ghrelin may be a potential regulator of reproductive function, and estrogen may have additional effect in ghrelin’s antidepressantlike actions. In this review, we summarize antidepressant-like effects of ghrelin and estrogen in basic and clinical studies, and provide new insight on ghrelin’s effect in depression. PMID:26412072

  19. Science Signaling podcast for 24 May 2016: Designer estrogens. (United States)

    Katzenellenbogen, Benita S; Katzenellenbogen, John A; Madak-Erdogan, Zeynep; VanHook, Annalisa M


    This Podcast features an interview with Zeynep Madak-Erdogan, Benita Katzenellenbogen, and John Katzenellenbogen, authors of a Research Article that appears in the 24 May 2016 issue of Science Signaling, about designer estrogens that have the therapeutic benefits of natural estrogens, but less cancer risk. In addition to controlling female reproduction and secondary sex characteristics, estrogen is also an important regulator of metabolism, the vasculature, and bone. Estrogen production decreases as women enter menopause, leading to changes in metabolism, a reduced ability to repair blood vessels, and decreased bone density. Although hormone replacement therapy can alleviate these symptoms, it can also promote the growth of uterine and breast cancers. Madak-Erdogan et al engineered synthetic forms of estrogen that activate the cytosolic signaling pathways that are associated with the beneficial effects of this hormone without also activating the nuclear signaling events associated with cancer growth.Listen to Podcast.

  20. Synthesis of a dendritic estrogen cluster: A potential tool for studies of nuclear versus extranuclear pathways of estrogen actions

    Institute of Scientific and Technical Information of China (English)

    Jian Chen; Hu Zheng; Yan Song; Yu Feng Liang; Qing Rong Qi


    A novel estrogen dendrimer has been synthesized through a combination of divergent and convergent approaches in 9 practical steps and in good yields.It was characterized and confirmed by elemental analysis,FT-IR,MS,1H NMR,13C NMR.The dendrimer contains 16 estrone units and is potentially a useful tool for the studies of estrogen actions.

  1. Licorice root components in dietary supplements are selective estrogen receptor modulators with a spectrum of estrogenic and anti-estrogenic activities. (United States)

    Boonmuen, Nittaya; Gong, Ping; Ali, Zulfiqar; Chittiboyina, Amar G; Khan, Ikhlas; Doerge, Daniel R; Helferich, William G; Carlson, Kathryn E; Martin, Teresa; Piyachaturawat, Pawinee; Katzenellenbogen, John A; Katzenellenbogen, Benita S


    Licorice root extracts are often consumed as botanical dietary supplements by menopausal women as a natural alternative to pharmaceutical hormone replacement therapy. In addition to their components liquiritigenin (Liq) and isoliquiritigenin (Iso-Liq), known to have estrogenic activity, licorice root extracts also contain a number of other flavonoids, isoflavonoids, and chalcones. We have investigated the estrogenic activity of 7 of these components, obtained from an extract of Glycyrrhiza glabra powder, namely Glabridin (L1), Calycosin (L2), Methoxychalcone (L3), Vestitol (L4), Glyasperin C (L5), Glycycoumarin (L6), and Glicoricone (L7), and compared them with Liq, Iso-Liq, and estradiol (E2). All components, including Liq and Iso-Liq, have low binding affinity for estrogen receptors (ERs). Their potency and efficacy in stimulating the expression of estrogen-regulated genes reveal that Liq and Iso-Liq and L2, L3, L4, and L6 are estrogen agonists. Interestingly, L3 and L4 have an efficacy nearly equivalent to E2 but with a potency ca. 10,000-fold less. The other components, L1, L5 and L7, acted as partial estrogen antagonists. All agonist activities were reversed by the antiestrogen, ICI 182,780, or by knockdown of ERα with siRNA, indicating that they are ER dependent. In HepG2 hepatoma cells stably expressing ERα, only Liq, Iso-Liq, and L3 stimulated estrogen-regulated gene expression, and in all cases gene stimulation did not occur in HepG2 cells lacking ERα. Collectively, these findings classify the components of licorice root extracts as low potency, mixed ER agonists and antagonists, having a character akin to that of selective estrogen receptor modulators or SERMs.

  2. Androgens and estrogens in skeletal sexual dimorphism. (United States)

    Laurent, Michaël; Antonio, Leen; Sinnesael, Mieke; Dubois, Vanessa; Gielen, Evelien; Classens, Frank; Vanderschueren, Dirk


    Bone is an endocrine tissue expressing androgen and estrogen receptors as well as steroid metabolizing enzymes. The bioactivity of circulating sex steroids is modulated by sex hormone-binding globulin and local conversion in bone tissue, for example, from testosterone (T) to estradiol (E2) by aromatase, or to dihydrotestosterone by 5α-reductase enzymes. Our understanding of the structural basis for gender differences in bone strength has advanced considerably over recent years due to increasing use of (high resolution) peripheral computed tomography. These microarchitectural insights form the basis to understand sex steroid influences on male peak bone mass and turnover in cortical vs trabecular bone. Recent studies using Cre/LoxP technology have further refi ned our mechanistic insights from global knockout mice into the direct contributions of sex steroids and their respective nuclear receptors in osteoblasts, osteoclasts, osteocytes, and other cells to male osteoporosis. At the same time, these studies have reinforced the notion that androgen and estrogen defi ciency have both direct and pleiotropic effects via interaction with, for example, insulin-like growth factor 1, inflammation, oxidative stress, central nervous system control of bone metabolism, adaptation to mechanical loading, etc., This review will summarize recent advances on these issues in the fi eld of sex steroid actions in male bone homeostasis.

  3. Androgens and estrogens in skeletal sexual dimorphism

    Directory of Open Access Journals (Sweden)

    Michaël Laurent


    Full Text Available Bone is an endocrine tissue expressing androgen and estrogen receptors as well as steroid metabolizing enzymes. The bioactivity of circulating sex steroids is modulated by sex hormone-binding globulin and local conversion in bone tissue, for example, from testosterone (T to estradiol (E2 by aromatase, or to dihydrotestosterone by 5α-reductase enzymes. Our understanding of the structural basis for gender differences in bone strength has advanced considerably over recent years due to increasing use of (high resolution peripheral computed tomography. These microarchitectural insights form the basis to understand sex steroid influences on male peak bone mass and turnover in cortical vs trabecular bone. Recent studies using Cre/LoxP technology have further refi ned our mechanistic insights from global knockout mice into the direct contributions of sex steroids and their respective nuclear receptors in osteoblasts, osteoclasts, osteocytes, and other cells to male osteoporosis. At the same time, these studies have reinforced the notion that androgen and estrogen defi ciency have both direct and pleiotropic effects via interaction with, for example, insulin-like growth factor 1, inflammation, oxidative stress, central nervous system control of bone metabolism, adaptation to mechanical loading, etc., This review will summarize recent advances on these issues in the fi eld of sex steroid actions in male bone homeostasis.

  4. Ligand-based identification of environmental estrogens

    Energy Technology Data Exchange (ETDEWEB)

    Waller, C.L. [Environmental Protection Agency, Research Triangle Park, NC (United States); Oprea, T.I. [Los Alamos National Lab., NM (United States); Chae, K. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States)] [and others


    Comparative molecular field analysis (CoMFA), a three-dimensional quantitative structure-activity relationship (3D-QSAR) paradigm, was used to examine the estrogen receptor (ER) binding affinities of a series of structurally diverse natural, synthetic, and environmental chemicals of interest. The CoMFA/3D-QSAR model is statistically robust and internally consistent, and successfully illustrates that the overall steric and electrostatic properties of structurally diverse ligands for the estrogen receptor are both necessary and sufficient to describe the binding affinity. The ability of the model to accurately predict the ER binding affinity of an external test set of molecules suggests that structure-based 3D-QSAR models may be used to supplement the process of endocrine disrupter identification through prioritization of novel compounds for bioassay. The general application of this 3D-QSAR model within a toxicological framework is, at present, limited only by the quantity and quality of biological data for relevant biomarkers of toxicity and hormonal responsiveness. 28 refs., 12 figs., 9 tabs.

  5. Determination of estrogen receptor {beta}-mediated estrogenic potencies of hydroxylated PCBS by a yeast two-hybrid assay

    Energy Technology Data Exchange (ETDEWEB)

    Kuroki, H.; Kumate, M.; Nakaoka, H.; Yonekura, S. [Daiichi Coll. of Pharmaceutical Sciences, Fukuoka (Japan); Nishikawa, J.; Nishihara, T. [Osaka Univ., Osaka (Japan)


    Several environmental phenolic chemicals such as Nonylphenol and Bisphenol A (BPA) have been previously shown to possess estrogenic properties. In the previous paper, we have investigated the estrogenic activity of a series of hydroxylated PCBs (OH-PCBs) by a yeast two-hybrid assay (estrogen receptor{alpha} (ER{alpha}) -TIF2), in which the expression of estrogenic activity is based on the interaction of chemicals with ER{alpha}, and demonstrated that 4'-OH-CB30 and 4'-OH-CB61 are more estrogenic than BPA, one of the environmental estrogens. We have showed that one chlorine substitution adjacent to 4-OH at 3- or 5-position significantly reduces the ER{alpha}-mediated estrogenic activity of 4-OH-PCBs. Thus, 4'-OH-CB25 and 4-OH-CB56 showed a very weak estrogenicity. We have also showed that 4-OH-PCBs with two chlorine substitutions adjacent to 4-OH at 3- and 5-position such as 4'-OH-CB79 (hydroxylated metabolite of CB77) and persistent 4-OH-PCBs retained in human blood (4-OH-CB107, 4-OH-CB146 and 4-OH-CB187) have no ER{alpha}-mediated estrogenic activity. ER is known to have two subtypes, namely ER{alpha} and ER{beta} and it is reported that ligand, some agonist and antagonist have a different binding affinity for ER{alpha} and ER{beta}. However, there is limited information on ER{beta}-mediated endocrine disrupting potency. In this study, we examined the ER{beta}-mediated estrogenic activity of a series of OH-PCBs, including environmentally relevant 4-OH-PCBs by a yeast two-hybrid assay (ER{beta}-TIF2).

  6. 21 CFR 862.1270 - Estrogens (total, in pregnancy) test system. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Estrogens (total, in pregnancy) test system. 862... Test Systems § 862.1270 Estrogens (total, in pregnancy) test system. (a) Identification. As estrogens (total, in pregnancy) test system is a device intended to measure total estrogens in plasma, serum,...

  7. Estrogens regulate the hepatic effects of growth hormone, a hormonal interplay with multiple fates

    DEFF Research Database (Denmark)

    Fernández-Pérez, Leandro; Guerra, Borja; Díaz-Chico, Juan C;


    -regulated endocrine and metabolic functions in the human liver by acting at the level of GHR-STAT5 signaling pathway. This crosstalk is relevant because the widespread exposition of estrogen or estrogen-related compounds in human. Therefore, GH or estrogen signaling deficiency as well as the influence of estrogens...

  8. Proapoptotic protein Bim attenuates estrogen-enhanced survival in lymphangioleiomyomatosis. (United States)

    Li, Chenggang; Li, Na; Liu, Xiaolei; Zhang, Erik Y; Sun, Yang; Masuda, Kouhei; Li, Jing; Sun, Julia; Morrison, Tasha; Li, Xiangke; Chen, Yuanguang; Wang, Jiang; Karim, Nagla A; Zhang, Yi; Blenis, John; Reginato, Mauricio J; Henske, Elizabeth P; Yu, Jane J


    Lymphangioleiomyomatosis (LAM) is a progressive lung disease that primarily affects young women. Genetic evidence suggests that LAM cells bearing TSC2 mutations migrate to the lungs, proliferate, and cause cystic remodeling. The female predominance indicates that estrogen plays a critical role in LAM pathogenesis, and we have proposed that estrogen promotes LAM cell metastasis by inhibition of anoikis. We report here that estrogen increased LAM patient-derived cells' resistance to anoikis in vitro, accompanied by decreased accumulation of the proapoptotic protein Bim, an activator of anoikis. The resistance to anoikis was reversed by the proteasome inhibitor, bortezomib. Treatment of LAM patient-derived cells with estrogen plus bortezomib promoted anoikis compared with estrogen alone. Depletion of Bim by siRNA in TSC2-deficient cells resulted in anoikis resistance. Treatment of mice with bortezomib reduced estrogen-promoted lung colonization of TSC2-deficient cells. Importantly, molecular depletion of Bim by siRNA in Tsc2-deficient cells increased lung colonization in a mouse model. Collectively, these data indicate that Bim plays a key role in estrogen-enhanced survival of LAM patient-derived cells under detached conditions that occur with dissemination. Thus, targeting Bim may be a plausible future treatment strategy in patients with LAM.

  9. In vitro estrogenic activity of Achillea millefolium L. (United States)

    Innocenti, G; Vegeto, E; Dall'Acqua, S; Ciana, P; Giorgetti, M; Agradi, E; Sozzi, A; Fico, G; Tomè, F


    Isolation and biological characterization of pure compounds was used to identify and characterize estrogenic activity and estrogen receptors (ER) preference in chemical components of Achillea millefolium. This medicinal plant is used in folk medicine as an emmenagogue. In vitro assay, based on recombinant MCF-7 cells, showed estrogenic activity in a crude extract of the aerial parts of A. millefolium. After fractionation of the crude extract with increasing polar solvents, estrogenic activity was found in the methanol/water fraction. Nine compounds were isolated and characterized by HR-MS spectra and 1D- and 2D-NMR techniques. In particular, dihydrodehydrodiconiferyl alcohol 9-O-beta-D-glucopyranoside - a glycosyl-neolignan - was isolated for the first time from the genus Achillea in addition to six flavone derivatives, apigenin, apigenin-7-O-beta-D-glucopyranoside, luteolin, luteolin-7-O-beta-D-glucopyranoside, luteolin-4'-O-beta-D-glucopyranoside, rutin, and two caffeic acid derivatives, 3,5-dicaffeoylquinic acid and chlorogenic acid. Apigenin and luteolin, the most important estrogenic compounds among those tested, were studied for their ability to activate alpha or beta estrogen receptors (ERalpha, ERbeta) using transiently transfected cells. Our results suggest that isolation and biological characterization of estrogenic compounds in traditionally used medicinal plants could be a first step in better assessing further (e.g. in vivo) tests of nutraceutical and pharmacological strategies based on phytoestrogens.

  10. Determination of estrogenic potential in waste water without sample extraction. (United States)

    Avberšek, Miha; Žegura, Bojana; Filipič, Metka; Uranjek-Ževart, Nataša; Heath, Ester


    This study describes the modification of the ER-Calux assay for testing water samples without sample extraction (NE-(ER-Calux) assay). The results are compared to those obtained with ER-Calux assay and a theoretical estrogenic potential obtained by GC-MSD. For spiked tap and waste water samples there was no statistical difference between estrogenic potentials obtained by the three methods. Application of NE-(ER-Calux) to "real" influent and effluents from municipal waste water treatment plants and receiving surface waters found that the NE-(ER-Calux) assay gave higher values compared to ER-Calux assay and GC-MSD. This is explained by the presence of water soluble endocrine agonists that are usually removed during extraction. Intraday dynamics of the estrogenic potential of a WWTP influent and effluent revealed an increase in the estrogenic potential of the influent from 12.9 ng(EEQ)/L in the morning to a peak value of 40.0 ng(EEQ)/L in the afternoon. The estrogenic potential of the effluent was estrogenic potential was 92-98%. Daytime estrogenic potential values varied significantly.

  11. Glyphosate induces human breast cancer cells growth via estrogen receptors. (United States)

    Thongprakaisang, Siriporn; Thiantanawat, Apinya; Rangkadilok, Nuchanart; Suriyo, Tawit; Satayavivad, Jutamaad


    Glyphosate is an active ingredient of the most widely used herbicide and it is believed to be less toxic than other pesticides. However, several recent studies showed its potential adverse health effects to humans as it may be an endocrine disruptor. This study focuses on the effects of pure glyphosate on estrogen receptors (ERs) mediated transcriptional activity and their expressions. Glyphosate exerted proliferative effects only in human hormone-dependent breast cancer, T47D cells, but not in hormone-independent breast cancer, MDA-MB231 cells, at 10⁻¹² to 10⁻⁶M in estrogen withdrawal condition. The proliferative concentrations of glyphosate that induced the activation of estrogen response element (ERE) transcription activity were 5-13 fold of control in T47D-KBluc cells and this activation was inhibited by an estrogen antagonist, ICI 182780, indicating that the estrogenic activity of glyphosate was mediated via ERs. Furthermore, glyphosate also altered both ERα and β expression. These results indicated that low and environmentally relevant concentrations of glyphosate possessed estrogenic activity. Glyphosate-based herbicides are widely used for soybean cultivation, and our results also found that there was an additive estrogenic effect between glyphosate and genistein, a phytoestrogen in soybeans. However, these additive effects of glyphosate contamination in soybeans need further animal study.

  12. Reviewing the options for local estrogen treatment of vaginal atrophy

    Directory of Open Access Journals (Sweden)

    Lindahl SH


    Full Text Available Sarah H Lindahl Sutter East Bay Medical Foundation, SEBMF – Diablo Division, Castro Valley, CA, USA Background: Vaginal atrophy is a chronic condition with symptoms that include vaginal dryness, pain during sex, itching, irritation, burning, and discharge, as well as various urinary problems. Up to 45% of postmenopausal women may be affected, but it often remains underreported and undertreated. This article aims to review the current recommendations for treatment of vaginal atrophy, and current data on the effectiveness and safety of local vaginal estrogen therapies. Methods: Literature regarding vaginal atrophy (2007–2012 was retrieved from PubMed and summarized, with emphasis on data related to the treatment of vaginal atrophy with local vaginal estrogen therapy. Results: Published data support the effectiveness and endometrial safety of low-dose local estrogen therapies. These results further support the general recommendation by the North American Menopause Society that a progestogen is not needed for endometrial protection in patients using low-dose local vaginal estrogen. Benefits of long-term therapy for vaginal atrophy include sustained relief of symptoms as well as physiological improvements (eg, decreased vaginal pH and increased blood flow, epithelial thickness, secretions. Conclusion: Currently available local vaginal estrogen therapies are well tolerated and effective in relieving symptoms of vaginal atrophy. Recent data support the endometrial safety of low-dose regimens for up to 1 year. Keywords: menopause, estrogen, local estrogen therapy, vaginal atrophy

  13. Immunoekspresi Reseptor α pada Poket Periodontal Lebih Banyak daripada Reseptor Estrogen β

    Directory of Open Access Journals (Sweden)

    Yuliana Mahdiyah Da’at Arina


    Full Text Available Studies have been reported on the association between menopause and periodontal disease related to estrogen deficiency. Although the estrogen receptor has been demonstrated on some oral tissues, the presence of estrogen receptors on periodontal pockets has not been discussed. This study was conducted to determine the difference of estrogen receptor α and β on periodontal pockets between menopausal and reproductive women. The results showed that the estrogen receptors α and β were expressed on periodontal pockets. The immunoexpression of estrogen receptor α in periodontal pocket epithelium of menopausal women was higher than that of estrogen receptor β, similarly to the reproductive women, but there was no significant difference in the immunoexpression of estrogen receptors α and β between menopausal and reproductive women. We concluded that the influence of estrogen on the periodontal pockets is more via estrogen receptor α both on menopausal and reproductive women.DOI: 10.14693/jdi.v15i1.84

  14. Radical-scavenging Activity of Estrogen and Estrogen-like Compounds Using the Induction Period Method

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa


    Full Text Available The radical-scavenging activity of estrogens (estrone, 2-hydroxyestradiol,estrogen-like compounds (diethylstilbestrol, DES; bisphenol A, BPA and the mono-phenolic compound 2,6-di-t-butyl-4-methoxyphenol (BMP was investigated using themethod of measuring the induction period for polymerization of methyl methacrylate(MMA initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN andbenzoyl peroxide (BPO at 70°C using differential scanning calorimetry (DSC. Thestoichiometric factor (n, number of free radicals trapped by one mole of antioxidantmoiety for the AIBN system declined in the order BMP (2.0, 2-hydroxyestradiol (2.0>DES (1.3 > BPA (1.2 > estrone (0.9, whereas that for the BPO system declined in theorder BMP (2.0 >DES (1.9, BPA (1.9 > estrone (1.3 > 2-hydroxyestradiol (0.7. Theinhibition rate constant (kinh x 10-3 M-1s-1 for the AIBN system declined in the orderestrone (2.2 > BPA (2.0 > DES (1.9 > 2-hydroxyestradiol (1.2 > BMP (1.1, whereasthat for the BPO system declined in the order 2-hydroxyestradiol (3.2 > estrone (1.4 >DES (1.2 > BPA (1.0 > BMP (0.9. The radical-scavenging activity for bioactivecompounds such as estrogens should be evaluated using these two methods (the n and kinhto elucidate the mechanism of a particular reaction. The great difference of the n and kinhfor estrogens between the AIBN and BPO system suggested that their oxidation process iscomplex.

  15. Biomarker Genes for Detecting Estrogenic Activity of Endocrine Disruptors via Estrogen Receptors


    Hyun Yang; Eui-Bae Jeung; Kyung-Chul Choi; Beum-Soo An; Eui-Man Jung


    Endocrine disruptors (EDs) are compounds used in various industrial products, drugs, and cosmetics. They can be found in the environment and disturb the endocrine and reproductive systems, resulting in adverse effects to humans and wildlife such as birth defects and developmental disorders. Since several EDs have a structure similar to that of endogenous steroid hormones such as estrogens, they intend to have an affinity for steroid hormone receptors and alter hormone-mediated metabolism by b...

  16. Mixture Effects of Estrogenic Pesticides at the Human Estrogen Receptor α and β. (United States)

    Seeger, Bettina; Klawonn, Frank; Nguema Bekale, Boris; Steinberg, Pablo


    Consumers of fruits and vegetables are frequently exposed to small amounts of hormonally active pesticides, some of them sharing a common mode of action such as the activation of the human estrogen receptor α (hERα) or β (hERβ). Therefore, it is of particular importance to evaluate risks emanating from chemical mixtures, in which the individual pesticides are present at human-relevant concentrations, below their corresponding maximum residue levels. Binary and ternary iso-effective mixtures of estrogenic pesticides at effect concentrations eliciting a 1 or 10% effect in the presence or absence of 17β-estradiol were tested experimentally at the hERα in the yeast-based estrogen screen (YES) assay as well as in the human U2-OS cell-based ERα chemical-activated luciferase gene expression (ERα CALUX) assay and at the hERβ in the ERβ CALUX assay. The outcome was then compared to predictions calculated by means of concentration addition. In most cases, additive effects were observed with the tested combinations in all three test systems, an observation that supports the need to expand the risk assessment of pesticides and consider cumulative risk assessment. An additional testing of mixture effects at the hERβ showed that most test substances being active at the hERα could also elicit additive effects at the hERβ, but the hERβ was less sensitive. In conclusion, effects of the same ligands at the hERα and the hERβ could influence the estrogenic outcome under physiological conditions.

  17. Light-Emitting Diodes: A Hidden Treasure (United States)

    Planinšic, Gorazd; Etkina, Eugenia


    LEDs, or light-emitting diodes, are cheap, easy to purchase, and thus commonly used in physics instruction as indicators of electric current or as sources of light (Fig. 1). In our opinion LEDs represent a unique piece of equipment that can be used to collect experimental evidence, and construct and test new ideas in almost every unit of a general…

  18. Light-Emitting Diodes: Learning New Physics (United States)

    Planinšic, Gorazd; Etkina, Eugenia


    This is the third paper in our Light-Emitting Diodes series. The series aims to create a systematic library of LED-based materials and to provide the readers with the description of experiments and pedagogical treatment that would help their students construct, test, and apply physics concepts and mathematical relations. The first paper, published…

  19. Neurobiology of estrogen status in deep craniofacial pain. (United States)

    Bereiter, David A; Okamoto, Keiichiro


    Pain in the temporomandibular joint (TMJ) region often occurs with no overt signs of injury or inflammation. Although the etiology of TMJ-related pain may involve multiple factors, one likely risk factor is female gender or estrogen status. Evidence is reviewed from human and animal studies, supporting the proposition that estrogen status acts peripherally or centrally to influence TMJ nociceptive processing. A new model termed the "TMJ pain matrix" is proposed as critical for the initial integration of TMJ-related sensory signals in the lower brainstem that is both modified by estrogen status, and closely linked to endogenous pain and autonomic control pathways.

  20. Estrogenic and anti-estrogenic activity of off-the-shelf hair and skin care products (United States)

    Myers, Sharon L.; Yang, Chun Z.; Bittner, George D.; Witt, Kristine L.; Tice, Raymond R.; Baird, Donna D.


    Use of personal care products is widespread in the United States but tends to be greater among African Americans than whites. Of special concern is the possible hazard of absorption of chemicals with estrogenic activity (EA) or anti-EA (AEA) in these products. Such exposure may have adverse health effects, especially when it occurs during developmental windows (e.g., prepubertally) when estrogen levels are low. We assessed the ethanol extracts of eight commonly used hair and skin products popular among African Americans for EA and AEA using a cell proliferation assay with the estrogen sensitive MCF-7:WS8 cell line derived from a human breast cancer. Four of the eight personal care products tested (Oil Hair Lotion, Extra-dry Skin Lotion, Intensive Skin Lotion, Petroleum Jelly) demonstrated detectable EA, whereas three (Placenta Hair Conditioner, Tea-Tree Hair Conditioner, Cocoa Butter Skin Cream) exhibited AEA. Our data indicate that hair and skin care products can have EA or AEA, and suggest that laboratory studies are warranted to investigate the in vivo activity of such products under chronic exposure conditions as well as epidemiologic studies to investigate potential adverse health effects that might be associated with use of such products. PMID:24849798

  1. Reproductive toxicities of methoxychlor based on estrogenic properties of the compound and its estrogenic metabolite, hydroxyphenyltrichloroethane. (United States)

    Aoyama, Hiroaki; Chapin, Robert E


    Methoxychlor is an organochlorine pesticide having a weak estrogenicity, which is estimated to be approximately 1000- to 14,000-fold less potent to a natural ligand, 17β-estradiol. However, its active metabolite, hydroxyphenyltrichloroethane, has much more potent estrogenic activity and probably acts in the target organs of animals exposed to methoxychlor at least 100 times stronger than the parent compound. A variety of in vivo reproductive toxicity studies have shown that treatment with methoxychlor exerts typical endocrine-disrupting effects manifest as estrogenic effects, such as formation of cystic ovaries resulting in ovulation failures, uterine hypertrophy, hormonal imbalances, atrophy of male sexual organs, and deteriorations of sperm production in rats and/or mice, through which it causes serious reproductive damages in both sexes of animals at sufficient dose levels. However, methoxychlor is not teratogenic. The no-observed-adverse-effect level of methoxychlor among reliable experimental animal studies in terms of the reproductive toxicity is 10 ppm (equivalent to 0.600 mg/kg/day) in a two-generation reproduction toxicity study.

  2. Biomarker Genes for Detecting Estrogenic Activity of Endocrine Disruptors via Estrogen Receptors

    Directory of Open Access Journals (Sweden)

    Hyun Yang


    Full Text Available Endocrine disruptors (EDs are compounds used in various industrial products, drugs, and cosmetics. They can be found in the environment and disturb the endocrine and reproductive systems, resulting in adverse effects to humans and wildlife such as birth defects and developmental disorders. Since several EDs have a structure similar to that of endogenous steroid hormones such as estrogens, they intend to have an affinity for steroid hormone receptors and alter hormone-mediated metabolism by binding to these receptors. EDs are therefore a global concern and assays should be developed to efficiently determine whether these compounds are detrimental to biological systems. Diverse experimental methods may help determine the endocrine disrupting potential of EDs and evaluate the adverse effects of a single and/or combination of these reagents. Currently, biomarkers have been employed to objectively measure EDs potency and understand the underlying mechanisms. Further studies are required to develop ideal screening methods and biomarkers to determine EDs potency at environmentally relevant concentrations. In this review, we describe the biomarkers for estrogenicity of EDs identified both in vitro and in vivo, and introduce a biomarker, cabindin-D9k (CaBP-9k, that may be used to assess estrogenic activity of EDs.

  3. Biomarker genes for detecting estrogenic activity of endocrine disruptors via estrogen receptors. (United States)

    Jung, Eui-Man; An, Beum-Soo; Yang, Hyun; Choi, Kyung-Chul; Jeung, Eui-Bae


    Endocrine disruptors (EDs) are compounds used in various industrial products, drugs, and cosmetics. They can be found in the environment and disturb the endocrine and reproductive systems, resulting in adverse effects to humans and wildlife such as birth defects and developmental disorders. Since several EDs have a structure similar to that of endogenous steroid hormones such as estrogens, they intend to have an affinity for steroid hormone receptors and alter hormone-mediated metabolism by binding to these receptors. EDs are therefore a global concern and assays should be developed to efficiently determine whether these compounds are detrimental to biological systems. Diverse experimental methods may help determine the endocrine disrupting potential of EDs and evaluate the adverse effects of a single and/or combination of these reagents. Currently, biomarkers have been employed to objectively measure EDs potency and understand the underlying mechanisms. Further studies are required to develop ideal screening methods and biomarkers to determine EDs potency at environmentally relevant concentrations. In this review, we describe the biomarkers for estrogenicity of EDs identified both in vitro and in vivo, and introduce a biomarker, cabindin-D(9k) (CaBP-9k), that may be used to assess estrogenic activity of EDs.

  4. Estrogenic and anti-estrogenic activity of off-the-shelf hair and skin care products. (United States)

    Myers, Sharon L; Yang, Chun Z; Bittner, George D; Witt, Kristine L; Tice, Raymond R; Baird, Donna D


    Use of personal care products is widespread in the United States but tends to be greater among African Americans than whites. Of special concern is the possible hazard of absorption of chemicals with estrogenic activity (EA) or anti-EA (AEA) in these products. Such exposure may have adverse health effects, especially when it occurs during developmental windows (e.g., prepubertally) when estrogen levels are low. We assessed the ethanol extracts of eight commonly used hair and skin products popular among African Americans for EA and AEA using a cell proliferation assay with the estrogen sensitive MCF-7:WS8 cell line derived from a human breast cancer. Four of the eight personal care products tested (Oil Hair Lotion, Extra-dry Skin Lotion, Intensive Skin Lotion, Petroleum Jelly) demonstrated detectable EA, whereas three (Placenta Hair Conditioner, Tea-Tree Hair Conditioner, Cocoa Butter Skin Cream) exhibited AEA. Our data indicate that hair and skin care products can have EA or AEA, and suggest that laboratory studies are warranted to investigate the in vivo activity of such products under chronic exposure conditions as well as epidemiologic studies to investigate potential adverse health effects that might be associated with use of such products.

  5. Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens (United States)

    Iwanowicz, Luke R.; Stafford, James L.; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W.; Blazer, Vicki


    Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines.

  6. Effect of combining in vitro estrogenicity data with kinetic characteristics of estrogenic compounds on the in vivo predictive value. (United States)

    Punt, Ans; Brand, Walter; Murk, Albertinka J; van Wezel, Annemarie P; Schriks, Merijn; Heringa, Minne B


    With the ultimate aim of increasing the utility of in vitro assays for toxicological risk assessment, a method was developed to calculate in vivo estrogenic potencies from in vitro estrogenic potencies of compounds by taking into account systemic availability. In vitro estrogenic potencies of three model compounds (bisphenol A, genistein, and 4-nonylphenol) relative to ethinylestradiol (EE2), determined with the estrogen receptor alpha (ERα) transcriptional activation assay using hER-HeLa-9903 cells, were taken from literature and used to calculate the EE2 equivalent (EE2EQ) effect doses in the predominantly ERα-dependent rat uterotrophic assay. Compound-specific differences in hepatic clearance relative to the reference compound EE2 were determined in vitro to examine whether in vivo estrogenic potencies reported in literature could be more accurately estimated. The EE2EQ doses allowed to predict in vivo uterotrophic responses within a factor of 6-25 and the inclusion of the hepatic clearance further improved the prediction with a factor 1.6-2.1 for especially genistein and bisphenol A. Yet, the model compounds still were less potent in vivo than predicted based on their EE2 equivalent estrogenic potency and hepatic clearance. For further improvement of the in vitro to in vivo predictive value of in vitro assays, the relevance of other kinetic characteristics should be studied, including binding to carrier proteins, oral bioavailability and the formation of estrogenic metabolites.

  7. Estrogen receptor beta agonists in neurobehavioral investigations. (United States)

    Choleris, Elena; Clipperton, Amy E; Phan, Anna; Kavaliers, Martin


    Neurobehavioral investigations into the functions of estrogen receptor (ER)alpha and ERbeta have utilized 'knockout' mice, phytoestrogens and, more recently, ER-specific agonists. Feeding, sexual, aggressive and social behavior, anxiety, depression, drug abuse, pain perception, and learning (and associated synaptic plasticity) are affected by ERalpha and ERbeta in a manner that is dependent upon the specific behavior studied, gender and developmental stage. Overall, ERalpha and ERbeta appear to function together to foster sociosexual behavior while inhibiting behaviors that, if occurring at the time of behavioral estrous, may compete with reproduction (eg, feeding). Recently developed pharmacological tools have limited selectivity and availability to the research community at large, as they are not commercially available. The development of highly selective, commercially available ERbeta-specific antagonists would greatly benefit preclinical and applied research.

  8. Estrogens can disrupt amphibian mating behavior.

    Directory of Open Access Journals (Sweden)

    Frauke Hoffmann

    Full Text Available The main component of classical contraceptives, 17α-ethinylestradiol (EE2, has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L, alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline.

  9. Estrogen Negatively Regulates the Pro-apoptotic Function of Mixed Lineage Kinase 3 in Estrogen Receptor Positive Breast Cancer


    Rangasamy, Velusamy; Mishra, Rajakishore; Mehrotra, Suneet; Sondarva, Gautam; Ray, Rajarshi S.; Rao, Arundhati; Chatterjee,Malay; Rana, Basabi; Rana, Ajay


    Estrogen stimulates growth and inhibits apoptosis of breast cancer cells via genomic and non-genomic actions. However, the detailed mechanism by which estrogen inhibits the pro-apoptotic pathways that might impede the normal homeostasis and action of chemotherapeutic drugs in breast cancer cells is not well understood. Here, we report a negative regulation of a pro-apoptotic kinase, Mixed Lineage Kinase 3 (MLK3) by 17β-estradiol (E2) that hinders cytotoxic drug-induced cell death in estrogen ...

  10. Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor. (United States)

    Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu


    Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the

  11. KBERG: KnowledgeBase for Estrogen Responsive Genes

    DEFF Research Database (Denmark)

    Tang, Suisheng; Zhang, Zhuo; Tan, Sin Lam;


    Estrogen has a profound impact on human physiology affecting transcription of numerous genes. To decipher functional characteristics of estrogen responsive genes, we developed KnowledgeBase for Estrogen Responsive Genes (KBERG). Genes in KBERG were derived from Estrogen Responsive Gene Database...... (ERGDB) and were analyzed from multiple aspects. We explored the possible transcription regulation mechanism by capturing highly conserved promoter motifs across orthologous genes, using promoter regions that cover the range of [-1200, +500] relative to the transcription start sites. The motif detection...... is based on ab initio discovery of common cis-elements from the orthologous gene cluster from human, mouse and rat, thus reflecting a degree of promoter sequence preservation during evolution. The identified motifs are linked to transcription factor binding sites based on the TRANSFAC database. In addition...

  12. Estrogen Intake and Copper Depositions: Implications for Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Florian Amtage


    Full Text Available We present a patient with chronic postmenopausal estrogen intake with presence of Kayser-Fleischer ring in the cornea and Alzheimer's disease and discuss the pathophysiological mechanisms of estrogen intake and copper accumulation in various tissues, including the central nervous system. Sonography was compatible with copper accumulation in the basal ganglia, but the patient showed no clinical signs of Wilson's disease. Magnetic resonance imaging and positron emission tomography revealed a typical pattern for Alzheimer's disease. We propose increased copper levels as a direct effect of estrogen intake due to an augmented ATP7A-mRNA in the intestine. Moreover, we discuss the impact of elevated free serum copper on accompanying Alzheimer's disease, knowing that copper plays a crucial role in the formation of amyloid plaques and tau aggregation. This might offer a partial explanation for the observation that postmenopausal estrogen therapy is associated with a higher risk of mild cognitive impairment and Alzheimer's disease.


    Institute of Scientific and Technical Information of China (English)

    CHUJin-Shong; WANGYi-Fei


    The specific estrogen binding site for 17β-estradiol has been investigated on human spermatozoa by electron microscopec autoradiography. The results show that the binding sites were distributed over the surface of human spermatozoa: acrosomal cap, equatorial


    Institute of Scientific and Technical Information of China (English)



    Monitoring of ovulation is necessary for induction of ovulation in clinical trials. Bakerfound that the conoentration of estrogen glucuronides was high in female urine and devel-oped a RIA method for direct measurment. Adlevcrefutz and some other five groups

  15. Postmenopausal Estrogen Therapy and Risk of Gallstone Disease

    DEFF Research Database (Denmark)

    Simonsen, Maja Hellfritzsch; Erichsen, Rune; Frøslev, Trine;


    BACKGROUND: Female gender and increasing age are key risk factors for gallstone disease; therefore, postmenopausal women are at high risk. Estrogen increases cholesterol saturation of bile and may further increase gallstone risk, but population-based evidence is sparse. OBJECTIVE: Our objective...... was to examine the association between postmenopausal estrogen therapy and risk of gallstone disease and the impact of duration of treatment and use of opposing progestin. STUDY DESIGN: We conducted a population-based case-control study. Cases were postmenopausal women (defined as aged ≥45 years) with gallstone...... disease identified in the period 1996-2010. For each case, we selected ten population controls matched to cases by age and sex. We defined exposure as any use of estrogen (opposed and unopposed by progestin). Cases/controls were categorized as current estrogen users if their last prescription was redeemed...

  16. Estrogenic involvement in social learning, social recognition and pathogen avoidance. (United States)

    Choleris, Elena; Clipperton-Allen, Amy E; Phan, Anna; Valsecchi, Paola; Kavaliers, Martin


    Sociality comes with specific cognitive skills that allow the proper processing of information about others (social recognition), as well as of information originating from others (social learning). Because sociality and social interactions can also facilitate the spread of infection among individuals the ability to recognize and avoid pathogen threat is also essential. We review here various studies primarily from the rodent literature supporting estrogenic involvement in the regulation of social recognition, social learning (socially acquired food preferences and mate choice copying) and the recognition and avoidance of infected and potentially infected individuals. We consider both genomic and rapid estrogenic effects involving estrogen receptors α and β, and G-protein coupled estrogen receptor 1, along with their interactions with neuropeptide systems in the processing of social stimuli and the regulation and expression of these various socially relevant behaviors.

  17. The estrogenic activity of phthalate esters in vitro. (United States)

    Harris, C A; Henttu, P; Parker, M G; Sumpter, J P


    A large number of phthalate esters were screened for estrogenic activity using a recombinant yeast screen. a selection of these was also tested for mitogenic effect on estrogen-responsive human breast cancer cells. A small number of the commercially available phthalates tested showed extremely weak estrogenic activity. The relative potencies of these descended in the order butyl benzyl phthalate (BBP) > dibutyl phthalate (DBP) > diisobutyl phthalate (DIBP) > diethyl phthalate (DEP) > diisiononyl phthalate (DINP). Potencies ranged from approximately 1 x 10(6) to 5 x 10(7) times less than 17beta-estradiol. The phthalates that were estrogenic in the yeast screen were also mitogenic on the human breast cancer cells. Di(2-ethylhexyl) phthalate (DEHP) showed no estrogenic activity in these in vitro assays. A number of metabolites were tested, including mono-butyl phthalate, mono-benzyl phthalate, mono-ethylhexyl phthalate, mon-n-octyl phthalate; all were wound to be inactive. One of the phthalates, ditridecyl phthalate (DTDP), produced inconsistent results; one sample was weakly estrogenic, whereas another, obtained from a different source, was inactive. analysis by gel chromatography-mass spectometry showed that the preparation exhibiting estrogenic activity contained 0.5% of the ortho-isomer of bisphenol A. It is likely that the presence of this antioxidant in the phthalate standard was responsible for the generation of a dose-response curve--which was not observed with an alternative sample that had not been supplemented with o,p'-bisphenol A--in the yeast screen; hence, DTDP is probably not weakly estrogenic. The activities of simple mixtures of BBP, DBP, and 17beta-estradiol were assessed in the yeast screen. No synergism was observed, although the activities of the mixtures were approximately additive. In summary, a small number of phthalates are weakly estrogenic in vitro. No data has yet been published on whether these are also estrogenic in vitro. No data has

  18. Agonistic and antagonistic estrogens in licorice root (Glycyrrhiza glabra). (United States)

    Simons, Rudy; Vincken, Jean-Paul; Mol, Loes A M; The, Susan A M; Bovee, Toine F H; Luijendijk, Teus J C; Verbruggen, Marian A; Gruppen, Harry


    The roots of licorice (Glycyrrhiza glabra) are a rich source of flavonoids, in particular, prenylated flavonoids, such as the isoflavan glabridin and the isoflavene glabrene. Fractionation of an ethyl acetate extract from licorice root by centrifugal partitioning chromatography yielded 51 fractions, which were characterized by liquid chromatography-mass spectrometry and screened for activity in yeast estrogen bioassays. One third of the fractions displayed estrogenic activity towards either one or both estrogen receptors (ERs; ERα and ERβ). Glabrene-rich fractions displayed an estrogenic response, predominantly to the ERα. Surprisingly, glabridin did not exert agonistic activity to both ER subtypes. Several fractions displayed higher responses than the maximum response obtained with the reference compound, the natural hormone 17β-estradiol (E(2)). The estrogenic activities of all fractions, including this so-called superinduction, were clearly ER-mediated, as the estrogenic response was inhibited by 20-60% by known ER antagonists, and no activity was found in yeast cells that did not express the ERα or ERβ subtype. Prolonged exposure of the yeast to the estrogenic fractions that showed superinduction did, contrary to E(2), not result in a decrease of the fluorescent response. Therefore, the superinduction was most likely the result of stabilization of the ER, yeast-enhanced green fluorescent protein, or a combination of both. Most fractions displaying superinduction were rich in flavonoids with single prenylation. Glabridin displayed ERα-selective antagonism, similar to the ERα-selective antagonist RU 58668. Whereas glabridin was able to reduce the estrogenic response of E(2) by approximately 80% at 6 × 10(-6) M, glabrene-rich fractions only exhibited agonistic responses, preferentially on ERα.

  19. Feeding on Phytoestrogens: Implications of Estrogenic Plants for Primate Ecology


    Wasserman, Michael David


    As most primates depend heavily on plant foods, the chemical composition of edible plant parts, both nutritional and detrimental, are of key importance in understanding primate ecology and evolution. One class of plant compounds of strong current interest due to their potential ability to alter the fertility, fecundity, and survival of both males and females are phytoestrogens. These plant compounds mimic the activity of vertebrate estrogens mainly through binding with the estrogen receptor...

  20. Phytoestrogens are partial estrogen agonists in the adult male mouse.


    Mäkelä, S; Santti, R; Salo, L; McLachlan, J A


    The intake, as well as serum and urinary concentrations, of phytoestrogens is high in countries where incidence of prostate cancer is low, suggesting a chemopreventive role for phytoestrogens. Their significance could be explained by the ability to antagonize the action of more potent endogenous estrogens in initiation or promotion of tumor formation. We have studied estrogenicity and antiestrogenicity of dietary soy and two phytoestrogens, coumestrol and daidzein, in our neoDES mouse model f...

  1. Estrogen Receptor Alpha G525L Knock-In Mice (United States)


    females on a soy-free diet (Table 1). This increase may be due to the loss of phytoestrogen -induced mutant ERα activation . These results, combined with...Ciana P, Raviscioni M, Mussi P, Vegeto E, Que I, Parker MG, Lowik C, Maggi A. 2003 In vivo imaging of transcriptionally active estrogen receptors...Nature Medicine. 2003 9:82-86 4. Jefferson WN, Padilla-Banks E, Clark G, Newbold RR. Assessing estrogenic activity of phytochemicals using

  2. SERMs and SERMs with estrogen for postmenopausal osteoporosis. (United States)

    Bolognese, Michael A


    Bone loss with aging places postmenopausal women at a higher risk for osteoporosis and its consequences such as fractures, pain, disability, and increased morbidity and mortality. Approximately 200 million patients worldwide are affected. The Third National Health and Nutrition Examination Survey (NHANES III) estimated that up to 18% of US women aged 50 and older have osteoporosis and up to 50% have osteopenia. Greater than 2 million osteoporotic related fractures occurred in the United States with direct healthcare costs exceeding $17 billion. Hormone Replacement Therapy (HRT) was a popular option for postmenopausal women before the Women's Health Initiative (WHI). Several agents are available in the U.S., including bisphosphonates, hormone therapy, calcitonin, parathyroid hormone and the selective estrogen receptor modulator (SERM) raloxifene. There are concerns about long term safety and compliance. Therefore, other agents are under investigation. SERMs are a diverse group of agents that bind to the estrogen receptor and each SERM appears to have a unique set of clinical responses, which are not always consistent with the typical responses seen with other SERMs. This article will discuss the SERMs approved in the United States, tamoxifene and raloxifene, and investigational SERMs. The ideal SERM would include the beneficial effects of estrogen in bone, heart and the central nervous system, with neutral or antagonistic effects in tissues where estrogen effects are undesirable(breast and endometrium). A new target in treating postmenopausal osteoporosis is the tissue estrogen complex or the pairing of a SERM with a conjugated estrogen known as a tissue selective estrogen complex (TSEC). This novel approach is currently being evaluated with bazodoxifene which could yield the beneficial effects of estrogens and SERMS, while potentially being more tolerable and safer than either therapy alone.

  3. BRCA1 Regulation of Estrogen Signaling in the Breast (United States)


    and purification of FLAG epitope-tagged human estrogen receptor (ERα) from insect Sf21 cells. ♦   Biochemical reconstitution of estrogen...HSP90, heat shock protein 90; NF-B, nuclear factor B; NP-40, Nonidet P-40; RNAi , RNA interference; siRNA, small interfering RNA. Molecular Endocrinology...biological consequence of the DBC- 1/ER interaction in human breast cancer cells, we first established conditions for RNA interference ( RNAi

  4. Mixtures of Estrogenic Chemicals Enhance Vitellogenic Response in Sea Bass


    Correia, AD; Freitas, S.; Scholze, M; Gonçalves, J; Booij, P.; Lamoree, MH; Mañanós, E; Reis-Henriques, MA


    BACKGROUND: The potential impact of natural and synthetic estrogens on aquatic ecosystems has attracted considerable attention because it is currently accepted that their joint effects are more severe when they are present in mixtures. Although it is well-known that they occur as mixtures in the marine environment, there is little information about the combined effects of estrogenic chemicals on marine biota. OBJECTIVE: In 14-day tests with juvenile sea bass, we analyzed singly and in combina...

  5. Validation of a rapid yeast estrogen bioassay, based on the expression of green fluorescent protein, for the screening of estrogenic activity in calf urine

    NARCIS (Netherlands)

    Bovee, T.F.H.; Heskamp, H.H.; Hamers, A.R.M.; Hoogenboom, L.A.P.; Nielen, M.W.F.


    Previously we described the construction and properties of a rapid yeast bioassay stably expressing human estrogen receptor a (hERa) and yeast enhanced green fluorescent protein (yEGFP) in response to estrogens. In the present study, this yeast estrogen assay was validated as a qualitative screening

  6. Rapid yeast estrogen bioassays stably expressing human estrogen receptors alpha and beta, and green fluorescent protein: a comparison of different compounds on both receptor types

    NARCIS (Netherlands)

    Bovee, T.F.H.; Helsdingen, J.R.; Rietjens, I.M.C.M.; Keijer, J.; Hoogenboom, L.A.P.


    Previously, we described the construction of a rapid yeast bioassay stably expressing human estrogen receptor (hER) and yeast enhanced green fluorescent protein (yEGFP) in response to estrogens. In the present study, the properties of this assay were further studied by testing a series of estrogenic

  7. Phytoestrogens from Psoralea corylifolia reveal estrogen receptor-subtype selectivity. (United States)

    Xin, D; Wang, H; Yang, J; Su, Y-F; Fan, G-W; Wang, Y-F; Zhu, Y; Gao, X-M


    The seed of Psoralea corylifolia L. (PCL), a well-known traditional Chinese medicine, has been applied as a tonic or an aphrodisiac agent and commonly used as a remedy for bone fracture, osteomalacia and osteoporosis in China. In our study, the estrogen receptor subtype-selective activities of the extracts and compounds derived from PCL were analyzed using the HeLa cell assay. The different fractions including petroleum ether, CH(2)Cl(2) and EtOAc fractions of the EtOH extract of PCL showed significant activity in activating either ERalpha or ERbeta whereas the n-BuOH fraction showed no estrogenic activity. Further chromatographic purification of the active fractions yielded seven compounds including the two coumarins isopsoralen and psoralen, the four flavonoids isobavachalcone, bavachin, corylifol A and neobavaisoflavone, and the meroterpene phenol, bakuchiol. In reporter gene assay, the two coumarins (10(-8)-10(-5)M) acted as ERalpha-selective agonists while the other compounds (10(-9)-10(-6)M) activated both ERalpha and ERbeta. The estrogenic activities of all compounds could be completely suppressed by the pure estrogen antagonist, ICI 182,780, suggesting that the compounds exert their activities through ER. Only psoralen and isopsoralen as ERalpha agonists promoted MCF-7 cell proliferation significantly. Although all the compounds have estrogenic activity, they may exert different biological effects. In conclusion, both ER subtype-selective and nonselective activities in compounds derived from PCL suggested that PCL could be a new source for selective estrogen-receptor modulators.

  8. Evaluation of the estrogenic effects of legume extracts containing phytoestrogens. (United States)

    Boué, Stephen M; Wiese, Thomas E; Nehls, Suzanne; Burow, Matthew E; Elliott, Steven; Carter-Wientjes, Carol H; Shih, Betty Y; McLachlan, John A; Cleveland, Thomas E


    Seven legume extracts containing phytoestrogens were analyzed for estrogenic activity. Methanol extracts were prepared from soybean (Glycine max L.), green bean (Phaseolus vulgaris L.), alfalfa sprout (Medicago sativa L.), mung bean sprout (Vigna radiata L.), kudzu root (Pueraria lobata L.), and red clover blossom and red clover sprout (Trifolium pratense L.). Extracts of kudzu root and red clover blossom showed significant competitive binding to estrogen receptor beta (ERbeta). Estrogenic activity was determined using an estrogen-dependent MCF-7 breast cancer cell proliferation assay. Kudzu root, red clover blossom and sprout, mung bean sprout, and alfalfa sprout extracts displayed increased cell proliferation above levels observed with estradiol. The pure estrogen antagonist, ICI 182,780, suppressed cell proliferation induced by the extracts, suggesting an ER-related signaling pathway was involved. The ER subtype-selective activities of legume extracts were examined using transiently transfected human embryonic kidney (HEK 293) cells. All seven of the extracts exhibited preferential agonist activity toward ERbeta. Using HPLC to collect fractions and MCF-7 cell proliferation, the active components in kudzu root extract were determined to be the isoflavones puerarin, daidzin, genistin, daidzein, and genistein. These results show that several legumes are a source of phytoestrogens with high levels of estrogenic activity.

  9. Regional differences in the prostate of the neonatally estrogenized mouse

    Energy Technology Data Exchange (ETDEWEB)

    Pylkkaenen, L.S.; Santti, R.; Newbold, R.; McLachlan, J.A. (Univ. of Turku (Finland))


    Neonatal estrogenization of the mouse with diethylstilbestrol resulted in time-of-exposure and dose-dependent inhibition of the growth of the prostatic lobes observed at the age of 2 mon. The critical time was the days 1-6 of postnatal life. In neonatally estrogenized (neoDES) mice, responses to 5 alpha-dihydrotestosterone in terms of nuclear 3H-thymidine labelling were altered concomitantly with the inhibition of growth and were in accordance with changes in the relative volumes of epithelium, glandular lumina, and interacinar stroma. Secondary estrogen treatment of neoDES mice with 17 beta-estradiol did not increase 3H-thymidine labelling in the prostate of control or neoDES mice. However, it induced squamous epithelial metaplasia in periurethral collecting ducts and proximal parts of coagulating glands of neoDES animals. In control mice only slight epithelial hyperplasia could be observed after similar treatment. Estrogen receptors, located immunocytochemically in nuclei of stromal cell, corresponded with the sites of increased estrogen sensitivity, observed as metaplastic transformation. When the neoDES animals aged, epithelial hyperplasia and dysplasia could be observed at distinct prostatic sites, ie, the periurethral collecting ducts and the coagulating glands and periurethral glands, and stromal inflammation become more extensive. Almost identical location of the epithelial changes and the altered estrogen response is suggestive of causal relationship.

  10. Distribution of estrogen and progesterone receptors in Epulis Fissuratum

    Directory of Open Access Journals (Sweden)

    Shahrabi Sh.


    Full Text Available Statement of Problem: Epulides Fissurata (EF are common proliferative and denture- induced lesions of the oral cavity with a predilection for female. This suggests a possible role for sex steroid hormones in the development and progression of these lesions. Purpose: The objective of this study was the immunohistochemical evaluation of epulis fissuratum of the oral cavity for estrogen and progesterone receptors expression in epithelial, stromal, inflammatory and endothelial cells populations. Materials and Methods: In this cross-sectional study, 15 samples of formalin- fixed, paraffin- embedded epulis fissuratums including marginal mucosal tissues in 4 cases as a control group, were immuno-histochemically evaluated for estrogen and progesterone receptors protein expression. Result: In 10 cases, estrogen receptor positivity was found within the epithelium and progesterone receptor immunoreactivity was present in 7 cases. Stromal cells exhibited estrogen and progesterone receptor immunostaining in many cases but only few cases showed expression of these receptors in the inflammatory and endothelial cells. Estrogen and progesterone receptors were also detected in some cases containing salivary glands tissue. Conclusion: Although chronic irritation may be the initiating factor for the occurence of epulis fissuratum, some of the cells in the lesion, could be potential targets for estrogen and progestrone hormones.

  11. A novel mechanism of non-feminizing estrogens in neuroprotection. (United States)

    Engler-Chiurazzi, Elizabeth B; Covey, Douglas F; Simpkins, James W


    Estrogens are potent and efficacious neuroprotectants both in vitro and in vivo in a variety of models of neurotoxicity. We determined the structural requirements for neuroprotection in an in vitro assay using a panel of >70 novel estratrienes, synthesized to reduce or eliminate estrogen receptor (ER) binding. We observed that neuroprotection could be enhanced by as much as 200-fold through modifications that positioned a large bulky group at the C2 or C4 position of the phenolic A ring of the estratriene. Further, substitutions on the B, C or D rings either reduced or did not markedly change neuroprotection. Collectively, there was a negative correlation between binding to ERs and neuroprotection with the more potent compounds showing no ER binding. In an in vivo model for neuroprotection, transient cerebral ischemia, efficacious compounds were active in protection of brain tissue from this pro-oxidant insult. We demonstrated that these non-feminizing estrogens engage in a redox cycle with glutathione, using the hexose monophosphate shunt to apply cytosolic reducing potential to cellular membranes. Together, these results demonstrate that non-feminizing estrogens are neuroprotective and protect brain from the induction of ischemic- and Alzheimer's disease (AD)-like neuropathology in an animal model. These features of non-feminizing estrogens make them attractive compounds for assessment of efficacy in AD and stroke, as they are not expected to show the side effects of chronic estrogen therapy that are mediated by ER actions in the liver, uterus and breast.

  12. Potent inhibition of estrogen sulfotransferase by hydroxylated PCB metabolites: a novel pathway explaining the estrogenic activity of PCBs

    NARCIS (Netherlands)

    M.H.A. Kester (Monique); A. Bergman (Åke); S.H. Safe; T.J. Visser (Theo); A. Brouwer (Abraham); A.G. Schuur; S. Bulduk; D. Tibboel (Dick); W. Meinl; H. Glatt; C.N. Falany; M.W. Coughtrie; G.G.J.M. Kuiper (George)


    textabstractPolychlorinated biphenyls (PCBs) are persistent environmental pollutants which exert a variety of toxic effects in animals, including disturbances of sexual development and reproductive function. The estrogenic effects of PCBs may be mediated in part by hydr

  13. Combined effects of estrogenic chemicals with the same mode of action using an estrogen receptor binding bioassay. (United States)

    Yang, Rong; Li, Na; Ma, Mei; Wang, Zijian


    The increasing amounts of various estrogenic chemicals coexisting in the aquatic environment may pose environmental risks. While the concept of estradiol equivalent (EEQ) has been frequently applied in studying estrogenic mixtures, few experiments have been done to prove its reliability. In this study, the reliability of EEQ and the related model concentration addition (CA) was verified based on the two-hybrid recombinant yeast bioassay when all mixture components had the same mode of action and target of action. Our results showed that the measured estrogenic effects could be well predicted by CA and EEQ for all laboratory-made mixtures using two designs, despite the varying estrogenic activity, concentration levels and ratios of the test chemicals. This suggests that when an appropriate endpoint and its relevant bioassay are chosen, CA should be valid and the application of EEQ in predicting the effect of non-equi-effect mixtures is feasible.

  14. Estrogen Receptor α (ERα) and Estrogen Related Receptor α (ERRα) are both transcriptional regulators of the Runx2-I isoform. (United States)

    Kammerer, Martial; Gutzwiller, Sabine; Stauffer, Daniela; Delhon, Isabelle; Seltenmeyer, Yves; Fournier, Brigitte


    Runx2 is a master regulator of bone development and has also been described as an oncogene. Estrogen Receptor α (ERα) and Estrogen Related Receptor α (ERRα), both implicated in bone metabolism and breast cancer, have been shown to share common transcriptional targets. Here, we show that ERα is a positive regulator of Runx2-I transcription. Moreover, ERRα can act as a transcriptional activator of Runx2-I in presence of peroxisome proliferator activated receptor gamma coactivator-1 alpha (PGC-1α). In contrast, ERRα behaves as a negative regulator of Runx2-I transcription in presence of PGC-1β. ERα and ERRα cross-talk via a common estrogen receptor response element on the Runx2-I promoter. In addition, estrogen regulates PGC-1β that in turn is able to modulate both ERα and ERRα transcriptional activity.

  15. Vertical-Cavity Surface-Emitting Lasers (United States)

    Wilmsen, Carl W.; Temkin, Henryk; Coldren, Larry A.


    1. Introduction to VCSELs L. A. Coldren, C. W. Wilmsen and H. Temkin; 2. Fundamental issues in VCSEL design L. A. Coldren and Eric R. Hegblom; 3. Enhancement of spontaneous emission in microcavities E. F. Schubert and N. E. J. Hunt; 4. Epitaxy of vertical-cavity lasers R. P. Schneider Jr and Y. H. Young; 5. Fabrication and performance of vertical-cavity surface-emitting lasers Kent D. Choquette and Kent Geib; 6. Polarization related properties of vertical cavity lasers Dmitri Kuksenkov and Henryk Temkin; 7. Visible light emitting vertical cavity lasers Robert L. Thornton; 8. Long-wavelength vertical-cavity lasers Dubrakovo I. Babic, Joachim Piprek and John E. Bowers; 9. Overview of VCSEL applications Richard C. Williamson; 10. Optical interconnection applications and required characteristics Kenichi Kasahara; 11. VCSEL-based fiber-optic data communications Kenneth Hahn and Kirk Giboney; 12. VCSEL-based smart pixels for free space optoelectronic processing C. W. Wilmsen.

  16. Ultrasonic vocalizations emitted by flying squirrels.

    Directory of Open Access Journals (Sweden)

    Meghan N Murrant

    Full Text Available Anecdotal reports of ultrasound use by flying squirrels have existed for decades, yet there has been little detailed analysis of their vocalizations. Here we demonstrate that two species of flying squirrel emit ultrasonic vocalizations. We recorded vocalizations from northern (Glaucomys sabrinus and southern (G. volans flying squirrels calling in both the laboratory and at a field site in central Ontario, Canada. We demonstrate that flying squirrels produce ultrasonic emissions through recorded bursts of broadband noise and time-frequency structured frequency modulated (FM vocalizations, some of which were purely ultrasonic. Squirrels emitted three types of ultrasonic calls in laboratory recordings and one type in the field. The variety of signals that were recorded suggest that flying squirrels may use ultrasonic vocalizations to transfer information. Thus, vocalizations may be an important, although still poorly understood, aspect of flying squirrel social biology.

  17. Principles of phosphorescent organic light emitting devices. (United States)

    Minaev, Boris; Baryshnikov, Gleb; Agren, Hans


    Organic light-emitting device (OLED) technology has found numerous applications in the development of solid state lighting, flat panel displays and flexible screens. These applications are already commercialized in mobile phones and TV sets. White OLEDs are of especial importance for lighting; they now use multilayer combinations of organic and elementoorganic dyes which emit various colors in the red, green and blue parts of the visible spectrum. At the same time the stability of phosphorescent blue emitters is still a major challenge for OLED applications. In this review we highlight the basic principles and the main mechanisms behind phosphorescent light emission of various classes of photofunctional OLED materials, like organic polymers and oligomers, electron and hole transport molecules, elementoorganic complexes with heavy metal central ions, and clarify connections between the main features of electronic structure and the photo-physical properties of the phosphorescent OLED materials.

  18. Passive secondary biological treatment systems reduce estrogens in dairy shed effluent. (United States)

    Gadd, Jennifer B; Northcott, Grant L; Tremblay, Louis A


    Steroid estrogens are found at high concentrations in untreated dairy shed effluents. Reduction of estrogenic activity and steroid estrogen concentrations was assessed in two systems used to treat dairy shed effluents: the two-pond system and the advanced pond system. Both include anaerobic and aerobic treatment stages. Samples of effluent were collected from the systems and analyzed for free estrogens, conjugated estrogens and total estrogenic activity using E-Screen assay. Both systems showed increases of up to 8000% in aqueous free estrogens and estrogenic activity after anaerobic treatment, followed by decreases after aerobic treatment (36-83%). The complete systems decreased total steroid estrogen concentrations by 50-100% and estrogen activity by 62-100%, with little difference between systems. Removal rates were lower in winter for both systems. Final effluents from the advanced pond system contained total estrogens at <15-1400 ng/L and estrogenic activity at 3.2-43 ng/L. Final effluent from the two-pond system contained total estrogens at <15-300 ng/L and estrogenic activity at 3.3-25 ng/L. At times the final effluent EEQs exceeded guideline values for protection of freshwater fish and suggest further treatment may be required.

  19. Safety of light emitting diodes in toys. (United States)

    Higlett, M P; O'Hagan, J B; Khazova, M


    Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

  20. The estrogen receptor-alpha in osteoclasts mediates the protective effects of estrogens on cancellous but not cortical bone. (United States)

    Martin-Millan, Marta; Almeida, Maria; Ambrogini, Elena; Han, Li; Zhao, Haibo; Weinstein, Robert S; Jilka, Robert L; O'Brien, Charles A; Manolagas, Stavros C


    Estrogens attenuate osteoclastogenesis and stimulate osteoclast apoptosis, but the molecular mechanism and contribution of these effects to the overall antiosteoporotic efficacy of estrogens remain controversial. We selectively deleted the estrogen receptor (ER)alpha from the monocyte/macrophage cell lineage in mice (ERalpha(LysM)(-/-)) and found a 2-fold increase in osteoclast progenitors in the marrow and the number of osteoclasts in cancellous bone, along with a decrease in cancellous bone mass. After loss of estrogens these mice failed to exhibit the expected increase in osteoclast progenitors, the number of osteoclasts in bone, and further loss of cancellous bone. However, they lost cortical bone indistinguishably from their littermate controls. Mature osteoclasts from ERalpha(LysM)(-/-) were resistant to the proapoptotic effect of 17beta-estradiol. Nonetheless, the effects of estrogens on osteoclasts were unhindered in mice bearing an ERalpha knock-in mutation that prevented binding to DNA. Moreover, a polymeric form of estrogen that is not capable of stimulating the nuclear-initiated actions of ERalpha was as effective as 17beta-estradiol in inducing osteoclast apoptosis in cells with the wild-type ERalpha. We conclude that estrogens attenuate osteoclast generation and life span via cell autonomous effects mediated by DNA-binding-independent actions of ERalpha. Elimination of these effects is sufficient for loss of bone in the cancellous compartment in which complete perforation of trabeculae by osteoclastic resorption precludes subsequent refilling of the cavities by the bone-forming osteoblasts. However, additional effects of estrogens on osteoblasts, osteocytes, and perhaps other cell types are required for their protective effects on the cortical compartment, which constitutes 80% of the skeleton.

  1. Does antimatter emit a new light? (United States)

    Santilli, Ruggero Maria


    Contemporary theories of antimatter have a number of insufficiencies which stimulated the recent construction of the new isodual theory based on a certain anti-isomorphic map of all (classical and quantum) formulations of matter called isoduality. In this note we show that the isodual theory predicts that antimatter emits a new light, called isodual light, which can be distinguished from the ordinary light emitted by matter via gravitational interactions (only). In particular, the isodual theory predicts that all stable antiparticles such as the isodual photon, the positron and the antiproton experience antigravity in the field of matter (defined as the reversal of the sign of the curvature tensor). The antihydrogen atom is therefore predicted to: experience antigravity in the field of Earth; emit the isodual photon; and have the same spectroscopy of the hydrogen atom, although subjected to an anti-isomorphic isodual map. In this note we also show that the isodual theory predicts that bound states of elementary particles and antiparticles (such as the positronium) experience ordinary gravitation in both fields of matter and antimatter, thus bypassing known objections against antigravity. A number of intriguing and fundamental, open theoretical and experimental problems of “the new physics of antimatter” are pointed out.

  2. Researches of odour emitted by household waste

    Directory of Open Access Journals (Sweden)

    Eglė Marčiulaitienė


    Full Text Available The article deals with odour emitted by household waste, the chemical composition of household waste. The experiment was made with food waste (1000 g placed in 5 litter containers. Food waste was containing products of animal origin (meat, fish, dairy products and plant origin (vegetables, fruit waste. Time of the experiment was 14 days 19±3 °C at environment temperature. Odour concentration is determined by dynamic olfactometry method. Studies have shown that the strongest odour of all household waste used in this experiment was emitted by meat and fish waste (76 444 OUE/m3. Meat and fish waste emits the strongest odour as waste contains proteins, their decomposition releases into the environment a strong unpleasant odour, hydrogen sulphide and ammonia. Protein degradation releases into the environment are, characterized by a strong unpleasant smell of hydrogen sulphide and ammonia gas. During the anaerobic decomposition of organic matter a variety of other fragrant compounds: alcohols (e.g., ethanol and methanol, vinegar, formic acid, etc. is found.

  3. Blue emitting organic semiconductors under high pressure

    DEFF Research Database (Denmark)

    Knaapila, Matti; Guha, Suchismita


    This review describes essential optical and emerging structural experiments that use high GPa range hydrostatic pressure to probe physical phenomena in blue-emitting organic semiconductors including π-conjugated polyfluorene and related compounds. The work emphasizes molecular structure and inter......This review describes essential optical and emerging structural experiments that use high GPa range hydrostatic pressure to probe physical phenomena in blue-emitting organic semiconductors including π-conjugated polyfluorene and related compounds. The work emphasizes molecular structure...... and intermolecular self-organization that typically determine transport and optical emission in π-conjugated oligomers and polymers. In this context, hydrostatic pressure through diamond anvil cells has proven to be an elegant tool to control structure and interactions without chemical intervention. This has been...... highlighted by high pressure optical spectroscopy whilst analogous x-ray diffraction experiments remain less frequent. By focusing on a class of blue-emitting π-conjugated polymers, polyfluorenes, this article reviews optical spectroscopic studies under hydrostatic pressure, addressing the impact of molecular...

  4. Estrogen withdrawal from osteoblasts and osteocytes causes increased mineralization and apoptosis. (United States)

    Brennan, M Á; Haugh, M G; O'Brien, F J; McNamara, L M


    Recent studies have demonstrated increased bone mineral heterogeneity following estrogen withdrawal in vivo. Such changes likely contribute to fracture risk during post-menopausal osteoporosis since tissue mineralization is correlated with bone strength and stiffness. However, the cellular mechanisms responsible for increased mineral variability have not yet been distinguished. The objective of this study is to elucidate how alterations in mineral distribution are initiated during estrogen depletion. Specifically, we tested two separate hypotheses; (1) estrogen deficiency directly alters osteoblast mineralization and (2) estrogen deficiency increases bone cell apoptosis. Osteoblast-like cells (MC3T3-E1) and osteocyte-like cells (MLO-Y4) were pretreated with or without estrogen (17β-estradiol) for 14 days. Estrogen deficiency was subsequently induced by either withdrawing estrogen from cells or blocking estrogen receptors using an estrogen antagonist, fulvestrant (ICI 182,780). Cell number (Hoechst DNA), alkaline phosphatase activity (p-NPP), mineralization (alizarin red) and apoptosis (Caspase 3/7) were evaluated. Whether estrogen withdrawal altered apoptosis rates in the presence of an apoptosis promoting agent (etoposide) was also determined. Interestingly, estrogen withdrawal from cells accustomed to estrogen exposure caused significantly increased osteoblast mineralization and osteocyte apoptosis compared with continued estrogen treatment. In contrast, blocking estrogen receptors with fulvestrant abrogated the mineralization induced by estrogen treatment. When apoptosis was induced using etoposide, cells undergoing estrogen withdrawal increased apoptosis compared to cells with continued estrogen treatment. Recognizing the underlying mechanisms regulating bone cell mineralization and apoptosis during estrogen deficiency and their consequences is necessary to further our knowledge of osteoporosis.

  5. Effects of gamma irradiation on the DNA-protein complex between the estrogen response element and the estrogen receptor

    Energy Technology Data Exchange (ETDEWEB)

    Stisova, Viktorie [Department of Radiation Dosimetry, Nuclear Physics Institute AS CR, Na Truhlarce 39/64, 18086 Praha 8 (Czech Republic); Goffinont, Stephane; Spotheim-Maurizot, Melanie [Centre de Biophysique Moleculaire CNRS, rue Charles Sadron, 45071 Orleans Cedex 2 (France); Davidkova, Marie, E-mail: davidkova@ujf.cas.c [Department of Radiation Dosimetry, Nuclear Physics Institute AS CR, Na Truhlarce 39/64, 18086 Praha 8 (Czech Republic)


    Signaling by estrogens, risk factors in breast cancer, is mediated through their binding to the estrogen receptor protein (ER), followed by the formation of a complex between ER and a DNA sequence, called estrogen response element (ERE). Anti-estrogens act as competitive inhibitors by blocking the signal transduction. We have studied in vitro the radiosensitivity of the complex between ERalpha, a subtype of this receptor, and a DNA fragment bearing ERE, as well as the influence of an estrogen (estradiol) or an anti-estrogen (tamoxifen) on this radiosensitivity. We observe that the complex is destabilized upon irradiation with gamma rays in aerated aqueous solution. The analysis of the decrease of binding abilities of the two partners shows that destabilization is mainly due to the damage to the protein. The destabilization is reduced when irradiating in presence of tamoxifen and is increased in presence of estradiol. These effects are due to opposite influences of the ligands on the loss of binding ability of ER. The mechanism that can account for our results is: binding of estradiol or tamoxifen induces distinct structural changes of the ER ligand-binding domain that can trigger (by allostery) distinct structural changes of the ER DNA-binding domains and thus, can differently affect ER-ERE interaction.

  6. Estrogenic and anti-estrogenic influences in cultured brown trout hepatocytes: Focus on the expression of some estrogen and peroxisomal related genes and linked phenotypic anchors. (United States)

    Madureira, Tânia Vieira; Malhão, Fernanda; Pinheiro, Ivone; Lopes, Célia; Ferreira, Nádia; Urbatzka, Ralph; Castro, L Filipe C; Rocha, Eduardo


    Estrogens, estrogenic mimics and anti-estrogenic compounds are known to target estrogen receptors (ER) that can modulate other nuclear receptor signaling pathways, such as those controlled by the peroxisome proliferator-activated receptor (PPAR), and alter organelle (inc. peroxisome) morphodynamics. By using primary isolated brown trout (Salmo trutta f. fario) hepatocytes after 72 and 96h of exposure we evaluated some effects in selected molecular targets and in peroxisomal morphological features caused by: (1) an ER agonist (ethinylestradiol-EE2) at 1, 10 and 50μM; (2) an ER antagonist (ICI 182,780) at 10 and 50μM; and (3) mixtures of both (Mix I-10μM EE2 and 50μM ICI; Mix II-1μM EE2 and 10μM ICI and Mix III-1μM EE2 and 50μM ICI). The mRNA levels of the estrogenic targets (ERα, ERβ-1 and vitellogenin A-VtgA) and the peroxisome structure/function related genes (catalase, urate oxidase-Uox, 17β-hydroxysteroid dehydrogenase 4-17β-HSD4, peroxin 11α-Pex11α and PPARα) were analyzed by real-time polymerase chain reaction (RT-PCR). Stereology combined with catalase immunofluorescence revealed a significant reduction in peroxisome volume densities at 50μM of EE2 exposure. Concomitantly, at the same concentration, electron microscopy showed smaller peroxisome profiles, exacerbated proliferation of rough endoplasmic reticulum, and a generalized cytoplasmic vacuolization of hepatocytes. Catalase and Uox mRNA levels decreased in all estrogenic stimuli conditions. VtgA and ERα mRNA increased after all EE2 treatments, while ERβ-1 had an inverse pattern. The EE2 action was reversed by ICI 182,780 in a concentration-dependent manner, for VtgA, ERα and Uox. Overall, our data show the great value of primary brown trout hepatocytes to study the effects of estrogenic/anti-estrogenic inputs in peroxisome kinetics and in ER and PPARα signaling, backing the still open hypothesis of crosstalk interactions between these pathways and calling for more mechanistic

  7. Light Emitting Transistors of Organic Single Crystals (United States)

    Iwasa, Yoshihiro


    Organic light emitting transistors (OLETs) are attracting considerable interest as a novel function of organic field effect transistors (OFETs). Besides a smallest integration of light source and current switching devices, OLETs offer a new opportunity in the fundamental research on organic light emitting devices. The OLET device structure allows us to use organic single crystals, in contrast to the organic light emitting diodes (OLEDs), the research of which have been conducted predominantly on polycrystalline or amorphous thin films. In the case of OFETs, use of single crystals have produced a significant amount of benefits in the studies of pursuit for the highest performance limit of FETs, intrinsic transport mechanism in organic semiconductors, and application of the single crystal transistors. The study on OLETs have been made predominantly on polycrystalline films or multicomponent heterojunctions, and single crystal study is still limited to tetracene [1] and rubrene [2], which are materials with relatively high mobility, but with low photoluminescence efficiency. In this paper, we report fabrication of single crystal OLETs of several kinds of highly luminescent molecules, emitting colorful light, ranging from blue to red. Our strategy is single crystallization of monomeric or oligomeric molecules, which are known to have a very high photoluminescence efficiency. Here we report the result on single crystal LETs of rubrene (red), 4,4'-bis(diphenylvinylenyl)-anthracene (green), 1,4-bis(5-phenylthiophene-2-yl)benzene (AC5) (green), and 1,3,6,8-tetraphenylpyrene (TPPy) (blue), all of which displayed ambipolar transport as well as peculiar movement of voltage controlled movement of recombination zone, not only from the surface of the crystal but also from the edges of the crystals, indicting light confinement inside the crystal. Realization of ambipolar OLET with variety of single crystals indicates that the fabrication method is quite versatile to various light

  8. The AlGaAs light emitting particle detector

    CERN Document Server

    Pozela, J; Silenas, A; Juciene, V; Dapkus, L; Jasutis, V; Tamulaitis, G; Zukauskas, A; Bendorius, R A


    An AlGaAs light emitting particle detector was fabricated and investigated experimentally. Light emitting semiconductor Al sub x Ga sub 1 sub - sub x As layers with graded-gap energy band structure were grown, and luminescence spectra were investigated. A light emitting X-ray detector was also fabricated. (author)

  9. Differential ligand binding affinities of human estrogen receptor-α isoforms


    Amanda H.Y. Lin; Li, Rachel W. S.; Ho, Eva Y. W.; George P H Leung; Susan W S Leung; Paul M Vanhoutte; Man, Ricky Y K


    Rapid non-genomic effects of 17β-estradiol are elicited by the activation of different estrogen receptor-α isoforms. Presence of surface binding sites for estrogen have been identified in cells transfected with full-length estrogen receptor-α66 (ER66) and the truncated isoforms, estrogen receptor-α46 (ER46) and estrogen receptor-α36 (ER36). However, the binding affinities of the membrane estrogen receptors (mERs) remain unknown due to the difficulty of developing of stable mER-transfected cel...

  10. Estrogenic and anti-estrogenic influences in cultured brown trout hepatocytes: Focus on the expression of some estrogen and peroxisomal related genes and linked phenotypic anchors

    Energy Technology Data Exchange (ETDEWEB)

    Madureira, Tânia Vieira, E-mail: [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U.Porto—University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); Institute of Biomedical Sciences Abel Salazar, U.Porto (ICBAS)—University of Porto, Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto (Portugal); Malhão, Fernanda; Pinheiro, Ivone; Lopes, Célia; Ferreira, Nádia [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U.Porto—University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); Institute of Biomedical Sciences Abel Salazar, U.Porto (ICBAS)—University of Porto, Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto (Portugal); Urbatzka, Ralph [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U.Porto—University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); Castro, L. Filipe C. [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U.Porto—University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); Faculty of Sciences (FCUP), U.Porto—University of Porto, Department of Biology, Rua do Campo Alegre, P 4169-007 Porto (Portugal); Rocha, Eduardo [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U.Porto—University of Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); Institute of Biomedical Sciences Abel Salazar, U.Porto (ICBAS)—University of Porto, Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto (Portugal)


    Highlights: • Evidence of crosstalk between estrogens and peroxisomal pathways in brown trout. • VtgA and ERα mRNA levels increased after 1, 10 and 50 μM of ethinylestradiol (EE2). • ERβ-1, catalase and urate oxidase mRNA levels decreased after estrogenic stimuli. • Estrogenic effects in VtgA, ERα and Uox mRNA levels were reverted by ICI 182,780. • Immunofluorescence/electron microscopy shows smaller peroxisomes after 50 μM of EE2. - Abstract: Estrogens, estrogenic mimics and anti-estrogenic compounds are known to target estrogen receptors (ER) that can modulate other nuclear receptor signaling pathways, such as those controlled by the peroxisome proliferator-activated receptor (PPAR), and alter organelle (inc. peroxisome) morphodynamics. By using primary isolated brown trout (Salmo trutta f. fario) hepatocytes after 72 and 96 h of exposure we evaluated some effects in selected molecular targets and in peroxisomal morphological features caused by: (1) an ER agonist (ethinylestradiol—EE2) at 1, 10 and 50 μM; (2) an ER antagonist (ICI 182,780) at 10 and 50 μM; and (3) mixtures of both (Mix I—10 μM EE2 and 50 μM ICI; Mix II—1 μM EE2 and 10 μM ICI and Mix III—1 μM EE2 and 50 μM ICI). The mRNA levels of the estrogenic targets (ERα, ERβ-1 and vitellogenin A—VtgA) and the peroxisome structure/function related genes (catalase, urate oxidase—Uox, 17β-hydroxysteroid dehydrogenase 4—17β-HSD4, peroxin 11α—Pex11α and PPARα) were analyzed by real-time polymerase chain reaction (RT-PCR). Stereology combined with catalase immunofluorescence revealed a significant reduction in peroxisome volume densities at 50 μM of EE2 exposure. Concomitantly, at the same concentration, electron microscopy showed smaller peroxisome profiles, exacerbated proliferation of rough endoplasmic reticulum, and a generalized cytoplasmic vacuolization of hepatocytes. Catalase and Uox mRNA levels decreased in all estrogenic stimuli conditions. VtgA and ERα m

  11. Estrogen receptor expression in adrenocortical carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xiao-cao SHEN; Cai-xiao GU; Yi-qing QIU; Chuan-jun DU; Yan-biao FU; Jian-jun WU


    Objective: Adrenocortical carcinoma (ACC) is a rare but highly malignant tumor, and its diagnosis is mostly delayed and prognosis is poor. We report estrogen receptor (ER) expression in this tumor and our clinical experiences with 17 ACC cases. Methods: The data of the 17 patients (9 females and 8 males, age range from 16 to 69 years, mean age of 42.6 years) with ACC were reviewed, and symptoms, diagnostic procedures, treatment, and results of follow-up were evaluated. Immunohistochemistry was used to detect ER expression in tumor samples from the 17 patients. Results: At the time of diagnosis, 4 tumors were classified as Stage Ⅰ, 4 as Stage Ⅱ, 3 as Stage Ⅲ, and 6 as Stage Ⅳ. Eight patients demonstrated positive nuclear immunostaining of ER. The prognosis of patients with ER positive was significantly better (P<0.05) than that of patients with ER negative, with 1- and 5-year survival rates at 86% and 60% for ER-positive patients, and 38% and 0% for ER-negative patients, respectively. Conclusion: ER-positivity may be one of the factors associated with a worse prognosis of ACC.


    Directory of Open Access Journals (Sweden)

    Susana eNovella


    Full Text Available Aging is a physiological process associated with structural and functional changes in vasculature, including endothelial dysfunction, arterial stiffening and remodeling, impaired angiogenesis, and defective vascular repair, and with an increasing prevalence of atherosclerosis. The risk of cardiovascular disease differs between men and women, remaining lower in women during their fertile years and reaching values similar to their male peers after menopause. Menopause is marked by the loss of endogenous estrogen production. Therefore, estrogens have been implicated in premenopausal protection from cardiovascular disease, an assumption supported by experimental and some clinical studies, where estrogen induces protective effects in vascular endothelium. Indeed, estradiol promotes endothelial vasodilator synthesis, including NO production through increased expression and activity of endothelial nitric oxide synthase, and modulates prostacyclin and thromboxane A2 release; the thromboxane A2 pathway plays a key role in regulating vascular tone in females in both normal and in pathophysiologic states.Contrary to experimental results, some clinical trials found no cardiovascular benefit from estrogen replacement therapy in aged postmenopausal women. These discrepancies could be due to the Timing Hypothesis which suggests that estrogen-mediated vascular benefits may occur only before the detrimental effects of aging are established in the vasculature. Thus, there is still a gap in the knowledge, understanding, and general awareness of mechanisms for cardiovascular aging in women.In this review, we discuss clinical and experimental data on the effects of aging, estrogens and hormonal replacement therapy on vascular function of females to delve into how menopause and aging contribute jointly to vascular aging and how estrogen modulates the vascular responses at different ages.

  13. Classical estrogen receptors and ERα splice variants in the mouse.

    Directory of Open Access Journals (Sweden)

    Debra L Irsik

    Full Text Available Estrogens exert a variety of effects in both reproductive and non-reproductive tissues. With the discovery of ERα splice variants, prior assumptions concerning tissue-specific estrogen signaling need to be re-evaluated. Accordingly, we sought to determine the expression of the classical estrogen receptors and ERα splice variants across reproductive and non-reproductive tissues of male and female mice. Western blotting revealed that the full-length ERα66 was mainly present in female reproductive tissues but was also found in non-reproductive tissues at lower levels. ERα46 was most highly expressed in the heart of both sexes. ERα36 was highly expressed in the kidneys and liver of female mice but not in the kidneys of males. ERβ was most abundant in non-reproductive tissues and in the ovaries. Because the kidney has been reported to be the most estrogenic non-reproductive organ, we sought to elucidate ER renal expression and localization. Immunofluorescence studies revealed ERα66 in the vasculature and the glomerulus. It was also found in the brush border of the proximal tubule and in the cortical collecting duct of female mice. ERα36 was evident in mesangial cells and tubular epithelial cells of both sexes, as well as podocytes of females but not males. ERβ was found primarily in the podocytes in female mice but was also present in the mesangial cells in both sexes. Within the renal cortex, ERα46 and ERα36 were mainly located in the membrane fraction although they were also present in the cytosolic fraction. Given the variability of expression patterns demonstrated herein, identification of the specific estrogen receptors expressed in a tissue is necessary for interpreting estrogenic effects. As this study revealed expression of the ERα splice variants at multiple sites within the kidney, further studies are warranted in order to elucidate the contribution of these receptors to renal estrogen responsiveness.

  14. In vitro estrogenic activity of two major compounds from the stem bark of Erythrina lysistemon (Fabaceae). (United States)

    Magne Nde, Chantal Beatrice; Njamen, Dieudonne; Tanee Fomum, Stephen; Wandji, Jean; Simpson, Evan; Clyne, Colin; Vollmer, Günter


    Plant-derived estrogen-like compounds, so called phytoestrogens, are given much attention due to their potential therapeutic use. In our previous work the ethylacetate extract of Erythrina lysistemon stem bark showed estrogenic effects on cell culture systems and ovariectomized Wistar rats. Using classical chromatographic methods, two constituents of Erythrina lysistemon have been isolated, referred to here as compounds 1 (alpinumisoflavone) and 2 (abyssinone V-4'-methyl-ether), and their structures successfully determined using spectroscopic techniques. To test their binding affinity, the ligand binding assay has been used on estrogen α receptor, and estrogen β receptor. Furthermore, transactivation assay in stably or transiently transfected human osteosarcoma (U2OS-estrogen α receptor and estrogen β receptor) cells were used to examine their estrogenic activity. The regulations of some estrogen receptor target genes were also investigated. Both compounds bind to estrogen α and β receptors. They significantly increased luciferase activity in a dose-dependent manner and induced the endogenous estrogen receptor-estrogen response element (ERE) interaction in U2OS-estrogen α receptor and estrogen β receptor cells. In contrast, when co-treated with E2, compound 2 did not antagonize E2 activity in both systems whereas, 1 significantly suppressed E2 activity despite its low binding affinity to estrogen β receptor. This result suggests a non-competitive mechanism. Both compounds also altered the expression of estrogen receptor target genes such as growth regulation by estrogen in breast cancer 1 (GREB1) and Cyclin D1 in breast cells. These results suggest that compounds 1 and 2 endow estrogenic activity and may be the active principles of Erythrina lysistemon.

  15. Laminated active matrix organic light-emitting devices (United States)

    Liu, Hongyu; Sun, Runguang


    Laminated active matrix organic light-emitting device (AMOLED) realizing top emission by using bottom-emitting organic light-emitting diode (OLED) structure was proposed. The multilayer structure of OLED deposited in the conventional sequence is not on the thin film transistor (TFT) backplane but on the OLED plane. The contact between the indium tin oxide (ITO) electrode of TFT backplane and metal cathode of OLED plane is implemented by using transfer electrode. The stringent pixel design for aperture ratio of the bottom-emitting AMOLED, as well as special technology for the top ITO electrode of top-emitting AMOLED, is unnecessary in the laminated AMOLED.

  16. Bipolar Host Materials for Organic Light-Emitting Diodes. (United States)

    Yook, Kyoung Soo; Lee, Jun Yeob


    It is important to balance holes and electrons in the emitting layer of organic light-emitting diodes to maximize recombination efficiency and the accompanying external quantum efficiency. Therefore, the host materials of the emitting layer should transport both holes and electrons for the charge balance. From this perspective, bipolar hosts have been popular as the host materials of thermally activated delayed fluorescent devices and phosphorescent organic light-emitting diodes. In this review, we have summarized recent developments of bipolar hosts and suggested perspectives of host materials for organic light-emitting diodes.

  17. Stallion spermatozoa: putative target of estrogens; presence of the estrogen receptors ESR1, ESR2 and identification of the estrogen-membrane receptor GPER. (United States)

    Arkoun, Brahim; Gautier, Camille; Delalande, Christelle; Barrier-Battut, Isabelle; Guénon, Isabelle; Goux, Didier; Bouraïma-Lelong, Hélène


    Among mammals, the stallion produces the largest amount of testicular estrogens. These steroid hormones are produced mainly by Leydig and Sertoli cells in the testis and also in the epididymis. Their role in horse testicular physiology and their ability to act on spermatozoa are still unknown. In order to determine if spermatozoa are targets for estrogens, the presence of estrogen receptors in mature ejaculated spermatozoa has been investigated. The presence of a single isoform of ESR1 (66kDa) and ESR2 (61kDa) was found by Western-blot analysis in samples from seven stallions. Confocal analysis mainly showed a flagellar localization for both receptors. Immuno-TEM experiments revealed that they are mostly located near the membranes, which are classically associated with rapid, non-genomic, effects. Moreover, we evidenced the expression of the seven transmembrane estradiol binding receptor GPER in colt testis. The protein was also localized at the connecting piece in mature spermatozoa. In conclusion, our results suggest that horse spermatozoa are a target for estrogens, which could act on several receptors either during the epididymal transit and/or in the female genital tract.

  18. Role of G protein-coupled estrogen receptor 1, GPER, in inhibition of oocyte maturation by endogenous estrogens in zebrafish. (United States)

    Pang, Yefei; Thomas, Peter


    Estrogen inhibition of oocyte maturation (OM) and the role of GPER (formerly known as GPR30) were investigated in zebrafish. Estradiol-17beta (E2) and G-1, a GPER-selective agonist, bound to zebrafish oocyte membranes suggesting the presence of GPER which was confirmed by immunocytochemistry using a specific GPER antibody. Incubation of follicle-enclosed oocytes with an aromatase inhibitor, ATD, and enzymatic and manual removal of the ovarian follicle cell layers significantly increased spontaneous OM which was partially reversed by co-treatment with either 100 nM E2 or G-1. Incubation of denuded oocytes with the GPER antibody blocked the inhibitory effects of estrogens on OM, whereas microinjection of estrogen receptor alpha (ERalpha) antisense oligonucleotides into the oocytes was ineffective. The results suggest that endogenous estrogens produced by the follicle cells inhibit or delay spontaneous maturation of zebrafish oocytes and that this estrogen action is mediated through GPER. Treatment with E2 and G-1 also attenuated the stimulatory effect of the teleost maturation-inducing steroid, 17,20beta-dihyroxy-4-pregnen-3-one (DHP), on OM. Moreover, E2 and G-1 down-regulated the expression of membrane progestin receptor alpha (mPRalpha), the intermediary in DHP induction of OM. Conversely DHP treatment caused a >50% decline in GPER mRNA levels. The results suggest that estrogens and GPER are critical components of the endocrine system controlling the onset of OM in zebrafish. A model is proposed for the dual control of the onset of oocyte maturation in teleosts by estrogens and progestins acting through GPER and mPRalpha, respectively, at different stages of oocyte development.

  19. Establishment of a transgenic yeast screening system for estrogenicity and identification of the anti-estrogenic activity of malachite green. (United States)

    Jiao, Baowei; Yeung, Eric K C; Chan, Chi Bun; Cheng, Christopher H K


    Endocrine disruptors refer to chemical compounds in the environment which interfere with the endocrine systems of organisms. Among them, environmental estrogens pose serious problems to aquatic organisms, in particular fish. It is therefore important and necessary to have a fast and low-cost system to screen the large number of different chemical compounds in the aquatic environment for their potential endocrine disrupting actions. In this study, a screening platform was developed to detect xenoestrogens in the aquatic environment using the fission yeast Schizosaccharomyces pombe, and applied for compound screening. The aim was to demonstrate any significant potential differences between the fish screening system and the human screening system. To this end, a yeast expression vector harboring a fish estrogen receptor alpha and a reporter vector containing the estrogen responsive element fused with the Escherichia coli LacZ gene were constructed. After transformation with these two vectors, the transformed yeast clones were confirmed by Western blotting and selected on the basis of the beta-galactosidase activity. In this transgenic yeast system, the natural estrogen (estradiol) and other known xenoestrogens such as diethylstilbestrol, bisphenol A, genistein and dichloro-diphenyl-trichloroethane exhibited dose-dependent activities. Using this system, more than 40 putative endocrine disruptors including phytoestrogens, pesticides, herbicides, industrial dyes and other industrial chemicals were screened. Ten of them were demonstrated to exhibit estrogenic actions. Industrial dyes such as malachite green (MG) that disrupt thyroid hormone synthesis are extensively used and are widely distributed in the aquatic environment. Using this system, MG did not show any estrogenic action, but was demonstrated to exhibit anti-estrogenic activity.

  20. Estrogenicity of food-associated estrogenic compounds in the fetuses of female transgenic mice upon oral and IP maternal exposure. (United States)

    Ter Veld, Marcel G R; Zawadzka, E; Rietjens, Ivonne M C M; Murk, Albertinka J


    The present study investigated to what extent seven food-associated in vitro estrogenic compounds can induce estrogenic effects in the fetuses of pregnant female mice with an estrogen receptor (ER)-mediated luciferase (luc) reporter gene system. The luc-induction was determined either 8h after maternal dosing with a single intraperitoneal (IP) dose or 24h after the last of a series of 8 daily oral dosages. Three known estrogens, 17beta-estradiol (E(2)), 17 alpha-ethynylestradiol (EE) and 17beta-estradiol 3,17-dipropionate (EP) were used as positive controls at 1mg/kgbw and DMSO as solvent control. The food-associated estrogenic compounds tested were: bisphenol A (BPA), nonylphenol (NP) both at 50mg/kgbw, dichlorodiphenyldichloroethylene (p,p'-DDE) at 50mg/kgbw, quercetin at 16.6 mg/kgbw, and di-isoheptyl phthalate (DIHP), di-(2-ethylhexyl) phthalate (DEHP) and di-(2-ethylhexyl) adipate (DEHA) all at 100mg/kgbw. Exposure to E(2), EE and EP resulted in significant luc inductions upon both oral and/or IP dosing in a variety of tissues including liver, tibia and femurs, and upon IP dosing also in fetuses. BPA, NP, DEHA, DEHP, DIHP, DDE and quercetin were unable to significantly induce luc activity in fetuses. However, after maternal oral exposure during gestation to NP, BPA and DIHP placental luc activity was significantly lowered. The results indicate that at the current levels of exposure to food-associated estrogenic compounds, estrogenic effects to the fetus are not expected. The significant luc reduction in the placenta, should be further studied for its significance for fetal development and relevance for the human situation.

  1. Activation of the G protein-coupled estrogen receptor, but not estrogen receptor α or β, rapidly enhances social learning. (United States)

    Ervin, Kelsy Sharice Jean; Mulvale, Erin; Gallagher, Nicola; Roussel, Véronique; Choleris, Elena


    Social learning is a highly adaptive process by which an animal acquires information from a conspecific. While estrogens are known to modulate learning and memory, much of this research focuses on individual learning. Estrogens have been shown to enhance social learning on a long-term time scale, likely via genomic mechanisms. Estrogens have also been shown to affect individual learning on a rapid time scale through cell-signaling cascades, rather than via genomic effects, suggesting they may also rapidly influence social learning. We therefore investigated the effects of 17β-estradiol and involvement of the estrogen receptors (ERs) using the ERα agonist propyl pyrazole triol, the ERβ agonist diarylpropionitrile, and the G protein-coupled ER 1 (GPER1) agonist G1 on the social transmission of food preferences (STFP) task, within a time scale that focused on the rapid effects of estrogens. General ER activation with 17β-estradiol resulted in a modest facilitation of social learning, with mice showing a preference up to 30min of testing. Specific activation of the GPER1 also rapidly enhanced social learning, with mice showing a socially learned preference up to 2h of testing. ERα activation instead shortened the expression of a socially learned food preference, while ERβ activation had little to no effects. Thus, rapid estrogenic modulation of social learning in the STFP may be the outcome of competing action at the three main receptors. Hence, estrogens' rapid effects on social learning likely depend on the specific ERs present in brain regions recruited during social learning.

  2. Light-emitting waveguide-plasmon polaritons

    CERN Document Server

    Rodriguez, S R K; Verschuuren, M A; Rivas, J Gomez


    We demonstrate the generation of light in an optical waveguide strongly coupled to a periodic array of metallic nanoantennas. This coupling gives rise to hybrid waveguide-plasmon polaritons (WPPs), which undergo a transmutation from plasmon to waveguide mode and viceversa as the eigenfrequency detuning of the bare states transits through zero. Near zero detuning, the structure is nearly transparent in the far-field but sustains strong local field enhancements inside the waveguide. Consequently, light-emitting WPPs are strongly enhanced at energies and in-plane momenta for which WPPs minimize light extinction. We elucidate the unusual properties of these polaritons through a classical model of coupled harmonic oscillators.

  3. Efficient organic light emitting-diodes (OLEDs)

    CERN Document Server

    Chang, Yi-Lu


    Following two decades of intense research globally, the organic light-emitting diode (OLED) has steadily emerged as the ultimate display technology of choice for the coming decades. Portable active matrix OLED displays have already become prevalent, and even large-sized ultra-high definition 4K TVs are being mass-produced. More exotic applications such as wearable displays have been commercialized recently. With the burgeoning success in displays, researchers are actively bringing the technology forward into the exciting solid-state lighting market. This book presents the knowledge needed for

  4. Silicon Light Emitting Devices in CMOS Technology

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-Da; LIU Hai-Jun; LIU Jin-Bin; GU Ming; HUANG Bei-Ju


    @@ Two silicon light emitting devices with different structures are realized in standard 0.35 μm complementary metal-oxide-semiconductor (CMOS) technology. They operate in reverse breakdown mode and can be turned on at 8.3 V. Output optical powers of 13.6nW and 12.1 nW are measured at 10 V and 100 mA, respectively, and both the calculated light emission intensities are more than 1 mW/cm2. The optical spectra of the two devices are between 600-790 nm with a clear peak near 760 nm.

  5. Deep ultraviolet light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, X.; Deng, J.; Zhang, J.P.; Lunev, A.; Bilenko, Y.; Katona, T.; Gaska, R. [Sensor Electronic Technology, Inc., 1195 Atlas Road, Columbia, SC 29209 (United States); Shur, M.S. [Department of Electrical Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Shatalov, M.; Khan, A. [Department of Electrical Engineering, University of South Carolina, Columbia, SC 29208 (United States)


    We report on the development of AlGaN-based deep UV light emitting diodes (LEDs) with emission wavelengths from 254 to 340 nm, focusing on the improvement of 280 nm LEDs efficiency. Under optimal device structure the UV LEDs efficiency was found to strongly depend on the AlGaN material quality. Milliwatt-power level LEDs were demonstrated for the 254-340 nm spectral range, and for 280 nm LEDs powers reaching 2.5 mW was achieved at 20 mA DC. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Atomically thin quantum light-emitting diodes (United States)

    Palacios-Berraquero, Carmen; Barbone, Matteo; Kara, Dhiren M.; Chen, Xiaolong; Goykhman, Ilya; Yoon, Duhee; Ott, Anna K.; Beitner, Jan; Watanabe, Kenji; Taniguchi, Takashi; Ferrari, Andrea C.; Atatüre, Mete


    Transition metal dichalcogenides are optically active, layered materials promising for fast optoelectronics and on-chip photonics. We demonstrate electrically driven single-photon emission from localized sites in tungsten diselenide and tungsten disulphide. To achieve this, we fabricate a light-emitting diode structure comprising single-layer graphene, thin hexagonal boron nitride and transition metal dichalcogenide mono- and bi-layers. Photon correlation measurements are used to confirm the single-photon nature of the spectrally sharp emission. These results present the transition metal dichalcogenide family as a platform for hybrid, broadband, atomically precise quantum photonics devices.

  7. Long wavelength vertical cavity surface emitting laser (United States)

    Choquette, Kent D.; Klem, John F.


    Selectively oxidized vertical cavity lasers emitting near 1300 nm using InGaAsN quantum wells are reported for the first time which operate continuous wave below, at and above room temperature. The lasers employ two n-type Al.sub.0.94 Ga.sub.0.06 As/GaAs distributed Bragg reflectors each with a selectively oxidized current aperture adjacent to the active region, and the top output mirror contains a tunnel junction to inject holes into the active region. Continuous wave single mode lasing is observed up to C.

  8. Effect of estrogen and testosterone replacement therapy on cognitive fatigue. (United States)

    Möller, Marika Christina; Rådestad, Angelique Flöter; von Schoultz, Bo; Bartfai, Aniko


    Both estrogen and testosterone insufficiency has been associated with reduced psychological well-being including fatigue. However, hormonal replacement studies on fatigue are rare. Therefore, we wanted to study the effect of testosterone and estrogen replacement therapy on cognitive fatigue and the relation between sex hormone levels and cognitive fatigue in oophorectomized women. Fifty women with surgically induced menopause (mean age: 54.0 ± 2.9 years) were randomly assigned to treatment with estradiol valerate in combination with testosterone undecanoate or placebo for 24 weeks in a double-blind cross-over study. Neuropsychological tests and questionnaires were used to assess cognitive fatigue and psychological well-being. Cognitive fatigue was significantly associated to poor self-rated health and higher body mass index but not to general psychological well-being or sex hormone levels. Treatment with testosterone + estrogen had no significant effect on cognitive fatigue but the results indicated a curvilinear relation for hormonal levels. The estrogen/testosterone ratio was more related to functions rather than high or low hormone levels per se. We found that cognitive fatigue is frequent in oophorectomized women and negatively associated to self-perceived health and positively associated to BMI. A well-balanced ratio between estrogen and testosterone levels may be important for cognitive fatigue.

  9. Immunohistochemical Expression of Estrogen and Progesterone Receptors in Epulis Fissuratum

    Directory of Open Access Journals (Sweden)

    Maryam Seyedmajidi


    Full Text Available Background: Epulis Fissuratum (Epulis Fissuratum (EF or Denture Epulis or inflammatory fibrous hyperplasia is a common hyperplastic tumor-like lesion with reactive nature, related to loose and ill-fitting, full or partial removable dentures and it is more common in women than men. For this reason, hormonal influences may also play role in its creation. The effect of steroid hormones especially sex hormones (Estrogen and progesterone on oral mucosa is identified in some studies. In the present study, the distribution pattern and presence of estrogen and progesterone receptors in epithelial, stromal, endothelial and inflammatory cells in Epulis Fissuratum was investigated. Materials and Methods: This cross-sectional study was carried out on 30 samples of paraffin blocks with Epulis Fissuratum diagnosis and 30 samples of normal mucosal tissues as a control group who have had surgery as a margin beside the above lesions and had been obtained from the oral and maxillofacial pathology departement of Babol Dental School since 2003 up to 2010. Intensity of staining and immunoreactivity were evaluated using subjective index and considering the positive control group (breast carcinoma.Results: Epithelial, stromal, endothelial and inflammatory cells didn’t show reaction with monoclonal antibodies against estrogen and progesterone in none of the samples. Conclusion: It seems that the hypothesis of the existence of estrogen and progesterone receptors in epulis fissuratum and normal oral mucosa is ruled out. The possibility of direct effect of estrogen and progesterone in occurring of epulis fissuratum is rejected.

  10. Screening of estrogenic and antiestrogenic activities from medicinal plants. (United States)

    Kim, In Gyu; Kang, Se Chan; Kim, Kug Chan; Choung, Eui Su; Zee, Ok Pyo


    The medicinal plant extracts commercially used in Asia were screened for their estrogenic and antiestrogenic activities in a recombinant yeast system featuring both a human estrogen receptor (ER) expression plasmid and a reporter plasmid. Pueraria lobata (flower) had the highest estrogenic relative potency (RP, 7.75×10(-3); RP of 17β-estradiol=1), followed by Amomum xanthioides (1.25×10(-3)). Next potent were a group consisting of Glycyrrhiza uralensis, Zingiber officinale, Rheum undulatum, Curcuma aromatica, Eriobotrya japonica, Sophora flavescens, Anemarrhena asphodeloides, Polygonum multiflorum, and Pueraria lobata (root) (ranging from 9.5×10(-4) to 1.0×10(-4)). Least potent were Prunus persica, Lycoppus lucidus, and Adenophora stricta (ranging from 9.0×10(-5) to 8.0×10(-5)). The extracts exerting antiestrogenic effects, Cinnamomum cassia and Prunus persica, had relative potencies of 1.14×10(-3) and 7.4×10(-4), respectively (RP of tamoxifen=1). The solvent fractions from selected estrogenic or antiestrogenic herbs had higher estrogenic relative potencies, with their RP ranging from 9.3×10(-1) to 2.7×10(-4) and from 8.2×10(-1) to 9.1×10(-3), respectively. These results support previous reports on the efficacy of Oriental medicinal plants used or not used as phytoestrogens for hormone replacement therapy.

  11. Bazedoxifene and bazedoxifene combined with conjugated estrogens for the management of postmenopausal osteoporosis. (United States)

    Lewiecki, E Michael


    Bazedoxifene acetate (WAY-140424; TSE-424) is an investigational non-steroidal indole-based selective estrogen receptor modulator (SERM) - also classified as an estrogen agonist/antagonist - that is being developed as a daily oral drug for the prevention and treatment of postmenopausal osteoporosis (PMO). Clinical studies have shown favorable effects on the skeleton, with prevention of bone loss in postmenopausal women without osteoporosis and reduction in vertebral fracture risk in women with PMO, without stimulation of endometrium or breast. Bazedoxifene combined with conjugated estrogens is an investigational tissue-selective estrogen complex, the first in a new class of therapeutic agents that pairs a selective estrogen receptor modulator with estrogens. Clinical trials with bazedoxifene/conjugated estrogens in postmenopausal women have shown skeletal benefit with improvement in menopausal vasomotor symptoms and little or no stimulation of endometrial or breast tissue. Bazedoxifene/conjugated estrogens is a potential agent for the prevention of PMO and control of menopausal symptoms.

  12. Estrogenic Activity of Perfluoroalkyl Acids in Juvenile Rainbow Trout (Oncorhynchus Mykiss) (United States)

    The potential estrogenic activity of perfluoroalkyl acids (PFAAs) was determined using separate screening and dose response studies with juvenile rainbow trout (Oncorhynchus mykiss). Results of this study indicate that some PFAAs may act as estrogens in fish.

  13. Tissue Specific Effects of Loss of Estrogen During Menopause and Aging

    Directory of Open Access Journals (Sweden)

    Korinna eWend


    Full Text Available The roles of estrogens have been best studied in the breast, breast cancers and in the female reproductive tract. However, estrogens have important functions in almost every tissue in the body. Recent clinical trials such as the Women’s Health Initiative have highlighted both the importance of estrogens and how little we know about the molecular mechanism of estrogens in these other tissues. In this review, we illustrate the diverse functions of estrogens in the bone, adipose tissue, skin, hair, brain, skeletal muscle and cardiovascular system, and how the loss of estrogens during aging affects these tissues. Early transcriptional targets of estrogen are reviewed in each tissue. We also describe the tissue-specific effects of selective estrogen receptor modulators (SERMs used for the treatment of breast cancers and post-menopausal symptoms.


    Many environmentally persistent xenobiotic chemicals appear to disrupt normal endocrine function by acting as ligands for endogenous steroid receptors, including the estrogen receptor. Xenobiotics that bind to the estrogen receptor may elicit several effects, one of which is acti...

  15. Estrogen receptor determination in endometrial carcinoma: ligand binding assay versus enzyme immunoassay

    DEFF Research Database (Denmark)

    Nyholm, H C; Nielsen, Anette Lynge; Lyndrup, J;


    We compared concentrations of cytosolic estrogen receptors (ERc) measured in 35 postmenopausal endometrial carcinomas by ligand binding method (LBA) (dextran-coated charcoal assay) and enzyme immunoassay (EIA). Correlations between ERc, nuclear estrogen receptors (ERn) determined by EIA...

  16. [Metrorrhagia caused by estrogen-progestin combinations]. (United States)

    Erny, R; Erny, N


    Changes in combined oral contraceptives (OCs) include reduction in the estrogen and progestogen dose and recourse to the third generation, less androgenic progestogens. They retain the efficacy and convenience of OCs while reducing the metabolic and cardiovascular effects and the need to identify contraindications and subjects at risk. OCs sometimes cause menstrual cycle problems: spotting and intercurrent bleeding or bleeding at any time other than menstruation (metrorrhagia). OCs cause loose and edematous stroma in the endometrium where glands maintain a proliferative-like phase throughout the cycle. Many dilated capillaries with hyperplasia of the endothelial cells rise to the surface. Forgetting or failure to take OC pills are often responsible for intercurrent bleeding. It is hard to determine what OCs cause less bleeding than other OCs. The third generation progestogen, gestodene, appears to have better cycle control than the two other third generation progestogens (desogestrel and norgestimate). It is not clear whether triphasic OCs with second generation progestogens are better than monophasic third generation OCs. The OC with low dose ethinyl estradiol (20 mcg) (Mercilon) has as low a bleeding rate as does the OC, Varnoline (30 mcg). Menstrual cycle disturbances rarely happen. Providers must emphasize to new OC users the possibility of spotting or intercurrent bleeding, especially during the first cycle. Providers must also inform them that these disturbances do not affect the effectiveness of the OCs and that they should not stop taking OCs if they are concerned about bleeding. Providers must instruct them what to do if they forget to take a pill(s). Providers should schedule an appointment after a new OC user has completed the third OC packet. They should do a gynecologic exam to search for a genital infection, endo-uterine polyp or fibroma, and hyperplasia of the endometrium. If bleeding persists during the third cycle, the client should change

  17. Comprehensive Assessment of Hormones, Phytoestrogens, and Estrogenic Activity in an Anaerobic Swine Waste Lagoon


    Yost, Erin E.; Meyer, Michael T.; Dietze, Julie E.; Meissner, Benjamin M.; Worley-Davis, Lynn; Williams, C. Michael; Lee, Boknam; Kullman, Seth W.


    In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were ...

  18. Estrogenic Activities of Fatty Acids and a Sterol Isolated from Royal Jelly


    Kazu-Michi Suzuki; Yoichiro Isohama; Hiroe Maruyama; Yayoi Yamada; Yukio Narita; Shozo Ohta; Yoko Araki; Takeshi Miyata; Satoshi Mishima


    We have previously reported that royal jelly (RJ) from honeybees (Apis mellifera) has weak estrogenic activity mediated by interaction with estrogen receptors that leads to changes in gene expression and cell proliferation. In this study, we isolated four compounds from RJ that exhibit estrogenic activity as evaluated by a ligand-binding assay for the estrogen receptor (ER) β. These compounds were identified as 10-hydroxy-trans-2-decenoic acid, 10-hydroxydecanoic acid, trans-2-decenoic acid a...

  19. Toxicity of endogenous and environmental estrogens: what is the role of elemental interactions?


    Stancel, G M; Boettger-Tong, H L; Chiappetta, C; Hyder, S.M.; Kirkland, J L; Murthy, L; Loose-Mitchell, D S


    Many naturally occurring and man-made chemicals present in the environment possess estrogenic activity. Examples include plant and fungal products, pesticides, plasticizers, and other agricultural and industrial chemicals. These environmental estrogens as well as endogenous ovarian estrogens are thought to initiate their physiological actions in target tissues largely via interactions with a nuclear receptor system. The resultant estrogen-receptor complex in turn affects transcription via its...

  20. Neuroprotection with Non-Feminizing Estrogen Analogues: An Overlooked Possible Therapeutic Strategy


    Simpkins, James W.; Richardson, Timothy E.; Yi, Kun Don; Perez, Evelyn; Covey, Douglas


    Although many of the effects of estrogens on the brain are mediated through estrogen receptors (ERs), there is evidence that neuroprotective activity of estrogens can be mediated by non-ER mechanisms. Herein, we review the substantial evidence that estrogens neuroprotection is in large part non-ER mediated and describe in vitro and in vivo studies that support this conclusion. Also, we described our drug discovery strategy for capitalizing on enhancement in neuroprotection while at the same t...

  1. Electrically and Optically Readable Light Emitting Memories (United States)

    Chang, Che-Wei; Tan, Wei-Chun; Lu, Meng-Lin; Pan, Tai-Chun; Yang, Ying-Jay; Chen, Yang-Fang


    Electrochemical metallization memories based on redox-induced resistance switching have been considered as the next-generation electronic storage devices. However, the electronic signals suffer from the interconnect delay and the limited reading speed, which are the major obstacles for memory performance. To solve this problem, here we demonstrate the first attempt of light-emitting memory (LEM) that uses SiO2 as the resistive switching material in tandem with graphene-insulator-semiconductor (GIS) light-emitting diode (LED). By utilizing the excellent properties of graphene, such as high conductivity, high robustness and high transparency, our proposed LEM enables data communication via electronic and optical signals simultaneously. Both the bistable light-emission state and the resistance switching properties can be attributed to the conducting filament mechanism. Moreover, on the analysis of current-voltage characteristics, we further confirm that the electroluminescence signal originates from the carrier tunneling, which is quite different from the standard p-n junction model. We stress here that the newly developed LEM device possesses a simple structure with mature fabrication processes, which integrates advantages of all composed materials and can be extended to many other material systems. It should be able to attract academic interest as well as stimulate industrial application.

  2. Spectrochemical studies with {beta}-emitting radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chesta, Miguel A.; Plivelic, Tomas S.; Mainardi, Raul T. [Cordoba Univ. Nacional (Argentina). Facultad de Matematica, Atronomia y Fisica


    Electrons emitted by {sup 90} Sr radioactive source and positrons from a {sup 22} Na source were used to produce ionizations in the constituents of a sample. The sources have similar energy spectra and this allowed us to compare the characteristic radiation emission efficiencies. The new proposed experimental set up for radioisotope excited x-ray fluorescence analysis (XRFA) is of a transparent source type and provides at least a ten times increase in the intensity of characteristic x-rays emitted by the sample as compared with a standard set up in XRFA. It is shown that this fact, together with the relatively high energy of the beta particles, make it possible to carry out a mirror elemental analysis in a few minutes using low intensity radioactive sources (no special handling license). Preliminary experimental results are shown using both electrons and positrons impinging on pure and composed samples and simple analytical expressions are provided for the characteristic radiation intensity as detected by an HPGe detector. (author). 7 refs., 4 figs.

  3. Organic bistable light-emitting devices (United States)

    Ma, Liping; Liu, Jie; Pyo, Seungmoon; Yang, Yang


    An organic bistable device, with a unique trilayer structure consisting of organic/metal/organic sandwiched between two outmost metal electrodes, has been invented. [Y. Yang, L. P. Ma, and J. Liu, U.S. Patent Pending, U.S. 01/17206 (2001)]. When the device is biased with voltages beyond a critical value (for example 3 V), the device suddenly switches from a high-impedance state to a low-impedance state, with a difference in injection current of more than 6 orders of magnitude. When the device is switched to the low-impedance state, it remains in that state even when the power is off. (This is called "nonvolatile" phenomenon in memory devices.) The high-impedance state can be recovered by applying a reverse bias; therefore, this bistable device is ideal for memory applications. In order to increase the data read-out rate of this type of memory device, a regular polymer light-emitting diode has been integrated with the organic bistable device, such that it can be read out optically. These features make the organic bistable light-emitting device a promising candidate for several applications, such as digital memories, opto-electronic books, and recordable papers.

  4. HF radiation emitted by chaotic leader processes (United States)

    Mäkelä, J. S.; Edirisinghe, M.; Fernando, M.; Montaño, R.; Cooray, V.


    This paper presents direct measurements of narrowband 10 MHz HF radiation from so-called “chaotic leaders” associated with subsequent return strokes. Although the term is controversial and poorly defined, we find that more than 30% of subsequent strokes in close lightning flashes contain electric field characteristics that are best described as “chaotic”. In earlier studies, return strokes have consistently been observed to be the strongest sources of HF radiation, but the results for leader processes are less consistent. We also observe return strokes to be the main HF emitter, and the leaders before the first return stroke in a flash sequence also emit HF though somewhat less intensely. The leaders preceding subsequent strokes typically emit little or no HF radiation, whether they are dart or dart-stepped leaders. However, it was observed that the presence of a chaotic component increases the leader HF intensity dramatically Defining the HF intensity unequivocally can be problematic for processes like chaotic leaders which have a combination of continuous and impulsive phenomena. Two time-domain methods were used to measure the HF intensity, the peak energy and the RMS energy. In the frequency domain these correspond to the energy spectral density (ESD) and power spectral density (PSD), respectively. It was found that the methods are not necessarily compatible. Thus, it is suggested that to clarify future work, leader processes should be characterized by the PSD rather than the ESD.

  5. Estrogen receptors in medaka (Oryzias latipes) and estrogenic environmental contaminants: an in vitro-in vivo correlation. (United States)

    Chakraborty, Tapas; Katsu, Yoshinao; Zhou, Lin Yan; Miyagawa, Shinichi; Nagahama, Yoshitaka; Iguchi, Taisen


    In many vertebrates, estrogens are necessary to promote the growth and differentiation of the female reproductive system during development, and have important reproductive roles in both males and females. Medaka (Oryzias latipes) has three estrogen receptor (ER) subtypes, ERα, ERβ1 and ERβ2. To evaluate the three medaka ER (mER)-ligand interactions, we applied the ERE-luciferase reporter assay system to characterize each ER subtype. In this transient transfection assay system using mammalian cells, the mER proteins displayed estrogen-dependent activation. 17β-Estradiol (E(2)) and op'-DDT showed high activation irrespective of ERs. Endosulfan also exhibited activation; with less/no transactivity measured using other pesticides, i.e., heptachlor, carbendazim, deltamethrin, acephate, dimethoate and amitraz. It was generally observed that ERβ2 had higher activation potential than ERα and ERβ1. To understand the molecular mechanism of estrogen action via ER, we also conducted E(2) treatment where we observed a trigger in ERβ2 expression upon E(2) exposure. The present data suggest that ERβ2 is essential for female gonad maintenance. The data were supported by induction of vitellogenin (VTG) mRNA in the liver and reduced VTG receptor mRNA expression in the gonad of both sexes. The present work will provide a basic tool allowing future studies to examine the receptor-ligand interactions and endocrine disrupting mechanisms, and also expands our knowledge of estrogen action on reproductive development in medaka.

  6. Female Mice Lacking Estrogen Receptor-α in Hypothalamic Proopiomelanocortin (POMC) Neurons Display Enhanced Estrogenic Response on Cortical Bone Mass. (United States)

    Farman, H H; Windahl, S H; Westberg, L; Isaksson, H; Egecioglu, E; Schele, E; Ryberg, H; Jansson, J O; Tuukkanen, J; Koskela, A; Xie, S K; Hahner, L; Zehr, J; Clegg, D J; Lagerquist, M K; Ohlsson, C


    Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor (ER)α. Central ERα exerts an inhibitory role on bone mass. ERα is highly expressed in the arcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ERα in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ERα expression specifically in POMC neurons (POMC-ERα(-/-)). Female POMC-ERα(-/-) and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 μg/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ERα(-/-) mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+126 ± 34%, P mass, ERα was silenced using an adeno-associated viral vector. Silencing of ERα in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ERα in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ERα activity in hypothalamic POMC neurons in ARC and stimulatory peripheral ERα-mediated effects in bone determines cortical bone mass in female mice.

  7. Immunomodulation of Mytilus hemocytes by individual estrogenic chemicals and environmentally relevant mixtures of estrogens: in vitro and in vivo studies. (United States)

    Canesi, Laura; Lorusso, Lucia Cecilia; Ciacci, Caterina; Betti, Michele; Rocchi, Marco; Pojana, Giulio; Marcomini, Antonio


    Endocrine disrupting compounds (EDCs) are almost ubiquitous in the aquatic environment. In the marine bivalve Mytilus the natural estrogen 17beta-estradiol (E2) and different EDCs have been recently demonstrated to affect the function of the immune cells, the hemocytes. The effects were Tamoxifen-sensitive and were mediated by rapid modulation of kinase-mediated transduction pathways. In this work we compared the in vitro effects of individual estrogenic chemicals (E2, EE: 17alpha-ethynyl estradiol; MES: mestranol; NP: nonylphenol; NP1EC: nonylphenol monoethoxylate carboxylate; BPA: bisphenol A; BP: benzophenone) on hemocyte parameters: lysosomal membrane stability (LMS), phagocytosis, lysozyme release. LMS was the most sensitive effect parameter, showing a decreasing trend at increasing concentrations of estrogens. EC50 values obtained from LMS data were utilized to calculate the estradiol equivalency factor (EEF) for each compound; these EEFs allowed for an estimation of the estrogenic potential of a synthetic mixture with a composition very similar to that previously found in waters of the Venice lagoon. Concentrated mixtures significantly affected hemocyte parameters in vitro and the effects were prevented by Tamoxifen. Significant effects of the mixture were also observed in vivo, at longer exposure times and at concentrations comparable with environmental exposure levels. The results indicate that Mytilus immune parameters can be suitably utilized to evaluate the estrogenic potential of environmental samples.

  8. Body size in relation to urinary estrogens and estrogen metabolites (EM) among premenopausal women during the luteal phase. (United States)

    Xie, Jing; Eliassen, A Heather; Xu, Xia; Matthews, Charles E; Hankinson, Susan E; Ziegler, Regina G; Tworoger, Shelley S


    Estrogen metabolism profiles may play an important role in the relationship between body size and breast carcinogenesis. Previously, we observed inverse associations between current body mass index (BMI) and plasma levels of parent estrogens (estrone and estradiol) among premenopausal women during both follicular and luteal phases. Using data from the Nurses' Health Study II, we assessed whether height, current BMI, and BMI at age 18 were associated with the urinary concentrations of 15 estrogens and estrogen metabolites (jointly referred to as EM) measured during the luteal phase among 603 premenopausal women. We observed inverse associations with total EM for height (P (trend) = 0.01) and current BMI (P (trend) = 0.01), but not BMI at age 18 (P (trend) = 0.26). Six EMs were 18-27% lower in women with a height 68+ versus ≤62 in., primarily in the methylated catechol pathway (P (trend) = 0.04). Eight EMs were 18-50% lower in women with a BMI of 30+ versus estrogen metabolism profiles in premenopausal women. Further studies with timed urine and blood collections are required to confirm and extend our findings.

  9. Estrogenic activity of the dichloromethane extract from Pueraria mirifica. (United States)

    Sookvanichsilp, N; Soonthornchareonnon, N; Boonleang, C


    Pueraria mirifica and its extracts are widely used as the ingredient(s) in many rejuvenating products. Up to now, the extract of P. mirifica roots that has been used in most studies, is the alcoholic extract. In the present study, we investigated the estrogenic activity using uterotropic and MCF-7 cell proliferation models of the dichloromethane extract as well as the water extract which was obtained from partitioning the ethanolic extract. The results indicated that among the three extracts, i.e. the ethanolic extract (PM1), the water extract (PM2) and dichloromethane extract (PM3), PM3 exhibited the most potent estrogenic activity in both models, followed by PM1. The extracts produced uterotropic activity associated with the increase of water content while uterotropic activity of 17beta-estradiol was related to the increase of muscle mass. The two isoflavonoids, genistein and daidzein, were not the major active phytoestrogens involving the estrogenic activity of these extracts.

  10. Weak estrogenic transcriptional activities of Bisphenol A and Bisphenol S. (United States)

    Grignard, Elise; Lapenna, Silvia; Bremer, Susanne


    In 2011, the European Commission has restricted the use of Bisphenol A in plastic infant feeding bottles. In a response to this restriction, Bisphenol S is now often used as a component of plastic substitutes for the production of babybottles. One of the major concerns leading to the restriction of Bisphenol A was its weak estrogenic activity. By using two highly standardised transactivation assays, we could demonstrate that the estrogenic activity of Bisphenol A and Bisphenol S is of a comparable potency. Furthermore, some insights about the structure-activity relationships of these two chemicals and their metabolites could be gained from in silico predictions of their relative estrogen receptor-binding affinities and their liver phase-I biotransformation.

  11. Bisphenol A in dental sealants and its estrogen like effect

    Directory of Open Access Journals (Sweden)

    Manu Rathee


    Full Text Available Bisphenol A or BPA-based epoxy resins are widely used in the manufacture of commercial products, including dental resins, polycarbonate plastics, and the inner coating of food cans. BPA is a precursor to the resin monomer Bis-GMA. During the manufacturing process of Bis-GMA dental sealants, Bisphenol A (BPA might be present as an impurity or as a degradation product of Bis-DMA through esterases present in saliva. Leaching of these monomers from resins can occur during the initial setting period and in conjunction with fluid sorption and desorption over time and this chemical leach from dental sealants may be bioactive. Researchers found an estrogenic effect with BPA, Bis-DMA, and Bis-GMA because BPA lacks structural specificity as a natural ligand to the estrogen receptor. It generated considerable concern regarding the safety of dental resin materials. This review focuses on the BPA in dental sealants and its estrogen-like effect.

  12. Estrogenicity of phytosterols evaluated in vitro and in vivo. (United States)

    Nakari, Tarja


    The estrogenic activity of two phytosterol preparations was evaluated in vitro and in vivo. For the in vitro evaluation, freshly separated hepatocytes of rainbow trout were used. By contrast, the in vivo evaluation was performed by injecting the phytosterols intraperitoneally into juvenile rainbow trout. Both assays confirmed the estrogenic activity of the phytosterols. The in vitro screening technique, based on the synthesis and secretion of vitellogenin from the isolated liver cells, produced a clear, significant curve in response to the presence of both phytosterol mixtures. In the in vivo tests, the phytosterol preparations caused significant increases in plasma vitellogenin concentrations of juvenile fish. These shortterm assays proved to be suitable for assessing the estrogenic activity of phytosterols.

  13. Estrogens induce expression of membrane-associated estrogen receptor α isoforms in lactotropes.

    Directory of Open Access Journals (Sweden)

    Sandra Zárate

    Full Text Available Estrogens are key to anterior pituitary function, stimulating hormone release and controlling cell fate to achieve pituitary dynamic adaptation to changing physiological conditions. In addition to their classical mechanism of action through intracellular estrogen receptors (ERs, estrogens exert rapid actions via cell membrane-localized ERs (mERs. We previously showed that E2 exerts a rapid pro-apoptotic action in anterior pituitary cells, especially in lactotropes and somatotropes, through activation of mERs. In the present study, we examined the involvement of mERα in the rapid pro-apoptotic action of estradiol by TUNEL in primary cultures of anterior pituitary cells from ovariectomized rats using a cell-impermeable E2 conjugate (E2-BSA and an ERα selective antagonist (MPP dihydrochloride. We studied mERα expression during the estrous cycle and its regulation by gonadal steroids in vivo by flow cytometry. We identified ERα variants in the plasma membrane of anterior pituitary cells during the estrous cycle and studied E2 regulation of these mERα variants in vitro by surface biotinylation and Western Blot. E2-BSA-induced apoptosis was abrogated by MPP in total anterior pituitary cells and lactotropes. In cycling rats, we detected a higher number of lactotropes and a lower number of somatotropes expressing mERα at proestrus than at diestrus. Acute E2 treatment increased the percentage of mERα-expressing lactotropes whereas it decreased the percentage of mERα-expressing somatotropes. We detected three mERα isoforms of 66, 39 and 22 kDa. Expression of mERα66 and mERα39 was higher at proestrus than at diestrus, and short-term E2 incubation increased expression of these two mERα variants. Our results indicate that the rapid apoptotic action exerted by E2 in lactotropes depends on mERα, probably full-length ERα and/or a 39 kDa ERα variant. Expression and activation of mERα variants in lactotropes could be one of the mechanisms through

  14. Role of estrogen receptors (ERs and G protein-coupled estrogen receptor (GPER in regulation of hypothalamic-pituitary-testis axis and spermatogenesis

    Directory of Open Access Journals (Sweden)

    Adele eChimento


    Full Text Available Male reproductive function is under the control of both gonadotropins and androgens through a negative feedback loop that involves the hypothalamus, pituitary and testis known as hypothalamus-pituitary-gonadal axis (HPG. Indeed, also estrogens play an important role in regulating HPG axis but the relative contribution to the inhibition of gonadotropins secretion exerted by the amount of estrogens produced within the hypothalamus and/or the pituitary or by the amount of circulating estrogens are still ongoing. Moreover, it is known that maintenance of spermatogenesis is controlled by gonadotrophins and testosterone, the effects of which are modulated by a complex network of locally produced factors, including estrogens. Physiological effects of estrogens are mediated by the classical nuclear estrogen receptor alpha (ESR1 and estrogen receptor beta (ESR2, which mediate both genomic and rapid signaling events. In addition, estrogens induce rapid non-genomic responses through a membrane-associated G protein-coupled receptor (GPER. Ours and other studies reported that, in the testis, GPER is expressed in both normal germ cells and somatic cells and it is involved in mediating the estrogen action in spermatogenesis controlling proliferative and/or apoptotic events. Interestingly, GPER expression has been revealed also in hypothalamus and in pituitary. However, its role in mediating estrogen rapid actions in this context is under investigation. Recent studies indicate that GPER is involved in modulating GnRH release as well as gonadotropins secretion. In this review, we will summarize the current knowledge concerning the role of estrogen/estrogen receptors (ERs molecular pathways in regulating GnRH, FSH and LH release at hypothalamic and pituitary level in male as well as in controlling specific testicular functions such as spermatogenesis, focusing our attention mainly on estrogen signaling mediated by GPER.

  15. Rigorous simulations of emitting and non-emitting nano-optical structures

    NARCIS (Netherlands)

    Janssen, O.T.A.


    In the next decade, several applications of nanotechnology will change our lives. LED lighting is about to replace the common light bulb. The main advantages are its energy efficiency and long lifetime. LEDs can be much more efficient, when part of the emitted light that is currently trapped in the

  16. White organic light-emitting diodes with an ultra-thin premixed emitting layer

    CERN Document Server

    Jeon, T; Tondelier, Denis; Bonnassieux, Yvan; Forget, Sebastien; Chenais, Sebastien; Ishow, Elena


    We described an approach to achieve fine color control of fluorescent White Organic Light-Emitting Diodes (OLED), based on an Ultra-thin Premixed emitting Layer (UPL). The UPL consists of a mixture of two dyes (red-emitting 4-di(4'-tert-butylbiphenyl-4-yl)amino-4'-dicyanovinylbenzene or fvin and green-emitting 4-di(4'-tert-butylbiphenyl-4-yl)aminobenzaldehyde or fcho) premixed in a single evaporation cell: since these two molecules have comparable structures and similar melting temperatures, a blend can be evaporated, giving rise to thin films of identical and reproducible composition compared to those of the pre-mixture. The principle of fine color tuning is demonstrated by evaporating a 1-nm-thick layer of this blend within the hole-transport layer (4,4'-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (\\alpha-NPB)) of a standard fluorescent OLED structure. Upon playing on the position of the UPL inside the hole-transport layer, as well as on the premix composition, two independent parameters are available to finel...

  17. Bone marrow oxytocin mediates the anabolic action of estrogen on the skeleton (United States)

    Estrogen withdrawal in women due to natural or artificial menopause is followed by rapid bone loss, osteoporosis, and a high fracture risk. Replacement with estrogen prevents this bone loss and reduces the risk of fracture. Estrogen uses two mechanisms to exert this effect: it inhibits bone resorpti...

  18. Detection of estrogenic activity in sediment-associated compounds using in vitro reporter gene assays

    NARCIS (Netherlands)

    Legler, J.; Dennekamp, M.; Vethaak, A.D.; Brouwer, A.; Koeman, J.H.; Burg, van der B.; Murk, A.J.


    Sediments may be the ultimate sink for persistent (xeno-) estrogenic compounds released into the aquatic environment. Sediment-associated estrogenic potency was measured with an estrogen receptor-mediated luciferase reporter gene (ER-CALUX) assay and compared with a recombinant yeast screen. The ER-

  19. Detection of estrogenic potency in wastewater and surface water with three in vitro bioassays

    NARCIS (Netherlands)

    Murk, A.J.; Legler, J.; Lipzig, van M.M.H.; Meerman, J.H.N.; Belfroid, A.C.; Spenkelink, A.; Burg, van der B.; Rijs, G.B.J.; Vethaak, D.


    A study was performed to optimize sample preparation and application of three in vitro assays for measuring estrogenic potency in environmental extracts. The three assays applied were an estrogen receptor (ER)-binding assay and two reporter gene effect assays: a yeast estrogen screen (YES) and the E

  20. Oral and transdermal estrogens both lower plasma total homocysteine in male-to-female transsexuals

    NARCIS (Netherlands)

    Giltay, E.J.; Verhoef, P.; Gooren, L.J.G.; Geleijnse, J.M.; Schouten, E.G.; Stehouwer, C.D.A.


    Plasma total homocysteine (tHcy) levels are on average lower in women versus men, indicating an estrogenic effect. Oral estrogens (absorbed via the liver) may be hypothesized to have stronger effects on hepatic homocysteine metabolism than transdermal estrogens. We randomly assigned 30 male-to-femal

  1. Estrogen metabolizing enzymes : biomarkers of exposure, effect and susceptibility for carcinogenesis

    NARCIS (Netherlands)

    Duursen, Majorie Beatrix Maria van


    In the etiology of breast cancer, estrogens and its metabolites play a key role as tumor initiators and promoters. Co-expression of estrogen synthesizing enzymes (aromatase and steroid sulfatase) and estrogen metabolizing enzymes (CYP1A1 and CYP1B1) in breast tissue makes it plausible that locally f

  2. Aromatase, estrogen receptors and brain development in fish and amphibians. (United States)

    Coumailleau, Pascal; Pellegrini, Elisabeth; Adrio, Fátima; Diotel, Nicolas; Cano-Nicolau, Joel; Nasri, Ahmed; Vaillant, Colette; Kah, Olivier


    Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  3. Rapid actions of xenoestrogens disrupt normal estrogenic signaling. (United States)

    Watson, Cheryl S; Hu, Guangzhen; Paulucci-Holthauzen, Adriana A


    Some chemicals used in consumer products or manufacturing (e.g. plastics, surfactants, pesticides, resins) have estrogenic activities; these xenoestrogens (XEs) chemically resemble physiological estrogens and are one of the major categories of synthesized compounds that disrupt endocrine actions. Potent rapid actions of XEs via nongenomic mechanisms contribute significantly to their disruptive effects on functional endpoints (e.g. cell proliferation/death, transport, peptide release). Membrane-initiated hormonal signaling in our pituitary cell model is predominantly driven by mERα with mERβ and GPR30 participation. We visualized ERα on plasma membranes using many techniques in the past (impeded ligands, antibodies to ERα) and now add observations of epitope proximity with other membrane signaling proteins. We have demonstrated a range of rapid signals/protein activations by XEs including: calcium channels, cAMP/PKA, MAPKs, G proteins, caspases, and transcription factors. XEs can cause disruptions of the oscillating temporal patterns of nongenomic signaling elicited by endogenous estrogens. Concentration effects of XEs are nonmonotonic (a trait shared with natural hormones), making it difficult to design efficient (single concentration) toxicology tests to monitor their harmful effects. A plastics monomer, bisphenol A, modified by waste treatment (chlorination) and other processes causes dephosphorylation of extracellular-regulated kinases, in contrast to having no effects as it does in genomic signaling. Mixtures of XEs, commonly found in contaminated environments, disrupt the signaling actions of physiological estrogens even more severely than do single XEs. Understanding the features of XEs that drive these disruptive mechanisms will allow us to redesign useful chemicals that exclude estrogenic or anti-estrogenic activities.

  4. 环境雌激素在环境中的迁移转化研究%Transport and Transformation of Environmental Estrogens in the Environment

    Institute of Scientific and Technical Information of China (English)

    马晶晶; 徐继润


    近年来,环境内分泌干扰物在各种环境介质中的普遍存在引起了全世界的关注.该类物质具有亲脂性、生物积累性和毒性,对生态环境和人类健康具有潜在的威胁.其中,通过自然过程和人为排放进入环境的天然和合成雌激素物质(环境雌激素)是研究的重点.结合近期国内外环境雌激素的研究成果,综述了这类物质进入环境后发生的吸附/解吸、光降解和生物降解等环境行为,着重分析了这些环境行为的机制.最后,在目前环境雌激素研究工作的基础上,对未来工作进行了展望.%Environmental endocrine disrupting chemicals are of great concern worldwide due to their existence in different environment mediums.Because of their lipotropy,bioaccumulation and toxicity,these chemicals present a potential threat to ecosystem and human health.This research focuses on the natural and synthetic estrogenic substances (environmental estrogens) which have been either emitted to the environment through natural processes or other human pathways.Based on recent research results worldwide,this paper reviews adsorption / desorption,photodegradation,biodegradation and other environemntal behaviors of environmental estrogens,analyzed mechanisum of these environmental behavior..Finally,based on the current studies on environmental estrogen,the prospocts of future work have been considered in this paper.

  5. Effect of diet on fecal and urinary estrogenic activity. (United States)

    Tucker, H A; Knowlton, K F; Meyer, M T; Khunjar, W O; Love, N G


    The United States Environmental Protection Agency has identified estrogens from animal feeding operations as a major environmental concern, but few data are available to quantify the excretion of estrogenic compounds by dairy cattle. The objectives of this study were to quantify variation in estrogenic activity in feces and urine due to increased dietary inclusion of phytoestrogens. Ten Holstein heifers were assigned to 2 groups balanced for age and days pregnant; groups were randomly assigned to treatment sequence in a 2-period crossover design. Dietary treatments consisted of grass hay or red clover hay, and necessary supplements. Total collection allowed for sampling of feed refusals, feces, and urine during the last 4 d of each period. Feces and urine samples were pooled by heifer and period, and base extracts were analyzed for estrogenic activity (estrogen equivalents) using the yeast estrogen screen bioassay. Feces and urine samples collected from 5 heifers were extracted and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify excretion of 7 phytoestrogenic compounds. Excretion of 17-beta estradiol equivalents in urine was higher and tended to be higher in feces for heifers fed red clover hay (84.4 and 120.2 mg/d for feces and urine, respectively) compared with those fed grass hay (57.4 and 35.6 mg/d). Analysis by LC-MS/MS indicated greater fecal excretion of equol, genistein, daidzein, coumestrol, and formononetin by heifers fed red clover hay (1634, 29.9, 96.3, 27.8, and 163 mg/d, respectively) than heifers fed grass hay (340, 3.0, 46.2, 8.8, and 18.3 mg/d, respectively). Diet had no effect on fecal biochanin A or 2-carbethoxy-5, 7-dihydroxy-4'-methoxyisoflavone. Four phytoestrogens were detected in urine (2-carbethoxy-5, 7-dihydroxy-4'-methoxyisoflavone, daidzein, equol, and formononetin) and their excretion was not affected by diet. Identifying sources of variation in estrogenic activity of manure will aid in the


    Directory of Open Access Journals (Sweden)

    Putu Andrika Kusuma


    Full Text Available Depression led to the decline quality of life. With more incidence in women due tohormonal cycle caused women more susceptible to depression. Hormone that fluctuatesand holds a key role in brain and nerve cells is estrogen. Estrogen in premenopausalwomen already decreases. Treatment of depression in premenopausal women who gopast the various considerations needs to consider the provision of hormonal therapy. Inthe case of patients treated with psychotherapy and pharmacotherapy in the form of 2 x20 mg Fluoxetine by mouth and hormonal therapy in the form of 1 x 2 mg Estradiol.Feasibility study to evaluate the hormonal therapy contraindications such as breastcancer also needs to be done.

  7. Keto-enol tautomerism in estrogen hormone. A theoretical study (United States)

    Jameh-Bozorghi, Saeed; Shirani, Hossein; Ghaempanah, Aram; Ghapanvari, Hamed


    The HF/6-311+G** calculation was used to investigate Keto-Enol tautomerism of Estrogen Hormone. Molecular geometries of keto, enol and transition state of this reaction were optimized and NBO calculations were performed. These calculation results showed that activation energy (Ea) of Keto-Enol tautomerization of Estrogen is 118.65 Kcal mol-1. Energetic study at B3LYP/6-311+G** level of theory revealed that keto tautomer is more stable structure. NBO analysis results have a good agreements with optimized geometries and experimental data.

  8. A helminth cestode parasite express an estrogen-binding protein resembling a classic nuclear estrogen receptor. (United States)

    Ibarra-Coronado, Elizabeth Guadalupe; Escobedo, Galileo; Nava-Castro, Karen; Jesús Ramses, Chávez-Rios; Hernández-Bello, Romel; García-Varela, Martìn; Ambrosio, Javier R; Reynoso-Ducoing, Olivia; Fonseca-Liñán, Rocío; Ortega-Pierres, Guadalupe; Pavón, Lenin; Hernández, María Eugenia; Morales-Montor, Jorge


    The role of an estrogen-binding protein similar to a known mammalian estrogen receptor (ER) is described in the estradiol-dependent reproduction of the helminth parasite Taenia crassiceps. Previous results have shown that 17-β-estradiol induces a concentration-dependent increase in bud number of in vitro cultured cysticerci. This effect is inhibited when parasites are also incubated in the presence of an ER binding-inhibitor (tamoxifen). RT-PCR assays using specific oligonucleotides of the most conserved ER sequences, showed expression by the parasite of a mRNA band of molecular weight and sequence corresponding to an ER. Western blot assays revealed reactivity with a 66 kDa protein corresponding to the parasite ER protein. Tamoxifen treatment strongly reduced the production of the T. crassiceps ER-like protein. Antibody specificity was demonstrated by immunoprecipitating the total parasite protein extract with anti-ER-antibodies. Cross-contamination by host cells was discarded by flow cytometry analysis. ER was specifically detected on cells expressing paramyosin, a specific helminth cell marker. Parasite cells expressing the ER-like protein were located by confocal microscopy in the subtegumental tissue exclusively. Analysis of the ER-like protein by bidimensional electrophoresis and immunoblot identified a specific protein of molecular weight and isoelectric point similar to a vertebrates ER. Sequencing of the spot produced a small fragment of protein similar to the mammalian nuclear ER. Together these results show that T. crassiceps expresses an ER-like protein which activates the budding of T. crassiceps cysticerci in vitro. To the best of our knowledge, this is the first report of an ER-like protein in parasites. This finding may have strong implications in the fields of host-parasite co-evolution as well as in sex-associated susceptibility to this infection, and could be an important target for the design of new drugs.

  9. Bazedoxifene/conjugated estrogens for managing the burden of estrogen deficiency symptoms. (United States)

    Mirkin, Sebastian; Ryan, Kelly A; Chandran, Arthi B; Komm, Barry S


    The bothersome vasomotor and vaginal symptoms and bone loss that accompany the menopausal transition are associated with significant direct costs due to physician visits and medication, as well as indirect costs from reduced health-related quality of life (HRQoL) and work productivity. With life expectancies increasing, the number of postmenopausal women is also increasing, and more women are remaining in the workforce. These factors have led to an increased burden of menopausal symptoms on healthcare systems. Hormone therapy (HT) has been shown to effectively reduce menopausal symptoms and significantly increase quality-adjusted life years in postmenopausal women, particularly in women experiencing severe symptoms. However, many women discontinue use of HT before their symptoms have dissipated due to safety and tolerability concerns. The tissue selective estrogen complex (TSEC) that pairs bazedoxifene (BZA) with conjugated estrogens (CE) has been developed to provide relief of menopausal symptoms and prevent bone loss without stimulating the breast or endometrium, and to have improved tolerability compared with HT. In this context, BZA 20mg/CE 0.45 and 0.625 mg were shown to prevent bone loss and effectively treat menopausal symptoms in postmenopausal women with an intact uterus, while also demonstrating a favorable safety/tolerability profile. BZA 20mg/CE 0.45 and 0.625 mg were further associated with clinically significant improvements in HRQoL, sleep, and treatment satisfaction. Taken together, the reduction in menopausal symptoms, improvement in HRQoL, and favorable safety/tolerability profile associated with BZA/CE suggest that it is a cost-effective alternative to HT for managing the burden of menopausal symptoms.

  10. Effect of estrogen withdrawal on energy-rich phosphates and prediction of estrogen dependence monitored by in vivo 31P magnetic resonance spectroscopy of four human breast cancer xenografts

    DEFF Research Database (Denmark)

    Kristensen, C A; Kristjansen, P E; Brünner, N


    The effect of estrogen withdrawal on energy metabolism was studied in four human breast cancer xenografts: the estrogen-dependent MCF-7 and ZR75-1 and the estrogen-independent ZR75/LCC-3 and MDA-MB-231. The tumors were grown in ovariectomized nude mice with a s.c. implanted estrogen pellet. After...

  11. The Expression of Estrogen Receptor is Dependent on the Estrogen Level and Associated with Cholesterol-Rich Diet in Female Rat's Heart and Vascular Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    吴赛珠; 刘建国; 周可祥; 刘长青; 马瑞; 孙飞; 隗和明


    Objective To study the effects of estrogen level and cholesterol - rich diet on the ex-pression of estrogen receptor (ER) in cardiovasculartissues including vascular endothelial cells (VEC) offemale rats. Methods The receptor binding assay(RBA) was adopted to measure the estrogen receptorlevel in aortic wall, heart and vascular endothelialcells of female rats on a cholesterol- rich diet. A ra-dioimmunoassay was employed to measure the level ofserum estradiol. Results The number of ER signif-icantly decreased in hearts, aorta and vascular en-dothelial cells in the ovariectomized rats and the ratson a cholesterol- rich diet. In contrast, the adminis-tration of estrogen somewhat restored the expression ofER. Conclusions For female rats, the level of es-trogen affects the expression of ER in cardiovascularsystem. The number of ER decreases along with thedecrease in the level of estrogen. A cholesterol -richdiet also can decrease the expression of ER in cardio-vascular system of female rats.

  12. Immunolocalization of aromatase, estrogen and estrogen receptor α and β in the epithelium of digestive tract and enteric neurons of amphioxus (Branchiostoma belcheri )

    Institute of Scientific and Technical Information of China (English)

    FANG Yongqiang; WENG Youzhu; YE Rongzhong; LIU Lili


    Immunohistochemical localization of aromatase, estrogen and estrogen receptor in the digestive tract and enteric neurons of amphioxus is investigated. It was found that immunoreactive proteins of aromatase, estrogen and ER-α and β are expressed in hepatic diverticulum, epithelial cells of anterior and posterior region of midgut, as well as in enteric neurons, while hindgut showed immunonegative. The results suggest that digestive tract of amphioxus may be able to synthesize estrogen and possess endocrine function, like rat gastric epithelium and enteric neurons in mammals. The present study provides authentic morphological evidence for explaining the action mechanism of estrogen in regulating the digestive function of gut and the functional evolution of estrogen, which has important theoretical significance in amphioxus.

  13. Light-emitting diodes for analytical chemistry. (United States)

    Macka, Mirek; Piasecki, Tomasz; Dasgupta, Purnendu K


    Light-emitting diodes (LEDs) are playing increasingly important roles in analytical chemistry, from the final analysis stage to photoreactors for analyte conversion to actual fabrication of and incorporation in microdevices for analytical use. The extremely fast turn-on/off rates of LEDs have made possible simple approaches to fluorescence lifetime measurement. Although they are increasingly being used as detectors, their wavelength selectivity as detectors has rarely been exploited. From their first proposed use for absorbance measurement in 1970, LEDs have been used in analytical chemistry in too many ways to make a comprehensive review possible. Hence, we critically review here the more recent literature on their use in optical detection and measurement systems. Cloudy as our crystal ball may be, we express our views on the future applications of LEDs in analytical chemistry: The horizon will certainly become wider as LEDs in the deep UV with sufficient intensity become available.

  14. Plasmonic Structures for Sensing and Emitting Devices (United States)

    Floris, Francesco; Fornasari, Lucia; Patrini, Maddalena; Figus, Cristiana; Mura, Andrea; Bongiovanni, Giovanni; Quochi, Francesco; Pellacani, Paola; Valsesia, Andrea; Marabelli, Franco


    We report on the study of a plasmonic nanostructure that could be adopted as platform for emitting and sensing applications. Several devices have been prepared and characterized by atomic force microscopy (AFM) and Fourier transform micro-reflectance (FT- pR) techniques. In addition, a modelling via finite-difference time-domain (FDTD) simulations have been developed in order to interpret the morphological shape and the optical response of the considered structures. Until now, remarkable performances as surface plasmon resonance (SPR) based optical sensor have been founded. Moreover, we are performing preliminary trials in order to establish a coupling between photoluminescence (PL) features of suitable emitters with respect to the plasmonic resonances.

  15. Near infrared polymer light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong; YANG Jian; HOU Qiong; MO Yueqi; PENG Junbiao; CAO Yong


    High efficiency of near infrared polymer light-emitting diodes with bilayer structure was obtained. The diode structure is ITO/PEDOT/L1/L2/Ba/Al, where L1 is phenyl-substituted poly [p-phenylphenylene vinylene] derivative (P-PPV), L2 is 9,9-dioctylfluorene (DOF) and 4,7- bis(3-hexylthiophen)-2-yl-2,1,3-naphthothiadiazole (HDNT) copolymer (PFHDNT10). The electroluminescence (EL) spectrum of diodes from PFHDNT10 is at 750 nm located in the range of near infrared. The maximum external quantum efficiency is up to 2.1% at the current density of 35 mA/cm2. The improvement of the diode's performances was considered to be the irradiative excitons confined in the interface between L1 and L2 layers.

  16. Recycling technology of emitted carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Hironori [National Inst. of Materials and Chemical Research (NIMC), Ibaraki (Japan)


    Ways to halt global warming are being discussed worldwide. Global warming is an energy problem which is mainly attributed to the large volumes of carbon dioxide (CO{sub 2}) released into the atmosphere from the rapid increase in energy consumption since the Industrial Revolution. The basic solution to the problem, therefore, is to cut consumption of fossil fuels. To this end, it is important to promote energy conservation by improving the fuel efficiency of machines, as well as shift to energy sources that do not emit carbon dioxide and develop related technologies. If current trends in economic growth continue in the devloping world as well as the developed countries, there can be no doubt that energy consumption will increase. Therefore, alongside energy conservation and the development of alternative energies, the importance of technologies to recover and fix CO{sub 2} will increase in the fight against global warming.

  17. Logarithmic current electrometer using light emitting diodes (United States)

    Acharya, Y. B.; Aggarwal, A. K.


    The limit of low current measurement using logarithmic current to voltage converter is improved by 6 - 7 orders of magnitude with the use of diodes of large band gap as compared with silicon diodes. Low cost commercially available light emitting diodes (LEDs) have been used for this purpose. A theoretical study and experimental measurement of device constant and reverse saturation currents of the whole class of commercially available LEDs has been carried out. A circuit has been developed which makes use of a new technique for temperature compensation and its performance is compared with the technique in common use. The performance of the amplifier is found to be stable in the temperature range 5 - 600957-0233/7/2/005/img5 for both polarity of signals from 0957-0233/7/2/005/img6 to 0957-0233/7/2/005/img7 A.

  18. SUMER: Solar Ultraviolet Measurements of Emitted Radiation (United States)

    Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, M. C. E.; Lemaire, P.; Marsch, E.; Poland, A. I.


    The SUMER (solar ultraviolet measurements of emitted radiation) experiment is described. It will study flows, turbulent motions, waves, temperatures and densities of the plasma in the upper atmosphere of the Sun. Structures and events associated with solar magnetic activity will be observed on various spatial and temporal scales. This will contribute to the understanding of coronal heating processes and the solar wind expansion. The instrument will take images of the Sun in EUV (extreme ultra violet) light with high resolution in space, wavelength and time. The spatial resolution and spectral resolving power of the instrument are described. Spectral shifts can be determined with subpixel accuracy. The wavelength range extends from 500 to 1600 angstroms. The integration time can be as short as one second. Line profiles, shifts and broadenings are studied. Ratios of temperature and density sensitive EUV emission lines are established.

  19. Estrogen-Mediated Upregulation of Noxa Is Associated with Cell Cycle Progression in Estrogen Receptor-Positive Breast Cancer Cells



    Noxa is a Bcl-2-homology domain (BH3)-only protein reported to be a proapoptotic member of the Bcl-2 family. Estrogen has been well documented to stimulate cell growth and inhibit apoptosis in estrogen receptor (ER)-positive breast cancer cells. Intriguingly, recent reports have shown that 17β-estradiol (E2) induces Noxa expression, although the mechanisms underlying E2-mediated induction of Noxa and its functional significance are unknown. Using MCF7 human breast cancer cells as an experimen...

  20. [Comparative study of the estrogenic activity of modified estrogens based on data of competitive binding analysis and biological assay]. (United States)

    Pokrovskaia, E V; Ivanenko, T I


    A series of bromo- and silyl-derivatives was studied in experiments on immature female rats in vivo and in vitro. All the estrogens studied were conventionally divided into 4 groups according to their ability for concurrent binding with the rat uterus cytosol receptors and their specific bioeffect: equally concurrent and bioeffective compounds (estrone, ethynyl estradiol); slightly concurrent substances with a pronounced uterotropic action (4-silyl estrogens, mestranol); little effective compounds with 4 to 8% of estradiol concurrent activity (2- and 4-bromo-and silyl estradiols, estriol); compounds, not having concurrent and biological effects (2-silyl estrones, 4-bromoestradiol diacetate).

  1. An Estrogen Model: The Relationship between Body Mass Index, Menopausal Status, Estrogen Replacement Therapy, and Breast Cancer Risk

    Directory of Open Access Journals (Sweden)

    Linda E. Green


    (kg/m2 for premenopausal women and an increase in the relative risk of 4% per unit increase in BMI for postmenopausal women who are not HRT users. When comparing postmenopausal women who use estrogen-only HRT to postmenopausal women who do not use HRT, the model predicts an increased risk of breast cancer associated with use of estrogen that diminishes with increasing BMI, with a relative risk of 1.6 for women with BMI of 18, 1.2 for women with BMI of 25, and 1.0 for women with BMI≥30. Model predictions agree with data from five major epidemiological studies.

  2. White and Red Organic Light Emitting Materials

    Institute of Scientific and Technical Information of China (English)

    CHOW Tahsin J.; CHIU Ching-Wen; TSAI Mu-Lin


    Derivatives of 2,3-(1,4-dialkoxyaceno)norbornadiene underwent ring-opening metathesis polymerization (ROMP) upon the catalysis of a ruthenium complex to afford the corresponding polymers. The polymeric materials containing anthracene chromophores emit white electro-luminescence, which can be fabricated into light-emitting diodes (LED). The broad emission band is composed of a blue emission from anthracene and a red emission from aggregates. A single layer device, ITO/polymer/Ca/Al, can be turned on at 7V and exhibits maximum intensity 427 cd/m2 at 15 V. A double layer device, ITO/polymer/TPBI/Mg:Ag (TPBI = (2,2′,2"-(1,3,5-benzenetriyl)-tris(1-phenyl-1H-benzimidazole)) displayed blue light with turn-on voltage 6 V and maximal intensity 930 cd/m2 at 15 V.Derivatives of bisindolylmaleimide were found to form amorphous solid films which exhibit intensive red luminescence. The property of forming glasses can be ascribed to the nonplanar geometry of these molecules. LED devices were fabricated by a layer of pure dye sandwiched between two charge transporting films. The yellow emission spectrum of the devices utilizing Alq (tris(8-hydoxyquinolinato)aluminum) contains a green component from Alq. Pure red emissions can be achieved by replacing Alq with TPBI. Typical devices can be turned on at ~3 V with maximal intensity 2000 cd/m2. White color devices are under current investigation, in which the green Alq layer is replaced by its blue derivative (bis(2-methyl-8-hydoxyquinolinato)(phenolato)aluminum).

  3. Why only some plants emit isoprene. (United States)

    Monson, Russell K; Jones, Ryan T; Rosenstiel, Todd N; Schnitzler, Jörg-Peter


    Isoprene (2-methyl-1,3-butadiene) is emitted from many plants and it appears to have an adaptive role in protecting leaves from abiotic stress. However, only some species emit isoprene. Isoprene emission has appeared and been lost many times independently during the evolution of plants. As an example, our phylogenetic analysis shows that isoprene emission is likely ancestral within the family Fabaceae (= Leguminosae), but that it has been lost at least 16 times and secondarily gained at least 10 times through independent evolutionary events. Within the division Pteridophyta (ferns), we conservatively estimate that isoprene emissions have been gained five times and lost two times through independent evolutionary events. Within the genus Quercus (oaks), isoprene emissions have been lost from one clade, but replaced by a novel type of light-dependent monoterpene emissions that uses the same metabolic pathways and substrates as isoprene emissions. This novel type of monoterpene emissions has appeared at least twice independently within Quercus, and has been lost from 9% of the individuals within a single population of Quercus suber. Gain and loss of gene function for isoprene synthase is possible through relatively few mutations. Thus, this trait appears frequently in lineages; but, once it appears, the time available for evolutionary radiation into environments that select for the trait is short relative to the time required for mutations capable of producing a non-functional isoprene synthase gene. The high frequency of gains and losses of the trait and its heterogeneous taxonomic distribution in plants may be explained by the relatively few mutations necessary to produce or lose the isoprene synthase gene combined with the assumption that isoprene emission is advantageous in a narrow range of environments and phenotypes.

  4. Select estrogens within the complex formulation of conjugated equine estrogens (Premarin® are protective against neurodegenerative insults: implications for a composition of estrogen therapy to promote neuronal function and prevent Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Brinton Roberta


    Full Text Available Abstract Background Results of the Women's Health Initiative Memory Study (WHIMS raised concerns regarding the timing and formulation of hormone interventions. Conjugated equine estrogens (CEE, used as the estrogen therapy in the WHIMS trial, is a complex formulation containing multiple estrogens, including several not secreted by human ovaries, as well as other biologically active steroids. Although the full spectrum of estrogenic components present in CEE has not yet been resolved, 10 estrogens have been identified. In the present study, we sought to determine which estrogenic components, at concentrations commensurate with their plasma levels achieved following a single oral dose of 0.625 mg CEE (the dose used in the WHIMS trial in women, are neuroprotective and whether combinations of those neuroprotective estrogens provide added benefit. Further, we sought, through computer-aided modeling analyses, to investigate the potential correlation of the molecular mechanisms that conferred estrogen neuroprotection with estrogen interactions with the estrogen receptor (ER. Results Cultured basal forebrain neurons were exposed to either β-amyloid25–35 or excitotoxic glutamate with or without pretreatment with estrogens followed by neuroprotection analyses. Three indicators of neuroprotection that rely on different aspects of neuronal damage and viability, LDH release, intracellular ATP level and MTT formazan formation, were used to assess neuroprotective efficacy. Results of these analyses indicate that the estrogens, 17α-estradiol, 17β-estradiol, equilin, 17α-dihydroequilin, equilinen, 17α-dihydroequilenin, 17β-dihydroequilenin, and Δ8,9-dehydroestrone were each significantly neuroprotective in reducing neuronal plasma membrane damage induced by glutamate excitotoxicity. Of these estrogens, 17β-estradiol and Δ8,9-dehydroestrone were effective in protecting neurons against β-amyloid25–35-induced intracellular ATP decline

  5. [A review on current situations of steroid estrogen in the water system]. (United States)

    Du, Shao-ting; Jin, Chong-wei; Liu, Yue


    Steroid estrogens are a group of biologically active endocrine disruptors. An extremely low level of steroid estrogens is sufficient to result in reproduction and behavior disorders, and larval mutation of both human being and animals. The ecological and environmental effects of steroid estrogens should be more direct on organisms in water system as compared with those in other environment systems. Therefore, in this paper we reviewed the physical and chemical properties of some frequently-used steroid estrogens, and their contamination status, origins and transfers in water system, so as to provide a theoretical basis for developing estrogen removal strategies.

  6. Estrogen and its signaling pathway in non-small cell lung cancer(NSCLC)

    Institute of Scientific and Technical Information of China (English)

    Ruitong Xu; Yongqian Shu


    Lung cancer is the most common cancer in the world. It is a highly lethal disease in women and men, and new treatments are urgently needed. Several studies have implicated a role of estrogens and estrogen receptors in lung cancer progression. This review will investigate the biological significance of estrogens in lung cancer cells, the expression and molecular mechanisms of estrogen receptors(ER α and ER β, elucidate the prognostic significance of estrogens and their receptors in lung carcinomas and provide new options for patients afflicted with lung malignancies.

  7. Profile of bazedoxifene/conjugated estrogens for the treatment of estrogen deficiency symptoms and osteoporosis in women at risk of fracture. (United States)

    Rossini, Maurizio; Lello, Stefano; Sblendorio, Ignazio; Viapiana, Ombretta; Fracassi, Elena; Adami, Silvano; Gatti, Davide


    Decreasing levels of estrogens during menopause are associated with reduced bone density and an increased risk of osteoporosis. Many women also experience bothersome vasomotor and vaginal symptoms during the menopausal transition. Results of systematic reviews and meta-analyses of randomized controlled trials have shown that both systemic estrogen therapy or hormone therapy (estrogen combined with a progestin) are useful to prevent bone loss, and they are the most effective treatment for such climacteric symptoms as hot flushes, sweating, vaginal dryness, and dyspareunia. Unfortunately, estrogen therapy and hormone therapy increase the risk of endometrial and breast cancer, respectively. The selective estrogen receptor modulators (SERMs) result in positive estrogenic effects on bone, with no negative effects on the endometrium and breast but do not provide relief from postmenopausal symptoms. The combination of a SERM with estrogen as a tissue selective estrogen complex (TSEC) is a new strategy for the prevention of bone loss and the treatment of climacteric symptoms. This combination is particularly interesting from a clinical point of view, taking into account that estrogen alone did not increase breast cancer risk by the Women's Health Initiative. TSEC is hypothesized to provide the benefits of estrogen-alone therapy, with an improved tolerability profile because the SERM component can make possible the elimination of progestin. The objective of this review was to critically evaluate the evidence from the reports published to date on the use of bazedoxifene (a third-generation SERM) in combination with conjugated estrogens in postmenopausal women. The conclusion is that effectively, the combination of bazedoxifene and conjugated estrogens may be a promising alternative to hormone therapy for the prevention of osteoporosis and the treatment of postmenopausal symptoms in non-hysterectomized postmenopausal women.

  8. Effects of environmental and natural estrogens on vitellogenin production in hepatocytes of the brown frog (Rana temporaria)

    NARCIS (Netherlands)

    Rouhani Rankouhi, T.; Sanderson, J.T.; Holsteijn, van I.; Kooten, van P.; Bosveld, A.T.C.; Berg, van den M.


    The objective of this study was to investigate the ability of the natural estrogens and synthetic estrogens as well as the estrogen mimics to induce estrogen-receptor mediated vitellogenesis in primary hepatocytes of the brown frog (Rana temporaria). Based on EC50 values the following order was dete

  9. Evaluation of the in vitro estrogenicity of emerging bisphenol analogs and their respective estrogenic contributions in municipal sewage sludge in China. (United States)

    Ruan, Ting; Liang, Dong; Song, Shanjun; Song, Maoyong; Wang, Hailin; Jiang, Guibin


    There is a potential risk to the environment from persistent estrogenic compounds in sewage sludge. In this study, eight bisphenols (BPs) were identified in sewage sludge collected from wastewater treatment plants in 15 cities in China. The estrogenic potencies of the eight BPs and the estrogenic activities of sludge samples were evaluated using a bioluminescence yeast estrogen screen (BLYES) assay. All sludge samples elicited considerable estrogenic activity at a range of 2.8-4.7 ng E2 g(-1) dry weight (dw). All BPs exhibited estrogenic activity in the BLYES assay, but there were significant differences between the potency of individual chemicals. Bisphenol AF had the highest activity, followed by tetrachlorobisphenol A, bisphenol F, bisphenol A, bisphenol E, bisphenol S and 2,4-dihydroxybenzophenone. Tetrabromobisphenol A showed weak estrogenic activity at 1×10(4)nM, but significant cytotoxicity above this concentration. The total estradiol equivalency quantities (EEQs) of BPs were in the range of 2.16-49.13 pg E2 g(-1) dw, accounting for 0.05-1.47% of the total EEQs in sewage sludge samples. The results indicate that BPs made a minor contribution to the estrogenic activity of the investigated sewage sludge. Nevertheless, our results suggest that considerable attention should be directed to the estrogenic potentials of emerging organic pollutants because of their widespread use and their potential to persist in the environment.

  10. Estrogenic activity of the phytoestrogens naringenin, 6-(1,1-dimethylallyl)naringenin and 8-prenylnaringenin. (United States)

    Zierau, Oliver; Gester, Sven; Schwab, Pia; Metz, Peter; Kolba, Susanne; Wulf, Marina; Vollmer, Günter


    Chemically synthesized naringenin derivatives, identical to natural occurring compounds, were tested for their estrogenic activity using two independent estrogen screening assays. Using a yeast based estrogen receptor assay, strong estrogenic activities were demonstrated for 6-(1,1-dimethylallyl)naringenin and 8-prenylnaringenin, while the parent compound naringenin did not show recognizable estrogenic activity. In MVLN cells, a bioluminescent MCF-7-derived cell line, the estrogenic activity of 8-prenylnaringenin and 6-(1,1-dimethylallyl)naringenin was detected at concentrations of 10(-6) M and 5 x 10(-6) M respectively. Naringenin demonstrated estrogenic activity but only at a concentration of 10(-5) M. These estrogenic effects are mediated by the ER, as the antiestrogen 4-hydroxytamoxifen inhibited these activities. In summary, this study provides the further confirmation that 8-prenylnaringenin demonstrates high estrogenic activity, and demonstrated for the first time for 6-(1,1-dimethylallyl)naringenin a reasonable high estrogenic activity, while naringenin exhibit low or no estrogenic activity.

  11. Electrochemical estrogen screen method based on the electrochemical behavior of MCF-7 cells. (United States)

    Li, Jinlian; Song, Jia; Bi, Sheng; Zhou, Shi; Cui, Jiwen; Liu, Jiguang; Wu, Dongmei


    It was an urgent task to develop quick, cheap and accurate estrogen screen method for evaluating the estrogen effect of the booming chemicals. In this study, the voltammetric behavior between the estrogen-free and normal fragmented MCF-7 cell suspensions were compared, and the electrochemical signal (about 0.68V attributed by xanthine and guanine) of the estrogen-free fragmented MCF-7 cell suspension was obviously lower than that of the normal one. The electrochemistry detection of ex-secretion purines showed that the ability of ex-secretion purines of cells sharp decreased due to the removing of endogenous estrogen. The results indicated that the electrochemical signal of MCF-7 cells was related to the level of intracellular estrogen. When the level of intracellular estrogen was down-regulated, the concentrations of the xanthine and hypoxanthine decreased, which led to the electrochemical signal of MCF-7 cells fall. Based on the electrochemical signal, the electrochemical estrogen screen method was established. The estrogen effect of estradiol, nonylphenol and bisphenol A was evaluated with the electrochemical method, and the result was accordant with that of MTT assay. The electrochemical estrogen screen method was simple, quickly, cheap, objective, and it exploits a new way for the evaluation of estrogenic effects of chemicals.

  12. Estrogen sulfotransferase/SULT1E1 promotes human adipogenesis. (United States)

    Ihunnah, Chibueze A; Wada, Taira; Philips, Brian J; Ravuri, Sudheer K; Gibbs, Robert B; Kirisci, Levent; Rubin, J Peter; Marra, Kacey G; Xie, Wen


    Estrogen sulfotransferase (EST/SULT1E1) is known to catalyze the sulfoconjugation and deactivation of estrogens. The goal of this study is to determine whether and how EST plays a role in human adipogenesis. By using human primary adipose-derived stem cells (ASCs) and whole-fat tissues from the abdominal subcutaneous fat of obese and nonobese subjects, we showed that the expression of EST was low in preadipocytes but increased upon differentiation. Overexpression and knockdown of EST in ASCs promoted and inhibited differentiation, respectively. The proadipogenic activity of EST in humans was opposite to the antiadipogenic effect of the same enzyme in rodents. Mechanistically, EST promoted adipogenesis by deactivating estrogens. The proadipogenic effect of EST can be recapitulated by using an estrogen receptor (ER) antagonist or ERα knockdown. In contrast, activation of ER in ASCs inhibited adipogenesis by decreasing the recruitment of the adipogenic peroxisome proliferator-activated receptor γ (PPARγ) onto its target gene promoters, whereas ER antagonism increased the recruitment of PPARγ to its target gene promoters. Linear regression analysis revealed a positive correlation between the expression of EST and body mass index (BMI), as well as a negative correlation between ERα expression and BMI. We conclude that EST is a proadipogenic factor which may serve as a druggable target to inhibit the turnover and accumulation of adipocytes in obese patients.

  13. Molecular cloning and characterization of hagfish estrogen receptors. (United States)

    Nishimiya, Osamu; Katsu, Yoshinao; Inagawa, Hiroyuki; Hiramatsu, Naoshi; Todo, Takashi; Hara, Akihiko


    One or more distinct forms of the nuclear estrogen receptor (ER) have been isolated from many vertebrates to date. To better understand the molecular evolution of ERs, we cloned and characterized er cDNAs from the inshore hagfish, Eptatretus burgeri, a modern representative of the most primitive vertebrates, the agnathans. Two er cDNAs, er1 and er2, were isolated from the liver of a reproductive female hagfish. A phylogenetic analysis placed hagfish ER1 into a position prior to the divergence of vertebrate ERs. Conversely, hagfish ER2 was placed at the base of the vertebrate ERβ clade. The tissue distribution patterns of both ER subtype mRNAs appeared to be different, suggesting that each subtype has different physiological roles associated with estrogen actions. An estrogen responsive-luciferase reporter assay using mammalian HEK293 cells was used to functionally characterize these hagfish ERs. Both ER proteins displayed estrogen-dependent activation of transcription. These results clearly demonstrate that the hagfish has two functional ER subtypes.

  14. Estrogenicity and metabolism of prenylated flavonoids and isoflavonoids

    NARCIS (Netherlands)

    Schans, van de M.G.M.


      Binding of (prenylated) flavonoids and isoflavonoids to the human estrogen receptors (hERs) might result in beneficial health effects in vivo. To understand structure-activity relationships of prenylated (iso)flavonoids towards the hERs, prenylated (iso)flavonoids were purified from extracts

  15. Sorption and degradation of estrogen conjugates in agricultural soils (United States)

    The natural estrogenic hormone, 17'-estradiol (E2), can disrupt the endocrine system of some aquatic species at ng/L concentrations. Laboratory studies have shown low potentials for E2 persistence and mobility in the environment due to high degradation and soil retention. However, field studies have...

  16. Membrane Estrogen and HER-2 Receptors in Human Breast Cancer (United States)


    H.R. Nusbaum, N. Razon , R. Kris, I. Lax, H. Soreq, N. Whittle, M.D. Waterfield, A. Ullrich and J. Schlessinger (1985). Amplification, enhanced...estrogen (41) are both known mito - antibodies and then immunoblotting with anti-ER antibod- gens for breast cancer cells. To assess the potential contri

  17. Endogenous estrogen exposure and cardiovascular mortality risk in postmenopausal women.

    NARCIS (Netherlands)

    Kleijn, M.J.J. de; Schouw, Y.T. van der; Verbeek, A.L.M.; Peeters, P.M.; Banga, J.D.; Graaf, Y. van der


    In this study, the authors investigated whether combined information on reproductive factors has additive value to the single reproductive factor age at menopause for assessing endogenous estrogen exposure and cardiovascular mortality risk in postmenopausal women. They conducted a population-based c

  18. Estrogen Receptor Mutants/Variants in Human Breast Cancer. (United States)


    Recherche Louis- Charles Simard, Montreal, Canada. Four nor- mal human breast tissues from reduction mammoplasties of pre- menopausal women were hormone resistance. Cancer Res 1990; 50: 6208-17. 22. Karnik PS, Kulkarni S, Lui XP, Budd GT, Bukowski RM. Estrogen receptor mutations in

  19. Deconjugation of soy isoflavone glucuronides needed for estrogenic activity

    NARCIS (Netherlands)

    Islam, M.A.; Bekele, R.; Berg, van den J.H.J.; Kuswanti, Y.; Thapa, O.; Soltani, S.; Leeuwen, F.X.R.; Rietjens, I.M.C.M.; Murk, A.J.


    Soy isoflavones (SIF) are present in the systemic circulation as conjugated forms of which the estrogenic potency is not yet clear. The present study provides evidence that the major SIF glucuronide metabolites in blood, genistein-7-O-glucuronide (GG) and daidzein-7-O-glucuronide (DG), only become e

  20. [Selective estrogen receptor modulators in treatment of postmenopausal osteoporosis]. (United States)

    Meczekalski, Błazej; Czyzyk, Adam


    Postmenopausal osteoporosis is associated with lack of estrogens, therefore, understandably one of the treatment options in osteoporosis is a group of medicines known as selective estrogen receptor modulators (SERMs). They can act as an estrogen receptor agonist in some tissues, whereas as an antagonist in others. In relation to this antago-antagonistic action, SERMs have a positive effect on bones, the serum lipid profile and the cardio-vascular system. Moreover, they can protect against some estrogen-dependent neoplasm development. The first used SERM was tamoxifen, but due to its negative effect on endometrium it is not indicated in osteoporosis. Raloxifen, which is currently in use, besides the reduction of vertebral fractures risk, has beneficial influence on endometrial and breast neoplasm development risk as well. On the other hand, raloxifen intensifies vasomotor symptoms and its bone-protecting effect is limited. At present, new SERMs (ospemifen, lasofoxifen, bazedoxifen, arzoxifen) are being researched in clinical trials. In the current stage of investigations they reveal beneficial influence on skeletal as well as extraskeletal tissues. Implementation of SERMs in combined therapy of osteoporosis is currently under research as well. SERM with parathormone or SERM with bisphosphonate might prove to be an advantageous treatment option for women with severe or resistant osteoporosis. An addition of SERM to conventional hormonal replacement therapy did not bring the anticipated benefits. Future studies on SERMs may result in new preparations adjusted to individual needs of the patients.

  1. EMAS clinical guide: selective estrogen receptor modulators for postmenopausal osteoporosis. (United States)

    Palacios, Santiago; Brincat, Mark; Erel, C Tamer; Gambacciani, Marco; Lambrinoudaki, Irene; Moen, Mette H; Schenck-Gustafsson, Karin; Tremollieres, Florence; Vujovic, Svetlana; Rees, Margaret; Rozenberg, Serge


    Osteoporosis and the resulting fractures are major public health issues as the world population is ageing. Various therapies such as bisphosphonates, strontium ranelate and more recently denosumab are available. This clinical guide provides the evidence for the clinical use of selective estrogen modulators (SERMs) in the management of osteoporosis in postmenopausal women.

  2. Lifetime estrogen exposure versus age at menopause as mortality predictor

    NARCIS (Netherlands)

    Jansen, S.C.; Temme, E.H.M.; Schouten, E.G.


    Objectives: The aim of this study was to evaluate the relation between lifetime estrogen exposure and mortality and compare this with menopausal age as exposure variable. Methods: We studied a cohort of 1462 naturally postmenopausal women, aged 37–77 at enrolment in the Belgian Interuniversity Resea

  3. Mouse models of estrogen receptor-positive breast cancer

    Directory of Open Access Journals (Sweden)

    Shakur Mohibi


    Full Text Available Breast cancer is the most frequent malignancy and second leading cause of cancer-related deaths among women. Despite advances in genetic and biochemical analyses, the incidence of breast cancer and its associated mortality remain very high. About 60 - 70% of breast cancers are Estrogen Receptor alpha (ER-α positive and are dependent on estrogen for growth. Selective estrogen receptor modulators (SERMs have therefore provided an effective targeted therapy to treat ER-α positive breast cancer patients. Unfortunately, development of resistance to endocrine therapy is frequent and leads to cancer recurrence. Our understanding of molecular mechanisms involved in the development of ER-α positive tumors and their resistance to ER antagonists is currently limited due to lack of experimental models of ER-α positive breast cancer. In most mouse models of breast cancer, the tumors that form are typically ER-negative and independent of estrogen for their growth. However, in recent years more attention has been given to develop mouse models that develop different subtypes of breast cancers, including ER-positive tumors. In this review, we discuss the currently available mouse models that develop ER-α positive mammary tumors and their potential use to elucidate the molecular mechanisms of ER-α positive breast cancer development and endocrine resistance.

  4. Microbial transformation of synthetic estrogen 17alpha-ethinylestradiol

    Energy Technology Data Exchange (ETDEWEB)

    Cajthaml, Tomas, E-mail: cajthaml@biomed.cas.c [Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20 Prague 4 (Czech Republic); Kresinova, Zdena; Svobodova, Katerina; Sigler, Karel; Rezanka, Tomas [Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20 Prague 4 (Czech Republic)


    Natural estrogens such as estrone, 17beta-estradiol, estriol, and the particularly recalcitrant synthetic estrogen 17alpha-ethinylestradiol used as oral contraceptive, accumulate in the environment and may give rise to health problems. The processes participating in their removal from soil, wastewater, water-sediments, groundwater-aquifer material, and wastewater or sewage treatment plant effluents may involve the action of bacterial and microbial consortia, and in some cases fungi and algae. This review discusses the different efficiencies of bacterial degradation of 17alpha-ethinylestradiol under aerobic and anaerobic conditions, the role of sulfate-, nitrate-, and iron-reducing conditions in anaerobic degradation, and the role of sorption. The participation of autotrophic ammonia oxidizing bacteria and heterotrophic bacteria in cometabolic degradation of estrogens, the estrogen-degrading action of ligninolytic fungi and their extracellular enzymes (lignin peroxidase, manganese-dependent peroxidase, versatile peroxidase, laccase), and of algae are discussed in detail. - Current knowledge of 17alpha-ethinylestradiol microbial transformation is summarized.

  5. A Role for Estrogen in Schizophrenia: Clinical and Preclinical Findings

    Directory of Open Access Journals (Sweden)

    Andrea Gogos


    Full Text Available Gender differences in schizophrenia have been extensively researched and it is being increasingly accepted that gonadal steroids are strongly attributed to this phenomenon. Of the various hormones implicated, the estrogen hypothesis has been the most widely researched one and it postulates that estrogen exerts a protective effect by buffering females against the development and severity of the illness. In this review, we comprehensively analyse studies that have investigated the effects of estrogen, in particular 17β-estradiol, in clinical, animal, and molecular research with relevance to schizophrenia. Specifically, we discuss the current evidence on estrogen dysfunction in schizophrenia patients and review the clinical findings on the use of estradiol as an adjunctive treatment in schizophrenia patients. Preclinical research that has used animal models and molecular probes to investigate estradiol’s underlying protective mechanisms is also substantially discussed, with particular focus on estradiol’s impact on the major neurotransmitter systems implicated in schizophrenia, namely, the dopamine, serotonin, and glutamate systems.

  6. Examining triclosan-induced potentiation of the estrogen uterotrophic effect (United States)

    Triclosan (TCS), a widely used antibacterial, has been shown to be an endocrine disruptor. We reported previously that TCS potentiated the estrogenic effect of ethinyl estradiol (EE) on uterine growth in rats orally administered 3 μg/kg EE and TCS (2 to 18 mg/kg) in the utero...

  7. Potential estrogenic effects of phosphorus-containing flame retardants. (United States)

    Zhang, Quan; Lu, Meiya; Dong, Xiaowu; Wang, Cui; Zhang, Chunlong; Liu, Weiping; Zhao, Meirong


    As the substitute of polybrominated diphenyl ethers (PBDEs), further assessments about the potential ecological safety and health risks of phosphorus-containing flame retardants (PFRs) are required because the worldwide demand for PFRs has been increasing every year. In this study, we examined the agonistic/antagonistic activity of a group of PFRs by three in vitro models (luciferase reporter gene assay, yeast two-hybrid assay, and E-screen assay). Molecule docking was used to further explain the interactions between ERα and PFRs. Data from luciferase reporter gene analysis showed three members of the nine tested PFRs significantly induced estrogenic effects, with the order of TPP > TCP > TDCPP, while TCEP and TEHP have remarkable antiestrogenic properties with calculated REC20 and RIC20 values of 10(-6) M or lower. Results from the luciferase reporter gene method are generally consistent with results obtained from the yeast two-hybrid assay and E-screen, except for the positive estrogenic activity of TBP in E-screen testing. Docking results showed that binding between ligands and ERα was stabilized by hydrophobic interactions. As a proposed alternative for brominated flame retardant, PFRs may have anti/estrogenic activity via ERα at the low dose typical of residue in environmental matrix or animals. PFRs with a short chain, halogen, and benzene ring in the substituent group tend to be estrogenic. Our research suggests that comprehensive evaluations, including health and ecological assessments, are required in determining whether PFRs are preferable as an emerging industrial substitute.

  8. QSAR modeling of estrogenic alkylphenols using bulk and electronic parameters

    Directory of Open Access Journals (Sweden)

    Mukherjee S


    Full Text Available Broad range of structurally diverse alkylphenols has been found to be considerably potential estrogenic agents in combating estrogen-linked pathologies, but their mechanism of action in mimicking responses of endogenous hormones is still to be understood. The present work explores pharmacophore signals of some varied alkylphenols and predicts estrogenic activities through generated linear relations implementing theoretical molecular modeling techniques. The binding affinity to estrogen receptor of alkylphenols has been modeled investigating large data set of whole molecular and atomic descriptors. Univariate and multivariate relationships were estimated using correlation analysis and statistical significance of the generated relations assessed. The predictive ability of the generated models was further verified using ′Leave-One-Out′ cross validation. The relationships with molecular properties could be developed with a maximum correlation exceeding 94%, with explained variance as high as 87% and cross-validated variances> 0.8. It was inferred that increased molecular bulk, enhanced molecular ionization potential, presence of electron donating groups in para position and branched chain terminal atoms might have influence on binding affinity to the receptor.

  9. Identification and function of coactivator of estrogen receptor: ERIAP

    Institute of Scientific and Technical Information of China (English)

    孟庆慧; 周立新; 曹建平; 高斌; 邵荣光; 李及友; 樊赛军


    Estrogen receptor (ER), one member of nuclear hormone receptor (NR) family, is an estrogen-dependent transcriptional factor that plays an important role in development, progression and treatment of breast cancer. Transcriptional co-factors (co-activators and co-repressors) are critical for ER to transduce hormone and metabolic signaling to target genes. A number of functional and structural studies have elucidated the precise mechanisms of co-activator interaction with the ligand-inducible activation domain in ER via one and several LXXLL motifs (where X is any amino acid) known as NR-Box. By the yeast two-hybrid system we have identified a novel ER-αinteracting protein ERIAP (Estrogen Receptor Interacting and Activating Protein) which contains two consensus LXXLL motifs. ERIAP associated with ER-α in a ligand-dependent manner, as demonstrated by in vivo immunoprecipitation and in vitro GST capture assays. The two NR boxes were essential for ERIAP interaction with ER-α. Furthermore, ERIAP specifically enhanced ligand-mediated ER-α transcriptional activity in a dose-dependent fasion and increased the expression of estrogen-responsive gene pS2. Thus, our present findings indicate that ERIAP funcions as a new coactivator for ER-α transcriptional activity, which may play an important role in development and progression of breast cancer.

  10. EADB: An Estrogenic Activity Database for Assessing Potential Endocrine Activity (United States)

    Endocrine-active chemicals can potentially have adverse effects on both humans and wildlife. They can interfere with the body’s endocrine system through direct or indirect interactions with many protein targets. Estrogen receptors (ERs) are one of the major targets, and many ...

  11. 21 CFR 862.1275 - Estrogens (total, nonpregnancy) test system. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Estrogens (total, nonpregnancy) test system. 862.1275 Section 862.1275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... infertility, amenorrhea (absence of menses) differentiation of primary and secondary ovarian...

  12. Estrogenic response of bisphenol A in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Lindholst, Christian; Pedersen, Knud Ladegaard; Pedersen, Søren Nørby


    Bisphenol A (BPA) previously shown to possess xenoestrogenic activities was administered to rainbow trout (Oncorhynchus mykiss) through a continuos flow system. The estrogenic response expressed as the induction of vitellogenin (VTG) synthesis was measured during 12 days of exposure, using a direct...

  13. Cohesin modulates transcription of estrogen-responsive genes. (United States)

    Antony, Jisha; Dasgupta, Tanushree; Rhodes, Jenny M; McEwan, Miranda V; Print, Cristin G; O'Sullivan, Justin M; Horsfield, Julia A


    The cohesin complex has essential roles in cell division, DNA damage repair and gene transcription. The transcriptional function of cohesin is thought to derive from its ability to connect distant regulatory elements with gene promoters. Genome-wide binding of cohesin in breast cancer cells frequently coincides with estrogen receptor alpha (ER), leading to the hypothesis that cohesin facilitates estrogen-dependent gene transcription. We found that cohesin modulates the expression of only a subset of genes in the ER transcription program, either activating or repressing transcription depending on the gene target. Estrogen-responsive genes most significantly influenced by cohesin were enriched in pathways associated with breast cancer progression such as PI3K and ErbB1. In MCF7 breast cancer cells, cohesin depletion enhanced transcription of TFF1 and TFF2, and was associated with increased ER binding and increased interaction between TFF1 and its distal enhancer situated within TMPRSS3. In contrast, cohesin depletion reduced c-MYC mRNA and was accompanied by reduced interaction between a distal enhancer of c-MYC and its promoters. Our data indicates that cohesin is not a universal facilitator of ER-induced transcription and can even restrict enhancer-promoter communication. We propose that cohesin modulates transcription of estrogen-dependent genes to achieve appropriate directionality and amplitude of expression.

  14. Estrogen Receptor Gene Polymorphisms Associated with Incident Aging Macula Disorder

    NARCIS (Netherlands)

    Boekhoorn, S.S.; Vingerling, J.R.; Uitterlinden, A.G.; Meurs, J.B.J. van; Duijn, C.M. van; Pols, H.A.P.; Hofman, A.; de Jong, P.T.V.M.


    PURPOSE. It has been suggested that early menopause increases the risk of aging-macula disorder (AMD), the major cause of incurable blindness with a dry and wet late subtype, and that exposure to endogenous or postmenopausal exogenous estrogens reduces this risk. This study was undertaken to investi

  15. Steroidal estrogen sources in a sewage-impacted coastal ocean. (United States)

    Griffith, David R; Kido Soule, Melissa C; Eglinton, Timothy I; Kujawinski, Elizabeth B; Gschwend, Philip M


    Estrogens are known to be potent endocrine disrupting chemicals that are commonly found in wastewater effluents at ng L(-1) levels. Yet, we know very little about the distribution and fate of estrogens in coastal oceans that receive wastewater inputs. This study measured a wide range of steroidal estrogens in sewage-impacted seawater using ultra high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS) together with the method of standard addition. In Massachusetts Bay, we find conjugated, free, and halogenated estrogens at concentrations that are consistent with dilution at sites close to the sewage source. At a site 6 miles down current of the sewage source, we observe estrone (E1) concentrations (520 ± 180 pg L(-1)) that are nearly double the nearfield concentrations (320 ± 60 pg L(-1)) despite 9-fold dilution of carbamazepine, which was used as a conservative sewage tracer. Our results suggest that background E1 concentrations in Massachusetts Bay (∼270 ± 50 pg L(-1)) are derived largely from sources unrelated to wastewater effluent such as marine vertebrates.

  16. Modulation of estrogen signaling in hepatic and vascular tissue

    NARCIS (Netherlands)

    Krom, Yvonne Duvera


    This thesis centers on the mechanisms of estrogen action and the effects on the development of atherosclerosis. We have focused on the liver as central organ in lipid and glucose metabolism and the vessel wall as the actual site where the injury occurs. To gain insight in tissue-specific actions of

  17. The healthy cell bias of estrogen action: mitochondrial bioenergetics and neurological implications. (United States)

    Brinton, Roberta Diaz


    The 'healthy cell bias of estrogen action' hypothesis examines the role that regulating mitochondrial function and bioenergetics play in promoting neural health and the mechanistic crossroads that lead to divergent outcomes following estrogen exposure. Estrogen-induced signaling pathways in hippocampal and cortical neurons converge upon the mitochondria to enhance aerobic glycolysis coupled to the citric acid cycle, mitochondrial respiration and ATP generation. Convergence of estrogen-induced signaling onto mitochondria is also a point of vulnerability when activated in diseased neurons which exacerbates degeneration through increased load on dysregulated calcium homeostasis. As the continuum of neurological health progresses from healthy to unhealthy so too do the benefits of estrogen or hormone therapy. The healthy cell bias of estrogen action hypothesis provides a lens through which to assess disparities in outcomes across basic and clinical science and on which to predict outcomes of estrogen interventions for sustaining neurological health and preventing age-associated neurodegenerative diseases such as Alzheimer's.

  18. Proteomic Analysis of Estrogen-Mediated Signal Transduction in Osteoclasts Formation

    Directory of Open Access Journals (Sweden)

    Qi Xiong


    Full Text Available Estrogen plays an important role in inhibiting osteoclast differentiation and protecting against bone loss from osteoporosis, especially in postmenopausal women. However, the precise mechanisms underlying the effect of estrogen on osteoclasts are not well known. In the present study, we performed proteomics analysis and bioinformatics analysis to comprehensively compare the differential expression of proteins in receptor activator of nuclear factor-κB ligand RANKL-induced osteoclasts in the presence and absence of estrogen. We identified 6403 proteins, of which 124 were upregulated and 231 were downregulated by estrogen. Bioinformatics analysis showed that estrogen treatment interfered with 77 intracellular pathways, including both confirmed canonical and unconfirmed pathways of osteoclast formation. Our findings validate the inhibitory effect of estrogen on osteoclasts via the promotion of apoptosis and suppression of differentiation and polarization and suggest that estrogen might inhibit osteoclast formation via other pathways, which requires further investigation and verification.

  19. Estrogenic activity of glyceollins isolated from soybean elicited with Aspergillus sojae. (United States)

    Kim, Hyo Jung; Suh, Hwa-Jin; Kim, Jeong Hwan; Kang, Sun Chul; Park, Sunmin; Lee, Choong Hwan; Kim, Jong-Sang


    Glyceollins, which are synthesized from daidzein in soybeans cultured with fungi, have been shown to have antifungal effects and cancer preventive properties. Several studies have proposed that isoflavones and their metabolites act as a mixed agonist/antagonist for estrogen. Although glyceollins were reported to suppress some cancer cells via anti-estrogenic activity, it is not clear whether the compounds possess estrogenic potential. In contrast to the anti-estrogenic action reported thus far, we observed estrogenic effects of glyceollins using E-screen assay and pS2 expression, whereas glyceollins showed higher affinity for estrogen receptor (ER) beta than ERalpha. We also found that glyceollins were more efficiently produced de novo in minced than in half-sliced soybean, following infection with Aspergillus sojae. In conclusion, glyceollins may be useful in the prevention or amelioration of postmenopausal complications because they had strong estrogenic activity, and their production could be variable depending upon processing prior to fungal inoculation.

  20. Estrogen directly attenuates human osteoclastogenesis, but has no effect on resorption by mature osteoclasts

    DEFF Research Database (Denmark)

    Sørensen, M G; Henriksen, K; Dziegiel, Morten Hanefeld;


    Estrogen deficiency arising with the menopause promotes marked acceleration of bone resorption, which can be restored by hormone replacement therapy. The inhibitory effects of estrogen seem to involve indirect cytokine- mediated effects via supporting bone marrow cells, but direct estrogen......-receptor mediated effects on the bone-resorbing osteoclasts have also been proposed. Little information is available on whether estrogens modulate human osteoclastogenesis or merely inhibit the functional activity of osteoclasts. To clarify whether estrogens directly modulate osteoclastic activities human CD14...... not affect bone resorption or TRACP activity. We investigated expression of the estrogen receptors, using immunocytochemistry and Western blotting. We found that ER-alpha is expressed in osteoclast precursors, whereas ER- beta is expressed at all stages, indicating that the inhibitory effect of estrogen...

  1. White organic light-emitting devices with mixed interfaces between light emitting layers (United States)

    Lee, Young Gu; Kee, In Seo; Shim, Hong Shik; Ko, Ick Hwan; Lee, Soonil; Koh, Ken Ha


    White organic light-emitting devices with mixed interfaces between emitting layers (MI-EML WOLEDs) showed luminance and efficiency as large as 26213cd/m2 and 9.85cd/A. Efficiencies of MI-EML WOLEDs were about 1.5 times better than those of conventional three-EML WOLEDs for luminance of 1000-5000cd/m2, and their half-decay lifetime showed 3.1 times improvement. Note that if the authors operate typical active-matrix mobile-phone displays based on combination of WOLED and color filters to produce standard white emission for high definition televisions and illumination sources, MI-EML WOLEDs will have advantages of 25% less power consumption and 2.8 times longer lifetime over conventional three-EML WOLEDs.

  2. Relative potencies and combination effects of steroidal estrogens in fish. (United States)

    Thorpe, Karen L; Cummings, Rob I; Hutchinson, Thomas H; Scholze, Martin; Brighty, Geoff; Sumpter, John P; Tyler, Charles R


    The natural steroids estradiol-17beta (E2) and estrone (E1) and the synthetic steroid ethynylestradiol-17alpha (EE2) have frequently been measured in waters receiving domestic effluents. All of these steroids bind to the estrogen receptor(s) and have been shown to elicit a range of estrogenic responses in fish at environmentally relevant concentrations. At present, however, no relative potency estimates have been derived for either the individual steroidal estrogens or their mixtures in vivo. In this study the estrogenic activity of E2, E1, and EE2, and the combination effects of a mixture of E2 and EE2 (equi-potent fixed-ratio mixture), were assessed using vitellogenin induction in a 14-day in vivo juvenile rainbow trout screening assay. Median effective concentrations, relative to E2, for induction of vitellogenin were determined from the concentration-response curves and the relative estrogenic potencies of each of the test chemicals calculated. Median effective concentrations were between 19 and 26 ng L(-1) for E2, 60 ng L(-1) for E1, and between 0.95 and 1.8 ng L(-1) for EE2, implying that EE2 was approximately 11 to 27 times more potent than E2, while E2 was 2.3 to 3.2 times more potent than E1. The median effective concentration, relative to E2, for the binary mixture of E2 and EE2 was 15 ng L(-1) (comprising 14.4 ng L(-1) E2 and 0.6 ng L(-1) EE2). Using the model of concentration addition it was shown that this activity of the binary mixture could be predicted from the activity of the individual chemicals. The ability of each individual steroid to contribute to the overall effect of a mixture, even at individual no-effect concentrations, combined with the high estrogenic potency of the steroids, particularly the synthetic steroid EE2, emphasizes the need to consider the total estrogenic load of these chemicals in our waterways.

  3. Light-Emitting Diodes: Phosphorescent Nanocluster Light-Emitting Diodes (Adv. Mater. 2/2016). (United States)

    Kuttipillai, Padmanaban S; Zhao, Yimu; Traverse, Christopher J; Staples, Richard J; Levine, Benjamin G; Lunt, Richard R


    On page 320, R. R. Lunt and co-workers demonstrate electroluminescence from earth-abundant phosphorescent metal halide nanoclusters. These inorganic emitters, which exhibit rich photophysics combined with a high phosphorescence quantum yield, are employed in red and near-infrared light-emitting diodes, providing a new platform of phosphorescent emitters for low-cost and high-performance light-emission applications.

  4. Fate of Estrogens in Soils and Detection by ELISA (United States)

    Caron, Emmanuelle; Sheedy, Claudia; Farenhorst, Annemieke; Zvomuya, Francis; Gaultier, Jeanette; Goddard, Tom


    Land application of manure can contribute to the release of estrogenic compounds in the environment. Estrogens may move from soils to water by processes such as runoff and leaching. The objectives of the present study were to determine the fate of estrogens in soils and to develop a detection method for these compounds. The sorption (soil sorption coefficient (Kd) and sorption coefficient per unit organic carbon (Koc)) of 17β-estradiol, estrone, estriol and equol were studied, using batch equilibrium experiments, in 121 surface soils from Alberta, Canada. The mineralization of [4-14C] 17β-estradiol was determined in soil microcosms in a subset of 36 samples. Quantitative relationships at the regional level were explored using partial least squares regression (PLS) (between Kd or Koc values and soil properties) and by ordinary least squares regression (between Kd or Koc values of different estrogens). Soil properties (r2 0.51-0.87 for Kd and 0.32-0.44 for Koc) provided better prediction models than using the data of different estrogens (r2 0.38-0.71 for Kd and 0.18-0.40 for Koc). PLS regression models for mineralization parameters of 17ß-estradiol had lower predictive power (lower r2)than models developed for sorption parameters. In addition, it has become of primary importance to develop sensitive detection methods that are able to detect low estrogen concentrations (ng L-1) in a wide variety of environmental matrices in order to validate the prediction of their fate and to study their presence in affected ecosystems. Conjugates were synthesized using a mixed anhydride reaction and two Enzyme-Linked Immunosorbent Assays (ELISAs) were developed using polyclonal antibodies. One ELISA was highly specific for 17β-estradiol (with an IC50 of 243 ng mL-1) and the second allowed for the broader detection of 17β-estradiol, estrone and estriol (with an IC50 of 18 ng mL-1 for 17β-estradiol). The cross-reactivity of both ELISAs was studied against 13 compounds (natural

  5. White organic light-emitting diodes based on C545T doped emitting system

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hua-Ping; Zhou, Fan; Zhang, Liang [Department of Materials Science, Shanghai University, Jiading, Shanghai (China); Li, Jun; Jiang, Xue-Yin; Zhang, Zhi-Lin; Zhang, Jian-Hua [Department of Materials Science, Shanghai University, Jiading, Shanghai (China); Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai (China); Zhang, Xiao-Wen [Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin (China)


    Fluorescent white organic light-emitting diodes (WOLEDs) with single-emitting layer (EML) and double-EML structures were demonstrated using a 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10(2-benzothiazolyl)quinolizine-[9,9a,1gh]coumarin (C545T) doped emitting system. With the incorporation of double-EML structure, white emission with Commission Internationale de L'Eclairage (CIE) color coordinates of (0.331, 0.335) and luminous efficiency of 8.04 cd/A was obtained. Moreover, WOLED with a single-EML structure shows superior electroluminescence performances such as lower voltage, higher luminance, and enhanced power efficiency. These improvements are attributed to its high energy transfer ability via the intermediation of C545T. The Forster's radius was given to clarify the actual energy transfer process. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Spectrum study of top-emitting organic light-emitting devices with micro-cavity structure

    Institute of Scientific and Technical Information of China (English)

    Liu Xiang; Wei Fuxiang; Liu Hui


    Blue and white top-emitting organic light-emitting devices OLEDs with cavity effect have been fabricated.TBADN:3%DSAPh and Alq3:DCJTB/TBADN:TBPe/Alq3:C545 were used as emitting materials of microcavity OLEDs.On a patterned glass substrate,silver was deposited as reflective anode,and copper phthalocyanine (CuPc)layer as HIL and 4'-bis[N-(1-Naphthyl)-N-phenyl-amino]biphenyl(NPB)layer as HTL were made.Al/Ag thin films were made as semi-transparent cathode with a transmittance of about 30%.By changing the thickness of indium tin oxide ITO,deep blue with Commission Internationale de L'Eclairage chromaticity coordinates(CIEx,y)of(0.141,0.049)was obtained on TBADN:3%DSAPh devices,and different color(red,blue and green)was obrained on Alq3:DCJTB/TBADN:TBPe/Alq3:C545 devices,full width at half maxima(FWHM)was only 17 nm.The spectral intensity and FWHM of emission in cavity devices have also been studied.

  7. Identification of estrogenic compounds in fish bile using bioassay-directed fractionation. (United States)

    Houtman, Corine J; Van Oostveen, Annemiek M; Brouwer, Abraham; Lamoree, Marja H; Legler, Juliette


    Conjugates of estrogenic chemicals, endogenous as well as xenobiotic, are mainly excreted via bile into the intestine. Therefore, measurement of estrogenic activity in bile yields useful information about an organism's internal exposure to (xeno-)estrogens. Although previous studies in The Netherlands have reported estrogenic activity in male fish bile, the contribution of natural hormones and xenobiotic substances to this activity is unknown. To identify compounds responsible for estrogenic activity in fish bile, we developed a bioassay-directed fractionation method for estrogenic chemicals. In this approach, the in vitro reporter gene assay ER-CALUX (Estrogen Responsive Chemical Activated Luciferase Gene Expression) was used to assess estrogenic activity in deconjugated bile samples and to direct RP-HPLC fractionation and chemical analysis (by GC-MS) of estrogenic compounds. The method was applied to bile from male breams (Abramis brama) collected at three locations in The Netherlands. At one of these locations, the River Dommel, extremely high levels of plasma vitellogenin and a high incidence of intersex gonads in these male breams have previously been observed, indicating the exposure to estrogens. In this study, the natural hormones 17beta-estradiol, estrone, and estriol accounted for the majority of estrogenic activity in male bream bile. At the River Dommel, the synthetic contraceptive pill component ethynylestradiol was found in effective concentrations as well. The detected natural and synthetic hormones may be responsible forthe estrogenic effects observed in wild bream from this location. Furthermore, a large number of xenobiotic chemicals was detected at relatively high levels in bile, including triclosan, chloroxylenol, and clorophene. Although chloroxylenol was shown for the first time to be weakly estrogenic, these compounds did not contribute significantly to the estrogenic activity observed.

  8. Recent advances in conjugated polymers for light emitting devices. (United States)

    Alsalhi, Mohamad Saleh; Alam, Javed; Dass, Lawrence Arockiasamy; Raja, Mohan


    A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review.

  9. Recent Advances in Conjugated Polymers for Light Emitting Devices

    Directory of Open Access Journals (Sweden)

    Mohan Raja


    Full Text Available A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review.

  10. Oxidative removal of aqueous steroid estrogens by manganese oxides. (United States)

    Xu, Lei; Xu, Chao; Zhao, Meirong; Qiu, Yuping; Sheng, G Daniel


    This study investigated the oxidative removal of steroid estrogens from water by synthetic manganese oxide (MnO2) and the factors influencing the reactions. Using 1 x 10(-5)M MnO2 at pH 4, estrone (E1), 17beta-estradiol (E2), estriol (E3) and 17alpha-ethinylestradiol (EE2), all at 4 x 10(-6)M, were rapidly removed within 220 min, indicating the effectiveness of MnO2 as an oxidizing agent towards estrogens. E2 removal increased with decreasing pH over the tested range of 4-8, due most likely to increased oxidizing power of MnO2 and a cleaner reactive surface in acidic solutions. Coexisting metal ions of 0.01 M (Cu(II), Zn(II), Fe(III) and Mn(II)) and Mn(II) released from MnO2 reduction competed with E2 for reactive sites leading to reduced E2 removal. Observed differential suppression on E2 removal may be related to different speciations of metals, as suggested by the MINTEQ calculations, and hence their different adsorptivities on MnO2. By suppressing the metal effect, humic acid substantially enhanced E2 removal. This was attributed to complexation of humic acid with metal ions. With 0.01 M ZnCl2 in solutions containing 1 mg l(-1) humic acid, the binding of humic acid for Zn(II) was determined at 251 mmol g(-1). An in vitro assay using human breast carcinoma MCF-7 cells indicated a near elimination of estrogenic activities without secondary risk of estrogen solutions treated with MnO2. Synthetic MnO2 is therefore a promising chemical agent under optimized conditions for estrogen removal from water. Metal chelators recalcitrant to MnO2 oxidation may be properly used to further enhance the MnO2 performance.

  11. Occurrence and removal of estrogens in Brazilian wastewater treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, Germana P. [Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Rua do Contorno, S/N Campus do Pici, Bl. 713, CEP: 60455-900, Fortaleza, CE (Brazil); Souza, Neyliane C. de [Department Sanitary and Environmental Engineering, State University of Paraíba, Rua Juvêncio Arruda, S/N, Campus Universitário, Bodocongó, CEP: 58109-790, Campina Grande, PB (Brazil); Vidal, Carla B.; Alves, Joana A.C.; Firmino, Paulo Igor M. [Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Rua do Contorno, S/N Campus do Pici, Bl. 713, CEP: 60455-900, Fortaleza, CE (Brazil); Nascimento, Ronaldo F. [Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, Rua do Contorno, S/N Campus do Pici, Bl. 940, CEP: 60451-970, Fortaleza, CE (Brazil); Santos, André B. dos, E-mail: [Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Rua do Contorno, S/N Campus do Pici, Bl. 713, CEP: 60455-900, Fortaleza, CE (Brazil)


    This paper evaluated the occurrence and removal efficiency of four estrogenic hormones in five biological wastewater treatment plants (WWTPs), located in the State of Ceará, Brazil. The five WWTPs comprised: two systems consisted of one facultative pond followed by two maturation ponds, one facultative pond, one activated sludge (AS) system followed by a chlorination step, and one upflow anaerobic sludge blanket (UASB) reactor followed by a chlorination step. Estrogen occurrence showed a wide variation among the analyzed influent and effluent samples. Estrone (E1) showed the highest occurrence in the influent (76%), whereas both 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) presented a 52% occurrence, and the compound 17β-estradiol 17-acetate (E2-17A), a 32% one. The occurrence in the effluent samples was 48% for E1, 28% for E2, 12% for E2-17A, and 40% for EE2. The highest concentrations of E1 and EE2 hormones in the influent were 3050 and 3180 ng L{sup −1}, respectively, whereas E2 and E2-17A had maximum concentrations of 776 and 2300 ng L{sup −1}, respectively. The lowest efficiencies for the removal of estrogenic hormones were found in WWTP consisted of waste stabilization ponds, ranging from 54 to 79.9%. The high-rate systems (AS and UASB), which have chlorination as post-treatment, presented removal efficiencies of approximately 95%. - Highlights: • The occurrence of four endocrine disrupting chemicals was evaluated. • The removal efficiency of four hormones in low-cost plants was examined. • Estrogen occurrence showed a wide variation in influent and effluent samples. • Estrone showed the highest occurrence in the influent and the effluent samples. • WSP treatment was observed to be less effective for removing estrogens.

  12. Sympathetic hyperinnervation of the uterus in the estrogen receptor alpha knock-out mouse. (United States)

    Zoubina, E V; Smith, P G


    Uterine innervation undergoes cyclical remodeling in the adult virgin rat. Previous studies showed that ovariectomy leads to increased uterine sympathetic nerve density, and this can be reduced by estrogen administration. However, the receptor mechanism by which estrogen modulates sympathetic innervation is unknown. The present study assessed the role of the estrogen receptor alpha in establishing levels of uterine innervation by comparing the nerve abundance in mice with a null mutation of the estrogen receptor alpha with those of the wild-type cycling mouse. Immunostaining for total uterine innervation using antibodies against the pan-neuronal marker protein gene product 9.5 showed that nerve numbers in normally cycling wild-type mice were high in diestrus when circulating estrogen is at its nadir, and low at estrus, coincident with high plasma estrogen. Uteri of the estrogen receptor alpha knock-out mice were smaller than those of wild-type mice, but even when corrected for differences in size, total innervation was 188% and 355% greater than that of wild-type mice at diestrus and estrus, respectively. This hyperinnervation is associated with increased numbers of nerves immunoreactive for the noradrenergic enzyme dopamine beta-hydroxylase, without obvious differences in those containing calcitonin gene-related peptide or the vesicular acetylcholine transporter. While estrogen supplementation of the ovariectomized wild-type mice significantly reduced total uterine innervation, neither ovariectomy nor estrogen supplementation affected uterine nerve density in estrogen receptor alpha knock-out mice.We conclude that estrogen acting through the estrogen receptor alpha determines the number of sympathetic nerve terminal branches within uterine smooth muscle target. In mice with low circulating estrogen, or high estrogen but lacking the functional estrogen receptor alpha, the uterus contains abundant sympathetic nerves, whereas estrogen acts via the estrogen receptor

  13. Mechanisms of estrogen action%雌激素作用分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    谈智; 王庭槐


    Estrogen has widespread biological actions. Besides sexual organs, estrogen plays an im-portant role in cardiovascular system, central nervous system and bone tissue. However, the mechanisms of es-trogen action are very complex and not fully understood. The actions of estrogen are not identical and even completely different in some organs system. In this review, we will focus on the new development of molecular mechanisms of estrogen action.

  14. Potent inhibition of estrogen sulfotransferase by hydroxylated PCB metabolites: a novel pathway explaining the estrogenic activity of PCBs

    NARCIS (Netherlands)

    Kester, M.H.A.; Bulduk, S.; Tibboel, D.; Meinl, W.; Glatt, H.; Falany, C.N.; Coughtrie, M.W.H.; Bergman, A.; Safe, S.H.; Kuiper, G.G.J.M.; Schuur, A.G.; Brouwer, A.; Visser, T.J.


    Polychlorinated biphenyls (PCBs) are persistent environmental pollutants which exert a variety of toxic effects in animals, including disturbances of sexual development and reproductive function. The estrogenic effects of PCBs may be mediated in part by hydroxylated PCB metabolites (PCB-OHs), but th

  15. Estrogenic endpoints in fish early life-stage tests: luciferase and vitellogenin induction in estrogen-responsive transgenic zebrafish

    NARCIS (Netherlands)

    Bogers, R.; Mutsaerds, E.; Druke, J.; Roode, de D.F.; Murk, A.J.; Burg, van der B.; Legler, J.


    This study incorporated specific endpoints for estrogenic activity in the early life-stage (ELS) test, as described in Guideline 210 of the Organization for Economic Cooperation and Development and traditionally used for toxicity screening of chemicals. A transgenic zebrafish model expressing an est

  16. Bioassay of estrogenicity and chemical analyses of estrogens in streams across the United States associated with livestock operations (United States)

    Animal manures, used as a nitrogen source for crop production, are often associated with negative impacts on nutrient levels in surface water. The concentration of estrogens in streams from these manures is of concern due to potential endocrine disruption in aquatic species. S...

  17. Estrogen Receptor (ER-α36 Is Involved in Estrogen- and Tamoxifen-Induced Neuroprotective Effects in Ischemic Stroke Models.

    Directory of Open Access Journals (Sweden)

    Wei Zou

    Full Text Available The neuroprotection by estrogen (E2 and tamoxifen is well documented in experimental stroke models; however, the exact mechanism is unclear. A membrane-based estrogen receptor, ER-α36, has been identified. Postmenopausal-levels of E2 act through ER-α36 to induce osteoclast apoptosis due to a prolonged activation of the mitogen-activated protein kinase (MAPK/extracellular signal-related kinase (ERK signaling. We hypothesized that ER-α36 may play a role in the neuroprotective activities of estrogen and tamoxifen. Here, we studied ER-α36 expression in the brain, as well as its neuroprotective effects against oxygen and glucose deprivation (OGD in PC12 cells. We found that ER-α36 was expressed in both rat and human brain. In addition, OGD-induced cell death was prevented by l nmol/L 17β-estradiol (E2β. E2β activates the MAPK/ERK signaling pathway in PC12 cells under basal and OGD conditions by interacting with ER-α36 and also induces ER-α36 expression. Low-dose of tamoxifen up-regulated ER-α36 expression and enhanced neuronal survival in an ovariectomized ischemic stroke model. Furthermore, low-dose of tamoxifen enhanced neuroprotective effects by modulating activates or suppress ER-α36. Our results thus demonstrated that ER-α36 is involved in neuroprotective activities mediated by both estrogen and tamoxifen.

  18. Laccase-mediated transformations of endocrine disrupting chemicals abolish binding affinities to estrogen receptors and their estrogenic activity in zebrafish. (United States)

    Torres-Duarte, Cristina; Viana, María Teresa; Vazquez-Duhalt, Rafael


    Endocrine disrupting chemicals (EDCs) are known to mainly affect aquatic organisms, producing negative effects in aquaculture. Transformation of the estrogenic compounds 17β-estradiol (E2), bisphenol-A (BPA), nonylphenol (NP), and triclosan (TCS) by laccase of Coriolopsis gallica was studied. Laccase is able to efficiently transform them into polymers. The estrogenic activity of the EDCs and their laccase transformation products was evaluated in vitro as their affinity for the human estrogen receptor alpha (hERα) and for the ligand binding domain of zebrafish (Danio rerio) estrogen receptor alpha (zfERαLBD). E2, BPA, NP, and TCS showed higher affinity for the zfERαLBD than for hERα. After laccase treatment, no affinity was found, except a marginal affinity of E2 products for the zfERαLBD. Endocrine disruption studies in vivo on zebrafish were performed using the induction of vitellogenin 1 as a biomarker (VTG1 mRNA levels). The use of enzymatic bioreactors, containing immobilized laccase, efficiently eliminates the endocrine activity of BPA and TCS, and significantly reduces the effects of E2. The potential use of enzymatic reactors to eliminate the endocrine activity of EDCs in supply water for aquaculture is discussed.

  19. NJK14013, a novel synthetic estrogen receptor-α agonist, exhibits estrogen receptor-independent, tumor cell-specific cytotoxicity. (United States)

    Kim, Hye-In; Kim, Taelim; Kim, Ji-Eun; Lee, Jun; Heo, Jinyuk; Lee, Na-Rae; Kim, Nam-Jung; Inn, Kyung-Soo


    Estrogens act through interactions with estrogen receptors (ERs) to play diverse roles in various pathophysiological conditions. A number of synthetic selective estrogen receptor modulators (SERMs), such as tamoxifen and raloxifene, have been developed and used to treat ER-related diseases, including breast cancer and osteoporosis. Here, we identified a novel compound, bis(4-hydroxyphenyl)methanone-O-isopentyl oxime, designated NJK14013, as an ER agonist. NJK14013 activated ER-dependent transcription in a concentration-dependent manner, while suppressing androgen receptor-dependent transcriptional activity. It induced the activation-related phosphorylation of ER and enhanced the transcription of growth regulation by estrogen in breast cancer 1 (GREB1), further supporting its ER-stimulating activity. NJK14013 exerted anti-proliferative effects on various cancer cell lines, including an ER-negative breast cancer cell line, suggesting that it is capable of suppressing the growth of cancer cells independent of its ER-modulating activity. In addition, NJK14013 treatment resulted in significant apoptotic death of MCF7 and Ishikawa cancer cells, but did not induce apoptosis in non-cancer human umbilical vein endothelial cells. Collectively, our findings demonstrate that NJK14013 is a novel SERM that can activate ER-mediated transcription in MCF7 cells and suppress the proliferation of various cancer cells, including breast cancer cells and endometrial cancer cells. These results suggest that NJK14013 has potential as a novel SERM for anticancer or hormone-replacement therapy with reduced risk of carcinogenesis.

  20. Expression of estrogen receptor and estrogen receptor messenger RNA in gastric carcinoma tissues

    Institute of Scientific and Technical Information of China (English)

    Xin-Han Zhao; Shan-Zhi Gu; Shan-Xi Liu; Bo-Rong Pan


    AIM: To study estrogen receptor (ER) and estrogen receptor messenger RNA (ERmRNA) expression in gastric carcinoma tissues and to investigate their association with the pathologic types of gastric carcinoma.METHODS: The expression of ER and ERmRNA in gastric carcinoma tissues (15 males and 15 females, 42-70 years old) was detected by immunohistochemistry and in situ hybridization, respectively.RESULTS: The positive rate of ER (immunohistochemistry)was 33.3% in males and 46.7% in females. In Borrmann Ⅳ gastric carcinoma ER positive rate was greater than that in other pathologic types, and in poorly differentiated adenocarcinoma and signet ring cell carcinoma the positive rates were greater than those in other histological types of both males and females (P<0.05). The ER was more highly expressed in diffused gastric carcinoma than in non-diffused gastric carcinoma (P<0.05). The ER positive rate was also related to regional lymph nodes metastases (P<0.05), and was significantly higher in females above 55 years old, and higher in males under 55 years old (P<0.05). The ERmRNA (in situ hybridization) positive rate was 73.3% in males and 86.7% in females. The ERmRNA positive rates were almost the same in Borrmann Ⅰ, Ⅱ, Ⅲ and Ⅳ gastric carcinoma (P>0.05). ERmRNA was expressed in all tubular adenocarcinoma, poorly differentiated adenocarcinoma and signet ring cell carcinoma (P<0.05). The ERmRNA positive rate was related to both regional lymph nodes metastases and gastric carcinoma growth patterns, and was higher in both sexes above 55 years old but without statistical significance (P>0.05). The positive rate of ERmRNA expression by in situ hybridization was higher than that of ER expression by immunohistochemistry (P<0.05).CONCLUSION: ERmRNA expression is related to the pathological behaviors of gastric carcinoma, which might help to predict the prognosis and predict the effectiveness of endocrine therapy for gastric carcinoma.

  1. Binding of estrogen receptor with estrogen conjugated to bovine serum albumin (BSA). (United States)

    Taguchi, Yasuto; Koslowski, Mirek; Bodenner, Donald L


    BACKGROUND: The classic model of estrogen action requires that the estrogen receptor (ER) activates gene expression by binding directly or indirectly to DNA. Recent studies, however, strongly suggest that ER can act through nongenomic signal transduction pathways and may be mediated by a membrane bound form of the ER. Estradiol covalently linked to membrane impermeable BSA (E2-BSA) has been widely used as an agent to study these novel membrane-associated ER events. However, a recent report suggests that E2-BSA does not compete for E2 binding to purified ER in vitro. To resolve this apparent discrepancy, we performed competition studies examining the binding of E2 and E2-BSA to both purified ER preparations and ER within intact cells. To eliminate potential artifacts due to contamination of commercially available E2-BSA preparations with unconjugated E2 (usually between 3-5%), the latter was carefully removed by ultrafiltration. RESULTS: As previously reported, a 10-to 1000-fold molar excess of E2-BSA was unable to compete with 3H-E2 binding to ER when added simultaneously. However, when ER was pre-incubated with the same concentrations of E2-BSA, the binding of 3H-E2 was significantly reduced. E2-BSA binding to a putative membrane-associated ER was directly visualized using fluorescein labeled E2-BSA (E2-BSA-FITC). Staining was restricted to the cell membrane when E2-BSA-FITC was incubated with stable transfectants of the murine ERalpha within ER-negative HeLa cells and with MC7 cells that endogenously produce ERalpha. This staining appeared highly specific since it was competed by pre-incubation with E2 in a dose dependent manner and with the competitor ICI-182,780. CONCLUSIONS: These results demonstrate that E2-BSA does bind to purified ER in vitro and to ER in intact cells. It seems likely that the size and structure of E2-BSA requires more energy for it to bind to the ER and consequently binds more slowly than E2. More importantly, these findings demonstrate

  2. Hole transport in blue and white emitting polymers

    NARCIS (Netherlands)

    Parshin, Mikhail A.; Ollevier, Jeroen; Van der Auweraer, Mark; de Kok, Margreet M.; Nicolai, Herman T.; Hof, Andre J.; Blom, Paul W. M.


    Hole transport in a blue emitting polyspirobifluorene polymer and in a white emitting polymer consisting of a polyspirobifluorene backbone and two dyes (green and red) was studied. The hole mobility was measured using the time-of-flight method as a function of the electric field and temperature in t

  3. Estrogen receptor beta participate in the regulation of metabolizm of extracellular matrix in estrogen alpha negative breast cancer.

    Directory of Open Access Journals (Sweden)

    Mariusz Kuźmicki


    Full Text Available The biology of breast cancer is closely releted to sex steroid hormones. Estrogen receptor beta is overexpressed in around 70% breast cancer cases, referrd to as "ER positive". Estrogens bind to estrogen receptor and stimulate the transcription of genes involved in control of cell proliferation. Moreover, estrogens may induce growth factors and components of extracellular matrix and interact with them in a complex manner. Extracellular matrix and integrins play an important role in cell functions and their aberrant expressions are implicated in breast cancer development, invasion and metastasis. ER beta is certainly associated with more differentiated tumors, while evidence of role of ER beta is controversial. The highly invasive breast cancer ER beta negative cell line MDA-MB 231 can be the model of exam the role of ER beta in breast cancer. The aim of this study was to examine the role of activation of ER beta on the metabolism of the extracellular matrix and the expression of beta-1 integrin in the breast cancer cell line MDA-MB 231. The cells were exposed on the estradiol, tamoxifen, raloxifen and genisteina in dose dependent concentrations. To determine the relative rate of collagen syntesis we measured the time-dependent reduction of collagen-bound radioactivity after pulse-chase labeling with [3 H] prolina by Peterkofsky methods. The expression of beta-1 integrin was determine by Western blot analysis. The activity of MMP2 and 9 were measured using gelatin zymography with an image analysis system. Our data suggest on the role of estrogen receptor beta on the metabolism of extracellular matrix in the breast cancer line MDA - MB 231. Estradiol and SERMs regulate the expression of ECM proteins: collagen, integrins and enhance activity of metaloproteinases 2 and 9.

  4. Estrogen receptor beta participate in the regulation of metabolizm of extracellular matrix in estrogen alpha negative breast cancer. (United States)

    Leśniewska, Monika; Miltyk, Wojciech; Swiatecka, Jolanta; Tomaszewska, Małgorzata; Kuźmicki, Mariusz; Pałka, Jerzy; Wołczyński, Sławomir


    The biology of breast cancer is closely releted to sex steroid hormones. Estrogen receptor beta is overexpressed in around 70% breast cancer cases, referrd to as "ER positive". Estrogens bind to estrogen receptor and stimulate the transcription of genes involved in control of cell proliferation. Moreover, estrogens may induce growth factors and components of extracellular matrix and interact with them in a complex manner. Extracellular matrix and integrins play an important role in cell functions and their aberrant expressions are implicated in breast cancer development, invasion and metastasis. ER beta is certainly associated with more differentiated tumors, while evidence of role of ER beta is controversial. The highly invasive breast cancer ER beta negative cell line MDA-MB 231 can be the model of exam the role of ER beta in breast cancer. The aim of this study was to examine the role of activation of ER beta on the metabolism of the extracellular matrix and the expression of beta-1 integrin in the breast cancer cell line MDA-MB 231. The cells were exposed on the estradiol, tamoxifen, raloxifen and genisteina in dose dependent concentrations. To determine the relative rate of collagen syntesis we measured the time-dependent reduction of collagen-bound radioactivity after pulse-chase labeling with [3 H] prolina by Peterkofsky methods. The expression of beta-1 integrin was determine by Western blot analysis. The activity of MMP2 and 9 were measured using gelatin zymography with an image analysis system. Our data suggest on the role of estrogen receptor beta on the metabolism of extracellular matrix in the breast cancer line MDA - MB 231. Estradiol and SERMs regulate the expression of ECM proteins: collagen, integrins and enhance activity of metaloproteinases 2 and 9.

  5. Bioactivation of dibrominated biphenyls by cytochrome P450 activity to metabolites with estrogenic activity and estrogen sulfotransferase inhibition capacity. (United States)

    van Lipzig, Marola M H; Commandeur, Jan N; de Kanter, Frans J J; Damsten, Micaela C; Vermeulen, Nico P E; Maat, Evelina; Groot, Ed J; Brouwer, Abraham; Kester, Monique H A; Visser, Theo J; Meerman, John H N


    Exposure of humans and wildlife to xenobiotics, such as halogenated biphenyls, that interfere with the endogenous estrogen balance may lead to endocrine disruption. Such compounds may either mimic or block estradiol's action by agonistic or antagonistic action, respectively. They may also affect endogenous estradiol concentrations by induction or inhibition of enzymes that metabolize estradiol. In the present study, we demonstrate that estrogenic metabolites of two brominated biphenyls, 2,2'-dibromobiphenyl (2,2'-DBB) and 4,4'-dibromobiphenyl (4,4'-DBB), are formed by rat liver microsomal cytochrome P450 (CYP) activity. Bioactivation of 2,2'-DBB and 4,4'-DBB yielded various mono- and dihydroxylated bromobiphenyl metabolites, which were collected by preparative HPLC and analyzed by LC/MS. Several of the metabolites bound to the estrogen receptor (ER) activated the ER and inhibited human estrogen sulfotransferase (hEST). Seven monohydroxylated metabolites were positively identified using synthetic monohydroxylated reference compounds. These synthetic monohydroxylated bromobiphenyls also bound to and activated the ER and inhibited hEST. The highest ER affinity was observed for 4-OH-2,2'-DBB, with an EC50 of 6.6 nM. The highest ER activation was observed for 4-OH-3,4'-DBB (EC50 of 74 nM) while 4-OH-4'-MBB and 4-OH-2,2'-DBB induced a supramaximal (as compared to estradiol) ER activation. The strongest hEST inhibition was found with 4-OH-3,4'-DBB (EC50 = 40 nM). In conclusion, we show that two dibrominated biphenyls are bioactivated by CYP activity into very potent estrogenic metabolites and inhibitors of hEST. These findings are of vital importance for accurate risk assessment of exposure to environmental contaminants, such as halogenated biphenyls. Neglecting bioactivation through biotransformation will lead to underestimation of health risks of this class of xenobiotics.

  6. Is There a Role for Base Excision Repair in Estrogen/Estrogen Receptor-Driven Breast Cancers? (United States)

    Abdel-Fatah, Tarek M.A.; Perry, Christina; Arora, Arvind; Thompson, Nicola; Doherty, Rachel; Moseley, Paul M.; Green, Andrew R.; Chan, Stephen Y.T.; Ellis, Ian O.


    Abstract Estrogen and estrogen metabolite-induced reactive oxygen species generation can promote oxidative DNA base damage. If unrepaired, base damaging lesions could accelerate mutagenesis, leading to a “mutator phenotype” characterized by aggressive behavior in estrogen-estrogen receptor (ER)-driven breast cancer. To test this hypothesis, we investigated 1406 ER+ early-stage breast cancers with 20 years' long-term clinical follow-up data for DNA polymerase β (pol β), flap endonuclease 1 (FEN1), AP endonuclease 1 (APE1), X-ray cross-complementation group 1 protein (XRCC1), single-strand monofunctional uracil glycosylase-1 (SMUG1), poly (ADP-ribose) polymerase 1 (PARP1), ataxia telangiectasia mutated and Rad3 related (ATR), ataxia telangiectasia mutated (ATM), DNA-dependent protein kinase catalytic subunit (DNA-PKcs), Chk1, Chk2, p53, breast cancer susceptibility gene 1 (BRCA1), and topoisomerase 2 (TOPO2) expression. Multivariate Cox proportional hazards model was used to calculate a DNA repair prognostic index and correlated to clinicopathological variables and survival outcomes. Key base excision repair (BER) proteins, including XRCC1, APE1, SMUG1, and FEN1, were independently associated with poor breast cancer-specific survival (BCSS) (ps≤0.01). Multivariate Cox model stratified patients into four distinct prognostic sub-groups with worsening BCSS (ps<0.01). In addition, compared with prognostic sub-group 1, sub-groups 2, 3, and 4 manifest increasing tumor size, grade, mitosis, pleomorphism, differentiation, lymphovascular invasion, high Ki67, loss of Bcl-2, luminal B phenotype (ps≤0.01), and poor survival, including in patients who received tamoxifen adjuvant therapy (p<0.00001). Our observation supports the hypothesis that BER-directed stratification could inform appropriate therapies in estrogen-ER-driven breast cancers. Antioxid. Redox Signal. 21, 2262–2268. PMID:25111287

  7. Colloidal quantum dot light-emitting devices

    Directory of Open Access Journals (Sweden)

    Vanessa Wood


    Full Text Available Colloidal quantum dot light-emitting devices (QD-LEDs have generated considerable interest for applications such as thin film displays with improved color saturation and white lighting with a high color rendering index (CRI. We review the key advantages of using quantum dots (QDs in display and lighting applications, including their color purity, solution processability, and stability. After highlighting the main developments in QD-LED technology in the past 15 years, we describe the three mechanisms for exciting QDs – optical excitation, Förster energy transfer, and direct charge injection – that have been leveraged to create QD-LEDs. We outline the challenges facing QD-LED development, such as QD charging and QD luminescence quenching in QD thin films. We describe how optical downconversion schemes have enabled researchers to overcome these challenges and develop commercial lighting products that incorporate QDs to achieve desirable color temperature and a high CRI while maintaining efficiencies comparable to inorganic white LEDs (>65 lumens per Watt. We conclude by discussing some current directions in QD research that focus on achieving higher efficiency and air-stable QD-LEDs using electrical excitation of the luminescent QDs.

  8. Photoswitchable NIR-Emitting Gold Nanoparticles. (United States)

    Bonacchi, Sara; Cantelli, Andrea; Battistelli, Giulia; Guidetti, Gloria; Calvaresi, Matteo; Manzi, Jeannette; Gabrielli, Luca; Ramadori, Federico; Gambarin, Alessandro; Mancin, Fabrizio; Montalti, Marco


    Photo-switching of the NIR emission of gold nanoparticles (GNP) upon photo-isomerization of azobenzene ligands, bound to the surface, is demonstrated. Photophysical results confirm the occurrence of an excitation energy transfer process from the ligands to the GNP that produces sensitized NIR emission. Because of this process, the excitation efficiency of the gold core, upon excitation of the ligands, is much higher for the trans form than for the cis one, and t→c photo-isomerization causes a relevant decrease of the GNP NIR emission. As a consequence, photo-isomerization can be monitored by ratiometric detection of the NIR emission upon dual excitation. The photo-isomerization process was followed in real-time through the simultaneous detection of absorbance and luminescence changes using a dedicated setup. Surprisingly, the photo-isomerization rate of the ligands, bound to the GNP surface, was the same as measured for the chromophores in solution. This outcome demonstrated that excitation energy transfer to gold assists photo-isomerization, rather than competing with it. These results pave the road to the development of new, NIR-emitting, stimuli-responsive nanomaterials for theranostics.

  9. Efficient semiconductor light-emitting device and method (United States)

    Choquette, Kent D.; Lear, Kevin L.; Schneider, Jr., Richard P.


    A semiconductor light-emitting device and method. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL).

  10. Identification of estrogen responsive genes using esophageal squamous cell carcinoma (ESCC) as a model

    KAUST Repository

    Essack, Magbubah


    Background: Estrogen therapy has positively impact the treatment of several cancers, such as prostate, lung and breast cancers. Moreover, several groups have reported the importance of estrogen induced gene regulation in esophageal cancer (EC). This suggests that there could be a potential for estrogen therapy for EC. The efficient design of estrogen therapies requires as complete as possible list of genes responsive to estrogen. Our study develops a systems biology methodology using esophageal squamous cell carcinoma (ESCC) as a model to identify estrogen responsive genes. These genes, on the other hand, could be affected by estrogen therapy in ESCC.Results: Based on different sources of information we identified 418 genes implicated in ESCC. Putative estrogen responsive elements (EREs) mapped to the promoter region of the ESCC genes were used to initially identify candidate estrogen responsive genes. EREs mapped to the promoter sequence of 30.62% (128/418) of ESCC genes of which 43.75% (56/128) are known to be estrogen responsive, while 56.25% (72/128) are new candidate estrogen responsive genes. EREs did not map to 290 ESCC genes. Of these 290 genes, 50.34% (146/290) are known to be estrogen responsive. By analyzing transcription factor binding sites (TFBSs) in the promoters of the 202 (56+146) known estrogen responsive ESCC genes under study, we found that their regulatory potential may be characterized by 44 significantly over-represented co-localized TFBSs (cTFBSs). We were able to map these cTFBSs to promoters of 32 of the 72 new candidate estrogen responsive ESCC genes, thereby increasing confidence that these 32 ESCC genes are responsive to estrogen since their promoters contain both: a/mapped EREs, and b/at least four cTFBSs characteristic of ESCC genes that are responsive to estrogen. Recent publications confirm that 47% (15/32) of these 32 predicted genes are indeed responsive to estrogen.Conclusion: To the best of our knowledge our study is the first

  11. Contribution of a Membrane Estrogen Receptor to the Estrogenic Regulation of Body Temperature and Energy Homeostasis (United States)

    Roepke, Troy A.; Bosch, Martha A.; Rick, Elizabeth A.; Lee, Benjamin; Wagner, Edward J.; Seidlova-Wuttke, Dana; Wuttke, Wolfgang; Scanlan, Thomas S.; Rønnekleiv, Oline K.; Kelly, Martin J.


    The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7–8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms. PMID:20685867

  12. Bioaugmentation Mitigates the Impact of Estrogen on Coliform-Grazing Protozoa in Slow Sand Filters. (United States)

    Haig, Sarah-Jane; Gauchotte-Lindsay, Caroline; Collins, Gavin; Quince, Christopher


    Exposure to endocrine-disrupting chemicals (EDCs), such as estrogens, is a growing issue for human and animal health as they have been shown to cause reproductive and developmental abnormalities in wildlife and plants and have been linked to male infertility disorders in humans. Intensive farming and weather events, such as storms, flash flooding, and landslides, contribute estrogen to waterways used to supply drinking water. This paper explores the impact of estrogen exposure on the performance of slow sand filters (SSFs) used for water treatment. The feasibility and efficacy of SSF bioaugmentation with estrogen-degrading bacteria was also investigated, to determine whether removal of natural estrogens (estrone, estradiol, and estriol) and overall SSF performance for drinking water treatment could be improved. Strains for SSF augmentation were isolated from full-scale, municipal SSFs so as to optimize survival in the laboratory-scale SSFs used. Concentrations of the natural estrogens, determined by gas chromatography coupled with mass spectrometry (GC-MS), revealed augmented SSFs reduced the overall estrogenic potency of the supplied water by 25% on average and removed significantly more estrone and estradiol than nonaugmented filters. A negative correlation was found between coliform removal and estrogen concentration in nonaugmented filters. This was due to the toxic inhibition of protozoa, indicating that high estrogen concentrations can have functional implications for SSFs (such as impairing coliform removal). Consequently, we suggest that high estrogen concentrations could impact significantly on water quality production and, in particular, on pathogen removal in biological water filters.

  13. Biomonitoring of estrogenic exposure and identification of responsible compounds in bream from Dutch surface waters. (United States)

    Houtman, Corine J; Booij, Petra; van der Valk, Karin M; van Bodegom, Peter M; van den Ende, Frank; Gerritsen, Anton A M; Lamoree, Marja H; Legler, Juliette; Brouwer, Abraham


    The exposure to and effects of estrogenic compounds in male breams from Dutch freshwater locations were investigated. Ovotestis was observed infrequently (maximum frequency 16%). However, plasma vitellogenin (VTG) concentration was elevated highly at some locations. Estrogenic activities in male bream plasma, liver, and in gastrointestinal content were measured in the estrogen-responsive chemical-activated luciferase gene expression (ER-CALUX) assay. Plasma concentrations of vitellogenin correlated very well with the estrogenic activities in gastrointestinal content. The ER-CALUX activity in gastrointestinal content thus could provide a biomarker for recent exposure to estrogenic compounds, and the gastrointestinal content was chosen as investigative matrix for the toxicity identification and evaluation ([TIE]; bioassay-directed fractionation) of estrogenic compounds in bream. The approach consisted of a reversed-phase high-performance liquid chromatography fractionation of gastrointestinal content extract, directed by ER-CALUX and followed by gas chromatography analysis. The estrogenic hormones 17beta-estradiol and its metabolite estrone were identified as major contributors to the activity at all locations (except the reference location), independent of the presence or absence of a known source of estrogenic activity, such as a sewage treatment plant. Chemical screening showed the presence of other pollutants, such as a lower chlorinated dioxin and the disinfectants clorophene and triclosan. However, these compounds did not have high estrogenic potencies and their concentrations were not high enough to contribute significantly to the observed estrogenic activity.

  14. Estrogen signalling and the DNA damage response in hormone dependent breast cancers

    Directory of Open Access Journals (Sweden)

    C Elizabeth Caldon


    Full Text Available Estrogen is necessary for the normal growth and development of breast tissue, but high levels of estrogen are a major risk factor for breast cancer. One mechanism by which estrogen could contribute to breast cancer is via the induction of DNA damage. This perspective discusses the mechanisms by which estrogen alters the DNA damage response (DDR and DNA repair through the regulation of key effector proteins including ATM, ATR, CHK1, BRCA1 and p53 and the feedback on estrogen receptor signalling from these proteins. We put forward the hypothesis that estrogen receptor signalling converges to suppress effective DNA repair and apoptosis in favour of proliferation. This is important in hormone-dependent breast cancer as it will affect processing of estrogen-induced DNA damage, as well as other genotoxic insults. DDR and DNA repair proteins are frequently mutated or altered in estrogen responsive breast cancer which will further change the processing of DNA damage. Finally the action of estrogen signalling on DNA damage is also relevant to the therapeutic setting as the suppression of a DNA damage response by estrogen has the potential to alter the response of cancers to anti-hormone treatment or chemotherapy that induces DNA damage.

  15. Estrogen and androgen regulate actin-remodeling and endocytosis-related genes during rat spermiation. (United States)

    Kumar, Anita; Dumasia, Kushaan; Gaonkar, Reshma; Sonawane, Shobha; Kadam, Leena; Balasinor, N H


    Spermiation, the sperm release process, is imperative to male fertility and reproduction. Morphologically, it is characterized by removal of atypical adherens junctions called ectoplasmic specializations, and formation of transient endocytic devices called tubulobulbar complexes requiring cytoskeleton remodeling and recruitment of proteins needed for endocytosis. Earlier, estrogen administration to adult male rats was seen to cause spermiation failure due to disruption of tubulobulbar complexes. This was accompanied by reduction in intratesticular testosterone levels and increase in intratesticular estrogen along with deregulation of genes involved in cytoskeleton remodeling (Arpc1b, Evl and Capg) and endocytosis (Picalm, Eea1 and Stx5a). In the present study, we aim to understand the role of estrogen and androgen in regulating these genes independently using seminiferous tubule culture system treated with estrogen, androgen or agonists and antagonists of estrogen receptors. We find that transcripts of Arpc1b, Evl and Picalm are responsive to estrogen while those of Picalm, Eea1 and Stx5a are responsive to androgen. We also find that the estrogen regulation of Arpc1b and Evl is mediated through estrogen receptor β and that of Picalm occurs through estrogen receptors α and β. Localization of these proteins at or in the vicinity of tubulobulbar complexes reveals that ARPC1B, EVL, PICALM, EEA1 and STX5A seem to be involved in spermiation. Thus, estrogen and androgen regulate specific genes in seminiferous tubules that could play a role in spermiation.

  16. A Bayesian network model for assessing natural estrogen fate and transport in a swine waste lagoon. (United States)

    Lee, Boknam; Kullman, Seth W; Yost, Erin; Meyer, Michael T; Worley-Davis, Lynn; Williams, C Michael; Reckhow, Kenneth H


    Commercial swine waste lagoons are regarded as a major reservoir of natural estrogens, which have the potential to produce adverse physiological effects on exposed aquatic organisms and wildlife. However, there remains limited understanding of the complex mechanisms of physical, chemical, and biological processes that govern the fate and transport of natural estrogens within an anaerobic swine lagoon. To improve lagoon management and ultimately help control the offsite transport of these compounds from swine operations, a probabilistic Bayesian network model was developed to assess natural estrogen fate and budget and then compared against data collected from a commercial swine field site. In general, the model was able to describe the estrogen fate and budget in both the slurry and sludge stores within the swine lagoon. Sensitivity analysis within the model demonstrated that the estrogen input loading from the associated barn facility was the most important factor in controlling estrogen concentrations within the lagoon slurry storage, whereas the settling rate was the most significant factor in the lagoon sludge storage. The degradation reactions were shown to be minor in both stores based on prediction of average total estrogen concentrations. Management scenario evaluations demonstrated that the best possible management options to reduce estrogen levels in the lagoon are either to adjust the estrogen input loading from swine barn facilities or to effectively enhance estrogen bonding with suspended solids through the use of organic polymers or inorganic coagulants.

  17. Estrogen-like activity of aqueous extract from Agrimonia pilosa Ledeb. in MCF-7 cells

    Directory of Open Access Journals (Sweden)

    Lee Young Min


    Full Text Available Abstract Background Postmenopausal women experience estrogen deficiency-related menopausal symptoms (e.g., hot flashes and mood swings and a dramatic increase in the incidence of chronic diseases. Although estrogen-replacement therapy (ERT can reduce mortality from cardiovascular disease and improve osteoporosis and menopausal symptoms, its side effects have limited recent use. This study investigated the estrogen-like activity of aqueous extract from Agrimonia pilosa Ledeb. Methods The estrogenic activity of A. pilosa was investigated by using several in vitro assays. The binding activity of A. pilosa on estrogen receptors was examined using a fluorescence polarization-based competitive binding assay. The proliferative activity of A. pilosa was also examined using MCF-7 cells. Furthermore, the effect of A. pilosa on the expression of 3 estrogen-dependent genes was assessed. Results Using liquid chromatography-mass spectrometry, the 3 major peaks of A. pilosa aqueous extract were identified as apigenin-hexose, luteolin-glucuronide, and apigenin-glucuronide. The aqueous extract induced the proliferation of estrogen receptor-positive MCF-7 cells (p A. pilosa-stimulated proliferation was blocked on adding the estrogen antagonist ICI 182,780. Moreover, A. pilosa treatment increased the mRNA expression of the estrogen-responsive genes pS2 and PR (p  Conclusions These results suggest A. pilosa can be used to improve estrogen deficiency-related menopausal symptoms or to treat diseases in postmenopausal women.

  18. Estrogens regulate the hepatic effects of Growth Hormone, a hormonal interplay with multiple fates

    Directory of Open Access Journals (Sweden)

    Leandro eFernandez-Perez


    Full Text Available The liver responds to estrogens and GH which are critical regulators of body growth, gender-related hepatic functions, and intermediate metabolism. The effects of estrogens on liver can be direct, through the direct actions of hepatic ER, or indirect, which include the crosstalk with endocrine, metabolic, and sex-differentiated functions of GH. Most previous studies have been focused on the influence of estrogens on pituitary GH secretion, which has a great impact on hepatic transcriptional regulation. However, there is strong evidence that estrogens can influence the GH-regulated endocrine and metabolic functions in the human liver by acting at the level of GHR-STAT5 signaling pathway. This cross-talk is relevant because the widespread exposition of estrogen or estrogen-related compounds in human. Therefore, GH or estrogen signaling deficiency as well as the influence of estrogens on GH biology can cause a dramatic impact in liver physiology during mammalian development and in adulthood. In this review, we will summarize the current status of the influence of estrogen on GH actions in liver. A better understanding of estrogen-GH interplay in liver will lead to improved therapy of children with growth disorders and of adults with GH deficiency.

  19. Impact of secondary treatment types and sludge handling processes on estrogen concentration in wastewater sludge. (United States)

    Marti, Erica J; Batista, Jacimaria R


    Endocrine-disrupting compounds (EDCs), such as estrogen, are known to be present in the aquatic environment at concentrations that negatively affect fish and other wildlife. Wastewater treatment plants (WWTPs) are major contributors of EDCs into the environment. EDCs are released via effluent discharge and land application of biosolids. Estrogen removal in WWTPs has been studied in the aqueous phase; however, few researchers have determined estrogen concentration in sludge. This study focuses on estrogen concentration in wastewater sludge as a result of secondary treatment types and sludge handling processes. Grab samples were collected before and after multiple treatment steps at two WWTPs receiving wastewater from the same city. The samples were centrifuged into aqueous and solid phases and then processed using solid phase extraction. Combined natural estrogens (estrone, estradiol and estriol) were measured using an enzyme-linked immunosorbent assay (ELISA) purchased from a manufacturer. Results confirmed that activated sludge treatments demonstrate greater estrogen removal compared to trickling filters and mass concentration of estrogen was measured for the first time on trickling filter solids. Physical and mechanical sludge treatment processes, such as gravity thickeners and centrifuges, did not significantly affect estrogen removal based on mass balance calculations. Dissolved air flotation thickening demonstrated a slight decrease in estrogen concentration, while anaerobic digestion resulted in increased mass concentration of estrogen on the sludge and a high estrogen concentration in the supernatant. Although there are no state or federally mandated discharge effluent standards or sludge application standards for estrogen, implications from this study are that trickling filters would need to be exchanged for activated sludge treatment or followed by an aeration basin in order to improve estrogen removal. Also, anaerobic digestion may need to be replaced

  20. Biolonical validation of a sample preparation method for ER-CALUX bioanalysis of estrogenic activity in sediment using mixtures of xeno-estrogens

    NARCIS (Netherlands)

    Houtman, C.J.; Houten, Van Y.K.; Leonards, P.E.G.; Brouwer, A.; Lamoree, M.H.; Legler, J.


    The combined estrogenic effects of mixtures of environmental pollutants in the in vitro ER-CALUX (chemical activated luciferase gene expression) bioassay were examined to biologically validate a sample preparation method for the analysis of estrogenic compounds in sediment. The method used accelerat

  1. Estrogenic Activity of Some Phytoestrogens on Bovine Oxytocin and Thymidine Kinase-ERE Promoter through Estrogen Receptor-α in MDA-MB 231 Cells

    Directory of Open Access Journals (Sweden)

    Ehsan Zayerzadeh


    Full Text Available Background: Phytoestrogens, a group of plant-derived polyphenolic compounds have recently come into considerable attention due to the increasing information on their potential adverse effects in human health. Some of phytoestrogens show estrogenic activity that may be carcinogenic for human. In the present study, we investigated the transcriptional effects of variety of phytoestrogens on the bovine oxytocin and the thymidine kinase-ERE promoter by estrogen receptor α in MDA-MB 231 breast cancer cell line. Materials and Methods: Cells were seeded for transfections into 12- well plates at a density of 100000 cells per well were transfected with a total of 3 μg of plasmid DNA using calcium phosphate coprecipitation. Estrogen and some phytoestrogens (naringenin, 8-prenyl-naringenin and 6-( 1, 1 - dimethylallyl naringenin were used for the stimulation of transfected cells. Results: Findings of our study clearly demonstrated the subtype-selective activation of estrogen receptor (ERα and (ERβ by the p hytoestrogen naringenin (activating estrogen receptor β and its substituted forms 8-prenyl-naringenin and 6-( 1, 1 - dimethylallyl naringenin (activating estrogen receptor α , on the ERE-controlled promoter as well as on the oxytocin gene promoter. Conclusion: The study revealed that some p hytoestrogen s show estrogenic activity by classical or non-classical mechanisms as well as exhibit estrogenic activity by undetermined mechanisms in transfected MDA-MB 231 cell line.

  2. AroER tri-screen™ is a novel functional assay to estimate both estrogenic and estrogen precursor activity of chemicals or biological specimens (United States)

    Kanaya, Noriko; Nguyen, Duc M.; Lu, Hannah; Wang, Yuan-Zhong; Hsin, Li-Yu; Petreas, Myrto; Nelson, David; Guo, Weihong; Reynolds, Peggy; Synold, Tim; Chen, Shiuan


    The purpose of the study is to define AroER tri-screen's utility for identifying endocrine-disrupting chemicals (EDCs) that target aromatase and/or estrogen receptor (ER), and to measure the total estrogenic activity in biological specimens. ER-positive, aromatase-expressing MCF-7 breast cancer cells were stably transfected with an estrogen responsive element (ERE)-driven luciferase reporter plasmid to yield a new high-throughput screening platform—the AroER tri-screen. AroER tri-screen was capable of identifying estrogen precursors, such as cortodoxone, which function as estrogens through a two-step conversion process in aromatase-expressing tissue. Furthermore, the system proved useful for assessing EDC activity in biologically relevant samples. Estimating these activities is critical because natural estrogens and estrogenic EDCs are important factors in ER-positive breast cancer risk. As our research demonstrates, incorporating functionally active aromatase into the AroER tri-screen produces a powerful and unique tool to (1) identify new EDCs targeting aromatase and/or ER; (2) discover novel EDCs activated by aromatase; and (3) estimate overall estrogenic activities in biological samples as a potential intermediate risk factor for breast cancer. PMID:25962693

  3. Comparison of in vitro estrogenic activity and estrogen concentrations in source and treated waters from 25 U.S. drinking water treatment plants (United States)

    In vitro bioassays have been successfully used to screen for estrogenic activity in wastewater and surface water, however, few have been applied to treated drinking water. Here, extracts of source and treated drinking water samples were assayed for estrogenic activity using T47D...

  4. AroER tri-screen™ is a novel functional assay to estimate both estrogenic and estrogen precursor activity of chemicals or biological specimens. (United States)

    Kanaya, Noriko; Nguyen, Duc M; Lu, Hannah; Wang, Yuan-Zhong; Hsin, Li-Yu; Petreas, Myrto; Nelson, David; Guo, Weihong; Reynolds, Peggy; Synold, Tim; Chen, Shiuan


    The purpose of the study is to define AroER tri-screen's utility for identifying endocrine-disrupting chemicals (EDCs) that target aromatase and/or estrogen receptor (ER), and to measure the total estrogenic activity in biological specimens. ER-positive, aromatase-expressing MCF-7 breast cancer cells were stably transfected with an estrogen responsive element (ERE)-driven luciferase reporter plasmid to yield a new high-throughput screening platform-the AroER tri-screen. AroER tri-screen was capable of identifying estrogen precursors, such as cortodoxone, which function as estrogens through a two-step conversion process in aromatase-expressing tissue. Furthermore, the system proved useful for assessing EDC activity in biologically relevant samples. Estimating these activities is critical because natural estrogens and estrogenic EDCs are important factors in ER-positive breast cancer risk. As our research demonstrates, incorporating functionally active aromatase into the AroER tri-screen produces a powerful and unique tool to (1) identify new EDCs targeting aromatase and/or ER; (2) discover novel EDCs activated by aromatase; and (3) estimate overall estrogenic activities in biological samples as a potential intermediate risk factor for breast cancer.

  5. Estradiol-induced modulation of estrogen receptor-beta and GABA within the adult neocortex: a potential transsynaptic mechanism for estrogen modulation of BDNF. (United States)

    Blurton-Jones, Mathew; Tuszynski, Mark H


    Estrogen influences brain-derived neurotrophic factor (BDNF) expression in the neocortex. However, BDNF-producing cortical neurons do not express detectable levels of nuclear estrogen receptors; instead, the most abundant cortical nuclear estrogen receptor, ER-beta, is present in GABAergic neurons, prompting us to test the hypothesis that estrogen effects on BDNF are mediated via cortical inhibitory interneurons. Adult female ovariectomized rats were provided acute estrogen replacement and the number of cortical GABA, ER-beta, and ER-beta/GABA double-labeled neurons was examined. Within 48 hours of injection of 17-beta-estradiol, the number of perirhinal neurons double-labeled for ER-beta/GABA was reduced by 28% (PBDNF-expressing cells, brain sections were double- or triple-labeled for ER-beta, GABAergic, and BDNF immunomarkers. The findings indicated that ER-beta-bearing inhibitory neurons project onto other GABAergic neurons that lack nuclear estrogen receptors; these inhibitory neurons in turn innervate BDNF-expressing excitatory cells. High estrogen states reduce cortical GABA levels, presumably releasing inhibition on BDNF-expressing neurons. This identifies a putative two-step transsynaptic mechanism whereby estrogen availability modulates expression of inhibitory transmitters, resulting in increased BDNF expression.

  6. A RIKILT yeast estrogen bioassay (REA) for estrogen residue detection in urine of calves experimentally treated with 17ß-estradiol

    NARCIS (Netherlands)

    Divari, S.; Maria, De R.; Cannizzo, F.T.; Spada, F.; Mulasso, C.; Bovee, T.F.H.; Capra, P.; Leporati, M.; Biolatti, B.


    17ß-Estradiol is one of the most powerful sex steroids illegally used in bovine production. The objective of this study was to evaluate the application and the specificity of the RIKILT yeast estrogen bioassay (REA) for the detection of molecules with estrogenic activities in the urine of calves exp

  7. Early expression of aromatase and the membrane estrogen receptor GPER in neuromasts reveals a role for estrogens in the development of the frog lateral line system. (United States)

    Hamilton, Christine K; Navarro-Martin, Laia; Neufeld, Miriam; Basak, Ajoy; Trudeau, Vance L


    Estrogens and their receptors are present at very early stages of vertebrate embryogenesis before gonadal tissues are formed. However, the cellular source and the function of estrogens in embryogenesis remain major questions in developmental endocrinology. We demonstrate the presence of estrogen-synthesizing enzyme aromatase and G protein-coupled estrogen receptor (GPER) proteins throughout early embryogenesis in the model organism, Silurana tropicalis. We provide the first evidence of aromatase in the vertebrate lateral line. High levels of aromatase were detected in the mantle cells of neuromasts, the mechanosensory units of the lateral line, which persisted throughout the course of development (Nieuwkoop and Faber stages 34-47). We show that GPER is expressed in both the accessory and hair cells. Pharmacological activation of GPER with the agonist G-1 disrupted neuromast development and migration. Future study of this novel estrogen system in the amphibian lateral line may shed light on similar systems such as the mammalian inner ear.

  8. Kinematics of Hα Emitting Stars in Andromeda (United States)

    Ilango, Megha; Ilango, Anita; Damon, Gabriel; Prichard, Laura; Guhathakurta, Puragra; PHAT Collaboration; SPLASH Collaboration


    Studying emission line stars helps improve our understanding of stellar evolution, types of stars, and their environments. In this study, we analyzed stars exhibiting Hα emission (Hα stars) in the Andromeda Galaxy. We used a combination of spectroscopic and photometric diagnostic methods to remove a population of foreground Milky Way (MW) star contaminants from our data set. The Hα stars were selected from a sample of 5295 spectra from the Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo (SPLASH) survey and accompanying photometric data from the Panchromatic Hubble Andromeda Treasury (PHAT) survey. Velocities of two classes of Hα stars, main sequence (MS) stars and asymptotic giant branch (AGB) stars, were analyzed through a novel Age-Velocity Difference Correlation (AVDC) method, which utilizes line-of-sight velocity differences (LOSVDs) in order to estimate the age of a rare stellar population. Histograms, weighted means, and weighted standard deviations of the LOSVDs were used to conclude that MS stars are more kinematically coherent than AGB stars, and that Hα stars are kinematically comparable and thus close in age to their non-Hα counterparts. With these results, it can definitively be inferred that mass loss is important in two stages of stellar evolution: massive MS and intermediate mass AGB. We hypothesized that this mass loss could either occur as a normal part of MS and AGB evolution, or that it could be emitted by only a subpopulation of MS and AGB stars throughout their life cycle. Our use of the novel AVDC method sets a precedent for the use of similar methods in predicting the ages of rare stellar subgroups.This research was supported by NASA and the National Science Foundation. Most of this work was carried out by high school students working under the auspices of the Science Internship Program at UC Santa Cruz.

  9. Use of adenovirus vector expressing the mouse full estrogen receptor alpha gene to infect mouse primary neurons

    Institute of Scientific and Technical Information of China (English)

    Xiao HU; Lei Lou; Jun Yuan; Xing Wan; Jianyi Wang; Xinyue Qin


    Estrogen plays important regulatory and protective roles in the central nervous system through estrogen receptor a mediation.Previous studies applied eukaryotic expression and lentiviral vectors carrying estrogen receptor a to clarify the undedying mechanisms,in the present study,an adenovirus vector expressing the mouse full estrogen receptor a gene was constructed to identify biological characteristics of estrogen receptor a recombinant adenovirus infecting nerve cells.Primary cultured mouse nerve cells were first infected with estrogen receptor a recombinant adenovirus at various multiplicities of infection,followed by 100 multiplicity of infection.Results showed overexpression of estrogen receptor a mRNA and protein in the infected nerve cells.Estrogen receptor a recombinant adenovirus at 100 multiplicity of infection successfully infected neurons and upregulated estrogen receptor a mRNA and protein expression.

  10. Estrogen-mediated regulation of Igf1 transcription and uterine growth involves direct binding of estrogen receptor alpha to estrogen-responsive elements. (United States)

    Hewitt, Sylvia C; Li, Yin; Li, Leping; Korach, Kenneth S


    Estrogen enables uterine proliferation, which depends on synthesis of the IGF1 growth factor. This proliferation and IGF1 synthesis requires the estrogen receptor (ER), which binds directly to target DNA sequences (estrogen-responsive elements or EREs), or interacts with other transcription factors, such as AP1, to impact transcription. We observe neither uterine growth nor an increase in Igf1 transcript in a mouse with a DNA-binding mutated ER alpha (KIKO), indicating that both Igf1 regulation and uterine proliferation require the DNA binding function of the ER. We identified several potential EREs in the Igf1 gene, and chromatin immunoprecipitation analysis revealed ER alpha binding to these EREs in wild type but not KIKO chromatin. STAT5 is also reported to regulate Igf1; uterine Stat5a transcript is increased by estradiol (E(2)), but not in KIKO or alpha ERKO uteri, indicating ER alpha- and ERE-dependent regulation. ER alpha binds to a potential Stat5a ERE. We hypothesize that E(2) increases Stat5a transcript through ERE binding; that ER alpha, either alone or together with STAT5, then acts to increase Igf1 transcription; and that the resulting lack of IGF1 impairs KIKO uterine growth. Treatment with exogenous IGF1, alone or in combination with E(2), induces proliferation in wild type but not KIKO uteri, indicating that IGF1 replacement does not rescue the KIKO proliferative response. Together, these observations suggest in contrast to previous in vitro studies of IGF-1 regulation involving AP1 motifs that direct ER alpha-DNA interaction is required to increase Igf1 transcription. Additionally, full ER alpha function is needed to mediate other cellular signals of the growth factor for uterine growth.

  11. Perovskite Materials for Light-Emitting Diodes and Lasers. (United States)

    Veldhuis, Sjoerd A; Boix, Pablo P; Yantara, Natalia; Li, Mingjie; Sum, Tze Chien; Mathews, Nripan; Mhaisalkar, Subodh G


    Organic-inorganic hybrid perovskites have cemented their position as an exceptional class of optoelectronic materials thanks to record photovoltaic efficiencies of 22.1%, as well as promising demonstrations of light-emitting diodes, lasers, and light-emitting transistors. Perovskite materials with photoluminescence quantum yields close to 100% and perovskite light-emitting diodes with external quantum efficiencies of 8% and current efficiencies of 43 cd A(-1) have been achieved. Although perovskite light-emitting devices are yet to become industrially relevant, in merely two years these devices have achieved the brightness and efficiencies that organic light-emitting diodes accomplished in two decades. Further advances will rely decisively on the multitude of compositional, structural variants that enable the formation of lower-dimensionality layered and three-dimensional perovskites, nanostructures, charge-transport materials, and device processing with architectural innovations. Here, the rapid advancements in perovskite light-emitting devices and lasers are reviewed. The key challenges in materials development, device fabrication, operational stability are addressed, and an outlook is presented that will address market viability of perovskite light-emitting devices.

  12. Power output and efficiency of beta-emitting microspheres (United States)

    Cheneler, David; Ward, Michael


    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire's theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer.

  13. Food-associated estrogenic compounds induce estrogen receptor-mediated luciferase gene expression in transgenic male mice. (United States)

    Ter Veld, Marcel G R; Zawadzka, E; van den Berg, J H J; van der Saag, Paul T; Rietjens, Ivonne M C M; Murk, Albertinka J


    The present paper aims at clarifying to what extent seven food-associated compounds, shown before to be estrogenic in vitro, can induce estrogenic effects in male mice with an estrogen receptor (ER)-mediated luciferase (luc) reporter gene system. The luc induction was determined in different tissues 8h after dosing the ER-luc male mice intraperitoneally (IP) or 14h after oral dosing. Estradiol-propionate (EP) was used as a positive control at 0.3 and 1mg/kg bodyweight (bw), DMSO as solvent control. The food-associated estrogenic compounds tested at non-toxic doses were bisphenol A (BPA) and nonylphenol (NP) (both at 10 and 50mg/kgbw), dichlorodiphenyldichloroethylene (p,p'-DDE; at 5 and 25mg/kgbw), quercetin (at 1.66 and 16.6mg/kgbw), di-isoheptyl phthalate (DIHP), di-(2-ethylhexyl) phthalate (DEHP) and di-(2-ethylhexyl) adipate (DEHA) all at 30 and 100mg/kgbw. In general IP dosing resulted in higher luc inductions than oral dosing. EP induced luc activity in the liver in a statistically significant dose-related way with the highest induction of all compounds tested which was 20,000 times higher than the induction by the DMSO-control. NP, DDE, DEHA and DIHP did not induce luc activity in any of the tissues tested. BPA induced luc in the liver up to 420 times via both exposure routes. BPA, DEHP and quercetin induced luc activity in the liver after oral exposure. BPA (50mg/kgbw IP) also induced luc activity in the testis, kidneys and tibia. The current study reveals that biomarker-responses in ER-luc male mice occur after a single oral exposure to food-associated estrogenic model compounds at exposure levels 10 to 10(4) times higher than the established TDI's for some of these compounds. Given the facts that (i) the present study did not include chronic exposure and that (ii) simultaneous exposure to multiple estrogenic compounds may be a realistic exposure scenario, it remains to be seen whether this margin is sufficiently high.

  14. Interplay between estrogen response element sequence and ligands controls in vivo binding of estrogen receptor to regulated genes. (United States)

    Krieg, Adam J; Krieg, Sacha A; Ahn, Bonnie S; Shapiro, David J


    To examine the role of the estrogen response element (ERE) sequence in binding of liganded estrogen receptor (ER) to promoters, we analyzed in vivo interaction of liganded ER with the imperfect ERE in the pS2 gene and the composite estrogen-responsive unit (ERU) in the proteinase inhibitor 9 (PI-9) gene. In transient transfections of ER-positive HepG2-ER7 cells, PI-9 was strongly induced by estrogen, moxestrol (MOX), and 4-hydroxytamoxifen (OHT). PI-9 was not induced by raloxifene or ICI 182,780. Quantitative reverse transcriptase-PCR showed that moxestrol strongly induced cellular PI-9 and pS2 mRNAs, whereas OHT moderately induced PI-9 mRNA and weakly induced pS2 mRNA. Chromatin immunoprecipitation experiments demonstrated strong and similar association of 17beta-estradiol-hERalpha and MOX-hERalpha with the PI-9 ERU and with the pS2 ERE. Binding of MOX-hERalpha to the PI-9 ERU and the pS2 ERE was rapid and continuous. Although MOX-hERalpha bound strongly to the PI-9 ERU and less well to the pS2 ERE in chromatin immunoprecipitation, gel shift assays showed that estrogen-hERalpha binds with higher affinity to the deproteinized pS2 ERE than to the PI-9 ERU. Across a broad range of OHT concentrations, OHT-hERalpha associated strongly with the pS2 ERE and weakly with the PI-9 ERU. ICI-hERalpha bound poorly to the PI-9 ERU and effectively to the pS2 ERE. Raloxifene-hERalpha and MOX-hERalpha exhibited similar binding to the PI-9 ERU and the pS2 ERE. These studies demonstrate that ER ligand and ERE sequence work together to regulate in vivo binding of ER to estrogen-responsive promoters.

  15. Chronic oxidative stress causes estrogen-independent aggressive phenotype, and epigenetic inactivation of estrogen receptor alpha in MCF-7 breast cancer cells. (United States)

    Mahalingaiah, Prathap Kumar S; Ponnusamy, Logeswari; Singh, Kamaleshwar P


    The role of chronic oxidative stress in the development and aggressive growth of estrogen receptor (ER)-positive breast cancer is well known; however, the mechanistic understanding is not clear. Estrogen-independent growth is one of the features of aggressive subtype of breast cancer. Therefore, the objective of this study was to evaluate the effect of oxidative stress on estrogen sensitivity and expression of nuclear estrogen receptors in ER-positive breast cancer cells. MCF-7 cells chronically exposed to hydrogen peroxide were used as a cell model in this study, and their growth in response to 17-β estradiol was evaluated by cell viability, cell cycle, and cell migration analysis. Results were further confirmed at molecular level by analysis of gene expressions at transcript and protein levels. Histone H3 modifications, expression of epigenetic regulatory genes, and the effect of DNA demethylation were also analyzed. Loss of growth in response to estrogen with a decrease in ERα expression was observed in MCF-7 cells adapted to chronic oxidative stress. Increases in mtTFA and NRF1 in these cells further suggested the role of mitochondria-dependent redox-sensitive growth signaling as an alternative pathway to estrogen-dependent growth. Changes in expression of epigenetic regulatory genes, levels of histone H3 modifications as well as significant restorations of both ERα expression and estrogen response by 5-Aza-2'-deoxycytidine further confirmed the epigenetic basis for estrogen-independent growth in these cells. In conclusion, results of this study suggest that chronic oxidative stress can convert estrogen-dependent nonaggressive breast cancer cells into estrogen-independent aggressive form potentially by epigenetic mechanism.

  16. SIRT1 Represses Estrogen-signaling, Ligand-Independent ERα-mediated Transcription, and Cell Proliferation in Estrogen-Responsive Breast Cells (United States)

    Moore, Robert L.; Faller, Douglas V.


    In prostate and breast cancer, the androgen and estrogen receptors mediate induction of androgen- and estrogen-responsive genes respectively, and stimulate cell proliferation in response to the binding of their cognate steroid hormones. Sirtuin 1 (SIRT1) is a nicotinamide adenosine dinucleotide (NAD+)-dependent class III histone deacetylase (HDAC) that has been linked to gene silencing, control of the cell cycle, apoptosis and energy homeostasis. In prostate cancer, SIRT1 is required for androgen-antagonist-mediated transcriptional repression and growth suppression of prostate cancer cells. Whether SIRT1 plays a similar role in the actions of estrogen or antagonists had not been determined. We report here that SIRT1 represses the transcriptional and proliferative response of breast cancer cells to estrogens, and this repression is estrogen receptor-alpha (ERα)-dependent. Inhibition of SIRT1 activity results in the phosphorylation of ERα in an AKT-dependent manner, and this activation requires phosphoinositide 3-kinase (PI3K) activity. Phosphorylated ERα subsequently accumulates in the nucleus, where ERα binds DNA ER-response elements and activates transcription of estrogen-responsive genes. This ER-dependent transcriptional activation augments estrogen-induced signaling, but also activates ER-signaling in the absence of estrogen, thus defining a novel and unexpected mechanism of ligand-independent ERα-mediated activation and target gene transcription. Like ligand-dependent activation of ERα, SIRT1 inhibition-mediated ERα activation in the absence of estrogen also results in breast cancer cell proliferation. Together, these data demonstrate that SIRT1 regulates the most important cell signaling pathway for the growth of breast cancer cells, both in the presence and the absence of estrogen. PMID:23169992

  17. Assessment of cellular estrogenic activity based on estrogen receptor-mediated reduction of soluble-form catechol-O-methyltransferase (COMT) expression in an ELISA-based system. (United States)

    Ho, Philip Wing-Lok; Tse, Zero Ho-Man; Liu, Hui-Fang; Lu, Song; Ho, Jessica Wing-Man; Kung, Michelle Hiu-Wai; Ramsden, David Boyer; Ho, Shu-Leong


    Xenoestrogens are either natural or synthetic compounds that mimic the effects of endogenous estrogen. These compounds, such as bisphenol-A (BPA), and phthalates, are commonly found in plastic wares. Exposure to these compounds poses major risk to human health because of the potential to cause endocrine disruption. There is huge demand for a wide range of chemicals to be assessed for such potential for the sake of public health. Classical in vivo assays for endocrine disruption are comprehensive but time-consuming and require sacrifice of experimental animals. Simple preliminary in vitro screening assays can reduce the time and expense involved. We previously demonstrated that catechol-O-methyltransferase (COMT) is transcriptionally regulated by estrogen via estrogen receptor (ER). Therefore, detecting corresponding changes of COMT expression in estrogen-responsive cells may be a useful method to estimate estrogenic effects of various compounds. We developed a novel cell-based ELISA to evaluate cellular response to estrogenicity by reduction of soluble-COMT expression in ER-positive MCF-7 cells exposed to estrogenic compounds. In contrast to various existing methods that only detect bioactivity, this method elucidates direct physiological effect in a living cell in response to a compound. We validated our assay using three well-characterized estrogenic plasticizers - BPA, benzyl butyl phthalate (BBP), and di-n-butyl phthalate (DBP). Cells were exposed to either these plasticizers or 17β-estradiol (E2) in estrogen-depleted medium with or without an ER-antagonist, ICI 182,780, and COMT expression assayed. Exposure to each of these plasticizers (10(-9)-10(-7)M) dose-dependently reduced COMT expression (pvitro assays of similar sensitivity. To satisfy the demand for in vitro assays targeting different cellular components, a cell-based COMT assay provides useful initial screening to supplement the current assessments of xenoestrogens for potential estrogenic activity.

  18. Revisiting Estrogen: Efficacy and Safety for Postmenopausal Bone Health

    Directory of Open Access Journals (Sweden)

    Sandra M. Sacco


    Full Text Available The rapid decline in endogenous estrogen production that occurs during menopause is associated with significant bone loss and increased risk for fragility fracture. While hormone therapy (HT is an effective means to re-establish endogenous estrogen levels and reduce the risk of future fracture, its use can be accompanied by undesirable side effects such as stroke and breast cancer. In this paper, we revisit the issue of whether HT can be both safe and effective for the prevention of postmenopausal bone loss by examining standard and alternative doses and formulations of HT. The aim of this paper is to continue the dialogue regarding the benefits and controversies of HT with the goal of encouraging the dissemination of-up-to date evidence that may influence how HT is viewed and prescribed.

  19. Androgens and estrogens in postmenopausal insulin-treated diabetic women

    DEFF Research Database (Denmark)

    Nyholm, H; Djursing, H; Hagen, C;


    Diabetic women may have an increased risk of developing endometrial carcinoma. Ovarian and adrenal activity seem to be factors in the genesis of this cancer. We have measured serum sex hormone-binding globulin (SHBG), free and bound fractions of estrogens and androgens, and gonadotropins in 20...... consecutive postmenopausal insulin-treated diabetic women and 16 normal postmenopausal women. The diabetics were nonketoacidotic, without nephropathy and without proliferative retinopathy. The groups were comparable regarding age and percent ideal body weight. The diabetic group had significantly increased...... levels were similar in the two groups, while serum PRL was significantly lower in the diabetic group (P less than 0.02). The hormonal changes in the diabetics were not related to control of the diabetes. We conclude that total estrogen levels are increased in postmenopausal women with insulin...

  20. RIME proteomics of estrogen and progesterone receptors in breast cancer

    Directory of Open Access Journals (Sweden)

    Clive D’Santos


    Full Text Available Nuclear receptors play an important role in transcriptional regulation of diverse cellular processes and is also relevant in diseases such as cancer. In breast cancer, the nuclear receptors – estrogen receptor (ER and progesterone receptor (PR are classical markers of the disease and are used to classify breast cancer subtypes. Using a recently developed affinity purification MS technique (RIME [1], we investigate the protein interactors of ER and PR in breast cancer cell lines upon stimulation by the ligands – estrogen and progesterone. The data is deposited at proteomeXchange (PXD002104 and is part of a publication [2] that explains the link between the two nuclear receptors and potential consequences of this in breast cancer. In this manuscript, we describe the methodology used and provide details on experimental procedures, analysis methods and analysis of raw data. The purpose of this article is to enable reproducibility of the data and provide technical recommendations on performing RIME in hormonal contexts.

  1. Flavonoids from Iris songarica and their antioxidant and estrogenic activity. (United States)

    Moein, Mahmood R; Khan, Shabana I; Ali, Zulfiqar; Ayatollahi, Syed A; Kobarfard, Farzad; Nasim, Shama; Choudhary, Muhammad I; Khan, Ikhlas A


    A new dihydroflavonol, songaricol ( 1) and seven known flavonoids, ayamenin A ( 2), irisflavone A ( 3), 5,7-dihydroxy-2',6-dimethoxyisoflavone ( 4), irilin B ( 5), 5,3'-dihydroxy-7,8,2'-trimethoxyisoflavone ( 6) and irisoid A ( 7) were isolated from rhizome and roots of IRIS SONGARICA. Structure elucidation of 1 was achieved through extensive NMR and circular dichroism techniques. Compounds 1, 5 and 7 showed antioxidant activity in HL-60 cells (IC50 values of 21, 11 and 3.8 microg/mL), whereas 2, 5 and the previously isolated irisone B were able to show estrogenic response (EC50 values of 305.5, 159.7 and 322.0 microg/mL) in yeast cells expressing human estrogen receptor (ER-alpha).

  2. Estrogenic activity of furanocoumarins isolated from Angelica dahurica. (United States)

    Piao, Xiang Lan; Yoo, Hye Hyun; Kim, Hyun Young; Kang, Tak Lim; Hwang, Gwi Seo; Park, Jeong Hill


    In our efforts to discover novel phytoestrogens to treat menopausal symptoms, eleven furanocoumarins were isolated from Angelica dahurica and tested for their estrogenic activity on the Ishikawa cell line. Among the compounds tested, 9-hydroxy-4-methoxypsoralen and alloisoimperatorin showed strong abilities to induce alkaline phosphatase (AP) with EC50 values of 1.1 and 0.8 microg/mL, respectively, whereas the other nine furanocoumarins were weakly or only slightly active.

  3. Breast Cancer Lymphatic Dissemination-Influence of Estrogen and Progesterone (United States)


    progesterone is diminished. Though progestin treatment led to a decrease in the percent of tumors that generated LN metastases, it is obvious that in... progestin dose and duration of treatment effect metastases is warranted. These studies complete task 2. Task 3. The third task in my approved...Results found that there are differences in estrogen responsiveness in breast tumors compared to the matched LN metastases, suggesting that aromatase

  4. Estrogen-Induced Monocytic Response Correlates with Temporomandibular Disorder Pain. (United States)

    Ribeiro-Dasilva, M C; Fillingim, R B; Wallet, S M


    Temporomandibular disorders (TMD) are a set of conditions characterized by pain and dysfunction in the temporomandibular joint and muscles of mastication. These pain conditions are associated with considerable morbidity, societal costs, and reduced quality of life. The prevalence varies between 4% and 10%, with females at higher risk, and a higher prevalence occurs during reproductive years. The increased prevalence of TMD in females and low prevalence in childhood reinforce that sex hormones, like estrogen, play an important, complex role in the pathophysiology of these disorders. The goal of this study was to determine whether women with TMD exhibit a monocytic hyperinflammatory response compared with control women, and to examine associations of monocytic inflammatory responses with clinical pain. Eighteen women, aged 18 to 35 y, were seen during their follicular menstrual phase. A blood sample was collected, a clinical questionnaire about pain history was administered, and a Research Diagnostic Criteria (RDC) exam was performed. Extracted monocytes were stimulated with the toll-like receptor (TLR)-4 ligand, lipopolysaccharide (LPS), in the presence and absence of estrogen, and the levels of IL6 expression evaluated. Women with TMD showed a systemic hyperinflammatory phenotype, manifested by an increased monocytic release of cytokines after an inflammatory insult, and this was further increased by estrogen. In addition, monocytes from participants who self-reported more pain on the VAS scale produced higher levels of IL6 compared with those from participants who self-reported lower pain sensitivity. These data suggest that an estrogen-induced hyperinflammatory phenotype in women with TMD may at least in part contribute to heightened clinical pain, perhaps via central sensitization.

  5. Estrogen Receptor-α Polymorphisms and Predisposition to TMJ Disorder


    Ribeiro-Dasilva, Margarete Cristiane; Line, Sérgio Roberto Peres; dos Santos, Maria Cristina Leme Godoy; Arthuri, Mariana Trevisani; Hou, Wei; Fillingim, Roger Benton; Barbosa,Célia Marisa Rizzatti


    Temporomandibular joint disorders (TMJD) affect women with greater frequency than men, and sex hormones may contribute to this female predominance. Therefore, this study investigated whether estrogen receptor-α (XbaI/PvuII) single nucleotide polymorphisms (SNPs) are associated with TMJD in women. DNA was obtained from 200 women with TMJD (100 with chronic pain and 100 with signs of TMJD but no pain) diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TM...

  6. Inter-laboratory exercise on steroid estrogens in aqueous samples

    DEFF Research Database (Denmark)

    Heath, E.; Kosjek, T.; Andersen, Henrik Rasmus;


    to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens...... in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones. (C) 2009 Elsevier Ltd All rights reserved....

  7. Bazedoxifene: a novel selective estrogen receptor modulator for postmenopausal osteoporosis. (United States)

    de Villiers, T J


    Several new selective estrogen receptor modulators (SERMs) are currently under clinical development for the prevention and/or treatment of postmenopausal osteoporosis, with the goal of optimizing the estrogen receptor agonist/antagonist activity in target tissues. Bazedoxifene is a novel SERM under clinical investigation for the prevention and treatment of postmenopausal osteoporosis. Emerging clinical data have shown that bazedoxifene is effective in preventing bone loss and osteoporotic fractures in postmenopausal women, with no evidence of breast or endometrial stimulation. Two large, prospective, international phase 3 studies have been completed. In postmenopausal women at risk for osteoporosis, bazedoxifene has been shown to preserve bone mineral density and to reduce bone turnover. In postmenopausal women with osteoporosis, bazedoxifene has demonstrated significant protection against new vertebral fractures and against non-vertebral fractures in women at higher fracture risk. The treatment effects of bazedoxifene were supported by findings from independent re-analyses using the Fracture Risk Assessment Tool (FRAX), which showed that bazedoxifene significantly reduced the risk of all clinical and morphometric vertebral fracture and of non-vertebral fracture in women at or above a FRAX-based threshold. Bazedoxifene was generally safe and well tolerated in the phase 3 studies and showed neutral effects on the breast and an excellent endometrial safety profile; such attributes allow for the partnering of bazedoxifene with conjugated estrogens for menopausal symptom relief. Collectively, these results suggest that bazedoxifene may be a promising new therapy for the prevention and treatment of postmenopausal osteoporosis as a monotherapy or in combination with conjugated estrogens in menopausal hormone therapy.

  8. Estrogen Receptor Mutants/Variants in Human Breast Cancer. (United States)


    Bethesda, MD, USA). detection sensitivity and increases the Human immunodeficiency virus type 2 Tamara Hiller, Linda Snell yield of the amplified products...was McBride- Putman 2 , S. Fuqua2, R. Luput. ’Georgetown University, Washington, D.C. observed for the estrogen receptor, cyclin DI, and CerbB-2. (3) A...Leygue, Linda Snell, Leigh C. Murphy and Peter H. Watson * *Affiliations of authors: A. Huang, L. Snell, and P.H. Watson (Department of Pathology), E

  9. Role for endogenous estrogen in prepubertal Sertoli cell maturation. (United States)

    Kao, Eddy; Villalon, Rosalina; Ribeiro, Salustiano; Berger, Trish


    Reducing prepubertal endogenous estrogens led to increased numbers of Sertoli cells and the associated increased testicular size and testicular sperm production capacity in boars. The increased number of Sertoli cells might be due to a longer time for proliferation; delayed differentiation of Sertoli cells during suppressed endogenous estrogens would be consistent with this hypothesized, prolonged proliferation interval. This study used immunohistochemical detection of anti-Müllerian hormone (AMH), a marker of immature Sertoli cells, and of CDKN1B, a cell cycle inhibitor associated with more mature Sertoli cells, to determine if suppressing endogenous estrogens detectably delayed "differentiation" of porcine Sertoli cells. Testes were from littermate pairs of boars previously treated with Letrozole, an aromatase inhibitor, or vehicle, from the first week of age until tissue collection at 2, 3, 4, 5 or 6 months of age. Four animals were examined at each age following Letrozole treatment and their corresponding littermates evaluated following treatment with vehicle. Amount of AMH protein in Sertoli cells decreased with age of boar and could not be detected at 6 months of age. The AMH labeling was greater in the Letrozole-treated boars compared with littermate vehicle controls at 4 months of age (P=0.03). The percentage of CDKN1B-labeled Sertoli cells apparently increased with age through 5 months of age. At 4 and 5 months of age, the mean percentage of CDKN1B-labeled Sertoli cells was less in the Letrozole-treated animals than in the vehicle control animals (P = 0.03 and 0.04, respectively). These results are consistent with the hypothesis that continual inhibition of aromatase (and concomitatant reduced estrogen synthesis) causes a delay in Sertoli cell maturation in boars.

  10. Guppy sexual behavior as an effect biomarker of estrogen mimics

    DEFF Research Database (Denmark)

    Bayley, M; Nielsen, J R; Baatrup, E


    There is widespread concern that some environmental chemicals can reduce the reproductive capability of humans and wildlife by mimicking natural estrogens and disrupting endocrine function. This potential threat to animal populations posed by xenoestrogens has, hardly surprisingly, been met...... strongly on the ability to perform the appropriate sexual behavior. The sexual display of the male guppy is strongly linked to reproductive success and is readily quantified under laboratory conditions. This preliminary study demonstrates that exposure of adult male guppies to water weakly contaminated...

  11. The Effects of Dopamine and Estrogen upon Cortical Parvalbumin Expression (United States)


    positive interneurons because studies indicate that the parvalbumin containing subclass of GABAergic neurons are contacted by mesocortical dopamine fibers...that both dopamine and estrogen enhance the maturation of cortical interneurons that express the calcium binding protein, parvalbumin , in the developing... parvalbumin expression in the deep cortical layers in the in vivo model. Dopamine D1 and D2 receptors are located on parvalbumin containing interneurons

  12. Evidence of coprostanol estrogenicity to the freshwater mussel Elliptio complanata. (United States)

    Gagné, F; Blaise, C; Lachance, B; Sunahara, G I; Sabik, H


    Coprostanol (5 beta (H)-cholestan-3 beta ol) is a reduced metabolite of cholesterol produced by micro-organisms found in the intestinal tract of mammals. This substance abounds in urban effluents and is accumulated by organisms living in the vicinity of municipal effluent outfalls. In an earlier study, freshwater mussels exposed to contaminated river water for 62 days accumulated large quantities of coprostanol (Cop) in their soft tissues (16 micrograms/g dry wt.). Moreover, these mussels were found to have elevated levels of vitellin in their hemolymphs, suggesting estrogenic effects. Although municipal wastewaters are known to contain other estrogenic compounds capable of inducing Vn synthesis in mussels, the estrogenic potential of coprostanol was singled out for examination. To this end, mussels were first injected with concentrations of coprostanol via the abductor muscle route, and allowed to stand in aerated water for 72 h at 15 degrees C. The levels of Vn in mussel hemolymph were assayed using the organic alkali-labile phosphate method. A competitive estradiol-binding assay was then devised to measure the ability of coprostanol to compete in the binding of fluorescein-labeled estradiol-albumin to cytosolic proteins. Coprostanol partially reversed the binding of labeled estradiol-albumin to cytosolic proteins with an EC50 of 1 mM. In addition, injections of coprostanol and estradiol-17 beta led to increased levels of vitellins in the hemolymph of treated mussels. Moreover, incubation of cop in gonad homogenate extracts in the presence of NADPH led to the formation of two compounds, as determined by high-performance thin-layer chromatography. One of these compounds appears to be the C17 oxidation product of coprostanol, whose polarity is similar to that of estradiol. The results present evidence that coprostanol is estrogenic to freshwater mussels.

  13. Rapid control of male typical behaviors by brain-derived estrogens. (United States)

    Cornil, Charlotte A; Ball, Gregory F; Balthazart, Jacques


    Beside their genomic mode of action, estrogens also activate a variety of cellular signaling pathways through non-genomic mechanisms. Until recently, little was known regarding the functional significance of such actions in males and the mechanisms that control local estrogen concentration with a spatial and time resolution compatible with these non-genomic actions had rarely been examined. Here, we review evidence that estrogens rapidly modulate a variety of behaviors in male vertebrates. Then, we present in vitro work supporting the existence of a control mechanism of local brain estrogen synthesis by aromatase along with in vivo evidence that rapid changes in aromatase activity also occur in a region-specific manner in response to changes in the social or environmental context. Finally, we suggest that the brain estrogen provision may also play a significant role in females. Together these data bolster the hypothesis that brain-derived estrogens should be considered as neuromodulators.

  14. Gene expression changes in rat prostate after activation or blocking of the androgen and estrogen receptor

    DEFF Research Database (Denmark)

    Nellemann, Christine Lydia; Dalgaard, Majken; Holst, Bjørn;


    Several endpoints of different molecular complexity were studied in the Hershberger assay in order to evaluate the specificity and suitability of this test as a broad screening model. Androgen and estrogen receptors were activated or blocked, and expression of typical estrogen- or androgen...... and the anti-estrogen, ICI 182780, only affected ODC expression. Therefore, estrogenic or anti-estrogenic compounds would not be expected to seriously affect the outcome of a Hershberger test. However, EB given alone to castrated rats resulted in various effects. EB increased seminal vesicle weight, an effect...... reversed by ICI 182780, and affected TRPM-2, PBP C3, ODC, IGF-1, AR, and ERa mRNA levels. AR expression in the prostate seemed to be under regulation of both estrogens and androgens, as ICI 182780 inhibited the testosterone-induced AR expression, and flutamide inhibited the EB-induced AR expression...

  15. Synthesis and Property of New Propeller Shaped Emitting Materials for Organic Light-Emitting Devices. (United States)

    Kang, Seokwoo; Lee, Hayoon; Kim, Beomjin; Park, Youngil; Park, Jongwook


    New propeller type emitting compound, namely 3,6-di-anthracen-9-yl-9,10-bis-(4-anthracen-9-yi-phenyl)-phenanthrene[TAnDAP] and 3,6-bis-(10-phenyl-anthracen-9-yl)-9,10-bis-[4-(10-phenyl-anthracen-9-yl)-phenyl]-phenanthrene [TAnPDAP] were synthesized through Suzuki and McMurry reactions. We investigated their physical properties such as optical, electrochemical, and electroluminescent properties. The two compounds were used as an emitting layer in OLED devices: ITO/2-TNATA (60 nm)/NPB (15 nm)/non-doped: TAnDAP or TAnPDAP (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). The TAnDAP OLED device showed C.I.E. value of (0.28, 0.41) and luminance efficiency of 3.81 cd/A at 10 mA/cm2. The TAnPDAP device showed C.I.E. value of (0.20, 0.27) and high luminance efficiency of 5.40 cd/A at 10 mA/cm2. TAnPDAP was found to show better luminance efficiency and C.I.E. value than TAnDAP because it has a bulky 9-phenylanthracene.

  16. High-contrast top-emitting organic light-emitting devices

    Institute of Scientific and Technical Information of China (English)

    Chen Shu-Fen; Chen Chun-Yan; Yang Yang; Xie Jun; Huang Wei; Shi Hong-Ying; Cheng Fan


    In this paper we report on a high-contrast top-emitting organic light-emitting device utilizing a moderate-reflection contrast-enhancement stack and a high refractive index anti-reflection layer.The contrast-enhancement stack consists of a thin metal anode layer,a dielectric bilayer,and a thick metal underlayer.The resulting device,with the optimized contrast-enhancement stack thicknesses of Ni (30 nm)/MgF2 (62 nm)/ZnS (16 nm)/Ni (20 nm) and the 25-nm-thick ZnS anti-reflection layer,achieves a luminous reflectance of 4.01% in the visible region and a maximum current efficiency of 0.99 cd/A (at 62.3 mA/cm2) together with a very stable chromaticity.The contrast ratio reaches 561∶1 at an on-state brightness of 1000 cd/m2 under an ambient illumination of 140 lx.In addition,the anti-reflection layer can als0 enhance the transmissivity of the cathode and improve light out-coupling by the effective restraint of microcavity effects.

  17. Nongenomic mechanisms of physiological estrogen-mediated dopamine efflux

    Directory of Open Access Journals (Sweden)

    Watson Cheryl S


    Full Text Available Abstract Background Neurological diseases and neuropsychiatric disorders that vary depending on female life stages suggest that sex hormones may influence the function of neurotransmitter regulatory machinery such as the dopamine transporter (DAT. Results In this study we tested the rapid nongenomic effects of several physiological estrogens [estradiol (E2, estrone (E1, and estriol (E3] on dopamine efflux via the DAT in a non-transfected, NGF-differentiated, rat pheochromocytoma (PC12 cell model that expresses membrane estrogen receptors (ERs α, β, and GPR30. We examined kinase, ionic, and physical interaction mechanisms involved in estrogenic regulation of the DAT function. E2-mediated dopamine efflux is DAT-specific and not dependent on extracellular Ca2+-mediated exocytotic release from vesicular monoamine transporter vesicles (VMATs. Using kinase inhibitors we also showed that E2-mediated dopamine efflux is dependent on protein kinase C and MEK activation, but not on PI3K or protein kinase A. In plasma membrane there are ligand-independent associations of ERα and ERβ (but not GPR30 with DAT. Conditions which cause efflux (a 9 min 10-9 M E2 treatment cause trafficking of ERα (stimulatory to the plasma membrane and trafficking of ERβ (inhibitory away from the plasma membrane. In contrast, E1 and E3 can inhibit efflux with a nonmonotonic dose pattern, and cause DAT to leave the plasma membrane. Conclusion Such mechanisms explain how gender biases in some DAT-dependent diseases can occur.

  18. Endogenous Estrogen-Mediated Heme Oxygenase Regulation in Experimental Menopause

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    Anikó Pósa


    Full Text Available Estrogen deficiency is one of the main causes of age-associated diseases in the cardiovascular system. Female Wistar rats were divided into four experimental groups: pharmacologically ovariectomized, surgically ovariectomized, and 24-month-old intact aging animals were compared with a control group. The activity and expression of heme oxygenases (HO in the cardiac left ventricle, the concentrations of cardiac interleukin-6 (IL-6 and tumor necrosis factor-α (TNF-α, the myeloperoxidase (MPO activity in the cardiac left ventricle, and the effects of heme oxygenase blockade (by 24-hour and 1-hour pretreatment with tin-protoporphyrin IX, SnPP on the epinephrine and phentolamine-induced electrocardiogram ST segment changes in vivo were investigated. The cardiac HO activity and the expression of HO-1 and HO-2 were significantly decreased in the aged rats and after ovariectomy. Estrogen depletion was accompanied by significant increases in the expression of IL-6 and TNF-α. The aged and ovariectomized animals exhibited a significantly elevated MPO activity and a significant ST segment depression. After pretreatment with SnPP augmented ST segment changes were determined. These findings demonstrate that the sensitivity to cardiac ischemia in estrogen depletion models is associated with suppression of the activity and expression of the HO system and increases in the secretion of proinflammatory cytokines and biomarkers.

  19. NAFLD, Estrogens, and Physical Exercise: The Animal Model

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    Jean-Marc Lavoie


    Full Text Available One segment of the population that is particularly inclined to liver fat accumulation is postmenopausal women. Although nonalcoholic hepatic steatosis is more common in men than in women, after menopause there is a reversal in gender distribution. At the present time, weight loss and exercise are regarded as first line treatments for NAFLD in postmenopausal women, as it is the case for the management of metabolic syndrome. In recent years, there has been substantial evidence coming mostly from the use of the animal model, that indeed estrogens withdrawal is associated with modifications of molecular markers favouring the activity of metabolic pathways ultimately leading to liver fat accumulation. In addition, the use of the animal model has provided physiological and molecular evidence that exercise training provides estrogens-like protective effects on liver fat accumulation and its consequences. The purpose of the present paper is to present information relative to the development of a state of NAFLD resulting from the absence of estrogens and the role of exercise training, emphasizing on the contribution of the animal model on these issues.


    Uchikova, E; Uchikov, A; Dimitrakova, E; Uchikov, P


    Morbidity and mortality from lung cancer has dramatically increased in women as compared to men over the past few years. Historically, smoking has been considered the major risk factor for lung cancer regardless of gender. Several recent lines of evidence implicate gender differences in the observed differences in prevalence and histologic type which cannot be explained based on the carcinogenic action of nicotine. Several recent studies underscore the importance of reproductive and hormonal factors in the carcinogenesis of lung cancer Lung cancer morbidity and mortality in Bulgaria was 16.2/100000 women and 14.6/ 100000 women, resp. Lung cancer morbidity in Europe was 39/100000 women. Lung cancer is extremely sensitive to estrogens. The latter act directly or as effect modifiers for the relationship between smoking and lung cancer. Further research examining the relationship between serum estrogen levels and the estrogen receptor expression in normal and tumor lung tissue samples can help elucidate the importance of reproductive and hormonal (exogenous and endogenous) factors in the carcinogenesis of lung cancer.