Gonadotrophin-releasing hormone antagonists: application in ovary-stimulating and sex-steroid dependent disorders

The hypothalamic gonadotrophin-releasing hormone (GnRH) stimulates synthesis and secretion of luteinizing hormone (LH) and follicle stimulating hormone (FSH) by the gonadotrophic cells of the pituitary. The mechanisms of action of GnRH antagonists and of agonists is completely different. Due tot competitive blockage of GnRH receptors by antagonist administration, LH (and to a lesser extent FSH) levels drop rapidly. Moreover pituitary function normalizes immediately following cessation of medication. The direct and rapid action of GnRH antagonists, the dose dependent suppression of LH and FSH and the rapid restoration of hypophyseal function after cessation of the use of antagonists may shorten and simplify in-vitro fertilization, with less chance of side effects or complications. Further studies are required to decide whether antagonists can usefully be applied for other gynecological indications such as the polycystic ovary syndrome. The possibilities of profitable long term treatment will increase considerably if it proves possible to develop a sustained action formulation

The androgen receptor is a tumor suppressor in estrogen receptor-positive breast cancer

Contains fulltext : 230524.pdf (Publisher’s version ) (Closed access)05 februari 202

The androgen receptor interacts with GATA3 to transcriptionally regulate a luminal epithelial cell phenotype in breast cancer

BACKGROUND: The androgen receptor (AR) is a tumor suppressor in estrogen receptor (ER) positive breast cancer, a role sustained in some ER negative breast cancers. Key factors dictating AR genomic activity in a breast context are largely unknown. Herein, we employ an unbiased chromatin immunoprecipitation-based proteomic technique to identify endogenous AR interacting co-regulatory proteins in ER positive and negative models of breast cancer to gain new insight into mechanisms of AR signaling in this disease. RESULTS: The DNA-binding factor GATA3 is identified and validated as a novel AR interacting protein in breast cancer cells irrespective of ER status. AR activation by the natural ligand 5α-dihydrotestosterone (DHT) increases nuclear AR-GATA3 interactions, resulting in AR-dependent enrichment of GATA3 chromatin binding at a sub-set of genomic loci. Silencing GATA3 reduces but does not prevent AR DNA binding and transactivation of genes associated with AR/GATA3 co-occupied loci, indicating a co-regulatory role for GATA3 in AR signaling. DHT-induced AR/GATA3 binding coincides with upregulation of luminal differentiation genes, including EHF and KDM4B, established master regulators of a breast epithelial cell lineage. These findings are validated in a patient-derived xenograft model of breast cancer. Interaction between AR and GATA3 is also associated with AR-mediated growth inhibition in ER positive and ER negative breast cancer. CONCLUSIONS: AR and GATA3 interact to transcriptionally regulate luminal epithelial cell differentiation in breast cancer regardless of ER status. This interaction facilitates the tumor suppressor function of AR and mechanistically explains why AR expression is associated with less proliferative, more differentiated breast tumors and better overall survival in breast cancer.Leila Hosseinzadeh, Zoya Kikhtyak, Geraldine Laven-Law, Stephen M. Pederson, Caroline G. Puiu, Clive S. D, Santos, Elgene Lim, Jason S. Carroll, Wayne D. Tilley, Amy R. Dwyer, and Theresa E. Hicke

Cardiovascular risk management after reproductive and pregnancy-related disorders: A Dutch multidisciplinary evidence-based guideline

BACKGROUND: In the past decades evidence has accumulated that women with reproductive and pregnancy-related disorders are at increased risk of developing cardiovascular disease (CVD) in the future. Up to now there is no standardised follow-up of these women becausee guidelines on cardiovascular risk management for this group are lacking. However, early identification of high-risk populations followed by prevention and treatment of CVD risk factors has the potential to reduce CVD incidence. Therefore, the Dutch Society of Obstetrics and Gynaecology initiated a multidisciplinary working group to develop a guideline for cardiovascular risk management after reproductive and pregnancy-related disorders. METHODS: The guideline addresses the cardiovascular risk consequences of gestational hypertension, preeclampsia, preterm delivery, small-for-gestational-age infant, recurrent miscarriage, polycystic ovary syndrome and premature ovarian insufficiency. The best available evidence on these topics was captured by systematic review. Recommendations for clinical practice were formulated based on the evidence and consensus of expert opinion. The Dutch societies of gynaecologists, cardiologists, vascular internists, radiologists and general practitioners reviewed the guideline to ensure support for implementation in clinical practice. RESULTS: For all reproductive and pregnancy-related disorders a moderate increased relative risk was found for overall CVD, except for preeclampsia (relative risk 2.15, 95% confidence interval 1.76-2.61). CONCLUSION: Based on the current available evidence, follow-up is only recommended for women with a history of preeclampsia. For all reproductive and pregnancy-related disorders optimisation of modifiable cardiovascular risk factors is recommended to reduce the risk of future CVD

Possible modification of BRSK1 on the risk of alkylating chemotherapy-related reduced ovarian function

Contains fulltext : 233980.pdf (Publisher’s version ) (Open Access

Serum AMH levels in healthy women from BRCA1/2 mutated families: are they reduced?

STUDY QUESTION: Do BRCA1/2 mutation carriers have a compromised ovarian reserve compared to proven non-carriers, based on serum anti-Mullerian hormone (AMH) levels? SUMMARY ANSWER: BRCA1/2 mutation carriers do not show a lower serum AMH level in comparison to proven non-carriers, after adjustment for potential confounders. WHAT IS KNOWN ALREADY: It has been suggested that the BRCA genes play a role in the process of ovarian reserve depletion, although previous studies have shown inconsistent results regarding the association between serum AMH levels and BRCA mutation status. Hence, it is yet unclear whether BRCA1/2 mutation carriers may indeed be at risk of a reduced reproductive lifespan. STUDY DESIGN, SIZE, DURATION: A multicenter, cross-sectional study was performed between January 2012 and February 2015 in 255 women. We needed to include 120 BRCA1/2 mutation carriers and 120 proven non-carriers to demonstrate a difference in AMH levels of 0.40 microg/l (SD +/- 0.12 microg/l, two-sided alpha-error 0.05, power 80%). PARTICIPANTS/MATERIALS, SETTING, METHOD: Healthy women aged 18-45 years who were referred to the Clinical Genetics Department and applied for predictive BRCA1/2 testing because of a familial BRCA1/2 mutation were asked to participate. A cross-sectional assessment was performed by measuring serum AMH levels and filling out a questionnaire. Multivariate linear regression analyses adjusted for age, current smoking and current hormonal contraceptive use were performed on log-transformed serum AMH levels. MAIN RESULTS AND THE ROLE OF CHANCE: Out of 823 potentially eligible women, 421 (51.2%) were willing to participate, and of those, 166 (39%) did not meet our inclusion criteria. Two hundred and fifty-five women were available for analyses; 124 BRCA1/2 mutation carriers and 131 proven non-carriers. The median [range] AMH level in carriers was 1.90 microg/l [0.11-19.00] compared to 1.80 microg/l [0.11-10.00] in non-carriers (P = 0.34). Adjusted linear regression analysis revealed no reduction in AMH level in the carriers (relative change = 0.98 (95%CI, 0.77-1.22); P = 0.76). LIMITATIONS, REASONS FOR CAUTION: Participants were relatively young. Power was insufficient to analyze BRCA1 and BRCA2 mutation carriers separately. AMH levels may have been influenced by the use of hormonal contraceptives, though similar proportions of carriers and non-carriers were current users and adjustments were made to correct for potential confounding in our analysis. WIDER IMPLICATIONS OF THE FINDINGS: Limitations of the current analysis and limitations of the existing literature argue for prospective, well-controlled follow-up studies with recurrent AMH measurements to determine whether carriers might be at risk for low ovarian reserve and to definitively guide care. STUDY FUNDING/COMPETING INTERESTS: This study was partially financially supported by a personal grant for Inge A.P. Derks-Smeets, kindly provided by the Dutch Cancer Society (Grant Number UM 2011-5249). Theodora C. van Tilborg, Inge A.P. Derks-Smeets, Anna M.E. Bos, Jan C. Oosterwijk, Christine E. de Die-Smulders, Lizet E. van der Kolk, Wendy A.G. van Zelst-Stams, Maria E. Velthuizen, Marinus J.C. Eijkemans and Margreet G.E.M. Ausems have nothing to disclose. Ron J. van Golde has received unrestricted research grants from Ferring and Merck Serono, outside the submitted work. Annemieke Hoek received an unrestricted educational grant from Ferring pharmaceutical BV, The Netherlands and a speaker's fee for post graduate education from MSD pharmaceutical company, outside the submitted work. Joop S.E. Laven has received unrestricted research grants from Ferring, Merck Serono, Merck Sharpe & Dome, Organon, and Schering Plough, outside the submitted work. Frank J.M. Broekmans is a member of the external advisory board for Merck Serono (The Netherlands), outside the submitted work. TRIAL REGISTRATION NUMBER: NTR no. 4324

Possibilities of utilisation different types of fly ashes in the production of oxidized asphalt insulation strips

Reducing the impact of modern industrial production on the environment and reducing the waste generated is undoubtedly one of the most discussed topics of the present time. In the production of fossil-fueled electricity, a large amount of fine-grained waste fly ash is generated. The possible use of ash as secondary raw materials in the construction and building materials industry is one of the many environmental challenges that the energy industry is concerned with. The aim of this diploma thesis was to verify possibilities of utilization of different kinds of power station fly ash as filler in asphalt mixtures for the production of oxidized asphalt insulation strips. The main emphasis was put on the clarification of the influence of the properties of the different types of fly ashes on the resulting rheological behavior of the mixture of asphalt binder and power fly ash, which is professionally called mastic. Mastic forms a technology-critical insulating layer in the asphalt insulation strip. The prediction of the rheological properties and therefore the workability of mastic appears to be an essential element in the management of production, especially under the conditions of the variability of input raw materials. In order to solve the assigned task it was necessary to perform detailed analyzes of fly ash properties, to select the corresponding quantification variable for assessment of the mastic processability and to find the signal fly ash properties, which appears to be a control parameter of workability. As a suitable method for assessing the processability of mastic, a shear viscosity measurement method was chosen. On the basis of the findings, it is possible to state that the use of fly ash from the production of oxidized asphalt bands is not recommended as the mastic prepared from these fly ashes are unprocessed at the assumed concentrations. The negative effect of fly ash after denitrification on the mastic processability has not been demonstrated

Simultaneous initiation of GnRH antagonist co-treatment and recFSH for ovarian hyperstimulation in IVF does not affect clinical outcome: a randomized controlled trial

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