Does local vaginal estrogen after tension-free transobturator vaginal tape reduce overactive bladder symptoms in postmenopausal women? A prospective randomized, controlled study

Objective:We aimed to evaluate the efficacy of topical estrogen after transvaginal tension-free vaginal tape-obturator(TVT-O)in the treatment of de novo overactive bladder symptoms that appear after surgery.Methods:This is a prospective randomized controlled study performed in the Urology and Gynecology Departments,Kasr Al Ainy Hospital,Cairo University,Cairo,Egypt.Two hundred and ten postmenopausal females presenting during the period between January 2017 and November 2020 with stress urinary incontinence were included in the study.Patients were divided into two groups,105 patients in Group A(treatment group)and 105 patients in Group B(control group).Patients in Group A underwent transvaginal TVT-O followed by local vaginal estrogen treatment for 6 months,while patients in Group B underwent transvaginal TVT-O only.The study included any postmenopausal female with urodynamic stress urinary incontinence.All patients had to fulfill a 3-day bladder diary,overactive bladder symptoms score,urine analysis,urodynamic study,and post-voiding residual urine measurement by abdominal ultrasound preoperatively and at 3-month and 6-month follow-ups.Results:At 6-month follow-up,daytime frequency was reduced to 8%in Group A(increased to 21%in Group B)with a statistically significant difference between both groups(p=0.009).At 6-month follow-up,nocturia was 8%in Group A(11%in Group B)with no statistically significant difference between both groups(p=0.469).There was a statistically significant difference between both groups as regards to urinary urgency at 6-month follow-up(p=0.024).There was a statistically significant difference in postoperative wound healing events as regards to cure,hyperemia,gapping,and wound infection 1 week after intervention between both groups(p=0.008).No local or systemic side-effects were reported from local estrogen use.Conclusion:Local vaginal estrogen treatment given to postmenopausal patients after midurethral sling procedures can reduce the symptoms of daytime frequency and urinary urgency.Long-term follow-up is needed.

Xenoestrogens challenge 17β-estradiol protective effects in colon cancer

Several epidemiological,cellular,and molecular studies demonstrate the role of environmental chemicals with endocrine disrupting activities,typical of Westernized societies,in the pathogenesis of numerous diseases including cancer.Nonetheless this information,the design and execution of studies on endocrine disruptors are not yet cognizant that the specific actions of individual hormones often change with development and ageing,they may be different in males and females and may be mediated by different receptors isoforms expressed in different tissues or at different life stages.These statements are particularly true when assessing the hazard of endocrine disruptors against 17β-estradiol(E2)actions in that this hormone is crucial determinant of sexrelated differences in anatomical,physiological,and behavioral traits which characterize male and female physiology.Moreover,E2 is also involved in carcinogenesis.The oncogenic effects of E2 have been investigated extensively in breast and ovarian cancers where hormone-receptor modulators are now an integral part of targeted treatment.Little is known about the E2preventive signalling in colorectal cancer,although this disease is more common in men than women,the difference being more striking amongst pre-menopausal women and age-matched men.This review aims to dissect the role and action mechanisms of E2 in colorectal cancer evaluating the ability of estrogen disruptors(i.e.,xenoestrogens)in impair these E2 actions.Data discussed here lead to define the possible role of xenoestrogens in the impairment and/or activation of E2signals important for colorectal cancer prevention.

Biodegradation of natural and synthetic estrogens in moving bed bioreactor

Estrogen hormones as a group of endocrine disruptive compounds （EDC） can interfere with endocrine system in humans and animals. The goal of this study was to investigate the elimination rate of Estrone （El）, 17β-estradiol （E2） and 17α-ethinyl estradiol （EE2） in Moving Bed Bioreactor （MBBR）. These analytes extracted by Dispersive Liquid-Liquid Microextraction （DLLME） technique, followed by derivatization, and detected by GC/MS. Estrogen removal efficiency in MBBR improved at high solid retention times （SRTs）, which notion is owing to development ofnitrification. Estrogenspecificremovalratewasbetween 0,22-1.45μg.（gVSS） 1.d -1 for natural and synthetic hormones. The adsorption rate was 0.9%-3.2% 0-1.3%, and 0.7%-5.7% for E1, E2, and EE2, respectively. In addition, the biodegradation rates were more than 95% for these compounds. These results illustrated that in MBBR, the hiodegradation and the adsorption to biomass are considered as two significant routes for elimination of estrogenic compounds. As a whole, the deterioration rate of estrogens enhanced by MBBR compared to other biological wastewater treatment processes such as conventional activated sludge.

17β-Estradiol,through activating the G protein-coupled estrogen receptor,exacerbates the complication of benign prostatic hyperplasia in type 2 diabetes mellitus patients by inducing prostate proliferation

Benign prostatic hyperplasia(BPH)is one of the major chronic complications of type 2 diabetes mellitus(T2DM),and sex steroid hormones are common risk factors for the occurrence of T2DM and BPH.The profiles of sex steroid hormones are simultaneously quantified by LC-MS/MS in the clinical serum of patients,including simple BPH patients,newly diagnosed T2DM patients,T2DM complicated with BPH patients and matched healthy individuals.The G protein-coupled estrogen receptor(GPER)inhibitor G15,GPER knockdown lentivirus,the YAP1 inhibitor verteporfin,YAP1 knockdown/overexpression lentivirus,targeted metabolomics analysis,and Co-IP assays are used to investigate the molecular mechanisms of the disrupted sex steroid hormones homeostasis in the pathological process of T2DM complicated with BPH.The homeostasis of sex steroid hormone is disrupted in the serum of patients,accompanying with the proliferated prostatic epithelial cells(PECs).The sex steroid hormone metabolic profiles of T2DM patients complicated with BPH have the greatest degrees of separation from those of healthy individuals.Elevated 17β-estradiol(E2)is the key contributor to the disrupted sex steroid hormone homeostasis,and is significantly positively related to the clinical characteristics of T2DM patients complicated with BPH.Activating GPER by E2 via Hippo-YAP1 signaling exacerbates high glucose(HG)-induced PECs proliferation through the formation of the YAP1-TEAD4 heterodimer.Knockdown or inhibition of GPER-mediated Hippo-YAP1 signaling suppresses PECs proliferation in HG and E2 co-treated BPH-1 cells.The anti-proliferative effects of verteporfin,an inhibitor of YAP1,are blocked by YAP1 overexpression in HG and E2 co-treated BPH-1 cells.Inactivating E2/GPER/Hippo/YAP1 signaling may be effective at delaying the progression of T2DM complicated with BPH by inhibiting PECs proliferation.

Biodegradation of Natural Estrogens by Biofilms from Biological Activated Carbon: Effect of Temperature

In order to obtain information on the biodegradation potential of biofilms involved in the removal of natural estrogens by biological activated carbon (BAC) columns, batch degradation of estrone (E1) and 17β-estradiol (E2) at temperature of 5℃, 20℃ and 35℃ by biofilms from four BAC columns (packed with activated carbon of particle size ranging from 0.5 - 0.59 mm and 1.0 - 1.19 mm into two bed depths) was studied. The results indicated that E2 was degraded faster by than E1 at all three temperatures and with the increasing of temperature, the amount of E1 converted from E2 increased. By fitting observed concentration data with a first-order rate expression, the bio-mass based degradation rate constants (kVSS) for E1 and E2 under all experimental conditions were estimated and linear relationship between lnkVSS and 1/T (T = absolute temperature) was demonstrated, resulting that with the increasing of the experimental temperature, degradation rate of biofilms for both E1 and E2 increased, and the increasing rate for E2 was higher than that for E1.

Radiation removal of synthetic estrogens in aqueous solution:influence of reduction or oxidation system and toxicity test

Estrogens as a kind of steroidal sex hormone are widely used in humans, especially quinestrol(QS),dienestrol(DS) and norethindrone(NET, 19-nor-17-alphaethinltestoster-one), which cannot be completely degraded after application. Steroidal estrogens at low concentration pulling into environment can disturb the normal biological function of wide life and thus lead to great threat to humans. So it is important to explore its degradation mechanism and its behavior in the environment. In this study, we investigated the oxidation or reduction system under gamma irradiation for reducing estrogenic activity in the aqueous solutions as well as degradation kinetics, its by-products and yield of transformation by different analytical methods such as GC–MS and HPLC. Gamma irradiation could effectively degrade estrogens in aqueous solution. The degradation reaction of estrogens could be depicted by first-order reaction kinetics. The total organic carbon of solution decreased with an increasing absorbed dose with the order: quinestrol [ norethindrone [ dienestrol. The toxicity of the three estrogens was declined after irradiation. Mono- and quadric-hydroxylated intermediates as well as organic acids were formed after gamma irradiation.

Prognostic implications of estrogen receptor 1 and vascular endothelial growth factor A expression in primary gallbladder carcinoma

AIM: To investigate the prognostic significance of estrogen receptor 1(ER1) and vascular endothelial growth factor A(VEGF-A) expression in primary gallbladder carcinoma(GBC) to identify new prognostic markers for this malignancy.METHODS: Using immunohistochemistry, we investigated ER1 and VEGF-A expression in 78 GBC and 78 cholelithiasis(CS) tissues. The results were correlated with clinicopathological features. Univariate and multivariate analyses were performed to evaluate the relationship between ER1 and VEGF-A expression and patients' prognosis. Further Kaplan-Meier survival analysis was also performed. RESULTS: ER1 and VEGF-A expression was significantly higher in GBC compared with CS(47/78 vs 28/78, P < 0.05; 51/78 vs 33/78, P < 0.05). ER1 expression was correlated with gender(P < 0.05) and VEGF-A expression was correlated with tumor differentiation in GBC patients(P < 0.05). In univariate analysis, age and tumor node metastasis(TNM) stage were factors associated with GBC prognosis(P < 0.05). Although there was no statistical difference between the expression of ER1 or VEGF-A and overall survival, the high expression of ER1 combined with VEGF-A predicted a poor prognosis for GBC patients(16.30 ± 1.87 vs 24.97 ± 2.09, log-rank P < 0.05). In multivariate analysis, combined expression of ER1 and VEGF-A and TNM stage were independent prognostic factors for GBC patients(P < 0.05).CONCLUSION: Combined expression of ER1 and VEGF-A is a potential prognostic marker for GBC patients. Clinical detection of ER1 and VEGF-A in surgically resected GBC tissues would provide animportant reference for decision-making of postoperative treatment programs.

Estrogen receptors in gastric cancer:Advances and perspectives

Worldwide, gastric cancer is one of the most common malignancies with high mortality. Various aspects of thedevelopment and progression of gastric cancer continue to be extensively investigated in order to further our understanding and provide more effective means for the prevention, diagnosis, and treatment of the disease. Estrogen receptors(ERs) are steroid hormone receptors that regulate cellular activities in many physiological and pathological processes in different tissues. There are two distinct forms of ERs, namely ERα and ERβ, with several alternative-splicing isoforms for each. They show distinct tissue distribution patterns and exert different biological functions. Dysregulation of ERs has been found to be associated closely with many diseases, including cancer. A number of studies have been conducted to investigate the role of ERs in gastric cancer, the possible mechanisms underlying these roles, and the clinical relevance of deregulated ERs in gastric cancer patients. To date, inconsistent associations of different ERs with gastric cancer have been reported. These inconsistencies may be caused by variations in in vitro cell models and clinical samples, including assay conditions and protocols with regard to different forms of ERs. Given the potential of the deregulated ERs as diagnostic/prognostic markers or therapeutic targets for gastric cancer, it will be important to identify/confirm the association of each ER isoform with gastric cancer, to determine the specific roles and interactions that these individual ER isoforms play under specific conditions in the development and/or progression of gastric cancer, and to elucidate precisely these mechanisms. In this review, we summarize the achievements from early ER studies in gastric cancer to the most up-to-date discoveries, with an effort to provide a comprehensive understanding of the role of ERs roles in gastric cancer and its possible mechanisms. Furthermore, we propose directions for future investigations.

Estrogens in males: what have we learned in the last 10 years?

This review focuses on the role of estrogen in men, mainly in male reproduction. The continuing increase in data obtained, and recent discoveries in this area will enable a better understanding of male physiology; these, in turn, will have important clinical implications.

17β-Estradiol Regulates Cultured Immature Boar Sertoli Cell Proliferation via the cAMP-ERK1/2 Pathway and the Estrogen Receptor β

Estrogen plays an important role in regulating Sertoli cell number in the testis. The objective of the study was to identify whether 17β-estradiol affected the proliferation of cultured, immature boar Sertoli cells via the estrogen receptor β （ERβ） and the cAMP-extracellular signal-regulated kinase （ERK1/2） pathway. Low levels （10-10-10-8 mol L-1） of 17β-estradiol increased cell number, but high levels （10-7-10-6 mol L-1） decreased it （P〈0.05）. Sertoli cell number began to recover for an additional 24 h in the medium without 17β-estradiol （10-6 mol L-l） （P〉0.05）. The effects of 17β-estradiol （10-9 mol L-1） peaked at the first 24 h （P〈0.05）. 17β-estradiol activated ERK1/2 from 5 min to 24 h, but the activiy of ERK1/2 began to decrease after 4 h. Both PD98059 and U0126, two ERK inhibitors, blocked cell division （P〈0.05）. 17β-estradiol （10-10-10-6 mol L-1） dose-dependently increased cAMP production （P 〈 0.05）, and both 17β-estradiol （10-9 mol L-1） and forskolin, which increases cAMP levels, induced cell proliferation and activated ERK1/2 （P〈 0.05）. Rp-cAMP, an antagonist of cAMP, blocked this 17β-estradiol activity （P〈 0.05）. Two estrogen receptor antagonists, ICI 182780 and ERβ antagonist （ERβAnt）, reduced Sertoli cell number, cAMP production and ERK1/2 activation （P〈 0.05）, but ERaAnt did not （P〉 0.05）. Therefore, 17β- estradiol mainly promotes pig Sertoli cell proliferation via ERβ to induce cAMP production and ERK activation to promote cell proliferation.

New insights into estrogenic regulation of O^6-methylguanine DNA-methyltransferase (MGMT) in human breast cancer cells： Co-degradation of ER-α and MGMT proteins by fulvestrant or O^6-benzylguanine indicates fresh avenues for therapy

Endocrine therapy using estrogen receptor-u （ER-α） antagonists for attenuating horm2one-driven cell proliferation is a major treatment modality for breast cancers. To exploit any DNA repair deficiencies associated with endocrine therapy, we investigated the functional and physical interactions of ER-α with O^6-methylguanine DNA methyltransferase （MGMT）, a unique DNA repair protein that confers tumor resistance to various anticancer alkylating agents. The ER-α -positive breast cancer cell lines （MCF-7, T47D） and ER- negative cell lines （MDAMB- 468, MDAMB-231）, and established inhibitors of ER-α and MGMT, namely, ICI-182,780 （Faslodex） and O^6- benzylguanine, respectively, were used to study MGMT- ER interactions. The MGMT gene promoter was found to harbor one full and two half estrogen-responsive elements （EREs） and two antioxidant-responsive elements （AREs）. MGMT expression was upregulated by estrogen, downregulated by tamoxifen in Western blot and promoter-linked reporter assays. Similarly, both transient and stable transfections of Nrf-2 （nuclear factor-erythroid 2-related factor-2） increased the levels of MGMT protein and activity 3 to 4-fold reflecting novel regulatory nodes for this dragresistance determinant. Of the different ER-α antagonists tested, the pure anti-estrogen fulvestrant was most potent in inhibiting the MGMT activity in a dose, time and ER-α dependent manner, similar to O^6-benzylguanine. Interestingly, fulvestrant exposure led to a degradation of both ER-α and MGMT proteins and O^6-benzylguanine also induced a specific loss of ER-a and MGMT proteins in MCF-7 and T47D breast cancer cells with similar kinetics. Immunoprecipitation revealed a specific association of ER-a and MGMT proteins in breast cancer cells. Furthermore, silencing of MGMT gene expression triggered a decrease in the levels of both MGMT and ER-a proteins. The involvement of proteasome in the drug-induced degradation of both proteins was also demonstrated. Fulvestrant enhanced the cytotoxicity of MGMT-targeted alkylating agents, namely, temozolomide and BCNU by 3 to 4-fold in ER-α positive cells, but not in ER-negative cells. We conclude that MGMT and ER-α proteins exist as a complex and are co-targeted for ubiquitin-conjugation and subsequent proteasomal degradation. The findings offer a clear rationale for combining alkylating agents with endocrine therapy.

基于ADE优化的IPMSM全速域无传感器控制

为了实现内置式永磁同步电机(IPMSM)全速域的无传感器控制和切换速域的平滑过渡,提出了一种基于自适应差分进化(ADE)算法优化的复合控制方法。分别在零低速域、中高速域采用旋转高频电压注入法和滑模观测器法来对电机转速和转子位置进行估算,并在切换速域采用基于ADE算法的权重系数优化法来实现上述两种控制方法的平滑切换,从而实现IPMSM全速域无传感器控制。仿真结果表明:提出的复合控制方法能够实现电机全速域的无感控制和切换速域的平滑过渡,且具有良好的稳定性。

phytoestrogens/insoluble fibers and colonic estrogen receptor β: randomized, double-blind, placebo-controlled study

AIM:To assess the safety and effect of the supplementation of a patented blend of dietary phytoestrogens and insoluble fibers on estrogen receptor (ER)-β and biological parameters in sporadic colonic adenomas. METHODS:A randomized, double-blind placebo-controlled trial was performed. Patients scheduled to undergo surveillance colonoscopy for previous sporadic colonic adenomas were identified, and 60 eligible patients were randomized to placebo or active dietary intervention (ADI) twice a day, for 60 d before surveillance colonoscopy. ADI was a mixture of 175 mg milk thistle extract, 20 mg secoisolariciresinol and 750 mg oat fiber extract. ER-β and ER-α expression, apoptosis and proliferation (Ki-67 LI) were assessed in colon samples. RESULTS:No adverse event related to ADI was recorded. ADI administration showed a significant increases in ER-β protein (0.822 ± 0.08 vs 0.768 ± 0.10, P = 0.04) and a general trend to an increase in ER-β LI (39.222 ± 2.69vs 37.708 ± 5.31,P = 0.06), ER-β/ER-α LI ratio (6.564 ± 10.04 vs 2.437 ± 1.53, P = 0.06), terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (35.592 ± 14.97 vs 31.541 ± 11.54, P = 0.07) and Ki-67 (53.923 ± 20.91 vs 44.833 ± 10.38, P = 0.07) approximating statistical significance. A significant increase of ER-β protein (0.805 ± 0.13 vs 0.773 ± 0.13,P = 0.04), mRNA (2.278 ± 1.19vs 1.105 ± 1.07, P < 0.02) and LI (47.533 ± 15.47 vs 34.875 ± 16.67,P < 0.05) and a decrease of ER-α protein (0.423 ± 0.06vs 0.532 ± 0.11,P < 0.02) as well as a trend to increase of ER-β/ER-α protein in ADI vs placebo group were observed in patients without polyps (1.734 ± 0.20 vs 1.571 ± 0.42, P = 0.07). CONCLUSION:The role of ER-β on the control of apoptosis, and its amenability to dietary intervention, are supported in our study.

Removal characteristics of steroid estrogens in trickling filters

The discharge of steroid estroens from sewage treatment works (STW) is to be regulated by Environmental Quality Standard in the UK,thus requiring the understanding of removal characteristics of steroid estroens in trickling filters to benefit UK water industry with trickling filters used in 75% STWs. Two pilot-scale trickling filters were operated in parallel to treat synthetic sewage spiked with oestrone (E1),oestradiol (E2) and 17α-ethinyl oestradiol (EE2) at environmentally related concentrations. Control experiments show that biodegradation is the dominant removal mechanism although adsorption onto biofilm solids prior to biodegradation would be part of the overall mechanisms of estrogen removal. Approximately 44.7%-58.9% is removed by the pilot trickling filter normally operated,whilst the 1:1 recirculation increases 29.0%-32.2% estrogen removals by improved wetting rate and hydraulic retention time supported by tracer experiment with lithium chloride. Extra feed solids with 32.0% higher suspended solids levels inhibited estrogen removals by 10.8%-34.4% rather than helping bridge adsorption to the biofilm,and the change of particle characteristics with higher adsorption potency would benefit the removal.

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

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 com- prehensive literature search and analyzed the available data regarding estrogen and estrogen receptor expres- sion, and the possible sex-specific links with esopha- geal 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 13 expression in esophageal adenocarcinoma development. The current literature supports speculation on an etiological role for estrogen in the male gender bias in esophageal adenocarcino- ma, but further studies are required.

Protective effects of estrogens and caloric restriction during aging on various rat testis parameters

Aim： To investigate the effects of 17β-estradiol （E2）, Peganum harmala extract （PHE） and caloric restriction （CR） on various testis parameters during aging. Methods： Twelve-month-old male rats were treated for 6 months with either E2 or PHE, or submitted to CR （40%）. Results： Our results show that estrogens and CR are able to protect the male gonad by preventing the decrease of testosterone and E2 levels as well as the decrease of aromatase and estrogen receptor gene expressions. Indeed, E2, PHE and CR treatments induced an increase in the superoxide dismutase activities and decreased the activity of testicular enzymes： gamma-glutamyl transferase, alkaline phosphatase, lactate deshydrogenase as well as the aspartate and lactate transaminases in aged animals. In addition, the testicular catalase and gluthatione peroxidase activities were enhanced in E2, PHE and CR-treated rats compared to untreated animals at 18 months of age. Moreover, the positive effects of estradiol, PHE and CR were further supported by a lower level of lipid peroxidation. Recovery of spermatogenesis was recorded in treated rats. Conclusion： Besides a low caloric diet which is beneficial for spermatogenesis, a protective antioxydant role of estrogens is suggested. Estrogens delay testicular cell damage, which leads to functional senescence and, therefore, estrogens are helpful in protecting the reproductive functions from the adverse effects exerted by reactive oxygen species （ROS） produced in large quanti- ties in the aged testis.

Androgens and estrogens in skeletal sexual dimorphism

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 5（x-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 refined 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 deficiency 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 field of sex steroid actions in male bone homeostasis.

Estrogens and the pathophysiology of the biliary tree

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 JERK1/2 （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.

Estrogen deficiency leads to telomerase inhibition, telomere shortening and reduced cell proliferation in the adrenal gland of mice

Estrogen deficiency mediates aging, but the underlying mechanism remains to be fully determined. We report here that estrogen deficiency caused by targeted disruption of aromatase in mice results in significant inhibition of telomerase activity in the adrenal gland in vivo. Gene expression analysis showed that, in the absence of estrogen, telomerase reverse transcriptase （TERT） gene expression is reduced in association with compromised cell proliferation in the adrenal gland cortex and adrenal atrophy. Stem cells positive in c-kit are identified to populate in the parenchyma of adrenal cortex. Analysis of telomeres revealed that estrogen deficiency results in significantly shorter teiomeres in the adrenal cortex than that in wild-type （WT） control mice. To further establish the causal effects of estrogen, we conducted an estrogen replacement therapy in these estrogen-deficient animals. Administration of estrogen for 3 weeks restores TERT gene expression, telomerase activity and cell proliferation in estrogen-deficient mice. Thus, our data show for the first time that estrogen deficiency causes inhibitions of TERT gene expression, telomerase activity, telomere maintenance, and cell proliferation in the adrenal gland of mice in vivo, suggesting that telomerase inhibition and telomere shortening may mediate cell proliferation arrest in the adrenal gland, thus contributing to estrogen deficiency-induced aging under physiological conditions.

儿童维生素AD滴剂,这样吃才对

众所周知,维生素A、D对孩子的生长发育至关重要。而补充维生素A、D,最好选择专门的维生素AD制剂,比如维生素AD滴剂。但许多家长对其又不甚了解,有诸多疑问。以下,笔者将一一进行解答。