213,880 research outputs found
The effects of uterine artery embolisation and surgical treatment on ovarian function in women with uterine fibroids
Objective The aim of this study was to evaluate and compare both ovarian function and menstrual characteristics following uterine artery embolisation (UAE) and surgery. Design Subgroup of women from a randomised controlled trial. Setting Gynaecology and radiology units in Scotland, UK. Population Ninety-six women from the randomised controlled trial comparing embolisation with surgery as a treatment for fibroids (REST), which recruited 157 patients (106 UAE; 51 surgery). Methods Seventy-three women undergoing UAE and 23 women undergoing surgery (with ovarian conservation) had serum follicle-stimulating hormone (FSH) measurements taken on day 3 of the menstrual cycle prior to treatment, and at 6 and 12 months post-treatment. Data on menstrual cycle characteristics was also collected. Main outcome measures Ovarian failure, as defined by an FSH level of > 40 iu/l, and change in duration of menses and length of menstrual cycle. Results There was no significant difference in the rate of ovarian failure at 12 months between UAE (11%) and surgical patients (18%) (P = 0.44). This finding was not influenced by age. The mean duration of menstrual flow decreased significantly, from baseline to 12 months, by 1.7 days (SD 3.8), (95% CI 0.8-2.6). There was no statistically significant change in mean cycle length at 12 months (0.7 days [SD 4.9]; 95% CI [-0.5, 1.9]). Conclusions There is no evidence for UAE accelerating a deterioration in ovarian function at 1 year, when compared with surgery. UAE is associated with a decrease in the duration of menstrual flow at 1 yea
Ovarian function during hormonal contraception assessed by endocrine and sonographic markers: a systematic review
This systematic review focuses on the literature evidence for residual ovarian function during treatment with hormonal contraceptives. We reviewed all papers which assessed residual ovarian activity during hormonal contraceptive use, using endocrine markers such as serum anti-Müllerian hormone (AMH) concentrations, FSH, LH, oestradiol, progesterone and sonographic markers such as antral follicle count (AFC), ovarian volume and vascular indices. We considered every type (oestroprogestin or only progestin) and dosage of hormonal contraceptive and every mode of administration (oral, vaginal ring, implant, transdermal patch). We performed an electronic database search for papers published from 1 January 1990 until 30 November 2015 using PubMed and MEDLINE. We pre-selected 113 studies and judged 48 studies suitable for the review. Most studies showed that follicular development continues during treatment with hormonal contraceptives, and that during treatment there is a reduction in serum concentrations of FSH, LH and oestradiol, and also a reduction in endometrial thickness, ovarian volume and the number and size of antral follicles. The ovarian reserve parameters, namely AFC and ovarian volume, are lower among users than among non-users of hormonal contraception; regarding the effect of hormonal contraception on AMH, there are still controversies in the literature
Constitutively active transforming growth factor β receptor 1 in the mouse ovary promotes tumorigenesis
Despite the well-established tumor suppressive role of TGFβ proteins, depletion of key TGFβ signaling components in the mouse ovary does not induce a growth advantage. To define the role of TGFβ signaling in ovarian tumorigenesis, we created a mouse model expressing a constitutively active TGFβ receptor 1 (TGFBR1) in ovarian somatic cells using conditional gain-of-function approach. Remarkably, these mice developed ovarian sex cord-stromal tumors with complete penetrance, leading to reproductive failure and mortality. The tumors expressed multiple granulosa cell markers and caused elevated serum inhibin and estradiol levels, reminiscent of granulosa cell tumors. Consistent with the tumorigenic effect, overactivation of TGFBR1 altered tumor microenvironment by promoting angiogenesis and enhanced ovarian cell proliferation, accompanied by impaired cell differentiation and dysregulated expression of critical genes in ovarian function. By further exploiting complementary genetic models, we substantiated our finding that constitutively active TGFBR1 is a potent oncogenic switch in mouse granulosa cells. In summary, overactivation of TGFBR1 drives gonadal tumor development. The TGFBR1 constitutively active mouse model phenocopies a number of morphological, hormonal, and molecular features of human granulosa cell tumors and are potentially valuable for preclinical testing of targeted therapies to treat granulosa cell tumors, a class of poorly defined ovarian malignancies
Molecular Targets of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) within the Zebrafish Ovary: Insights into TCDD-induced Endocrine Disruption and Reproductive Toxicity
TCDD is a reproductive toxicant and endocrine disruptor, yet the mechanisms by which it causes these reproductive alterations are not fully understood. In order to provide additional insight into the molecular mechanisms that underlie TCDD\u27s reproductive toxicity, we assessed TCDD-induced transcriptional changes in the ovary as they relate to previously described impacts on serum estradiol concentrations and altered follicular development in zebrafish. In silico computational approaches were used to correlate candidate regulatory motifs with observed changes in gene expression. Our data suggest that TCDD inhibits follicle maturation via attenuated gonadotropin responsiveness and/or depressed estradiol biosynthesis, and that interference of estrogen-regulated signal transduction may also contribute to TCDD\u27s impacts on follicular development. TCDD may also alter ovarian function by disrupting various signaling pathways such as glucose and lipid metabolism, and regulation of transcription. Furthermore, events downstream from initial TCDD molecular-targets likely contribute to ovarian toxicity following chronic exposure to TCDD. Data presented here provide further insight into the mechanisms by which TCDD disrupts follicular development and reproduction in fish, and can be used to formulate new hypotheses regarding previously documented ovarian toxicity
Rodent Models of Polycystic Ovary Syndrome
Rodents are clearly valuable models for assessing disruption of fertility. The effects of different steroid treatments at different stages of reproductive life through from fetal to adult have been assessed for effects on fertility, ovarian morphology, hypothalamic- pituitary function or metabolic consequences. The results show that steroid treatments do disrupt fertility in many cases, but the underlying mechanisms are complicated by the effects of the different treatments at multiple sites. As models for PCOS at the ovarian level however, there are a number of problems particularly related to the fact that rodents are multi-ovular species. Apart from an absence of ovulation and corpora lutea, many of the different steroid regimes result in an increase in large atretic, or cystic follicles that do not parallel PCOS in women. Indeed a number of treatments are given at times when they will cause disruption of the positive feedback effects of estradiol, thus blocking ovulation in adult life. The resulting ovarian morphology thus appears to be like that of PCOS but is in fact not a clear mimic. This review of the various studies highlights parallels and problems with the use of rodents to study the mechanisms underlying the development of PCOS in women
MicroRNAs and ovarian function
MicroRNAs (miRNAs) are a class of small non-coding RNAs which function in gene regulation with an important role in cell proliferation, maturation, and activity. The regulatory role of these small RNA molecules has recently begun to be explored in ovarian cells, uncovering their influence on gonadal development, steroidogenesis, apoptosis, ovulation, and corpus luteum development. This emerging area of research has extended and reshaped our understanding on how ovarian function is regulated. Here, we review the current understanding of miRNA biogenesis, the role and mechanism that miRNAs play in post-transcriptional gene expression regulation, and specifically the current evidence of miRNA involvement in ovarian development and function. Future comprehensive understanding of the role of miRNAs in the ovary in both physiological and pathological conditions may offer new treatment strategies for infertility and other ovarian disorders
Proteome profiling outperforms transcriptome profiling for coexpression based gene function prediction
Histone deacetylases as new therapy targets for platinum-resistant epithelial ovarian cancer
Introduction: In developed countries, ovarian cancer is the fourth most common cancer in women. Due to the nonspecific symptomatology associated with the disease many patients with ovarian cancer are diagnosed late, which leads to significantly poorer prognosis. Apart from surgery and radiotherapy, a substantial number of ovarian cancer patients will undergo chemotherapy and platinum based agents are the mainstream first-line therapy for this disease. Despite the initial efficacy of these therapies, many women relapse; therefore, strategies for second-line therapies are required. Regulation of DNA transcription is crucial for tumour progression, metastasis and chemoresistance which offers potential for novel drug targets. Methods: We have reviewed the existing literature on the role of histone deacetylases, nuclear enzymes regulating gene transcription. Results and conclusion: Analysis of available data suggests that a signifant proportion of drug resistance stems from abberant gene expression, therefore HDAC inhibitors are amongst the most promising therapeutic targets for cancer treatment. Together with genetic testing, they may have a potential to serve as base for patient-adapted therapies
Leptin receptor in the chicken ovary: potential involvement in ovarian dysfunction of ad libitum-fed broiler breeder hens
In hens, the ovarian follicles committed to ovulation are arranged in an ordered follicular hierarchy. In standard broiler breeders hens genetically selected for high growth rate the reproductive function is clearly dysfunctional. Feed restriction is needed during reproductive development to limit the formation of excessive numbers of ovarian yellow follicles arranged in multiple hierarchies. To determine whether leptin is involved in the nutritional and reproductive interactions controlling follicular hierarchy in hens, blood leptin levels and ovarian expression of the leptin receptor mRNA were determined during follicle maturation in three chicken lines; a slow growing broiler "Label" genotype without reproductive dysfunction, a fast growing "Standard" genotype fed ad libitum or restricted and a fast growing "Experimental" line with intermediate reproductive performance levels. Whereas expression of the leptin receptor mRNA did not change in the theca, it clearly decreased with follicular differentiation in the granulosa of slow growing hens. In fast growing standard hens fed ad libitum and presenting significant reproductive dysfunction, the decrease was disrupted and dramatic up-regulation of granulosa cell expression of the leptin receptor was observed. On the other hand, feed restriction decreased the overall level of expression of the leptin receptor mRNA and restored the decrease with follicular growth. The level of expression of the leptin receptor probably modulates the action of leptin on follicular differentiation. Since blood leptin and other metabolic factors were not affected by the genotype or by nutritional state, the factors involved in the regulation of leptin receptor gene expression remain to be determined. This study demonstrates the involvement of leptin in the nutritional control of reproduction in birds. Leptin action on the ovary probably controls follicular hierarchy through the regulation of steroidogenesis
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