Androgens and the ovary

Between 10-15% of women suffer from polycystic ovary syndrome (PCOS), making it the most common cause of female infertility. Clinical features of PCOS include high circulating levels of ovarian androgens (T and A4), anovulation and obesity. The aetiology of this reproductive endocrinopathy is likely to be multifactorial, through the interplay of genetics, epigenetics and environmental factors. Primate research into sexual behaviour development noted that fetally androgenised monkeys developed symptoms like those of PCOS. There are now multiple animal models of PCOS using primates, sheep, rats and transgenic mice. The investigations described in this thesis use rodent models to examine the role of androgens in the pathogenesis of female infertility. An attempt to generate a granulosa cell specific androgen receptor knockout mouse model will first be described, followed by several studies into the developmental programming of female Wistar rat infertility and metabolism by steroid hormones. Initial investigations showed that testosterone proprionate (TP) administered to female rats during different windows of fetal and neonatal life alters the reproductive and metabolic axes of the adult animals. Fetal plus neonatal TP exposure led to complete ovarian dysgenesis, while postnatal exposure produced a PCOS-like phenotype. Animals which received TP postnatally were heavier and had an increased proportion of primordial follicles in their ovaries by postnatal day (pnd) 90 of life. Evaluation of this PCOS model showed that neonatally androgenised rats had ovarian follicles with larger antra and a greater ovarian stromal compartment. In addition, these animals were heavier when compared to controls. However, unlike human studies, neonatally androgenised rats showed no differences in circulating gonadotrophin or ovarian androgen levels. Nor did they show any programming effect of neonatal TP upon the theca interna by pnd 90. Further investigations to narrow the windows and dose of TP required to produce a PCOS phenotype showed that TP administered in an early window of neonatal life, between postnatal days (pnd) 1-6 not only led to anovulation, but potentially reprogrammed the hypothalamic-pituitary axis, as there was minimal gonadotrophin response to reduced ovarian negative feedback (inhibin B and estradiol) in these rats. Neonatal TP also affected the rat metabolic axis with adult animals becoming heavier after weaning without any change in food intake. Animals developed mesenteric and retroperitoneal obesity along with insulin resistance (IR). Increased hepatic glucocorticoid turnover and altered adipokine expression were also noted in neonatally androgenised females, possibly contributing to the pathogenesis of obesity. No effect of TP dose upon the severity of infertility or metabolic abnormalities in adult animals was observed. To delineate which features of the rat PCOS model resulted from androgenic, estrogenic or corticosteroid action, a final study used administration of different steroids during the early window of postnatal life: TP, estradiol valerate (EV), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA) and dexamethasone (DEX). The anovulatory PCO-like phenotype observed with TP was also seen in animals which received EV, but not those which received DHT, DHEA or DEX. TP and EV treatment also resulted in a reduction of ovarian follicle numbers and activated follicle proportions, with an increase in primordial follicle proportions. Although glucose tolerant, animals treated with TP and EV were highly IR. Unlike dexamethasone, DHT and DHEA also produced IR in adult animals, to a lesser extent than TP and EV. Taken collectively, the results described in this thesis demonstrate that the PCOS-like phenotype observed in the neonatally androgenised female rat is likely to be due to the estrogenic actions of testosterone, potentially through as yet unknown epigenetic mechanisms. The programming of the metabolic components described may additionally be due to the actions of androgens. Furthermore, these studies demonstrate a novel estrogenic effect of neonatal steroids upon primordial follicle populations and show that the neonatally androgenised rat may be a rational PCOS model in a poly-ovulatory species

Effect of androgen treatment during foetal and/or neonatal life on ovarian function in prepubertal and adult rats

We investigated the effects of different windows of testosterone propionate (TP) treatment during foetal and neonatal life in female rats to determine whether and when excess androgen exposure would cause disruption of adult reproductive function. Animals were killed prepubertally at d25 and as adults at d90. Plasma samples were taken for hormone analysis and ovaries serial sectioned for morphometric analyses. In prepubertal animals, only foetal+postnatal and late postnatal TP resulted in increased body weights, and an increase in transitory, but reduced antral follicle numbers without affecting total follicle populations. Treatment with TP during both foetal+postnatal life resulted in the development of streak ovaries with activated follicles containing oocytes that only progressed to a small antral (smA) stage and inactive uteri. TP exposure during foetal or late postnatal life had no effect upon adult reproductive function or the total follicle population, although there was a reduction in the primordial follicle pool. In contrast, TP treatment during full postnatal life (d1-25) resulted in anovulation in adults (d90). These animals were heavier, had a greater ovarian stromal compartment, no differences in follicle thecal cell area, but reduced numbers of anti-Mullerian hormone-positive smA follicles when compared with controls. Significantly reduced uterine weights lead reduced follicle oestradiol production. These results support the concept that androgen programming of adult female reproductive function occurs only during specific time windows in foetal and neonatal life with implications for the development of polycystic ovary syndrome in women

Scleroderma and related disorders: 223. Long Term Outcome in a Contemporary Systemic Sclerosis Cohort

Background: We have previously compared outcome in two groups of systemic sclerosis (SSc) patients with disease onset a decade apart and we reported data on 5 year survival and cumulative incidence of organ disease in a contemporary SSc cohort. The present study examines longer term outcome in an additional cohort of SSc followed for 10 years. Methods: We have examined patients with disease onset between years 1995 and 1999 allowing for at least 10 years of follow-up in a group that has characteristics representative for the patients we see in contemporary clinical practice. Results: Of the 398 patients included in the study, 252 (63.3%) had limited cutaneous (lc) SSc and 146 (36.7%) had diffuse cutaneous (dc) SSc. The proportion of male patients was higher among the dcSSc group (17.1% v 9.9%, p = 0.037) while the mean age of onset was significantly higher among lcSSc patients (50 ± 13 v 46 ± 13 years ± SD, p = 0.003). During a 10 year follow-up from disease onset, 45% of the dcSSc and 21% of the lcSSc subjects developed clinically significant pulmonary fibrosis, p < 0.001. Among them approximately half reached the endpoint within the first 3 years (23% of dcSSc and 10% of lcSSc) and over three quarters within the first 5 years (34% and 16% respectively). There was a similar incidence of pulmonary hypertension (PH) in the two subsets with a steady rate of increase over time. At 10 years 13% of dcSSc and 15% of lcSSc subjects had developed PH (p=0.558), with the earliest cases observed within the first 2 years of disease. Comparison between subjects who developed PH in the first and second 5 years from disease onset demonstrated no difference in demographic or clinical characteristics, but 5-year survival from PH onset was better among those who developed this complication later in their disease (49% v 24%), with a strong trend towards statistical significance (p = 0.058). Incidence of SSc renal crisis (SRC) was significantly higher among the dcSSc patients (12% v 4% in lcSSc, p = 0.002). As previously observed, the rate of development of SRC was highest in the first 3 years of disease- 10% in dcSSc and 3% in lcSSc. All incidences of clinically important cardiac disease developed in the first 5 years from disease onset (7% in dcSSc v 1% in lcSSc, p < 0.001) and remained unchanged at 10 years. As expected, 10-year survival among lcSSc subjects was significantly higher (81%) compared to that of dcSSc patients (70%, p = 0.006). Interestingly, although over the first 5 years the death rate was much higher in the dcSSc cohort (16% v 6% in lcSSc), over the following years it became very similar for both subsets (14% and 13% between years 5 and 10, and 18% and 17% between years 10 and 15 for dcSSc and lcSSc respectively). Conclusions: Even though dcSSc patients have higher incidence for most organ complications compared to lcSSc subjects, the worse survival among them is mainly due to higher early mortality rate. Mortality rate after first 5 years of disease becomes comparable in the two disease subsets. Disclosure statement: The authors have declared no conflicts of interes

Androgens and the ovary

Between 10-15% of women suffer from polycystic ovary syndrome (PCOS), making it the most common cause of female infertility. Clinical features of PCOS include high circulating levels of ovarian androgens (T and A4), anovulation and obesity. The aetiology of this reproductive endocrinopathy is likely to be multifactorial, through the interplay of genetics, epigenetics and environmental factors. Primate research into sexual behaviour development noted that fetally androgenised monkeys developed symptoms like those of PCOS. There are now multiple animal models of PCOS using primates, sheep, rats and transgenic mice. The investigations described in this thesis use rodent models to examine the role of androgens in the pathogenesis of female infertility. An attempt to generate a granulosa cell specific androgen receptor knockout mouse model will first be described, followed by several studies into the developmental programming of female Wistar rat infertility and metabolism by steroid hormones. Initial investigations showed that testosterone proprionate (TP) administered to female rats during different windows of fetal and neonatal life alters the reproductive and metabolic axes of the adult animals. Fetal plus neonatal TP exposure led to complete ovarian dysgenesis, while postnatal exposure produced a PCOS-like phenotype. Animals which received TP postnatally were heavier and had an increased proportion of primordial follicles in their ovaries by postnatal day (pnd) 90 of life. Evaluation of this PCOS model showed that neonatally androgenised rats had ovarian follicles with larger antra and a greater ovarian stromal compartment. In addition, these animals were heavier when compared to controls. However, unlike human studies, neonatally androgenised rats showed no differences in circulating gonadotrophin or ovarian androgen levels. Nor did they show any programming effect of neonatal TP upon the theca interna by pnd 90. Further investigations to narrow the windows and dose of TP required to produce a PCOS phenotype showed that TP administered in an early window of neonatal life, between postnatal days (pnd) 1-6 not only led to anovulation, but potentially reprogrammed the hypothalamic-pituitary axis, as there was minimal gonadotrophin response to reduced ovarian negative feedback (inhibin B and estradiol) in these rats. Neonatal TP also affected the rat metabolic axis with adult animals becoming heavier after weaning without any change in food intake. Animals developed mesenteric and retroperitoneal obesity along with insulin resistance (IR). Increased hepatic glucocorticoid turnover and altered adipokine expression were also noted in neonatally androgenised females, possibly contributing to the pathogenesis of obesity. No effect of TP dose upon the severity of infertility or metabolic abnormalities in adult animals was observed. To delineate which features of the rat PCOS model resulted from androgenic, estrogenic or corticosteroid action, a final study used administration of different steroids during the early window of postnatal life: TP, estradiol valerate (EV), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA) and dexamethasone (DEX). The anovulatory PCO-like phenotype observed with TP was also seen in animals which received EV, but not those which received DHT, DHEA or DEX. TP and EV treatment also resulted in a reduction of ovarian follicle numbers and activated follicle proportions, with an increase in primordial follicle proportions. Although glucose tolerant, animals treated with TP and EV were highly IR. Unlike dexamethasone, DHT and DHEA also produced IR in adult animals, to a lesser extent than TP and EV. Taken collectively, the results described in this thesis demonstrate that the PCOS-like phenotype observed in the neonatally androgenised female rat is likely to be due to the estrogenic actions of testosterone, potentially through as yet unknown epigenetic mechanisms. The programming of the metabolic components described may additionally be due to the actions of androgens. Furthermore, these studies demonstrate a novel estrogenic effect of neonatal steroids upon primordial follicle populations and show that the neonatally androgenised rat may be a rational PCOS model in a poly-ovulatory species.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The effects of global change on soil faunal communities: a meta-analytic approach

Human impacts are causing an unprecedented change of biodiversity across scales. To quantify the nature and degree of the biodiversity change, there have been a number of meta-analysis studies investigating the effects of global change drivers (land use, climate, etc.). However, these studies include few primary literature studies of soil biodiversity. Soil biodiversity is important for a variety of ecosystem services that are critical for human wellbeing. Yet, we know little about how soil organisms may respond to changing environmental conditions. Although studies have investigated the impact of global change drivers on soil biodiversity, they lack sufficient depth in the number of drivers and/or taxa included. Additionally, the previous focus on aboveground organisms has also resulted in a bias towards certain global change drivers in the primary literature. For example, climate change and land use change are more often studied, whilst pollution is typically understudied as a global change driver. Building on previous studies, we will conduct a meta-analysis to compare the effects of global change drivers (land use, habitat fragmentation/loss, fire, climate change, invasive species, pollution, and nutrient enrichment) on soil fauna (micro- to macro-invertebrates). This project aims to fill the current gaps in the literature, and actively participate in incorporating soil biodiversity into future global biodiversity assessments, by creating the first global open-acess dataset on the impacts of multiple global change drivers on soil fauna

Tailoring sexual health interventions for middle-aged and older adults, including vulnerable populations: A Scoping Review

Objectives This scoping review aims to synthesize existing literature on good practice in sexual health interventions for adults over 45 years and in vulnerable groups. Methods Using PRISMA-ScR guidelines, search terms focused on sexual health, good practice, and vulnerable groups, in over-45s. Results Of the 9 studies that met the inclusion criteria, 7 were focused on HIV and risk reduction. Use of alternative methods of communication, alongside inclusion of behavioral and cognitive measures such as condom use and perceived stigma, was key to tailoring interventions. Conclusion This review highlights the imperative for further research on sexual health interventions with these overlooked populations

Tailoring sexual health interventions for middle-aged and older adults, including vulnerable populations: A scoping review

This scoping review aims to synthesize existing literature on good practice in sexual health interventions for adults over 45 years and in vulnerable groups. Methods Using PRISMA-ScR guidelines, search terms focused on sexual health, good practice, and vulnerable groups, in over-45s. Results Of the 9 studies that met the inclusion criteria, 7 were focused on HIV and risk reduction. Use of alternative methods of communication, alongside inclusion of behavioral and cognitive measures such as condom use and perceived stigma, was key to tailoring interventions. Conclusion This review highlights the imperative for further research on sexual health interventions with these overlooked populations