Endocrine Abstracts

INTRODUCTIONThe plasma concentrations and urinary excretion rates of 18-OH-F and 18-oxo-F are high in Conn's syndrome and glucocorticoid suppressible hyperaldosteronism, reputedly because aldosterone synthase (AS) has abnormal access to cortisol (F). However, both compounds are also excreted in normal subjects. Two enzymes, 11beta-hydroxylase (11OH) and AS, located in the zona fasiculata (ZF) and zona glomerulosa (ZG) respectively, are capable of 18-hydroxylation but only ...

Aldosterone synthase and 11beta-hydroxylase catalyse the final steps of glucocorticoid (corticosterone) and mineralocorticoid (aldosterone) production in the rat adrenal cortex. They are encoded by the CYP11B2 and CYP11B2 genes respectively. Recent studies have shown that CYP11B1 and CYP11B2 are also expressed in the brain, the vascular system and the heart where it has been suggested that aldosterone influences cardiac function and plays a role in cardiac fibrosis. However, i...

BACKGROUND: Healthy and Adult Growth Hormone Deficient (AGHD) women exhibit elevated leptin concentrations compared with men. AGHD is characterised by obesity and associated with increased leptin concentration and decreased leptin pulsatility, however the gender variation in rhythm and pulse parameters is yet to be defined. Following growth hormone replacement (GHR), leptin concentration decreases and pulsatility increases preceding a reduction in body fat mass (BFM).<p cl...

TSH-secreting pituitary adenomas (TSHomas) are rare. Previously, the reported prevalence was one case per million populations although this is probably an underestimate. A recently published study reported a prevalence of TSHomas in Sweden of 2.8/million inhabitants.Methods/design: Observational study conducted in four tertiary referral centres in Ireland. We retrospectively collected data on the prevalence, demographics, hormonal profile, tumour charact...

Observational studies suggest reduced vitamin D levels are associated with an increased incidence of type 2 diabetes mellitus. We examined the relationship with insulin resistance (assessed using a two-step euglycaemic hyperinsulinaemic clamp technique) in 92 overweight, non-diabetic individuals with no history of cardiovascular disease - mean age 56 years (range 40–77 years), 64% males, 36% females, BMI 30.9 kg/m2 (range 26.4–36.9 kg/m2), fasti...

Introduction: Recently low circulating levels of sex hormone binding globulin (SHBG) have been shown to be a strong predictor of the risk of developing type 2 diabetes. Genetic studies suggest that this may be a primary causal abnormality and the mechanism may relate to effects on insulin resistance.Methods: Insulin resistance was assessed using a two-step euglycaemic hyperinsulinaemic clamp (EHC) in 87 (59 male and 28 post-menopausal female) overweight ...

Introduction: Effects on fertility have been seen as important late effects of treatment for childhood cancer.Aim: To evaluate the impact of chemotherapy and radiotherapy treatment for childhood medulloblastoma on gonadal function.Methods: Retrospective cohort study of all children treated for medulloblastoma (diagnosed from 2–18 years) in a single institution in the UK between 1983–2011 and a minimum relapse-free surviva...

Testicular dysgenesis syndrome (TDS) is a group of associated conditions (testicular germ cell tumours (TGCT), cryptorchidism, hypospadias and low sperm counts) that are thought to have a common origin in fetal life. Exposure of fetal rats to environmental chemicals such as the endocrine disrupting chemical di(n-butyl) phthalate (DBP) results in a TDS-like syndrome. However, exposed rats do not develop TGCT and the rodent is a poor model in this context. The effects of ...

Meningitis is associated with high mortality and morbidity predominantly driven by meningeal inflammation. Herpes Simplex virus (HSV) is a major cause of viral meningitis typically progressing to HSV encephalitis. Numerous studies highlight the importance of glucocorticoids in lowering inflammation in bacterial meningitis, but very limited data exists on the use of glucocorticoids in viral meningitis. We aimed to characterise 11β-HSD1 (which interconverts inactive cortiso...

Macroprolactinaemia is defined as hyperprolactinaemia with a predominance of macroprolactin. It is present in approx 15–36% of cases of hyperprolactinaemia. Controversy exists as to the clinical relevance of macroprolactinaemia with a number of short-term studies demonstrating fewer classical symptoms of hyperprolactinaemia. The long-term prognosis is unknown.We have previously reported the findings after 5 years follow-up of a cohort of 55 patients...