Endocrine Abstracts

Oxytocin is a peptide hormone consisting of 9 amino acids, with a mass of 1007 Da. It is synthesised in the hypothalamus and secreted from the posterior pituitary. It has well known roles in lactation and uterine contraction, however it is also thought to act within the brain to influence complex social behaviours such as bonding, empathy, and trust. Recently there has been increasing interest in the potential role of oxytocin in the pathophysiology...

Oxytocin is a peptide hormone consisting of 9 amino acids, with a mass of 1007 Da. It is synthesised in the hypothalamus and secreted from the posterior pituitary. It has well known roles in lactation and uterine contraction, however it is also thought to act within the brain to influence complex social behaviours such as bonding, empathy, and trust. Recently there has been increasing interest in the potential role of oxytocin in the pathophysiology...

Background: The 1 mg overnight dexamethasone suppression test (ONDST) is recommended as a first-line test for the investigation of Cushing Syndrome. Measurement of dexamethasone alongside cortisol in a 9am serum sample has been credited with improving diagnostic sensitivity of the test. Previous studies have also looked at the utility of salivary dexamethasone and have observed poor correlation with serum dexamethasone. Herein we introduce the concept of measuring 11-dehydrode...

Introduction: Tc99m-Sestamibi+I-123 subtraction using planar and SPECT-CT (SPECT-CT 99mTc-MIBI parathyroid) is commonly used to investigate primary hyperparathyroidism (PHPT). We previously reported the sensitivity and positive predictive value of 4D CT parathyroid as the second line investigation in patients with non-diagnostic SPECT-CT 99mTc-MIBI parathyroid (https://www.endocrine-abstrac...

Introduction: Tc99m-Sestamibi+I-123 subtraction using planar and SPECT-CT is commonly used to investigate PHPT. Our centre previously published sensitivity and specificity of 92 and 86% respectively for Tc99m-Sestamibi+I-123 subtraction. Five false-negative studies required neck exploratory surgery. One false-positive study incorrectly localised a PA which was not found in surgery (n=67). In recent years 4D-CT parathyroid has emerged as a useful technique to detect an...

Background: 5-hydroxyindole acetic acid (5-HIAA), a metabolite of serotonin, is used as a marker for patients with serotonin-secreting neuroendocrine tumours (NET). Currently, the majority of laboratories measure 5-HIAA excretion in 24 h urine samples. Given the practicality and analytic problems of these samples, our laboratory successfully developed a LC–MS/MS method for the analysis of 5-HIAA in serum samples. Further to this, we have now developed a method to measure ...

Introduction: Methodological differences in the immunoassay measurement of cortisol are apparent when reviewing External Quality Assessment scheme data. A bimodal distribution is often observed, particularly for samples from female subjects. It has been postulated that some immunoassays are inefficient at removing cortisol from its binding proteins and therefore have the potential to under-recover from female samples. We investigated the results obtained from two immunoassays ...

Introduction: There has been much interest recently in measuring both salivary cortisol and cortisone due to the presence of 11β-hydroxysteroid dehydrogenase type 2 enzyme in the salivary glands. This enzyme facilitates the conversion of cortisol to cortisone; hence the concentration of cortisone in saliva may also be of interest. Studies have shown recently that salivary cortisone and cortisol are good markers of serum free cortisol status.Methods:...

The measurement of plasma renin activity is required in a number of clinical situations, in particular screening for primary aldosteronism (PA) and monitoring mineralocorticoid replacement therapy. PA is a treatable cause of hypertension and has an estimated prevalence of up to 20% amongst resistant hypertensives. Consequently, recent guidelines now recommend screening for PA in all patients groups with a high prevalence of PA. At present, the most reliable method of screening...

Introduction: It has been recognised in EQA schemes in Europe and America that the reproducibility between labs using LC–MS for testosterone analysis is not optimal for this technique. We decided to conduct a calibration exercise to investigate the variability seen between labs.Methods: Aqueous and matrix matched serum samples were sent to labs participating in the NEQAS testosterone scheme. The labs were asked to measure these samples blind using t...