Ragini Bhake

Automated 24-hours sampling of subcutaneous tissue free cortisol in humans

Abstract Hormonal systems are major regulators of metabolic and cognitive function and many of these, including the critical stress-responsive hypothalamic-pituitary-adrenal (HPA) axis, release their constituent hormones in a circadian manner. This circadian rhythmicity is made up from an underlying approximate hourly ultradian rhythm. In order to understand the importance of both circadian and ultradian rhythms in man it is important to be able to carry out multiple sampling studies over extended periods in a subject’s home setting, which is the most meaningful physiological setting for homeostatically important hormones. This study has developed a novel automated sampling system that, when used in combination with a microdialysis system, collects timed samples of microdialysis fluid over a full 24 h in individuals going about their normal everyday activity. The apparatus has the capacity to provide sufficient sample volumes to measure changes in hormone concentration over 24 h, including the important period when subjects are asleep.

Subcutaneous pulsatile glucocorticoid replacement therapy

The glucocorticoid hormone cortisol is released in pulses resulting in a complex and dynamic ultradian rhythm of plasma cortisol that underlies the classical circadian rhythm. These oscillating levels are also seen at the level of tissues such as the brain and trigger pulses of gene activation and downstream signalling. Different patterns of glucocorticoid presentation (constant vs pulsatile) result not only in different patterns of gene regulation but also in different neuroendocrine and behavioural responses. Current ‘optimal’ glucocorticoid replacement therapy results in smooth hormone blood levels and does not replicate physiological pulsatile cortisol secretion. Validation of a novel portable pulsatile continuous subcutaneous delivery system in healthy volunteers under dexamethasone and metyrapone suppression. Pulsatile subcutaneous hydrocortisone more closely replicates physiological circadian and ultradian rhythmicity.

Amiodarone‐induced thyrotoxicosis, an overview of UK management

Association, 276, 1575–1579. 3 Tessitore, A., Sinisi, A.A., Pasquali, D., et al. (1999) A novel case of multiple endocrine neoplasia type 2A associated with two de novo mutations of the RET protooncogene. Journal of Clinical Endocrinology and Metabolism, 84, 3522–3527. 4 Martinelli, P., Margotti, G.M., Pasquali, D., et al. (2004) Genetic prenatal RET testing and pregnancy management of multiple endocrine neoplasia Type II A (MEN2): a case report. Journal of Endocrinological Investigation, 27, 357–360. 5 Toledo, R.A., Wagner, S.M., Coutinho, F.L. et al. (2010) High penetrance of pheocromocytoma associated with the novel C634Y/Y791F double germline mutation in the RET protoncogene. Journal of Clinical Endocrinology and Metabolism, 95, 1318– 1327.

Long-term follow-up of a large prospective cohort of patients with nonfunctioning pituitary adenomas: The outcome of a conservative management policy

To assess the clinical outcome of a strategy of conservative monitoring of patients with nonfunctioning pituitary adenomas (NFPA) after pituitary surgery and in patients without surgery.

Cardiac Paraganglioma associated with SDHB mutation and elevated 3-methoxytyramine levels

Discussion Paragangliomas almost all produce catecholamines. These catecholamines are metabolized by the tumor within the chromaffin cells to form the orthomethylated products, which are metanephrine (MN), normetanephrine (NM), and 3-methoxytyramine (3-MT) [4]. Sometimes the tumour secretes only these metabolites, and not the catecholamines making it a more sensitive way to detect these tumours. The catecholamine’s and their metabolites are excreted in the urine. The persistently high 3-MT in the absence of high MN or NM in this case is an uncommon biochemical presentation of a paraganglioma.

Siadh associated with neuromyelitis optica involving hypothalamus

Case report • Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a cause of hyponatraemia which has been associated with many central nervous system (CNS) disorders . However, its association with neuromyelitis optica (NMO) or NMO spectrum disorders (NMOSD) is rare. • NMO and NMOSD are inflammatory, autoimmune, demyelinating disorders of CNS predominantly affecting optic nerves and spinal cord but also certain brain regions. They are associated with the presence of IgG antibodies to aquaporin-4 (highly expressed in hypothalamus, brainstem, periventricle & spine). • We report here a case of NMOSD relapse which presented with hyponatraemia due to SIADH.