Jeannie Todd

Measurement of basal growth hormone (GH) is a useful test of disease activity in treated acromegalic patients.

Background  Nadir GH during oral glucose tolerance test (OGTT) is the gold‐standard test of GH secretion in treated acromegaly. However, it was recently reported that variability in GH is reduced postradiotherapy, making basal GH a potential surrogate marker for nadir GH in such patients.

Severe hypercalcaemia from secretion of parathyroid hormone-related peptide

A 47-year-old woman was referred to our institution with severe hypercalcaemia. 5 years before referral she was diagnosed with liver metastases, and a biopsy sample showed a neuroendocrine tumour. Initial assessment did not include immunohistochemical analysis for production of parathyroid hormone or parathyroid hormone-related peptide, and no archived tissue is available for further assessment.

Localization of gastrinomas by selective intra-arterial calcium injection in patients on proton pump inhibitor or H2 receptor antagonist therapy

Preoperative localization is important for the successful treatment of gastrinomas. The aim of this study was to investigate whether selective intra-arterial calcium injection and hepatic venous sampling was able to localize gastrinomas in four patients who remained on proton pump inhibitor or H2 antagonist therapy. Calcium gluconate was injected directly into the arteries supplying the pancreas and liver after standard selective angiography. Gastrin levels were then measured in samples taken from the right hepatic vein. Calcium gluconate produced a diagnostic rise (at least 2-fold) in serum gastrin and unequivocally localized the tumour to a specific vascular territory in each case. One patient did not undergo surgery. In the remaining three patients, surgery confirmed the position and histology of the tumour. This study shows that in four patients with a confirmed gastrinoma we were able to localize the gastrinoma by selective intra-arterial calcium injection and hepatic venous sampling, whilst the patients remained on proton pump inhibitor or H2 antagonist therapy, thereby reducing their risk of gastrointestinal perforation.

Neuropeptide Y (NPY) actions on the corticotroph cell of the anterior pituitary gland are not mediated by a direct effect

Neuropeptide Y has been implicated in the activation of the hypothalamic-pituitary-adrenal (HPA) axis, the regulation of growth and sexual function, and is the most potent stimulant of feeding yet reported. The actions of NPY on the HPA axis are thought to be mediated via an activation of the corticotrophin releasing hormone (CRH) neurones within the paraventricular nucleus of the hypothalamus. The ability of NPY to directly influence the corticotroph cell is currently controversial. These studies investigated whether NPY could have a direct influence on anterior pituitary adrenocorticotrophic hormone (ACTH) release. In dispersed male rat anterior pituitary cells, NPY (1-1000 nM) had no effect on either basal or CRH (1 nM) stimulated ACTH release. Basal release, NPY (1000 nM) 111 +/- 6% vs. control 103 +/- 5%. CRH stimulated release, CRH (1 nM) with NPY (1000 nM) 226 +/- 23% vs. CRH (1 nM) alone 228 +/- 20%. In addition, NPY (1000 nM) had no effect on either basal or CRH (1 nM) stimulated ACTH release in the mouse corticotroph cell line, AtT-20. Thus, in two models of the anterior pituitary corticotroph NPY had no effect on ACTH release. NPY induced activation of the HPA axis is likely to be mediated via a modulation of hypothalamic CRH and not via a direct action at the level of the anterior pituitary.

Frequent falls and confusion: recurrent hypoglycemia in a patient with tuberous sclerosis complex

Recurrent hypoglycemia is common, but its presentation is often insidious resulting in delays in diagnosis and significant morbidity. We describe a case of an insulinoma presenting with falls and confusion in a patient with tuberous sclerosis, demonstrating the importance of early hypoglycemia identification and a potential shared molecular pathogenesis.

A rare case of Cushing's syndrome caused by 'cyclical' ectopic ACTH secretion

A 61 year old lady presented in April 2013 with rapid onset of lethargy and reduced mobility with inability to use stairs over one month. Prior to this, she was fit and well and had no significant medical history and was a lifelong non-smoker. At presentation, it was noted that she was overweight with a BMI of 35 kg/m2 and had evidence of skin bruising, severe proximal myopathy of her legs and bilateral leg cellulitis.