Endocrine Abstracts

The leptin receptor (ObR) exists in multiple isoforms. In humans, there is no mRNA encoding soluble receptor (LBP). We investigated the hypothesis that human LBP can be generated by proteolytic cleavage of membrane anchored leptin receptors (ObRb and ObRa). LBP, of similar size to that previously detected in human serum, was detected in medium of cells transfected with ObRa by HPLC, Immunofluorometric assay, and Ligand mediated immunofluorometric assay, but not by ELISA. The L...

Background: Leptin is a multi-functional hormone of which low levels are associated with immuno-deficiency. We and others have shown that leptin promotes secretion of inflammatory cytokines (TNF-alpha and IL-6) by monocytes (1) and activated lymphocytes (2). The leptin receptor (Ob-R) is expressed on neutrophils and leptin enhances oxidative species production by stimulated neutrophils.Aim: To access whether CD11b expression on human neutrophils is a di...

AIM: 1) To determine GH dose requirement in GH deficient patients aged over 60 years. METHODS: The study was approved by the local Ethics Committee. Patients were started on Genotropin 0.4 units (0.13 mg)/day after baseline assessment. Serum IGF-I was repeated at 2-weekly intervals. Maintenance GH dose was achieved when serum IGF-1 was between the median and upper end of the age-related range. RESULTS: 16 patients (10 men & 6 women) were recruited. Their median (range) age...

Background: The 250microgram synacthen test may give false negative responses, and will not allow easy discrimination between primary and secondary dysfunction. Furthermore, the use of synacthen is contra-indicated on the data sheet in certain common conditions such as asthma, and may not easily be interpreted in women taking oral oestrogen. Some patients with incipient adrenal failure may have elevated plasma ACTH, whilst passing the synacthen test. We have routinely measured...

Background: Cut-offs for basal cortisol (early morning) have been determined to predict the 30-minute cortisol level post-synacthen, but not for determining when patients with suspected tertiary adrenal insufficiency (AI) are weaned off glucocorticoids.Aims: The aim of this study was to compare the predictive values of basal cortisol, basal ACTH and basal cortisol:ACTH ratio to determine appropriate thresholds to reduce ...

Background: Long-term glucocorticoids can result in iatrogenic Cushing’s syndrome with adrenal suppression. Most patients reactivate their hypothalamic-pituitary-adrenal axis once they’re weaned off glucocorticoids. During glucocorticoid withdrawal, many clinicians switch patients to hydrocortisone to benefit from its short half-life1. However, in some patients, hypothalamic-pituitary-adrenal axis recovery is delayed despite the above. It is unclear whethe...

G protein-coupled receptors (GPCRs) are critical for signal transduction within neuroendocrine signalling pathways, and genetic mutations in G protein-coupled GPCRs underlie numerous diseases. Inactivating GPCR mutations can impede ligand interactions or signal transduction, or can result in misfolding of nascent receptor proteins and subsequent retention in the endoplasmic reticulum (ER) and thus failure to traffic to the cell surface. Examination of the functionality and cel...

Background: We observed patients with well-differentiated NETs who received PRRT with 177Lu-dotatate and later developed rapid disease progression with biopsy-proven histologic transformation to NECs, an outcome that has not been previously described. In this series, we characterize the clinicopathologic features and outcomes of patients whose tumors underwent poorly-differentiated transformation.Methods: After obtaining IRB approval, we condu...

The granulation pattern of somatotroph adenoma is well known to be associated with differing clinical and biochemical characteristics and it has been shown that sparsely granulated tumors respond poorly to commonly used somatostatin analogs. We report a challenging case of acromegaly with a sparsely granulated tumor, resistant to multiple modalities of treatment given over several years and ultimately achieving biochemical control with pasireotide. A 26-year-old lady presented...

Background: Data examining HLA associations in Addison’s disease (AD) from South Africa (SA) are limited. We wished to determine the HLA in South African AD patients either positive or negative for 21 hydroxylase autoantibodies (21 OH-AA) and matched healthy controls, hypothesising that certain HLA alleles could predominate, but there may be differences from Western countries.Methods: SA patients (n=73) were enrolled as part of a nationwide...