International survey on high- and low-dose synacthen test and assessment of accuracy in preparing low-dose synacthen.

OBJECTIVE: The short synacthen test (SST) is widely used to assess patients for adrenal insufficiency, but the frequency and protocols used across different centres for the low-dose test (LDT) are unknown. This study aimed to survey centres and test the accuracy of ten different synacthen preparation strategies used for the LDT. METHODS: Members of 6 international endocrine societies were surveyed regarding diagnostic tests used for adrenal insufficiency, and in particular the SST. Synacthen was diluted for the LDT and concentrations measured using a synacthen ELISA. RESULTS: Survey responses were received from 766 individuals across 60 countries (52% adult, 45% paediatric endocrinologists). The SST is used by 98% of centres: 92% using high-dose (250 µg), 43% low-dose and 37% both. Ten low-dose dilution methods were assessed and variation in synacthen concentration was demonstrated with intramethod coefficients of variation (CV) ranging from 2.1% to 109%. The method using 5% dextrose as a diluent was the least variable (CV of 2.1%). The variation in dilution methods means that the dose of synacthen administered in a LDT may vary between 0.16 and 0.81 µg. CONCLUSIONS: The high-dose SST is the most popular diagnostic test of adrenal insufficiency, but up to 72% of paediatric endocrinologists use a LDT. There is considerable variation observed both within and between low-dose synacthen dilution methods creating considerable risk of inaccurate dosing and thereby invalid results.

Novel carbonic anhydrase IX-targeted therapy enhances the anti-tumour effects of cisplatin in small cell lung cancer.

Small cell lung cancer (SCLC) has an extremely poor prognosis and methods of improving chemotherapeutic intervention are much sought after. A promising approach lies in inhibiting the tumour-associated enzyme, carbonic anhydrase IX (CA IX), which supports tumour cell survival. The aim of this study was to assess the potential of CA IX inhibition using 4-(3'-(3″,5″-dimethylphenyl)ureido)phenyl sulfamate (S4), for the treatment of human SCLC alone and in combination with cisplatin chemotherapy. Treating SCLC cell lines (DMS 79 and COR-L24) with 100 µM S4 reduced viability in vitro and enhanced cell death when combined with 7 µM cisplatin, most prominently under hypoxic conditions (0.1% O2 ). When either cell line was grown as a xenograft tumour in nude mice, intraperitoneal injection of 50 mg/kg S4 alone and in combination with 3 mg/kg cisplatin led to significantly reduced tumour growth. Combination therapy was superior to single agents and response was greatly accentuated when administering repeated doses of cisplatin in DMS 79 tumours. The mechanism of therapeutic response was investigated in vitro, where S4 treatment increased apoptosis under hypoxic conditions in both DMS 79 and COR-L24 cells. DMS 79 tumours receiving S4 in vivo also displayed increased apoptosis and necrosis. Combining S4 with cisplatin reduced both the area of hypoxia and CA IX-positive cells within tumours and increased necrosis, suggesting hypoxia-specific targeting. This study presents a novel, targeted approach to improving current SCLC therapy via inhibition of CA IX, which enhances apoptosis and significantly inhibits xenograft tumour growth when administered alone and in combination with cisplatin chemotherapy.

Cushing syndrome in a child due to pro-opiomelanocortin (POMC) secretion from a yolk sac tumor.

CONTEXT: Pituitary microadenomas and adrenal tumours are the most common causes for endogenous Cushing syndrome (CS) in children. CASE DESCRIPTION: We describe a two-year old girl with Cushing syndrome due to ectopic pro-opiomelanocortin (POMC) production from an abdominal yolk sac tumor. Cortisol concentrations were elevated but adrenocorticotropic hormone (ACTH) concentrations were equivocal. The use of antibodies specifically detecting ACTH precursors revealed that plasma ACTH precursors were elevated. Additionally, an ACTH assay with a low cross-reactivity for precursors showed low concentrations of ACTH. Immunohistochemistry suggested POMC but not ACTH production by the tumour. CONCLUSION: We describe a yolk sac tumour as a novel source of ectopic POMC production leading to CS in a young girl.

Irradiation Decreases the Neuroendocrine Biomarker Pro-Opiomelanocortin in Small Cell Lung Cancer Cells In Vitro and In Vivo.

BACKGROUND: Small cell lung cancer (SCLC) is an extremely aggressive disease, commonly displaying therapy-resistant relapse. We have previously identified neuroendocrine and epithelial phenotypes in SCLC tumours and the neuroendocrine marker, pro-opiomelanocortin (POMC), correlated with worse overall survival in patients. However, the effect of treatment on these phenotypes is not understood. The current study aimed to determine the effect of repeated irradiation treatment on SCLC cell phenotype, focussing on the neuroendocrine marker, POMC. RESULTS: Human SCLC cells (DMS 79) were established as subcutaneous xenograft tumours in CBA nude mice and then exposed to repeated 2Gy irradiation. In untreated animals, POMC in the blood closely mirrored tumour growth; an ideal characteristic for a circulating biomarker. Following repeated localised irradiation in vivo, circulating POMC decreased (p< 0.01), in parallel with a decrease in tumour size, but remained low even when the tumours re-established. The excised tumours displayed reduced and distinctly heterogeneous expression of POMC compared to untreated tumours. There was no difference in the epithelial marker, cytokeratin. However, there were significantly more N-cadherin positive cells in the irradiated tumours. To investigate the tumour response to irradiation, DMS79 cells were repeatedly irradiated in vitro and the surviving cells selected. POMC expression was reduced, while mesenchymal markers N-cadherin, ß1-integrin, fibroblast-specific protein 1, ß-catenin and Zeb1 expression were amplified in the more irradiation-primed cells. There were no consistent changes in epithelial marker expression. Cell morphology changed dramatically with repeatedly irradiated cells displaying a more elongated shape, suggesting a switch to a more mesenchymal phenotype. CONCLUSIONS: In summary, POMC biomarker expression and secretion were reduced in SCLC tumours which regrew after irradiation and in repeatedly irradiation (irradiation-primed) cells. Therefore, POMC was no longer predictive of tumour burden. This highlights the importance of fully evaluating biomarkers during and after therapy to assess clinical utility. Furthermore, the gain in mesenchymal characteristics in irradiated cells could be indicative of a more invasive phenotype.

Biomarkers for small cell lung cancer: neuroendocrine, epithelial and circulating tumour cells.

Small cell lung cancer (SCLC) is characterised by an aggressive clinical course with invariable resistance to chemotherapy despite initially high response rates. There has been little improvement in outcome over the past few decades, with no breakthrough yet in targeted therapies. Recent preclinical data and studies of circulating tumour cells (CTCs) highlight distinct cellular heterogeneity within SCLC. Better understanding of how these phenotypes contribute to metastasis and tumour progression might pave the way for development of more successful targeted therapies. Here we review these studies, their implications for future research and for the incorporation of biomarkers reflecting neuroendocrine, epithelial and mesenchymal phenotypes in clinical studies.

A comprehensive e-education engine for a virtual diabetes centre.

It seems likely that the development of effective diabetes education for patients, carers and staff would prove highly cost-effective. Diabetes-e is an electronic diabetes encyclopaedia designed to provide comprehensive education to patients, carers (e.g. family, schools, care homes) and health professionals (specialist and non-specialist). In addition, educational media such as information leaflets (that can be printed during a consultation), streaming educational video and slide resource packs are available. Self-assessment questionnaires with feedback guide further education and facilitate targeted continuing professional development (CPD) for health professionals. The prototype has been developed with a particular emphasis on patient input. It is anticipated that Diabetes-e will be implemented across Central Nottinghamshire, including training of key personnel, by the end of 2005. The project has already gone live for insulin commencement.