Salusin-β is an endogenous parasympathomimetic proatherosclerotic peptide. Salusin-β was initially predicted from bioinformatic analyses and later immunologically detected in human biofluids. However, elucidation of salusin-β bioactivity has faced enormous challenges because of its unique physicochemical characteristics that cause it to strongly adhere to laboratory apparatus materials. In the strictest sense, the discovery of bioactive peptides is not complete until their exact native sequences have been confirmed in the peripheral circulation. In this study, we determined the plasma molecular form and levels of free salusin-β to determine its pathophysiological significance. Ultra-high-yield enrichment and preseparation of non-tryptic human plasma was followed by LC-MS/MS, and full-length salusin-β and seven different endogenous fragment sequences were identified. We established a new ELISA that specifically detects plasma free salusin-β without cross-reacting with any of its identified endogenous fragments. Free salusin-β levels exhibited a profound early morning nadir and rapidly decreased in response to parasympathetic nervous augmentation. Our technical advance in plasma native peptide analysis successfully identified a hard-to-detect bioactive peptide, salusin-β, together with its formerly unrecognized fragments, and further suggests that conventional immunological measurements of target peptides may not be fully representative.

The patient was a 61-year-old woman who had a well-differentiated pancreatic neuroendocrine tumor (PNET) with lymph node metastasis. After 15 months of octreotide treatment, glucose control deteriorated and pigmentation of the tongue and moon face developed, leading to the diagnosis of ectopic adrenocorticotropic hormone (ACTH) syndrome. An abnormal secretion of growth hormone (GH) was identified, and the plasma growth hormone-releasing hormone (GHRH) level was elevated. A tumor biopsy specimen positively immunostained for ACTH and GHRH. Ectopic hormone secretion seems to have evolved along with the progression of the PNET.

A 73-year-old Japanese woman with untreated Graves' hyperthyroidism developed glucocorticoid-induced adrenal insufficiency (AI) after a supraphysiological dose of prednisolone therapy for bronchial asthma. Days later, she had high plasma adrenocorticotropic hormone (ACTH) levels and was expected to recover from glucocorticoid-induced AI. Her plasma ACTH levels remained high over 3 months during a physiological dose of hydrocortisone replacement. However, she suffered a further decrease in her serum cortisol level and was diagnosed with isolated adrenocorticotropin deficiency (IAD), in which bioinactive ACTH likely caused the high ACTH value. IAD should be considered as an unusual disorder associated with Graves' disease, especially in older patients.

OBJECTIVE Human chorionic gonadotropin (HCG) can be detected in a certain population of patients with a germinoma, but the frequency of germinoma HCG secretion and the prognostic value of HCG in the CSF are unknown. METHODS The authors measured HCG levels in sera and CSF in patients with a histologically confirmed germinoma by using a highly sensitive assay known as an immune complex transfer enzyme immunoassay (EIA), which is more than 100 times as sensitive as the conventional method, and they analyzed the correlation between HCG levels and the prognoses of patients with a germinoma. RESULTS HCG levels in sera and CSF of 35 patients with a germinoma were examined with the immune complex transfer EIA. The median CSF HCG levels in patients with a germinoma during the pretreatment and posttreatment evaluations were 192.5 pg/ml (range 1.2-13,116.5 pg/ml) and 18.7 pg/ml (1.2-283.9 pg/ml), respectively. Before treatment, the CSF HCG level was greater than the cutoff value in 85.7% of the patients with a germinoma. The authors compared survival rates among the patients by using a CSF HCG cutoff level of 1000 pg/ml, and the difference was statistically significant between the groups (p = 0.029, log-rank test). CONCLUSIONS Results of this study demonstrate that most germinomas secrete HCG. Patients with a germinoma that secretes higher amounts of HCG in their CSF experienced recurrence more frequently than those with lower CSF HCG levels.

Solitary fibrous tumors occasionally present with hypoglycemia because of the excessive release of insulin-like growth factor II. We report the first case of pancreatic solitary fibrous tumor causing ectopic adrenocorticotropic hormone syndrome. An 82-year-old Japanese man presented with lower limb edema, uncontrolled hypertension, hypokalemia, and baseline hypercortisolism. Distal pancreatectomy was performed after the clinical diagnosis of a neuroendocrine tumor with ectopic secretion of adrenocorticotropic hormone. On histological examination, the tumor showed spindle cells in a fascicular arrangement. The diagnosis of the solitary fibrous tumor was confirmed by the identification of the NAB2-STAT6 fusion gene and positive immuno-histochemical staining for STAT6 and CD34. Using quantitative real-time polymerase chain reaction, mRNA that encoded proopiomelanocortin, precursor of adrenocorticotropic hormone, was detected. Proopiomelanocortin production through the demethylation of the promoter region Domain IV was detected. Pancreatic solitary fibrous tumors represent a new cause of ectopic adrenocorticotropic hormone syndrome.

A 64-year-old Japanese man with mild reticular shadows in both lungs developed a lung tumor causing ectopic Cushing's syndrome. He was prescribed an adrenal inhibitor, which controlled his hypercortisolemia. However, he developed acute exacerbation of idiopathic pulmonary fibrosis (IPF) and died within weeks. Previous studies have suggested a dosage reduction of corticosteroids for IPF as a triggering event for acute exacerbation. The present case suggests that IPF coexisting with Cushing's syndrome may have been exacerbated after the correction of hypercortisolemia. Therefore, close monitoring of cortisol levels along with the clinical course of IPF is required in similar cases that require the correction of hypercortisolemia.

BACKGROUND:We developed a novel, ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for determination of glutamic acid decarboxylase autoantibody concentrations in serum samples from patients with type 2 diabetes.METHODS:We developed an immune complex transfer enzyme immunoassay for glutamic acid decarboxylase autoantibody and measured glutamic acid decarboxylase autoantibody from 22 patients with type 1 diabetes, 29 patients with type 2 diabetes, and 32 healthy controls.RESULTS:A conventional ELISA kit identified 10 patients with type 1 diabetes and one patient with type 2 diabetes as glutamic acid decarboxylase autoantibody positive, whereas 15 patients with type 1 diabetes and six patients with type 2 diabetes were identified as glutamic acid decarboxylase autoantibody positive using immune complex transfer enzyme immunoassay.CONCLUSIONS:Immune complex transfer enzyme immunoassay is a highly sensitive and specific assay for glutamic acid decarboxylase autoantibody and might be clinically useful for diabetic onset prediction and early diagnosis.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Objectives: We developed an ultrasensitive enzyme immunoassay (ICT-EIA) for insulin autoantibody (IAA) measurements to better understand the pathophysiology of diabetes.Design and methods: We developed ICT-EIA for IAA and measured IAA in 24 patients with type 1 diabetes, 30 patients with type 2 diabetes. 30 patients with methimazole-treated Graves' disease, 20 patients with Hashimoto's disease, 9 patients with hyperinsulinemia, and 73 healthy control subjects.Results: The conventional ELISA identified 3 patients with type 1 diabetes and 2 patients with type 2 diabetes as IAA positive, whereas 15 patients with type 1 diabetes, 7 patients with type 2 diabetes, and 4 patients with methimazole-treated Graves' disease were identified as IAA positive using ICT-EIA.Conclusions: The ICT-EIA is an ultrasensitive and specific assay for IAA, and its use may provide a better understanding of the role of IAA in diabetes onset and progression. (c) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

視床下部と下垂体の疾患は高血圧や糖尿病に比較して，稀少疾患である．たとえばACTH単独欠損症は人口100万人あたり有病率は19.1人，新規の年間発症率は0.9人と少ない．これら疾患の稀少性により，日常診療では見落とされがちで，診断と治療の遅れにつながりやすい．視床下部・下垂体疾患の診療では内分泌系と神経系にまたがる臨床徴候を手がかりに，フィードバック調節を含めたホルモン分泌調節とその異常を定量的に評価する．特に，視床下部・下垂体周辺の腫瘍や炎症性病変ではmass effectにより，頭痛，視野狭窄（典型的には両耳側半盲）や視力低下を訴えることが多い．経時的かつ階層的に進行する下垂体ホルモン分泌低下症に対して，適切な診断を行う．また，われわれが開発したホルモン・ペプチドの超高感度測定法は下垂体機能低下症の病態解明に有用である．そして，視床下部・下垂体部の形態異常をMRI検査で評価する．さらに，必要時，遺伝子検査や病理検査を加えることにより，確定診断に至る．2009年10月より，間脳-下垂体の7疾患・病態が厚生労働省難治性疾患克服研究事業の対象疾患と指定され，公費医療助成の対象疾患に指定されている．患者から認定の依頼があった場合は，担当医師は「間脳下垂体機能障害に関する調査研究班」からの診断と治療の手引き（ガイドライン）に従い，申請し，審査を受けることになっている．現在，本ガイドラインの基礎となる各種ホルモン測定値の標準化（国際化を含む）と，疫学研究に基づく診療ガイドラインの構築と国際比較が喫緊の課題である．

Immunoassay control surveys, were conducted by the Subcommittee for Radioisotope in vitro Test, the Medical Science and Pharmaceutical Committee, and the Japan Radioisotope Association, between 1978 to 2008. A total of 40 analytes for 26 hormones, 14 tumor markers and pharmaceutical drugs were investigated in participating facilities. In the first immunoassay control survey in 1978, samples were measured using only RI kits, however, non-RI kits increased gradually during the next 30 years. In the 30th immunoassay control survey, more than 90% samples were measured using non-RI kits. Coefficient variation (CV) of intra-kits has been decreasing yearly in all analytes for hormones as well as tumor markers. However, improvement of CV in inter-kits has not been seen in the past 30 years by a lack of international standards, although there has been continuous effort over the years for the standardization of immunoassay. Growth hormone (GH) deficiency has been diagnosed using various loading tests. However, the clinical diagnosis varies according to the GH kit used. Standardization for GH measurement has been possible by using recombinant GH as the standard among commercial GH kits. The diagnosis of subclinical Cushing's syndrome also varies according to the cortisol kits being used. Candidate reference measurement procedure and low level cortisol standards have been developed by the Biomedical Standard Section, of the National Metrology Institute of Japan. Standardization of measurement is necessary for improvement of immunoassay.

BACKGROUND AND IMPORTANCE: The case presented here describes the clinical evolution of a pituitary carcinoma from an atypical prolactinoma after temozolomide (TMZ) treatment. The mechanism of acquisition of TMZ resistance was analyzed.CLINICAL PRESENTATION: A 60-year-old woman with atypical prolactinoma had been treated for 7 years with multiple therapies, including dopamine agonists, surgical intervention (5 times), conventional radiotherapy, and radiosurgery. The patient deteriorated as a result of tumor enlargement. Ten cycles of TMZ therapy, 200 mg/m(2) for 5 days every 4 weeks, improved the patient's performance status and caused tumor shrinkage. Six months after discontinuation of TMZ, the tumor progressed into pituitary carcinoma with tumor regrowth and intraventricular dissemination. TMZ therapy was ineffective this time. A sixth surgery and salvage chemotherapy failed to improve the patient's condition, and she died 9 years after the first diagnosis. Throughout the treatment course, O6-methyl-guanine-DNA methyltransferase (MGMT) was immuno-negative in the tumor specimens, including the TMZ-refractory pituitary carcinoma. Mutation of p53 was identified in both the atypical prolactinoma and pituitary carcinoma. In contrast, major differences were noted for mismatch repair protein MSH6 immunostaining: Although MSH6 was diffusely immunopositive in the atypical adenoma, it became immunonegative when the tumor evolved into TMZ-refractory pituitary carcinoma.CONCLUSION: Loss of MSH6 occurred during the progression from an atypical prolactinoma to a pituitary carcinoma, which may have caused resistance to TMZ treatment. This case suggests that preserving MSH6 function is essential for responsiveness to TMZ treatment in MGMT-negative and p53-mutated atypical pituitary adenoma or pituitary carcinoma.

A 58-year-old woman and a 71-year-old woman presented with extremely rare skull base metastases from follicular thyroid carcinoma (FTC). Surgical removal and external radiotherapy were performed followed by iodine-131 (131I) brachytherapy and thyroid hormone administration. The metastatic tumors in the skull base were well controlled. Treatment for skull base metastasis from FTC includes surgical debulking of the metastatic lesion, as well as complete resection of the thyroid gland, followed by internal irradiation with 131I, external irradiation, and administration of thyroid hormone to prevent tumor growth by suppression of endogenous thyroid-stimulating hormone. Skull base metastases may be the initial clinical presentation of FTC, with silent primary sites. The possibility of skull base metastasis from FTC should be considered in patients with clinical symptoms of cranial nerve dysfunction and radiological findings of bone destruction.