Multiple endocrine neoplasia type 1 with Zollinger-Ellison syndrome: clinicopathological analysis of a Japanese family with focus on menin immunohistochemistry

Background

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by the occurrence of multiple epithelial neuroendocrine tumors (NETs) and non-NETs in various organs. MEN1 encodes a 610-amino acid-long tumor suppressor protein, menin. The optimal treatment for multiple tumors, identification of the most critical tumors for patient prognosis, and menin immunohistochemistry findings remain controversial. Therefore, we aimed to elucidate these issues through a histological analysis of tumors and tumor-like lesions in a Japanese family, comprising a father and his two sons, who had MEN1 with Zollinger-Ellison syndrome (ZES).

Patients and methods

All family members had a germline alteration in exon 10, c.1714-1715 del TC of MEN1, and exhibited multiple synchronous and metachronous tumors. The patients had pulmonary NETs, hyperparathyroidism, hypergastrinemia, pituitary adenomas, pancreaticoduodenal NETs, adrenocortical adenoma with myelolipoma, nodular goiter of the thyroid, lipomas, and angiofibroma. Most tumors were resected and histologically examined. We compared their clinical courses and tumor histology, and conducted menin immunohistochemistry (IHC).

Results

Two patients died of pulmonary NET G2. One patient who underwent pancreaticoduodenectomy was cured of ZES; however, the two other patients who did not undergo pancreaticoduodenectomy suffered persistent ZES despite treatment with octreotide. Menin IHC revealed varying NET intensities, ranging from positive to negative stains.

Conclusion

Pancreaticoduodenectomy is the most effective treatment for ZES. Long-term follow-up is essential for pulmonary NET G2 owing to the risk of distant metastasis and/or multiplicity. Moreover, the variability of menin IHC in MEN1-related tumors may indicate the pattern of tumor formation rather than the diagnostic utility of menin in MEN1.

Effects of Isometric Handgrip Training on Home Blood Pressure Measurements in Hypertensive Patients: A Randomized Crossover Study

Objective We aimed to examine the effects of isometric handgrip (IHG) training on home blood pressure (BP) levels in hypertensive Japanese patients undergoing treatment. Methods Fifty-three hypertensive patients (mean age, 61.7 years; 56.6% men) with a home systolic BP ≥135 mmHg and/or a home diastolic BP ≥85 mmHg were randomly assigned to either group A or B. As per the crossover design, group A performed 8 weeks of IHG training, followed by an equivalent training-free, control period, while the reverse protocol was performed by group B. The baseline characteristics were similar between both groups. The individualized daily IHG training comprised four sets of 2-min isometric contractions at 30% of the individual's maximum voluntary contraction capacity, including 1 min of rest between sets, for ≥3 days/week. The outcome measure was morning and evening home BP readings taken over the last 2 weeks of the training and control periods. Results A combined data analysis for both groups showed that IHG training was significantly associated with the lowering of both systolic and diastolic BP in the morning (137.9±9.3 vs. 135.3±9.5 mmHg, p=0.007 and 83.0±9.5 vs. 81.2±9.3 mmHg, p<0.001, respectively) and evening (130.0±10.7 vs. 127.6±10.1 mmHg, p=0.003 and 75.8±10.4 vs. 73.8±9.2 mmHg, p<0.001, respectively), while no significant change was observed after the control period. A larger increase in the maximum grip strength due to IHG training was associated with greater BP reductions. Conclusion An 8-week period of IHG training significantly lowered both the morning and evening home BP in hypertensive Japanese patients undergoing treatment.

Evaluation of growth hormone-releasing peptide-2 for diagnosis of thyrotropin-producing pituitary adenomas

Thyrotropin (TSH)-producing adenomas are a rare cause of hyperthyroidism and are a type of functional pituitary adenoma. The diagnosis of TSH-producing adenoma is a challenging problem in clinical endocrinology. Since growth hormone-releasing peptide-2 (GHRP-2) fails to induce TSH secretion in normal subjects, the effect of GHRP-2 on TSH levels was therefore examined in patients with TSH-producing adenomas. A total of 5 patients (4 women and 1 man) referred to our departments for further evaluation of pituitary hormones were followed-up using the GHRP-2, TSH-releasing hormone (TRH), octreotide, and bromocriptine tests to examine and evaluate TSH secretory dynamics in TSH-producing adenomas. Of 5 patients, 2 (40%) showed such a significant response, defined as a >50% increase in serum TSH level above baseline in the GHRP-2 test. Additionally, 1 patient showed a 48% increase in serum TSH level. In 1 patient whose adenoma was completely removed, basal serum concentrations of TSH were sufficiently suppressed after the operation, and serum TSH levels failed to increase in response to GHRP-2 administration. In 4 patients (80%), a poor response of serum TSH levels was observed in the TRH test. In 2 out of 5 patients (40%), serum TSH levels were significantly decreased following octreotide administration. No patient demonstrated a significant response to the bromocriptine test. In addition to TRH test, the GHRP-2 test as a potential diagnostic tool for TSH-producing pituitary adenomas.

Evaluation of the (1-24) adrenocorticotropin stimulation test for the diagnosis of primary aldosteronism

OBJECTIVE

The purpose of this study was to investigate the diagnostic power of the adrenocorticotropin (ACTH) stimulation test in patients with primary aldosteronism (PA) and those with aldosterone-producing adenoma (APA).

DESIGN

This study was based on a retrospective database analysis.

SUBJECTS AND METHODS

We assessed 158 hypertensive patients with a high plasma aldosterone-to-renin ratio (ARR) including 97 with at least one positive confirmatory test result who did not undergo surgery and comprised a "possible PA" group, 19 with negative results in all tests who were the "non-PA" group, and 41 diagnosed with APA following surgery who were the APA group. The "confirmed PA group" included APA patients and patients from the possible PA group showing both high ARR and hypokalemia. One case was diagnosed as a metastasis.

RESULTS

Receiver-operating characteristic (ROC) analysis showed that the diagnostic accuracy of ACTH test was not very effective in differentiating between APA patients and possible PA and non-PA patients. The optimal cut-off value of maximal plasma aldosterone concentration for differentiating between patient in the confirmed PA group and other patients showed moderate accuracy.

CONCLUSIONS

The ACTH test may not be useful as a screening or confirmatory test, but the test may be useful for differentiating between patients with confirmed PA and the rest of the cohort. The positive finding of the ACTH test may at least support a higher likelihood of lateralizing on adrenal venous sampling.

A case of ectopic ACTH syndrome treated with intermittent administration of dopamine agonists

ACTH-dependent Cushing's syndrome includes Cushing's disease and ectopic ACTH syndrome (EAS). The differential diagnosis of Cushing's disease from EAS in cases of ACTH-dependent Cushing's syndrome is a challenging problem. We report here a case of EAS with an unknown source of ACTH secretion. Extensive imaging procedures, involving computed tomography (neck to pelvis), pituitary magnetic resonance imaging, and whole-body (18)F-fluorodeoxyglucose-positron emission tomography, failed to reveal the source of ACTH secretion. Intermittent administration of bromocriptine, a short-acting and nonselective dopamine agonist, has afforded adequate suppression of plasma ACTH and cortisol levels over the long term.

LEARNING POINTS

Tumor excision is the primary treatment for EAS. However, when surgery is impossible, medical therapy is needed to treat hypercortisolism.In cases where the source of ACTH secretion is unknown, inhibitors of steroidogenesis, such as metyrapone, mitotane, ketoconazole, and etomidate, are mostly used to suppress cortisol secretion.Medications that suppress ACTH secretion are less effective, therefore less popular, as standard treatments.In the present case, short-term treatment with dopamine agonists was effective for the long-term suppression of both ACTH and cortisol levels.

Involvement of Nurr-1/Nur77 in corticotropin-releasing factor/urocortin1-induced tyrosinase-related protein 1 gene transcription in human melanoma HMV-II cells

Recent molecular and biochemical analyses have revealed the presence of corticotropin-releasing factor (CRF) and urocortin (Ucn), together with their corresponding receptors in mammalian skin. The melanosomal enzyme tyrosinase-related protein 1 (TRP1) is involved in modulation of pigment production in response to stressors. Although CRF and Ucn are thought to have potent effects on the skin system, their possible roles and regulation have yet to be fully determined. This study aimed to explore the effects of CRF and Ucn on TRP1 gene expression using human melanoma HMV-II cells. The mRNA of CRF, Ucn1, Ucn2, and CRF receptor type 1 (CRF1 receptor) was detected in HMV-II cells. CRF and Ucn1 stimulated TRP1 gene transcription via the CRF1 receptor, and increased both Nurr-1 and Nur77 mRNA expression levels. Both CRF- and Ucn1-induced Nurr-1/Nur77 acted via a NGFI-B response element on the TRP1 promoter. The combination of Nurr-1/Nur77 and microphthalmia-associated transcription factor, a melanocyte-specific transcription factor gene induced by α-melanocyte-stimulating hormone, had additive effects on activation of TRP1 gene transcription. The findings suggest that in human melanoma HMV-II cells both CRF and Ucn1 regulate TRP1 gene expression via Nurr-1/Nur77 production, independent of pro-opiomelanocortin or α-melanocyte-stimulating hormone stimulation.

Pheochromocytoma with histologic transformation to composite type, complicated by watery diarrhea, hypokalemia, and achlorhydria syndrome

OBJECTIVE

To describe the rare occurrence of histologic transformation of a pheochromocytoma to a composite type of tumor during a long-term follow-up, which was complicated by watery diarrhea, hypokalemia, and achlorhydria syndrome.

METHODS

We report the case of a 12-year-old girl who presented with headache, hypertension, and elevated catecholamine levels in the blood and urine. A tumor was found in the right adrenal gland and resected. When she was 15 years of age, multiple metastatic nodules were found in the lung and liver. Intensive chemotherapy was ineffective, and she underwent follow-up with conservative therapy. At 25 years of age, she complained of diarrhea. Laboratory studies revealed hypokalemia and an increase in the level of serum vasoactive intestinal polypeptide (VIP). A year later, she died of extensive metastatic disease. The primary and recurrent tumors at autopsy were histologically examined.

RESULTS

The primary tumor was pure pheochromocytoma, and the tumors at autopsy were a composite type of pheochromocytoma and ganglioneuroma. Only a few VIP-positive cells were found in the primary tumor, whereas both pheochromocytoma and ganglioneuroma cells of composite tumors were frequently positive for VIP.

CONCLUSION

Our case showed histologic transformation from pheochromocytoma to a composite type of tumor during a 14-year clinical course, which was associated with additional hormone production and a change in symptoms. Careful attention should be paid to the alteration of endocrine symptoms and hormone levels during prolonged follow-up of pheochromocytoma in young patients.

Evaluation of the diagnostic criteria for Cushing's disease in Japan

Adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome is caused by an ACTH-producing tumor, as is the case with Cushing's disease and ectopic ACTH syndrome (EAS). Diagnosis and differential diagnosis of Cushing's disease from EAS in ACTH-dependent Cushing's syndrome are thus challenging problems in clinical endocrinology. The diagnostic criteria for Cushing's disease in Japan, established by the working group of the Japan Ministry of Health, Labour and Welfare, were originally reported in 2003 and revised in 2007 and 2010. In addition, criteria for subclinical Cushing's disease were established in Japan in 2010. In this review, we evaluate the usefulness and accuracy of the most recent diagnostic criteria. Previous data suggest that as an initial test of Cushing's syndrome, 0.5 mg dexamethasone is more sensitive than 1 mg in the overnight dexamethasone suppression test (DST). Here, we recommend 0.5 mg plus a plasma cortisol cut-off level of 3 µg/dL as a suitable low-dose overnight DST for screening of all cases of ACTH-dependent Cushing's syndrome in Japan. Recently, standardization of cortisol measurements by the ID-LC/MS/MS method using seven assay kits with standard plasma material containing synthetic hydrocortisone-d4 was carried out in Japan. The resulting relative standard deviation was within 10%. The cut-off value remains valid even after standardization of plasma cortisol measurements. Although the recent diagnostic criteria achieve higher diagnostic specificity, care should be taken since data for Cushing's disease partially overlaps with some cases of EAS. Overall, therefore, this review suggests that the accuracy of each diagnostic test should be considered.

An adult case of 22q11.2 deletion syndrome diagnosed in a 36-year-old woman with hypocalcemia caused by hypoparathyroidism and Hashimoto's thyroiditis

22q11.2 Deletion syndrome is recognized to be a major cause of congenital hypoparathyroidism, and affected patients exhibit a range of autoimmune characteristics. The syndrome becomes apparent in early childhood and is rarely diagnosed in adulthood. This report describes an adult case of 22q11.2 deletion syndrome first diagnosed in a 36-year-old woman with hypocalcemia caused by hypoparathyroidism and Hashimoto's thyroiditis. It is important to diagnose 22q11.2 deletion syndrome in adults because such patients are still at high risk for developing treatable diseases, such as hypocalcemia and autoimmune diseases.

The frequency of type 2 diabetic patients who meet the endocrinological screening criteria of subclinical Cushing's disease

Cushing's syndrome, including its mild form/state of adrenal-dependent subset (subclinical Cushing's syndrome; subCS), is known to enhance glucose intolerance, hypertension and obesity. Recently, subclinical Cushing's disease (subCD) has been identified, but its prevalence and the extent of consequent metabolic derangement are unclear. We screened 90 type 2 diabetic patients hospitalized in our department for subCD, according to the diagnostic guideline proposed by the working group of Japanese Ministry of Health, Welfare and Labor in 2006. Plasma ACTH and cortisol levels in the morning and at midnight were determined, and overnight 0.5 mg dexamethasone suppression test (DST) was performed. Those who showed poor cortisol suppression in DST underwent the desmopressin (DDAVP) test. Fifty-seven patients (63.3%) demonstrated abnormally high midnight cortisol levels (>or=2.5 microg/dL), while only nine of them failed to suppress plasma cortisol levels to <3 microg/dL after DST. Although none of the eight patients who underwent the DDAVP test demonstrated the anticipated paradoxical rise in plasma ACTH, these eight patients (8.9%) endocrinologically met the screening criteria of subCD. Since a considerable percentage of pituitary adenomas causing overt Cushing's disease are not identifiable in magnetic resonance imaging, many of those causing subCD may also be unidentifiable. Further follow-up studies including confirmatory testing and pituitary imaging are necessary.

Evaluation of plasma, salivary, and urinary cortisol levels for diagnosis of Cushing's syndrome

As a screening test for Cushing's syndrome, the evaluation of late-night cortisol levels is indispensable. We evaluated the usefulness and accuracy of plasma, urinary, and salivary cortisol levels measured late at night for the diagnosis of Cushing's syndrome. High cortisol levels (> 5 microg/dL) during the night are indicative of Cushing's syndrome, although night plasma cortisol levels are not readily reproducible because of the stressful situation. There was no correlation between plasma and urinary cortisol levels late at night, and late-night urinary cortisol levels provided weak information for the diagnosis of Cushing's syndrome. By contrast, late-night plasma and salivary cortisol levels showed a positive correlation, and salivary cortisol sampling was found to be useful for the diagnosis of Cushing's syndrome, because more than 0.4 microg/dL of late-night salivary cortisol levels gave a sensitivity of 86% and a specificity of 100% in our hospital. This method is also useful for the diagnosis of early or mild stage Cushing's syndrome, so-called subclinical Cushing's syndrome. Inherent differences between assays make it difficult to define optimal diagnostic criteria. However, the relative levels of salivary cortisol ratio, which is presented as a relative level, compared with the mean levels of healthy subjects in each institute, is useful for the screening of Cushing's syndrome as the cut-off level of 1.5 shows both high sensitivity and specificity in subclinical and overt Cushing's syndrome. Late-night salivary cortisol measurement is therefore a primary method of choice in the screening of patients suspected of having Cushing's syndrome.

Growth hormone-releasing peptide-2 stimulates secretion and synthesis of adrenocorticotropic hormone in mouse pituitary

Growth hormone (GH)-releasing peptides (GHRPs) are synthetic peptides which induce strong GH release in both animals and humans. Among them, GHRP-2 is known to stimulate GH release by acting at both hypothalamic and pituitary sites, but also induces adrenocorticotropic hormone (ACTH) release in healthy subjects. GHRP-2 may stimulate ACTH release directly via GHRP receptor type 1a in ACTH-producing tumors. GHRP-2 increases ACTH secretion in rat in vivo, but not ACTH release from rat primary pituitary cells. In the present study, in order to elucidate the mechanism underlying ACTH secretion by GHRPs, mouse pituitary cells were stimulated by GHRP-2. GHRP receptor mRNA was expressed in the mouse pituitary, and GHRP-2 directly stimulated secretion and synthesis of ACTH in the mouse anterior pituitary cells. GHRP-2 increased intracellular cyclic AMP production. H89, a potent protein kinase A (PKA) inhibitor, and bisindolylmaleimide I, a selective protein kinase C (PKC) inhibitor, inhibited the GHRP-2-induced ACTH release, and that H89, but not bisindolylmaleimide I, inhibited the GHRP-2-induced proopiomelanocortin mRNA levels. Together, the GHRP-2-induced ACTH release was regulated via both PKA and PKC pathways in the mouse pituitary cells, while ACTH was synthesized by GHRP-2 only via the PKA pathway.

Endothelial cyst of the adrenal gland associated with adrenocortical adenoma: preoperative images simulate carcinoma

A 68-year-old woman was referred for characterization of a left adrenal incidentaloma. Endocrinological examinations indicated subclinical Cushing's syndrome, whereas the large volume (10 cm in diameter) and heterogeneous configuration of the tumor raised a strong suspicion of adrenal carcinoma. Hence, left adrenalectomy was performed. Histopathologically, this lesion was a thick hyaline-walled endothelial cyst, flanked with a compressed adrenocortical adenoma. The puzzling image resemblance of a variation of adrenal cyst to carcinoma necessitated histological examination for confirmative diagnosis. This is the first reported case of adrenal endothelial cyst associated with adrenocortical adenoma, the former of which alone is a rarity.

Deficiency of growth hormone in an adult man case of idiopathic adrenocorticotropin deficiency

Growth hormone (GH) deficiency is transient in most cases of adrenocorticotropin (ACTH) deficiency, while deficiency of both selective ACTH and GH in adults, as in the present case, is rare among hypopituitarism cases. In this patient, one year after hydrocortisone replacement for ACTH deficiency, data on GH secretion by insulin tolerance test and GH-releasing peptide-2 injection showed a partial improvement, but still there was lack of an adequate response. We consider that the patient had the deficiency of both selective GH and ACTH. Therefore, careful monitoring of GH function after the glucocorticoid replacement is required in cases of ACTH deficiency.

Evaluation of diagnostic tests for ACTH-dependent Cushing's syndrome

We evaluated the usefulness and accuracy of diagnostic tests for adrenocorticotropic hormone (ACTH)- dependent Cushing's syndrome, based on our experience of 88 cases, including 73 cases with Cushing's disease, and 15 cases with ectopic ACTH syndrome (EAS). In our study, 0.5 mg of dexamethasone failed to suppress the morning cortisol secretion in 100% of cases with Cushing's disease and EAS. Plasma ACTH levels were significantly increased by desmopressin (DDAVP) in 86% of cases with Cushing's disease, especially in microadenomas (90%), while these levels were not affected in normal subjects. In EAS, 44% responded to DDAVP. Plasma ACTH levels were increased in response to the human corticotropin-releasing hormone (CRH) test in 100% of microadenomas and 73% of macroadenomas with Cushing's disease, but only in 27% of cases with EAS. A high dose (8 mg) of dexamethasone suppressed the morning cortisol secretion in 89% of microadenomas with Cushing's disease, and in 82% of all cases with Cushing's disease, while it did in only 20% of cases with EAS. Taken together, the 0.5 mg dexamethasone suppression test (DST) and DDAVP test are considerably useful for the screening of ACTH-dependent Cushing's syndrome. The CRH test and 8 mg DST would be effective for the diagnosis of Cushing's diseases, because our study shows a sensitivity of 81% in cases with Cushing's disease when these tests are considered together. These data were submitted to prepare the diagnostic criteria for Cushing's disease, suggested by the working group of the Ministry of Health, Labour, and Welfare of Japan.

Development and validation of a 0.5 mg dexamethasone suppression test as an initial screening test for the diagnosis of ACTH-dependent Cushing's syndrome

For the diagnosis of Cushing' s syndrome (CS), the overnight 1 mg dexamethasone suppression test (DST) has been widely used as a standard low-dose DST. However, it is evident that 1 mg DST may not be sensitive enough to detect CS when the cortisol cut-off concentration is 5 microg/dL. Therefore, we developed and validated 0.5 mg DST as a new screening method for diagnosis of ACTH-dependent CS. To compare 0.5 mg DST with 1 mg DST, 110 patients with ACTH-dependent CS were enrolled, including 88 with Cushing' s disease (CD), 8 with subclinical CD and 14 with ectopic ACTH syndrome, as well as 134 control subjects. Subjects were given either 0.5 mg or 1 mg dexamethasone orally at 23:00 on different days, with blood samples collected the following morning between 8:00 and 9:00 to determine plasma cortisol concentration. The area under the receiver operator characteristics curve observing the 0.5 mg DST was higher than that of the 1 mg DST. The most sensitive and specific cut-off value of plasma cortisol concentration using 0.5 mg DST was found to be 3.05 microg/dL with 99.1% sensitivity and 98.4% specificity, identical to the 3 microg/dL cut-off currently used in the Japanese guideline for diagnosis of subclinical CD. In conclusion, 0.5 mg DST is a sensitive and specific screening test for diagnosis of ACTH-dependent CS. We recommend 0.5 mg DST with a cortisol cut-off concentration of 3 microg/dL to be used as the initial step in diagnosing ACTH-dependent CS.

Involvement of regulatory elements on corticotropin-releasing factor gene promoter in hypothalamic 4B cells

INTRODUCTION

Corticotropin-releasing factor (CRF) plays a central role in controlling the hypothalamic-pituitary-adrenal (HPA) axis during stressful periods. CRF is synthesized and secreted in the hypothalamic paraventricular nucleus (PVN) in response to stress, and stimulates ACTH in the pituitary corticotrophs. ACTH stimulates the release of glucocorticoids from the adrenal glands, and glucocorticoids sequentially inhibit hypothalamic PVN production of CRF and pituitary production of ACTH. The effects of glucocorticoids on CRF gene regulation, however, are possibly tissue-specific since glucocorticoids stimulate CRF gene expression in the placenta and the bed nucleus of the stria terminalis, while they inhibit it in the hypothalamus.

METHODS AND RESULTS

In a hypothalamic cell line, 4B, we found that forskolin-stimulated CRF gene transcription was mediated by a functional cAMP-response element (CRE), which included -220 to -233 bp on the CRF 5'-promoter region. Protein kinase A, protein kinase C, and p38 mitogen-activated protein kinase pathways contributed to forskolin-induced transcriptional activity of CRF in hypothalamic 4B cells. Glucocorticoid-dependent repression of cAMP-stimulated transcriptional activity of CRF was localized to promoter sequences between -278 and -233 bp, which included a glucocorticoid regulatory element and a serum response element.

CONCLUSION

Taken together, these findings indicate that the regulatory elements, including CRE, negative glucocorticoid regulatory element, and a serum response element on the promoter, contribute to the regulation of CRF gene transcription in hypothalamic 4B cells.

Corticotropin-releasing factor (CRF) is involved in the acute anorexic effect of alpha-melanocyte-stimulating hormone: a study using CRF-deficient mice

Alpha-melanocyte-stimulating hormone (alpha-MSH) and its receptors are critical and indispensable for maintaining appropriate feeding behavior and energy homeostasis in both mice and humans. Corticotropin-releasing factor (CRF) is a candidate for mediating the anorexic effect of alpha-MSH. In the present study, we examined whether CRF and its receptors are involved in the anorexic effect of alpha-MSH, using CRF-deficient (CRFKO) mice and a CRF receptor antagonist. Intracerebroventricular administration of NDP-MSH, a synthetic alpha-MSH analogue, suppressed food intake in wild-type (WT) mice. This effect was abolished by pretreatment with a non-selective CRF receptor antagonist, astressin, suggesting that the effect of alpha-MSH-induced anorexia was mediated by a CRF receptor. In CRFKO mice, administration with NDP-MSH did not affect food intake at an early phase (0-4h). In addition, CRF mRNA levels in the hypothalamus were significantly increased in NDP-MSH-treated mice. Therefore, our findings, using CRFKO, strongly support evidence that CRF is involved in the acute anorexic effect of alpha-MSH. On the other hand, NDP-MSH administered to CRFKO mice led to suppressed food intake at the late phase (4-12h), similar to the effect in WT mice. Further, NDP-MSH similarly reduced food intake during the late phase in all types of mice, including WT, CRFKO, and CRFKO with corticosterone replacement. The results would suggest that alpha-MSH-induced suppression of food intake at late phase was independent of glucocorticoids and CRF.

Diagnostic usefulness of the growth hormone-releasing peptide-2 test as a substitute for the insulin tolerance test in hypopituitarism

Adrenal insufficiency can result from primary disorder of the adrenal gland or occurs secondarily due to deficiency in adrenocorticotropic hormone (ACTH) or corticotropin-releasing hormone (CRH). To prevent adrenal crisis, it is thus important to test the remaining function of the adrenal gland. Tests for the function of the hypothalamic-pituitary-adrenal (HPA) axis are also useful for examining localization of disease causing adrenal insufficiency. Generally, the insulin tolerance test (ITT) is useful for examining the HPA axis in both hypothalamic and pituitary diseases; however, ITT has a number of disadvantages. The growth hormone-releasing peptide (GHRP)-2 test may be a useful tool for diagnosing secondary adrenal insufficiency such as hypothalamic disorder and pituitary damage. In the present study, we examined the diagnostic usefulness of the GHRP-2 test as a substitute for ITT in hypopituitarism. We showed that patients with significant ACTH response to ITT also had significant response to the GHRP-2 test, while patients with no significant ACTH response to ITT also had no significant response to the GHRP-2 test. These data suggest that the GHRP-2 test may be a useful diagnostic tool for secondary adrenal insufficiency such as hypothalamic disorder and pituitary damage.

A male case of nonclassical 21-hydroxylase deficiency first manifested in his sixties with adrenocortical incidentaloma

Nonclassical form of 21-hydroxylase deficiency (NC 21OHD) as a frequent variant on the milder end of the disease spectrum has been widely acknowledged, but its potential contribution to adrenocortical tumorigenesis has not been fully elucidated. We report a 66-year old male case of bilateral adrenocortical incidentaloma, associated with partial 21OHD without any episodes of hypoadrenocorticism in his past history. He was demonstrated to be a compound heterozygous mutant of CYP21A2 gene (IVS2-13A/C>G/I172N). The two tumors in the left adrenal, which were interpreted as myelolipoma by imaging studies, were followed by sequential observation, whereas the contralateral large solid tumor associated with inhomogeneous radiological appearance was subsequently removed. The resected tumor was diagnosed an adrenocortical adenoma, which was devoid of P450c21 immunoreactivity. 21OHD is often associated with benign adrenocortical tumors, but bilateral adrenal tumors with heterogeneous components in both adrenals have not been reported to the best of our knowledge.

A progressive case of lymphocytic hypophysitis accompanied by paresis of the left abducens nerve

We describe a rare and interesting progressive case of lymphocytic hypophysitis accompanied later by paresis of the left abducens nerve. A 42-year-old woman was diagnosed as having lymphocytic hypophysitis accompanied by diabetes insipidus and hypopituitarism. She had no symptoms of visual disturbance at that time. She was not treated with steroids because she is a carrier of the hepatitis B virus. Later, in 2006, she complained of progression of symptoms and double vision for a few months. Her pituitary gland showed further enlargement. The patient was diagnosed as having progressive lymphocytic hypophysitis accompanied by paresis of the left abducens nerve, which was subsequently confirmed by biopsy. The progression of lymphocytic hypophysitis in patients not receiving steroid therapy should be carefully monitored.

A case of thyrotropin-producing pituitary adenoma, accompanied by an increase in anti-thyrotropin receptor antibody after tumor resection

We describe a rare, but interesting, case of TSH-producing adenoma (TSHoma), accompanied by increases in both anti-TSH receptor antibody (TRAb) and thyroid-stimulating antibody (TSAb) after tumor resection. A 21-yr-old woman was referred to our department for further evaluation of pituitary tumor. In a nearby hospital, she had been diagnosed as having pituitary tumor. Her serum free T4, free T3, and TSH levels were all elevated concomitantly. On the basis of a diagnosis of pituitary adenoma with TSH production, transsphenoidal resection of the pituitary adenoma was performed. Two weeks after the operation, the blood concentrations of TSH were undetectable, whereas both TRAb and TSAb levels were elevated. TSAb levels gradually increased further from 2 weeks to 3 months after the operation, accompanied by an increase in TSH and free T4 levels. TSH is an important hormone in maintaining physiology and regulating immunomodulators in thyrocytes, as it can influence a variety of immune-regulating cytokine-like activities and inhibit expressions of Fas antigen, intracellular adhesion molecule-1, and class II trans-activator. Changes in TSH would modulate the immune circumstances in the thyroid, and then induce TRAb and TSAb. Autoimmune parameters with thyroid function should be observed carefully when managing patients with TSHoma.

Expression of adrenocorticotropic hormone, prolactin and transcriptional factors in clinically nonfunctioning pituitary adenoma

We describe here a case of a clinically nonfunctioning pituitary adenoma, but with expression of ACTH and PRL. A 42-year-old woman was referred to our department for further evaluation of pituitary tumor. She had no acromegaloid features, and no typical Cushingoid features. She had no galactorrhea, and had regular menses. GH, IGF-I, LH, FSH, TSH, ACTH and cortisol levels in blood were all within the normal ranges, while PRL levels were mildly elevated. Both ACTH and cortisol levels were adequately increased in response to CRH, and both were suppressed by a small dose of dexamethasone. Plasma ACTH and cortisol levels were decreased at night, suggesting the circadian rhythms for plasma ACTH levels were undisturbed. Based on these findings we did not clinically suspect ACTH-producing tumor, however immunohistochemistry revealed ACTH immunoreactivity in the pituitary adenoma. Therefore, the tumor was considered a silent corticotroph adenoma. PRL was co-expressed in a significant subpopulation of ACTH-immunoreactive tumor cells. Ptx1, Neuro D1, and T pit were densely expressed and Pit-1 was sparsely expressed in the nuclei of adenoma cells. It is therefore possible that a tumor originating in an immature or uncommited adenohypophysial stem cell may later differentiate into different cell types due to a combination of certain specific transcriptional factors.

Pituitary adenylate cyclase-activating polypeptide stimulates corticotropin-releasing factor, vasopressin and interleukin-6 gene transcription in hypothalamic 4B cells

Corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) are the two major regulatory peptides in the hypothalamic-pituitary-adrenal axis. CRF, produced in the hypothalamic paraventricular nucleus (PVN) in response to stress, is secreted into the pituitary portal circulation, resulting in the release of adrenocorticotropic hormone from the anterior pituitary. AVP is synthesized in the PVN and supraoptic nucleus by various stressors. Hypothalamic 4B cells coexpress CRF and AVP. In 4B cells transfected with either a CRF or an AVP promoter-luciferase construct, forskolin increased the transcriptional activity of CRF or AVP. In the present study, we tried to determine whether pituitary adenylate cyclase-activating polypeptide (PACAP) regulates both CRF and AVP genes in the hypothalamic cells, because receptors for PACAP were expressed in the hypothalamic cells. PACAP stimulated activity of both CRF and AVP promoter via protein kinase A pathway. PACAP stimulated interleukin (IL)-6 promoter activity and the levels of IL-6 mRNA and protein. IL-6 stimulated activity of both CRF and AVP promoter in a dose-dependent manner. Finally, we found that the stimulatory effects of PACAP on both activities were significantly inhibited by treatment with anti-IL-6 monoclonal antibody. These data suggest that PACAP is involved in regulating the synthesis of IL-6 mRNA and IL-6 protein, and that the increase in endogenous IL-6 also contributes to stimulate the expression of both CRF and AVP genes. Taken together, these findings indicate that PACAP stimulates the transcription of CRF, AVP, and IL-6 genes in hypothalamic 4B cells.

Ampulla (Takotsubo) cardiomyopathy caused by secondary adrenal insufficiency in ACTH isolated deficiency

We describe here a case of reversible ampulla (takotsubo) cardiomyopathy caused by secondary adrenal insufficiency in ACTH isolated deficiency. A 53-year-old woman was referred to our department for evaluation and treatment of unconsciousness. On admission, her plasma glucose level was 34 mg/dL, suggesting loss of consciousness due to hypoglycemia. Basal levels of ACTH, cortisol, and dehydroepiandrosterone sulfate in blood, and urinary free cortisol levels were all decreased. ACTH and cortisol levels were not adequately increased in response to CRH administration and the insulin tolerance test. Electrocardiography showed ST segment elevation and T wave inversion in leads V 1-6. The coronary arteries were free of organic stenosis, and a left ventriculogram revealed severe hypokinesis, particularly in the anterior and posterior walls. Based on a diagnosis of adrenocortical insufficiency caused by ACTH isolated deficiency, hydrocortisone was administered. Two weeks after treatment, ultrasound studies of the heart showed recovery of left ventricular wall motion. Activation of the sympathetic nervous system, adrenocortical failure, and hypoglycemic attack were considered to be triggering factors for the takotsubo cardiomyopathy. Careful monitoring of cardiac function and appropriate treatments for both cardiomyopathy and adrenocortical failure are required to recover cardiac dysfunction.

Gene analysis of the calcium channel 1 subunit and clinical studies for two patients with hypokalemic periodic paralysis

Hypokalemic periodic paralysis (HypoPP) is a skeletal muscle disorder in which episodic attacks of muscle weakness occur; they are associated with decreased serum potassium (K+) levels. Recent molecular approaches have clarified that the condition is caused by mutations in the skeletal muscle voltage-gated calcium channel 1 subunit (CACNA1S). We describe two unrelated patients with HypoPP, followed by their relevant clinical studies and gene analysis. Clinical studies included an oral glucose tolerance test (OGTT), food-loading and insulin tolerance tests (ITT). For Case 1, serum K+ levels were extremely decreased following insulin tolerance testing compared with levels for controls. These results support the hypothesis that no efflux of K+ ion occurs in patients because of low activity of adenosine triphosphate (ATP)-sensitive K+ channel (KATP) channels. Mutational analysis of the CACNA1S gene showed a duplicate insertion of 14 base pairs (bp) from 52 to 65 in intron 26, present in the heterozygous state in both patients. No other mutations were detected in the CACNA1S gene, the muscle sodium channel gene (SCN4A) or the voltage-gated K+ channel gene (KCN3) of either patient. Further analysis showed that this duplicate insertion of 14 bp in intron 26 of the CACNA1S gene was found in 23.7% of healthy subjects. K+ dynamics studies are useful for confirming this syndrome, while further gene analysis for various ion channels using amplification and direct sequencing are required to evaluate the molecular basis of the disorder in the individual patient.

Urocortin induces interleukin-6 gene expression via cyclooxygenase-2 activity in aortic smooth muscle cells

Corticotropin-releasing factor (CRF) plays a central role in controlling stress-related activity of the hypothalamic-pituitary-adrenal axis. Four CRF-related peptides have been found in mammals: CRF and urocortins (Ucns) 1-3. Ucns bound to CRF(2beta) receptors have a physiological role in the cardiovascular system. We previously found that both Ucn1 and -2 induced accumulation of intracellular cAMP via CRF(2beta) receptor binding and significantly increased IL-6 secretion by A7r5 aortic smooth muscle cells. In the present study, we investigated Ucn effects on IL-6 gene expression and IL-6 synthesis in A7r5 aortic smooth muscle cells. Ucn1 and -2 stimulated IL-6 gene transcription and IL-6 secretion via CRF(2) receptors. Indomethacin, a cyclooxygenase (COX) inhibitor, suppressed IL-6 gene transcription and IL-6 secretion by Ucn1 or -2. NS-398, a COX-2 inhibitor, suppressed IL-6 induction to the same extent as indomethacin. These results suggest that the COX-2 pathway is involved downstream in regulation of Ucn-increased IL-6 gene expression and IL-6 secretion. In addition, COX-2 expression levels were increased at 6 h with the combination of Ucn1 and IL-1, compared with single peptide activation. Ucn1 showed a potent stimulatory effect on IL-6 output, whereas IL-1 alone had no significant effects. However, when Ucn1 was simultaneously used with IL-1, it markedly potentiated the increments in IL-6 output and promoter activity produced by Ucn1. Taken together, these findings indicate that the COX-2 pathway plays a major role in increasing IL-6 levels stimulated by Ucn and IL-1 in A7r5 cells.

G protein-coupled receptor kinase 2 involvement in desensitization of corticotropin-releasing factor (CRF) receptor type 1 by CRF in murine corticotrophs

Hypothalamic CRF stimulates synthesis and secretion of ACTH via CRF receptor type 1 (CRFR1) in the anterior pituitary gland. After agonist-activated stimulation of receptor signaling, CRFR1 is down-regulated and desensitized. Generally, it is thought that G protein-coupled receptors may be desensitized by G protein-coupled receptor kinases (GRKs). However, the role of GRKs in corticotropic cells has not been determined. In this study we focused on involvement of GRKs in desensitization of CRFR1 by CRF in corticotropic cells. We found that GRK2 (but not GRK3) mRNA and protein were expressed in rat anterior pituitary cells and AtT-20 cells (a line of mouse corticotroph tumor cells). To determine the role of GRK2 in CRF-induced desensitization of CRFR1 in mouse corticotrophs, AtT-20 cells were transfected with a dominant-negative mutant GRK2 construct. CRF desensitized the cAMP-dependent response by CRFR1. Desensitization of CRFR1 by CRF was significantly less in AtT-20 cells transfected with the dominant-negative mutant GRK2 construct compared with desensitization in control (an empty vector-transfected) AtT-20 cells. Furthermore, pretreatment with a protein kinase A inhibitor also partially blocked desensitization of CRFR1 by CRF. These results suggest that GRK2 is involved in CRF-induced desensitization of CRFR1 in AtT-20 cells, and the protein kinase A pathway may also have an important role in desensitization of CRFR1 by CRF seen in corticotropic cells.

Differential regulation of corticotropin-releasing factor receptor type 1 (CRF1 receptor) mRNA via protein kinase A and mitogen-activated protein kinase pathways in rat anterior pituitary cells

Corticotropin-releasing factor (CRF) receptor type 1 (CRF(1) receptor) mRNA levels are down-regulated by CRF via the cyclic AMP-protein kinase A (PKA) pathway. In this study, we focused on the involvement of both the mitogen-activated protein (MAP) kinase pathway and PKA in this regulation. Real-time PCR (RT-PCR) revealed that a MAP kinase, extracellular signal-regulated kinases 1/2, pathway was also involved in the down-regulation of CRF(1) receptor mRNA levels by CRF in the rat anterior pituitary (AP). Down-regulation of CRF(1) receptor mRNA levels was caused by a post-transcriptional system such as mRNA degradation, as incubation with CRF significantly decreased the half-life of CRF(1) receptor mRNA. Furthermore, pre-treatment with a PKA inhibitor completely blocked CRF-induced CRF(1) receptor mRNA destabilization, while pre-treatment with an extracellular signal-regulated kinases 1/2 inhibitor had no inhibitory effect. These results suggested that in the rat AP, down-regulation of CRF(1) receptor mRNA levels is caused by mRNA degradation via PKA, but not by the MAP kinase pathway.

Diagnosis of a case of Gitelman's syndrome based on renal clearance studies and gene analysis of a novel mutation of the thiazide-sensitive Na-Cl cotransporter

Gitelman's syndrome is a recessively inherited renal tubular disorder characterized by low plasma potassium and magnesium levels, reduced calcium excretion, metabolic alkalosis, and increased plasma renin activity and plasma aldosterone concentration with normal blood pressure levels. A 23-yr-old man was referred to our department for further evaluation of hypokalemia. The patient also had hypomagnesemia and markedly reduced urinary calcium excretion. Renal clearance studies and gene analysis of the thiazide-sensitive Na-Cl cotransporter (TSC) were performed in the patient. In response to an iv injection of furosemide, chloride clearance (CCl) increased markedly, while distal fractional chloride reabsorption CH2O/(CH2O+CCl) was considerably reduced. In contrast, thiazide ingestion had no significant effects on these parameters. The patient had compound heterozygous mutations in the alleles encoding the TSC gene, one of which has not been formerly reported. Renal clearance studies and TSC gene analysis by amplification and direct sequencing are useful diagnostic tools for confirming a diagnosis of Gitelman's syndrome.

Usefulness of the Thyrotropin-Releasing Hormone Test in Pre-Clinical Acromegaly

Acromegaly is caused primarily by pituitary growth hormone (GH)-secreting tumors. It is usually recognized because of characteristic manifestations, and diagnosed clinically. However, there exists a mild stage of acromegaly, which poses a diagnostic problem due to the absence of typical clinical manifestations. Here we present four patients with pre-clinical acromegaly, who showed minimal acromegaloid features with elevated levels of insulin-like growth factor-I. Basal GH levels were within normal levels in 3 of 4 cases, while insulin-like growth factor-I levels were elevated above normal in all cases. Plasma GH levels were elevated in response to thyrotropin-releasing hormone (TRH) in all cases, indicating a diagnostic value of the TRH stimulation test. In contrast, an oral glucose tolerance test was not useful for the diagnosis, because of the low GH levels (less than 1 ng/ml) and/or secondary to diabetes mellitus. In response to a dopamine agonist, GH levels were increased in the two cases, whereas GH levels were decreased or remained unchanged in the other two cases. We therefore suggest that the TRH stimulation test would be helpful to examine the presence of pre-clinical acromegaly. Diagnosis of the early stages of acromegaly is important to prevent progression to overt acromegaly.

Physiological roles of urocortins, human homologues of fish urotensin I, and their receptors

Urocortin 1, a human homologue of fish urotensin I, together with its related-compounds (urocortins 2 and 3), comprises a distinct family of stress peptides. Urocortin 1 has a high affinity for both corticotropin-releasing factor (CRF) type 1 receptor (CRF1) and CRF type 2 receptor (CRF2), and urocortins 2 and 3 have a high affinity for CRF2, while CRF has a low affinity for CRF2 and a high affinity for CRF1. These differences of the binding affinity with receptors make the biological actions of these peptides. Besides the binding affinity with receptors, the limited overlap of the distribution of CRF and urocortins may also contribute to the differences of physiological roles of each peptide. Urocortins show 'stress-coping' responses such as anxiolysis and dearousal in the brain. In the periphery, recent studies show the potent effects of urocortins on the cardiovascular and immune systems. In this review article, we take a look over the series of peptides included in this family, especially in terms of the versatility of biological actions, along with the various characters of the receptors.

Impaired leptin expression and abnormal response to fasting in corticotropin-releasing hormone-deficient mice

Leptin has been postulated to comprise part of an adipostat, whereby during states of excessive energy storage, elevated levels of the hormone prevent further weight gain by inhibiting appetite. A physiological role for leptin in this regard remains unclear because the presence of excessive food, and therefore the need to restrain overeating under natural conditions, is doubtful. We have previously shown that CRH-deficient (Crh(-/-)) mice have glucocorticoid insufficiency and lack the fasting-induced increase in glucocorticoid, a hormone important in stimulating leptin synthesis and secretion. We hypothesized that these mice might have low circulating leptin. Indeed, Crh(-/-) mice exhibited no diurnal variation of leptin, whereas normal littermates showed a clear rhythm, and their leptin levels were lower than their counterparts. A continuous peripheral CRH infusion to Crh(-/-) mice not only restored corticosterone levels, but it also increased leptin expression to normal. Surprisingly, 36 h of fasting elevated leptin levels in Crh(-/-) mice, rather than falling as in normal mice. This abnormal leptin change during fasting in Crh(-/-) mice was corrected by corticosterone replacement. Furthermore, Crh(-/-) mice lost less body weight during 24 h of fasting and ate less food during refeeding than normal littermates. Taken together, we conclude that glucocorticoid insufficiency in Crh(-/-) mice results in impaired leptin production as well as an abnormal increase in leptin during fasting, and propose that the fast-induced physiological reduction in leptin may play an important role to stimulate food intake during the recovery from fasting.

Urocortin III, a brain neuropeptide of the corticotropin-releasing hormone family: modulation by stress and attenuation of some anxiety-like behaviours

Following its discovery 20 years ago, corticotropin-releasing hormone (CRH) has been postulated to mediate both hormonal and behavioural responses to stressors. Here, we characterize and describe a behavioural role for the murine gene, UcnIII, which encodes a recently discovered CRH-related neuropeptide, urocortin III. We found that mouse UcnIII is expressed predominantly in regions of the brain known to be involved in stress-related behaviours, and its expression in the hypothalamus increases following restraint. In addition, we found that intracerebroventricular administration of mUcnIII stimulates behaviours that are associated with reduced anxiety, including exploration of an open field and decreased latency to enter the lit compartment of a dark-light chamber, but has no effect on the elevated-plus maze. Finally, we found that mUcnIII does not exert any effects on the hormonal stress response. Based upon our findings, UcnIII may be an endogenous brain neuropeptide that is modulated by stress and stimulates behaviours associated with reduced anxiety. In this capacity, UcnIII may attenuate stress-related behaviours, which may be useful both to help cope with stressful situations as well as to avoid pathology associated with excessive reaction to stressors.

Central actions of neuromedin U via corticotropin-releasing hormone

Neuromedin U (NMU), a hypothalamic peptide, has been known to be involved in feeding behavior as a catabolic signaling molecule. However, little is known about the participation of NMU in the neuronal network. One NMU receptor, NMU2R, is abundantly expressed in the hypothalamic paraventricular nucleus, where corticotrophin-releasing hormone (CRH) is synthesized. The functions of CRH, regulation of stress response and feeding behavior, are comparable with those of NMU. Here, we have investigated the functional relationships between NMU and CRH using CRH knockout (KO) mice. Intracerebroventricular administration of NMU suppressed dark-phase food intake and fasting-induced feeding in wild-type mice. In contrast, these suppressions were not observed in CRH KO mice. NMU-induced increases in oxygen consumption and body temperature were attenuated in CRH KO mice. These results suggest that NMU plays a role in feeding behavior and catabolic functions via CRH. This study demonstrates a novel hypothalamic pathway that links NMU and CRH in the regulation of feeding behavior and energy homeostasis.

A case of pseudoaldosteronism, accompanied with hypocalcemia and exaggerated ACTH response

Glycyrrhizic acid (GA) inhibits the activity of 11beta-hydroxysteroid dehydrogenase type 2 in the kidney, with the resulting increase in intrarenal cortisol concentration leading to hypertension and suppression of the renin-aldosterone system. In this paper we describe an interesting case of pseudoaldosteronism, associated with hypocalcemia and an exaggerated ACTH response. A 72-year-old woman was referred to our department for further evaluation of hypokalemia and hypocalcemia. The patient had been taking GA (150 mg/day) for the previous year for treatment of liver damage. Plasma renin activity and aldosterone concentration were both within lower normal limits. Urinary excretion of potassium and calcium was within the upper limit of the normal range and increased with administration of supplements. Plasma ACTH levels increased markedly in response to an intravenous injection of CRH. Cessation of GA and the potassium and calcium supplements on admission, led to a gradual normalization of serum potassium and calcium levels and blood pressure. The hypocalcaemia in our patient was related to decreased tubular reabsorption of calcium as a consequence of renal corticoid excess. It is possible that an increase in the number of CRH receptors in the pituitary following GA treatment caused the exaggerated ACTH response in association with pseudoaldosteronism. The existence of hypocalcemia and an exaggerated ACTH response should be observed carefully when managing pseudoaldosteronism.

Hypoglycemia associated with big insulin-like growth factor II produced during development of malignant fibrous histiocytoma

We describe a rare case of hypoglycemia associated with a high molecular weight form of insulin-like growth factor II (big IGF-II) produced during the development of malignant fibrous histiocytoma (MFH). A 66-year-old man was referred to our department for further evaluation of hypoglycemia. At the age of 59, he had been diagnosed as having a MFH in the retroperitoneum, and underwent incomplete resection of the tumor. He had no symptoms of hypoglycemia at that time. Within the last few years, he developed symptoms of hypoglycemia in the early morning. Computerized tomography scans of the abdomen showed multiple tumors around the peritoneum and the liver. Serum insulin levels were decreased although no other hormonal deficiencies were observed. Serum IGF-II levels were elevated as a result of big IGF-II production. Taken together, these results indicated that hypoglycemia in this patient was associated with the production of big IGF-II by the MFH. The most effective therapeutic modality in patients with non-islet cell tumor hypoglycemia is resection of the tumor. In our case, as complete resection was impossible, dexamethasone and glucagon were administered and proved to be effective for preventing hypoglycemia.

A case of preclinical Cushing's disease, accompanied with thyroid papillary carcinoma and adrenal incidentaloma

A 75-year-old woman had tumors in her pituitary, thyroid and left adrenal gland. Plasma ACTH and cortisol levels were both mildly elevated. Both plasma ACTH and cortisol concentrations were partially suppressed by 1 mg of overnight dexamethasone suppression test, while both were inhibited with a dosage of 8 mg dexamethasone. Plasma ACTH and cortisol levels were increased in response to human CRH and desmopressin. Together with the observation of pituitary microadenoma, the patient had a pituitary ACTH-producing tumor. The patient, however, had no typical Cushingoid features, hypertension, or impaired glucose tolerance, suggesting that the tumor had an autonomic ACTH secretion that was insufficient for expressing clinical symptoms, the so-called preclinical Cushing's disease. A case of preclinical Cushing's disease is extremely rare. Further, the patient had thyroid papillary carcinoma and non-functioning adrenal tumor. Molecular genetic analysis demonstrated a polymorphism of the menin gene in the patient. Even without Cushingoid features in pituitary incidentaloma, we concluded that the elevated ACTH and cortisol levels should be followed up by CRH, desmopressin and dexamethasone suppression tests. This patient with preclinical Cushing's disease would be observed whether the physical conditions in the patient develop to overt Cushing's disease.

A multihormonal pituitary adenoma with growth hormone and adrenocorticotropic hormone production, causing acromegaly and Cushing disease

Pituitary adenoma with growth hormone (GH) and corticotropin (ACTH) production causing apparent acromegaly and Cushing disease is extremely rare. A 45-year-old woman had a pituitary macroadenoma and severe insulin resistance. Physical examination showed a fully developed acromegaly associated with mild Cushingoid features. Serum GH, insulin-like growth factor-I, ACTH, and cortisol levels were all elevated. Hormonal loading tests resulted in GH levels increasing paradoxically in response to thyrotropin-releasing hormone (TRH), but not corticotropin-releasing hormone (CRH). A similar unexpected increase in ACTH and cortisol levels occurred in response to TRH and GH-releasing hormone. After trans-sphenoidal resection of the pituitary macroadenoma immunohistochemistry revealed the presence of either diffuse but faintly GH-positive cells or sparse but distinct ACTH-stained cells. A marked amelioration of insulin resistance was observed postoperatively. The elevated ACTH and cortisol levels should therefore be investigated by CRH and dexamethasone suppression tests for the coexistence of Cushing disease to exclude the possibility of underlying ACTH-producing tumors.

A role for neuromedin U in stress response

Neuromedin U (NMU) is a hypothalamic peptide that has been recently found to reduce food intake, but few is known about its other functions in the central nervous system. We here studied behavioral activities induced by an intracerebroventricular (ICV) administration of NMU in rats and mice. NMU increased gross locomotor activity, face washing behavior, and grooming. NMU-induced stress response was significantly abolished by pretreatment with an antagonist of corticotropin-releasing hormone (CRH), alpha-helical CRH (9-41) (alpha-hCRH), or anti-CRH IgG. NMU did not induce locomotor activity in CRH knockout mice. NMU that interacts anatomically and/or functionally with the CRH system is a novel physiological regulator of stress response.

Covariation of cigarette smoking and other health-risk behaviors among Japanese high school students: a preliminary study

This study aims to determine if cigarette smoking is associated with engaging in other health-risk behaviors among high school students in Japan. Self-administered anonymous questionnaires were conducted in 1999 using a sample of 1,466 students (male: 50.5%, female: 49.5%) in grades 10 through 12 at seven public senior high schools in urban areas of Okinawa, Japan. Health-risk behaviors studiedal included cigarette smoking, alcohol drinking, thinner use, sexual intercourse, suicidal ideation, nonuse of seat belts, physical inactivity, and weight loss practices. In the logistic regression models, controlled for sociodemographic variables, smoking was significantly associated with all health-risk behaviors except physical inactivity. In particular, associations of alcohol drinking and sexual intercourse with smoking were strong. Among male students, statistically significant odds ratios existed for alcohol drinking, sexual intercourse, and nonuse of seat belts. Among female students, all of the odds ratios for health-risk behaviors were statistically significant, except for physical inactivity. Generally, the odds ratios of female students were higher than those of male students. In conclusion, high school students who smoked cigarettes in this study may be at higher risk for engaging in other health-risk behaviors. Particularly, alcohol drinking and sexual intercourse are more likely to co-occur with smoking. These findings suggest that smoking prevention programs should be integrated with other health-risk behaviors.

Psychosocial correlates of depressive symptoms among Japanese high school students

PURPOSE

To determine the psychosocial factors associated with the presence and persistence of depressive symptoms among high school students in Okinawa, Japan.

METHODS

The study sample was 3202 students from 12 public senior high schools. Students completed self-administered questionnaires from October through December 1997. We measured depressive symptomatology using the Center for Epidemiologic Studies Depression Scale. We asked students to report whether they had depressive symptoms at any time in the immediate past week, and whether those symptoms persisted for 5-7 days. The psychosocial variables examined were life stressors, perceived social support, health practices, self-esteem, and Locus of Control. The relationship between the psychosocial factors and depressive symptoms was examined using hierarchical multiple regression analyses.

RESULTS

After controlling for the effects of demographic and other psychosocial variables, presence of depressive symptoms was positively associated with life stressors in the domains of friends, family, and teachers. Similarly, persistence of depressive symptoms was also positively associated with life stressors in the domains of friends and teachers. Presence and persistence of depressive symptoms were negatively associated with positive health practices, more social support, high self-esteem, and internal Locus of Control.

CONCLUSIONS

The psychosocial variables associated with presence and persistence of depressive symptoms were remarkably consistent. Life stressors might be risk factors; on the contrary, positive health practices, perceived social support, high self-esteem, and internal Locus of Control might be protective factors of depressive symptoms among Japanese adolescents.

Patterns of health-risk behavior among Japanese high school students

This study explored patterns of health-risk behaviors among Japanese high school students and examined if a cluster and an accumulation of health-risk behaviors existed. Self-administered questionnaires were employed in 1999 using a sample of 1,466 students (male 50.5%, female 49.5%) in grades 10 through 12 at seven public senior high schools in Okinawa, Japan. Health-risk behaviors studied included cigarette smoking, alcohol use, thinner use, nonuse of seat belts, suicide ideation, sexual intercourse, weight loss practices, and physical inactivity. Among male and female students, cigarette smoking, alcohol use, and sexual intercourse clustered. Accumulation of these risk behaviors also occurred because the observed proportion was greater than the expected proportion assuming independent occurrence. Vocational high school students and upper graders were strongly associated with accumulation of health risk behaviors. These findings identify a high-risk target group among Japanese adolescents and suggest that preventive intervention strategies should take into consideration the cluster and accumulation of health-risk behaviors.

Gender differences in the association between psychosocial factors and depressive symptoms in Japanese junior high school students

To determine psychosocial factors associated both with depressive symptoms and with gender differences in depressive symptoms among junior high school students, we conducted self-administered questionnaires using a sample of 2,660 students of 13 public junior high schools in Okinawa, Japan. Depressive symptomatology was measured by the Center for Epidemiologic Studies Depression Scale (CES-D). The psychosocial variables examined were life stresses, social support, health practices, self-esteem, and locus of control. Depressive symptoms were positively associated with life stresses and negatively associated with health practices, social support, self-esteem, and internal locus of control. In addition, female students were likely to report more depressive symptoms, life stresses, and low self-esteem and poor health practices. After controlling for the psychosocial variables differed by gender, gender differences in depressive symptoms were eliminated. In conclusion, for depressive symptoms of junior high school students, life stresses might be risk factors, but positive health practices, social support, high self-esteem, and internal locus of control might be protective factors. Gender differences in depressive symptoms could be explained by the females' elevation on these psychosocial variables.

Risk factors for cigarette smoking among high school students in Okinawa, Japan

The purpose of this study was to examine the relationships between risk factors and smoking status among high school students in Okinawa, Japan. We also examined if there is a dose-response relation between the number of risk factors and smoking status. Self-reported questionnaires including smoking status and potential risk factors were conducted using a sample of 1,029 students of a public senior high school in Okinawa. The percentage of smokers was 40.0% for males and 10.6% for females, and it was significantly higher for males than females. As a result of multivariate analysis, we identified four significant risk factors; peer smoking, attitude of peer toward subject smoking, intention to smoke at the age 20, and alcohol drinking. The number of these risk factors was linearly associated with increased percentage of smokers, and a linear trend was significant for both gender students. Additionally, magnitude of risk for smoking among females became considerably great compared with those of males as the number of risk factors increased. In conclusion, this study was the first study in Japan to indicate a significant dose-response relationship between the number of risk factors and smoking status among high school students. We also found that females with many risk factors had extremely increased vulnerability to smoking compared to male counterpart. These findings may be useful to identify high-risk students who need more intensive smoking prevention programs and to develop the content of effective interventions.