In skeletal muscle and adipose tissue, insulin-stimulated glucose uptake is dependent upon translocation of the insulin-responsive glucose transporter GLUT4 from intracellular storage compartments to the plasma membrane. This insulin-induced redistribution of GLUT4 protein is achieved through a series of highly organized membrane trafficking events, orchestrated by insulin receptor signals. Recently, several key molecules linking insulin receptor signals and membrane trafficking have been identified, and emerging evidence supports the importance of subcellular compartmentalization of signaling components at the right time and in the right place. In addition, the translocation of GLUT4 in adipocytes requires insulin stimulation of dynamic actin remodeling at the inner surface of the plasma membrane (cortical actin) and in the perinuclear region. This results from at least two independent insulin receptor signals, one leading to the activation of phosphatidylinositol (PI) 3-kinase and the other to the activation of the Rho family small GTP-binding protein TC10. Thus, both spatial and temporal regulations of actin dynamics, both beneath the plasma membrane and around endomembranes, by insulin receptor signals are also involved in the process of GLUT4 translocation.

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To examine hormone levels after androgen replacement therapy (ART) in Japanese male patients with hypogonadism, nine Japanese male patients with hypogonadism (serum total testosterone (tT) or free testosterone (fT) levels of ≤ 2.7 ng/mL or ≤ 10 pg/mL, respectively; average age, 59 years) were enrolled. They were treated with 125 mg of testosterone enanthate by single intramuscular injection. Blood samples were collected on the morning of the day of treatment, pre-ART, as well as on days 1 to 7 and day 14 after administration. Serum levels of tT, fT, estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) were determined. On day 1 after administration, the mean serum levels of tT and fT were 7.62 ng/mL and 23.22 pg/mL, respectively. Serum levels of tT and fT on day 14 after administration were lower than their pre-ART values. One patient exhibited abnormally high serum tT and fT levels of 19.6 ng/mL and 44.4 pg/mL, respectively. Serum levels of LH and FSH began to decrease gradually on day 5 after administration. Serum levels of SHBG did not change throughout the observation period. Serum levels of E2 increased 1.7 times on day 1 after administration but returned to its pre-ART value by day 14 after administration. The dose of testosterone enanthate for male patients with hypogonadism requiring ART should be determined carefully because some patients exhibited high serum levels of androgen beyond the physiological range and gonadotropin was suppressed in all treated patients.

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We report an instructive case of primary hyperparathyroidism in which cyclical secretion of PTH may have caused repeated hypercalcemic crises followed by temporary remission with a spontaneous drop in PTH. A 64-year-old man was admitted to our hospital twice with severe hypercalcemic crisis (corrected calcium (cCa) 15.0 mg/dl and 16.7 mg/dl) accompanied by an increase in intact PTH (220 pg/ml and 470 pg/ml). During both events, the serum PTH values spontaneously dropped followed by remission of the hypercalcemia. The tumor, detected at the left-upper side, showed neither vascularity on ultrasound examination nor washout delay on MIBI scintigraphy, suggesting that two parathyroid adenoma infarctions had occurred. Cervical exploration was undertaken. The histopathological examinations confirmed that the tumor was parathyroid adenoma. Contrary to our expectation, however, it did not reveal necrotic tissue that would indicate recent infarction. The findings in this case may be explained by cyclical secretion of PTH from a parathyroid adenoma. Although cyclical Cushing's syndrome is well known, to our knowledge this is the first documented case suggesting cyclical primary hyperparathyroidism.

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Calcitonin (CT) and calcitonin receptor (CTR) have been reported to play an important role in mammary tissue during pregnancy, lactation, and involution. In the present study, the expression and distribution of CTR mRNA in rat mammary tissue during pregnancy and lactation were investigated. As measured by real-time RT-PCR, CTR mRNA levels were increased only slightly during pregnancy, but increased markedly immediately postpartum and remained elevated through lactation, with the highest levels observed 14 days postpartum. In situ hybridization analysis showed that intense CTR mRNA signals were detected in the whole mammary gland. We performed immunohistochemistry to determine distribution of CTR in the mammary epithelium. CTR has been reported to act as an amylin receptor when heterodimerized with receptor activity modifying protein-1 (RAMP1) or RAMP3. mRNA expression of RAMP1 and RAMP3 in mammary tissue decreased during pregnancy and lactation, and amylin mRNA was undetectable, suggesting that up-regulated CTR in lactating mammary tissues binds CT rather than amylin. In primary cultures of mammary cells isolated from rat dams 14 days postpartum, CT produced a statistically significant decrease in thymidine incorporation. These results suggest that up-regulation of CTR during lactation may contribute to inhibition of mammary epithelial cell proliferation.

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It is well known that pioglitazone, a potent thiazolidinedione, improves metabolic control. However, weight gain or peripheral edema may be of major clinical concern when using this agent. The purpose of our study was to prospectively evaluate the effects of low-dose pioglitazone (7.5 mg/day) on metabolic control, weight gain and the incidence of edema compared with a standard dose of pioglitazone (15.0 mg/day) in patients with type 2 diabetes mellitus (T2DM). Ninety-five Japanese female patients (mean age 58.4 ± 10.4 years) with newly diagnosed T2DM were selected for this study. They were randomly divided into the following 2 groups according to therapy regimens, and examined every month for 6 months after diagnosis. Group A consisted of 54 patients treated with low-dose pioglitazone orally; Group B, the control-group, consisted of 41 patients treated with standard-dose pioglitazone orally. The incidence of peripheral edema was significantly much lower in group A (2/54) than in group B (11/41) (p = 0.0014). In addition, % change of body weight during the 6-month treatment in group A was significantly less than that in group B (p<0.0001). On the other hand, the % change of biochemical parameters including HbA1c did not differ significantly between group A and group B, although glucose and lipid control significantly improved from baseline in both groups. Our results demonstrate the safety and efficacy of low-dose pioglitazone, suggesting that it could be another good choice of treatment for Japanese women with T2DM.

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Fetal and neonatal exposure to diethylstilbestrol (DES) is known to cause many abnormalities, such as cancer, in the male and female reproductive tracts later in life, and epigenetic mechanisms, such as DNA methylation, may be involved in these processes. In the present study, newborn C57BL/6 male mice were exposed to 3 μg of DES from postnatal days 1 to 5. Subsequently, the expression levels of the DNA methyltransferases Dnmt1, Dnmt3a and Dnmt3b and the transcription factors Sp1 and Sp3, which have been reported to regulate the expression of Dnmts, were examined at days 5, 14 and 30. Furthermore, restriction landmark genomic scanning (RLGS), which can analyze genome-wide DNA methylation, was performed to clarify whether or not aberrant DNA methylation was present in the epididymis of the DES-treated mice at day 30. Increased expression of Dnmt3b was observed at days 5 and 14, followed by increased expression of Dnmt1 and Dnmt3a at day 30, as evaluated by real-time RT-PCR. The expression of Sp1 was also increased at day 30. The RLGS analysis revealed that 7 loci of the genomic DNA were demethylated and 1 locus was methylated in the epididymis of the DES-treated mice. Four of these loci specifically demethylated in DES-treated mice were cloned, and all were found to be located within CpG islands near genes. In conclusion, our results indicated the possibility that DES-induced abnormalities of reproductive organs are associated with altered expression levels of DNA methyltransferases and DNA methylation.

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An 85-year-old man who had undergone a right hemicolectomy for colon cancer presented with severe hypothyroidism and hoarseness 21 months after the operation. The serum thyrotropin (TSH) was markedly elevated to 118.14 μIU/mL and serum free thyroxine (fT4) level was markedly suppressed to 0.34 ng/dL. Symptoms of hoarseness and neck swelling were already evident 4 months prior at which time tests for normal thyroid function were performed. The patient was referred due to aggravated pain on his diffusely enlarged hard goiter. An enlarged thyroid with some calcification was noticed in the neck ultrasonography with multiple cervical lymphadenopathies. Core biopsy of the thyroid gland showed invasion of poorly differentiated adenocarcinoma cells. Immunohistochemical studies showed positive staining only for carcinoembryonic antigen (CEA). There were multiple lung parenchymal nodules and adrenal masses at the time of evaluation. The patient was started on palliative chemotherapy with thyroid hormone replacement and gradually became euthyroid. From these findings and the clinical observations, thyroid metastasis with hypothyroidism developing acutely from metastatic colon adenocarcinoma was diagnosed.

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Serum C-reactive protein (CRP) concentrations have been reported to be associated with body fat, especially visceral fat accumulation, but most studies up to now have been conducted on non-diabetic subjects. In this study, we investigated the association between the serum CRP concentrations and parameters of adiposity and insulin resistance in both Japanese type 2 diabetes patients and non-diabetic subjects. A total of 248 Japanese subjects (140 type 2 diabetes patients and 108 non-diabetic subjects) were enrolled for the study. The degree of insulin resistance was estimated by the homeostasis model assessment (HOMA-R) method. Fat accumulation was evaluated by measuring visceral and subcutaneous fat areas at the level of the umbilicus in abdominal CT scans. To assess hepatic fat content, the ratio of CT attenuation value of the liver to that of the spleen (L/S ratio) was calculated. Serum CRP was found to be significantly correlated with various indices of adiposity, including L/S ratio, visceral fat area (VFA), subcutaneous fat area (SFA), and HOMA-R, in both the diabetic patients and the non-diabetic subjects. After adjustment for five variables (age, gender, serum CRP, HbA1c, and smoking), serum CRP was still significantly correlated with L/S ratio, VFA, SFA, and HOMA-R in the diabetic patients. We also found that changes in serum CRP concentrations were correlated with changes in the VFA and SFA at 1 year after the baseline in 24 diabetic patients. We conclude that serum CRP may be closely related to the degree of liver steatosis and visceral fat accumulation in Japanese type 2 diabetes mellitus patients.

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A case of hypothyroid Graves' disease occurred following external radiation therapy to the cervical region is described. Severe hypothyroidism developed in a 56-year-old man 6 months after external radiation therapy for submandibular cancer. Serological evaluation of thyroid autoimmunity revealed the presence of antithyroid antibodies and thyrotropin-binding inhibitory immunogloblins (TBII). Diplopia, limitation of downward gaze, and palpebral edema developed 2 years after levothyroxine replacement therapy. Ocular magnetic resonance imaging revealed marked hypertrophy of the bilateral extraocular muscles with signal hyperintensity on T2-weighted images. This infiltrative ophthalmopathy showed marked improvement after additional treatment with high-dose methylprednisolone and orbital radiation, in parallel with a decrease in TBII. These results suggest that radiation-associated thyroidal injury might be associated with the etiology of hypothyroid Graves' disease.

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A 55-year-old female was admitted to our hospital with severe hypertension (274/140 mmHg). Endocrinological examination revealed that her plasma levels of norepinephrine (NE) was elevated with high levels of urinary NE, normetanephrine and vanillylmandelic acid (VMA), suggesting the presence of pheochromocytoma. However, neither computed tomography nor MIBG scintigraphy detected any catecholamine-producing tumor in or outside the adrenal glands. She was screened with full polysomnography because of heavy snoring, and the diagnosis of severe obstructive sleep apnea syndrome (OSAS) was made. She was treated with calcium channel blocker for three weeks, but severe hypertension persisted. After treatment with nasal continuous positive airway pressure (CPAP) was added, her blood pressure gradually lowered week by week. Concomitantly, the levels of plasma and urinary NE, urinary normetanephrine and urinary VMA were normalized following nasal CPAP therapy for 2 weeks. Additional treatments with alpha-adrenergic blocker further decreased her home blood pressure. After a year, she continued nasal CPAP therapy and her blood pressure was nearly below 160/100 mmHg. Urinary NE level was slightly above normal range and other catecholamines stayed within the normal range. This case shows that patients with OSAS could develop severe hypertension through elevated sympathetic tone, mimicking pheochromocytoma. Nasal CPAP therapy is recommended not only to improve hypertension and catecholamine excess but also to distinguish the condition from pheochromocytoma.

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Frasier syndrome is characterized by slowly progressive nephropathy, male pseudohermaphroditism, streak gonad, and high risk of gonadoblastoma development. Here we report a case of a 46,XY phenotypic female with Frasier syndrome, who was under hemodialysis. While her serum estradiol level was gradually increasing annually, gonadotropin level was constantly extremely high, and her appearance was still prepubertal. She was heterozygous for a novel guanine>adenine point mutation at position +1 of the splice donor site within intron 9 (IVS 9 + 1G>A) of the Wilms' tumor 1 gene. The possibility of this disease should be taken into consideration whenever we encounter a patient with steroid-resistant nephrotic syndrome and delayed puberty.

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Type 1 diabetes likely is mediated by T-helper (Th) 1 lymphocytes, while Graves' disease may involve Th2 predominance. We investigated the balance between Th1 and Th2 cells and between Th1- and Th2-associated chemokine receptor expression on peripheral lymphocytes in subjects including patients with coexisting type 1 diabetes and Graves' disease. Peripheral blood mononuclear cells of all subjects were examined by flow cytometry for intracellular cytokines (IFN-γ for Th1; IL-4 for Th2) and expression of the chemokine receptors CXCR3 (Th1-associated) and CCR4 (Th2-associated). Plasma concentrations of interferon-inducible protein (IP)-10, a CXCR3 ligand, and thymus and activation-regulated chemokine (TARC), a CCR4 ligand, were measured by enzyme-linked immunosorbent assays. IFN-γ producing-T lymphocytes were significantly fewer in patients with coexisting type 1 diabetes and Graves' disease (12.4 ± 6.8%, n = 6) than in healthy control subjects (19.9 ± 4.1%, n = 6; P<0.01) or patients with type 2 diabetes (19.1 ± 4.5%, n = 5; P<0.05). We found no significant difference in IFN-γ-producing T lymphocytes between healthy controls and patients with only type 1 diabetes (n = 8) or Graves' disease (n = 5). Plasma IP-10 concentrations were significantly higher in patients with coexisting type 1 diabetes and Graves' disease than in control subjects (106.3 ± 30.48 vs. 66.7 ± 25.3 pg/ml, P = 0.0343). Considering only patients with type 1 diabetes alone, duration of diabetes correlated positively with IFN-γ-producing T lymphocytes (r = 0.773, P = 0.0242) and the ratio of CXCR3 to CCR4 receptor expression (r = 0.947, P = 0.0004). In conclusion, Th1-associated T lymphocytes were fewer in peripheral blood from patients having both type 1 diabetes and Graves' disease than in those with either disease alone. Numbers of peripheral Th1 lymphocytes increased with increasing time from onset of type 1 diabetes in patients with type 1 diabetes alone.

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Measurement of serum glycated albumin (GA) is accepted as an alternative method to evaluate chronic glycemic control in diabetic patients in whom measurement of HbA_1c is inadequate for some reason. Although GA levels are known to be influenced by serum albumin turnover besides glycemia, little is known about the physiological and pathological conditions affecting GA levels. This study was aimed to prove the effects of body mass index (BMI) on GA measurement in diabetic patients. We studied 209 patients with type 2 diabetes mellitus whose HbA_1c levels had been stable for at least the past three months. In the study patients HbA_1c and GA levels were found to be correlated to one another. Fasting plasma glucose (FPG) was significantly correlated with HbA_1c and GA. BMI showed a significant negative correlation with GA levels, whereas there was no correlation of BMI with HbA_1c levels. Multivariate regression analyses revealed that only FPG was positively correlated with HbA_1c, while FPG was positively and BMI was negatively correlated with GA. Only BMI was negatively correlated with the ratio of GA to HbA_1c. These results clearly demonstrate that GA levels are negatively influenced by BMI in diabetic patients.

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Hepatitis C-Associated Osteosclerosis (HCAO) is characterized by a marked increase in bone mass with deep bone pain. Since 1992, eleven cases of HCAO have been reported. This report describes an elderly Japanese man with HCAO, whose clinical course we followed for 3 years. A 68-year-old man developed pain in both pretibial regions in June 2000, and he had frequent episodic loss of muscular strength in his hands. He had recieved blood transfusion for a bleeding ulcer 43 years before and was seropositive for hepatitis C virus. His serum alkaline phosphatase (ALP) level was markedly increased, while his serum calcium was slightly decreased and serum phosphate was normal. Skeletal radiographs of the lower extremities showed a progressive increase in skeletal density, but did not show any apparent deformity. Administration of nonsteroidal anti-inflammatory drugs led to a reduction in bone pain. Treatment with vitamin D3 and calcium decreased the number of episodes of sudden muscular weakness and maintained serum calcium within the normal range. Three years after the onset of the disease, bone mineral density of his lumbar vertebrae and left hip rose from 0.963 g/cm² to 1.096 g/cm², and from 0.938 g/cm² to 1.383 g/cm², respectively. His serum ALP level decreased from 2889 to 277 IU/L (normal range: 104-338) and serum calcium normalized. These findings were accompanied by a decrease in bone pain. This case and previous reports suggest that the skeletal tissue of this disease appears to be of good quality.

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Serious side effects of statins, including severe myopathy and rhabdomyolysis, are rare but important in general practice. Hypothyroidism can cause secondary hypercholesterolemia and myopathy. There have been few reports on the risk of statins in patient with unnoticed hypothyroidism. We analyzed the characteristics of 77 patients with primary hypothyroidism in our hospital. Nine patients (11%) accidentally received statins in the treatment of hypercholesterolemia without diagnosis of hypothyroidism. In such patients, free T₄ (FT₄) levels were lower, and those of LDH, CK were higher than those in patients not receiving statins. In patients accidentally receiving statins, an inverse correlation between CK and FT₄ could not be shown (which was recognized in patients not receiving them). Even after FT₄ levels were matched, levels of CK were still higher in the patients accidentally receiving statins. Patients with high CK levels over 1000 U/L were 5 times more frequent (56%) in patients accidentally receiving statins than in those not receiving statins (11%). The present study confirms that statins enhances levels of CK in patients with hypothyroidism. We must not begin and continue to use these drugs without checking the possibility of hypothyroidism.

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Adenine is widely used in clinical field, however, an excess of adenine is harmful. It is known that the feeding of an adenine-rich diet induces renal failure and decreases bone mineral density (BMD) and the serum testosterone level in male rats. However, there is little information about the influence of adenine on female animals. We compared the effects of adenine treatment between male and female rats. Young male and female rats were administered adenine adjusted with distilled water (6 mg/ml, 50 mg/ml and 100 mg/ml) for 8 weeks (3 times/week, 8-16 week old). In male rats, renal failure was induced by 100 mg/ml adenine treatment and renal dysfunction was induced by 50 mg/ml adenine treatment. Bone loss and the reduction of the testosterone level were also caused by both concentrations of adenine. However, the serum testosterone level and BMD in male rats were decreased by 6 mg/ml adenine treatment by which renal dysfunction was not caused. It is suggested that adenine directly affected bone metabolism and sex steroidgenesis in male animals, not through altering renal dysfunction. In female rats, conversely, renal dysfunction was induced only in the 100 mg/ml group, which was somewhat different from the observation in male rats. The serum 17-beta estradiol level and the BMD in female rats were not affected by adenine treatment at all. In conclusion, there is a significant difference of the effects of adenine, which is commonly contained in medicine and general foods, on steroidgenesis and renal function between male and female rats.

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A 70-year-old man with abdominal aortic aneurysm underwent surgical repair with Hemashield vascular graft. Postoperatively, he was found to have very low plasma cortisol levels, which failed to increase after stimulation with ACTH. A tentative diagnosis of adrenal insufficiency was made despite the lack of its clinical manifestations and a replacement therapy with hydrocortisone was started. He had also elevated plasma levels of TSH, thyroid hormones and estrogen without any clinical manifestations. Such abnormal hormone levels were spontaneously normalized three months after operation, which was later proven to be factitious by different immunometric assays (IMA). Since the vascular graft coated with bovine type I collagen has been reported to induce a transient immune response in some patients after surgery, we speculated that certain antibodies generated against heterologous collagen and/or yet-unknown components derived from the graft may have caused such factitious data; exogenous addition of bovine type I collagen and albumin to patient's serum, however, failed to affect the assay results. Whatever the cause, caution must be paid that some patients with surgical repair using heterologous materials may have such factitious hormone data by IMAs.

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Resistance to thyroid hormone (RTH) is characterized by decreased tissue responsiveness to thyroid hormone, due mainly to mutation of the thyroid hormone receptor (TR) β gene. It has been reported that serum of patients with RTH lacks autoantibodies against thyroglobulin (Tg) and thyroid peroxidase (TPO), except in rare cases where there is co-occurrence of coincidental autoimmune thyroiditis. Here we describe the five-year medical history of a Japanese woman and her father with RTH and coincidental chronic thyroiditis. The woman, aged 28 years, was referred to our hospital because of suspected hyperthyroidism. She showed a normal level of TSH and elevated levels of free triiodothyronine (FT3) and free thyroxine (FT4). Anti-Tg and anti-TPO antibodies were slightly positive. Since RTH was suspected, her parents were investigated with informed consent. Her father showed elevated levels of TSH, FT3 and FT4, and was positive for both anti-Tg antibody and anti-TPO antibody. Her mother had hypothyroidism caused by chronic thyroiditis. Sequencing of the TR β gene showed that the patient and her father had a codon 453 mutation resulting in a CCT (proline) to ACT (threonine) substitution. The patient gradually developed emotional disturbance, and was admitted to a psychiatry ward for two months, where she was treated with lorazepam and her condition improved. Her father, on the other hand, has been doing well for five years. The patient and the father showed different clinical courses, even though they carried the same mutation of the TR β gene. The fact that the father showed an elevated TSH level, whereas the patient did not, was thought to be due to decreased thyroid function caused by chronic thyroiditis.

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Steroidogenic acute regulatory protein (StAR) is a 30-kDa phosphorylated protein that rapidly appears in mitochondria of steroidogenic cells following tropic stimulation, and is required in the acute regulation of steroidogenesis. It was reported that mutations in the STAR gene encoding StAR cause congenital lipoid adrenal hyperplasia (CLAH), an autosomal recessive disorder characterized by impaired synthesis of all adrenal and gonadal steroid hormones. We previously reported a D203A polymorphism in the STAR gene in Japanese patients with CLAH as well as in normal Japanese subjects. In the present study, we analyzed the ability of the A203 StAR and D203 StAR to stimulate steroidogenesis using the in vitro functional expression system. The A203 StAR caused a twelve-fold increase in pregnenolone secretion over COS-1 cells transfected with an NH₂-cholesterol side-chain cleavage enzyme (P450scc)-adrenodoxin reductase-adrenodoxin-COOH fusion protein expressing plasmid (F2) and an empty vector, whereas the D203 StAR increased pregnenolone production no more than threefold. Western blot analysis detected mainly two species of StAR consisting of the 37-kDa precursor and the 30-kDa mature form. Together, these results indicate that the alanine at position 203 in human StAR is functionally important and that the D203 StAR is extremely unlikely to be a polymorphism.

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