A somatotropin-producing pituitary adenoma with an isolated adrenocorticotropin-producing pituitary adenoma in a female patient with acromegaly, subclinical Cushing's disease and a left adrenal tumor.

A 67-year-old female with hypertension and impaired glucose tolerance was admitted to our hospital because of a typical acromegalic appearance, including large, thickened bulky hands and feet, and a large prominent forehead and tongue. She did not have a Cushingoid appearance, such as a moon-face, buffalo hump, purple striae or central obesity. The laboratory data revealed a serum GH level of 4.6 ng/mL and serum insulin-like growth factor-1 level of 811 ng/mL. The oral glucose tolerance test showed no suppression of the GH values. An endocrine examination showed a lack of circadian rhythmicity of ACTH and cortisol. Cortisol was not suppressed by a low dose of dexamethasone during the suppression test, but was suppressed by a high dose of dexamethasone. A radiological study revealed two isolated adenomas in the pituitary and a left adrenal tumor. These findings strongly suggested a diagnosis of acromegaly with subclinical Cushing's disease and a left adrenal incidentaloma. Transsphenoidal surgery was performed. Hematoxylin and eosin staining showed that the left and right pituitary adenomas were composed of basophilic and acidophilic cells, respectively. Immunohistochemical staining showed the left adenoma to be positive for ACTH and negative for GH. In contrast, the right adenoma was GH-positive and ACTH-negative. This is a rare case of independent double pituitary adenomas with distinct hormonal features. We also provide a review of the previously reported cases of double pituitary adenomas and discuss the etiology of these tumors.

Cytosolic T3-binding protein modulates dynamic alteration of T3-mediated gene expression in cells.

µ-Crystallin (CRYM) is also known as NADPH-dependent cytosolic T3-binding protein. A study using CRYM-null mice suggested that CRYM stores triiodothyronine (T3) in tissues. We previously established CRYM-expressing cells derived from parental GH3 cells. To examine the precise regulation of T3-responsive genes in the presence of CRYM, we evaluated serial alterations of T3-responsive gene expression by changing pericellular T3 concentrations in the media. We estimated the constitutive expression of three T3-responsive genes, growth hormone (GH), deiodinase 1 (Dio1), and deiodinase 2 (Dio2), in two cell lines. Subsequently, we measured the responsiveness of these three genes at 4, 8, 16, and 24 h after adding various concentrations of T3. We also estimated the levels of these mRNAs 24 and 48 h after removing T3. The levels of constitutive expression of GH and Dio1 were low and high in C8 cells, respectively, while Dio2 expression was not significantly different between GH3 and C8 cells. When treated with T3, Dio2 expression was significantly enhanced in C8 cells, while there were no differences in GH or Dio1 expression between GH3 and C8 cell lines. In contrast, removal of T3 retained the mRNA expression of GH and Dio2 in C8 cells. These results suggest that CRYM expression increases and sustains the T3 responsiveness of genes in cells, especially with alteration of the pericellular T3 concentration. The heterogeneity of T3-related gene expression is dependent on cellular CRYM expression in cases of dynamic changes in pericellular T3 concentration.

Efficacy and Safety of Low-dose Spironolactone for Chronic Kidney Disease in Type 2 Diabetes.

CONTEXT: Although adding spironolactone to renin-angiotensin system blockers reduces albuminuria in adults with chronic kidney disease and type 2 diabetes, it increases the risk of hyperkalemia. OBJECTIVE: To assess whether a lower dose of spironolactone (12.5 mg/d) reduces the risk of hyperkalemia while maintaining its effect on reducing albuminemia. DESIGN: Multicenter, open-label, randomized controlled trial. SETTING: This study was conducted from July 2016 to November 2020 in ambulatory care at 3 diabetes medical institutions in Japan. PATIENTS: We enrolled 130 Japanese adults with type 2 diabetes and albuminuria (≥30 mg/gCre), estimated glomerular filtration rate ≥30 mL/min/1.73 m2, and serum potassium level <5.0 mEq/L. INTERVENTIONS: The participants were randomly assigned to the spironolactone-administered and control groups. MAIN OUTCOME MEASURES: Changes in urine albumin-to-creatinine ratio (UACR) from baseline over the 24-week interventional period. RESULTS: The spironolactone group showed a significant reduction in UACR from baseline (mean decrease, 103.47 ± 340.80 mg/gCre) compared with the control group, which showed an increased UACR (mean increase, 63.93 ± 310.14 mg/gCre; P = .0007, Wilcoxon rank-sum test and t test). Although the spironolactone group had a statistically significant increase in serum potassium levels, none of the participants had a potassium level ≥5.5 mEq/L at 24 weeks. Further, participants with a higher initial serum potassium level tended to have a smaller increase (estimate, -0.37, analysis of covariance). CONCLUSIONS: Low-dose spironolactone administration reduced albuminuria without causing hyperkalemia. Spironolactone administration, the oldest known and most cost-effective mineralocorticoid receptor antagonist, at lower doses should be reconsidered.

Amiodarone-induced thyrotoxicosis with thyroid papillary cancer in multinodular goiter: case report.

OBJECTIVE: To report a case of amiodarone-induced thyrotoxicosis (AIT) concomitant with thyroid cancer in multinodular goiter (MNG). CLINICAL PRESENTATION AND INTERVENTION: A 61-year-old man treated with amiodarone for 5 years presented with mild sweating. He was found to have AIT simultaneously with thyroid papillary cancer and MNG. Administration of amiodarone was stopped, and he was treated with methimazole for AIT. Five weeks after the initial treatment, thyroid function normalized. Total thyroidectomy was considered to enable use of amiodarone again. CONCLUSION: This case showed that thyrotoxicosis, MNG and amiodarone may contribute to thyroid carcinogenesis. Amiodarone should be carefully commenced in cases with MNG.

Lymphocytic infundibuloneurohypophysitis: long-term follow-up of a case cured with glucocorticoid.

OBJECTIVE: To report a case of infundibuloneurohypophysitis treated with steroid. CLINICAL PRESENTATION: A 65-year-old woman who was well until 4 weeks before admission and was not taking any medication presented with acute development of polydipsia and polyuria. Urinary volume was increased to 4,500 ml/day. She showed elevated serum osmolality and low urine osmolality, together with shortage of antidiuretic hormone. Magnetic resonance imaging (MRI) of the pituitary revealed marked nodular thickening of the neurohypophysis. Endocrinologically, anterior pituitary function appeared normal. Based on these examinations, she was diagnosed as having central diabetes insipidus due to lymphocytic infundibuloneurohypophysitis. INTERVENTION: Prednisolone (1 mg/kg/day, p.o.) and D-deaminovasopressin (5 microg/day, intranasal) were commenced. Ten days after the administration of the agents, MRI showed a dramatic improvement in the thickening of the neurohypophysis. Ten weeks later, abnormalities found in earlier MRI had disappeared. The drugs were withdrawn gradually, and diabetes insipidus ceased 25 weeks later. Recurrence was not seen in the subsequent MRI, and the function of the posterior pituitary gland was completely normalized even 7 years after discontinuation of treatments. CONCLUSION: This case shows that noninvasive diagnosis and appropriate steroid administration can effectively cure lymphocytic infundibuloneurohypophysitis; it is recommended with long-term follow-up.

Effects of Sitagliptin on Pancreatic Beta-Cells in Type 2 Diabetes With Sulfonylurea Treatment: A Prospective Randomized Study.

BACKGROUND: This prospective randomized, multicenter, open-label, comparative study was performed to analyze the effects of sitagliptin on glycemic control and maintenance of beta-cell function in patients with poorly controlled type 2 diabetes treated with low-dose glimepiride. METHODS: Forty-one patients with type 2 diabetes mellitus treated with low-dose glimepiride (≤ 2 mg/day) were prospectively enrolled in this study (age: 20 - 75 years; hemoglobin A1c (HbA1c): 7.4- 9.4%). The patients were randomized into two groups: the glimepiride (G) group, in which glimepiride dose was increased gradually to 6 mg/day, and the sitagliptin (S) group, in which sitagliptin was added at a dose of 50 mg/day. RESULTS: HbA1c level was significantly decreased after 24 weeks, but not 12 weeks, in the G group, while a significant decrease was seen after 12 weeks in the S group. Although there were no significant differences in HbA1c level at 24 weeks between the two groups (P = 0.057). The overall trend of changes in HbA1c level suggested that the glucose-lowering effects were superior in the S group. Furthermore, a significant change in fasting glucose was seen in the S group, but not in the G group. Glycemic control target was achieved in 36.7% and 16.7% patients in the S group and the G group, respectively. The proinsulin/insulin (P/I) ratio was significantly increased in the G group, whereas it tended to decrease in the S group. After 24 weeks of treatment, no significant difference was observed in the P/I ratio between the two groups, whereas a significant difference was noted in the ΔP/I (amount of change). Albuminuria tended to increase in the G group compared with the S group. CONCLUSION: The results of the present study suggested that sitagliptin effectively lowered hyperglycemia and that it may have a protective effect on pancreatic beta-cells when combined with a low dose of glimepiride. Therefore, sitagliptin may represent a useful combination therapy with low-dose sulfonylurea, not only for achieving glycemic control but also for protection of pancreatic beta-cells.

Biphasic function of focal adhesion kinase in endothelial tube formation induced by fibril-forming collagens.

Migration and tube formation of endothelial cells are important in angiogenesis and require a coordinated response to the extra-cellular matrix (ECM) and growth factor. Since focal adhesion kinase (FAK) integrates signals from both ECM and growth factor, we investigated its role in angiogenesis. Type I and II collagens are fibril-forming collagens and stimulate human umbilical vein endothelial cells (HUVECs) to form tube structure. Although knockdown of FAK restrained cell motility and resulted in inhibition of tube formation, FAK degradation and tube formation occurred simultaneously after incubation with fibril-forming collagens. The compensation for the FAK degradation by a calpain inhibitor or transient over-expression of FAK resulted in disturbance of tube formation. These phenomena are specific to fibril-forming collagens and mediated via alpha2beta1 integrin. In conclusion, our data indicate that FAK is functioning in cell migration, but fibril-forming collagen-induced FAK degradation is necessary for endothelial tube formation.

Efficacy of oral glucocorticoid and cyclosporine in a case of rituximab-refractory type B insulin resistance syndrome.

We describe a case of type B insulin resistance syndrome associated with systemic lupus erythematosus (SLE) that was refractory to rituximab and successfully treated with a combination of oral glucocorticoids and cyclosporine. Prior to treatment, insulin resistance was severe, and application of a hyperinsulinemic euglycemic clamp was not possible despite the continuous intravenous infusion of insulin at a maximum rate of 9.0 mU/kg/min. The addition of cyclosporine to oral glucocorticoid therapy resulted in remission of insulin resistance. The combination of oral prednisolone and cyclosporine might be effective in treating type B insulin resistance syndrome, particularly in rituximab-resistant cases. However, nephrotoxicity is a particular concern for patients receiving long-term cyclosporine therapy.

Nicotinamide adenine dinucleotide phosphate-dependent cytosolic T(3) binding protein as a regulator for T(3)-mediated transactivation.

Nicotinamide adenine dinucleotide phosphate (NADPH)- dependent cytosolic T(3) binding protein (CTBP) plays a role in the regulation of nuclear transport of T(3) in vitro. However, it is not known whether CTBP regulates the T(3) action. In this study, we examined the effects of CTBP on cellular translocation of T(3) and on transcriptional activation using established CTBP-expressing CHO or GH3 cells. The expression of CTBP increased cellular and nuclear uptake of T(3) in the CTBP-expressing cells. The efflux rate was decreased by induction of CTBP. Efflux from nuclei also inhibited by induction of CTBP. Expression of CTBP suppressed the T(3)-regulated luciferase activity in GH3 cells. Suppression was observed to be related to the expression level of CTBP. T(3) induction of rat GH mRNA was lower in the cells expressing CTBP than that in CTBP-null cells. These results suggest that CTBP regulates the T(3)-induced gene expression, with which an increase in the nuclear content of the T(3) is associated. Because we observed that a part of CTBP could be transported into nuclei and that acceptor protein for CTBP is present in nuclei as previously reported, interaction of CTBP with certain proteins, including transcription factors or nuclear T(3) receptor, may contribute to the regulation.

Tumor-specific gene therapy for undifferentiated thyroid carcinoma utilizing the telomerase reverse transcriptase promoter.

A tumor-specific targeting system for cancer gene therapy was studied using the human telomerase reverse transcriptase (hTERT) promoter. Telomerase activity is increased in most tumors but not detected in most normal cells. We developed the recombinant adenovirus, carrying human herpes simplex virus thymidine kinase gene under the control of the hTERT promoter (AdhTERTtk) to obtain restricted expression of a suicide gene only in tumor cells. We found that transcriptional activity of hTERT was 2- to 9-fold higher in undifferentiated thyroid carcinoma cell lines than that of the Simian virus 40 promoter in transient transfection assay. Undifferentiated thyroid carcinoma cell lines were infected with AdhTERTtk, and sensitivity to ganciclovir (GCV) was analyzed. Cell viability was decreased in a GCV dose-dependent manner after treatment with AdhTERTtk/GCV. The cell-killing ability of AdhTERTtk in all thyroid or nonthyroid carcinoma cell lines tested was similar to AdCMVtk, which carries herpes simplex virus thymidine kinase gene driven by the cytomegalovirus promoter. However, normal cell lines were largely unaffected by AdhTERTtk/GCV, whereas these cells were also sensitive to GCV after infection with AdCMVtk. A xenograft model was established by transplanting human differentiated or undifferentiated thyroid carcinoma cells into Balb-C nude mice. The injections of AdhTERTtk into tumors and ip administration of GCV showed significant inhibition of tumor growth, similar to AdCMVtk/GCV treatment. Systemic administrations of adenovirus and GCV to normal rats demonstrated remarkable increase of serum liver transaminase levels and severe hepatic damages in pathological examinations in AdCMVtk-injected rats but not in the AdhTERTtk group. These results indicate that the AdhTERTtk/GCV system is a promising therapy for undifferentiated thyroid carcinoma, which is one of the most malignant tumors, without damage to normal tissues.

Adenovirus-mediated tumor-specific combined gene therapy using Herpes simplex virus thymidine/ganciclovir system and murine interleukin-12 induces effective antitumor activity against medullary thyroid carcinoma.

The present treatment of advanced and metastatic medullary thyroid carcinoma (MTC) is unsatisfactory. Tissue-specific cancer gene therapy is a novel alternative approach. We developed a recombinant adenovirus expressing Herpes simplex type 1 thymidine kinase (HSVtk) driven by a modified CALC-I promoter TCP (AdTCPtk). Infection with this virus showed efficient cytotoxic effect on MTC cell lines (rMTC and TT cells) after treatment with ganciclovir (GCV) in vitro. In a syngenic WAG/Rij rat model, the combination of AdTCPtk/GCV treatment with administration of murine interleukin-12 (mIL-12) expressing adenovirus under control of TCP (AdTCPmIL-12) resulted in effective growth suppression of tumor at the treated site and also at a distant untreated site, in comparison to treatment with AdTCPtk/GCV or AdTCPmIL-12 alone. Moreover, intravenous injection of AdTCPtk, or AdTCPtk+AdTCPmIL-12, followed by administration of GCV, did not cause evident toxicity after administration of GCV. These results indicate that this combined system can provide an effective therapy for metastatic MTC with minimal toxicity.

A tandemly repeated thyroglobulin core promoter has potential to enhance efficacy for tissue-specific gene therapy for thyroid carcinomas.

Recombinant adenoviruses, carrying herpes simplex virus thymidine kinase (HSVtk) genes, were developed to evaluate the possibility of tissue-specific gene therapy for thyroid carcinomas. The HSVtk gene was driven by a minimal thyroglobulin (TG) promoter (AdTGtk) and a tandemly repeated minimal TG promoter (Ad2 x TGtk) to obtain thyroid-specific cell killing ability. The transduction of HSVtk genes by infection with Ad2 x TGtk followed by ganciclovir (GCV) treatment showed more powerful cytotoxicity for TG-producing FRTL5 cells, a rat normal thyroid cell line, and FTC-133 cells, a human follicular thyroid carcinoma cell line, than when infected with AdTGtk in vitro. The cell killing ability of Ad2 x TGtk was 10- to 30-fold higher than that of AdTGtk and similar to that of AdCMVtk, which carries HSVtk under the control of CMV promoter. Whereas after treatment with adenovirus/GCV to non-TG-producing cell lines (undifferentiated thyroid carcinoma cell lines and carcinoma cell lines from other tissues), Ad2 x TGtk and AdTGtk needed more than 100-fold concentrated GCV to reach IC(50) compared to AdCMVtk. We confirmed the enhanced efficacy of Ad2 x TGtk for tissue-specific cytotoxicity in vivo. After adenovirus/GCV treatment for FTC-133 tumor-bearing nude mice, Ad2 x TGtk enhanced tumor growth inhibition and survival rates compared to AdTGtk. Tumor growth inhibition and survival rates by Ad2 x TGtk were similar to that by AdCMVtk. Moreover, any toxic effect for rat normal tissues was not revealed after intravenous injections with Ad2 x TGtk and intraperitoneal administrations with GCV in vivo, whereas severe liver damages were observed after treatment with AdCMVtk/GCV. These data indicate a beneficial effect of Ad2 x TGtk for tissue-specific gene therapy for TG-producing thyroid carcinomas without toxicity for normal tissues.

Expression of thyroid hormone receptor alpha in 3T3-L1 adipocytes; triiodothyronine increases the expression of lipogenic enzyme and triglyceride accumulation.

Thyroid hormone receptors (TR) are members of the nuclear receptor superfamily. There are at least two TR isoforms, TRalpha and TRbeta, which act as mediators of thyroid hormone in tissues. However, the relative expression of each TR isoform in target tissues is still elusive. Herein, we have developed an RT-PCR and restriction enzyme digestion method to determine the expression of TRalpha1 and TRbeta1. We analyzed the expression of TR isoforms in 3T3-L1 preadipocytes induced to differentiate by an adipogenic cocktail in the presence or absence of 100 nM triiodothyronine (T(3)). The TRalpha1 isoform was predominantly expressed in 3T3-L1 adipocytes, and its expression was increased at the stage of development concomitant with the emergence of lipid droplets. Little, if any, TRbeta1 mRNA was detected in adipocytes. Administration of T(3) to the differentiating 3T3-L1 cells enhanced the accumulation of triglyceride. The expression profile of TRalpha1 in T(3)-treated adipocytes was similar to that in non-treated cells. The transcripts of adipogenic factors, CCAAT/enhancer binding protein beta (C/EBPbeta) and peroxisome proliferator activated receptor gamma (PPARgamma), were not altered by T(3). Lipid binding protein, aP2, that is downstream of these transcription factors was also unaffected by T(3). In contrast, the lipogenic enzyme, glyceraldehyde-3-phosphate dehydrogenase mRNA was significantly increased in the presence of T(3). Therefore, T(3) appears to be a hormone capable of modulating the expression of lipogenic enzyme and augments the accumulation of lipid droplets. We conclude that the TRalpha isoform might play an important role in the generation and maintenance of the mature adipocyte phenotype, regulating the expression of lipogenic enzymes.

Cell-specific expression of NADPH-dependent cytosolic 3,5,3'-triiodo-L-thyronine-binding protein (p38CTBP).

We have previously shown that cytosolic 3,5,3'-triiodo-L-thyronine (T3)-binding protein (CTBP) possesses a high affinity for T3 binding in the presence of nicotinamide adenine dinucleotide phosphate in vitro, and that p38CTBP increases intracellular content of T3, and suppresses T3-mediated transactivity. Screening of mRNA expression in 73 different human tIssues has demonstrated that p38CTBP mRNA is expressed at high levels in brain and heart. We have examined the intracellular localization and tissue-specific distribution of this protein by using a specific antibody against human p38CTBP. Western blotting and immunoprecipitation studies have shown that the antibody recognizes human p38CTBP. Interaction of p38CTBP with the antibody did not affect the T3-binding activity of p38CTBP, and its dimer formation in vitro. Western blotting analysis has shown that p38CTBP is expressed in brain and heart predominantly, similar to the distribution of mRNA. Immunohistochemical studies have demonstrated p38CTBP in neural cells and cardiac muscle cells. p38CTBP localizes in cytoplasm rather than in nuclei in neural cells. The evidence for the presence of tIssue-specific localization of p38CTBP has indicated that p38CTBP has a tIssue-specific function, such as the regulation of T3 delivery from cytoplasm to nuclei.

Gender-specific regulation of response to thyroid hormone in aging.

BACKGROUND: Similar to other systems, the endocrine system is affected by aging. Thyroid hormone, the action of which is affected by many factors, has been shown to be associated with longevity. The most useful marker for the assessment of thyroid hormone action is TSH level. Although age and gender are believed to modify the pituitary set point or response to free thyroid hormone concentration, the precise age- and gender-dependent responses to thyroid hormone have yet to be reported. METHODS: We analyzed the results of 3564 thyroid function tests obtained from patients who received medication at both out- and inpatient clinics of Shinshu University Hospital. Subjects were from among those with thyroid function test results in the normal or mildly abnormal range. Based on a log-linear relationship between the concentrations of FHs and TSH, we established the putative resistance index to assess the relation between serum FH and TSH levels. RESULTS: Free thyroid hormone and TSH concentration showed an inverse log-linear relation. In males, there was a negative relationship between the free T3 resistance index and age. In females, although there were no relationships between age and FHs, the indices were positively related to age. CONCLUSIONS: These findings indicated that there is a gender-specific response to thyroid hormone with aging. Although the TSH level is a useful marker for the assessment of peripheral thyroid hormone action, the values should be interpreted carefully, especially with regard to age- and gender-related differences.

Pituitary resistance to thyroid hormones: pathophysiology and therapeutic options.

Thyroid hormone secretion suppresses the expression of thyroid stimulating hormone (TSH), both of which are strictly controlled by a negative feedback loop between the hypothalamus-pituitary and thyroid. Pituitary resistance to thyroid hormone (PRTH) is defined as resistance to the action of thyroid hormone that is more severe in the pituitary than at the peripheral tissue level. Although the molecular basis of PRTH is not well understood, the clinical issue mainly involves imbalance between the hypothalamus-pituitary and peripheral thyroid hormone responsivity, which may induce peripheral thyrotoxic phenomena. Here, we review the pathogenesis and molecular aspects of PRTH, present a single case with inappropriate TSH secretion suffering from thyrotoxicosis treated with PTU, and discuss the possible choice of therapeutic options to correct the imbalance of thyroid hormone responsivity in both the hypothalamus-pituitary and peripheral tissues.

Distinct clinical courses in type 1 diabetes mellitus induced by peg-interferon-alpha treatment for chronic hepatitis C.

We report two cases of type 1 diabetes mellitus (T1DM) which developed after interferon (IFN) therapy for chronic hepatitis C. The patients had experienced abrupt hyperglycemia with positive anti-glutamic acid decarboxylase antibodies, resulting in initiation of insulin therapy. In one case, insulin therapy could be discontinued because endogenous insulin secretion was preserved at the onset and pancreatic beta cell function was recovered thereafter. In the other case with Hashimoto's thyroiditis and Sjögren's syndrome, continuation of insulin therapy was necessary because blood glucose levels were unstably controlled. Lasting autoimmunity superior to immunosuppressive mechanism may be associated with distinct clinical courses in these cases.