[Prostate Cancer Diagnosed during Androgen Replacement Therapy for Late-Onset Hypogonadism Treatment: A Case Report].

We report a 60-year-old man with prostate cancer diagnosed during androgen replacement therapy (ART) for late onset hypogonadism after surgery for pituitary adenoma. He was refered to the department of urology since prostate specific antigen values were elevated after 6 months of ART. After the diagnosis of prostate cancer, ART was discontinued, and robot-asssited laparoscopic radical prostatectomy with pelvic lymphadenoctomy was performed. Pathological examination revealed Gleason score 4 + 5 prostate adenocarcinoma with seminal vesicle invasion and lymph node metastasis(pT3bN1). He has stayed biochemically and radiologically disease-free 33 months postoperatively.

Thyroid hormone replacement therapy for primary hypothyroidism leads to significant improvement of renal function in chronic kidney disease patients.

BACKGROUND: The interactions between kidney and thyroid functions have been known for many years; however, there are few studies on the extent of the improvements and long-term changes of renal function after thyroid hormone replacement therapy (THRT) in chronic kidney disease (CKD) patients. The purpose of this study was to determine how THRT affects the estimated glomerular filtration rate (eGFR) in CKD patients with primary hypothyroidism. METHODS: A retrospective investigation was performed on 51 Japanese patients (15 men and 36 women) with primary hypothyroidism. The changes in eGFR after THRT were examined according to the existence of CKD and severity of thyroid function. RESULTS: eGFR increased rapidly over the first 6 months after THRT in CKD patents, which was followed by a plateau. There was a correlation between eGFR and the severity of hypothyroidism, which was independent of age, and eGFR in severely hypothyroid patients significantly increased up to levels that were similar to mildly hypothyroid patients after THRT. eGFR improved more in the lower initial eGFR group and increased about 30 % in CKD patients (47.5 ± 7.7 vs. 62.1 ± 9.5 ml/min/1.73 m(2), P < 0.01). Moreover, eGFR in CKD patients with mild to moderate hypothyroidism was significantly increased compared to that in non-CKD patients. CONCLUSION: Our data suggested that hypothyroidism contributed to the reduction in eGFR, especially in CKD patients; therefore, patients with CKD should positively be examined for thyroid function, and appropriate THRT should be started if needed.

Matrix extracellular phosphoglycoprotein is expressed in causative tumors of oncogenic osteomalacia.

Oncogenic osteomalacia (OOM), or tumor-induced osteomalacia, is a rare disease characterized by renal phosphate wasting and osteomalacia. It arises due to the secretion of fibroblast growth factor 23 (FGF-23) from causative tumors. Matrix extracellular phosphoglycoprotein (MEPE) is predominantly expressed in odontoblasts, osteoblasts, and osteocytes. Although the presence of MEPE mRNA has been reported in some OOM tumors, little is known about the prevalence of MEPE expression in OOM tumors. In this study, the expression of MEPE and FGF-23 in OOM tumors was investigated at the transcriptional and translational levels. Eleven causative OOM tumors were analyzed by quantitative real-time reverse transcription-polymerase chain reaction and immunohistochemistry for MEPE and FGF-23 expression. Hemangiopericytomas and giant cell tumors, pathological diagnoses that are common in cases of OOM, were obtained from non-osteomalacic patients and analyzed as controls. The gene expression level of FGF23 and MEPE in OOM tumors was 10(4)- and 10(5)-times higher, respectively, than in non-OOM tumors. Immunohistochemical staining revealed that FGF-23 protein was expressed in all OOM tumors, and MEPE was expressed in 10 out of 11 OOM tumors. Thus, MEPE expression was common in OOM tumors, similar to FGF-23. These results indicate that, in addition to the hypophosphatemic effects of FGF-23, MEPE or the MEPE-derived acidic serine aspartate-rich MEPE-associated motif peptide may contribute to decreased bone mineralization in OOM patients.

Overexpression of CNP in chondrocytes rescues achondroplasia through a MAPK-dependent pathway.

Achondroplasia is the most common genetic form of human dwarfism, for which there is presently no effective therapy. C-type natriuretic peptide (CNP) is a newly identified molecule that regulates endochondral bone growth through GC-B, a subtype of particulate guanylyl cyclase. Here we show that targeted overexpression of CNP in chondrocytes counteracts dwarfism in a mouse model of achondroplasia with activated fibroblast growth factor receptor 3 (FGFR-3) in the cartilage. CNP prevented the shortening of achondroplastic bones by correcting the decreased extracellular matrix synthesis in the growth plate through inhibition of the MAPK pathway of FGF signaling. CNP had no effect on the STAT-1 pathway of FGF signaling that mediates the decreased proliferation and the delayed differentiation of achondroplastic chondrocytes. These results demonstrate that activation of the CNP-GC-B system in endochondral bone formation constitutes a new therapeutic strategy for human achondroplasia.

The levels of somatostatin receptors in causative tumors of oncogenic osteomalacia are insufficient for their agonist to normalize serum phosphate levels.

Oncogenic osteomalacia (OOM) is a rare disease characterized by renal phosphate wasting and osteomalacia and is caused by the secretion of fibroblast growth factor 23 (FGF-23) from causative tumors. Scintigraphy with octreotide, which binds to somatostatin receptors (SSTRs), is a useful way to locate causative tumors in OOM patients. However, the therapeutic effects of octreotide acetate are still controversial. Two OOM patients were administered octreotide acetate intramuscularly. Ten causative OOM tumors, including two resected from the patients participating in the octreotide administration study, were examined for expression of genes encoding SSTRs by quantitative real-time RT-PCR and immunohistochemistry. Octreotide therapy did not improve hypophosphatemia in either case, despite temporal decreases in FGF-23 levels in one patient. The mean expression levels of SSTR1, SSTR3, and SSTR5 were similar in the OOM and non-OOM tumors. Expression of SSTR2 was significantly higher in the OOM tumors than in the non-OOM tumors. Immunohistochemical examinations revealed the presence of SSTR2A, SSTR2B, and SSTR5 in both the OOM and non-OOM tumors. The expression of SSTR genes in OOM tumors contributes to positive imaging using octreotide scintigraphy. However, the levels of SSTRs seem to be insufficient for the octreotide therapy to improve hypophosphatemia. Further studies are needed to clarify the mechanisms by which FGF-23 secretion from OOM tumors is suppressed by octreotide acetate.

Increased bone turnover in patients with hypercholesterolemia.

Osteoporosis has been linked with arteriosclerotic vascular diseases, suggesting that hypercholesterolemia or dyslipidemia may be a common pathogenetic factor underlying these diseases. However, little is known about the relationship between osteoporosis and hypercholesterolemia. The purpose of this study was, therefore, to investigate the effects of hypercholesterolemia upon bone metabolism, by measuring bone turnover markers in hypercholesterolemic patients. This study included 281 Japanese patients with hypercholesterolemia, and 267 control subjects. Serum bone-specific alkaline phosphatase (BAP) of the patients was significantly higher than that of the controls in women. Serum N-terminal telopeptide of type I collagen (NTx) of the patients was significantly higher than that of the controls in both men and women. In addition, both BAP and NTx in men showed a significantly negative correlation with high density lipoprotein cholesterol (HDL-C). On the other hand, in women, both BAP and NTx showed a significantly positive correlation with total cholesterol and low density lipoprotein cholesterol (LDL-C). These results indicate increased bone turnover in hypercholesterolemic or dyslipidemic patients regardless of gender, and suggest the importance of treating hypercholesterolemia or dyslipidemia in order to prevent not only arteriosclerotic complications but also osteoporotic bone loss and subsequent fractures.

Efficacy of combined treatment with raloxifene and alfacalcidol on bone density and biochemical markers of bone turnover in postmenopausal osteoporosis.

Because both raloxifene (RLX) and alfacalcidol (ALF) have been established as therapeutic agents for osteoporosis, it is tempting to speculate that the combination therapy of RLX and ALF might provide benefits over that of either one alone. However, the efficacy of the combination therapy has not been reported yet. The purpose of this study was thus to assess the efficacy of the combination therapy on bone mineral density (BMD) and bone turnover in patients with postmenopausal osteoporosis. Sixty postmenopausal patients (mean age 71.62 +/- 9.9 years) with untreated osteoporosis were selected for this study, and were randomly divided into two groups by therapeutic regimen. Group A consisted of 28 patients treated with RLX plus ALF, while Group B consisted of 32 patients with RLX alone. Among them, 20 in group A and 22 in group B completed this study. Contrary to our expectations, at either 6 months or 12 months after the initiation of treatment, RLX plus ALF did not increase BMD at any of the skeletal sites measured, including lumbar spine, femur, and radius, nor did it reduce bone-specific alkaline phosphatase or N-terminal telopeptide of type I collagen more than RLX alone. Our results do not support the hypothesis that the combination therapy of RLX and ALF exerts more beneficial effects on bone compared than with RLX alone. However, it still remains unclear from this study whether the combination therapy of RLX and ALF is more efficacious in preventing fractures compared with RLX alone. Further studies are needed to clarify these issues.

Association between baseline values of bone turnover markers and bone mineral density and their response to raloxifene treatment in Japanese postmenopausal women with osteoporosis.

It has been well established that raloxifene improves bone turnover, increases bone mineral density (BMD), and reduces the risk of fractures. However, it remains obscure which patients are more likely to respond to treatment with raloxifene in patients with postmenopausal osteoporosis. The purpose of this study was to investigate associations between baseline values of BMD and bone turnover markers (BTMs) and changes of those values after 1-year treatment with raloxifene. Sixty-eight Japanese postmenopausal women with untreated osteoporosis were selected for this study, among whom 58 patients (mean age 70.40 +/- 9.2 years) completed this study. Lower baseline values of BMD at the lumbar spine, the femoral neck, and the distal radius were significantly correlated with greater increases of BMD at those corresponding sites after 1-year treatment with raloxifene. On the other hand, higher baseline values of bone-specific alkaline phosphatase (BAP) and serum N-terminal telopeptide of type I collagen (NTx) were significantly correlated with greater reductions of BAP and NTx, respectively, after 1-year treatment with raloxifene. Although longer and larger studies with fracture endpoints are needed, our findings suggest that baseline values of BMD and BTMs can be used to predict subsequent skeletal response to raloxifene therapy in Japanese postmenopausal women with osteoporosis.

A case of cortisol producing adrenal adenoma without phenotype of Cushing's syndrome due to impaired 11beta-hydroxysteroid dehydrogenase 1 activity.

This report concerns a case of cortisol-producing adrenocortical adenoma without the phenotype of Cushing's syndrome. A left adrenal tumor was incidentally detected in this patient. A diagnosis of adrenal Cushing's syndrome was based on the results of endocrinological and radiological examinations, although she showed none of the physical signs of Cushing's syndrome, glucose intolerance, hypertension or dyslipidermia. After a successful laparoscopic left adrenalectomy, the pathological diagnosis was adrenocortical adenoma. Slow tapering of glucocorticoids was needed to prevent adrenal insufficiency after surgery, and the plasma ACTH level remained high even though the serum cortisol level had reached the upper limit of the normal range. Further examination showed a urinary THF + allo-THF/THE ratio of 0.63, which was lower than that of control (0.90 +/- 0.13, mean +/- SD). Serum cortisol/cortisone ratios after the cortisone acetate administration were also decreased, and the serum half-life of cortisol was shorter than the normal range which has been reported. These findings indicated a partial defect in 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) activity, which converts cortisone to cortisol. Our case suggests that a change in 11beta-HSD1 activity results in inter-individual differences in glucocorticoid efficacy.

Clinical significance of 1-year treatment with raloxifene on bone and lipid metabolism in Japanese postmenopausal women with osteoporosis.

It has been well established that raloxifene (RLX) has beneficial effects on bone primarily in Caucasian women. However, to date, there is a dearth of data for Japanese postmenopausal women. In this study, we prospectively evaluated the effects of RLX on bone and lipid metabolism in fifty Japanese postmenopausal patients with untreated osteoporosis. We measured bone mineral density (BMD) by dual-energy X-ray absorptiometry at 7 sites including the lumbar spine, femoral neck, and distal radius. BMD was significantly increased at the lumbar spine both at 6 months and at 12 months compared with at baseline (p<0.01 for both), although the possibility could not be completely excluded that this increase may be partly explained by an apparent increase induced by degenerative changes in lumbar vertebrae since we had no control subjects to compare and be more certain of the findings in this study. Both bone-specific alkaline phosphatase (BAP) and serum N-terminal telopeptide of type I collagen (NTx) significantly decreased both at 6 months (p<0.01 for both) and at 12 months (p<0.01 for both) compared with at baseline, but not below the lower limit of the reference value. Total cholesterol and low-density lipoprotein cholesterol were significantly improved while triglycerides and high-density lipoprotein cholesterol were unaltered. Although longer and larger studies with fracture endpoints are needed to draw definite conclusions, our findings suggest the favorable effects of RLX on bone and lipid metabolism in Japanese postmenopausal women with osteoporosis as in Caucasian women.

[Parathyroid and bone. Medical management of primary hyperparathyroidism].

Although the role of medical management for primary hyperparathyroidism (PHPT) is still controversial, there are subsets of symptomatic patients with PHPT who may benefit from medical rather than surgical treatments. Estrogen remains an excellent option for selected postmenopausal women. Bisphophonates may be useful to provide skeletal protection and to treat osteoporosis associated with PHPT.

Hyponatremia in an Elderly Patient due to Isolated Hypoaldosteronism Occurring after Licorice Withdrawal.

Hyponatremia is one of the most common electrolyte disorders encountered in the elderly. We present the case of an 81-year-old man who developed hyponatremia due to isolated hypoaldosteronism occurring after licorice withdrawal. He had severe hypokalemia with hypertension and was diagnosed with pseudoaldosteronism. He had been taking a very small dose of licorice as a mouth refresher since his early adulthood. Five months after licorice withdrawal, he developed hypovolemic hyponatremia, which was resolved with administration of fludrocortisone acetate. Our experience with this case suggests that isolated hypoaldosteronism occurring after licorice withdrawal should be considered as a potential cause of hyponatremia in elderly patients.

Interferon-alpha improves bone resorption and osteopenia in patients with chronic hepatitis C.

BACKGROUND: Interferon (IFN)-beta is known to be involved in the regulation of bone homeostasis. As IFN-alpha and -beta share the same receptor complex and signaling pathway, we speculated that treatment with IFN-alpha for chronic hepatitis C (CHC) may provide a beneficial effect on bone loss. METHODS: Urinary deoxypyridinoline (uDPD) of 41 patients with CHC who had been receiving IFN-alpha for 24 weeks was examined during the period of observation. Among them, eight patients showed a bone mineral density (BMD) of less than 0.850g/cm(2) before IFN therapy and they were examined a BMD again after completion of IFN administration. Relationships between the percentage difference of uDPD after discontinuation of IFN and various factors related to CHC were also examined. RESULTS: A mean uDPD of 7.1+/-3.4nM/mM creatinine before IFN therapy decreased to 4.5+/-2.4 in the 4th week and 4.2+/-2.7 in the 24th week of IFN therapy, respectively (p<0.0001). The reduction in uDPD was more prominent in cases with a lower viral load (p=0.0266). The BMD of the eight patients, which was less than 0.850g/cm(2) before IFN therapy, showed significant increase after the end of therapy (p=0.0172). CONCLUSION: IFN-alpha can improve bone resorption in CHC patients, especially in those with a lower viral load, and increased BMD. These effects are thought to be a result of direct action of IFN on bone homeostasis.

[Negative correlation between BMD and HbA1C in patients with type 2 diabetes].

This study included 145 patients with type 2 diabetes, and 95 non-diabetic control. We measured bone mineral density (BMD) at the sites with different cortical/cancellous bone ratio (lumbar spine, femoral neck, and distal radius). BMD and Z score at the distal radius were significantly lower in type 2 diabetic patients than those in control subjects. In type 2 diabetic patients, negative correlation between BMD and the mean HbA(1C) during the last 2 years was found significantly at the distal radius in both sexes. These results indicate the selective cortical bone loss in type 2 diabetes, and suggest the importance of evaluating BMD at the radius as well and keeping good metabolic control to prevent bone loss in type 2 diabetic patients.

Complementary antagonistic actions between C-type natriuretic peptide and the MAPK pathway through FGFR-3 in ATDC5 cells.

We previously reported that C-type natriuretic peptide (CNP) stimulates endochondral ossification and corrects the reduction in body length of achondroplasia model mouse with constitutive active fibroblast growth factor receptor 3 (FGFR-3). In order to examine the interaction between CNP and FGFR-3, we studied intracellular signaling by using ATDC5 cells, a mouse chondrogenic cell line, and found that FGF2 and FGF18 markedly reduced CNP-dependent intracellular cGMP production, and that these effects were attenuated by MAPK inhibitors. Western blot analysis demonstrated that the level of GC-B, a particulate guanylyl cyclase specific for CNP, was not changed by treatment with FGFs. Conversely, CNP and 8-bromo-cGMP strongly and dose-dependently inhibited the induction of ERK phosphorylation by FGF2 and FGF18 without changing the level of FGFR-3, although they did not affect the phosphorylation of STAT-1. In the organ-cultured fetal mouse tibias, CNP and FGF18 counteracted on the longitudinal bone growth, and both the size and number of hypertrophic chondrocytes. The FGF/FGFR-3 pathway is known as the negative regulator of endochondral ossification. We found that FGFs inhibited CNP-stimulated cGMP production by disrupting the signaling pathway through GC-B while CNP antagonized the activation of the MAPK cascade by FGFs. These results suggest that the CNP/GC-B pathway plays an important role in growth plate chondrocytes and constitutes the negative cross talk between FGFs and the activity of MAPK. Our results may explain one of the molecular mechanisms of the growth stimulating action of CNP and suggest that activation of the CNP/GC-B pathway may be effective as a novel therapeutic strategy for achondroplasia.

Expression of the adrenomedullin gene in adipose tissue.

Adrenomedullin (AM) is a potent vasodilating peptide originally isolated from human pheochromocytoma cells. This report concerns the expression and secretion of AM from adipose tissue. Northern blot analysis demonstrated marked expression of AM mRNA in mouse adipose tissue. Expression levels in adipose tissues were 2.5-3.2 times higher than in the kidney. AM mRNA level in mature adipocytes was 7.3 times higher than in the stroma-vascular fraction of adipose tissue. In mature adipocyte culture, time-dependent increase of AM peptide concentration in the culture medium was detected. AM expression was also detected in human subcutaneous adipose tissue. Adipose AM expression significantly increased in obesity mouse model, high-fat diet fed mice and ob/ob mice. These results suggest that adipose tissue, especially mature adipocytes, is major source of AM in the body, and that adipocyte-derived AM plays a pathophysiological role in obesity.

Primary hyperparathyroidism presumably caused by chronic parathyroiditis manifesting from hypocalcemia to severe hypercalcemia.

A 67-year-old woman who presented with hypocalcemia compatible with idiopathic hypoparathyroidism gradually changed into a state of primary hyperparathyroidism. The left upper parathyroid gland, which was larger and harder than other glands, was resected. Despite the operation, hypercalcemia and high levels of intact PTH persisted. Six weeks later total parathyroidectomy was done to induce remission. The resected gland in the first operation had clusters of lymphoid follicles with germinal centers indicating a chronic autoimmune inflammation. This case suggests a transition from hypoparathyroidim to hyperparathyroidism associated with chronic parathyroiditis, possibly by a mechanism analogous to that observed in chronic thyroiditis.

Thyroid hormones promote chondrocyte differentiation in mouse ATDC5 cells and stimulate endochondral ossification in fetal mouse tibias through iodothyronine deiodinases in the growth plate.

Thyroid hormones (THs), 3,3',5-triiodo-L-thyronine (T3) and L-thyroxine (T4), are important for the normal development of the growth plate (GP); congenital TH deficiency leads to severe dwarfism. In mouse chondrogenic cell line, ATDC5, T3 enhanced differentiation and increased Alizarin red staining, but did not affect Alcian blue staining. In organ-cultured mouse tibias, THs stimulated the cartilage growth, especially in the hypertrophic zone. Interestingly, T4 was as equally potent as T3 in organ-cultured tibias, which suggests that T4 is metabolized locally to T3, because T4 is a prohormone and must be converted to T3 for its activity. Two enzymes catalyze the conversion; type I deiodinase (D1) and type II deiodinase (D2). D1 has a ubiquitous distribution and D2, with a high affinity for T4, is present where the maintenance of intracellular T3 concentration is critical. Messenger RNAs (mRNAs) for D1 and D2 were detected in neonatal mouse tibias and ATDC5 cells. The enzyme activity was unaffected by the D1 inhibitor 6-propyl-2-thiouracil, suggesting that D2 mainly catalyzes the reaction. D2 mRNA was detected in differentiated ATDC5 cells. In organ-cultured mouse tibias, D2 activity was greater at later stages. In contrast, thyroid hormone receptors (TRs) were expressed in neonatal mouse tibias and ATDC5 cells, but their expression levels in ATDC5 cells were stable throughout the culture periods. Therefore, increased T3 production at later stages by D2 is likely to contribute to the preferential effects of THs in the terminal differentiation of GP. This article is the first to show that T4 is activated locally in GP and enhances the understanding of TH effects in GP.

Cyclic GMP-dependent protein kinase II plays a critical role in C-type natriuretic peptide-mediated endochondral ossification.

Longitudinal bone growth is determined by endochondral ossification at the growth plate, which is located at both ends of long bones and vertebrae, and involves many systemic hormones and local regulators. C-type natriuretic peptide (CNP), a third member of the natriuretic peptide family, occurs at the growth plate and acts locally as a positive regulator of endochondral ossification through the intracellular accumulation of cyclic GMP (cGMP). The increase in cGMP concentrations is known to activate different signaling mediators, such as cyclic nucleotide phosphodiesterases, cGMP-regulated ion channels, and cGMP-dependent protein kinases (cGKs). The type II cGK (cGKII)-deficient mice (Prkg2(-/-) mice) develop dwarfism as a result of impaired endochondral ossification, suggesting that cGKII is important for the CNP-mediated endochondral ossification. However, given that Prkg2(-/-) mice differ from CNP-deficient mice (Nppc(-/-) mice) in the growth plate histology, which downstream mediator(s) of cGMP play key roles in the process is still an enigma. Here we show that targeted expression of CNP in the growth plate chondrocytes fails to rescue the skeletal defect of Prkg2(-/-) mice. Using cultured fetal mouse tibias, an in vitro model system of endochondral ossification, we also demonstrated that CNP cannot increase the longitudinal bone growth, and chondrocytic proliferation and hypertrophy, and cartilage matrix synthesis in Prkg2(-/-) mice. This study provides in vivo and in vitro genetic evidence that cGKII plays a critical role in CNP-mediated endochondral ossification.

Over expression of bone morphogenetic protein-3b (BMP-3b) using an adenoviral vector promote the osteoblastic differentiation in C2C12 cells and augment the bone formation induced by bone morphogenetic protein-2 (BMP-2) in rats.

BMP-3b is a novel BMP-3-related protein and its biological functions are unknown. In order to investigate the biological actions of BMP-3b, we constructed a BMP-3b-expressing recombinant adenoviral vector (AxCAKBMP-3b). We show that over expression of BMP-3b stimulated the induction of differentiation and the osteoinduction activity of a human BMP-2-expressing recombinant adenoviral vector (AxCAOBMP-2). C2C12 cells were infected in vitro with AxCAKBMP-3b, AxCAOBMP-2 and a control vector containing no foreign genes (AxCAwt). Cells infected with AxCAOBMP-2 and AxCAKBMP-3b produced more alkaline phosphatase and secreted more osteocalcin into the culture medium than cells infected with AxCAOBMP-2 and AxCAwt. When AxCAOBMP-2, AxCAKBMP-3b, and AxCAwt were injected into the calf muscles of nude rats (F 344/N Jcl-rnu), the osteoinduction seen with AxCAOBMP-2 and AxCAKBMP-3b was greater than that seen with AxCAOBMP-2 and AxCAwt.