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Biomedical subjects

Yosuke Okada

Publications and source records attributed to Yosuke Okada.

At least 19 recordsLinked to original sources

Benign symmetric lipomatosis associated with alcoholism.

A 46-year-old man was diagnosed as having benign symmetric lipomatosis (BSL) based on the grotesque physical examination findings and subcutaneous fat tissue biopsy. Although markedly overweight, the glucose tolerance was normal and insulin levels indicated no remarkable insulin resistance on the 75 g oral glucose tolerance test. Furthermore his visceral fat tissue was very slight and the circulating adiponectin concentration was high those which suggesting a high insulin sensitivity. In addition, the relevance of alcohol in the onset of BSL is strongly suggested based on alcoholic hepatopathy and the history of the development of grotesque physical appearance associated with increased alcohol consumption.

Adiponectin↗

Serum hyaluronan concentration as a marker of angiopathy in patients with diabetes mellitus.

Accumulation of hyaluronan (HA) around smooth muscle cells in lesions of atherosclerosis in diabetic patients suggests that this protein plays an important role in diabetic angiopathy. The aim of this study was to determine the correlation between serum HA concentrations and diabetic angiopathy. Diabetic patients treated with or without an oral hypoglycemic agent and/or insulin for at least 1 year were recruited (n = 95). We also included 20 non-diabetic control subjects. We measured serum levels of HA, body mass index (BMI), fasting plasma glucose (FPG), HbA1c, total cholesterol, triglyceride, glycated albumin (GA), high sensitivity CRP (hs-CRP), monocyte chemoattractant protein (MCP)-1 and evaluated diabetes mellitus history, drug use and presence of related complications. Serum HA levels were significantly (P<0.05) higher in diabetic patients (83.6 +/- 5.6 ng/ml, mean +/- SEM) than in normal subjects (41.7 +/- 12 ng/ml). In diabetic patients, serum HA concentration significantly correlated with FPG, HbA1c, GA, triglyceride and also significantly correlated with BMI, hs-CRP and MCP-1 and tended to be higher in diabetic patients with complications than in those without such complications. Our data suggest that serum HA level correlates with poor blood glucose control and diabetic angiopathy and that it could be used as a marker of diabetic angiopathy.

Blood Glucose↗

Intravenous cyclophosphamide pulse therapy is effective for refractory Graves' ophthalmopathy.

Graves' ophthalmopathy is the most frequent extrathyroidal manifestation of Graves' disease. Although glucocorticoids and orbital radiotherapy have been used and are effective for the disease, we often experience cases refractory to either therapy. We report here a case that did not respond satisfactorily to either therapy and was later successfully treated by intravenous cyclophosphamide (IV-CY) pulse therapy. A 31 year old woman presented with typical Graves' disease and ophthalmopathy. After establishing a euthyroid state, she received intravenous glucocorticoid pulse therapy and orbital radiotherapy. Although this induced the resolution of the ophthalmopathy, it was temporary and thyroid-stimulating antibody (TSAb) increased to high titers, associated with relapse of ophthalmopathy 2 months after the treatment. Four courses of IV-CY pulse therapy were administered, which resulted in complete improvement of the symptoms and normalization of the TSAb titers. We suggest that IV-CY pulse therapy might be useful for Graves' ophthalmopathy, especially for patients refractory to glucocorticoid pulse therapy.

Adult↗

Increased expression levels of monocyte CCR2 and monocyte chemoattractant protein-1 in patients with diabetes mellitus.

Increased monocyte recruitment into subendothelial space in atherosclerotic lesions is one of the hallmarks of diabetic angiopathy. The aim of this study was to determine the state of peripheral blood monocytes in diabetes associated with atherosclerosis. Diabetic patients treated with/without an oral hypoglycemic agent and/or insulin for at least 1 year were recruited (n=106). We also included 24 non-diabetic control subjects. We measured serum levels of monocyte chemoattractant protein (MCP)-1, fasting plasma glucose (FPG), HbA1c, total cholesterol, triglyceride, body mass index (BMI), high sensitivity CRP (hs-CRP) and evaluated CCR2, CD36, CD68 expression on the surface of monocytes. Serum MCP-1 levels were significantly (p<0.05) higher in diabetic patients than in normal subjects. In diabetic patients, serum MCP-1 levels correlated significantly with FPG, HbA1c, triglyceride, BMI, and hs-CRP. The expression levels of CCR2, CD36, and CD68 on monocytes were significantly increased in diabetic patients and were more upregulated by MCP-1 stimulation. Our data suggest that elevated serum MCP-1 levels and increased monocyte CCR2, CD36, CD68 expression correlate with poor blood glucose control and potentially contribute to increased recruitment of monocytes to the vessel wall in diabetes mellitus.

Cells, Cultured↗

[Marked weight loss in two female patients with prader-willi syndrome by behavioral modification and improvement of the environment].

Prader-Willi Syndrome (PWS) is a complex neurogenetic disorder with considerable clinical variability, and is considered to be mainly the result of a hypothalamic defect. PWS is characterized by hyperphagia, obesity, mental retardation and hypogonadism from a young age. Hyperphagia is one of the most serious problems, which is organic in origin, inducing morbid obesity and leading to respiratory failure. Most studies attempting to control obesity in children with PWS by dietary management reported limited success due to difficulty in controlling foraging and food stealing. Here we report 16- and 20-year-old female patients with PWS who showed marked weight loss and improvement of respiratory failure by behavior modification and improvement of the environment.

Adolescent↗

Successful treatment of insulinoma by a single daily dose of octreotide in two elderly female patients.

We report two cases of insulinoma in advanced age patients considered unsuitable for surgery, in whom single daily doses of octreotide successfully improved hypoglycemia and hyperinsulinemia. The biological half-life of octreotide is about 100 min, hence it is customary to use two or three administrations per day to prevent hypoglycemia in insulinoma patients. The first case was a 76-year-old woman who presented with hyperinsulinemic hypoglycemia. Computed tomography (CT) and magnetic resonance imaging did not identify a tumor in the pancreas but a 1.5-cm tumor was found in the pancreatic body on abdominal angiography and selective arterial calcium stimulation and hepatic venous sampling (ASVS) were compatible with insulinoma. The patient refused surgery, but was successfully treated with octreotide at 50 microg subcutaneous injection once daily. Since the treatment was started (1 year), she has not suffered hypoglycemia. Case 2 was an 85-year-old woman who presented with hyperinsulinemic hypoglycemia. CT identified a 1.5-cm tumor in the pancreatic uncus, but she was considered unsuitable for surgery due to advanced age, obesity and cardiopulmonary dysfunction. Octreotide at 100 microg subcutaneous injection once daily prevented further hypoglycemic attacks, but two months later, postprandial plasma glucose was elevated. Octreotide was gradually reduced to 50 microg once daily. Three years have passed since the treatment without any hypoglycemic attack. Successful treatment with octreotide once daily could be due to old-age-related slow metabolism and could be potentially considered as the treatment of choice for elderly patients with insulinoma especially those considered unsuitable for surgery.

Age Factors↗

A rare case of adult-onset nesidioblastosis treated successfully with diazoxide.

A 54-year-old man was admitted to our hospital for evaluation of hypoglycemia. He had frequent episodes of loss of concentration before dinner. The ratio of IRI to plasma glucose (PG) was 0.8-1.0. Abdominal CT revealed no pancreatic tumor, and angiography of splenic artery showed no definite tumor stain within the pancreas. Based on the results of selective arterial calcium stimulation and hepatic venous sampling (ASVS), the provisional diagnosis was a small insulinoma in the pancreatic body. The patient underwent subtotal distal pancreatectomy. However, histopathological and immunohistochemical examinations of the resected tissue showed hypertrophy of islets of Langerhans islands and beta cells around pancreatic ducts. The final diagnosis was adult-onset nesidioblastosis. Postoperatively, the patient continued to exhibit hyperinsulinemia and nighttime hypoglycemia. Octreotide, voglibose and diet therapies failed to improve the nocturnal hypoglycemia. However, treatment with diazoxide at a starting dose of 200 mg/day resulted in immediate amelioration of nocturnal hypoglycemia. This is the first Japanese adult case of nesidioblastosis treated successfully with diazoxide. This case report suggests that diazoxide may be effective for adult-onset nesidioblastosis in a manner similar to that described for pediatric cases.

Angiography↗

[Primary hyperparathyroidism complicated with flail chest due to severe osteoporosis].

We report a 61-year-old woman who was admitted to our hospital in August 2004 with severe hypercalcemia and osteoporosis. Although she was found to have hypercalcemia five years earlier, she has never been treated. The patient was transferred to our hospital for further management of a recently-identified left neck mass. Serum calcium level was 15.0 mg/dL and intact parathyroid hormone (PTH) 3,321 pg/mL. (99m)Tc-methoxyisobutylisonitrile (MIBI) scintigraphy showed marked accumulation in the left neck. We diagnosed the tumor as parathyroid gland tumor and it was enucleated surgically. Although serum Ca level returned to normal after surgery, the patient suffered multiple rib fractures, complicated with marked paradoxical breathing. Internal fixation of the thorax was necessary due to deterioration of the heart failure. Progression of severe osteoporosis was associated with multiple fractures of the ribs and other serious complications including congestive heart failure occurred after surgery, reflecting the extreme difficulty in treating this patient.

Female↗

[Diabetic vascular calcification and abnormal bone metabolism: the relation between bone and vascular].

High-frequency severe atherosclerosis/calcinosis is observed in diabetes mellitus and chronic dialysis, which leads to cardiovascular events. However, the effective treatment for suppressing the progression of vascular calcification has not been established. Here we review the mechanism of vascular calcification and present our findings that a first generation of bisphosphonate is useful in prevention of vascular calcification in diabetes and chronic renal failure.

Arteriosclerosis↗

[A rare case of primary aldosteronism caused by bilateral functioning adrenocortical adenomas with renal cell carcinoma].

We report a rare case of bilateral primary aldosteronism with renal cell carcinoma. A 55-year-old woman developed symptoms of hypertension and hypokalemia. The cause of these symptoms was suspected to be primary aldosteronism, based on the high levels of plasma aldosterone concentrations (PAC) and low levels of plasma rennin activity (PRA), resulting in a high PAC/PRA ratio. Abdominal CT and MRI revealed tumor masses in both adrenal glands, and a large left renal mass. The preoperative diagnosis was primary aldosteronism due to bilateral functioning adrenocortical adenomas and left renal cell carcinoma. The patient underwent left radical nephrectomy and right partial adrenalectomy. The Pathological diagnosis was left renal cell carcinoma and bilateral functioning adrenocortical adenomas. Primary aldosteronism due to bilateral functioning adrenocortical adenomas is relatively rare and its complication with renal cell carcinoma is an extremely rare case.

Adrenal Cortex Neoplasms↗

Glycated albumin and cross-linking of CD44 induce scavenger receptor expression and uptake of oxidized LDL in human monocytes.

Functional role of CD44, a principal receptor of hyaluronan, and glycated albumin for differentiation of resting human monocytes isolated by counterflow centrifugal elutriation was investigated. Flow cytometric analysis revealed that amadori-modified glycated albumin induced expression of CD44 as well as macrophage scavenger receptors (MSRs) such as CD36 and CD68 on resting monocytes. Crosslinking of CD44 on monocytes also induced MSR expression. Furthermore, CD44 crosslinking and/or glycated albumin enhanced the uptake of oxidized-low density lipoprotein in monocytes and foam cell formation. Taken together, engagement of CD44 (e.g., hyaluronan) and glycated albumin induced the differentiation of resting monocytes into foam macrophages through the induction of MSRs, implying that CD44 could be involved in atherosclerotic lesions of those such as diabetic patients.

Cells, Cultured↗

Indication for nateglinide in type 2 diabetes mellitus.

Nateglinide is a novel rapid- and short-acting insulin secretagogue that ameliorates postprandial hyperglycemia by improving insulin secretory dynamics to a near normal level more effectively than sulfonylureas. Recent epidemiological studies have demonstrated that postprandial hyperglycemia can result in arteriosclerosis, and that advanced arteriosclerosis is present in the initial stage of impaired glucose tolerance. Since postprandial hyperglycemia could be well treated by nateglinide, we examined the background factors of type 2 diabetic patients to determine the optimal indication for nateglinide. Our results indicate that nateglinide is most effective in young and obese patients. Furthermore, fewer responders had microangiopathy or were previously on oral hypoglycemic agents or sulfonylureas compared with non-responders. Although nateglinide is generally indicated for patients with mild HbA1c level, the present findings indicate that the drug was effective in the aforementioned patients regardless of pretreatment HbA1c levels. In one obese patient, nateglinide improved late hyperinsulinemia to near normal secretory dynamics. Our findings suggest that nateglinide is a physiologically preferable and useful drug for early type 2 diabetes without microangiopathy.

Age Factors↗

Osteoblasts and osteoclasts in bone remodeling and inflammation.

Bone homeostasis is maintained by a balance between bone resorption by osteoclasts and bone formation by osteoblasts. Osteoblasts not only play a central role in bone formation by synthesizing multiple bone matrix proteins, but regulate osteoclast maturation by soluble factors and cognate interaction, resulting in bone resorption. Osteoclast maturation requires stimulation by RANKL expressed on osteoblasts, and the cognate interaction is mediated by firm adhesion via ICAM-1. During the processes, pro-inflammatory cytokines such as IL-1 and TNF-alpha, cause an imbalance in bone metabolism, by favoring bone resorption via the induction of RANKL and ICAM-1 on osteoblasts. These inflammatory signals originate from the immune system, the largest source of cell-derived regulatory signals, and such immunological signals to the bone are transmitted primarily via osteoblasts to induce osteoclast maturation, resulting in secondary osteoporosis. Actually, such phenomena mainly occur at the interface between proliferating synovium and bone tissue in rheumatoid arthritis (RA). Thus, therapeutic strategies for these conditions, an anti-TNF-alpha antibody and an IL-1 receptor antagonist, effective for treating RA disease activity, also reduce secondary osteoporosis and joint destruction. Based on an improved understanding of immune signals, investigation of the suppression of cell functions may lead to improved understanding and better treatment of diseases of bone metabolism and osteoporosis.

Animals↗

Vertebral fracture and bone mineral density in women receiving high dose glucocorticoids for treatment of autoimmune diseases.

OBJECTIVE: To evaluate the factors influencing the occurrence of vertebral fracture in patients receiving high dose glucocorticoids (GC). METHODS: A cross-sectional study was performed on women who had received at least 0.5 mg/kg of oral glucocorticoid for the treatment of autoimmune diseases for more than 1 month between 1998 and 2003. Logistic regression analysis and chi-square test were used to examine the effects of glucocorticoid dose and other factors on vertebral fractures. Receiver-operating characteristics curve (ROC) analysis was used to determine the bone mineral density (BMD) cutoff value for the risk of vertebral fracture. RESULTS: The study population comprised 160 women, including 35 with vertebral fractures. In ROC analysis, the BMD threshold of the risk of fracture for postmenopausal women (0.787 g/cm2 , T score -2.1) was lower than that for premenopausal women (0.843 g/cm2 , T score -1.7). Among patients with fractures, 7 of 16 premenopausal patients had normal BMD values (T score > -1), whereas only one of 19 postmenopausal patients showed a comparable level of BMD. Additionally, vertebral fracture was more frequent for patients with high total cholesterol values (> 280 mg/dl) than for those with normal total cholesterol values (< 220 mg/dl). Moreover, patients with high total cholesterol values had lower BMD values than those with normal total cholesterol values. CONCLUSION: The fact that vertebral fracture frequently occurred in premenopausal patients with normal BMD and evidence that hyperlipidemia correlated with fracture suggest the pathology of vertebral fracture secondary to high dose glucocorticoid therapy is multifactorial and possibly involves lipid metabolism.

Adolescent↗

Macrophage inflammatory protein-1alpha induces hypercalcemia in adult T-cell leukemia.

UNLABELLED: Hypercalcemia is observed in >80% of ATL. Serum MIP-1alpha levels were elevated in all 24 ATL with hypercalcemia but undetectable in all 10 patients with humoral hypercalcemia of malignancy with solid tumors and in 34 of 37 ATL without hypercalcemia. We propose that serum MIP-1alpha is a clinical hallmark for hypercalcemia in ATL. INTRODUCTION: High serum cytokines levels are not always associated with hypercalcemia in patients with adult T-cell leukemia (ATL), suggesting that other factors are involved in the pathogenesis of ATL patients with hypercalcemia. This study was designed to determine the role of macrophage inflammatory protein-1alpha (MIP-1alpha), a chemokine recently described as an osteoclast stimulatory factor, in ATL-associated hypercalcemia. MATERIALS AND METHODS: We measured serum interleukin (IL)-1beta, IL-6, TNF-alpha, parathyroid hormone-related protein (PTHrP), and MIP-1alpha levels in ATL patients by enzyme-linked immunosorbent assays. FACScan was used to measure the expression of RANKL on ATL cells. Osteoclast formation in cocultures of ATL cells and peripheral blood mononuclear cells (PBMCs) was evaluated by TRACP staining. RESULTS: High serum MIP-1alpha levels were noted in all 24 ATL patients with hypercalcemia and in 3 of 37 ATL patients without hypercalcemia. The elevated levels of MIP-1alpha and calcium in ATL patients decreased after effective chemotherapy, emphasizing the role of MIP-1alpha in ATL hypercalcemia. ATL cells spontaneously produced MIP-1alpha. MIP-1alpha significantly enhanced human monocyte (precursor cells of osteoclasts) migration and induced RANKL expression on ATL cells. ATL cell-induced osteoclast formation from PBMCs was inhibited by anti-MIP-1alpha antibody and osteoprotegerin. CONCLUSION: Our results suggest that MIP-1alpha can induce RANKL on ATL cells in autocrine fashion and that RANKL seems to mediate the hypercalcemic effect of MIP-1alpha in ATL. We propose that MIP-1alpha is the clinical hallmark of hypercalcemia in ATL and could be a potentially useful therapeutic target.

Carrier Proteins↗

Induction of RANKL expression and osteoclast maturation by the binding of fibroblast growth factor 2 to heparan sulfate proteoglycan on rheumatoid synovial fibroblasts.

OBJECTIVE: Rheumatoid arthritis (RA) is characterized by progressive joint destruction. The aim of this study was to clarify the relevance of RA synovial fibroblasts (RASFs) and fibroblast growth factor 2 (FGF-2), which is produced abundantly by RASFs, to the osteoclastogenesis and bone resorption in RA. METHODS: Synovial fibroblasts were prepared from the synovial tissues of 10 patients with active RA and 7 patients with osteoarthritis (OA). The expression of RANKL, intercellular adhesion molecule 1 (ICAM-1), FGF receptor 1 (FGFR-1), and heparan sulfate proteoglycan (HSPG) on synovial fibroblasts was measured by FACScan. Osteoclast formation in cocultures of RASFs and peripheral blood mononuclear cells (PBMCs) was evaluated by tartrate-resistant acid phosphatase staining and a pit-formation assay using dentin slices. RESULTS: FGF-2 induced the expression of both RANKL and ICAM-1 on RASFs more so than on OA synovial fibroblasts (OASFs). FGF-2-induced up-regulation of RANKL and ICAM-1 was inhibited by anti-FGF-2 antibody. Although FGFR-1 was equally expressed on RASFs and OASFs, HSPG was highly expressed on RASFs. Up-regulation of RANKL by FGF-2 on RASFs was diminished by the removal of heparan sulfate with heparitinase. Osteoclast formation from PBMCs induced by RASFs was inhibited by the addition of either heparitinase, anti-ICAM-1 antibody, anti-FGF-2 antibody, or osteoprotegerin. FGF-2-induced RANKL on RASFs and osteoclast formation were suppressed by an inhibitor of ERK. CONCLUSION: FGF-2 was transferred to FGFR-1 through binding to HSPG, which is characteristically expressed on RASFs, resulting in RANKL- and ICAM-1-mediated maturation of osteoclasts via ERK activation. Thus, we propose that FGF-2 not only augments the proliferation of RASFs, but also is involved in osteoclast maturation, which leads to bone destruction in RA.

Arthritis, Rheumatoid↗