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Biomedical subjects

S Nagasaka

Publications and source records attributed to S Nagasaka.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Intracerebral hemorrhage in a patient with moyamoya phenomenon caused by tuberculous arteritis: a case report].

A case of intracerebral hemorrhage which probably had been caused by a rupture of abnormal "moyamoya vessels" due to tuberculous arteritis was reported. A 42-year-old female had a history of tuberculous meningitis at the age of 2 years and suffered from a sudden onset of severe headache in January of 1998. CT scan disclosed a medium-sized intracerebral hematoma in the left frontal base and many calcifications in the basal cistern. Subsequent angiography demonstrated high-grade stenosis in the terminal portion of the right internal carotid artery and near-by "moyamoya vessels". No surgery was performed on the patient. A second angiography was carried out two months later and it newly disclosed ophthalmic artery-feeding "moyamoya vessels" in the place where the intracerebral hematoma had been located. This led us to conclude that a rupture of "moyamoya vessels" was the cause of the intracerebral hemorrhage and "moyamoya vessels" were not visible in the first angiograms because they had been compressed by the hematoma. Although cerebral infarction is common in tuberculous arteritis, cerebral hemorrhage is uncommon. The pathogenesis of cerebral hemorrhage due to tuberculous arteritis and its difference from that of hemorrhage caused by moyamoya disease is discussed.

Adult↗
PubMed1999

[Surgical treatment of 2 cases of irradiation induced constrictive pericarditis].

A 72-years-old man underwent radiation therapy (62 Gy) for esophageal carcinoma. Twelve months later, symptoms of heart failure such as syncope, cough and hepatomegaly manifested. On catheter study, a dip and plateau pattern of right ventricular pressure curve was evident. Pericardiectomy without extracorporeal circulation was performed. Operative findings and pathological results were compatible with radiation-induced constrictive pericarditis. He recovered from the heart failure, and has been doing well 3 months after the surgery. A 54-years-old man underwent thymectomy for malignant thymoma. He underwent a radiation therapy (52 Gy) postoperatively. After 12 months from the irradiation, syncope and dyspnea manifested. On catheter study, a dip and plateau pattern of right ventricular pressure curve was observed. Pericardiectomy with extracorporeal circulation was performed. He recovered from the heart failure after pericardiectomy, however he died of radiation-induced pneumonitis 6 months later.

Aged↗
PubMed1998

Association of endogenous insulin secretion and mode of therapy with body fat and serum leptin levels in diabetic subjects.

Insulin is one of the hormonal regulators of leptin synthesis and participates in adipose tissue maintenance. The present study was undertaken to clarify the association of endogenous insulin secretion and mode of therapy with body fat and serum leptin levels in diabetic subjects. We measured the fasting serum C-peptide level, as an estimate of endogenous insulin secretion, and the serum leptin level in 176 Japanese diabetic subjects (79 men and 97 women; age, 55.9+/-14.3 years; body mass index [BMI], 23.8+/-4.1 kg/m2 [mean+/-SD]). Thirty-one subjects were treated with diet therapy alone, 66 with sulfonylurea (SU), and 79 with insulin (including 29 with type I diabetes mellitus). Body fat was analyzed by the impedance method. Serum leptin levels significantly correlated with the BMI and body fat and were higher in women, mainly because of their greater body fat. Serum C-peptide concentrations positively correlated with body fat and serum leptin in subjects treated with diet and SU. In insulin-treated type II diabetic subjects, both serum C-peptide and the daily insulin dose were weakly associated with body fat and serum leptin. In those subjects, despite a lower percent body fat and body fat mass, serum leptin concentrations (10.3+/-8.4 ng/mL) were comparable to the levels in subjects treated with diet (8.8+/-8.5 ng/mL). When compared within the same BMI and body fat groups (BMI 20 to 25 and > 25 kg/m2) including the control subjects matched for age and sex, serum leptin levels were higher in insulin-treated type II diabetic subjects versus the control subjects and diabetic patients treated with diet or SU. Stepwise regression analysis for all of the diabetic subjects showed that both the serum C-peptide level and exogenous insulin administration, as well as the BMI, gender, and age, were determinants of the serum leptin level. In conclusion, endogenous insulin secretion is closely associated with body fat and serum leptin in diabetic subjects treated with diet therapy and SU. In Japanese insulin-treated type II diabetic subjects, both endogenous and exogenous insulin are associated with body fat and serum leptin, which is maintained at levels comparable to or somewhat higher than the levels in control subjects and diabetic patients treated without insulin.

Adipose Tissue↗
PubMed1998

Exaggerated urinary excretion of aquaporin-2 in the pathological state of impaired water excretion dependent upon arginine vasopressin.

The present study was undertaken to determine whether urinary excretion of aquaporin-2 (UAQP-2) is of value to diagnose the pathological state of water retention and hyponatremia. UAQP-2 under ad libitum water drinking was 429 fmol/mg creatinine in the patients with water retention, a value significantly greater than that of 153 fmol/mg creatinine in the normal subjects. An acute oral water load test (20 mL/kg BW) was performed in 7 normal subjects (22-25 yr old) and 10 patients with water retention and hyponatremia (55-75 yr old). The percent excretion of the water load was only 30% in the patient group compared with 70% in the control group (P < 0.01). In the control group, minimal urinary osmolality was as low as 131 mosmol/kg H2O, which was responsible for the decrease in plasma arginine vasopressin (AVP) levels after the reduction in plasma osmolality. In the patient group, minimal urinary osmolality was 320 mosmol/kg H2O, and free water clearance remained below 0.6 mL/min after the water load. This impaired water excretion was consistent with the nonsuppressible levels of plasma AVP despite hypoosmolality. The nadir of UAQP-2 was obtained at 60-90 min. The minimal UAQP-2 was reduced to 284 fmol/mg creatinine, a value significantly greater than that of 76 fmol/mg creatinine in the control group. Similar results were obtained in the 6 patients with hypopituitarism, who had impaired water excretion and marked hyponatremia. Water excretion was totally normalized after the replacement of hydrocortisone (excretion of water load, 31% vs. 102%; P < 0.01). Hydrocortisone replacement also significantly reduced the minimal UAQP-2 from 225 to 49 fmol/mg creatinine after the acute oral water load, a value comparable to that in the control subjects. These results indicate that UAQP-2 is a potent marker to diagnose the pathological state of impaired water excretion and hyponatremia, dependent upon AVP, in patients with water retention and hypopituitarism.

Adult↗
PubMed1998

Contribution of a missense mutation (Trp64Arg) in beta3-adrenergic receptor gene to multiple risk factors in Japanese men with hyperuricemia.

Epidemiological data reveal that hyperuricemia is a risk factor of atherosclerosis. The risk is possibly caused by a link between hyperuricemia and insulin resistance-related metabolic syndrome. Recently it has been proposed that a missense mutation (Trp64Arg) in the beta3-adrenergic receptor (beta3-AR) gene may contribute to the accumulation of multiple risk factors related to insulin resistance. The present study was undertaken to further clarify an association between the Trp64Arg mutation and the metabolic syndrome in 47 Japanese men with hyperuricemia, who are substantially at high risk of atherosclerosis. One patient (2%) had the homozygous mutation, 12 (26%) were heterozygous for the mutation, and 31 (72%) had no mutation found by the PCR-RFLP analysis. The Trp64Arg mutation was not related to past maximal body mass index (BMI), BMI and waist/hip ratio. The subjects with the heterozygous mutation showed a slightly higher incidence of impaired glucose tolerance and diabetes mellitus in the 75 g oral glucose challenge (67%), as compared with those without the mutation (39%). Serum insulin response at 60 min and the sum of serum insulin in the glucose challenge were greater in the former subjects than those in the latter subjects (P=0.041 and 0.076, respectively). An increase in serum lipoprotein(a) was also observed in the subjects with the heterozygous mutation, but the Trp64Arg mutation was not associated with other dyslipidemia, blood pressure or ischemic changes on the electrocardiogram. These results indicate that the heterozygous mutation of Trp64Arg in the beta3-AR gene partly contributes to the accumulation of multiple risk factors in male subjects with hyperuricemia. A larger prospective study is necessary to elucidate a possible role of the Trp64Arg mutation in atherosclerotic diseases in future.

Adult↗
PubMed1997

Successful treatment of intraoperative pulmonary tumor embolism from renal cell carcinoma.

During left nephrectomy in a 35-year-old woman with a left renal cell carcinoma extending into the inferior vena cava (IVC) and right atrium, cardiac arrest occurred. Immediate transesophageal echocardiography demonstrated that the event was caused by a pulmonary tumor embolism. Emergent cardiopulmonary bypass (CPB) was established and the tumors in the pulmonary arteries were successfully removed. The left nephrectomy was completed. The patient recovered in the intensive care unit without any neurological deficit. A postoperative pulmonary perfusion scintigram showed no defect in the pulmonary circulation. Transesophageal echocardiography was useful for making a rapid diagnosis of an intraoperative pulmonary embolism originating from a tumor of the IVC or right atrium.

Adult↗
PubMed1997

Antithyroid therapy improves bony manifestations and bone metabolic markers in patients with Graves' thyrotoxicosis.

OBJECTIVE: Abnormal bone metabolism in patients with Graves' thyrotoxicosis is well documented, but the precise time-course of its recovery remains poorly understood. The present study was undertaken to clarify longitudinal improvement in bony manifestations, especially in cortical bone, and bone metabolic markers in thyrotoxicosis. DESIGN: Two year prospective follow-up study in patients with Graves' disease. PATIENTS: Ten consecutive patients with Graves' disease (seven males and three females, of mean (+/-SEM) age 39.3 +/- 3.9 years) were enrolled in the study and treated with antithyroid drugs. Thirteen sex- and age-matched patients with the disease in remission served as controls. MEASUREMENTS: Bony manifestations were evaluated both by fine cortical bone striations in the metacarpals on magnified roentgenograms and lumbar bone mineral density (BMD) measurement. Urinary deoxypyridinoline (dPYR) and serum pyridinoline cross-linked telopeptide domain of type I collagen (ICTP) were monitored as markers of bone resorption, as well as serum osteocalcin (OC), carboxy-terminal propeptide of type I procollagen (PICP) and alkaline-phosphatase (ALP) as markers of bone formation. RESULTS: Initial elevated free thyroid hormone levels were normalized within a month of starting therapy. Striation indices of the metacarpals were 1.89 +/- 0.16 before therapy, higher than those of 0.49 +/- 0.12 in the controls (P < 0.0001); the indices gradually decreased to 1.00 +/- 0.20 (12 months) and 0.48 +/- 0.12 (24 months). Lumbar BMD Z-scores increased from -0.22 +/- 0.46 to 0.21 +/- 0.47 (12 months) and 0.68 +/- 0.48 (24 months) (P = 0.0029). Before therapy, urinary dPYR and serum ICTP concentrations were much higher than the control values (dPYR, +553%; ICTP, -396%, P < 0.0001), which declined promptly in the 2nd month. Serum OC, PICP and ALP were also significantly higher than in controls at first (OC, +287%; PICP, +225%; ALP, +196%), and remained elevated until 4 or 8 months. CONCLUSIONS: Bone resorption and cortical bone striations occur in untreated patients with Graves' thyrotoxicosis. The bone resorption rapidly ameliorates after normalization of thyroid hormone levels. In contrast, the accelerated bone formation persists for at least 4-8 months, suggesting positive uncoupling of bone remodelling. This dominant bone formation could result in the improvement in cortical bone striations and the increase in bone mineral density of trabecular bone.

Adolescent↗
PubMed1997

Longitudinal changes of metacarpal cortical striation in Graves' disease.

RATIONALE AND OBJECTIVES: The authors verify whether metacarpal cortical striation can be used to assess longitudinal changes in bone turnover in Graves' disease. METHODS: Eight patients with untreated Graves' disease (5 men, 3 women; age 36 +/- 12 years) and six patients with the disease in remission (1 man, 5 women; age 38 +/- 12) were studied. Posteroanterior radiographs of the bilateral hands were obtained using fine-grain mammography film and direct magnification. Three observers independently determined the grade of cortical striation (striation index; SI) of the second and third metacarpals in randomly presented radiographs. RESULTS: The SI determined by all observers decreased significantly after the beginning of antihyperthyroid therapy compared with the SI before treatment (P < 0.05). Significant correlation was found between the observers' assessments (r = 0.74, P < 0.001). The average kappa value and percent agreement were 0.27 and 51.8%, respectively. Intraobserver variability provided relatively good kappa statistics (kappa: 0.56; percent agreement: 79.9%). Longitudinal decrease in the SI was in accordance with a decline in urinary pyridinoline cross-link excretion, a decline in serum osteocalcin, and an increase in bone mineral density of lumbar spine. CONCLUSIONS: The change in the SI can be used to detect increased and decreased bone turnover. Thus, the SI can be used as one index of bone turnover in patients with Graves' disease.

Absorptiometry, Photon↗
PubMed1997

Extracellular ATP promotes cellular growth of renal inner medullary collecting duct cells mediated via P2u receptors.

The present study was undertaken to determine whether extracellular adenosine 5'-triphosphate (ATP) promotes cellular proliferation of cultured rat renal inner medullary collecting duct cells. Extracellular ATP increased inositol 1,4,5-triphosphate (IP3) production and cellular free calcium concentration - [Ca2+]i - in a dose-dependent manner. ATP also caused a transient cellular acidification. Extracellular ATP activated mitogen-activated protein (MAP) kinase and [3H]thymidine incorporation in a dose-dependent manner. However, such effects were not obtained with adenosine 5'-diphosphate, adenosine monophosphate, and adenosine. In addition, uridine triphosphate, a P(2u) purinergic agonist, increased IP3 production and activated MAP kinase. 2-Methylthio ATP, a P(2y) purinergic agonist, also increased IP3 production, but did not affect the MAP kinase activity. We also examined the effect of arginine vasopressin on cellular growth. Arginine vasopressin did not alter MAP kinase activity and [3H]thymidine incorporation in cultured rat renal inner medullary collecting duct cells. These results indicate that extracellular ATP activates phospholipase C mediated through P(2u) and P(2y) purinergic receptors and promotes cellular proliferation mediated through P(2u) purinergic receptors in renal inner medullary collecting duct cells.

Adenosine Triphosphate↗
PubMed1997

Cerebellar gliomas with exophytic growth--three case reports.

Three patients presented with cerebellar hemispheric astrocytic tumors which showed an exophytic growth pattern. The neuroimaging appearances of these cases mimicked a cerebellopontine angle tumor in two cases, and a posterior fossa extra-axial tumor in the other, which arose from the left cerebellar hemisphere with exophytic extension into the left crural and quadrigeminal cisterns and compressed the midbrain directly. All patients underwent surgical resection, and two patients also received adjuvant radiation therapy and chemotherapy. Intraoperative findings confirmed that the tumors had intramedullary origins from the cerebellar hemisphere, and extended exophytically into the subarachnoid space forming an extra-axial mass lesion. The histological diagnoses were mixed malignant oligo-astrocytoma (grade III), astrocytoma (grade II), and glioblastoma (grade IV). Cerebellar gliomas with exophytic growth to the cerebellopontine angle cistern should be considered in the differential diagnosis of cerebellopontine angle tumors.

Aged↗
PubMed1997

[Extended aortoplasty for supravalvular aortic stenosis with Williams syndrome].

We report a male case of supravalvular aortic stenosis associated with Williams syndrome requiring surgery at age 11. At 5 years of age, this boy presented with a harsh systolic heart murmur and was diagnosed as having a supravalvular aortic stenosis. In association with mental retardation, elfin face and bilateral inguinal hernias, he was diagnosed as a Williams syndrome confirmed by the chromosomal analysis revealing the deletion of 7q11.23. The pressure gradient across the stenotic lesion of the ascending aorta, which had been 35 mmHg at age 5, progressed to 80 mmHg at age 11 years. Extended aortoplasty was performed using a patch of 20 mm Hemashield graft prosthesis. Postoperative cardiac catheterization confirmed that the pressure gradient in the ascending aorta completely disappeared following surgery.

Aorta↗
PubMed1996

Cellular signaling and proliferative action of AVP in mesangium of SHR: effect of low density lipoprotein.

The present study was undertaken to determine whether low density lipoprotein (LDL) modulates the cellular action of arginine vasopressin (AVP) in cultured glomerular mesangial cells of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). The AVP-induced cellular signal transduction, including inositol 1,4,5-trisphosphate (IP3) production, fura-2 intracellular calcium measurements and cellular alkalinization, was significantly greater in cells of SHR than those of WKY. This is based on an increase in AVP V1 receptor number in cells of the SHR. Also, the AVP activation of mitogen-activated protein (MAP) kinase and [3H]thymidine incorporation was significantly exaggerated in cells of SHR compared with those of WKY. LDL at a concentration of 10 micrograms/ml augmented the cellular signaling and proliferative action of AVP in cells of WKY, but not in those of SHR. Since [3H]AVP receptor binding was not affected by the LDL pretreatment, LDL modulates the signal transduction between a location distal to the AVP receptors and proximal from the production of IP3 and diacylglycerol. These results indicate that an increase in AVP receptor capacity has a profound effect on the AVP-induced cellular signaling and proliferation, and that LDL has a slight alteration on the action of AVP in glomerular mesangial cells of SHR.

Animals↗
PubMed1996

A case of silent 21-hydroxylase deficiency with persistent adrenal insufficiency after removal of an adrenal incidentaloma.

A case of an adrenal incidentaloma in a 57-year-old man with silent 21-hydroxylase deficiency is reported. Abdominal computed tomography revealed a right adrenal tumour of 6cm in diameter. There was no evidence of adrenal hormone excess. However, after surgical removal of the adrenal tumour, the patient developed acute adrenal insufficiency. Adrenocortical function has remained low ever since surgery. Pathological examination of the tumour revealed a cortical adenoma. On the basis of increased plasma renin activity and serum 17 alpha-hydroxyprogesterone concentration and decreased 21-hydroxylase activity of the adenoma tissue, the patient was diagnosed as having systemic 21-hydroxylase deficiency. There are two possible mechanisms for the persistent adrenal insufficiency; first the residual left adrenal gland may have been originally hypo-functioning for some reason and, second, the left gland may have lost the ability to regenerate following prolonged suppression by the adenoma. In cases of adrenal incidentalomas with 21-hydroxylase deficiency, the indications for surgical removal should be carefully considered.

Adenoma↗