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H Sanada

Publications and source records attributed to H Sanada.

At least 19 recordsLinked to original sources
PubMed2001

The improvement of insulin resistance in patients with adrenal incidentaloma by surgical resection.

OBJECTIVE: Several recent studies have indicated that patients with adrenal incidentaloma often have disturbed glucose tolerance or/and hypertension. It is unclear whether these metabolic conditions could be caused by adrenal incidentaloma. We investigated the prevalence of disturbed glucose tolerance, hypertension and insulin resistance in the patients with non-functioning adrenal incidentaloma and evaluated the changes of the parameters such as glucose tolerance, blood pressure and insulin sensitivity after adrenalectomy. PATIENTS AND METHODS: Among 15 patients with incidentally discovered adrenal tumours in our department from 1996 to 1999, 4 patients were diagnosed as having pre-clinical Cushing's syndrome and the other 11 as having non-functioning tumours based on detailed endocrinological examinations including dexamethasone suppression testing. Four tumours with pre-clinical Cushing's syndrome and 8 tumours out of 11 patients with non-functioning tumours were diagnosed histopathologically as adrenocortical adenomas and the other 3 as of non-adrenal origin including a myelolipoma, an adrenal vascular cyst and an endothelioma. The prevalence of disturbed glucose tolerance was determined with an oral glucose tolerance test, and insulin sensitivity was evaluated by the method of steady state of plasma glucose (SSPG). RESULTS: All 12 patients with adrenocortical adenoma exhibited insulin resistance based on the SSPG (6.9-13.2 mmol/l). Before surgical removal of the tumours, the SSPG titre was relatively higher in the patients with pre-clinical Cushing's syndrome than in those with non-functioning with adrenocortical adenoma (mean value 11.65 vs. 8.99 mmol/l), whereas 2 of the 3 patients with non-adrenocortical tumours did not have insulin resistance. Among the 12 patients with adrenocortical adenoma, 7 (58%) and 9 (75%) patients exhibited hypertension and disturbed glucose tolerance, respectively. After removal of the tumours, SSPG of the patients with adrenocortical adenoma, but not that of the other 3 patients with non-cortical tumours, was significantly decreased compared to pre-adrenalectomy values. There are no significant differences in the changes of SSPG titres between in pre-clinical Cushing's syndrome and in non-functioning adrenocortical adenoma. Systolic blood pressure, but not diastolic blood pressure, was also significantly decreased in the patients with adrenocortical adenoma. CONCLUSION: High prevalences of disturbed glucose tolerance, insulin resistance and hypertension were found among the patients with non-functioning adrenocortical tumours. Adrenocortical adenoma may be one of the risk factors for insulin resistance that is believed to induce disturbed glucose tolerance and/or hypertension. Therefore, it is useful to evaluate insulin resistance for the patients with adrenal incidentalomas since results are likely to be helpful in deciding whether to remove the tumour by surgery.

Adenoma↗
PubMed2001

Analysis of cortisol secretion in hormonally inactive adrenocortical incidentalomas: study of in vitro steroid secretion and immunohistochemical localization of steroidogenic enzymes.

Adrenal incidentalomas have recently increased in incidence, and thus it has become important to establish clinical management of these patients. It is also important to evaluate whether these tumors are different from preclinical or overt Cushing's syndrome in their steroidogenesis. In this study, we therefore examined steroidogenesis of hormonally inactive adrenal incidentalomas via short-term culture of tumor specimens, in addition to an immunohistochemical study of steroidogenic enzymes. Five patients (two men and three women) diagnosed with adrenocortical incidentaloma without any clinical signs of adrenocortical hormonal excess except for hypertension and disturbed glucose tolerance, were recruited for this study. Hormonal findings, including circadian rhythms for cortisol and ACTH secretion, the response of ACTH to CRH infusion and results of dexamethasone suppression test were all within normal limits in these patients. Immunoreactivity for all steroidogenic enzymes involved in cortisol production was detected in tumor cells in all cases examined. Results of in vitro steroidogenesis analysis using short-term culture revealed that levels of cortisol secretion varied among the cases. There were no differences in the immunolocalization of steroidogenic enzymes and/or the levels of cortisol secretion between these hormonally inactive tumors and preclinical and/or overt Cushing's syndrome. Dehydroepiandrosterone-sulfotransferase (DHEA-ST) immunoreactivity in nonneoplastic regions was suppressed in one case in which the tumor secreted cortisol similar to preclinical and/or overt Cushing's syndrome. These results demonstrate that the levels of in vitro steroid production and/or the immunolocalization of steroidogenic enzymes in hormonally inactive adrenocortical tumors vary markedly and are not overtly different from those of preclinical and/or overt Cushing's syndrome.

17-alpha-Hydroxyprogesterone↗
PubMed2000

Enhancement by homocysteine of plasminogen activator inhibitor-1 gene expression and secretion from vascular endothelial and smooth muscle cells.

In order to elucidate the relationship between homocysteine and the fibrinolytic system, we examined the effect of homocysteine on plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) gene expression and protein secretion in cultured human vascular endothelial and smooth muscle cells in vitro. PAI-1 mRNA and secreted protein levels were both enhanced by homocysteine in a dose dependent manner, with significant stimulation of PAI-1 secretion observed at concentrations greater than 0.5 mM homocysteine. In contrast, secretion and mRNA expression of tPA were not significantly altered by homocysteine stimulation. Secretion of TGFbeta (transforming growth factor beta) and TNFalpha (tumor necrosis factor alpha), possible regulators of PAI-1 expression and secretion, were not stimulated by treatment with 1.0 mM homocysteine. These results suggests that hyperhomocysteinemia-induced atherosclerosis and/or thrombosis may be caused by homocysteine-induced stimulation of PAI-1 gene expression and secretion in the vasculatures by a mechanism independent from paracrine-autocrine activity of TGFbeta and TNFalpha.

Arteriosclerosis↗
PubMed2000

SSPG titer is a diagnostic marker for adrenocortical adenoma in patients with non-functioning adrenal incidentaloma.

We analyzed insulin resistance-related clinical markers as well as imaging characteristics of adrenal masses in 11 patients with incidentally discovered adrenal tumors that were diagnosed as non-functioning according to the results of the 1 mg dexamethasone suppression test and then voluntarily resected. Histologic examination of the resected tumors revealed adrenocortical adenoma in eight patients, and non-cortical tumors: a myelolipoma. an endothelioma and an adrenal vascular cyst in three patients. All eight patients with adrenocortical adenoma exhibited insulin resistance as estimated by the steady-state plasma glucose (SSPG). The mean systolic blood pressure of the patients with adrenocortical adenoma was higher than that of the patients with non-cortical tumors, even though three of eight patients were normotensive. HOMA-R, EIRI on 75 g oGTT. diastolic blood pressure and serum triglyceride were not significantly different between the patients with adrenocortical adenomas and those with non-cortical tumors. Imaging characteristic such as tumor size, shape and heterogeneity in the mass did not distinguish these two groups either. These results suggest that the presence of insulin resistance estimated by SSPG may be a diagnostic marker for adrenocortical adenoma in patients with a non-functioning incidentaloma.

Adenoma↗
PubMed2000

The effect of docarpamine, a dopamine pro-drug, on blood pressure and catecholamine levels in spontaneously hypertensive rats.

We studied the effects of bolus intravenous injection of the dopamine prodrug, docarpamine (200 microg/kg), on mean arterial pressure (MAP) and heart rate (HR) in Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHRs). In WKY rats (n=18), MAP and HR increased 5 min after docarpamine and then returned to baseline levels within 15 min. In contrast, in SHRs (n=15), MAP and HR gradually decreased, reaching a nadir 20 min after injection. Five min after docarpamine, plasma dopamine and 3,4-dihydroxy phenyl acetic (DOPAC) levels increased in both WKY rats (n=5) and SHRs (n=5). The docarpamine-induced changes in MAP and HR in both rat strains (n=5/strain) were blocked by the D1-like antagonist, SCH23390. alpha-Adrenergic (n=4) and vasopressin V1 (n=3) receptor blockade also abrogated the effects of docarpamine in WKY rats. We conclude that docarpamine differentially affects MAP and HR in WKY and SHRs. In SHRs, the depressor and bradycardiac effects of docarpamine are mediated by D1-like receptors. In WKY rats, the pressor and tachycardiac responses are caused by an interaction among D1-like, alpha-adrenergic, and V1 receptors.

Adrenergic alpha-Antagonists↗
PubMed2000

Urinary excretion of type IV collagen as a specific indicator of the progression of diabetic nephropathy.

AIMS AND METHODS: This study was carried out to clarify whether the urinary excretion of type IV collagen (u-IV collagen) detected by specific radioimmunoassay, can be used as an indicator for the progression of diabetic nephropathy. RESULTS: u-IV collagen was higher in diabetic subjects with microalbuminuria and overt proteinuria than those with normoalbuminuria, IgA nephropathy, membranoproliferative glomerulonephritis, membranous nephropathy, or control normal subjects. u-IV collagen was positively correlated with serum and urinary beta(2)-microglobulin and negatively with creatinine clearance only in diabetic patients, but not in patients with other glomerular diseases. The serum type IV collagen was not different between all the groups, and not correlated with its urinary excretion. In the advanced diabetic nephropathy, immunoreactive type IV collagen was detected in glomerular basement membrane (GBM), tubular basement membrane and Bowman's capsule much more than that in the normal kidney. CONCLUSION: These findings indicated increased production and degeneration of type IV collagen in diabetic nephropathy. It is suggested that augmented turnover of type IV collagen in GBM and tubular basement membrane results in increased concentrations of free u-IV collagen. Therefore, measurement of u-IV collagen may be a useful, specific indicator of the progression of diabetic nephropathy.

Adult↗
PubMed2000

[Loop diuretics].

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Diuretics↗
PubMed1999

Dopamine-1 receptor coupling defect in renal proximal tubule cells in hypertension.

The ability of the dopamine-1 (D1)-like receptor to stimulate adenylyl cyclase (AC) and phospholipase C (PLC), inhibit sodium transport in the renal proximal tubule (RPT), and produce natriuresis is attenuated in several rat models of hypertension. Since the inhibitory effect of D1-like receptors on RPT sodium transport is also reduced in some patients with essential hypertension, we measured D1-like receptor coupling to AC and PLC in cultures of human RPT cells from normotensive (NT) and hypertensive (HT) subjects. Basal cAMP concentrations were the same in NT (n=6) and HT (n=4). However, the D1-like receptor agonist fenoldopam increased cAMP production to a greater extent in NT (maximum response=67+/-1%) than in HT (maximum response=17+/-5%), with a potency ratio of 105. Dopamine also increased cAMP production to a greater extent in NT (32+/-3%) than in HT (14+/-3%). The fenoldopam-mediated increase in cAMP production was blocked by SCH23390 (a D1-like receptor antagonist) and by antisense D1 oligonucleotides in both HT and NT, indicating action at the D1 receptor. The stimulatory effects of forskolin and parathyroid hormone-related protein of cAMP accumulation were not statistically different in NT and HT, indicating receptor specificity and an intact G-protein/AC pathway. The fenoldopam-stimulated PLC activity was not impaired in HT, and the primary sequence and expression of the D1 receptor were the same in NT and HT. However, D1 receptor serine phosphorylation in the basal state was greater in HT than in NT and was not responsive to fenoldopam stimulation in HT. These studies demonstrate the expression of D1 receptors in human RPT cells in culture. The uncoupling of the D1 receptor in both rats (previously described) and humans (described here) suggests that this mechanism may be involved in the pathogenesis of hypertension; the uncoupling may be due to ligand-independent phosphorylation of the D1 receptor in hypertension.

Aged↗
PubMed1999

Effects of various kinds of dietary amino acids on the hepatotoxic action of D-galactosamine in rats.

The protective effects of various kinds of dietary amino acids against the hepatotoxic action of D-galactosamine (GalN) were examined. Male Wistar rats fed with 20% casein diets containing 10% or 5% amino acid for one week were injected with GalN (800 mg/kg body weight), and the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) activities, the hepatic glycogen concentration, and the serum glucose-level were examined 20 hours after the injection. In the groups with the 10% amino acid diets, activities of AST, ALT, and LDH in serum of 10% L-glutamine (Gln), 10% L-asparagine (Asn), and 10% L-serine (Ser) groups were significantly lower than those of the control group, and in the groups with the 5% amino acid diets, those activities of 5% L-histidine (His), 5% L-tyrosine (Tyr), 5% L-lysine (Lys), and 5% L-glycine (Gly) groups were also lower than those of the control group. The concentration of liver glycogen of 10% Gln-, 10% Asn-, and 10% Ser- groups and those levels of 5% His-, 5% Tyr-, 5% Lys-, and 5% Gly-groups were also significantly higher than that of the control group. As a result, it was found that some kinds of dietary amino acid such as L-Ser, L-Asn, L-His, L-Lys, L-Tyr, and L-Gly, in addition to L-Gln were effective to protect the rats from GalN-induced injury.

Alanine Transaminase↗
PubMed1999

Tryptophan-niacin metabolism in liver cirrhosis rat caused by carbon tetrachloride.

We investigated the change of tryptophan-niacin metabolism induced by carbon tetrachloride (CCl4) in rats with liver cirrhosis. The rats were injected with CCl4 (0.5 or 1 mL of 50% olive oil solution/kg body weight) twice a week for 1 or 2 mo and given phenobarbital water simultaneously. The urinary excretions of nicotinamide (Nam) and its metabolites were assayed. As the result, the urinary excretion of Nam, N1-methyl-4-pyridone-3-carboxamide (4-Py), Nam + N1-methylnicotinamide (MNA) + N1-methyl-2-pyridone-5-carboxamide (2-Py) + 4-Py was lower in the CCl4-treated groups than in the non-treated group (control) regardless of the experimental period (1 mo and 2 mo) or dosing amount of CCl4 (0.5 and 1 mL). Moreover, we investigated which pathway of tryptophan-niacin metabolism was affected in CCl4-treated rat. As the result, the possibility that the MNA-->4-Py reaction is inhibited by CCl4 treatment was suggested in this experiment.

Alanine Transaminase↗
PubMed1999

Modified cervical cerclage in pregnant women with advanced bulging membranes: knee-chest positioning.

BACKGROUND: Emergent cervical cerclage is often unsuccessful in patients with severely protruding fetal membranes for the following reasons: (1) difficulty in pushing the bulging membranes into the cervix; (2) risk of premature rupture of membranes during the operative procedures; and (3) displacement of the cerclage tape by the shortened cervix. METHODS: We performed Shirodkar's cervical cerclage with a slight modification. Using a metreurynter, a primary suture was made with the patient placed in the knee-chest position; a Shirodkar's cerclage was then performed in the dorsal lithotomy position. RESULTS: Since 1992, we have performed this procedure on five patients whose fetal membranes bulged into the vagina, at a gestational period of 20-24 weeks. When a patient was placed in the knee-chest position, the bulging membranes intruded spontaneously into the uterine cavity, but the procedure did not cause the membranes to rupture in any patient. The procedure prolonged the pregnancy to longer than 36 gestational weeks in two of the five patients. Three infants survived intact. CONCLUSIONS: Our promising experience warrants further studies on the advantages of the knee-chest position during the application of cervical cerclage in pregnant women who present with fetal membranes that bulge through a widely dilated cervix.

Adult↗
PubMed1998

Myelodysplastic syndrome resembling chronic myeloproliferative disorders in clinicopathological aspects.

We report on a patient with myelodysplastic syndrome (MDS) which resembled chronic myeloproliferative disorder (CMPD). A 67-year-old male was admitted to our hospital in June 1990. A diagnosis of refractory anemia with excess of blasts in transformation (RAEB-T) was based on the peripheral blood and bone marrow findings on admission. However, since thrombocytosis and bone marrow fibrosis was noted, the patient was diagnosed as MDS with myelofibrosis. Low-dose cytosine arabinoside therapy was performed. Although complete remission could not be achieved, a high quality of life could be maintained by appropriate transfusion. In January 1993, the patient was readmitted because of a marked increase in mature neutrophils, showing a moderate increase of blasts, chromosomal aberration (46,XY,12p-) and hepatosplenomegaly; but no fibrosis of bone marrow was observed. These findings suggested that neoplastic proliferation at the level more differentiated to granulocytic lineage occurred at the terminal stage and that his clinical feature was located between MDS and CMPD. This case may be important in considering various aspects of MDS.

Aged↗
PubMed1998

Effect of indigestible oligosaccharides on the hepatotoxic action of D-galactosamine in rats.

The effects of dietary oligosaccharides on the hepatotoxic action of D-galactosamine (GalN) were investigated in this study. Male Wistar rats fed with 20% casein diets containing 10% oligosaccharide or D-galactose (Gal) for 2 weeks were injected with GalN (1,900 mg/kg of body weight), and the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and the hepatic glycogen concentration were examined 20 hours after the injection. The plasma AST and ALT activities in experiment 1 for the Gal + neomycin (NEO) group were significantly lower than those for the control (C), NEO, raffinose (RAF) + NEO and galacto-oligosaccharide (GA-LO) + NEO groups. In experiment 2, these activities were significantly lower in the Gal, Gal + NEO and RAF groups than in the RAF + NEO group when the groups were treated with GalN. On the other hand, in respect of the hepatic glycogen concentration in experiment 1, that of the Gal + NEO group was higher than that of the C, NEO, RAF + NEO or GALO + NEO groups. In experiment 2, this parameter was significantly higher in the Gal, Gal + NEO and RAF groups than in the RAF + NEO group after the GalN treatment. As a result, it is suggested that the GalN-hepatitis-suppressive effects of indigestible oligosaccharides such as RAF or GALO is mediated by the action of intestinal bacteria.

Alanine Transaminase↗
PubMed1998

Dietary linoleic acid alters alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD), a key enzyme of niacin synthesis from tryptophan, in the process of protein expression in rat liver.

alpha-Amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) [EC 4.1.1.45] is a key enzyme of niacin synthesis from tryptophan. In this study, we examined whether dietary linoleic acid alters the protein expression of ACMSD in rat liver. Antibody against rat liver ACMSD was prepared by injecting mice with the purified enzyme. With the use of this polyclonal antibody and analysis by two-dimensional electrophoresis, we studied the mechanism by which the level of liver ACMSD activity was varied in rats fed a linoleic acid diet. In the rats fed a dietary linoleic acid (L), ACMSD protein levels in the liver were strongly suppressed as compared with the rats fed a fat-free diet (FF). These results suggest that the expression level of ACMSD might be modulated by linoleic acid or their metabolites.

Animals↗