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Biomedical subjects

Y Sumida

Publications and source records attributed to Y Sumida.

At least 37 records · Page 2Linked to original sources
PubMed2000

Elevated plasma levels of alpha-melanocyte stimulating hormone (alpha-MSH) are correlated with insulin resistance in obese men.

OBJECTIVE: The role of alpha-melanocyte stimulating hormone (MSH) in obesity has been well-documented. However, circulating alpha-MSH concentrations in obese men and their relationship with clinical indicators of obesity and glucose metabolism have not as yet been evaluated. METHODS: We measured the plasma concentrations of alpha-MSH in 15 obese and 15 non-obese male subjects. The relationship of the plasma concentrations of alpha-MSH with body mass index (BMI), body fat mass (measured by bioelectric impedance), body fat distribution (measured by computed tomography), insulin levels, insulin resistance (assessed by the glucose infusion rate (GIR) during an euglycemic hyperinsulinemic clamp study) and with the serum concentrations of leptin and TNF-alpha were also evaluated. RESULTS: In obese men, the plasma alpha-MSH concentrations were significantly increased compared with those in non-obese men (P< 0.02). The plasma levels of alpha-MSH were positively correlated with BMI (r= 0.560, P< 0.05), fasting insulin levels (r=0.528, P< 0.05) and with visceral fat area (r=0.716, P<0.01), but negatively correlated with GIR (r= -0.625, P< 0.02) in obese male subjects. There were significant correlations between plasma concentrations of alpha-MSH and visceral fat area (r=0.631, P< 0.02), and GIR (r = -0.549, P< 0.05) in non-obese male subjects. Circulating concentrations of alpha-MSH were not significantly correlated with the serum concentrations of leptin and TNF-alpha in both obese and non-obese men. CONCLUSION: Circulating concentrations of alpha-MSH are significantly increased and correlated with insulin resistance in obese men.

Adult↗
PubMed2000

Troglitazone reduces plasma levels of tumour necrosis factor-alpha in obese patients with type 2 diabetes.

We evaluated the effect of troglitazone (given orally 400 mg/day) on glucose intolerance and on the plasma levels of tumour necrosis factor-alpha (TNF-alpha) in 12 obese patients with type 2 diabetes for 12 weeks. Troglitazone significantly decreased fasting plasma glucose, serum C-peptide, serum insulin and HbA1c levels. Plasma levels of TNF-alpha were significantly reduced by troglitazone administered for 8 and 12 weeks. Troglitazone administration significantly improved insulin resistance, but did not affect pancreatic beta-cell function as evaluated by the homeostasis model assessment (HOMA). In the present study, we reported for the first time that troglitazone administration significantly reduces plasma levels of TNF-alpha in obese patients with type 2 diabetes.

Blood Glucose↗
PubMed2000

Thioredoxin levels in the sera of untreated viral hepatitis patients and those treated with glycyrrhizin or ursodeoxycholic acid.

Thioredoxin (TRX), a thiol-containing protein, is induced by various oxidative stresses. Serum TRX levels were measured with a sandwich enzyme-linked immunosorbent assay kit in 210 hepatitis C virus (HCV)-infected patients, 39 hepatitis B virus (HBV)-infected patients, and 17 healthy volunteers. The effects of hepatoprotective drugs on TRX levels were also examined. The median TRX levels were significantly higher in HCV-infected patients than in controls (34.2 vs. 23.5 ng/ml, respectively; p < 0.005), but were not elevated in HBV-infected patients (26.7 ng/ml). The TRX levels were significantly correlated with serum lipid peroxide levels and indocyanine green exclusion test values, and were markedly decreased following treatment with Stronger Neo-Minophagen C or ursodeoxycholic acid. In conclusion serum TRX levels, a marker of oxidative stress, were higher in patients with HCV infection than those with HBV infection and healthy controls. The therapeutic efficacy of hepatoprotective drugs may be connected with the decrease in oxidative stress in hepatitis patients.

Adult↗
PubMed2000

Changes in the leukocyte distribution and surface expression of adhesion molecules accompanied with hypothalamically induced restlessness in the cat.

One type of emotional behavior called restlessness occurs when the anteromedial hypothalamus is stimulated in cats. We examined the changes in the distribution and surface expression of adhesion molecules in leukocytes accompanied with restlessness. Mature female cats were used for this study. The cats were stimulated with 60 Hz sine wave train pulses (20-90 microA, 10 s in duration, at 5-min intervals) for 60 min. Samples of blood were collected from 30 min before stimulation up to several hours after the final stimulation. The number of granulocytes increased just after stimulation, while at the same time the expression of L-selectin decreased. On the other hand, the number of CD4+ and CD8+ T lymphocytes decreased at 1-2 h after the end of the stimulation, while the expression of L-selectin increased. In addition, the expression of LFA-1 and VLA-4 did not change. These data suggest that hypothalamically elicited restlessness is thus accompanied by a leukocyte distribution change, which might be mediated by changes in the expression of L-selectin on leukocytes. Plasma cortisol increased during stimulation in restlessness. However, during in vitro culture experiments, cortisol did not alter the expression of leukocyte L-selectin which thus indicated that cortisol does not directly affect the surface expression of L-selectin. These results thus suggest that hypothalamically induced restlessness is a useful stress model for psychoneuroimmunological studies.

Animals↗
PubMed2000

A case of obesity, diabetes and hypertension treated with very low calorie diet (VLCD) followed by successful pregnancy with intrauterine insemination (IUI).

The patient was a 32-year-old obese woman with a history of type 2 diabetes and hypertension for 6 years. Although she was treated with antihypertensive agents and intensive insulin therapy, her hyperglycemia was difficult to control. She wanted to have a baby but pregnancy was not recommended because her diabetes was under poor control and the use of antihypertensive medication. To achieve good control of obesity, diabetes and hypertension, she was admitted to our clinical department for weight reduction using very low calorie diet (VLCD). During VLCD she had a 19.8 kg reduction in body weight and her blood glucose and blood pressure were in good control without the use of drugs. Five months later, she became pregnant after the fourth trial of intrauterine insemination (IUI) and gave birth to a female baby under insulin therapy. This is the first report that showed the usefulness of VLCD for prepregnant control of glucose metabolism and blood pressure in an obese hypertensive patient with type 2 diabetes mellitus.

Adult↗
PubMed2000

[Colpocephaly].

Explore the source record for details and available documents.

Cerebral Ventricles↗
PubMed1999

Ursodeoxycholic acid protects hepatocytes against oxidative injury via induction of antioxidants.

The therapeutic efficacy of ursodeoxycholic acid (UDCA) has been widely demonstrated in various liver diseases, suggesting that UDCA might protect hepatocytes against common mechanisms of liver damage. A candidate for such protection is oxidative injury induced by reactive oxygen species. This study was designed to assess the effects of UDCA on oxidative injury and antioxidative systems in cultured rat hepatocytes. The viability of the hepatocytes dose-dependently decreased after hydrogen peroxide or cadmium administration. Pretreatment with UDCA significantly prevented this decrease in viability. The amounts of glutathione (GSH) and protein thiol increased significantly, but the activities of antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and catalase were unchanged in UDCA-treated hepatocytes. The mRNA levels of gamma-glutamylcysteine synthetase and metallothionein (MT) were significantly higher in UDCA-treated hepatocytes than in controls. In conclusion, UDCA increased hepatocyte levels of GSH and thiol-containing proteins such as MT, thereby protecting hepatocytes against oxidative injury. Our results provide a new perspective on the hepatoprotective effect of UDCA.

Animals↗
PubMed1999

High serum concentrations of sialyl Tn antigen in carcinomas of the biliary tract and pancreas.

Sialyl-Tn (STn) antigen is a cancer-associated carbohydrate antigen expressed in cancers of the digestive tract. In the present study, we compared the serum level of STn antigen in 14 patients with benign diseases of the biliary tract and pancreas, 15 patients with bile duct cancers, and 9 patients with cancer of the pancreas. High levels of serum STn (>45 U/ml) were frequently detected in patients with carcinoma of the biliary tract (53.3%) or pancreas (55.6%), compared with the detection of high levels in those with benign diseases (14.3%; P < 0.05). Serum levels of STn did not correlate with the presence of jaundice, cholangitis, or pancreatitis, or with the level of carcinoembryonic antigen (CEA) or carbohydrate antigen (CA) 19-9. In cancer tissues, the expression of STn antigen detected by immunostaining correlated significantly with serum STn (P < 0.05). Our results indicate that measurement of serum STn level may be potentially useful for the diagnosis of carcinomas of the biliary tract and pancreas, particularly when combined with other tumor markers such as CEA or CA19-9.

Adult↗
PubMed1999

Expression of multidrug resistance protein in metastatic colorectal carcinomas.

To clarify the relationship between multidrug resistance protein (MRP) and clinicopathologic features, the influence of adjuvant chemotherapy, and prognosis of patients who underwent resection of metastatic liver carcinomas originating from colorectal carcinomas, we examined the expression of MRP in tumor tissues by immunostaining. Specimens of 38 primary colorectal tumors and 44 metastatic liver tumors of colorectal origin were examined (metastatic group). We also examined 28 nonmetastatic colorectal carcinomas. The percentages of nonmetastatic tumors and of primary and metastatic tumors of the metastasis group that expressed MRP were similar. MRP expression in primary and metastatic tumors did not correlate with any clinicopathologic features. The use of adjuvant chemotherapy after operation for primary colorectal carcinomas was associated with increased MRP expression among metastatic liver tumors. Expression of MRP in the tumor did not influence the prognosis or survival rate after resection of primary or metastatic tumors. Our data suggest that MRP expression in metachronous liver metastases from colorectal carcinomas may be induced by administration of anticancer drugs but is not associated with clinicopathologic features of the tumor, liver metastasis, or prognosis.

ATP-Binding Cassette Transporters↗
PubMed1999

Codon 54 polymorphism of the fatty acid binding protein gene and insulin resistance in the Japanese population.

AIM: To determine the relationship of the polymorphism at codon 54 of the intestinal fatty acid binding protein gene (FABP2) with insulin resistance and susceptibility to Type 2 diabetes mellitus (DM) in the Japanese population. METHODS: We evaluated the polymorphism by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 150 Type 2 DM patients and 147 healthy control subjects. The frequency of alleles encoding threonine (Thr54) and alanine (Ala54) at codon 54 of FABP2 in Type 2 DM patients was compared with that of healthy controls. Insulin sensitivity was assessed by the hyperinsulinaemic euglycaemic clamp in Type 2 DM patients with Ala54 homozygotes, Ala54/Thr54 heterozygotes and Thr54 homozygotes and by homeostasis model assessment (HOMA) in the nondiabetic group. RESULTS: The frequency of alleles encoding Ala54 and Thr54 was 0.59 and 0.41 in Type 2 DM patients, respectively, similar to that observed in nondiabetic controls (0.64 for Ala54 and 0.36 for Thr54). Insulin sensitivity was not significantly different between subjects with and without Thr54 allele either within the DM group or healthy controls. CONCLUSIONS: The allele encoding threonine in the FABP2 does not predispose to Type 2 DM or insulin resistance in the Japanese population.

Carrier Proteins↗
PubMed1999

Transfer of nitric oxide from the liver to erythrocytes--an ESR study using nitroglycerin-treated mice.

Nitric oxide (NO) formation in the liver and blood of the mouse following intraperitoneal treatment with nitroglycerin (glycerol trinitrate, GTN) was determined using electron spin resonance (ESR) spectroscopy. ESR signals of heme-NO complexes were detected at maximum levels within 5 min in the liver, but increased to a maximum level about 15-30 min later in the blood. GTN is not metabolized to release NO in vitro in the blood of the mouse. The hepatic microsomes which showed the heme-NO complexes ESR signals were incubated with mouse erythrocytes, with the result that a hemoglobin-NO signal was obtained from the erythrocytes. The activities of microsomal cytochrome P-450, the hepatic level of glutathione, and the reduction rate of nitroxide radicals in the in vivo liver, measured using L-band ESR spectroscopy, were temporarily decreased following GTN administration. In conclusion, NO in the liver could be scavenged by circulating erythrocytes, which might minimize NO-induced liver damage.

Animals↗
PubMed1999

Renin-angiotensin system and fibronectin gene expression in Dahl Iwai salt-sensitive and salt-resistant rats.

OBJECTIVE: The tissue renin-angiotensin system and extracellular matrix are involved in the cardiovascular hypertrophy and remodeling induced by hypertension. In this study, we examined the gene expression of the tissue renin-angiotensin system and fibronectin in inbred Dahl Iwai salt-sensitive and salt-resistant rats. MATERIALS AND METHODS: Eight pairs of 6-week-old male Dahl Iwai salt-sensitive and salt-resistant rats were fed either a low- or high-salt diet (0.3% or 8% NaCl, respectively) for 4 weeks. Activities of the circulating renin-angiotensin system were measured by radioimmunoassay and the gene expression of tissue angiotensinogen, the angiotensin II type 1 receptor (AT1) and fibronectin were analyzed by Northern blot analysis. RESULTS: Salt loading significantly increased blood pressure and produced cardiovascular hypertrophy and nephrosclerosis in the salt-sensitive rats. Activities of the circulating renin-angiotensin system were lower in salt-sensitive rats than in salt-resistant rats fed the low-salt diet, and salt loading lowered these activities in salt-resistant rats but not in salt-sensitive rats. In salt-resistant rats, salt loading increased renal, cardiac and aortic angiotensinogen, AT1 and fibronectin messenger (m)RNA expression except for aortic fibronectin mRNA expression. In contrast, in the salt-sensitive rats, salt loading stimulated the expression of cardiac fibronectin and aortic angiotensinogen, AT1 and fibronectin mRNAs. Furthermore, the cardiac and aortic fibronectin mRNA levels in salt-sensitive rats were higher than those in salt-resistant rats when both strains were fed the high-salt diet. CONCLUSIONS: These results demonstrate that the expression of tissue angiotensinogen, AT1 and fibronectin mRNAs is regulated differently in Dahl Iwai salt-sensitive and salt-resistant rats, and indicate that salt-mediated hypertension activates the cardiac fibronectin gene independently of the tissue renin-angiotensin system and stimulates the aortic fibronectin gene with activation of the tissue renin-angiotensin system.

Angiotensin I↗
PubMed1999

Insulin sensitivity is not affected by mutation of codon 972 of the human IRS-1 gene.

We investigated the relationship of codon 972 polymorphism of the insulin receptor substrate-1 (IRS-1) gene with insulin resistance in the Japanese population. Among 130 patients with type-2 diabetes mellitus (DM), we identified 6 who were heterozygous for the Gly972Arg mutation. Among 144 healthy subjects, 6 were heterozygous and 1 was homozygous for the mutation. A hyperinsulinemic euglycemic clamp study was performed in 3 of 6 diabetic patients with the heterozygous Gly972Arg mutation and in 60 without it. Both groups showed almost the same levels of insulin sensitivity (glucose infusion rate, GIR = 50.2 +/- 3.0 vs. 51.3 +/- 12.1 micromol/kg/min). Similarly, there was no difference in insulin sensitivity between healthy subjects with and without the mutation using the homeostasis model assessment (HOMA index = 1.14 +/- 0.50 vs. 1.02 +/- 0.63). The frequency of the Gly972Arg allele was not increased in diabetic patients compared with control subjects even in aged (>50 years old) or obese (BMI >/=25) subjects. Among healthy subjects, we identified a 25-year-old male with the homozygous Gly972Arg allele. He was slightly obese (BMI = 25.5) but showed relatively high insulin sensitivity, almost equal to that of healthy subjects without the mutation (GIR = 67.2 vs. 71.8 +/- 22.0 micromol/kg/min). Because the GIR in healthy subjects was significantly higher compared with that in type-2 DM patients, we speculate that another genetic or environmental factor producing a more deleterious effect on insulin sensitivity may exist in diabetic patients. We conclude that this gene abnormality does not play a role in the pathogenesis of insulin resistance and type-2 DM.

Adult↗
PubMed1999

Plasma brain natriuretic peptide levels in normotensive noninsulin-dependent diabetic patients with microalbuminuria.

Brain natriuretic peptide (BNP), a member of the natriuretic peptide family, is produced and released from cardiac ventricles. BNP regulates the body fluid volume, blood pressure, and vascular tones through the A-type guanylate cyclase-coupled receptor. The presence of renal dysfunction in patients with diabetes affects the plasma levels of atrial natriuretic peptide (ANP). In the present study, we investigated the plasma levels of BNP and ANP and their relationship in normotensive diabetic patients with normoalbuminuria and microalbuminuria. Forty-seven normotensive lean noninsulin-dependent diabetic patients (31 with normoalbuminuria, 16 with microalbuminuria), with normal cardiac function, and 30 age-matched control subjects were enrolled in this study. The plasma levels of BNP in diabetic patients with microalbuminuria were significantly higher than those in diabetic patients with normoalbuminuria (16.7+/-2.4 vs. 9.6+/-1.3 pg/mL, P<0.01) or normal subjects (16.7+/-2.4 vs. 7.0+/-0.6 pg/mL, P<0.01). There was a significant positive correlation between plasma BNP levels and urinary albumin excretion rate in all diabetic patients (r = 0.58, P<0.0001). There was also a significantly positive correlation between plasma BNP and ANP levels in diabetic patients (r = 0.62, P<0.0001). The increased plasma level of BNP in patients with microalbuminuria and its significant correlation with urinary albumin excretion rate suggest that the elevated circulating levels of BNP are caused by the presence of diabetic nephropathy. Down-regulation of A-type guanylate cyclase-coupled receptor of renal tubules may explain the increased plasma levels of both BNP and ANP in normotensive diabetic patients with microalbuminuria.

Albuminuria↗
PubMed1999

Significance of exercise QT dispersion in patients with coronary artery disease who do not have exercise-induced ischemic ST-segment changes.

The poor sensitivity and the poor predictive value of ST-segment depression have limited the usefulness of the exercise electrocardiogram (ECG) in the diagnosis and evaluation of coronary artery disease (CAD). The QT dispersion (QTD), recorded as the difference between maximal and minimal QT intervals on a 12-lead exercise ECG, is sensitive to myocardial ischemia and may improve the accuracy of exercise testing in patients with CAD who do not show an ST-segment depression. Exercise ECGs were analyzed in 50 subjects who had undergone coronary angiography for clinical indications. None of them showed an ST-segment depression during or after exercise: There were 25 patients with significant coronary artery stenosis and 25 without significant stenosis. The QTD measured before, immediately after, and 1 min after exercise was similar in the 2 groups. The QTD at 3 and 5 min after exercise was significantly greater in patients with CAD than in the controls, and the most marked difference in QTD was observed at 3 min after exercise. A QTD at 3 min after exercise of >60 ms had a sensitivity of 80% and specificity of 88% regarding the diagnosis of CAD. When a deltaQTD (post-exercise QTD minus QTD at rest) at 3 min after exercise of >0 ms was added to a QTD of >60 ms as a condition for positivity, the specificity increased to 96%. QTD measured at 3 min after exercise increases the accuracy of exercise testing in patients with CAD who do not show an ST-segment depression.

Adult↗
PubMed1999

Influence of exercise on QT dispersion in hypertensive patients with left ventricular hypertrophy without coronary artery disease.

In hypertensive patients with left ventricular hypertrophy (LVH), the influence of exercise on the regional variations in ventricular repolarization is not well understood. The present study compared dispersions of QT and QT apex (QTD and QTaD), which are indices of regional variations in ventricular repolarization, between hypertensive patients with echocardiographic evidence of LVH and those without LVH. Seventy essential hypertensive patients underwent a modified Bruce protocol exercise test, and QTD and QTaD were measured at rest and at peak exercise level. All subjects had undergone coronary angiography and did not have coronary artery disease. None of them showed ST-segment depression during or after exercise. There were 20 patients with LVH and 50 patients without LVH. The QTD and QTaD at rest were not different between the patients with LVH and those without LVH (56+/-32 vs 57+/-28 ms, 52+/-20 vs 49+/-23 ms). At peak exercise level, QTaD was significantly decreased compared with the baseline in hypertensive patients without LVH (49+/-23 to 42+/-16ms, p<0.05), whereas in patients with LVH QTaD increased (52+/-20 to 67+/-17ms, p<0.05). QTaD at peak exercise level was positively correlated with the left ventricular mass index (r=0.357, p=0.0024). These data were unchanged after correction for heart rate using Bazett's equation. In conclusion, QTaD increased after exercise in hypertensive patients with LVH. Inhomogeneity of repolarization is induced by exercise stress in hypertensives with LVH.

Adult↗
PubMed1999

Tissue-specific changes of type 1 angiotensin II receptor and angiotensin-converting enzyme mRNA in angiotensinogen gene-knockout mice.

This study examined whether type 1 angiotensin II receptor (AT1) and angiotensin-converting enzyme (ACE) mRNAs are regulated during dietary salt loading in angiotensinogen gene-knockout (Atg-/-) mice which are genetically deficient in endogenous production of angiotensin II. Wild-type (Atg+/+) and Atg-/- mice were fed a normal-salt (0.3% NaCl) or a high-salt (4% NaCl) diet for 2 weeks. The mRNA levels were measured by Northern blot analysis. In Atg+/+ mice, concentrations of plasma angiotensin peptides were decreased by salt loading, whereas the treatment increased the brainstem, cardiac, pulmonary, renal cortex, gastric and intestinal AT1 mRNA levels. Salt loading also enhanced renal cortex ACE mRNA levels in Atg+/+ mice. Although plasma angiotensin peptides and urinary aldosterone excretion were not detected in Atg-/- mice, salt loading increased blood pressure in Atg-/- mice. In Atg-/- mice, pulmonary, renal cortex, gastric and intestinal AT1, and renal cortex and intestinal ACE mRNA levels were higher than those in Atg+/+ mice. However, salt loading upregulated AT1 mRNA expression only in the liver of Atg-/- mice, and the treatment did not affect ACE mRNA levels in Atg-/- mice. Furthermore, although the levels of ACE enzymatic activity showed the same trend with the ACE mRNA levels in the lung, renal cortex and intestine of both Atg-/- and Atg+/+ mice, the results of radioligand binding assay showed that cardiac expression of AT1 protein was regulated differently from AT1 mRNA expression both in Atg-/- and Atg+/+ mice. Thus, expression of AT1 and ACE is regulated by salt loading in a tissue-specific manner that appears to be mediated, at least partly, by a mechanism other than changes in the circulating or tissue levels of angiotensin peptides.

Angiotensin II↗