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Biomedical subjects

H Sumino

Publications and source records attributed to H Sumino.

49 records · Page 3Linked to original sources
PubMed1996

Rate of nitric oxide release in the lung and factors influencing the concentration of exhaled nitric oxide.

The level of nitric oxide (NO) in exhaled air fluctuates in normal individuals depending on the physiological conditions. We evaluated the effects of duration of exhalation and breath-holding on the exhaled concentrations of NO in 16 normal human volunteers. Exhaled gas corresponding to vital capacity was collected in 6-liter Tedlar bags and analyzed by chemiluminescence. The NO concentration in exhaled gas increased significantly in proportion to the duration of exhalation [P = 0.009 +/- 0.011 (SD)] and was increased after breath-holding. There was no significant difference in the exhaled NO concentration among 10-s phases of a 30-s exhalation, as determined from multiple breath collections. The NO released from the airways is presumably unaffected by fluctuation of exhalation speed. The NO release rate, calculated from a single regression analysis between the NO concentration and the duration of exhalation, was 39 +/- 29 pmol/s, a value which was about fourfold greater in nine patients with bronchial asthma.

Adult↗
PubMed1996

Lack of inhibitory effect of dexamethasone on exhalation of nitric oxide by healthy humans.

Nitric oxide (NO) is present in the breath exhaled from healthy humans. The location and subtype of the NO synthase responsible for the expired NO are unknown. As dexamethasone inhibits the induction of NO synthase, we evaluated the effect of administering dexamethasone (4 mg/day for 2 days) on the amount of NO exhaled by eight healthy men. The amount of NO showed a significant linear correlation with the duration of exhalation, allowing the rate of NO release to be calculated. The rate of NO release was 0.047 +/- 0.023 nmol/s before drug administration. There was no significant change in the release rate at the end of the 2-day administration of drug or at 5 days after cessation. Serum concentrations of interferon-gamma and interleukin-1 beta were unaffected by the administration of dexamethasone. These results suggest that the NO released from the human airway under normal conditions is not generated by the action of inducible NO synthase.

Adult↗
PubMed1995

Myocardial infarction secondary to coronary aneurysm in systemic lupus erythematosus. An autopsy case.

The authors report a thirty-seven-year-old woman with systemic lupus erythematosus (SLE), a coronary aneurysm, and myocardial infarction. SLE was diagnosed at twenty-three years of age and treated with prednisolone. Seven years later, she developed inferior myocardial infarction, and coronary angiography showed an aneurysm in the proximal right coronary artery without associated stenosis. At the age of thirty-seven years, she died from cerebral infarction and sepsis. Autopsy revealed an aneurysm (6 mm in diameter) in the proximal right coronary artery and an old inferior myocardial infarction. Histologic examination showed recanalization and fibrosis in the media of the aneurysm wall. This case suggests that coronary aneurysm may cause myocardial infarction in SLE and that aneurysm formation may be a sequela of arteritis.

Adult↗
PubMedDate not supplied

Effect of long-term hormone replacement therapy on angiotensin-converting enzyme activity and bradykinin in postmenopausal women with essential hypertension and normotensive postmenopausal women.

OBJECTIVE: Hormone replacement therapy (HRT) reduces the incidence of cardiovascular disease in postmenopausal women. Three-month short-term HRT in postmenopausal women with essential hypertension increased the plasma concentrations ofbradykinin with decreased serum angiotensin-converting enzyme (ACE) activity, which may be partially responsible for the cardioprotective effects of HRT. The objective was to determine whether 12-month long-term HRT in postmenopausal women with essential hypertension would maintain the decreased ACE activity and increased bradykinin levels and whether long-term HRT would increase the plasma bradykinin concentrations of normotensive postmenopausal women who had shown no significant changes in the 3-month HRT study, despite their decreased serum ACE activity. DESIGN: Twenty hypertensive and 15 normotensive postmenopausal women were treated with conjugated estrogens (0.625 mg/day) and medroxyprogesterone (2.5 mg/day) for 12 months. Twenty hypertensive and 15 normotensive postmenopausal women were used as controls. The controls were not treated with HRT. Serum ACE activity and plasma bradykinin concentrations were measured at baseline and at 12 months. RESULTS: Long-term HRT in both hypertensive and normotensive postmenopausal women significantly decreased serum ACE activity from 15.5+/-0.7 IU/L and 16.0+/-0.9 IU/L, respectively, at baseline to 13.3+/-0.5 IU/L and 14.2+/-0.9 IU/L, respectively, 12 months after the start of HRT (p < 0.05 and p < 0.05, respectively). Long-term HRT in both hypertensive and normotensive postmenopausal women also significantly increased plasma bradykinin concentrations from 22.1+/-4.4 pg/mL and 19.2+/-3.0 pg/mL, respectively, at baseline to 86.7+/-21.2 pg/mL and 73.5+/-23.0 pg/mL, respectively, 12 months after the start of HRT (p < 0.01 and p < 0.05, respectively). No significant changes in serum ACE activity or plasma bradykinin concentrations were observed in the control groups. CONCLUSIONS: Long-term HRT in hypertensive and normotensive postmenopausal women decreases their serum ACE activity and increases their plasma bradykinin concentrations. Thus, maintenance of elevated bradykinin with decreased serum ACE activity by HRT may be useful in reducing the risk of cardiovascular disease in both hypertensive and normotensive postmenopausal women.

Administration, Oral↗
PubMedDate not supplied

Plasma adiponectin levels in post-menopausal women receiving hormone replacement therapy.

This study aimed to evaluate the correlation between plasma adiponectin levels and plasma lipid and lipoprotein levels in post-menopausal women (PMW) receiving hormone replacement therapy (HRT). Various clinical and biochemical parameters, including plasma lipid and lipoprotein concentrations and adiponectin levels, were measured in 54 healthy PMW before and after 3 and 6 months of HRT. Control groups consisted of women aged < 40 years (n = 20) or > 60 years (n = 17). PMW had significantly lower baseline adiponectin levels compared with the younger or older control groups, but adiponectin concentrations were not significantly altered after 3 or 6 months of HRT. Adiponectin levels in PMW were positively correlated with plasma high-density lipoprotein-cholesterol levels and were negatively correlated with body mass index and triglyceride levels. Our data suggest that circulating adiponectin may contribute to lipid homeostasis in PMW. Further studies are needed to elucidate the effects of HRT and oestrogen on adiponectin levels.

Adiponectin↗
PubMedDate not supplied

Clinical features associated with circulating concentration of soluble leptin receptor in patients with diabetes.

We aimed to determine if there were any clinical features that were significantly associated with the circulating concentration of soluble leptin receptor (OB-Re) in 67 Japanese subjects with diabetes mellitus. The characteristics evaluated included age, height, body weight, body mass index (BMI), systolic and diastolic blood pressure, duration of diabetes, haemoglobin A1C and blood lipid concentrations, urinary albumin excretion rate, circulating concentrations of leptin, tumour necrosis factor-alpha (TNF-alpha), TNF-alpha receptor 1 and genotypes of the angiotensin-converting enzyme (ACE) gene. We found statistically significant negative correlations between circulating OB-Re concentration and body weight, BMI, diastolic blood pressure, concentrations of leptin and TNF-alpha receptor 1. Serum OB-Re concentration was not associated with any of the other clinical characteristics that were measured, or with the different ACE genotypes. Our results suggest that OB-Re might have an important influence on the biological activity of leptin in diabetic subjects.

Diabetes Mellitus↗
PubMedDate not supplied

Effect of antihypertensive therapy on blood rheology in patients with essential hypertension.

Hypertension is an important risk factor for cardiovascular disease, and antihypertensive drugs can decrease the occurrence of such events in hypertensive patients. This study compared the rheological properties of blood in 22 untreated hypertensive patients, 42 patients taking antihypertensive drugs and 74 normotensive subjects. Using a microchannel method, the whole blood passage time was measured and blood movement was observed with a microscope connected to an image display unit. The blood passage time in untreated hypertensive patients was significantly higher than in treated hypertensive patients or normotensive subjects, but was similar in the latter two groups. Microscopic observations showed that platelet aggregation and leucocyte adhesion were increased in untreated hypertensive patients, resulting in poor flow, while blood samples from treated hypertensive patients and normotensive subjects passed smoothly through the microchannels. These rheological differences could contribute to the decrease in cardiovascular disease seen when hypertensive patients are treated effectively.

Adult↗
PubMedDate not supplied

Adiponectin replacement therapy attenuates myocardial damage in leptin-deficient mice with viral myocarditis.

The effects of adiponectin replacement therapy on myocardial damage were studied in leptin-deficient (OB) mice with acute viral myocarditis. Encephalomyocarditis virus was injected intraperitoneally into OB and wild-type (WT) mice. One subgroup of OB mice received no intervention and another subgroup received daily adiponectin replacement, simultaneously with viral inoculation. Differences in heart weight, cardiac histological score, numbers of infiltrating or apoptotic cells in the myocardium and the immunoreactivity of adiponectin receptors in myocytes were determined. The reactivity of adiponectin receptor 1 in myocytes from OB mice on day 4 and day 8 after viral inoculation was significantly decreased compared with that in myocytes from WT mice; the OB mice also had elevated cardiac weights and severe inflammatory myocardial damage. Adiponectin replacement in OB mice inhibited the development of severe myocarditis by augmenting myocyte adiponectin receptor 1 reactivity. Exogenously administered adiponectin may inhibit the progression of viral myocarditis through binding to the adiponectin receptor 1 in leptin-deficient conditions.

Adiponectin↗
PubMedDate not supplied

Adiponectin, T-cadherin and tumour necrosis factor-alpha in damaged cardiomyocytes from autopsy specimens.

This study determined the presence of adiponectin, T-cadherin (an adiponectin receptor) and tumour necrosis factor-alpha (TNF-alpha) in damaged myocytes from autopsied patients with acute or old myocardial infarction (MI) or dilated cardiomyopathy (DCM), using immunohistochemical staining. The enrolled patients included eight with acute MI, six with old MI and seven with DCM. Four autopsied individuals with no cardiac lesions were also enrolled as controls. Adiponectin and TNF-alpha were not observed in normal myocytes from control subjects, but T-cadherin was weakly detected. Immunoreactivity for adiponectin and T-cadherin was observed at the periphery of damaged myocytes from MI and DCM patients; intracellular reactivity for TNF-alpha was also seen. There were no statistically significant differences in the degree of reactivity for each molecule in the myocytes between the MI and DCM patients. These results suggest that the presence of adiponectin and TNF-alpha in damaged myocytes may contribute to the processes of myocardial injury occurring in MI and DCM.

Adiponectin↗
PubMedDate not supplied

Angiotensin-II receptor antagonist alleviates non-alcoholic fatty liver in KKAy obese mice with type 2 diabetes.

We examined the effects of the angiotensin-II receptor antagonist candesartan on non-alcoholic fatty liver (NAFL) and circulating adiponectin concentrations in KKAy obese mice with type 2 diabetes mellitus. The KKAy mice were randomly assigned to receive either candesartan at a once-daily dose of 10 mg/kg (n = 5) or placebo (n = 5). The differences in liver weight, histological evaluation of hepatic lipid infiltration, serum adiponectin concentration and hepatic adiponectin mRNA levels between the two groups were determined on day 7 after treatment was initiated. Candesartan-treated mice demonstrated significantly lower liver weights and reduced lipid droplets in hepatic cells compared with control mice. The circulating adiponectin levels and hepatic expression of adiponectin mRNA were significantly higher in candesartan-treated mice than control mice. These results suggest that candesartan might alleviate NAFL through elevation of circulating adiponectin levels in KKAy obese mice with type 2 diabetes mellitus.

Adiponectin↗
PubMedDate not supplied

Impaired blood rheology in critically ill patients in an intensive care unit.

Critically ill patients are at increased risk of thromboembolic complications. Japanese patients admitted to the intensive care unit of Gunma University Hospital were divided into critically ill (high score) and moderately ill (low score) groups according to mean Acute Physiology and Chronic Health Evaluation (APACHE) II score. White blood cell count, potassium, creatinine, immunoglobulin G and blood passage time, measured using the microchannel method, were significantly higher and the platelet aggregation score and platelet count were significantly lower in the high-score group than in the low-score group, but other haemorheological parameters did not differ significantly between the two groups. White blood cell count, potassium, creatinine, APACHE II score and levels of immunoglobulins G, A and M were positively correlated with blood passage time in all patients. Critically ill patients had impaired blood rheology, which could result from increased white blood cell count, potassium, creatinine and immunoglobulins and may be associated with the pathophysiology of the thromboembolic process.

Adolescent↗
PubMedDate not supplied

A new murine model of coronary artery thrombosis and role of interleukin-8 in the development of coronary thrombosis.

Occlusive vascular disease most often results from thrombosis superimposed on atherosclerotic plaque. In the case of an acute coronary syndrome including an acute myocardium infarction or an unstable angina pectoris thrombus in coronary artery takes significant part as known. There are few reports about animal models of acute coronary artery thrombi, because of the difficulties of operative significance. We have succeeded in making thrombus at murine coronary arteries with ferric chloride. Slight or moderate IL-8 expressions were found in the endothelial cells in the thrombus formed vessel analyzed by immunohistochemistry. The interleukin-8 (IL-8) receptor knockout mice formed the slight thrombus in coronary arteries treated with ferric chloride. We propose a role for IL-8 in the pathogenesis of acute coronary artery thrombi. This hypothesis lends itself to testing using interventions to influence IL-8 secretion and actions in the early phase of coronary thrombotic formation.

Animals↗