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Biomedical subjects

H Kano

Publications and source records attributed to H Kano.

At least 91 records · Page 5Linked to original sources
PubMed1997

Vascular dopamine-I receptors and atherosclerosis.

Vascular smooth muscle cell (VSMC) migration and proliferation are believed to play key roles in atherosclerosis. To elucidate the role of vascular dopamine D1-like receptors in atherosclerosis, the effects of dopamine, specific D1-like agonists SKF 38,393, and YM 435 on platelet-derived growth factor (PDGF) BB-mediated VSMC migration, proliferation, and hypertrophy were studied. We observed that cells stimulated by 5 ng/ml PDGF BB showed increased migration, proliferation and hypertrophy. These effects were prevented by coincubation with dopamine, SKF 38,393, or YM 435 at 1-10 mumol/l, and this prevention was reversed by Sch 23,390 (1-10 mumol/l), a specific D1-like antagonist. These actions are mimicked by 1-10 mumol/l forskolin, a direct activator of adenylate cyclase and 8-bromocyclic AMP at 0.1-1 mmol/l. The actions are blocked by a specific protein kinase A (PKA) inhibitor N-[2-(p-bromocinnamylamino) ethyl]-5-isoquinoline-sulfonamide (H 89), but are not blocked by its negative control, N-[2-(N-formyl-p-chlorocinnamylamino) ethyl]-5-isoquinoline sulfonamide (H 85). PDGF-BB (5 ng/ml)-mediated activation of phospholipase D (PLD), protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) activity were significantly suppressed by coincubation with dopamine. These results suggest that vascular D1-like receptor agonists inhibit migration, proliferation and hypertrophy of VSMC, possibly through PKA activation and suppression of activated PLD, PKC and MAPK activity.

Animals↗
PubMed1997

Changes in plasma cardiac natriuretic peptides concentrations during 1 year treatment with angiotensin-converting enzyme inhibitor in elderly hypertensive patients with left ventricular hypertrophy.

Plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP) are high in patients with hypertension and congestive heart failure. The present study examined changes in plasma ANP and BNP concentrations during 1 year of monotherapy with enalapril in elderly hypertensive patients with left ventricular (LV) hypertrophy. Eight elderly hypertensive patients with LV hypertrophy were treated with enalapril for 1 year, during which time serial changes were recorded in LV mass index, LV systolic function, and plasma concentrations of ANP and BNP. Enalapril maintained systolic and diastolic blood pressure in the normal range for over 1 year. Treatment significantly reduced posterior wall thickness at 6 months, and more so at 1 year, and tended to reduce septal wall thickness and LV mass index at 1 year. LV ejection fraction was slightly but significantly increased at 1 year. Plasma ANP and BNP, which were markedly elevated at study entry, both decreased after 1 year of enalapril. These results suggest that 1 year of treatment with enalapril caused both a modest regression of LV hypertrophy and a modest improvement in LV systolic function in our selected group of elderly hypertensive patients. The drug reduced elevated plasma ANP and BNP levels but did not alter BUN and serum creatinine levels. Enalapril appears to be useful for the treatment of elderly hypertensive patients with LV hypertrophy.

Aged↗
PubMed1997

Zinostatin stimalamer-transcatheter arterial embolization for hepatocellular carcinoma: a comparison with lipiodol-transcatheter arterial embolization.

Twenty patients with unresectable hepatocellular carcinoma were treated by zinostatin stimalamer-transcatheter arterial embolization (SMANCS-TAE). After administration of SMANCS, a superselective catheterization technique was used to inject gelatin sponge particles into the artery or artery branch supplying the cancer-bearing segment. We compared the results of SMANCS-TAE with Lipiodol (Yamanouchi, Tokyo, Japan)-TAE performed during the same period. In 18 of 20 patients (90%), a tumor necrosis rate of 100% (grade 4) was obtained after one or two courses of SMANCS-TAE. The SMANCS group was superior to the Lipiodol-TAE group in terms of the tumor reduction rate, alpha-fetoprotein reduction rate, and cumulative 1.5-year survival rate, but not significantly. No severe side effects were noted after SMANCS-TAE. SMANCS-TAE appears to have potential as a new treatment for hepatocellularcarcinoma, and patients treated with this technique will be monitored to elucidate the long-term effects.

Aged↗
PubMed1997

[A surgical case of severe Ebstein's anomaly, pulmonary atresia in the neonate: experience of modified Starnes operation].

We report a surgical case of severe Ebstein's anomaly associated with pulmonary atresia in the neonate. The baby had remarkable cardiomegaly (CTR > or = 90%) soon after birth and presented severe respiratory distress. He underwent modified Starnes operation (closure of tricuspid valve using a perforated patch, enlargement of interatrial communication, modified Blalock shunt, and PDA ligation) at the age of 12 days. He survived the procedure and cardiopulmonary failure was improved. However, he died from arrhythmia on the 3rd postoperative day. We think this procedure is useful regard to improvement of cardiopulmonary failure due to this fatal congenital heart disease.

Cardiac Surgical Procedures↗
PubMed1997

Expression of inducible nitric oxide synthase in T lymphocytes and macrophages in vessels with advanced atherosclerosis.

While endothelial nitric oxide synthase is expressed in the endothelial cells of normal and atherosclerotic vessels, there are few reports about inducible nitric oxide synthase (iNOS) in atheroma. We investigated the expression of iNOS and its relation to inflammatory cells in atheroma. New Zealand White rabbits received a 1% cholesterol diet for 9 weeks (atherogenic diet) or a 1% cholesterol diet for 9 weeks then a normal diet for 36 weeks (reversible diet). The aortas were examined by immunohistochemical staining for anti-iNOS antibody, as well as antibodies for macrophages, T lymphocytes, and muscle actin. No iNOS was detected in normal aortas, intimal thickening, or fatty streaks. Although iNOS was detected in advanced plaques, it was not seen in smooth muscle-derived cells or endothelial cells, but was found in some macrophage-derived cells and in T lymphocytes. In regressive atherosclerotic aortas, iNOS was detected only in advanced plaques and not in macrophage-derived cells, but in T lymphocytes. These findings suggest that T lymphocytes and some macrophages induce iNOS through cytokine production in atheroma.

Animals↗
PubMed1996

Relation between oxygen uptake and carbon dioxide output during constant work rate exercise in patients with mild congestive heart failure.

The gas exchange (anaerobic) threshold, a useful index of exercise capacity, is determined as the oxygen uptake (VO2) value at which the ratio of the increase in carbon dioxide output (VCO2) to the increase in VO2 becomes > 1 during incremental exercise (V-slope method). However, this method has not been applied to the constant work rate exercise. We evaluated whether a similar threshold phenomenon (i.e., the gas exchange threshold) could be detected during exercise performed at a constant work rate. Thirty-seven patients with a variety of cardiovascular diseases and 27 normal subjects performed symptom-limited incremental exercise and 6 minutes of 50 W constant work rate exercise. The gas exchange threshold could be determined during both symptom-limited incremental exercise (GETi) and constant work rate exercise (GETc) in all subjects, except for 3 normal subjects, by using the V-slope method. There was a significant correlation between GETc and GETi (r=0.80, p<0.0001). GETc was significantly correlated with peak VO2 obtained during the incremental exercise test (r=0.69, p<0.0001). The results suggest that the gas exchange threshold during constant work rate exercise, which does not require the subject's maximal effort, is a useful measure of exercise capacity in patients with cardiovascular disease.

Adult↗
PubMed1996

An accelerated increase of plasma adrenomedullin in acute asthma.

A novel vasorelaxant peptide, adrenomedullin (AM), has been isolated from the acid extract of human pheochromocytoma. We have recently shown that AM inhibits histamine- and acetylcholine-induced bronchoconstriction in anesthetized guinea pigs in vivo, and this bronchodilatory effect is long-lasting. Here, we measured plasma AM concentrations in nine patients with an acute attack of bronchial asthma. The results were compared with values in 30 age-matched normal control subjects and seven age-matched stable asthmatic patients. The mean AM concentrations of patients with an acute asthma attack (98 +/- 22 pg/mL) were clearly higher than those of normal control subjects (18 +/- 2 pg/mL) and stable asthmatic patients (21 +/- 3 pg/mL). Reverse-phase high-performance liquid chromatography (HPLC) showed that the major component of plasma immunoreactive AM in patients with an asthma attack and in normal subjects equally corresponded to authentic human AM(1-52). Our results suggest that plasma AM is markedly increased in many of the patients during an acute attack of bronchial asthma, but it is not observed in stable asthmatic patients. Although this report is preliminary, the observed increase of circulating AM during an acute asthma attack may represent a compensatory mechanism against the bronchoconstriction, probably through its bronchodilatory action.

Acute Disease↗
PubMed1996

Plasma brain natriuretic peptide during ergometric exercise in hypertensive patients with left ventricular hypertrophy.

Cardiac ventricle is shown to be an important source of circulating brain natriuretic peptide (BNP) in hypertensive rats with left ventricular hypertrophy (LVH). This study examined the effect of short-term exercise with a bicycle ergometer on plasma BNP concentrations in 21 essential hypertension patients with LVH established by echocardiography. The results were compared with those from 24 age-matched hypertensives without LVH. Blood pressure, heart rate, plasma renin activity (PRA), and plasma norepinephrine level increased during exercise, but the mean increases of these parameters were not different in the two groups. Resting BNP levels were slightly but significantly higher in the LVH group than in the non-LVH group. This peptide increased during exercise in the two groups, but the exercise-induced increase (percent increase) in plasma BNP was significantly greater in the LVH group than in the non-LVH group (207% +/- 50% v 141% +/- 36%, P < .05). The exercise-induced increase in BNP was significantly correlated with the left ventricular (LV) mass index (N = 45, r = .60, P < .01). By contrast, the exercise-induced increase in BNP was not correlated with the exercise-induced increase in heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure, PRA, or noradrenaline level. These results suggest that short-term exercise induces an accelerated increase of plasma BNP in hypertensive subjects with LVH. The LV mass appeared to be related to the observed increase of plasma BNP concentration, at least in our hypertensive patients with LVH.

Adult↗
PubMed1996

Adrenomedullin as a novel antiproliferative factor of vascular smooth muscle cells.

OBJECTIVE: The present study was designed to examine whether adrenomedullin affects fetal calf serum (FCS)-stimulated proliferation in cultured rat vascular smooth muscle cells (VSMCs). METHODS: Rat VSMCs were grown from explants of Sprague-Dawley rat aorta and were grown using the standard cell culture method. After incubation for 24 h with various concentrations of adrenomedullin in the presence of 5% FCS, trichloroacetic acid-insoluble tritiated thymidine was measured in a liquid scintillation counter. After incubation for 48 h, cell counts were performed. Cyclic adenosine 3',5'-monophosphate (AMP) levels were determined by radioimmunoassay. RESULTS: Rat adrenomedullin exhibited concentration-dependent inhibition of the FCS-stimulated increase in thymidine incorporation between 10(-7) and 10(-9) mol/l and of cell number at 10(-7) mol/l. However, the calcitonin generelated peptide (CGRP) receptor antagonist human CGRP(8-37) abolished these antiproliferative effects of rat adrenomedullin. Inhibition by adrenomedullin of FCS-stimulated cellular proliferation was paralleled by an increase in the cellular level of cyclic AMP. 8-Bromocyclic AMP, a cyclic AMP analogue, and forskolin, an activator of adenylate cyclase, inhibited the FCS-stimulated increase in thymidine incorporation and cell number. CONCLUSIONS: These results suggest that adrenomedullin inhibits FCS-stimulated proliferation in cultured rat VSMCs, probably through a cyclic AMP-dependent process. Taken together with the finding that adrenomedullin is synthesized in and secreted from vascular endothelial cells, adrenomedullin may play a role as an antiproliferative factor for VSMCs in a paracrine fashion.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1996

Urbanization in post-revolution Iran.

"Post-revolution Iran adopted a development strategy centering around the three main tactics of controlling the expansion of Tehran, redistributing various functions to major regional cities, and promoting the growth of smaller cities in rural areas. The present paper will take up the problems pertaining to the urbanization ingredient of the new development plan by investigating if smaller regional cities have in fact during the post-revolutionary period been absorbing population surpluses created in Tehran; and if so, to what scale such population absorption is functioning."

Asia↗
PubMed1996

Plasma adrenomedullin concentrations in essential hypertension.

We designed the present study to assess any changes in plasma concentrations of the novel vasorelaxant peptide adrenomedullin in patients with essential hypertension. Plasma adrenomedullin concentrations were measured in 45 patients with untreated essential hypertension, 15 patients with borderline hypertension, and 30 normotensive control subjects. After 4 weeks of effective calcium channel blocker-based antihypertensive therapy, adrenomedullin concentrations were measured again. The concentrations were higher in hypertensive patients with increased serum creatinine levels or decreased glomerular filtration rates compared with borderline hypertensive patients and normotensive subjects, although values in normotensive and hypertensive individuals overlapped. Plasma adrenomedullin concentrations were positively correlated with serum creatinine levels and inversely correlated with glomerular filtration rates in the hypertensive patients, whereas adrenomedullin values were not correlated with blood pressure level, left ventricular mass index, or left ventricular ejection fraction. Despite blood pressure control with antihypertensive therapy, plasma adrenomedullin concentrations were not changed. Reversed-phase high-performance liquid chromatographic analysis showed that a major component of immunoreactive adrenomedullin in the plasma of normotensive subjects and hypertensive patients is human adrenomedullin-(1-52). These results indicate that plasma adrenomedullin concentrations are elevated in many hypertensive patients with renal dysfunction and its major component is human adrenomedullin-(1-52).

Adrenomedullin↗
PubMed1996

Interaction of adrenomedullin and platelet-derived growth factor on rat mesangial cell production of endothelin.

Adrenomedullin has recently been isolated from human pheochromocytoma. We designed the present study to examine the effect of adrenomedullin on the production of the vasoconstrictive and growth-promoting peptide endothelin-1 (ET-1) after stimulation with platelet-derived growth factor (PDGF) in cultured rat glomerular mesangial cells. PDGF stimulated ET-1 production in a concentration-dependent manner. Rat adrenomedullin inhibited this stimulated ET-1 production in a concentration-dependent manner between 10(-7) and 10(-8) mol/L. Rat adrenomedullin also increased the cellular level of cAMP in a concentration-dependent manner between 10(-7) and 10(-8) mol/L. Human adrenomedullin was less effective than rat adrenomedullin with respect to inhibiting ET-1 production and increasing cAMP levels. The addition of 8-bromo-cAMP (10(-3) and 10(-4) mol/L) reduced PDGF-induced ET-1 production. Furthermore, forskolin (10(-4) and 10(-5) mol/L), an activator of adenylate cyclase, reduced PDGF-induced ET-1 production. In contrast, the basal production of ET-1 was not significantly altered by rat and human adrenomedullin. These results indicate that adrenomedullin inhibits PDGF-induced ET-1 production in cultured rat mesangial cells, probably through a cAMP-dependent process.

Adrenomedullin↗
PubMed1996

Possible involvement of phospholipase D and protein kinase C in vascular growth induced by elevated glucose concentration.

Hyperglycemia is believed to be a major cause of diabetic vascular complications. To elucidate the effect of hyperglycemia on vascular response, we studied hyperproliferation, hypertrophy, and the natriuretic peptide response of vascular smooth muscle cells under high-glucose conditions. We observed that cells cultured in high glucose (22.2 mmol/L) showed hyper-proliferation and hypertrophy and that natriuretic peptide receptor responses were suppressed compared with cells cultured in normal glucose (5.6 mmol/L). We also examined phospholipase D and protein kinase C activities and found that in high-glucose conditions such activities are higher than in cells cultured in normal glucose. The activation of phospholipase D was not prevented by coincubation with 1 mumol/L protein kinase C(19-36), a specific protein kinase C inhibitor, but the activation of protein kinase C was. Protein kinase C(19-36) also markedly attenuated vascular hyperproliferation and hypertrophy as well as glucose-induced suppression of natriuretic peptide receptor response. These results show that hyperglycemia may be linked to vascular hyperproliferation, hypertrophy, and a suppressed natriuretic peptide receptor response, which are caused by increased phospholipase D and protein kinase C activities.

Animals↗
PubMed1996

[Surgery for bone metastasis of testicular tumor: a case report].

A 31-year-old man was admitted to our hospital with the chief complaint of painful right scrotal swelling. Based on the diagnosis of right testicular tumor with multiple lung metastasis and L2 vertebral body metastasis, right high orchiectomy and three courses of chemotherapy (peplomycin, etoposide, CDDP) were performed. Histological diagnosis was teratocarcinoma. With the complete remission for lung metastasis and no change for bone metastasis, L2 spondylectomy and additional four courses of the same chemotherapy were performed. The patient has been free of the disease for 11 months after the spondylectomy.

Adult↗
PubMed1996

Case report: development of hepatocellular carcinoma in a patient with chronic hepatitis C infection after a complete and sustained response to interferon-alpha.

A 60-year-old man with a chronic hepatitis C virus (HCV) infection and histological features of chronic active hepatitis was treated with interferon-alpha (IFN). He successfully responded to IFN with normalization of serum ALT and disappearance of serum HCV-RNA. His liver biochemistry profile remained normal and serum HCV-RNA was not detected throughout the entire follow-up period. One year later, a small hepatocellular carcinoma (HCC) was detected by routine ultrasonographic screening. Laparotomy revealed a small tumour with no metastasis and the non-tumorous liver demonstrated macronodular cirrhosis. Although no space-occupying lesions were detected by frequent radiological examinations prior to IFN therapy, the small size of the tumour suggested de novo development of HCC. Patients with chronic HCV infection, including those who have complete responses to IFN and lack clinical and histological evidence of cirrhosis, should be followed up for the potential development of HCC.

Antiviral Agents↗
PubMed1995

Effects of nicorandil on kinetics of oxygen uptake at the onset of exercise in patients with coronary artery disease.

The beneficial effects of coronary vasodilators on exercise capacity in patients with angina pectoris are well known. However, their effects on oxygen uptake (VO2) kinetics at the onset of exercise have not been elucidated. The present study was undertaken to determine the acute effects of nicorandil, a newer coronary vasodilator, on the kinetics of VO2 at the onset of exercise in patients with ischemic heart disease. Ten patients with significant coronary stenosis performed constant mild-intensity cycle exercise (32 +/- 3 W) for 6 minutes after oral administration of 10 mg of nicorandil or an identical placebo in a double-blind, crossover manner. Nicorandil had no effect on resting heart rate, blood pressure, or VO2. However, the time constant for the increase in VO2 during constant work rate exercise was significantly shorter (the kinetics of VO2 were faster) after administration of nicorandil than after placebo (46.5 +/- 13.3 vs 51.1 +/- 11.9 seconds; p = 0.039). The increase in VO2 at 6 minutes compared with 3 minutes of constant work, which reflects the VO2 kinetics, also was reduced with nicorandil (3.8 +/- 37.9 vs 27.5 +/- 27.1 ml/min; p = 0.022). Nicorandil was found to increase the rate of VO2, increase during the onset of constant work rate exercise, probably as a result of an improved response in cardiac output. Analysis of VO2 kinetics provides new and useful parameters for the evaluation of circulatory adjustments at the onset of exercise in patients with ischemic heart disease.

Adult↗
PubMed1995

Increased nitric oxide production in patients with hypotension during hemodialysis.

OBJECTIVE: To determine the involvement of nitric oxide production in hemodialysis-induced hypotension. DESIGN: Examination of nitric oxide synthesis, cyclic guanosine 3'5'-monophosphate (cGMP) levels, and endothelin-1 levels in plasma before and after hemodialysis. SETTING: Veterans Affairs medical center. PATIENTS: 13 patients with end-stage renal failure who were receiving hemodialysis: Six patients had hypotensive episodes during dialysis and 7 did not. INTERVENTION: Patients received heparin at a bolus dose of 2000 U at the initiation of dialysis followed by 1000 U/h during 4-hour hemodialysis sessions. RESULTS: Nitric oxide production markedly increased during hemodialysis-induced hypotensive episodes; this increase was not seen in patients who did not have a hypotensive episode. In both groups, the plasma cGMP and endothelin-1 levels decreased after hemodialysis. According to multiple regression analysis, standard coefficients of nitric oxide production, plasma cGMP levels, and endothelin-1 levels with mean blood pressure after hemodialysis were -0.743, -0.07, and 0.31, respectively. CONCLUSION: Nitric oxide production increased in patients who had a hypotensive episode during hemodialysis but did not increase in those who did not have a hypotensive episode.

Aged↗