Biomedical subjects

K Hiwada

Publications and source records attributed to K Hiwada.

At least 109 records · Page 6Linked to original sources

PubMed1998

A case of effusive-constructive pericarditis: an efficacy of GD-DTPA enhanced magnetic resonance imaging to detect a pericardial thickening.

A 38-year-old man underwent pericardiectomy because of effusive-constrictive pericarditis. The gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging showed pericardial thickening separate from the effusion, which could not be shown by unenhanced computed tomography. Gd-DTPA enhanced magnetic resonance imaging could be useful for the early detection of effusive-constrictive pericarditis.

Adult↗

PubMed1998

Increased contraction of myocytes isolated from the young spontaneously hypertensive rat: relationship between systolic and diastolic function.

This study was designed to assess heart performance in young (10-week-old) spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats, in terms of whole heart function in vivo and mechanics of isolated ventricular myocytes in vitro. The data suggest that left ventricular pressure (LVP) generation is greater, and the maximal velocities of LVP generation and decline are faster in SHR than in WKY. Two-dimensional morphologic measurements show that SHR myocytes are hypertrophied and that augmented contractile function is also present in isolated cells as determined by the extent of shortening and velocity of shortening. Relaxation is also faster at the myocyte level as determined by velocity of relengthening. However, the slope of the relationship between myocyte peak shortening and velocity of relaxation was similar in both groups. These results suggest that hyperdynamic myocyte relengthening may reflect changes in elastic recoil from increased shortening rather than intrinsic changes in cellular mechanisms, which are independent of shortening.

Animals↗

PubMed1998

Left ventricular geometry as an independent predictor for extracardiac target organ damage in essential hypertension.

Left ventricular hypertrophy (LVH) is an independent cardiovascular risk factor. It has not been established, however, whether left ventricular geometry is an independent predictor of extracardiac target organ damage in essential hypertension. Study groups were classified according to relative wall thickness: 27 patients with concentric LVH and 50 patients with eccentric LVH. Age and left ventricular mass indexes of two groups were matched. As indexes of extracardiac target organ damage, retinal funduscopic grade, and serum creatinine level were measured. The severity of hypertensive retinopathy and the renal involvement were more severe in patients with concentric LVH than in patients with eccentric LVH. Extracardiac target organ damage was consistently higher in patients with concentric LVH than in those with eccentric LVH. Systemic hemodynamics paralleled ventricular geometric patterns, with higher peripheral resistance and lower aortic compliance in patients with concentric LVH, whereas end-diastolic volumes and stroke volumes were higher in patients with eccentric LVH than in patients with concentric LVH. In addition, total peripheral resistance was related to retinal fundoscopic grade (r = 0.41, P < .01), and serum creatinine level (r = 0.28, P < .05). Even in the presence of an identical degree of LVH, echocardiographically determined left ventricular geometry may provide a further independent stratification of extracardiac target organ damage in essential hypertension.

Aged↗

PubMed1998

Postprandial hypotension: evaluation by ambulatory blood pressure monitoring.

To elucidate whether postprandial hypotension (PPH) is associated with any diurnal change of blood pressure, ambulatory blood pressure monitoring was performed on 121 hospitalized essential hypertensive patients who received standardized meals. Postprandial change in blood pressure was defined as the difference between mean systolic blood pressure (SBP) 1 h before and 2 h after each meal. The postprandial decline of SBP showed age-dependent augmentation. The degree of PPH was significantly related to the level of preprandial blood pressure for each meal. Patients were divided into the following three groups according to the mean PPH of three meals: Normal group (n = 79); mean postprandial decline of SBP <5 mm Hg, PPH-1 group (n = 24); 5 mm Hg ' mean PPH < 10 mm Hg, and PPH-2 group (n = 18); PPH 2 > or = 10 mm Hg. There was no difference in 24-h, nighttime, or daytime blood pressure among the three groups. The prevalence of dipper and nondipper patients was not different among the three groups. However, patients in PPH-2 showed significantly greater daytime and 24-h blood pressure variability. Furthermore, there was a significant positive relationship between the morning surge of SBP and PPH after breakfast (r = 0.36, P < .001). These findings indicate that PPH increases blood pressure variability independently of nocturnal change in blood pressure.

Adult↗

PubMed1998

Alteration of carotid circulation in essential hypertensive patients with left ventricular hypertrophy.

To investigate carotid haemodynamic characteristics in essential hypertensive patients with left ventricular hypertrophy, we evaluated the structure and function as well as blood flow of the common carotid artery by using a combination of B-mode ultrasound and pulsed-Doppler in control subjects (n = 38), and hypertensive patients with (n = 40) and without (n = 27) left ventricular hypertrophy. Hypertensive patients had a higher intima-medial thickness compared with control subjects. Diastolic/systolic flow velocity ratio as well as flow volume ratio was significantly decreased in hypertensive patients with left ventricular hypertrophy in association with decline of distensibility of the common carotid artery. In the hypertensive patients with left ventricular hypertrophy, diastolic/systolic flow velocity ratio as well as flow volume ratio had significant correlation with diastolic blood pressure, pulse pressure and carotid arterial distensibility. These findings indicate that diastolic blood flow in the common carotid artery is impaired in hypertensive patients with left ventricular hypertrophy. Decreased distensibility and low diastolic perfusion pressure may be the underlying mechanisms.

Carotid Arteries↗

PubMed1998

Increased plasma levels of adrenomedullin in patients with hypertrophic cardiomyopathy: its relation to endothelin-I, natriuretic peptides and noradrenaline.

1. The aim of this study was to elucidate the pathophysiological role of adrenomedullin and the relation between adrenomedullin and other hormones in patients with hypertrophic cardiomyopathy. 2. Fourteen patients with hypertrophic obstructive cardiomyopathy (HOCM), 26 patients with hypertrophic non-obstructive cardiomyopathy (HNCM) and 14 normal control subjects participated in this study. Radioimmunoassay for plasma adrenomedullin concentration was performed with adrenomedullin-M antibody. Plasma levels of endothelin-1, atrial and brain natriuretic peptides and noradrenaline were also measured. 3. Plasma levels of adrenomedullin were higher in patients with hypertrophic cardiomyopathy (8.43 +/- 3.73 pmol/l) than in normal controls (5.24 +/- 0.44 pmol/l, P < 0.005). There was no significant difference between HOCM and HNCM patients. There was a weak correlation between plasma levels of adrenomedullin and total 12-lead QRS voltage in patients with hypertrophic cardiomyopathy (r = 0.323, P < 0.05). 4. Plasma levels of endothelin-1, atrial and brain natriuretic peptides were higher in hypertrophic cardiomyopathy than in normal controls. Endothelin-1 showed no significant difference between HOCM and HNCM patients, but atrial and brain natriuretic peptides were higher in HOCM than in HNCM patients. There was a positive correlation between plasma levels of adrenomedullin and endothelin-1 (r = 0.575, P < 0.0001), but no correlation between plasma levels of adrenomedullin and atrial natriuretic peptide, brain natriuretic peptide and noradrenaline. 5. Our results indicate that adrenomedullin may play an important role to maintain haemodynamics in patients with hypertrophic cardiomyopathy, and its action may be related to endothelin-1 but independent of atrial natriuretic peptide, brain natriuretic peptide and noradrenaline.

Adrenomedullin↗

PubMed1998

Molecular structure and function of rat platelet-derived growth factor beta-receptor gene promoter.

OBJECTIVE: To understand the regulatory mechanism of platelet-derived growth factor beta-receptor gene expression. METHODS: A 1.7 kb genomic fragment was obtained from a rat genomic library. After we had determined an entire sequence of this fragment, transcription start sites were determined both by primer extension analysis and by riboprobe mapping. We performed a functional promoter assay by using a dual-luciferase reporter system. Progressive 5'-deletions of the fragment and site-directed mutagenesis for the CCAAT motif located at -67 or -94 were used for the assay, and their promoter activities in vascular smooth muscle cells were assessed. Gel-mobility shift analysis was also performed for the CCAAT motif at -67. Effects of the upstream sequence spanning -310 through -120 on heterologous gene promoters were also investigated. RESULTS: Multiple transcription start sites were observed in the 5'-flanking region, and the 1.7 kb sequence was actually active as a functional promoter in vascular smooth muscle cells. Two important sequences responsible for the basal transcriptional activity were identified by the functional promoter assay. One was the CCAAT motif at -67 which acts as a promoter itself, and the other was the upstream region spanning -310 through -210 which positively regulates the basal promoter activity. CONCLUSION: The basal promoter activity of the rat platelet-derived growth factor beta-receptor gene is mainly regulated by the interaction or coordination of two sequences, the CCAAT motif and the upstream control element.

Animals↗

PubMed1998

Comparative evaluation of sialylated carbohydrate antigens, KL-6, CA19-9 and SLX as serum markers for interstitial pneumonia.

We compared diagnostic values of three serum carbohydrate antigens, KL-6, CA19-9 and SLX to discriminate interstitial pneumonia (IP) from alveolar pneumonia and healthy volunteers. Subjects consisted of 13 patients with idiopathic pulmonary fibrosis and 10 associated with collagen vascular diseases, 12 patients with sarcoidosis and 70 controls (52 healthy volunteers and 18 patients with alveolar pneumonia). Cut-off values were determined at the level at which the diagnostic accuracy became the highest for each marker, 449 U/mL for KL-6, 26 U/mL for CA19-9 and 41 U/mL for SLX. The sensitivity, the specificity and the diagnostic accuracy were 74.3% (26/35), 98.6% (69/70) and 90.5% (95/105) in KL-6, 42.9% (15/35), 94.3% (66/70) and 77.1% (81/105) in CA19-9, and 20.0% (7/35) and 95.7% (67/70) and 70.5% (74/105) in SLX, respectively. Receiver operating characteristic curves revealed that KL-6 was far superior to both CA19-9 and SLX. These results suggest that KL-6 is the best marker for interstitial pneumonia among these carbohydrate antigens.

Adult↗

PubMed1998

Circulating KL-6 predicts the outcome of rapidly progressive idiopathic pulmonary fibrosis.

Searching for early predictive markers of the therapeutic effects of high-dose corticosteroids ("pulse therapy") on patients with rapidly progressing idiopathic pulmonary fibrosis (IPF), we evaluated 14 such patients, who had received weekly pulse therapy for at least 3 wk. Eight patients responded to the treatment and survived. However, six patients failed to respond, and all of them died within 3 mo after treatment. Serum levels of KL-6 (MUC1 mucin), neutrophil elastase (NE), and lactate dehydrogenase (LDH) were measured before, and at 1 wk and 3 wk after treatment. Levels of KL-6 decreased significantly in patients who lived, whereas KL-6 levels tended to increase in patients who died. The values of NE did not change significantly. LDH levels decreased significantly at 1 wk, and tended to decrease at 3 wk in patients who lived. However, in patients who died, they did not significantly change. At the first cycle of treatment when clinical effects may not be evident, the decrease in KL-6 but not LDH levels was significantly related to a favorable outcome, whereas their increase was related to a poor outcome. Results suggest that monitoring with KL-6 may contribute to early clinical decisions for alternative therapy in the management of rapidly progressing IPF.

Aged↗

PubMed1998

Beneficial hemodynamic effects of oral prostacyclin (PGI2) analogue, beraprost sodium, on a patient with primary pulmonary hypertension--a case report.

A 65-year-old woman was admitted to our hospital because of exertional dyspnea in 1987. A diagnosis of primary pulmonary hypertension was confirmed by right heart catheterization. She had received conventional therapy in the outpatient clinic. She was readmitted with the deterioration of exertional dyspnea in 1995. Stabilization of pulmonary hemodynamics, while not achieved with conventional therapy, was achieved with additive administration of an oral prostacyclin (PGI2) analogue, beraprost sodium.

Administration, Oral↗

PubMed1998

Coronary vasospasm at the site of myocardial bridge--report of two cases.

Two patients with angina pectoris and postmyocardial infarction angina due to coronary vasospasm at the site of myocardial bridge are described. Intracoronary injection of isosorbide dinitrate led to resolution of coronary vasospasm on acetylcholine provocation test, and vasospastic angina pectoris has been well controlled after treatment with calcium channel blockers.

Angina Pectoris↗

PubMed1998

Clinical characteristics in Japanese patients with coexistent hypertrophic cardiomyopathy and coronary vasospasm.

There are only a few reports concerning coexistent hypertrophic cardiomyopathy (HCM) and vasospastic angina. Clinical characteristics in patients with both diseases have not been clarified yet. This study was designed to elucidate the relationship between chest pain and coronary vasospasm in HCM patients and to delineate clinical characteristics in patients with both HCM and coronary vasospasm. First, 36 patients with HCM underwent acetylcholine provocation test for coronary vasospasm and were divided into two groups on the basis of presence or absence of coronary vasospasm. Next, the following risk factors for coronary artery disease were compared between the two groups: hypertension, smoking, hyperlipidemia, diabetes mellitus, and hyperuricemia. Coronary vasospasm was induced in 10 (28%) of 36 patients with HCM. There were no significant differences in age and male gender between the two groups. Smoking was more prominent in HCM patients with than without coronary vasospasm (80% vs 35%, p<0.05), but there were no differences in the prevalence of other risk factors between the two groups. In conclusion, coronary vasospasm appears to play a significant role in the etiology of myocardial ischemia in Japanese patients with HCM, and smoking might be a major risk factor for coexistence of HCM and coronary vasospasm.

Adult↗

PubMed1998

An early systolic sound associated with midventricular obstruction in a patient with hypertrophic cardiomyopathy.

A 57-year-old woman was admitted for examination because of chest discomfort. Transthoracic echocardiography was performed and she was diagnosed as having hypertrophic cardiomyopathy. An echocardiogram also revealed that she had midventricular obstruction with a pressure gradient of 125 mmHg determined by Doppler echocardiography. A phonocardiogram showed an early systolic sound and the beginning of the sound coincided with the time of septal-posterior wall contact. In addition, the timing also corresponded to the sudden obstruction of blood flow in the region of the midventricular narrowing. Furthermore, this sound markedly decreased with the reduction in pressure gradient caused by cibenzoline treatment. Thus, it was concluded that the early systolic sound was associated with midventricular obstruction and produced by a rapid deceleration of the interventricular flow caused by midventricular obstruction.

Anti-Arrhythmia Agents↗

PubMed1998

Increased circulating soluble form of Fas in patients with dilated cardiomyopathy.

To examine the prognostic role of the circulating soluble form of Fas (sFas), circulating sFas levels were measured in 33 patients with dilated cardiomyopathy (DCM) and 12 age-matched normal control subjects (NC) using an enzyme-linked immunosorbent assay (ELISA). Circulating sFas levels in DCM were significantly higher than those in NC (2.42+/-1.02 vs 1.66+/-0.20 ng/ml, p=0.015). Patients with DCM were stratified into 2 groups [group I (n=15): sFas > or =2.06 ng/ml; group II (n=18): sFas <2.06 ng/ml] on the basis of the mean value plus 2SD of circulating sFas level in NC. The circulating sFas level was significantly increased in relation to the severity of heart failure and correlated positively to left ventricular end-diastolic pressure in DCM. However, there were no significant differences in left ventricular dimension between the 2 groups. There were 5 deaths from worsening heart failure in group II, but there were no deaths in group I during the follow-up period. In conclusion, circulating sFas levels were increased in patients with DCM. Circulating sFas levels are increased in proportion to the severity of heart failure and may provide prognostic information independent of left ventricular geometry.

Cardiomyopathy, Dilated↗

PubMed1998

Characterization of left ventricular opacification using sonicated serum albumin in patients with dilated cardiomyopathy and myocardial infarction.

To elucidate whether the mode of left ventricular opacification using sonicated serum albumin (SSA) is dependent upon the severity of left ventricular dysfunction, SSA was administered intravenously to 26 patients with dilated cardiomyopathy, 24 patients with anteroseptal myocardial infarction, and 9 normal control subjects. The left ventricular inflow pattern in echocardiograms on the apical 4-chamber view was classified into 2 types: straight or whirling. The ratio of left ventricular opacified area to left ventricular end-diastolic area, called the percent left ventricular effective fraction (%LVEF), was also calculated. The inflow pattern was straight in all normal control subjects and 9 myocardial infarction patients, whereas 15 myocardial infarction and all dilated cardiomyopathy patients showed the whirling pattern. Percent LVEF was significantly smaller in patients with dilated cardiomyopathy (45 +/- 22%, p < 0.0001) and myocardial infarction (65 +/- 14%, p < 0.001) than in normal control subjects (84 +/- 7%). The area that was not opacified was observed only in the infarcted area in cases of myocardial infarction, and over wide regions in cases of dilated cardiomyopathy. In addition, there were significant correlations between %LVEF and ejection fraction or peak filling rate. These findings indicate that contrast echocardiography using SSA can reflect sensitively the severity of left ventricular dysfunctions and detect the regions involved in patients with dilated cardiomyopathy and myocardial infarction.

Adult↗

PubMed1998

Relation between coronary blood flow and left ventricular mass in hypertension: noninvasive quantification of coronary blood flow by thallium-201 myocardial scintigraphy.

This study was conducted to quantify coronary blood flow (CBF) noninvasively according to the fractionation principle and to elucidate the relation between CBF and left ventricular hypertrophy. CBF/cardiac output (CO), estimated on the basis of the ratio of myocardial uptake/total injected dose of thallium-201 (% cardiac uptake), was determined in 14 control subjects and 40 patients with essential hypertension. CBF and CBF per 100 g of myocardium (unit CBF) were calculated according to the following formulas: CBF= % cardiac uptake x CO, and unit CBF = (CBF/LVM) X 100, where CO and left ventricular mass (LVM) are echocardiographically determined. There was good reproducibility of % cardiac uptake (r = 0.983, p < 0.0001). Percent cardiac uptake was greater in hypertensive patients (4.65+/-1.44%) than in control subjects (3.64+/-0.64%), and there was a positive correlation between % cardiac uptake and LVM. CBF (ml/min) was greater in hypertensive patients (240.7+/-80.5) than in control subjects (194.9+/-36.9), but unit CBF (ml/min/100 g) was less in hypertensive patients (102.2+/-26.7) than in control subjects (150.3+/-30.5). Multiple regression analyses showed that LVM was the most potent independent predictor of resting CBF in hypertension. Our results indicate that CBF, determined by thallium-201 myocardial scintigraphy, increases parallel to the increase in LVM, but unit CBF decreases even in the resting condition in patients with essential hypertension.

Adult↗

PubMed1998

KL-6 as a serologic indicator of Pneumocystis carinii pneumonia in immunocompromised hosts.

KL-6, a serum marker for interstitial pneumonitis, was evaluated in patients with Pneumocystis carinii pneumonia (PCP). Patient 1 was a 56-year-old woman with rheumatoid arthritis treated with immunosuppressive drugs and corticosteroids. Patient 2 was a 59-year-old man with a glioblastoma who received anti-cancer drugs and corticosteroids. In both patients, serum KL-6 showed an abnormally high level due to the complication of PCP, and it decreased following successful treatment. These results indicate that PCP is one of the diseases in which serum KL-6 increases.

Antigens↗

PubMed1998

Effect of pranlukast, a leukotriene receptor antagonist, in patients with severe asthma refractory to corticosteroids.

We investigated the effect of pranlukast (ONO-1078), a cysteinyl leukotriene receptor antagonist, in 11 patients with severe bronchial asthma. The patients had been treated with 1600 micrograms/day of beclomethasone or 800-1600 micrograms/day of beclomethasone plus 2.5-20 mg/day of prednisolone, but remained symptomatic. After a 2-week baseline period, the patients received 225 mg of pranlukast twice daily for 8 weeks. Morning and evening peak expiratory flow rate (PEF) and symptom scores (cough, dyspnea, sleep) were recorded in an asthma diary. Ten patients completed the study. Symptom scores, especially dyspnea and sleep scores, and the number of rescue beta 2-agonist inhalations were significantly decreased. The morning PEF significantly improved from a mean baseline value of 311 to 341 L/min by the end of the study period. The evening PEF also improved, from 328 to 348 L/min, although the difference was not significant. These results suggest that pranlukast may be effective in treating patients with severe asthma who are refractory to corticosteroid therapy.

Aged↗