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Biomedical subjects

N Hata

Publications and source records attributed to N Hata.

At least 91 records · Page 5Linked to original sources
PubMed1990

Angiographic response to a vasodilating drug, nicorandil, in patients with coronary artery disease.

To investigate the usefulness of nicorandil as an antianginal drug, we compared the coronary vasodilatory response in nonstenotic coronary artery segments and the hemodynamic response in 26 coronary artery disease patients. Both responses were studied prior to sublingual administration of 10 mg of this drug and 10, 30 and 60 min afterward. The plasma nicorandil concentration was determined up to 120 min after administration. The mean coronary dilating ratio of nicorandil was 117% 30 min after administration (p less than 0.01) and showed a good correlation to the plasma nicorandil concentration. The mean maximum dilating ratio of each patient was 125%. There was no difference between individual coronary arteries or between proximal and distal segments in terms of the coronary artery dilating ratio. The plasma nicorandil concentration required for 120% dilation of the coronary arteries was 26 ng/ml, 89 ng/ml and 142 ng/ml for those cases with variant angina, exertional angina and postinfarction angina, respectively. Hemodynamic changes due to administration of this drug included a decrease in blood pressure, and a reduction in total peripheral resistance, rate-pressure product, pulmonary capillary pressure and stroke-work index. These results indicate that the antianginal effects of nicorandil are derived from its coronary vasodilatory action and an inhibitory effect on myocardial oxygen consumption.

Administration, Sublingual↗
PubMed1990

Evaluation of a new vasodilating beta-blocking agent, carvedilol, in exertional angina using holter monitoring.

Antianginal and antiischemic effects and clinical pharmacologic actions of carvedilol, a novel beta-blocking agent with a vasodilator action, were determined by Holter electrocardiographic monitoring in 13 patients with exertional angina. The patients were observed for 1 week prior to entry into the study, followed by 1 to 2 weeks of treatment with carvedilol. During the observation period the patients received one placebo tablet daily, and during the treatment period one 20 mg tablet of carvedilol daily. Before and after the treatment 24-hour Holter electrocardiographic tracings were obtained. The mean interval of Holter monitoring was 11.2 +/- 4.5 days for the observation and treatment periods, and the mean time of drug administration was 8:25 a.m. (+/- 30 min). The Holter electrocardiographic tracings which were obtained twice in 9 patients during the observation period showed a high degree of reproducibility with respect to the frequency, magnitude and duration of ST-segment depression. The total frequency of ST depression per patient was 4.5 +/- 3.4 events/day pre-drug and 2.1 +/- 2.1 events/day post-drug. There was a significant reduction in total frequency of ST depression post-drug (p less than 0.01). The frequency of asymptomatic ST depression was similarly decreased post-drug (p less than 0.01), and the total magnitude and duration of ST depression were significantly improved post-drug (p less than 0.01 and p less than 0.05, respectively). These effects of carvedilol lasted for 24 hours after administration. Considering that the heart rate was not excessively reduced during the night, and nocturnal myocardial ischemic episodes were not exacerbated, the mode of action of this drug seems to be based on not only a beta-blocking action but also on a vasodilator action. Carvedilol benefits exertional angina when used in a 20 mg s.i.d. regimen.

Adrenergic beta-Antagonists↗
PubMed1989

Membrane filters for the concentration of trace elements in water: distribution of ion pairs between membrane filter and aqueous phases.

The sorption of ion pairs on membrane filters (MFs) has been studied by taking the membrane filter as one of the homogeneous phases. The sorbability of some ionic species and the sorption abilities of different types of MF were evaluated in terms of the sorption constant defined by Ksor,CA = [(C+,A-)f]/[C+][A-], where C+, A- and (C+,A-) refer to the cation, anion and the ion pair, respectively, and f refers to the filter phase. The values of Ksor,CA were determined for many combinations of ionic complexes of cobalt(III) with pyridylazophenols, either as cations or anions, and oppositely charged organic ions having different alkyl chain lengths, with MFs made of different materials: nitrocellulose (NC; Toyo Advantec), acetylcellulose (AC; Fuji Film), regenerated cellulose (RC; Toyo Advantec) and polyethersulphone (PS; Toyo Advantec). For a given cobalt complex ion, the value of log Ksor,CA increased linearly with the increasing number of carbons in the counter ion. Membrane filters made of different materials showed different sorption abilities, the order being NC greater than PS greater than RC greater than AC. It was shown that the surface area of the MF is of greater significance than the volume of the matrix of the MF in determining the sorption constant.

Elements↗
PubMed1989

Coronary artery-left ventricular fistulae with atrial septal defect.

We describe a 65-year-old woman who had coronary artery-left ventricular fistula associated with atrial septal defect of the sinus venosus type, and left-sided heart failure. Although a cardiac valve anomaly associated with coronary artery fistula has been described, atrial septal defect has not been reported previously in this condition.

Aged↗
PubMed1989

Clinical significance and management of silent myocardial ischemia in patients with angina pectoris and myocardial infarction.

The present study was canued out to clarify the relationship between silent myocardial ischemia in patients with angina pectoris and onset of myocardial infarction, and the former's prognostic significance. The peak incidences of onset of myocardial infarction in patients were at 2 a.m., 9 a.m., 2 p.m., 8 p.m., and 9 p.m., and the peak onsets of transient silent myocardial ischemia in angina pectoris patients were at 9 a.m., 2 p.m., 8 p.m., and 9 p.m. Thus the most likely onset times were almost the same with both events. Of 169 patients with coronary artery disease admitted for treatment, 128 patients had no anginal attacks during follow-up and the remaining 41 had persistent angina despite adequate medical treatment. Holter monitoring electrocardiography was performed twice with the non-angina patients, during admission. Of these 128 patients, 54 showed no silent myocardial ischemia on either of the electrocardiographic recordings, 34 showed silent ischemia with the first Holter monitoring but not with the second one, and the remaining 41 showed silent myocardial ischemia on both tests. The subsequent incidences of "cardiac events" were 9.4%, 14.7%, and 36.6%, respectively for these three groups. Therefore, it is concluded that the presence of silent myocardial ischemia is closely related to onset of myocardial infarction and is an important prognostic factor in patients with coronary artery disease.

Adult↗
PubMed1989

[The clinical significance of the low level treadmill exercise test in acute myocardial infarction].

To clarify the clinical significance of the exercise test in acute myocardial infarction (AMI), the relationship between the results of exercise test and clinical features was studied. The low level treadmill exercise test (maximum exercise time was 1080 seconds and the maximum oxygen consumption was 7 METs) were performed in 111 patients within 2 months after the onset of AMI. The exercise time, the endpoint of the exercise test, the exercise-induced ST-segment deviation and ventricular premature beats (VPC) were evaluated from the exercise tests. Among the clinical features, age, sex, the severity in the acute period (Killip's classification and Forrester's hemodynamic subset), the findings in cardioangiography (the number of diseased coronary arteries, left ventricular ejection fraction and abnormal wall motion in the left ventricle) and short term prognosis after AMI were evaluated. The prognosis was judged as poor when cardiac death, congestive heart failure, postinfarction angina, the decrease of exercise tolerance and reattack of AMI occurred, or when an aorto-coronary bypass graft or percutaneous transluminal coronary angioplasty was performed. The exercise time was shorter in patients over the age of 60 years (578 +/- 360 seconds) than in younger patients (818 +/- 296 seconds), and also in females (487 +/- 392 seconds) than in males (767 +/- 319 seconds). The patients classed as Forrester's hemodynamic subset IV had shorter exercise time than the others. But, there was no relationship between the exercise time and Killip's classification. Low left ventricular ejection fraction (55% or less) was associated with short exercise time and the apperance of exercise-induced VPC. But the number of diseased coronary artery and abnormal wall motion in the left ventricle were not related to the exercise test. The patients with high exercise tolerance (4.2 METs or more) in the AMI recovery period showed better prognosis than those with low exercise tolerance within one year after AMI (96% vs 50%, p less than 0.0001, respectively). In conclusion, the low level exercise test in AMI was influenced by age, sex and cardiac function, and it was useful in evaluating the short term prognosis after AMI.

Adult↗
PubMed1989

Characteristics of symptomatic and asymptomatic myocardial ischemia during ambulatory electrocardiographic monitoring in patients with angina pectoris.

The purpose of the present study was to clarify the characteristics of myocardial ischemic attacks in patients with exertional angina (EA, 56 cases), exertional and rest angina (ERA, 28 cases), rest angina (RA, 4 cases), and variant angina (VA, 39 cases). The Holter electrocardiographic findings were compared among the four types of angina pectoris. The frequency of symptomatic ischemic attacks in descending order was 46.0% in EA, 29.0% in ERA, 28.1% in RA, and 21.6% in VA, while the frequency of asymptomatic ischemic attacks was in the reverse order. The maximal heart rates during symptomatic ischemic attacks were in descending order, EA, ERA, RA, and VA. The maximal heart rate during ischemic attacks was significantly lower in patients with spontaneous angina than in those with exercise-induced ischemia for all types of angina (p less than 0.05, respectively). Further, the difference in maximal heart rate during ischemic attacks between the ambulatory electrocardiogram and exercise test was greater in patients with RA and VA than in those with EA. Therefore, this suggests that increased coronary vascular tone is a cause of spontaneous ischemic attacks in each type of angina pectoris.

Aged↗
PubMed1989

Prognostic value of low-level exercise testing in patients with myocardial infarction.

The prognostic value of low-level exercise testing (EXT) before hospital discharge was assessed in 111 patients with uncomplicated acute myocardial infarction (AMI). Of 111 patients, 94 were followed for 1 year after AMI to find that 22 carried a poor prognosis: reduction in duration of EXT (6 patients), postinfarction angina (2 patients), congestive heart failure (3 patients), coronary bypass graft surgery (7 patients) and reinfarction (4 patients). The prognosis was poor in 3.7% of 54 patients who tolerated exercise for 721 seconds or longer (4.2 METs) and 50% of 40 patients tolerating it no longer than 720 sec (p less than 0.0001). Of 22 patients who turned out to be carriers of a poor prognosis, 12 (54.5%) had an ST segment change during EXT, but 10 of the 12 patients were asymptomatic. Our results suggest that reduction in duration of exercise and asymptomatic ST segment changes during EXT provide important clues to establishing the short-term prognosis of AMI.

Adult↗
PubMed1988

Urinary iodide excretion measured with an iodide-selective ion electrode: studies on normal subjects of varying ages and patients with thyroid diseases.

As a part of studies concerning clinical application of the measurement of urinary iodide with an iodide-selective ion electrode, we report here the reference values for the iodide content or concentration in morning spot urine specimens from normal subjects of varying ages and studies with patients with thyroid diseases in Japan. The number distribution of the iodide content or concentration in the morning specimens appeared logarithmic normal in adults, children and infants. Normal ranges found in 95 per cent of populations of healthy subjects were 5.3 to 62.0 mumoles/g Creatinine (Cr) for adults, 5.3 to 42 mumoles/g Cr for children, and 1.9 to 56 microM for infants, respectively. Urinary iodide concentrations in breast-fed infants varied widely compared with those in bottle-fed infants. Mean values were 16.4 microM for breast-fed infants and 8.6 microM for bottle-fed infants, and they were not statistically different. Urine samples from the infants with transient hypothyroidism, who had undergone amniofetography showed extraordinarily high iodide concentrations, even though they were measured at 20th, 29th and 30th days after birth. Although urinary iodide excretion in patients with simple goiter was within normal limits, the mean was statistically lower than that in normal controls (p less than 0.001). Because of the simplicity and rapidity of the electrode method, we strongly recommend it for use in examining iodide excretion in patients with various thyroid diseases.

Adolescent↗
PubMed1988

A case of progressive muscular dystrophy with numerous arterioluminal vessels.

A 48-year-old man had histologically demonstrated cardiac involvement associated with progressive muscular dystrophy. On coronary arteriography, numerous vascular communications between the coronary arteries and the left ventricular chamber were found. These vascular communications are considered to be the arterioluminal vessels. This is the first report of a case of progressive muscular dystrophy with numerous arterioluminal vessels.

Coronary Angiography↗
PubMed1988

Evaluation of a new antianginal agent, nipradilol, in effort angina using holter monitoring.

The purpose of this study was to investigate the efficacy, effective dose, administration frequency and antianginal effect of a new antianginal agent, nipradilol, in 12 patients with stable effort angina. A single blind design was employed; the test consisted of an observation period (1 week) and a treatment period (1-2 weeks). Twenty four hour Holter monitoring was performed on the penultimate day of each period. Nipradilol was administered twice a day at a daily dose of 3-12 mg (mean 7.9 +/- 3.3 mg). The mean frequency of ST-segment depression was 7.1 +/- 6.7 times per day at baseline and 3.1 +/- 2.7 after drug administration, showing a significant reduction (p less than 0.05). The suppression of ST-segment depression and decrease in heart rate due to this drug persisted for 12 hours following administration. The plasma drug concentration at a daily dose of 12 mg peaked at 9.5 +/- 2.4 ng/ml 1 hour after administration and the 12 hour value was 2.3 +/- 1.2 ng/ml. No side effects were observed. Therefore, it seems that, when administered twice a day (total daily dose 6 mg) this drug is effective in effort angina and that the antianginal effect is mainly attributable to beta-adrenoceptor blockade.

Adrenergic alpha-Antagonists↗
PubMed1988

Highly specific enzyme immunoassay for the beta-subunit of human thyrotropin with use of monoclonal antibodies.

A highly specific enzyme-linked "sandwich" immunoassay is described for determining free human thyrotropin (hTSH) beta-subunit in serum by using a anti-hTSH beta-subunit monoclonal antibody conjugated with beta-D-galactosidase (EC 3.2.1.23) and a solid phase consisting of silicone rods coated with another monoclonal antibody. We could detect as little as 0.04 ng of beta-subunit per assay. The measurable range of hTSH beta-subunit concentrations in serum was 0.4 to 50 micrograms/L. The assay demonstrated little or no cross reactivity with intact hTSH, hTSH alpha-subunit, or human choriogonadotropin. The mean CVs were 12.2% within assay, 13.9% between assay. The hTSH beta-subunit was not detectable in sera from healthy subjects, patients with hyperthyroidism, or two patients with pituitary tumors producing TSH. It was measurable (at concentrations of 0.65 to 2.70 micrograms/L) in sera from eight of 23 hypothyroid patients. In five of the hypothyroid patients examined, the concentration of hTSH beta-subunit in serum increased after administration of thyroliberin. This method may be useful in elucidating the physiological and pathological significance of the hTSH beta-subunit and in examining the function of the hypothalamus-pituitary-thyroid axis.

Adolescent↗
PubMed1987

Prognosis of patients with persistent negative U wave following myocardial infarction.

In order to clarify the clinical significance of a persistent negative U wave in patients with myocardial infarction, the clinical features and prognosis of a group of such patients were compared with a group without negative U waves. The persistent negative U wave was defined as the presence of a negative U wave at the time of discharge. The subjects were classified into 2 groups: group A--55 patients (50 males and 5 females, 59 +/- 10 years) with negative U waves; group B--70 patients (55 males and 15 females, 61 +/- 9 years) without negative U waves. The average follow-up periods were 49 +/- 21 months in group A and 42 +/- 18 months in group B. Negative U waves appeared in leads where r or R waves were present, but were not observed in leads with a QS pattern. The incidences of a diseased left anterior descending artery, multi-vessel disease, left ventricular wall motion abnormality and left ventricular ejection fraction below 50% were higher in group A than in group B. The recurrence of myocardial infarction was 18.2% in group A and 7.1% in group B, and the number of patients treated with antianginal drugs was higher in group A than in group B. The rate of recurrence of myocardial infarction at 1, 3 and 5 years was 6%, 17% and 26%, respectively in group A and 6%, 8% and 11%, respectively in group B. Thus, it was concluded that patients in group A require more active treatment than those in group B.

Adult↗
PubMed1987

Factors influencing the clinical course and the long-term prognosis of patients with variant angina.

The purpose of this study was to clarify the factors influencing the clinical course and prognosis in variant angina. Also, the mechanism of acute myocardial infarction in variant angina is reviewed. The subjects were 110 patients with variant angina who, after the initial visit or admission, were observed for a period of at least 2 months, the average observation period being 68 +/- 49 months (range: 2 months-16 years). The incidence of acute myocardial infarction was 21.8% of these patients and 87.5% of the infarctions occurred within 1 month of the initial visit or admission. In variant angina, the average rate over 1 year was 2.2%; however, in classical angina the rate was 3.7% and in postinfarction angina 5.0%. The mortality rate was 5.5%, with death in the majority of cases occurring within 1 month, as in myocardial infarction. When treatment was stopped, spontaneous remission occurred in at least 26 of the 110 cases (23.6%). Beyond 3 months, the remission continued in 19 of these 26 cases. Seven cases had acute myocardial infarction in spite of the suppression of anginal attacks with administration of calcium antagonists. Apparently coronary spasm is the cause of anginal attacks, and the cause of acute myocardial infarction in patients with variant angina appears to be coronary thrombus formation.

Adult↗