Search PubMed⌕ Search

Biomedical subjects

C Kawai

Publications and source records attributed to C Kawai.

At least 91 records · Page 5Linked to original sources

A questionnaire study of beta-adrenergic blockade in dilated cardiomyopathy in Japan.

A questionnaire study on the effect of beta-blockade in dilated cardiomyopathy was performed. In 89 cases obtained from 24 institutions, either metoprolol (72 patients, 41.4 +/- 29.3 mg/day, 14.1 +/- 13.2 months, mean +/- SD), propranolol (5 patients, 23.8 +/- 24.3 mg/day, 25.0 +/- 25.3 months), carteolol (4 patients, 7.5 +/- 2.9 mg/day, 9.0 +/- 2.8 months) or another beta-blockers (8 patients) was administered. Nine patients died during the follow-up period. Overall effectiveness as evaluated by the attending physicians showed improvement in 51 patients (57.3%), no change in 26 patients (29.2%), deterioration in 11 patients (12.4%) or was indeterminate in one patient. New York Heart Association (NYHA) functional class improved significantly from 2.6 to 2.3 (p less than 0.01). Heart rate decreased from 83.1 to 70.1 (p less than 0.01). Cardiothoracic ratio decreased from 55.5% to 53.9% (p less than 0.01). Left ventricular ejection fraction of the left ventricle measured by echocardiogram increased from 29.8% to 37.8% (p less than 0.01). Exercise tolerance during a treadmill test and ventricular arrhythmias in Holter electrocardiograms improved significantly. There was no change in blood pressure. When the patients in different functional classes were compared, the patients of NYHA class III improved more frequently than those of NYHA class II (69% vs 53% p less than 0.01). Improvement of left ventricular end-diastolic dimension and left ventricular ejection fraction was more prominent in patients of class III than in those of class II. NYHA functional class and cardiothoracic ratio were significantly improved only in class III.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

[New oral drugs for the treatment of congestive heart failure].

The crucial issues in the management of congestive heart failure (CHF) are improvement of depressed myocardial contractility and reduction of excessive load. For this purpose, positive inotropic agents and vasodilators have been developed as new oral drugs. The former include Denopamine which possesses beta 1 stimulating effect, Xamoterol which is a unique agent acting as a beta 1-partial agonist, and Ibopamine, Docarpamine and Phosphodiesterase Inhibitors which possess both inotropic and vasodilating effects and are called "Inodilators". The latter include Angiotensin Converting Enzyme Inhibitors. In addition, new vasodilators, such as, Vasopressin Antagonist have also been developed. However, careful long-term clinical trials are required with regard to the efficacy and adverse effects before these agents are widely used with safety in the management of CHF.

Administration, Oral↗

Combination treatment with ribavirin and interferon for coxsackievirus B3 replication.

The effects of combined treatment with ribavirin and recombinant human leukocyte interferon-alpha A/D against Coxsackievirus B3 replication were investigated in cultured cells. Recombinant human leukocyte interferon-alpha A/D was applied 12 hours before Coxsackievirus B3 inoculation and ribavirin was applied 1 hour after Coxsackievirus B3 inoculation on FL (human amnion) cell monolayers. These drugs inhibited Coxsackievirus B3 replication synergistically by plaque-reduction assay. This method of applying drugs may be useful in preventing and treating Coxsackie B virus infection.

Cell Line↗

Viable myocardium identified by reinjection thallium-201 imaging: comparison with regional wall motion and metabolic activity on FDG-PET.

Reinjection thallium-201 scans were performed in 68 patients with coronary artery disease after the routine stress-delayed scans for more accurate identification of new fill-in. Following the stress and 3 hour delayed thallium-201 SPECT scans, 40 MBq (1.1 mCi) was injected at rest, and 10 min later, the reinjection SPECT scan was obtained. To determine whether the reinjection method can aid in identifying ischemic but viable myocardium, the thallium-201 findings were compared with regional wall motion on radionuclide ventriculography in 61 patients and with metabolic activity on positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) in 18 patients. The reinjection scan identified new fill-in which had not been shown on the stress-delayed scans in 6 of the 22 patients (27%) or in 29 of the 105 segments (28%). Regional wall motion was preserved more in the segments that exhibited new fill-in after reinjection (wall motion score = 1.64 +/- 1.29) than in those without new fill-in (score = 2.72 +/- 1.04) (p < 0.01). In the comparative study with FDG-PET, persistent FDG uptake was observed in all segments with new fill-in (20/20 segments: 100%); whereas, it was seen in only 7 of the 28 segments (25%) without new fill-in after reinjection (p < 0.05). We concluded that the segments having new fill-in after reinjection may represent ischemic but viable myocardium. Thus, the reinjection thallium-201 scan should be performed to identify ischemic myocardium which occasionally cannot be detected by the routine stress-delayed thallium-201 scans.

Adult↗

[The pitfalls in the clinical diagnosis of dissecting aortic aneurysm].

It is sometimes very difficult to diagnose dissecting aortic aneurysms (DAA), particularly in its early stage, due to manifold signs and symptoms. The purpose of this study is to clarify the reasons for such erroneous diagnoses. A total of 41 patients with DAA were referred to our hospitals for further examination and/or surgery from April 1986 to August 1989. In 18 of these patients, the diagnostic possibility of an underlying DAA was overlooked by the referring physicians. Among these 18 patients, 2 were mistakenly diagnosed as uncomplicated myocardial infarction (MI), one as pneumonia, 2 as cerebral infarction, 6 as acute abdominal disease, one as cholelithiasis, 5 as thrombosis of the lower extremities, and one as malignant metastasis to the pericardium. The following is the detail: In 2 cases thought to be uncomplicated MI, an expanding dissecting ascending aorta had crushed the lumen of the left coronary artery, causing MI, in turn, wasting clinical treatment and consuming precious time. In one case, enlargement of the descending aorta on the chest radiography was overlooked and the patient's symptoms were mistakenly attributed to pneumonia. In 2 cases in which symptoms of cerebral ischemia were thought to be attributed to cerebral thrombosis, the real cause turned out to be occlusion of the brachiocephalic artery following aortic dissection. Among 6 cases which were initially considered to have only acute abdominal disease, 3 presented with symptoms and signs of ileus, and their exploratory laparotomies yielded no positive findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Acid-base disturbances in heart failure].

Disturbance in acid-base balance is commonly observed in patients with heart failure. The most common disturbance is metabolic alkalosis combined with hypokalemia, as a result of the excessive use of loop diuretics. Occasionary, hypoxia due to pulmonary edema stimulates ventilation, resulting in respiratory alkalosis. When pulmonary edema develops, carbon dioxide retention occurs, resulting in respiratory acidosis. Decreased tissue oxygen delivery may also produce lethal lactic acidosis. Compensatory mechanisms, coexistence of independent acid-base disorders and changes in electrolytes complicate acid-base balance in the individual patients. As acid-base disturbances have harmful effects on the cardiovascular system, precise diagnosis and proper treatment are highly important.

Acidosis↗

[False aneurysm formation during the chronic phase of myocardial infarction at the margin of a previously-detected true aneurysm].

The patient was a 59-year-old man who had acute extensive anterior myocardial infarction in October, 1989. One month later, he was transferred to Kyoto University Hospital and underwent cardiac catheterization. Left ventricular aneurysm and significant stenosis in the proximal portion of the left anterior descending artery were documented. Because he experienced chest pain on slight exertion accompanied by a slight increase in the depth of the negative T wave on electrocardiogram, percutaneous transluminal coronary angioplasty (PTCA) was performed. Thereafter, chest pain disappeared, and the patient was discharged. Three months later, he was re-admitted to Kyoto University Hospital for a repeat cardiac catheterization after PTCA. PTCA site was found to be restenosed, and a small diverticulous aneurysm was found at the margin of the previously-detected ventricular aneurysm. As the diverticulous aneurysm was considered likely to precipitate the ventricular aneurysm into rupture, expeditious left ventricular aneurysmectomy was performed to prevent cardiac rupture. Ventricular aneurysms, common complications in myocardial infarction, are of two types, either true or false. Most aneurysms develop during the acute phase of myocardial infarction, and rupture of true aneurysms during the chronic phase of myocardial infarction rarely occurs. However, in the present case, a small diverticulous aneurysm, which was not demonstrated at the initial cardiac catheterization, developed during the chronic phase of myocardial infarction. Pathological examination revealed that the diverticulous aneurysm was a false aneurysm due to incomplete rupture. When the common pathogenesis of ventricular aneurysms in myocardial infarction is considered, the present report might represent an extraordinary rare case.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm, Ruptured↗

Regional metabolic abnormality in relation to perfusion and wall motion in patients with myocardial infarction: assessment with emission tomography using an iodinated branched fatty acid analog.

The clinical usefulness of single-photon tomography using both a beta-methyl-branched fatty acid analog, 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) and 201TI was assessed in 4 normal subjects and 28 patients with myocardial infarction. A homogeneous distribution of the tracer in the left ventricular myocardium was observed in each normal subject. BMIPP uptake was decreased compared to 201TI (discordant) in 17/28 patients (61%) and in 49/196 myocardial segments (25%). Such discordant BMIPP uptake was observed more often in areas of acute myocardial infarction (59% at less than or equal to 4 wk versus 31% at greater than 4 wk after onset) (p less than 0.01) and areas supplied with revascularized arteries (74% for revascularized versus 28% for nonrevascularized areas) (p less than 0.01). In addition, the discordant BMIPP uptake was seen more often in the segments exhibiting a wall motion score lower than the perfusion score (46%) in comparison to segments showing a similar decrease in both the wall motion and perfusion scores (12%) (p less than 0.01). Thus, BMIPP imaging may play a major role in increasing our understanding of the relationship between perfusion and wall motion, particularly in patients with acute myocardial infarction and those who received revascularization therapy.

Fatty Acids↗

[A case of successful repair of aorto-pulmonary artery fistula secondary to aortic arch aneurysm].

A report of a rare case of successful repair of rupture of an aortic aneurysm into the pulmonary artery. A 55-year-old male was transferred to our hospital because of dyspnea with sudden onset, hemoptysis and palpitation. A loud, continuous, "machine-like" murmur was heard on the anterior wall of the chest. Various examinations revealed an acquired shunt between the thoracic aortic aneurysm and the pulmonary artery and high-output heart failure. Aortic arch replacement was performed expeditiously and the patient recovered, and was able to return to work. 108 cases of rupture of a thoracic aortic aneurysm into the pulmonary artery have been reported in the literature. Operation for repair was performed in only thirteen of these. Only four cases have been reported in the literature in which the patients were successfully treated.

Aorta, Thoracic↗

Purification of nitric oxide synthase from rat macrophages.

Nitric oxide (NO) synthase (EC 1.14.23) has been purified to apparent homogeneity from rat macrophages. The purification procedure involves affinity chromatography with adenosine 2',5'-diphosphate-agarose and gel filtration chromatography on a Superose 12 HR 10/30 column. The apparent molecular weight is 300,000 by gel filtration. On polyacrylamide gel electrophoresis in sodium dodecyl sulfate, the enzyme migrates as a single protein band with Mr = 150,000. The purified enzyme is colorless, and an absorption maximum is observed at 280 nm. The half-life of the enzyme activity is 6 h at pH 7.4 and 4 degrees C. The enzyme activity required the presence of NADPH, (6R)-5,6,7,8-tetrahydro-L-biopterin, and dithiothreitol. Although the cerebellar and endothelial enzyme require Ca2+ and calmodulin, these are not required by the macrophage enzyme. The macrophage nitric oxide synthase (an inducible enzyme) seems to be different from the cerebellar and endothelial enzyme (a constitutive enzyme).

Amino Acid Oxidoreductases↗

Dependence of Doppler echocardiographic transmitral early peak velocity on left ventricular systolic function in coronary artery disease.

The influence of systolic function on pulsed Doppler echocardiographic transmitral flow velocity patterns was assessed before and after postextrasystolic (PES) potentiation in 12 normal subjects (control group) and in 25 patients with previous healed myocardial infarction (MI) group. Simultaneous high-fidelity left ventricular pressure measurements were performed in all patients. A programmed single-coupled right ventricular extrasystole was induced during echocardiographic and subsequent cineangiocardiographic recordings. Adequate angiograms for volumetric analysis in both baseline and PES beats were obtained in 23 patients (7 in the control group and 16 in the MI group). PES potentiation of contraction was more pronounced in the MI group than in the control group. PES changes in ejection fraction, stroke volume and end-systolic volume were significantly greater in the MI group than in the control group (11 vs 5%, p less than 0.005; 15 vs 5 ml/m2, p less than 0.005; and -13 vs -4 ml/m2, p less than 0.01, respectively). In contrast, PES potentiation prolonged the time constants of left ventricular pressure decline derived from exponential curve fits with a zero (Tw) and non-zero (Tb) asymptote pressure in the MI group to the same extent as in the control group (4 vs 5 ms, difference not significant [NS], and 9 vs 11 ms, NS, respectively). In the PES beat, peak E velocity remained unaltered (48 vs 49 cm/s, NS) in the control group, whereas it increased significantly (p less than 0.0001) from 47 to 51 cm/s in the MI group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Calmodulin-independent nitric oxide synthase from rat polymorphonuclear neutrophils.

Recently, the purification of nitric oxide synthase (EC 1.14.23) from rat cerebellum has been reported, and the enzyme is a calmodulin-requiring enzyme (Bredt, D. S., and Snyder, S. H. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 682-685). In this paper, nitric oxide synthase has been purified to near homogeneity from the cytosol fraction of rat polymorphonuclear neutrophils. The purification procedure involves affinity chromatography with adenosine 2',5'-diphosphate-agarose and an anion exchange column, DEAE-Bio-Gel A. On polyacrylamide gel electrophoresis in sodium dodecyl sulfate, the enzyme migrated as a single protein band with Mr = 150,000. The molecular weight was estimated to be 150,000 by gel filtration on a Superose 12 HR 10/30. The purified enzyme was unstable with a half-life of 3 h at pH 7.4 and 4 degrees C. The enzyme activity required the presence of Ca2+, NADPH, FAD, and (6R)-5,6,7,8-tetrahydro-L-biopterin. Calmodulin antagonists (W5, W7, W13, and trifluoperazine dihydrochloride) did not inhibit the enzyme activity, and the addition of calmodulin was also ineffective for the increase in the enzyme activity. The neutrophil enzyme appears to be a calmodulin-independent type of nitric oxide synthase.

Amino Acid Oxidoreductases↗

Receptors for modified low-density lipoproteins on human endothelial cells: different recognition for acetylated low-density lipoprotein and oxidized low-density lipoprotein.

We examined the uptake pathway of acetylated low-density lipoprotein and oxidatively modified LDL (oxidized LDL) in human umbilical vein endothelial cells in culture. Proteolytic degradation of 125I-labeled Ac-LDL or Ox-LDL in the confluent monolayer of human endothelial cells was time-dependent and showed saturation kinetics in the dose-response relationship, which suggests that their incorporation is receptor-mediated. Cross-competition studies between acetylated LDL and oxidized LDL showed that the degradation of 125I-labeled acetylated LDL was almost completely inhibited by excess amount of unlabeled acetylated LDL, while only partially inhibited by excess unlabeled oxidized LDL. On the other hand, the degradation of 125I-labeled oxidized LDL was equally inhibited by excess amount of either acetylated or oxidized LDL. Cross-competition results of the cell-association assay paralleled the results shown in the degradation assay. These data indicate that human endothelial cells do not have any additional receptors specific only for oxidized LDL. On the contrary, they may have additional receptors, as we previously indicated on mouse macrophages, which recognize acetylated LDL, but not oxidized LDL.

Binding, Competitive↗