Search PubMed⌕ Search

Biomedical subjects

T Kamiya

Publications and source records attributed to T Kamiya.

At least 379 records · Page 21Linked to original sources
PubMed1984

Phase-dependent polymerization and depolymerization of actin in Physarum polycephalum nuclei.

G- and F-actin contents in physarum polycephalum nuclei isolated during the progress of cell cycle were estimated and compared both by the inhibiting activity of deoxyribonuclease I (DNase I) and by the fractionation on DEAE-Toyopearl column chromatography. The inhibition of DNase appeared maximal in late S phase or early G2 phase and decreased to a minimal value in late G2 phase or M phase, while total actin content in a nucleus, which was analyzed by SDS-polyacrylamide gel electrophoresis as well as by DNase inhibition assay in the presence of 0.75 M guanidine-HCl, did not show such phase-dependent dynamics through the cell cycle.

Actins↗
PubMed1984

Plasminogens Tochigi II and Nagoya: two additional molecular defects with Ala-600----Thr replacement found in plasmin light chain variants.

Previous studies in our laboratories (Miyata, T., et al. (1982) Proc. Natl. Acad. Sci. U.S. 79, 6132-6136) showed that the structural defect in a hereditarily abnormal plasminogen, plasminogen Tochigi, is due to replacement of Ala by Thr at position 600 from the NH2-terminal end. In the present studies, two abnormal plasminogens, plasminogens Tochigi II and Nagoya, obtained from other family members were analyzed to identify the structural impairment in these molecules. Amino acid sequence analysis of one of the tryptic peptides isolated, respectively, from plasminogens Tochigi II and Nagoya indicated that in both cases, Ala-600 (equivalent to Ala-55 of the chymotrypsin numbering system) had been replaced by Thr. No other substitutions at the active site and substrate-binding site residues, namely, His-57, Asp-102, Ser-195, and Asp-189, were found in the plasmin light chain variants, indicating that all these residues are intact. Moreover, the NH2-terminal heptapeptide sequences of the plasmin light chain variants isolated from plasminogens Tochigi II and Nagoya were identical to the sequence determined for the normal control. These results indicate that the absence of proteolytic activity of both abnormal molecules is due to the same amino acid substitution as that of previously reported plasminogen Tochigi.

Alanine↗
PubMed1984

Ventricular arrhythmias in children: the validity of exercise stress tests for their diagnosis and management.

One hundred ninety-six children ranging in age from 4 years to 15 years with premature ventricular contraction (PVC) on a resting electrocardiogram (ECG) underwent exercise tests and 29 of them were found to have significant ventricular arrhythmias. They included 8 patients with 2 PVC's in row, 8 patients with 3-4 PVC's in row, and 13 patients with more than 5 PVC's in row (ventricular tachycardia: VT). These 29 patients were evaluated with exercise tests by two-step exercise ECG (TSE) and by treadmill (TM), and with 24 hour continuous ECG monitoring (Holter monitoring). 141 ECG's, 77 TSE's, 77 TM's and 46 Holter monitoring were obtained in total, and the incidence of the each study revealing findings compatible with the final diagnosis was 3%, 15%, 51% and 26%, respectively. For detection of 2 PVC's in row, the sensitivity of TSE and TM was not different, but for picking up 3-4 PVC's in row and VT, TM was significantly superior to TSE. Among the VT patients, there were a few cases in whom neither TM nor Holter monitoring alone was sufficient to confirm the diagnosis. Children with symptoms suggestive of ventricular arrhythmias should be carefully evaluated with a combination of exercise tests and Holter monitoring.

Adolescent↗
PubMed1984

A network data base system for children with cardiac disease--echocardiographic data of MCLS.

We developed a computer-assisted network data base system for children with cardiac diseases. It aims at storage and exchange of medical information from many hospitals to prevent school children from sudden death caused by heart diseases. The computer system used was PANAFACOM U-1500 introduced at Shimane Medical University Hospital in 1980. The format of the questionnaire is designed to standardize the computer-assisted data-entry method among different hospitals. The entries of questionnaires are composed of basic information about the patient and laboratory information. The former is identification data of the patient, and the latter principally the values of M-mode echocardiographic measurement. Two types of output-tables were made from the data base. One is a table of each disease, and the other each hospital.

Child↗
PubMed1984

Studies of 7 beta-[2-(aminoaryl)acetamido]-cephalosporin derivatives. I. Synthesis and structure-activity relationships in the aminopyridine series.

The synthesis and in vitro activity of 7 beta-(2-aminopyridyl-2-alkoxyiminoacetamido)cephalosporins with various substituents at the 3-position are described. The effects of substitution pattern on the pyridine ring, oxime substituent and 3-substituent were studied as a function of the MIC values. Of these various kinds of derivatives, 7 beta-[2-(2-aminopyridin-6-yl)-2-alkoxyiminoacetamido]cephalo sporins exhibited significantly higher activity against most of micro-organisms.

Aminopyridines↗
PubMed1984

Studies of 7 beta-[2-(aminoaryl)acetamido]-cephalosporin derivatives. II. Synthesis and structure-activity relationships in the aminopyrimidine series.

The synthesis and the antibacterial activity of 7 beta-[2-(aminopyrimidinyl)-2-oxyiminoacetamido]cephalosporin s with various substituents at the 3-position in the cephem nucleus are described. The 7 beta-[2-(4-aminopyrimidin-2-yl)-2 -methoxyiminoacetamido]cephalosporin derivative (1) showed significantly higher activity than the corresponding 2-aminopyrimidin-4-yl derivative (2) against Gram-negative bacteria. It was also higher in potency against Escherichia coli and Serratia marcescens than the aminopyridyl compound (4).

Bacteria↗
PubMed1984

[A case of multicentric early carcinoma of the stomach--preoperative diagnosis].

A 59-year-old man was admitted complaining of substernal pain and anorexia. Upper GI series revealed a benign gastric ulcer in the posterior wall, and gastrofiberscopy was done. Besides the benign lesion, two early carcinomas of type IIc were found. Biopsy specimens of both lesions showed malignancy and gastrectomy was performed. Histological investigation revealed poorly differentiated adenocarcinoma in the anterior wall and well differentiated tubular adenocarcinoma in the posterior wall. Both lesions were absolutely independent and isolated. In most instances, multicentric or multiple early gastric carcinomas manifest similar histological features, but in our case, the lesions were of different types.

Adenocarcinoma↗
PubMed1984

[Diagnosis of myocardial ischemia in Kawasaki disease: thallium-201 myocardial imagings at rest, with exercise and with dipyridamole administration].

Thallium-201 myocardial imaging was performed at rest in 131 children with coronary arterial lesions due to Kawasaki disease. The coronary arterial lesions were assessed by selective coronary angiography within a few days of the isotope study. Twenty-one children had occlusive lesions, and segmental stenotic lesions were seen in 16 children. Perfusion defects of the myocardial images were detected in nine of the former and in three of the latter. The locations of the perfusion defects coincided with the perfusion areas of the affected vessels on coronary angiography. Twelve patients with initial perfusion defects at rest had a follow-up study and the defects disappeared in five. These patients had re-establishment of coronary blood flow in the initially affected areas by either development of collateral vessels or recanalization. Myocardial imaging with exercise was performed in 27 patients including four with coronary arterial occlusion and two with segmental stenosis on coronary angiography. All with coronary artery lesions showed perfusion defects on the imaging with exercise, while the resting study showed the defects only in one patient, in whom more extensive perfusion defects were observed after exercise. Myocardial imaging following intravenous injection of dipyridamole was carried out in 43 patients. Perfusion defects after the injection were noted in 15 of 17 patients with coronary occlusion and in nine of 13 patients with segmental stenosis. In four patients with perfusion defects at rest, additional or more extensive defects were revealed by this drug in the areas of additional coronary arterial involvements. In 20 patients with perfusion defects only after dipyridamole injection, the perfusion defects coincided with the angiographic findings very well. A perfusion defect was documented following dipyridamole injection in one exceptional patient who had no stenotic lesions, but had three giant coronary aneurysms of the right coronary artery. Thus the dilated coronary lesions seemed to give a perfusion defect. In some of the patients whose perfusion defects disappeared at rest on a follow-up study, the defects were disclosed by exercise and/or dipyridamole administration. Thus, thallium-201 myocardial imagings combining resting and exercise or dipyridamole studies were valuable for the detection and assessment of coronary arterial lesions of Kawasaki disease.

Adolescent↗
PubMed1984

[Thallium-201 myocardial imaging in patients with congenital heart disease following open-heart surgery].

Thallium-201 myocardial imaging was performed for 77 patients with congenital heart disease to evaluate myocardial damage following open-heart surgery. There were 23 patients with ventricular septal defects, 33 with tetralogy of Fallot, 12 with atrial septal defects, and nine with other diseases. The imaging results were compared with the angiographic and electrocardiographic findings. Patchy perfusion defects or images of poor thallium uptake were noted in five of 77 patients, among whom four had accompanying serious ventricular arrhythmias. This suggested a close correlation of the post-operative ventricular arrhythmias with myocardial damage. For 20 of 77 patients, vents were inserted through the left ventricle, and for the remaining 57 through the left atrium. Perfusion defects were found at the apex in three, and left ventriculography showed a paradoxical motion of the apex in five in patients whose vents were inserted through the left ventricle. Sensitivity and specificity in detecting myocardial damage of the apex were 60% and 98%, respectively. In one case, myocardial infarction was demonstrated immediately after the repair of the ventricular septal defect. Myocardial imaging was useful in evaluating the infarcted area and for follow-up study. Thus, thallium-201 myocardial imaging was regarded useful for assessing myocardial damage following open-heart surgery in congenital heart disease patients.

Adolescent↗
PubMed1984

Regional right ventricular wall motion in patients with obstruction of the right coronary artery due to the mucocutaneous lymph node syndrome.

The present study quantitatively analyzed the shortening fraction of regional wall motion (RWM) of the right ventricle (RV) in 18 patients with obstruction of the right coronary artery due to the mucocutaneous lymph node syndrome (MCLS). None of the patients had any apparent lesion of the left coronary artery by selective coronary angiography. The radial approach was used except for the right ventricular outflow tract in the lateral view, using the Siemens AVD system. There was no correlation between the occlusion and segmental stenosis, nor was there any correlation between dysfunction of the RWM of the RV and the posterior wall of the left ventricle (LVPW). The second cineangiography one year later showed that shortening of three segments (II, III, and VIII) of the RV was significantly reduced, as compared with that during the first study. We believe that dysfunction of the LVPW may not be contributory in diagnosing RV infarction. Not only LV-graphy, but RV-graphy as well, are recommended for patients with RV dysfunction due to obstruction of the right coronary artery in the MCLS.

Child, Preschool↗
PubMed1984

Decrease in L-type pyruvate kinase activity in rat liver by some promoters of hepatocarcinogenesis.

A probably promoter-specific decrease of L-type pyruvate kinase (L-PK) in Wistar rat liver is described. The possibility of utilizing the decrease in L-PK activity for screening of hepatic promoters is discussed. A significantly decreased level of activity of L-PK was observed during continuous feedings of the hepatocarcinogen 3'-methyl-4-dimethylaminoazobenzene [(3'-MeDAB) CAS: 55-80-1], which initiates and promotes hepatocarcinogenesis, and of the known hepatic promoters phenobarbital [(PB) CAS: 50-06-6] and dichlorodiphenyltrichloroethane (CAS: 50-29-3) for at least 4 weeks. In contrast, if it occurred, the decrease in L-PK activity by the nonpromoting agents amobarbital (CAS: 57-43-2) and diphenylhydantoin. (CAS: 57-41-0) was temporary and almost overcome by the 4th week. The depression of L-PK activity caused by PB was reversible, was inversely correlated with PB concentration in the diet, and seemed to be organ-specific. Although hepatic promoters lowered L-PK activity in this study, data are so limited that a much more extensive study is necessary before a general conclusion can be drawn. In contrast to L-PK activity, the activity of K-type pyruvate kinase (K-PK) was induced by injections of the carcinogen diethylnitrosamine (CAS: 55-18-5) or the hepatotoxin CCl4 (CAS: 56-23-5) or by the feeding of 3'-MeDAB. However, feeding of PB or 2-methyl-4-dimethylaminoazobenzene (CAS: 54-88-6), which initiates but does not promote hepatocarcinogenesis, did not increase K-PK activity.

Animals↗
PubMed1983

Periodic paralysis with cardiac arrhythmia.

In 1963, Klein et al. first described two girls with normokalemic periodic paralysis and cardiac arrhythmia. We have observed a 15-year-old girl with cardiac arrhythmia and normokalemia but with some features of hyperkalemic, periodic paralysis. The patient showed a waddling gait and Gower's sign. She had atrophy of the proximal muscles and deep tendon reflexes were reduced. Her ECG showed bigeminy with multifocal premature ventricular contractions. At the start of an episode of muscle weakness, the serum potassium concentration rose from 3.1 to 4.4 mEq/l. Muscle weakness was not provoked by intravenous administration of 45 g glucose or of 72 g glucose followed by 10 units of regular insulin. Muscle weakness was evoked by the ingestion of 4 g potassium chloride. During the provoked muscle weakness, the ECG showed normal sinus rhythm temporarily.

Adolescent↗
PubMed1983

Platelet function in bilateral acute retinal necrosis.

We tested platelet function in seven patients (four men and three women, ranging in age from 26 to 57 years) with bilateral acute retinal necrosis. Hyperaggregation was detected in six of the seven. Antiplatelet therapy (aspirin, 500 mg/day) together with corticosteroids or other drugs produced satisfactory results. Despite administration of antiplatelet drugs, two retinal detachments developed; both were surgically repaired. A lower dosage of antiplatelet agents in one case and late administration of it in another were thought to have caused the retinal detachments. After the acute stage was over or the retina was reattached, there were no further recurrences during a follow-up period of more than one year.

Acute Disease↗