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Biomedical subjects

I Kubota

Publications and source records attributed to I Kubota.

At least 163 records · Page 9Linked to original sources
PubMed1985

The clinical significance of exercise-induced ST-segment elevation in previous anterior myocardial infarction.

To investigate the mechanism of exercise-induced ST elevation in previous anterior myocardial infarction, exercise body surface mapping was performed on 22 patients with anterior myocardial infarction. ST elevation was compared with the findings of exercise radionuclide ventriculography and exercise thallium-201 myocardial perfusion imaging. ST-segment was quantified by the integral of ST-segment voltage. The maximal value of ST segment integral out of the 87 leads on the body surface was defined as ST max. The percent of change in ST max after exercise was closely correlated to the decrease in ejection fraction (r = 0.76). Furthermore, 9 of the 12 patients with increased ST max after exercise had exercise-induced regional wall motion abnormalities mainly in the apical and anterolateral segments, while other 10 patients without increased ST max did not (p less than 0.01). There was no difference in % change of ST max a) between anterior reversible defect (+) group and the (-) group; b) between inferior reversible defect (+) group and the (-) group; c) between single vessel (isolated left anterior descending artery stenosis) group and the multivessel group. This fact indicated that exercise-induced ST elevation did not result from the exercise-induced myocardial ischemia of the infarctional segment or the remote non-infarctional segment. We concluded that exercise-induced ST elevation in previous anterior myocardial infarction is mainly due to the aggravation of anterior wall motion abnormalities induced by exercise.

Adult↗
PubMed1984

Identification in rat atrial tissue of multiple forms of natriuretic polypeptides of about 3,000 daltons.

Rat atrial natriuretic peptides of relatively low molecular weight have been isolated from the alpha-component of rectum relaxant activity corresponding to about 3,000 daltons, which was obtained as a side fraction in our previous isolation of beta-rat atrial natriuretic polypeptide (beta- rANP ). In contrast to the same fraction from human atria, the rat atrial alpha-component was found to contain six or more distinct but related peptides, eliciting a potent natriuretic activity. Six of them (B-II, C, D, E, B-I and A), containing 35, 33, 32, 31, 28 and 25 amino acid residues, respectively, have been purified to homogeneity and sequenced. All these peptides were found to correspond to the C-terminal sequence of beta- rANP composed of 48 residues, with varying N-terminal elongations. This indicates that these peptides are derived from beta- rANP . Peptide B-I, composed of 28 residues, is identical to alpha-human atrial polypeptide(alpha- hANP ), with a single replacement of Ile for Met at position 12.

Amino Acids↗
PubMed1984

Studies on phospholipase A inhibitor in blood plasma. I. Purification and characterization of phospholipase A inhibitor in bovine plasma.

Phospholipase A inhibitor was found in bovine, human and porcine plasma. The inhibitor was purified about 300-fold from bovine plasma by ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 gel filtration and anti-BSA antibody-agarose column chromatography to remove albumin. The purified material was homogeneous as judged by immunoelectrophoresis and 0.7% agarose-2% polyacrylamide gel electrophoresis. The inhibitor suppressed not only rat and human plasma phospholipase A2 activity, but also purified Mamushi (Agkistrodon halys blomhoffi) venom phospholipase A2-II. Bovine plasma inhibitor was shown to be a lipoprotein containing phosphatidylcholine, sphingomyelin, cholesterol ester, and triacyl glycerol as major lipid components. The molecular weight of the native inhibitor was nearly the same as that of bovine plasma high density lipoprotein (HDL) when determined by the gel filtration method. The molecular weights of two subunits of the inhibitor observed on polyacrylamide gel electrophoresis in the presence of SDS were about 10K and 42K. The anti-inhibitor antiserum obtained from rabbits immunized with the highly purified inhibitor cross-reacted with bovine plasma alpha-lipoprotein (HDL). The lipid composition of the inhibitor was similar to that of HDL, but apoinhibitor and apoHDL were different in molecular weight and solubility in various buffers.

Animals↗
PubMed1984

Determination of the left ventricular asynergic site by QRST isointegral mapping in patients with myocardial infarction.

QRST isointegral maps were made from 87 body surface ECGs in 41 patients with prior myocardial infarction. To evaluate the abnormalities of QRST isointegral maps, a deviation map was constructed from a deviation index, which expressed the deviation of the QRST time-integral value from the normal value at each lead point. Patients were divided into 3 groups according to the asynergic site on left ventriculograms: patients with anterior wall asynergy (n = 13), those with inferior wall asynergy (n = 13) and those with both anterior and inferior asynergies (n = 15). A consistent deviation map pattern was obtained in each group regardless of the QRS duration. Consequently, the deviation map was considered to be a practical method of identifying the asynergic site in patients with myocardial infarction, especially in those with intraventricular conduction disturbances. It is suggested that the deviation map can reveal abnormally altered intrinsic ventricular recovery properties resulting from a loss of the electromotive force of the infarcted myocardium.

Adult↗
PubMed1984

Electrocardiographic study of chronic pulmonary emphysema by means of body surface mapping.

In order to investigate the electrocardiographic changes in patients with chronic pulmonary emphysema (CPE), 87 unipolar electrocardiograms were simultaneously recorded in 20 normal subjects and 22 patients with CPE. The voltages and the sites of Max. R (most positive R) and Max. S (most negative S) in these 87 leads were investigated. Further, the voltages and the sites of the maximum and the minimum on isopotential maps during the QRS period were examined. In patients with CPE, the sites of Max. R, Max. S, the maximum and the minimum were all positioned lower than in normal subjects. However, the voltages of Max. R and Max. S in CPE were not significantly different from those in normal subjects. It was considered that the most prominent change in the body surface maps in CPE was the downward shift of potential distribution. This change seems to be due mainly to the downward displacement of the diaphragm and the heart resulting from the overinflation of the lung.

Adult↗
PubMed1984

Attenuation of exercise-induced R wave increase after diltiazem in effort angina pectoris.

Body surface mapping was used to study the effects of diltiazem on exercise-induced QRS amplitude changes in 7 patients with stable effort angina pectoris. Body surface areas showing R or S amplitude changes (greater than 0.2 mV) after treadmill exercise were calculated. After the administration of 90 mg of diltiazem, the R increased area was significantly smaller than that without diltiazem (p less than 0.02), although the same workload was performed. It was suggested that diltiazem diminished the exercise-induced myocardial ischemia and this improvement of ischemia resulted in the reduction of the R increased area after exercise.

Adult↗
PubMed1984

Human atrial natriuretic polypeptides (hANP): purification, structure synthesis and biological activity.

In the present survey for natriuretic factors in human atrial extract, conducted by using in vitro assay for the relaxant activity of chick rectum, three distinct human atrial natriuretic polypeptides (hANP) (alpha-, beta- and gamma-hANP), differing in molecular weight (alpha, 3000; beta, 6000, gamma, 13 000 daltons) have been purified and sequenced. gamma-hANP, of 13 000 daltons, has been identified as a 126-residue peptide which carries the whole sequence of alpha-hANP of 28-amino acids at the C-terminus, while beta-hANP has been proved to be an antiparallel dimeric form of alpha-hANP. Synthetic alpha-hANP at a dose of 0.2 nmol induces diuresis and natriuresis as well as hypotension, when injected into assay rats [1]. Natriuretic activity of beta- and gamma-hANP was estimated to be about one-fifth or less on molar base than that of alpha-hANP.

Amino Acid Sequence↗
PubMed1983

Isointegral analysis of body surface maps for the assessment of location and size of myocardial infarction.

To estimate the location and size of myocardial infarction (MI), an isointegral mapping technique was adopted from among various body surface electrocardiographic mapping techniques. QRS isointegral and departure maps were made in 35 patients with MI. These patients were separated into 3 groups, based on the location of MI: anterior, inferior, and anterior plus inferior. The severity and location of MI were estimated by thallium-201 myocardial perfusion imaging and the degree of scintigraphic defect was represented by a defect score. The extent of MI was expected to be reflected on the QRS isointegral maps as a distribution of negative QRS complex time-integral values. However, the extent and the location of MI were hardly detectable by the original maps. A departure mapping technique was then devised to observe the distribution of departure index on the body surface. Particular attention was given to the area where the departure index was less than -2, and this area was expected to reflect the location and size of specific abnormality of isointegral map due to MI. There were strong correlations between departure area and defect score in the anterior and inferior MI cases (r = 0.88 and r = 0.79, respectively). However, patients with anterior MI plus inferior MI showed no such correlation. Q-wave mapping was compared with QRS isointegral mapping, and QRS isointegral mapping was found to be more accurate in the estimation of the location and size of MI than Q wave mapping. Thus, QRS isointegral mapping, especially departure mapping, is more useful and convenient for detecting the location and size of MI than methods such as isopotential and Q wave mapping.

Adult↗
PubMed1983

The nucleotide sequence of the yeast PHO5 gene: a putative precursor of repressible acid phosphatase contains a signal peptide.

The nucleotide sequence of the PHO5 gene of the yeast, Saccharomyces cerevisiae, which encodes repressible acid phosphatase (APase) was determined. Comparison of N-terminal amino acid sequence deduced from the nucleotide sequence with that of the purified repressible APase revealed the existence of a putative signal peptide in the precursor protein. The signal peptide was shown to contain 17 amino acid residues and its structural features were quite similar to those of higher eukaryotic and prokaryotic signal peptides. The nucleotide sequence of 5' and 3' noncoding flanking regions of the PHO5 gene are also discussed.

Acid Phosphatase↗
PubMed1983

Expression of chemically synthesized alpha-neo-endorphin gene fused to E. coli alkaline phosphatase.

An alpha-neo-endorphin (alpha NE) gene, which we previously synthesized chemically and inserted into E. coli beta-galactosidase gene of pK013 plasmid, has been excised and fused to E. coli alkaline phosphatase (APase) gene. One of the transformants was named E15/pA alpha NE1. Under the APase gene regulation, APase-alpha NE chimeric protein was expressed at 1.3 X 10(6) molecules per cell, and accounted for about 60% of total cellular proteins. The HPLC pattern of CNBr treated E15/pA alpha NE1 was very simple reflecting the high content of the chimeric protein and low numbers of methionine residues in it. A series of genes encoding APase-alpha NE chimeric proteins in which 30 to 94 C-terminal amino acid residues were replaced by (met)-alpha NE, was cloned in E. coli. Transportation of the chimeric proteins to periplasmic space was studied. All chimeric proteins were apparently processed by signal peptidase but few, if any, was transported to the periplasmic space.

Alkaline Phosphatase↗
PubMed1983

Body surface distribution of exercise-induced ST depression in patients with angina pectoris.

In 38 patients with angina pectoris, 87 unipolar lead electrocardiograms were recorded from different sites over the entire thoracic surface both before and after submaximal treadmill exercise. The site of exercise-induced ST depression on the body surface was correlated with the findings of the coronary arteriography. The number of leads which showed exercise-induced ST depression was 7.2 +/- 1.8 in one vessel disease, 15.6 +/- 2.1 in two vessel disease, and 23.6 +/- 2.0 in three vessel disease (values are mean +/- SEM). Thus, the number of leads showing ST depression was proportional to the severity of the coronary artery disease. Exercise-induced ST depression was most often seen in left anterior chest leads, especially in V5 of the standard 12-ECG. However, it was not possible to identify the obstructed coronary artery from the body surface distribution of ST depression.

Aged↗
PubMed1982

Treadmill stress test using body surface mapping in coronary artery disease--the clinical significance of ST depression.

In this study we assessed in 27 patients with coronary artery disease whether the size of the ST-depression area, which was measured by body surface maps recorded before and after treadmill exercise, could be a useful indicator for evaluating coronary artery disease (CAD) quantitatively. The patients were divided into 3 groups on the basis of the findings of the left ventriculograms: patients with anterior asynergy (n = 6), those with inferior asynergy (n = 6) and those with no asynergy (n = 15). Coronary arteriograms were evaluated according to Pujadas, and epsilon Grade, as an index of the severity of CAD, was developed by adding the grade numbers of the 4 main coronary stems (right coronary artery, main trunk of the left coronary artery, left anterior descending artery and left circumflex artery). Patients with inferior asynergy and with no asynergy have ST-depression areas in proportion to their epsilon Grade (r = 0.845, p less than 0.001), whereas none of the patients with anterior asynergy showed ST-depression areas regardless of their epsilon Grade. Of 6 patients who had anterior asynergy, 5 (83%) had pathologic Q waves in the left anterior chest leads. These findings emphasize the clinical value of the ST-depression are for the quantitative and non-invasive diagnosis of CAD, especially in patients without pathologic Q waves in the left anterior chest leads.

Adult↗