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Biomedical subjects

I Kubota

Publications and source records attributed to I Kubota.

At least 145 records · Page 8Linked to original sources
PubMed1987

Body surface mapping for the assessment of left ventricular hypertrophy in patients with essential hypertension.

To investigate the electrocardiographic abnormalities of left ventricular hypertrophy (LVH), body surface potential maps were acquired from 42 patients with essential hypertension. We adopted the time integral technique for analyzing body surface mapping data and used echocardiographic left ventricular muscle mass (LV mass) as the index of advance of LVH. The QRS, ST-T and QRST isointegral maps in normal volunteers all demonstrated smooth bipolar surface distribution patterns, with positive values located over the precordium and negative values over the right upper chest and back. In patients with essential hypertension, changes in the isointegral maps were observed as LVH advanced; A QRS increased on the upper left lateral chest and decreased (became more negative) on the right chest, A ST-T decreased on the lower left lateral chest and increased on the right upper chest, and areas of significant difference in A QRS and A ST-T were expanded as LVH advanced. A QRST decreased on the lower left lateral chest and increased on the right upper chest only in patients with severe LVH. We conclude that the changes of QRS and ST-T isointegral maps depend on the degree of advance of LVH and the severe grade of LVH causes the alterations in intrinsic repolarization properties.

Adult↗
PubMed1987

Changes of Ca2+-ATPase and cytochrome oxidase activity of myocardial cell under early and late ischemia:--comparison with ultrastructural changes.

Using the histo- and cytochemical technique we assessed the Ca2+-transporting function of mitochondria (Mit) and sarcoplasmic reticulum (SR), and the ATP producing function of Mit in the ischemic myocardial cell of a dog's heart. In comparing ultrastructural ischemic changes, cytochrome oxidase (CO) and Ca2+-ATPase were cytochemically and histochemically measured when the myocardium was subjected to the ischemia of left anterior descending coronary artery occlusion for 15 min, and 60 min. After 15 min of occlusion the ischemic alterations consisted of a wide I band, decreased glycogen (G) and Mit swelling with a slight reduction of matrix density. Although CO activity was not reduced, Ca2+-ATPase had decreased mainly in Mit. Sixty min of ischemia resulted in loss of G, intermyofibrillar edema, marked Mit swelling with loss of matrix density and partial disruption of cristae, and dilatation of SR. Ca2+-ATPase activity was significantly reduced in Mit, SR and myofibrils. Although there was Mit swelling with partial disruption of cristae after 60 min of ischemia, CO activity was found to still exist in the remaining cristae. These findings suggest that intracellular organelle dysfunction progresses in the ischemic myocardial cell at different rates, and that disruption of intracellular Ca2+-homeostasis may occur early in the ischemic state.

Animals↗
PubMed1987

Determination of the site of myocardial infarction by QRST isointegral mapping in patients with abnormal ventricular activation sequence.

QRST isointegral maps were constructed from 87-lead ECGs in 37 patients with abnormal ventricular activation, such as ventricular premature beats, WPW syndrome, left bundle branch block and right bundle branch block. Patients were divided into 2 groups, the old myocardial infarction (OMI) group (n = 18) and the non-infarction group (n = 19). In the latter group, QRST isointegral maps showed smooth bipolar surface distributions, with positive values located over the precordium and negative values over the right upper anterior chest and the back, independent of the ventricular activation sequence. In the OMI group, for individual patients, the distribution patterns of QRST isointegral maps were similar between normal sinus rhythm and VPB or WPW conduction. Including the patients with BBB, a decrease of the time-integral value was consistently found in leads which corresponded to an asynergic site indicated by left ventriculography. To evaluate the abnormalities of QRST isointegral maps, particular attention was given to the area where the QRST time-integral value was less than the lower limit determined by 40 normal subjects; this area was designated as the negative departure area. Characteristic distribution patterns of the negative departure area seem to indicate the asynergic site, independent of the activation sequence. Thus, the QRST isointegral map may be useful for identifying the asynergic site in patients with abnormal ventricular activation sequence, that is hardly detected with conventional electrocardiograms.

Adolescent↗
PubMed1987

Determination of the hypertrophic site of the left ventricle by body surface mapping in patients with hypertension.

To estimate the hypertrophic sites of the left ventricle by body surface mapping (MAP), we performed MAP in 55 patients with hypertension and compared the MAP data with echocardiographic findings. MAP data were analyzed using the departure map technique reported by Flowers et al. The mean and standard deviation (SD) of the normal control were obtained from 40 normal volunteers. We constructed departure maps at 20, 30, 40, 50 and 60 msec from the onset of the QRS. Each map indicates the area of abnormally increased potential outside the normal range at the time. Subjects were classified into 5 groups according to the appearance time of the abnormal positive area. Septal thickness was significantly increased in groups that had an abnormal positive area at 20 msec, and left ventricular posterior wall thickness was significantly increased in the groups that had an abnormal positive area at 60 msec. We postulate that the increased electrical potential due to hypertrophy of the interventricular septum is represented by the abnormal positive area at 20 msec, and the increased potential of the left ventricular posterior wall by the abnormal positive area at 60 msec. MAP, especially the departure map technique, is a useful method to detect the abnormal electrical potential distribution in patients with left ventricular hypertrophy.

Adult↗
PubMed1987

[Predictability of stress-induced myocardial ischemia from coronary arteriography in patients with organic coronary artery stenosis].

A quantitative index for describing the severity and extent of coronary artery disease has not been established yet, although it is certain that the stenosis causes myocardial ischemia induced by stress. To establish the most meaningful scoring system, we developed the grading of stenosis which is "critical" or significant in the single-, double-, and triple-vessel method (SDT), and the extent of improvement in the predictive value which may be induced by accounting for the predominance of the three major coronary arteries nourishing the left ventricle. Thirty-three patients (six were women), whose average age was 58.6 years, all having exertional angina pectoris and fixed organic coronary artery stenosis documented by coronary arteriography, but no old myocardial infarction, were the subjects of this study. For these patients the mean redistribution index (RDI) was determined by ergometer stress myocardial perfusion imaging using 201T1. The number (nST) of significant ST segment depressions by body surface ECG mapping after treadmill stress tests was compared with the sigma Pujadas grade, which is the sum of each grade assigned to each of the three major coronary arteries, and with the Pujadas score, which is the weighted sum of grades by dominance in the coronary artery distribution. The SDT method was a better predictor of ischemia if the criterion for critical stenosis is selected at a more severe stenosis (greater than 90% diameter stenosis). Among factors predicting ischemia, the length of the stenosis and the presence of collaterals did not seem to be definitive. However, the distribution of the arteries was an important factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1987

An evaluation of fecal occult blood screening in automated multiphasic health testing and services.

In the present paper, the efficacy of fecal occult blood screening in automated multiphasic health testing and services (AMHTS) is evaluated, and some problems with it are also discussed. A total of 54,735 subjects were screened for occult blood by the Shionogi slide 1-day method. According to a follow-up survey of the 715 subjects judged (+ +), 42 cases of colorectal polyp and 13 of colorectal cancer were confirmed. Eight of the 12 cases of primary colorectal cancer, excluding a case of metastatic transverse colon cancer, were located in the colon's right-side. The result may have arisen from the fact that most subjects in AMHTS are relatively young and free of symptoms. This suggests that fecal occult blood testing in AMHTS may be useful for detecting colon cancers of the right side as well as of the left. Of the nine cases of primary colorectal cancer previously screened, five had been judged (+) in previous testing. This fact indicates an especially rigorous examination of subjects judge (+) to be necessary in AMHTS. Meanwhile, of the 45 cases of gastric cancer detected by enhanced X-ray testing, only eight (17.8%) subjects were judged (+) or (+ +). It is suggested that fecal occult blood testing may not, therefore, be too effective in screening for gastric cancer.

Adult↗
PubMed1986

Non-invasive detection of coronary artery disease by body surface electrocardiographic mapping after dipyridamole infusion.

Electrocardiographic changes after dipyridamole infusion (0.568 mg/kg/4 min) were studied in 41 patients with coronary artery disease and compared with those after submaximal treadmill exercise by use of the body surface mapping technique. Patients were divided into three groups; 19 patients without myocardial infarction (non-MI group), 14 with anterior infarction (ANT-MI) and eight with inferior infarction (INF-MI). Eighty-seven unipolar electrocardiograms (ECGs) distributed over the entire thoracic surface were simultaneously recorded. After dipyridamole, ischemic ST-segment depression (0.05 mV or more) was observed in 84% of the non-MI group, 29% of the ANT-MI group, 63% of the INF-MI group and 61% of the total population. Exercise-induced ST depression was observed in 84% of the non-MI group, 43% of the ANT-MI group, 38% of the INF-MI group and 61% of the total. For individual patients, there were no obvious differences between the body surface distribution of ST depression in both tests. The increase in pressure rate product after dipyridamole was significantly less than that during the treadmill exercise. The data suggest that the dipyridamole-induced myocardial ischemia is caused by the inhomogenous distribution of myocardial blood flow. We conclude that the dipyridamole ECG test is as useful as the exercise ECG test for the assessment of coronary artery disease.

Adult↗
PubMed1986

Two acyl-coenzyme A oxidases in peroxisomes of the yeast Candida tropicalis: primary structures deduced from genomic DNA sequence.

We report the complete nucleotide sequence of two genes encoding major peroxisomal polypeptides (PXPs) of Candida tropicalis. One, POX4, encodes PXP-4, which is the most abundant polypeptide in cells grown on oleic acid, and the other, POX5, is the gene for PXP-5. Each of the two polypeptides was found to be the subunit of a distinct long-chain acyl-coenzyme A oxidase: acyl-CoA oxidase II (PXP-4) or acyl-CoA oxidase I (PXP-5). Both the genes had no intron and gave a single open reading frame. The NH2-terminal sequences, except the initiator methionine, and the calculated molecular weights of the deduced polypeptides were consistent with those of the respective PXPs. Well-conserved sequences of 12 and 16 hydrophobic amino acids were present in the middle of the polypeptide, instead of at the NH2 terminus, and may be internal signal sequences for the peroxisomal location of PXPs. Although the two polypeptides were significantly homologous throughout their sequences, the local homologies in two regions out of five were markedly diverged from the average (63%); the homology in the second region was 93%, whereas that in the fourth one was only 24%. The implications of this finding are discussed in respect to the multiplicity of peroxisomal enzymes and the presence of multifunctional proteins in peroxisomes.

Acyl Coenzyme A↗
PubMed1986

Purification of natural human interferon-gamma by antibody affinity chromatography: analysis of constituent protein species in the dimers.

A simple procedure for purifying human interferon-gamma from leukocytes was established, based on monoclonal antibody affinity chromatography. The recovery of interferon activity was essentially quantitative, and the specific activity of the product was (4-12) x 10(7) international units/mg protein. SDS-polyacrylamide gel electrophoresis reproducibly revealed four components associated with interferon activity (and no other proteins): two major ones with molecular weights (MW) of 24,000-25,000 (25K) and 19,000-20,000 (20K), a minor one with MW 14,000-15,000 (15K) (these three bands were doublets), and a still less prominent one(s) with MV 40,000-48,000. Gel filtration in neutral solution indicated that all the 25K, 20K, and 15K species exist as oligomers, probably dimers. By means of experiments using a cleavable crosslinking reagent, the dimers were shown to comprise both homo-and heterodimers. Gel filtration in alkali (the condition used during purification) indicated that the molecules are largely in a monomeric state. Thus, the molecules once dissociated in alkali appear to reassociate at random upon neutralization; this process takes place without being accompanied by inactivation.

Amino Acid Sequence↗
PubMed1986

Comparison of the electrocardiographic changes induced by dipyridamole infusion and treadmill exercise in patients with coronary artery disease.

To determine whether dipyridamole infusion can be used as an alternative method to physical exercise, 87 lead body surface mapping was performed to compare the distribution patterns of ST-segment depression after 0.568 mg/kg/4 min dipyridamole infusion (D) and after submaximal treadmill exercise (T) in 21 patients with coronary artery disease. Significant ST-segment depression (greater than or equal to 0.05 mV) was observed in 19 patients after D and in 18 after T. After D and T, each patient showed a similar distribution pattern of ST-segment depression. There were no significant differences in the number of leads which showed ST-segment depression (nST: D, 15.6 +/- 11.1 vs T, 15.2 +/- 10.8) and in the maximal value of ST-segment depression (STmax: D, -0.24 +/- 0.16 vs T, -0.20 +/- 0.13 mV). Good correlations were observed in nST (r = 0.84) and in STmax (r = 0.87) between D and T. The increase in mean pressure-rate product after T was 89%, while the increase after D was only 22%. Our results suggest that this pharmacologic test to induce myocardial ischemia may be useful in the evaluation of coronary artery disease in patients who are physically unable to perform adequate exercise.

Aged↗
PubMed1985

Body surface distributions of ST segment changes after exercise in effort angina pectoris without myocardial infarction.

To investigate the sites of exercise-induced ST segment changes on the body surface in effort angina pectoris without myocardial infarction, we performed 87-lead ECG mapping in 61 patients before and 1.5 and 5 minutes after treadmill exercise. ST segment depression most often occurred in the left anterior chest leads and ST segment elevation developed mainly in the right upper chest leads. There was a good correlation between the number of lead points that showed ST segment depression (nSTd) and the number of those that showed ST segment elevation (nSTe) 1.5 minutes after exercise (r = 0.92). From 1.5 to 5 minutes after exercise, changes in nSTd for individual patients correlated well with changes in nSTe (r = 0.89). It was suggested that the ST segment elevation observed in this study directly reflected the subendocardial ischemia of the left ventricle. In patients with one-vessel disease (n = 32), there was wide overlap in the sites of ST segment changes among patients with left anterior descending artery disease (n = 19), those with left circumflex artery disease (n = 6), and those with right coronary artery disease (n = 7). These findings should lead to a better understanding of exercise-induced ST segment changes for the diagnosis of coronary artery disease.

Adult↗
PubMed1985

Noninvasive assessment of left ventricular wall motion abnormalities by QRS isointegral maps in previous anterior infarction.

In order to determine to what extent left ventriculographic abnormalities can be predicted from ECG changes in myocardial infarction (MI), 87 unipolar ECGs were simultaneously recorded in 22 patients with previous anterior MI with no conduction defects. We adopted a QRS isointegral mapping technique for analyzing body surface mapping data. Particular attention was given to the area where the QRS time-integral value was less than the lower limit (mean minus two standard deviations) of the normal, and this area was designated as the departure area. Left ventricular wall motion was assessed by left ventriculography and correlated with the departure area. The departure area demonstrated a close correlation with the left ventricular ejection fraction (r = -0.93) and the extent of asynergy (r = 0.74). It is suggested that the departure area reflects the loss of electromotive force due to MI. We conclude from this study that the QRS isointegral map is a useful method for evaluating left ventricular function in patients with anterior MI.

Adult↗
PubMed1985

Detection of posterior myocardial infarction by body surface mapping: a comparative study with 12 lead ECG and VCG.

To examine the diagnostic ability of body surface mapping in posterior myocardial infarction (PMI), mapping was performed in 11 patients with PMI proven by left ventriculography and T1-201 myocardial perfusion imaging (PMI group) and in 44 normal subjects (N group). Map data was analysed by the following methods: (1) potential departure maps at 10, 20, 30, 40 and 50 msec after the onset of QRS; each map indicates the area of decreased potential out of the normal range at the time. (2) AQRS departure map which indicates the area of decreased time-integral value of QRS out of the normal range. True positive (TP) in the PMI group and false positive (FP) in the N group were calculated for each method, and were compared with those of various criteria for PMI with standard 12-lead electrocardiogram (ECG) and Frank lead vectorcardiogram (VCG). The potential departure maps and the AQRS departure map had high TP (10/11 and 8/11) and low FP (0/44 and 0/44). The diagnostic ability of mapping is considered to be higher than that of ECG and VCG. Mapping, especially the departure map technique, is a sensitive and specific method to detect posterior infarction.

Electrocardiography↗
PubMed1985

P-wave changes in obstructive and restrictive lung diseases.

To evaluate the P wave changes in the electrocardiogram (ECG) in chronic lung diseases, we examined ECGs from twenty patients with interstitial pulmonary fibrosis (the FLD group) and twenty patients with chronic obstructive lung disease (fifteen with pulmonary emphysema and five with bronchial asthma, the COLD group). In the COLD group, the amplitude of P waves in leads II and III increased and the axis of the P wave shifted rightward. In the FLD group, however, these changes were not observed. Furthermore, the axis of the P wave exceeded +70 degrees in all the patients in the COLD group, and was less than +70 degrees for all the patients in the FLD group. The increased P wave terminal force in lead V1 was found in nine patients (45%) of the FLD group and in ten patients (50%) in the COLD group. We concluded that the rightward shift of the axis of the P wave was a characteristic of obstructive lung disease and that it was mainly caused by the overinflation of the lung. This P wave change was not observed in interstitial pulmonary fibrosis.

Adult↗
PubMed1985

Detection of local abnormalities in ventricular activation sequence by body surface isochrone mapping in patients with previous myocardial infarction.

Body surface isochrone mapping was performed in 36 normal subjects and in 85 patients with previous myocardial infarction. Eighty-seven unipolar electrocardiograms distributed over the anterior chest and the back were recorded simultaneously. For each lead, activation time was measured as the time from the onset of QRS to the peak of the R wave. The lead points where R waves were not observed were designated the "no R wave area" (NR area). Isochrone maps of normal subjects had a consistent pattern, with isochrone lines extending from the right upper anterior chest to the left anterior chest and then to the back. NR area was small and was located only on the right upper chest or the upper back. On the isochrone maps of patients with myocardial infarction, abnormal findings were observed; NR area was found in 26 of 28 patients with anterior infarction on the upper to middle anterior chest, in 13 of 22 patients with inferior infarction on the lower chest, and in 24 of 25 patients with anterior and inferior infarction on the upper to lower anterior chest. Activation time was delayed near the NR area (peri-NR area delay) in 37 patients. In patients with apical infarction, an islandlike zone of delayed activation was typically found on the left precordium. These abnormal patterns are considered to indicate local abnormalities in the activation of infarcted myocardium; the NR area indicates dead unexcitable scar, and the peri-NR area delay and islandlike zone of delayed activation indicate partially infarcted myocardium of slow activation. Patients with NR area had greater degree of left ventricular asynergy and lower ejection fraction than those without.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Effects of lung volume on body surface electrocardiogram. Isointegral analysis of body surface maps in patients with chronic pulmonary emphysema.

To evaluate the effects of lung volume changes on the body surface electrocardiogram, we performed body surface potential mapping (87 lead points) in 20 normal subjects (group N) and in 21 patients with chronic pulmonary emphysema (group CPE). P-wave, QRS, ST-segment, ST-T and QRST iso-integral maps were constructed. Group-mean maps and the mean value of the maximum (max) and the minimum (min) on each map were compared between group N and group CPE. In group CPE, the body surface distribution of the P, QRS, ST, ST-T and QRST time integrals were all positioned downwards compared with those of group N. In addition, we also detected an increase in the max of P and decreases in the min of P; max and min of QRS; and in max of ST-T and QRST integrals. It was suggested that these changes were caused by the downward shift and clockwise rotation of the heart, and also by the decreased electrical conductivity of the lungs.

Adult↗
PubMed1985

Diagnosis of coronary artery disease by body surface mapping--body surface distribution of exercise-induced ST changes in patients without myocardial infarction.

In 36 patients with effort angina pectoris without myocardial infarction, the sites of exercise-induced ST changes (depression and elevation) on the body surface were investigated. Exercise-induced ST depression was most often seen in left anterior chest leads. The body surface distribution of ST depression failed to identify the obstructed coronary artery. Exercise-induced myocardial ischemia was thought to extend to the greater part of the subendocardial region of the left ventricle. Exercise-induced ST elevation was mainly found on the upper right anterior chest. It has been suggested that these leads face the interior of the left ventricle and the observed ST elevation directly reflects subendocardial ischemia of the left ventricle. This data is important for evaluating ST changes in exercise electrocardiography.

Coronary Disease↗