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Biomedical subjects

K Takami

Publications and source records attributed to K Takami.

At least 127 records · Page 7Linked to original sources
PubMed1985

Localization of chick retinal 24,000 dalton protein (visinin)-like immunoreactivity in the rat lower brain stem.

The distribution of visinin, a 24,000 dalton peptide, in the lower brain stem of the rat was examined by means of an indirect immunofluorescent method. Visinin-immunoreactive structures were found to be unevenly distributed only in the neuronal elements. The following neuronal systems were strongly labeled by the antiserum; the Purkinje cell system, mammillotegmental system, habenulointerpeduncular system, the second layer of the superior colliculus, ventral tegmental area, substantia nigra pars lateralis, area medial to the medial geniculate body, parabrachial area, dorsal and ventral nuclei of the lateral lemniscus, pontine reticular formation just medial to the trigeminal principal nucleus, superior olivary nucleus, solitarii nucleus, external layer of the inferior colliculus and spinal trigeminal nucleus. The densities of the labeled fibers in these areas paralleled those of the labeled cells. In addition, highly dense visinin-immunoreactive fiber plexuses were seen in the zona compacta of the substantia nigra, lateral portion of the interpeduncular nucleus, ventral tegmental nucleus of Gudden and vestibular nucleus.

Afferent Pathways↗
PubMed1985

[Ventricular activation sequence estimated by body surface isochrone map].

This study was performed to evaluate the usefulness of the body surface isochrone map (VAT map) for identifying the ventricular activation sequence, and it was correlated with the isopotential map. Subjects consisted of 42 normal healthy adults, 18 patients with artificial ventricular pacemakers, and 100 patients with ventricular premature beats (VPB). The sites of pacemaker implantations were the right ventricular endocardial apex (nine cases), right ventricular epicardial apex (five cases), right ventricular inflow tract (one case), left ventricular epicardial apex (one case), and posterior base of the left ventricle via the coronary sinus (two cases). An isopotential map was recorded by the mapper HPM-6500 (Chunichi-Denshi Co.) on the basis of an 87 unipolar lead ECG, and a VAT isochrone map was drawn by a minicomputer. The normal VAT map was classified by type according to alignment of isochrone lines, and their frequency was 57.1% for type A, 16.7% for type B, and 26.2% for type C. In the VAT map of ventricular pacing, the body surface area of initial isochrone lines represented well the sites of pacemaker stimuli. In the VAT map of VPB, the sites of origin of VPB agreed well with those as determined by the previous study using an isopotential map. The density of the isochrone lines suggested the mode of conduction via the specialized conduction system or ventricular muscle. The VAT map is a very useful diagnostic method to predict the ventricular activation sequence more directly in a single sheet of the map.

Bundle-Branch Block↗
PubMed1985

[Quantitative evaluation of various cardiac diseases using body surface mapping].

Body surface mapping (map) was used to evaluate various cardiac diseases quantitatively. For 30 cases with old anterior myocardial infarction (AMI), map parameters were compared with infarct size assessed by left ventriculography and 201Tl myocardial scintigraphy (LV% asynergy and 201Tl% defect, respectively). Parameters used in the present study were nSubtraction 40 (sigma Subtr. 40), which were obtained by the summation of voltages less than the lower limit of normal range (mean--2SD) at 40 msec from the QRS onset and nSubtraction 10-60 (sigma Subtr. 10-60), which was obtained by the integral of voltages below the normal range, calculated each 10 msec to 60 msec, as well as the number of lead points with Q waves of 30, 40 msec duration (nQ30, nQ40), and the summation of R voltages over the entire body surface (sigma R). In 19 cases with aortic regurgitation (AR), R and S voltages in each lead were compared with left ventricular diastolic dimension (LVDd) obtained by echocardiography. In 43 healthy persons and two patients with RV pacing, the ventricular activation time was measured in each lead (VAT map). In AMI, nSubtr. 40 correlated best with LV% asynergy (r = 0.70, p less than 0.001). EF and 201Tl% defect were related to nSubtr. 10-60 (r = 0.83, p less than 0.001 and r = 0.85, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Determination of trialkyltin, dialkyltin, and triphenyltin compounds in environmental water and sediments.

An analytical procedure for the determination of trialkyltin (tributyltin, tripropyltin), triphenyltin and dialkyltin (dibutyltin) compounds in environmental water and sediment was studied. Water samples were extracted into benzene with hydrochloric acid and sodium chloride. Sediment samples were extracted into methanolic hydrochloric acid and converted into benzene. Silica gel, which was impregnated with hydrochloric acid and activated, was used for clean-up of these compounds. These extracts of organotin chlorides were hydrogenated with an ethanol solution of sodium borohydride. Organotin hydrides were measured by gas chromatography with electron-capture detection. Recoveries of these compounds were ca. 70-95% from river water and sediment samples. The detection limits were 0.4-0.8 micrograms/l in water and 0.02-0.04 micrograms/g in sediment samples.

Chromatography, Gas↗
PubMed1984

[Effects of heart rate on body surface potential distribution in patients with atrial pacemaker].

Nine patients of sick sinus syndrome with atrial programmable pacemaker (3 males and 6 females, aged from 53 to 72 years) were studied to assess the effect of heart rate on the body surface potential distribution. Body surface maps (87 lead points) and M-mode echocardiograms were recorded at 20-beat increments of heart rate from 60 to 140 beats/min during atrial pacing. The potential changes of R and S voltages were evaluated quantitatively and were correlated with the changes of echocardiographically measured left ventricular dimension. As the heart rate increased, left ventricular dimension in end-diastole (LVDd) decreased gradually (Table 1), and a significant decrease was observed when the heart rate increased from 80 to 100 beats/min and from 100 to 120 beats/min, respectively, (p less than 0.05). With a decrease in LVDd, the distance between the left ventricular posterior wall and the anterior chest wall decreased and the left ventricular wall increased in its thickness. These changes, however, were not statistically significant. With an increase in the heart rate, R voltages decreased gradually in the left lateral chest and the sum of R voltages (sigma R) of six lead points in the left lateral chest including leads V5-6 decreased significantly when the heart rate increased from 60 to 100 beats/min and from 80 to 120 beats/min, respectively (p less than 0.02) (Table 2). On the other hand, R voltages remained unchanged in the left anterior chest during atrial pacing, then the sum of R voltages of six lead points in the left anterior chest including leads V2-4 and the sum of R voltages of 87 lead points did not show any significant changes (Table 2). An increase in the absolute value of S voltages was observed in the left anterior chest and the sum of S voltages of six lead points in the left anterior chest including leads V2-4 increased when the heart rate increased from 60 to 100 beats/min and from 80 to 120 beats/min, respectively (p less than 0.1) (Table 3) A decrease of R voltages in the left lateral chest was consistent with the reduction in LVDd (p less than 0.005). It is concluded that the changes in body surface QRS amplitudes during atrial pacing are related to those in the left ventricular dimension and that R voltages in the left lateral chest are fairly sensitive to see the changes in LVDd in cases with no abnormal wall motion of the left ventricle.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1984

[Clinical application of body surface mapping and its limitations].

The importance of detecting the high fidelity electrical activity of the heart was cited in respect to making diagnosis and providing optimal treatment. Standard 12 lead electrocardiograms (ECG) and vectorcardiograms (VCG) are used in daily practice with well-documented theoretical and experimental bases. However, this system is somewhat inadequate because of its simplicity both in records and basic assumptions. The development of a better lead system is thus mandatory for a high diagnostic sensitivity and specificity and for both qualitative and quantitative assessments of collected data. In recent years, great progress has been promised in "body surface mapping methods" by the medical application of computer technology, providing abundant information including four-dimensional displays; two-dimensional surface spreads of electricity as well as the magnitudes and time references. This method appears to be a powerful diagnostic tool, despite problems inherent in ECG and some unfavorable aspects yet to be settled. The present status, prospects and limitations of this new, powerful strategy are discussed.

Aged↗
PubMed1983

Distribution of abnormal Q waves on body surface in relation to left ventricular wall motion abnormalities in myocardial infarction.

This study was undertaken to determine the possible one-to-one relationship between each site of asynergy of the left ventricle and the body surface area to which ensuing abnormal electrical phenomena are reflected. In 140 post-myocardial infarction (MI) patients, distribution of abnormal Q waves on the body surface was correlated with the abnormal segments of LV wall motion identified by left ventriculography (LVG). Unipolar lead electrocardiograms (ECGs) were recorded from 87 lead points over the precordium and the back with Wilson's central terminal as the reference point. Data acquisition and mapping was accomplished through a mapping system HPM 5100 microcomputer. In all cases, coronary arteriography (CAG) and LVG were performed at least 2 months after the acute episode of MI. The LVG findings were evaluated separately in seven wall segments in accordance with the American Heart Association (AHA) reporting system. Sensitivity, specificity, diagnostic accuracy, positive predictive value, and negative predictive value of the abnormal Q wave in each lead point were obtained in cases with abnormal wall motion in segments 2, 3, and 6, respectively, and in infero-posterior segments 4 or 5. Statistical analysis was performed by comparing two groups of patients with or without asynergy of each wall segment concerned. Results of the study revealed some abnormal Q areas of high diagnostic accuracy that correlated highly with the site of abnormal contractility.

Journal Article↗
PubMed1982

Hydrophobic-ionic chromatography: its application to microbial glucose oxidase, hyaluronidase, cholesterol oxidase, and cholesterol esterase.

Glucose oxidase from Aspergillus niger, hyaluronidase from Streptomyces hyalurolyticus, and cholesterol oxidase and cholesterol esterase from Pseudomonas fluorescens were effectively adsorbed on an Amberlite CG-50 column, when the cell-free cultured medium or the cultured medium with cell extract and without cell debris was applied without desalting but at pH less than or equal to 4.5. At the acidic pH, all the ion-exchange groups (-COOH) exist in the protonated form; the adsorption is not due to electrostatic attraction, but to hydrophobic interaction. The enzymes thus adsorbed were effectively eluted by increasing pH, at which the ion-exchange groups became dissociated. This type of adsorption-elution is called hydrophobic-ionic chromatography. By a single run of chromatography, glucose oxidase, hyaluronidase, cholesterol oxidase, and cholesterol esterase were purified 30-fold, 12-fold, 45-fold, and 20-fold with yields of 82%, 83%, 80%, and 90%, respectively. This indicates that hydrophobic-ionic chromatography on an Amberlite CG-50 column is effective for the purification of various enzymes, provided that they are stable at the acidic pH.

Aspergillus niger↗