Juntendo Medical Journal
Online ISSN : 2188-2134
Print ISSN : 0022-6769
ISSN-L : 0022-6769
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Volume 22, Issue 2
Displaying 1-16 of 16 articles from this issue
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Contents
  • Studies on The Cultured Rat Heart Muscle Cells
    I. Morphological Study on The Cultured Cardiac Cells II. Electrophysiological Study on The Cultured Neonatal Cardiac Cells
    TAKESHI IEMOTO
    1976 Volume 22 Issue 2 Pages 171-189
    Published: June 10, 1976
    Released on J-STAGE: November 21, 2014
    DOIhttps://doi.org/10.14789/pjmj.22.171
    JOURNAL FREE ACCESS
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    The extensive studies on the cultured heart muscle cells from the stand points of morphology and electrophysiology were to be reported. The myocardial cells of neonatal rat were cultured in the medium of Eagle's MEM with ten percent calf serum in it after dispersed with trypsin. Spontaneous beating of single cells and clusters with a few layers and of a diameter of hundreds microns was observed with a regular or irregular rate of 20 to 160 beats per minute (average 65/min). The maximum rate of beating was seen in the specimen of 3 to 7-day in culture. The histochemical studies on the cultured cells, compared with those of the rat heart before culture by serial sections revealed that Large Polygonal Cells (LPC, 5%) under culture originated from cells of conduction system, Usual Polygonal Cells (UPC, 70%) from working cells, which both were considered as myoblasts with autorhythmicity. Spindle Cells (SC, 25%), nonbeating fibroblasts in culture were supposed to be connective tissue in vivo. The ultrastructural features by electron microscopy seemed essentially similar to that of in vivo. By the introduction of microelectrode technique, the intracellular electrical phenomena were studied. The prepotentials were present in all records, plateau in over 90 percent of action potentials, the magnitude of action potential was 78.3±3.9 (48-102) mV, that of resting potential 57.1±3.1 (37-75) mV, and action potential duration 234 (150-320) msec. The effects of catecholamines, Glucagon and Dibutyryl cyclic AMP (DBcAMP) on transmembrane potentials were investigated, especially focused on the prepotentials. It was understood that the positive chronotropic actions of those agents resulted primarily in the increased slope of prepotentials. The order of positive chronotropic effects of those agents was as follows, Isoproterenol (10-7M) > Noradrenaline (10-7M) > Dopamine (10-5M) ≅Glucagon (10-5M) > DBcAMP (10-4M) The increase in extracellular Ca++ augmented the actions of Glucagon and ABcAMP to give rise to steeper slope of prepotentials and vise versa. This may indicate that Ca++ might play some role even in diastole to increase in rate of firing as well as in systole for augmented contractility by those cardiotonic agents.
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  • Relationship Between Hypnotic and Hypothermic Action of Barbiturates and Brain 5-Hydroxytryptamine in the Rats
    KOKO HASEGAWA
    1976 Volume 22 Issue 2 Pages 190-200
    Published: June 10, 1976
    Released on J-STAGE: November 21, 2014
    DOIhttps://doi.org/10.14789/pjmj.22.190
    JOURNAL FREE ACCESS
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    Barbiturates increased the concentration of brain 5-hydroxytryptamine (5-HT) in rats, when administered in the doses that produced sleep and hypothermia. The increase of 5-HT followed by the increase of 5-hydroxyindoleacetic acid (5-HIAA) in the brain. Brain 5-HT increased immediately after the administration of thiopental sodium and pentobarbital sodium, and the righting reflex disappeared, simultaneously. With phenobarbital sodium, the significant increase in brain 5-HT and the loss of righting reflex were observed 30 minutes after the administration. With barbital sodium, the significant increase in brain 5-HT occurred 30 minutes after the administration, and the righting reflex disappeared 60 minutes after the administration. In each of the barbiturates used, the time course of hypothermia induced by barbiturate was similar to that of the 5-HT increase in brain by the drug. The brain 5-HT level was higher in cases treated with reserpine and pentobarbital sodium successively than in those with reserpine alone. Brain 5-HIAA was, also, markedly increased in reserpinized rats and more increased with the combined administration of pentobarbital sodium and reserpine. Barbiturates did not inhibit monoamine oxidase activity both in vivo and in vitro. The increase of brain 5-HT concentration is supposed not due to the inhibition of monoamine oxidase activity but depends on the activation of 5-HT synthesis. The 5-HIAA level was higher in rats treated with thiopental sodium and probenecid than in those with probenecid alone. It suggests that the increase in brain 5-HIAA does not depend on the inhibition of the active transport of 5-HIAA but depends on the increase of 5-HT turnover by barbiturates. These results suggest that the increase of brain 5-HT and its utilization play an important role in the loss of righting reflex and hypothermia induced by the barbiturates used.
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  • Ca2+-. Sr2+-and Ba2+- Activated Tension of Glycerinated Smooth Muscles of Guinea-pig Taenia Coli
    MASAKO AIZU
    1976 Volume 22 Issue 2 Pages 201-210
    Published: June 10, 1976
    Released on J-STAGE: November 21, 2014
    DOIhttps://doi.org/10.14789/pjmj.22.201
    JOURNAL FREE ACCESS
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    1. The effects of free Ca2+, Sr2+ or Ba2+ concentration on the tension of the glycerinated smooth muscles of guinea pig taenia coli induced by ATP were examined in the presence of chelating agent, Mg2+ and ATP, and the sensitivity of the preparation to Sr2+ and Ba2+ was compared with that to Ca2+. 2. In the presence of 5mM MgCl2 and 5mM ATP, a contracted glycerinated smooth muscle was relaxed by the addition of 1mM EGTA and the tension decreased by 75%, which was reversed by the addition of 1mM CaCl2. The result indicates that a minute amount of Ca2+ contributes to the contraction of the preparation. 3. After removal of Mg2+, the ATP-contraction decreased to almost zero level. The result indicates that Mg2+ is essential for the ATP-contraction of the preparation. 4. The tension of the preparation increased with the increase of ATP concentration up to 4mM in the presence of 5mM Mg2+ without adding Ca2+. However, in the concentration range of ATP from 4mM to 7mM no futher increase of the tension was observed. 5. The threshold concentration of free Ca2+ for the ATP contraction was measured in the Ca-buffer solution and it was pCa = 5.5; the maximum tension being produced at pCa = 3.8. 6. The pSr-tension curve shifted to the right compared with that of pCatension curve; the threshold concentration was pSr=4 and the almost maximal tension was recorded at pSr = 2.6. 7. The pBa-tension curve shifted to the right in comparison with that of pSr-tension; the threshold concentration was pBa=3.5 and only 76.2% of the maximum tension was obtained at pBa = 2.6. 8. The relative sensitivity of the preparation to Sr2+ and Ba2+ as compared with that to Ca2+ was Ca2+ : Sr2+ : Ba2+ =1 : 1/28 : 1/67.
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  • Automatic Care System of Serious Cases
    --Experiences in Juntendo University Hospital--
    MAKOTO ABE
    1976 Volume 22 Issue 2 Pages 211-226
    Published: June 10, 1976
    Released on J-STAGE: November 21, 2014
    DOIhttps://doi.org/10.14789/pjmj.22.211
    JOURNAL FREE ACCESS
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    In major hospitals, they usually have special wards named ICU and CCU, where special equipments and facilities are provided to take care of severe patients. These equipments and facilities should be set up for continuous processing the clinical data of the patients during postoperative period and securing their lives. By the recent improvement of medical techniques, the clinical data of patients have been obtained more exactly and in details. It has resulted in a remarkable accumulation of relevant informations and needed increasing medical staffs. In order to resolve these problems, the computer system (16KW) was recently introduced in our hospital. The author and the associates have tested the function of a computer system as a medical equipment since June 1974. This computer system is characterized as an aid for diagnosis of patients status and as trend-graphs, in which the input data consists of more than 50 items, including urine volume, ECG, blood pressure, body temperature, peripheral pulse wave, cardiac output, total peripheral resistance, respiratory rate, etc. Each datum can de summarized during some period and unified into a trend-graph by which the change of the physical status can be observed continuously. In this trend-graph, the time range of axis will be changed for 4 hours to 3 weeks, and also the data of physical status up to three items can be superimposed on the display board. Each of them may be separately observed on-line 4 beds and off-line 8 beds at maximum. The author practically tried the automatic care of mainly postoperative patients with heart disease in ICU and CCU by the computer system. The computer system now could not be available for the estimation of patients status, although it could be highly evaluated in the trend-graphs of the individual physical informations. The author succeeded in on-line analysis of the cardiac output and could put it on the trend-graph. Further problems still remained in the reliability of the individual informations, for example, analysis of arrhythmia, measurment of ST changes, urine volume, etc. However, the automatic care system would be practically more available by making development. The medical application may be the first trials as an automatic care system for serious patients in ICU and CCU in our country.
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