1701
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Okuno G, Tako M, Fukuda H, Okamoto K. [Proceedings: Comparison of changes in blood sugar, electrolyte and IRI levels in man following intravenous injection of 1.0, 0.1 or 0.01 mg of glucagon]. NIHON NAIBUNPI GAKKAI ZASSHI 1974; 50:218. [PMID: 4476356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1702
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Yamori Y, Okamoto K. Spontaneous hypertension in the rat. A model for human "essential" hypertension. VERHANDLUNGEN DER DEUTSCHEN GESELLSCHAFT FUR INNERE MEDIZIN 1974; 80:168-70. [PMID: 4454512 DOI: 10.1007/978-3-642-85449-1_25] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1703
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Okamoto K, Yonezawa H, Izumiya N. Preparation of pure peptides from a mixture of gramicidins and of tyrocidines by droplet countercurrent chromatography. J Chromatogr A 1974. [DOI: 10.1016/s0021-9673(00)97199-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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1704
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Yutsudo M, Okamoto K. Immediate-early expression of the gene causing superinfection breakdown in bacteriophage T4B. J Virol 1973; 12:1628-30. [PMID: 4586782 PMCID: PMC356810 DOI: 10.1128/jvi.12.6.1628-1630.1973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Superinfection breakdown appears to belong to the "immediate-early" functions induced by T4 phage.
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1705
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1706
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Yoshida Y, Okamoto K, Matsuo K, Kwo EH, Retnasabapathy A. The occurrence of Ancylostoma braziliense (de Faria, 1910) and Ancylostoma ceylanicum (Looss, 1911) in Malaysia. THE SOUTHEAST ASIAN JOURNAL OF TROPICAL MEDICINE AND PUBLIC HEALTH 1973; 4:498-503. [PMID: 4787651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1707
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Okamoto K, Shimamura S. [4-Morpholinyl ester as an activated ester in peptide synthesis. II (author's transl)]. YAKUGAKU ZASSHI 1973; 93:1509-13. [PMID: 4798537 DOI: 10.1248/yakushi1947.93.11_1509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1708
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Yamori Y, Ooshima A, Okamoto K. Deviation of central norepinephrine metabolism in hypertensive rats. JAPANESE CIRCULATION JOURNAL 1973; 37:1235-45. [PMID: 4801198 DOI: 10.1253/jcj.37.1235] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1709
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Yamori Y, Okamoto K. Spontaneous hypertension in rats versus essential hypertension in man. Singapore Med J 1973; 14:393-4. [PMID: 4777918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1710
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Okamoto K, Quastel JH. Spontaneous action potentials in isolated guinea-pig cerebellar slices: effects of amino acids and conditions affecting sodium and water uptake. PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. SERIES B, BIOLOGICAL SCIENCES 1973; 184:83-90. [PMID: 4147949 DOI: 10.1098/rspb.1973.0032] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The effects of incubation conditions on the frequency of spontaneous action potentials exhibited by guinea-pig cerebellar slices, and recorded with an extracellular microelectrode, have been investigated. Various incubation conditions that lead to tetrodotoxin-sensitive uptakes of water and of sodium ions by the incubated cerebellar slices lead to enhanced frequencies of the spontaneous action potentials, e. g. the presence of protoveratrine or of ouabain, the absence of glucose or the onset of anoxia. The frequency of the spikes is also enhanced by acetylcholine (in presence of neostigmine) or by the presence of excitatory amino acids, such as L-glutamate, D-glutamate or L-aspartate. It is suppressed by tetrodotoxin, or by the inhibitory amino acids, e. g.
γ
-aminobutyrate, glycine or taurine, or by ammonium ions or by pentobarbital. It is concluded that guinea-pig cerebellar slices, incubated under specified conditions, may provide a suitable means for quantitative correlation of neurochemical data with data obtained by electrophysiological techniques in tissue incubated under similar conditions and also for quantitative assessment of the effects of amino acids on cerebellar electrical activity.
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1711
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Okamoto K, Yamori Y, Nosaka S, Ooshima A, Hazama F. Studies on hypertension in spontaneously hypertensive rats. CLINICAL SCIENCE AND MOLECULAR MEDICINE. SUPPLEMENT 1973; 45 Suppl 1:11s-4. [PMID: 4593558 DOI: 10.1042/cs045011s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
1. The pathogenesis and complications occurring in spontaneously hypertensive rats (SHR) have been studied.
2. Genetic factors are important both in the development of hypertension and in determining susceptibility to vascular lesions.
3. Selective substrains of SHR may be particularly prone to develop cerebrovascular lesions.
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1712
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Okamoto K. [Adverse effects of synthetic detergents]. [HOKENFU ZASSHI] THE JAPANESE JOURNAL FOR PUBLIC HEALTH NURSE 1973; 29:470-1. [PMID: 4490849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1713
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1714
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Cooke JD, Okamoto K, Quastel DM. The role of calcium in depolarization-secretion coupling at the motor nerve terminal. J Physiol 1973; 228:459-97. [PMID: 4346994 PMCID: PMC1331306 DOI: 10.1113/jphysiol.1973.sp010095] [Citation(s) in RCA: 94] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
1. The relation between m.e.p.p. frequency (F) and [Ca] was studied at the mouse neuromuscular junction, at varied concentrations of K(+) and at nerve terminals depolarized by focal depolarization.2. Under all conditions the relation between log F and log [Ca] was sigmoid, with a maximum slope that increased with depolarization or raised [K(+)]. In addition, depolarization or raised K(+) caused a progressive shift of the sigmoid curve upward and to the left (to reduced log [Ca]) and increased the range over which log F could be altered by [Ca].3. Reduction of osmotic pressure changed the relation between log F and log [Ca] in the same way as increase of depolarization, while increase of osmotic pressure did the opposite.4. Raised [Mg] acted in two ways: (a) to shift the curve of log F vs. log [Ca] to the right and (b) to reduce maximum Delta log F/Delta log [Ca] without altering the range of log F sensitive to [Ca].5. The relation between log quantal content of e.p.p.s and log [Ca] was similar to that between log m.e.p.p. frequency and log [Ca].6. Individual nerve terminals varied in both Ca-dependent and Ca-independent fractions of log F; a large Ca-independent portion appears to be associated with a low Ca-dependent portion and vice versa. With large prolonged depolarization the Ca-independent portion was increased, apparently at the expense of the Ca-dependent portion.7. The results of all experiments were summarized in terms of parameters found by fitting the observed log release -log [Ca] curves to two theoretical equations, each derived on the basis of a model: (a) all-or-nothing activation of release probability by Ca-complex(es) and (b) graded activation of release probability by Ca complex(es).8. On the basis of the all-or-nothing model, from which follows alinear relation between F and amounts of Ca complex(es), the number of Ca(2+) atoms that ;cooperate' to mediate release appeared to increase progressively with presynaptic depolarization, to a value of 4 or more with a presynaptic action potential.9. On the basis of the graded activation model, which predicts an exponential relation between F and amount of Ca complex, the number of Ca(2+) atoms that combine with Ca receptor appears to be independent of presynaptic depolarization.10. Various models which could account for the data are discussed. It was concluded that all the data are consistent with a model in which:(i) quantal release probability is continuously graded with the amount of a simple Ca complex (CaX) inside the nerve terminal.(ii) Ca entry is governed by presynaptic membrane potential (increasing exponentially with depolarization) and by the amount of a Ca complex (Ca(2)Y) on or in the membrane.(iii) Mg(2+) competes with Ca(2+) at both receptors, X and Y.(iv) The internal Ca receptor X is also increased by presynaptic depolarization.
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1715
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Yokokawa A, Okamoto K, Yoshida A, Suzuki Y, Watanabe A. [Cytological and electron microscopic studies on the ganglia of the spiral organ and the cells of vestibular nerves of bats]. NIHON JIBIINKOKA GAKKAI KAIHO 1972; 75:1017-8. [PMID: 4676064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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1716
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Ooshima A, Yamori Y, Okamoto K. Cardiovascular lesions in the selectively-bred group of spontaneously hypertensive rats with severe hypertension. JAPANESE CIRCULATION JOURNAL 1972; 36:797-812. [PMID: 4678659 DOI: 10.1253/jcj.36.797] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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1717
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Okamoto K, Quastel JH. Uptake and release of glutamate in cerebral-cortex slices from the rat. Biochem J 1972; 128:1117-24. [PMID: 4643696 PMCID: PMC1174000 DOI: 10.1042/bj1281117] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
1. Cerebral-cortex slices from rat brain, loaded with labelled l-glutamate as a result of aerobic incubation with labelled glucose, lost less than 15% of this glutamate on subsequent incubation in the presence of unlabelled glucose and l-glutamate. This indicates that very little exchange occurs between extracellular l-glutamate and glutamate accumulated in the neurons as a result of glucose metabolism. 2. Slices, loaded with labelled l-glutamate as a result of aerobic incubation in a medium containing unlabelled glucose and labelled l-glutamate, lost more than half of this glutamate on subsequent incubation in the presence of unlabelled l-glutamate. This indicates that exchange occurs between extracellular glutamate and glutamate accumulated in brain slices as a result of its uptake from the incubation medium. 3. Evidence was obtained suggesting that only a part of the glutamate, accumulated in brain slices as a result of its uptake from an incubation medium containing both glucose and l-glutamate, entered the neurons; apparently almost all the rest entered the glia. 4. It is concluded that the slices contain a pool of glutamate, derived from glucose and located in the neurons, which is poorly exchangeable with extracellular glutamate, and another pool of glutamate, derived from extracellular glutamate and located in the glia, which is freely exchangeable with extracellular glutamate.
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1718
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Okamoto K, Koizumi M. Hymenolepis nana: effect of antithymocyte serum on acquired immunity in mice. Exp Parasitol 1972; 32:56-61. [PMID: 5049758 DOI: 10.1016/0014-4894(72)90009-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1719
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Yamori Y, Ooshima A, Okamoto K. Genetic factors involved in spontaneous hypertension in rats an analysis of F 2 segregate generation. JAPANESE CIRCULATION JOURNAL 1972; 36:561-8. [PMID: 4678248 DOI: 10.1253/jcj.36.561] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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1720
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Aoki K, Yamori Y, Ooshima A, Okamoto K. Effects of high or low sodium intake in spontaneously hypertensive rats. JAPANESE CIRCULATION JOURNAL 1972; 36:539-45. [PMID: 4678246 DOI: 10.1253/jcj.36.539] [Citation(s) in RCA: 101] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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1721
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Okamoto K, Yamori Y, Oshima A, Tanaka T. Development of substrains in spontaneously hypertensive rats: genealogy, isozymes and effect of hypercholesterolemic diet. JAPANESE CIRCULATION JOURNAL 1972; 36:461-70. [PMID: 5068728 DOI: 10.1253/jcj.36.461] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1722
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Okamoto K, Hamano S, Kikuchi K, Kano Y. [Diagnosis and surgical treatment of pulmonary aspergillosis]. IRYO 1972; 26:397-407. [PMID: 5039903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1723
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Okamoto K, Azuma K, Yamamura S. [Nursing of fever in patients with gynecologic diseases]. [KANGO GIJUTSU] : [NURSING TECHNIQUE] 1972; 18:104-13. [PMID: 4481611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1724
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Okamoto K, Hazeyama F, Yoshida A, Yokokawa A. [Median longitudinal fasciculus syndrome with vertical nystagmus]. IRYO 1972; 26:204-16. [PMID: 5027288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1725
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Quastel DM, Hackett JT, Okamoto K. Presynaptic action of central depressant drugs: inhibition of depolarization-secretion coupling. Can J Physiol Pharmacol 1972; 50:279-84. [PMID: 5032123 DOI: 10.1139/y72-042] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Chlorpromazine, like raised osmotic pressure, not only increases spontaneous miniature endplate potential frequency (F) in mouse diaphragm (in vitro) but also depresses the slope of log F versus focal presynaptic depolarization. It also depresses the slope of log F versus [Ca], in raised K+ (constant depolarization). Similar effects are seen with pentobarbital, chloral hydrate, chloroform, and lowered pH. The drugs have similar actions in locust muscle, where the transmitter is not acetylcholine.
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