21 results on '"Kuno, M."'
Search Results
2. Simultaneous boost radiotherapy versus conventional dose radiotherapy for patients with newly diagnosed glioblastoma: a multi-institutional analysis.
- Author
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Takano S, Tomita N, Kuno M, Niwa M, Torii A, Takaoka T, Kita N, Okazaki D, Yamamoto S, Kawai T, Sugie C, Ogawa Y, Matsumoto K, Uchiyama K, Otsuka S, Matsui T, Miyakawa A, Mizuno T, Iida M, Tanikawa M, Mase M, and Hiwatashi A
- Subjects
- Humans, Male, Female, Middle Aged, Aged, Adult, Radiotherapy Dosage, Kaplan-Meier Estimate, Progression-Free Survival, Treatment Outcome, Glioblastoma radiotherapy, Glioblastoma mortality, Radiotherapy, Intensity-Modulated methods, Brain Neoplasms radiotherapy, Brain Neoplasms mortality
- Abstract
We compared survival outcomes of high-dose concomitant boost radiotherapy (HDCBRT) and conventional dose radiotherapy (CRT) for newly diagnosed glioblastoma (GB). Patients treated with intensity-modulated radiation therapy for newly diagnosed GB were included. In HDCBRT, specific targets received 69, 60, and 51 Gy in 30 fractions, while 60 Gy in 30 fractions was administered with a standard radiotherapy method in CRT. Overall survival (OS) and progression-free survival (PFS) were compared using the Log-rank test, followed by multivariate Cox analysis. The inverse probability of treatment weighting (IPTW) method was also applied to each analysis. Among 102 eligible patients, 45 received HDCBRT and 57 received CRT. With a median follow-up of 16 months, the median survival times of OS and PFS were 21 and 9 months, respectively. No significant differences were observed in OS or PFS in the Kaplan-Meier analyses. In the multivariate analysis, HDCBRT correlated with improved OS (hazard ratio, 0.49; 95% confidence interval, 0.27-0.90; P = 0.021), and this result remained consistent after IPTW adjustments (P = 0.028). Conversely, dose suppression due to the proximity of normal tissues and IMRT field correlated with worse OS and PFS (P = 0.008 and 0.049, respectively). A prospective study with a stricter protocol is warranted to validate the efficacy of HDCBRT for GB., (© 2024. The Author(s).)
- Published
- 2024
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- View/download PDF
3. Third HLA-haploidentical stem cell transplantation using post-transplant cyclophosphamide for relapsed acute leukemia.
- Author
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Harada N, Okamura H, Makuuchi Y, Kuno M, Takakuwa T, Nakamae M, Nishimoto M, Nakashima Y, Koh H, Hino M, and Nakamae H
- Subjects
- Humans, Cyclophosphamide therapeutic use, Hematopoietic Stem Cell Transplantation, Leukemia, Myeloid, Acute therapy, Graft vs Host Disease
- Published
- 2023
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4. Effect of graft cell dose on second transplantation from a haploidentical donor with post-transplantation cyclophosphamide for relapsed/refractory acute leukemia.
- Author
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Nakaya Y, Nakamae H, Harada N, Okamura H, Sakatoku K, Ido K, Makuuchi Y, Kuno M, Takakuwa T, Hirose A, Nakamae M, Nishimoto M, Nakashima Y, Koh H, and Hino M
- Subjects
- Humans, Cyclophosphamide therapeutic use, Acute Disease, Transplantation Conditioning, Retrospective Studies, Leukemia therapy, Graft vs Host Disease, Hematopoietic Stem Cell Transplantation, Leukemia, Myeloid, Acute therapy
- Published
- 2023
- Full Text
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5. Hidden chamber discovery in the underground Hellenistic necropolis of Neapolis by muography.
- Author
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Tioukov V, Morishima K, Leggieri C, Capriuoli F, Kitagawa N, Kuno M, Manabe Y, Nishio A, Alexandrov A, Gentile V, Iuliano A, and De Lellis G
- Abstract
We report in this paper the muography of an archaeological site located in the highly populated "Sanità" district in the center of Naples, ten meters below the current street level. Several detectors capable of detecting muons - high energy charged particles produced by cosmic rays in the upper layers of atmosphere - were installed underground at the depth of 18 m, to measure the muon flux over several weeks. By measuring the differential flux with our detectors in a wide angular range, we have produced a radiographic image of the upper layers. Despite the architectural complexity of the site, we have clearly observed the known structures as well as a few unknown ones. One of the observed new structures is compatible with the existence of a hidden, currently inaccessible, burial chamber., (© 2023. The Author(s).)
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- 2023
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6. Characterization of readmission after allogeneic hematopoietic cell transplantation.
- Author
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Yamaguchi K, Inamoto Y, Tajima K, Sakatoku K, Kuno M, Kawajiri A, Takemura T, Tanaka T, Ito A, Kurosawa S, Kim SW, and Fukuda T
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- Adolescent, Adult, Aged, Humans, Middle Aged, Patient Readmission, Retrospective Studies, Risk Factors, Young Adult, Graft vs Host Disease etiology, Hematopoietic Stem Cell Transplantation adverse effects
- Abstract
To elucidate the incidence, causes, and risk factors associated with readmission due to transplant-related complications, we studied 213 consecutive patients who were discharged without progression of primary disease after their first allogeneic hematopoietic cell transplantation at our center between 2013 and 2016. The median patient age was 50 years (range, 18-71 years). Eighty-three patients had AML or MDS, 66 had lymphoma, 28 had ALL, 23 had ATL, and 13 had other diseases. The median duration of hospitalization for transplantation was 56 days (range 27-325 days). The cumulative incidences of readmission due to transplant-related complications were 8% at 30 days, 16% at 100 days, and 25% at 1 year after discharge. The most frequent cause of readmission was infection, followed by graft-versus-host disease throughout the first year. In multivariate analysis, steroid use at discharge was the only risk factor associated with readmission within 30 days, and steroid use at discharge, absolute lymphocyte count < 500/µl at discharge, and documented bacterial infection during admission were risk factors associated with readmission within 1 year. Our results indicated that factors during hospitalization or discharge, but not at transplantation, were associated with readmission. Patients with these risk factors should be monitored carefully after discharge.
- Published
- 2021
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7. Can lasers really refrigerate CdS nanobelts?
- Author
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Morozov YV, Zhang S, Pant A, Jankó B, Melgaard SD, Bender DA, Pauzauskie PJ, and Kuno M
- Published
- 2019
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8. Severe immune-related complications early after allogeneic hematopoietic cell transplantation for nivolumab-pretreated lymphoma.
- Author
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Kuno M, Ito A, Tanaka T, Inamoto Y, Kurosawa S, Kim SW, and Fukuda T
- Subjects
- Adult, Female, Hematopoietic Stem Cell Transplantation methods, Humans, Lymphoma drug therapy, Male, Transplantation Conditioning methods, Young Adult, Hematopoietic Stem Cell Transplantation adverse effects, Lymphoma complications, Nivolumab adverse effects, Transplantation Conditioning adverse effects
- Published
- 2019
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- View/download PDF
9. Discovery of a big void in Khufu's Pyramid by observation of cosmic-ray muons.
- Author
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Morishima K, Kuno M, Nishio A, Kitagawa N, Manabe Y, Moto M, Takasaki F, Fujii H, Satoh K, Kodama H, Hayashi K, Odaka S, Procureur S, Attié D, Bouteille S, Calvet D, Filosa C, Magnier P, Mandjavidze I, Riallot M, Marini B, Gable P, Date Y, Sugiura M, Elshayeb Y, Elnady T, Ezzy M, Guerriero E, Steiger V, Serikoff N, Mouret JB, Charlès B, Helal H, and Tayoubi M
- Abstract
The Great Pyramid, or Khufu's Pyramid, was built on the Giza plateau in Egypt during the fourth dynasty by the pharaoh Khufu (Cheops), who reigned from 2509 bc to 2483 bc. Despite being one of the oldest and largest monuments on Earth, there is no consensus about how it was built. To understand its internal structure better, we imaged the pyramid using muons, which are by-products of cosmic rays that are only partially absorbed by stone. The resulting cosmic-ray muon radiography allows us to visualize the known and any unknown voids in the pyramid in a non-invasive way. Here we report the discovery of a large void (with a cross-section similar to that of the Grand Gallery and a minimum length of 30 metres) situated above the Grand Gallery. This constitutes the first major inner structure found in the Great Pyramid since the nineteenth century. The void, named ScanPyramids' Big Void, was first observed with nuclear emulsion films installed in the Queen's chamber, then confirmed with scintillator hodoscopes set up in the same chamber and finally re-confirmed with gas detectors outside the pyramid. This large void has therefore been detected with high confidence by three different muon detection technologies and three independent analyses. These results constitute a breakthrough for the understanding of the internal structure of Khufu's Pyramid. Although there is currently no information about the intended purpose of this void, these findings show how modern particle physics can shed new light on the world's archaeological heritage.
- Published
- 2017
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10. CETSA quantitatively verifies in vivo target engagement of novel RIPK1 inhibitors in various biospecimens.
- Author
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Ishii T, Okai T, Iwatani-Yoshihara M, Mochizuki M, Unno S, Kuno M, Yoshikawa M, Shibata S, Nakakariya M, Yogo T, and Kawamoto T
- Subjects
- Animals, Apoptosis drug effects, Automation, Brain metabolism, HT29 Cells, Humans, Leukocytes, Mononuclear drug effects, Leukocytes, Mononuclear metabolism, Mice, Inbred C57BL, Necrosis, Protein Kinase Inhibitors chemistry, Receptor-Interacting Protein Serine-Threonine Kinases metabolism, Reproducibility of Results, Spleen metabolism, Biological Assay methods, Protein Kinase Inhibitors pharmacology, Receptor-Interacting Protein Serine-Threonine Kinases antagonists & inhibitors, Temperature
- Abstract
The proof of target engagement (TE) is a key element for evaluating potential investment in drug development. The cellular thermal shift assay (CETSA) is expected to facilitate direct measurement of intracellular TE at all stages of drug development. However, there have been no reports of applying this technology to comprehensive animal and clinical studies. This report demonstrates that CETSA can not only quantitatively evaluate the drug-TE in mouse peripheral blood, but also confirm TE in animal tissues exemplified by using the receptor interacting protein 1 kinase (RIPK1) lead compound we have developed. Our established semi-automated system allows evaluation of the structure-activity relationship using native RIPK1 in culture cell lines, and also enables estimation of drug occupancy ratio in mouse peripheral blood mononuclear cells. Moreover, optimized tissue homogenisation enables monitoring of the in vivo drug-TE in spleen and brain. Our results indicate that CETSA methodology will provide an efficient tool for preclinical and clinical drug development.
- Published
- 2017
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11. CRACM3 regulates the stability of non-excitable exocytotic vesicle fusion pores in a Ca(2+)-independent manner via molecular interaction with syntaxin4.
- Author
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Liu S, Sahid MN, Takemasa E, Kiyoi T, Kuno M, Oshima Y, and Maeyama K
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- Animals, Calcium Channels genetics, Calcium Release Activated Calcium Channels metabolism, Cell Line, Tumor, Exocytosis drug effects, Membrane Fusion physiology, Qa-SNARE Proteins genetics, Rats, Secretory Vesicles metabolism, Single-Cell Analysis, Thapsigargin pharmacology, Calcium metabolism, Calcium Channels physiology, Exocytosis physiology, Qa-SNARE Proteins metabolism
- Abstract
Ca(2+) release-activated calcium channel 3 (CRACM3) is a unique member of the CRAC family of Ca(2+)-selective channels. In a non-excitable exocytosis model, we found that the extracellular L3 domain and the cytoplasmic C-terminus of CRACM3 interacted in an activity-dependent manner with the N-peptide of syntaxin4, a soluble N-ethylmaleimide-sensitive factor attachment receptor protein. Our biochemical, electrophysiological and single-vesicle studies showed that knockdown of CRACM3 suppressed functional exocytosis by decreasing the open time of the vesicle fusion pore without affecting Ca(2+) influx, the activity-dependent membrane capacitance (Cm) change, and the total number of fusion events. Conversely, overexpressing CRACM3 significantly impaired cell exocytosis independent of Ca(2+), led to an impaired Cm change, decreased the number of fusion events, and prolonged the dwell time of the fusion pore. CRACM3 changes the stability of the vesicle fusion pore in a manner consistent with the altered molecular expression. Our findings imply that CRACM3 plays a greater role in exocytosis than simply acting as a compensatory subunit of a Ca(2+) channel.
- Published
- 2016
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12. Unregulated insulin secretion by pancreatic beta cells in hyperinsulinism/hyperammonemia syndrome: role of glutamate dehydrogenase, ATP-sensitive potassium channel, and nonselective cation channel.
- Author
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Kawajiri M, Okano Y, Kuno M, Tokuhara D, Hase Y, Inada H, Tashiro F, Miyazaki J, and Yamano T
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- Adenosine Triphosphate metabolism, Animals, Cell Line, Glutamate Dehydrogenase genetics, Humans, Ion Channels metabolism, Mice, Patch-Clamp Techniques, Syndrome, Glutamate Dehydrogenase metabolism, Hyperammonemia metabolism, Hyperinsulinism metabolism, Insulin metabolism, Insulin-Secreting Cells metabolism, Potassium Channels metabolism
- Abstract
The hyperinsulinism/hyperammonemia (HI/HA) syndrome is caused by "gain of function" of glutamate dehydrogenase (GDH). Several missense mutations have been found; however, cell behaviors triggered by the excessive GDH activity have not been fully demonstrated. This study was aimed to clarify electrophysiological mechanisms underlying the dysregulated insulin secretion in pancreatic beta cells with GDH mutations. GDH kinetics and insulin secretion were measured in MIN6 cells overexpressing the G446D and L413V. Membrane potentials and channel activity were recorded under the perforated-patch configuration that preserved intracellular environments. In mutant MIN6 cells, sensitivity of GDH to guanosine triphosphate (GTP) was reduced and insulin secretion at low glucose concentrations was enhanced. The basal GDH activity was elevated in L413V bearing a mutation in the antenna-like structure. The L413V cells were depolarized without glucose, often accompanying by repetitive Ca2+ firings. The depolarization was maintained in the presence of adenosine triphosphate (ATP) and disappeared by depleting ATP, suggesting that the depolarization depended on intracellular ATP. In L413V cells, the ATP-sensitive potassium channel (K(ATP) channel) was suppressed and the nonselective cation channel (NSCC) was potentiated, while sensitivity of the channels to their specific blockers or agonists was not impaired. These data suggest that the L413V cells increase the intracellular ATP/adenosine diphosphate (ADP) ratio, which in turn causes sustained depolarization not only by closure of the K(ATP) channel, but also by opening of the NSCC. The resultant activation of the voltage-gated Ca2+ channel appears to induce hyperinsulinism. The present study provides evidence that multiple channels cooperate in unregulated insulin secretion in pancreatic beta cells of the HI/HA syndrome.
- Published
- 2006
- Full Text
- View/download PDF
13. cDNA cloning of bovine substance-K receptor through oocyte expression system.
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Masu Y, Nakayama K, Tamaki H, Harada Y, Kuno M, and Nakanishi S
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cattle, Female, Molecular Sequence Data, Oocytes metabolism, Promoter Regions, Genetic, Receptors, Neurokinin-2, Sequence Homology, Nucleic Acid, Cloning, Molecular, DNA metabolism, Receptors, Neurotransmitter genetics, Transcription, Genetic
- Abstract
The neuropeptide receptors which are present in very small quantities in the cell and are embedded tightly in the plasma membrane have not been well characterized. Mammals contain three distinct tachykinin neuropeptides, substance P, substance K and neuromedin K, and it has been suggested that there are multiple tachykinin receptors. By electrophysiological measurement, we have previously shown that Xenopus oocytes injected with brain and stomach mRNAs faithfully express mammalian substance-P and substance-K receptors, respectively. Here we report the isolation of the cDNA clone for bovine substance-K receptor (SKR) by extending this method to develop a new cloning strategy. We constructed a stomach cDNA library with a cloning vector that allowed in vitro synthesis of mRNAs and then identified a particular cDNA clone by testing for receptor expression following injection of the mRNAs synthesized in vitro into the oocyte system. Because oocytes injected with exogenous mRNAs can express numerous receptors and channels, our new strategy will be applicable in the general molecular cloning of these proteins. The result provides the first indication that the neuropeptide receptor has sequence similarity with rhodopsin-type receptors (the G-protein-coupled receptor family) and thus possesses multiple membrane-spanning domains.
- Published
- 1987
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14. Ion channels activated by inositol 1,4,5-trisphosphate in plasma membrane of human T-lymphocytes.
- Author
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Kuno M and Gardner P
- Subjects
- Cell Line, Cell Membrane physiology, Electric Conductivity, Humans, Inositol 1,4,5-Trisphosphate, Lymphocyte Activation, Phytohemagglutinins pharmacology, Calcium physiology, Inositol Phosphates physiology, Ion Channels physiology, Sugar Phosphates physiology, T-Lymphocytes physiology
- Abstract
Hydrolysis of membrane-associated phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)-P2) to water soluble inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) is a common response by many different kinds of cells to a wide variety of external stimuli (see refs 1 and 2 for review). Ins (1,4,5)P3 is a putative second messenger which increases intracellular Ca2+ by mobilizing internal Ca2+ stores, a hypothesis which has been substantiated by studies with chemically permeabilized cells and with isolated microsomal membrane fractions. But the possibility that Ins(1,4,5)P3 could induce in intact cells an influx of external Ca2+ through transmembrane channels, originally hypothesized by Michell in 1975, has never been directly tested. We report here single-channel recordings of an Ins(1,4,5)P3-activated conductance in excised patches of T-lymphocyte plasma membrane. The Ins(1,4,5)P3-activated transmembrane channel appears to be identical to the recently described mitogen-regulated, voltage-insensitive Ca2+ permeable channel involved in T-cell activation. We suggest that Ins(1,4,5)P3 acts as the second messenger mediating transmembrane Ca2+ influx through specific Ca2+-permeable channels in mitogen-stimulated T-cell activation.
- Published
- 1987
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15. C-19393 S2 and H2, new carbapenem antibiotics. IV. Inhibitory activity against beta-lactamases.
- Author
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Okonogi K, Nozaki Y, Imada A, and Kuno M
- Subjects
- Bacteria enzymology, beta-Lactams pharmacology, Anti-Bacterial Agents pharmacology, Thienamycins, beta-Lactamase Inhibitors
- Abstract
New carbapenem antibiotics, C-19393 S2 and H2, have been found to be potent and broad-spectrum inhibitors of beta-lactamases. Among 11 types of beta-lactamases tested, those from Escherichia coli (plasmid-bearing), Klebsiella pneumoniae, Proteus vulgaris, Serratia marcescens and Bacteroides fragilis were especially sensitive. They also inhibited cephalosporinases insensitive to clavulanic acid. The inhibition by C-19393 S2 and H2 was of progressive type, except for the inhibition of E. coli enzyme (plasmid-mediated type I) by C-19393 H2. The inhibition of E. coli beta-lactamase by C-19393 S2 was irreversible, while that by C-19393 H2 was reversible.
- Published
- 1981
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- View/download PDF
16. Synthesis and structure-activity relationships of carbapenems related to C-19393 H2.
- Author
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Natsugari H, Matsushita Y, Tamura N, Yoshioka K, Kondo M, Okonogi K, Kuno M, and Ochiai M
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- Indicators and Reagents, Magnetic Resonance Spectroscopy, Microbial Sensitivity Tests, Pseudomonas aeruginosa drug effects, Stereoisomerism, Structure-Activity Relationship, Thienamycins chemical synthesis
- Abstract
By applying the synthetic process reported in our previous paper, we synthesized new carbapenems having various (substituted) thio and alkoxy groups at the C(3) position and 1-hydroxy-1-methylethyl and analogous groups at the C(6) position with cis- and trans-stereochemistry; the in vitro antibacterial and beta-lactamase inhibitory activities of these new carbapenems were examined. Compared to C-19393 H2, some of these compounds (e.g., 11A-a-3 approximately 5) showed improved in vitro antibacterial activity especially against Pseudomonas aeruginosa; they showed a strong beta-lactamase inhibitory activity as well. Two noteworthy effects of substituent variation at the C(6) position on the activities were observed: 1) the trans-configuration caused a definite loss; and 2) introduction of 1-hydroxycyclobutyl and 1-hydroxy-1-methylpropyl groups in place of the 1-hydroxy-1-methylethyl group caused a diminution. The carbapenem (13A-a-2) with an alkoxy group at the C(3) position had a marked decrease in activity compared to the corresponding thio-substituted carbapenem (11A-a-12).
- Published
- 1983
- Full Text
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17. Expression of functional acetylcholine receptor from cloned cDNAs.
- Author
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Mishina M, Kurosaki T, Tobimatsu T, Morimoto Y, Noda M, Yamamoto T, Terao M, Lindstrom J, Takahashi T, and Kuno M
- Subjects
- Animals, Cloning, Molecular, DNA genetics, Female, Gene Expression Regulation, Genetic Vectors, Macromolecular Substances, Oocytes physiology, Structure-Activity Relationship, Torpedo, Xenopus laevis, Receptors, Cholinergic genetics
- Abstract
The cloned cDNAs encoding the four subunits of the Torpedo californica acetylcholine receptor, each carried by a simian virus 40 vector, direct the synthesis of the functional receptor in a combined expression system consisting of COS monkey cells and Xenopus oocytes. Our results suggest that all four subunits are required to elicit a normal nicotinic response to acetylcholine, whereas only the alpha-subunit is indispensable for alpha-bungarotoxin binding activity.
- Published
- 1984
- Full Text
- View/download PDF
18. Single-channel and whole-cell recordings of mitogen-regulated inward currents in human cloned helper T lymphocytes.
- Author
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Kuno M, Goronzy J, Weyand CM, and Gardner P
- Subjects
- Electric Conductivity, Humans, Membrane Potentials, Phytohemagglutinins pharmacology, Calcium physiology, Ion Channels physiology, Lymphocyte Activation, T-Lymphocytes, Helper-Inducer physiology
- Abstract
Cytoplasmic free Ca2+ [( Ca2+]i) appears to be an important signal for DNA synthesis in early stages of lymphocyte activation. In spite of many experimental studies which employ fluorescent Ca2+ indicator dye to demonstrate an early increase of [Ca2+]i in T-lymphocytes after stimulation with lectins, specific antigens, and monoclonal antibodies to T-lymphocyte receptors, the mechanism responsible for the rise of [Ca2+]i is unknown. We have used the extracellular patch clamp technique to investigate this mechanism. Unitary inward currents, mediated by Ca2+ or Ba2+, were recorded in the membrane of T-lymphocytes. The inward current channel was characterized by a conductance of 7 pS and extrapolated reversal potential (Erev) 110 mV positive to resting potential (Vr). While gating kinetic parameters were not affected by membrane potential changes, the probability of channel opening markedly increased upon activation of the T-lymphocyte by the mitogenic lectin, phytohaemagglutinin (PHA). PHA also evoked a cadmium-sensitive, inward Ba2+ current on whole-cell clamp. We suggest that this mitogen-regulated channel introduces Ca2+ into the cytoplasm upon activation and represents a new class of voltage-independent Ca2+ channels.
- Published
- 1986
- Full Text
- View/download PDF
19. Interactions of formylamino- and methoxy-substituted beta-lactam antibiotics with beta-lactamases.
- Author
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Okonogi K, Sugiura A, Kuno M, Ono H, Harada S, and Higashide E
- Subjects
- Drug Stability, Enzyme Induction, Hydrolysis, Kinetics, Structure-Activity Relationship, beta-Lactams, Anti-Bacterial Agents pharmacology, beta-Lactamases biosynthesis
- Abstract
Cephem and nocardicin-type monocyclic beta-lactam antibiotics with a formylamino substituent were highly resistant to hydrolysis by both penicillinases and cephalosporinases. Among antibiotics with a methoxy substituent, an N-sulfonated monocyclic beta-lactam antibiotic, sulfazecin was resistant to beta-lactamases, but cephem antibiotics were sensitive to the cephalosporinase of Enterobacter cloacae. The resistance of the antibiotics to the beta-lactamases depended primarily on the presence of the substituent, but affinity for the beta-lactamases was affected not only by the substituent but also by the presence of other side chains. Formylamino compounds and sulfazecin were as good inducers of beta-lactamases as semisynthetic 7-methoxycephalosporins, but naturally occurring 7-methoxycephalosporins were poor inducers. The inducer activities of the antibiotics were not necessarily related to their beta-lactamase stabilities. The stabilities of the compounds to the beta-lactamases were well reflected in their antibacterial activities against beta-lactamase producing bacteria.
- Published
- 1985
- Full Text
- View/download PDF
20. Beta-lactamase inhibitory activities and synergistic effects of 5,6-cis-carbapenem antibiotics.
- Author
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Okonogi K, Harada S, Shinagawa S, Imada A, and Kuno M
- Subjects
- Bacteria enzymology, Drug Synergism, Structure-Activity Relationship, Anti-Bacterial Agents pharmacology, Bacteria drug effects, Thienamycins pharmacology, beta-Lactamase Inhibitors
- Abstract
Twelve 5,6-cis-carbapenem antibiotics were examined for their beta-lactamase inhibitory activities, their types of inhibitions, and their synergistic activities with other beta-lactam antibiotics. All the carbapenems inhibited eight types of beta-lactamases including cephalosporinases which were insensitive to clavulanic acid and sulbactam. The sulfonyloxy ethyl carbapenems were the most active inhibitors; they inhibited all beta-lactamases in a progressive fashion, whereas some of the hydroxyl compounds exerted non-progressive inhibition against several beta-lactamases such as those of Escherichia coli TN713 and Proteus vulgaris GN4413. Several carbapenems were inactivated by the beta-lactamases of Citrobacter freundii GN1706, P. vulgaris GN4413, E. coli TN713, and Klebsiella pneumoniae TN1698. Most of the carbapenems potentiated the antibacterial activities of ampicillin and cefotiam against beta-lactamase-producing bacteria.
- Published
- 1982
- Full Text
- View/download PDF
21. Expression of functional sodium channels from cloned cDNA.
- Author
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Noda M, Ikeda T, Suzuki H, Takeshima H, Takahashi T, Kuno M, and Numa S
- Subjects
- Animals, Female, Membrane Proteins biosynthesis, Oocytes, RNA, Messenger isolation & purification, RNA, Messenger physiology, Rats, Recombinant Proteins biosynthesis, Recombinant Proteins genetics, Xenopus laevis, DNA genetics, DNA, Recombinant physiology, Ion Channels metabolism, Membrane Proteins genetics, Sodium Channels
- Abstract
The voltage-gated sodium channel is a transmembrane protein essential for the generation of action potentials in excitable cells. It has been reported that sodium channels purified from the electric organ of the electric eel, Electrophorus electricus, and from chick cardiac muscle consist of a single polypeptide of relative molecular mass (Mr) approximately 260,000, whereas those purified from rat brain and from rat and rabbit skeletal muscle contain, in addition to the large polypeptide, one or two smaller polypeptides of Mr 33,000-43,000. The primary structures of the Electrophorus sodium channel and two distinct sodium channel large polypeptides (designated as sodium channels I and II) from rat brain have been elucidated by cloning and sequencing the complementary DNAs. The purified sodium channel preparations from Electrophorus electroplax and from mammalian muscle and brain, when reconstituted into lipid vesicles or planar lipid bilayers, exhibit some functional activities. The successful reconstitution with the Electrophorus preparation would imply that the large polypeptide alone is sufficient to form functional sodium channels. However, studies with the rat brain preparation suggest that the smaller polypeptide of Mr 36,000 is also required for the integrity of the saxitoxin (STX) or tetrodotoxin (TTX) binding site of the sodium channel. Here we report that the messenger RNAs generated by transcription of the cloned cDNAs encoding the rat brain sodium channel large polypeptides, when injected into Xenopus oocytes, can direct the formation of functional sodium channels.
- Published
- 1986
- Full Text
- View/download PDF
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