414 results on '"Koichi Ishikawa"'
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102. Sphingosine 1-phosphate induces expression of early growth response-1 and fibroblast growth factor-2 through mechanism involving extracellular signal-regulated kinase in astroglial cells
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Fumikazu Okajima, Michio Ui, Koichi Ishikawa, and Koichi Sato
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MAPK/ERK pathway ,Sphingosine kinase ,Naphthalenes ,Mitogen-activated protein kinase kinase ,Immediate-Early Proteins ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,GTP-Binding Proteins ,Sphingosine ,Tumor Cells, Cultured ,Animals ,RNA, Messenger ,Virulence Factors, Bordetella ,Sphingosine-1-phosphate ,Molecular Biology ,Cells, Cultured ,Protein Kinase C ,Protein kinase C ,Early Growth Response Protein 1 ,Flavonoids ,Platelet-Derived Growth Factor ,biology ,Endothelins ,Glioma ,Molecular biology ,Rats ,DNA-Binding Proteins ,Animals, Newborn ,Gene Expression Regulation ,Pertussis Toxin ,chemistry ,Astrocytes ,biology.protein ,Tetradecanoylphorbol Acetate ,Fibroblast Growth Factor 2 ,Lysophospholipids ,Mitogen-Activated Protein Kinases ,Signal transduction ,Platelet-derived growth factor receptor ,Transcription Factors - Abstract
In rat type I astrocytes and C6 glioma cells, sphingosine 1-phosphate (S1P) clearly induced the expression of fibroblast growth factor-2 (FGF-2) mRNA to an extent comparable to that achieved by platelet-derived growth factor (PDGF) and endothelin. In C6 cells, Western blotting showed that S1P also induced expression of early growth response-1 (Egr-1), one of the immediate early gene products and an essential transcriptional factor for FGF-2 expression. On the other hand, sphingosine, a substrate for sphingosine kinase which forms intracellular S1P, was a very weak activator for the expression of either FGF-2 or Egr-1. The S1P-induced Egr-1 expression was partially inhibited by treatment of the cells with either calphostin C, an inhibitor of protein kinase C (PKC), or pertussis toxin (PTX), and completely inhibited by the combination of these agents. Essentially, the same inhibitory pattern by these agents has been observed for S1P-induced extracellular signal-regulated kinase (ERK) activation. The S1P-induced expression of Egr-1 was also completely inhibited in association with complete inhibition of ERK by PD 98059, an ERK kinase inhibitor. Thus, the S1P-induced activation of the Egr-1/FGF-2 system may be mediated through ERK activation, which may involve at least two signaling pathways, i.e., a PTX-sensitive G-protein-dependent pathway and a PKC-dependent pathway.
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- 1999
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103. 13CO2 Peak Value of -[1-13C]phenylalanine Breath Test Reflects Hepatopathy
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Koichi Ishikawa, Isaburou Hosoi, Tadashi Kohno, Shigeru Suzuki, Satoshi Asai, Masashi Fujii, Yukimoto Ishii, Munehiro Ishii, and Shigetomi Iwai
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Male ,Choleretic ,medicine.medical_specialty ,Phenylalanine ,medicine.medical_treatment ,chemistry.chemical_compound ,Internal medicine ,Respiration ,medicine ,Animals ,Hepatectomy ,Rats, Wistar ,Antidote ,Breath test ,Carbon Isotopes ,Methionine ,medicine.diagnostic_test ,Chemistry ,Liver Diseases ,Body Weight ,Organ Size ,Carbon Dioxide ,Rats ,Endocrinology ,Breath Tests ,Liver ,Surgery ,Quantitative analysis (chemistry) - Abstract
BACKGROUND: Using a rat model of hepatectomy, we investigated whether the severity of hepatopathy could be quantitatively measured from changes in expiratory (13)CO(2) levels after intravenous administration of L-[1-(13)C]methionine or L-[1-(13)C]phenylalanine. MATERIALS AND METHODS: Under nembutal anesthesia, 30 mg/kg L-[1-(13)C]phenylalanine or 40 mg/kg L-[1-(13)C]methionine was administered to rats through the femoral vein, and expiratory (13)CO(2) levels were measured for 15 min. A 30, 70, or 90% hepatectomy was performed. In the control group, simple laparotomy was performed. Breath test was conducted 20 min after laparotomy. We examined the correlation of the total (13)CO(2) output over 15 min or peak (13)CO(2) level with liver weight/body weight (%). RESULTS: In breath test graphs, L-[1-(13)C]methionine did not show any peak level during measurement. L-[1-(13)C]phenylalanine showed a specific peak level 6 +/- 1 min after administration. The correlation coefficient between total (13)CO(2) output over 15 min after L-[1-(13)C]methionine administration and liver weight/body weight was 0.922 (P < 0.001). The correlation coefficient between total (13)CO(2) output over 15 min after L-[1-(13)C]phenylalanine administration and liver weight/body weight was 0.883 (P < 0.001). The correlation coefficient between peak L-[1-(13)C]phenylalanine level and liver weight/body weight was highest, 0.927 (P < 0.001). CONCLUSION: In a breath test with intravenously administered L-[1-(13)C]methionine or L-[1-(13)C]phenylalanine, hepatopathy could be quantitatively evaluated by measuring expiratory (13)CO(2) levels over 15 min. After administration of L-[1-(13)C]phenylalanine, hepatopathy could be quantitatively evaluated in a short period by measuring the peak expiratory (13)CO(2) level.
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- 1999
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104. Effects of brain temperature on CBF thresholds for extracellular glutamate release and reuptake in the striatum in a rat model of graded global ischemia
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Koichi Ishikawa, Heng Zhao, Satoshi Asai, and Tadashi Kohno
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Male ,medicine.medical_specialty ,Microdialysis ,Fever ,Extracellular glutamate ,Rat model ,Ischemia ,Glutamic Acid ,Hypothermia ,Striatum ,Body Temperature ,Brain Ischemia ,Reuptake ,Internal medicine ,medicine ,Animals ,Monitoring methods ,Rats, Wistar ,Chemistry ,General Neuroscience ,Glutamate receptor ,Brain ,medicine.disease ,Rats ,Disease Models, Animal ,Endocrinology ,Cerebrovascular Circulation ,Anesthesia ,Extracellular Space ,Microelectrodes - Abstract
We simultaneously measured extracellular glutamate ([Glu]e) elevation and local CBF using a real-time monitoring method and laser-Doppler flowmetry, respectively, in the rat striatum in a modified graded global ischemia model. Ischemic brain temperatures were kept at 32 degrees C, 37 degrees C and 39 degrees C. Three distinct types of intraischemic [Glu]e elevation, reflecting mild, moderate and massive glutamate release, were observed. Brain temperature plays an important role in determining CBF thresholds for each of the three types of [Glu]e elevation. CBF thresholds for [Glu]e elevations shifted to a lower level range as brain temperature was reduced. In mild or moderate ischemia, there is no exposure to sustained [Glu]e elevation, which is seen only in relatively severe ischemia characterized by biphasic [Glu]e elevation.
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- 1998
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105. Effects of DIF-1, an Anti-Tumor Agent Isolated from Dictyostelium discoideum, on Rat Gastric Mucosal RGM-1 and Leptomeningeal Cells
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Yuzuru Kubohara, Koichi Ishikawa, Kenji Kabeya, and Hirofumi Matsui
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biology ,Cell growth ,Cellular differentiation ,fungi ,Cell ,Myeloid leukemia ,Anatomy ,biology.organism_classification ,behavioral disciplines and activities ,humanities ,In vitro ,Dictyostelium discoideum ,Cell biology ,body regions ,medicine.anatomical_structure ,Slime mold ,medicine ,Animal Science and Zoology ,human activities ,Morphogen - Abstract
DIF-1 is a putative morphogen that induces stalk cell formation in the cellular slime mold Dictyostelium discoideum. We have previously discovered that DIF-1 suppresses cell growth and induces cell differentiation in vitro in some tumor cells, and also that relatively low concentrations of DIF-1 promote retinoic acid-induced cell differentiation in the human myeloid leukemia HL-60 cells. In this study, to verify cell biological and therapeutic potential of DIF-1, we have examined whether and how DIF-1 affects normal mammalian cells in vitro, using rat leptomeningeal (RLM) cells and rat gastric mucosal RGM-1 cells. In growing phase of both cells, DIF-1 at 5–40 μM suppressed cell growth in a dose-dependent manner. High concentrations (15–40 μM) of DIF-1 were toxic to the growing cells so that the cells showed unusual morphology, but many of them were still alive even at Day 3–4. Withdrawal of DIF-1 allowed the cells to grow. In confluent phase of the cells, DIF-1 at more than 15 μM promoted medium ...
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- 1998
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106. Experimental study of a structural magnesium alloy with high absorption energy under dynamic loading
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Toshiji Mukai, Mamoru Nakamura, Kenji Higashi, Koichi Ishikawa, T. Mohri, and Mamoru Mabuchi
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Materials science ,Magnesium ,Mechanical Engineering ,Alloy ,Metallurgy ,Metals and Alloys ,chemistry.chemical_element ,Fractography ,Izod impact strength test ,engineering.material ,Strain rate ,Condensed Matter Physics ,Microstructure ,chemistry ,Mechanics of Materials ,engineering ,General Materials Science ,Magnesium alloy ,Ductility - Abstract
It has been demonstrated that pure Mg exhibits low ductility under dynamic loading at room temperature owing to its HCP structure. Very limited data are currently available for magnesium alloys under dynamic loading. In order to be used for structural components, it is necessary to improve the mechanical properties of magnesium alloys. Lahaise et al. reported the yield strength of the AZ91 magnesium alloy increased with refining its microstructure. Mohri et al. has already been reported the ductility enhancement of a Mg-Y-RE(Rare Earth) alloy by hot extrusion. They mentioned the enhancement of ductility is due to the refining microstructure of magnesium. Thus refining microstructure enables to raise the possibility for the development of a structural magnesium alloy with high ductility at dynamic strain rate. In this paper, the possibility of a fine-grained WE43 magnesium alloy is investigated to raise the high speed impact performance against the foreign object damage by the enhancement of ductility and absorption energy under dynamic loading.
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- 1998
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107. Central nervous system action of melatonin on gastric acid and pepsin secretion in pylorusligated rats
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Kimitoshi Kato, Yoshiaki Matsuno, Koichi Ishikawa, Yasuyuki Arakawa, Ichiro Murai, Ariyoshi Iwasaki, Hanzo Kurosaka, Sachiko Komuro, Yasuo Takahashi, and Satoshi Asai
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Central Nervous System ,Male ,endocrine system ,medicine.medical_specialty ,Microinjections ,Secretory Rate ,Central nervous system ,Drug Evaluation, Preclinical ,Biology ,Urethane ,Antioxidants ,Injections ,Melatonin ,Gastric Acid ,Rats, Sprague-Dawley ,Pepsin ,Stress, Physiological ,Internal medicine ,Cisterna Magna ,Gastrins ,Pyloric Antrum ,medicine ,Gastric mucosa ,Animals ,Secretion ,Anesthesia ,Pylorus ,Dose-Response Relationship, Drug ,Stomach ,General Neuroscience ,Constriction ,Pepsin A ,Rats ,medicine.anatomical_structure ,Endocrinology ,Gastric Mucosa ,biology.protein ,Gastric acid ,hormones, hormone substitutes, and hormone antagonists ,Injections, Intraperitoneal ,medicine.drug - Abstract
We recently demonstrated that centrally administered melatonin at low doses inhibits the induction of gastric lesions by water-immersion restraint stress. To investigate the mechanism of the potent anti-ulcer action of melatonin, the central nervous system (CNS) effects of melatonin on gastric acid and pepsin secretion were studied in conscious pylorus-ligated rats. Intracisternal (i.c.) melatonin (1-100 ng) dose-dependently decreased acid and pepsin output, while a higher i.p. dose (1 microg) had no inhibitory effect. The i.c. melatonin did not change serum gastrin concentrations. Serum melatonin concentrations at 1 and 4 h after i.c. administration of 10-100 ng melatonin did not differ from those in rats receiving i.c. vehicle. The present results suggest that melatonin administered centrally modulates the secretion of gastric acid and pepsin which may explain, at least in part, the protective, anti-stress role of melatonin in the gastric mucosa observed in our previous study.
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- 1998
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108. Sequence Note: Genetic and Phylogenetic Analysis of HIV Type 1 Strains from Southern Ghana
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James Brandful, Koichi Ishikawa, Naohiko Yamamoto, F. A. Apeagyei, Simeon Aidoo, William Ampofo, Wouter Janssens, Yaw Adu-Sarkodie, F. Anyomi, Tetsutaro Sata, and Takeshi Kurata
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Genetics ,Infectious Diseases ,Type (biology) ,Molecular epidemiology ,Phylogenetic tree ,Phylogenetics ,Virology ,Immunology ,Genotype ,Human immunodeficiency virus (HIV) ,medicine ,Biology ,medicine.disease_cause - Published
- 1998
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109. Characteristics of a thermal mass-flow sensor in vacuum systems
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Kei Toda, Noriyuki Kimura, Koichi Ishikawa, Yasuko Maeda, and Isao Sanemasa
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Convective heat transfer ,Chemistry ,Capillary action ,Flow (psychology) ,Metals and Alloys ,Thermodynamics ,Mechanics ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Torr ,Heat transfer ,Thermal ,Thermal mass ,Electrical and Electronic Engineering ,Resistor ,Instrumentation - Abstract
The housing of a thermal mass-flow sensor has been evacuated in order to improve the sensor characteristics and simplify its manufacture. Two thermosensitive resistors are coiled around a stainless-steel capillary and their temperatures are individually controlled. The difference in power consumption between the two coils increases in proportion to the gas-flow rate. When the sensor housing is exhausted, the power consumption in the absence of gas flow decreases until it reaches a constant value below 10 −2 torr. The power consumption is reduced to half of its initial value by evacuation of the inside of the sensor housing. The temperature profile of the capillary has been modelled, and the temperatures of the gas and the amount of heat transfer calculated. In the vacuum system, the experimental results of the change in power consumption agree with the theoretical data. The tilting effect caused by thermal convection is decreased by evacuating the inside of the sensor housing. This evacuated sensor does not require large power consumption, and a large change ratio of signal output to gas flow is obtained. This sensor can be manufactured readily without the troublesome filling of quartz wool inserted into ordinary mass-flow sensors in order to prevent the tilting effect.
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- 1998
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110. Prostaglandin-D-synthase (β-trace protein) levels in rat cerebrospinal fluid
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Yoshihide Ohe, Masatomo Mori, Koichi Ishikawa, Kenji Kabeya, Masatomo Watanabe, Kenji Katakai, and Katsumi Wakabayashi
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Male ,Aging ,Thyroid Hormones ,medicine.medical_specialty ,Time Factors ,Blotting, Western ,Beta-Globulins ,Retinoic acid ,Tretinoin ,Beta globulins ,Lipocalin ,Prostaglandin-D synthase ,Beta-Trace Protein ,chemistry.chemical_compound ,Cerebrospinal fluid ,Internal medicine ,medicine ,Animals ,Rats, Wistar ,chemistry.chemical_classification ,biology ,General Neuroscience ,Lipocalins ,Rats ,Intramolecular Oxidoreductases ,Endocrinology ,Enzyme ,chemistry ,Fluorescent Antibody Technique, Direct ,biology.protein ,Steroids ,medicine.drug - Abstract
The precise role of prostaglandin-D-synthase (beta-trace protein), the major constituent of cerebrospinal fluid, is unclear. In the present study, a sensitive and highly specific fluoroimmunoassay was developed. The measurement of the enzyme levels in rat CSF revealed a developmental change in the CSF levels with the highest value of 66 +/- 8 microg/ml at 7 days after birth. No significant difference in the levels was seen between different times of day. Subcutaneous injections of all-trans retinoic acid caused a dramatic decrease in the protein levels in a dose- and time-dependent manner. These findings may raise the possibility that prostaglandin-D-synthase in CSF is involved in retinoic acid action on the brain.
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- 1998
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111. A culture substratum appropriate for brain cells is a chondroitin sulfate glycosaminoglycan in serum
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Koichi Ishikawa, Masatomo Watanabe, and Kazuhiko Tatemoto
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Histology ,Neurite ,Size-exclusion chromatography ,Cell ,Cell Culture Techniques ,Biology ,Chromatography, DEAE-Cellulose ,Culture Media, Serum-Free ,Pathology and Forensic Medicine ,chemistry.chemical_compound ,Hyaluronidase ,medicine ,Animals ,Chondroitin sulfate ,Cells, Cultured ,Cerebral Cortex ,Neurons ,Chondroitin Sulfates ,Cell Biology ,Trypsin ,Culture Media ,Rats ,Superose ,medicine.anatomical_structure ,Animals, Newborn ,Biochemistry ,chemistry ,Chromatography, Gel ,Cattle ,Electrophoresis, Polyacrylamide Gel ,Fetal bovine serum ,medicine.drug - Abstract
When cells dissociated from the neonatal rat brains are plated on a poly-lysine-coated surface in a serum-free medium, they display a strange morphology: a dark and extended cell body. Preincubation of the surface with fetal bovine serum was found to inhibit the appearance of this strange contraction of the basal cell sheets in a dose-dependent manner. This finding indicated the presence of a factor(s) in the serum, which might be an appropriate substratum for prolonged survival of brain neurons. In the current study, this factor was highly purified through DEAE ion-exchange chromatography followed by gel filtration. The factor was eluted from a Superose column at fractions corresponding to a molecular weight greater than 1000 kDa. By SDS-PAGE analysis, these fractions were found to contain a major band (/=1000 kDa) positive for alcian blue and few minor bands faintly stainable with Coomassie blue. The activity of the purified sample, inducing the morphological change in cells, was diminished by incubation with chondroitinase ABC. Neither heparitinase II, hyaluronidase, nor trypsin modified the activity. An authentic chondroitin sulfate (type B) mimicked the serum action on the morphology of brain cells in early stages of culture. Taking these findings together, it is suggested that the factor in serum beneficial for the attachment of brain cells is composed of a chondroitin sulfate with a Mr greater than 1000 kDa. Cortical cells dissociated from the neonatal rat brain attached well to the purified factor-coated surface and displayed a healthy morphology: an optically-reflective cell body with thick neurites for at least 3 days in the absence of serum.
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- 1998
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112. Consumer Health Information Service for Patients and Medical Consumers. National Cancer Center-Cancer Information Service
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Koichi Ishikawa, Hiroshi Mizushima, Naoto Yamaguchi, Tetsu Shinkai, and Furmhiko Wakao
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Service (business) ,Consumer health ,medicine ,Cancer ,Center (algebra and category theory) ,Business ,Marketing ,Service provider ,medicine.disease - Published
- 1998
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113. Experimental investigation of battery-induced esophageal burn injury in rabbits
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Takuma Yoshikawa, Yoshinori Takekawa, Satoshi Asai, Koichi Ishikawa, and Akinori Kida
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Male ,Battery (electricity) ,medicine.medical_specialty ,business.industry ,Esophageal disease ,Burns, Electric ,Chemical burn ,ESOPHAGEAL BURN ,Critical Care and Intensive Care Medicine ,medicine.disease ,University hospital ,Surgery ,Trachea ,Esophagus ,medicine.anatomical_structure ,Swallowing ,Animals ,Medicine ,Ingestion ,Rabbits ,business - Abstract
Objective In recent years, small high-performance batteries have become very popular. With this increasing miniaturization of batteries, clinicians have noted an increasing frequency rate of esophageal injury due to battery ingestion by infants. The sltuation is associated with severe injury to the esophagus due to the electrical current produced, particularly in the case of high-performance batteries producing high currents. The pathophysiologic features and complications of esophageal battery burns have not been thoroughly investigated. Our study intended to investigate the pathophysiologic features and complications of esophageal battery burn. Design Open, randomized, controlled study. Setting Experimental animal laboratory in a university hospital. Subjects Male adult mixed-breed rabbits, 22 wks old and weighing 3 to 3.5 kg. Interventions The experimental rabbit model of esophageal injury due to battery ingestion described herein was designed to study not only the direct influence of contact with the battery but also damage to neighboring tissues and the biochemical and pathologic mechanisms of injury. We investigated the relationship between the direction of the inserted battery and the mechanism underlying these complications. Esophageal burn injury was created by placing a 3-V battery into the esophagus for 9 hrs. Measurements and Main Results The cathode side of the esophagus became increasingly alkaline, while the anode side was acidic. Low-voltage battery burns are likely to be due to secondary chemical reactions caused by the electric current because of acid generated at the anode and alkall at the cathode using a micro pH meter. Injury was significantly more severe on the alkaline side when a battery was placed with its cathode directed toward the trachea. Alkaline complications affecting neighboring tissues were more severe than acid complications. These results indicate that as well as the esophageal mucosa itself being injured, deleterious effects are exerted on surrounding tissues, the severity of which vary depending on the orientation and duration of the battery being lodged in the esophagus. Conclusions The direction of the battery cathode, which produces alkali, is important in determining the severity of complications. Based on our investigation of the underlying mechanisms of these complications, we advocate the establishment of treatment guidelines for battery swallowing accidents. (Crit Care Med 1997; 25:2039-2044)
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- 1997
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114. Affinity and kinetic studies for the evaluation of lectin-reactive α-fetoprotein with a biosensor based on surface plasmon resonance
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Yasuyuki Arakawa, Koichi Ishikawa, Satoshi Asai, Yuichi Tominaga, Kimitoshi Kato, and Hiroko Taga
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Hepatology ,biology ,Chemistry ,education ,Surface plasmon ,Kinetics ,Lectin ,Lens culinaris agglutinin ,digestive system diseases ,Sugar binding ,Infectious Diseases ,Biochemistry ,Concanavalin A ,biology.protein ,Surface plasmon resonance ,Biosensor - Abstract
Affinity and kinetic analyses for the evaluation of lectin-reactive α -fetoprotein (AFP) were performed using a biosensor based on surface plasmon resonance (SPR). Human AFP, purified from HCC (hepatocellular carcinoma) patients, was immobilized on the surface of a sensor chip. The interaction of this bound AFP with three lectins, Lens culinaris agglutinin [LCA], concanavalin A [Con-A] and erythroagglutinating phytohemagglutinin [E-PHA]) were monitored in real-time with the change in the SPR response. These three lectins produced an increase in the SPR response, indicating that all three bound specifically to the immobilized AFP. The association ( k ass ) and the dissociation ( k diss ) rate constants clearly differed among the three lectin-AFP interactions. These affinity and kinetic analyses of the sugar binding specificities of lectins, employing a biosensor based on SPR, are expected to serve as a new technique with the potential for simple rapid evaluation of lectin-reactive AFP.
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- 1997
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115. Central effect of melatonin against stress-induced gastric ulcers in rats
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Hanzo Kurosaka, Yoshihiro Matsukawa, Koichi Ishikawa, Satoshi Asai, Sachiko Komuro, Yoshiaki Matsuno, Kimitoshi Kato, Ariyoshi Iwasaki, Ichiro Murai, and Yasuyuki Arakawa
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Central Nervous System ,Male ,Peptic Ulcer ,endocrine system ,medicine.medical_specialty ,Central nervous system ,Rats, Sprague-Dawley ,Melatonin ,Stress, Physiological ,Internal medicine ,Gastric mucosa ,Animals ,Medicine ,Dose-Response Relationship, Drug ,business.industry ,General Neuroscience ,Stomach ,Stress induced ,Rats ,medicine.anatomical_structure ,Endocrinology ,Gastric Mucosa ,Water immersion ,Restraint stress ,business ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug ,Hormone - Abstract
We investigated the role of melatonin in the induction of gastric lesions induced by water immersion restraint stress or centrally administered thyrotropin-releasing hormone (TRH). Melatonin (0.1-1 ng) injected intracisternally (i.c) 30 min prior to stress dose-dependently inhibited the induction of gastric lesions by water immersion restraint stress, while 100 micrograms/kg, i.p. failed to protect the gastric mucosa. Preadministration of melatonin (1 ng, i.c.) significantly reduced (83%) the severity of gastric lesions induced by a TRH analogue (500 ng, i.c.). Serum melatonin concentrations 30 min after administration of 1 ng melatonin i.c. did not differ from those of rats receiving i.c. vehicle. These results suggest that melatonin plays a protective, anti-stress, role in the gastric mucosa via a mechanism involving the central nervous system.
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- 1997
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116. A Case of Sporadic Gastric Carcinoid Tumor Treated Successfully by Laparoscopy-Assisted Distal Gastrectomy
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Kenji Kashima, Masafumi Inomata, Akio Shiromizu, Koichi Ishikawa, Seigo Kitano, Norio Shiraishi, and Tsuyoshi Etoh
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Male ,medicine.medical_specialty ,Biopsy ,Distal gastrectomy ,Carcinoid Tumor ,Lesion ,Gastrectomy ,Stomach Neoplasms ,Gastric mucosa ,Humans ,Medicine ,Laparoscopy ,medicine.diagnostic_test ,Gastric body ,business.industry ,digestive, oral, and skin physiology ,Ultrasound ,Middle Aged ,digestive system diseases ,medicine.anatomical_structure ,Gastric Carcinoid Tumor ,Surgery ,Radiology ,medicine.symptom ,business ,Follow-Up Studies - Abstract
A 49-year-old man was referred to us for treatment of a gastric carcinoid tumor. Gastroscopy revealed a superficial elevated lesion with a central depression covered with nonspecific gastric mucosa located in the anterior wall of the gastric body. The lesion was diagnosed on biopsy as a gastric carcinoid tumor. Preoperative ultrasound and computed tomography examinations revealed a tumor confined to the gastric submucosa and without lymph node metastasis. Therefore, laparoscopy-assisted distal gastrectomy (LADG) was performed. Macroscopically, the resected specimen contained an elevated lesion measuring 0.9 x 0.8-cm with a central depression. The postoperative course was uneventful, and the patient remains free of recurrence 10 months after surgery. There are few cases of sporadic gastric carcinoid tumor successfully treated by LADG. LADG may be useful for treatment of patients with sporadic gastric carcinoid tumor and possible lymph node metastasis.
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- 2005
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117. Simple temperature compensation of thermal air-flow sensor
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Isao Sanemasa, Koichi Ishikawa, and Kei Toda
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Wheatstone bridge ,business.industry ,Chemistry ,Mass flow sensor ,Metals and Alloys ,Electrical engineering ,Mechanics ,Condensed Matter Physics ,Signal ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Compensation (engineering) ,law.invention ,Volumetric flow rate ,Degree (temperature) ,law ,Thermal ,Electrical and Electronic Engineering ,Resistor ,business ,Instrumentation - Abstract
The thermal air-flow sensor, which is heated to a temperature with a constant degree of difference (Δt) from that of the gas, provides power consumption according to the flow rates. The flow signal output of the sensor decreases depending on the rise in ambient temperature. This effect is easily compensated by inserting two identical compensation resistors (Rcom) in the Wheatstone bridge circuit without Δt change. This compensation is accomplished based on the influential change of ambient temperature on the sensor power consumption in proportion to the ratio of Rcom to the bridge resistor.
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- 1996
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118. Sequence Note: Genetic and Phylogenetic Analysis of HIV Type 1 env Subtypes in Ghana, West Africa
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Naohiko Yamamoto, William Ampofo, James Brandful, Yutaka Takebe, Wouter Janssens, Takeshi Kurata, Mubarak Osei-Kwasi, Yoshio Koyanagi, Tetsutaro Sata, Leo Heyndrickx, Koichi Ishikawa, G van der Groen, and S. Yamazaki
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Veterinary medicine ,Molecular epidemiology ,Phylogenetic tree ,Genetic heterogeneity ,Immunology ,Human immunodeficiency virus (HIV) ,Biology ,medicine.disease_cause ,Virology ,West africa ,Infectious Diseases ,Phylogenetics ,Genetic variation ,medicine ,Typing - Abstract
The authors examined HIV-1 genetic variation among 19 HIV-1-infected people of mean age 34.5 years living in Accra Akwatia Kumasi and Ho in Ghana. One person was of unknown origin. Blood samples were collected between December 1993 and January 1996. 16 of the HIV-1 specimens clustered with members of subtype A but the clustering was not supported by 70% or more of the bootstrap tests. Two samples clustered with subtype D strains supported by 92.5% of the bootstrap trees and one sample clustered with subtype G strains supported by 96.2% of the bootstrap trees. For the Ghanaian specimens belonging to subtype A interhost distances at the nucleotide level averaged 14.9% of range 7.83-20.9%. The interhost distance between the two subtype D samples was 8.2%. A cocirculation of subtypes A D and G was identified in Akwatia.
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- 1996
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119. Activation of iron handling system within the gerbil hippocampus after cerebral ischemia
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Yuji Maruyama, Akira Takahashi, Hirohisa Ishimaru, Kazuhiko Tatemoto, Yoshihide Ohe, and Koichi Ishikawa
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Male ,medicine.medical_specialty ,Iron ,Ischemia ,Hippocampus ,Nerve Tissue Proteins ,Biology ,Gerbil ,Prosencephalon ,Antibody Specificity ,Internal medicine ,Glial Fibrillary Acidic Protein ,medicine ,Animals ,Molecular Biology ,chemistry.chemical_classification ,Microglia ,Pyramidal Cells ,General Neuroscience ,medicine.disease ,Immunohistochemistry ,Ferritin ,medicine.anatomical_structure ,Endocrinology ,nervous system ,chemistry ,Ischemic Attack, Transient ,Transferrin ,Ferritins ,biology.protein ,Neuroglia ,Neurology (clinical) ,Atrophy ,Gerbillinae ,Neuroscience ,Developmental Biology ,Astrocyte - Abstract
Analyzing the distribution pattern of transferrin (Tf) and ferritin, we investigated the changes in iron metabolism related proteins in the process of neuronal death induced by 5 min ischemia. In the control animals, Tf immunoreactivity was localized in the oligodendrocytes. Ferritin was distributed in both neurons and gliacytes, particularly microglia. In parallel with the delayed neuronal death, Tf-positive atrophied neurons and numerous ferritin-positive gliacytes appeared in the CA1 subfield of the hippocampus 4 days after ischemia, when glia fibrillary acidic protein (GFAP)-positive astrocytes also appeared throughout the hippocampal structure. A considerable number of ferritin-positive phagocytes (reactive microglia) appeared in the stratum pyramidale from the seventh day. Our data show clearly that the mobilization of Tf and ferritin-positive phagocytes are linked with the degeneration of neurons induced by cerebral ischemia. These events may suggest an activation of iron handling system under the postischemic condition.
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- 1996
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120. Real time monitoring of biphasic glutamate release using dialysis electrode in rat acute brain ischemia
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Koichi Ishikawa, Yuji Iribe, Tadashi Kohno, and Satoshi Asai
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Male ,Microdialysis ,Ischemia ,Glutamic Acid ,Brain ischemia ,chemistry.chemical_compound ,Computer Systems ,medicine ,Extracellular ,Animals ,Neurotransmitter ,business.industry ,General Neuroscience ,Glutamate receptor ,Electroencephalography ,Hydrogen Peroxide ,medicine.disease ,Rats, Inbred F344 ,Electrodes, Implanted ,Rats ,chemistry ,Ischemic Attack, Transient ,Linear Models ,Biophysics ,Amino Acid Oxidoreductases ,business ,Dialysis (biochemistry) ,Oxidation-Reduction ,Neuroscience ,Perfusion ,Body Temperature Regulation - Abstract
Glutamate has been proposed to play a critical role in acute ischemic pathophysiology in the brain. In this study, glutamate was monitored by the dialysis electrode technique, in which glutamate is oxidized by glutamate oxidase producing hydrogen peroxide which is then amperometrically detected on a platinum electrode set at +650 mV vs Ag/AgCl. A dialysis electrode, which consists of a microdialysis probe with a built-in platinum electrode, provides a continuous glutamate oxidase perfusion inside of the probe. Perfusion with this solution allows real-time monitoring of glutamate dynamics in the extracellular space during ischemia. This study was designed to collect detailed information on rapid changes in the extracellular glutamate concentration of the rat striatum and demonstrated two distinct phases of glutamate release during early severe brain ischemia.
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- 1996
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121. Cystatin C and apolipoprotein E immunoreactivities in CA1 neurons in ischemic gerbil hippocampus
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Yuji Maruyama, Yoshihide Ohe, Koichi Ishikawa, Akira Takahashi, and Hirohisa Ishimaru
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Male ,Apolipoprotein E ,medicine.medical_specialty ,Time Factors ,Immunocytochemistry ,Central nervous system ,Ischemia ,Hippocampus ,Cysteine Proteinase Inhibitors ,urologic and male genital diseases ,Gerbil ,Brain Ischemia ,Apolipoproteins E ,Internal medicine ,Glial Fibrillary Acidic Protein ,medicine ,Animals ,Cystatin C ,Molecular Biology ,reproductive and urinary physiology ,Neurons ,biology ,Pyramidal Cells ,General Neuroscience ,Anatomy ,medicine.disease ,Cystatins ,Immunohistochemistry ,female genital diseases and pregnancy complications ,Endocrinology ,medicine.anatomical_structure ,nervous system ,biology.protein ,Neurology (clinical) ,Cystatin ,Gerbillinae ,Developmental Biology - Abstract
The distribution patterns of cystatin C and apolipoprotein E (apo E) were studied immunocytochemically in the gerbil hippocampus before and after 5 min ischemia. In the controls, cystatin C was distributed mainly in astrocytes. In addition, a large number of dots positive for cystatin C were observed around the outlines of neuronal perikarya in the CA1 subfields. One day after ischemia, cystatin C-positive stainings outlining neuronal cell bodies disappeared. On the fourth day, intense stainings for cystatin C appeared in atrophied pyramidal neurons and these stainings in neurons disappeared by the 14th day. A remarkable increase in the number of cystatin C-positive astrocytes occurred on the fourth day and thereafter these spread over the whole of the CA1 subfield. Apo E was also distributed in astrocytes in the control specimens. From the fourth day, extra- and/or intracellular distribution of apo E-immunoreactivities was noted in the stratum pyramidale. Apo E-positive astrocytes disappeared transiently on the fourth day and then reappeared and increased remarkably by the 14th day. These findings indicate that cystatin C and apo E are involved in the degeneration process of brain neuronal cells.
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- 1996
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122. Influence of strain rate on the mechanical properties in fine-grained aluminum alloys
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Koichi Ishikawa, Toshiji Mukai, and Kenji Higashi
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Materials science ,Strain (chemistry) ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,Flow stress ,Strain rate ,Condensed Matter Physics ,Grain size ,Carbide ,chemistry ,Mechanics of Materials ,Aluminium ,General Materials Science ,Extrusion ,Composite material ,Elongation - Abstract
Fine-grained IN905XL aluminum alloys with five grain sizes between 0.8 and 8.1 μm have been developed by a combination of mechanical alloying and conventional extrusion in order to investigate the influence of the strain rate on the mechanical properties. Negative strain rate sensitivity of flow stress is observed up to 10 s −1 for all samples. Above the strain rate of 1 × 10 3 s −1 , however, all samples show the positive strain rate sensitivity of strength. Total elongation at high strain rates is generally larger than that at low strain rates. Flow stresses increase with decreasing grain size for all strain rates. The measured values of strength of the coarse grained IN905XL with sizes above 4.3 μm agree with the values estimated from a cooperation of the strengthening by the grain size refinement, magnesium solute atoms and oxides and carbides dispersion. In the Hall-Petch relations at high strain rates, the gradient of the curve increases with increasing reciprocal square root of the grain size. For fine-grained samples, therefore, an additional strengthening mechanism should be considered such as the difference in the characteristics of the boundary.
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- 1995
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123. Strength and ductility under dynamic loading in fine- grained IN905XL aluminum alloy
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Koichi Ishikawa, Toshiji Mukai, and Kenji Higashi
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Materials science ,Strain (chemistry) ,Mechanics of Materials ,Metallurgy ,Metals and Alloys ,Grain boundary ,Flow stress ,Strain rate ,Elongation ,Condensed Matter Physics ,Ductility ,Microstructure ,Grain size - Abstract
Three IN905XL aluminum alloys with fine grain (1 μm), intermediate grain (3 μm), and coarse grain (5 μm) have been developed by a combination of mechanical alloying (MA) and conventional extrusion in order to investigate their mechanical properties at dynamic strain rates of 1 × 103 and 2 × 103 s−1 and a quasi-static strain rate of 10-3 s−1. Flow stresses are found to increase with decreasing grain size for all the strain rates tested. Negative strain-rate sensitivity of flow stress is observed up to 1 × 103 s−1 in both intermediate- and coarse-grained IN905XL. At the highest strain rate of 2 × 103 s−1 however, all samples showed a positive strain-rate sensitivity of strength. Total elongation at high strain rates is generally larger than that at low strain rates. Total elongation also decreases with grain size for all the strain rates. This decrease in elongation results from an initiation of microcracks at interfaces between the matrix and particles finely dispersed near grain boundary regions, introduced during MA processing; then, this initiation leads elongation of alloys to small limited values.
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- 1995
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124. Meninges play a neurotrophic role in the regeneration of vasopressin nerves after hypophysectomy
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Masatomo Mori, Kenji Kabeya, Kenji Katakai, Motoo Shinoda, Koichi Ishikawa, and Kazuhiko Tatemoto
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Male ,Vasopressin ,medicine.medical_specialty ,Cerebellum ,Hypophysectomy ,Cell Survival ,Cell Transplantation ,Vasopressins ,medicine.medical_treatment ,Central nervous system ,Biology ,Meninges ,Nerve Fibers ,Fetal Tissue Transplantation ,Internal medicine ,medicine ,Animals ,Rats, Wistar ,Molecular Biology ,Cells, Cultured ,Neurons ,Pia mater ,General Neuroscience ,Median Eminence ,Immunohistochemistry ,Nerve Regeneration ,Rats ,medicine.anatomical_structure ,Endocrinology ,Culture Media, Conditioned ,Median eminence ,Magnocellular cell ,Neurology (clinical) ,Developmental Biology - Abstract
Following hypophysectomy the regenerating fibers of magnocellular neurons are known to establish new neurohemal connections with reorganized vasculatures in the median eminence, which lead to establishment of a posterior pituitary-like structure. In order to examine the role of the meninges (the pia mater and the arachnoid) in this regeneration process, we implanted the meningeal tissues obtained from neonatal rat pups into the third ventricle of the adult rats, and then hypophysectomized the host animals. Ten days after hypophysectomy, the meningeal tissue grafts were found to be densely innervated by regenerating vasopressin-immunoreactive fibers. Such fibers had dots and frequently formed large punctuations. On the contrary, few vasopressin fibers were found within the cortical tissue grafts. Further, the exposure of primary hypothalamic cell cultures to the medium conditioned by meningeal cell cultures promoted not only the survival of vasopressin-immunoreactive neurons but also the outgrowth and aborization of the neurites. The survivals of cortical and cerebellum neurons in culture were also promoted by the conditioned medium. These findings raise the possibility that the meninges play an important role in the axonal regeneration process after hypophysectomy.
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- 1995
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125. Ductility at Dynamic Strain Rate in Mechanically Alloyed Aluminum IN905XL
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Koichi Ishikawa, Toshiji Mukai, Yoshihira Okanda, and Kenji Higashi
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Thesaurus (information retrieval) ,Materials science ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,chemistry.chemical_element ,Strain rate ,Industrial and Manufacturing Engineering ,Search engine ,chemistry ,Aluminium ,Materials Chemistry ,Science, technology and society ,Ductility - Published
- 1995
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126. Neurobiology of learning and memory and antidementia drug
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Koichi Ishikawa
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Pharmacology ,medicine ,Explicit memory ,Memory formation ,Dementia ,Semantic memory ,Long-term potentiation ,Chemistry (relationship) ,medicine.disease ,Psychology ,Neuroscience ,Immediate early gene ,Declarative memory - Abstract
Discoveries of long-term potentiation and immediate early gene in the central nervous system have enabled new developments in experiments on learning and memory. These experiments are conducted in many kinds of animals with different procedures, physiology, chemistry and pharmacology. However, there is still some confusion when these various procedures are discussed. Memory is defined as information storage of an animal's previous experiences. The memory induces changes in behavioral performance. This means that memory must be observed in whole animals, and one question that can occur is how does long-term potentiation, for example, correlate with memory. Furthermore, memory has been divided into two major classifications, declarative and non-declarative, from the comparison of amnesias observed in humans and animals. The declarative memory can be observed in human subjects, but not in animals. This article presents a neuronal circuit concerning memory formation and some results obtained from benzodiazepines, and it discusses some problems encountered executing when experiments on learning and memory. In addition, the discussion speculates over the possibility for an "anti-dementia drug".
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- 1995
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127. Short- and long-term outcomes of neoadjuvant-synchronus S-1+radiotherapy for locally advanced rectal cancer: Multicenter phase II study
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Manabu Tojigamori, Shigeo Ninomiya, Yoshitake Ueda, Tomotaka Shibata, Toshio Bando, Yu Takeuchi, Akio Shiromizu, Kyuzo Fujii, Kazuaki Hiroishi, Shinichiro Empuku, Kentaro Nakajima, Hidefumi Shiroshita, Koichi Ishikawa, Takahiro Hiratsuka, Koichiro Tahara, Tsuyoshi Etoh, Toshifumi Matsumoto, Atsushi Sasaki, Masafumi Inomata, and Tomonori Akagi
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Cancer Research ,medicine.medical_specialty ,business.industry ,Colorectal cancer ,medicine.medical_treatment ,Rectum ,Phases of clinical research ,Perioperative ,medicine.disease ,Total mesorectal excision ,Surgery ,Radiation therapy ,medicine.anatomical_structure ,Oncology ,Fluorouracil ,medicine ,Radiology ,business ,Chemoradiotherapy ,medicine.drug - Abstract
720 Background: Fluorouracil-based chemoradiotherapy (CRT) is regarded as a standard perioperative treatment in locally advanced rectal cancer. We investigated the efficacy and safety of substituting fluorouracil with the oral prodrug S-1. Methods: A multi-institutional (17 specialized centers), interventional phase II trial, was conducted from April 2009 to August 2011. For inclusion, patients must fulfill the following requirements before neoadjuvant CRT: (i) histologically proven rectal carcinoma; (ii) tumor located in the rectum (upper, lower); (iii) cancer classified as T3-4, N0–3 and M0; Two cycles of neoadjuvant CRT with S-1 (100 mg/m2 on days 1-5, 8-12, 22-26, and 29-33) was administered, and irradiation (total 45Gy/25fr, 1.8Gy/day, on days 1-5, 8-12, 15-19, 22-26, and 29-33) was performed. Total mesorectal excision was performed during the 4th and 8th week after the end of the neoadjuvant CRT. The primary endpoint is rate of complete treatment of neoadjuvant CRT. Secondary endpoints are response rate of neoadjuvant CRT, short-term clinical outcomes, rate of curative resection, and pathological response (grade2/3). Results: This trial included 37 patients (clinical StageIIA: 8, IIIB: 19, IIIC: 10; tumor located in the upper rectum; 4, the lower rectum; 33). A complete treatment of neoadjuvant CRT was found in 86.5% of patients (95%CI;75.5-97.5%), and an adverse event (grade 3/4) occurred in 4 patients(11.1%). Response rate (PR/CR;RECIST 1.0) was 56.8% (95%CI; 40.8-72.7%), and pathologic response rate (grade2/3) was 48.6% (95%CI; 32.5-64.8%). The median operating time was 448.5 min (IQR 340.5-505.5), and median blood loss was 422.5 mL (IQR 182.5-1125). Grade 3-4 postoperative complications occurred in 6 (16.7%) patients. The most common grade 3 or 4 postoperative complication was anastomotic leakage (2 [5.6%]). The 3-year overall survival rate was 88.5%. The 3-year disease free survival rate was 70.9%. Median length of follow-up was 42 months. Conclusions: A neoadjuvant-synchronus S-1+Radiotherapy for locally advanced rectal cancer is feasible in terms of pathological response, adverse events, accompany with favorable long-term outcome. Clinical trial information: 03396.
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- 2016
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128. Resistance to Lettuce Big-Vein Disease in Lettuce Cultivars
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Koichi Ishikawa, Takahide Sasaya, Masatake Fujino, Hiroya Fujii, and Akane Takezaki
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biology ,viruses ,General Engineering ,food and beverages ,Lactuca ,Horticulture ,biology.organism_classification ,Virus ,Agronomy ,General Earth and Planetary Sciences ,Cultivar ,Lettuce big vein virus ,General Environmental Science - Abstract
In a field where lettuce big-vein disease had occurred, the relationship between symptom expression and two viruses associated with the disease (Lettuce big-vein virus and Mirafiori lettuce virus) was investigated in a total of 60 lettuce cultivars (Lactuca saliva L.). Both viruses were detected in all lettuce cultivars. In the crisphead type, the degree of resistance to symptom expression was related to the stage at which the virus was detected, especially with Mirafiori lettuce virus. In the butterhead, cos, stem and red leaf types, both viruses were detected in the early growing stages, while few or no typical symptoms were observed at harvest.
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- 2003
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129. Successful perioperative management of a patient with idiopathic thrombocytopenic purpura undergoing emergent appendectomy: Report of a case
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Yoshitaka Toyomasu, Fumiaki Kishihara, Takashi Matsumata, Erito Mochiki, Daihiko Eguchi, Rinshun Shimabukuro, Yasurou Fukuyama, Koichi Ishikawa, Hiroyuki Kuwano, and Hatsuo Moriyama
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Autoimmune disease ,Disseminated intravascular coagulation ,medicine.medical_specialty ,biology ,Perioperative management ,business.industry ,C-reactive protein ,medicine.disease ,Thrombocytopenic purpura ,Article ,Surgery ,Platelet transfusion ,medicine.anatomical_structure ,Normal bone ,immune system diseases ,hemic and lymphatic diseases ,White blood cell ,medicine ,biology.protein ,business ,Operation - Abstract
INTRODUCTIONIdiopathic thrombocytopenic purpura (ITP) is an autoimmune disease characterized by a low platelet count and normal bone marrow. Patients with ITP undergoing surgery are thought to have increased risk for postoperative complications because of their thrombocytopenia.PRESENTATION OF CASEwe report the case of a 66-year-old woman with ITP who required an emergency operation for acute appendicitis associated with disseminated intravascular coagulation. Preoperative therapy consisted of platelet transfusions only, and intraoperative hemostasis was achieved. Postoperatively, high-dose intravenous immunoglobulin (IVIg) therapy led to an increased, stable, and adequate platelet count and good hemostasis.DISCUSSIONThe outcome of this case suggests that IVIg therapy is not always required for preoperative management of patients with.CONCLUSIONIVIg therapy may be useful for postoperative management after emergency surgery.
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- 2012
130. Detection of Mycobacterium ulcerans by the Loop Mediated Isothermal Amplification Method
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Diana Amissah, Toshio Yamazaki, Koichi Ishikawa, Ben Hatano, Tetsutaro Sata, I.F. Aboagye, Harutaka Katano, and Anthony Ablordey
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Buruli ulcer ,lcsh:Arctic medicine. Tropical medicine ,lcsh:RC955-962 ,Loop-mediated isothermal amplification ,Microbiology ,Sensitivity and Specificity ,Medicine ,Humans ,Mycobacterium avium complex ,Biology ,Buruli Ulcer ,Africa South of the Sahara ,Bacteriological Techniques ,biology ,Mycobacterium ulcerans ,business.industry ,lcsh:Public aspects of medicine ,Disease progression ,Public Health, Environmental and Occupational Health ,lcsh:RA1-1270 ,biology.organism_classification ,medicine.disease ,Virology ,Infectious Diseases ,Molecular Diagnostic Techniques ,business ,Nucleic Acid Amplification Techniques ,Research Article - Abstract
Background Buruli ulcer (BU) caused by Mycobacterium ulcerans (M. ulcerans) has emerged as an important public health problem in several rural communities in sub-Saharan Africa. Early diagnosis and prompt treatment are important in preventing disfiguring complications associated with late stages of the disease progression. Presently there is no simple and rapid test that is appropriate for early diagnosis and use in the low-resource settings where M. ulcerans is most prevalent. Methodology We compared conventional and pocket warmer loop mediated isothermal amplification (LAMP) methods (using a heat block and a pocket warmer respectively as heat source for amplification reaction) for the detection of M. ulcerans in clinical specimens. The effect of purified and crude DNA preparations on the detection rate of the LAMP assays were also investigated and compared with that of IS2404 PCR, a reference assay for the detection of M. ulcerans. Thirty clinical specimens from suspected BU cases were examined by LAMP and IS2404 PCR. Principal Findings The lower detection limit of both LAMP methods at 60°C was 300 copies of IS2404 and 30 copies of IS2404 for the conventional LAMP at 65°C. When purified DNA extracts were used, both the conventional LAMP and IS2404 PCR concordantly detected 21 positive cases, while the pocket warmer LAMP detected 19 cases. Nine of 30 samples were positive by both the LAMP assays as well as IS2404 PCR when crude extracts of clinical specimens were used. Conclusion/Significance The LAMP method can be used as a simple and rapid test for the detection of M. ulcerans in clinical specimens. However, obtaining purified DNA, as well as generating isothermal conditions, remains a major challenge for the use of the LAMP method under field conditions. With further improvement in DNA extraction and amplification conditions, the pwLAMP could be used as a point of care diagnostic test for BU, Author Summary In order to develop a simple and rapid test that can be used to diagnose Buruli ulcer under field conditions, we modified the conventional LAMP assay by using a disposable pocket warmer as a heating device for generating a constant temperature for the test reaction and employed the use of crude sample preparations consisting of boiled and unboiled extracts of the clinical specimen instead of using purified DNA as the diagnostic specimen. Thirty clinical specimens from suspected Buruli ulcer patients were investigated by the modified LAMP (or pocket warmer LAMP) and the conventional LAMP, as well as IS2404 PCR, a reference method for the detection of Mycobacterium ulcerans. There was no significant difference in the detection rate (63–70%) in all of the methods when purified samples were used for the tests. On the other hand the use of crude specimen preparation resulted in a drop in detection rate (30–40%). This study demonstrates that the LAMP test can be used for rapid detection of M. ulcerans when purified DNA preparations are used. With further improvements in the sample reaction, as well as in specimen purification, the pocket warmer LAMP may provide a simple and rapid diagnostic test for Buruli ulcer.
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- 2012
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131. Effects of several 5-HT1A agonists on hippocampal rhythmical slow activity in unanesthetized rats
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Naoki Ueda, Koichi Ishikawa, K. Kasamo, Takuya Kojima, M. Kogure, and K. Tada
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Male ,Agonist ,endocrine system ,medicine.medical_specialty ,Spiperone ,medicine.drug_class ,Walking ,Propranolol ,Hippocampus ,Buspirone ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Internal medicine ,Flesinoxan ,medicine ,Animals ,Biogenic Monoamines ,Rats, Wistar ,Pindolol ,Pharmacology ,8-Hydroxy-2-(di-n-propylamino)tetralin ,Behavior, Animal ,Dose-Response Relationship, Drug ,8-OH-DPAT ,Fenclonine ,Ipsapirone ,Electroencephalography ,Rats ,Serotonin Receptor Agonists ,Endocrinology ,nervous system ,chemistry ,Serotonin Antagonists ,medicine.drug - Abstract
We examined the effect of 5-hydroxytryptamine (5-HT) 1A agonists on walking related, atropineresistant, rhythmical slow activity (wr-RSA) of the hippocampus in rats. Selective 5-HT 1A agonists, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), flesinoxan, buspirone and ipsapirone significantly decreased the power value of 7–9 Hz band activity and the median frequency of wr-RSA. The order of potency was 8-OH-DPAT > flesinoxan = buspirone in power reduction. The 5-HT 1A antagonists, (−)pindolol, (−)propranolol and spiperone, inhibited the effect of 8-OH-DPAT on wr-RSA. Pretreatment with parachlorophenylalanine did not abolish the effect of 8-OH-DPAT. These results indicate that 5-HT 1A agonists reduce both power and median frequency values of wr-RSA through activation of post-synaptic 5-HT 1A receptors in the forebrain in unanesthetized rats, in vivo .
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- 1994
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132. Morphological Changes of Somatostatin Neurons in the Suprachiasmatic Nucleus by Hypophysectomy of the Rat
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Koichi Ishikawa, Toyohiko Miura, and Motoo Shinoda
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Male ,endocrine system ,medicine.medical_specialty ,Vasopressin ,Hypophysectomy ,medicine.medical_treatment ,Circadian clock ,Immunocytochemistry ,Vasoactive intestinal peptide ,General Biochemistry, Genetics and Molecular Biology ,Internal medicine ,medicine ,Animals ,Circadian rhythm ,Rats, Wistar ,Neurons ,Behavior, Animal ,General Veterinary ,Suprachiasmatic nucleus ,Chemistry ,General Medicine ,Immunohistochemistry ,Circadian Rhythm ,Rats ,Somatostatin ,Endocrinology ,nervous system ,Suprachiasmatic Nucleus ,Animal Science and Zoology ,sense organs ,hormones, hormone substitutes, and hormone antagonists - Abstract
After hypophysectomy, behavioral circadian rhythmicities in the rat became indistinct and phase shift was observed. Therefore, it was thought that the suprachiasmatic nucleus (SCN), which is the circadian oscillator in mammals, was affected by hypophysectomy. We investigated the effects of hypophysectomy on SCN neurons using immunohistochemical staining. Wistar-Imamichi strain male rats were hypophysectomized at 60 days old. Their brains were fixed by acrolein perfusion at 10, 30 and 60 days after the operation, and then vasopressin (AVP)-, vasoactive intestinal polypeptide (VIP)- and somatostatin (SRIH)- neurons in the SCN were stained immunohistochemically. Ten days after the operation, SRIH-neurons were not found in the SCN. At 30 and 60 days after the operation, a few SRIH-positive cell bodies were recognized. In contrast, AVP- and VIP- neurons did not change in morphology in comparison with normal rats. These results suggest that hypophysectomy produces an essential change in SRIH neurons in the SCN, and that such change is responsible for the abnormal behavioral rhythms.
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- 1994
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133. Inhibition of the early phase of free fatty liberation during cerebral ischemia by excitatory amino acid antagonist administered
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Koichi Ishikawa, Y. Katayama, Tatsuro Kawamata, Takashi Tsubokawa, and Takeshi Maeda
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chemistry.chemical_classification ,Microdialysis ,medicine.medical_specialty ,biology ,General Neuroscience ,Ischemia ,Glutamate receptor ,Fatty acid ,medicine.disease ,chemistry.chemical_compound ,Kynurenic acid ,Phospholipase A2 ,Endocrinology ,chemistry ,Biochemistry ,Internal medicine ,medicine ,biology.protein ,Liberation ,lipids (amino acids, peptides, and proteins) ,Neurology (clinical) ,Neurotransmitter ,Molecular Biology ,Developmental Biology - Abstract
In order to determine the role of excitatory amino acids (EAAs) in free fatty acid (FFA) liberation during cerebral ischemia, we examined the effect of in situ administration of kynurenic acid, a broad-spectrum antagonist of EAA receptors, by microdialysis on the increase in FFA levels during ischemia in the rat hippocampus. A transient rapid increase in FFA levels, superimposed on a continued slow increase, was observed beginning at 1-2 min after ischemia induction. The early rapid increase in FFAs was profoundly inhibited by kynurenic acid, suggesting that EAAs are critically involved in the early phase of FFA liberation. Development of massive ionic shifts during cerebral ischemia can be delayed for several minutes by kynurenic acid administered by the same procedure, suggesting a vital role for EAAs in the early appearance of anoxic depolarization. The observed inhibition of early FFA liberation may thus be attributable to the delay in development of massive ionic shifts and resultant neurotransmitter release which may activate phospholipase A2 and C.
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- 1994
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134. Prevalence of Blood-Borne Infectious Diseases in Blood Donors in Ghana
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Simeon Aidoo, Koichi Ishikawa, James Brandful, Justina Ansah, Nicholas Israel Nii-Trebi, Victor Nuvor, Kenji Abe, Naoki Yamamoto, David Ofori-Adjei, William Ampofo, and Hideo Naito
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Adult ,Microbiology (medical) ,Blood transfusion ,Adolescent ,medicine.medical_treatment ,Hepatitis C virus ,Blood Donors ,Hepacivirus ,Antibodies, Viral ,medicine.disease_cause ,Ghana ,Virus ,Flaviviridae ,Virology ,medicine ,Humans ,Seroprevalence ,Syphilis ,Treponema pallidum ,Aged ,Human T-lymphotropic virus 1 ,biology ,business.industry ,HIV ,Transfusion Reaction ,Middle Aged ,medicine.disease ,biology.organism_classification ,Antibodies, Bacterial ,Virus Diseases ,Immunology ,Viral disease ,business - Abstract
Transfusion-transmissible infections among 808 blood donors in Ghana were investigated in 1999. Antibody seroprevalences of 3.8, 0.7, 8.4, and 13.5%, respectively, for human immunodeficiency virus, human T-cell lymphotrophic virus type 1, hepatitis C virus (HCV), and Treponema pallidum were obtained. The seroprevalence of HCV infection was confirmed to be 0.9% after supplementary testing, and the transfusion risk potential of these pathogens was demonstrated.
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- 2002
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135. High-Strain-Rate Superplasticity in an AZ91 Magnesium Alloy Processed by Ingot Metallurgy Route
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Koichi Ishikawa, Kenji Higashi, Hiroyuki Watanabe, and Toshiji Mukai
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High strain rate ,Materials science ,Mechanical Engineering ,Metallurgy ,Superplasticity ,Strain rate ,Condensed Matter Physics ,Reduction ratio ,Grain size ,Mechanics of Materials ,General Materials Science ,Extrusion ,Ingot ,Magnesium alloy - Abstract
High-strain-rate superplastic magnesium alloy, AZ91, was processed through the ingot metallurgy route. The relationship between working temperature and resulting grain size indicated that the grain size tends to decrease with decreasing working temperature in AZ91. Based on this preliminary result, the ingot was hot extruded at a relatively low temperature of 523 K with a reduction ratio of 44. A very fine grain size of 1.7 µm was attained only by hot extrusion. The fine-grained structure was stable blow 573 K. Owing to the fine grain size, high-strain-rate superplasticity was observed at temperatures of ∼ 548 K.
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- 2002
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136. [Practical use of DPC information for occupational health consultation]
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Ichiro Oyama, Tatsuhiko Kubo, Koichi Ishikawa B, Kenshi Hayashida, Shinya Matsuda, Yoshihisa Fujino, and Noriyuki Manabe
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Standardization ,Inpatient care ,business.industry ,media_common.quotation_subject ,Public Health, Environmental and Occupational Health ,Medical information ,General Medicine ,Disease ,Length of Stay ,Toxicology ,medicine.disease ,Transparency (behavior) ,Occupational safety and health ,Hospitalization ,Japan ,medicine ,Humans ,Christian ministry ,Medical emergency ,business ,Welfare ,Diagnosis-Related Groups ,Occupational Health ,media_common - Abstract
BACKGROUND The Diagnosis Procedure Combination (DPC) is a national administrative case-mix classification system for acute inpatient care which was launched in Japan in 2003. This system was designed to increase the standardization and transparency of medical information. The system has collected medical information in a unified format nationwide from acute hospitals. Significant parts of the data has been published by Ministry of Health, Labour and Welfare, including average length of hospital stay and number of patients by disease and hospital. This information is valuable for medical consultation in occupational health settings. OBJECTIVES This article provides an overview of the DPC system and how to utilize the data from the perspective of occupational health practitioners.
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- 2011
137. Mutations of p53, E-cadherin, alpha- and beta-catenin genes and tyrosine phosphorylation of beta-catenin in human gastric carcinomas
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S Iwai, T Mazaki, Koichi Ishikawa, Yukimoto Ishii, and Masashi Fujii
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Silent mutation ,Cancer Research ,Beta-catenin ,biology ,Cadherin ,Tyrosine phosphorylation ,Gene mutation ,medicine.disease_cause ,chemistry.chemical_compound ,Oncology ,chemistry ,Catenin ,biology.protein ,Cancer research ,medicine ,Missense mutation ,Carcinogenesis - Abstract
We investigated whether dysfunction of p53 and E-cadherin participate in invasiveness and metastasis of human gastric carcinoma. We examined twenty-five human gastric carcinomas for p53, E-cadherin, alpha- and beta-catenin gene alteration by the reverse transcription-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) method and sequencing analysis. Three samples (13%) showed p53 gene mutation (two missense mutations and 6 bp deletion). 25% (3/12) of the carcinomas with lymph node metastasis had p53 gene mutations. One sample (4%) showed E-cadherin silent mutation. We were not able to detect alpha- or beta-catenin gene alteration. Therefore we investigated tyrosine-phosphorylation of E-cadherin, a and beta-catenin. Tyrosine-phosphorylated beta-catenin was detected in 13% (2/15) of poorly differentiated carcinomas. These results suggest that the p53 gene mutations have some correlation with lymph node metastasis, and tyrosine phosphorylation of beta-catenin rather than cadherin/catenin gene mutation is at least partly responsible for the loosening of cell-cell contact and invasiveness of poorly differentiated carcinomas.
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- 2011
138. Laparoscopic cholecystectomy with and without abdominal prophylactic drainage
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Koichi, Ishikawa, Takashi, Matsumata, Fumiaki, Kishihara, Yasuro, Fukuyama, Hidetaka, Masuda, and Seigo, Kitano
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Adult ,Male ,Cholecystolithiasis ,Length of Stay ,Middle Aged ,Unnecessary Procedures ,Polyps ,Postoperative Complications ,Cholecystectomy, Laparoscopic ,Risk Factors ,Drainage ,Humans ,Female ,Gallbladder Neoplasms ,Aged ,Retrospective Studies - Abstract
As techniques in laparoscopic cholecystectomy (LC) have improved, the role of routine prophylactic abdominal drainage may be limited. A retrospective review was carried out of patients undergoing elective LC to evaluate the benefit of routine drainage in simple uncomplicated procedures.This study of 295 patients with cholecystolithiasis or gallbladder polyp included 145 patients who underwent LC with drainage and 150 patients who underwent LC without drainage between 2003 and 2007. Allocation to drain or not to drain was non-randomized and based on surgeon preference according to intraoperative findings. Patient characteristics, operative results, and postoperative outcomes were compared between the two groups with univariate analysis.Time to first flatus and length of postoperative hospital stay in the LC without drainage group were shorter than in the LC with drainage group. There was no significant difference between the two groups with respect to postoperative complication rate. No complications were noted due to the lack of drain placement.The use of drain after simple elective uncomplicated LC could safely be limited to appropriate patients as judged by the operating surgeon.
- Published
- 2011
139. Effect of Systemic Administration of N-Methyl-d-Aspartic Acid on Extracellular Taurine Level Measured by Microdialysis in the Hippocampal CA1 Field and Striatum of Rats
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Miki Kogure, Megumi Sugahara, Koichi Ishikawa, and Shinji Shibanoki
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Male ,Microdialysis ,Taurine ,N-Methylaspartate ,Time Factors ,Pyramidal Tracts ,N-Methyl-D-aspartic acid ,Pharmacology ,Hippocampus ,Biochemistry ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Animals ,Amino Acids ,Rats, Wistar ,Chromatography, High Pressure Liquid ,Chemistry ,Glutamate receptor ,Corpus Striatum ,Rats ,Glutamine ,Kinetics ,2-Amino-5-phosphonovalerate ,nervous system ,Glycine ,Systemic administration ,NMDA receptor ,Dizocilpine Maleate ,Extracellular Space ,Injections, Intraperitoneal - Abstract
The extracellular concentrations of amino acids in the hippocampal CA1 field and striatum of conscious freely moving rats were monitored simultaneously by in vivo brain microdialysis using HPLC with electrochemical detection. Under basal conditions, aspartate, glutamate, glutamine, glycine, taurine, and alanine were detected, but gamma-aminobutyric acid was undetectable in both regions. Intraperitoneal injection of N-methyl-D-aspartic acid (NMDA; 10 mg/kg) caused a significant increase (three- to fivefold) in the taurine concentration in the dialysate obtained from both the hippocampal CA1 and striatum, whereas other amino acids (aspartate, glutamate, and alanine) did not show significant changes. Local application of NMDA (300 microM) to both regions via the dialysis probes also caused a similar increase (three- to fivefold) in both regions. Under infusion of hypertonic Ringer's solution containing 150 mM sucrose, the effect of NMDA on the level of taurine in both the regional dialysates was not affected. The effect of NMDA was totally reduced by intraperitoneal administration of MK-801 (0.3-1.0 mg/kg), a noncompetitive antagonist of NMDA receptors. Continuous infusion of DL-2-amino-5-phosphonovaleric acid (1.0 mM), a competitive antagonist of NMDA receptors, via the dialysis probes completely inhibited the effect of NMDA. These findings suggest that systemic administration of NMDA is effective as well as local administration into the brain and that NMDA receptors might be involved in the regulation of the extracellular taurine level in the brain without dependence on cell swelling.
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- 1993
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140. Neonatal glutamate can destroy the hippocampal CA1 structure and impair discrimination learning in rats
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Taizo Kubo, Ryutaro Kohira, Tadao Okano, and Koichi Ishikawa
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medicine.medical_specialty ,Monosodium glutamate ,Neurotoxins ,Central nervous system ,Pyramidal Tracts ,Hippocampus ,Hippocampal formation ,Discrimination Learning ,chemistry.chemical_compound ,Glutamates ,Internal medicine ,Sodium Glutamate ,medicine ,Animals ,Discrimination learning ,Rats, Wistar ,Molecular Biology ,Dose-Response Relationship, Drug ,General Neuroscience ,Glutamate receptor ,Antagonist ,Frontal Lobe ,Rats ,Endocrinology ,medicine.anatomical_structure ,Monoamine neurotransmitter ,Animals, Newborn ,chemistry ,Organ Specificity ,Neurology (clinical) ,Excitatory Amino Acid Antagonists ,Neuroscience ,Developmental Biology - Abstract
Neonatal Wistar rats were subcutaneously injected with 0.1, 1, or 2 mg/g b.wt. of monosodium glutamate (MSG) at 1, 3, 5, 7, and 9 days after birth. The animals were observed for degeneration of pyramidal cells in the hippocampus. The histological change disappeared when the animals were concurrently injected with glutamate diethyl ester (GDEE), an antagonist of the glutamate receptor. When ligh-dark discrimination learning was carried out at 10 weeks old, the correct response in the acquisition period was impaired in the animals given 1 and 2 mg/g of neonatal MSG. Their retention scores were also impaired in comparison with the control animal. The behavioral impairment recovered with pre-treatment with GDEE. No significant changes were observed in the concentrations of transmitter substances, including amino acids and monoamines. These results suggest that neonatal MSG destroys the hippocampus and impairs acquisition and retention of discrimination learning through the mechanism of glutamate receptors.
- Published
- 1993
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141. A simple test method for QoI sensitivity of Pestalotiopsis longiseta using boiled tea leaves
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Kengo Yamada, Koichi Ishikawa, and Ryoichi Sonoda
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Chromatography ,biology ,Simple (abstract algebra) ,Botany ,General Medicine ,Test method ,Sensitivity (control systems) ,Pestalotiopsis longiseta ,biology.organism_classification - Published
- 2014
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142. Overexpression of SUGT1 in human colorectal cancer and its clinicopathological significance
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Masaaki Iwatsuki, Koshi Mimori, Tetsuya Sato, Masaki Mori, Hiroyuki Toh, Koichi Ishikawa, Fumiaki Tanaka, Takehiko Yokobori, and Hideo Baba
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Cancer Research ,Candidate gene ,DNA, Complementary ,Microarray ,Colorectal cancer ,Cell Cycle Proteins ,Biology ,Gene expression ,medicine ,Humans ,Oligonucleotide Array Sequence Analysis ,Proportional Hazards Models ,Laser capture microdissection ,Models, Genetic ,Oncogene ,Reverse Transcriptase Polymerase Chain Reaction ,Gene Expression Profiling ,Lasers ,Nucleic Acid Hybridization ,Cancer ,Prognosis ,medicine.disease ,Gene Expression Regulation, Neoplastic ,Oncology ,Disease Progression ,Cancer research ,Colorectal Neoplasms ,Microdissection ,Comparative genomic hybridization - Abstract
As recent technological innovations make it possible to clarify the concordant relationship between genomic alterations and aberrant gene expression during the progression of colorectal cancer (CRC), we aimed at identifying new overexpressing genes with genomic amplification on the responsible loci in CRC. The candidate gene was found using cDNA microarray and array-based comparative genomic hybridization (CGH) analysis after laser microdissection (LMD) in 132 Japanese CRC. We focused on SUGT1, which is associated with the assembling of kinetochore proteins at the metaphase of the cell cycle, with significant association between genetic alterations and expression. SUGT1 mRNA expression was evaluated in 98 CRC cases to determine the clinicopathological significance of SUGT1 expression. The mean level of SUGT1 mRNA expression in tumor tissue specimens was significantly higher than in non-tumor tissue. The high SUGT1 expression group was characterized by a significantly elevated frequency of recurrence and a significantly poorer prognosis than the low expression group. There was a significant association between poor prognosis of CRC cases and the overexpression of SUGT1 with genomic amplification of the loci concordantly. The amplification of SUGT1 might give rise to promote the transcription of the gene directly subsequent to the progression of CRC cases with worsening prognosis.
- Published
- 2010
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143. Enkephalin hydrolysis by mouse plasma
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Koichi Ishikawa, Susan B. Weinberger, Gery Schulteis, Joe L. Martinez, and Shinji Shibanoki
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chemistry.chemical_classification ,endocrine system ,Enkephalin ,Chemistry ,Metabolite ,digestive, oral, and skin physiology ,Enkephalinase ,General Medicine ,Aminopeptidase ,General Biochemistry, Genetics and Molecular Biology ,In vitro ,chemistry.chemical_compound ,Enzyme ,nervous system ,Biochemistry ,polycyclic compounds ,General Pharmacology, Toxicology and Pharmaceutics ,Opioid peptide ,Neprilysin ,hormones, hormone substitutes, and hormone antagonists - Abstract
Hydrolysis of [Leu]- and [Met]enkephalin was determined in samples of pooled whole mouse plasma in vitro by using HPLC-ECD to measure accumulation of Tyr-containing metabolites. More Tyr-Gly-Gly accumulated from [Met]enkephalin than from [Leu]enkephalin hydrolysis, and [Met]enkephalin's half-life in mouse plasma was approximately half that of [Leu]enkephalin. Comparisons of metabolite formation in the presence versus the absence of inhibitors with high selectivity for various peptidases demonstrated that a bestatin-sensitive aminopeptidase, presumably aminopeptidase M, as well as enkephalinase and angiotensin converting enzyme, participate in the hydrolysis of enkephalin in mouse plasma.
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- 1992
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144. Neurotrophic Effects of Fibroblast Growth Factors on Peptide-Containing Neurons in Culture from Postnatal Rat Hypothalamus
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Koichi Ishikawa, Mitsuo Suzuki, Yukie Okutomi, Yoshihide Ohe, and Toshiyuki Takeuchi
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medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Basic fibroblast growth factor ,Hypothalamus ,Neuropeptide ,Biology ,Fibroblast growth factor ,Immunoenzyme Techniques ,Cellular and Molecular Neuroscience ,Insulin-like growth factor ,chemistry.chemical_compound ,Endocrinology ,Neurotrophic factors ,Internal medicine ,medicine ,Animals ,Insulin-Like Growth Factor I ,Cells, Cultured ,Neurons ,Endocrine and Autonomic Systems ,Neuropeptides ,Rats, Inbred Strains ,Somatomedin ,Rats ,Fibroblast Growth Factors ,Somatostatin ,Animals, Newborn ,nervous system ,chemistry ,biology.protein ,Neurotrophin - Abstract
Basic fibroblast growth factor (bFGF) has been thought to act as a neurotrophic factor during early developmental stages in various brain regions, including the hypothalamus. In the present paper, we have studied the effect of bFGF on peptide-containing neurons cultured from the postnatal (1-3 days and 14 days after birth) rat hypothalamus. The addition of bFGF, or acid FGF (aFGF), to serum-free culture medium increased both survival and neurite growth of growth hormone-releasing factor (GRF)-containing neurons. The potency of bFGF was more than 10 times as great as that of aFGF. Insulin-like growth factor I (IGF-I) did not have any significant effect on the survival of GRF neurons. Further, neither IGF-I nor aFGF modified the survival-promoting effect of bFGF on GRF neurons. bFGF promoted the survival of somatostatin- and vasoactive intestinal polypeptide-containing neurons, too.
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- 1992
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145. PartⅡ Impact of the Crisis on Production and Trade : Commentary to PartⅡ
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Mikimasa, Yoshida, Koichi, Ishikawa, and Satoru, Okuda
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- 1999
146. Further evidence of Mirafiori lettuce big-vein virus but not of Lettuce big-vein associated virus with big-vein disease in lettuce
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Koichi Ishikawa, Hiroki Koganezawa, Hiroya Fujii, and Takahide Sasaya
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biology ,Zoospore ,Host (biology) ,Inoculation ,Blotting, Western ,Fungi ,Plant Science ,Lettuce ,biology.organism_classification ,Virology ,Virus ,Plant Viruses ,Varicosavirus ,Mycovirus ,Seasons ,Lettuce big-vein associated virus ,Agronomy and Crop Science ,Cucurbitaceae ,Soil Microbiology ,Plant Diseases - Abstract
Mirafiori lettuce big-vein virus (MLBVV) and Lettuce big-vein associated virus (LBVaV) are found in association with big-vein disease of lettuce. Discrimination between the two viruses is critical for elucidating the etiology of big-vein disease. Using specific antibodies to MLBVV and LBVaV for western blotting and exploiting differences between MLBVV and LBVaV in host reaction of cucumber and temperature dependence in lettuce, we separated the two viruses by transfering each virus from doubly infected lettuce plants to cucumber or lettuce plants. A virus-free fungal isolate was allowed to acquire the two viruses individually or together. To confirm the separation, zoospores from MLBVV-, LBVaV-, and dually infected lettuce plants were used for serial inoculations of lettuce seedlings 12 successive times. Lettuce seedlings were infected at each transfer either with MLBVV alone, LBVaV alone, or both viruses together, depending on the virus carried by the vector. Lettuce seedlings infected with MLBVV alone developed the big-vein symptoms, while those infected with LBVaV alone developed no symptoms. In field surveys, MLBVV was consistently detected in lettuce plants from big-vein-affected fields, whereas LBVaV was detected in lettuce plants not only from big-vein-affected fields but also from big-vein-free fields. LBVaV occurred widely at high rates in winter-spring lettuce-growing regions irrespective of the presence of MLBVV and, hence, of the presence of the big-vein disease.
- Published
- 2008
147. Inhibition of HIV-1 replication by long-term treatment with a chimeric RNA containing shRNA and TAR decoy RNA
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Jacob Samson Barnor, Naoko Miyano-Kurosaki, Koichi Ishikawa, Norio Yamamoto, Hiroshi Takaku, Yuichiro Habu, and Naoki Yamamoto
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Pharmacology ,Small interfering RNA ,Anti-HIV Agents ,viruses ,virus diseases ,RNA-dependent RNA polymerase ,RNA ,Biology ,Virus Replication ,Virology ,Antisense RNA ,Small hairpin RNA ,RNA silencing ,DNA-directed RNA interference ,Transcription (biology) ,HIV-1 ,Leukocytes, Mononuclear ,vif Gene Products, Human Immunodeficiency Virus ,Humans ,RNA Interference ,RNA, Small Interfering ,Cells, Cultured ,HIV Long Terminal Repeat - Abstract
Combinatorial therapies for the treatment of HIV-1 infection are effective for reducing patient viral loads and slowing the progression to AIDS. Our strategy was based on an anti-HIV-1 shRNA vector system in which HIV-1 vif-shRNA was fused to a decoy TAR RNA (mini-TAR RNA) to generate vif-shRNA-decoy TAR RNA under the control of the human U6 Pol III promoter. Upon expression in human cells, the RNA molecule was cleaved into its component parts, which inhibited HIV-1 replication in a synergistic manner. This chimeric RNA expressed a dual RNA moiety and greatly enhanced the inhibition of HIV-1 replication under the production of resistant virus by short interference RNA (siRNA) in long-term culture assays. We suggest that this technique provides a practical basis for the application of siRNA-based gene therapy in the treatment of HIV/AIDS.
- Published
- 2008
148. Clinical significance of HLA class I heavy chain expression in patients with gastric cancer
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Seigo Kitano, Norio Shiraishi, Koichi Ishikawa, Yoshitake Ueda, and Shigeo Yokoyama
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Adult ,Male ,Pathology ,medicine.medical_specialty ,Gastroenterology ,Antigen ,Stomach Neoplasms ,Internal medicine ,medicine ,Humans ,Clinical significance ,Neoplasm Invasiveness ,Aged ,Aged, 80 and over ,business.industry ,Incidence (epidemiology) ,Cell Membrane ,Histocompatibility Antigens Class I ,Cancer ,Retrospective cohort study ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Immunohistochemistry ,Oncology ,Tumor progression ,Relative risk ,Lymphatic Metastasis ,Surgery ,Female ,Neoplasm Recurrence, Local ,business - Abstract
Background Little is known about the relation between HLA-I expression and the prognosis of patients with gastric cancer. The aim of this retrospective study was to clarify the clinical significance of HLA-I heavy chain expression in gastric cancer. Methods The study subjects were 202 patients with gastric cancer who had undergone curative surgery. Tumors were examined for expression of HLA-I heavy chain antigens by immunohistochemistry. We analyzed the association of HLA-I heavy chain expression with clinicopathological parameters and patient prognosis. Results HLA-B/C expression showed association with deeper tumor invasion, higher incidence of lymph node metastasis, more advanced tumor stage, and higher incidence of recurrence. Patients with positive HLA-B/C expression had shorter 5-year overall and 5-year disease-free survival compared with patients whose tumors showed mixed and negative expression (P
- Published
- 2008
149. Role of central serotonergic systems in the development of hypertension in spontaneously hypertensive rats
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Shinji Shibanoki, Koichi Ishikawa, Teruhisa Ito, Miki Kogure, and Taizo Kubo
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Serotonin ,medicine.medical_specialty ,Hypothalamus ,Hemodynamics ,Vena Cava, Inferior ,Serotonergic ,chemistry.chemical_compound ,Catecholamines ,Spontaneously hypertensive rat ,Rats, Inbred SHR ,Internal medicine ,medicine ,Animals ,cardiovascular diseases ,Neurotransmitter ,Molecular Biology ,Portal Vein ,business.industry ,General Neuroscience ,Anastomosis, Surgical ,Portacaval anastomosis ,Rats, Inbred Strains ,Hydroxyindoleacetic Acid ,Rats ,Blood pressure ,Endocrinology ,chemistry ,Hypertension ,cardiovascular system ,Neurology (clinical) ,business ,circulatory and respiratory physiology ,Developmental Biology - Abstract
The spontaneously hypertensive rat (SHR) maintained a higher blood pressure level at and after 8 weeks old than the genetical control Wistar-Kyoto strain (WKY). At 10 weeks old, the turnover rate of 5-hydroxytryptamine (5-HT) was lower in the hypothalamus of SHR than of WKY. Following portacaval anastomosis (PCA) in SHR, the blood pressure was significantly decreased in comparison with that of sham-operated control SHR. In WKY, no significant change in the blood pressure response was observed. PCA treatment increased the 5-HT turnover including that in SHR. If the SHR with PCA was bred with food pellets containing higher concentrations of leucine and isoleucine, the blood pressure increased and the 5-HT turnover decreased. These findings suggest that the central serotonergic system is involved in the development of hypertension.
- Published
- 1990
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150. Sensitive method for measuring hydrolysis of enkephalins in plasma, using high-performance liquid chromatography with electrochemical detection
- Author
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Koichi Ishikawa, Shinji Shibanoki, Susan B. Weinberger, and Joe L. Martinez
- Subjects
Male ,animal structures ,Working electrode ,Enkephalin ,Enkephalin, Methionine ,Molecular Sequence Data ,Electrochemical detection ,Electrochemistry ,Aminopeptidases ,High-performance liquid chromatography ,Mice ,Hydrolysis ,Endopeptidases ,Animals ,Amino Acid Sequence ,Chromatography, High Pressure Liquid ,chemistry.chemical_classification ,Chromatography ,integumentary system ,Rats, Inbred Strains ,Enkephalins ,General Chemistry ,Plasma ,Peptide Fragments ,Rats ,Enzyme ,chemistry ,embryonic structures ,Chickens ,Enkephalin, Leucine - Abstract
This paper describes a simple and sensitive method for detection of [Leu]- and [Met]enkephalin and their N-terminal tyrosine-containing metabolic fragments (Tyr, Tyr-Gly, Tyr-Gly-Gly, and Tyr-Gly-Gly-Phe), using high-performance liquid chromatography with electrochemical detection. The method employs a carbon graphite working electrode with increased working electrode surface area (40 mm2). The procedures were applied to assay of the activities of enkephalin-degrading enzymes in whole plasma collected from rats, mice, and chicks.
- Published
- 1990
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