80 results on '"Ishidao T"'
Search Results
2. Hydrolysis of starch or pullulan by glucoamylase or pullulanase immobilized on poly(N-isopropylacrylamide) gel
- Author
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Ohtani, N., Ishidao, T., Iwai, Y., and Arai, Y.
- Published
- 1999
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- View/download PDF
3. Solvent concentrations of dimethylsulfoxide-water and 1-propanol-water solutions inside and outside poly (N-isopropylacrylamide) gel
- Author
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Ishidao, T., Hashimoto, Y., Iwai, Y., and Arai, Y.
- Published
- 1994
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4. electrophysiology and immunohistochemistry in the hippocampal ca1 and the dentate gyrus of rats chronically exposed to 1-bromopropane, a substitute for specific chlorofluorocarbons
- Author
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Fueta, Y., Fukuda, T., Ishidao, T., and Hori, H.
- Published
- 2004
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5. Electrophysiological evaluation of developmental neurotoxicity induced by the prenatal exposure to 1-bromopropane
- Author
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Fueta, Y., primary, Ishidao, T., additional, Yoshida, S., additional, Hori, H., additional, Yamasaki, D., additional, Kanda, Y., additional, and Ueno, S., additional
- Published
- 2018
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6. P1017 Effect of 2-ethyl-1-hexanol concentrations and species on metabolic systems(Poster Presentation,Occupational Health in the Age of Decentralization Reform in Japan,The 79th Annual Meeting of Japan Society for Occupational Health)
- Author
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Ishidao, T., primary
- Published
- 2006
- Full Text
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7. Measurement of organic solvents in blood and their metabolites in urine in rats exposed to multicomponent vapors.
- Author
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Ishidao, T., primary
- Published
- 1998
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8. Swelling equilibria of poly(N-isopropylacrylamide) gel in aqueous polymer solutions
- Author
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Ishidao, T., primary, Akagi, M., additional, Sugimoto, H., additional, Onoue, Y., additional, Iwai, Y., additional, and Arai, Y., additional
- Published
- 1995
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9. Phase equilibria for polymer systems.
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IWAI, Y., primary, FURUYA, T., additional, ISHIDAO, T., additional, and ARAI, Y., additional
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- 1995
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10. Estimation of solid molar volumes using the neighboring factor with application to isomeric compounds
- Author
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Ishidao, T., primary, Iwai, Y., additional, Arai, Y., additional, and Sakoguchi, A., additional
- Published
- 1993
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11. Hydrolysis of starch or pullulan by glucoamylase or pullulanase immobilized on poly( N-isopropylacrylamide) gel.
- Author
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Ohtani, N., Ishidao, T., Iwai, Y., and Arai, Y.
- Abstract
Starch or pullulan was hydrolyzed using glucoamylase or pullulanase immobilized on N-isopropylacrylamide gel. The gel used is temperature sensitive; its mesh size becomes smaller at higher temperatures (30 °C) and larger at lower temperatures (20 °C). The molecular weight distribution of starch is wide and it consists of high-molecular-weight amylopectin, amylose and glucose. From the change in the chromatograms for the substrate and products, it was found that the hydrolysis rate at 30 °C was faster than that at 20 °C for amylose, though it was the reverse for amylopectin. This finding suggests that the smaller molecular sized amylose can enter the gel phase at both temperature, while the larger molecular sized amylopectin can hardly do so; only the end group, which can partly enter the gel phase at 20 °C (larger mesh size), was hydrolyzed. Further, several molecular weight pullulans (monodisperse) were hydrolyzed and the experimental chromatograms for substrate and products confirm the hydrolysis mechanism estimated. [ABSTRACT FROM AUTHOR]
- Published
- 1999
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12. Bubble points of hydrogen chloride-water-isopropanol and hydrogen chloride-water-isopropanol-benzene systems and liquid-liquid equilibria of hydrogen chloride-water-benzene and hydrogen chloride-water-isopropanol-benzene systems
- Author
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Ishidao, T., Iwai, Y., Arai, Y., Ochi, K., Yamamura, T., and Ishikawa, T.
- Published
- 2001
- Full Text
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13. Swelling equilibria of poly(N-isopropylacrylamide) gel in glucose and starch aqueous solution
- Author
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Ishidao, T., Song, I.-S., Ohtani, N., Sato, K., Iwai, Y., and Arai, Y.
- Published
- 1997
- Full Text
- View/download PDF
14. Reducing exposure levels of immersion washing workers to ortho-phthalaldehyde by improving exhaust systems.
- Author
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Yamamoto S, Hachiya Y, Goto M, Takeuchi A, Ishidao T, Hori H, and Miyauchi H
- Subjects
- Humans, Threshold Limit Values, Equipment Design, Occupational Exposure analysis, Occupational Exposure prevention & control, o-Phthalaldehyde, Air Pollutants, Occupational analysis, Ventilation
- Abstract
Objectives: The American Conference of Governmental Industrial Hygienists recommends a threshold limit value-ceiling (TLV-C) of 0.1 ppb for occupational exposure to ortho-phthalaldehyde (OPA) used in washing endoscope probes. To adhere to this extremely low exposure limit, this case study aimed to reduce OPA exposure concentrations of workers during immersion washing of an endoscope probe body. This was achieved by attaching a new duct and hood to the existing ceiling exhaust system., Methods: The type of hood was determined by calculating and comparing the capture velocity obtained by assuming either an exterior or an enclosing hood. Additionally, the effect on improving the working environment was tested before and after the installation of the hood by measuring the OPA vapor concentration., Results: The calculated capture velocities of the exterior and enclosing hoods were 0.05 m/s and 0.19 m/s, respectively. Considering the operability, the exterior hood was more appropriate; however, the calculated capture velocity indicated potential inadequacy in meeting the TLV-C requirement, leading to the adoption of the enclosing hood. The OPA vapor concentration in ceiling value measurements taken after the enclosing hood was fitted was reduced to 0.2 ppb, that is, 1/10 of the original concentration., Conclusions: Although the environmental concentration after the improvement still exceeded the TLV-C of 0.1 ppb, this study's findings indicate that even substances with extremely low occupational exposure limits can be managed with appropriate local exhaust ventilation., (© The Author(s) [2024]. Published by Oxford University Press on behalf of Journal of Occupational Health.)
- Published
- 2024
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15. Inflammogenic effect of polyacrylic acid in rat lung following intratracheal instillation.
- Author
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Nishida C, Tomonaga T, Izumi H, Wang KY, Higashi H, Ishidao T, Takeshita JI, Ono R, Sumiya K, Fujii S, Mochizuki S, Sakurai K, Yamasaki K, Yatera K, and Morimoto Y
- Subjects
- Animals, Bronchoalveolar Lavage Fluid, Male, Rats, Rats, Inbred F344, Acrylic Resins, Lung
- Abstract
Background: Some organic chemicals are known to cause allergic disorders such as bronchial asthma and hypersensitivity pneumonitis, and it has been considered that they do not cause irreversible pulmonary fibrosis. It has recently been reported, however, that cross-linked acrylic acid-based polymer, an organic chemical, might cause serious interstitial lung diseases, including pulmonary fibrosis. We investigated whether or not intratracheal instillation exposure to cross-linked polyacrylic acid (CL-PAA) can cause lung disorder in rats., Methods: Male F344 rats were intratracheally instilled with dispersed CL-PAA at low (0.2 mg/rat) and high (1.0 mg/rat) doses, and were sacrificed at 3 days, 1 week, 1 month, 3 months and 6 months after exposure to examine inflammatory and fibrotic responses and related gene expressions in the lungs. Rat lungs exposed to crystalline silica, asbestos (chrysotile), and NiO and CeO
2 nanoparticles were used as comparators., Results: Persistent increases in total cell count, neutrophil count and neutrophil percentage, and in the concentration of the cytokine-induced neutrophil chemoattractant (CINC)-1, CINC-2 and C-X-C motif chemokine 5 (CXCL5), which correlated with lung tissue gene expression, were observed in bronchoalveolar lavage fluid (BALF) from 3 days until at least 1 month following CL-PAA intratracheal instillation. Persistent increases in heme oxygenase-1 (HO-1) in the lung tissue were also observed from 3 days to 6 months after exposure. Histopathological findings of the lungs demonstrated that extensive inflammation at 3 days was greater than that in exposure to silica, NiO nanoparticles and CeO2 nanoparticles, and equal to or greater than that in asbestos (chrysotile) exposure, and the inflammation continued until 1 month. Fibrotic changes also progressed after 1 month postexposure., Conclusion: Our results suggested that CL-PAA potentially causes strong neutrophil inflammation in the rat and human lung., (© 2022. The Author(s).)- Published
- 2022
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16. Cerebral excitability in pup rats prenatally exposed to 1-bromopropane is suppressed by bromide accumulated in the brain.
- Author
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Fueta Y, Hinoue M, Noguchi H, Matsuno M, Ishidao T, Garner CE, and Hori H
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- Animals, Brain, Female, Hydrocarbons, Brominated, Pregnancy, Rats, Rats, Wistar, Bromides, Prenatal Exposure Delayed Effects chemically induced
- Abstract
Previously, we reported that prenatal exposure to 1-bromopropane (1-BP) causes the accumulation of bromide (Br-) in the brain of rat pups. Here, we aimed to investigate the effects of Br- accumulation in rat pups prenatally exposed to 1-BP vapor. Dam rats were exposed to 1-BP (400 or 700 ppm; 1-BP group) by inhalation, or to NaBr (20 mM; Br- group) in drinking water during gestation days 1-20. We also analyzed pentylenetetrazole (PTZ, 60 mg/kg, ip)-induced behavioral changes in pups prenatally exposed to 1-BP or Br- on postnatal day (PND) 14. PTZ-induced epileptic convulsions were inhibited in both 1-BP (700 ppm) and Br- groups. The inhibition of neuronal excitability induced by Br- was evaluated electrophysiologically using the hippocampal slices obtained from PND14-16 pups. PTZ (2 mM) failed to induce epileptiform discharge in the presence of 1.2 mM Br- in the slices obtained from the control group. However, it induced epileptiform discharge following the removal of Br-, by perfusing artificial cerebrospinal fluid into the slices obtained from the Br- group. Our results indicate that Br- accumulates in the brain of neonatal rat pups prenatally exposed to 1-BP vapor suppressed neuronal excitability.
- Published
- 2021
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17. Exposure to 1-bromopropane vapors during pregnancy enhances the development of hippocampal neuronal excitability in rat pups during lactation.
- Author
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Fueta Y, Ueno S, Ishidao T, Yoshida Y, Kanda Y, and Hori H
- Subjects
- Animals, Female, Hydrocarbons, Brominated adverse effects, Pregnancy, Rats, Rats, Wistar, CA1 Region, Hippocampal drug effects, Cortical Excitability drug effects, Inhalation Exposure, Lactation, Prenatal Exposure Delayed Effects chemically induced
- Abstract
Objectives: Although 1-Bromopropane (1-BP) exposure has been reported to cause neurotoxicity in adult humans and animals, its effects on the development of the central nervous system remain unclear. Recently, we reported delayed developmental neurotoxicity (DNT) upon 1-BP exposure in rats. Here we aimed to study the effect of prenatal 1-BP exposure on the hippocampal excitability in the juvenile offspring., Methods: Pregnant Wistar rats were exposed to vaporized 1-BP for 20 days (6 h/d) with concentrations of 0 (control), 400, or 700 ppm. Hippocampal slices were prepared from male offspring during postnatal days (PNDs) 13, 14, and 15. Field excitatory postsynaptic potential (fEPSP) and population spike (PS) were recorded simultaneously from the CA1 region., Results: In the exposed groups, the stimulation/response relationships of fEPSP slope and PS amplitude were enhanced more than in the control group at PND 14. Analysis of fEPSP-spike coupling demonstrated increased values of Top and Eslope50 in the exposed groups. Real-time PCR analysis showed a significant increase in the mRNA levels of the adult type Na
v 1.1 Na+ channel subunit and the GluR1 glutamate receptor subunit in the hippocampus of the 700 ppm group at PND 14., Conclusions: Our results provide evidence that prenatal exposure to 1-BP accelerates developmental enhancement of hippocampal excitability in the pups before eye-opening. The current study suggests that our evaluation method of DNT is applicable to the industrial chemical 1-BP., (© 2020 The Authors. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.)- Published
- 2020
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18. Evaluation of the ceiling levels of ortho-phthalaldehyde exposure among health care workers engaged in endoscope disinfection: A new methodology using video-exposure monitoring.
- Author
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Yamamoto S, Hachiya Y, Yuasa E, Takeuchi A, Ishidao T, Mihara M, Terauchi Y, Ichiba M, and Hori H
- Subjects
- Disinfectants adverse effects, Equipment Contamination prevention & control, Humans, Inhalation Exposure, Surveys and Questionnaires, Video Recording, o-Phthalaldehyde adverse effects, Disinfectants analysis, Endoscopes, Environmental Monitoring methods, Health Personnel, Occupational Exposure analysis, o-Phthalaldehyde analysis
- Abstract
Objectives: The present study aimed to develop a method for measuring the ceiling level of ortho-phthalaldehyde (OPA) exposure and evaluate the ceiling levels of OPA exposure among health care workers who handle disinfectant solutions containing OPA for the disinfection of endoscopes., Methods: The study consisted of a preliminary survey and main survey. In the preliminary survey, processes involving high-concentration exposure to OPA were identified by video-exposure monitoring (VEM). In the main survey, the ceiling levels of OPA exposure for high-concentration exposure processes identified from the results of the preliminary survey were determined using a measuring method combining sampling using a 2,4-dinitrophenylhydrazine-silica cartridge and analysis by high-performance liquid chromatography tandem mass spectrometry., Results: In the preliminary survey, seven processes involving high-concentration exposure to OPA were identified by VEM. The duration of each process was short, lasting from 20 seconds to a few minutes. In the main survey, the OPA concentrations for the identified high-concentration exposure processes ranged from 1.18 to 4.49 ppb, which markedly exceeded the threshold limit value ceiling (TLV-C) of 0.1 ppb recommended by the American Conference of Governmental Industrial Hygienists., Conclusions: The method for measuring the ceiling level of OPA exposure was established using VEM and the highly sensitive method of chemical analysis; and we successfully evaluated the ceiling levels of OPA exposure among health care workers engaged in endoscope disinfection. This approach can also be applied to other chemical substances with recommended TLV-Cs, and important information for reducing exposure can thus be obtained., (© 2020 The Authors. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.)
- Published
- 2020
- Full Text
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19. Development of a measurement method to determine the ceiling exposure concentration of ortho-phthalaldehyde handling workers.
- Author
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Yamamoto S, Takeuchi A, Ishidao T, Ohkuma H, Ichiba M, and Hori H
- Subjects
- Chromatography, High Pressure Liquid, Humans, Mass Spectrometry, Molecular Structure, Phenylhydrazines, Silicon Dioxide, Air Pollutants, Occupational analysis, Environmental Monitoring methods, Occupational Exposure analysis, Threshold Limit Values, o-Phthalaldehyde analysis
- Abstract
Objectives: The purpose of this research was to develop and validate an analytical method for rapid determination of the exposure of workers to ortho-phthalaldehyde (OPA) at the ceiling threshold concentration., Methods: A 2,4-dinitrophenylhydrazine (DNPH)-silica cartridge was chosen as a sampler. OPA collected by the DNPH-silica cartridge was subsequently extracted with 5 mL of acetonitrile. A 50-µL aliquot of phosphoric acid/acetonitrile solution (2%, v/v) was added to 950 µL of the extraction solution and allowed to stand for 30 minutes at room temperature. This solution was then analyzed by high-performance liquid chromatography tandem mass spectrometry. The basic characteristics of the proposed method, such as recovery, repeatability, limit of quantification, and storage stability of the samples, were examined., Results: The overall recoveries of OPA from OPA-spiked DNPH-silica cartridges were 93.6%-100.1% with relative standard deviations, representing the repeatability, of 1.5%-10.8%. The limit of quantification was 0.165 ng/sample. The recovery of OPA from DNPH-silica cartridges after 5 days of storage in a refrigerator exceeded 95%., Conclusions: The proposed method enabled the determination of the OPA concentration corresponding to the Threshold Limit Value-Ceiling of 0.1 ppb recommended by the American Conference of Governmental Industrial Hygienists, with a minimum sampling time of 18 seconds (corresponding to a sampling volume of 300 mL at 25°C and 1 atm). Thus, this method will be useful for estimating worker exposures to OPA., (© 2019 The Authors. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.)
- Published
- 2020
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20. Prenatal exposure to 1-bromopropane causes delayed adverse effects on hippocampal neuronal excitability in the CA1 subfield of rat offspring.
- Author
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Fueta Y, Ishidao T, Ueno S, Yoshida Y, Kanda Y, and Hori H
- Subjects
- Animals, Female, Hydrocarbons, Brominated toxicity, Male, Neurotoxicity Syndromes etiology, Pregnancy, Prenatal Exposure Delayed Effects chemically induced, Rats, Rats, Wistar, CA1 Region, Hippocampal drug effects, Cortical Excitability drug effects, Neurotoxicity Syndromes physiopathology, Prenatal Exposure Delayed Effects physiopathology
- Abstract
Objectives: Neurotoxicity of 1-bromopropane (1-BP) has been reported in occupational exposure, but whether the chemical exerts developmental neurotoxicity is unknown. We studied the effects of prenatal 1-BP exposure on neuronal excitability in rat offspring., Methods: We exposed dams to 1-BP (700 ppm, 6 h a day for 20 days) and examined hippocampal slices obtained from the male offspring at 2, 5, 8, and 13 weeks of age. We measured the stimulation/response (S/R) relationship and paired-pulse ratios (PPRs) of the population spike (PS) at the interpulse intervals (IPIs) of 5 and 10 ms in the CA1 subfield., Results: Prenatal 1-BP exposure enhanced S/R relationships of PS at 2 weeks of age; however, the enhancement diminished at 5 weeks of age until it reached control levels. Prenatal 1-BP exposure decreased PPRs of PS at 2 weeks of age. After sexual maturation, however, the PPRs of PS increased at 5-ms IPI in rats aged 8 and 13 weeks., Conclusions: Our findings indicate that prenatal 1-BP exposure in dams can cause delayed adverse effects on excitability of pyramidal cells in the hippocampal CA1 subfield of offspring.
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- 2018
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21. Anaerobic bacterial contamination after use and assessment of countermeasures a dust mask facepiece.
- Author
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Hinoue M, Ishimatsu S, Ishidao T, Fueta Y, and Hori H
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- Bacterial Load, Detergents, Ethanol, Water, Bacteria, Anaerobic isolation & purification, Equipment Contamination prevention & control, Masks microbiology
- Published
- 2016
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22. A cross-fostering analysis of bromine ion concentration in rats that inhaled 1-bromopropane vapor.
- Author
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Ishidao T, Fueta Y, Ueno S, Yoshida Y, and Hori H
- Subjects
- Animals, Body Weight, Female, Hydrocarbons, Brominated pharmacokinetics, Pregnancy, Rats, Rats, Wistar, Volatilization, Inhalation Exposure analysis, Ions analysis, Maternal-Fetal Exchange
- Abstract
Objective: Inhaled 1-bromopropane decomposes easily and releases bromine ion. However, the kinetics and transfer of bromine ion into the next generation have not been clarified. In this work, the kinetics of bromine ion transfer to the next generation was investigated by using cross-fostering analysis and a one-compartment model., Methods: Pregnant Wistar rats were exposed to 700 ppm of 1-bromopropane vapor for 6 h per day during gestation days (GDs) 1-20. After birth, cross-fostering was performed between mother exposure groups and mother control groups, and the pups were subdivided into the following four groups: exposure group, postnatal exposure group, gestation exposure group, and control group. Bromine ion concentrations in the brain were measured temporally., Results: Bromine ion concentrations in mother rats were lower than those in virgin rats, and the concentrations in fetuses were higher than those in mothers on GD20. In the postnatal period, the concentrations in the gestation exposure group decreased with time, and the biological half-life was 3.1 days. Conversely, bromine ion concentration in the postnatal exposure group increased until postnatal day 4 and then decreased. This tendency was also observed in the exposure group. A one-compartment model was applied to analyze the behavior of bromine ion concentration in the brain. By taking into account the increase of body weight and change in the bromine ion uptake rate in pups, the bromine ion concentrations in the brains of the rats could be estimated with acceptable precision.
- Published
- 2016
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23. Estimation of Equilibrated Vapor Concentrations Using the UNIFAC Model for the Tetrachloroethylene-Chlorobenzene System.
- Author
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Ishidao T, Ishimatsu S, and Hori H
- Subjects
- Models, Theoretical, Solvents, Temperature, Volatilization, Air Pollutants, Occupational analysis, Chlorobenzenes analysis, Occupational Exposure analysis, Tetrachloroethylene analysis
- Abstract
Equilibrated vapor concentrations at 25°C of the tetrachloroethylene-chlorobenzene system were obtained in the presence of air to establish a method for estimating vapor concentrations in work environments where multicomponent organic solvents are used. The experimental data were correlated by introducing activity coefficients calculated by the UNIFAC (Universal Quasichemical Functional Group Activity Coefficient) model. There were four interaction parameters between groups in this solution system, and three had already been determined.However, the fourth parameter--the interaction parameter between ACCl and Cl-(C=C) groups--remains unknown. Therefore, this parameter was determined by a nonlinear least-squares method to obtain the best fit for the experimental data. The calculated values were found to be in good agreement with the experimental values.
- Published
- 2016
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24. Decomposition Characteristics of Toluene Vapor Using Titanium Dioxide Photocatalyst and Zeolite Thermally Sprayed on an Aluminum Fiber Filter.
- Author
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Hori H, Hinoue M, Ishimatsu S, Fueta Y, Ishidao T, Takabatake K, Yakiyama N, and Yamamoto K
- Subjects
- Volatilization, Aluminum chemistry, Photochemical Processes, Titanium chemistry, Toluene chemistry, Zeolites chemistry
- Abstract
Decomposition characteristics of toluene vapor by titanium dioxide photocatalyst and zeolite that are prepared by thermal spraying on an aluminum fiber filter (photocatalyst filter) were investigated. Toluene vapor was injected into a small chamber made of stainless steel, and an air cleaner equipped with the photocatalyst filter was operated. The vapor concentration in the chamber decreased exponentially. The decreasing rate of toluene vapor in the chamber depended on the initial toluene concentration, and the higher the initial vapor concentration was, the lower the decreasing rate was obtained. The decreasing rate was constant during each decomposition experiment, although the concentration decreased with time. To investigate the effect of zeolite on the reduction of the vapor concentration, we compared the decreasing rates of toluene vapor by photocatalyst filters with and without zeolite.The decreasing rate of toluene concentration using the filter without zeolite was larger than that with zeolite. The reason for this would be that photocatalyst decomposed toluene not only in air but also adsorbed in zeolite.
- Published
- 2016
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25. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds.
- Author
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Kanemitsu M, Fueta Y, Ishidao T, Aou S, and Hori H
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- Animals, Diffusion Chambers, Culture, Hydrocarbons, Brominated analysis, Hydrocarbons, Brominated toxicity, Male, Neuronal Plasticity drug effects, Phase Transition, Rats, Tissue Culture Techniques, Volatile Organic Compounds analysis, Dentate Gyrus drug effects, Synapses drug effects, Volatile Organic Compounds toxicity
- Abstract
Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we report a new exposure system for VOCs that we developed in which a high concentration of oxygen is dissolved to a perfused medium applying a gas-liquid equilibrium, and in which the tubing is made of Teflon, non adsorptive material. Using our system, the bath concentration of the perfused 1-BP remained stable for at least 2 h in the slice chamber. Both 6.4 and 2.2 mM of 1-BP did not change the paired-pulse response, but fully suppressed long-term potentiation in the dentate gyrus (DG) of hippocampal slices obtained from rats, suggesting that 1-BP decreases synaptic plasticity in the DG at the concentrations tested. Our new system can be applicable for investigating the underlying mechanisms of the neurotoxicity of VOCs at the cellular level.
- Published
- 2016
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26. Effective recovery of highly purified CD326(+) tumor cells from lavage fluid of patients treated with a novel cell-free and concentrated ascites reinfusion therapy (KM-CART).
- Author
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Kimura Y, Harada Y, Yasuda N, Ishidao T, Yusa S, Matsusaki K, and Yonemitsu Y
- Abstract
For the production of tumor-specific vaccines, including dendritic cell (DC) vaccines, the tumor cells themselves are an ideal source. Floating tumor cells in the ascites fluid from patients with malignant ascites are a good candidate source, but it is not easy to obtain pure tumor cells from ascites because of various types of cell contamination as well as protein aggregates. We here report an effective method to recover pure tumor cells from malignant ascites. We used lavage fluid from 13 patients with malignant ascites who were treated with modified cell-free and concentrated ascites reinfusion therapy (KM-CART). Cellular components were separated from the lavage fluid by centrifugation, enzymatic digestion and hemolysis. Tumor cells were purified by depleting CD45(+) leukocytes with antibody-conjugated magnetic beads. The tumor cell lysate was extracted by freeze-and-thaw cycles. The mean obtained total cell number was 7.50 × 10(7) cells (range 4.40 × 10(6)-2.48 × 10(8) cells). From this fraction, 6.39 × 10(6) (range 3.23 × 10(5)-2.53 × 10(7)) CD45(-) cells were collected, and the tumor cell purity was over 80 % defined as CD45(-)CD326(+). A sufficient amount of tumor lysate, average = 2416 μg (range 25-8743 μg), was extracted from CD45(-)CD326(+) tumor cells. We here established an effective method to produce highly purified tumor cells from KM-CART lavage fluid. The clinical feasibility of this simple preparation method for generating tumor lysate should be examined in clinical studies of DC vaccines.
- Published
- 2015
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27. Prenatal Exposure to 1-Bromopropane Suppresses Kainate-Induced Wet Dog Shakes in Immature Rats.
- Author
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Fueta Y, Kanemitsu M, Egawa S, Ishidao T, Ueno S, and Hori H
- Subjects
- Animals, Female, Hydrocarbons, Brominated adverse effects, Hydrocarbons, Brominated metabolism, Hydrocarbons, Brominated toxicity, Male, Maternal-Fetal Exchange, Pregnancy, Rats, Wistar, Behavior, Animal drug effects, Dyskinesia, Drug-Induced etiology, Inhalation Exposure adverse effects, Kainic Acid adverse effects, Mental Disorders chemically induced, Prenatal Exposure Delayed Effects chemically induced
- Abstract
1-Bromopropane (1-BP) is used in degreasing solvents and spray adhesives. The adverse effects of 1-BP have been reported in human cases and adult animal models, and its developmental toxicity has also been reported, but its effects on developmental neurotoxicity have not been investigated in detail. We evaluated the effects in rat pups of prenatal exposure to 1-BP on behaviors such as scratching and wet dog shakes (WDS), which were induced by injection of kainate (KA). Pregnant Wistar rats were exposed to vaporized 1-BP with 700 ppm from gestation day 1 to day 20 (6 h/day). KA at doses of 0.1, 0.5, and 2.0 mg/kg were intraperitoneally injected into a control group and a 1-BP-exposed group of pups on postnatal day 14. There was no significant difference in scratching between the control and the prenatally 1-BP-exposed groups, while suppression of the occurrence ratio of WDS was observed at the low dose of 0.1 mg/kg of KA in the prenatally 1-BP-exposed pups. Our results suggest that prenatal exposure to 1-BP affects neurobehavioral responses in the juvenile period.
- Published
- 2015
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28. Gemcitabine treatment enhances HER2 expression in low HER2-expressing breast cancer cells and enhances the antitumor effects of trastuzumab emtansine.
- Author
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Kan S, Koido S, Okamoto M, Hayashi K, Ito M, Kamata Y, Komita H, Ishidao T, Nagasaki E, and Homma S
- Subjects
- Ado-Trastuzumab Emtansine, Breast Neoplasms genetics, Breast Neoplasms metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Deoxycytidine pharmacology, Drug Synergism, Female, Humans, MCF-7 Cells, Maytansine pharmacology, Paclitaxel pharmacology, Receptor, ErbB-2 metabolism, Trastuzumab, Gemcitabine, Antibodies, Monoclonal, Humanized pharmacology, Antineoplastic Agents pharmacology, Breast Neoplasms drug therapy, Deoxycytidine analogs & derivatives, Maytansine analogs & derivatives, Receptor, ErbB-2 genetics, Up-Regulation
- Abstract
Trastuzumab emtansine (T-DM1), trastuzumab-conjugated with a cytotoxic agent, has shown promising antitumor effects in breast cancer. Since a good therapeutic response using T-DM1 treatment requires high human epidermal growth factor receptor 2 (HER2) expression, breast cancers with low or no HER2 expression have not been used for T-DM1 treatment. The aim of the present study was to show that treatment of low HER2-expressing breast cancer cells with gemcitabine (GEM) enhanced HER2 expression using RT-qPCR, immunoblot and flow cytometric analysis. The results showed that GEM treatment significantly enhanced HER2 expression in MDA-MB-231, MCF7 and BT-20 breast cancer cells, while paclitaxel (PTX) treatment induced lower or no enhancement in HER2 expression. The expression of HER2 mRNA was also enhanced in GEM-treated MCF7 cells. Treatment with an inhibitor for nuclear factor-(NF)-κB suppressed GEM-induced HER2 upregulation, indicating that NF-κB activation by GEM may be associated with HER2 upregulation. T-DM1 binding to HER2 on MCF-7 cells was enhanced by GEM pretreatment and the combined treatment of GEM and T-DM1 synergistically inhibited the proliferation of MCF7 cells. Thus, the combined treatment with GEM and T-DM1 may be a promising therapeutic modality for low HER2-expressing breast cancers, which was facilitated by the unique HER2-upregulating effect of GEM.
- Published
- 2015
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29. Comparison of sensor characteristics of three real-time monitors for organic vapors.
- Author
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Hori H, Ishimatsu S, Fueta Y, Hinoue M, and Ishidao T
- Subjects
- Air Pollution, Indoor analysis, Chromatography, Gas, Flame Ionization, Gases analysis, Humans, Japan, Occupational Exposure prevention & control, Solvents classification, Volatilization, Environmental Monitoring methods, Volatile Organic Compounds analysis
- Abstract
Objective: Sensor characteristics and performance of three real-time monitors for volatile organic compounds (VOC monitor) equipped with a photo ionization detector (PID), a sensor using the interference enhanced reflection (IER) method and a semiconductor gas sensor were investigated for 52 organic solvent vapors designated as class 1 and class 2 of organic solvents by the Ordinance of Organic Solvent Poisoning Prevention in Japan., Methods: Test vapors were prepared by injecting each liquid solvent into a 50 l Tedlar® bag and perfectly vaporizing it. The vapor concentration was from one-tenth to twice the administrative control level for all solvents. The vapor concentration was measured with the monitors and a gas chromatograph equipped with a flame ionization detector simultaneously, and the values were compared., Results: The monitor with the PID sensor could measure many organic vapors, but it could not detect some vapors with high ionization potential. The IER sensor could also detect many vapors, but a linear response was not obtained for some vapors. A semiconductor sensor could detect methanol that could not be detected by PID and IER sensors., Conclusions: Working environment measurement of organic vapors by real-time monitors may be possible, but sensor characteristics and their limitations should be known.
- Published
- 2015
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30. Treatment with chemotherapy and dendritic cells pulsed with multiple Wilms' tumor 1 (WT1)-specific MHC class I/II-restricted epitopes for pancreatic cancer.
- Author
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Koido S, Homma S, Okamoto M, Takakura K, Mori M, Yoshizaki S, Tsukinaga S, Odahara S, Koyama S, Imazu H, Uchiyama K, Kajihara M, Arakawa H, Misawa T, Toyama Y, Yanagisawa S, Ikegami M, Kan S, Hayashi K, Komita H, Kamata Y, Ito M, Ishidao T, Yusa S, Shimodaira S, Gong J, Sugiyama H, Ohkusa T, and Tajiri H
- Subjects
- Adenocarcinoma immunology, Adenocarcinoma mortality, Adenocarcinoma secondary, Adenocarcinoma therapy, Adult, Aged, Antimetabolites, Antineoplastic therapeutic use, Bile Duct Neoplasms immunology, Bile Duct Neoplasms mortality, Bile Duct Neoplasms secondary, Bile Duct Neoplasms therapy, Bile Ducts, Intrahepatic immunology, Biomarkers, Tumor analysis, CD8-Positive T-Lymphocytes immunology, Carcinoma, Pancreatic Ductal immunology, Carcinoma, Pancreatic Ductal mortality, Carcinoma, Pancreatic Ductal secondary, Carcinoma, Pancreatic Ductal therapy, Cholangiocarcinoma immunology, Cholangiocarcinoma mortality, Cholangiocarcinoma secondary, Cholangiocarcinoma therapy, Combined Modality Therapy, Deoxycytidine therapeutic use, Female, Follow-Up Studies, Humans, Male, Middle Aged, Neoplasm Staging, Pancreatic Neoplasms immunology, Pancreatic Neoplasms mortality, Pancreatic Neoplasms pathology, Peptide Fragments immunology, Prognosis, Survival Rate, T-Lymphocytes, Cytotoxic immunology, Vaccination, Gemcitabine, Dendritic Cells immunology, Deoxycytidine analogs & derivatives, Epitopes immunology, Histocompatibility Antigens Class I immunology, Histocompatibility Antigens Class II immunology, Pancreatic Neoplasms therapy, WT1 Proteins immunology
- Abstract
Purpose: We performed a phase I trial to investigate the safety, clinical responses, and Wilms' tumor 1 (WT1)-specific immune responses following treatment with dendritic cells (DC) pulsed with a mixture of three types of WT1 peptides, including both MHC class I and II-restricted epitopes, in combination with chemotherapy., Experimental Design: Ten stage IV patients with pancreatic ductal adenocarcinoma (PDA) and 1 patient with intrahepatic cholangiocarcinoma (ICC) who were HLA-positive for A*02:01, A*02:06, A*24:02, DRB1*04:05, DRB1*08:03, DRB1*15:01, DRB1*15:02, DPB1*05:01, or DPB1*09:01 were enrolled. The patients received one course of gemcitabine followed by biweekly intradermal vaccinations with mature DCs pulsed with MHC class I (DC/WT1-I; 2 PDA and 1 ICC), II (DC/WT1-II; 1 PDA), or I/II-restricted WT1 peptides (DC/WT1-I/II; 7 PDA), and gemcitabine., Results: The combination therapy was well tolerated. WT1-specific IFNγ-producing CD4(+) T cells were significantly increased following treatment with DC/WT1-I/II. WT1 peptide-specific delayed-type hypersensitivity (DTH) was detected in 4 of the 7 patients with PDA vaccinated with DC/WT1-I/II and in 0 of the 3 patients with PDA vaccinated with DC/WT1-I or DC/WT1-II. The WT1-specific DTH-positive patients showed significantly improved overall survival (OS) and progression-free survival (PFS) compared with the negative control patients. In particular, all 3 patients with PDA with strong DTH reactions had a median OS of 717 days., Conclusions: The activation of WT1-specific immune responses by DC/WT1-I/II combined with chemotherapy may be associated with disease stability in advanced pancreatic cancer., (©2014 American Association for Cancer Research.)
- Published
- 2014
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31. Prognostic factors related to add-on dendritic cell vaccines on patients with inoperable pancreatic cancer receiving chemotherapy: a multicenter analysis.
- Author
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Kobayashi M, Shimodaira S, Nagai K, Ogasawara M, Takahashi H, Abe H, Tanii M, Okamoto M, Tsujitani S, Yusa S, Ishidao T, Kishimoto J, Shibamoto Y, Nagaya M, and Yonemitsu Y
- Subjects
- Adult, Aged, Aged, 80 and over, Combined Modality Therapy, Female, Humans, Male, Middle Aged, Pancreatic Neoplasms drug therapy, Pancreatic Neoplasms immunology, Pancreatic Neoplasms pathology, Prognosis, Retrospective Studies, Survival Analysis, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Cancer Vaccines therapeutic use, Dendritic Cells immunology, Pancreatic Neoplasms therapy
- Abstract
Objective: Dendritic cell (DC)-based cancer vaccines may have a significant benefit to patients with advanced pancreatic cancer. However, variations among clinical studies make it difficult to compare clinical outcomes. Here, we identified factors that determined the clinical benefits by analyzing data obtained at seven Japanese institutions that employed the same DC preparation and treatment regimens., Methods: Of 354 patients who met the inclusion criteria, 255 patients who received standard chemotherapy combined with peptide-pulsed DC vaccines were analyzed., Results: The mean survival time from diagnosis was 16.5 months (95 % CI 14.4-18.5) and that from the first vaccination was 9.9 months (95 % CI 8.0-12.9). Known prognostic baseline factors related to advanced pancreatic cancer, namely ECOG-PS, peritoneal metastasis, liver metastasis, and the prognostic nutrition index, were also representative. Importantly, we found that erythema reaction after vaccination was an independent and treatment-related prognostic factor for better survival and that OK-432 might be a good adjuvant enhancing the antitumor immunity during DC vaccination., Conclusions: This is the first report of a multicenter clinical study suggesting the feasibility and possible clinical benefit of an add-on DC vaccine in patients with advanced pancreatic cancer who are undergoing chemotherapy. These findings need to be addressed in well-controlled prospective randomized trials.
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- 2014
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32. [Bacterial contamination after use and assessment of countermeasures a dust mask facepiece].
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Hinoue M, Simada Y, Ishimatsu S, Ishidao T, Fueta Y, and Hori H
- Subjects
- Colony Count, Microbial, Ethanol, Humans, Male, Skin microbiology, Temperature, Time Factors, Water, Bacteria isolation & purification, Disinfection methods, Dust, Masks microbiology, Respiratory Protective Devices microbiology
- Abstract
Objective: Bacteria on the facepiece of a dust respirator were measured just after use and after 24-hours storage at a room temperature after being worn, and bacteria disinfection methods other than ethanol were examined., Methods: The existence of bacteria on a facepiece of a mask that had been worn for about one hour in a laboratory was investigated. In order to eliminate bacteria before use on the next day, five methods of bacteria disinfection were investigated: wiping with a facial tissue impregnated with ethanol as a control; wiping with a facial tissue wetted with tap water; wiping with a dry facial tissue after wiping with one wetted with tap water; wiping with a dry facial tissue after wiping with one wetted with distilled water; and wiping with a dry facial tissue two times. The tests were carried out using silicone rubber sheets plated with bacteria collected from human skin. The disinfection methods that were as effective as facial paper wetted with ethanol, were then assayed on the facepiece of the dust respirator., Results: Bacteria were detected on the facepiece immediately after it had been worn. Bacteria were also detected on the facepiece after it had been stored at 25°C for 24-hours after being worn. The methods of wiping with a dry facial tissue after wiping with either tap water or distilled water were almost as statistically effective as wiping with ethanol wetted facial paper. Bacteria on the facepiece were decreased by wiping with a dry facial tissue after wiping with one wetted with tap water., Discussion: Colonies of bacteria were detected on a facepiece that had been stored 24 hours after being worn, which suggests that bacteria disinfection just after a respirator has been worn should be recommended. It is very important that the water on the facepiece should be removed after wiping with a wet facial tissue.
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- 2014
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33. Characteristics of a real time monitor using the interference enhanced reflection method for organic vapors.
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Hori H, Ishimatsu S, Fueta Y, Hinoue M, and Ishidao T
- Subjects
- Chromatography, Gas, Computer Systems, Environmental Monitoring methods, Flame Ionization, Solvents analysis, Workplace, Chemistry Techniques, Analytical methods, Volatile Organic Compounds analysis
- Abstract
Performance and sensor characteristics of a monitor for volatile organic compounds (VOC monitor) using the interference enhanced reflection (IER) method were investigated for 52 organic solvent vapors that are designated as class 1 and class 2 organic solvents by the Ordinance of Organic Solvent Poisoning Prevention in Japan. Test vapors were prepared by injecting 1 to 3 μl of liquid solvent into a 20 l Tedlar(®) bag and perfectly vaporizing them. The vapor concentration was simultaneously measured with the monitor and a gas chromatograph (GC) equipped with flame ionization detector, and both values were compared. The monitor could detect all the solvent vapors that we used. Linear response was obtained between the concentration measured by the monitor and those by the GC. The monitor could detect 1/10 of the administrative control level for 37 of 52 solvent vapors, including toluene and xylenes. For 15 vapors, on the other hand, the monitor could not be used for the working environment measurement because the sensor response was low or the regression lines did not pass through the origin.
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- 2013
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34. Evaluation of a real-time method for monitoring volatile organic compounds in indoor air in a Japanese university.
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Hori H, Ishimatsu S, Fueta Y, and Ishidao T
- Subjects
- Environmental Monitoring instrumentation, Japan, Seasons, Semiconductors, Time Factors, Universities, Air Pollutants analysis, Air Pollution, Indoor analysis, Environmental Monitoring methods, Volatile Organic Compounds analysis
- Abstract
Objective: Real time monitoring of total volatile organic compounds (TVOC) in rooms of Japanese university buildings was carried out to understand the temporal changes in actual indoor air quality., Methods: The TVOC concentrations in seven different rooms, consisting of a lecture room, a seminar room, three laboratories, a computer room and a library, were monitored continuously for 24 h via a personal VOC monitor equipped with a semiconductor gas sensor. An active sampling-thermal desorption method using stainless steel tubes packed with Tenax-TA was also carried out simultaneously to verify the usability of the monitor., Results: The TVOC concentrations measured by the personal VOC monitor were closely correlated with those measured by the active sampling method. The TVOC concentration in all rooms was generally low during the day and increased during the night. This concentration change corresponded to the ventilation cycle in the building. During the day, the TVOC concentration was generally lower than the provisional target criterion (advisable value) of indoor air quality in Japan (400 μg/m³). During the night, however, it exceeded this criterion in several rooms, especially during the summer season., Conclusion: The real-time monitor using a semiconductor gas sensor can provide useful data on changes in the TVOC concentration in indoor air with high sensitivity.
- Published
- 2013
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35. Impact of dendritic cell vaccines pulsed with Wilms' tumour-1 peptide antigen on the survival of patients with advanced non-small cell lung cancers.
- Author
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Takahashi H, Okamoto M, Shimodaira S, Tsujitani S, Nagaya M, Ishidao T, Kishimoto J, and Yonemitsu Y
- Subjects
- Adenocarcinoma immunology, Adenocarcinoma mortality, Adenocarcinoma therapy, Adult, Aged, Aged, 80 and over, Carcinoma, Large Cell immunology, Carcinoma, Large Cell mortality, Carcinoma, Large Cell therapy, Carcinoma, Non-Small-Cell Lung immunology, Carcinoma, Non-Small-Cell Lung mortality, Carcinoma, Squamous Cell immunology, Carcinoma, Squamous Cell mortality, Carcinoma, Squamous Cell therapy, Dendritic Cells immunology, Female, Follow-Up Studies, Humans, Lung Neoplasms immunology, Lung Neoplasms mortality, Male, Middle Aged, Neoplasm Recurrence, Local immunology, Neoplasm Recurrence, Local mortality, Neoplasm Recurrence, Local therapy, Neoplasm Staging, Prognosis, Retrospective Studies, Survival Rate, T-Lymphocytes, Cytotoxic immunology, Cancer Vaccines therapeutic use, Carcinoma, Non-Small-Cell Lung therapy, Dendritic Cells transplantation, Lung Neoplasms therapy, Peptide Fragments immunology, WT1 Proteins immunology
- Abstract
Purpose: Dendritic cell (DC)-based vaccines have been expected to serve as new therapeutic approaches for advanced non-small cell lung cancers (NSCLCs); however, their clinical outcomes have not been fully elucidated. We report a single-centre clinical study analysing factors affecting the survival of patients with advanced NSCLCs who received DC vaccines pulsed with or without Wilms' tumour protein-1 (WT1) peptide., Methods: Among 62 patients with previously treated inoperable or postoperatively relapsed NSCLCs who met the inclusion criteria, DCs from 47 (76%) patients who showed HLA-A2402/0201/0206 were pulsed with one or more corresponding WT1 peptide antigens. DC vaccines were intradermally injected biweekly., Results: Clinical responses based on response evaluation criteria in solid tumours (RECIST) were found in 31 (50%) patients at 3 months after the first DC vaccine (complete response: 1 (1.6%), partial response: 4 (6.5%), stable disease: 26 (41.9%)). Median survival time was 27 months (82% in 1 year and 54% in 2 years) from initial diagnosis, and that was 12 months (48% in 1 year and 22% in 2 years) from the first DC vaccination. Importantly, multivariate analyses revealed that only two factors, blood haemoglobin and the use of WT1 peptides, significantly affected the overall survival of patients from both initial diagnosis and first vaccination., Conclusions: This study is the first to suggest that DC vaccines pulsed with WT1 may hold a significant impact to prolong the overall survival of patients with advanced NSCLCs., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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36. [Sensing characteristics of a real-time monitor using a photoionization detector on organic solvent vapors].
- Author
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Hori H, Ishematsu S, Fueta Y, Hinoue M, and Ishidao T
- Subjects
- Computer Systems, Workplace, Air Pollution, Indoor analysis, Chemistry Techniques, Analytical instrumentation, Environmental Monitoring instrumentation, Solvents analysis
- Abstract
Measurements of organic solvents in the work environment are carried out by either direct sampling using plastic bags/gas chromatography, solid sorbent adsorption using charcoal tubes/gas chromatography, or by a direct reading method using detector tubes. However, these methods cannot always measure the work environment accurately because the concentration of hazardous materials changes from time to time, and from space to space. In this study, the sensor characteristics of a real time monitor using a photoionization detector that can monitor vapor concentration continuously were investigated for 52 organic solvent vapors that are required to be measured in the work environment by the Ordinance of Organic Solvent Poisoning Prevention in Japan. The sensitivity of the monitor was high for the solvents with low ionization potential. However, the sensitivity for the solvents with high ionization potential was low, and the sensor could not detected 7 solvents. Calibration of the sensor using a standard gas was desirable before being used for measurement because the sensitivity of the sensor was variable.
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- 2012
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37. One-step detection of the 2009 pandemic influenza A(H1N1) virus by the RT-SmartAmp assay and its clinical validation.
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Kawai Y, Kimura Y, Lezhava A, Kanamori H, Usui K, Hanami T, Soma T, Morlighem JÉ, Saga S, Ishizu Y, Aoki S, Endo R, Oguchi-Katayama A, Kogo Y, Mitani Y, Ishidao T, Kawakami C, Kurata H, Furuya Y, Saito T, Okazaki N, Chikahira M, Hayashi E, Tsuruoka S, Toguchi T, Saito Y, Ban T, Izumi S, Uryu H, Kudo K, Sakai-Tagawa Y, Kawaoka Y, Hirai A, Hayashizaki Y, and Ishikawa T
- Subjects
- Aged, Child, DNA Primers genetics, Drug Resistance, Viral, Female, Hemagglutinin Glycoproteins, Influenza Virus genetics, Humans, Influenza A Virus, H1N1 Subtype drug effects, Influenza A Virus, H1N1 Subtype genetics, Influenza, Human virology, Oseltamivir pharmacology, RNA, Viral genetics, RNA, Viral isolation & purification, Time Factors, Influenza A Virus, H1N1 Subtype isolation & purification, Influenza A Virus, H1N1 Subtype pathogenicity, Influenza, Human epidemiology, Nucleic Acid Amplification Techniques methods, Pandemics, RNA-Directed DNA Polymerase metabolism
- Abstract
Background: In 2009, a pandemic (pdm) influenza A(H1N1) virus infection quickly circulated globally resulting in about 18,000 deaths around the world. In Japan, infected patients accounted for 16% of the total population. The possibility of human-to-human transmission of highly pathogenic novel influenza viruses is becoming a fear for human health and society., Methodology: To address the clinical need for rapid diagnosis, we have developed a new method, the "RT-SmartAmp assay", to rapidly detect the 2009 pandemic influenza A(H1N1) virus from patient swab samples. The RT-SmartAmp assay comprises both reverse transcriptase (RT) and isothermal DNA amplification reactions in one step, where RNA extraction and PCR reaction are not required. We used an exciton-controlled hybridization-sensitive fluorescent primer to specifically detect the HA segment of the 2009 pdm influenza A(H1N1) virus within 40 minutes without cross-reacting with the seasonal A(H1N1), A(H3N2), or B-type (Victoria) viruses., Results and Conclusions: We evaluated the RT-SmartAmp method in clinical research carried out in Japan during a pandemic period of October 2009 to January 2010. A total of 255 swab samples were collected from outpatients with influenza-like illness at three hospitals and eleven clinics located in the Tokyo and Chiba areas in Japan. The 2009 pdm influenza A(H1N1) virus was detected by the RT-SmartAmp assay, and the detection results were subsequently compared with data of current influenza diagnostic tests (lateral flow immuno-chromatographic tests) and viral genome sequence analysis. In conclusion, by the RT-SmartAmp assay we could detect the 2009 pdm influenza A(H1N1) virus in patients' swab samples even in early stages after the initial onset of influenza symptoms. Thus, the RT-SmartAmp assay is considered to provide a simple and practical tool to rapidly detect the 2009 pdm influenza A(H1N1) virus.
- Published
- 2012
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38. [Relationship between physical configuration of hood and velocity for local exhaust systems].
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Ishidao T, Ishimatsu S, and Hori H
- Subjects
- Air Movements, Equipment Design methods, Ventilation instrumentation
- Abstract
The hood performance of a local exhaust ventilation system is determined by the capture velocity and the air flow rate. The equation proposed by Dalla Valle has been widely used to speculate this relationship. However, Dalla Valle used different formulae for slot and plain opening (rectangular) hoods, and the calculated values near the boundary between the slot and plain opening by these formulae do not always match each other. In this study, we measured capture velocity of four hoods by changing the distance from the hood face for different aspect ratios. We also tried to develop an empirical formula to express a relationship that could be applied to both types of hoods. As a result, it was found that the relationship between air velocity in front of exterior hoods and air flow rate could be expressed as the sum of two exponential functions with distance. In addition, when the hood aspect ratio was less than 9 the values of the capture velocity calculated by the proposed equation were in good agreement with the experimental ones.
- Published
- 2011
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39. Method of estimating changes in vapor concentrations continuously generated from two-component organic solvents.
- Author
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Hori H, Ishidao T, and Ishimatsu S
- Subjects
- Chromatography, Gas instrumentation, Flame Ionization, Time Factors, Volatilization, Acetates analysis, Air Pollutants, Occupational analysis, Chromatography, Gas methods, Methanol analysis, Solvents, Toluene analysis
- Abstract
We measured vapor concentrations continuously evaporated from two-component organic solvents in a reservoir and proposed a method to estimate and predict the evaporation rate or generated vapor concentrations. Two kinds of organic solvents were put into a small reservoir made of glass (3 cm in diameter and 3 cm high) that was installed in a cylindrical glass vessel (10 cm in diameter and 15 cm high). Air was introduced into the glass vessel at a flow rate of 150 ml/min, and the generated vapor concentrations were intermittently monitored for up to 5 hours with a gas chromatograph equipped with a flame ionization detector. The solvent systems tested in this study were the methanoltoluene system and the ethyl acetate-toluene system. The vapor concentrations of the more volatile component, that is, methanol in the methanol-toluene system and ethyl acetate in the ethyl acetate-toluene system, were high at first, and then decreased with time. On the other hand, the concentrations of the less volatile component were low at first, and then increased with time. A model for estimating multicomponent organic vapor concentrations was developed, based on a theory of vapor-liquid equilibria and a theory of the mass transfer rate, and estimated values were compared with experimental ones. The estimated vapor concentrations were in relatively good agreement with the experimental ones. The results suggest that changes in concentrations of two-component organic vapors continuously evaporating from a liquid reservoir can be estimated by the proposed model.
- Published
- 2010
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40. Association between breast cancer risk and the wild-type allele of human ABC transporter ABCC11.
- Author
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Ota I, Sakurai A, Toyoda Y, Morita S, Sasaki T, Chishima T, Yamakado M, Kawai Y, Ishidao T, Lezhava A, Yoshiura K, Togo S, Hayashizaki Y, Ishikawa T, Ishikawa T, Endo I, and Shimada H
- Subjects
- Breast Neoplasms blood, Breast Neoplasms pathology, Case-Control Studies, Female, Genetic Predisposition to Disease, Humans, Middle Aged, Polymorphism, Single Nucleotide, ATP-Binding Cassette Transporters genetics, Alleles, Breast Neoplasms genetics
- Abstract
Background: International mortality and frequency rates for breast cancer have been associated with the wet type of human earwax. It was recently found that earwax type is determined by a single nucleotide polymorphism (SNP), 538G>A (Gly180Arg), in ABCC11. The G allele determines the wet type of earwax as a Mendelian trait with a dominant phenotype. The present study examined the association between the frequency rate of breast cancer and the frequency of the G allele of ABCC11., Patients and Methods: Using blood samples from patients with invasive breast cancer (n = 270) and control volunteers (n = 273), the 538G>A SNP in ABCC11 was genotyped using the SmartAmp method., Results: The frequency of the G allele in breast cancer patients was higher than that in healthy controls. The odds ratio for the genotypes (G/G+G/A) to develop breast cancer was estimated to be 1.63 (p-value = 0.026), suggesting that the G allele in ABCC11 is associated with breast cancer risk., Conclusion: This study showed that Japanese women with wet earwax have a higher relative risk of developing breast cancer than those with dry earwax. The ABCC11 SNPs that determine these phenotypes should be further investigated in order to obtain insights into the mechanisms by which breast cancer develops and progresses.
- Published
- 2010
41. Exciton Primer-mediated SNP detection in SmartAmp2 reactions.
- Author
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Lezhava A, Ishidao T, Ishizu Y, Naito K, Hanami T, Katayama A, Kogo Y, Soma T, Ikeda S, Murakami K, Nogawa C, Itoh M, Mitani Y, Harbers M, Okamoto A, and Hayashizaki Y
- Subjects
- Benzothiazoles, Diamines, Fluorescent Dyes chemistry, Genotype, Humans, Mixed Function Oxygenases genetics, Organic Chemicals metabolism, Quinolines, Vitamin K Epoxide Reductases, DNA Primers metabolism, Polymerase Chain Reaction methods, Polymorphism, Single Nucleotide genetics
- Abstract
Most commonly used intercalating fluorescent dyes in DNA detection are lacking any sequence specificity, whereas so-called Exciton Primers can overcome this limitation by functioning as "sequence-specific dyes." After hybridization to complementary sequences, the fluorescence of Exciton Primers provides sequence-specific signals for real-time monitoring of amplification reactions. Applied to the SmartAmp2 mutation detection process, Exciton Primers show high signal strength with low background leading to a superior specificity and sensitivity compared to SYBR Green I. Signal strength can be further enhanced using multiple dyes within one Exciton Primer or use of multiple Exciton Primers in the same amplification reaction. Here we demonstrate the use of Exciton Primers for genotyping a single nucleotide polymorphism (SNP) in the VKORC1 locus (-1639G>A) relevant for Warfarin dosing as an example for Exciton Primers mediated genotyping by SmartAmp2. The genotyping assay can use only one labeled Exciton Primer for endpoint detection, or simultaneously by real-time monitoring detect wild-type and mutant alleles in a one-tube reaction using two Exciton Primers having different dyes. Working directly from blood samples, Exciton Primer mediated genotyping by SmartAmp2 offers superior solutions for rapid point-of-care testing., ((c) 2010 Wiley-Liss, Inc.)
- Published
- 2010
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42. Thermal reconditioning characteristics of a respirator cartridge for organic vapors using humid air as the desorption gas.
- Author
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Hori H, Ishidao T, and Ishimatsu S
- Subjects
- Charcoal, Humans, Japan, Poisoning prevention & control, Protective Devices, Respiratory Protective Devices, Volatilization, Adsorption, Gases analysis, Humidity, Solvents poisoning, Thermodynamics, Ventilators, Mechanical standards
- Abstract
Objectives: Thermal reconditioning characteristics of organic vapors from a respirator cartridge were studied by introducing humid air into a cartridge that had adsorbed organic vapors in order to develop a thermal reconditioning method., Methods: Five different organic vapors (methanol, 2-propanol, acetone, dichloromethane and methyl acetate), most of which have relatively weak adsorption affinity to charcoal, were used in this study. Adsorption was carried out at a temperature of 25 degrees C. The relative humidity of the adsorption air with organic vapor was 50%. When the vapor concentration in the downstream of the respirator exceeded the breakthrough concentration, that is, the occupational exposure limits in Japan, the vapor supply was stopped. Then, desorption was started by introducing clean humid air from opposite side of the cartridge under a heated condition. When the desorbed vapor concentration fell below the limit of quantification, desorption process was ended and the next adsorption cycle was started after the temperature had returned to room temperature. This adsorption - desorption cycle was repeated more than three times. The desorption temperature was 65 degrees C and the relative humidity of desorption air was 20%, 50% or 70% at 25 degrees C., Results: When the relative humidity was 20%, the breakthrough times of regenerated cartridges were shorter than that of a new one, but no difference was observed in the breakthrough curves when the relative humidity was greater than 50%., Conclusion: The results suggest that the thermal reconditioning of respirator cartridges using humid air is possible for these vapors.
- Published
- 2010
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43. Usefulness of peptide nucleic acid (PNA)-clamp smart amplification process version 2 (SmartAmp2) for clinical diagnosis of KRAS codon 12 mutations in lung adenocarcinoma: comparison of PNA-clamp SmartAmp2 and PCR-related methods.
- Author
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Araki T, Shimizu K, Nakamura K, Nakamura T, Mitani Y, Obayashi K, Fujita Y, Kakegawa S, Miyamae Y, Kaira K, Ishidao T, Lezhava A, Hayashizaki Y, Takeyoshi I, and Yamamoto K
- Subjects
- Adenocarcinoma diagnosis, Cell Line, Tumor, DNA Mutational Analysis economics, Humans, Lung Neoplasms diagnosis, Polymerase Chain Reaction economics, Proto-Oncogene Proteins p21(ras), Sensitivity and Specificity, Sequence Analysis, DNA, Time Factors, Adenocarcinoma genetics, DNA Mutational Analysis methods, Lung Neoplasms genetics, Mutation, Polymerase Chain Reaction methods, Proto-Oncogene Proteins genetics, ras Proteins genetics
- Abstract
KRAS is an oncogene that can be activated by mutations. Patients with non-small cell lung cancer who have KRAS mutations do not respond to tyrosine kinase inhibitors; therefore, accurate detection of KRAS mutations is important for deciding therapeutic strategies. Although sequencing-related techniques have been frequently used, they are usually too complex, have low sensitivity, and are time-consuming for routine screening in clinical situations. We evaluated peptide nucleic acid (PNA)-clamp smart amplification process version 2 (SmartAmp2) as a detection method for KRAS codon 12 mutations in patient specimens compared with traditional sequencing and polymerase chain reaction-related methods. Among 172 lung adenocarcinoma samples, direct sequencing, enzyme-enriched sequencing, and PNA-enriched sequencing showed that 16 (9.3%), 26 (15.7%), and 28 (16.3%) tumors, respectively, contained KRAS mutations in codon 12. Using PNA-clamp SmartAmp2, we could identify 31 (18.0%) tumors that had KRAS mutations in codon 12 within 60 minutes, three of which were undetected by polymerase chain reaction-related methods. On the other hand, we examined 30 nonmalignant peripheral lung tissue specimens and found no mutations in any of the samples using PNA-clamp SmartAmp2. In this study, we confirmed that PNA-clamp SmartAmp2 has high sensitivity and accuracy and is suitable for the clinical diagnosis of KRAS codon 12 mutations.
- Published
- 2010
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44. Isothermal single nucleotide polymorphism genotyping and direct PCR from whole blood using a novel whole-blood lysis buffer.
- Author
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Victor ST, Lezhava A, Ishidao T, Endo R, Mitani Y, Kawaoka Y, and Hayashizaki Y
- Subjects
- Aldehyde Dehydrogenase genetics, Aldehyde Dehydrogenase, Mitochondrial, Buffers, Genotype, Humans, Hemolysis physiology, Polymerase Chain Reaction methods, Polymorphism, Single Nucleotide genetics, Temperature
- Abstract
Cell lysis and subsequent release of genomic DNA is an ongoing dilemma for molecular biological techniques. In most cases, technologies such as PCR and other amplification techniques require DNA extraction and purification steps. The Smart Amplification Process Version 2 (SmartAmp2) is an isothermal and integrated amplification technology that eliminates the need for time-consuming sample preparation for the rapid detection of nucleic acids, including single nucleotide polymorphisms (SNPs), mutations, and other targets. In addition, DNA amplification directly from whole blood is beneficial and lessens the risk of cross-contamination. Traditional SmartAmp2 assays entail two steps and require an alkali pretreatment step at 98 degrees C prior to the 60 degrees C run. To make SmartAmp2 truly isothermal and to simplify DNA amplification, we hereby introduce the SmartAmp Isothermal Lysis Buffer (SIL-B), a newly developed chaotropic lysis buffer that enables the simultaneous recovery and denaturation of genomic material directly from whole blood at a uniform 60 degrees C. The improved method for isolating nucleic acids from whole blood is a critical milestone in making SmartAmp2 truly isothermal from start to finish at one temperature, increasing its potential to be routinely used in field point-of-care testing. Furthermore, pretreatment with SIL-B enables the PCR amplification of genomic material directly from whole blood.
- Published
- 2009
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45. Effects of 1-bromopropane, a substitute for chlorofluorocarbons, on BDNF expression.
- Author
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Yoshida Y, Nakano Y, Ueno S, Liu J, Fueta Y, Ishidao T, Kunugita N, Yanagihara N, Sugiura T, Hori H, and Yamashita U
- Subjects
- Animals, Astrocytes metabolism, Brain-Derived Neurotrophic Factor biosynthesis, Cell Line, Tumor, Cells, Cultured, Cyclic AMP Response Element-Binding Protein antagonists & inhibitors, Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors, Humans, Hydrocarbons, Brominated pharmacology, Mice, Mice, Inbred C57BL, Astrocytes drug effects, Brain-Derived Neurotrophic Factor antagonists & inhibitors, Cyclic AMP Response Element-Binding Protein metabolism, Cyclic AMP-Dependent Protein Kinases metabolism
- Abstract
1-Bromopropane (1-BP) has been widely used as an alternative to ozone-depleting chlorofluorocarbons in various industries. Although the neurotoxicity of 1-BP has been recently reported, there is little information about the effect of 1-BP on the cells in brain by experimental approach. Here we studied the effect of 1-BP on brain-derived neurotrophic factor (BDNF) expression in astrocytes in vitro. The BDNF mRNA level was remarkably decreased by 1-BP in a human astrocytoma cell line, U251, and in mouse primary astrocytes. The DNA-binding and specific reporter activity of cAMP response element-binding transcription factor (CREB), which is one of the key molecules regulating BDNF expression, were reduced by 1-BP in U251 and/or mouse primary astrocytes. Additionally, protein kinase A (PKA) activity was suppressed by 1-BP in U251. These results suggest that BDNF expression was affected by 1-BP through at least PKA.
- Published
- 2009
- Full Text
- View/download PDF
46. Rapid single-nucleotide polymorphism detection of cytochrome P450 (CYP2C9) and vitamin K epoxide reductase (VKORC1) genes for the warfarin dose adjustment by the SMart-amplification process version 2.
- Author
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Aomori T, Yamamoto K, Oguchi-Katayama A, Kawai Y, Ishidao T, Mitani Y, Kogo Y, Lezhava A, Fujita Y, Obayashi K, Nakamura K, Kohnke H, Wadelius M, Ekström L, Skogastierna C, Rane A, Kurabayashi M, Murakami M, Cizdziel PE, Hayashizaki Y, and Horiuchi R
- Subjects
- Aryl Hydrocarbon Hydroxylases classification, Aryl Hydrocarbon Hydroxylases metabolism, Base Sequence, Cytochrome P-450 CYP2C9, Dose-Response Relationship, Drug, Humans, Mixed Function Oxygenases metabolism, Molecular Sequence Data, Sequence Alignment, Time Factors, Vitamin K Epoxide Reductases, Aryl Hydrocarbon Hydroxylases analysis, Aryl Hydrocarbon Hydroxylases genetics, Mixed Function Oxygenases analysis, Mixed Function Oxygenases genetics, Nucleic Acid Amplification Techniques methods, Polymorphism, Single Nucleotide genetics, Warfarin pharmacology
- Abstract
Background: Polymorphisms of the CYP2C9 (cytochrome P450, family 2, subfamily C, polypeptide 9) gene (CYP2C9*2, CYP2C9*3) and the VKORC1 (vitamin K epoxide reductase complex, subunit 1) gene (-1639G>A) greatly impact the maintenance dose for the drug warfarin. Prescreening patients for their genotypes before prescribing the drug facilitates a faster individualized determination of the proper maintenance dose, minimizing the risk for adverse reaction and reoccurrence of thromboembolic episodes. With current methodologies, therapy can be delayed by several hours to 1 day if genotyping is to determine the loading dose. A simpler and more rapid genotyping method is required., Methods: We developed a single-nucleotide polymorphism (SNP)-detection assay based on the SMart Amplification Process version 2 (SMAP 2) to analyze CYP2C9*2, CYP2C9*3, and VKORC1 -1639G>A polymorphisms. Blood from consenting participants was used directly in a closed-tube real-time assay without DNA purification to obtain results within 1 h after blood collection., Results: We analyzed 125 blood samples by both SMAP 2 and PCR-RFLP methods. The results showed perfect concordance., Conclusions: The results validate the accuracy of the SMAP 2 for determination of SNPs critical to personalized warfarin therapy. SMAP 2 offers speed, simplicity of sample preparation, the convenience of isothermal amplification, and assay-design flexibility, which are significant advantages over conventional genotyping technologies. In this example and other clinical scenarios in which genetic testing is required for immediate and better-informed therapeutic decisions, SMAP 2-based diagnostics have key advantages.
- Published
- 2009
- Full Text
- View/download PDF
47. The indoor air pollutant 2-ethyl-hexanol activates CD4 cells.
- Author
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Yoshida Y, Liu J, Sugiura T, Ishidao T, Ueno S, Yanagita H, Fueta Y, Kunugita N, Hori H, and Yamashita U
- Subjects
- Air Pollution, Indoor, Animals, Biomarkers metabolism, CD4-Positive T-Lymphocytes immunology, CD4-Positive T-Lymphocytes metabolism, CD8-Positive T-Lymphocytes drug effects, CD8-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes metabolism, Cell Proliferation drug effects, Cells, Cultured, Female, Interleukin-2 metabolism, Macrophages, Peritoneal drug effects, Macrophages, Peritoneal immunology, Macrophages, Peritoneal metabolism, Mice, Mice, Inbred BALB C, NF-kappa B metabolism, NFATC Transcription Factors metabolism, Spleen metabolism, Air Pollutants, Occupational toxicity, CD4-Positive T-Lymphocytes drug effects, Hexanols toxicity, Lymphocyte Activation drug effects, Plasticizers toxicity, Spleen drug effects
- Abstract
It has been reported that the numbers of people suffering from occupational asthma and skin rashes triggered by various chemicals in indoor air have increased markedly. Two-ethyl-hexanol (2-EH) is known to be an indoor air pollutant and its influence on health is of great concern. However, there are only a few reports regarding its effect on immune cells. Thus, we investigated the effects of 2-EH on immune responses in vitro with respect to effects on regulation of transcription factors as well as on 2-EH induced proliferation of spleen cells in vitro. The production of interleukin (IL)-6 and immunoglobulin were not induced by 2-EH. To characterize the effector cells of 2-EH, we prepared CD4-positive, CD8-positive, and peritoneal exudate cells (PEC). IL-2 was induced by 2-EH in CD4 cells, but not in CD8 cells. CD3-induced IL-2 expression was enhanced by 2-EH in CD4 cells, but not in CD8 cells. Moreover, IL-6 production was not induced by 2-EH in PEC. Nuclear factor-kappa B, nuclear factor of activated T, and signal transducer and activator of transcription-5 were activated by 2-EH in CD4 cells. Taken together, 2-EH activated CD4 cells, where this was accompanied by the activation of transcription factors. This suggested that the indoor pollutant 2-EH could function as a modulator of immune response.
- Published
- 2009
- Full Text
- View/download PDF
48. Rapid screening assay for KRAS mutations by the modified smart amplification process.
- Author
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Tatsumi K, Mitani Y, Watanabe J, Takakura H, Hoshi K, Kawai Y, Kikuchi T, Kogo Y, Oguchi-Katayama A, Tomaru Y, Kanamori H, Baba M, Ishidao T, Usui K, Itoh M, Cizdziel PE, Lezhava A, Ueda M, Ichikawa Y, Endo I, Togo S, Shimada H, and Hayashizaki Y
- Subjects
- Aged, Aged, 80 and over, Alleles, DNA Mutational Analysis instrumentation, Female, Humans, Male, Middle Aged, Nucleic Acid Amplification Techniques instrumentation, Proto-Oncogene Proteins p21(ras), Sensitivity and Specificity, Sequence Analysis, DNA instrumentation, DNA Mutational Analysis methods, Nucleic Acid Amplification Techniques methods, Point Mutation, Proto-Oncogene Proteins genetics, Sequence Analysis, DNA methods, ras Proteins genetics
- Abstract
Previously, the smart amplification process version 2 (SMAP-2) was developed to detect mutations from tissue and in crude cell lysates and has been used for rapid diagnosis of specific somatic mutations with single-nucleotide precision. The purpose of this study was to develop a rapid and practical method to detect cancer and metastasis in specimens using the SMAP-2 assay. We developed modified SMAP-2 assays that enabled detection of any change in a single codon using a single assay. Rapid SMAP-2 screening assays are suitable for routine clinical identification of critical amino acid substitutions such as codon 12 mutations in KRAS. Primers bracketing the first two nucleotides of KRAS codon 12 were designed so that all possible alleles would be amplified by the SMAP-2 assay. In combination with the peptide nucleic acid (PNA) with exact homology to the wild-type allele, our assay amplified all mutant alleles except for the wild-type sequence. With this new assay design (termed PNA-clamp SMAP-2), we could detect KRAS mutations within 60 minutes, including sample preparation. We compared results from PNA-clamp SMAP-2 assay, polymerase chain reaction-restriction fragment length polymorphism, and direct sequencing of clinical samples from pancreatic cancer patients and demonstrated perfect concordance. The PNA-clamp SMAP-2 method is a rapid, simple, and highly sensitive detection assay for cancer mutations.
- Published
- 2008
- Full Text
- View/download PDF
49. A B-Myb complex containing clathrin and filamin is required for mitotic spindle function.
- Author
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Yamauchi T, Ishidao T, Nomura T, Shinagawa T, Tanaka Y, Yonemura S, and Ishii S
- Subjects
- Animals, Clathrin isolation & purification, Contractile Proteins isolation & purification, Fibroblasts metabolism, Filamins, Genomic Instability, HeLa Cells, Humans, Mice, Microfilament Proteins isolation & purification, Mitosis, Multiprotein Complexes isolation & purification, Multiprotein Complexes metabolism, Proto-Oncogene Proteins c-myb isolation & purification, Clathrin metabolism, Contractile Proteins metabolism, Microfilament Proteins metabolism, Proto-Oncogene Proteins c-myb metabolism, Spindle Apparatus metabolism
- Abstract
B-Myb is one member of the vertebrate Myb family of transcription factors and is ubiquitously expressed. B-Myb activates transcription of a group of genes required for the G2/M cell cycle transition by forming the dREAM/Myb-MuvB-like complex, which was originally identified in Drosophila. Mutants of zebrafish B-myb and Drosophila myb exhibit defects in cell cycle progression and genome instability. Although the genome instability caused by a loss of B-Myb has been speculated to be due to abnormal cell cycle progression, the precise mechanism remains unknown. Here, we have purified a B-Myb complex containing clathrin and filamin (Myb-Clafi complex). This complex is required for normal localization of clathrin at the mitotic spindle, which was previously reported to stabilize kinetochore fibres. The Myb-Clafi complex is not tightly associated with the mitotic spindles, suggesting that this complex ferries clathrin to the mitotic spindles. Thus, identification of the Myb-Clafi complex reveals a previously unrecognized function of B-Myb that may contribute to its role in chromosome stability, possibly, tumour suppression.
- Published
- 2008
- Full Text
- View/download PDF
50. Abnormal development of urogenital organs in Dlgh1-deficient mice.
- Author
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Iizuka-Kogo A, Ishidao T, Akiyama T, and Senda T
- Subjects
- Adaptor Proteins, Signal Transducing metabolism, Animals, Cell Proliferation, Discs Large Homolog 1 Protein, Epithelial Cells cytology, Epithelial Cells metabolism, Female, Guanylate Kinases, Kidney embryology, Male, Membrane Proteins metabolism, Mice, Mice, Knockout, Mullerian Ducts embryology, Ureter embryology, Urogenital System metabolism, Urothelium cytology, Wolffian Ducts embryology, Adaptor Proteins, Signal Transducing genetics, Membrane Proteins genetics, Urogenital Abnormalities genetics, Urogenital System embryology
- Abstract
Dlgh1 (discs large homolog 1) is a mammalian homolog of the Drosophila tumor suppressor Discs large 1, and is a member of the membrane-associated guanylate kinase (MAGUK) scaffolding proteins that contain three PSD-95/Dlg/ZO-1 (PDZ) domains. Discs large 1 is involved in epithelial polarization and cell-cell adhesion complex formation during Drosophila development. However, the functions of Dlgh1 during mammalian development remain to be elucidated. We generated Dlgh1-knockout mice and found that homozygous Dlgh1-knockout mice developed various abnormalities in their renal and urogenital organs. The kidneys and ureters were hypoplastic and the lower ends of the ureters were ectopic. In addition, the vagina and seminal vesicle, which are derived from the lower part of the Müllerian and Wolffian duct, respectively, were absent. Unexpectedly, loss of Dlgh1 function in the developing ureters did not disrupt cell-cell junctional complexes, but did impair cellular proliferation in the epithelium. These results suggest a novel role for Dlgh1 in regulating epithelial duct formation and morphogenesis during mammalian development. Although congenital absence of the vagina associated with other variable Müllerian duct abnormalities has been reported in humans, its mechanism has not yet been clarified. Our findings might contribute to a better understanding of such abnormalities.
- Published
- 2007
- Full Text
- View/download PDF
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