72 results on '"Iwamuro, Y."'
Search Results
2. Near-infrared spectroscopy in carotid artery stenting predicts cerebral hyperperfusion syndrome
- Author
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Matsumoto, S., primary, Nakahara, I., additional, Higashi, T., additional, Iwamuro, Y., additional, Watanabe, Y., additional, Takahashi, K., additional, Ando, M., additional, Takezawa, M., additional, and Kira, J. I., additional
- Published
- 2009
- Full Text
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3. Percutaneous angioplasty and stenting of subclavian arteries before surgical coronary revascularization in a patient with an aberrant right subclavian artery
- Author
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Taha, M.M., primary, Nakahara, I., additional, Higashi, T., additional, Iwamuro, Y., additional, Watanabe, Y., additional, and Taki, W., additional
- Published
- 2007
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4. Result of Neck Clipping and Coil Embolization as a Treatment for Unruptured Aneurysm
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Iwamuro, Y., primary, Nakahara, I., additional, Higashi, T., additional, Iwaasa, M., additional, Watanabe, Y., additional, Tsunetoshi, K., additional, Munemitsu, T., additional, and Taha, M., additional
- Published
- 2007
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5. Result of Neck Clipping and Coil Embolization as a Treatment for Subarachnoid Haemorrhage
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Iwamuro, Y., primary, Nakahara, I., additional, Higashi, T., additional, Watanabe, Y., additional, Oku, T., additional, and Hirata, E., additional
- Published
- 2006
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6. Dynamic response of PPF-coated QCR sensor: Model based on sorption/desorption behaviours of gas molecules and adsorbed water.
- Author
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Takahashi, K., Iwamuro, Y., and Sugimoto, I.
- Published
- 2011
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7. Untitled.
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Lee, K., Morita, H., Iwamuro, Y., Zhang, X.-F., Okamoto, Y., Nakagawa, T., Hasegawa, H., Furutani, H., Miwa, S., and Masaki, T.
- Abstract
To clarify the mechanism for the endothelin-1 (ET-1)-induced release of catecholamines from the adrenal gland, we examined the effects of removal of extracellular Ca
2+ , blockers of L-, N-, P- and Q-types of voltage-operated Ca2+ channels (VOCC) such as nifedipine (L-type), ω-conotoxin GVIA (N-type), ω-agatoxin IVA (P-type) and ω-conotoxin MVIIC (Q-type) and blockers of voltage-independent Ca2+ entry channel such as SK&F 96365 and LOE 908 on release of catecholamines, the cytosolic free Ca2+ concentration ([Ca2+ ]i ), and45 Ca2+ uptake in cultured bovine adrenal chromaffin cells. ET-1 but not ET-3 induced increases in release of catecholamines, [Ca2+ ]i , and45 Ca2+ uptake. The responses to ET-1 were abolished by the antagonist for ETA receptors, BQ-123, but not by the antagonist for ETB receptors, BQ-788, and they were abolished by removal of extracellular Ca2+ . The increases were only partially inhibited (to about 65% of control) by nifedipine but unaffected by any of the ω-toxins. The nifedipine-resistant increase was inhibited by SK&F 96365 (to about 40%) and abolished by LOE 908 alone. These results indicate that ET-1 augments the release of catecholamines from adrenal chromaffin cells through ETA receptors, by activating two types of Ca2+ entry channels in addition to L-type VOCC: one (nonselective cation channel-1; NSCC-1) is sensitive to LOE 908 but resistant to SK&F 96365, whereas the other (NSCC-2) is sensitive to both LOE 908 and SK&F 96365. [ABSTRACT FROM AUTHOR]- Published
- 1999
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8. Pharmacological characterization of Ca2+ entry channels in endothelin-1-induced contraction of rat aorta using LOE 908 and SK&F 96365.
- Author
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Zhang, Xiao-Feng, Iwamuro, Yasushi, Enoki, Taijiro, Okazawa, Makoto, Lee, Ken, Komuro, Taro, Minowa, Tetsuya, Okamoto, Yasuo, Hasegawa, Hiroshi, Furutani, Hidekatsu, Miwa, Soichi, Masaki, Tomoh, Zhang, X F, Iwamuro, Y, Enoki, T, Okazawa, M, Lee, K, Komuro, T, Minowa, T, and Okamoto, Y
- Published
- 1999
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9. Activation of three types of voltage-independent Ca2+ channel in A7r5 cells by endothelin-1 as revealed by a novel Ca2+ channel blocker LOE 908.
- Author
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Iwamuro, Yasushi, Miwa, Soichi, Zhang, Xiao-Feng, Minowa, Tetsuya, Enoki, Taijiro, Okamoto, Yasuo, Hasegawa, Hiroshi, Furutani, Hidekatsu, Okazawa, Makoto, Ishikawa, Masatsune, Hashimoto, Nobuo, Masaki, Tomoh, Iwamuro, Y, Miwa, S, Zhang, X F, Minowa, T, Enoki, T, Okamoto, Y, Hasegawa, H, and Furutani, H
- Published
- 1999
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10. Activation of two types of Ca2+-permeable nonselective cation channel by endothelin-1 in A7r5 cells.
- Author
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Iwamuro, Yasushi, Miwa, Soichi, Minowa, Tetsuya, Enoki, Taijiro, Zhang, Xiao-Feng, Ishikawa, Masatsune, Hashimoto, Nobuo, Masaki, Tomoh, Iwamuro, Y, Miwa, S, Minowa, T, Enoki, T, Zhang, X F, Ishikawa, M, Hashimoto, N, and Masaki, T
- Published
- 1998
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11. Role of nonselective cation channels as Ca^2^+ entry pathway in endothelin-1-induced contraction and their suppression by nitric oxide
- Author
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Zhang, X.-F., Komuro, T., Miwa, S., Minowa, T., Iwamuro, Y., Okamoto, Y., Ninomiya, H., Sawamura, T., and Masaki, T.
- Published
- 1998
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12. [Spontaneous improvement of idiopathic intracranial carotid artery dissection: a case report]
- Author
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Iwamuro, Y., Nakahara, I., Higashi, T., Watanabe, Y., Shoji Matsumoto, Takahashi, K., Kikuchi, T., Ando, M., and Takezawa, M.
13. [Cost Comparison of Carotid Endarterectomy versus Carotid Stenting in Japan]
- Author
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Sadamasa, N., Masaomi Koyanagi, Iwamuro, Y., Chin, M., Handa, A., and Yamagata, S.
14. Development of two fully automated quick, easy, cheap, effective, rugged, and safe pretreatment methods for the extraction of psychotropic drugs from whole blood samples.
- Author
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Murakami T, Ishimaru R, Minami E, Iwamuro Y, Takamura N, Torai A, Watanabe T, Miki A, Katagi M, Kusano M, Tsuchihashi H, Zaitsu K, and Chinaka S
- Subjects
- Chromatography, Liquid methods, Psychotropic Drugs, Acetonitriles chemistry, Chromatography, High Pressure Liquid methods, Tandem Mass Spectrometry methods, Solid Phase Extraction methods
- Abstract
Quick, easy, cheap, effective, rugged, and safe extraction strategies are becoming increasingly adopted in various analytical fields to determine drugs in biological specimens. In the present study, we developed two fully automated quick, easy, cheap, effective, rugged, and safe extraction methods based on acetonitrile salting-out assisted liquid-liquid extraction (method 1) and acetonitrile salting-out assisted liquid-liquid extraction followed by dispersive solid-phase extraction (method 2) using a commercially available automated liquid-liquid extraction system. We applied these methods to the extraction of 14 psychotropic drugs (11 benzodiazepines and carbamazepine, quetiapine, and zolpidem) from whole blood samples. Both methods prior to liquid chromatography-tandem mass spectrometry analysis exhibited high linearity of calibration curves (correlation coefficients, > 0.9997), ppt level detection sensitivities, and satisfactory precisions (< 8.6% relative standard deviation), accuracies (within ± 16% relative error), and matrix effects (81-111%). Method 1 provided higher recovery rates (80-91%) than method 2 (72-86%), whereas method 2 provided higher detection sensitivities (limits of detection, 0.003-0.094 ng/mL) than method 1 (0.025-0.47 ng/mL) owing to the effectiveness of its dispersive solid-phase extraction cleanup step. These fully automated extraction methods realize reliable, labor-saving, user-friendly, and hygienic extraction of target analytes from whole blood samples., (© 2022 Wiley-VCH GmbH.)
- Published
- 2023
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15. Regioisomer Differentiation of Ring-Substituted Chloromethcathinones and Bromomethcathinones Using Gas Chromatography/Electron Ionization-Triple Quadrupole Energy-Resolved Mass Spectrometry.
- Author
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Murakami T, Sakamoto Y, Sugimura N, Minami E, Iwamuro Y, Ishimaru R, Chinaka S, and Hasegawa H
- Abstract
Positional isomers o -, m -, and p -chloromethcathinones (CMCs) and m - and p -bromomethcathinones (BMCs) were effectively differentiated using gas chromatography (GC) and energy-resolved mass spectrometry (ERMS) analyses. GC demonstrated that the free bases of CMC and BMC isomers were simultaneously baseline-separated at a slow column heating rate (5 °C/min) using a conventional low-polar capillary column. ERMS showed that the trifluoroacetyl derivatives of the positional isomers differed in mass spectral abundances of both halophenyl and halobenzoyl cations. Moreover, the logarithmic plots of the abundance ratio of the two cations as a function of the collision energy (CE) exhibited marked differences among the isomers at each CE, following the order of ortho < para < meta for CMCs and para < meta for BMCs. The performed theoretical calculations of dissociation energy agreed well with the ERMS measurements. The GC and ERMS methodologies enabled unambiguous and reliable differentiation of CMC and BMC isomers. The developed approach is expected to significantly contribute to the accurate structural identification of new psychoactive substances in forensic, toxicological, and clinical fields.
- Published
- 2021
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16. Differentiation of o-, m-, and p-fluoro-α-pyrrolidinopropiophenones by Triton B-mediated one-pot reaction.
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Murakami T, Iwamuro Y, Ishimaru R, Chinaka S, Hasegawa H, Kavthe RD, and Asao N
- Abstract
Positional isomer differentiation is crucial for the analysis of forensic drugs. Presently, it is difficult to distinguish among ortho, meta, and para positional isomers of ring-fluorinated synthetic cathinones, a major class of new psychoactive substances (NPSs), because they exhibit similar chromatographic properties and mass spectral patterns. We describe herein that the ring-fluorinated synthetic cathinone positional isomers, viz. o-, m-, and p-fluoro-α-pyrrolidinopropiophenones (o-, m-, and p-FPPPs), can be discriminated by their benzyltrimethylammonium hydroxide (Triton B)-mediated one-pot reaction with methanol at ambient temperature, followed by chromatographic and mass spectral analyses of the corresponding products. For p-FPPP, fluorine was nucleophilically substituted by the methoxy group to afford p-methoxy-α-pyrrolidinopropiophenone, while o- and m-FPPPs afforded the corresponding FPPP-enamine-pyrrolidine adducts, which allowed the above positional isomers to be unambiguously differentiated by comparing the reaction product chromatograms and mass spectra. The adopted approach, which does not require excess heating or use of metallic catalysts and features the advantages of simplicity and convenience, is expected to contribute toward practical NPS identification., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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17. Energy-resolved mass spectrometry for differentiation of the fluorine substitution position on the phenyl ring of fluoromethcathinones.
- Author
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Murakami T, Iwamuro Y, Ishimaru R, Chinaka S, Kato N, Sakamoto Y, Sugimura N, and Hasegawa H
- Abstract
A reliable method for structural analysis is crucial for the forensic investigation of new psychoactive substances (NPSs). Towards this end, mass spectrometry is one of the most efficient and facile methods for the identification of NPSs. However, the differentiation among 2-, 3-, and 4-fluoromethcathinones (o-, m-, and p-FMCs), which are ring-fluorinated positional isomers part of the major class of NPSs referred to as synthetic cathinones, remains a challenge. This is mostly due to their similar retention properties and nearly identical full scan mass spectra, which hinder their identification. In this study, we describe a novel and practical method for differentiating the fluorine substitution position on the phenyl ring of FMCs, based on energy-resolved mass spectrometry (ERMS) using an electron ionization-triple quadrupole mass spectrometer. ERMS measurements showed that the three FMC positional isomers exhibited differences in relative abundances of both the fluorophenyl cation (m/z 95) and the fluorobenzoyl cation (m/z 123). The logarithmic plots of the abundance ratio of these two cations (m/z 95 to m/z 123) as a function of the collision energy (CE) followed the order of o-FMC < p-FMC < m-FMC at each CE, which allowed the three isomers to be unambiguously and reliably differentiated. The theoretical dissociation energy calculations confirmed the relationship obtained by ERMS analyses, and additional ERMS measurements of methylmethcathinone positional isomers showed that the differences in abundance among the FMCs were attributed to the differences in their collision-induced dissociation reactivities arising from the halogen-induced resonance effects on the phenyl ring. Moreover, the method for differentiation described herein was successfully applied to the actual samples containing seized drugs. We expect that the described methodology will also contribute significantly to the reliable and accurate structural identification of NPSs in the fields of therapeutic, clinical, and forensic toxicology., (© 2018 John Wiley & Sons, Ltd.)
- Published
- 2019
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18. Molecularly imprinted polymer solid-phase extraction of synthetic cathinones from urine and whole blood samples.
- Author
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Murakami T, Iwamuro Y, Ishimaru R, Chinaka S, and Hasegawa H
- Subjects
- Alkaloids chemical synthesis, Humans, Molecular Structure, Alkaloids blood, Alkaloids urine, Molecular Imprinting, Polymers chemistry, Solid Phase Extraction
- Abstract
In forensic drug analysis, extractive pretreatment is required prior to instrumental analysis to ensure successful detection of the target compounds. However, conventional extraction methods such as hydrophilic polymer-based solid-phase extraction and liquid-liquid extraction are unsuitable for an emerging class of new psychoactive substances, namely, synthetic cathinones, because they exhibit a lack of class selectivity and increased risk of target analyte decomposition during extraction. To address these issues, we describe a highly class-selective sample clean-up method for the extraction of synthetic cathinones from urine and whole blood samples, exploiting a molecularly imprinted polymer solid-phase extraction cartridge. In terms of the influence of the synthetic cathinone molecular structure on the extraction recovery, we showed that while longer alkyl side chains slightly reduced the extraction efficiency, substituent variation on the aromatic ring exerted no effect. Molecularly imprinted polymer solid-phase extraction of 11 synthetic cathinones from urine samples yielded higher recoveries than the two conventional extraction methods, and smaller matrix effect was observed than that with hydrophilic polymer-based solid-phase extraction. Molecularly imprinted polymer solid-phase extraction from whole blood samples gave recoveries comparable to those of urine samples. Therefore, the proposed method is applicable for the extraction and quantitative determination of synthetic cathinones in biological samples., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2018
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19. Differentiation of AB-FUBINACA and its five positional isomers using liquid chromatography-electrospray ionization-linear ion trap mass spectrometry and triple quadrupole mass spectrometry.
- Author
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Murakami T, Iwamuro Y, Ishimaru R, Chinaka S, Takayama N, and Hasegawa H
- Abstract
Purpose: Positional isomer differentiation is crucial for forensic analysis. The aim of this study was to differentiate AB-FUBINACA positional isomers using liquid chromatography (LC)-electrospray ionization (ESI)-linear ion trap mass spectrometry (LIT-MS) and LC-ESI-triple quadrupole mass spectrometry (QqQ-MS)., Methods: AB-FUBINACA, its two fluorine positional isomers on the phenyl ring, and three methyl positional isomers in the carboxamide side chain were analyzed by LC-ESI-LIT-MS and LC-ESI-QqQ-MS., Results: Four of the positional isomers, excluding AB-FUBINACA and its 3-fluorobenzyl isomer, were chromatographically separated on an ODS column in isocratic mode. ESI-LIT-MS could discriminate only three isomers, i.e., the 2-fluorobenzyl isomer, the N -(1-amino-2-methyl-1-oxobutan-2-yl) isomer, and the N -(1-amino-1-oxobutan-2-yl)- N -methyl isomer, based on their characteristic product ions observed at the MS
3 stage in negative mode. ESI-QqQ-MS differentiated all six isomers in terms of the relative abundances of the product ions that contained the isomeric moieties involved in collision-induced dissociation reactions. The six isomers were more clearly and significantly differentiated upon comparison of the logarithmic values of the product ion abundance ratios as a function of collision energy., Conclusions: The present LC-MS methodologies were useful for the differentiation of a series of AB-FUBINACA positional isomers., Competing Interests: Compliance with ethical standardsThe authors declare that they have no conflict of interest.This article does not contain any studies involving human participants or animals performed by any of the authors.- Published
- 2018
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20. Choroidal fissure acts as an overflow device in cerebrospinal fluid drainage: morphological comparison between idiopathic and secondary normal-pressure hydrocephalus.
- Author
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Yamada S, Ishikawa M, Iwamuro Y, and Yamamoto K
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- Age of Onset, Aged, Aged, 80 and over, Cerebrospinal Fluid Leak diagnostic imaging, Choroid Plexus diagnostic imaging, Choroid Plexus physiopathology, Female, Humans, Hydrocephalus, Normal Pressure classification, Hydrocephalus, Normal Pressure diagnostic imaging, Hydrocephalus, Normal Pressure physiopathology, Lateral Ventricles diagnostic imaging, Lateral Ventricles physiopathology, Magnetic Resonance Imaging methods, Male, Subarachnoid Space diagnostic imaging, Subarachnoid Space physiopathology, Cerebrospinal Fluid Leak physiopathology, Choroid Plexus abnormalities, Hydrocephalus, Normal Pressure pathology, Lateral Ventricles abnormalities, Subarachnoid Space abnormalities
- Abstract
To clarify the pathogenesis of two different types of adult-onset normal-pressure hydrocephalus (NPH), we investigated cerebrospinal fluid distribution on the high-field three-dimensional MRI. The subarachnoid spaces in secondary NPH were smaller than those in the controls, whereas those in idiopathic NPH were of similar size to the controls. In idiopathic NPH, however, the basal cistern and Sylvian fissure were enlarged in concurrence with ventricular enlargement towards the z-direction, but the convexity subarachnoid space was severely diminished. In this article, we provide evidence that the key cause of the disproportionate cerebrospinal fluid distribution in idiopathic NPH is the compensatory direct CSF communication between the inferior horn of the lateral ventricles and the ambient cistern at the choroidal fissure. In contrast, all parts of the subarachnoid spaces were equally and severely decreased in secondary NPH. Blockage of CSF drainage from the subarachnoid spaces could cause the omnidirectional ventricular enlargement in secondary NPH.
- Published
- 2016
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21. Differentiation of AB-FUBINACA positional isomers by the abundance of product ions using electron ionization-triple quadrupole mass spectrometry.
- Author
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Murakami T, Iwamuro Y, Ishimaru R, Chinaka S, Sugimura N, and Takayama N
- Subjects
- Cannabinoids chemistry, Designer Drugs chemistry, Electrons, Ions chemistry, Isomerism, Models, Chemical, Spectrometry, Mass, Electrospray Ionization, Tandem Mass Spectrometry methods, Indazoles chemistry
- Abstract
Mass spectrometric differentiation of structural isomers is important for the analysis of forensic samples. Presently, there is no mass spectrometric method for differentiating halogen positional isomers of cannabimimetic compounds. We describe here a novel and practical method for differentiating one of these compounds, N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide (AB-FUBINACA (para)), and its fluoro positional (ortho and meta) isomers in the phenyl ring by electron ionization-triple quadrupole mass spectrometry. It was found that the three isomers differed in the relative abundance of the ion at m/z 109 and 253 in the product ion spectra, while the detected product ions were identical. The logarithmic values of the abundance ratio of the ions at m/z 109 to 253 (ln(A
109 /A253 )) were in the order meta < ortho < para and increased linearly with collision energy. The differences in abundances were attributed to differences in the dissociation reactivity between the indazole moiety and the fluorobenzyl group because of the halogen-positional effect on the phenyl ring. Our methodology, which is based on the abundance of the product ions in mass spectra, should be applicable to determination of the structures of other newly encountered designer drugs. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)- Published
- 2016
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22. Characterization of the chemical diversity of glycosylated mycosporine-like amino acids in the terrestrial cyanobacterium Nostoc commune.
- Author
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Nazifi E, Wada N, Asano T, Nishiuchi T, Iwamuro Y, Chinaka S, Matsugo S, and Sakamoto T
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- Antioxidants metabolism, Chlorophyll analysis, Chlorophyll A, Chromatography, High Pressure Liquid, Cyclohexanols isolation & purification, Cyclohexanols metabolism, Cyclohexanones analysis, Electrophoresis, Capillary, Genotype, Glycine analogs & derivatives, Glycine analysis, Glycosylation, Molecular Weight, Nostoc commune genetics, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S metabolism, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Spectrophotometry, Ultraviolet, Cyclohexanols analysis, Nostoc commune metabolism
- Abstract
Mycosporine-like amino acids (MAAs) are UV-absorbing pigments, and structurally unique glycosylated MAAs are found in the terrestrial cyanobacterium Nostoc commune. In this study, we examined two genotypes of N.commune colonies with different water extract UV-absorption spectra. We found structurally distinct MAAs in each genotype. The water extract from genotype A showed a UV-absorbing spectrum with an absorption maximum at 335nm. The extract contained the following compounds: 7-O-(β-arabinopyranosyl)-porphyra-334 (478Da), pentose-bound shinorine (464Da), hexose-bound porphyra-334 (508Da) and porphyra-334 (346Da). The water extract from genotype B showed a characteristic UV-absorbing spectrum with double absorption maxima at 312 and 340nm. The extract contained hybrid MAAs (1050Da and 880Da) with two distinct chromophores of 3-aminocyclohexen-1-one and 1,3-diaminocyclohexen linked to 2-O-(β-xylopyranosyl)-β-galactopyranoside. A novel 273-Da MAA with an absorption maximum at 310nm was also identified in genotype B. The MAA consisted of a 3-aminocyclohexen-1-one linked to a γ-aminobutyric acid chain. These MAAs had potent radical scavenging activities in vitro and the results confirmed that the MAAs have multiple roles as a UV protectant and an antioxidant relevant to anhydrobiosis in N. commune. The two genotypes of N. commune exclusively produced their own characteristic glycosylated MAAs, which supports that MAA composition could be a chemotaxonomic marker for the classification of N. commune., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2015
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23. Highly Sensitive Detection of Organophosphorus Pesticides Using 5,10,15,20-Tetrakis(4-hydroxyphenyl)porphyrin.
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Murakami T, Iwamuro Y, Chinaka S, Takayama N, and Komatsu T
- Abstract
We describe a unique UV-visible absorption spectral property of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (THPP) in the presence of organophosphorus (OP) pesticides. Upon titrating each 16 among total 40 different OP pesticides, the Soret band was significantly red-shifted, and a very intense Q band appeared. They were attributed to the diprotonation of THPP. A suitable solvent for this reaction was determined to be methanol. THPP would become a potential sensor molecule used to detect OP pesticides with high sensitivity in the concentration range of 10(-6) - 10(-4) M.
- Published
- 2015
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24. [Cost Comparison of Carotid Endarterectomy versus Carotid Stenting in Japan].
- Author
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Sadamasa N, Koyanagi M, Iwamuro Y, Chin M, Handa A, and Yamagata S
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- Carotid Stenosis economics, Female, Hospitalization, Humans, Insurance, Health economics, Japan, Male, Retrospective Studies, Treatment Outcome, Cost-Benefit Analysis statistics & numerical data, Endarterectomy, Carotid economics, Stents economics
- Abstract
Carotid artery stenting (CAS) has been covered by the health insurance system in Japan since 2008. There have been few studies concerning medical costs and charges for patients who received CEA or CAS in Japan. The aim of this study was to elucidate the difference in the costs between the patients who received CEA and those who received CAS in Japan. Between 2010 and 2011, 19 patients who received CEA and 20 patients who received CAS were retrospectively reviewed. Age, sex, symptomatic/asymptomatic, emergent/scheduled, length of stay, outcome, cost for the procedure (professional fee), supply for the operation, the total medical service fee, and copayment of the patients was compared between the two treatment groups. No significant difference was detected between the two groups except for the supply of the operation and the total medical service fee (CEA:mean 1,565,580 yen vs CAS 2,758,360 yen, p=0.0001). On the other hand, no significant difference was obtained in the copayment of the patients (CEA 71,895 yen, CAS 72,458 yen). Even when limited to the scheduled cases, similar results were obtained. There is a monthly copayment limit in the health insurance system in Japan, which results in a reasonable charge for patients who received CAS, despite the fact that the rest of the fee including high costs for the supplies was paid by the company and the nation. To reduce the medical costs, Japanese have to be aware of the high costs in CAS, most of which is due to the supplies.
- Published
- 2013
25. Analysis of 11-nor-Δ9 -tetrahydrocannabinol-9-carboxylic acid and its glucuronide in urine by capillary electrophoresis/mass spectrometry.
- Author
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Iwamuro Y, Iio-Ishimaru R, Chinaka S, Takayama N, and Hayakawa K
- Subjects
- Ammonium Hydroxide, Dronabinol chemistry, Dronabinol urine, Female, Formates chemistry, Glucuronides chemistry, Humans, Hydrogen-Ion Concentration, Hydroxides chemistry, Limit of Detection, Male, Reproducibility of Results, Substance Abuse Detection methods, Dronabinol analogs & derivatives, Electrophoresis, Capillary methods, Glucuronides urine, Mass Spectrometry methods
- Abstract
Δ(9) -Tetrahydrocannabinol is the primary psychoactive component in cannabis, one of the most commonly used illicit drugs in the world. This paper describes a simple and rapid method for direct analysis of major metabolites of Δ(9) -tetrahydrocannabinol; 11-nor-Δ(9) -tetrahydrocannabinol-9-carboxylic acid and its glucuronide in urine by capillary electrophoresis/mass spectrometry. The only pretreatment needed for a urine sample was dilution with methanol containing an internal standard and centrifugation. Electrophoresis was carried out in an untreated fused-silica capillary (50 µm i.d. × 85 cm) filled with 40 m m ammonium formate (pH 6.4). An analysis could be completed within 10 min. For both compounds, the assay was linear over the range 0.1-10 µg/mL in urine with correlation coefficients (r(2) ) >0.99 and the limit of detection was 0.5 pg (10 nL injection). The detection yields and reproducibilities were determined at three different concentrations (0.1, 0.5 and 2 µg/mL in urine). The mean detection yields were 60-99%. The intra- and inter-day relative standard deviations of migration times were 0.063-0.19 and 0.18-0.36%, and those of peak areas were 4.2-18 and 5.9-25%, respectively. The proposed method successfully analyzed the urine samples of cannabis users., (Copyright © 2012 John Wiley & Sons, Ltd.)
- Published
- 2012
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26. Analysis of phosphorus-containing amino acid-type herbicides by sheathless capillary electrophoresis/electrospray ionization-mass spectrometry using a high sensitivity porous sprayer.
- Author
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Kawai M, Iwamuro Y, Iio-Ishimaru R, Chinaka S, Takayama N, and Hayakawa K
- Subjects
- Aminobutyrates analysis, Aminobutyrates chemistry, Electrophoresis, Capillary, Glycine analogs & derivatives, Glycine analysis, Glycine chemistry, Molecular Structure, Organophosphorus Compounds analysis, Organophosphorus Compounds chemistry, Porosity, Spectrometry, Mass, Electrospray Ionization, Surface Properties, Glyphosate, Amino Acids chemistry, Herbicides analysis, Herbicides chemistry, Phosphorus analysis, Phosphorus chemistry
- Abstract
We describe a new practical capillary electrophoresis/electrospray ionization-mass spectrometry (CE/ESI-MS) method for the forensic analysis of phosphorus-containing amino acid-type herbicides, glyphosate (GLYP), glufosinate (GLUF) and bialaphos (BIAL). A new sheathless interface, a high sensitivity porous sprayer (HSPS), was used in this study. The limits of detections of GLYP, GLUF and BIAL were 7.6, 0.61 and 0.57 pg, respectively. These values were 4-36 times lower than these obtained by conventional CE/ESI-MS using a sheath liquid. The developed method was successfully applied to the analysis of beverages spiked with the herbicides., (2011 © The Japan Society for Analytical Chemistry)
- Published
- 2011
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27. Intraoperative stenting for brachiocephalic and carotid artery stenosis.
- Author
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Nakahara I, Higashi T, Iwamuro Y, Watanabe Y, Nakagaki H, Takezawa M, Murata D, and Taha M
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- Aged, Aortic Dissection surgery, Aorta, Thoracic surgery, Aortic Aneurysm surgery, Constriction, Pathologic surgery, Female, Humans, Intraoperative Period, Male, Middle Aged, Brachiocephalic Trunk surgery, Carotid Stenosis surgery, Endarterectomy, Carotid methods, Stents
- Abstract
Objective: Endovascular stenting is an alternative treatment for brachiocephalic artery stenosis, replacing standard surgical approaches such as carotid endarterectomy. However, a percutaneous approach may be difficult because various conditions such as severe arteriosclerosis of iliac or femoral arteries and aortic disease. We report our experience with intraoperative stenting for these lesions, presenting indications, strategy, and results., Methods: Seven patients underwent intraoperative stent placement via an open cervical approach. The sites of lesions included 1 innominate artery, 1 common carotid artery, and 5 cervical carotid arteries. Stenting was performed with a sheath introducer placed through a surgically exposed common carotid artery via a small skin incision or common carotid artery exposed for simultaneously performed carotid endarterectomy. Distal protection was used in 6 patients with an endovascular protective balloon or external clamping with forceps., Results: Sufficient dilation of stenosis was obtained in all cases. No complications such as transient ischemic attack, cerebral infarction, and hyperperfusion were encountered. Wound hematoma was not experienced despite perioperative antiplatelet therapy and heparinization during the procedure. Angiographic follow-up over 1 year showed no restenosis in 5 available patients., Conclusion: Intraoperative stenting may be an excellent alternative for patients in whom both direct surgical approach and standard percutaneous endovascular approach are not possible.
- Published
- 2010
- Full Text
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28. Fibro-fatty volume of culprit lesions in Virtual Histology intravascular ultrasound is associated with the amount of debris during carotid artery stenting.
- Author
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Matsumoto S, Nakahara I, Higashi T, Iwamuro Y, Watanabe Y, Takezawa M, Murata D, Yokota T, Kira J, and Yamada T
- Subjects
- Aged, Carotid Arteries diagnostic imaging, Debridement, Endarterectomy, Carotid, Female, Humans, Male, Pilot Projects, Retrospective Studies, Ultrasonography, Interventional, Angioplasty, Balloon methods, Carotid Stenosis diagnostic imaging, Carotid Stenosis therapy, Stents
- Abstract
Objectives: This study aimed to evaluate the relationship between the amount of aspirated debris during distal balloon-protected carotid artery stenting (CAS) and the pre-intervention plaque composition, as assessed by Virtual Histology (VH) intravascular ultrasound (IVUS)., Methods: The study subjects were 25 consecutive patients (mean age, 73.0 +/- 5.2 years; 20 males and 5 females) who underwent CAS under distal balloon protection. The average rate of carotid stenosis was 74.6 +/- 12.9% by North American Symptomatic Carotid Endarterectomy Trial criteria. We assessed culprit plaque components by VH-IVUS before CAS. Aspirated debris was filtered, stained with HE and mounted onto glass slides. The quantity of debris was evaluated by measuring its surface area. We evaluated the relationship between the quantity of aspirated debris and VH-IVUS measurements before CAS., Results: The amount of debris during CAS was positively correlated with the total plaque volume in grayscale IVUS (Rs = 0.480, p = 0.015) and fibro-fatty volumes over the entire lesion length in VH-IVUS (Rs = 0.561, p = 0.001)., Conclusions: Culprit lesions with large plaque volumes, especially larger fibro-fatty volumes, as imaged by VH-IVUS, are associated with large amounts of debris during balloon-protected CAS., (Copyright 2010 S. Karger AG, Basel.)
- Published
- 2010
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29. Interventional neuroradiological techniques for the treatment of aneurysms of the supra-aortic extracranial arteries.
- Author
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Taha MM, Nakahara I, Higashi T, Iwamuro Y, Watanabe Y, and Taki W
- Subjects
- Aged, Aneurysm surgery, Angiography instrumentation, Arteries pathology, Brachiocephalic Trunk diagnostic imaging, Brachiocephalic Trunk surgery, Carotid Artery, Common diagnostic imaging, Carotid Artery, Common surgery, Carotid Artery, Internal diagnostic imaging, Carotid Artery, Internal surgery, Embolization, Therapeutic methods, Follow-Up Studies, Humans, Male, Middle Aged, Neuroradiography instrumentation, Stents, Subclavian Artery diagnostic imaging, Subclavian Artery surgery, Treatment Outcome, Aneurysm diagnostic imaging, Angiography methods, Arteries surgery, Neuroradiography methods, Radiography, Interventional methods
- Abstract
Aneurysms in the supra-aortic extracranial arteries are rare in neurovascular pathology. Conventional surgery is effective but technically demanding and successful endovascular repair is reported. We treated 5 patients with supra-aortic extracranial artery aneurysms at our hospital (mean age 53.8 years). There were 2 aneurysms of the common carotid artery, 1 of the extracranial internal carotid artery, 1 of the subclavian artery, and 1 located at the innominate artery. Four patients were symptomatic. The lesion was the result of trauma in 3 patients. The procedure was conducted using bare stent placement and coil embolization of the aneurysm in 2 patients, covered stent in 2 patients, and bare stent only in 1 patient. No periprocedural complications occurred. Follow-up angiography revealed asymptomatic stent thrombosis in a patient treated using a covered stent, but the remaining 4 patients showed successful treatment of the aneurysms with the parent arteries remaining patent. Follow-up clinical assessment ranged between 30 and 81 months. The patient with stent thrombosis died of unrelated pathology; the remaining patients did not experience aneurysm recurrence, hemorrhage, or distal thromboembolism.
- Published
- 2010
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30. Angioplasty and stent deployment in acute sinus thrombosis following endovascular treatment of dural arteriovenous fistulae.
- Author
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Hirata E, Higashi T, Iwamuro Y, Watanabe Y, Ando M, Arakawa Y, and Nakahara I
- Subjects
- Aged, Central Nervous System Vascular Malformations surgery, Humans, Male, Sinus Thrombosis, Intracranial diagnostic imaging, Angioplasty, Balloon, Cerebral Angiography methods, Sinus Thrombosis, Intracranial therapy, Stents, Vascular Surgical Procedures adverse effects
- Abstract
We report on the successful treatment of acute sinus thrombosis associated with endovascular treatment of intracranial dural arteriovenous fistulae (DAVF) by sinus angioplasty with stent deployment. A 76-year-old man presented with intracerebral hemorrhage, Cognard type IIa+b DAVF of the left sigmoid sinus, and type IIa DAVF of the torcular herophili. During transvenous sinus embolization, acute thrombosis of the stenotic lesion in the left transverse sinus occurred. The thrombosis caused isolated sinus and cortical venous reflux (CVR). The patient was treated by stent-supported sinus angioplasty, which led to an immediate improvement of the sinus thrombosis and associated CVR.
- Published
- 2009
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31. [Spontaneous improvement of idiopathic intracranial carotid artery dissection: a case report].
- Author
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Iwamuro Y, Nakahara I, Higashi T, Watanabe Y, Matsumoto S, Takahashi K, Kikuchi T, Ando M, and Takezawa M
- Subjects
- Aged, Carotid Artery, Internal, Dissection physiopathology, Humans, Imaging, Three-Dimensional, Male, Remission, Spontaneous, Tomography, X-Ray Computed, Carotid Artery, Internal, Dissection diagnosis
- Abstract
We report a rare case of spontaneous intracranial carotid artery dissection presenting with multiple infarctions. A 65-year-old man became aware of transient visual disturbance in the right eye and headache. Magnetic resonance imaging (MRI) at a local neurosurgical clinic depicted fresh multiple infarctions of the right cerebral hemisphere along with severe right carotid artery stenosis and delayed cerebral blood flow on the right side. The patient was transferred to our hospital. Three-dimensional computed tomography (3D-CT) showed an intimal flap in the righ petrous internal carotid artery and we diagnosed spontaneous intracranial carotid artery dissection of the petrous portion. We started conservative therapy including anti-coagulant and antiplatelet drug and blood pressure control. Two weeks after admission, angiography, 3D-CT, MR angiography demonstrated that the dissection had improved and the patient was discharged without neurological deficit. In this case, 3D-CT was effective for the diagnosis of intracranial carotid artery dissection. We report this rare case along with a literature review of the clinical profile and related neuroimaging findings.
- Published
- 2008
32. Structure-activity relationship study of novel NR2B-selective antagonists with arylamides to avoid reactive metabolites formation.
- Author
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Kawai M, Sakurada I, Morita A, Iwamuro Y, Ando K, Omura H, Sakakibara S, Masuda T, Koike H, Honma T, Hattori K, Takashima T, Mizuno K, Mizutani M, and Kawamura M
- Subjects
- Amides chemical synthesis, Amides metabolism, Animals, Cell Line, Glutathione chemistry, Humans, Mice, Molecular Structure, Neurons drug effects, Neurons metabolism, Phenol chemistry, Phenols chemistry, Structure-Activity Relationship, Amides chemistry, Amides pharmacology, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors, Receptors, N-Methyl-D-Aspartate metabolism
- Abstract
A novel potent NMDA-NR2B selective antagonist without the reactive metabolites formation issue was identified. Through this study, a close correlation between reactive metabolites formation and calculated HOMO energies of parent compounds was found.
- Published
- 2007
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33. Different modalities of treatment of intracranial mycotic aneurysms: Report of 4 cases.
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Nakahara I, Taha MM, Higashi T, Iwamuro Y, Iwaasa M, Watanabe Y, Tsunetoshi K, and Munemitsu T
- Subjects
- Adult, Brain blood supply, Brain diagnostic imaging, Brain pathology, Cerebral Angiography, Cerebral Arteries diagnostic imaging, Embolization, Therapeutic instrumentation, Embolization, Therapeutic methods, Embolization, Therapeutic standards, Endocarditis, Bacterial complications, Endocarditis, Bacterial microbiology, Endocarditis, Bacterial physiopathology, Hematoma, Subdural, Intracranial etiology, Hematoma, Subdural, Intracranial physiopathology, Hematoma, Subdural, Intracranial surgery, Humans, Intracranial Aneurysm physiopathology, Intracranial Hypertension etiology, Intracranial Hypertension physiopathology, Intracranial Hypertension surgery, Male, Middle Aged, Neurosurgical Procedures instrumentation, Neurosurgical Procedures methods, Retrospective Studies, Surgical Instruments, Tomography, X-Ray Computed, Treatment Outcome, Vascular Surgical Procedures instrumentation, Vascular Surgical Procedures methods, Vascular Surgical Procedures standards, Cerebral Arteries microbiology, Cerebral Arteries pathology, Intracranial Aneurysm microbiology, Intracranial Aneurysm therapy
- Abstract
Background: Intracranial mycotic aneurysms, although rare neurovascular pathology, represented a neurosurgical challenge that required careful stepwise decision making. Different approaches for their management were used. We present our experience with 4 patients treated in terms of indications and efficacy of different treatment modalities., Methods: Four patients with infective endocarditis and 5 intracranial mycotic aneurysms were treated during the last 5 years. All of the patients were men; their ages ranged between 29 and 62 years (mean, 47.3 years). Distal MCA was the commonest site (3 patients) of aneurysm, 1 was located at the distal PCA, whereas the remaining aneurysm was at the distal ACA. Angiographic studies were done in 2 patients because of neurologic signs and for screening in 2 patients with documented endocarditis., Results: One patient was treated conservatively because of his moribund general condition; 1 patient was treated with direct surgical clipping; 1 patient was treated with surgical trapping and resection of the aneurysm without revascularization; and the remaining patient, harboring 2 distal mycotic aneurysms, was treated with selective embolization for his PCA aneurysm and endovascular trapping for the distal ACA aneurysm. Follow-up angiographic results showed stable occlusion of the aneurysms. No periprocedural technical complications were reported, and none of the patients, including the patient with medical treatment only, has ever experienced new neurologic events after definitive treatment., Conclusions: Prolonged courses of antibiotics are recommended for all patients with mycotic aneurysms. Selective endovascular embolization or trapping with soft and ultrasoft electrolytically detachable coils seems to be an effective technique that should be considered for treatment of dynamic unruptured mycotic aneurysms, with conventional surgical repair restricted for ruptured aneurysms with associated hematoma and high intracranial pressure.
- Published
- 2006
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34. Endovascular embolization vs surgical clipping in treatment of cerebral aneurysms: morbidity and mortality with short-term outcome.
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Taha MM, Nakahara I, Higashi T, Iwamuro Y, Iwaasa M, Watanabe Y, Tsunetoshi K, and Munemitsu T
- Subjects
- Adult, Aged, Aged, 80 and over, Aneurysm, Ruptured mortality, Aneurysm, Ruptured physiopathology, Aneurysm, Ruptured therapy, Causality, Cerebral Arteries pathology, Cerebral Arteries physiopathology, Embolization, Therapeutic instrumentation, Embolization, Therapeutic methods, Female, Humans, Hydrocephalus etiology, Hydrocephalus mortality, Hydrocephalus physiopathology, Intracranial Aneurysm physiopathology, Intracranial Hypertension complications, Intracranial Hypertension physiopathology, Male, Middle Aged, Mortality trends, Patient Selection, Postoperative Complications etiology, Postoperative Complications mortality, Postoperative Complications physiopathology, Retrospective Studies, Subarachnoid Hemorrhage mortality, Subarachnoid Hemorrhage physiopathology, Subarachnoid Hemorrhage therapy, Surgical Instruments standards, Surgical Instruments statistics & numerical data, Treatment Outcome, Vascular Surgical Procedures instrumentation, Vascular Surgical Procedures methods, Vasospasm, Intracranial etiology, Vasospasm, Intracranial mortality, Vasospasm, Intracranial physiopathology, Cerebral Arteries surgery, Embolization, Therapeutic mortality, Intracranial Aneurysm mortality, Intracranial Aneurysm therapy, Surgical Instruments adverse effects, Vascular Surgical Procedures mortality
- Abstract
Background: Endovascular embolization of cerebral aneurysms has evolved rapidly worldwide within the last years, and has gained more popularity at the expense of surgical clipping; however, both regimens have inherent risks. This study was undertaken to asses the cerebral complications associated with both modalities of cerebral aneurysm treatment., Methods: We retrospectively reviewed the charts, operative and embolization reports, and imaging of patients who underwent surgical clipping or embolization for cerebral aneurysms at our institution between October 2001 and October 2004. Patients were divided into 2 groups: group A, patients who had confirmed subarachnoid hemorrhage; group B, patients with unruptured cerebral aneurysms. Patients belonging to group A were evaluated according to the Hunt and Hess scale with their computed tomography scan evaluated according to Fisher scale. Short-term outcome was measured with Glasgow Outcome Scale for both groups., Results: One hundred thirty-three patients with 168 aneurysms were treated; 95 (71.4%) were women and 38 (28.6%) men; mean age was 60.28 years. Hypertension (29.6%) was the most commonly encountered risk factor; average size of aneurysms treated was 7.21 mm; 53 patients belonged to group A. Seven patients were Hunt and Hess grade I, 23 grade II, 11 grade III, 7 grade IV, and 5 grade V. Eighty patients belonged to group B; for both groups, the periprocedural technical complication rate associated with coiling was 8.4% vs 19.35% with clipping. Follow-up angiographic results were better with clipping, as total aneurysm occlusion was 81.4% vs 57.5% with coiling. In group A, the incidence of angiographic vasospasm was 17.4% vs 45.4% with coiling vs clipping, whereas the incidence of shunt-dependant hydrocephalus was comparable with embolization and clipping. In group A, excellent outcome was achieved in 62% vs 44% (endovascular vs surgical) of subgroups, whereas in group B, it was 93% vs 81%, respectively., Conclusion: With rapidly evolving technology of endovascular embolization, accumulated experience, and good selection of patients with optimum angioanatomical criteria and endovascular accessibility, our results of morbidity and mortality associated with both modalities of cerebral aneurysm treatment with short-term outcome show that endovascular embolization of cerebral aneurysms is a safe alternative to surgical clipping in the treatment of both ruptured and unruptured cerebral aneurysms; however, long-term outcome needs to be evaluated.
- Published
- 2006
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35. Tentorial dural arteriovenous fistula presenting symptoms due to mass effect on the dilated draining vein: case report.
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Iwamuro Y, Nakahara I, Higashi T, Iwaasa M, Watanabe Y, Hirata E, Tsunetoshi K, and Taha M
- Subjects
- Aged, Arteriovenous Fistula complications, Cerebral Angiography, Constriction, Pathologic etiology, Embolization, Therapeutic, Female, Humans, Intracranial Arteriovenous Malformations complications, Magnetic Resonance Angiography, Magnetic Resonance Imaging, Mesencephalon blood supply, Neurosurgical Procedures methods, Tomography, Emission-Computed, Single-Photon, Tomography, X-Ray Computed, Vascular Surgical Procedures methods, Arteriovenous Fistula diagnosis, Arteriovenous Fistula surgery, Cerebral Veins pathology, Dura Mater blood supply, Intracranial Arteriovenous Malformations diagnosis, Intracranial Arteriovenous Malformations surgery, Mesencephalon pathology
- Abstract
Background: Tentorial dural arteriovenous fistula (AVF) presented symptoms due to mass effect on the dilated draining vein. We report a patient presenting left hemisensory disturbance because of compression of the midbrain by a dilated draining vein of the AVF. The AVF has disappeared completely by drainer clipping after feeder embolization., Case Description: A 66-year-old woman presented with left hemisensory disturbance due to compression of the midbrain by a dilated draining vein with tentorial dural AVF. On admission, she complained of left hemisensory disturbance. Enhanced computed tomography (CT), magnetic resonance imaging, and magnetic resonance angiogram revealed the midbrain compressed by a mass lesion, which was a draining vein with AVF fed by numerous feeding arteries neighboring the right tentorial edge. The single-photon emission CT (SPECT) did not depict any laterality., Conclusion: This is a rare case of a tentorial dural AVF which caused left hemisensory disturbance not by venous congestion, but by a compression of the midbrain by the dilated draining vein, because SPECT showed no laterality. In this case, magnetic resonance angiogram, 3-dimensional CT angiography, and SPECT were useful in the diagnosis and planning the strategy for treatment.
- Published
- 2006
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36. Chondrosarcoma of the clivus presenting with intratumoral hemorrhage: case report.
- Author
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Harada K, Nakahara I, Hayashi J, Tanaka M, Akiyama Y, Iwamuro Y, and Fujimoto M
- Subjects
- Adult, Chondrosarcoma complications, Chondrosarcoma surgery, Chordoma pathology, Cranial Fossa, Posterior surgery, Diagnosis, Differential, Headache etiology, Humans, Intracranial Hemorrhages surgery, Male, Neoplasm, Residual surgery, Radiosurgery, Skull Base Neoplasms complications, Skull Base Neoplasms surgery, Tomography, X-Ray Computed, Chondrosarcoma pathology, Cranial Fossa, Posterior pathology, Intracranial Hemorrhages etiology, Skull Base Neoplasms pathology
- Published
- 2006
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37. Urgent endovascular stent-graft placement for a ruptured traumatic pseudoaneurysm of the extracranial carotid artery.
- Author
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Akiyama Y, Nakahara I, Tanaka M, Iwamuro Y, Hayashi J, Harada K, and Fujimoto M
- Subjects
- Accidents, Traffic, Acute Disease, Aneurysm, False diagnostic imaging, Aneurysm, False etiology, Aneurysm, Ruptured diagnostic imaging, Aneurysm, Ruptured etiology, Angiography, Carotid Artery Injuries diagnostic imaging, Carotid Artery Injuries etiology, Dyspnea etiology, Emergencies, Facial Injuries complications, Hematoma diagnostic imaging, Hematoma etiology, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Motorcycles, Pain etiology, Platelet Aggregation Inhibitors therapeutic use, Polytetrafluoroethylene, Tomography, X-Ray Computed, Treatment Outcome, Unconsciousness etiology, Wounds, Nonpenetrating complications, Aneurysm, False surgery, Aneurysm, Ruptured surgery, Blood Vessel Prosthesis Implantation instrumentation, Carotid Artery Injuries surgery, Hematoma surgery, Stents
- Published
- 2005
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38. Occlusion of the vertebral artery secondary to dissection of the subclavian artery--case report.
- Author
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Iwamuro Y, Nakahara I, Tanaka M, Higashi T, Watanabe Y, Harada K, Fujimoto M, and Oku T
- Subjects
- Adult, Aortic Dissection diagnosis, Aortic Dissection therapy, Arterial Occlusive Diseases diagnosis, Arterial Occlusive Diseases therapy, Cerebral Infarction diagnosis, Cerebral Infarction therapy, Humans, Male, Aortic Dissection complications, Arterial Occlusive Diseases complications, Cerebral Infarction etiology, Subclavian Artery, Vertebral Artery
- Abstract
A 34-year-old man presented with occlusion of the left vertebral artery (VA) secondary to dissection of the left subclavian artery manifesting as vertigo, nausea, vomiting, and neck pain. On admission, he was alert with left limb and truncal ataxia. Magnetic resonance (MR) imaging and MR angiography showed left cerebellar infarction and occlusion of the left VA. Conventional angiography and three-dimensional computed tomography (3D-CT) angiography showed stenosis with thrombosed pseudo-lumen of the left subclavian artery, and occlusion of the left VA. Presumably the idiopathic dissection of the left subclavian artery had reached the orifice of the left VA, and an embolism from the dissection had caused occlusion of the VA, leading to cerebellar infarction. After one month, he was discharged without severe neurological deficits. Idiopathic dissection of the subclavian artery is very rare. 3D-CT angiography is very useful for the diagnosis of arterial dissection.
- Published
- 2005
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39. [Multiple intracranial aneurysms and vascular abnormalities associated with neurofibromatosis type 1: a case report].
- Author
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Fujimoto M, Nakahara I, Tanaka M, Iwamuro Y, Watanabe Y, and Harada K
- Subjects
- Cerebral Angiography, Female, Humans, Intracranial Aneurysm diagnostic imaging, Middle Aged, Middle Cerebral Artery abnormalities, Subarachnoid Hemorrhage etiology, Tomography, X-Ray Computed, Cerebral Arteries abnormalities, Intracranial Aneurysm etiology, Neurofibromatosis 1 complications
- Abstract
We present an unusual case of multiple intracranial aneurysms, persistent primitive trigeminal artery (PPTA), and fenestration of the middle cerebral artery (MCA), associated with type 1 neurofibromatosis (NF 1). The patient was a 55-year-old woman in a state of semicoma. We observed widespread neurofibromas and café au lait spots on her trunk and limbs. Computed tomography (CT) scan revealed diffuse subarachnoid hemorrhage and right frontal intracerebral hemorrhage (WFNS grade IV, Fisher's classification group 4). Cerebral angiography showed two intracranial aneurysms at the anterior communicating artery, an aneurysm at the cavernous portion of the right carotid artery, a PPTA, and MCA fenestration. The patient remained in an apallic state, even after successful clipping of the anterior communicating artery aneurysms.
- Published
- 2004
40. [Therapeutic strategy and outcome of stenting for subclavian and innominate artery occlusive disease].
- Author
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Harada K, Nakahara I, Tanaka M, Iwamuro Y, Watanabe Y, and Fujimoto M
- Subjects
- Aged, Embolism prevention & control, Female, Humans, Male, Middle Aged, Treatment Outcome, Vertebral Artery, Arterial Occlusive Diseases therapy, Brachiocephalic Trunk, Catheterization methods, Stents, Subclavian Artery
- Abstract
We performed stenting for the subclavian artery (SA) and innominate artery occlusive disease in 14 patients between April, 2000 and March, 2003. In 13 of 14 patients, good dilatation was obtained with stenting. In one patient with left SA occlusion, true lumen could not be detained from either proximal or distal sides of the occluded lesion, so stent deployment was not performed. From June, 2002, we performed stenting using combined femoral and brachial approaches in 6 of 8 patients. In patients in whom occlusive lesion existed in the proximal portion of the SA, it was useful strategy to create a "pull-through" system to stabilize the guiding catheter position in the aorta or the proximal portion of the SA, and to protect the vertebral artery (VA) with a balloon catheter. Post-operative morbidity was 0%. Restenosis was manifested in one patient (8%) two years after stent placement, and in-stent PTA was carried out. In stenting for the subclavian and innominate arteries, the pull-through system is considered useful for stabilization of the guiding catheter, and protection of the VA for prevention of distal embolism to the VA.
- Published
- 2004
41. [Comparison of the findings of multislice CT and angiography after stenting for supraaortic arteries].
- Author
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Harada K, Nakahara I, Tanaka M, Iwamuro Y, Watanabe Y, and Fujimoto M
- Subjects
- Carotid Artery Thrombosis diagnostic imaging, Carotid Artery Thrombosis etiology, Graft Occlusion, Vascular diagnostic imaging, Graft Occlusion, Vascular etiology, Humans, Hyperplasia diagnostic imaging, Hyperplasia etiology, Intracranial Thrombosis diagnostic imaging, Intracranial Thrombosis etiology, Tunica Intima pathology, Angiography, Carotid Arteries diagnostic imaging, Cerebral Arteries diagnostic imaging, Stents adverse effects, Tomography, Spiral Computed
- Abstract
We compared the findings of multislice computed tomography (MSCT) with angiography after stenting for supraaortic arteries. Twelve cases that underwent both MSCT and angiography were evaluated. In 4 cases, stenotic findings were shown by neither MSCT nor angiography. Lumen diameters measured by MSCT tended to be shorter than those measured by angiography. In-stent stenosis evaluated by MSCT was found in 6 cases, and all of them revealed low density areas in the inner stent lumen. In 4 of them, intimal hyperplasia was indicated by angiography, but in 2 of them, unexpectedly, no stenotic findings were found by angiography. In one case, using MSCT the part two stents partially lying over one another revealed severe artifact in the inner stent lumen, but no stenosis was found by angiography. In 2 cases, unevenly spread extra-stent space was found, but that was not revealed by angiography. We conclude that MSCT is useful to evaluate lumen diameter, in-stent intimal hyperplasia, in-stent thrombus, and extra-stent space.
- Published
- 2004
42. Ca2+ entry channels involved in contractions of rat aorta induced by endothelin-1, noradrenaline, and vasopressin.
- Author
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Furutani H, Zhang XF, Iwamuro Y, Lee K, Okamoto Y, Takikawa O, Fukao M, Masaki T, and Miwa S
- Subjects
- Animals, Calcium metabolism, Calcium pharmacology, Cells, Cultured, Drug Interactions, Male, Muscle, Smooth, Vascular metabolism, Rats, Rats, Wistar, Calcium Channels drug effects, Endothelin-1 pharmacology, Muscle, Smooth, Vascular drug effects, Norepinephrine pharmacology, Vasoconstriction drug effects, Vasodilator Agents pharmacology, Vasopressins pharmacology
- Abstract
Endothelin-1 (ET-1) has been shown to activate three types of Ca2+ channel, namely two Ca2+-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and a store-operated Ca2+ channel (SOCC), and that these channels can be discriminated by Ca2+ channel blockers such as LOE 908 (a blocker of NSCC-1 and NSCC-2) and SK&F 96365 (a blocker of NSCC-2 and SOCC). This study pharmacologically compared Ca2+ entry channels involved in contractions of rat thoracic aorta without endothelium induced by ET-1, noradrenaline (NA), or arginine-vasopressin (AVP). These agonists-induced contractions of aortic rings without endothelium and increases in the intracellular free Ca2+ concentration ([Ca2+]i) of cultured aortic smooth muscle cells were abolished by removal of extracellular Ca2+. A blocker of L-type voltage-operated Ca2+ channel (VOCC), nifedipine had no effect on the responses to ET-1, but it suppressed the responses to NA and AVP to 70% and 65% of control responses, respectively. LOE 908 partially suppressed the nifedipine-resistant responses to ET-1 and AVP, but not those to NA. SK&F 96365 also partially suppressed the nifedipine-resistant responses to ET-1 and AVP, whereas it abolished the responses to NA. LOE 908 in combination with SK&F 96365 abolished the nifedipine-resistant responses to either of the agonists. These results show that the contraction of rat aorta involves different Ca2+ entry channel depending on agonists: (a) NSCC-1, NSCC-2, and SOCC for ET-1; (b) VOCC and SOCC for NA; and (c) VOCC, NSCC-1, NSCC-2, and SOCC for AVP.
- Published
- 2002
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43. [A case report of a scalp dermoid cyst containing watery-clear fluid].
- Author
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Iwamuro Y, Shirahata M, Jito J, Tokime T, Hosotani K, and Tokuriku Y
- Subjects
- Dermoid Cyst pathology, Dermoid Cyst surgery, Female, Head and Neck Neoplasms pathology, Head and Neck Neoplasms surgery, Humans, Infant, Skin Neoplasms pathology, Skin Neoplasms surgery, Dermoid Cyst diagnosis, Head and Neck Neoplasms diagnosis, Scalp, Skin Neoplasms diagnosis
- Abstract
We report a case of a 7-month-old female with a dermoid cyst on the anterior fontanelle. She was born with a vacuum extractor. Two weeks later, her scalp on the anterior fontanelle bulged. A doctor was consulted when she was 3 months old, because the tumor was enlarging. Magnetic resonance image (MRI) showed a cystic mass on the anterior fontanelle. She was brought to our institute. At the first medical examination, she was alert and had no neurological deficit. The tumor was suspected to be a sinus pericranii or a pseudo meningocele. She was observed as an out patient, but the tumoral size become more enlarged. When she was seven months old, we punctured the cystic tumor and the tumor collapsed. But, two weeks later, it enlarged again. The cystic fluid was watery clear and the composition differed from cerebrospinal fluid (CSF). The tumor was resected totally. The histological examination revealed a dermoid cyst which involved ducts of the eccrine glands and folliculi pili. The cystic fluid was thought to be secreted from the eccrine glands.
- Published
- 2002
44. Intrathecal and intraperitoneal germinomas occurring 20 years after total removal of a pineal teratoma. Case report.
- Author
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Iwamuro Y, Seo S, Hirose Y, Jito J, Shirahata M, Tokime T, Hosotani K, and Tokuriki Y
- Subjects
- Adolescent, Adult, Child, Humans, Male, Time Factors, Ventriculoperitoneal Shunt, Abdominal Neoplasms pathology, Abdominal Neoplasms therapy, Brain Neoplasms pathology, Brain Neoplasms therapy, Germinoma pathology, Germinoma therapy, Neoplasms, Second Primary pathology, Neoplasms, Second Primary therapy, Pineal Gland pathology, Teratoma pathology, Teratoma therapy
- Abstract
In 1980, a 10-year-old boy was admitted to the authors' hospital with consciousness disturbance and vomiting. Computerized tomography (CT) scans revealed a pineal mass lesion and hydrocephalus. The tumor was totally removed and a ventriculoperitoneal (VP) shunt was inserted. Histological investigation of a surgical specimen revealed that it was a teratoma. Five years later, the patient was readmitted to the same institution with polyuria. Magnetic resonance (MR) imaging revealed a mass lesion in the suprasellar region. The patient received systemic chemotherapy, and the tumor disappeared; however, 2 years after the chemotherapy, MR imaging demonstrated a right lateral ventricular mass. The tumor was totally resected, and histopathological investigation revealed a teratocarcinoma. Three years after the chemotherapy, CT scanning revealed suprasellar and right lateral ventricular tumor recurrences, for which the patient received irradiation and chemotherapy. The tumors disappeared and the patient achieved complete remission that lasted longer than 10 years. On January 25, 2000, however, he noticed hip pain. Lumbar MR imaging demonstrated a spinal tumor below L-4 and also an abdominal tumor. The abdominal tumor was totally removed, and the histological findings identified it as a germinoma. The patient received systemic chemotherapy and the tumor disappeared completely. The authors believe that the suprasellar tumor was a metachronous germinoma and that it had metastasized through the intrathecal route and the VP shunt.
- Published
- 2002
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45. Transient ischemic attack due to dissection of the middle cerebral artery--case report.
- Author
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Iwamuro Y, Jito J, Shirahata M, Tokime T, Hosotani K, and Tokuriki Y
- Subjects
- Aortic Dissection diagnosis, Diagnosis, Differential, Follow-Up Studies, Humans, Intracranial Aneurysm diagnosis, Ischemic Attack, Transient diagnosis, Magnetic Resonance Angiography, Male, Middle Aged, Aortic Dissection complications, Intracranial Aneurysm complications, Ischemic Attack, Transient etiology, Middle Cerebral Artery pathology
- Abstract
A 57-year-old man presented with a transient ischemic attack due to dissection of the middle cerebral artery. He suffered total aphasia and clouding of consciousness for several minutes. On admission, he was alert without neurological deficit. Magnetic resonance (MR) angiography and conventional angiography depicted irregularity and double lumen of the left middle cerebral artery. The diagnosis was dissection of the middle cerebral artery. After 1 month, he left our institute with no neurological deficit. Transient ischemic attack associated with dissection of an intracranial artery is unusual. The source images of MR angiography are useful for the essential follow up of dissection.
- Published
- 2001
- Full Text
- View/download PDF
46. Failure of endothelin-1 to activate store-operated Ca2+ channels by lack of mobilization from intracellular Ca2+ stores in cultured bovine adrenal chromaffin cells.
- Author
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Lee K, Morita H, Iwamuro Y, Zhang XF, Okamoto Y, and Miwa S
- Subjects
- Acetamides pharmacology, Animals, Calcium Channel Blockers pharmacology, Cattle, Cells, Cultured, Enzyme Inhibitors pharmacology, Ion Channels drug effects, Isoquinolines pharmacology, Thapsigargin pharmacology, Calcium metabolism, Calcium Channels, L-Type metabolism, Chromaffin Cells metabolism, Endothelin-1 physiology, Imidazoles pharmacology
- Abstract
We have recently shown that in addition to L-type voltage-operated Ca2+ channel (VOC), endothelin-1 (ET-1) stimulation opens two types of Ca2+-permeable nonselective cation channels [designated nonselective cation channel-1 (NSCC-1) and NSCC-2]. However, in this Ca2+ entry, the involvement of store-operated Ca2+ channel (SOCC), which is suggested to exist in chromaffin cells, was unclear. Those NSCCs as well as SOCC can be pharmacologically discriminated using Ca2+ channel blockers such as SK&F 96365 and LOE 908. To clarify whether SOCC should actually exist and play a role in Ca2+ entry in chromaffin cells stimulated with ET-1, we examined the effects of removal of extracellular Ca2+, thapsigargin (TG, an inhibitor of endoplasmic reticulum Ca2+-ATPase), LOE 908 and SK&F 96365 on cytosolic free Ca2+ concentrations ([Ca2+]i) in cultured bovine adrenal chromaffin cells. After the cells were exposed to Ca2+-free medium followed by exposure to TG to deplete Ca2+ from the intracellular Ca2+ store, restoration of extracellular Ca2+ caused a gradual increase in [Ca2+]i (to about 200% of control). The increase was unaffected by LOE 908, but completely abolished by SK&F 96365. In the Ca2+-free medium, no increase in [Ca2+]i by ET-1 was observed, but the subsequent restoration of extracellular Ca2+ induced a rapid increase in [Ca2+]i (to the same level of [Ca2+]i as that evoked by ET-1 in the normal medium (1.0 mM Ca2+)). Since SK&F 96365 is also a blocker of SOCC, these results indicate that in bovine adrenal chromaffin cells, Ca2+ entry through SOCC (Ca2+ influx through the capacitative Ca2+ entry system) occurs but is comparably weak, and that it virtually does not work on the stimulation of ET-1.
- Published
- 2001
- Full Text
- View/download PDF
47. Pharmacological properties of calcium entry channels in A7r5 cells activated by endothelin-1.
- Author
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Miwa S, Iwamuro Y, Zhang XF, Okamoto Y, Furutani H, and Masaki T
- Subjects
- Acetamides pharmacology, Calcium metabolism, Calcium Channels physiology, Cell Line, Imidazoles pharmacology, Isoquinolines pharmacology, Calcium Channels drug effects, Endothelin-1 pharmacology
- Abstract
Using whole-cell recordings of patch-clamp and monitoring of the intracellular free calcium (Ca2+) concentration ([Ca2+]i), we characterized Ca2+ entry channels in A7r5 cells activated by endothelin-1 (ET-1). ET-1 activates three types of voltage-independent Ca2+ entry channels: two types of Ca2+-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and store-operated Ca2+ channel (SOCC). Furthermore, it was found that these channels can be discriminated pharmacologically using Ca2+ channel blockers such as 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl)-1-H-imidazoe l hydrochloride (SK&F 96365) and (RS)-(3,4-dihydro-6,7-dimethoxyisoquinoline-1-gamma l)-2-phenyl-N,N-di-[2-(2,3,4-trimethoxyphenyl)ethoxyl]acetamide (LOE 908). NSCC-1 is resistant to SK&F 96365 but sensitive to LOE 908, whereas NSCC-2 is sensitive to both drugs: SOCC is sensitive to SK&F 96365 but resistant to LOE 908. Using these channel blockers, we analyzed the Ca2+ entry channels involved in the ET-1-induced increase in [Ca2+]i of the cells. The increase induced by lower concentrations of ET-1 (< or = 0.1 nM) was unaffected by SK&F 96365 but it was abolished by LOE 908. In contrast, the increase caused by higher concentrations of ET-1 (> or = 1 nM) was suppressed by SK&F 96365 or LOE 908 to about 35% of controls, and abolished by combined treatment with SK&F 96365 and LOE 908. These results show that the increase in [Ca2+]i resulting from lower concentrations of ET-1 (< or = 0.1 nM) involves Ca2+ entry through only NSCC-1, whereas that resulting from higher concentrations of ET-1 involves Ca2+ entry through NSCC-1, NSCC-2 and SOCC, contributing 35%, 30% and 30%, respectively, to total Ca2+ entry.
- Published
- 2000
- Full Text
- View/download PDF
48. Endothelin-1-induced contraction of rat thoracic aorta depends on calcium entry through three types of calcium channel.
- Author
-
Zhang XF, Iwamuro Y, Okamoto Y, Kawanabe Y, Masaki T, and Miwa S
- Subjects
- Acetamides pharmacology, Animals, Aorta, Thoracic physiology, Imidazoles pharmacology, In Vitro Techniques, Isoquinolines pharmacology, Rats, Aorta, Thoracic drug effects, Calcium metabolism, Calcium Channels physiology, Endothelin-1 pharmacology, Vasoconstriction drug effects
- Abstract
We have recently shown that endothelin-1 (ET-1) activates two types of Ca2+-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and store-operated Ca2+ channel (SOCC). These channels can be pharmacologically discriminated using 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1-H-imidazoe l hydrochloride (SK&F 96365) (a blocker of NSCC-2 and SOCC) and (RS)-(3,4-dihydro-6,7-dimethoxyisoquinoline-1-gamma l)-2-phenyl-N,N-di-[2-(2,3,4-trimethoxyphenyl)ethyl]acetamide (LOE 908) (a blocker of NSCC-1 and NSCC-2). For our study we characterized Ca2+ channels involved in ET-1-induced contractions and increases in the intracellular free Ca2+ concentration ([Ca2+]i) using these blockers. Our results show that the response to lower concentrations of ET-1 involves only one Ca2+ channel which is sensitive to SK&F 96365 and LOE 908 (NSCC-2). In contrast, the response to higher concentrations of ET-1 involves two types of Ca2+ channel in addition to NSCC-2: one is sensitive to SK&F 96365 but resistant to LOE 908 (SOCC), and the other is resistant to SK&F 96365 but sensitive to LOE 908 (NSCC-1). Furthermore, the percentage contribution of Ca2+ entry through NSCC-1, NSCC-2 and SOCC is calculated to be 10%, 50-60% and 30-40%, respectively.
- Published
- 2000
- Full Text
- View/download PDF
49. [Characterization of voltage-independent Ca2+ channels activated by endothelin-1].
- Author
-
Iwamuro Y, Zhang XF, Okamoto Y, Miwa S, and Masaki T
- Subjects
- Acetamides pharmacology, Animals, Calcium Channel Blockers pharmacology, Cell Line, Imidazoles pharmacology, Isoquinolines pharmacology, Patch-Clamp Techniques, Rats, Calcium Channels drug effects, Calcium Channels physiology, Endothelin-1 physiology, Muscle, Smooth, Vascular physiology
- Abstract
To clarify Ca2+ entry channels involved in the endothelin-1 (ET-1)-induced increase in the intracellular concentration ([Ca2+]i), we performed whole-cell recordings of patch-clamp techniques and monitoring of [Ca2+]i with Ca2+ indicators fura-2 and fluo-3 in A7r5 cells (a cell line derived from rat thoracic aortic smooth muscle cells). With whole-cell recordings, lower concentrations (< or = 1 nM) of ET-1 activated a Ca(2+)-permeable nonselective cation channel (designated NSCC-1). In contrast, higher concentrations (> or = 1 nM) of ET-1 activated two types of Ca(2+)-permeable nonselective cation channel (designated NSCC-1 and NSCC-2) and store-operated Ca2+ channel (SOCC). Importantly, we found that these Ca2+ channels can be pharmacologically discriminated using blockers of the so-called receptor operated Ca2+ influx such as SK&F 96365 and LOE 908. That is, NSCC-1 is resistant to SK&F 96365 but sensitive to LOE 908; NSCC-2 is sensitive to both SK&F 96365 and LOE 908; SOCC is sensitive to SK&F 96365 but resistant to LOE 908. Using these blockers, we analyzed the ET-1-induced increase in [Ca2+]i. The increase in [Ca2+]i induced by lower concentrations of ET-1 was resistant to SK&F 96365 but sensitive to LOE 908. In contrast, the increase in [Ca2+]i induced by higher concentrations of ET-1 was partially suppressed to approximately 30% of controls by either SK&F 96365 or LOE 908 alone, and it was abolished by their combination. These results show that the increase in [Ca2+]i induced by lower concentrations (< or = 1 nM) of ET-1 results from Ca2+ influx through NSCC-1, whereas the increase in [Ca2+]i induced by higher concentrations (> or = 10 nM) of ET-1 results from Ca2+ influx through NSCC-1, NSCC-2 and SOCC.
- Published
- 1999
- Full Text
- View/download PDF
50. [Analysis of Ca2+ entry channels in endothelin-1-induced contraction of rat aorta using new blockers].
- Author
-
Zhang XF, Iwamuro Y, Okamoto Y, Miwa S, and Masaki T
- Subjects
- Acetamides pharmacology, Animals, Aorta, Thoracic, Imidazoles pharmacology, In Vitro Techniques, Isoquinolines pharmacology, Nifedipine pharmacology, Rats, Calcium Channel Blockers pharmacology, Calcium Channels drug effects, Calcium Channels physiology, Endothelin-1 physiology, Vasoconstriction drug effects
- Abstract
1) We have recently shown that endothelin-1 (ET-1) activates two types of Ca(2+)-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and store-operated Ca2+ channel (SOCC). These channels can be pharmacologically discriminated using Ca2+ channel blockers such as SK&F 96365 and LOE 908. Here we characterized Ca2+ entry channels involved in ET-1-induced contractions of rat thoracic aortic rings and increases in the intracellular free Ca2+ concentration ([Ca2+]i) of single smooth muscle cells using these blockers. 2) LOE 908 or a blocker of voltage-operated Ca2+ channel nifedipine had no effect on the contractions and increases in [Ca2+]i induced by thapsigargin, whereas SK&F 96365 abolished them. 3) The contractions and increases in [Ca2+]i induced by ET-1 depended on extracellular Ca2+ but were resistant to nifedipine. The responses to lower concentrations (< or = 0.1 nM) of ET-1 were abolished by either SK&F 96365 or LOE 908. The responses to higher concentrations (> or = 1 nM) were abolished by SK&F 96365, but were partially resistant to LOE 908. 4) These results show that the contractions and increases in [Ca2+]i of rat aortic smooth muscles at lower concentrations of ET-1 involve only one Ca2+ entry channel which is sensitive to SK&F 96365 and LOE 908 (NSCC-2), whereas those at higher concentrations of ET-1 involve another Ca2+ entry channel which is sensitive to SK&F 96365 but resistant to LOE 908 (SOCC) in addition to the former channel.
- Published
- 1999
- Full Text
- View/download PDF
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