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Suda T, Nagasawa T, Wara-aswapati N, Kobayashi H, Iwasaki K, Yashiro R, Hormdee D, Nitta H, Ishikawa I, Izumi Y. Regulatory roles of β-catenin and AP-1 on osteoprotegerin production in interleukin-1α-stimulated periodontal ligament cells. ACTA ACUST UNITED AC 2009; 24:384-9. [DOI: 10.1111/j.1399-302x.2009.00529.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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77
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Abstract
Characteristics of twelve cytochromes P450 (CYPs) from cynomolgus monkeys were compared with those of human CYPs that play an important role in drug metabolism. Eleven members of CYP1A, CYP2A, CYP2C, CYP2D, CYP2E, and CYP3A subfamilies from cynomolgus monkeys exhibited a high degree of homologies (more than 90%) in cDNA and amino acid sequences with corresponding human CYPs, and catalysed typical reactions of corresponding human CYPs. One member of the cynomolgus monkey CYP2C subfamily, CYP2C76, exhibited a lower homology (around 70%) in amino acid sequences with other cynomolgus monkey and human CYP2C subfamilies. CYP2C76 catalysed typical CYP2C substrates with low activities, and has not been found in humans. CYPs identified in cynomolgus monkeys were similar to CYP1A1, CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP3A5 in humans. These results indicate that cynomolgus monkeys express CYPs similar to human CYPs that are important in drug metabolism.
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Emoto C, Iwasaki K. Approach to predict the contribution of cytochrome P450 enzymes to drug metabolism in the early drug-discovery stage: The effect of the expression of cytochromeb5with recombinant P450 enzymes. Xenobiotica 2009; 37:986-99. [PMID: 17896325 DOI: 10.1080/00498250701620692] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In order to evaluate the potential adverse effects due to genetic polymorphism and/or inter-individual variation, it is necessary to calculate the cytochrome P450 (CYP) contribution to the metabolism of new drugs. In the current study, the in vitro intrinsic clearance (CL(int)) values of marker substrates and drugs were determined by measuring metabolite formation and substrate depletion, respectively. Recombinant CYP microsomes expressing CYP2C9, CYP2C19 and CYP3A4 with co-expressed cytochrome b(5) were used, but those expressing CYP1A2 and CYP2D6 did not have co-expressed cytochrome b(5). The following prediction methods were compared to determine the CL(int) value using data from recombinant CYP enzymes: (1) relative CYP enzyme content in human liver microsomes; (2) relative activity factor (RAF) estimated from the V(max) value; and (3) RAF estimated from the CL(int) value. Estimating RAF from CL(int) proved the most accurate prediction method among the three tested, and differences in the CYP3A4 marker reactions did not affect its accuracy. The substrate depletion method will be useful in the early drug-discovery stage when the main metabolite and/or metabolic pathway has not been identified. In addition, recombinant CYP microsomes co-expressed with cytochrome b(5) might be suitable for the prediction of the CL(int) value.
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Yamada M, Kai K, Ogawa K, Iwasaki K, Kuroda S, Takahashi S, Oita M. PHYSICAL CHARACTERISTICS OF A HIGH-DOSE-RATE MODE LINEAR ACCELERATOR DESIGNED FOR STEREOTACTIC IRRADIATION. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)73223-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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80
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Feghali K, Iwasaki K, Tanaka K, Komaki M, Machigashira M, Ishikawa I, Izumi Y. Human gingival fibroblasts release high-mobility group box-1 protein through active and passive pathways. ACTA ACUST UNITED AC 2009; 24:292-8. [DOI: 10.1111/j.1399-302x.2009.00508.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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81
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Sawa Y, Tatsumi E, Funakubo A, Horiuchi T, Iwasaki K, Kishida A, Masuzawa T, Matsuda K, Nishimura M, Nishimura T, Tomizawa Y, Yamaoka T, Watanabe H. Journal of Artificial Organs 2008: the year in review. J Artif Organs 2009; 12:1-7. [PMID: 19330497 DOI: 10.1007/s10047-009-0451-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Indexed: 11/29/2022]
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82
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Iwasaki K, Yamasaki S, Kusachi S, Takeuchi K, Matano S, Kita T. Coronary artery stenting with high-pressure post-dilation followed by adjunctive thrombolysis after failed coronary angioplasty for acute myocardial infarction: report of three cases. Clin Cardiol 2009; 20:398-401. [PMID: 9098602 PMCID: PMC6655923 DOI: 10.1002/clc.4960200418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We successfully implanted coronary stents into refractory reoccluded lesions after failed coronary angioplasty in three patients with acute myocardial infarction (AMI). Lesion location was the proximal left anterior descending coronary artery in two patients and the dominant right coronary artery in one patient. The reference diameters of the lesions were 3.64, 3.33, and 3.50 mm, respectively. A stent with a luminal diameter of 3.0 mm was implanted in all patients. Poststenting dilation of the stent was performed at high pressure (18 atm), and urokinase was administered immediately thereafter. Heparin was administered for 24 h with maintenance of activated coagulation time within 180-200 s. Warfarin was then administered to keep the international normalized ratio within 2.5-3.5. Luminal diameters immediately after stenting were 3.14, 2.89, and 3.26 mm, and those at 1 month after stenting were 3.09, 2.81, and 3.12 mm, respectively, indicating good patency. Our experience in these cases suggests that coronary stenting can be applied after unsuccessful coronary angioplasty in selected patients with AMI. The present report includes informative reference data on diameter, postdilation, adjunctive thrombolytic agent administration, and adequate anticoagulation therapy in coronary stenting in this acute application.
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Maekawa K, Yoshimura T, Saito Y, Fujimura Y, Aohara F, Emoto C, Iwasaki K, Hanioka N, Narimatsu S, Niwa T, Sawada J. Functional characterization of CYP3A4.16: Catalytic activities toward midazolam and carbamazepine. Xenobiotica 2009; 39:140-7. [DOI: 10.1080/00498250802617746] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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84
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Wakasa S, Yagi T, Akimoto Y, Tokunaga N, Iwasaki K, Umezu M. Microscale Visualization of Erythrocyte Deformation by Colliding with a Rigid Surface Using a High-Speed Impinging Jet. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/978-3-540-92841-6_351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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85
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Iwasaki K, Komaki M, Mimori K, Leon E, Izumi Y, Ishikawa I. IL-6 Induces Osteoblastic Differentiation of Periodontal Ligament Cells. J Dent Res 2008; 87:937-42. [DOI: 10.1177/154405910808701002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Interleukin (IL)-6 has been considered as an osteolytic factor involved in periodontal disease. However, the function of IL-6 in osteoblastic differentiation of periodontal ligament cells is not clear. We examined the effects of IL-6 and its soluble receptor (sIL-6R) on osteoblastic differentiation of periodontal ligament cells. Osteoblastic differentiation was induced by ascorbic acid. Osteoblast markers, including alkaline phosphatase activity and Runx2 gene expression, were examined. The mechanism of action of IL-6 on osteoblastic differentiation was evaluated by insulin-like growth factor (IGF)-I production and specific inhibitors for the IL-6-signaling molecule. IL-6/sIL-6R enhanced alkaline phosphatase activity and Runx2. Alkaline phosphatase activity was reduced by anti-IGF-I antibody. Mitogen-activated protein kinase and Janus protein tyrosine kinase inhibitors diminished alkaline phosphatase induced by IL-6/sIL-6R. We conclude that IL-6/sIL-6R increases ascorbic-acid-induced alkaline phosphatase activity through IGF-I production, implying that IL-6 acts not only as an osteolytic factor, but also as a mediator of osteoblastic differentiation in periodontal ligament cells.
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86
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Emoto C, Yamato Y, Sato Y, Ohshita H, Katoh M, Tateno C, Yokoi T, Yoshizato K, Iwasaki K. Non-invasive method to detect induction of CYP3A4 in chimeric mice with a humanized liver. Xenobiotica 2008; 38:239-48. [DOI: 10.1080/00498250701760159] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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87
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Abstract
1. During the characterization of recombinant CYP2C19, it was observed that this enzyme metabolized midazolam, which is generally regarded as CYP3A4/5 substrate, and we therefore decided to pursue this observation further. 2. CYP2C19 showed a Michaelis-Menten pattern for midazolam 1'-hydroxylation and was inhibited by (+)-N-3-benzylnirvanol and S-mephenytoin, which are a standard potent inhibitor and a substrate of CYP2C19, respectively. 3. The inhibitory potency by CYP3A4/5 inhibitor on the midazolam 1'-hydroxylation in human liver microsomes (HLM) was correlated with the CYP3A4/5 specific catalytic activity, but such correlation was not observed in CYP2C19 enzyme. The in vitro intrinsic clearance value for midazolam 1'-hydroxylation was not changed by the addition of (+)-N-3-benzylnirvanol in four individual HLM preparations. 4. These results indicated that although CYP2C19 is capable of catalyzing midazolam 1'-hydroxylation, CYP3A4/5 play a more important role.
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Emoto C, Murase S, Iwasaki K. Approach to the prediction of the contribution of major cytochrome P450 enzymes to drug metabolism in the early drug-discovery stage. Xenobiotica 2008; 36:671-83. [PMID: 16891248 DOI: 10.1080/00498250600709778] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
It is important to determine the cytochrome P450 (CYP) contribution of certain drugs by taking into consideration the attrition due to issues such as genetic polymorphism and inter-individual variation. In many cases in the early discovery stage, the metabolites of a new chemical have not been identified. Therefore, the present paper devised an approach in which the in vitro intrinsic clearance (CLint) value for new chemicals was determined by measuring substrate depletion. The following prediction methods were compared to calculate CLint using data from recombinant CYP enzymes: (1) the relative CYP content in human liver microsomes; (2) the relative activity factor (RAF) based on the Vmax value; and (3) the RAF value based on the CLint value. The most accurate prediction method was RAF based on CLint. This method would be useful in the early drug-discovery process in cases in which the main metabolite is not identified.
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89
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Nakashima A, Kawashita H, Masuda N, Saxer C, Niina M, Nagae Y, Iwasaki K. Identification of cytochrome P450 forms involved in the 4-hydroxylation of valsartan, a potent and specific angiotensin II receptor antagonist, in human liver microsomes. Xenobiotica 2008; 35:589-602. [PMID: 16192110 DOI: 10.1080/00498250500158175] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Valsartan is known to be excreted largely as unchanged compound and is minimally metabolized in man. Although the only notable metabolite is 4-hydroxyvaleryl metabolite (4-OH valsartan), the responsible enzyme has not been clarified at present. The current in vitro studies were conducted to identify the cytochrome P450 (CYP) enzymes involved in the formation of 4-OH valsartan. Valsartan was metabolized to 4-OH valsartan by human liver microsomes and the Eadie-Hofstee plots were linear. The apparent Km and Vmax values for the formation of 4-OH valsartan were 41.9-55.8 microM and 27.2-216.9 pmol min(-1) mg(-1) protein, respectively. There was good correlation between the formation rates of 4-OH valsartan and diclofenac 4'-hydroxylase activities (representative CYP2C9 activity) of 11 individual microsomes (r = 0.889). No good correlation was observed between any of the other CYP enzyme marker activities (CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP4A). Among the recombinant CYP enzymes examined (CYPs 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4, 3A5 and 4A11), CYP2C9 notably catalysed 4-hydroxylation of valsartan. For the specific CYP inhibitors or substrates examined (furafylline, diclofenac, S(+)-mephenytoin, quinidine and troleandomycin), only diclofenac inhibited the formation of 4-OH valsartan. These results showed that CYP2C9 is the only form responsible for 4-hydroxylation of valsartan in human liver microsomes. Although CYP2C9 is involved in valsartan metabolism, CYP-mediated drug-drug interaction between valsartan and other co-administered drugs would be negligible.
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90
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Katoh M, Watanabe M, Tabata T, Sato Y, Nakajima M, Nishimura M, Naito S, Tateno C, Iwasaki K, Yoshizato K, Yokoi T. In vivoinduction of human cytochrome P450 3A4 by rifabutin in chimeric mice with humanized liver. Xenobiotica 2008; 35:863-75. [PMID: 16308281 DOI: 10.1080/00498250500296231] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The induction of human cytochrome P450 enzymes (CYPs) often poses a serious problem in clinical practice. The induction of CYP3A leads to a decrease in the pharmacological potency of drugs, since many drugs are substrates of CYP3A. The present study examined the in vivo induction potency of human CYP3A in chimeric mice with humanized liver, recently established in Japan, by a specific inducer of human CYP3A enzyme activity in this experimental condition, rifabutin, which is an analogue of rifampicin. The chimeric mice were treated intraperitoneally daily for 4 days with rifabutin (50 mg kg(-1) day(-1)). The mRNA, protein and enzyme activity in liver of the chimeric mice were measured by reverse-transcriptase polymerase chain reaction, Western blot analysis and high-performance liquid chromatography, respectively. In the chimeric mice, the human CYP3A4 mRNA expression, CYP3A4 protein content, testosterone 6ss-hydroxylase activity and dexamethasone 6-hydroxylase activity were increased 7.4-, 3.0-, 2.4- and 1.9-fold, respectively, by treatment with rifabutin. The mRNA expression of other human CYPs, transporters and nuclear receptors was not significantly changed by rifabutin. On the other hand, rifabutin was demonstrated not to increase the murine Cyp3a enzyme activities in the control mice. It was demonstrated that human CYP3A4 expressed in the chimeric mice with humanized liver was induced by rifabutin, suggesting that human CYP3A4 in the chimeric mice had induction potency. This chimeric mouse model may be a useful animal model to estimate and predict the in vivo induction of CYPs in human.
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91
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Iwasaki K, Miyazaki N, Ito T, Takagi J. Structures of the laminin-binding integrins. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308080641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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92
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Kato K, Tanaka H, Sumizawa T, Yamashita E, Yoshimura M, Zhou Y, Yao M, Tanaka I, Iwasaki K, Tsukihara T. Structure of vault purified from rat liver. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308089113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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93
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Suzuki H, Iwasaki K, Nakamura H. EM Navigator– 3D electron microscopy data navigator. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308080665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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94
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Sawa Y, Tatsumi E, Funakubo A, Horiuchi T, Iwasaki K, Kishida A, Masuzawa T, Matsuda K, Nishimura M, Nishimura T, Tomizawa Y, Yamaoka T, Watanabe H. Journal of Artificial Organs 2007: the year in review. J Artif Organs 2008. [DOI: 10.1007/s10047-008-0412-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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95
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Sato Y, Yamada H, Iwasaki K, Tateno C, Yokoi T, Yoshizato K, Horii I. Human Hepatocytes Can Repopulate Mouse Liver: Histopathology of the Liver in Human Hepatocyte-Transplanted Chimeric Mice and Toxicologic Responses to Acetaminophen. Toxicol Pathol 2008; 36:581-91. [DOI: 10.1177/0192623308318212] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A human hepatocyte-transplanted chimeric mouse has been established by transplantation of human hepatocytes to urokinase-type plasminogen activator transgenic/severe combined immunodeficiency (uPA+/+/SCID) mice. These chimeric mice have various amounts of human hepatocytes that proliferate extensively and progressively replace mouse hepatocytes. In the chimeric liver, hepatic cords and sinusoid-like structures were observed. The human hepatocytes expressed human albumin, human cytochrome P450 enzymes, and human transporter proteins. Furthermore, electron microscopic analysis demonstrated bile canaliculi associated with human hepatocytes in the chimeric mouse livers. These results indicate that the chimeric mouse livers contain functionally intact and differentiated human hepatocytes. Additionally, the toxicologic response of hepatocytes to acetaminophen (APAP) administration was compared in normal and chimeric mouse livers. Following 1,400 mg/kg APAP, mild hepatocellular degeneration was observed in the human hepatocyte areas in the chimeric mice, compared with severe centrilobular hepatocellular necrosis in the ICR mouse livers. In conclusion, these chimeric livers contain functionally differentiated human hepatocytes, and are less susceptible to APAP toxicity, compared to ICR mice.
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Ayoub SRA, Uchiyama H, Iwasaki K, Doi T, Inaba K. Effects of several surfactants and high-molecular-weight organic compounds on decomposition of trichloroethylene with zerovalent iron powder. ENVIRONMENTAL TECHNOLOGY 2008; 29:363-373. [PMID: 18619141 DOI: 10.1080/09593330801984126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We investigated the effects of coexisting surfactants and high-molecular-weight organic compounds on the reductive dechlorination of trichloroethylene by zerovalent iron powder to determine whether these additives had utility as washing reagents for remediation of soil and groundwater pollution. During the dechlorination reaction, the amount of trichloroethylene decreased, and the formation of cis-1,2-dichloroethylene was observed. The decomposition of trichloroethylene was found to be first-order with respect to the trichloroethylene and zerovalent iron concentrations when the solution contained no additives. The rates of decomposition of trichloroethylene in the presence of the additives were lower than the rate in the absence of the additives: the rate constant was reduced by a factor of 0.7 for the cationic surfactant cetyltrimethylammonium bromide; by a factor of 0.5 for the anionic surfactants sodium n-dodecylbenzenesulfonate, sodium n-dodecylsulfate, and sodium n-dodecanesulfonate and for the high-molecular-weight organic compounds soluble starch, beta-cyclodextrin, and polyethyleneglycol 6000; and by a factor of 0.2 for sodium laurate and the nonionic surfactants Triton X-100, Tween 20, Tween 60, Brij 35, and Brij 58. Comparison of the concentrations of the nonionic surfactants with their critical micellar concentrations indicated that the rate-reducing effect of these additives was due to solubilization of trichloroethylene into the micellar phase. The adsorption of trichloroethylene onto the zerovalent iron surface was also affected by the presence of the additives. Thus, our results indicated that the changes in the decomposition rate of trichloroethylene were determined by several factors.
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97
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Oura M, Kobayashi N, Takeda S, Iwasaki K, Umezu M. Development of a compact mock circulation system and a new flow-cell model for pulse spectrophotometry. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2008; 2008:670-673. [PMID: 19162744 DOI: 10.1109/iembs.2008.4649241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have developed an extremely compact mock circulation system. This system can simulate artery blood circulation and generate a pulse wave with a very small amount of blood. We were also able to measure the in vitro pulsatile optical density ratio (Phivt) using this system with a flow cell [1]. Results showed a difference between Phivt and the in vivo pulsatile optical density ratio (Phivi) for the same oxygen saturations. To explain this difference, we proposed a new flow-cell model that includes venous flow and arterial flow. Because these systems can simulate the in vivo environment with very accurately, they can be applied to various pulse spectrophotometry studies. Moreover, the required blood volume is very small so the system can evaluate artificial blood or artificial red cells at very low cost. Thus, this system can reduce the time and cost of developing new pulse photometry techniques and other medical equipment.
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98
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Leon ER, Iwasaki K, Komaki M, Kojima T, Ishikawa I. Osteogenic effect of interleukin-11 and synergism with ascorbic acid in human periodontal ligament cells. J Periodontal Res 2007; 42:527-35. [DOI: 10.1111/j.1600-0765.2007.00977.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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99
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Nishida H, Hirai H, Emoto C, Iwasaki K. Metabolism of CJ-036878, N-(3-phenethoxybenzyl)-4-hydroxybenzamide, in liver microsomes and recombinant cytochrome P450 enzymes: metabolite identification by LC-UV/MS(n) and (1)H-NMR. Xenobiotica 2007; 37:1394-407. [PMID: 18033636 DOI: 10.1080/00498250701670549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The identification of metabolites in the early stages of drug discovery is important not only for guiding structure-activity relationships (SAR) and structure-metabolism relationships (SMR) strategies, but also for predicting the potential for adverse events. The present study investigated the phase I metabolism of CJ-036878 (N-(3-phenethoxybenzyl)-4-hydroxybenzamide), a potent antagonist of the N-methyl-D-asparatate (NMDA) receptor, using liver microsomes and representative recombinant cytochrome P450 enzymes. The structures of the oxidative metabolites M1-M11 were confirmed by LC-UV/MS(n) and/or (1)H-nuclear magnetic resonance (NMR). It was found that CJ-036878 is metabolized through three routes: (1) aliphatic hydroxylation that generates M1 and M2; (2) aromatic hydroxylation that produces M3-M5, M7 and M8; and (3) dimerization through an oxidative phenol coupling reaction that yields M10 and M11. The use of recombinant human cytochrome P450 enzymes suggested that CYP3A4 is the major enzyme involved in the oxidative metabolism of CJ-036878, with minor contributions from CYP1A2, CYP2C19, and CYP2D6.
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100
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Sano K, Mishima K, Koushi E, Orito K, Egashira N, Irie K, Takasaki K, Katsurabayashi S, Iwasaki K, Uchida N, Egawa T, Kitamura Y, Nishimura R, Fujiwara M. Delta 9-tetrahydrocannabinol-induced catalepsy-like immobilization is mediated by decreased 5-HT neurotransmission in the nucleus accumbens due to the action of glutamate-containing neurons. Neuroscience 2007; 151:320-8. [PMID: 18083311 DOI: 10.1016/j.neuroscience.2007.10.026] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 10/26/2007] [Accepted: 11/01/2007] [Indexed: 11/30/2022]
Abstract
Delta(9)-tetrahydrocannabinol (THC) has been reported to induce catalepsy-like immobilization, but the mechanism underlying this effect remains unclear. In the present study, in order to fully understand the neural circuits involved, we determined the brain sites involved in the immobilization effect in rats. THC dose-dependently induced catalepsy-like immobilization. THC-induced catalepsy-like immobilization is mechanistically different from that induced by haloperidol (HPD), because unlike HPD-induced catalepsy, animals with THC-induced catalepsy became normal again following sound and air-puff stimuli. THC-induced catalepsy was reversed by SR141716, a selective cannabinoid CB(1) receptor antagonist. Moreover, THC-induced catalepsy was abolished by lesions in the nucleus accumbens (NAc) and central amygdala (ACE) regions. On the other hand, HPD-induced catalepsy was suppressed by lesions in the caudate putamen (CP), substantia nigra (SN), globus pallidus (GP), ACE and lateral hypothalamus (LH) regions. Bilateral microinjection of THC into the NAc region induced catalepsy-like immobilization. This THC-induced catalepsy was inhibited by serotonergic drugs such as 5-hydroxy-L-tryptophan (5-HTP), a 5-HT precursor, and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), a 5-HT receptor agonist, as well as by anti-glutamatergic drugs such as MK-801 and amantadine, an N-methyl-d-aspartate (NMDA) receptor antagonist. THC significantly decreased 5-HT and glutamate release in the NAc, as shown by in vivo microdialysis. SR141716 reversed and MK-801 inhibited this decrease in 5-HT and glutamate release. These findings suggest that the THC-induced catalepsy is mechanistically different from HPD-induced catalepsy and that the catalepsy-like immobilization induced by THC is mediated by decreased 5-HT neurotransmission in the nucleus accumbens due to the action of glutamate-containing neurons.
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