M Takeuchi

Okayama University, Okayama, Okayama, Japan

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Publications (26)78.52 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: 1. The liver is the target organ for the lipid-regulating effect of rosuvastatin, a new 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, and liver-selective uptake of this drug is therefore a desirable property. The uptake kinetics of rosuvastatin were investigated and compared with those of pravastatin using isolated rat hepatocytes. 2. Uptake for both drugs involved both active transport and passive diffusion processes. The Michaelis constant (K(m)) of uptake rate for rosuvastatin (9.17 micro M) was approximately half that for pravastatin (16.5 micro M). However, the maximum uptake rate (V(max)) and carrier-mediated uptake clearance (V(max)/K(m)) of rosuvastatin were significantly (p < 0.01) greater than those of pravastatin, and a larger contribution of carrier-mediated uptake clearance to total uptake clearance was shown for rosuvastatin (contribution ratio 0.903 versus pravastatin 0.654). 3. Sodium and chloride ions did not play a significant role in the uptake of rosuvastatin and pravastatin, but the uptake of both drugs was inhibited both by depletion of cellular ATP and by organic anions such as bromosulfophthalein. 4. Rosuvastatin competitively inhibited the uptake of pravastatin, with an inhibition constant (K(i)) (2.75 micro M) relatively similar to its K(m). 5. The results suggest that an organic anion transport protein is the main mediator of the hepatic uptake of rosuvastatin and pravastatin, which occurs in an ATP-dependent manner. Our results indicated that rosuvastatin was taken up by the hepatocytes via the same transport systems as pravastatin, but with a greater affinity and efficiency than pravastatin.
    Xenobiotica 04/2003; 33(4):379-88. DOI:10.1080/0049825031000066259
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    ABSTRACT: A new synthetic retinoid, Am80, is effective in treating acute promyelocytic leukemia relapsed from all-trans-retinoic acid-induced complete remission (CR). We report here the long-term clinical outcomes of patients who achieved second CR with Am80. Of 24 evaluable patients, 14 achieved a second CR by Am80 therapy. Of those patients, 4 relapsed within 6 months, despite subsequent consolidation chemotherapy. Six patients underwent sibling or unrelated HLA-matched allogeneic bone marrow transplantation (BMT), and 4 are alive without relase for more than 49 months after achieving second CR. Four of 8 patients who did not receive BMT are alive without relapse for more than 49 months. Promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR alpha) fusion transcript was undetectable by reverse transcriptase-polymerase chain reaction in all living patients. Therefore, if patients achieve second CR with Am80 and HLA-matched donors are available, BMT is the treatment of choice. However, it is noteworthy that CR was maintained for more than 49 months in half of the patients who did not receive BMT.
    International Journal of Hematology 01/2001; 72(4):470-3.
  • Atherosclerosis 07/2000; 151(1):39-39. DOI:10.1016/S0021-9150(00)80177-X
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    ABSTRACT: There are few molecular biologic determinants that are prognostic for patients with acute myeloid leukemia (AML). Hence, we examined whether cellular levels of the cyclin-dependent kinase inhibitor p27Kip1 in acute myeloid leukemia could be used to predict clinical outcome in AML. Using immunoblot analysis, levels of p27 were assessed in blast cells from 72 AML patients who were registered and treated by the identical chemotherapy protocol. AML cases were classified into three groups on the basis of the percentage of the expression level of p27 compared to a control cell line. AML cases exhibiting p27 expression at low, moderate, and high levels were 43, 9, and 20 cases, respectively. No significant differences in the rates of complete remission (CR) were observed among the three groups. Although the level of p27 expression was not correlated with any other possible prognostic markers, such as age, white blood cell count, chromosome abnormalities, and FAB subclasses, patients with high p27 expression had a significantly increased disease-free survival (DFS) (78% vs 19%, P = 0.004). We further examined the expression of cyclin E at the protein level in all 72 AML cases. We observed a statistically significant correlation between a high cyclin E level and a high p27 level (P < 0.005). However, we failed to find any correlation between the rates of CR or DFS and cyclin E expression. The present study reveals that levels of p27 expression can be one of the useful prognostic molecular markers for AML. Leukemia (2000) 14, 28-33.
    Leukemia 02/2000; 14(1):28-33. DOI:10.1038/sj.leu.2401640
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    M Takeuchi, A Tamaoki, R Soda, K Takahashi
    Leukemia 03/1999; 13(2):313-4. DOI:10.1038/sj.leu.2401304
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    ABSTRACT: All-trans retinoic acid (ATRA), a potent differentiating drug for acute promyelocytic leukemia (APL), induces a high incidence of complete remission (CR) in patients with APL and is now established as a first-line therapy. However, ATRA resistance has become a clinical problem. Patients who relapsed after ATRA-induced CR have had difficulty in obtaining a second CR with ATRA therapy. Although several mechanisms have been postulated, treatment strategies to overcome resistance have not been established. We used a new synthetic retinoid, Am-80, as reinduction therapy for APL relapse after from ATRA-induced CR. Am-80 was several times more potent than ATRA in inducing differentiation in vitro. At a 6 mg/m2 dose, there were 24 evaluable patients; 14 (58%) achieved CR between days 20 and 58 (median, 37 days). Clinical response correlated with the in vitro response to Am-80. Adverse effects included retinoic acid syndrome (n = 1), hyperleukocytosis (n = 1), xerosis (n = 9), cheilitis (n = 8), hypertriglyceridemia (n = 16), and hypercholesterolemia (n = 15). Am-80 is active in APL after relapse from ATRA-induced CR. Further clinical trials are needed to establish strategies to overcome ATRA resistance.
    Leukemia and Lymphoma 12/1998; 31(5-6):441-51. DOI:10.3109/10428199809057604
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    ABSTRACT: A 64-year-old woman underwent an ileocecal resection for ileus. The specimen revealed a diffuse large B cell lymphoma. The diagnosis was stage IIA non-Hodgkin's lymphoma. She received chemotherapy with the CHOP-etoposide regimen, resulting in partial remission. High-dose etoposide was used for PBSC mobilization before auto-PBSCT. Conditioning was ranimustine, carboplatin, etoposide and cyclophosphamide. Her renal function deteriorated gradually, starting 3 months post-PBSCT. Eight months post-transplant, serum creatine concentration was 7.1 mg/dl, and BUN was 59.2 mg/dl. Her hemoglobin concentration decreased to 5.3 g/dl, with no evidence of hemolysis. Renal biopsy revealed fibrous crescent formations in glomeruli, and mononuclear cell infiltration in interstitial spaces. Renal injury in this patient differs from BMT nephropathy, which is similar to hemolytic uremic syndrome, and represents another type of late renal injury after PBSCT.
    Bone Marrow Transplantation 11/1998; 22(7):725-7. DOI:10.1038/sj.bmt.1701410
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    ABSTRACT: 1. S-1153, a non-nucleoside agent that is under development in the USA as a new anti-HIV agent, has potent antiviral activity based on the inhibition of reverse transcriptase. 2. S-1153 was incubated with rat liver microsomes and NADPH, and seven metabolites were formed. The main metabolites were identified as the S-oxide, N-oxide and sulphone of S-1153. 3. Two other minor metabolites were assumed to be S-1153 hydroxylated on the isopropyl moiety. 4. Our findings confirmed the existence of at least three oxidative metabolic pathways of S-1153.
    Xenobiotica 10/1998; 28(9):877-86. DOI:10.1080/004982598239119
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    ABSTRACT: 1. The pharmacokinetics of a novel benzodiazepine partial inverse agonist (S-8510) were studied in the Fischer 344 (F344) rat and B6C3F1 mouse to obtain information for the planning of carcinogenicity studies. Sprague-Dawley (SD) rats were also included for comparison. 2. Clear non-linear elimination of S-8510 was observed after single oral administration of S-8510 in all animals tested (F344 rat, 1-50 mg/kg; SD rat and B6C3F1 mouse, 1-150 mg/kg). 3. Exposure of S-8510 after single oral administration was in the order F344 rat > B6C3F1 mouse > SD rat. 4. Multiple oral administration to F344 rat and B6C3F1 mouse decreased the exposure to S-8510. 5. These results indicate that it is very important to evaluate pharmacological and toxicological studies based on exposure and to be careful in selecting the species and strains of animal used in toxicology studies.
    Xenobiotica 06/1998; 28(5):515-25. DOI:10.1080/004982598239434
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    ABSTRACT: To clarify which process in renal secretion is responsible for the stereoselective renal secretion of organic anions, the renal handling of enantiomers of 5-monomethylsulfamoyl-6,7-dichloro-2, 3-dihydrobenzofuran-2-carboxylic acid (MBCA) was studied by the multiple-indicator dilution method, using isolated perfused rat kidney. After bolus injection of (R)-(+)-[14C]MBCA or (S)-(-)-[14C]MBCA into the renal artery, the outflow patterns for the perfusate and the urinary excretion rate profiles were estimated by statistical moment analysis. AUC values and mean transit times in kidney for the MBCA enantiomers indicated that (R)-(+)-MBCA was excreted much more extensively in urine and that it had a higher affinity for renal tissue than did (S)-(-)-MBCA. A significantly larger intrinsic clearance of secretion for (R)-(+)-MBCA attested to the R-(+)-preferential renal secretion. The uptake rate constant across the basolateral membrane, the ratio of the uptake rate constant to the free fraction in the perfusate, and the intracellular distribution volume were significantly larger for (R)-(+)-MBCA than for (S)-(-)-MBCA, indicating that uptake across the basolateral membrane and intracellular distribution were R-(+)-preferential. However, the mean time across renal epithelial cells for secreted molecules, the single-pass mean residence time in renal epithelial cells, and the rate constant for secretion across the brush-border membrane were not significantly different between enantiomers. The simultaneous presence of (R)-(+)-MBCA decreased the intrinsic clearance of secretion, the ratio of the uptake rate constant to the free fraction in the perfusate, and the intracellular distribution volume for (S)-(-)-[14C]MBCA, although the secretion rate constant, the mean time across renal epithelial cells for secreted molecules, and the single-pass mean residence time in renal epithelial cells were not influenced by (R)-(+)-MBCA, confirming that uptake across the basolateral membrane and intracellular distribution were stereoselective processes.
    Drug Metabolism and Disposition 03/1998; 26(2):138-45.
  • M Takeuchi, A Tada, R Soda, K Takahashi
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    ABSTRACT: 53-year-old man with chronic lymphocytic leukemia resistant to alkylating agent containing regimens, was treated with fludarabine phosphate. Hematological data before the administration of fludarabine phosphate was as follows: RBC 216 x 10(4)/microliter, Hb 7.7 g/dl, WBC 69,400/microliter (lymphocyte 96%), PLT 0.2 x 10(4)/microliter. Bone marrow was fully occupied with lymphocytes. Red blood cells and platelets transfusions were frequently required. Fludarabine phosphate was administered at a dose of 40 mg (23 mg/m2) intravenously for 5 days every 4 weeks. After the start of the therapy, peripheral lymphocyte counts were markedly decreased and recovery of normal hematopoiesis was observed in bone marrow. Any transfusions were no longer necessary. Fludarabine phosphate may be active even for advanced, refractory and terminal stage chronic lymphocytic leukemia.
    [Rinshō ketsueki] The Japanese journal of clinical hematology 10/1997; 38(9):792-4.
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    ABSTRACT: Differentiation therapy with all-trans retinoic acid (ATRA) has marked a major advance and become the first choice drug in the treatment of acute promyelocytic leukemia (APL). However, patients who relapse from ATRA-induced complete remission (CR) have difficulty in obtaining a second CR with a second course of ATRA therapy alone. We tested the efficacy of a new synthetic retinoid, Am80, in APL that had relapsed from CR induced by ATRA in a prospective multicenter study. Am80 is approximately 10 times more potent than ATRA as an in vitro differentiation inducer, is more stable to light, heat, and oxidation than ATRA, has a low affinity for cellular retinoic acid binding protein, and does not bind to retinoic acid receptor-gamma. Patients received Am80, 6 mg/m2, orally alone daily until CR. Of 24 evaluable patients, 14 (58%) achieved CR. The interval from the last ATRA therapy was not different between CR and failure cases. The clinical response was well correlated with the in vitro response to Am80 in patients examined. Adverse events included 1 retinoic acid syndrome, 1 hyperleukocytosis, 9 xerosis, 8 cheilitis, 16 hypertriglyceridemia, and 15 hypercholesterolemia, but generally milder than those of ATRA, which all patients had received previously. Am80 is effective in APL relapsed from ATRA-induced CR and deserves further trials, especially in combination with chemotherapy.
    Blood 09/1997; 90(3):967-73.
  • International Journal of Hematology 11/1996; 64(3-4):293-5.
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    ABSTRACT: In order to determine the indication of B7 (B7-1 and B7-2) molecules-mediated immuno-gene therapy for human leukemias, we investigated 94 human leukemic samples for the expression of MHC molecules required for tumor antigen-specific signals and of B7-1, B7-2, and ICAM-1 molecules required for non-specific costimulatory signals. All samples were strongly positive for MHC class I and 84% for class II antigen. B7-1, B7-2 and ICAM-1 were expressed in 5%, 22% and 16% of the total cases, respectively. Especially in 54 AML samples, B7-1 was only expressed in one case, while B7-2 was detected in as many as 15 cases (28%). We have also examined 13 human myelo/monocytic cell lines for the expression of class II and costimulatory molecules and found that significant expression of costimulatory molecules was induced in human leukemic cells by some suitable drugs, among which interferon-gamma (IFN-gamma) was the most potent inducer. Our results indicate that when the B7-mediated immuno-gene therapy was applied to human leukemias, especially to AML, B7-1 was rather preferable to B7-2 in that the latter was more widely expressed on human leukemic cells. Furthermore, since gene-transfer systems occasionally accompany serious problems, it should be taken into account that costimulatory molecules on human myelo/monocytic leukemic cells could be induced ex vivo without the introduction of exogenous genes.
    Leukemia 08/1996; 10(7):1168-76.
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    ABSTRACT: Twenty-one consecutive patients with high-risk myelodysplastic syndromes (MDS) including six with refractory anemia with excess blasts (RAEB) and 15 with RAEB in transformation (RAEBt) were treated with daily oral low-dose melphalan (2 mg/day). Seven patients achieved complete remission (CR), one patient partial response, and four minor response while the remaining eight did not respond. The median age of the patients was 65 (range 56-83 years). The mean total amount of melphalan given was 140+/-19 mg in patients who achieved CR. The median duration of CR was 14.5 months. Serious toxicity was not encountered in any of the cases. Neither marrow suppression nor pancytopenia was observed during the administration of melphalan in patients who achieved CR. The clinical features of CR patients included normal karyotype and hypocellular marrow in biopsied specimen from the lilac bone. These observations suggest that melphalan may exert some differentiation effects on leukemic cells in addition to cytotoxic effects. Our study indicates that daily administration of low-dose melphalan is worth trying in the treatment of elderly patients with high-risk MDS.
    Leukemia 05/1996; 10(4):609-14.
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    ABSTRACT: Production of interferon (IFN)-alpha and IFN-gamma were examined in 31 patients with acute tuberculosis, 12 patients with atypical mycobacterial disease. IFN production was examined in cultures of unseparated fresh whole blood. Production of IFN-alpha was induced by hemagglutinating virus of Japan and production of IFN-gamma was induced by PHA. Patients with mycobacterial disease produced significantly less IFN-alpha than healthy subjects. In patients with acute tuberculosis, effective chemotherapy for 2 months restored IFN-alpha production. Patients produced less IFN-gamma than healthy subjects, but the difference was not significant. Patients with high serum CRP levels tended to produce little IFN-alpha. These results suggest that measurement of IFN production is useful for immunological evaluation of patients with mycobacterial disease.
    Nihon Kyōbu Shikkan Gakkai zasshi 03/1995; 33(2):114-9.
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    ABSTRACT: A 58-year-old female was diagnosed as myelodysplastic syndrome (MDS) [refractory anemia with excess of blasts (RAEB)]. Although melphalan was administered, no response was obtained in the peripheral blood. Sixteen months after diagnosis, she developed RAEB in transformation (RAEB-t), and then overt leukemia. White blood cell (WBC) count elevated to 28,600/microliters with 34% of blasts. She was administered cytarabine ocfosfate (200 mg-->300 mg/day) orally, resulting in decrease of WBC count and blasts in peripheral blood. The drug has been given for 11 months, and her hematological data have now remained stable in RAEB. Cytarabine ocfosfate might be a useful drug for the treatment of high risk MDS such as RAEB and RAEB-t.
    Gan to kagaku ryoho. Cancer & chemotherapy 02/1995; 22(1):141-4.
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    ABSTRACT: A prostaglandin derivative, (5Z,9 alpha,11 alpha,13E)-9,11-dihydroxyprosta- 5,13-dienoic acid sodium salt (S-1033), that lowers intraocular pressure with little adverse effect, may have clinical value in the treatment of glaucoma. After [14C]S-1033 (0.2% solution) was instilled into the eye of a white rabbit, radioactivity and S-1033 appeared in systemic plasma so rapidly (tmax, 5 min) and S-1033 was eliminated very rapidly with half-lives of 2.8 and 11.0 min at alpha- and beta-phases, respectively. The metabolite, M-1, [1R-[1 alpha,2 beta-(1E),3 alpha,5 alpha]]-3,5-dihydroxy-2-(1- octenyl)-cyclopentanepropanoic acid (tetranor-S-1033), appeared in plasma very rapidly (tmax, 5 min), suggesting that a fast metabolism was a major factor in the rapid elimination of S-1033 from plasma. The values for the ratios of the area under the curve of ocular instillation to intravenous administration for radioactivity and S-1033 were 1.01 and 0.52, respectively, indicating that more than half of the S-1033 instilled was transported into the systemic circulation. To clarify the contributing pathway of the massive and rapid systemic absorption of S-1033 after topical dosing, plasma levels of S-1033 were investigated after instillation to rabbits in which the nasolacrimal ducts were occluded. Plasma concentrations of S-1033 were slightly higher than those in intact rabbits, suggesting that conjunctiva would be as important as nasal mucosae for the systemic absorption under the physiological condition. As for the intraocular distribution, the highest levels of radioactivity were found in the cornea, conjunctiva, and anterior sclera.(ABSTRACT TRUNCATED AT 250 WORDS)
    Drug Metabolism and Disposition 02/1995; 23(1):35-43.
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    ABSTRACT: We studied the therapeutic potential of utilizing sparfloxacin (SPFX), a newly developed quinolone, to prevent various mycobacterial infections. The in vitro activity of SPFX as a preventive agent for various mycobacteria was determined using the actual count method on Ogawa egg medium. The minimal inhibitory concentrations (MICs) of SPFX were as follows: ofloxacin-sensitive M. tuberculosis, 0.16-0.32 microgram/ml; ofloxacin-resistant M. tuberculosis, 0.63-2.5 micrograms/ml; M. avium; 0.63-10 micrograms/ml (MICs were equal or less than 1.25 micrograms/ml in seven out of 11 strains); M. intracellulare, 2.5-10 micrograms/ml (MICs were equal or more than 10 micrograms/ml in 17 out of 23 strains); M. kansasii, < or = 0.08-0.16 microgram/ml; M. fortuitum, < or = 0.08 microgram/ml; M. chelonae subsp. abscessus, > 10 micrograms/ml; M. chelonae subsp. chelonae, 0.63 microgram/ml; M. scrofulaceum, < or = 0.08 microgram/ml; M. nonchromogenicum, 1.25 micrograms/ml; M. xenopi, < or = 0.08 microgram/ml; M. gordonae, < or = 0.08 microgram/ml. The average serum concentrations of SPFX during the period of multiple oral administration (200 mg once a day) were 0.35 +/- 0.16 microgram/ml before administration, 0.67 +/- 0.32 microgram/ml after one hour, 1.13 +/- 0.21 microgram/ml after two hours, 1.27 +/- 0.32 microgram/ml after four hours and 1.31 +/- 0.34 micrograms/ml after six hours. These results indicate that SPFX has a strong therapeutic potential to prevent infections due to M. tuberculosis, M. kansasii, M. fortuitum, M. chelonae subsp. chelonae, M. scrofulaceum, M. xenopi and M. gordonae. Moreover, it may be expected to be a promising agent against infections due to ofloxacin-resistant M. tuberculosis, M. avium and M. nonchromogenicum.
    Kekkaku: [Tuberculosis] 05/1994; 69(5):351-6.
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    ABSTRACT: A 34-year-old man was admitted to our hospital because of cough and fever. Chest radiograph showed multiple cavities mainly on the right lung. His sputum was positive for acid-fast bacilli on smear, and he was treated with daily isoniazide, rifampicin and streptomycin. Antituberculous treatment was successfully performed, so acid-fast bacilli of his sputa disappeared on smear and culture. Five months later, he developed a purpuric lesions over both legs accompanied by low grade fever and arthralgia, but proteinuria and abdominal pain could not be observed. Laboratory findings showed a normal platelet count and a normal bleeding time. High levels of serum IgG, IgA, C3 and C4 were evident. ASLO and ASK titer were elevated and they markedly increased within two weeks. A direct invasion of the vessel wall by tubercle bacilli is deniable because antituberculous treatment was successfully continued. Henoch-Schönlein purpura was diagnosed judging from these findings. High levels of ASLO and ASK suggest a preceding streptococcal infection for developing purpura but a possible infectious focus could not be identified. He was treated with 15 mg of prednisolone daily for two weeks and the lesion was subsided. The effect of prednisolone suggests that a subsequent antigen-antibody interaction caused by a streptococcal infection may participate in the formation of the purpura.
    Kekkaku: [Tuberculosis] 02/1994; 69(1):21-5.

Publication Stats

371 Citations
78.52 Total Impact Points

Institutions

  • 2003
    • Okayama University
      • Faculty of Pharmaceutical Science
      Okayama, Okayama, Japan
  • 2001
    • Tokoha University
      Hamamatu, Shizuoka, Japan
  • 1995–2000
    • Minami Okayama Medical Center
      Okayama, Okayama, Japan
  • 1989–1998
    • Shionogi & Co., Ltd.
      Ōsaka, Ōsaka, Japan