Yasuo Takeda

Publications of Yasuo Takeda

• Involvement of NF-κB activation in the cisplatin resistance of human epidermoid carcinoma KCP-4 cells.

  Authors: Shigeru Oiso, Ryuji Ikeda, Kazuo Nakamura, Yasuo Takeda, Shin-Ichi Akiyama, Hiroko Kariyazono

  Oncology reports. 05/2012;

  cis-Diamminedichloroplatinum II (cisplatin) is one of the most potent antitumor agents for the treatment of various types of cancer. In spite of its therapeutic usefulness, the intrinsic resistancecis-Diamminedichloroplatinum II (cisplatin) is one of the most potent antitumor agents for the treatment of various types of cancer. In spite of its therapeutic usefulness, the intrinsic resistance acquired under continuous treatment limits its benefit in cancer therapy. KCP-4, a cisplatin-resistant cell line, was derived from human epidermoid carcinoma KB-3-1 cells. Since the accumulation of cisplatin in KCP-4 cells is markedly reduced by the presence of an efflux pump, this pump is thought to be related to cisplatin resistance of the KCP-4 cells. However, given that KCP-4 cells are tremendously resistant to cisplatin compared with KB-3-1 cells, it is possible that another mechanism exists. The aim of this study was to investigate whether the activation of nuclear factor-kappa B (NF-κB) contributes to the cisplatin resistance of KCP-4 cells. We used the level of translocated NF-κB into the nucleus, determined by immunoblot analysis, as the indicator of NF-κB activation. The activation level of NF-κB was higher in KCP-4 cells than in KB-3-1 cells. KCP-4 cells were treated with a combination of cisplatin and curcumin, an inhibitor of NF-κB activation, and the cell viabilities were subsequently determined by the MTT assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. In the presence of 10 µmol/l curcumin, we found that the sensitivity of KCP-4 cells to 100 and 300 µmol/l cisplatin was augmented. Additionally, curcumin reduced the activation levels of NF-κB in KCP-4 cells, and suppressed the expression levels of Bcl-2, Bcl-xL and survivin, which are apoptosis-related proteins regulated by NF-κB. Our results suggest that the high cisplatin resistance of KCP-4 cells compared with KB-3-1 cells results from multiple mechanisms other than increased cisplatin efflux, including the activation of NF-κB.

• Reduction in the incidence of MRSA with use of alcohol-based hand rub solutions and gloves.

  Authors: Kazuaki Matsumoto, Akari Shigemi, Keiko Yaji, Yoshihiro Shimodozono, Yasuo Takeda, Kazuro Ikawa, Norifumi Morikawa, Hiroaki Miyanohara, Hideki Kawamura, Michiyo Orita, Koichi Tokuda, Junichiro Nishi, Katsushi Yamada

  Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy. 09/2011;

  Methicillin-resistant Staphylococcus aureus (MRSA) is highly contagious. It is spread by direct contact with MRSA-infected people or objects. Healthcare workers' hands are the most common vehicle forMethicillin-resistant Staphylococcus aureus (MRSA) is highly contagious. It is spread by direct contact with MRSA-infected people or objects. Healthcare workers' hands are the most common vehicle for the transmission of healthcare-associated pathogens from patient to patient and within the healthcare environment. The present study aimed to investigate the correlation between the incidence of MRSA among Staphylococcus aureus recovered from clinical culture and the use of alcohol-based hand rub solutions or gloves and antimicrobial use density (AUD). All data were examined every 6 months between January 2005 and June 2008. The increasing use of alcohol-based hand rub solutions was correlated with a decreasing incidence of recovery of MRSA from clinical cultures (r (2) = 0.58). A statistically significant (P < 0.05) correlation (r (2) = 0.68) was observed between glove use and the incidence of MRSA. On the other hand, we did not find any correlation between the AUD of each antibiotic group and the incidence of MRSA. Thus, we suggest that it is important to use not only alcohol-based hand rubs, but also gloves, because MRSA is transmitted from patient to patient by the hands of healthcare workers.

• Safety analysis of liposomal amphotericin B in adult patients: anaemia, thrombocytopenia, nephrotoxicity, hepatotoxicity and hypokalaemia.

  Authors: Akari Shigemi, Kazuaki Matsumoto, Kazuro Ikawa, Keiko Yaji, Yoshihiro Shimodozono, Norifumi Morikawa, Yasuo Takeda, Katsushi Yamada

  International journal of antimicrobial agents. 08/2011; 38(5):417-20.

  Liposomal amphotericin B (L-AmB), which was developed to reduce side effects, has been shown to have a better safety profile than both the deoxycholate and lipid complex forms of amphotericin B;Liposomal amphotericin B (L-AmB), which was developed to reduce side effects, has been shown to have a better safety profile than both the deoxycholate and lipid complex forms of amphotericin B; however, the frequency of major side effects is still unclear. Thus, the aim of the present study was to assess retrospectively the frequency of L-AmB-induced anaemia, thrombocytopenia, nephrotoxicity, hepatotoxicity and hypokalaemia as well as the relationship between daily dose of L-AmB and these side effects. A low red blood cell (RBC) count (post-/pre-treatment) and anaemia were observed in 7 and 10 of 21 adult patients, respectively. Thrombocytopenia was observed in 11 of 19 adult patients. Doses of L-AmB that are estimated to cause side effects of a low RBC count, anaemia and thrombocytopenia with 50% probability are 4.0, 3.3 and 3.0mg/kg/day, respectively. Nephrotoxicity was observed in 6 of 22 patients. Variations of total bilirubin, γ-glutamyl transpeptidase, aspartate aminotransferase and alanine aminotransferase used as indices of hepatotoxicity were observed in 6, 7, 8 and 8 of 22 patients, respectively. Hypokalaemia was observed in 4 of 9 patients; however, nephrotoxicity, hepatotoxicity and hypokalaemia were not caused in a dose-dependent manner. In conclusion, the present analyses showed that L-AmB dose-dependently induced anaemia and thrombocytopenia in adult patients. It is important to pay attention to causing anaemia and thrombocytopenia when patients are receiving L-AmB at doses of >3.3mg/kg/day and >3.0mg/kg/day, respectively.

• An initial dosing method for teicoplanin based on the area under the serum concentration time curve required for MRSA eradication.

  Authors: Naoko Kanazawa, Kazuaki Matsumoto, Kazuro Ikawa, Tomohide Fukamizu, Akari Shigemi, Keiko Yaji, Yoshihiro Shimodozono, Norifumi Morikawa, Yasuo Takeda, Katsushi Yamada

  Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy. 04/2011; 17(2):297-300.

  Teicoplanin is a glycopeptide antibacterial agent that has a long serum half-life and therefore takes time to achieve steady-state conditions. An appropriate initial dosing is needed for teicoplaninTeicoplanin is a glycopeptide antibacterial agent that has a long serum half-life and therefore takes time to achieve steady-state conditions. An appropriate initial dosing is needed for teicoplanin to promptly reach an effective serum trough concentration. However, little information is available on tailoring the initial dosing for patients with various characteristics. The objective of this study was to develop a nomogram for determining teicoplanin initial dose to promptly reach an effective trough concentration (≥ 13 μg/mL). A logistic regression analysis was performed to test whether the area under the concentration time curve (AUC) is a significant predictor of microbiological response (persistence 0; eradication 1). The study included 24 adult patients with methicillin-resistant Staphylococcus aureus infections [minimal inhibitory concentration (MIC) for the isolates was <2 μg/mL). Each AUC was estimated using individual dose, creatinine clearance (CL(cr)), and body weight data. The target value, which gives about a 0.9 microbiological eradication probability, was 750 μg h/mL for AUC from zero to 24 h (AUC(0-24 h)). Using published population pharmacokinetic parameters, the dose required to achieve the AUC(0-24 h) target was calculated as dose (mg) = 750 × (0.00498 × CL(cr) (mL/min) + 0.00426 × body weight (kg). For various combinations of CL(cr) and body weight, we checked the calculated doses using a therapeutic drug monitoring (TDM)-supporting software and developed a nomogram. The nomogram would be useful for initial dose adjustment to promptly reach an effective serum trough concentration and avoid adverse events of teicoplanin.

• Multidrug resistance protein 2 implicates anticancer drug-resistance to sorafenib.

  Authors: Yoshihiko Shibayama, Kou Nakano, Hiroshi Maeda, Miyuki Taguchi, Ryuji Ikeda, Mitsuru Sugawara, Ken Iseki, Yasuo Takeda, Katsushi Yamada

  Biological & pharmaceutical bulletin. 01/2011; 34(3):433-5.

  Sorafenib and sunitinib is a small molecule inhibitor of certain receptor tyrosine kinases, and have improved outcomes for patients with advanced renal cell carcinoma. Inhibitory concentration of 50%Sorafenib and sunitinib is a small molecule inhibitor of certain receptor tyrosine kinases, and have improved outcomes for patients with advanced renal cell carcinoma. Inhibitory concentration of 50% cell growth of sorafenib significantly rose to 6.4-fold in a multidrug resistance protein 2 (MRP2) transfected cell line versus control cell line. The concentration of sorafenib was significantly decreased to 74% of control cells after 3 h treatment. In contrast, a tyrosine kinase inhibitor sunitinib did not show alteration of inhibitory concentration of 50% cell growth and accumulation into the cells of MRP2 transfected cells. The present study suggest that sorafenib is a substrate for MRP2, suggesting that MRP2 may implicate drug resistance to sorafenib.

• Effect of 5-fluorouracil treatment on SN-38 absorption from intestine in rats.

  Authors: Yoshihiko Shibayama, Yoshitaka Iwashita, Yoshimi Yoshikawa, Tomoko Kondo, Ryuji Ikeda, Yasuo Takeda, Takayuki Osada, Mitsuru Sugawara, Katsushi Yamada, Ken Iseki

  Biological & pharmaceutical bulletin. 01/2011; 34(9):1418-25.

  5-Fluorouracil (5-FU)-based chemotherapies with irinotecan have been applied for the treatment of cancers, and a common dose-limiting toxicity is neutropenia and diarrhea. In this study, we5-Fluorouracil (5-FU)-based chemotherapies with irinotecan have been applied for the treatment of cancers, and a common dose-limiting toxicity is neutropenia and diarrhea. In this study, we investigated the effect of 5-FU treatment on expression levels of drug transporters for SN-38 transportation and SN-38 absorption from the intestine following 5-FU treatment. Expression levels of several drug transporters and nuclear receptors in rats after 5-FU treatment were evaluated. SN-38 absorption from the intestine was evaluated by SN-38 concentration levels in serum following SN-38 injection into the intestine of 5-FU treated rats. The levels of renal multidrug resistance protein 2 (Mrp2) on day 4 after treatment (400 mg/kg) showed significant upregulation, 359.2 ± 33.2% (mean ± S.E.) of control. Mrp2 levels in the intestine were downregulated to 26.2 ± 8.4% of control. 5-FU treatment (400 mg/kg) also significantly downregurated expression levels of P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) to 41.2 ± 14.7%, 15.7 ± 4.3% of control, respectively. To evaluate SN-38 absorption from the intestine, SN-38 was loaded in to the intestine on day 4 after 5-FU treatment. Pretreatment with 5-FU significantly increased SN-38 concentration in the blood 30, 60 and 90 min after SN-38 administration. The area under the curve for SN-38 in the 5-FU group was significantly higher than in vehicle groups. 5-FU treatment decreased expression levels of P-glycoprotein and Bcrp in intestine. The present study suggests that combination chemotherapy of 5-FU with irinotecan (CPT-11) may elevate SN-38 absorption from intestine.

• The role of thymidine phosphorylase in the induction of early growth response protein-1 and thrombospondin-1 by 5-fluorouracil in human cancer carcinoma cells.

  Authors: Shigeto Matsushita, Ryuji Ikeda, Yukihiko Nishizawa, Xiao-Fang Che, Tatsuhiko Furukawa, Kazutaka Miyadera, Sho Tabata, Mina Ushiyama, Yusuke Tajitsu, Masatatsu Yamamoto, Yasuo Takeda, Kentaro Minami, Hironori Mataki, Tamotsu Kanzaki, Katsushi Yamada, Takuro Kanekura, Shin-Ichi Akiyama

  International journal of oncology. 05/2010; 36(5):1193-200.

  Thymidine phosphorylase (TP) is an enzyme involved in reversible conversion of thymidine to thymine. TP is identical to an angiogenic factor, pletelet-derived endothelial cell growth factor (PD-ECGF)Thymidine phosphorylase (TP) is an enzyme involved in reversible conversion of thymidine to thymine. TP is identical to an angiogenic factor, pletelet-derived endothelial cell growth factor (PD-ECGF) and the expression levels of TP in a variety of malignant tumors were higher than the adjacent non-neoplastic tissues. To investigate the molecular basis for the effect of TP on the metabolic process and the anticancer effect of 5-fluorouracil (5-FU), human gastric carcinoma AZ521 cells and epidermoid carcinoma KB cells were transfected with TP cDNA, and AZ521/TP and KB/TP were cloned. AZ521/TP and KB/TP cells overexpressed TP and were more sensitive to 5-FU than the counterpart parental cells. TPI, a newly synthesized inhibitor for TP (Ki=2.36 x 10(-9) M), decreased the sensitivity to 5-FU of the TP expressing cells but not of the parental cells. 5-Formyl-tetrahydrofolate (leucovorin; LV) stabilized the complex of thymidylate synthase (TS) and 5-fluoro-deoxyuridine-monophosphate (FdUMP), increased the sensitivity to 5-FU of TP expressing AZ521 cells, but not of the parental cells. The levels of FdUMP in TP expressing cells were significantly higher than in parental cells and TPI considerably decreased FdUMP to the level comparable to that in the parental cells. 5-FU increased the expression of early growth response protein-1 (Egr-1) and an angiogenesis inhibitor, thrombospondin-1 (TSP-1), in KB/TP cells but only slightly in KB/CV cells, if any. TPI attenuated the induction of Egr-1 and TSP-1 mRNA by 5-FU, while LV increased the expression of Egr-1 and TSP-1 mRNA in KB/TP cells. These findings demonstrate that the TP has a principal role in the production of FdUMP and the enhanced responses to 5-FU by leucovorin in TP-overexpressing KB and AZ521 cells, and FdUMP but not FUTP is implicated in the induction of Egr-1 and TSP-1 in KB cells.

• Higher linezolid exposure and higher frequency of thrombocytopenia in patients with renal dysfunction.

  Authors: Kazuaki Matsumoto, Ayumi Takeshita, Kazuro Ikawa, Akari Shigemi, Keiko Yaji, Yoshihiro Shimodozono, Norifumi Morikawa, Yasuo Takeda, Katsushi Yamada

  International journal of antimicrobial agents. 04/2010; 36(2):179-81.

  The major adverse event associated with linezolid treatment is reversible myelosuppression, mostly thrombocytopenia. Recent studies have reported that the incidence of linezolid-inducedThe major adverse event associated with linezolid treatment is reversible myelosuppression, mostly thrombocytopenia. Recent studies have reported that the incidence of linezolid-induced thrombocytopenia was higher in patients with renal failure than in patients with normal renal function, although the underlying mechanisms of this toxicity are still unknown. The present study thus aimed to investigate the relationship between renal function and linezolid exposure as well as the effects of drug exposure on thrombocytopenia. A statistically significant (P<0.01) strong correlation (r=0.933) was observed between linezolid clearance and creatinine clearance. A negative correlation (r=-0.567) was also shown between linezolid clearance and blood urea nitrogen, although the correlation was not statistically significant. In thrombocytopenic patients, the trough concentration was 14.4-35.6 mg/L and the area under the plasma linezolid concentration-time curve for 24h (AUC(24h)) was 513.1-994.6 mg h/L; in non-thrombocytopenic patients, drug exposure was relatively low (6.9 mg/L and 7.2mg/L for trough concentration and 294.3 mg h/L and 323.6 mg h/L for AUC(24h)). These results provide a pharmacokinetic explanation for the mechanism of the adverse event that renal dysfunction increased linezolid trough concentration and AUC and that higher drug exposure induced thrombocytopenia.

• Determination of teicoplanin trough concentration target and appropriate total dose during the first 3 days: a retrospective study in patients with MRSA infections.

  Authors: Kazuaki Matsumoto, Naoko Kanazawa, Kazuro Ikawa, Tomohide Fukamizu, Akari Shigemi, Keiko Yaji, Yoshihiro Shimodozono, Norifumi Morikawa, Yasuo Takeda, Katsushi Yamada

  Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy. 03/2010; 16(3):193-9.

  An initial loading procedure has been recommended to enable teicoplanin to promptly reach an effective serum concentration for the treatment of methicillin-resistant Staphylococcus aureus (MRSA).An initial loading procedure has been recommended to enable teicoplanin to promptly reach an effective serum concentration for the treatment of methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to retrospectively evaluate the pharmacokinetics and pharmacodynamics of teicoplanin to determine the therapeutic target for the teicoplanin trough concentration and an appropriate dosing method during the first 3 days. The mean trough concentrations were 13.2 mg/L for patients with eradication of MRSA. Moreover, logistic regression analysis showed that the teicoplanin trough concentration was 13 mg/L to achieve MRSA eradication with a probability of 89.0%. The rates of achieving >or=13 mg/L in <or=24, 24-36 and >or=36 mg/kg (total dose during the first 3 days) groups were 9.1, 48.4 and 87.5%, respectively. These results suggest that the administration of >or=36 mg/kg during the first 3 days is appropriate to promptly obtain a trough concentration target of >or=13 mg/L for the initial treatment of MRSA infections.

• Major vault protein forms complexes with hypoxia-inducible factor (HIF)-1alpha and reduces HIF-1alpha level in ACHN human renal adenocarcinoma cells.

  Authors: Ken-ichi Iwashita, Ryuji Ikeda, Yasuo Takeda, Tomoyuki Sumizawa, Tatsuhiko Furukawa, Tatsuya Yamaguchi, Shin-ichi Akiyama, Katsushi Yamada

  Cancer science. 02/2010; 101(4):920-6.

  Vaults are evolutionarily highly conserved ribonucleoprotein (RNP) particles with a hollow barrel-like structure. Although roles in multidrug resistance and innate immunity have been suggested, theVaults are evolutionarily highly conserved ribonucleoprotein (RNP) particles with a hollow barrel-like structure. Although roles in multidrug resistance and innate immunity have been suggested, the physiological function of vaults remains unclear. Major vault protein (MVP), the main component of the vault particle, has been reported to be induced by hypoxia. However, there are no reports about the effect of vaults on cellular responses to hypoxia. We thus examined whether vaults are implicated in cellular responses to hypoxia. In this study, we focused on hypoxia-inducible factor-1alpha (HIF-1alpha), which is a master regulator of hypoxic responses, and found that: (i) MVP knockdown by RNA interference increases HIF-1alpha protein levels induced by hypoxia and hypoxia mimetics; (ii) MVP knockdown does not affect HIF-1alpha mRNA levels, but decreases the ubiquitination and degradation of HIF-1alpha protein; and (iii) vaults form complexes with HIF-1alpha, PHD2, and pVHL. Taken together, these results suggest that vaults function as scaffolds in HIF-1alpha degradation pathway and promote the ubiquitination and degradation of HIF-1alpha.

• Synaptic formation in subsets of glutamatergic terminals in the mouse hippocampal formation is affected by a deficiency in the neural cell recognition molecule NB-3.

  Authors: Kunie Sakurai, Manabu Toyoshima, Yasuo Takeda, Yasushi Shimoda, Kazutada Watanabe

  Neuroscience letters. 02/2010; 473(2):102-6.

  The neural cell recognition molecule NB-3, which is also referred to as contactin-6, is a member of the contactin subgroup molecules that are expressed prominently in the developing nervous systemThe neural cell recognition molecule NB-3, which is also referred to as contactin-6, is a member of the contactin subgroup molecules that are expressed prominently in the developing nervous system after birth. In mice, an NB-3 deficiency impairs motor coordination and reduces the synaptic density between parallel fibers and Purkinje cells in the cerebellum. Here, we studied the role of NB-3 in the formation of glutamatergic synapses in the hippocampal formation. At postnatal day 5, NB-3 immunoreactivity was detected in the subiculum, the stratum lacunosum-moleculare of the CA1 region and the hilus of the dentate gyrus. NB-3 expression in the strata radiatum and oriens was weak, and it was very weak in the granule cell layer of the dentate gyrus, the pyramidal cell layer of regions CA3 to CA1 and the stratum lucidum. NB-3-positive puncta partially overlapped with vesicular glutamate transporter 1 (VGLUT1) and 2 (VGLUT2), excitatory presynaptic markers, but not with vesicular GABA transporter (VGAT), an inhibitory presynaptic marker. The density of VGLUT1 and VGLUT2 puncta in the regions where NB-3 was strongly expressed in wild-type mice was reduced by approximately 20-30% in NB-3 knockout mice relative to wild-type mice, whereas that of VGAT puncta was not affected by NB-3 deficiency. Thus, NB-3 has key roles in the formation of glutamatergic, but not GABAergic, synapses during postnatal development of the hippocampal formation as well as the cerebellum.

• Deficiency of neural recognition molecule NB-2 affects the development of glutamatergic auditory pathways from the ventral cochlear nucleus to the superior olivary complex in mouse.

  Authors: Manabu Toyoshima, Kunie Sakurai, Kuniko Shimazaki, Yasuo Takeda, Yasushi Shimoda, Kazutada Watanabe

  Developmental biology. 10/2009;

  Neural recognition molecule NB-2/contactin 5 is expressed transiently during the first postnatal week in glutamatergic neurons of the central auditory system. Here, we investigated the effect of NB-2Neural recognition molecule NB-2/contactin 5 is expressed transiently during the first postnatal week in glutamatergic neurons of the central auditory system. Here, we investigated the effect of NB-2 deficiency on the auditory brainstem in mouse. While almost all principal neurons are wrapped with the calyces of Held in the medial nucleus of the trapezoid body (MNTB) in wild type, 8% of principal neurons in NB-2 knockout (KO) mice lack the calyces of Held at postnatal day (P) 6. At P10 and P15, apoptotic principal neurons were detected in NB-2 KO mice, but not in wild type. Apoptotic cells were also increased in the ventral cochlear nucleus (VCN) of NB-2 KO mice, which contains bushy neurons projecting to the MNTB and the lateral superior olive (LSO). At the age of 1 month, the number of principal neurons in the MNTB and of glutamatergic synapses in the LSO was reduced in NB-2 KO mice. Finally, interpeak latencies for auditory brainstem response waves II-III and III-IV were significantly increased in NB-2 KO mice. Together, these findings suggest that NB-2 deficiency causes a deficit in synapse formation and then induces apoptosis in MNTB and VCN neurons, affecting auditory brainstem function.

• Correlation between meropenem and doripenem use density and the incidence of carbapenem-resistant Pseudomonas aeruginosa.

  Authors: Akari Shigemi, Kazuaki Matsumoto, Keiko Yaji, Yoshihiro Shimodozono, Yasuo Takeda, Hiroaki Miyanohara, Hideki Kawamura, Michiyo Orita, Koichi Tokuda, Junichiro Nishi, Katsushi Yamada

  International journal of antimicrobial agents. 09/2009;

  Optimal use of carbapenems is an important issue in the prevention of resistance in Pseudomonas aeruginosa. In this study, we investigated the correlation between antimicrobial use density (AUD) ofOptimal use of carbapenems is an important issue in the prevention of resistance in Pseudomonas aeruginosa. In this study, we investigated the correlation between antimicrobial use density (AUD) of carbapenems and imipenem/cilastatin (IPM/CS) or meropenem (MEPM) susceptibility of P. aeruginosa strains. The AUD of five carbapenems [IPM/CS, panipenem/betamipron, biapenem, MEPM and doripenem (DRPM)] was examined every 6 months between 2006 and 2008. The AUD was calculated using the defined daily doses methodology developed by the World Health Organisation. A minimum inhibitory concentration of IPM/CS or MEPM of </=4mg/L was considered to be sensitive. There was a significant negative correlation between MEPM susceptibility and the total AUD of MEPM and DRPM [r=-0.823, 95% confidence interval (CI) -0.035 to -0.980; P=0.044]. Furthermore, there was a significant correlation between MEPM susceptibility and IPM/CS susceptibility (r=0.839, 95% CI 0.084 to 0.981; P=0.037). Cross-resistance was therefore investigated and only 5.6% of MEPM-insensitive strains were susceptible to IPM/CS, although 43.3% of IPM/CS-insensitive strains were susceptible to MEPM. These results suggest that curtailing the use of MEPM and DRPM may curb the emergence not only of MEPM-resistant strains but also IPM/CS-resistant strains.

• Contribution of the neural cell recognition molecule NB-3 to synapse formation between parallel fibers and Purkinje cells in mouse.

  Authors: Kunie Sakurai, Manabu Toyoshima, Hidehiro Ueda, Kota Matsubara, Yasuo Takeda, Domna Karagogeos, Yasushi Shimoda, Kazutada Watanabe

  Developmental neurobiology. 09/2009;

  The neural cell recognition molecule NB-3, also referred to as contactin-6, is expressed prominently in the developing nervous system after birth and its deficiency has been shown to cause impairmentThe neural cell recognition molecule NB-3, also referred to as contactin-6, is expressed prominently in the developing nervous system after birth and its deficiency has been shown to cause impairment in motor coordination. Here, we investigated the contribution of NB-3 to cerebellar development, focusing on lobule 3 where NB-3 was expressed in granule cells but not in Purkinje cells. In the developing molecular layer, the neural cell recognition molecules TAG-1, L1, and NB-3 formed distinct expression zones from the external granule cell layer to the internal granule cell layer (IGL), respectively. The NB-3-immunoreactive zone did not overlap with TAG-1-immunoreactive zone. By contrast, the L1-immunoreactive zone overlapped with both the TAG-1- and NB-3-immunoreactive zones. NB-3-positive puncta overlapped with vesicular glutamate transporter 1, a presynaptic marker and were apposed close to metabotropic glutamate receptor 1A, a postsynaptic marker, indicating that NB-3 is localized presynaptically at glutamatergic synapses between parallel fibers and Purkinje cells. In NB-3 knockout mice, L1 immunoreactive signals were increased in the IGL at postnatal day (P) 5, suggesting the increase in the number of immature granule cells of the IGL. In addition, the density of parallel fiber synaptic terminals was reduced in NB-3 knockout mice relative to wild-type mice at P5 to P10. In parallel with these findings, caspase-dependent cell death was significantly increased in the NB- 3-deficient cerebellum at P15. Collectively, our results indicate that NB-3 deficiency affects synapse formation during postnatal cerebellar development. (c) 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009.

• Effect of methotrexate treatment on expression levels of organic anion transporter polypeptide 2, p-glycoprotein and bile salt export pump in rats.

  Authors: Yoshihiko Shibayama, Yasuo Takeda, Katsushi Yamada

  Biological & pharmaceutical bulletin. 04/2009; 32(3):493-6.

  High-dose methotrexate (HDMTX) chemotherapy with leucovorin (LV) rescue has been used as a therapeutic strategy in oncology since the 1970s. Adverse reactions following extension of methotrexateHigh-dose methotrexate (HDMTX) chemotherapy with leucovorin (LV) rescue has been used as a therapeutic strategy in oncology since the 1970s. Adverse reactions following extension of methotrexate (MTX) elimination are a crucial problem in HDMTX chemotherapy. MTX is a substrate for drug transporters, which are multidrug resistance protein 2 (Mrp2), organic anion transporter polypeptide 2 (Oatp2) and other transporters. We previously reported that MTX treatment downregulated the expression level of Mrp2 in rats. Here we examined the effect of MTX treatment on the expression of Oatp2, P-glycoprotein (P-gp) and bile salt export pump (Bsep) in rats. MTX was single-injected intraperitoneally at a dose of 150 mg/kg, and Western blot analysis was performed. The levels of Oatp2, P-gp and Bsep in the liver on day 4 after treatment were downregulated to 36.3+/-6.9%, 51.5+/-5.2% and 61.8+/-5.5% (mean+/-S.E.M.) of controls, respectively. Expression levels of P-gp in the kidney and ileum were also downregulated to 38.5+/-1.6% and 16.2+/-1.6% of controls, respectively. These effects of MTX were partially recovered by LV, which rescues normal cells from MTX toxicity. In conclusion, the result indicates that MTX treatment downregulates expression levels of Oatp2, P-gp and Bsep.

• Correlation between voriconazole trough plasma concentration and hepatotoxicity in patients with different CYP2C19 genotypes.

  Authors: Kazuaki Matsumoto, Kazuro Ikawa, Kazuko Abematsu, Naoko Fukunaga, Kentaro Nishida, Tomohide Fukamizu, Yoshihiro Shimodozono, Norifumi Morikawa, Yasuo Takeda, Katsushi Yamada

  International journal of antimicrobial agents. 03/2009;

  Voriconazole metabolism is mostly mediated via the cytochrome P450 (CYP) 2C19 isozyme. The non-wild (mutant) type of CYP2C19 is generally found in 60-70% of Asian populations. Because theVoriconazole metabolism is mostly mediated via the cytochrome P450 (CYP) 2C19 isozyme. The non-wild (mutant) type of CYP2C19 is generally found in 60-70% of Asian populations. Because the voriconazole trough plasma concentration has been reported to correlate with hepatotoxicity, this study investigated the effect of CYP2C19 polymorphism on the relationship between voriconazole trough concentrations and liver function abnormalities in 29 Japanese patients with fungal infections (CYP2C19 wild-type, n=10; non-wild-type, n=19). Hepatotoxicity, defined as liver enzyme abnormality according to the National Cancer Institute criteria, was observed in 10 (34.5%) of 29 patients with a trough concentration >/=3.9mg/L. Logistic regression analysis suggested that the therapeutic range for the voriconazole trough concentration should be 2-4mg/L. Non-linear pharmacokinetic analysis suggested that voriconazole therapy should be initiated with a dose of 7.2-8.9mg/kg/day for CYP2C19 wild-type and 4.4-6.5mg/kg/day for the non-wild-type in Japanese patients. These recommended initial dosages and subsequent dose adjustment for the target concentration range by therapeutic drug monitoring should avoid adverse events and thus enable continued effective voriconazole therapy for Japanese patients with mycoses.

• Preferential localization of neural cell recognition molecule NB-2 in developing glutamatergic neurons in the rat auditory brainstem.

  Authors: Manabu Toyoshima, Kunie Sakurai, Kuniko Shimazaki, Yasuo Takeda, Masatoshi Nakamoto, Shou Serizawa, Yasushi Shimoda, Kazutada Watanabe

  The Journal of comparative neurology. 02/2009; 513(4):349-362.

  NB-2 is a neuronal cell recognition molecule that is preferentially expressed in auditory pathways. Mice deficient in the NB-2 gene exhibit aberrant responses to acoustic stimuli. Here we examinedNB-2 is a neuronal cell recognition molecule that is preferentially expressed in auditory pathways. Mice deficient in the NB-2 gene exhibit aberrant responses to acoustic stimuli. Here we examined the expression and localization of NB-2 in the auditory brainstem during development in the rat. NB-2 was strongly expressed in the ventral cochlear nucleus (VCN), ventral acoustic stria, lateral and medial superior olivary complex (SOC), superior paraolivary nucleus, medial nucleus of the trapezoid body (MNTB), ventrolateral lemniscus, and central nucleus of the inferior colliculus (CIC). In the VCN and CIC, NB-2 was expressed in the regions that are known to respond to high frequencies. In situ hybridization combined with immunohistochemistry suggested that NB-2 is expressed only in neurons. NB-2 was colocalized with glutamatergic elements in the neuropil and the calyces of Held but not with glycinergic or GABAergic elements. NB-2 expression in the SOC was first detected at embryonic day (E)19, reached a maximum level at postnatal day (P)7, and declined thereafter. Immunolabeling with VGLUT1 and VGLUT2, markers for mature and premature glutamatergic synapses, respectively, in combination with NB-2 immunolabeling revealed that NB-2 is expressed at glutamatergic synapses. Collectively, our findings suggest that NB-2 plays a key role in maturation of glutamatergic synapses in the brainstem during the final stages of auditory development. J. Comp. Neurol. 513:349-362, 2009. (c) 2009 Wiley-Liss, Inc.

• Contactin-associated protein (Caspr) 2 interacts with carboxypeptidase E in the central nervous system.

  Authors: Shigeru Oiso, Yasuo Takeda, Toshitaka Futagawa, Takehiko Miura, Satoshi Kuchiiwa, Kentaro Nishida, Ryuji Ikeda, Hiroko Kariyazono, Kazutada Watanabe, Katsushi Yamada

  Journal of neurochemistry. 02/2009;

  To identify proteins interacting with the intracellular domain of the neural cell adhesion molecule contactin-associated protein 2 (Caspr2), yeast two-hybrid screening was performed. We identifiedTo identify proteins interacting with the intracellular domain of the neural cell adhesion molecule contactin-associated protein 2 (Caspr2), yeast two-hybrid screening was performed. We identified carboxypeptidase E (CPE) as a Caspr2-interacting candidate protein. Glutatione S-transferase pull-down and immunoprecipitation analyses indicated that Caspr2 was associated with CPE in vitro and in vivo. Both Caspr2 and CPE were expressed predominantly in the central nervous system. Immunohistochemical analyses revealed that both Caspr2- and CPE-like immunoreactivities were found to co-localize in the apical dendrites and cell bodies of rat cortical neurons. In subcellular localization analysis, Caspr2- and CPE-like immunoreactivities were comigrated in the fractions of Golgi/ER. Additionally, in COS-7 cells cotransfected with CPE and Caspr2 cDNAs, Caspr2- and CPE-immunoreactivities were co-localized in both Golgi and membrane, whereas it was only observed in Golgi of either COS-7 cell transfected with CPE or Caspr2 cDNA alone. It is known that the membrane-bound form of CPE functions as a sorting receptor of prohormones in the trans-Golgi network. Taken together, our data suggest that CPE may be a key molecule to regulate Caspr2 trafficking to the cell membrane.

• Contactin-associated protein (Caspr) 2 interacts with carboxypeptidase E in the CNS

  Authors: Shigeru Oiso, Yasuo Takeda, Toshitaka Futagawa, Takehiko Miura, Satoshi Kuchiiwa, Kentaro Nishida, Ryuji Ikeda, Hiroko Kariyazono, Kazutada Watanabe, Katsushi Yamada

  J Neurochem. 01/2009; 109(1):158-67.

  To identify proteins interacting with the intracellular domain of the neural cell adhesion molecule contactin-associated protein 2 (Caspr2), yeast two-hybrid screening was performed. We identifiedTo identify proteins interacting with the intracellular domain of the neural cell adhesion molecule contactin-associated protein 2 (Caspr2), yeast two-hybrid screening was performed. We identified carboxypeptidase E (CPE) as a Caspr2-interacting candidate protein. Glutathione S-transferase pull-down and immunoprecipitation analyses indicated that Caspr2 was associated with CPE in vitro and in vivo. Both Caspr2 and CPE were expressed predominantly in the CNS. Immunohistochemical analyses revealed that both Caspr2- and CPE-like immunoreactivities were found to co-localize in the apical dendrites and cell bodies of rat cortical neurons. In subcellular localization analysis, Caspr2- and CPE-like immunoreactivities were co-migrated in the fractions of Golgi/ER. Additionally, in COS-7 cells co-transfected with CPE and Caspr2 cDNAs, Caspr2- and CPE-immunoreactivities were co-localized in both Golgi and membrane, whereas it was only observed in Golgi of either COS-7 cell transfected with CPE or Caspr2 cDNA alone. It is known that the membrane-bound form of CPE functions as a sorting receptor of prohormones in the trans-Golgi network. Taken together, our data suggest that CPE may be a key molecule to regulate Caspr2 trafficking to the cell membrane.

• Renal function as a predictor of linezolid-induced thrombocytopenia.

  Authors: Kazuaki Matsumoto, Yasuo Takeda, Ayumi Takeshita, Naoko Fukunaga, Akari Shigemi, Keiko Yaji, Yoshihiro Shimodozono, Katsushi Yamada, Kazuro Ikawa, Norifumi Morikawa

  International journal of antimicrobial agents. 10/2008;