Tatsuya Higashi

Summary

Affiliation: Tokyo University of Science
Country: Japan

Publications

  1. ncbi request reprint LC/MS/MS of steroids having vicinal diol as electrospray-active boronates
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
    Chem Pharm Bull (Tokyo) 61:326-32. 2013
  2. doi request reprint Overestimation of salivary 25-hydroxyvitamin D3 level when using stimulated saliva with gum-chewing
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278 8510, Japan
    Steroids 78:884-7. 2013
  3. doi request reprint Derivatization of chiral carboxylic acids with (S)-anabasine for increasing detectability and enantiomeric separation in LC/ESI-MS/MS
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
    J Sep Sci 35:2840-6. 2012
  4. doi request reprint Influence of saliva flow rate stimulated by gum-chewing on salivary concentrations of catecholamine metabolites
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda 278 8510, Japan
    Clin Chim Acta 414:248-52. 2012
  5. ncbi request reprint Salivary hormone measurement using LC/MS/MS: specific and patient-friendly tool for assessment of endocrine function
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
    Biol Pharm Bull 35:1401-8. 2012
  6. doi request reprint Diels-Alder derivatization for sensitive detection and characterization of conjugated linoleic acids using LC/ESI-MS/MS
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
    Anal Bioanal Chem 403:495-502. 2012
  7. ncbi request reprint Application of 4-(4-nitrophenyl)-1,2,4-triazoline-3,5-dione to analysis of 25-hydroxyvitamin D3 in human plasma by liquid chromatography/electron capture atmospheric pressure chemical ionization-mass spectrometry
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Kanazawa University, 13 1 Takara machi, Kanazawa 920 0934, Japan
    Anal Sci 19:941-3. 2003
  8. ncbi request reprint A novel Cookson-type reagent for enhancing sensitivity and specificity in assessment of infant vitamin D status using liquid chromatography/tandem mass spectrometry
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278 8510, Japan
    Rapid Commun Mass Spectrom 27:2453-60. 2013
  9. doi request reprint An efficient synthesis of 7α,12α-dihydroxy-4-cholesten-3-one and its biological precursor 7α-hydroxy-4-cholesten-3-one: Key intermediates in bile acid biosynthesis
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba 278 8510, Japan
    Steroids 78:927-37. 2013
  10. doi request reprint (S)-1-(4-Dimethylaminophenylcarbonyl)-3-aminopyrrolidine: a derivatization reagent for enantiomeric separation and sensitive detection of chiral carboxylic acids by LC/ESI-MS/MS
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278 8510, Japan
    J Chromatogr B Analyt Technol Biomed Life Sci 940:7-14. 2013

Collaborators

Detail Information

Publications15

  1. ncbi request reprint LC/MS/MS of steroids having vicinal diol as electrospray-active boronates
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
    Chem Pharm Bull (Tokyo) 61:326-32. 2013
    ....
  2. doi request reprint Overestimation of salivary 25-hydroxyvitamin D3 level when using stimulated saliva with gum-chewing
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278 8510, Japan
    Steroids 78:884-7. 2013
    ..The aim of this study was to clarify whether the concentration of 25(OH)D3 in whole saliva is influenced by gum-chewing...
  3. doi request reprint Derivatization of chiral carboxylic acids with (S)-anabasine for increasing detectability and enantiomeric separation in LC/ESI-MS/MS
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
    J Sep Sci 35:2840-6. 2012
    ....
  4. doi request reprint Influence of saliva flow rate stimulated by gum-chewing on salivary concentrations of catecholamine metabolites
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda 278 8510, Japan
    Clin Chim Acta 414:248-52. 2012
    ..However, the rate of saliva production may affect the salivary concentrations of these catecholamine metabolites. We clarified whether the salivary concentrations of HVA and MHPG are dependent on the rate of salivation...
  5. ncbi request reprint Salivary hormone measurement using LC/MS/MS: specific and patient-friendly tool for assessment of endocrine function
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
    Biol Pharm Bull 35:1401-8. 2012
    ..Practical derivatization to enhance the detectabilities of hormones in ESI-MS/MS is also discussed, because a major disadvantage of using saliva is low hormone concentrations...
  6. doi request reprint Diels-Alder derivatization for sensitive detection and characterization of conjugated linoleic acids using LC/ESI-MS/MS
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan
    Anal Bioanal Chem 403:495-502. 2012
    ....
  7. ncbi request reprint Application of 4-(4-nitrophenyl)-1,2,4-triazoline-3,5-dione to analysis of 25-hydroxyvitamin D3 in human plasma by liquid chromatography/electron capture atmospheric pressure chemical ionization-mass spectrometry
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Kanazawa University, 13 1 Takara machi, Kanazawa 920 0934, Japan
    Anal Sci 19:941-3. 2003
    ..This derivatization-LC/ECAPCI-MS method was applied to a plasma 25-hydroxyvitamin D3 assay, and gave satisfactory results in sensitivity, specificity, measurable range and throughput of the analysis...
  8. ncbi request reprint A novel Cookson-type reagent for enhancing sensitivity and specificity in assessment of infant vitamin D status using liquid chromatography/tandem mass spectrometry
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278 8510, Japan
    Rapid Commun Mass Spectrom 27:2453-60. 2013
    ..The objective of this study was the development of a novel Cookson-type reagent surpassing PTAD in terms of sensitivity and specificity in the LC/ESI-MS/MS assay of 25(OH)D3...
  9. doi request reprint An efficient synthesis of 7α,12α-dihydroxy-4-cholesten-3-one and its biological precursor 7α-hydroxy-4-cholesten-3-one: Key intermediates in bile acid biosynthesis
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba 278 8510, Japan
    Steroids 78:927-37. 2013
    ....
  10. doi request reprint (S)-1-(4-Dimethylaminophenylcarbonyl)-3-aminopyrrolidine: a derivatization reagent for enantiomeric separation and sensitive detection of chiral carboxylic acids by LC/ESI-MS/MS
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278 8510, Japan
    J Chromatogr B Analyt Technol Biomed Life Sci 940:7-14. 2013
    ....
  11. doi request reprint Stereoselective synthesis and NMR characterization of C-24 epimeric pairs of 24-alkyl oxysterols
    Shoujiro Ogawa
    Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba 278 8510, Japan
    Lipids 48:197-207. 2013
    ..The present method may be useful for determining the stereochemical configuration at C-24 of this type of 24-alkyl oxysterols...
  12. ncbi request reprint Studies on neurosteroids XVI. Levels of pregnenolone sulfate in rat brains determined by enzyme-linked immunosorbent assay not requiring solvolysis
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Kanazawa University, Takara machi, Japan
    Biol Pharm Bull 26:709-11. 2003
    ..37-1.29 ng/g tissue). These results demonstrate that, in rats, the brain PREGS may be derived from peripheral sources, and its actual levels are much lower than those previously measured by indirect methods...
  13. ncbi request reprint Detection and characterization of 20-oxosteroids in rat brains using LC-electron capture APCI-MS after derivatization with 2-nitro-4-trifluoromethylphenylhydrazine
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Kanazawa University, 13 1 Takara machi, Kanazawa 920 0934, Japan
    Analyst 128:130-3. 2003
    ..Pregnenolone, progesterone, 5alpha-dihydroprogesterone, allopregnanolone and epiallopregnanolone were clearly detected with a 50 mg sample of the brain tissue...
  14. ncbi request reprint Derivatization of neutral steroids to enhance their detection characteristics in liquid chromatography-mass spectrometry
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Kanazawa University, 13 1 Takara machi, 920 0934 Kanazawa, Japan
    Anal Bioanal Chem 378:875-82. 2004
    ..The introduction of moieties with proton affinity or electron affinity enhances the analyte signals in positive and negative atmospheric pressure chemical ionization MS, respectively...
  15. ncbi request reprint Electron-capturing derivatization of neutral steroids for increasing sensitivity in liquid chromatography/negative atmospheric pressure chemical ionization-mass spectrometry
    Tatsuya Higashi
    Faculty of Pharmaceutical Sciences, Kanazawa University, 13 1 Takara machi, Kanazawa 920 0934, Japan
    Anal Sci 18:1301-7. 2002
    ..The developed derivatization procedures were applied to analyses of small amounts of steroids in human plasma and gave satisfactory results...