Development of High-purity Certified Reference Materials for 17 Proteinogenic Amino Acids by Traceable Titration Methods

Kato, Megumi; Yamazaki, Taichi; Kato, Hisashi; Eyama, Sakae; Goto, Mari; Yoshioka, Mariko; Takatsu, Akiko

doi:10.2116/analsci.31.805

Cited by 12 publications

(7 citation statements)

References 20 publications

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“…In order to establish a certified reference material of C-peptide having traceability to SI, the NMIJ developed isotope-dilution mass spectrometry (IDMS) (25, 26) methods for amino acid analysis and amino acid certified reference materials (CRM)(27). The certification process of C-peptide candidate CRM consisted of impurity quantification, and homogeneity and stability testing.…”

Section: Efforts To Harmonize C-peptide Resultsmentioning

confidence: 99%

“…The candidate standard was also shown to have appropriate immunological activity in the immunoassay systems included in the study. C-peptide is measured clinically in serum/plasma and urine, and so, using a difference in bias approach (27)in ten of these immunoassay systems to assess the commutability of the candidate standard with serum and urine samples, it was additionally shown that with the exception of two of these assays the candidate standard demonstrated commutability with respect to the serum and urine samples included in the study (30). The First International Standard for C-peptide is now available from NIBSC.…”

Section: Efforts To Harmonize C-peptide Resultsmentioning

confidence: 99%

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Implementing a Reference Measurement System for C-Peptide: Successes and Lessons Learned

et al. 2017

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Background Assessment of endogenous insulin secretion by measuring C-peptide concentrations is widely accepted. Recent studies have shown that preservation of even small amounts of endogenous C-peptide production in patients with Type 1 diabetes reduces risks for diabetic complications. Harmonization of C-peptide results will facilitate comparison of data from different research studies and later among clinical laboratory results at different sites using different assay methods. Content This review provides an overview of the general process of harmonization and standardization and the challenges encountered with implementing a reference measurement system for C-peptide. Summary Efforts to harmonize C-peptide results are described including those by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)-led C-peptide Standardization Committee in the US, activities in Japan, efforts by the National Institute for Biological Standards and Control (NIBSC) in the UK, activities led by the Bureau International des Poids et Mesures (BIPM) and the National Metrology Institute in China (NIM China). A traceability scheme is proposed along with next steps for implementation. Suggestions are made for better collaboration in an effort to optimize the harmonization process for other measurands.

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Section: Efforts To Harmonize C-peptide Resultsmentioning

confidence: 99%

Section: Efforts To Harmonize C-peptide Resultsmentioning

confidence: 99%

Implementing a Reference Measurement System for C-Peptide: Successes and Lessons Learned

et al. 2017

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“…Analysis of the data revealed that the CM fruiting body water extract contained 29.04% polysaccharides, 20.45% total proteins, 6.01% cordycepic acid, 0.204% adenosine and 0.347% cordycepin. The polysaccharides were measured via phenol-sulfuric acid method ( 23 ), the total proteins were analysed via Kjeldahl method ( 24 ), and the cordycepic acid, adenosine and cordycepin were analysed via high performance liquid chromatography ( 25 ).…”

Section: Methodsmentioning

confidence: 99%

Cordyceps militaris induces tumor cell death via the caspase-dependent mitochondrial pathway in HepG2 and MCF-7 cells

Song

Wang

Teng

et al. 2016

Molecular Medicine Reports

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Cordyceps militaris (CM), an entomopathogenic fungus belonging to the class ascomycetes, possesses various pharmacological activities, including cytotoxic effects, on various types of human tumor cells. The present study investigated the anti-hepatocellular carcinoma (HCC) and anti-breast cancer effects of CM in in vitro and in vivo models. CM aqueous extract reduced cell viability, suppressed cell proliferation, inhibited cell migration ability, caused the over-release of lactate dehydrogenase, induced mitochondrial dysfunction and enhanced apoptotic rates in MCF-7 and HepG2 cells. The expression levels of cleaved poly (ADP ribose) polymerase and caspase-3, biomarkers of apoptosis, were increased following treatment with CM aqueous extract for 24 h. Furthermore, in the MCF-7 and HepG2 cells, enhanced levels of B cell-associated X protein and cleaved caspase-8 were observed in the CM-treated cells. Finally, the antitumor activities of CM in HCC and breast cancer were also confirmed in MCF-7- and HepG2-xengraft nude mice models. Collectively, the data obtained in the present study suggested that the cytotoxic effects of CM aqueous extract on HCC and breast cancer are associated with the caspase-dependent mitochondrial pathway.

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“…14 The CRM of potassium hydrogen phthalate (PHP) with a purity of (1.0000 ± 0.00027)kg kg -1 as IS was obtained from NMIJ. Deuterium oxide (D2O) was purchased from Acros Organics (NJ, USA).…”

Section: Methodsmentioning

confidence: 99%

Concentration Measurement of Amino Acid in Aqueous Solution by Quantitative 1H NMR Spectroscopy with Internal Standard Method

2017

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We describe a procedure to determine concentrations of amino acid standard solutions by quantitative NMR spectroscopy using an internal standard. The measurement samples were prepared by solvent exchange to remove any intense solvent signal in the 1 H NMR spectra. The method was demonstrated on valine aqueous solutions of different concentrations. The accuracy of the measured concentrations that fell well within the range of the expanded uncertainty is also discussed. All of the results are in good agreement with the preparation values. We believe that this approach should be useful to determine the concentrations of standard solutions whose solute components are difficult to weigh because of extremely small amount or hygroscopicity.

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Development of High-purity Certified Reference Materials for 17 Proteinogenic Amino Acids by Traceable Titration Methods

Cited by 12 publications

References 20 publications

Implementing a Reference Measurement System for C-Peptide: Successes and Lessons Learned

Implementing a Reference Measurement System for C-Peptide: Successes and Lessons Learned

Cordyceps militaris induces tumor cell death via the caspase-dependent mitochondrial pathway in HepG2 and MCF-7 cells

Concentration Measurement of Amino Acid in Aqueous Solution by Quantitative 1H NMR Spectroscopy with Internal Standard Method

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