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Tsurumi ku, Japan

Aoyama K.,Food and Agricultural Materials Inspection Center | Akashi H.,Nisshin Seifun Group Inc. | Mochizuki N.,Asahi Breweries Ltd. | Ito Y.,Kirin Group Office Co. | And 15 more authors.
Journal of the Food Hygienic Society of Japan | Year: 2012

To evaluate LC methods with UV or MS detection for simultaneous analysis of deoxynivalenol (DON) and nivalenol (NIV) in wheat, an interlaboratory study was conducted in 11 laboratories. DON and NIV were purified using a multifunctional column, and their concentrations were determined using LC-UV or LC-MS(/MS). No internal standards were used. Three fortified wheat samples (0.1, 0.5 and 1 mg/kg), one naturally contaminated wheat sample, and one blank wheat sample were used. The recoveries ranged from 90% to 110% for DON and from 76% to 83% for NIV. For DON, the relative standard deviations for repeatability (RSDr) ranged from 1.1% to 7.6%. The relative standard deviations for reproducibility (RSDr) ranged from 7.2% to 25.2%. For NIV, the RSDr ranged from 2.0% to 10.7%, and the RSDr ranged from 7.0% to 31.4%. Regardless of sample and detector, the HorRat values for DON and NIV ranged from 0.4 to 1.4. Both LC-UV and LC-MS(/MS) methods were considered to be suitable for application as an official method. Source

Tsuji T.,Kirin Holdings Company | Konoeda Y.,Kirin Group Office Co. | Kanai K.,Kirin Holdings Company | Yokoyama A.,Kirin Holdings Company | Yoshida S.,Kirin Holdings Company
Food Chemistry | Year: 2013

Iron is essential for human health, but it sometimes causes an unpleasant taste, rusty colour and a decrease in the stability of food products. Previously, we found that ethanol-treated yeast (ETY) cells could remove iron from wine and juice, and reduce the fishy aftertaste induced by iron in wine-seafood pairings. However, the mechanism of iron sorption by ETY cells is undefined; thus, there is no indicator that can be used to estimate the iron sorption capacity of these cells. In this study, we showed that cell wall components are not mainly associated with iron sorption by investigating ETY cells with the cell wall removed. Moreover, plasma membrane permeability was correlated with the iron sorbing capacity of the cells. Microscopic analysis showed that iron accumulated within ETY cells. Proteinase-treated ETY cells had no iron sorbing capacity. On the basis of these results, we conclude that intracellular proteins are involved in iron sorption by ETY cells. © 2013 Elsevier Ltd. Source

Kadota T.,Kirin Group Office Co. | Kadota T.,Gifu University | Kimura M.,RIKEN | Hirano S.,Kirin Group Office Co. | And 4 more authors.
Rapid Communications in Mass Spectrometry | Year: 2011

A method coupling liquid chromatography with tandem mass spectrometry (LC/MS/MS) was developed for the simultaneous quantitative determination of trichothecenes, nivalenol, deoxynivalenol, deoxynivalenol-3-glucoside, fusarenon-X, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, isotrichodermin, calonectrin, 3-deacetylcalonectrin, 15-deacetylcalonectrin, 3,15- diacetylnivalenol, 4,15-diacetylnivalenol, 3,15-diacetyldeoxynivalenol, and 3,4,15-triacetylnivalenol. The analytical parameters of trichothecenes and their derivatives were optimized to enable their highly sensitive detection. Evaluation of clean-up procedures using Multisep #226 and #227 indicated that Multisep #227 was more suitable for their simultaneous detection in wheat. In performance validation studies using the LC/MS/MS method with Multisep #227 cleanup, good recoveries ranging from 84% to 115% with relative standard deviations from 0.4% to 7.2% were measured. The limits of detection and quantification ranged from 0.03 to 1.4 ng·g -1 and from 0.1 to 4.7 ng·g -1, respectively. The effect of matrices using matrix-matched calibration was estimated to range from 80% to 117% after Multisep #227 cleanup. Multisep #227 clean-up procedure with matrix-free standard calibration achieved accurate quantification without having a considerable effect on matrix compounds. Using the developed method, several trichothecene derivatives and precursors were detected in fungally inoculated wheat samples. The developed LC/MS/MS method is a practical technique that can be used for the quantification of trichothecenes in wheat. This study is the first report of an analytical method used for the simultaneous quantification of major trichothecenes, their derivatives and precursors. Copyright © 2011 John Wiley & Sons, Ltd. Source

Dertinger S.D.,Litron Laboratories, Ltd. | Phonethepswath S.,Litron Laboratories, Ltd. | Weller P.,Litron Laboratories, Ltd. | Nicolette J.,Abbott Laboratories | And 32 more authors.
Environmental and Molecular Mutagenesis | Year: 2011

A collaborative international trial was conducted to evaluate the reproducibility and transferability of an in vivo mutation assay based on the enumeration of CD59-negative rat erythrocytes, a phenotype that is indicative of Pig-a gene mutation. Fourteen laboratories participated in this study, where anti-CD59-PE, SYTO 13 dye, and flow cytometry were used to determine the frequency of CD59-negative erythrocytes (RBC CD59-) and CD59-negative reticulocytes (RET CD59-). To provide samples with a range of mutant phenotype cell frequencies, male rats were exposed to N-ethyl-N-nitrosourea (ENU) via oral gavage for three consecutive days (Days 1-3). Each laboratory studied 0, 20, and 40 mg ENU/kg/day (n = 5 per group). Three sites also evaluated 4 mg/kg/day. At a minimum, blood samples were collected three times: predosing and on Days 15 and 30. Blood samples were processed according to a standardized sample processing and data acquisition protocol, and three endpoints were measured: %reticulocytes, frequency of RET CD59-, and frequency of RBC CD59-. The methodology was found to be reproducible, as the analysis of technical replicates resulted in experimental coefficients of variation that approached theoretical values. Good transferability was evident from the similar kinetics and magnitude of the dose-related responses that were observed among different laboratories. Concordance correlation coefficients showed a high level of agreement between the reference site and the test sites (range: 0.87-0.99). Collectively, these data demonstrate that with adequate training of personnel, flow cytometric analysis is capable of reliably enumerating mutant phenotype erythrocytes, thereby providing a robust in vivo mutation assay that is readily transferable across laboratories. © 2011 Wiley-Liss, Inc. Source

Kawamura Y.,Meiji Seika Pharma Co. | Hayashi H.,Meiji Seika Pharma Co. | Tajima O.,Kirin Group Office Co. | Yamada S.,Kirin Group Office Co. | And 5 more authors.
Genes and Environment | Year: 2012

Transgenic rat gene-mutation assays can be used to assess genotoxicity of chemicals in target organs for carcinogenicity. Since gene mutations in transgenes are genetically neutral and thus accumulate along with treatment periods, the assays are suitable for genotoxicity risk assessment of chemicals using repeated-dose treatment methodologies. However, few studies have been conducted to examine the suitability of the assays in repeat-dose treatment protocols. In order to prove the utility of the transgenic rat assays, we treated gpt delta rats with aristolochic acid at 0.3 and 1 mg/kg by gavage daily for 28 days, and autopsied the rats 3 days after the final treatment, which is a protocol recommended by the International Workshop on Genotoxicity Testing (IWGT). Aristolochic acid exists in herbs and some other plants, and is carcinogenic in the kidney, bladder and stomach in rats. The mutant frequency (MF) in both the kidney and the liver increased significantly in a dose-dependent manner when the rats were treated with aristolochic acid. We concluded that the gpt delta rat assay is sensitive enough to detect gene mutations induced by aristolochic acid and also that the 28-day repeated-dose protocol is suitable for assessing genotoxicity of chemicals. © The Japanese Environmental Mutagen Society. Source

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