Yokohama City Institute of Public Health

Kawasaki, Japan

Yokohama City Institute of Public Health

Kawasaki, Japan

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Sato Y.,Yokohama City Institute of Public Health | Sugaya N.,Yokohama City Institute of Public Health | Morita M.,Ehime University
Yakugaku Zasshi | Year: 2015

We established an analytical method for the detection of seven phthalates, dimethyl phthalate, diethyl phthalate (DEP), benzyl butyl phthalate, di-i-butyl phthalate, dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and din- octhyl phthalate, using an ultra high performance liquid chromatograph equipped with a photodiode array detector. This method is quick, with minimal contamination, and was applied to the analysis of aromatic and deodorant aerosol products. Phthalates were detected in 15 of 52 samples purchased from 1999 to 2012 in Yokohama. Three types of phthalate (DEP, DBP, DEHP) were detected, and their concentrations ranged from 0.0085-0.23% DEP in nine samples, 0.012-0.045%DBP in four samples, and 0.012-0.033% DEHP in four samples. No other phthalate esters were detected. Furthermore, we estimated phthalate exposure via breathing in commonly used aromatic and deodorant aerosol products, then evaluated the associated risk. The estimated levels of phthalate exposure were lower than the tolerated daily limit, but the results indicated that aromatic and deodorant aerosol products could be a significant source of phthalate exposure. © 2015 The Pharmaceutical Society of Japan.


PubMed | Hokkaido Institute of Public Health, Fukuoka Institute of Health Environmental, Japan Institute for Environmental Sciences, Chiba Prefectural Institute of Public Health and 7 more.
Type: | Journal: Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology | Year: 2016

An easy and reliable assay for detection of the rubella virus is required to strengthen rubella surveillance. Although a TaqMan RT-PCR assay for detection of the rubella virus has been established in Japan, its utility for diagnostic purposes has not been tested.To allow introduction of the TaqMan RT-PCR into the rubella surveillance system in Japan, the sensitivity of the assay was determined using representative strains for all genotypes and clinical specimens.The detection limits of the method for individual genotypes were examined using viral RNA extracted from 13 representative strains. The assay was also tested at 10 prefectural laboratories in Japan, designated as local reference laboratories for measles and rubella, to allow nationwide application of the assay.The detection limits and amplification efficiencies of the assay were similar among all the representative strains of the 13 genotypes. The TaqMan RT-PCR could detect approximately 90% of throat swab and urine samples taken up to 5days of illness. These samples were determined positive by a highly sensitive nested RT-PCR.The TaqMan RT-PCR could detect at least 10 pfu of rubella virus. Although the sensitivity was somewhat lower than that of the conventional nested RT-PCR, the TaqMan RT-PCR could be more practical to routine tests for rubella laboratory diagnosis and detection in view of the rapid response and reducing risks of contamination.


Kumazaki M.,Yokohama City Institute of Public Health | Usuku S.,Yokohama City Institute of Public Health
PLoS ONE | Year: 2015

Noroviruses (NoVs) are the leading cause of acute gastroenteritis, both in sporadic cases and outbreaks. Since the 1990s, the emergence of several GII.4 variants has been reported worldwide. To investigate the epidemic status of NoV, 6,724 stool samples collected from outbreaks in Yokohama, Japan, from the 2006-2007 to 2013-2014 seasons were assessed for NoVs. We genotyped one specimen from each GII outbreak and conducted a sequence analysis of the VP1 gene for several GII.4 strains. Of the 947 NoV outbreaks during our study, GII was detected in 835, and GII.4 was the predominant genotype of GII. Five different GII.4 variants, Yerseke 2006a, Den Haag 2006b (2006b), Apeldoorn 2007, New Orleans 2009, and Sydney 2012, were detected. During this study period, the most prevalent variant of GII.4 was 2006b, and in each individual season, either 2006b or Sydney 2012 was the predominant variant. Out of the 16 detected 2006b strains, 12 had some amino acid substitutions in their blockade epitope, and these substitutions were concentrated in three residues. Two of the 2006b strains detected in the 2012-2013 season had a S368E substitution, which is consistent with the amino acid residues at same site of NSW0514 (Sydney 2012 prototype). Among the 16 detected strains of Sydney 2012, a phylogenetic analysis showed that all five strains detected in Yokohama during the 2011-2012 season clustered away from the other Sydney 2012 strains that were detected in the 2012-2013 and 2013-2014 seasons. These five strains and other Sydney 2012 strains in Yokohama had a few amino acid differences in the blockade epitopes compared with NSW0514. The amino acid substitutions observed in this study provide informative data about the evolution of a novel GII.4 variant. © 2015 Kumazaki, Usuku. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Ochi N.,Yokohama City Institute of Public Health | Okuda T.,Kanagawa Industrial Technology Center | Fujii H.,Kanagawa Industrial Technology Center
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2016

Two unknown dyes (purple and purplish-red) were detected by TLC in two pickled vegetable (sakura-zuke daikon) samples containing Acid Red 52 (AR) and New Coccine as food colorants. HPLC with diode-array detection and LC/MS analyses suggested that the purple dye is monobrominated AR and the purplish-red dye is its N-desethyl derivative, which would be generated mainly during sample preparation. For the identification of the purple dye, a reference compound was prepared by bromination of AR followed by isolation of the monobrominated AR, the structure of which was elucidated as 4′-brominated AR (4′BrAR) by LC/ToF-MS and 1H-NMR spectroscopy. The purple dye was confirmed as 4′BrAR by comparison of its retention time, ultraviolet-visible spectrum and mass spectrum with those of the prepared reference compound. To our knowledge, this is the first report of the detection of 4′BrAR in foods. © 2016 Informa UK Limited, trading as Taylor & Francis Group


Momoki T.S.,Yokohama City Institute of Public Health
Japanese Journal of Infectious Diseases | Year: 2013

A survey of mumps infections from 1999 to 2010 was conducted in Yokohama City, Japan, and 17 cases-including 4 cases of aseptic meningitis-were positive for mumps virus (MuV). Based on the phylogenetic analysis of the small hydrophobic gene of the MuV genome, 3, 2, and 12 of the isolates were classified into genotypes B, L, and G, respectively. The results were supported by phylogenetic analysis of hemagglutinin-neuraminidase genes. The 3 isolates of genotype B, obtained in 2000, 2004, and 2007, were closely related to indigenous lineages and vaccine strains in Japan. Two isolates obtained from 1999 to 2000 were assigned to genotype L. Twelve isolates obtained from 2000 to 2010 were classified into genotype G, in which 8 isolates obtained from 2000 to 2006 and 4 isolates obtained in 2010 were closely related to MuVi/Gloucester.GBR/32.96 and MuVi/London.GBR/0.03, respectively. Precise analyses of nucleotide sequences suggested that the 4 viruses isolated in 2010 were not directly derived from the evolution of MuV existing before 2006 in the Yokohama area.


PubMed | Yokohama City Institute of Public Health
Type: Journal Article | Journal: PloS one | Year: 2015

Noroviruses (NoVs) are the leading cause of acute gastroenteritis, both in sporadic cases and outbreaks. Since the 1990s, the emergence of several GII.4 variants has been reported worldwide. To investigate the epidemic status of NoV, 6,724 stool samples collected from outbreaks in Yokohama, Japan, from the 2006-2007 to 2013-2014 seasons were assessed for NoVs. We genotyped one specimen from each GII outbreak and conducted a sequence analysis of the VP1 gene for several GII.4 strains. Of the 947 NoV outbreaks during our study, GII was detected in 835, and GII.4 was the predominant genotype of GII. Five different GII.4 variants, Yerseke 2006a, Den Haag 2006b (2006b), Apeldoorn 2007, New Orleans 2009, and Sydney 2012, were detected. During this study period, the most prevalent variant of GII.4 was 2006b, and in each individual season, either 2006b or Sydney 2012 was the predominant variant. Out of the 16 detected 2006b strains, 12 had some amino acid substitutions in their blockade epitope, and these substitutions were concentrated in three residues. Two of the 2006b strains detected in the 2012-2013 season had a S368E substitution, which is consistent with the amino acid residues at same site of NSW0514 (Sydney 2012 prototype). Among the 16 detected strains of Sydney 2012, a phylogenetic analysis showed that all five strains detected in Yokohama during the 2011-2012 season clustered away from the other Sydney 2012 strains that were detected in the 2012-2013 and 2013-2014 seasons. These five strains and other Sydney 2012 strains in Yokohama had a few amino acid differences in the blockade epitopes compared with NSW0514. The amino acid substitutions observed in this study provide informative data about the evolution of a novel GII.4 variant.


PubMed | Yokohama City Institute of Public Health
Type: Journal Article | Journal: Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan | Year: 2017

Twenty-four primary aromatic amines (PAAs) derived from azo colorants, which are controlled by the Act on Control of Household Products Containing Harmful Substances by the Japan Ministry of Health, Labour and Welfare, aniline and 1,4-phenylendiamine were analyzed in 86 samples of 40 textile products by GC-MS. Even though these PAAs detected in the samples did not exceed the regulation value (30 g/g), 14 kinds of PAAs were detected that exceeded the limit of quantification. 4,4-Methylenedianiline, in amounts that exceeded the limit of quantification, was detected in 20 textile samples containing synthesis fiber (16 samples made from polyurethane, two samples made from polyester, and two samples made from acryl); however, it was not detected in natural fiber textile samples. Of these samples, 4,4-methylenedianiline was detected in 16 out of 19 samples (84%) made from polyurethane fiber. This suggests that 4,4-methylenedianiline is formed from polyurethane. The origin of 3,3-dichlorobenzidine was investigated in three samples releasing more than 3 g/g (3.9-15 g/g) of 3,3-dichlorobenzidine using atmospheric pressure solids analysis probe-mass spectrometry and Pigment Orange 13 was identified as the orange colorant in the textile printing parts. This result suggests that 3,3-dichlorobenzidine detected in these three samples was generated by the reduction of Pigment Orange 13.


PubMed | Kanagawa Industrial Technology Center and Yokohama City Institute of Public Health
Type: Journal Article | Journal: Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment | Year: 2016

Two unknown dyes (purple and purplish-red) were detected by TLC in two pickled vegetable (sakura-zuke daikon) samples containing Acid Red 52 (AR) and New Coccine as food colorants. HPLC with diode-array detection and LC/MS analyses suggested that the purple dye is monobrominated AR and the purplish-red dye is its N-desethyl derivative, which would be generated mainly during sample preparation. For the identification of the purple dye, a reference compound was prepared by bromination of AR followed by isolation of the monobrominated AR, the structure of which was elucidated as 4-brominated AR (4BrAR) by LC/ToF-MS and (1)H-NMR spectroscopy. The purple dye was confirmed as 4BrAR by comparison of its retention time, ultraviolet-visible spectrum and mass spectrum with those of the prepared reference compound. To our knowledge, this is the first report of the detection of 4BrAR in foods.


PubMed | Yokohama City Institute of Public Health
Type: Journal Article | Journal: BMC infectious diseases | Year: 2016

Noroviruses (NoVs) are the most frequent cause of acute gastroenteritis worldwide among people of all ages and the leading cause of gastrointestinal disease outbreaks in various settings. To clarify the differences in epidemic situations among different settings, we investigated epidemiological trends and the distribution of NoV genotypes in Yokohama, Japan.Between September 2007 and August 2015, 746 outbreaks of NoV gastroenteritis were reported in kindergarten/nursery schools (K/Ns), primary schools (PSs), and nursing homes for the aged (NHs). Stool samples were collected for NoV testing, and the NoV gene was amplified and sequenced to determine the genotype.During the eight seasons, 248 NoV outbreaks occurred in K/Ns, 274 outbreaks in PSs, and 224 outbreaks in NHs. These outbreaks occurred throughout the year, except in August, and the number increased in November and peaked in December. The number of outbreaks that occurred from November to February comprised 76.8% of all outbreaks. The outbreaks originated in K/Ns or PSs in every season, except for one season. Five genogroup (G)I and nine GII genotypes in K/Ns, six GI and 10 GII genotypes in PSs, and three GI and six GII genotypes in NHs were detected during the eight seasons. GII.4 was the most prevalent genotype in K/Ns and NHs. However, GII.6 was the most prevalent genotype in PSs. The epidemic genotypes in K/Ns and PSs changed by NoV season, although GII.4 was always predominant in NHs. Moreover, the distribution of genotypes was significantly different between epidemic and non-epidemic periods in each facility (p<0.01 for all).The epidemic situation of NoV outbreaks differs by facility, NoV season, and month. The genotype distribution is likely dependent on the facility and is significantly different between epidemic and non-epidemic periods.


PubMed | Yokohama City Institute of Public Health
Type: Journal Article | Journal: Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan | Year: 2015

We established an analytical method for the detection of seven phthalates, dimethyl phthalate, diethyl phthalate (DEP), benzyl butyl phthalate, di-i-butyl phthalate, dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and di-n-octhyl phthalate, using an ultra high performance liquid chromatograph equipped with a photodiode array detector. This method is quick, with minimal contamination, and was applied to the analysis of aromatic and deodorant aerosol products. Phthalates were detected in 15 of 52 samples purchased from 1999 to 2012 in Yokohama. Three types of phthalate (DEP, DBP, DEHP) were detected, and their concentrations ranged from 0.0085-0.23% DEP in nine samples, 0.012-0.045% DBP in four samples, and 0.012-0.033% DEHP in four samples. No other phthalate esters were detected. Furthermore, we estimated phthalate exposure via breathing in commonly used aromatic and deodorant aerosol products, then evaluated the associated risk. The estimated levels of phthalate exposure were lower than the tolerated daily limit, but the results indicated that aromatic and deodorant aerosol products could be a significant source of phthalate exposure.

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