Publications by authors named "Keiko Nakata"

Article Synopsis
  • The study investigated the connection between inactivated influenza vaccination and viral load in children under 6 in Japan over several flu seasons.
  • Researchers analyzed 1,185 influenza-positive children and found that the viral loads did not significantly differ based on vaccination status, with median values around 5.5 for all groups.
  • Key factors impacting viral load included specific influenza subtypes and children's temperature, indicating that vaccination status did not play a role in viral load differences.
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In Japan, major mumps outbreaks still occur every 4-5 years because of low mumps vaccine coverage (30-40%) owing to the voluntary immunization program. Herein, to prepare for a regular immunization program, we aimed to reveal the nationwide and long-term molecular epidemiological trends of the mumps virus (MuV) in Japan. Additionally, we performed whole-genome sequencing (WGS) using next-generation sequencing to assess results from conventional genotyping using MuV sequences of the small-hydrophobic (SH) gene.

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Article Synopsis
  • This study investigates how prior vaccination affects the effectiveness of the current influenza vaccine in children aged 1-5 years during the 2016/17 and 2017/18 seasons in Japan.
  • The research looked at 799 influenza cases and 1196 controls, categorizing their vaccination status into six groups to analyze vaccine effectiveness (VE). Overall, the effectiveness varied by vaccination history, but one- and two-dose VEs were significant regardless of prior vaccination.
  • The findings suggest that even with prior vaccinations, the current season's vaccines maintain effectiveness, as demonstrated by varying VE percentages among different vaccination groups.
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Background: For the 2017-18 influenza season, A/Saitama/103/2014 (CEXP-002) (Saitama strain) was antigenically more similar to prior circulating strains than A/Hong Kong/4801/2014 (X-263) (Hong Kong strain) in a ferret model and was selected as the A(H3N2) vaccine virus strain in Japan. However, the Saitama strain grew poorly, and the Japanese government switched to the Hong Kong strain, raising public concerns of poor effectiveness. To enhance understanding of the correlation between antigenicity in experimental models and immunogenicity, as a surrogate measure of vaccine effectiveness, in the human population, we compared the immunogenicity of specially-prepared single dose monovalent influenza A(H3N2) vaccines containing the Saitama or the Hong Kong strain.

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Enterovirus and human parechovirus (HPeV) are RNA viruses belonging to the family Picornaviridae that frequently infect infants. These infections show a wide variety of clinical manifestations, from mild to severe. However, there are no known early clinical markers for diagnosis and prediction of disease severity.

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Human adenovirus (HAdV) strains isolated from respiratory specimens of 139 children were analyzed to evaluate the endemic situation of HAdV infections in Osaka, Japan, between 2008 and 2015. The cases increased during spring and winter, and the infections were confirmed mainly in children aged ≤ 5 years, comprising 91.9% of the total population examined.

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Human parechovirus type 3 (HPeV3) can cause serious conditions in neonates, such as sepsis and encephalitis, but data for adults are lacking. The case of a pregnant woman with HPeV3 infection is reported herein. A 28-year-old woman at 36 weeks of pregnancy was admitted because of myalgia and muscle weakness.

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Enterovirus 71 (EV71) is a causative agent of hand, foot and mouth disease (HFMD). EV71 causes fever, rash, diarrhoea and, in some cases, acute encephalopathy/encephalitis, which can be fatal. No specific treatment is currently available for EV71 infection.

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Unlabelled: Pediatric acute encephalopathy (AE) was sometimes attributed to virus infection. However, viral infection does not always result in AE. The risk factors for developing infantile AE upon virus infection remain to be determined.

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In the winter influenza epidemic season, patients with respiratory illnesses including respiratory syncytial virus (RSV) infections increase among young children. Therefore, we evaluated the effectiveness of influenza vaccine against influenza-like illness (ILI) using a technique to identify outbreaks of RSV infection and to distinguish those patients from ILI patients. The study subjects were 101 children aged 12 to 84 months attending nursery school.

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To evaluate antibody response induced by trivalent inactivated influenza vaccine (TIV) against circulating influenza A (H3N2) strains in healthy adults during the 2010/11 and 2011/12 seasons, a hemagglutination-inhibition (HI) assay was utilized to calculate geometric mean antibody titer (GMT), seroprotection rate (post vaccination HI titers of ≥1 :40), and seroresponse rate (4-fold increase in antibody level). In the 2010/11 season, GMT increased 1.8- to 2.

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Human norovirus is a major cause of viral acute gastroenteritis worldwide. However, the transition of endemic norovirus genotypes remains poorly understood. The characteristics of natural immunity against norovirus are unclear because few studies have been performed in the natural infection setting.

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In humans, emaciation from long-term dietary deficiencies, such as anorexia, reportedly increases physical activity and brain atrophy. However, the effects of single short-term fasting on brain tissue or behavioral activity patterns remain unclear. To clarify the impact of malnutrition on brain function, we conducted a single short-term fasting study as an anorexia model using male adult mice and determined if changes occurred in migratory behavior as an expression of brain function and in brain tissue structure.

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To indicate the possibility of a new approach to creating mineral density profiles, and to examine longitudinal changes in 'the rate of remineralization (RA)' and 'the mineral density (DAs) at 4 different depths' (surface zone: SZ, lesion body: LB, middle zone: MZ, deep zone near to sound area: DZ) in enamel subsurface lesions, eight demineralized bovine enamel-dentin blocks were remineralized for 1 to 4 week and investigated using Micro-focus X-ray CT (micro-CT). After CT scanning, mineral density profiles were created.Mineral densities at each depth after demineralization were SZ is approximately equal to LB View Article and Find Full Text PDF

We evaluated the norovirus (NoV) detection reagent kit, which uses immunochromatography (IC), against outbreaks of food-borne acute viral gastroenteritis having occurred in Osaka Prefecture between November 2008 and March 2009. A total of 33 outbreaks, RT-PCR identified 27 NoV-positive cases, whereas the IC kit identified 26 cases. Out of 103 specimens positive for NoV using RT-PCR, the IC kit identified 68 positive cases, with a positive conformity ratio of 66%.

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The purpose of this study was to assess the relationship between quantitative light-induced fluorescence (QLF) values and demineralization depths in an enamel erosion model in vitro. Flat labial enamel surfaces of bovine incisors were ground with 800-grit SiC and coated with nail varnish, but also leaving rectangular windows of enamel uncoated. Subsequently, they were immersed in a lactic acid gel (pH 5.

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Recent studies have shown that carbon nanotubes (CNTs) can be used as biomedical materials because of their unique properties. CNTs effect nucleation of hydroxyapatite, because of which considerable interest has been generated regarding the use of CNTs in dentistry. However, there are only a few reports on the use of CNTs as dental materials.

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