Publications by authors named "Soichiro Hirata"

In Japan, domiciliary care fees are only covered by the public health insurance system if the clinic concerned is located within 16 km of the patient's residence. This nationwide rule does not take local conditions into account and therefore may not be appropriate. The goal of the present study was to assess the current state of domiciliary dental care nationwide in view of this restriction to clarify the current situation and any inherent problems.

View Article and Find Full Text PDF

Dietary ω3 fatty acids have important health benefits and exert their potent bioactivity through conversion to lipid mediators. Here, we demonstrate that microbiota play an essential role in the body's use of dietary lipids for the control of inflammatory diseases. We found that amounts of 10-hydroxy-cis-12-cis-15-octadecadienoic acid (αHYA) and 10-oxo-cis-12-cis-15-octadecadienoic acid (αKetoA) increased in the feces and serum of specific-pathogen-free, but not germ-free, mice when they were maintained on a linseed oil diet, which is high in α-linolenic acid.

View Article and Find Full Text PDF

Atherosclerosis is a chronic inflammatory disease associated with macrophage aggregate and transformation into foam cells. In this study, we sought to investigate the impact of dietary intake of ω3 fatty acid on the development of atherosclerosis, and demonstrate the mechanism of action by identifying anti-inflammatory lipid metabolite. Mice were exposed to a high-fat diet (HFD) supplemented with either conventional soybean oil or α-linolenic acid-rich linseed oil.

View Article and Find Full Text PDF

ω3 fatty acids show potent bioactivities via conversion into lipid mediators; therefore, metabolism of dietary lipids is a critical determinant in the properties of ω3 fatty acids in the control of allergic inflammatory diseases. However, metabolic progression of ω3 fatty acids in the skin and their roles in the regulation of skin inflammation remains to be clarified. In this study, we found that 12-hydroxyeicosapentaenoic acid (12-HEPE), which is a 12-lipoxygenase metabolite of eicosapentaenoic acid, was the prominent metabolite accumulated in the skin of mice fed ω3 fatty acid-rich linseed oil.

View Article and Find Full Text PDF

Homeostatic generation of T cells, which occurs in the thymus, is controlled at least in part by endogenous cytokines and ligands. In addition, nutritional factors are other key regulators for the homeostasis of host immunity, but whether and how nutrition affects the homeostatic generation of thymocytes remains to be established. Here, we showed that vitamin B1 deficiency resulted in a bias toward the maturation of γδ thymocytes accompanied by decreased differentiation into double-positive thymocytes during thymic involution.

View Article and Find Full Text PDF
Article Synopsis
  • The study highlights the health benefits of ω3 fatty acids, specifically identifying 17,18-epoxyeicosatetraenoic acid (17,18-EpETE) as a valuable lipid with anti-allergic and anti-inflammatory properties.
  • Researchers found that the enantiomers of 17,18-EpETE differ in their effectiveness, with only one enantiomer (17(),18()-EpETE) exhibiting significant anti-inflammatory effects in reducing skin hypersensitivity.
  • The research also emphasizes the potential of using a bacterial enzyme, cytochrome P450 BM-3, to produce the beneficial enantiomer in a stereoselective way, presenting a promising method for mass-producing useful lipid metabolites.
View Article and Find Full Text PDF

Maintaining dental and oral health and increasing healthy life expectancy are important issues for Japan as it deals with the rapid aging of its population. The purpose of this study was to determine effective dental health measures aimed at increasing the number of present teeth in the elderly. Change in the number of present teeth was determined based on data obtained from the 2009 and 2014 "Good Teeth Tokyo (Ii-ha Tokyo)" surveys carried out by the Tokyo Metropolitan Government.

View Article and Find Full Text PDF

Background: Maternal dietary exposures are considered to influence the development of infant allergies through changes in the composition of breast milk. Cohort studies have shown that ω3 polyunsaturated fatty acids (PUFAs) in breast milk may have a beneficial effect on the preventing of allergies in infants; however, the underlying mechanisms remain to be investigated. We investigated how the maternal intake of dietary ω3 PUFAs affects fatty acid profiles in the breast milk and their pups and reduced the incidence of allergic diseases in the pups.

View Article and Find Full Text PDF

A new concept of semiconductor wafer bonding, mediated by optical wavelength conversion materials, is proposed and demonstrated. The fabrication scheme provides simultaneous bond formation and interfacial function generation, leading to efficient device production. Wavelength-converting functionalized semiconductor interfacial engineering is realized by utilizing an adhesive viscous organic matrix with embedded fluorescent particles.

View Article and Find Full Text PDF

The metabolism and generation of bioactive lipid mediators are key events in the exertion of the beneficial effects of dietary omega-3 fatty acids in the regulation of allergic inflammation. Here, we found that dietary linseed oil, which contains high amounts of alpha-linolenic acid (ALA) dampened allergic rhinitis through eosinophilic production of 15-hydroxyeicosapentaenoic acid (15-HEPE), a metabolite of eicosapentaenoic acid (EPA). Lipidomic analysis revealed that 15-HEPE was particularly accumulated in the nasal passage of linseed oil-fed mice after the development of allergic rhinitis with the increasing number of eosinophils.

View Article and Find Full Text PDF

The purpose of this study was to investigate the effectiveness of the Communication Studies Program at Tokyo Dental College as a tool in behavioral education. The number of Patient Community members who had participated in multiple sets of the program for third-year students in the same year within the 3-year period spanning 2016 to 2018 (152, 148, and 129 students in 2016, 2017, and 2018 respectively), and the period during which they had participated in multiple sets were investigated. Comments on student behavior, including on hairstyle, clothes, and attitude, were also analyzed.

View Article and Find Full Text PDF

Leukotriene B receptor 1 (BLT1) triggers the migration of granulocytes and activated T cells; however, its role in B-cell function remains unclear. Here we report that BLT1 is required to induce the production of antigen-specific IgA against oral vaccine through mediating innate immune signals from commensal bacteria. B cells acquire BLT1 expression during their differentiation to IgA B cells and plasma cells in Peyer's patches and the small intestinal lamina propria, respectively.

View Article and Find Full Text PDF

Coconut oil is used as a dietary oil worldwide, and its healthy effects are recognized by the fact that coconut oil is easy to digest, helps in weight management, increases healthy cholesterol, and provides instant energy. Although topical application of coconut oil is known to reduce skin infection and inflammation, whether dietary coconut oil has any role in decreasing skin inflammation is unknown. In this study, we showed the impact of dietary coconut oil in allergic skin inflammation by using a mouse model of contact hypersensitivity (CHS).

View Article and Find Full Text PDF

Food poisonings caused by Clostridium perfringens and Shiga toxin (Stx)-producing Escherichia coli (STEC) occur frequently worldwide; however, no vaccine is currently available. Therefore, we aimed to develop a bivalent vaccine against C. perfringens and STEC infections.

View Article and Find Full Text PDF

We previously reported that Ag85B-expressing human parainfluenza type 2 virus (Ag85B-rHPIV2) was effective as a nasal vaccine against tuberculosis in mice; however, the mechanism by which it induces an immune response remains to be investigated. In the present study, we found that organogenesis of inducible bronchus-associated lymphoid tissue (iBALT) played a role in the induction of antigen-specific T cells and IgA antibody responses in the lung of mice intra-nasally administered Ag85B-rHPIV2. We found that expression of Ag85B was dispensable for the development of iBALT, suggesting that HPIV2 acted as an iBALT-inducing vector.

View Article and Find Full Text PDF

Background: Metabolites of eicosapentaenoic acid exert various physiologic actions. 17,18-Epoxyeicosatetraenoic acid (17,18-EpETE) is a recently identified new class of antiallergic and anti-inflammatory lipid metabolite of eicosapentaenoic acid, but its effects on skin inflammation and the underlying mechanisms remain to be investigated.

Objective: We evaluated the effectiveness of 17,18-EpETE for control of contact hypersensitivity in mice and cynomolgus macaques.

View Article and Find Full Text PDF

The number of patients with allergic and inflammatory disorders has been increasing during the past several decades. Accumulating evidence has refined our understanding of the relationship between allergic diseases and the gut microbiome. In addition, the gut microbiome is now known to produce both useful and harmful metabolites from dietary materials.

View Article and Find Full Text PDF

Metagenomic analysis based on the 16S rRNA gene is generally performed to examine the diversity and abundance of commensal bacteria in feces, which is now recognized to be associated with human health and diseases. Guanidine thiocyanate (GuSCN) solution is used as a less onerous way compared with a frozen method to transport and stock fecal samples at room temperature for DNA analysis; however, optimal methods to measure fecal bacterial composition in GuSCN solution remain to be investigated. Here, we examined the influence of various factors such as pretreatment (e.

View Article and Find Full Text PDF

The purpose of the present study was to investigate the reasons governing selection of geographical location of workplace by postgraduate dental trainees. We believe that such data would aid in the development of measures aimed at reducing regional disparities in the number of dentists. A total of 10 dental colleges and faculties in Japan were invited to participate in the study.

View Article and Find Full Text PDF

In 2009, the Ministry of Education, Culture, Sports, Science and Technology launched its "Program for Promoting University Education and Student Support, Theme A: Program for Promoting University Education Reform". The ministry's stated aims were to 1) enhance student training centered on the needs of the individual patient; 2) improve their ability to make comprehensive diagnosis and treatment plans; and 3) instill high ethical standards and good communication skills. One of the main pillars of this project was to establish an educational organization aimed at encouraging public participation, the "Patient Community".

View Article and Find Full Text PDF

Change in oral function was evaluated longitudinally in elderly persons participating in an Exercises for Healthy Oral Function program implemented as part of the Long-Term Care Prevention Project. The participants comprised high-risk and healthy persons aged 65 yr or over. A questionnaire was used to classify them into two groups ('every day or sometimes' or 'rarely') at the end of the study for a comparison of change in repetitive saliva swallowing test (RSST) scores and oral diadochokinesis between 3 time points: at before, at immediately after, and at 1 yr after completion of the program.

View Article and Find Full Text PDF

As of fiscal year 2006, it became compulsory for all newly licensed dentists in Japan to undergo a year of practical training at one of the designated training facilities found throughout the country as part of their postgraduate programs. The goal of this training is for the trainees to acquire diagnostic and therapeutic skills. While officially trainees, they are nonetheless regarded as members of staff.

View Article and Find Full Text PDF

Career paths and aspirations were investigated among postgraduate dental trainees on completion of clinical training at Tokyo Dental College between 2006, when clinical residency became mandatory, and 2011. Overall, those finding employment with independent general dental practitioners accounted for the majority (34%), followed by those entering postgraduate courses at the Chiba Hospital (20%), those embarking on a postgraduate clinical specialty course at the Chiba Hospital (16%), and those going on to other universities (7%). At the Chiba Hospital, the number selecting postgraduate courses, residency training (including further residency training or a postgraduate clinical specialty course), or employment with a general dental practitioner was almost the same; however, the number selecting postgraduate courses at the Suidobashi Hospital was low, showing a strong tendency toward becoming a general or clinical practitioner.

View Article and Find Full Text PDF

The aim of this study was to investigate cases of accidental ingestion or aspiration occurring at Tokyo Dental College Chiba Hospital over the last 4 years in order to determine how the incidence of such events could be reduced. Forty cases of accidents occurring at our hospital over a 4-year period commencing in 2008 (representing 27% of the total number of accidents) included accidental ingestion in 39 patients and aspiration in one. Most of these accidents occurred during the removal or placement of restorations or prosthetics, and the ingested objects were mostly crowns and inlays.

View Article and Find Full Text PDF

A new semi-quantitative enumeration system has been developed for the detection of Streptococcus mutans in saliva. Using two kinds of species-specific monoclonal antibodies, this system can quickly detect salivary S. mutans within 30 min and classify the results into three levels.

View Article and Find Full Text PDF