Publications by authors named "Ryoji Hirota"

We studied the effect of three months' use of electrolyzed hydrogen water (EHW, Electrolyzed Hydrogen Water conditioner produced by Nihon Trim Co., Ltd.) on metabolic and pre-metabolic syndrome groups.

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The prevalence of allergic diseases, such as bronchial asthma, atopic dermatitis, nasal allergies (pollinosis), and food allergies, has been increasing in many countries. The hygiene hypothesis was recently considered from the perspective of exposure to antimicrobial agents and preservatives, such as parabens (CAS number, 94-13-3). It currently remains unclear whether parabens, which are included in many daily consumer products such as cosmetics, shampoos, and personal care products as preservative antimicrobial agents, induce or aggravate allergies.

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This study investigated whether the individual and combined effects of using biomass energy and living in the neighborhood of a cement plant were associated with the risk of COPD and respiratory symptoms among Congolese women. A total of 235 women from two neighborhood communities of a cement plant participated in this cross-sectional study. Participants were classified into the more exposed group (MEG = 137) and a less exposed group (LEG = 98), as well as into biomass users (wood = 85, charcoal = 49) or electricity users (101 participants).

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Background: Previous studies have reported that exposure to paraben (Pb) and triclosan (TCS) is associated with allergies. However, Pb and TCS exposure in the Japanese population is not fully understood.

Objectives: The present study was aimed to examine such exposure among Japanese individuals with allergic diseases.

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Chronic exposure to cement dust may induce adverse health effects, including a significant decrease in lung function. The study investigated whether the prevalence of COPD and respiratory symptoms was associated with working at different tasks exposed to varying levels of cement dust. The cross-sectional study was carried out among 223 exposed and 156 less exposed workers from two cement factories from November 20 to December 15, 2016 in DRC.

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Objectives: Road-traffic emissions (RTE) induce adverse health effects, notably respiratory symptoms and respiratory diseases, as a result of pollutants deposited into the respiratory tract. The aim of this study was to evaluate the association between occupation groups of Congolese transit workers exposed to RTE, particularly bus conductors and respiratory health, in Kinshasa.

Methods: A cross-sectional study was conducted from 2015 April 20 to May 14, whose participants were bus conductors (n = 110), bus drivers (n = 107), taxi-motorcyclists (n = 102) and high school teachers (control group; n = 106).

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Atopic dermatitis (AD) is a skin disorder characterized by filaggrin (FLG) defect. We evaluated sacran's effects on dust-mite extracts (DME)-induced AD-like disease and also its effect on profilaggrin (proFLG) in a murine model of 2,4-dinitroflurobenze (DNFB)-induced contact hypersensitivity. In the murine AD-like disease model, allergic NC/Nga mice (N=60) were randomly divided into five treatment groups of 12 animals each: 0.

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Individuals exposed to fibrogenic mineral dust may exhibit an impaired antioxidant system and produce high levels of reactive oxygen and nitrogen species through immune cells, contributing to the perturbation of immune cell function, inflammation, fibrosis and lung cancer. The lung diseases which are caused by inhalation of fibrogenic mineral dust, known as pneumoconioses, develop progressively and irreversibly over decades. At the moment there is no known cure.

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Objectives: The aim of this study was to investigate workplace violence by patients or their relatives towards health-care workers in Congolese hospitals.

Methods: Through the autumn of 2012, a cross-sectional survey on workplace violence was conducted in a sample of 2,210 registered health-care workers (989 males and 1,221 females, aged 33 ± 8 years) from 436 hospitals located in the province of Katanga, Democratic Republic of the Congo. Verbal aggression, harassment and physical violence perpetrated by patients or their relatives within the previous year along with factors contributing to violence, were recorded, and the response rate was 99%.

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Allergy to laboratory animals is a well known occupational hazard and remains a health concern for individuals in contact with lab animals. This study evaluates the prevalence of allergy symptoms among medical researchers exposed to laboratory animals. We analyzed data from a cross-sectional survey, involving subjects (n=169, 21-59 yr), working in Kochi Medical School, Japan.

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Objectives: The mechanism by which muscle weakness leads to an increased risk of death remains a subject of interest. In this context, the aim of this study is to assess the relationship between urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and muscle strength, and other risk factors contributing to poor muscle strength in older persons.

Methods: This was a cross-sectional study in which a total of 86 participants, both men and women, aged 65 years or above were screened for urinary 8-OHdG, and muscle strength as measured by handgrip strength.

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Objective: The aim of our study was to investigate the natural course of silicosis in terms of radiographic progression among Japanese tunnel workers.

Methods: Tunnel workers with silicosis were included in our study between January 2008 and June 2011. We retrospectively assessed workers' radiographs from their first through last visits to see whether there was progression.

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Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritic and eczematous skin lesions. In this study, AD-like disease was induced in NC/Nga mice so as to evaluate the anti-allergic effects of Vernonia amygdalina leaf extracts (VAM).

Methods: Forty NC/Nga mice were purchased for each of the two protocols (prophylactic and curative) of the study.

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Objectives: Selenoprotein P (SeP) is a selenium (Se) supply protein, which is an antioxidant micronutrient considered to be vital for human health. The aim of this study was to assess the serum selenium status in patients with silicosis.

Methods: We conducted a retrospective case-control study where serum samples from a total of 78 patients (males with a median age of 73.

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Limonene is one of the main flavonoids which is reported to inhibit the inflammatory response by suppressing the production of reactive oxygen species. The aim of this study was to evaluate whether limonene can inhibit Dermatophagoides farinae-induced airway hyperresponsiveness (AHR), eosinophilic infiltration and other histological changes in the lung, T helper (Th) 2 cytokine production and airway remodeling in a mice model of asthma. Treatment with limonene significantly reduced the levels of IL-5, IL-13, eotaxin, MCP-1, and TGF-β₁ in bronchoalveolar lavage fluid.

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Aim: Good nutrition is beneficial both for the health and the functional capacity of the elderly. However, malnutrition is a serious health problem among the elderly, particularly the elderly living in rural areas in many developing countries. The aim of the present study was to carry out a cross-sectional study of the elderly in the city of Luozi, Democratic Republic of Congo, through the use of the long and the short forms of the Mini Nutritional Assessment (MNA) scale.

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Background: Sacran is a newly discovered sulfated polysaccharide extracted from an algae, Aphanothece sacrum, grown in a river of the Kyushu region in Japan.

Objective: To evaluate sacran's inhibitory effect in 2,4,6-trinitrochlorobenzene (TNCB)-induced allergic dermatitis in NC/Nga mice.

Methods: Sacran was extracted by acid and alkaline treatment of A sacrum cyanobacterial biomaterials.

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Background: Oxidative stress is believed to play a crucial role in aging and age-related diseases, and is widely thought to increase morbidity and mortality in the elderly. Assessment of biomarkers of oxidative stress, such as 8-isoprostane and 8-hydroxy-2-deoxyguanosine, are considered to be useful in predicting disease risks at the population level.

Objective: The aim of the present study was to assess the health status of the elderly by comparing their lifestyles and levels of oxidative stress biomarkers.

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Objective: Sub-Saharan Africa remains the region most heavily affected by HIV infection. This study aimed to evaluate the knowledge, attitudes, and practices of Congolese students of risk behaviors for sexual transmission of HIV in comparison with their Japanese counterparts.

Methods: Of the 1,747 undergraduate students who participated in the survey, there were 1,326 respondents (752 Japanese, 574 Congolese) who voluntarily and fully filled out the auto-administered questionnaire.

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Background: Airway hyperresponsiveness (AHR) is one of the important traits that characterize bronchial asthma. Goishi tea is a post-heating fermented tea that has been reported to have higher free radical scavenging activity. In this study, we evaluated the prophylactic effects of Goishi tea on AHR in BALB/c mice.

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The extent of occupational injuries among health care workers in central Africa, particularly in the Democratic Republic of Congo, is not documented. We sought to determine the incidence of percutaneous injury and exposure to blood and other body fluids in Congolese urban and rural hospitals in the previous year. Our data show high rates of percutaneous injury and exposure to blood and other body fluids, reflecting poor safety conditions for most Congolese health care workers.

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Yuzu (Citrus junos Tanaka) has been used as a traditional medicine in Japan. We investigated in vitro anti-inflammatory effects of limonene from yuzu peel on human eosinophilic leukemia HL-60 clone 15 cells. To examine anti-inflammatory effects of limonene on the cells, we measured the level of reactive oxygen species (ROS), monocyte chemoattractant protein-1 (MCP-1), nuclear factor (NF) kappa B, and p38 mitogen-activated protein kinase (MAPK).

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