Entity

Time filter

Source Type


Oguri T.,University of Tokyo | Oguri T.,Nagoya City University | Yoshinaga J.,University of Tokyo | Toshima H.,University of Tokyo | And 3 more authors.
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2016

Inorganic arsenic (iAs) has been known as a testicular toxicant in experimental rodents. Possible association between iAs exposure and semen quality (semen volume, sperm concentration, and sperm motility) was explored in male partners of couples (n = 42) who visited a gynecology clinic in Tokyo for infertility consultation. Semen parameters were measured according to WHO guideline at the clinic, and urinary iAs and methylarsonic acid (MMA), and dimethylarsinic acid concentrations were determined by liquid chromatography-hydride generation-ICP mass spectrometry. Biological attributes, dietary habits, and exposure levels to other chemicals with known effects on semen parameters were taken into consideration as covariates. Multiple regression analyses and logistic regression analyses did not find iAs exposure as significant contributor to semen parameters. Lower exposure level of subjects (estimated to be 0.5 μg kg−1 day−1) was considered a reason of the absence of adverse effects on semen parameters, which were seen in rodents dosed with 4–7.5 mg kg−1. © 2016 Taylor & Francis Group, LLC Source


Suzuki G.,Military Medicine Research Unit | Tokuno S.,National Defense Medical College | Nibuya M.,National Defense Medical College | Ishida T.,Military Medicine Research Unit | And 6 more authors.
PLoS ONE | Year: 2014

Decreased concentrations of plasma brain-derived neurotrophic factor (BDNF) and serum BDNF have been proposed to be a state marker of depression and a biological indicator of loaded psychosocial stress. Stress evaluations of participants in military mission are critically important and appropriate objective biological parameters that evaluate stress are needed. In military circumstances, there are several problems to adopt plasma BDNF concentration as a stress biomarker. First, in addition to psychosocial stress, military missions inevitably involve physical exercise that increases plasma BDNF concentrations. Second, most participants in the mission do not have adequate quality or quantity of sleep, and sleep deprivation has also been reported to increase plasma BDNF concentration. We evaluated plasma BDNF concentrations in 52 participants on a 9-week military mission. The present study revealed that plasma BDNF concentration significantly decreased despite elevated serum enzymes that escaped from muscle and decreased quantity and quality of sleep, as detected by a wearable watch-type sensor. In addition, we observed a significant decrease in plasma vascular endothelial growth factor (VEGF) during the mission. VEGF is also neurotrophic and its expression in the brain has been reported to be up-regulated by antidepressive treatments and down-regulated by stress. This is the first report of decreased plasma VEGF concentrations by stress. We conclude that decreased plasma concentrations of neurotrophins can be candidates for mental stress indicators in actual stressful environments that include physical exercise and limited sleep. © 2014 Suzuki et al. Source


Toshima H.,University of Tokyo | Suzuki Y.,University of Tokyo | Imai K.,University of Tokyo | Yoshinaga J.,University of Tokyo | And 5 more authors.
International Journal of Hygiene and Environmental Health | Year: 2012

The concentrations of chemicals with suspected endocrine disrupting effect were measured in urine samples collected from 42 Japanese male partners of couples who had infertility consultation at a gynecology clinic in Tokyo. The urinary analytes included metabolites of 5 phthalate diesters, pyrethroid insecticide (3-phenoxybenzoic acid, 3-PBA) and soy isoflavones (daidzein and equol), and cadmium. The semen parameters (semen volume, concentration and motility) of the male subjects were examined at the clinic as a diagnostic screening. Multiple regression analysis using one of the semen parameters examined as dependent variable and urinary biomarkers with age, body mass index, abstinent period, alcohol drinking, smoking and consumption frequency of selected foods as independent variables. For sperm concentration, urinary mono-n-butyl phthalate was selected as a significant independent variable with positive beta, while urinary daidzein was with negative beta. Consumption frequency of coffee (negative) and fruits (positive) were also significant. For sperm motility, urinary 3-PBA was selected as significant with negative beta as well as detectability of equol and frequency of coffee consumption with negative beta while smoking was with positive beta. This pilot study suggested the pyrethroid exposure level and dietary habit (coffee and soy products) as a significant contributor to poorer semen quality. © 2011 Elsevier GmbH. Source


Hatano B.,Japan National Institute of Infectious Diseases | Hatano B.,Military Medicine Research Unit | Hatano B.,U.S. Army | Goto M.,Military Medicine Research Unit | And 33 more authors.
Journal of Medical Virology | Year: 2011

The 2009 pandemic H1N1 influenza A virus spread quickly worldwide in 2009. Since most of the fatal cases were reported in developing countries, rapid and accurate diagnosis methods that are usable in poorly equipped laboratories are necessary. In this study, a mobile detection system for the 2009 H1N1 influenza A virus was developed using a reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) kit with a disposable pocket-warmer as a heating device (designated as pwRT-LAMP). The pwRT-LAMP can detect as few as 100 copies of the virus-which is nearly as sensitive as real-time reverse-transcription polymerase chain reaction (RT-PCR)-and does not cross-react with RNA of seasonal influenza viruses. To evaluate the usefulness of the pwRT-LAMP system, nasal swab samples were collected from 56 patients with flu-like symptoms and were tested. Real-time RT-PCR confirmed that the 2009 H1N1 influenza A virus was present in 27 of the 56 samples. Of these 27 positive samples, QuickVue Influenza A+B immunochromatography detected the virus in only 11 samples (11/27; 40.7%), whereas the pwRT-LAMP system detected the virus in 26 of the 56 samples (26/27 of the positive samples; 96.3%). These findings indicate that the mobile pwRT-LAMP system is an accurate diagnostic system for the 2009 H1N1 influenza A virus, and has great potential utility in diagnosing future influenza pandemics. © 2011 Wiley-Liss, Inc. Source


Matsumoto Y.,Japan Self Defense Force Central Hospital | Matsushita Y.,Japan Self Defense Force Central Hospital | Hatano B.,Japan Self Defense Force Central Hospital | Nawashiro H.,National Defense Medical College | Shima K.,National Defense Medical College
Neurological Surgery | Year: 2010

With the increase in terrorist activity in recent times, the number of blast injuries has also increased in civilian and military settings. In a recent war, the number of patients who suffered blast traumatic brain injury (bTBI) increased, so treatment of bTBI is currently a very important issue. Blast injury is complicated and can be divided into 4 categories: primary, secondary, tertiary, and quaternary. Primary blast injury results from exposure to blast waves; secondary blast injury is trauma caused by fragments of explosive devices; tertiary blast injury is the result of collision with objects; and quaternary blast injury is the result of exposure to toxic and other substances. Blast waves mainly injure air-containing organs such as the lung, bowel, and ear. The brain may also be affected by blast waves. From the clinical perspective, hyperemia and severe cerebral edema occur frequently in patients who sustain significant bTBI. Penetrating or closed head injury caused by the explosion may be associated with vasospasm and pseudoaneurysm formation. Mild traumatic brain injury during war can be associated with posttraumatic stress disorder. To elucidate the mechanism of bTBI, many research works using animal models and computer analysis are underway. Such studies have so far shown that blast waves can cause damage to the brain tissue and cognitive deficits; however, detailed investigations on this topic are still required. Treatment of bTBI patients may require clinical knowledge and skills related to intensive care, neurology, and neurosurgery. Moreover, further research is required in this field. Source

Discover hidden collaborations