298 research outputs found

    Measurement of radon and thoron concentrations in the Tokyo Metropolitan University Arakawa Campus building

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    Smoking and radon inhalation are the primary causes of lung cancer in many countries. The world average annual dose due to radon inhalation is 1.26 mSv y^, which is more than half of the annual exposure dose from natural radiation sources, 2.40 mSv y^. In this study, radon and thoron radioactivity concentrations( hereafter referred to simply as concentrations) measurements were carried out in the Tokyo Metropolitan University Arakawa Campus building using a pulse type ionization chamber and passive radon and thoron discriminative monitors. The respective average (±σ) radon concentrations (Bq m^) for each day of the week from Sunday to Saturday were: 21 ± 7, 20 ± 7, 20 ± 8, 22 ± 6, 21 ± 7, 20 ± 6, 23 ± 7. On week days, the radon concentration peaked daily at 8:00 am with a value of 25 ±6 Bq m^, it decreased until 7:00 pm reaching a value of 17 ±7 Bq m^, and then, showed a rising trend to the next morning’s peak. Radon concentration tended to show a higher value and less fluctuation on weekends. No seasonal change was observed. No correlation was observed between radon concentration and thoron concentration. In Japan, the repor ted arithmetic average radon concentration indoors is 15.5 Bq m^ and the arithmetic average concentration outdoors is 5.4 Bq m^. The annual effective dose of radon by inhalation in Japan is 0.64 mSv y^. The average radon concentration of reinforced concrete buildings tends to be higher, though a radon concentration survey in reinforced concrete buildings in Japan is lacking. Calculated annual average exposure dose in the campus reinforced concrete building was 0.15 mSv y^. Annual average exposure dose considering an indoor environment other than the Arakawa Campus building was 0.42 mSv y^

    Endothelin-1 Production by Normal Human Cultured Keratinocytes and its Regulation

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    The possibility that cultured keratinocytes produce endothelins were investigated. The results showed that cultured keratinocytes derived from normal human skin produce endothelin-1. Moreover, keratinocyte endothelin-1 production was completely inhibited by the presence of actinomycin D in the medium. As in the case of endothelial cells, recombinant interleukin-1β was capable of promoting endothelin-1 production in keratinocytes, whereas herapin inhibited it. Thrombin also inhibited endothelin-1 production. These results indicate that the mechanism of endothelin-1 production in keratinocytes is slightly different from the mechanism in vascular endothelial cells

    Contribution ratios of natural radionuclides to ambient dose rate in air after the Fukushima Daiichi Nuclear Power Plant Accident

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    It is important that the contribution ratio of natural radioactivity to ambient dose rate in air is clarified after the accident at the Fukushima Daiichi Nuclear Power Plant. In this study, ambient dose rates in air were observed at 34 places in eastern Japan and the contribution ratios were clarified. The mean contribution ratio of the natural radionuclides was 71% (range: 0–100%). In most places, the natural radionuclides made a larger contribution to the ambient dose rate in air

    Investigation of radon and thoron concentrations in a landmark skyscraper in Tokyo

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    The temporal variation of the radon concentration, and the radon and thoron concentrations every three months for a year were measured using two types of devices in a landmark skyscraper, the Tokyo Metropolitan Government Daiichi Building. In the measurement of temporal variation of the radon concentration using a pulse type ionization chamber, the average radon concentration was 21 ± 13 Bq m-3 (2 - 68 Bq m-3). The measured indoor radon concentration had a strong relationship with the operation of the mechanical ventilation system and the activities of the office workers. The radon concentration also increased together with temperature. Other environmentalparameters, such as air pressure and relative humidity, were not related to the radon concentration. In the long-term measurements using a passive radon and thoron discriminative monitor, no seasonal variation was observed. The annual average concentrations of radon and thoron were 16 ± 8 Bq m-3 and 16 ± 7 Bq m-3, respectively. There was also no relationship between the two concentrations. The annual average effective dose for office workers in this skyscraper was estimated to be 0.08 mSv y-1 for 2000 working hours per year. When considering the indoor radon exposure received from their residential dwellings using the annual mean radon concentration indoors in Japan (15.5 Bq m-3), the annual average effective dose was estimated to be 0.37 mSv y-1. This value was 31 % of the worldwide average annual effective dose

    The nucleotide and deduced amino acid sequences of porcine liver proline-β-naphthylamidase swEvidence for the identity with carboxylesterase

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    AbstractA cDNA clone for porcine liver proline-β-naphthylamidase was isolated and sequenced. The deduced amino acid sequence of 567 residues was highly homologous with those of carboxylesterases (EC 3.1.1.1) previously reported for other species. In addition, proline-β-naphthylamidase purified from porcine liver was shown to have strong activity towards p-nitrophenylacetate, a representative substrate for carboxylesterases. These results suggest that proline-β-naphthylamidase is identical with carboxylesterase

    Characterization of Tight Junctions and Their Disruption by UVB in Human Epidermis and Cultured Keratinocytes

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    It has not been confirmed whether tight junctions (TJs) function as a paracellular permeability barrier in adult human skin. To clarify this issue, we performed a TJ permeability assay using human skin obtained from abdominal plastic surgery. Occludin, a marker protein of TJs, was expressed in the granular layer, in which a subcutaneously injected paracellular tracer, Sulfo-NHS-LC-Biotin (556.59Da), was halted. Incubation with ochratoxin A decreased the expression of claudin-4, an integral membrane protein of TJs, and the diffusion of paracellular tracer was no longer prevented at the TJs. These results demonstrate that human epidermis possesses TJs that function as an intercellular permeability barrier at least against small molecules (∼550Da). UVB irradiation of human skin xenografts and human skin equivalents (HSEs) resulted in functional deterioration of TJs. Immunocytochemical staining of cultured keratinocytes showed that occludin was localized into dot-like shapes and formed a discontinuous network when exposed to UVB irradiation. Furthermore, UVB irradiation downregulated the active forms of Rac1 and atypical protein kinase C, suggesting that their inactivation caused functional deterioration of TJs. In conclusion, TJs function as a paracellular barrier against small molecules (∼550Da) in human epidermis and are functionally deteriorated by UVB irradiation

    DIP during perioperative chemotherapy

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    Purpose : Drug-induced interstitial pneumonia (DIP) that occurs during chemotherapy for breast cancer is a rare but a serious adverse event. Treatments of DIP requires interruption of breast cancer treatment, which may affect the patient’s prognosis. However, there are few reports which discuss DIP during breast cancer treatments. Purpose of this report is to make clear how DIP occurred and influenced breast cancer treatment in our hospital. Patients and Methods : A total of 74 patients who started perioperative chemotherapy in Tokushima Municipal Hospital for breast cancer from January 2019 to December 2020 were evaluated for DIP. Patients’ and tumors’ characteristics, and regimens which caused DIP were investigated. The clinical courses of the DIP patients were also followed up. Results : Twelve of the 74 patients developed DIP. All 12 patients had histories of cyclophosphamide administration ; however, the causative drug could not be determined. Ten of the 12 patients were treated with steroids, and all the patients recovered ultimately from the interstitial pneumonia. While chemotherapy was administered in six patients after mild DIP, no relapse of pneumonia was observed. Conclusion : DIP during perioperative chemotherapy for breast cancer was resolved with appropriate treatment. Patients were able to resume breast cancer treatment with minimal interruption

    NMDAR2B tyrosine phosphorylation regulates anxiety-like behavior and CRF expression in the amygdala

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    <p>Abstract</p> <p>Background</p> <p>Anxiety disorders are a highly prevalent and disabling class of psychiatric disorders. There is growing evidence implicating the glutamate system in the pathophysiology and treatment of anxiety disorders, though the molecular mechanism by which the glutamate system regulates anxiety-like behavior remains unclear.</p> <p>Results</p> <p>In this study, we provide evidence suggesting that tyrosine phosphorylation of the NMDA receptor, an ionotropic glutamate receptor, contributes to anxiety-like behavior. The GluN2B subunit of the NMDA receptor is tyrosine-phosphorylated: Tyr-1472 is the major phosphorylation site. Homozygous knock-in mice that express a Tyr-1472-Phe mutant of GluN2B, which prevents phosphorylation of this site, show enhanced anxiety-like behavior in the elevated plus-maze test. Expression of corticotropin-releasing factor (CRF), which is important for the regulation of anxiety-like behavior, is increased in the amygdala of the knock-in mice. Furthermore, injection of CRF receptor antagonist attenuated the enhanced anxiety-like behavior of the knock-in mice. We also show that elevated plus-maze exposure simultaneously induced de-phosphorylation of Tyr-1472 and increased CRF expression.</p> <p>Conclusions</p> <p>These data suggest that Tyr-1472 phosphorylation on GluN2B is important for anxiety-like behavior by negative regulation of CRF expression in the amygdala.</p
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