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Sci Rep ; 11(1): 8380, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863960


Healthcare workers (HCWs) are highly exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The actual coronavirus disease (COVID-19) situation, especially in regions that are less affected, has not yet been determined. This study aimed to assess the seroprevalence of SARS-CoV-2 in HCWs working in a frontline hospital in Tokyo, Japan. In this cross-sectional observational study, screening was performed on consented HCWs, including medical, nursing, and other workers, as part of a mandatory health checkup. The screening test results and clinical characteristics of the participants were recorded. The antibody seroprevalence rate among the 4147 participants screened between July 6 and August 21, 2020, was 0.34% (14/4147). There was no significant difference in the seroprevalence rate between frontline HCWs with a high exposure risk and HCWs working in other settings with a low exposure risk. Of those seropositive for SARS-CoV-2, 64% (9/14) were not aware of any symptoms and had not previously been diagnosed with COVID-19. In conclusion, this study provides insights into the extent of infection and immune status in HCWs in Japan, which has a relatively low prevalence of COVID-19. Our findings aid in formulating public health policies to control virus spread in regions with low-intensity COVID-19.

COVID-19/diagnóstico , Adulto , Idoso , Anticorpos Antivirais/sangue , COVID-19/epidemiologia , COVID-19/virologia , Estudos Transversais , Feminino , Pessoal de Saúde , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/isolamento & purificação , Tóquio/epidemiologia , Adulto Jovem
Dent Mater J ; 40(4): 877-884, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33678732


The influence of sulfinate agents applied as a dentin pretreatment or a mixture with multi-mode one-step self-etch adhesives (1-SEAs) on the degree of conversion (DC) and micro-tensile bond strength (µTBS) of light-cured 1-SEAs was investigated. 1-SEAs Clearfil Universal Bond Quick (UBQ) or Scotchbond Universal Adhesive (SBU) were applied to dentin in etch&rinse or self-etch mode using various application strategies: 1) no pretreatment, 2) pretreatment with 90 wt% ethanol, 3) pretreatment with a sulfinate agent Clearfil DC Activator (UDC) or Scotchbond Universal DCA (SDC), or 4) a mixture of UBQ+UDC or SBU+SDC. µTBS was measured after 24 h. Additionally, DC was measured using attenuated total reflectance Fourier-transform infrared spectroscopy. Pretreatment with sulfinate agents resulted in the highest µTBS and DC, significantly improving them especially in etch&rinse mode. The mixture of sulfinate agents with 1-SEAs was less effective. Pretreatment with ethanol significantly improved µTBS in etch&rinse mode but compromised µTBS in self-etch mode.

Colagem Dentária , Adesivos , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração
Sci Rep ; 5: 16330, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26573481


UV-DDB, an initiation factor for the nucleotide excision repair pathway, recognizes 6-4PP lesions through a base flipping mechanism. As genomic DNA is almost entirely accommodated within nucleosomes, the flipping of the 6-4PP bases is supposed to be extremely difficult if the lesion occurs in a nucleosome, especially on the strand directly contacting the histone surface. Here we report that UV-DDB binds efficiently to nucleosomal 6-4PPs that are rotationally positioned on the solvent accessible or occluded surface. We determined the crystal structures of nucleosomes containing 6-4PPs in these rotational positions, and found that the 6-4PP DNA regions were flexibly disordered, especially in the strand exposed to the solvent. This characteristic of 6-4PP may facilitate UV-DDB binding to the damaged nucleosome. We present the first atomic-resolution pictures of the detrimental DNA cross-links of neighboring pyrimidine bases within the nucleosome, and provide the mechanistic framework for lesion recognition by UV-DDB in chromatin.

DNA/química , Nucleossomos/metabolismo , Dímeros de Pirimidina/química , Raios Ultravioleta , Cristalografia por Raios X , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Histonas/genética , Histonas/metabolismo , Humanos , Maleimidas/química , Mutagênese Sítio-Dirigida , Conformação de Ácido Nucleico , Ligação Proteica , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificação
Mutat Res ; 699(1-2): 62-6, 2010 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-20394837


Individuals with inherited xeroderma pigmentosum (XP) disorder and Cockayne syndrome (CS) are deficient in nucleotide excision repair and experience hypersensitivity to sunlight. Although there are several diagnostic assays for these disorders, the recovery of RNA synthesis (RRS) assay that can discriminate between XP cells and CS cells is very laborious. Here, we report on a novel non-radioisotope RRS assay that uses bromouridine (a uridine analog) as an alternative to (3)H-uridine. This assay can easily detect RNA polymerase I transcription in nucleoli and RNA polymerase II transcription in nuclei. The non-RI RSS assay also can rapidly detect normal RRS activity in HeLa cells. Thus, this assay is useful as a novel and easy technique for CS diagnosis. Because RRS is thought to be related to transcription-coupled DNA repair, which is triggered by the blockage of transcriptional machinery by DNA lesions, this assay may be of use for analysis of DNA repair, transcription, and/or genetic toxicity.

Bioensaio , Dano ao DNA/efeitos da radiação , RNA/biossíntese , Uridina/análogos & derivados , Bromouracila/análogos & derivados , Linhagem Celular , Síndrome de Cockayne/genética , Reparo do DNA , Células HeLa , Humanos , Microscopia de Fluorescência , RNA Polimerase I/metabolismo , RNA Polimerase II/metabolismo , Raios Ultravioleta/efeitos adversos , Uridina/metabolismo , Xeroderma Pigmentoso/genética