Assuntos
Aneurisma Infectado/diagnóstico por imagem , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Hemorragia Gastrointestinal/diagnóstico por imagem , Fístula Intestinal/diagnóstico por imagem , Aneurisma Infectado/microbiologia , Aneurisma Infectado/cirurgia , Aneurisma da Aorta Abdominal/microbiologia , Aneurisma da Aorta Abdominal/cirurgia , Coma/complicações , Angiografia por Tomografia Computadorizada , Duodeno/diagnóstico por imagem , Duodeno/patologia , Endoscopia , Endoscopia do Sistema Digestório , Fístula/cirurgia , Hemorragia Gastrointestinal/microbiologia , Hemorragia Gastrointestinal/cirurgia , Humanos , Fístula Intestinal/microbiologia , Fístula Intestinal/cirurgia , Masculino , Melena/complicações , Pessoa de Meia-Idade , Infecções por Salmonella/sangue , Choque/complicações , VômitoRESUMO
This study presents a ball center alignment method based on the Michelson interferometer where one of the reflecting mirrors is replaced by a lens and steel ball. By locating the ball away from the focal length of the lens, the beam is reflected as a spherical wave. The interference ring formed by the planar and spherical waves can be clearly observed using a camera without a lens. The distance of the offset of the ball center can be enhanced by more than 140% using this method. A fast ring profile fitting method can reduce circle fitting time to around a third of that needed for Hough transformation.
RESUMO
Influenza A virus RNA synthesis is catalyzed by the viral polymerase comprised of the PA, PB1, and PB2 proteins. We show that the host DDX21 RNA helicase restricts influenza A virus by binding PB1 and inhibiting polymerase assembly, resulting in reduced viral RNA and protein synthesis. Later during infection, the viral NS1 protein overcomes this restriction by binding to DDX21 and displacing PB1. DDX21 binds to a region of the NS1 N-terminal domain that also participates in other critical functions. A virus mutant whose NS1 protein is unable to bind DDX21 exhibits reduced viral protein synthesis at both late and early times of infection, a phenotype converted to wild-type upon DDX21 knockdown. As sequential interaction of PB1 and NS1 with DDX21 leads to temporal regulation of viral gene expression, influenza A virus likely uses the DDX21-NS1 interaction not only to overcome restriction, but also to regulate the viral life cycle.
Assuntos
RNA Helicases DEAD-box/metabolismo , Vírus da Influenza A/genética , Proteínas não Estruturais Virais/metabolismo , Proteínas Virais/metabolismo , Animais , Sítios de Ligação , Linhagem Celular Tumoral , RNA Helicases DEAD-box/genética , Cães , Células HEK293 , Células HeLa , Humanos , Células Madin Darby de Rim Canino , Inibidores da Síntese de Ácido Nucleico , Ligação Proteica , Biossíntese de Proteínas/genética , Estrutura Terciária de Proteína , Interferência de RNA , RNA Interferente Pequeno , RNA Viral/biossíntese , Replicação ViralRESUMO
The Soj and Spo0J proteins, together with one or more parS sequences, are crucial to chromosome segregation and the progression of cell cycle in many bacteria. In Helicobacter pylori, genes coding for Soj and a plasmid replication-partition-related protein containing a Spo0J or ParB conserved domain, together with two putative parS sites identified in this study, were found to be located within the origin-proximal 20-30% of the circular chromosome. Recombinant H. pylori Spo0J bound specifically to the two putative parS sequences and that of Bacillus subtilis. In addition, hydrolysis of ATP by H. pylori Soj was accelerated in the presence of parS and/or Spo0J. Protein-protein interactions, intracellular levels, and subcellular localization of Soj and Spo0J were analyzed through polyclonal antibodies directed against recombinant Soj and Spo0J. This study was the first implication of the existence of a functional parABS system in H. pylori.