Comparative Study Between Gemcitabine-Based and Gemcitabine Plus S1-Based Preoperative Chemoradiotherapy for Localized Pancreatic Ductal Adenocarcinoma, With Special Attention to Initially Locally Advanced Unresectable Tumor

application/pdf内容の要旨・審査結果の要旨 / 三重大学大学院医学系研究科 生命医科学専攻 臨床医学系講座 肝胆膵・移植外科学分

Comparative Study Between Gemcitabine-Based and Gemcitabine Plus S1-Based Preoperative Chemoradiotherapy for Localized Pancreatic Ductal Adenocarcinoma, With Special Attention to Initially Locally Advanced Unresectable Tumor

application/pdf要約 / 三重大学大学院医学系研究科 生命医科学専攻 臨床医学系講座 肝胆膵・移植外科学分

Early Stage of Establishment of Persistent Sendai Virus Infection: Unstable Dynamic Phase and Then Selection of Viruses Which Are Tightly Cell Associated, Temperature Sensitive, and Capable of Establishing Persistent Infection

We obtained 157 cloned cell lines persistently infected with Sendai virus; these cell lines were generated independently of each other. Infectious viruses could be isolated from 123 of these cloned cell lines by inoculation of culture fluids or infected cells into embryonated eggs. The majority of the viruses carried by cells persistently infected with viruses showed high cytotoxicity and did not have the ability to establish persistent infection. The association of carried virus with cells became stronger and virus isolation correspondingly became more difficult as cells persistently infected with virus were subcultured. Viruses derived from virus-infected cells eventually acquired the ability to establish persistent infection, although the ways in which the viruses acquired this ability varied. The viruses also acquired temperature sensitivity as persistently infected cells were subcultured. First, the hemagglutinin-neuraminidase and M proteins acquired temperature sensitivity, and then the polymerase(s) did so. The M proteins were localized in the nuclei of cells infected with cloned viruses that had the ability to establish persistent infection. Cells infected with viruses capable of establishing persistent infection showed no or slight staining by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling. Specific amino acid substitutions accumulated in the M protein and the L protein as virus-infected cells were subcultured. This study shows that there is an unstable dynamic phase at an early stage of the establishment of persistent Sendai virus infection (steady state), and then viruses capable of establishing persistent infection are selected