ABSTRACT
Epidemiological and clinical characteristics of patients with COVID-19 have been reported in the last two years. A few studies reported clinical course of illness of median 22 days, including viral shedding of median 20 days, but there are several cases with a longer time of viral shedding. In this study, we included four cases with a longer illness course of more than 40 days who had been discharged or still in hospital by March 15, 2020. Demographic, clinical treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records. We described the epidemiological and clinical characteristics and the course of viral shedding. Two patients had comorbidity, one with hypertension and the other with diabetes. We found smoking was not an independent risk factor. D-dimer maybe related to the severity of illness but not to the course of the illness. Nucleic acid detection suggested that maybe more sampling sites represented more virus replication sites and longer course of illness. In this study we found some non-critical severe relatively young patients whose character was different from former studies described to provide a basis for reference to assess the risk of transmission and the isolation duration of patients.
ABSTRACT
To investigate the invasive ability of the residual tumor cells after immunotherapy and explore the feasible approach suppressing the invasion, mice were inoculated with B16 cells, and then treated by gene therapy with p4-1BBL/psPD-1 or IFN-gamma. The production and activities of MMP-9 and MMP-2 in residual tumor tissues were analyzed with gelatin zymography 1 day and 7 days after the termination of the immunotherapy. The production of MMP-9 and MMP-2 by B16 cells treated with IFN-gamma was also analyzed. IFN-gamma-treated B16 cells were inoculated to mice via subcutaneous injection. The invasion of tumor to muscular tissue was analyzed. Gene therapy with CH50 was used to suppress the invasive growth of tumor. The results showed that the expression and the activities of MMP-9 and MMP-2 were significantly increased 7 days after the end of immunotherapy. The response of tumor cells to ECM molecules was intensified after the removal of IFN-gamma, resulting in significant increase of both the production and activities of MMP-9 and MMP-2, and the increased invasion of tumor. Gene therapy with CH50 effectively suppressed the invasive growth of tumor. It is concluded that the termination of immunotherapy may result in a higher metastatic potential of residual tumor cells. Suppressing tumor invasion by suitable treatment will improve the efficacy of immunotherapy.
