Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease (COVID-19) and the evidence of person-to-person transmission. Limited data are available for asymptomatic infections. This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers. Epidemiological investigations were conducted among all close contacts of COVID-19 patients (or suspected patients) in Nanjing, Jiangsu Province, China, from Jan 28 to Feb 9, 2020, both in clinic and in community. Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples. Their clinical records, laboratory assessments, and chest CT scans were reviewed. As a result, none of the 24 asymptomatic cases presented any obvious symptoms while nucleic acid screening. Five cases (20.8%) developed symptoms (fever, cough, fatigue, etc.) during hospitalization. Twelve (50.0%) cases showed typical CT images of ground-glass chest and 5 (20.8%) presented stripe shadowing in the lungs. The remaining 7 (29.2%) cases showed normal CT image and had no symptoms during hospitalization. These 7 cases were younger (median age: 14.0 years; P=0.012) than the rest. None of the 24 cases developed severe COVID-19 pneumonia or died. The median communicable period, defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests, was 9.5 days (up to 21 days among the 24 asymptomatic cases). Through epidemiological investigation, we observed a typical asymptomatic transmission to the cohabiting family members, which even caused severe COVID-19 pneumonia. Overall, the asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization. However, the communicable period could be up to three weeks and the communicated patients could develop severe illness. These results highlighted the importance of close contact tracing and longitudinally surveillance via virus nucleic acid tests. Further isolation recommendation and continuous nucleic acid tests may also be recommended to the patients discharged.

• Neutralizing antibody evaluation helps to assess the risk of re-infection. • Some COVID-19 patients may not develop neutralizing antibody after recovery. • SARS-CoV-2 neutralizing antibody levels are correlated with COVID-19 disease severity.

Objective: The aims of this study were to compare the clinical outcomes between ultrasound-guided percutaneous microwave ablation (US-PMWA) and surgical resection (SR) in patients with recurrent intrahepatic cholangiocarcinoma (ICC) and to identify the prognostic factors associated with the two treatment methods. Methods: This retrospective study was institutional review board approved. A total of 121 patients (102 men and 19 women) with 136 ICCs after hepatectomy from April 2011 to January 2017 were reviewed. Fifty-six patients underwent US-PMWA and 65 patients underwent SR. Survival, recurrence and liver function were compared between the two groups. Effect of changes in key parameters [i.e., overall survival (OS) and recurrence-free survival (RFS)] was statistically analyzed with the log-rank test. Univariate and multivariate analysis were performed on clinicopathological variables to identify factors affecting long-term outcome. Results: The OS and RFS after MWA were comparable to that of SR (p = .405, and p = .589, respectively). Estimated 5-year OS rates were 23.7% after MWA and 21.8% after SR; for RFS, estimated 3-year RFS rates were 33.1% after MWA and 30.6% after SR. Major complication rates in SR group were higher than that in MWA (p < .001) (SR, 13.8% vs. MWA, 5.3%). Multivariate analysis showed tumor number (p = .012), ALBI grade (p = .007), and metastasis (p = .016), may become OS rate predictors. Conclusions: US-PMWA had comparable oncologic outcomes with SR and could be a safe and effective treatment for recurrent ICC after hepatectomy.

Patients with non-small-cell lung cancer (NSCLC) frequently develop radioresistance, resulting in poor response to radiation and unfavourable prognosis. Early detection of radioresistance hence can guide the adjustment of treatment regimens in time. Exosomes are lipid bilayer-enclosed vesicles with sub-micrometer size that are released by various cells. Exosomes contain a tissue-specific signature wherein a variety of proteins and nucleic acids are selectively packaged. Growing evidence shows exosomes are involved in cancer pathophysiology and exosomes as the latest addition to the liquid biopsy portfolio have been used in cancer diagnosis. Compared to cell free RNA, exosomal lipid envelope can effectively protect RNA cargo against degradation. Therefore, exosomes may hold great promise for the identification of radioresistance. Here, we report six plasma exosomal miRNAs could be used to distinguish radioresistant NSCLC patients from radiosensitive NSCLC patients and to evaluate the prognosis of NSCLC. Samples were obtained from 52 NSCLC patients with or without radioresistance and 45 age-matched healthy volunteers. Exosomes in 1 ml plasma were isolated followed by extraction of small RNA. The expression levels of miRNAs were determined by quantitative real-time PCR. Potential miRNA markers were further evaluated in additional 52 NSCLC patients. We found exosomal miR-1246 and miR-96 are significantly overexpressed in NSCLC patients. Moreover, exosomal miR-96 in patients with radioresistant NSCLC is significantly higher than that of controls. Exosomal miR-96 also demonstrates a significant correlation with vascular invasion and poor overall survival. Altogether, our results indicate that exosomal miR-96 could be a non-invasive diagnostic and prognostic marker of radioresistant NSCLC.