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This study aims to identify differentially expressed microRNAs (miRNAs) in gastric cancer by comparing gastric cancerous tissues with normal tissues, explore the potential roles. The miRNA expression microarray was employed on gastric cancer tissues, and apparently normal para-cancerous tissues from 3 patients undergoing radical surgery were matched. Quantitative RT-PCR was performed on the other 7 patients to validate the findings of the microarray. Furthermore, Gene Ontology (GO) analysis and enrichment analysis of KEGG Pathway were performed for 5 dysregulated candidate miRNAs, including 3 upregulated (miR-31-3p, miR-6736-3p, and miR-147b) and 2 downregulated (miR-3065-5p and miR-3921) miRNAs, in order to determine the role of miRNAs in tumorigenesis and development. Among these miRNAs, 17 miRNAs were found to be upregulated, and 19 miRNAs were found to be downregulated. The dysregulated expression of 5 candidate miRNAs, including miR-31-3p, miR-147b, miR-6736-3p, miR-3065-5p, and miR-3921, were verified by quantitative RT-PCR in the validation set. Among these miRNAs, miR-31-3p, miR-6736-3p, miR-3065-5p, and miR-3921 had 551 target gene intersections. The GO and KEGG Pathway analyses Revealed that miR-31-3p, miR-6736-3p, miR-3065-5p, and miR-3921 may participate in multiple pathophysiological processes, such as foreign substance metabolism and chemical carcinogenesis. The profile of differentially expressed miRNAs was successfully screened, and 4 miRNAs (i.e., miR-31-3p, miR-6736-3p, miR-3065-5p, and miR-3921) appeared to be involved in gastric carcinogenesis. These might serve as promising biomarkers for gastric cancer.

A new type of coronavirus-induced pneumonia eventually termed “coronavirus disease 2019” (COVID-19) was diagnosed in patients in Wuhan (Hubei Province, China) in December 2019, and soon spread worldwide. To improve the detection rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we analyzed the results of viral nucleic acid and serum-specific antibody tests on clinical samples from 20 patients with SARS-CoV-2 infection diagnosed at the First Affiliated Hospital of Guangzhou Medical University in China. By comparing various sample types collected from COVID-19 patients, we revealed multiple pathways for SARS-CoV-2 shedding, and a prolonged detectable period for viral nucleic acid test in sputum specimens, demonstrating that the timeline of the viral shedding is of great value in determining the time of release from quarantine or discharge from hospital. We also recommend for the application of serological test to assist in confirming SARS-CoV-2 infection judged by viral nucleic acid test, especially when COVID-19-related symptoms have appeared and the viral nucleic acid test was negative. Our findings are critical for the diagnosis of SARS-CoV-2 infection and for determining deadline of restriction measures to prevent transmission caused by convalescent patients with COVID-19.

CXC chemokine receptor 4 (CXCR4) is a co-receptor for HIV-1 entry into target cells. Its natural ligand, the chemokine SDF-1, inhibits viral entry mediated by this receptor. However, the broad expression pattern of CXCR4 and its critical roles in various physiological and pathological processes indicate that the direct application of SDF-1 as an entry inhibitor might have severe consequences. Previously, we constructed an effective SDF-1 mutant, SDF-1/54, by deleting the &alpha, helix of the C-terminal functional region of SDF-1. Of note, SDF-1/54 shows remarkable decreased chemotoxic ability, but maintains a similar binding affinity to CXCR4, suggesting SDF-1/54 might better serve as a CXCR4 inhibitor. Here, we found that SDF-1/54 exhibited potent antiviral activity against various X4 HIV-1 strains, including the infectious clone HIV-1 NL4-3, laboratory-adapted strain HIV-1 IIIB, clinical isolates and even drug-resistant strains. By using time-of-addition assay, non-infectious and infectious cell&ndash, cell fusion assay and CXCR4 internalization assay, we demonstrated SDF-1/54 is an HIV-1 entry inhibitor. A combination of SDF-1/54 with several antiretroviral drugs exhibited potent synergistic anti-HIV-1 activity. Moreover, SDF-1/54 was stable and its anti-HIV-1 activity was not significantly affected by the presence of seminal fluid, vaginal fluid simulant and human serum albumin. SDF-1/54 showed limited in vitro cytotoxicity to lymphocytes and vaginal epithelial cells. Based on these findings, SDF-1/54 could have a therapeutic potential as an HIV-1 entry inhibitor.