OBJECTIVETo investigate the effect of bone marrow mesenchymal stem cells (BMSCs) on secretion of inflammatory cytokines in macrophages stimulated by lipopolysacharide (LPS).

METHODSRat BMSCs and macrophages were isolated, cultured, and identified. The BMSCs and macrophages, cultured alone or in co-culture, were treated with LPS or PBS or without treatment and tested for interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α) concentrations in the supernatants at 1, 3, 5, 7, 12, and 24 h after the treatment using enzyme-linked immunosorbent assay.

RESULTSExposure to LPS caused significantly increased IL-10 and TNF-α concentrations in the supernatant of cultured macrophages but not in BMSC culture. Macrophages co-cultured with BMSCs showed significantly lowered IL-10 and TNF-α secretions in response to LPS exposure as compared with the macrophages cultured alone.

CONCLUSIONBMSCs can reduce LPS-induced secretion of inflammatory cytokines by the macrophages to ameliorate inflammatory reactions.

Animals ; Cells, Cultured ; Coculture Techniques ; Enzyme-Linked Immunosorbent Assay ; Inflammation ; Interleukin-10 ; secretion ; Lipopolysaccharides ; Macrophages ; secretion ; Mesenchymal Stromal Cells ; cytology ; Rats ; Tumor Necrosis Factor-alpha ; secretion

OBJECTIVE: To compare the diagnostic efficacy among three RT-PCR test kits for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection. METHODS: The throat swab samples from 40 hospitalized patients clinically diagnosed as coronavirus disease 2019 (COVID-19) and 16 hospitalized non-COVID-19 patients were recruited. The SARS-CoV-2 nucleic acid was detected in throat swab samples with RT-PCR test kits from Sansure Biotech ("Sansure" for short), Jiangsu Bioperfectus Technologies ("Bioperfectus" for short) and BGI Genomics ("BGI" for short). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Kappa value were analyzed. The viral nucleic acid was extracted from the throat swab samples by one-step cleavage and magnetic bead methods, and the efficacy of two extraction methods was also compared. The results of magnetic bead method for nucleic acid extraction by two different extractors (Sansure Natch CS S12C Fully Automated Nucleic Acid Extraction System vs. Tianlong NP968-C Nucleic Acid Extractor) were also compared. RESULTS: The sensitivity, specificity, PPV, NPV and kappa value were 95.00%, 87.50%, 95.00%, 87.50%and 0.825 for Sansure kit; 90.00%, 87.50%, 94.74%, 77.78%and 0.747 for the Bioperfectus kit, and 82.50%, 81.25%, 91.67%, 65.00%and 0.593 for the BGI kit, respectively. The positive, negative and total coincident rates and kappa value of viral nucleic acid detection results using the samples extracted by one-step cleavage and magnetic bead methods were 95.24%, 100.00%, 96.43%and 0.909, respectively, but the one-step cleavage method took only 25 min, while the magnetic bead method required 180 min. The positive, negative and total coincident rates and kappa value of viral nucleic acid detection results using the samples extracted by the two different nucleic acid extractors were 85.00%, 100.00%, 89.29% and 0.764, respectively. CONCLUSIONS The detection efficacy for SARS-CoV-2 nucleic acid by the Sansure kit is relatively higher and the one-step cleavage method has advantages of convenient operation and less time consuming.
Betacoronavirus ; genetics ; isolation & purification ; Coronavirus Infections ; diagnosis ; virology ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; virology ; RNA, Viral ; genetics ; isolation & purification ; Reagent Kits, Diagnostic ; standards