Passively Sensing SARS-CoV-2 RNA in Public Transit Buses

Affordably tracking the transmission of respiratory infectious diseases in urban transport infrastructures can inform individuals about potential exposure to diseases and guide public policymakers to prepare timely responses based on geographical transmission in different areas in the city. Towards that end, we designed and tested a method to detect SARS-CoV-2 RNA in the air filters of public buses, revealing that air filters could be used as passive fabric sensors for the detection of viral presence. We placed and retrieved filters in the existing HVAC systems of public buses to test for the presence of trapped SARS-CoV-2 RNA using phenol-chloroform extraction and RT-qPCR. SARS-CoV-2 RNA was detected in 14% (5/37) of public bus filters tested in Seattle, Washington, from August 2020 to March 2021. These results indicate that this sensing system is feasible and that, if scaled, this method could provide a unique lens into the geographically relevant transmission of SARS-CoV-2 through public transit rider vectors, pooling samples of riders over time in a passive manner without installing any additional systems on transit vehicles. SynopsisPassive sensing of viral presence on urban transit infrastructure is proven, with forward-looking benefits for tracking pandemic spread.

A mechanism study of the inhibition of the adhesion of human gastric cancer MKN1 cells and suppression of the expression of integrin ?_1 gene by dextran sulfate / 中国药理学通报

Aim To observe the adhesive process of the human gastric cancer cell line MKN1,and study the expression of integrin ?1;to investigate the mechanism of the inhibition of the adhesion process of MKN1 cells by destran sulfate(DS).Methods The MKN1 cells were cultured with DS or PBS,then stained with immunofluorescent cytochemistry and observed in fixed or living conditions with confocal laser scanning microscope.RT-PCR was used to analyze the cDNA expression of MKN1 cells.Results MKN1 cells adhered to culture dishes by the process of forming filopodia,changed into a flat shape,and then adhered to other cells to form a cell-monolayer.Integrin ?1 was intensively expressed in the cell membrane,where integrin ?1 formed clusters.DS inhibted the expression of integrin ?1 in cell membrane,and decreased the area of integrin ?1 clusters.DS-treated cells also tended to maintain a round shape by contracting the filopodia.In DS-containing culture dishes,some cells kept floating 4 hours after seeding.DS decreased the level of the cDNA expression of the adhered cells to 74% and of the floating cells to 38% of that of the cells in un-treated group,respectively.Conclusion The inhibition of the adhesion of MKN1 cells by DS was related to the suppression of the expression of integrin ?1.

Study on the enhanced anti-tumoral immune function of human peritoneal macrophages by Sapylin / 中国免疫学杂志

Objective:To investigate the mechanism for intraperitoneal injection of sapylin to enhance the anti-tumoral immune functions of peritoneal macrophages.Methods:72 cases of patients with early or middle stage gastrointestinal cancer were peritoneally injected saline or sapylin, 48 h or 24 h before operation. The peritoneal macrophages(PM?) was harvested during their operations. The number of the PM? was counted. The phagocytosis, the enzyme activity of LDH and ACP,and the NO secretion were analyzed. Using human gastric cancer cell line MKN1 as target cells, the anti-tumoral cytotoxicity of the PM? was observed.The greater omentum was harvested,both the number and the size of the omental milky spots were measured.Results:I.p. injection of sapylin significantly increased the number, the phagocytosis, the enzyme activities,NO secretion and anti-tumoral cytotoxicity of the PM?, as well as the number and the size of omental milky spots.Conclusion:By activating omental milky spots, intraperitoneal injection of sapylin increased the number and enhanced the immune function of PM?, the activated PM? showed enhancement of anti-tumoral cytotoxicity.