Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures

Cold-chain environment could extend the survival duration of SARS-CoV-2 and increases the risk of transmission. However, the effect of clod-chain environmental factors and packaging materials on SARS-CoV-2 stability and the efficacy of intervention measures to inactivate SARS-CoV-2 under cold-chain environment remains uncertain. This study aimed to unravel cold-chain environmental factors that preserved the stability of SARS-CoV-2 and disinfection measures against SARS-CoV-2 under the cold-chain environment. The spike gene of SARS-CoV-2 isolated from Wuhan hu-1 was used to construct the SARS-CoV-2 pseudovirus and used as model of the SARS-CoV-2 virus. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, various types of packaging material surfaces i.e., PE plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of LED visible light(wavelength 450 nm-780 nm) and airflow movement on the stability of SARS-CoV-2 pseudovirus at -18{degrees} C were subsequently assessed. The results show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surface compared with the non-porous surfaces including PE plastic, stainless steel and Teflon. Compared with 25{degrees} C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperature. Seawater preserved viral stability both at -18{degrees} C and repeated freeze-thawing cycles compared with deionized water. LED visible light illumination and airflow movement environment at -18{degrees} C reduced the SARS-CoV-2 pseudovirus stability. In conclusion, our results indicate cold-chain temperature and seawater as risk factors for SARS-CoV-2 transmission and LED visible light illumination and airflow movement as possible disinfection measures of SARS-CoV-2 under the cold-chain environment. ImportanceIt is widely recognized that low temperature is a condition for maintaining virus vitality, and cold-chain transportation spreads the events of the SARS-CoV-2 were reported. This study provides that the decay rate of the SARS-CoV-2 pseudovirus at low temperatures varies on different packaging materials, and salt ions present in frozen foods such as seafood may protect virus survival. These results provide evidence for the possibility of SARS-CoV-2 transmission through cold-chain transport and also suggest the importance for disinfection of items. However, the commonly used disinfection methods of ultraviolet radiation and chemical reagents are generally not suitable for the disinfection of frozen food. Our study shows LED visible light illumination and airflow movement as possible disinfection measures of SARS-CoV-2 under the cold-chain environment. This has implications for reducing the long-distance transmission of the virus through cold-chain transportation.

Inhibitory effect of andrographolide on angiogenesis induced by the supernatant from cultured tumor cells / 中南大学学报(医学版)

To determine the effect of andrographolide (Andro) on angiogenesis of human umbilical vein endothelial cells (HUVECs).
 Methods: HUVECs were treated with different concentrations of Andro and the cell viability was detected with Cell Counting Kit-8 (CCK-8). HUVECs were treated with half lethal dose (IC50) of Andro. Matrigel was used to make capillary formation of HUVECs and the effect of Andro on capillary formation was evaluated by calculating the percentage of capillary formation. Moreover, the effects of Andro and the supernatant from cultured A549 tumor cells on capillary formation were evaluated by calculating the percentage of capillary formation. The effect of Andro on the expression of matrix metalloproteinase-9 (MMP-9) was determined with Western blot.
 Results: The cell viability of HUVECs decreased with the increase of Andro concentrations. IC50 was 20 μmol/L. The capillary formation of HUVECs was inhibited when treated with 20 μmol/L Andro for 24 hours. Moreover, Andro was able to antagonize the promotion of the capillary formation induced by the supernatant from cultured tumor cells. Andro could suppress the expression of MMP-9 and antagonize the capillary formation.
 Conclusion: Andro inhibits the capillary formation of HUVECs and can antagonize the promotion of angiogenesis induced by the supernatant from cultured tumor cells.

Effect of human growth hormone releasing hormone receptor splice variant type 1 on proliferation of human liver cancer HepG2 cells / 吉林大学学报(医学版)

Objective:To investigate the effect of human growth hormone releasing hormone receptor splice variant type 1 (GHRHR SV1) on the proliferation of human liver cancer HepG2 cells,and to clarify the proliferation effect of GHRHR SV1 on the human cancer cells.Methods:The GHRHR SV1 plasmids were transfected into the human HepG2 cells to construct the HepG2-SV1 cell line.HepG2 group(HepG2 cells),HepG2-empty group(HepG2-pcDNA3.0 cell line) and HepG2-SV1 group(HepG2-SV1 cells) were set up.PCR and Western blotting methods were used to identify the HepG2-SV1 cell line;CCK-8 method was used to detect prolifernation rate of cells;colony formation assay was used to detect the colony formation rate of cells;cell wound healing assay was used to evaluate the migration rate of cells.Results:The PCR and Western blotting results showed the HepG2-SV1 cell line expressed GHRHR SV1 steadily.The CCK-8 results showed that the proliferation rate of the HepG2-SV1 cells in HepG2-SV1 group was higher than that of the HepG2-pcDNA3.0 cells in HepG2-empty group(P<0.05).The colony formation assay results showed that the colony formation rate of HepG2-SV1 cells in HepG2-SV1 group was 3.5 times higher than that of the HepG2-pcDNA3.0 cells in HepG2-empty group(P<0.05).The cell wound scratch assay results showed that the migration rate of the HepG2-SV1 cells in HepG2-SV1 group was higher than that of the HepG2-pcDNA3.0 cells in HepG2-empty group(P<0.05).Conclusion:GHRHR SV1 could increase the proliferation of HepG2 cells.