ABSTRACT
Since December 2019, Corona Virus Disease (COVID-19), a new emerging infection disease occurred in Wuhan, has spread in 27 countries and regions. The clusters of many cases were reported with the epidemic progresses. We collected currently available information for 377 COVID-19 clusters (1 719 cases), excluded the hospital clusters and Hubei cases, during the period from January 1, 2020 to February 20, 2020. There were 297 family clusters (79%), case median 4; 39 clusters of dining (10%), case median 5; 23 clusters of shopping malls or supermarkets (6%), case median 13; 12 clusters of work units (3%), case median 6, and 6 clusters of transportation. We selected 325 cases to estimate the incubation period and found its range is 1 to 20 days, median was 7 days, and mode was 4 days. The analysis of the epidemic situation in a department store in China indicates that there is a possibility of patients as the source of infection during the incubation period of the epidemic. From February 5, 2020 to February 21, 2020, 634 persons were infected in the Diamond Princess Liner. All persons are susceptible to SARS-CoV-2. The older, patients during the incubation period and the worse environment may be the cause of the cases rising. The progress of the two typical outbreaks clearly demonstrates the spread of the early cases in Wuhan. Whatever happens, screening and isolating close contacts remains essential except for clinical treatment during the epidemic. Especially for the healthy people in the epidemic area, isolation is the key.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the protein expression of heme oxygenase-1 (HO-1) and platelet endothelial cell adhesion molecules-1 (PECAM-1) in human coronary artery endothelial cells induced with Zinc Oxide Nanoparticle (ZnO-NPs).</p><p><b>METHODS</b>MTT assay was used to determine the cell viability of ZnO-NPs. Levels of HO-1 and PECAM-1 protein in culture supernatants were measured using ELISA after human coronary artery endothelial cells were treated with different concentrations (0, 10, 20, 40µg/ml) of ZnO-NPs for 24 h.</p><p><b>RESULTS</b>The cell viability of human coronary artery endothelial cells in each group was 89.76%, 83.61%, 63.10%, 53.20%, 48.11%, 42.35%, 38.06%, 25.44% respectively when treated with different concentrations of ZnO-NPs (12.5, 25, 50, 70, 80, 90, 100, 200µg/ml). Protein levels of HO-1 (ng/L) in each group were 0.041±0.011, 0.512±0.076, 0.906±0.059, 1.062±0.089 respectively after the stimulation of different concentrations of ZnO-NPs (0, 10, 20, 40µg/ml). Comparisons in each group were statistically significant (P < 0.05). Protein levels of PECAM-1 (µg/L) in each group were 7.966 ± 0.046, 7.993 ± 0.036, 8.629 ± 0.052, 8.811 ± 0.039 respectively after the stimulation of different concentrations of ZnO-NPs (0, 10, 20, 40 µg/ml). Compared with the control group, protein levels of PECAM-1 increased (P < 0.05) when the concentration of ZnO-NPs was 20µg/ml or 40 µg/ml.</p><p><b>CONCLUSION</b>ZnO-NPs stimulation could inhibit the viability of human coronary artery endothelial cells and upregulate the protein expression of HO-1 and PECAM-1.</p>