Hui Wang

Background: Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV2) is spreading all over the world and poses a great threat to humans. This study aimed to systematically review the current situation and public health burden associated with children infected with SARS‐CoV2.Methods: We searched four electronic databases without language limitations. The pooled proportion or odds ratio (OR) and 95% CI confidence interval (CI) were calculated for each analysis to explore the prevalence of asymptomatic infection and coinfection, as well as to assess the sex of SARS‐CoV‐2‐infected children.Results: We obtained data from 14 eligible studies with 410 patients for the meta‐analysis. The pooled proportion of asymptomatic infection was 40.45% (95% CI, 24.04‐56.85), while coinfection was 10.14% (95% CI, 3.97‐16.30), of which Mycoplasma pneumonia (50%; 95% CI, 28.24‐71.76) and influenza virus or parainfluenza virus (22.76%; 95% CI, 4.76‐40.77) were the most common pathogens. Both male and female children were susceptible to SARS‐CoV2 infection. And the pooled proportion of family clustering infection was 83.63% (95% CI, 77.54‐89.72).Conclusion: A high proportion of asymptomatic infections occurs in children infected with SARS‐CoV2, who are also susceptible to coinfection regardless of sex. These data affirm the increasing public health burden arising from infected children regarding the causation of asymptomatic infection or misdiagnosis and as a significant contributor to virus spread. The public should pay more attention to children during epidemics and conduct multimethod detection to further effectively identify infected children and control the source of infection.

We extracted six Hong Kong brown seaweed species with hot water for their antiviral properties. The cytotoxicity and antiviral activity of these extracts were tested by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenlytetrezolium bromide] method, cytopathic effect reduction assay, and plaque reduction assay. The antiviral effect was further determined by flow cytometric analysis. The results showed that most of these extracts inhibited the propagation of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) standard strains with very low cytotoxicity to the host cells. The extracts of Hydroclathrus clathratus and Lobophora variegata showed more potential anti-HSV activities than the extracts of the other four seaweeds. They also had moderate antirespiratory syncytial virus (RSV) activities but could not inhibit influenza A virus. Hydroclathrus clathratus was further extracted by diluted acid and alkali and the antiviral effects of the extracts were also detected. The result showed that the hot water extract contained the main carbohydrate components that exhibited the antiviral activities against various strains of HSV, including the acyclovir-resistant strain. HI-3, a compound fractionated from this hot water extract, showed a dose-dependent anti-HSV activity in flow cytometric analysis and plaque reduction assay.

To detect the cytotoxicity and in vitro antiproliferative effects of the flavones compounds isolated from some Yao herbal medicines, and analyze the basic structure-activity relationship. The cytotoxicity on normal cells and antiproliferative effect on tumor cells were tested by MTT reduction assay respectively. Among the 6 flavones, the Eriodictyol-7-O-a-D-glucoside, Naringenin-7-O-beta-D-glucoside, quercetin and quercetin-3-O-beta-D-glucoside showed very low cytotoxicity to the two normal cells, Vero and MC cells, while the naringenin was high toxic to both of them. The eriodictyol was no toxic to Vero Cell but could affect MC cell at low concentration. The naringenin exhibited a wide-spectrum antiproliferative effect on all of the 7 tested cancer cell lines especially on the MCF-7 with low IC50 about 50 microg/ml. Among these cancer cells, the MCF-7 and HepG2 were more sensitive to the flavones compounds than the others. Both of them were inhibited by eriodictyol, quercetin and naringenin even at low test concentration. Furthermore, the antiproliferative effects of these compounds were concentration-related. Some of flavones compounds isolated from some Yao herb medicines showed high antiproliferative effect on cancer cells with low cytotoxicity on normal cells.