Psychological impact of the COVID-19 pandemic on Chinese population: An online survey.

BACKGROUND: The ongoing coronavirus disease 2019 (COVID-19) pandemic infiltrates every aspect of our life, including the psychological impact. China has experienced the first wave of this epidemic, and it is now affecting the global population. AIM: This study aimed to investigate the prevalence and associated factors of post-traumatic stress disorder (PTSD) among the general Chinese population. METHODS: A detailed questionnaire, comprising of 38 questions designed in both English and Chinese, was developed. The survey was conducted via WeChat, a multi-purpose messaging, social media, and mobile payment app, which is widely used by the Chinese population. RESULTS: In total, 1082 individuals from 31 provinces, autonomous regions, and municipalities participated in the survey by filling the questionnaires through the WeChat app. 97.8% of the participants had an Impact of Event-Scale-Revised (IES-R) total score above 20, which is an indicator of PTSD. The IES-R total and all the three subscales, including intrusion, avoidance, and hyperarousal, are significantly correlated with age. In addition, age, profession, marital status, and level of education are significantly correlated with the degree of PTSD symptoms. CONCLUSION: The COVID-19 epidemic has widely caused PTSD among the general Chinese population. These results bear important implications for regions struggling with the pandemic to implement effective interventions to cope with these mental health problems.

Antitumor activities of Grifola frondosa (Maitake) polysaccharide: A meta-analysis based on preclinical evidence and quality assessment.

ETHNOPHARMACOLOGICAL RELEVANCE: The antitumor effects of Grifola frondosa/maitake polysaccharide (GFP) have been reported in many preclinical studies, especially in vivo experiments. The present meta-analysis aimed to provide an in vivo evidence and theoretical basis for future clinical trials by assessing the efficacy and underlying mechanisms of GFP in tumor treatment. MATERIALS AND METHODS: English and Chinese databases were examined to include animal experiments to study the antitumor activity of GFP. Literature screening, data extraction, and meta-analysis were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In addition, the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias (RoB) tool was used to assess the risk of bias of the included animal studies. RESULTS: Potentially relevant studies (442) were identified, and finally 24 eligible studies (all in English) were included. The meta-analysis revealed that GFP has significant effects in inhibiting tumor growth (high dose: mean difference (MD) = -1.34, 95% confidence interval (CI) = [-1.73, -0.95]; low dose: MD = -5.68, 95% CI = [-7.27, -4.09]), improving tumor remission rate (odds ratio = 25.59, 95% CI = [9.08, 72.11]), and enhancing immune function in both cellular (CD4+ T cell percentage: MD = 3.03, 95% CI = [1.16, 4.90]; CD8+ T cell percentage: MD = 1.10, 95% CI = [-0.29, 2.49]) and humoral immunity (MD and [95% CI] of interleukin (IL)-2, IL-12 and tumor necrosis factor-α were 7.86 [6.29, 9.44], 35.95 [5.18, 66.72], and 10.03 [8.71, 11.36], respectively), and the differences between the two groups of the above indicators were statistically significant (all P < 0.01) except CD8+ T cell percentage. Additionally, the quality of the included studies was not high, and the risk of bias mainly concentrated on selection, detection, and reporting biases. CONCLUSION: GFP is a potential candidate for tumor treatment and clinical trials. TRIAL REGISTRATION: The review protocol for this study was registered with the PROSPERO database before beginning the review process (CRD42018108897).

COVID-19 impact on high school student's education and mental health: A cohort survey in China.

BACKGROUND: The ongoing coronavirus disease 2019 (COVID-19) pandemic and the universal implementation of control measures are fundamentally affecting every aspect of our society and daily lives. AIM: To evaluate the prevalence of post-traumatic stress disorder symptoms and their associated factors as well as the effects and attitudes towards online education in Chinese high school students. METHODS: A total of 883 students were included. The first, second and third-year students of a high school in Lanzhou, Gansu province of China were invited to participate in this study. They were requested to involve their parents to complete the survey together. A detailed questionnaire of 65 questions was designed and divided into five sections. The survey was anonymously conducted via WeChat, a Chinese multipurpose messaging, social media and mobile payment app. RESULTS: Overall, 32.94% of students experienced post-traumatic stress disorder due to the COVID-19 epidemic. The majority of students (60.82%) felt that online education was not (10.76%) or less effective (50.06%) in terms of gaining knowledge and improving practical and communications skills. Correlation analysis revealed that the class level, residential background and whether living with parents were significantly linked with the effectiveness and satisfaction of the online education system. Of the final year students, 74.2% said that the COVID-19 outbreak has negatively affected their preparation for the college entrance exam, and 68% of students felt that this outbreak increased psychological pressure for their college entrance examination preparation. In case of having COVID-19 symptoms during the exam, 50.7%, 13.3%, and 10.2% would notify the proctor, teacher and parents, respectively. CONCLUSION: We found a high prevalence rate of post-traumatic stress disorder symptoms in high school students. Thus, our results call for urgent attention from both government and schools to implement effective interventions to cope with the psychological effects and the disturbance of education by COVID-19 on children.

COVID-19 knowledge, risk perception, and information sources among Chinese population.

BACKGROUND: Measures for effective control of the coronavirus disease 2019 (COVID-19) pandemic include identifying the causal organisms, applying appropriate therapies, and developing vaccines, as well as improving understanding among the general public. AIM: To evaluate the knowledge, awareness, perception, and response of the general public to COVID-19 in China. METHODS: A detailed questionnaire comprising 47 questions designed in both English and Chinese was developed. The survey was conducted via WeChat, a multipurpose messaging, social media, and mobile payment app that is widely used by the Chinese population. In total, 1006 participants responded, and most of them were from different provinces of mainland China. RESULTS: Overall, this comprehensive survey revealed that the general public in China is highly aware of the basic information concerning COVID-19 and its precautions. Interestingly, more respondents (99.3%) were aware of the term severe acute respiratory syndrome (SARS) than COVID-19 (97.2%) and Middle East respiratory syndrome (MERS) (73.4%). Among them, 2.4%, 1.6%, and 0.9% said that they or their family members or friends were affected by COVID-19, SARS, and MERS, respectively. The majority of the respondents (91.2%) indicated that knowledge about COVID-19 was received mainly from WeChat, followed by TV (89%), friends (76.1%), and QQ (a Chinese instant messaging software service) (57.7%). CONCLUSION: The general public in China is highly aware of COVID-19 and the necessary precautions. Unexpectedly, 2.8% of the participants were unaware of the current epidemic. The remaining information gaps highlight the necessity of further enhancing awareness and preparedness.

The nucleotide usages significantly impact synonymous codon usage in Mycoplasma hyorhinis.

Five annotated genomes of Mycoplasma hyorhinis were analyzed for clarifying evolutionary dynamics driving the overall codon usage pattern. Information entropy used for estimating nucleotide usage pattern at the gene level indicates that multiple evolutionary dynamics participate in forcing nucleotide usage bias at every codon position. Moreover, nucleotide usage bias directly contributes to synonymous codon usage biases with two different extremes. The overrepresented codons tended to have A/T in the third codon position, and the underrepresented codons strongly used G/C in the third position. Furthermore, correspondence analysis and neutrality plot reflect an obvious interplay between mutation pressure and natural selection mediating codon usage in M. hyorhinis genome. Due to significant bias in usages between A/T and G/C at the gene level, different selective forces have been proposed to contribute to codon usage preference in M. hyorhinis genome, including nucleotide composition constraint derived from mutation pressure, translational selection involved in natural selection, and strand-specific mutational bias represented by different nucleotide skew index. The systemic analyses of codon usage for M. hyorhinis can enable us to better understand the mechanisms of evolution in this species.

Establishment of a low-tumorigenic MDCK cell line and study of differential molecular networks.

Influenza is an acute respiratory infection caused by the influenza virus, and vaccination against influenza is considered the best way to prevent the onset and spread. MDCK (Madin-Darby canine kidney) cells are typically used to isolate the influenza virus, however, their high tumorigenicity is the main controversy in the production of influenza vaccines. Here, MDCK-C09 and MDCK-C35 monoclonal cell lines were established, which were proven to be low in tumorigenicity. RNA-seq of MDCK-C09, MDCK-C35, and MDCK-W73 cells was performed to investigate the putative tumorigenicity mechanisms. Tumor-related molecular interaction analysis of the differentially expressed genes indicates that hub genes, such as CUL3 and EGFR, may play essential roles in tumorigenicity differences between MDCK-C (MDCK-C09 and MDCK-C35) and MDCK-W (MDCK-W73) cells. Moreover, the analysis of cell proliferation regulation-associated molecular interaction shows that downregulated JUN and MYC, for instance, mediate increased proliferation of these cells. The present study provides a new low-tumorigenic MDCK cell line and describes the potential molecular mechanism for the low tumorigenicity and high proliferation rate.

RETRACTED: Function of the PLZF gene in early development and self-renewal of T cells in mice.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).. This article has been retracted at the request of < the Editor in Chief. The Editor in Chief has been made aware of numerous problems with this paper regarding authorship, poor or insufficient supervision of researchers and the unauthorized use of data acquired from a lab visit by one of the authors.

Induction and Suppression of Innate Antiviral Responses by Hepatitis A Virus.

Hepatitis A virus (HAV) belongs to the family Picornaviridae. It is the pathogen of acute viral hepatitis caused by fecal-oral transmission. RNA viruses are sensed by pathogen-associated pattern recognition receptors (PRRs) such as Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I (RIG-I), and melanoma differentiation-associated gene 5 (MDA5). PRR activation leads to production of type 1 interferon (IFN-α/ß), serving as the first line of defense against viruses. However, HAV has developed various strategies to compromise the innate immune system and promote viral propagation within the host cells. The long coevolution of HAV in hosts has prompted the development of effective immune antagonism strategies that actively fight against host antiviral responses. Proteases encoded by HAV can cleave the mitochondrial antiviral signaling protein (MAVS, also known as IPS-1, VISA, or Cardif), TIR domain- containing adaptor inducing IFN-ß (TRIF, also known as TICAM-1) and nuclear factor-κB (NF-κB) essential modulator (NEMO), which are key adaptor proteins in RIG-I-like receptor (RLR), TLR3 and NF-κB signaling, respectively. In this mini-review, we summarize all the recent progress on the interaction between HAV and the host, especially focusing on how HAV abrogates the antiviral effects of the innate immune system.

Type I Interferon Induced and Antagonized by Foot-and-Mouth Disease Virus.

Viral infections trigger the innate immune system, serving as the first line of defense, and are characterized by the production of type I interferon (IFN). Type I IFN is expressed in a broad spectrum of cells and tissues in the host and includes various subtypes (IFN-α, IFN-ß, IFN-δ, IFN-ε, IFN-κ, IFN-τ, IFN-ω, IFN-ν, and IFN-ζ). Since the discovery of type I IFN, our knowledge of the biology of type I IFN has accumulated immensely, and we now have a substantial amount of information on the molecular mechanisms of the response and induction of type I IFN, as well as the strategies utilized by viruses to evade the type I IFN response. Foot-and-mouth disease virus (FMDV) can selectively alter cellular pathways to promote viral replication and evade antiviral immune activation of type I IFN. RNA molecules generated by FMDV are sensed by the cellular receptor for pathogen-associated molecular patterns (PAMPs). FMDV preferentially activates different sensor molecules and various signal transduction pathways. Based on knowledge of the virus or RNA pathogen specificity as well as the function-structure relationship of RNA sensing, it is necessary to summarize numerous signaling adaptors that are reported to participate in the regulation of IFN gene activation.

Adaptation of Borrelia burgdorferi to its natural hosts by synonymous codon and amino acid usage.

Lyme disease, caused by Borrelia burgdorferi, is a focally endemic tick-transmitted zoonotic infection. In this study, the major factors underlying synonymous codon-related amino acid usage in the B. burgdorferi genome and bias in synonymous codon usage of the translation initiation region of coding sequences were analyzed. Additionally, adaptation of B. burgdorferi to several of its hosts was analyzed in the context of synonymous codon usage. Principal component analysis (PCA) revealed that nucleotide content at the third synonymous position of a codon influenced the synonymous codon usage pattern, but the strand-specific factor did not influence the synonymous codon usage pattern of B. burgdorferi. In terms of the low GC content of B. burgdorferi coding sequences, the effective number of codons (ENC) showed a significant correlation with GC3 content (at the synonymous position). For the amino acid usage pattern for B. burgdorferi, PCA showed that the strand-specific factor did not contribute to this pattern, while the properties (aromaticity and hydrophobicity) of the amino acids themselves showed strong correlations with this pattern. Under-represented codons, which were frequently selected in the translation initiation region, possibly play roles in regulating gene expression in B. burgdorferi. In terms of co-evolution and synonymous codon usage patterns, adaptation of B. burgdorferi to different intermediate hosts was apparent to different degrees, and the degree of adaptation of this spirochete to wild animals was stronger than that of humans or mice.

Comparative genomic analysis for nucleotide, codon, and amino acid usage patterns of mycoplasmas.

The evolutionary factors in influencing the genetic characteristics of nucleotide, synonymous codon, and amino acid usage of 18 mycoplasma species were analyzed. The nucleotide usage at the 1st and 2nd codon position which determines amino acid composition of proteins has a significant correlation with the total nucleotide composition of gene population of these mycoplasma species, however, the nucleotide usage at the 3rd codon position which affects synonymous codon usage patterns has a slight correlation with either the total nucleotide composition or the nucleotide usage at the 1st and 2nd codon position. Other evolutionary factors join in the evolutionary process of mycoplasma apart from mutation pressure caused by nucleotide usage constraint based on the relationships between effective number of codons/codon adaptation index and nucleotide usage at the 3rd codon position. Although nucleotide usage of gene population in mycoplasma dominates in forming the overall codon usage trends, the relative abundance of codon with nucleotide context and amino acid usage pattern show that translation selection involved in translation accuracy and efficiency play an important role in synonymous codon usage patterns. In addition, synonymous codon usage patterns of gene population have a bigger power to represent genetic diversity among different species than amino acid usage. These results suggest that although the mycoplasmas reduce its genome size during the evolutionary process and shape the form, which is opposite to their hosts, of AT usages at high levels, this kind organism still depends on nucleotide usage at the 1st and 2nd codon positions to control syntheses of the requested proteins for surviving in their hosts and nucleotide usage at the 3rd codon position to develop genetic diversity of different mycoplasma species. This systemic analysis with 18 mycoplasma species may provide useful clues for further in vivo genetic studies on the related species.

The analyses of relationships among nucleotide, synonymous codon and amino acid usages for E2 gene of bovine viral diarrhea virus.

In this study, the systemic analyses of nucleotide, codon and amino acid usages for E2 gene of bovine viral diarrhea virus (BVDV) were carried out for estimating its genetic features. The nucleotide usage pattern at the first codon position was strongly influenced by the overall nucleotide composition, while the nucleotide usage patterns at the second and third codon positions seemed to have little link to the overall nucleotide composition. The result indicated that the mutation pressure from nucleotide composition constraint was not the single evolutionary force for genetic features of BVDV E2 gene. Just 18 out of 59 synonymous codons were similar with synonymous codon usage patterns for E2 gene between BVDV1 and BVDV2, while all synonymous codons which contain CpG dinucleotides were selected at the low level by E2 gene, suggesting that this gene suppressed the usages of codons containing CpG dinucleotides to regulate E2 gene replicate and transcript efficiently and avoid immune response from infected hosts. Amino acid usage patterns of E2 protein were generally different between BVDV1 and BVDV2. The patterns of synonymous codon and amino acid usages for E2 gene might be caused by the equilibrium of evolutionary forces from virus and host. Our work gave new investigations into the role of host origin in the formations of synonymous codon/amino acid usages and the evolutionary trend of BVDV E2 gene. The genetic characteristics that codon/amino acid usages of E2 gene adapted to the internal environment of individual animals might assist in understanding the changes of genetics and antigenicity for newly emerging BVDV.

Immunogenicity of adenovirus and DNA vaccines co-expressing P39 and lumazine synthase proteins of Brucella abortus in BALB/c mice.

Brucella poses a great threat to animal and human health. Vaccination is the most promising strategy in the effort to control Brucella abortus (B. abortus) infection, but the currently used live vaccines interfere with diagnostic tests and could potentially result in disease outbreak. Therefore, new subunit vaccines and combined immunization strategies are currently under investigation. In this study, immunogenicity and protection ability of a recombinant adenovirus and plasmid DNA vaccine co-expressing P39 and lumazine synthase proteins of B. abortus were evaluated based on the construction of the two molecular vaccines. Four immunization strategies (single adenovirus, single DNA, adenovirus/DNA, DNA/adenovirus) were investigated. The results showed that the immunization strategy of DNA priming followed by adenovirus boosting induced robust humoral and cellular immune responses, and it significantly reduced the numbers of B. abortus in a mouse model. These results suggest that it could be a potential antigen candidate for development of a new subunit vaccine against B. abortus infection.

Analyses of nucleotide, codon and amino acids usages between peste des petits ruminants virus and rinderpest virus.

Peste des petits ruminants virus (PPRV) and rinderpest virus (RPV) are two causative agents of an economically important disease for ruminants (i.e., sheep, cattle and goat). In this study, the nucleotide, codon and amino acid usages for PPRV and RPV have been analyzed by multivariate statistical methods. Relative synonymous codon usage (RSCU) analysis represents that ACG for Thr and GCG for Ala are selected with under-representation in both PPRV and RPV, and AGA for Arg in PPRV and AGG for Arg in RPV are used with over-representation. The usage of nucleotide pair (CpG) tends to be removed from viral genes of the two viruses, suggesting that other evolutionary forces take part in evolutionary processes for viral genes in addition to mutation pressure from nucleotide usage at the third codon position. The overall nucleotide usage of viral gene is not major factor in shaping synonymous codon usage patterns, while the nucleotide usages at the third codon position and the nucleotide pairs play important roles in shaping synonymous codon usage patterns. Although PPRV and RPV are closely related antigenically, the codon and amino acid usage patterns for viral genes represent a significant genetic diversity between PPRV and RPV. Moreover, the overall codon usage trends for viral genes between PPRV and RPV are mainly influenced by mutation pressure from nucleotide usage at the third codon position and translation selection from hosts. Taken together, this is first comprehensive analyses for nucleotide, codon and amino acid usages of viral genes of PPRV and RPV and the findings are expected to increase our understanding of evolutionary forces influencing viral evolutionary pathway and adaptation toward hosts.

In vitro and in vivo studies of nematophagous fungi Arthrobotrys musiformis and Arthrobotrys robusta against the larvae of the trichostrongylides.

Six isolates of Arthrobotrys musiformis and five isolates of Arthrobotrys robusta were assessed in in vitro test regarding the capacity of prey larvae of the natural mixed trichostrongylides. In 5 isolates of A. robusta, the decrease percentage of infective larvae (L3) of trichostrongylides ranged from 97.71%-99.98% and for the isolates of A. musiformis, 5 isolates ranged from 97.99%-99.95% and only NF015 isolate 60.72%. In the following, the isolate (NPS045) of A. musiformis was selected to assess its excretion time in feces after oral administration of goats. Regarding L3 reduction rate, results demonstrated by NPS045 at each time point after fungal administration were 31.65% (12 h), 51.25% (24 h), 41.07% (48 h), 6.44% (72 h), 0% (96 h) and (120 h) (p<0.05) respectively, when compared to the control group. In the plates of the treated groups, the presence of the isolate (NPS045) was detected in samples at 12, 24 and 48 h after the fungus dose and 72 h later was not done. All native isolates of nematophagous fungi, including 6 isolates of A. musiformis and 5 isolates of A. robusta were assessed in vivo regarding the capacity of supporting the passage through goat gastrointestinal tract. The 3 isolates of A. musiformis could be able to pass through the digestive tract of goats without complete loss of ability of preying larvae of trichostrongylides in feces and their efficacies ranged from 47.60% to 55.93%. The two isolates of A. robusta survived the passage and the percentage reduction of L3 in feces were 41.96% and 66.97%, respectively. The remaining isolates were negative for both the efficacy of L3 reduction and the fungal examination in feces. In this study, the native isolates whose efficacies are good in vivo test have preliminarily demonstrated to be potential for the biological control of small ruminant parasite.

In vitro predatory activity of Arthrobotrys oligospora and after passing through gastrointestinal tract of small ruminants on infective larvae of trichostrongylides.

In vitro predatory activity of 157 native isolates of Arthrobotrys oligospora from China on larvae of trichostrongylides (Trichostrongylus colubriformis and Haemonchus contortus) in feces of sheep were assessed. The results showed that 135 of tested isolates of A. oligospora reduced the development of trichostrongylide larvae in feces by 90-99.99%, 11 isolates by 80-89.46% and 11 isolates by 14.58-78.82%. To understand their capacity of passing through gastrointestinal tract of sheep, 50 native isolates of A. oligospora were selected and assessed in sheep. Among these isolates, 16 isolates significantly reduced the number of larvae developing in the feces (P < 0.05); their percentage reduction of L3 ranged from 42.87% to 99.51% and the isolates tested were harvested in 5 g sub-samples of from sheep in each treatment group, indicating that these isolates had the capacity of preying larvae of trichostrongylides after the passage through gastrointestinal tract of sheep. The remaining isolates of A. oligospora were not able to survive after passage through gastrointestinal tract of sheep. In the following, the 16 isolates that presented more or less viability after sheep gastrointestinal passage were selected and assessed in goats. The results showed that the 11 isolates out of them could be able to pass through the digestive tract of goats without loss of ability of preying larvae of trichostrongylides in feces and their efficacies ranged from 53.88% to 94.28%, and that the isolates tested were harvested in 5 g sub-samples of feces from goats in each treatment group. In the current study, these isolates which demonstrated outstanding properties in vitro and could survive in the passage through the alimentary tract of sheep and goat should be potential candidates as a possible feed additive.

Screening of different sample types associated with sheep and cattle for the presence of nematophagous fungi in China.

A total of 1502 samples, including feces of sheep (793) and cattle (348), pasture soil (118), dung compost (147) and barn soil (96), were examined between October 2012 and August 2014 to discover potential strains of nematophagous fungi for the biological control of livestock-parasitic nematodes. These samples were collected from 87 sites located in 48 counties of 20 provinces (autonomous regions/municipalities) of China. Fungi were identified down to a species level. Four hundred and seventy-seven isolates, which were distributed in 8 genera and 28 taxa, were identified as nematophagous fungi. Nematode-trapping fungi included 17 species and one unidentified species of Arthrobotrys, two of Dactylella, Drechslerella dactyloides, and Duddingtonia flagrans. Five identified species and two unidentified species of endoparasitic fungi were isolated. The predominant species from all regions were Arthrobotrys oligospora, followed by Arthrobotrys musiformis, Arthrobotrys (Monacrosporium) thaumasiun, and Arthrobotrys (Monacrosporium) microscaphoides. Species with adhesive networks were the most frequently isolated. Among the endoparasitic fungi, Podocrella harposporifera (Harposporium anguillulae) was the most common species, followed by Harposporium lilliputanum and Harposporium arcuatum. Based on Shannon diversity index, the diversity levels of nematophagous fungi were relatively higher in samples associated with cattle, barn soil, and subtropical monsoon climate zone. Three species isolated from this study, namely, Duddingtonia flagrans, Arthrobotrys salina (Monacrosporium salinum), and Arthrobotrys oligospora var. sarmatica, are newly recorded in China, and 20 species (including one unidentified species) are newly recorded in sheep and cattle barn soils worldwide.