Conditional reprogrammed human limbal epithelial cell model for anti-SARS-CoV-2 drug screening.

To minimize the global pandemic COVID-19 spread, understanding the possible transmission routes of SARS-CoV-2 and discovery of novel antiviral drugs are necessary. We describe here that the virus can infect ocular surface limbal epithelial, but not other regions. Limbal supports wild type and mutant SARS-CoV-2 entry and replication depending on ACE2, TMPRSS2 and possibly other receptors, resulting in slight CPE and arising IL-6 secretion, which symbolizes conjunctivitis in clinical symptoms.

Direct blue 53, a biological dye, inhibits SARS-CoV-2 infection by blocking ACE2 and spike interaction in vitro and in vivo.

COVID-19 is a global health problem caused by SARS-CoV-2, which has led to over 600 million infections and 6 million deaths. Developing novel antiviral drugs is of pivotal importance to slow down the epidemic swiftly. In this study, we identified five azo compounds as effective antiviral drugs to SARS-CoV-2, and mechanism study revealed their targets for impeding viral particles' ability to bind to host receptors.

The effect of influenza A (H1N1) pdm09 virus infection on cytokine production and gene expression in BV2 microglial cells.

Acute influenza infection has been reported to be associated with neurological symptoms such as influenza-associated encephalopathy (IAE). Although the pathophysiology of this condition remain unclear, neuroinflammation and associated alterations in the central nervous system (CNS) are usually induced. Microglia (MGs), CNS-resident macrophages, are generally the first cells to be activated in response to brain infection or damage.

RP1, a RAGE antagonist peptide, can improve memory impairment and reduce Aβ plaque load in the APP/PS1 mouse model of Alzheimer's disease.

Amyloid-β (Aβ) accumulation is a pathological hallmark of Alzheimer's disease (AD). The receptor for advanced glycation end products (RAGE) is involved in the production and accumulation of Aβ. RP1, a peptide antagonist of RAGE, was screened by phage display technology in our previous studies, and its neuroprotective effects on an AD cell model have been confirmed.

Forecasting influenza epidemics from multi-stream surveillance data in a subtropical city of China.

Background: Influenza has been associated with heavy burden of mortality and morbidity in subtropical regions. However, timely forecast of influenza epidemic in these regions has been hindered by unclear seasonality of influenza viruses. In this study, we developed a forecasting model by integrating multiple sentinel surveillance data to predict influenza epidemics in a subtropical city Shenzhen, China.

[Applicability of a sensitive duplex real-time PCR assay for identifying B/Yamagata and B/Victoria lineages of influenza virus].

Objective: To develop a novel sensitive duplex real-time PCR assay for accurately identifying B/Yamagata and B/Victoria lineages of influenza virus type B.

Methods: 50 HA (hemagglutinin) gene sequences coding for B/Yamagata and B/Victoria lineage, respectively, were randomly downloaded for GenBank and analyzed by software MEGA. Primers and probes specific for HA gene of B/Yamagata and B/Victoria lineages were designed by Primer Primer and then applied in the duplex real-time RT-PCR method that was followed developed.

[Compare real-time RT-PCR with two culture methods for influenza virus detection].

Objective: Real-time RT-PCR, cell culture and embryonated eggs culture for influenza detection were compared by analyzing the data of influenza surveillance in Shenzhen in second half of 2009.

Methods: 1092 clinical samples (throat swabs) collected during second half of 2009 were tested by real-time RT-PCR, cell culture and embryonated eggs culture, and the results were analyzed by statistical methods.

Results: The positive rate were 54.

[Analyses of serological and genetic characteristics on novel H1N1 influenza A virus from the infected patient in Shenzhen].

Analysis of serological and genetic characteristics on 2009 swine-origin influenza A (H1N1) virus (S-OIV) isolated from four patients with severe disease in Shenzhen were performed. Microneutralization assay showed that the neutralizing antibody titers of the infected patients did not exceed 1 : 20 in a short term post infection, which could not neutralize the viruses efficiently. Hemagglutination inhibition (HI) tests confirmed that the antigenicity of S-OIV from the patients was distinct from the seasonal influenza A virus, but similar to the reference strains of S-OIV.

[Association of cooking oil fumes exposure and oxidative DNA damage among occupational exposed populations].

Background: Previous investigations indicate that cooks are exposed to polycyclic aromatic hydrocarbons (PAH) from cooking oil fumes (COF). However, Emission of PAH and their carcinogenic potencies from cooking oil fumes sources have not been investigated among cooks.

Aims: To investigate the urinary excretion of a marker for oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG), in different groups of cooks and different exposure groups, and to study the association between 8-OHdG and 1-hydroxypyrene (1-OHP), a biological marker for PAH exposure.

Three fatal cases of pandemic 2009 influenza A virus infection in Shenzhen are associated with cytokine storm.

China had taken strict measures for pandemic 2009 H1N1 infection with enhanced surveillance and hospital isolation since April 2009. In Shenzhen, over 1200 confirmed cases of H1N1 infection were identified. Three young patients died of severe pneumonia.

[The preparation of P particle of the norovirus strain SZ9711 from China and its affinity analysis with human histo-blood group antigens in saliva].

Objective: To study the binding profile of NV strain SZ9711 (GII-4) with human histo-blood group antigens (HBGAs).

Methods: The P domain-encoding fragment was amplified by RT-PCR from the stain SZ9711 and cloned into the pGEX-4T-1 vector. The recombinant fusion protein was expressed in E.

[Epidemiological and molecular characterization of seasonal influenza A/H3N2 viruses circulating in Shenzhen, 2005 - 2007].

Objective: To determine the epidemiological characteristics of seasonal influenza in Shenzhen from 2005 to 2007 and the molecular variation of HA1 domain of influenza H3N2 viruses.

Methods: The consultation rate for influenza-like illness (ILI) were calculated weekly for indicating the influenza activities (the Shenzhen Influenza Surveillance System mainly consisted of 16 institutions with 9 hospitals, 6 districts and one municipal centers of disease control and prevention). Pharyngeal swabs from the cases of ILI, which were collected during 2005 to 2007 from the city-wide and quality-controlled surveillance network, were used to propagate the viruses.

[Study on molecular epidemiological characteristics of influenza H1N1 viruses circulating in Shenzhen, China from 2005 to 2007].

Objective: To study the genetic and epidemiological characteristics of HA1 of influenza H1N1 viruses circulating in Shenzhen from 2005 to 2007.

Methods: The HA1 region was analyzed by RT-PCR and subsequently sequenced to analyze the HA1 genetic evolution. Phylogenetic analysis was confirmed on the homology of nucleotide comparing with the reference viruses of vaccines recommended by WHO and representative virus confirmed by China CDC.

[Laboratory diagnosis and molecular characterization analysis of the H5N1 influenza virus isolated from the first human case in Shenzhen, China].

The tracheal aspirates and serum samples of a suspected human case of high-pathogenic avian influenza (firstly found in Shenzhen, China) were collected and tested by a series of assays. The results showed that the RNA extracted from the tracheal aspirate specimens of the patient was confirmed positive for H5N1 avian influenza virus by Real-time PCR. The H5N1 avian influenza virus was isolated from patient's tracheal aspirates on MDCK cell and was named A/Guangdong/2/06(H5N1).

[Rapid detection of influenza virus A by fluorescence quantitative RT-PCR].

Objective: To develop a method to rapidly detect influenza virus type A by fluorescence real-time quantitative RT-PCR.

Methods: According to conservative sequence of influenza virus type A M2 gene, a pair primers and Taqman probe were designed, respectively. After the quantitative curve of the assay were established using tenfold serial dilution of TCID50, the sensitivity and the specificity of clinic samples were determined.

[Chemical modification of chymopapain with monomethoxypolyethylene glycol and its effect on enzymic activity and antigenicity].

Objective: To study the effect of chemical modification of chymopapain with monomethoxypolyethylene glycol on enzymic activity and antigenicity.

Methods: Under the substrate protecting and non-substrate protecting, the chymopapain (Cp) was modified with two types of mPEG derivatives mPEG1 and mPEG2. The average ratio of modified-NH2 was tested by trinitrobenzenesulfonic acid (TNBS) method, the enzymic activity was tested with macromolecular casein and ATEE as substrates, the antigenicity of modified enzyme was determined by ELISA method.

[Evaluation on construction and expression in vitro of nucleic acid vaccine of nucleoprotein of influenza virus A].

Objective: Constructing nucleic acid vaccine of influenza virus A to study the protective effects.

Methods: NP gene was reverse transcripted from influenza virus A and linked with pSECTAG 2/Hygro A to constructed nucleic acid vaccine of influenza virus A. The constructed nucleic acid vaccine was transinfected into VERO cell resorting to lipofectamineTM2000.

[Detection of SARS-coronavirus in both human and animals by RT-PCR].

Objective: To find the most suitable RT-PCR detection method for SARS-Coronavirus (SARS-CoV) detection in both human and animals, and to study the source of SARS virus by investigating the condition of virus carried by wild, domestic animals and animals sold in market.

Methods: 350 throat washes of confirmed, suspected and observed SARS cases were tested by TaqMan and molecular beacon fluorescence RT-PCR methods. 386 animals with 442 nasal-throat swabs, fecal swabs of animals and cell cultured were detected by TaqMan method and conventional RT-PCR method.

[Expression and assay in vitro of phage single chain antibody against nucleoprotein of influenza virus A type].

Objective: To expression the phage single chain antibody against nucleoprotein of influenza virus A type in E. coli strain HB2151 by screening the positive clone from the phage antibody library against nucleoprotein, which will prepare for the construction of fast leak kit of Influenza virus A type.

Methods: The positive clone ratio in the phage antibody library was enriched by three-round continual solid panning, ELISA, SDS-PAGE and Western-blot methods were used to analyze the protein secreted into the supemants and periplasmic.

[Clone expression and purification of influenza A virus nucleoprotein gene].

Objective: To clone the influenza A virus NP gene into expression vector and to purify the target protein, which was used to study the preparation of monoclonal antibody.

Methods: The RNA of influenza A virus was extracted and primers were designed according the NP gene sequence, then the NP gene of influenza A virus was expressed in E.coli DH5alpha and the NP protein was purified by affinity chromatography.

[Application of fluorescent real-time reverse transcriptase-polymerase chain reaction in detecting influenza viruses].

Objective: To apply fluorescent real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in detecting influenza viruses.

Methods: A total of 207 oral swab samples were obtained in 16 collections from SARS patients and suspected influenza outbreak cases. They were subjected to influenza virus detection by fluorescent real-time RT-PCR, MDCK cell culture, and hemagglutinin inhibition assay.