Publications by authors named "Wen-da Guan"

Background: Few studies have analyzed influenza B virus lineages based on hemagglutinin A (HA) gene sequences in southern China. The present study analyzed the HA gene and the lineages of influenza B virus isolates from Guangzhou during 2016, and compared our results with the WHO-recommended vaccine strain.

Methods: Ninety patients with influenza B were recruited from the First Hospital of Guangzhou Medical University.

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Article Synopsis
  • Researchers aimed to estimate the severity and prevalence of human infections caused by the influenza A(H7N9) virus in Guangzhou by analyzing stored blood samples from hospital patients between 2013 and 2014.
  • The study tested 5,360 blood samples, resulting in the identification of only two positive cases, leading to an estimated total of 64,000 infections with a relatively low fatality risk of 3.6 deaths per 10,000 infections.
  • The findings indicate that the actual incidence of A(H7N9) infections was much higher than previously reported laboratory-confirmed cases, highlighting the need for larger studies to better understand the virus's impact.
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Background: Influenza A(H1N1)pdm09, A(H3N2) and B viruses have co-circulated in the human population since the swine-origin human H1N1 pandemic in 2009. While infections of these subtypes generally cause mild illnesses, lower respiratory tract infection (LRTI) occurs in a portion of children and required hospitalization. The aim of our study was to estimate the prevalence of these three subtypes and compare the clinical manifestations in hospitalized children with LRTI in Guangzhou, China during the post-pandemic period.

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Background: The second wave of avian influenza H7N9 virus outbreak in humans spread to the Guangdong province of China by August of 2013 and this virus is now endemic in poultry in this region.

Methods: Five patients with H7N9 virus infection admitted to our hospital during August 2013 to February 2014 were intensively investigated. Viral load in the respiratory tract was determined by quantitative polymerase chain reaction (Q-PCR) and cytokine levels were measured by bead-based flow cytometery.

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Millions of individuals are vaccinated worldwide each year to stimulate their adaptive immune systems to produce protective antibodies and T-cell response against pathogens. Since glycosylation of the Fc region of immunoglobulin G (IgG) can be influenced by the host's immune status, it was inferred that glycosylation profile of IgG might be altered as a result of the immune response. Therefore, subclass-specific glycosylation profiles of serum IgGs from 26 healthy adults before and after vaccination with a trivalent subunit influenza virus vaccine were comprehensively analyzed to explore glycomic signatures for vaccination.

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Article Synopsis
  • The first confirmed case of the H7N9 virus in Guangdong Province, China, occurred in August 2013, outside the usual flu season, prompting an investigation into its source and transmission.
  • A female patient with poultry exposure experienced severe respiratory symptoms and quickly moved to an ICU but ultimately recovered after four weeks, with no additional cases reported.
  • Genetic analysis showed the virus shares similarities with other H7N9 strains and is susceptible to certain antiviral medications, highlighting a potential ongoing risk for H7N9 re-emergence in China, especially from environmental sources.
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Background And Objective: Respiratory syncytial virus (RSV) results in acute wheezing in infants and is frequently associated with recurrent wheezing. Although RSV-induced wheezing clinically resembles that of asthma, corticosteroids are not equivalently effective in RSV-associated wheezing. The study sought to determine the mechanisms of RSV-induced wheezing by establishing an in vitro model of RSV-infected human bronchial epithelial cells (16-HBEC).

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Comparisons of the clinical characteristics of contemporaneous pandemic (H1N1) 2009 influenza A virus (A(H1N1)pdm09)- and seasonal influenza viruses-infected patients are important for both clinical management and epidemiological studies. A prospective multicenter observational study was conducted using a preestablished sentinel surveillance system in Guangzhou, China during 2009. In this study, the clinical presentations of patients with either acute respiratory infection or community-acquired pneumonia were recorded, and nasopharyngeal swab samples were collected for detection of respiratory virus strains using cell cultures or real-time reverse transcription/real-time polymerase chain reaction.

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To develop a stable cell line that could express the RSV NS1, the full-length RSV NS1 gene was generated by RT-PCR amplification from respiratory syncytial virus. NS1 gene was ligated with pBABE-puro to construct the recombinant retroviral expression plasmid pBABE-NS1, which was cotransfected into 293FT packaging cells with PIK packaging plasmid by calcium phosphate co-precipitation. The supernatant of 293FT was collected to infect HEp-2 cells, the resulting cell clones stably expressing NS1 were screened by puromycin.

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Article Synopsis
  • - This study focuses on CD4(+) T regulatory cells, specifically the CD4(+) CD25(HIGH) FOXP3(+) subset, to understand their role in chronic autoimmune urticaria, an immune system disorder that causes hives.
  • - Flow cytometry analysis revealed that patients with chronic autoimmune urticaria have a significantly lower frequency and intensity of FOXP3 expression in these regulatory T cells compared to healthy individuals.
  • - The findings suggest that the reduced levels of CD4(+) CD25(+) FOXP3(+) regulatory T cells might play a role in the autoimmune processes underlying chronic autoimmune urticaria.
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This study was to investigate the antiviral effects of a hot water soluble extract S-03 isolated from Isatis indigotica root on different subtypes of influenza A and B viruses in MDCK cell cultures, using plaque reduction, immunofluorescence and hemo-agglutination inhibition (HAD) assays. Chemical analysis of the extract S-03 showed that it contained high proportion of polysaccharides. The antiviral effects in vitro showed that the S-03 had no effect on different influenza viruses if the drug was used before virus adsorption, but S-03 showed obvious activities against influenza viruses if treatment after virus adsorption or direct reaction of drug and virus before virus adsorption.

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Objective: To study the prevalence of adamantane-resistance among influenza A viruses isolated from Guangzhou between January and October in 2009, and to provide more information for clinical usage of adamantane drugs.

Methods: Totally 311 influenza A strains isolated from 6 hospitals in Guangzhou between January and October in 2009 were selected, and the MP gene of all 311 strains (159 strains of H1 subtype, 152 strains of H3 subtype) was sequenced. The susceptibility of viruses to rimantadine was assayed by biological methods in cells.

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Objective: This study was undertaken to describe the viral etiology and clinical features in patients with influenza-like illness (ILI) in Guangzhou.

Methods: The nasopharyngeal and throat swabs were collected from 882 patients presenting with ILI between January and September, 2009. Viral pathogens were cultured and identified by immunofluorescence technique using the Shell-Vial method.

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Objective: To observe the cytopathogenic inhibitory effect of resveratrol on vary respiroviruses and explore the mechanism of resveratrol against viruses.

Methods: MDCK, A549, HEp-2 cell and MRC-5 were infected with Influenza virus type A FM1 strain, rhinovirus type R14, RS virus, AD virus type 7 separately, and the antiviral activity of resveratrol were observed.

Results: Resveratrol significantly inhibited cytopathogenic effect of AD virus type 7 at the concentration 120 microg/ml.

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1. Currently, there is no satisfactory treatment for pulmonary fibrosis. Emodin, a component in Chinese herbs, has been shown to have an antifibrotic effect on pancreatic fibrosis and liver fibrosis.

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