Liu-mei Xu

Bio: Liu-mei Xu is an academic researcher. The author has contributed to research in topics: Medicine & Virology. The author has an hindex of 3, co-authored 7 publications receiving 99 citations.

[To investigate pathogen of hand, foot and mouth disease in Shenzhen in 2008].

Abstract: Objective To investigate EV71 and CA16 pathogen of HFMD in Shenzhen in 2008,and to provide the evidence for the prevention and treatment HFMD.Method Using RT-PCR technology to detect the EV71 and CoxA16 genes of 307 samples HFMD;sequencing the purified PCR products from 14 samples.Using ClustaIW2 online analysis software for sequence and phylogenetic analysis of enterovirus 71.Result Percentnge of positive EV71 from different samples is shown as follows respectively:positive EV71 from stool samples is 24.4%(75/307),from throat swab-7.8%(24/307),from peripheral blood-12.5%(1/8).Percentage of positive CoxA16 is shown as follows respectively:positive EV71 from stool samples is 13.8%(28/203),from throat swab11.0%(20/181).Among all the 307 samples,three are positive for both EV71 and CoxA16.EV71 and CoxA16 are not detected in the samples of cerebrospinal fluid.Comparative analysis of nucleotide sequences of EV71 with those of strains BrCr and 11 deposited in GenBank demonstrated numerous disparities from 8 samples,but residue 595 from 2 samples and residue 658 from 1 sample are variable.The phylogenetic analysis based on VP1 region demonstrates that strains from 2 samples has the nearest genetic relationship with anhui strains,the farthest with BrCr and SHH02-6,SHZH02-40,SHZH03-58 strains,also strains from other 12 samples have the farthest genetic relationship with them.The genotypes A,B and C were classified as proposed by Brown et al.(1999).The EV71 from 14 samples were the member of genotype C.Conclusion EV71 among the pathogen of HFMD in Shenzhen in 2008 was majority.These EV71 may belong to the same genegroup with Anhui predominant strains. Key words: Enterovirus; Hand,foot and mouth disease/Etiology; Sequence analysis

IgG Antibody Responses and Immune Persistence of Two Doses of BBIBP-CorV Vaccine or CoronaVac Vaccine in People Living with HIV (PLWH) in Shenzhen, China

Abstract: The purpose of this study was to preliminarily evaluate the immunogenicity and immune persistence of inactivated SARS-CoV-2 vaccines in PLWH in the real world. We collected blood samples from 132 PLWH aged 18–59 years who were vaccinated with two doses of BBIBP-CorV vaccine (Sinopharm) or CoronaVac vaccine (SinoVac) at 28 ± 7 days and 180 ± 20 days the after second dose, to detect the level of Spike receptor binding domain-protein specific IgG (S-RBD-IgG) by using chemiluminescence. We found that the BBIBP-CorV vaccine or the CoronaVac vaccine induced lower S-RBD-IgG antibody seropositivity rates and levels in PLWH than in healthy controls (HCs). The BBIBP-CorV vaccine or the CoronaVac vaccine induced lower humoral immune responses in PLWH, having lower CD4+T cell counts (<350 cells/μL) compared to PLWH, and having higher CD4+T cell counts (≥350 cells/μL) after a second dose of vaccination. The BBIBP-CorV vaccine or the CoronaVac vaccine induced lower S-RBD-IgG antibody levels in PLWH, having CD4+T cell counts ≥350 cells/μL compared to HCs. No negative effects were observed in terms of the CD4+T cell counts and HIV RNA viral load (VL) of PLWH after vaccination. Ninety-nine PLWH and eighty-three HCs completed a second blood collection for testing; we found a statistically significant decrease in the humoral immune response both in PLWH and HCs from 28 days to 180 days after a second dose of BBIBP-CorV vaccine or CoronaVac vaccine. The S-RBD-IgG antibody induced by the BBIBP-CorV vaccine or the CoronaVac vaccine declined faster in the PLWH population than in the healthy population, and two doses of the BBIBP-CorV vaccine or the CoronaVac vaccine may not be enough to provide PLWH with persistent immunity against SARS-CoV-2. It is necessary for PLWH to be prioritized for a third dose over the healthy population, but the immunogenicity of the third dose of the homologous or heterologous vaccine requires further study.

[Immunosuppression induced by measles virus in adult patients is not related to CD4+ CD25+ regulatory T cell induction].

Abstract: ：Objective To investigateof the relationship of the immunosuppression induced by Measles virus in adult patientsand CD4+ CD25+ regulatory T cell. Methods Thirty-four patients with measles and 27healthycontrol subjects were included in this study. The whole blood was collected and CD4+ CD25+cell andFoxP33 cell were analyzed by flow cytometry, and CD4+ CD25- and CD4+CD25+ Tlymphocytes were isolated from PBMCs of patients with measles or healthy donors, CD4+CD25- T cells were cultured in absence or presence of anti-CD3, or BCG, or live attenuatedMV. The cell culture supernatant was collected after 72 hours and the concentration ofIFN-γ and IL-10 was determined.Results Compared to healthy donors, we observed a reduction of the number of white bloodcells and lymphocytes in patients with measles, but there was not significantly differentin the frequency of CD4+ CD25+ T cells and CD4+ CD25high T cells with in the total CD4+population in the blood. Treg from both measles patients and healthy controlssignificantly inhibited IFN-γ production by CD4+ CD25- T cells in response to anti-CD3stimulation. Conclusion Induction and expansion of Treg may not represent a mechanisminvolved in the establishment of immune suppression by MV. Key words: Measles virus; Immunosuppression; CD4 Lymphocyte count; CD25 Lymphocyte counts

[High throughput detection of drug-resistance gene mutations in HBV using MALDI-TOF mass spectrometry].

Abstract: Objective To develop a high-throughput clinical method on drag-resistance gene mutations of HBV using MALDI-TOF-MS. Method Using MassArray Assay Design software designed the iPLEX primers and followed the iPLEX instruction for amplification, SAP reaction, primer extenction, desalination, dispensing, MALDI-TOF-MS screening and data analysis of the gene mutation locus. 138 serum samples of chronic HBV patients with single drug-resistance or multiple drug-resistance on Lamivudin, adefovi, Entecavir were detected. Result The HBV gene mutation platform was successfully developed and applied on the high-throughput dectection of clinical serum samples. It was also a high throughput assay which could be used to detect for more than 138 samples once. The MALDI-TOF-MS technology and the DNA sequencing simultaneously examine 33 samples, in which result of 10 sample is inconsistent, the including 2 samples by MALDI-TOF-MS technology has not tested, 1 sample has 2 inconsistent mutations. Conclusion Detction of HBV gene mutations using MALDI-TOF-MS is highly-sensitive, highly-accuate, high-thoughput,fast achieved and suithle to use in the diagnosis and monitoring of HBV. Key words: Hepatitis B Virus; MALDI-TOF-MS; DNA; Seqences analysis

Associations Between Hepatitis B Virus Mutations and the Risk of Hepatocellular Carcinoma: A Meta-Analysis

Abstract: Background The association between hepatitis B virus (HBV) mutations and hepatocarcinogenesis remains controversial because of conflicting data in the literature. We conducted a meta-analysis of case–control and cohort studies to examine HBV PreS, enhancer II (EnhII), basal core promoter (BCP), and precore mutations in relation to the risk of hepatocellular carcinoma (HCC).

Update on epidemiology of hepatitis B and C in China.

Abstract: A high rate of chronic hepatitis B virus (HBV) infection in China is mainly caused by perinatal or early childhood transmission. Administration of universal HBV vaccination in infants has led to a dramatic decrease in HBV epidemiology, with hepatitis B surface antigen (HBsAg) prevalence declining from 9.75% in 1992 to 7.18% in 2006. The major HBV genotypes are B and C, with B being more prevalent in the southern part and C more prevalent in the northern part of China. A national survey carried out in 1992 showed that the hepatitis C virus (HCV) infection rate was 3.20% in general population in China. After implementation of mandatory HCV screening for blood transfusion and other precautions to prevent blood-borne disease since 1993, the new cases of HCV infection associated with blood or blood product has become very rare. Although the anti-HCV prevalence would be much higher in high-risk groups, a survey carried in 2006 showed that the anti-HCV prevalence rate was only 0.43% in general population. This sharp decline in HCV infection rate was mainly due to stringent administration and monitoring of blood donors and blood products, but may also be related to the remarkably improved specificity of anti-HCV test. The predominant HCV genotype in China is genotype 1b (60–70%), and the host interleukin-28b rs12979860 CC genotype is very frequent in Chinese population (over 80%).

Hepatitis B virus burden in developing countries.

Abstract: Hepatitis B virus (HBV) infection has shown an intermediate or high endemicity level in low-income countries over the last five decades. In recent years, however, the incidence of acute hepatitis B and the prevalence of hepatitis B surface antigen chronic carriers have decreased in several countries because of the HBV universal vaccination programs started in the nineties. Some countries, however, are still unable to implement these programs, particularly in their hyperendemic rural areas. The diffusion of HBV infection is still wide in several low-income countries where the prevention, management and treatment of HBV infection are a heavy burden for the governments and healthcare authorities. Of note, the information on the HBV epidemiology is scanty in numerous eastern European and Latin-American countries. The studies on molecular epidemiology performed in some countries provide an important contribution for a more comprehensive knowledge of HBV epidemiology, and phylogenetic studies provide information on the impact of recent and older migratory flows.