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1.  Avian Influenza A(H7N9) Virus Screening in Patients with Fever and Flu-Like Symptoms in a Tertiary Hospital in an Area with Confirmed Cases 
PLoS ONE  2013;8(12):e82613.
Novel avian influenza A(H7N9) virus was isolated in fatal patients in Yangtze River Delta of China in March 2013. We aimed to screen the virus in febrile patients in a tertiary hospital in an area with confirmed cases. Throat-swab specimens collected from consecutive patients with fever (≥38°C) and flu-like symptoms from April 15 to April 25, 2013 were subjected to detect novel avian influenza A(H7N9) virus with real-time PCR. The clinical outcomes in the patients and close contacts were followed up. Of total 200 patients screened, one (0.5%) was positive for avian influenza A(H7N9) virus and 199 others were negative. The infected patient experienced respiratory failure and had diffuse infiltrates in the right lower lobe in chest CT images. He received symptomatic and antibacterial treatments as well as oseltamivir. His condition was substantially improved within three days after admission; avian influenza A(H7N9) virus was not detected after 5 days' antiviral therapy. The hemagglutinin inhibition test showed that the serum titers against avian influenza A(H7N9) virus increased from <1∶20 at the early phase to 1∶80 at the convalescent phase. Follow-up of 23 close contacts showed that none of them developed fever and other symptoms within two weeks. Our findings suggest that although the infection rate of avian influenza A(H7N9) virus in patients with fever and flu-like symptoms is rare, the screening is valuable to rapidly define the infection, which will be critical to improve the clinical outcomes.
doi:10.1371/journal.pone.0082613
PMCID: PMC3867373  PMID: 24367529
2.  Effect of elective cesarean section on the risk of mother-to-child transmission of hepatitis B virus 
Background
Many clinicians and hepatitis B virus (HBV)-infected pregnant women prefer elective caesarean section (ECS) to prevent mother-to-child transmission of HBV, since some studies found higher transmission of HBV in infants born by vaginal delivery (VD) than by cesarean section. However, other studies showed that ECS does not reduce the risk of being infected with HBV in infants. In this study, we aimed to clarify whether ECS may reduce the risk of mother-to-child transmission of HBV.
Methods
Totally 546 children (1–7-year-old) born to 544 HBsAg-positive mothers from 15 cities and rural areas across Jiangsu Province, China, were enrolled. Of these children, 137 (2 pairs of twins) were born to HBeAg-positive mothers; 285 were delivered by ECS and 261 others by VD (one pair of twin in each group). HBV serologic markers were tested by enzyme or microparticle immunoassay.
Results
The maternal and gestational ages, maternal HBeAg-positive rates, and children’s ages, gender ratios, hepatitis B vaccine coverage and administrations of HBIG were comparable between ECS and VD groups (all p >0.05). The overall prevalence of HBsAg in the 546 children was 2.4%, with 2.5% (7/285) and 2.3% (6/261) in those born by ECS and VD respectively (p = 0.904). Further comparison of chronic HBV infection in the 137 children of HBeAg-positive mothers showed that the HBsAg-positive rates in ECS and VD groups were 10.3% (7/68) and 8.7% (6/69) respectively (p = 0.750), while the mothers had similar HBV DNA levels (2.38 × 106 vs. 2.35 × 106 IU/ml, p = 0.586). Additionally, the overall rate of anti-HBs ≥10 mIU/ml in the children was 71.6%, with 72.3% and 70.9% in those born by ECS and VD respectively (p = 0.717).
Conclusions
With the recommended immunoprophylaxis against hepatitis B, ECS does not reduce the risk of mother-to-child transmission of HBV. Therefore, ECS should not be used in HBsAg-positive pregnant women to prevent mother-to-child transmission of HBV.
doi:10.1186/1471-2393-13-119
PMCID: PMC3664615  PMID: 23706093
Hepatitis B virus; Mother-to-child transmission; Vaginal delivery; Caesarean section
3.  Breastfeeding Is Not a Risk Factor for Mother-to-Child Transmission of Hepatitis B Virus 
PLoS ONE  2013;8(1):e55303.
Background
Many clinicians do not encourage breastfeeding in hepatitis B virus (HBV) carriers, since HBV DNA can be detected in breast milk and breast lesions may increase exposure of infants to HBV. The aim of this study was to determine whether breastfeeding may add risk for perinatal HBV transmission.
Methodology/Principal Findings
Totally 546 children (1–7-year-old) of 544 HBV-infected mothers were investigated, with 397 breastfed and 149 formula-fed; 137 were born to HBeAg-positive mothers. All children had been vaccinated against hepatitis B but only 53.3% received hepatitis B immune globulin (HBIG). The overall prevalence of HBsAg+, HBsAg−/anti-HBc+, and anti-HBs (≥10 mIU/ml) in children was 2.4%, 3.1%, and 71.6% respectively. The HBsAg prevalence in breast- and formula-fed children was 1.5% and 4.7% respectively (P = 0.063); the difference was likely due to the higher mothers' HBeAg-positive rate in formula-fed group (formula-fed 49.0% vs. breastfed 15.9%, P<0.001). Further logistic regression analyses showed that breastfeeding was not associated with the HBV infection in the children, adjusting for the effect of maternal HBeAg status and other factors different between the two groups.
Conclusions/Significance
Under the recommended prophylaxis, breastfeeding is not a risk factor for mother-to-child transmission of HBV. Therefore, clinicians should encourage HBV-infected mothers to breastfeed their infants.
doi:10.1371/journal.pone.0055303
PMCID: PMC3557270  PMID: 23383145
4.  Kinetics of IgG antibody to cytomegalovirus (CMV) after birth and seroprevalence of anti-CMV IgG in Chinese children 
Virology Journal  2012;9:304.
Background
Prevalence of cytomegalovirus (CMV) infection is 90–100% in developing countries; however, the kinetics of anti-CMV IgG in infants remains elusive.
Methods
Sera from 112 mother-newborn pairs and longitudinal samples from 41 infants up to 2-year old were tested for anti-CMV IgG and IgM. Additionally, samples from 837 healthy children were included.
Results
Of 112 mothers, 108 (96.4%) were anti-CMV IgG positive; their 108 newborns were also seropositive. In a 2-year follow-up among 40 infants of positive mothers, anti-CMV IgG level in 8 individuals decreased with time and became undetectable by age of 3.5–8 months, and that in 32 others decreased at 1- and 3.5-month old, and then increased. Based on the positive IgM, rising IgG levels, and low anti-CMV IgG avidity index, 76.7% of the primary infections were demonstrated to occur during 1–3.5 months of age. The overall seroprevalence of anti-CMV in 837 children was 82.4%, which was generally constant from 2 to 8 years old (χ2 = 3.150, p = 0.790).
Conclusions
The maternally acquired anti-CMV IgG in infants disappears before 8-month old. Primary CMV infection in Chinese children mostly occurs during 1–3.5 months of age. Whether the relatively lower seroprevalence of anti-CMV in Chinese children found in this survey may reflect the positive rate in child-bearing age women in the future remains to be further studied.
doi:10.1186/1743-422X-9-304
PMCID: PMC3544651  PMID: 23228149
Cytomegalovirus; Anti-CMV IgG; Kinetics; Primary infection; Children
5.  Gaps in the prevention of perinatal transmission of hepatitis B virus between recommendations and routine practices in a highly endemic region: a provincial population-based study in China 
BMC Infectious Diseases  2012;12:221.
Background
Hepatitis B virus (HBV) infection is endemic in China; perinatal transmission is the main source of chronic HBV infection. Simultaneous administration of hepatitis B immune globulin (HBIG) and hepatitis B vaccine is highly effective to prevent perinatal transmission of HBV; however, the effectiveness also depends on full adherence to the recommended protocols in daily practice. In the present investigation, we aimed to identify gaps in immunoprophylaxis of perinatal transmission of HBV between recommendations and routine practices in Jiangsu Province, China.
Methods
Totally 626 children from 6 cities and 8 rural areas across Jiangsu Province, China, born from February 2003 to December 2004, were enrolled; 298 were born to mothers with positive hepatitis B surface antigen (HBsAg) and 328 were born to HBsAg-negative mothers. Immunoprophylactic measures against hepatitis B were retrospectively reviewed for about half of the children by checking medical records or vaccination cards and the vaccine status was validated for most of children.
Results
Of 298 children born to HBV carrier mothers, 11 (3.7%) were HBsAg positive, while none of 328 children born to non-carrier mothers was HBsAg positive (P < 0.01). The rates of anti-HBs ≥ 10 mIU/ml in children of carrier and non-carrier mothers were 69.5% and 69.2% respectively (P = 0.95). The hepatitis B vaccine coverage in two groups was 100% and 99.4% respectively (P = 0.50), but 15.1% of HBV-exposed infants did not receive the timely birth dose. Prenatal HBsAg screening was performed only in 156 (52.3%) of the carrier mothers. Consequently, only 112 (37.6%) of HBV-exposed infants received HBIG after birth. Furthermore, of the 11 HBV-infected children, only one received both HBIG and hepatitis B vaccine timely, seven missed HBIG, two received delayed vaccination, and one missed HBIG and received delayed vaccination.
Conclusions
There are substantial gaps in the prevention of perinatal HBV infection between the recommendations and routine practices in China, which highlights the importance of full adherence to the recommendations to eliminate perinatal HBV infection in the endemic regions.
doi:10.1186/1471-2334-12-221
PMCID: PMC3462156  PMID: 22984924
Hepatitis B virus; Perinatal infection; Immunoprophylaxis; Gaps
6.  High hepatitis B virus load is associated with hepatocellular carcinomas development in Chinese chronic hepatitis B patients: a case control study 
Virology Journal  2012;9:16.
Background
Persistent hepatitis B virus (HBV) infection is a risk factor for hepatocellular carcinoma (HCC) development. This study aimed to clarify whether the high HBV DNA level is associated with HCC development by comparing HBV DNA levels between HBV infected patients with and without HCC.
Results
There were 78 male and 12 female patients in each group and there was no statistical difference between these two group patients' average ages. The HBV DNA level in the HCC patients was 4.73 ± 1.71 Log10 IU/ml while 3.90 ± 2.01 Log10 IU/ml in non-HCC patients (P < 0.01). The HBeAg positive rate was 42.2% (38/90) in the HCC group while 13.3% (12/90) in the non-HCC group (P < 0.001). Compared with patients with HBV DNA level of < 3 Log10 IU/ml, the patients with level of 3 to < 4, 4 to < 5, 5 to < 6, or ≥ 6 Log10 IU/ml had the odds ratio for HCC of 1.380 (95% CI, 0.544-3.499), 3.671 (95% CI, 1.363-9.886), 5.303 (95% CI, 1.847-15.277) or 3.030 (95% CI, 1.143-8.036), respectively.
Conclusions
HBV-related HCC patients had higher HBV DNA level than non-HCC counterparts. Our findings imply that active HBV replication is associated with the HCC development.
doi:10.1186/1743-422X-9-16
PMCID: PMC3349554  PMID: 22244446
7.  Transplacentally Acquired Maternal Antibody against Hepatitis B Surface Antigen in Infants and its Influence on the Response to Hepatitis B Vaccine 
PLoS ONE  2011;6(9):e25130.
Background
Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs) in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown.
Methodology/Principal Findings
Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC) of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively). In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≥1000 mIU/ml, 94 children of mothers with anti-HBs 10–999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521), respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726), respectively.
Conclusions/Significance
The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B.
doi:10.1371/journal.pone.0025130
PMCID: PMC3178586  PMID: 21966434
8.  Soluble CD40 ligand-activated human peripheral B cells as surrogated antigen presenting cells: A preliminary approach for anti-HBV immunotherapy 
Virology Journal  2010;7:370.
Background
We aimed to clarify whether soluble CD40 ligand (sCD40L) activated B cells may be loaded with HBcAg18-27 peptide and served as antigen-producing cells (APCs) to induce HBV-specific cytolytic T lymphocytes (CTLs).
Results
Human B cells could be cultured in the presence of sCD40L up to 54 days, and the proportion of B cells in the S phase increased from 0% to 8.34% in the culture. The expression of CD80, CD86, major histocompatibility complex (MHC) classes I and II molecules on the sCD40L-activated B cell was significantly increased after long-time culture. Cytometry and fluorescence microscopy showed that more than 98% sCD40L-activated B cells were loaded by the HBcAg peptide. Furthermore, the peptide-pulsed activated B cells could induce HBcAg18-27 specific CTLs.
Conclusions
Our results demonstrate that sCD40L-activated B cells may function as APCs and induce HBV-specific CTLs.
doi:10.1186/1743-422X-7-370
PMCID: PMC3018399  PMID: 21176236
9.  Application of Truncated Immunodominant Polypeptide from Hepatitis E Virus (HEV) ORF2 in an Assay To Exclude Nonspecific Binding in Detecting Anti-HEV Immunoglobulin M ▿  
Journal of Clinical Microbiology  2009;48(3):779-784.
The diagnosis of recent hepatitis E virus (HEV) infection depends on serologic testing for anti-HEV IgM; however, false-positive results may occur. In the present study, we cloned the ORF2 fragment of genotype 4 HEV and demonstrated that a subregion covering amino acids 459 to 607 in ORF2 forms the immunodominant B-cell epitopes, as it does in genotype 1 viruses. Truncation of several residues from either the N or C terminus of the polypeptide abolished the reactivity of anti-HEV from naturally infected persons. By the combination of high reactivity of the immunodominant polypeptide and poor reactivity of the truncated polypeptide, we established an indirect enzyme-linked immunosorbent assay (ELISA) to detect anti-HEV IgM. In this assay, all 37 sera that were HEV RNA positive reacted with the immunodominant polypeptide but not with the truncated one, and none of 159 sera from healthy persons reacted with either of the polypeptides. In retesting of 117 sera that originally tested positive for anti-HEV IgM, using a Genelabs kit, only 34 were positive and 83 were negative. Western blot analyses and other experiments strongly indicated that these 83 discordant sera were negative for anti-HEV IgM. Furthermore, among the 117 sera, 5 reacted with both the immunodominant and truncated polypeptides, with comparable optical densities at 450 nm. However, their reactivity was demonstrated to result from nonspecific binding. Together, the data indicate that the poor reactivity of a truncated ORF2 polypeptide can be used to exclude nonspecific binding in the detection of anti-HEV IgM.
doi:10.1128/JCM.01671-09
PMCID: PMC2832410  PMID: 20042615
10.  Detection of hepatitis B virus DNA among accepted blood donors in Nanjing, China 
Virology Journal  2010;7:193.
Background
Posttransfusion hepatitis B virus (HBV) infection still occurs although its incidence has been substantially reduced since the introduction of screening of hepatitis B surface antigen (HBsAg) in blood donors. This study aimed to investigate the occult HBV infection in accepted blood donors in Nanjing, China.
Results
The lower detection limit of the nested PCR in this study was estimated to be 20 copies/ml HBV DNA. The positive rate of occult HBV infection was 0.13% (5 of 2972) in the accepted blood donors. Sequencing data showed that the amplified HBV sequences were not identical each other and to the known sequences cloned in our laboratory, excluding the false-positive caused by cross-contamination. Phylogenetic analysis showed that the HBV in all five donors was genotype B; a single base deletion was detected in the S region of HBV DNA from one donor, and no mutation was observed in the "a" determinant of HBsAg from four other donors. All five donors were negative for anti-HBs and one was positive for anti-HBc.
Conclusions
The prevalence of occult HBV infection in the accepted blood donors in Nanjing, China is relatively high. The data would be meaningful in adapting strategy to eliminate posttransfusion HBV infection in China.
doi:10.1186/1743-422X-7-193
PMCID: PMC2931482  PMID: 20718994
11.  Low titers of measles antibody in mothers whose infants suffered from measles before eligible age for measles vaccination 
Virology Journal  2010;7:87.
Background
Resurgence or outbreak of measles recently occurred in both developed and developing countries despite long-standing widespread use of measles vaccine. Measles incidence in China has increased since 2002, particularly in infants and in persons ≥ 15 years of age. It is speculated that infants may acquire fewer measles IgG from their mothers, resulting in the reduced duration of protection during their early months of life. This study aimed to clarify the reason of increased susceptibility to measles in young infants in China. Measles IgG in 24 measles infants ≤ 9 months of age and their vaccinated mothers was quantitatively measured. The mean measles neutralizing titer in the vaccinated mothers and in 13 age-match women with the histories of clinical measles were compared.
Results
All the mothers were confirmed to be vaccinated successfully by the presence of measles IgG. Six vaccinated mothers were positive for measles IgM and had high concentrations of measles IgG and the neutralizing antibody, indicating underwent natural boosting. The mean measles neutralizing titer in 18 vaccinated mothers without natural boosting were significantly lower than that in 13 age-match women with the histories of clinical measles (1:37 vs 1:182, P < 0.05).
Conclusions
Our results suggest that infants born to mothers who acquired immunity to measles by vaccination may get a relatively small amount of measles antibody, resulting in loss of the immunity to measles before the vaccination age. Measures to improve the immunity in young infants not eligible for measles vaccination would be critical to interrupt the measles transmission in China.
doi:10.1186/1743-422X-7-87
PMCID: PMC2874774  PMID: 20444295
12.  Monitoring human cytomegalovirus infection with nested PCR: comparison of positive rates in plasma and leukocytes and with quantitative PCR 
Virology Journal  2010;7:73.
Background
Human cytomegalovirus (HCMV) infection poses a significant health threat to immunocompromised individuals. Here we performed this study to set up a highly sensitive nested PCR method applicable for detecting HCMV infection in high-risk individuals. In this work, 106 blood specimens from 66 patients with potential HCMV infection were obtained. Total DNA was extracted separately from plasma and peripheral blood leukocytes (PBL) of each sample. HCMV DNA was detected in parallel by nested PCR and quantitative real-time PCR (qRT-PCR), and the results were compared.
Results
Serial dilution test revealed that the detection limit of nested PCR was 180 copies/ml. The nested PCR showed a higher positive rate than qRT-PCR (34.9% vs. 12.3%, p < 0.001). The positive rate of nested PCR based on PBL DNA was significantly higher than that based on plasma DNA (34.9% vs. 18.9%, p = 0.002). Of the 14 patients with serial samples, 11 were positive for HCMV DNA in PBL while only 7 were positive in plasma. Moreover, for each patient, nested PCR using PBL DNA also detected more positive samples than that using plasma DNA.
Conclusion
Combined use of nested PCR with PBL DNA is highly sensitive in defining HCMV infection. This assay is particularly useful in the case of quantification not essential.
doi:10.1186/1743-422X-7-73
PMCID: PMC2859376  PMID: 20398295
13.  Mutations within Potential Glycosylation Sites in the Capsid Protein of Hepatitis E Virus Prevent the Formation of Infectious Virus Particles▿  
Journal of Virology  2007;82(3):1185-1194.
Hepatitis E virus is a nonenveloped RNA virus. However, the single capsid protein resembles a typical glycoprotein in that it contains a signal sequence and potential glycosylation sites that are utilized when recombinant capsid protein is overexpressed in cell culture. In order to determine whether these unexpected observations were biologically relevant or were artifacts of overexpression, we analyzed capsid protein produced during a normal viral replication cycle. In vitro transcripts from an infectious cDNA clone mutated to eliminate potential glycosylation sites were transfected into cultured Huh-7 cells and into the livers of rhesus macaques. The mutations did not detectably affect genome replication or capsid protein synthesis in cell culture. However, none of the mutants infected rhesus macaques. Velocity sedimentation analyses of transfected cell lysates revealed that mutation of the first two glycosylation sites prevented virion assembly, whereas mutation of the third site permitted particle formation and RNA encapsidation, but the particles were not infectious. However, conservative mutations that did not destroy glycosylation motifs also prevented infection. Overall, the data suggested that the mutations were lethal because they perturbed protein structure rather than because they eliminated glycosylation.
doi:10.1128/JVI.01219-07
PMCID: PMC2224450  PMID: 18032496
14.  Arabidopsis NMD3 Is Required for Nuclear Export of 60S Ribosomal Subunits and Affects Secondary Cell Wall Thickening 
PLoS ONE  2012;7(4):e35904.
NMD3 is required for nuclear export of the 60S ribosomal subunit in yeast and vertebrate cells, but no corresponding function of NMD3 has been reported in plants. Here we report that Arabidopsis thaliana NMD3 (AtNMD3) showed a similar function in the nuclear export of the 60S ribosomal subunit. Interference with AtNMD3 function by overexpressing a truncated dominant negative form of the protein lacking the nuclear export signal sequence caused retainment of the 60S ribosomal subunits in the nuclei. More interestingly, the transgenic Arabidopsis with dominant negative interference of AtNMD3 function showed a striking failure of secondary cell wall thickening, consistent with the altered expression of related genes and composition of cell wall components. Observation of a significant decrease of rough endoplasmic reticulum (RER) in the differentiating interfascicular fiber cells of the transgenic plant stems suggested a link between the defective nuclear export of 60S ribosomal subunits and the abnormal formation of the secondary cell wall. These findings not only clarified the evolutionary conservation of NMD3 functions in the nuclear export of 60S ribosomal subunits in yeast, animals and plants, but also revealed a new facet of the regulatory mechanism underlying secondary cell wall thickening in Arabidopsis. This new facet is that the nuclear export of 60S ribosomal subunits and the formation of RER may play regulatory roles in coordinating protein synthesis in cytoplasm and transcription in nuclei.
doi:10.1371/journal.pone.0035904
PMCID: PMC3338764  PMID: 22558264

Results 1-14 (14)