Objective To analyse distribution and antibacterial resistance status of pathogenic bacteria isolated from blood cul‐tures of hospitalized infants ,in order to provide references for rational use of antimicrobial agents in the treatment of bloodstream infection .Methods A total of 299 strains of pathogenic bacteria isolated from positive blood culture specimens from infants(3 or less than 3 months of age) suspected with bloodstream infections in this hospital from January 2011 to May 2015 were collected ,the bacteria identification and drug sensitivity test were carried out by using the VITEK 2 Compact automatic microorganism analyzer . The composition and antibacterial resistance of these isolates were analyzed .Results Among the 299 strains of pathogenic bacteria , there were 169 strains of gram‐positive cocci(accounted for 56 .5% ) ,including 95 strains of coagulase negative Staphylococcus (ac‐counted for 31 .8% ) which was the main isolates ,and followed by 28 strains of Staphylococcus aureus(accounted for 9 .4% );there were 120 strains of gram‐negative bacilli (accounted for 40 .1% ) and mainly were Escherichia coli (53 strains ,accounted for 17 .7% );otherwise ,there were 8 strains of fungi (accounted for 2 .7% ) and 2 strains of gram‐positive bacillus (accounted for 0 .7% ) .The results of drug susceptibility test indicated that the gram‐positive cocci had multiple drug resistance to antibacterial a‐gents except for vancomycin and linezolid;the gram‐negative bacilli shown multiple drug resistance except for amikacin ,imipenem and meropenem .The fungus ,however ,displayed high sensitivty to all antifungal drugs .Conclusion Gram‐positive and gram‐nega‐tive bacteria are the main pathogens of hospitalized infants with bloodstream infection ,and are severely resistant to antibacterial a‐gents .Rational use of antimicrobial agents should be recommend for improving clinical efficacy and prohibiting the emergence of drug‐resistant strains .

Objective To compare the influences of different dilution titers on the ANA detection by the indirect immunofluores‐cence assay(IIF) in children for investigating the necessity of reducing serum initial dilution titer .Methods Serum ANA was detec‐ted by using the indirect immunofluorescence assay at a serial of dilution titer in 110 healthy controls and the results were compared with the results of specific ANAs by the linear immunoassay (LIA);meanwhile the ANA‐LIA results in clinical children patients with ANA‐IIF negative were also analyzed .Results With the dilution titers gradual decrease from 1∶80 ,1∶40 and 1∶20 in the samples of the health group ,the positive detection rates of ANA‐IIF were risen ,which were 7 .3% ,9 .1% and 10 .9% respectively , but the differences were not statistically significant (P>0 .05) ,the weak‐positive rates were 7 .3% ,15 .5% and 31 .8% respective‐ly ,the differences were statistically significant (P<0 .01) .Among 110 healthy children under going the physical examination ,the specific ANA was detected out in 8 samples ,the positive rate was 7 .3% .Among 8 positive cases at the dilution titer of 1∶80 by the IIF method ,specific ANA was in 2 cases;in 4 added cases of fluorescence ANA positive samples at the dilution titers of 1∶40 and 1∶20 ,specific ANA was in 1 case .If with any positive of ANA‐IIF(1∶80) or ANA‐LIA as the ANA positive ,the ANA positive rate was risen from 7 .3% to 12 .7% .In the clinical samples among 29 cases of ANA‐IIF(1∶80) negative autoimmune liver disease related autoantibody detection ,the specific ANA‐LIA positive was detected in 5 cases (17 .2% ) .Conclusion Reducing the initial ti‐ter of children serum is unable to obviously increase the ANA‐IIF positive detection rate ,on the contrary increases the non‐specific weak positive .Therefore ,clinical laboratory does not change the dilution titer of children routine ANA sample .The detection by combining with the specific ANA‐LIA spectrum is conducive to find ANA .

Objective To explore the infection rate of hepadnaviruses and non-hepatotropic virus in infants with biliary atresia(BA)and their relationship between the onset and development of BA.Methods The data and pathogen test records from 184 BA infants who were hospitalized at Guangzhou Women and Children's Medical Center from January 1,2010 to December 31,2014 were reviewed,and the infection rates caused by 3 hepadnaviruses including hepatitis A virus(HAV),hepatitis B virus(HBV),hepatitis E virus(HEV)as well as 5 non-hepatotropic viruses including cytomegalovirus(CMV),Epstein-Barr virus(EBV),herpes simplex virus(HSV),enterovirus(EV),Coxsackie-virus were analyzed.The outpatients or inpatients without BA and immunodeficiency were selected as controls.Results In BA patients,the infection rates of CMV were highest(40.21％,39/97 cases)caused by 3 hepadnaviruses(HAV,HBV,HEV)and 5 non-hepatotropic viruses(CMV,EBV,HSV,EV,Cox),while the infection rates of HAV,HEV,HBV,EBV,HSV,EV or Coxsackievirus were all low,and mixed virus infection was found in 9 patients.The positive rate of CMV IgM in BA group[34.94％(29/83 cases)] was significantly higher than that in the control group[15.69％(8/51 cases)],and the difference was statistically significant(x2=5.86,P<0.05);and the positive rate of CMV DNA in BA group[28.57％(20/70 cases)] was significantly higher than that in the control group[3.70％(1/27 cases)],and the difference was statistically significant(x2=7.10,P<0.05).In BA infants under 60 days,the detection rate of CMV DNA was 45.45％(15/33 cases),which was higher than that in the ones over 60 days[25.48％(5/37 cases)],and the difference was statistically significant(x2=8.72,P<0.01);while the positive rate of CMV IgM had no significant difference among≤60 d group,60-90 d group and ≥90 d group[47.22％(17/36 cases),20.00％(6/30 cases),35.29％(6/17 cases)](x2=5.62,P>0.05).No statistical difference in age was found in BA patients on detection between the positive and the negative group,and the consistency of CMV DNA and CMV IgM was not ideal(Kappa value<0.4).Conclusions Infection of CMV is quite common in BA patients,BA infants under 60 days old show higher detection rate of CMV DNA than the older ones,but there is no difference in detection rate of CMV IgM among different ages,CMV is not supported as a secondary infection and may play a role in the occurrence and development of BA.

Objective To investigate the correlation between the degree of liver fibrosis and Aspartate aminotransferase-to-Platelet Ratio Index ( APRI ) in children with biliary atresia ( BA ) , and evaluate the clinical significance of liver fibrosis in biliary atresia.Methods A total of 97 patients with diagnosed BA were recruited between January 2010 and June 2013.AST, PLT and APRI were determined one week before laparotomy.The severity of hepatic tibrosis was.Judged by Metavir system the correlation among AST, PLT, APRI and severity of liver fibrosis were evaluated, and their diagnostic value for degree of liver fibrosis was analyzed by ROC.Results Sera AST levels and PLT counts of BA patients were found to be positively(r=0.367, P<0.01) and negatively(r=-0.403, P<0.01) correlated with Metavir scores of liver fibrosis, respectively.There existed positive correlation between APRI and the severity of hepatic fibrosis (r=0.541, P<0.01).The area under ROC curve of APRI to diagnose none or mild fibrosis and moderately severe fibrosis was 0.78, with sensitivity of 77.9%and specificity of 62.1%at the optimal cut-off value of 0.75; the area under ROC curve of APRI to diagnose moderately severe fibrosis with liver cirrhosis arrived 0.85, with sensitivity of 75.0% and specificity of 89.4% at the optimal cut-off value of 1.77.The accuracy of none or mild fibrosis, moderate fibrosis and cirrhosis diagnosed by APRI were 73.2%, 64.9%, 87.6%, respectively.Conclusion APRI can be used as a non-invasive parameter to assess the severity of hepatic fibrosis with BA.

Objective Newborn bilirubin encephalopathy seriously threatens the life and health of newborns, Both the mortality and morbidity are high.Cerebrospinal fluid bilirubin concentration can better reflect the blood-brain barrier function and brain bilirubin levels, which can help the diagnosis of bilirubin encephalopathy.Methods In order to meet the clinical needs, we confirmed the detection performance of the existing serum bilirubin detection system for cerebrospinal fluid bilirubin, including precision, accuracy and analysis of measurement range.Results The results showed that the detection system was linear at 1.0-25.1μmol/L, and the daytime CVat normal and pathological values was less than the precision requirement (6％) .The bias of each sample and the average bias are less than the allowable bias (5％) , the total error is less than the total allowable error (15％) .Conclusion Therefore, the performance of the detection system meet the industry standards, can be used for neonatal cerebrospinal fluid bilirubin detection.

OBJECTIVETo determine the immune repertoires of peripheral CD4+T cell receptor (TCR) Vb CDR3 in primary biliary cirrhosis (PBC) and analyze TCR diversity and preferred usage at sequence-level resolution.

METHODSARM-PCR and high-throughput sequencing were used to obtain millions of TCR Vb CDR3 sequences from peripheral CD4+T cells isolated from 7 patients with PBC and healthy volunteers. All sequencing data were analyzed, together with corresponding clinical information, by bioinformatic software. The Mann-Whitney U test was used for statistical analysis.

RESULTSThe PBC patients showed a lower level of diversity among the peripheral CD4+TCR Vb CDR3 than the healthy volunteers, and patients with higher level progression of the disease showed a greater lack of diversity. In addition, 4 specific preferred-usage amino acid sequences were discovered for the PBC patients: ASSFTGGPVEQY, ASSLISSGNNEQF, ATSRDTLAGGPGDTQY, and SASLEGNTEAF; these sequences were also found in higher frequencies in patients with later stages of PBC.

CONCLUSIONSDecreased TCR Vb CDR3 diversities and specific preferred usage of TCR CDR3 sequences in peripheral CD4+T lymphocytes in PBC suggest that clonal expansion of a large number of CD4+T cells may be an important factor for PBC progression. These data provide a better understanding about the general characteristics of CD4+T cells in PBC patients and related to pathogenesis of the disease, and may provide useful insights into potential targets for immunotherapy.

Amino Acid Sequence ; CD4-Positive T-Lymphocytes ; High-Throughput Nucleotide Sequencing ; Humans ; Liver Cirrhosis, Biliary ; Polymerase Chain Reaction ; Receptors, Antigen, T-Cell