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The transcranial doppler ultrasonography (TCD) is a non-invasive detection methods of evaluating intracranial artery.Since the 1980s,TCD has been extensively used in various fields of clinical work.Because of its simple operation,good repeatability,and the continuous bedside observation of patients,TCD is especially suitable for severe patients.Increased intracranial pressure is one of the important reasons for the deadly disease in children,it can make the cerebral blood flow perfusion decreased,causing serious consequences,such as brain dysfunction,so intracranial pressure monitoring has important clinical significance.TCD as a noninvasive monitoring tool,can monitor the patients with increased intracranial pressure dynamically,according to the blood flow velocity,the related parameters and the wave of cerebral hemodynamics,so as to achieve the purpose of monitoring intracranial pressure change.This article focused on the TCD application progress in several common children's diseases of increased intracranial pressure.
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Objective To establish an anti-hepatitis E virus (HEV) enzyme-linked immunosorbent assay (ELISA) one-step assay based on seven glutathione S-transferase (GST)-fusion recombinant proteins derived from different HEV genotypes and subtypes. Methods Concentration of the coating antigen was optimized by block titration. The cut-off values were determined for anti-HEV IgG and IgM, respectively. Assay sensitivity, specificity and reproducibility were investigated using samples with confirmed anti-HEV positive. Results An optimal concentration of mixture of recombinant proteins (Mix166) was 1.5 mg/L for antigen coating. Coefficient of variations (CV) of anti-HEV within-run and between-run were 8.67% and 10.85%, respectively. CV of anti-HEV IgM within-run and between-run were 4.56% and 5.99%, respectively. Positive rates of anti-HEV IgG and IgM were both 94% for 50 HEV-polymerase chain reaction (PCR) positive sera tested with the one step assay. Using one-step assay to detect 674 serum samples from healthy people, 52 samples were found anti-HEV IgG positive and 3 samples were anti-HEV lgM positive. A series of serum specimens collected at different time points until 76 weeks from a chimpanzee challenged with HEV Mexican strain were anti-HEV IgM positive during week 1--6 and anti-HEV IgG positive during week 2--76 determined by the one step ELISA. However, import ELISA kits were lack of both the IgM and lgG reactivity to all of the serial chimpanzee sera. Conclusions The sensitivity and specificity of anti-HEV ELISA one-step assay based on the Mix166 antigen are high and could be used for the diagnosis of HEV infection.
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Objective To establish a double-antigen sandwich ELISA(S-ELISA) for detection of total antibodies against hepatitis C virus(HCV).Methods Recombinant HCV proteins fusion-expressed with His-tag and GST-tag were separately used as coating and HRP-labeling antigen of the S-ELISA.Serum samples were tested with both the S-ELISA and another commercial indirect ELISA(I-ELISA) kit(Beijing Wantai Biological Pharmacy Enterprise Co.Ltd.).HCV RNA in some of the samples were tested by RT-nested PCR.Results Among 1 968 tested samples,190(9.7%) were total anti-HCV-positive while 1 761(89.5%) were negative by both of the S-ELISA and I-ELISA,with a resultant concordance rate of 99.1% of the two ELISA assays.However,the results of 17(0.9%) were not consistent in the two assays,in which 14 were S-ELISA negative but I-ELISA positive and 3 were S-ELISA positive but I-ELISA negative.One of the 14 samples(0.7%) with S-ELISA negative was detected as HCV RNA-positive,while 2 of the 3(66.7%) samples with S-ELISA positive were detected as HCV RNA-positive.In addition,HCV RNA was detectable in 23 of 31(74.19%) samples which were total anti-HCV positive in both S-ELISA and I-ELISA.Taking the PCR data together into account,the sensitivity of the S-ELISA and I-ELISA were 99.48% and 98.96% and specificity were 99.94% and 99.27%,respectively.Conclusions The established S-ELISA in this study may provide a novel means for detection of HCV antibody with high sensitivity and specificity.
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Objective:To find a short, neutralizing antibody-inducible, ORF2-encoded protein by means of comparing the immunogenicity of pN472-C617 and pN477-C613 which represent amino acids 472-617 and 477-613 of HEV ORF2-encoded protein of hepatitis E virus(HEV) genotype 4, respectively.Methods:The two recombinant proteins were expressed, purified, and then used to immunize BALB/c mice. Anti-HEV titers in the immune sera were detected by ELISA. Anti-HEV neutralizing activity was tested by a PCR-based in vitro neutralization assay.Results:Both of the two recombinant proteins were efficiently expressed in E.coli in soluble forms. The purified proteins induced mice to develop high levels of anti-HEV specific antibodies. However, only the immune sera obtained from the mice immunized with pN472-C617 showed the neutralizing activity to the homologous HEV strain by preventing the virus from absorption on PLC/PRF/5 cells surfaces and replication in the cells. The immune sera against pN477-C613, which was truncated five amino acids from both N- and C-terminal of pN472-C617, had no HEV neutralizing activity.Conclusion:The pN472-C617 is the shortest neutralizing antibody-inducible ORF2-encoded protein of HEV reported in literatures so far. It may be considered as a potential candidate for a novel HEV subunit vaccine in our future study.