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Articles by H. L.Y Chan
Total Records ( 2 ) for H. L.Y Chan
  J Luan , J Yuan , X Li , S Jin , L Yu , M Liao , H Zhang , C Xu , Q He , B Wen , X Zhong , X Chen , H. L.Y Chan , J. J.Y Sung , B Zhou and C. Ding
 

Background: Variations in the hepatitis B virus (HBV) genome may develop spontaneously or under selective pressure from antiviral therapy. Such variations may confer drug resistance or affect virus replication capacity, resulting in failure of antiviral therapy.

Methods: A duplex PCR was used to amplify the region of the reverse transcriptase gene, the precore promoter, and the basal core promoter of the HBV genome. Four multiplex primer-extension reactions were used to interrogate 60 frequently observed HBV variants during antiviral therapy. Automated MALDI-TOF mass spectrometry (MS) was used for mutation detection. Capillary sequencing was used to confirm the MS results.

Results: The limit of quantification was 1000 HBV copies/mL for multiplex detection of HBV variants. Fifty-three variants (88.3%) were analyzed successfully in at least 90% of the sera from 88 treatment-naive patients and 80 patients with virologic breakthrough. MS was able to detect twice as many minor variants as direct sequencing while achieving close to full automation. MS and direct sequencing showed only 0.1% discordance in variant calls.

Conclusions: This platform based on multiplex primer extension and MALDI-TOF MS was able to detect 60 HBV variants in 4 multiplex reactions with accuracy and low detection limits.

  R. W.Y Chan , J Wong , H. L.Y Chan , T. S.K Mok , W. Y.W Lo , V Lee , K. F To , P. B.S Lai , T. H Rainer , Y.M. D Lo and R. W.K. Chiu
 

Background: We hypothesized that liver-derived mRNA, such as ALB (albumin) mRNA, would be released into human plasma with liver cell death.

Methods: We genotyped ALB mRNA molecules in samples of plasma and whole blood from liver and bone marrow transplant recipients by RNA single-nucleotide polymorphism analysis. Plasma and whole blood ALB mRNA genotypes were compared with the DNA genotypes of the recipients and donors. A reverse-transcription quantitative real-time PCR assay was used to measure plasma ALB mRNA concentrations in 107 patients [hepatocellular carcinoma (HCC), cirrhosis, or chronic hepatitis B (CHB)] and 207 healthy controls.

Results: The RNA genotype data revealed ALB mRNA in plasma to be liver derived, whereas tissue compartments other than the liver also contributed to the ALB mRNA detected in whole blood. Statistically significant increases in plasma ALB mRNA concentrations were observed for HCC, cirrhosis, and active CHB, compared with controls. A cutoff of 835 copies/mL of plasma ALB mRNA identified by ROC curve analysis showed 85.5% diagnostic sensitivity and 92.8% diagnostic specificity for the detection of liver pathologies. Only 21.5% of patients with liver pathologies had increased alanine aminotransferase (ALT) activities, whereas 73.8% had increased plasma ALB mRNA concentrations. Only 48.6% of the HCC patients had increased serum -fetoprotein concentrations, whereas 91.4% had increased plasma ALB mRNA concentrations.

Conclusions: ALB mRNA is liver specific in plasma, but not in whole blood. Plasma ALB mRNA is increased in some liver pathologies and may be more diagnostically sensitive than -fetoprotein and ALT.

 
 
 
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