METHODS: Screening of genotypes was performed by enzyme immunoassay and/or polymerase chain reaction INVADER method in 222 patients with HBV. The full-length nucleotide sequences of unusual strains were compared to those in the database, followed by construction of a phylogenetic tree.
RESULTS: Unusual HBV strains were isolated from two patients: a 27-year-old Japanese bisexual man with acute hepatitis B with HIV co-infection and a 52-year-old Japanese man with chronic hepatitis B. The former strain was classified as genotype H, showing an overall identity of 99.8% to the Thailand strain (EU498228), while the nucleotide sequence of the latter strain showed similarity to the genotype B strains isolated in Malaysia (JQ027316) and Indonesia (JQ429079) between DR2 and DR1 in the X region, with identities of 96.9%. However, this strain was classified as genotype H by full-length sequence analysis, and the sequence between nt2023 and nt2262 showed no similarity to that in any previously reported strains.
CONCLUSION: HBV strains showing recombination between genotype B and H strains were found even in chronic hepatitis patients in Japan. Globalization may yield HBV strains of possible novel genotypes containing novel nucleotide sequences in the precore/core region.
MATERIALS AND METHODS: A total of 53 paired tissue samples from breast cancer patients were frozen-sectioned to characterize the tumour and normal tissues. Only tissues with 80% tumour cells were used in this study. For confirmation, Q-PCR was used to determine the HER-2/neu DNA amplification.
RESULTS: We found 20/53 (37.7%) of the tumour tissues to be positive for HER-2/neu protein overexpression using IHC. Out of these twenty, only 9/53 (17%) cases were in agreement with the Q-PCR results. The concordance rate between IHC and Q-PCR was 79.3%. Approximately 20.7% of positive IHC cases showed no HER-2/neu gene amplification using Q-PCR.
CONCLUSION: In conclusion, IHC can be used as an initial screening method for detection of the HER-2/neu protein overexpression. Techniques such as Q-PCR should be employed to verify the IHC results for uncertain cases as well as determination of HER-2/neu gene amplification.