ABSTRACT
In order to investigate the distribution of Hepatitis C virus (HCV) genotypes in Thailand, we performed phylogenetic analysis based on the virus core region and in this way we identified and reliably distinguished HCV genotypes 1-6 as well as subtypes. Among 100 plasma samples randomly selected from blood donors positive for antibodies to HCV (anti-HCV) 90 (90%) were found positive for HCV RNA and 77 of them were subjected to nucleotide sequencing. The following types and subtypes were identified in this group: 1a in 16 samples (20.8%), 1b in 14 samples (18.2%), 3a in 29 samples (37.7%), 3b in 5 samples (6.5%), and 6a in 13 samples (16.9%). Although this study allowed identification and characterization of HCV among blood donors, more extensive studies are needed to explore the HCV distribution in other population groups and in other geographical regions and to exploit the virus core-based characterization of HCV for evaluation of treatment and clinical outcome and epidemiological purposes.
Subject(s)
Blood Donors , Hepacivirus/genetics , Hepatitis C/virology , Blood Donors/statistics & numerical data , Hepacivirus/isolation & purification , Hepatitis C/epidemiology , Humans , Phylogeny , Prevalence , Thailand/epidemiology , Viral Core Proteins/analysis , Viral Core Proteins/geneticsABSTRACT
TT virus (TTV) is not only an infectious agent of worldwide distribution but has also been demonstrated in various non-human primates in addition to humans. In the present study, we subjected the sera of 67 gibbons to PCR and nucleotide sequencing, with subsequent phylogenetic analysis to determine the nature of the relationship between TTV found in humans and non-human primates. We discovered the virus in 9/67 (13.4%) of the gibbon sera and subjected 6 of those to direct sequencing. The phylogenetic tree constructed encompassed all TTV species known to date, revealing a close proximity between the gibbon virus and those detected in Thai individuals, whereas the chimpanzee strains were phylogenetically more remote.
Subject(s)
DNA Virus Infections/veterinary , Hylobates/virology , Torque teno virus/genetics , Animals , Base Sequence , DNA Virus Infections/virology , DNA, Viral/chemistry , DNA, Viral/genetics , DNA, Viral/isolation & purification , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction/veterinary , Sequence Alignment , Sequence Analysis, DNA , Thailand , Torque teno virus/chemistryABSTRACT
An 11-year-old Thai boy who had received multiple blood transfusions from 12 different donors for treatment of Dengue shock syndrome presented with symptoms of acute hepatitis 5 weeks thereafter. He was found positive for antibodies to hepatitis C virus (HCV) and HCV-RNA was detected by reverse transcription PCR (RT-PCR). When his alanine aminotransferase (ALT) level peaked at 1,879 U/l in the 8th week, interferon therapy (3 million units, thrice weekly for 6 months ) was initiated. After initially decreasing to tenfold the normal level, the ALT dropped to fivefold the normal level at 6 months. HCV RNA is still detectable in his serum 6 months later. Using RT-PCR and subsequent restriction fragment length polymorphism (RFLP) analysis we identified one of the donors as harboring HCV genotype 3a, identical to that found in the patient. Moreover, polymorphism analysis on the hypervariable region employing five distinct restriction endonucleases suggested this donor as the source of infection. We hence recommend thorough screening of all blood donors as the only means of prevention presently feasible.
Subject(s)
Antibodies, Viral/blood , Carrier State/virology , Hepacivirus/classification , Hepatitis C/virology , Transfusion Reaction , Carrier State/diagnosis , Child , Gene Amplification , Genotype , Hepacivirus/genetics , Hepacivirus/immunology , Hepatitis C/diagnosis , Humans , Male , Polymorphism, Restriction Fragment Length , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction , Severe Dengue/therapyABSTRACT
Results obtained from studies using experimental animal model clearly showed that (1) A marker(s) for CCA does exist; 2) This marker is a glycoprotein with a molecular weight of 200 kDa; (3) It is produced and secreted in vitro by tumor cell lines; (4) It is highly immunogenic in mice and the MAb specific for this antigen is directed against the carbohydrate moiety; (5) This tumor antigen can be detected in serum and bile of tumor-bearing animals by a sandwich ELISA employing this MAb; (6) Kinetic studies show a gradual elevation of this antigen during tumor development; and (7) The elevation of this antigen can be detected at a time when no pathological changes have yet taken place, as judged by microscopic examination. Preliminary work from the human counterpart using human cholangiocarcinoma cell line showed promising results. CCA-specific antigen could be similarly identified and the MAbs produced were highly specific for this 160 kDa antigen.
