Biomedical subjects

H Triki

Publications and source records attributed to H Triki.

30 records · Page 2Linked to original sources

PubMed1990

cDNA cloning and transient expression of the Epstein-Barr virus-determined nuclear antigen EBNA3B in human cells and identification of novel transcripts from its coding region.

Recombinant plasmids containing sequences from the BamHI-E rightward reading frames 2a and 2b (BERF2a and 2b) of the Epstein-Barr virus (EBV) genome were isolated from a library of cDNA clones which had been previously made from the EBV B95-8 lymphoblastoid cell line (M. Bodescot, O. Brison, and M. Perricaudet, Nucleic Acids Res. 14:7103-7114, 1986). The characterization of these clones in combination with RNase mapping experiments led to the identification of one leftward and several rightward transcripts traversing the EBV-determined nuclear antigen EBNA3B coding region. One cDNA (T7) contains a continuous open reading frame generated by the splicing together of BERF2a and BERF2b. The T7 clone was used to reconstruct a complete fused BERF2a/2b open reading frame in an adenovirus-based expression vector. Western immunoblotting and immunofluorescence experiments using human 293 cells showed that the recombinant plasmid is capable of expressing a protein with a size, immunological characteristics, and a subcellular localization indistinguishable from those of native B95-8 EBNA3B.

Amino Acid Sequence↗

PubMed1974

[Not Available].

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Diet↗

PubMed1974

[Not Available].

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Diet↗

PubMed1973

[Not Available].

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Demography↗

PubMedDate not supplied

Seroepidemiology of hepatitis B, C and delta viruses in Tunisia.

Serum samples from 33,363 healthy people in Tunisia have been tested for serological markers of hepatitis B, C and delta viruses (HBV, HCV and HDV). Hepatitis B surface antigen (HBsAg) was detected in 6.5% of sera. The overall seroprevalence of HBV was 37.5%. Vertical and perinatal transmission of HBV in the first 3 months of life occurred in only 0.4% of 177 mother and child pairs. HBV seroprevalence was 10.7% in infants under 5 years old and increased with age rapidly till 25 years of age and then more slowly in adulthood, reaching 54% for people aged over 40 years. HBsAg seropositivity varied throughout the country, ranging from 3% to 13% with higher prevalences in the south and central-west regions. Overall seroprevalences for HDV and HCV were 17.7% and 0.4%, respectively. HDV superinfection occurred later than HBV and increased with age in parallel with HBV. Overall, HCV and HBV infections had different geographical distributions throughout the country. The study confirmed the high prevalence of HBV infection in Tunisia; it occurs mainly in children and teenagers, and vertical and perinatal transmission of HBV does not appear to be significant. HDV superinfection is quite common in Tunisia and occurs in almost 44% of individuals infected with HBV. In contrast, seroprevalence of HCV in the Tunisian general population was low (0.4%). These results indicate differences in the distribution of the viruses and/or different routes of transmission.

Adolescent↗

PubMedDate not supplied

[The isolated presence of anti-HBc antibodies: prevalence and interpretation based on the results of viral DNA research and anti-HBs antibodies measurement after vaccination].

In order to study the significance of the isolated presence of anti-HBc antibodies, we have looked for the 3 classic serological markers of the hepatitis B (HBs antigen, anti-HBs and anti-HBc antibodies) in 1,586 hospital agents who are to vaccinate in the framework of a campaign of systematic vaccination of the hospital personnel of university hospitals of Sfax for a period of 18 months. We identified subjects who presented isolated anti-HBc antibodies (33 individuals = 2.08%). In these subjects'serum, we performed a research of the DNA of hepatitis B virus (HBV) with a PCR hybridization technique using a couple of primers. One week after administration of a vaccine dose, we also measured anti-HBs antibodies in their sera. Among the tested 18 personnel with anti-HBc isolated antibodies, 11.1% had low rates of anti-HBs antibodies indicating that there is presumably primary antibody response and therefore a false positivity of anti-HBc antibodies in pre-vaccinal serology; while 11.1% others had higher rates of anti-HBs antibodies corresponding to a secondary antibody response, which witness a previous HBV immunisation. The research of the HBV-DNA was positive in 11.1% of tested personnel, testifying a presumably chronic portage of the virus with low rates of the HBs antigen undetectable with the serological techniques. For the remainder subjects with isolated anti-HBc antibodies (66.7%), the interpretation remains ambiguous.

DNA, Viral↗

PubMedDate not supplied

[Comparison of different methods of hepatitis C virus genotyping].

In order to introduce the approach of HCV genotyping in our laboratory, a comparative study of 3 molecular and 1 serological methods, was conducted on 62 HCV RNA positive sera. The molecular genotyping methods target the 5'untranslated (UTR) region of the virus genome and are based on an amplification of the viral genome, followed by partial sequencing, analyses of restriction fragment length polymorphisms (RFLP) or molecular hybridation (Inno LiPA, Innogenetics). The serological method or serotyping is based on the detection of antibodies to genotype specific epitopes derivated from the Non Structural (NS) 4 region of the viral genome (HCV 1-6 Serotyping Assay, Murex Biotech). "In house" methods, sequencing and RFLP, identified the genotype for 13 samples classified as non-typables by commercial kits Inno LiPA test and HCV 1-6 Serotyping Assay. Mixed infections revealed, especially by Inno LiPA, could not be identified by partial sequencing, which seems to detect only predominant genotype. For 4 samples, genotyping results of the methods targeting the 5'UTR were discordant with those of the serotyping of the NS4 region. Commercial kits are efficient to determine HCV genotypes, particularly in the context of antiviral therapy and patient's follow-up, sequencing remains the best alternative for more complete characterisation of viral strains and for epidemiological investigations.

Genotype↗

PubMedDate not supplied