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A Sönnerborg

Publications and source records attributed to A Sönnerborg.

At least 91 records · Page 5Linked to original sources
PubMed1997

Detection of hepatitis G virus (GB virus C) RNA in human saliva.

Using PCR and genomic sequencing, we confirmed the presence of and homology between hepatitis G virus (HGV) (also called GB virus C) RNA in six serum samples and that in two saliva samples obtained from 34 patients with chronic hepatitis C virus infections. Thus, HGV may be found outside the circulatory system.

Amino Acid Sequence↗
PubMed1997

Subtyping of human immunodeficiency virus type 1 strains by using antibodies specific for the third variable domain (V3) of gp120: results may be affected by divergent V3 sequences.

Human immunodeficiency virus type 1 serotype C was found in 545 of 712 Ethiopian patients by peptide enzyme immunoassay. Serotyping failed in 146 samples due to the absence of V3 antibodies or multiple reactivities. In 6 of 34 samples, discordant results were obtained by serotyping and genotyping, possibly due to divergent V3 sequences.

Amino Acid Sequence↗
PubMed1996

Full-length sequence of an ethiopian human immunodeficiency virus type 1 (HIV-1) isolate of genetic subtype C.

Genetic subtype C of the human immunodeficiency virus type-1 (HIV-1) has established foci of infection in India and in at least eight African countries, and is expected to contribute significantly to the global pandemic. Here we report the first almost full-length sequence of a subtype C HIV-1 from Ethiopia. Clone C2220, 9031 nt in length, was derived by long PCR amplification of proviral DNA from virus cultured on primary peripheral blood mononuclear cells, and contains all but 74 nt of the unique sequence information of the HIV-1 genome. This clone resembles HIV-1 isolates of subtypes A, B, and D in its genome organization with one notable exception: the core promoter contains not two, but three potential binding sites for the transcription factor NF-kB. The extra NF-kB site was found in all other Ethiopian strains analyzed, as well as in subtype C viruses from Zambia, suggesting it is typical for the C-subtype of HIV-1. The phylogenetic relationship of C2220 to other HIV-1 isolates is also presented. Subtype C viruses circulating in Ethiopia exhibit the low interisolate diversity typical of other, newly established HIV-1 epidemics, and C2220 is both representative of Ethiopian subtype C viruses and a suitable prototype for the development of vaccines against HIV-1 subtype C.

Amino Acid Sequence↗
PubMed1996

A novel ribozyme target site located in the HIV-1 nef open reading frame.

We have tested the sequence UUC CAG UCA GAC CU, at position 9016--9029 within the HIV-1(SF2) nef open reading frame, for accessibility to antisense and hammerhead ribozyme attack. The accessibility was first studied using a phosphorothioate-modified 14-nt DNA oligo (complementary to the nef9016--9029 site). A dose-dependent repression of HIV-1(SF2) growth was observed in human peripheral blood mononuclear cells after exogenous administration of the oligo to the cell culture medium. A hammerhead ribozyme with a 6+7-nt antisense specificity for the nef9016--9029 site (hhRz.nef9016--9029) was constructed and transfected into the human T-cell line HUT78. Again, a dose-dependent repression of virus growth was observed when different individual clones expressing hhRz.nef9016--9029 were infected with HIV-1(SF2). A complete abrogation of virus production was observed after infection with a low (0.5 TCID50) HIV-1 titer. Increasing doses (2.5 and 12.5 TCID50) of HIV-1 virus yielded a low production (10(3)-fold reduced) of virus particles in most cases; but a complete, or close to complete, abrogation was observed even in individual cultures infected with the highest dose. Presence of proviral pol and gag sequences in hhRz.nef9016--9029-expressing HUT78 clones was assayed, using PCR. Interestingly, since no pol and gag PCR products could be detected, the results strongly indicated that the hammerhead ribozyme was already acting on the infecting HIV RNA before its reverse transcription and integration as proviral DNA. In summary, the results obtained in this study support the nef9016--9029 site as a strong new candidate for ribozymal gene therapy against HIV-1 infection.

Base Sequence↗
PubMed1996

Discrepancy of hepatitis C virus genotypes as determined by phylogenetic analysis of partial NS5 and core sequences.

The use of phylogenetic analyses of partial NS5 and core regions for hepatitis C virus (HCV) genotyping was evaluated by analysing seven Honduran and 24 European HCV strains. Core primers were designed with which HCV genotypes 1, 2, and 3 were readily amplified. The reliability of phylogenetic analysis of a 111-bp core sequence was verified by comparing the typing results with those obtained using the whole core gene of 52 reference strains. Accordant genotypes (1a, 1b, 2b, and 3a) were obtained when phylogenetic analyses were undertaken on both the partial core and a 222-bp NS5 sequence in all of the European HCV strains. Genotypes 1a, 1b, and 3a were identified among the Honduran strains by phylogenetic analysis of the partial NS5 sequence. Interestingly, two of three Honduran type 3a strains, as determined by the NS5 sequence analysis, turned out to be type 1a by core sequence analysis. These two strains were also classified as type 1a, but not 3a, by a core type-specific PCR. Furthermore, the E2/NS1 regions were similar to HCV-PT, a representative strain of genotype 1a. The results indicate that chimeral HCV strains exist, although in most cases a good concordance is found when phylogenetic analysis of partial core and NS5 sequences are used for genotyping. This finding should be taken into account when HCV is genotyped by phylogenetic analysis of a partial HCV sequence from a single genomic region.

Amino Acid Sequence↗
PubMed1996

Effect of N-acetylcysteine(NAC) treatment on HIV-1 infection: a double-blind placebo-controlled trial.

OBJECTIVE: In a double-blind placebo-controlled trial, human immunodeficiency virus (HIV)-seropositive patients with a CD4 lymphocyte cell count of more than 200 x 10(6) . l-1 were randomised to receive either 800 mg N-acetylcysteine (NAC) or placebo for 4 months. Before treatment low plasma cysteine levels, high free radical activity in neutrophils in the presence of autologous plasma-measured by the nitroblue tetrazolium (NBT) test- and increased tumor necrosis factor (TNF)-alpha levels were found in the HIV positive patients. RESULTS: After treatment the low plasma cysteine level in the NAC group increased to normal, and the decline of the CD4+ lymphocyte count before the study start, was less steep in the NAC group than in the placebo group after treatment. There was also a reduction in TNF-alpha level. However, NAC had no effect on the radical production by neutrophils, and although it did not increase the CD4+ cell count, it may have decreased the decline in CD4+ cells. CONCLUSION: Further controlled trials with NAC are needed to determine whether it has a beneficial effect in the treatment of asymptomatic HIV-infected individuals.

Acetylcysteine↗
PubMed1996

Site-directed serology of HIV-1 subtype B infection: relation between virus specific antibody levels and disease progression.

Activated T helper (Th) cell-dependent (TD) antibody responses were determined over an 8-10 year period in 28 patients infected with HIV-1 subtype B. Twelve patients remain asymptomatic with normal CD4+ cell counts for 101-114 months. These individuals were defined as long-term asymptomatic (LTA). Sixteen patients progressed to severe immunodeficiency within 58-120 months. In samples derived close to the diagnosis of HIV-1, CD4+ cell counts were higher among the LTAs (P < 0.01). Antibody production driven by activated Th cells was determined using peptides corresponding to HIV-1 V3US/Eur, gp41, and the hepatitis C virus (HCV) core proteins. The less Th cell-dependent B cell antibody response was represented by measles virus immunity. Close to HIV-1 diagnosis, variable third (V3), gp41, HCV core, and measles antibody titres were at similar levels among the LTAs and the progressors. With time the LTAs displayed unchanged levels of V3 and gp41 antibodies, and slightly decreasing levels of HCV core antibodies (P < 0.05). In contrast, the progressors showed a decrease in all these antibody responses (P < 0.05, for all). In both groups, the levels of measles antibody remained stable. Our data show that no significant change of the antibody responses of LTAs is seen, even after 101-114 months of known HIV-1 infection. Furthermore, the marked decrease of TD antibody production in the progressors suggests that activated Th cells may be excellent targets for HIV-1 infection.

Adult↗
PubMed1995

Long-term effects of hepatitis C virus infection in allogeneic bone marrow transplant recipients.

A total of 161 patients transplanted between 1978 and 1991 and who had survived at least 2 years after allogeneic bone marrow transplantation (BMT) were studied. Of 161 surviving patients, 28 (17.4%) were positive for hepatitis C virus (HCV) either by serology or polymerase chain reaction (PCR). Twenty-five patients were positive for HCV RNA by PCR, and 26 of the 28 patients had HCV antibodies detected by enzyme-linked immunosorbent assay (ELISA). The median follow-up time of HCV-positive patients was 6.1 years (range, 2.8 to 14.0 years). There was no difference in the frequency or degree of liver dysfunction between patients who were PCR-positive or -negative before BMT. Six patients developed severe liver dysfunction after BMT, and five of these patients did so after discontinuation or tapering of immunosuppression. No patient has developed liver failure. Serum transaminases were abnormal at the time of last follow up in 19 of 28 (68%) patients. Fifteen patients have had liver biopsies. No biopsy showed development of cirrhosis. We conclude that HCV is not a major contributing factor to morbidity and mortality during the first 5 to 10 years after allogeneic BMT.

Adolescent↗
PubMed1995

Evaluation of a multiple peptide assay for typing of antibodies to the hepatitis C virus: relation to genomic typing by the polymerase chain reaction.

A panel of 16 type-specific synthetic peptides corresponding to variable antigenic regions within the hepatitis C virus (HCV) core, nonstructural 4 (NS4), and NS5 proteins was synthesised. The peptide panel was used to develop an enzyme immunoassay (EIA) for the detection of antibodies directed to HCV type 1 (genotypes I/1a and II/1b), type 2 (genotypes III/2a and IV/2b), and type 3 (genotype V/3). The peptides corresponded to residues 68-81 of the HCV core (types 1, 2, and 3), residues 1692-1705 and 1710-1728 of HCV NS4 (types 1a, 1b, 2a, 2b, and 3), and residues 2303-2319 of HCV NS5 (types 1a, 1b, 2a, and 2b). The 16-peptide panel was evaluated using human sera from 46 carriers of HCV, which were genotyped in parallel by the polymerase chain reaction (PCR) using primers specific for types I, II, III, IV, and V of HCV core. Of the 46 carriers, 14 (30%) were infected by HCV genotype I, 7 (15%) by genotype II, 16 (35%) by HCV genotype IV, and 6 (13%) by HCV of genotype V. Two carriers had double infections of types I and II, and the HCV strain of one carrier could not be genotyped. Using the serotyping system, 40 (89%) out of the 45 genotyped carriers were found to contain type-specific antibodies corresponding to the genotypes identified by PCR. In 5 of the 23 carriers infected by genotypes I and/or II, antibodies specific for HCV type 1 could not be detected, whereas all 16 carriers infected by genotype IV were serologically typed as type 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

Detection of hepatitis C virus RNA in the cell fraction of saliva before and after oral surgery.

The presence of hepatitis C virus (HCV) RNA in serum, whole saliva, and saliva from the submaxillary glands was investigated before and after oral surgery. The presence of HCV RNA (positive and negative-strand RNA) was determined in serum and saliva by a nested polymerase chain reaction in 26 anti-HCV positive patients, of whom 11 were coinfected with human immunodeficiency virus-1. Oral surgery was carried out on five occasions on four of the patients. HCV RNA was detected in the sera of 23 of 26 (88%) patients, and in the saliva of 4 of the 23 (17%) of the viremic patients. In all four cases, HCV RNA was detected only in the cell fraction derived from centrifugation of whole saliva. Negative-stranded HCV RNA was not detected. At one of five occasions of oral surgery, HCV RNA was detected in saliva sampled immediately after surgery, but not before or 24 hours after surgery. The results suggest that HCV is present in saliva in less than 25% of HCV viremic persons. The presence of the virus in saliva is restricted to the cell fraction. Thus, saliva may serve as a possible, but low, nonparenteral transmission route of HCV. Contamination of saliva by blood during and after oral surgery may result in an increased risk of viral exposure. Except for trauma caused by sharp instruments during surgery, this might contribute to the higher HCV seropositivity found among dentists.

Dentists↗
PubMed1995

Combined treatment with interferon alpha-2b and ribavirin for chronic hepatitis C in patients with a previous non-response or non-sustained response to interferon alone.

Ten patients with chronic hepatitis C, six of whom had not responded and four of whom had responded in a non-sustained fashion to interferon-alpha treatment alone, were given interferon alpha-2b and ribavirin in combination during 24 weeks. Interferon alpha-2b was given subcutaneously, at a dose of 3 MU thrice weekly, together with ribavirin orally, at a dose of 1,000-1,200 mg/day. All four patients with a prior non-sustained response to interferon alone had normal alanine aminotransferase (ALT) levels at the end of treatment as well as during follow-up (> or = 24 weeks post treatment). Furthermore, all four lost serum HCV-RNA at the end of treatment and three continued to be negative during follow-up. Among patients with a prior non-response to interferon alone three of six had normal ALT levels at the end of treatment and one at follow-up. Two of six became HCV-RNA negative at cessation of treatment, one of whom was negative also at follow-up. All former non-sustained responders and one of six non-responder patients thus showed a sustained biochemical response with eradication of HCV-RNA from serum in all cases but one. It is concluded that combination therapy with interferon alpha-2b and ribavirin offers a chance of sustained biochemical response with eradication of the viremia in patients who have not shown a persistent response to interferon-alpha alone.

Adult↗