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| 2. |
- Almroth, Gabriel, et al.
(författare)
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Monitoring Hepatitis C Infection in a Major Swedish Nephrology Unit and Molecular Resolution of a New Case of Nosocomial Transmission
- 2010
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Ingår i: Journal of Medical Virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 82:2, s. 249-256
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis C virus (HCV) infection is a frequent problem in hemodialysis units. The prevalence and incidence of HCV infection over a decade were studied in a nephrology unit affected by previous nosocomial HCV transmission. The HCV non-structural 5B protein gene was sequenced to achieve phylogenetic analysis of a new (incident) case of infection. Proportions of patients who were and were not infected with HCV remained similar over the period, as did the inflow and outflow of patients infected previously. In 1997, 12/157 (8%) of patients at the unit (treatment: hemodialysis, peritoneal dialysis, and renal transplant recipients) were positive in HCV RNA, whereas in 2007 the overall number was 9/239 (4%). One patient acquired an HCV infection, and the NS5B sequence in that case clustered with genotype 2b sequences found in patients from an earlier outbreak. Comparing the HCV from the incident patient with several stored longitudinal samples and cloned PCR products from the most likely source patient revealed close phylogenetic relationship with an HCV quasispecies member from the possible source. The source patient and the incident newly infected patient were not scheduled on the same dialysis shift, although the records showed that simultaneous treatment occurred on two occasions during the months preceding transmission. In conclusion, over the 10-year period, the proportion of HCV-infected patients at the unit was unchanged. Only one new infection occurred, which originated from a fellow patient's quasispecies. This establishes phylogenetic analysis as a valuable tool for tracing patient sources of HCV transmission. J. Med. Virol. 82:249-256, 2010. (C) 2009 Wiley-Liss, Inc.
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| 3. |
- Anagandula, Mahesh, et al.
(författare)
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Infection of Human Islets of Langerhans With Two Strains of Coxsackie B Virus Serotype 1 : Assessment of Virus Replication, Degree of Cell Death and Induction of Genes Involved in the Innate Immunity Pathway
- 2014
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 86:8, s. 1402-1411
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes mellitus is believed to be triggered, in part, by one or more environmental factors and human enteroviruses (HEVs) are among the candidates. Therefore, this study has examined whether two strains of HEV may differentially affect the induction of genes involved in pathways leading to the synthesis of islet hormones, chemokines and cytokines in isolated, highly purified, human islets. Isolated, purified human pancreatic islets were infected with strains of Coxsackievirus B1. Viral replication and the degree of CPE/islet dissociation were monitored. The expression of insulin, glucagon, CXCL10, TLR3, IF1H1, CCL5, OAS-1, IFN beta, and DDX58 was analyzed. Both strains replicated in islets but only one of strain caused rapid islet dissociation/CPE. Expression of the insulin gene was reduced during infection of islets with either viral strain but the gene encoding glucagon was unaffected. All genes analyzed which are involved in viral sensing and the development of innate immunity were induced by Coxsackie B viruses, with the notable exception of TLR3. There was no qualitative difference in the expression pattern between each strain but the magnitude of the response varied between donors. The lack of virus induced expression of TLR3, together with the differential regulation of IF1H1, OAS1 and IFN beta, (each of which has polymorphic variants influence the predisposition to type 1 diabetes), that might result in defective clearance of virus from islet cells. The reduced expression of the insulin gene and the unaffected expression of the gene encoding glucagon by Coxsackie B1 infection is consistent with the preferential beta-cell tropism of the virus.
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| 4. |
- Ayukekbong, James, et al.
(författare)
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Enteric viruses in healthy children in Cameroon: viral load and genotyping of norovirus strains.
- 2011
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Ingår i: Journal of medical virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 83:12, s. 2135-42
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Tidskriftsartikel (refereegranskat)abstract
- Data regarding prevalence of noroviruses (NoVs) among asymptomatic persons are scarce. The current study carried out on samples from Cameroon describes the asymptomatic shedding of NoVs and other enteric viruses in healthy children and in adults infected with HIV but lacking symptoms of gastroenteritis. Enteric viruses were common with a prevalence of 53.7% in the children, and 35.5% in the adult participants. Multiple enteric viruses (2-5 agents) were detected in fecal samples from 65% of the children, and co-infection with NoV was demonstrated in almost all cases of multiple infections. NoV viral loads in the healthy children were within disease causing range and significantly higher than those observed in the adults (P<0.01). Sequencing and genotyping of NoV strains by phylogeny showed a marked diversity within two distinct genogroups, GI and GII, and strains clustered with genotypes GI.3, GII.17, GII.8, and GII.4. Genetic similarities to recent outbreak strains from other continents suggest a rapid circulation of NoVs that includes healthy children, who may constitute a reservoir for pathogenic NoVs.
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| 6. |
- Berg, Anna-Karin, et al.
(författare)
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Enterovirus Markers and Serum CXCL10 in Children With Type 1 Diabetes
- 2010
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 82:9, s. 1594-1599
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Tidskriftsartikel (refereegranskat)abstract
- Most patients with type 1 diabetes are considered to have a T-cell mediated autoimmune disease. The chemokine CXCL10 promotes the migration of activated T-cells. Virus infections might contribute to the pathogenesis of type 1 diabetes and enterovirus protein and/or genome have been detected in beta-cells from a majority of tested newly diagnosed children with type 1 diabetes. The chemokine CXCL10 is induced in human islet cells by enterovirus infections in vivo and in vitro, but is not expressed in islets from normal organ donors. Since CXCL10 is a chemokine known to be induced by virus infections and/or cellular damage, our aim was to study if levels of CXCL10 are elevated in serum from children with type 1 diabetes and whether it correlates to the presence of enterovirus markers. CXCL10, neutralizing antibody titer rises against certain enterovirus, and antibodies against GAD65 were measured in serum, and enterovirus PCR was performed on whole blood from 83 type 1 diabetes patients at onset, 48 siblings and 69 controls. CXCL10 was also measured in serum from 46 patients with proven enterovirus infection and in serum from 46 patients with other proven virus infections. The CXCL10 serum levels were not elevated in children at onset of type 1 diabetes and there was a considerable overlap between the groups with 99(8-498) pg/ml in serum from children with type 1 diabetes, 120 (17-538) pg/ml in serum from controls, and 117 (7-448) pg/ml in siblings of the children with type 1 diabetes. The CXCL10 serum levels in patients with proven enterovirus infection were slightly increased compared to the levels in the other groups, 172 (0-585) pg/ml but there was no statistically significant difference. In contrast, CXCL10 serum levels in patients with other proven virus infections were clearly elevated 418 (34-611) pg/ml. Despite that elevated CXCL10 levels have been demonstrated in some groups of patients with type 1 diabetes, in this study the mean CXCL10 serum levels were not elevated in patients with type 1 diabetes neither in patients with proven enterovirus infection. In contrast, in patients with other virus infections the CXCL10 levels were elevated, presumably reflecting the severity or the site of infection. This suggests that local production of CXCL10 in the affected organ cannot be measured reproducible in serum and that its potential use in clinical practice is limited.
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| 7. |
- Chatterjee, Koushik, et al.
(författare)
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A Fas Gene Polymorphism Influences Herpes Simplex Virus Type 2 Infection in South African Women
- 2010
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 82:12, s. 2082-2086
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 2 (HSV-2) is a common sexually transmitted infection (STI) worldwide that causes genital infection. Among several factors responsible, host genetic factors may play an important role in susceptibility to HSV-2 infection. Apoptosis is a vital mechanism in eliminating virus-infected cells and controlling viral infections. Apoptosis can be regulated and triggered by the interaction between Fas and Fas Ligand (FasL). Polymorphisms in genes encoding Fas and FasL might result in altered apoptosis and contribute in susceptibility to viral infections. Two polymorphisms in Fas gene (FasR-1377G > A, FasR-670A > G) and one in FasL gene (FasL-844T > C) have been well studied and associated with different diseases. These polymorphisms were investigated in 407 South African women of black African and mixed-ancestry origin to determine if they were associated with HSV-2 seropositivity. Two hundred sixty-five women were HSV-2 infected and 142 were non-infected. HSV-2 was detected using HerpeSelect ELISA test and genotyping was performed using TaqMan assay. FasR-1377A allele showed a statistically significant association (P = 0.008) with reduced risk of HSV-2 infection. Analyzing the FasR haplotypes also showed a statistically significant association (P = 0.0001) with FasR-1377/FasR-670 AG haplotype and reduced risk of HSV-2 infection. There was no significant association found with FasR-670A > G and FasL-844T > C polymorphisms and risk of HSV-2 infection. This is, to our knowledge, the first time a non-HLA genetic link with HSV-2 infection has been reported.
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| 8. |
- Hamalainen, Sanna, et al.
(författare)
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Coxsackievirus B1 Reveals Strain Specific Differences in Plasmacytoid Dendritic Cell Mediated Immunogenicity
- 2014
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 86:8, s. 1412-1420
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Tidskriftsartikel (refereegranskat)abstract
- Enterovirus infections are usually mild but can also cause severe illnesses and play a role in chronic diseases, such as cardiomyopathies and type 1 diabetes. Host response to the invading virus can markedly modulate the course of the infection, and this response varies between individuals due to the polymorphism of immune response genes. However, it is currently not known if virus strains also differ in their ability to stimulate the host immune system. Coxsackievirus B1 (CBV1) causes severe epidemics in young infants and it has recently been connected with type 1 diabetes in seroepidemiological studies. This study evaluated the ability of different field isolates of CBV1 to induce innate immune responses in PBMCs. CBV1 strains differed markedly in their capacity to induce innate immune responses. Out of the 18 tested CBV1 strains two induced exceptionally strong alpha interferon (IFN-alpha) response in PBMC cultures. The responding cell type was found to be the plasmacytoid dendritic cell. Such a strong innate immune response was accompanied by an up-regulation of several other immune response genes and secretion of cytokines, which modulate inflammation, and adaptive immune responses. These results suggest that enterovirus-induced immune activation depends on the virus strain. It is possible that the immunotype of the virus modulates the course of the infection and plays a role in the pathogenesis of chronic immune-mediated enterovirus diseases.
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| 9. |
- Hammarin, Anna-Lena, et al.
(författare)
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Systematic Screening of BK Virus by Real-Time PCR Prevents BK Virus Associated Nephropathy in Renal Transplant Recipients
- 2011
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Ingår i: Journal of Medical Virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 83:11, s. 1959-1965
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Tidskriftsartikel (refereegranskat)abstract
- BK virus associated nephropathy occurs in approximately 5% of renal transplant recipients. Quantitation of BKV DNA in serum/plasma early in the course of disease has been suggested to be an important diagnostic tool for polymavirus-associated nephropathy (PVAN). The aim of this study was to develop a BKV real-time PCR (qPCR), which could be included in a diagnostic qPCR platform. Additionally, the significance of the assay as a surrogate marker for PVAN was investigated. Quantitation of BKV DNA by qPCR was carried out on 234 serum samples from a retrospective study including 31 renal transplant recipients monitored for at least 6 months post-transplantation. BKV viremia was detected in 9 out of 31 patients. Four patients had a viral load of >10,000 copies/ml at least on one occasion. In two of these patients, PVAN was diagnosed clinically during the study period. In retrospect, these patients were shown to be BKV positive before the clinical diagnosis of PVAN was made. Another two patients had a permanent graft dysfunction, but were never clinically diagnosed with PVAN. None of the remaining five patients with BKV DNA (<10,000 copies/ml) had renal impairment. Based on these results, an algorithm was introduced at the study center in 2006 and to date, August 2011, no cases of PVAN with loss of graft have been observed. The concept of including different PCR protocols in a common qPCR platform allows laboratories with small sample numbers to perform regularly a variety of assays at a reasonable cost. Med. Virol. 83:1959-1965, 2011. (C) 2011 Wiley-Liss, Inc.
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