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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Regulation und funktionelle Bedeutung der zellulären und humoralen Immunantwort in der Pathogenese der chronischen Hepatitis-C-Virusinfektion

Hempel, Gerd. January 2001 (has links) (PDF)
Mainz, Univ., Diss., 2001.
42

Klonierung und Charakterisierung eines Konsensusgenoms des Hepatitis-C-Virus als Grundlage der Etablierung eines Zellkultursystems

Körner, Frank. January 2001 (has links) (PDF)
Mainz, Univ., Diss., 2001.
43

Evaluation of Newer Drug Therapies for Hepatitis C at a Specialty Pharmacy

Garfunkel, Michelle, Hoehn, David, Thompson, Kayleen, Mathews, Kelly, Patel, Sarjit January 2016 (has links)
Class of 2016 Abstract / Objectives: To compare the SVR12 rates of newer hepatitis C therapies, approved between November 2013 and December 2014, in patients at Avella Specialty Pharmacy to SVR12 rates from published literature. Insurance coverage rates will be compared to determine a difference among insurances. Methods: Data were collected electronically from patient charts utilizing the existing computer system and manually through chart review. A complete data collection form in excel compiled the collected data and included the SVR12 rates by therapy, and sub-analysis data such as demographic and descriptive variables. Therapies included Harvoni, Olysio + Sovaldi ± Ribavirin (RBV), Viekira Pak ± RBV, or Sovaldi + RBV. Demographic and descriptive variables included gender, medical insurance, hepatitis C genotype, fibrosis score, treatment-experienced, treatment-naïve, and adverse effects. Insurance coverage rates were also collected through a separate electronic report. Results: A total of 578 patients were included in the analysis of SVR12 (mean age = 59, 60% male). There were 50% of patients with genotype 1a, 18% had cirrhosis, and 60% were treatment-naïve. The overall SVR12 rate achieved by patients at Avella was not significantly different from published clinical trials (91% vs 91%, p = 0.75). Data for coverage rates included a total of 6,284 patients and revealed that Medicare had the highest coverage rate (85%) while Medicaid had the lowest (30%). Conclusions: Newer hepatitis C therapies used in a real world setting had similar SVR12 rates to published literature. Medicaid had a lower coverage rate compared to Medicare and commercial insurances while Medicare had the highest coverage rate.
44

Epidemiology, molecular characterisation and tropism of the Hepatitis G Virus / GBV-C

Tucker, Timothy Johan Paul 14 July 2017 (has links)
The hepatitis G virus and GBV-C are recently discovered variants of the same virus belonging to the family Flavivirus (HGV/GBV-C). Although initially thought to be a hepatitis virus, it has been shown to have no association with liver disease. No work has been performed on the prevalence or molecular characteristics of HGV/GBV-C in southern Africa. In addition, although it is clear that the liver is not the primary site of replication, there is no data on the sites of HGV/GBV-C replication in normal subjects. Thus, this study aimed to assess the prevalence of HGV/GBV-C carriage in the urban and rural adult Black communities of the Western and Eastern Cape Provinces of South Africa, and compare it to the prevalence of serological markers of the hepatitis viruses A-E. In addition, this study aimed to assess the molecular features of South African HGV/GBV-C isolates and demonstrate the organs where viral replication was present. The mean prevalences of antibodies to hepatitis A lgG, hepatitis B surface antigen and antibodies to hepatitis B surface antigen were 98%, 4.3% and 61.1 % respectively. The mean prevalence of antibodies to hepatitis C was 1.8%. No significant differences in prevalence were shown between the urban and rural regions for these viruses. The mean anti-hepatitis E prevalence varied from 5.8% to 19.1 % in the different regions. Those living in mud houses without access to chlorinated tap water had a significantly higher prevalence of antihepatitis E. No anti-hepatitis D positive samples were isolated. The overall prevalence of HGV/GBV-C was 26.9%, with rural communities having a significantly lower prevalence than urban communities. A significant relationship was observed between HGV/GBV-C infection with the use of illicit drugs, female gender, younger age and past blood transfusions. Phylogenetic analysis demonstrated a novel fourth South African HGV/GBV-C genotype, distinct from the previously described genotypes 1-3. In addition, certain isolates showed a major deletion in the highly conserved 5' non-coding region of HGV/GBV-C. Analysis of 23 tissue biopsies from infected cadavers suggested that the spleen and bone marrow were the primary sites of HGV/GBVC replication.
45

DNA unwinding mechanism of the helicase from hepatitis C virus /

Levin, Mikhail Konstantinovich. January 2002 (has links)
No description available.
46

Influência da Resposta inflamatória na resposta virológica sustentada em pacientes com hepatite C crônica genótipo 1 durante o tratamento antiviral com terapia tripla

Winckler, Fernanda Cristina. January 2016 (has links)
Orientador: Giovanni Faria Silva / Coorientador: Marjorie de Assis Golim / Resumo: A hepatite C é uma doença infecciosa que torna-se crônica em cerca de 85% dos infectadosque poderão desenvolver cirrose e carcinoma hepato celular. O tratamento antiviral em muitosdos pacientes não é eficaz, principalmente quando estes portam o genótipo 1 e fibroseavançada, a resposta inflamatória também desempenha seu papel sobre a resposta virológicasustentada (RVS) durante o tratamento com Interferon Peguilado (PegIFN) associado aRibavirina (RBV). Nesse estudo nosso objetivo principal foi avaliar a influência da respostainflamatória através de células e citocinas/quimiocinas sobre a resposta virológica do pacienteem tratamento antiviral com terapia tripla. Incluimos pacientes com RNA VHC+, nuncatratados (naive), portadores do genótipo 1, ambos os sexos e com fibrose avançada F3 (n=6);F4 (n=21) candidatos ao tratamento em regime triplo. Os pacientes tiveram suas amostrascoletadas e analizadas nas semanas 0 e 12 do tratamento e os seguintes parâmetros foramanalisados: IL-2, IL-4, IL-6, IL-8, IL-10, IL-17A, TNF-α, IFN-γ, RANTES, MCP-1, MIG, IP-10, através de citometria de fluxo (método CBA). Foram incluídos 15 voluntários saudáveis(grupo controle) e 27 pacientes que foram separados em G1(RVS) e G2 (não RVS), a taxa deRVS foi de 63%. Os pacientes com hepatite C crônica tiveram os níveis circulantes de IP10,MCP-1, MIG, RANTES, IL-8 e IL-6 mais elevados quando comparados com voluntáriossaudáveis, quando comparados G1xG2 os níveis de RANTES (p=0,04... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
47

Investigating the modulation of viral translation by the Hepatitis C virus nonstructural protein 5A

2015 April 1900 (has links)
Hepatitis C virus NS5A is a multi-functional viral protein essential for viral replication and assembly, although the exact role the protein plays in the viral lifecycle remains unclear. A vast array of functions have been attributed to NS5A in recent years, despite the lack of enzymatic activity. NS5A has been found to interact with over 130 host proteins including many which are central to cellular signaling pathways. NS5A is composed of three domains separated by regions of low complexity. All three domains perform important functions in the viral lifecycle. Domains I and II are essential for viral replication whereas domain III is required for viral assembly. However, the role that NS5A and its individual domains may play in modulating viral translation remains controversial. Previous studies have utilized translation reporter systems that do not accurately reflect the role of the viral 3´-UTR in modulating viral translation. We and others have shown that NS5A binds to the poly-U/UC region of the 3´-UTR. In addition to serving as the initiation site for negative strand synthesis the 3´-UTR functions to significantly enhance viral translation. The mechanism of translation enhancement remains unclear but may involve long range RNA-RNA interaction with the IRES, the binding of cellular proteins which stimulate translation and/or the recycling of ribosomes. Therefore, the protein-RNA interaction between NS5A and the poly-U/UC region has the potential to modulate viral translation. Therefore we set out to determine the role of NS5A and its individual domains in modulating viral translation and the role of the NS5A-poly-U/UC region interaction in this modulation. Utilizing monocistronic RNA reporters which contain the viral 5´- and 3´-UTRs and an internal Renilla luciferase reporter gene, we determined that NS5A specifically down-regulates viral translation in a dose-dependent manner through a mechanism dependent upon the presence of the poly-U/UC region in the viral 3´-UTR. Furthermore, we have re-tested the effect using full-length HCV genomic RNA reporters. These results suggest that NS5A is able to interfere with the stimulation of viral translation exerted by the 3´-UTR. This down-regulatory function of NS5A may function in mediating a switch from translation to replication, a step required in the lifecycle of a positive sensed RNA virus. Having established a role for NS5A in modulating viral translation, we then aimed to determine which region of NS5A was responsible for this effect. We found that each of NS5A domains was capable of this modulatory effect on viral translation independently. Although surprising, this finding is not entirely unexpected as each domain has been shown to retain the ability to bind to the poly-U/UC region. Within NS5A domain I we identified a 61 aa. region sufficient for translation down-regulation. Furthermore, we have identified a number of positively charged residues within this region involved in the modulation of viral translation, in particular arginine 112 (R112). This residue has previously been found to be at the domain I dimer contact interface and to form an intermolecular hydrogen bond with glutamic acid 148 (E148). We found that mutations R112A and E148A individually negate the ability of domain I to modulate viral translation and these mutations impede the formation of domain I dimers. Additionally, the R112A mutation appears to affect the ability of domain I to interact with the poly-U/UC region of the viral 3´-UTR alluding to the possible mechanism of translation modulation. Finally this mutation was lethal in an HCV subgenomic replication, confirming the link between NS5A dimerization, RNA binding and viral replication. These results collectively point to a crucial role for the NS5A arginine 112 residue in the modulation of HCV lifecycle by NS5A. Within NS5A domain II, we identified a 47 aa. region sufficient for translation modulation. Through the mutation of positively charged amino acids within this region, we found that lysine 312 (K312) was essential for this effect. The ability of this domain to modulate viral translation was completely lost when K312 was mutated within a full domain II protein fragment. The mechanism behind this modulation remains unclear but the 47 aa. region identified has been previously found to contain a region proposed to make contact with poly-U RNA and the K312 residue was suspected to interact directly with such RNA. Furthermore, this region interacts with the host protein cyclophilin A, an interaction that enhances the RNA binding ability of domain II. These findings strongly suggest that domain II modulates viral translation by binding within the poly-U/UC region. While investigating the modulation of viral translation by NS5A domain III we determined that the C-terminal 31 aa. are sufficient for the effect of this domain on viral translation. Through alanine scanning mutagenesis we identified glutamic acid 446 (E446) as playing a key role in the modulatory function of this region. Within a domain III protein fragment mutation of this E446 residue abolishes the modulatory function of this domain towards HCV translation. The mechanism behind this modulation and the role of E446 in this effect remains to be determined. These findings suggest that in addition to being essential for viral replication and assembly, NS5A has an important role in modulating viral translation through a mechanism requiring the poly-U/UC region of the viral 3´-UTR. Furthermore, each domain of NS5A appears to contribute to this effect. These results support the description of NS5A as a multi-functional protein and the further characterization of its functions may aid in the development of novel antivirals targeting the numerous functions of this complex, and at times puzzling, viral protein.
48

Development of an intra- and intergenotypic HCV cell culture method to phenotype and assess antiviral susceptibilities and resistance development of HCV NS3 protease genes from HCV genotypes 1-6

Imhof, Ingrid January 2010 (has links)
The development of specific antiviral drugs directly targeting the hepatitis C virus (HCV) is clinically important, as the current standard interferon/ribavirin combination treatment is only partially effective, expensive and often associated with severe side effects. Inhibitors of the NS3 protease (PI) therefore represent a promising alternative or additional therapy. To date, the development and in vitro evaluation of PIs is restricted to the genotype 1/2 based replicon and the genotype 2a full length viral cell culture system. However, proteases of the different HCV genotypes vary substantially in their amino acid sequence and secondary structure and require separate evaluation of their efficacy before they go into clinical trials. To address this issue, a panel of intra- and intergenotypic recombinants based on the recombinant infectious clone Jc1 (pFK JFH1/J6/C-846) was developed in this work. The viability of these recombinants was assessed in the Huh7.5 cell culture system, where replicating viruses were detected by HCV-NS5A immunostaining. Intergenotypic recombinants containing genotype 1a, 1b, 3a, 4a and 6a derived proteases were replication defective, whereas the recombinant with genotype 5a derived protease replicated efficiently after acquiring cell culture adaptive mutations. The replacement of not only the NS3 protease gene region, but also its cofactor NS4A, allowed the generation of replication competent intra- and intergenotypic recombinants for all 6 major genotypes. Replacing the NS3 protease of the recombinants with that of patientderived proteases also generated replicating recombinants, greatly expanding the panel of intergenotypic recombinants available for phenotyping and PI evaluation. However, intra- and intergenotypic recombinants showed substantial differences in their replication kinetics, which may be influenced by naturally occurring polymorphism between genotypes and the differential requirement of adaptive/attenuating cell culture mutations. Genotype 1a recombinants replicated very poorly, which may be due to incompatibilities between the type 1a NS3/4A protease and the type 2a backbone. 50% inhibitory concentrations (IC50) of different PIs were measured using Foci Forming Units/ml (FFU/ml) reductions and replication inhibition assays. The different recombinants showed consistent, genotype-associated differences in their susceptibility to the PI BILN 2061, with genotypes 2a, 3a and 5a derived recombinants showing approximately 100-fold lower susceptibility than genotype 1b, 4a and 6a derived recombinants. These observations are consistent with major differences in response rates found in recent treatment trials of genotype 1, 2 and 3 infected patients. Differences in susceptibility were also observed for VX-950, with genotype 1b, 2a and 6a derived recombinants being twice as susceptible than genotype 3a, 4a and 5a derived recombinants. Passaging the intra- and intergenotypic recombinants under increasing concentrations of PI allowed the identification of PI resistance mutations. Resistance mutations to BILN 2061 mapped to the previously identified positions 156 and 168 within the NS3 protease, with a great diversity of amino acid substitutions observed within each genotype. Reintroduction of the identified resistance mutations into the original recombinant viruses conferred increased resistance towards BILN 2061 and some mutations also affected replication kinetics of the recombinants. The developed system will be of major value for the phenotypic characterisation of naturally occurring and treatment induced resistance mutations within all 6 major HCV genotypes towards different PIs. This will allow treatment response predictions for newly developed PIs before they enter clinical trials and the development of individually tailored antiviral treatment regimes.
49

Genotype specific peripheral lipid profile changes with hepatitis C therapy

Pedersen, Mark R, Patel, Amit, Backstedt, David, Choi, Myunghan, Seetharam, Anil B January 2016 (has links)
AIM To evaluate magnitude/direction of changes in peripheral lipid profiles in patients undergoing direct acting therapy for hepatitis C by genotype. METHODS Mono-infected patients with hepatitis C were treated with guideline-based DAAs at a university-based liver clinic. Patient characteristics and laboratory values were collected before and after the treatment period. Baseline demographics included age, ethnicity, hypertension, diabetes, hyperlipidemia, treatment regimen, and fibrosis stage. Total cholesterol (TCHOL), high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides (TG), and liver function tests were measured prior to treatment and ETR. Changes in lipid and liver function were evaluated by subgroups with respect to genotype. Mean differences were calculated for each lipid profile and liver function component (direction/magnitude). The mean differences in lipid profiles were then compared between genotypes for differences in direction/magnitude. Lipid profile and liver function changes were evaluated with Levene's test and student's t test. Mean differences in lipid profiles were compared between genotypes using ANOVA, post hoc analysis via the Bonferroni correction or Dunnett T3. RESULTS Three hundred and seventy five patients enrolled with 321 (85.6%) achieving sustained-viral response at 12 wk. 72.3% were genotype 1 (GT1), 18.1% genotype 2 (GT2), 9.7% genotype 3 (GT3). Baseline demographics were similar. Significant change in lipid profiles were seen with GT1 and GT3 (Delta GT1, p and Delta GT3, p), with TCHOL increasing (+ 5.3, P = 0.005 and + 16.1, P < 0.001), HDL increasing (+ 12.5, P < 0.001 and + 7.9, P = 0.038), LDL increasing (+ 7.4, P = 0.058 and + 12.5, P < 0.001), and TG decreasing (-5.9, P = 0.044 and -9.80 P = 0.067). Among genotypes (Delta GT1 v.Delta GT2 v.Delta GT3, ANOVA), significant mean differences were seen with TCHOL (+ 5.3 v. + 0.1 v. + 16.1, P = 0.017) and HDL (+ 12.3 v. + 2 v. + 7.9, P = 0.040). Post-hoc, GT3 was associated with a greater increase in TCHOL than GT1 and GT2 (P = 0.028 and P = 0.019). CONCLUSION Successful DAA therapy results in increases in TCHOL, LDL, and HDL and decrease in TG, particularly in GT1/ GT3. Changes are most pronounced in GT3.
50

ZUSAMMENHÄNGE KOGNITIVER FÄHIGKEITEN UND DER BEFINDLICHKEIT BEI PATIENTINNEN MIT HEPATITIS C AUS DER ANTI-D-KOHORTE

Klose, Lisa 02 November 2016 (has links) (PDF)
Diese Arbeit beschäftigt sich mit Zusammenhängen kognitiver Fähigkeiten und der Befindlichkeit bei Patientinnen mit Hepatitis C aus der sogenannten „Anti-D-Kohorte“. Die Frauen (n=2867) dieser spezifischen Gruppe wurden 1978/79 im Rahmen einer Anti-D-Immunprophylaxe mit dem Hepatitis C (1b) Virus infiziert. Häufig werden von Patienten, welche mit Hepatitis C infiziert sind, Beschwer-den wie Abgeschlagenheit, Ermüdung und Depressivität beklagt. In Studien wurden zudem Einschränkungen in der Kognition, insbesondere der Aufmerk-samkeit und des Gedächtnis festgestellt. Dazu wurden im Rahmen eines größeren Forschungsprojektes (Herzig et al in prep) 58 Hepatitis C Patientinnen und 25 gesunde Kontrollprobandinnen aus-gewählt. In dieser Arbeit werden die Ergebnisse der psychometrischen Testun-gen von Kognition und der Befindlichkeit vorgestellt und diskutiert. In den Komponenten Aufmerksamkeit und kognitive Flexibilität sowie in der Befindlichkeit konnten signifikante Unterschiede zur Kontrollgruppe nachgewiesen werden. Zudem fiel ein tendenzieller Vorteil antiviral therapierter Patientinnen und Patientinnen ohne nachweisbare Viruslast auf, sodass selbst HCV negative Frauen nicht als „gesund“ angesehen werden können und die Empfehlung zur medikamentösen Therapie aller viruspositiven Patientinnen besteht.

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