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Continuum of care in hepatitis C screening and treatment: a survey among clients of low-threshold programs for people who use drugs
Věžníková, Martina ; Mravčík, Viktor (advisor) ; Janíková, Barbara (referee)
Background: Half of the people with hepatitis C virus infection in the Czech Republic are injecting drug users. Low-threshold harm reduction-based treatment programs are an important pillar in the prevention and elimination of hepatitis C virus (HCV);and for the continuity of care, it is essential to actively search for people with the infection (high rate of testing) and to follow up with further diagnosis and treatment.Identifying and responding to client barriers is necessary to maintain the continuum of care. Objectives: Theaim of the bachelor thesis was to describe the continuum of care in case of hepatitis C virus in clients of an outpatient and outreach programme for substance abusers in a low-threshold centre in Jihlava, from anti-HCV antibody screening to treatment entry and completion, and to describe the factors that influence the continuum of care. Methods: In June and July 2022, aquantitative analysis of existing data was conductedamong clients of a low-threshold facility for drug users in Jihlava. For the monitored period from 2017 to 2021, 243 clients of the outpatient program and 171 clients of the outreach program were included in the research. The obtained data were analysed in Microsoft Excel using descriptive statistics. Results: The research shows that 81 (33 %) clients of the...
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Molecular diagnostics of hepatitis C in a selected group of patients
KALINAYOVÁ, Daniela
This bachelor thesis deals with the occurrence of hepatitis C and its detection focused on direct evidence of the virus. The theoretical part describes and divides hepatitis C into acute and chronic, focuses on its genetic variability and explains how this virus behaves, is transmitted and mutated. Mutation creates other variants of it, which must be distinguished from each other if we want to set up an effective treatment. The practical part gives us information about the incidence of HCV among men and women, which are clearly divided in tables according to the year of birth, positivity and negativity. It also deals with the determination of a given genotype / subtype.
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Effect of ADAR1 enzyme on hepatitis C virus life cycle
Kubů, Martin ; Vopálenský, Václav (advisor) ; Fraiberk, Martin (referee)
Hepatitis C virus (HCV) is a virus of the family Flaviviridae whose genome consists of ,,+RNA" molecule. It causes the disease hepatitis Cepatitida typu C, which affects tens of millions of people worldwide. Although there is an effective treatment for this type of hepatitis, a preventive vaccine against the HCV virus has not yet been developed. Several ambigious works focused on the relationship between HCV and the enzyme adenosine deaminase acting on double-stranded RNA 1 (ADAR1) were published in the past. This dimeric double-stranded RNA binding enzyme is a part of innate immunity and causes catalytic conversion of adenosine to inosine, which is recognized by cellular mechanisms as guanine, which ultimately leads to mutations in the affected dsRNA molecule. The works published so far attribute an antiviral function to the ADAR1 enzyme in the context of HCV infection. However, vectors containing the entire HCV genome were not used in these works, and a cell line with deletion od the ADAR1 gene has never been used so far. The actual relationship between the ADAR1 enzyme and the HCV virus has not yet been reliably verified. The aim of this thesis was to gain a deeper understanding of the relationship between the HCV virus and the ADAR1 enzyme. For this task, HCV permissive Huh7.5 cell lines with...
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Novel hepatitis C virus proteins
Zeman, Jakub ; Vopálenský, Václav (advisor) ; Horníková, Lenka (referee)
The hepatitis C virus (HCV) is a major etiological agent of chronic liver diseases. More than 170 million people worldwide are chronically infected, and more than 100 thousand of them develop hepatocellular carcinoma a year. HCV is an enveloped, positive-sense single-stranded RNA virus (+ssRNA virus) of the family Flaviviridae. Its genome is translated to produce a single polyprotein precursor that is further processed by cellular and viral proteases to form 10 viral proteins. Moreover, there is another protein encoded in an alternative reading frame. Two alternative translation mechanisms have been proposed for expression of this alternative reading frame protein (ARFP): a frameshift mechanism and translation initiating from internal start codons. Despite ten years of research its role in vivo is not yet explained. It appears that secondary structures in the core encoding region of HCV genome but not ARFP expression are required for robust viral translation and replication. The results of recent studies suggest that mutations distorting these structures may result not only in slowing down the viral cycle but also in a brand new and utterly unusual serological profile in patients as well as an increased level of expression of ARFP.
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Screening for the HCV IRES interacting proteins
Roučová, Kristina ; Pospíšek, Martin (advisor) ; Kuthan, Martin (referee)
Hepatitis C virus (HCV) is a worldwide spread pathogen infecting up to 3 % of the human population. Nowadays, research of new drugs against this virus is focused on the individual steps in its life cycle, including the translation initiation. In the case of HCV translation initiation is dependent on the internal ribosome entry site (IRES). Besides of components of the translational machinery also other components of the cell, so called IRES trans-acting factors (ITAF), contribute to its proper progress. This work continues in previous research of our laboratory focused on searching for new ITAF. In order to search for potential ITAF increasing HCV IRES activity new recombinant plasmid vectors and reference strains were prepared and selection conditions of the selection system were optimized. The differences in the growth characteristics of the reference strains were analyzed and quantified under selective and non-selective conditions. A set of pilot high efficiency transformations of the yeast strain pJ69-4A carrying bicistronic construct with HCV IRES were conducted using human expression cDNA library in order to optimize the efficiency of transformation and selection conditions and to attempt to identify new ITAF. Several dozens of randomly selected clones from these transformations obtained under...
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Exosomes in viral infection and cancer
Sekavová, Alžběta ; Španielová, Hana (advisor) ; Hirsch, Ivan (referee)
Exosomes facilitate intercellular communication and transport of cellular cargo. Understanding the mechanisms underlying the cargo sorting to exosomes and the transport itself is crucial for vaccine development and diagnostic research. Exosome-mediated transfer contributes to immune response as well as progression of several diseases, including cancer and viral infections. Research on exosomes and their role in life cycles of tumorigenic viruses links already known mechanisms of viral carcinogenesis to the transport mechanisms of both cellular and viral proteins and nucleic acids. Epstein-Barr virus employs exosomes for transmission of the LMP1 oncoprotein and regulatory RNAs, whereas human immunodeficiency virus exploits cellular exosomal pathway for hijacking its membrane during budding, which helps it evade the immune system. It has been discovered that hepatitis C virus transfers its infectious virions between cells in exosomes. Exosomes containing oncoproteins and viral RNAs are also released from cells infected with other human tumorigenic viruses. However, mechanisms and implications of such events remain to be discovered. Keywords: exosome, cancer, viral infection, tumorigenic viruses, immunity, in- tercellular communication, hepatitis C virus, Epstein-Barr virus, human immuno- deficiency virus
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Exosomes in viral infection and cancer
Sekavová, Alžběta ; Španielová, Hana (advisor) ; Hirsch, Ivan (referee)
Exosomes facilitate intercellular communication and transport of cellular cargo. Understanding the mechanisms underlying the cargo sorting to exosomes and the transport itself is crucial for vaccine development and diagnostic research. Exosome-mediated transfer contributes to immune response as well as progression of several diseases, including cancer and viral infections. Research on exosomes and their role in life cycles of tumorigenic viruses links already known mechanisms of viral carcinogenesis to the transport mechanisms of both cellular and viral proteins and nucleic acids. Epstein-Barr virus employs exosomes for transmission of the LMP1 oncoprotein and regulatory RNAs, whereas human immunodeficiency virus exploits cellular exosomal pathway for hijacking its membrane during budding, which helps it evade the immune system. It has been discovered that hepatitis C virus transfers its infectious virions between cells in exosomes. Exosomes containing oncoproteins and viral RNAs are also released from cells infected with other human tumorigenic viruses. However, mechanisms and implications of such events remain to be discovered. Keywords: exosome, cancer, viral infection, tumorigenic viruses, immunity, in- tercellular communication, hepatitis C virus, Epstein-Barr virus, human immuno- deficiency virus
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The Heme Catabolic Pathway in Chronic Hepatitis C
Subhanová, Iva ; Zima, Tomáš (advisor) ; Průša, Richard (referee) ; Kráslová, Ivana (referee)
This thesis focuses on the importance of the heme catabolic pathway in chronic hepatitis C (HCV). The aim is mainly to investigate, whether expresion/activity of key enzymes of the heme catabolic pathway, heme oxygenase (HMOX) and biliverdin reductase (BLVRA) in the liver and blood (study A) or promoter variations of HMOX1 and UDP- glucuronosyltransferase (UGT1A1) (study B) may be associated with the progression of fibrosis and may also predict antiviral treatment outcome in patients chronically infected with HCV. We set up a new sensitive method to quantify HMOX activity by reduction gas chromatography. We developed and extensively validated RealTime PCR assay for HMOX and BLVRA expression in the liver and peripheral blood leucocytes (PBL). The (GT)n and (TA)n dinucleotide variations in HMOX1 and UGT1A1 gene promoters, respectively, were determined by fragment analysis. No association was detected between either expression of HMOX/BLVRA or the HMOX1/ UGT1A1 promoter variants and the individual histological stages of liver disease in the HCV positive patients. A marked difference in BLVRA expression in PBL between the sustained responders (SVR) and patients with treatment failure (NVR) was detected before antiviral treatment and during the follow-up. Our data suggests, that BLVRA basal expression...
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Screening for the HCV IRES interacting proteins
Roučová, Kristina ; Pospíšek, Martin (advisor) ; Kuthan, Martin (referee)
Hepatitis C virus (HCV) is a worldwide spread pathogen infecting up to 3 % of the human population. Nowadays, research of new drugs against this virus is focused on the individual steps in its life cycle, including the translation initiation. In the case of HCV translation initiation is dependent on the internal ribosome entry site (IRES). Besides of components of the translational machinery also other components of the cell, so called IRES trans-acting factors (ITAF), contribute to its proper progress. This work continues in previous research of our laboratory focused on searching for new ITAF. In order to search for potential ITAF increasing HCV IRES activity new recombinant plasmid vectors and reference strains were prepared and selection conditions of the selection system were optimized. The differences in the growth characteristics of the reference strains were analyzed and quantified under selective and non-selective conditions. A set of pilot high efficiency transformations of the yeast strain pJ69-4A carrying bicistronic construct with HCV IRES were conducted using human expression cDNA library in order to optimize the efficiency of transformation and selection conditions and to attempt to identify new ITAF. Several dozens of randomly selected clones from these transformations obtained under...
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Novel hepatitis C virus proteins
Zeman, Jakub ; Vopálenský, Václav (advisor) ; Horníková, Lenka (referee)
The hepatitis C virus (HCV) is a major etiological agent of chronic liver diseases. More than 170 million people worldwide are chronically infected, and more than 100 thousand of them develop hepatocellular carcinoma a year. HCV is an enveloped, positive-sense single-stranded RNA virus (+ssRNA virus) of the family Flaviviridae. Its genome is translated to produce a single polyprotein precursor that is further processed by cellular and viral proteases to form 10 viral proteins. Moreover, there is another protein encoded in an alternative reading frame. Two alternative translation mechanisms have been proposed for expression of this alternative reading frame protein (ARFP): a frameshift mechanism and translation initiating from internal start codons. Despite ten years of research its role in vivo is not yet explained. It appears that secondary structures in the core encoding region of HCV genome but not ARFP expression are required for robust viral translation and replication. The results of recent studies suggest that mutations distorting these structures may result not only in slowing down the viral cycle but also in a brand new and utterly unusual serological profile in patients as well as an increased level of expression of ARFP.
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