疾病及处理

The improvement of instruments and technology enabled the first visualization of viral particles by means of electron microscopy in 1939 (1). In particular, the negative staining technique provided high-resolution electron microscopic images of viral particles This technique ...

Many studies of the molecular biology of hepatitis C virus (HCV) begin by obtaining representative cDNA clones of the viral genome. Most cloning strategies have been devised to deal with the low levels of HCV RNA present in starting material used for RNA isolation and cDNA synthesis. Typical sour ...

HCV and related viruses are now classified as a separate genus in the family Flaviviridae (1), which includes two other genera, Flavivirus (2), and Pestivirus (3). The positive-strand HCV genome RNA is approx 9.4 kb in length and contains a highly conserved 5′ noncoding region followed by a long open rea ...

Hepatitis C virus (HCV) is a positive-stranded RNA virus with a genome size of about 9–10 kb. The genome of this virus encodes a polyprotein with a length of over 3000 amino acids. This polyprotein is cleaved by cellular and viral proteases to generate at least 10 viral gene products. Recent reports have ind ...

The 5′-untranslated region of hepatitis C virus (HCV) has been shown to function as an internal ribosomal entry site, or IRES. The biological function of the HCV IRES has been shown to be essential for initiation of translation of the viral proteins by host ribosomes. With this critical role in HCV repli ...

Heterologous expression systems have been widely used to study hepatitis C virus (HCV) proteins in lieu of an efficient method for establishing HCV infections in cell culture. Studies of HCV polyprotein processing in both mammalian-cell-based and cell-free expression systems have s ...

The hepatitis C virus (HCV) NS3 protein has two distinct biochemical domains. The N-terminal 20 kDa has serine protease activity (see Chapter 31) and the C-terminal 50 kDa has both nucleoside triphosphatase (NTPase) and helicase activities (1–4)

The overexpression of a gene in a heterologous system is often the prelude to or the prerequisite of the elucidation and characterization of a given protein, in particular where the protein is difficult to obtain in sufficient quantity from natural sources. Prokaryotic expression system ...

The hepatitis C virus (HCV) chronically infects approx 4 million patients in the United States alone, and constitutes a major cause of chronic liver disease and hepatocellular carcinoma (1–3). Current antiviral therapies for chronic hepatitis C remain relatively ineffective and have ...

The 3′-end region of the HCV genome is composed of three characteristic elements: conventional 3′-untranslated region, subsequent poly (U) stretch, and a newly identified 3′-terminal sequence named the 3′X tail (1,2). The 3′X tail is thought to be a common structure of the HCV genome, and should have im ...

Hepatitis C virus (HCV) is an encapsidated RNA virus, known to cause devastating liver diseases among the majority of infected individuals (1–3). Latest breakthrough in molecular technology has greatly assisted the advancement in diagnostics and monitoring of virological respon ...

The appropriate formation of specific RNA-protein complexes regulates the normal synthesis, trafficking, and metabolism of intracellular RNA. For RNA viruses, these interactions are essential for replication and translation of the viral genome, as well as packaging of progeny st ...

The liver cell response to hepatitis C, a positive-strand RNA virus of the flaviviridiae, varies considerably from acute disease to chronic hepatitis, and from inapparent infection to cirrhosis. The cellular injury to the host depends on host—viral interactions (Table 1): in general, the m ...

Peripheral blood mononuclear cells (PBMC) contain NK cells, cytotoxic T-lymphocytes (CTL), helper T-cells, and B-cells that respond to viral infection and act to eliminate the virus from infected individuals. CTLs are not only thought to be a major host defense against viral infection, but are ...

T-cells are the key players in the field on which the virus and the immune response try to defeat or at least control each other. Two categories of T-cells are involved: CD4+ and CD8+ T-cells. CD4+ and CD8+ T-cells have different characteristics and functions and different roles in the immune response to vir ...

Cellular immune responses, especially those mediated by cytotoxic T-lymphocytes (CTLs), are an important component of the host immune response in many viral infections. For many years, it has been observed that CD8+ cells were present in large numbers in the liver of patients with chronic HCV (1 ...

The host immune response to hepatitis C virus (HCV) infection comprises both humoral and cellular components, which accompany all viral infections. The cellular immune response involves both nonspecific and antigen-specific phases, with recovery thought to be largely dependent ...

Human monoclonal antibodies (hMAb) provide novel ways to probe the B-cell repertoire in health and disease. However, the development of hMAb technology has met with several difficulties owing to the instability of the cell lines, the low level of specific antibody secretion, and the poor clon ...

Because of the very low level of HCV present in the serum of infected individuals, as well as the low level of replication in the host, reverse transcription-polymerase chain reaction (RT-PCR) assays are the only method suitable for the routine detection of HCV RNA. The use of RT-PCR to monitor HCV repli ...

Hepatitis C virus (HCV), the genome of which was molecularly cloned in the US and Japan, causes most, if not all, cases of posttransfusional non-A, non-B hepatitis (NANBH) and nearly half those of sporadic hepatitis. Prospective and retrospective studies revealed that nearly half of patients wi ...