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HBcAg
HBcAg (core antigen) is a hepatitis B viral protein. It is an indicator of active viral replication; this means the person infected with Hepatitis B can likely transmit the virus on to another person (i.e. the person is infectious). Structure and function HBcAg is an antigen that can be found on the surface of the nucleocapsid core (the inner most layer of the hepatitis B virus). While both HBcAg and HBeAg are made from the same open reading frame, HBcAg is not secreted. HBcAg is considered "particulate" and it does not circulate in the blood but recent study show it can be detected in serum by Radioimmunoassay. However, it is readily detected in hepatocytes after biopsy. The presence of both HBcAg and HBeAg proteins together act as a marker of viral replication, and antibodies to these antigens are a marker of declining replication. Interactions Tapasin can interact with HBcAg18-27 and enhance cytotoxic T-lymphocyte response against HBV. See also *HBeAg *HBsAg HBsAg (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B Virus
''Hepatitis B virus'' (HBV) is a partially double-stranded DNA virus, a species of the genus ''Orthohepadnavirus'' and a member of the ''Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Disease Despite there being a vaccine to prevent Hepatitis B, HBV remains a global health problem. Hepatitis B can be acute and later become chronic, leading to other diseases and health conditions. In addition to causing hepatitis, infection with HBV can lead to cirrhosis and hepatocellular carcinoma. It has also been suggested that it may increase the risk of pancreatic cancer. Roles in disease Viral infection by ''Hepatitis B virus'' (HBV) causes many hepatocyte changes due to the direct action of a protein encoded by the virus, HBx, and to indirect changes due to a large increase in intracellular reactive oxygen species (ROS) after infection. HBx appears to dysregulate a number of cellular pathways. HBx causes dysregulation in part by binding to genomic DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBeAg
HBeAg is a hepatitis B viral protein, produced by the HBcAg reading frame. It is an indicator of active viral replication; this means the person infected with Hepatitis B can likely transmit the virus on to another person (i.e. the person is infectious). HBeAg is considered a marker for cccDNA replication. Structure HBeAg is an antigen that can be found between the icosahedral nucleocapsid core and the lipid envelope (the outer most layer of the hepatitis b virus). However, HBeAg is considered "nonparticulate" or "secretory". While both HBeAg and HBcAg are made from the same reading frame (multiple protein products can be produced from the same DNA sequence and when the genes "ORF Core" and "Pre C" are translated together, the result is HBeAg), HBeAg is secreted and accumulates in serum as an immunologically distinct soluble antigen. Hence the reason why the presence of both proteins together acts as a marker of viral replication, and why antibodies to these antigens are a ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B
Hepatitis B is an infectious disease caused by the ''Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. For others, symptoms may appear 30 to 180 days after becoming infected and can include a rapid onset of sickness with nausea, vomiting, yellowish skin, fatigue, dark urine, and abdominal pain. Symptoms during acute infection typically last for a few weeks, though some people may feel sick for up to six months. Deaths resulting from acute stage HBV infections are rare. An HBV infection lasting longer than six months is usually considered chronic. The likelihood of developing chronic hepatitis B is higher for those who are infected with HBV at a younger age. About 90% of those infected during or shortly after birth develop chronic hepatitis B, while less than 10% of those infected after the age of five develop chronic cases. Most of those wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBsAg
HBsAg (also known as the Australia antigen) is the surface antigen of the hepatitis B virus (HBV). Its presence in blood indicates current hepatitis B infection. Structure and function The viral envelope of an enveloped virus has different surface proteins from the rest of the virus which act as antigens. These antigens are recognized by antibody proteins that bind specifically to one of these surface proteins. Immunoassay Today, these antigen-proteins can be genetically manufactured (e.g. transgene '' E. coli'') to produce material for a simple antigen test, which detects the presence of HBV. It is present in the sera of patients with viral hepatitis B (with or without clinical symptoms). Patients who developed antibodies against HBsAg (anti-HBsAg seroconversion) are usually considered non-infectious. HBsAg detection by immunoassay is used in blood screening, to establish a diagnosis of hepatitis B infection in the clinical setting (in combination with other disease markers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBV Genome , a former German trade union
{{disambiguation ...
HBV may refer to: * Buskerud and Vestfold University College (Norwegian: ') * Hamengkubuwono V, 19th-century ruler of Yogyakarta, Java * ''Handbuch der Vögel Mitteleuropas'' (''Handbook of the Birds of Central Europe'') * HBV hydrology model * Hepatitis B virus * Hepatitis B vaccine * Heterostructure barrier varactor * Trade, Banking and Insurance Union The Trade, Banking and Insurance Union (german: Gewerkschaft Handel, Banken und Versicherungen, HBV) was a trade union representing workers in commerce and finance in Germany. During 1947 and 1948, German trade unionists were regrouping and the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Protein
A viral protein is both a component and a product of a virus. Viral proteins are grouped according to their functions, and groups of viral proteins include structural proteins, nonstructural proteins, regulatory proteins, and accessory proteins. Viruses are non-living and do not have the means to reproduce on their own, instead depending on their host cell's resources in order to reproduce. Thus, viruses do not code for many of their own viral proteins, and instead use the host cell's machinery to produce the viral proteins they require for replication. Viral structural proteins Most viral structural proteins are components for the capsid and the envelope of the virus. Capsid The genetic material of a virus is stored within a viral protein structure called the capsid. The capsid is a "shield" that protects the viral nucleic acids from getting degraded by host enzymes or other types of pesticides or pestilences. It also functions to attach the virion to its host, and enable the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. The term ''antigen'' originally referred to a substance that is an antibody generator. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of monosaccharides/simple sugars), lipids, or nucleic acids. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react and bind more than one antigen. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleocapsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid. Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while the helical shape resembles the shape of a spring, taking the space of a cylinder but not being a cylinder itself. The capsid faces may consist of one or more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Reading Frame
In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames will be "open" (the "reading", however, refers to the RNA produced by transcription of the DNA and its subsequent interaction with the ribosome in translation). Such an ORF may contain a start codon (usually AUG in terms of RNA) and by definition cannot extend beyond a stop codon (usually UAA, UAG or UGA in RNA). That start codon (not necessarily the first) indicates where translation may start. The transcription termination site is located after the ORF, beyond the translation stop codon. If transcription were to cease before the stop codon, an incomplete protein would be made during translation. In eukaryotic genes with multiple exons, introns are removed and exons are then joined together after transcription to yield the final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioimmunoassay
A radioimmunoassay (RIA) is an immunoassay that uses radiolabeled molecules in a stepwise formation of immune complexes. A RIA is a very sensitive in vitro assay technique used to measure concentrations of substances, usually measuring antigen concentrations (for example, hormone levels in blood) by use of antibodies. Although the RIA technique is extremely sensitive and extremely specific, requiring specialized equipment, it remains among the least expensive methods to perform such measurements. It requires special precautions and licensing, since radioactive substances are used. In contrast, an immunoradiometric assay (IRMA) is an immunoassay that uses radiolabeled molecules but in an immediate rather than stepwise way. A radioallergosorbent test (RAST) is an example of radioimmunoassay. It is used to detect the causative allergen for an allergy. Method Classically, to perform a radioimmunoassay, a known quantity of an antigen is made radioactive, frequently by labeling it wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatocyte
A hepatocyte is a cell of the main parenchymal tissue of the liver. Hepatocytes make up 80% of the liver's mass. These cells are involved in: * Protein synthesis * Protein storage * Transformation of carbohydrates * Synthesis of cholesterol, bile salts and phospholipids * Detoxification, modification, and excretion of exogenous and endogenous substances * Initiation of formation and secretion of bile Structure The typical hepatocyte is cubical with sides of 20-30 μm, (in comparison, a human hair has a diameter of 17 to 180 μm).The diameter of human hair ranges from 17 to 181 μm. The typical volume of a hepatocyte is 3.4 x 10−9 cm3. Smooth endoplasmic reticulum is abundant in hepatocytes, in contrast to most other cell types. Microanatomy Hepatocytes display an eosinophilic cytoplasm, reflecting numerous mitochondria, and basophilic stippling due to large amounts of smooth endoplasmic reticulum and free ribosomes. Brown lipofuscin granules are also observed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is then fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions. History T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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