Hepatitis Delta Virus
Hepatitis D
Hepatitis Antigens
Hepatitis D, Chronic
RNA, Catalytic
Marmota
Hepatitis B
Hepatitis B virus
Hepatitis B Surface Antigens
Virus Replication
Molecular Sequence Data
Hepatitis C
Nucleic Acid Conformation
Hepatitis A
Hepatitis Antibodies
Base Sequence
RNA Editing
Hepatitis B Virus, Woodchuck
Superinfection
Hepatitis B, Chronic
Viroids
Pan troglodytes
Virus Assembly
Hepatitis A virus
Virion
Transfection
Hepatitis C, Chronic
Defective Viruses
Amino Acid Sequence
Hepatitis, Viral, Human
Antiviral Agents
Amanitins
Adenosine Deaminase
Hepatitis, Chronic
Hepatitis B Antibodies
Hepatitis B Vaccines
Protein Prenylation
Liver
Hepacivirus
RNA, Satellite
Hepatitis B Core Antigens
Hepatitis A Vaccines
Hepatitis E virus
Hepatitis B e Antigens
Genotype
Transcription, Genetic
Gene Expression Regulation, Viral
RNA
Hepatitis B Antigens
Base Pairing
Hepatitis Viruses
Hepatitis E
RNA Processing, Post-Transcriptional
Hepatitis C Antibodies
RNA-Binding Proteins
Mutational analysis of the antigenomic trans-acting delta ribozyme: the alterations of the middle nucleotides located on the P1 stem. (1/502)
Our previous report on delta ribozyme cleavage using a trans -acting antigenomic delta ribozyme and a collection of short substrates showed that the middle nucleotides of the P1 stem, the substrate binding site, are essential for the cleavage activity. Here we have further investigated the effect of alterations in the P1 stem on the kinetic and thermodynamic parameters of delta ribozyme cleavage using various ribozyme variants carrying single base mutations at putative positions reported. The kinetic and thermodynamic values obtained in mutational studies of the two middle nucleotides of the P1 stem suggest that the binding and active sites of the delta ribozyme are uniquely formed. Firstly, the substrate and the ribozyme are engaged in the formation of a helix, known as the P1 stem, which may contain a weak hydrogen bond(s) or a bulge. Secondly, a tertiary interaction involving the base moieties in the middle of the P1 stem likely plays a role in defining the chemical environment. As a con-sequence, the active site might form simultaneously or subsequently to the binding site during later steps of the pathway. (+info)Mutations in the carboxyl-terminal domain of the small hepatitis B virus envelope protein impair the assembly of hepatitis delta virus particles. (2/502)
The carboxyl-terminal domain of the small (S) envelope protein of hepatitis B virus was subjected to mutagenesis to identify sequences important for the envelopment of the nucleocapsid during morphogenesis of hepatitis delta virus (HDV) virions. The mutations consisted of carboxyl-terminal truncations of 4 to 64 amino acid residues and small combined deletions and insertions spanning the entire hydrophobic domain between residues 163 and 224. Truncation of as few as 14 residues partially inhibited glycosylation and secretion of S and prevented assembly or stability of HDV virions. Short internal combined deletions and insertions were tolerated for secretion of subviral particles with the exceptions of those affecting residues 164 to 173 and 219 to 223. However, mutants competent for subviral particle secretion had a reduced capacity for HDV assembly compared to that of the wild type. One exception was a mutant carrying a deletion of residues 214 to 218, which exhibited a twofold increase in HDV assembly (or stability), whereas deletions of residues 179 to 183, 194 to 198, and 199 to 203 were the most inhibitory. Substitutions of single amino acids between residues 194 and 198 demonstrated that HDV assembly deficiency could be assigned to the replacement of the tryptophan residue at position 196. We concluded that assembly of stable HDV particles requires a specific function of the carboxyl terminus of S which is mediated at least in part by Trp-196. (+info)Cell cycle arrest mediated by hepatitis delta antigen. (3/502)
Hepatitis delta antigen (HDAg) is the only viral-encoded protein of the hepatitis delta virus (HDV). This protein has been extensively characterized with respect to its biochemical and functional properties. However, the molecular mechanism responsible for persistent HDV infection is not yet clear. Previously, we reported that overexpression of HDAg protects insect cells from baculovirus-induced cytolysis [Hwang, S.B. Park, K.-J. and Kim, Y.S. (1998) Biochem. Biophys. Res. Commun. 244, 652-658]. Here we report that HDAg mediates cell cycle arrest when overexpressed in recombinant baculovirus-infected insect cells. Flow cytometry analysis has shown that HDAg expression in Spodoptera frugiperda cells causes an accumulation of substantial amounts of polyploid DNA in the absence of cell division. This phenomenon may be partly responsible for the persistent infection of chronic HDV patients. (+info)A nested double pseudoknot is required for self-cleavage activity of both the genomic and antigenomic hepatitis delta virus ribozymes. (4/502)
The crystal structure of a genomic hepatitis delta virus (HDV) ribozyme 3' cleavage product predicts the existence of a 2 bp duplex, P1.1, that had not been previously identified in the HDV ribozymes. P1.1 consists of two canonical C-G base pairs stacked beneath the G.U wobble pair at the cleavage site and would appear to pull together critical structural elements of the ribozyme. P1.1 is the second stem of a second pseudoknot in the ribozyme, making the overall fold of the ribozyme a nested double pseudoknot. Sequence comparison suggests the potential for P1.1 and a similar fold in the antigenomic ribozyme. In this study, the base pairing requirements of P1.1 for cleavage activity were tested in both the genomic and antigenomic HDV ribozymes by mutagenesis. In both sequences, cleavage activity was severely reduced when mismatches were introduced into P1.1, but restored when alternative base pairing combinations were incorporated. Thus, P1.1 is an essential structural element required for cleavage of both the genomic and antigenomic HDV ribozymes and the model for the antigenomic ribozyme secondary structure should also be modified to include P1.1. (+info)Characterization of the 5' ends for polyadenylated RNAs synthesized during the replication of hepatitis delta virus. (5/502)
The genome of hepatitis delta virus (HDV) is a 1,679-nucleotide (nt) single-stranded circular RNA that is predicted to fold into an unbranched rodlike structure. During replication, two complementary RNAs are also detected: an exact complement, referred to as the antigenome, and an 800-nt polyadenylated RNA that could act as the mRNA for the delta antigen. We used a 5' rapid amplification of cDNA ends procedure, followed by cloning and sequencing, to determine the 5' ends of the polyadenylated RNAs produced during HDV genome replication following initiation under different experimental conditions. The analyzed RNAs were from the liver of an infected woodchuck and from a liver cell line at 6 days after transfection with either an HDV cDNA or ribonucleoprotein (RNP) complexes assembled in vitro with HDV genomic RNA and purified recombinant small delta protein. In all three situations the 5' ends mapped specifically to nt 1630. In relationship to what is called the top end of the unbranched rodlike structure predicted for the genomic RNA template, this site is located 10 nt from the top, and in the middle of a 3-nt external bulge. Following transfection with RNP, such specific 5' ends could be detected as early as 24 h. We next constructed a series of mutants of this predicted bulge region and of an adjacent 6-bp stem and the top 5-nt loop. Some of these mutations decreased the ability of the genome to undergo antigenomic RNA synthesis and accumulation and/or altered the location of the detected 5' ends. The observed end located at nt 1630, and most of the novel 5' ends, were consistent with transcription initiation events that preferentially used a purine. The present studies do not prove that the detected 5' ends correspond to initiation sites and do not establish the hypothesis that there is a promoter element in the vicinity, but they do show that the location of the observed 5' ends could be controlled by nucleotide sequences at and around nt 1630. (+info)Mimicry of the hepatitis delta virus replication cycle mediated by synthetic circular oligodeoxynucleotides. (6/502)
BACKGROUND: Hepatitis delta virus (HDV) is a circular single-stranded RNA pathogen whose monomeric form results from self-processing. Although studies have examined minimal HDV ribozyme activities, the mechanism for forming the circular virus remains unclear, and the trans catalytic properties of self-processed forms of HDV ribozymes have not been studied. In addition, HDV ribozymes have not previously been engineered to cleave a non-HDV sequence. RESULTS: Long repeating RNAs have been produced from in vitro rolling-circle transcription of synthetic circular oligodeoxynucleotides encoding catalytically active subsets of the entire antigenomic RNA virus. Like full-length HDV, these multimeric RNAs undergo self-processing to monomer length; importantly, cyclization is found to occur efficiently, but only in the presence of the circular template. Linear and circular monomer ribozymes and engineered variants are shown to be active in cleaving HDV and HIV RNA targets in trans, despite having self-binding domains. CONCLUSIONS: Mimicry of the rolling-circle replication pathway for HDV replication has led to a new proposal for cyclization of HDV RNA. Under these conditions, cyclization is mediated by the complementary circular template. In addition, it has been shown that self-processed HDV ribozymes can be catalytically active in trans despite the presence of antisense sequences built into their structure. (+info)Unique properties of the large antigen of hepatitis delta virus. (7/502)
The large form of the hepatitis delta virus (HDV) protein (L) can be isoprenylated near its C terminus, and this modification is considered essential for particle assembly. Using gel electrophoresis, we separated L into two species of similar mobilities. The slower species could be labeled by the incorporation of [(14)C]mevalonolactone and is interpreted to be isoprenylated L (L(i)). In serum particles, infected liver, transfected cells, and assembled particles, 25 to 85% of L was isoprenylated. Isoprenylation was also demonstrated by (14)C incorporation in vitro with a rabbit reticulocyte coupled transcription-translation system. However, the species obtained migrated even slower than that detected by labeling in vivo. Next, in studies of HDV particle assembly in the presence of the surface proteins of human hepatitis B virus, we observed the following. (i) Relative to L, L(i) was preferentially assembled into virus-like particles. (ii) L(i) could coassemble the unmodified L and the small delta protein, S. (iii) In contrast, a form of L with a deletion in the dimerization domain was both isoprenylated and assembled, but it could not support the coassembly of S. Finally, to test the expectation that the isoprenylation of L would increase its hydrophobicity, we applied a phase separation strategy based on micelle formation with the nonionic detergent Triton X-114. We showed the following. (i) The unique C-terminal 19 amino acids present on L relative to S caused a significant increase in the hydrophobicity. (ii) This increase was independent of isoprenylation. (iii) In contrast, other, artificial modifications at either the N or C terminus of S did not increase the hydrophobicity. (iv) The increased hydrophobicity was not sufficient for particle assembly; nevertheless, we speculate that it might facilitate virion assembly. (+info)Presence of a coordinated metal ion in a trans-acting antigenomic delta ribozyme. (8/502)
We have investigated the cleavage induced by metal ions in an antigenomic form of a trans-acting delta ribozyme. A specific Mg(2+)-induced cleavage at position G(52)at the bottom of the P2 stem was observed to occur solely within catalytically active ribozyme-substrate complexes (i.e. those that performed the essential conformational transition step). Only the divalent cations which support catalytic activity permitted the detection of specific induced cleavages in this region. Using various mutant ribozymes and substrates, we demonstrated a correlation between enzymatic activity and the Mg(2+)-induced cleavage pattern. We show that the efficiency of the coordination of the magnesium to its binding site is related to the nature of the base pair in the middle of the P1 stem (i.e. Rz(23)-S(8)). Together with additional evidence from nuclease probing experiments that indicates the occurrence of a structural rearrangement involving the bottom of the P2 stem upon formation of the P1 helix, these results show that an intimate relationship exists between the folding and the catalytic activity of the delta ribozyme. (+info)Hepatitis Delta Virus (HDV) is not a traditional virus but rather a defective RNA particle that requires the assistance of the hepatitis B virus (HBV) to replicate. It's also known as delta agent or hepatitis D. HDV is a unique pathogen that only infects individuals who are already infected with HBV.
The virus causes a more severe form of viral hepatitis than HBV alone, leading to a higher risk of fulminant hepatitis (acute liver failure) and chronic hepatitis, which can progress to cirrhosis and hepatocellular carcinoma. HDV is primarily transmitted through percutaneous or sexual contact with infected blood or body fluids.
Prevention strategies include vaccination against HBV, which also prevents HDV infection, and avoiding high-risk behaviors such as intravenous drug use and unprotected sex with multiple partners. There is no specific treatment for HDV; however, antiviral therapy for HBV can help manage the infection.
Hepatitis Delta Antigens (HDAg) are proteins found on the surface of the Hepatitis Delta Virus (HDV), a defective virus that requires the assistance of the Hepatitis B Virus (HBV) to replicate. There are two types of HDAg: small (S-HDAg) and large (L-HDAg). S-HDAg is a 195-amino acid protein that is essential for viral replication, while L-HDAg is a 214-amino acid protein that regulates the packaging of the viral genome into new virus particles. The presence of HDAg can be used to diagnose HDV infection and distinguish it from other forms of hepatitis.
Hepatitis D, also known as Delta hepatitis, is a viral infection of the liver that can only occur in people who have a current infection with the hepatitis B virus (HBV). It's caused by the hepatitis delta virus (HDV), which is a small, enveloped, single-stranded RNA virus.
HDV requires the presence of HBV for its replication and survival, so it can't infect someone who doesn't already have HBV. When both viruses are present, they can interact in ways that lead to more severe liver disease than either virus would cause alone.
Hepatitis D can be an acute or chronic infection, and it can range from mild to severe, with symptoms similar to those of other types of viral hepatitis, such as jaundice, fatigue, loss of appetite, nausea, vomiting, abdominal pain, and joint pain. In some cases, hepatitis D can lead to serious complications, including liver failure and death.
Hepatitis D is primarily spread through contact with infected blood or other bodily fluids, such as during sexual contact, sharing needles, or mother-to-child transmission during childbirth. It's preventable through vaccination against hepatitis B, which provides immunity to both viruses. There is no specific treatment for hepatitis D, but antiviral therapy for hepatitis B can help manage the infection and prevent complications.
Hepatitis antigens are proteins or molecules present on the surface or inside the hepatitis viruses (hepatitis A, B, C, D, and E) that can stimulate an immune response in the body. These antigens are targeted by the immune system to produce antibodies to fight against the infection.
For example, the Hepatitis B surface antigen (HBsAg) is a protein found on the surface of the hepatitis B virus and its presence in the blood indicates an ongoing infection or evidence of past infection/vaccination. Similarly, the core antigen (HBcAg) is a protein found inside the hepatitis B virus and is a marker of active viral replication.
Detection of these antigens in clinical samples such as blood is useful for diagnosing hepatitis infections and monitoring the effectiveness of treatment.
Chronic Hepatitis D is a liver infection caused by the hepatitis delta virus (HDV). It is often considered a serious form of hepatitis because it can lead to more severe liver disease than hepatitis B alone. HDV is a defective virus that requires the presence of hepatitis B surface antigen (HBsAg) to replicate and cause infection. Therefore, chronic hepatitis D only occurs in individuals who have an underlying chronic hepatitis B infection.
Chronic hepatitis D is characterized by persistent inflammation and damage to the liver, which can lead to scarring (fibrosis), cirrhosis, liver failure, and increased risk of liver cancer over time. Symptoms may include fatigue, joint pain, loss of appetite, nausea, vomiting, abdominal pain, dark urine, and jaundice. However, some people with chronic hepatitis D may not have any symptoms until the disease has progressed to a more advanced stage.
Chronic hepatitis D is diagnosed through blood tests that detect HDV antibodies and antigens, as well as liver function tests and imaging studies to assess liver damage. Treatment typically involves antiviral therapy to suppress the replication of both HBV and HDV, as well as supportive care to manage symptoms and prevent complications. In some cases, a liver transplant may be necessary for individuals with advanced liver disease due to chronic hepatitis D.
A catalytic RNA, often referred to as a ribozyme, is a type of RNA molecule that has the ability to act as an enzyme and catalyze chemical reactions. These RNA molecules contain specific sequences and structures that allow them to bind to other molecules and accelerate chemical reactions without being consumed in the process.
Ribozymes play important roles in various biological processes, such as RNA splicing, translation regulation, and gene expression. One of the most well-known ribozymes is the self-splicing intron found in certain RNA molecules, which can excise itself from the host RNA and then ligase the flanking exons together.
The discovery of catalytic RNAs challenged the central dogma of molecular biology, which held that proteins were solely responsible for carrying out biological catalysis. The finding that RNA could also function as an enzyme opened up new avenues of research and expanded our understanding of the complexity and versatility of biological systems.
"Marmota" is a genus of large ground squirrels that are native to North America and Eurasia. These animals, also known as woodchucks or whistle pigs, are well-known for their ability to hibernate during the winter months. They typically live in burrows that they dig themselves, and their diet consists mainly of grasses, leaves, and shrubs. Marmotas are social creatures and often live in colonies with a dominant male and several females. While "Marmota" is a valid term in medical literature, it is more commonly found in the fields of biology and zoology rather than medicine.
A viral RNA (ribonucleic acid) is the genetic material found in certain types of viruses, as opposed to viruses that contain DNA (deoxyribonucleic acid). These viruses are known as RNA viruses. The RNA can be single-stranded or double-stranded and can exist as several different forms, such as positive-sense, negative-sense, or ambisense RNA. Upon infecting a host cell, the viral RNA uses the host's cellular machinery to translate the genetic information into proteins, leading to the production of new virus particles and the continuation of the viral life cycle. Examples of human diseases caused by RNA viruses include influenza, COVID-19 (SARS-CoV-2), hepatitis C, and polio.
Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease. The virus is transmitted through contact with infected blood, semen, and other bodily fluids. It can also be passed from an infected mother to her baby at birth.
Acute hepatitis B infection lasts for a few weeks to several months and often causes no symptoms. However, some people may experience mild to severe flu-like symptoms, yellowing of the skin and eyes (jaundice), dark urine, and fatigue. Most adults with acute hepatitis B recover completely and develop lifelong immunity to the virus.
Chronic hepatitis B infection can lead to serious liver damage, including cirrhosis and liver cancer. People with chronic hepatitis B may experience long-term symptoms such as fatigue, joint pain, and depression. They are also at risk for developing liver failure and liver cancer.
Prevention measures include vaccination, safe sex practices, avoiding sharing needles or other drug injection equipment, and covering wounds and skin rashes. There is no specific treatment for acute hepatitis B, but chronic hepatitis B can be treated with antiviral medications to slow the progression of liver damage.
Hepatitis B virus (HBV) is a DNA virus that belongs to the Hepadnaviridae family and causes the infectious disease known as hepatitis B. This virus primarily targets the liver, where it can lead to inflammation and damage of the liver tissue. The infection can range from acute to chronic, with chronic hepatitis B increasing the risk of developing serious liver complications such as cirrhosis and liver cancer.
The Hepatitis B virus has a complex life cycle, involving both nuclear and cytoplasmic phases. It enters hepatocytes (liver cells) via binding to specific receptors and is taken up by endocytosis. The viral DNA is released into the nucleus, where it is converted into a covalently closed circular DNA (cccDNA) form, which serves as the template for viral transcription.
HBV transcribes several RNAs, including pregenomic RNA (pgRNA), which is used as a template for reverse transcription during virion assembly. The pgRNA is encapsidated into core particles along with the viral polymerase and undergoes reverse transcription to generate new viral DNA. This process occurs within the cytoplasm of the hepatocyte, resulting in the formation of immature virions containing partially double-stranded DNA.
These immature virions are then enveloped by host cell membranes containing HBV envelope proteins (known as surface antigens) to form mature virions that can be secreted from the hepatocyte and infect other cells. The virus can also integrate into the host genome, which may contribute to the development of hepatocellular carcinoma in chronic cases.
Hepatitis B is primarily transmitted through exposure to infected blood or bodily fluids containing the virus, such as through sexual contact, sharing needles, or from mother to child during childbirth. Prevention strategies include vaccination, safe sex practices, and avoiding needle-sharing behaviors. Treatment for hepatitis B typically involves antiviral medications that can help suppress viral replication and reduce the risk of liver damage.
Hepatitis B Surface Antigens (HBsAg) are proteins found on the surface of the Hepatitis B virus. They are present in the blood of individuals infected with the Hepatitis B virus and are used as a marker for the presence of a current Hepatitis B infection. The detection of HBsAg in the blood indicates that an individual is infectious and can transmit the virus to others. It is typically used in diagnostic tests to detect and diagnose Hepatitis B infections, monitor treatment response, and assess the risk of transmission.
Virus replication is the process by which a virus produces copies or reproduces itself inside a host cell. This involves several steps:
1. Attachment: The virus attaches to a specific receptor on the surface of the host cell.
2. Penetration: The viral genetic material enters the host cell, either by invagination of the cell membrane or endocytosis.
3. Uncoating: The viral genetic material is released from its protective coat (capsid) inside the host cell.
4. Replication: The viral genetic material uses the host cell's machinery to produce new viral components, such as proteins and nucleic acids.
5. Assembly: The newly synthesized viral components are assembled into new virus particles.
6. Release: The newly formed viruses are released from the host cell, often through lysis (breaking) of the cell membrane or by budding off the cell membrane.
The specific mechanisms and details of virus replication can vary depending on the type of virus. Some viruses, such as DNA viruses, use the host cell's DNA polymerase to replicate their genetic material, while others, such as RNA viruses, use their own RNA-dependent RNA polymerase or reverse transcriptase enzymes. Understanding the process of virus replication is important for developing antiviral therapies and vaccines.
Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.
Hepatitis C is a liver infection caused by the hepatitis C virus (HCV). It's primarily spread through contact with contaminated blood, often through sharing needles or other equipment to inject drugs. For some people, hepatitis C is a short-term illness but for most — about 75-85% — it becomes a long-term, chronic infection that can lead to serious health problems like liver damage, liver failure, and even liver cancer. The virus can infect and inflame the liver, causing symptoms like jaundice (yellowing of the skin and eyes), abdominal pain, fatigue, and dark urine. Many people with hepatitis C don't have any symptoms, so they might not know they have the infection until they experience complications. There are effective treatments available for hepatitis C, including antiviral medications that can cure the infection in most people. Regular testing is important to diagnose and treat hepatitis C early, before it causes serious health problems.
An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. Viral antigens are antigens that are found on or produced by viruses. They can be proteins, glycoproteins, or carbohydrates present on the surface or inside the viral particle.
Viral antigens play a crucial role in the immune system's recognition and response to viral infections. When a virus infects a host cell, it may display its antigens on the surface of the infected cell. This allows the immune system to recognize and target the infected cells for destruction, thereby limiting the spread of the virus.
Viral antigens are also important targets for vaccines. Vaccines typically work by introducing a harmless form of a viral antigen to the body, which then stimulates the production of antibodies and memory T-cells that can recognize and respond quickly and effectively to future infections with the actual virus.
It's worth noting that different types of viruses have different antigens, and these antigens can vary between strains of the same virus. This is why there are often different vaccines available for different viral diseases, and why flu vaccines need to be updated every year to account for changes in the circulating influenza virus strains.
Nucleic acid conformation refers to the three-dimensional structure that nucleic acids (DNA and RNA) adopt as a result of the bonding patterns between the atoms within the molecule. The primary structure of nucleic acids is determined by the sequence of nucleotides, while the conformation is influenced by factors such as the sugar-phosphate backbone, base stacking, and hydrogen bonding.
Two common conformations of DNA are the B-form and the A-form. The B-form is a right-handed helix with a diameter of about 20 Ã… and a pitch of 34 Ã…, while the A-form has a smaller diameter (about 18 Ã…) and a shorter pitch (about 25 Ã…). RNA typically adopts an A-form conformation.
The conformation of nucleic acids can have significant implications for their function, as it can affect their ability to interact with other molecules such as proteins or drugs. Understanding the conformational properties of nucleic acids is therefore an important area of research in molecular biology and medicine.
Hepatitis A is a viral infection that specifically targets the liver, causing inflammation and impaired function. This disease is caused by the hepatitis A virus (HAV), which spreads primarily through the fecal-oral route, often due to poor sanitation and hygiene. Individuals can become infected by consuming food or water contaminated with HAV or by coming into direct contact with an infected person's stool.
The symptoms of hepatitis A may include fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay-colored bowel movements, joint pain, and jaundice (yellowing of the skin and eyes). However, in some cases, particularly in children under six years old, the infection may be asymptomatic.
While hepatitis A can be unpleasant and cause serious complications, it is rarely fatal and most people recover completely within a few months. Preventive measures include vaccination, practicing good hygiene, and avoiding potentially contaminated food and water.
A viral genome is the genetic material (DNA or RNA) that is present in a virus. It contains all the genetic information that a virus needs to replicate itself and infect its host. The size and complexity of viral genomes can vary greatly, ranging from a few thousand bases to hundreds of thousands of bases. Some viruses have linear genomes, while others have circular genomes. The genome of a virus also contains the information necessary for the virus to hijack the host cell's machinery and use it to produce new copies of the virus. Understanding the genetic makeup of viruses is important for developing vaccines and antiviral treatments.
Hepatitis antibodies are proteins produced by the immune system in response to an infection caused by a hepatitis virus. There are several types of hepatitis viruses, including A, B, C, D, and E, each with their own specific antibodies.
The presence of hepatitis antibodies in the blood can indicate a current or past infection with the corresponding hepatitis virus. For example, the detection of anti-HAV (hepatitis A virus) antibodies indicates a past infection or immunization against hepatitis A, while the detection of anti-HBs (hepatitis B surface antigen) antibodies indicates immunity due to vaccination or recovery from a hepatitis B infection.
It's important to note that some hepatitis antibodies may not provide immunity to future infections, and individuals can still be infected with the virus even if they have previously produced antibodies against it. Therefore, regular testing and vaccination are essential for preventing the spread of hepatitis viruses and protecting public health.
A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.
RNA editing is a process that alters the sequence of a transcribed RNA molecule after it has been synthesized from DNA, but before it is translated into protein. This can result in changes to the amino acid sequence of the resulting protein or to the regulation of gene expression. The most common type of RNA editing in mammals is the hydrolytic deamination of adenosine (A) to inosine (I), catalyzed by a family of enzymes called adenosine deaminases acting on RNA (ADARs). Inosine is recognized as guanosine (G) by the translation machinery, leading to A-to-G changes in the RNA sequence. Other types of RNA editing include cytidine (C) to uridine (U) deamination and insertion/deletion of nucleotides. RNA editing is a crucial mechanism for generating diversity in gene expression and has been implicated in various biological processes, including development, differentiation, and disease.
Hepatitis B virus (Woodchuck) refers to the hepadnavirus that naturally infects North American woodchucks (Marmota monax). This virus is closely related to the human Hepatitis B virus (HBV), and it is used as a model for studying HBV infection and related liver diseases in woodchucks. The woodchuck hepatitis virus (WHV) can cause both acute and chronic hepatitis, liver fibrosis, cirrhosis, and liver cancer in its natural host. The virus-host interactions and the disease progression in woodchucks closely mimic those observed in humans with HBV infection. Therefore, studies of WHV infection in woodchucks have contributed significantly to our understanding of HBV biology, host immune responses, and the development of novel therapies for HBV infection in humans.
Superinfection is a medical term that refers to a secondary infection which occurs during or following the treatment of an initial infection. This second infection is often caused by a different microorganism that is resistant to the medication used to treat the first infection. Superinfections can occur in various parts of the body, such as the skin, respiratory system, gastrointestinal tract, or urinary tract, and are more common in individuals with weakened immune systems, chronic illnesses, or those who have been on antibiotics for an extended period.
Superinfections can lead to more severe complications, prolonged hospital stays, increased healthcare costs, and higher mortality rates if not promptly diagnosed and treated appropriately. Healthcare providers must be vigilant in monitoring patients' responses to treatment and recognizing signs of superinfection, such as worsening symptoms or the development of new ones, to ensure timely intervention and optimal patient outcomes.
Chronic Hepatitis B is a persistent infection of the liver caused by the hepatitis B virus (HBV), which can lead to chronic inflammation and scarring of the liver over time. It is defined as the presence of hepatitis B surface antigen (HBsAg) in the blood for more than six months.
The infection can be asymptomatic or may cause nonspecific symptoms such as fatigue, loss of appetite, nausea, and joint pain. A small percentage of people with chronic HBV infection may develop serious complications, including cirrhosis, liver failure, and liver cancer. Treatment options for chronic hepatitis B include antiviral medications that can help to suppress the virus and reduce the risk of liver damage. Vaccination is available to prevent hepatitis B infection.
Viroids are the smallest known pathogens that can infect plants. They are similar to viruses in that they consist of nucleic acid, but unlike viruses, viroids do not contain protein and are not encapsidated within a protective coat. Instead, viroids are simply small, naked circles of RNA that can replicate inside plant cells by using the host's enzymes.
Viroids can cause various diseases in plants, such as stunting, leaf distortion, and reduced yield. They can be transmitted through seed, vegetative propagation, or mechanical means, such as grafting or pruning tools. Because of their small size and simple structure, viroids are difficult to detect and control, making them a significant challenge in plant pathology.
"Pan troglodytes" is the scientific name for a species of great apes known as the Common Chimpanzee. They are native to tropical rainforests in Western and Central Africa. Common Chimpanzees are our closest living relatives, sharing about 98.6% of our DNA. They are highly intelligent and social animals, capable of using tools, exhibiting complex behaviors, and displaying a range of emotions.
Here is a medical definition for 'Pan troglodytes':
The scientific name for the Common Chimpanzee species (genus Pan), a highly intelligent and social great ape native to tropical rainforests in Western and Central Africa. They are our closest living relatives, sharing approximately 98.6% of our DNA. Known for their complex behaviors, tool use, and emotional expression, Common Chimpanzees have been extensively studied in the fields of anthropology, psychology, and primatology to better understand human evolution and behavior.
Formamides are organic compounds that contain a functional group with the structure R-C(=O)NH2, where R can be a hydrogen atom or any organic group. The simplest formamide is formic acid amide (methanamide), which has the formula HC(=O)NH2. Formamides are important in biological systems and are also used in industry as solvents and intermediates in the synthesis of other chemicals.
Virus assembly, also known as virion assembly, is the final stage in the virus life cycle where individual viral components come together to form a complete viral particle or virion. This process typically involves the self-assembly of viral capsid proteins around the viral genome (DNA or RNA) and, in enveloped viruses, the acquisition of a lipid bilayer membrane containing viral glycoproteins. The specific mechanisms and regulation of virus assembly vary among different viral families, but it is often directed by interactions between viral structural proteins and genomic nucleic acid.
A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.
Hepatitis A virus (HAV) is the causative agent of hepatitis A, a viral infection that causes inflammation of the liver. It is a small, non-enveloped, single-stranded RNA virus belonging to the Picornaviridae family and Hepatovirus genus. The virus primarily spreads through the fecal-oral route, often through contaminated food or water, or close contact with an infected person. After entering the body, HAV infects hepatocytes in the liver, leading to liver damage and associated symptoms such as jaundice, fatigue, abdominal pain, and nausea. The immune system eventually clears the infection, providing lifelong immunity against future HAV infections. Preventive measures include vaccination and practicing good hygiene to prevent transmission.
Hepatitis is a medical condition characterized by inflammation of the liver, often resulting in damage to liver cells. It can be caused by various factors, including viral infections (such as Hepatitis A, B, C, D, and E), alcohol abuse, toxins, medications, and autoimmune disorders. Symptoms may include jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting, and dark urine. The severity of the disease can range from mild illness to severe, life-threatening conditions, such as liver failure or cirrhosis.
A virion is the complete, infectious form of a virus outside its host cell. It consists of the viral genome (DNA or RNA) enclosed within a protein coat called the capsid, which is often surrounded by a lipid membrane called the envelope. The envelope may contain viral proteins and glycoproteins that aid in attachment to and entry into host cells during infection. The term "virion" emphasizes the infectious nature of the virus particle, as opposed to non-infectious components like individual capsid proteins or naked viral genome.
Viral DNA refers to the genetic material present in viruses that consist of DNA as their core component. Deoxyribonucleic acid (DNA) is one of the two types of nucleic acids that are responsible for storing and transmitting genetic information in living organisms. Viruses are infectious agents much smaller than bacteria that can only replicate inside the cells of other organisms, called hosts.
Viral DNA can be double-stranded (dsDNA) or single-stranded (ssDNA), depending on the type of virus. Double-stranded DNA viruses have a genome made up of two complementary strands of DNA, while single-stranded DNA viruses contain only one strand of DNA.
Examples of dsDNA viruses include Adenoviruses, Herpesviruses, and Poxviruses, while ssDNA viruses include Parvoviruses and Circoviruses. Viral DNA plays a crucial role in the replication cycle of the virus, encoding for various proteins necessary for its multiplication and survival within the host cell.
Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.
Chronic Hepatitis C is a liver infection caused by the hepatitis C virus (HCV) that lasts for more than six months. This long-term infection can lead to scarring of the liver (cirrhosis), which can cause serious health problems, such as liver failure or liver cancer, in some individuals. The infection is usually asymptomatic until complications arise, but it can be detected through blood tests that identify antibodies to the virus or viral RNA. Chronic hepatitis C is typically managed with antiviral therapy, which can help clear the virus from the body and reduce the risk of liver damage.
Defective viruses are viruses that have lost the ability to complete a full replication cycle and produce progeny virions independently. These viruses require the assistance of a helper virus, which provides the necessary functions for replication. Defective viruses can arise due to mutations, deletions, or other genetic changes that result in the loss of essential genes. They are often non-infectious and cannot cause disease on their own, but they may interfere with the replication of the helper virus and modulate the course of infection. Defective viruses can be found in various types of viruses, including retroviruses, bacteriophages, and DNA viruses.
An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.
Viral hepatitis in humans refers to inflammation of the liver caused by infection with viruses that primarily target the liver. There are five main types of human viral hepatitis, designated as Hepatitis A, B, C, D, and E virus (HAV, HBV, HCV, HDV, and HEV). These viruses can cause a range of illnesses, from acute self-limiting hepatitis to chronic hepatitis, which can lead to cirrhosis and liver cancer.
1. Hepatitis A virus (HAV) is typically spread through the fecal-oral route, often through contaminated food or water. It usually results in an acute self-limiting infection, but rarely can cause chronic hepatitis in individuals with weakened immune systems.
2. Hepatitis B virus (HBV) is primarily transmitted through contact with infected blood, semen, and other bodily fluids. It can lead to both acute and chronic hepatitis, which may result in cirrhosis and liver cancer if left untreated.
3. Hepatitis C virus (HCV) is predominantly spread through exposure to infected blood, such as through sharing needles or receiving contaminated blood transfusions. Chronic hepatitis C is common, and it can lead to serious liver complications like cirrhosis and liver cancer if not treated.
4. Hepatitis D virus (HDV) is an incomplete virus that requires the presence of HBV for its replication. HDV infection occurs only in individuals already infected with HBV, leading to more severe liver disease compared to HBV monoinfection.
5. Hepatitis E virus (HEV) is primarily transmitted through the fecal-oral route, often through contaminated food or water. It usually results in an acute self-limiting infection but can cause chronic hepatitis in pregnant women and individuals with weakened immune systems.
Prevention measures include vaccination for HAV and HBV, safe sex practices, avoiding sharing needles, and ensuring proper hygiene and sanitation to prevent fecal-oral transmission.
Antiviral agents are a class of medications that are designed to treat infections caused by viruses. Unlike antibiotics, which target bacteria, antiviral agents interfere with the replication and infection mechanisms of viruses, either by inhibiting their ability to replicate or by modulating the host's immune response to the virus.
Antiviral agents are used to treat a variety of viral infections, including influenza, herpes simplex virus (HSV) infections, human immunodeficiency virus (HIV) infection, hepatitis B and C, and respiratory syncytial virus (RSV) infections.
These medications can be administered orally, intravenously, or topically, depending on the type of viral infection being treated. Some antiviral agents are also used for prophylaxis, or prevention, of certain viral infections.
It is important to note that antiviral agents are not effective against all types of viruses and may have significant side effects. Therefore, it is essential to consult with a healthcare professional before starting any antiviral therapy.
Amanitins are a type of bicyclic octapeptide toxin found in several species of mushrooms belonging to the Amanita genus, including the death cap (Amanita phalloides) and the destroying angel (Amanita virosa). These toxins are part of the group of compounds known as amatoxins.
Amanitins are highly toxic to humans and other animals, affecting the liver and kidneys in particular. They work by inhibiting RNA polymerase II, an enzyme that plays a crucial role in gene expression by transcribing DNA into messenger RNA (mRNA). This interference with protein synthesis can lead to severe damage to cells and tissues, potentially resulting in organ failure and death if left untreated.
Symptoms of amanitin poisoning typically appear in two phases. The first phase, which occurs within 6-24 hours after ingestion, includes gastrointestinal distress such as vomiting, diarrhea, and abdominal pain. This initial phase may subside for a short period, giving a false sense of recovery. However, the second phase, which can occur 3-7 days later, is characterized by liver and kidney damage, with symptoms such as jaundice, disorientation, seizures, coma, and ultimately, multiple organ failure if not treated promptly and effectively.
Treatment for amanitin poisoning usually involves supportive care, such as fluid replacement and addressing any complications that arise. In some cases, medications like silibinin (from milk thistle) or activated charcoal may be used to help reduce the absorption and toxicity of the amanitins. Additionally, liver transplantation might be considered in severe cases where organ failure is imminent. Prevention is key when it comes to amanitin poisoning, as there is no antidote available. Being able to identify and avoid potentially deadly mushrooms is essential for foragers and those who enjoy gathering wild fungi.
Adenosine Deaminase (ADA) is an enzyme that plays a crucial role in the immune system by helping to regulate the levels of certain chemicals called purines within cells. Specifically, ADA helps to break down adenosine, a type of purine, into another compound called inosine. This enzyme is found in all tissues of the body, but it is especially active in the immune system's white blood cells, where it helps to support their growth, development, and function.
ADA deficiency is a rare genetic disorder that can lead to severe combined immunodeficiency (SCID), a condition in which babies are born with little or no functional immune system. This makes them extremely vulnerable to infections, which can be life-threatening. ADA deficiency can be treated with enzyme replacement therapy, bone marrow transplantation, or gene therapy.
Chronic hepatitis is a type of liver inflammation that lasts for more than six months and can lead to scarring of the liver (cirrhosis), liver failure, and even liver cancer in some cases. It can be caused by various factors, including viral infections such as Hepatitis B and C, autoimmune disorders, alcohol abuse, and non-alcoholic fatty liver disease. The symptoms of chronic hepatitis may include fatigue, loss of appetite, nausea, vomiting, abdominal pain, joint pain, dark urine, and jaundice (yellowing of the skin and eyes). Treatment for chronic hepatitis depends on the underlying cause and may include antiviral medications, immunosuppressive drugs, or lifestyle changes.
Hepatitis B antibodies are proteins produced by the immune system in response to the presence of the Hepatitis B virus. There are two main types of Hepatitis B antibodies:
1. Hepatitis B surface antibody (anti-HBs): This is produced when a person has recovered from a Hepatitis B infection or has been successfully vaccinated against the virus. The presence of anti-HBs indicates immunity to Hepatitis B.
2. Hepatitis B core antibody (anti-HBC): This is produced during a Hepatitis B infection and remains present for life, even after the infection has been cleared. However, the presence of anti-HBC alone does not indicate immunity to Hepatitis B, as it can also be present in people who have a chronic Hepatitis B infection.
It's important to note that testing for Hepatitis B antibodies is typically done through blood tests and can help determine whether a person has been infected with the virus, has recovered from an infection, or has been vaccinated against it.
"Hepatitis B vaccines are vaccines that prevent infection caused by the hepatitis B virus. They work by introducing a small and harmless piece of the virus to your body, which triggers your immune system to produce antibodies to fight off the infection. These antibodies remain in your body and provide protection if you are exposed to the real hepatitis B virus in the future.
The hepatitis B vaccine is typically given as a series of three shots over a six-month period. It is recommended for all infants, children and adolescents who have not previously been vaccinated, as well as for adults who are at increased risk of infection, such as healthcare workers, people who inject drugs, and those with certain medical conditions.
It's important to note that hepatitis B vaccine does not provide protection against other types of viral hepatitis, such as hepatitis A or C."
Viral genes refer to the genetic material present in viruses that contains the information necessary for their replication and the production of viral proteins. In DNA viruses, the genetic material is composed of double-stranded or single-stranded DNA, while in RNA viruses, it is composed of single-stranded or double-stranded RNA.
Viral genes can be classified into three categories: early, late, and structural. Early genes encode proteins involved in the replication of the viral genome, modulation of host cell processes, and regulation of viral gene expression. Late genes encode structural proteins that make up the viral capsid or envelope. Some viruses also have structural genes that are expressed throughout their replication cycle.
Understanding the genetic makeup of viruses is crucial for developing antiviral therapies and vaccines. By targeting specific viral genes, researchers can develop drugs that inhibit viral replication and reduce the severity of viral infections. Additionally, knowledge of viral gene sequences can inform the development of vaccines that stimulate an immune response to specific viral proteins.
Protein prenylation is a post-translational modification process in which a lipophilic group, such as a farnesyl or geranylgeranyl moiety, is covalently attached to specific cysteine residues near the carboxy-terminus of proteins. This modification plays a crucial role in membrane targeting and protein-protein interactions, particularly for proteins involved in signal transduction pathways, such as Ras family GTPases. The enzymes responsible for prenylation are called protein prenyltransferases, and their dysfunction has been implicated in various diseases, including cancer and neurodegenerative disorders.
The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:
1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.
Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.
Hepacivirus is a genus of viruses in the family Flaviviridae. The most well-known member of this genus is Hepatitis C virus (HCV), which is a major cause of liver disease worldwide. HCV infection can lead to chronic hepatitis, cirrhosis, and liver cancer.
Hepaciviruses are enveloped viruses with a single-stranded, positive-sense RNA genome. They have a small icosahedral capsid and infect a variety of hosts, including humans, non-human primates, horses, and birds. The virus enters the host cell by binding to specific receptors on the cell surface and is then internalized through endocytosis.
HCV has a high degree of genetic diversity and is classified into seven major genotypes and numerous subtypes based on differences in its RNA sequence. This genetic variability can affect the virus's ability to evade the host immune response, making treatment more challenging.
In addition to HCV, other hepaciviruses have been identified in various animal species, including equine hepacivirus (EHCV), rodent hepacivirus (RHV), and bat hepacivirus (BtHepCV). These viruses are being studied to better understand the biology of hepaciviruses and their potential impact on human health.
A satellite RNA is a type of non-coding RNA that does not encode proteins but instead plays a role in the regulation of gene expression. It is so named because it can exist as a separate, smaller molecule that "satellites" around a larger RNA molecule called the helper RNA. Satellite RNAs are often associated with viruses and can affect their replication and packaging. They can also be found in some eukaryotic cells, where they may play a role in regulating the expression of certain genes or in the development of diseases such as cancer.
Hepatitis B core antigen (HBcAg) is a protein found in the core of the hepatitis B virus (HBV). It is present during active replication of the virus and plays a crucial role in the formation of the viral capsid or core. The antibodies produced against HBcAg (anti-HBc) can be detected in the blood, which serves as a marker for current or past HBV infection. It is important to note that HBcAg itself is not detectable in the blood because it is confined within the viral particle. However, during the serological testing of hepatitis B, the detection of anti-HBc IgM indicates a recent acute infection, while the presence of anti-HBc IgG suggests either a past resolved infection or an ongoing chronic infection.
Hepatitis A vaccines are inactivated or live attenuated viral vaccines that are administered to prevent infection and illness caused by the hepatitis A virus. The vaccine contains antigens that stimulate an immune response in the body, leading to the production of antibodies that protect against future infection with the virus.
The inactivated hepatitis A vaccine is made from viruses that have been chemically treated to destroy their ability to cause disease while preserving their ability to stimulate an immune response. This type of vaccine is typically given in two doses, six months apart, and provides long-term protection against the virus.
The live attenuated hepatitis A vaccine contains a weakened form of the virus that is unable to cause illness but can still stimulate an immune response. This type of vaccine is given as a single dose and provides protection against the virus for at least 20 years.
Hepatitis A vaccines are recommended for people who are at increased risk of infection, including travelers to areas where hepatitis A is common, men who have sex with men, people who use injection drugs, and people with chronic liver disease or clotting factor disorders. The vaccine is also recommended for children in certain states and communities where hepatitis A is endemic.
Hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus that belongs to the family Hepeviridae and genus Orthohepevirus. It primarily infects the liver, causing acute hepatitis in humans. The virus is transmitted through the fecal-oral route, often through contaminated water or food sources. Ingestion of raw or undercooked pork or deer meat can also lead to HEV infection.
HEV infection typically results in self-limiting acute hepatitis, characterized by symptoms such as jaundice, fatigue, loss of appetite, abdominal pain, and dark urine. In some cases, particularly among pregnant women and individuals with weakened immune systems, HEV infection can lead to severe complications, including fulminant hepatic failure and death.
There are four main genotypes of HEV that infect humans: genotype 1 and 2 are primarily found in developing countries and are transmitted through contaminated water; genotype 3 and 4 are found worldwide and can be transmitted through both zoonotic and human-to-human routes.
Prevention measures include improving sanitation, access to clean water, and food safety practices. Currently, there is no specific antiviral treatment for HEV infection, but supportive care can help manage symptoms. A vaccine against HEV is available in China and has shown efficacy in preventing the disease.
RNA viruses are a type of virus that contain ribonucleic acid (RNA) as their genetic material, as opposed to deoxyribonucleic acid (DNA). RNA viruses replicate by using an enzyme called RNA-dependent RNA polymerase to transcribe and replicate their RNA genome.
There are several different groups of RNA viruses, including:
1. Negative-sense single-stranded RNA viruses: These viruses have a genome that is complementary to the mRNA and must undergo transcription to produce mRNA before translation can occur. Examples include influenza virus, measles virus, and rabies virus.
2. Positive-sense single-stranded RNA viruses: These viruses have a genome that can serve as mRNA and can be directly translated into protein after entry into the host cell. Examples include poliovirus, rhinoviruses, and coronaviruses.
3. Double-stranded RNA viruses: These viruses have a genome consisting of double-stranded RNA and use a complex replication strategy involving both transcription and reverse transcription. Examples include rotaviruses and reoviruses.
RNA viruses are known to cause a wide range of human diseases, ranging from the common cold to more severe illnesses such as hepatitis C, polio, and COVID-19. Due to their high mutation rates and ability to adapt quickly to new environments, RNA viruses can be difficult to control and treat with antiviral drugs or vaccines.
Hepatitis B e antigen (HBeAg) is a protein produced by the hepatitis B virus (HBV) during its replication process. It can be found in the blood of individuals infected with HBV. The presence of HBeAg generally indicates that the virus is actively replicating in the liver and that the individual has high levels of viral load.
HBeAg is a serological marker used to assess the severity and activity of HBV infection, as well as the response to antiviral treatment. In particular, the disappearance of HBeAg from the blood (known as seroconversion) is often associated with a decrease in viral replication and an improvement in liver disease. However, the presence of HBeAg does not necessarily mean that the individual will develop symptoms or liver damage, as some people can remain asymptomatic carriers of the virus for many years.
It's important to note that not all HBV strains produce HBeAg, and some mutant strains may not produce detectable levels of this antigen even when the virus is actively replicating. Therefore, additional tests may be needed to confirm the presence or absence of HBV infection in these cases.
Genotype, in genetics, refers to the complete heritable genetic makeup of an individual organism, including all of its genes. It is the set of instructions contained in an organism's DNA for the development and function of that organism. The genotype is the basis for an individual's inherited traits, and it can be contrasted with an individual's phenotype, which refers to the observable physical or biochemical characteristics of an organism that result from the expression of its genes in combination with environmental influences.
It is important to note that an individual's genotype is not necessarily identical to their genetic sequence. Some genes have multiple forms called alleles, and an individual may inherit different alleles for a given gene from each parent. The combination of alleles that an individual inherits for a particular gene is known as their genotype for that gene.
Understanding an individual's genotype can provide important information about their susceptibility to certain diseases, their response to drugs and other treatments, and their risk of passing on inherited genetic disorders to their offspring.
Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.
During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.
Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.
Gene expression regulation, viral, refers to the processes that control the production of viral gene products, such as proteins and nucleic acids, during the viral life cycle. This can involve both viral and host cell factors that regulate transcription, RNA processing, translation, and post-translational modifications of viral genes.
Viral gene expression regulation is critical for the virus to replicate and produce progeny virions. Different types of viruses have evolved diverse mechanisms to regulate their gene expression, including the use of promoters, enhancers, transcription factors, RNA silencing, and epigenetic modifications. Understanding these regulatory processes can provide insights into viral pathogenesis and help in the development of antiviral therapies.
RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.
Hepatitis B antigens are proteins or particles present on the surface (HBsAg) or inside (HBcAg, HBeAg) the hepatitis B virus.
1. HBsAg (Hepatitis B surface antigen): This is a protein found on the outer surface of the hepatitis B virus. Its presence in the blood indicates an active infection with hepatitis B virus. It's also used as a marker to diagnose hepatitis B infection and monitor treatment response.
2. HBcAg (Hepatitis B core antigen): This is a protein found inside the hepatitis B virus core. It's not usually detected in the blood, but its antibodies (anti-HBc) are used to diagnose past or present hepatitis B infection.
3. HBeAg (Hepatitis B e antigen): This is a protein found inside the hepatitis B virus core and is associated with viral replication. Its presence in the blood indicates high levels of viral replication, increased infectivity, and higher risk of liver damage. It's used to monitor disease progression and treatment response.
These antigens play a crucial role in the diagnosis, management, and prevention of hepatitis B infection.
Base pairing is a specific type of chemical bonding that occurs between complementary base pairs in the nucleic acid molecules DNA and RNA. In DNA, these bases are adenine (A), thymine (T), guanine (G), and cytosine (C). Adenine always pairs with thymine via two hydrogen bonds, while guanine always pairs with cytosine via three hydrogen bonds. This precise base pairing is crucial for the stability of the double helix structure of DNA and for the accurate replication and transcription of genetic information. In RNA, uracil (U) takes the place of thymine and pairs with adenine.
Hepatitis viruses refer to a group of viral agents that primarily target the liver, causing inflammation and damage to hepatocytes (liver cells). This results in various clinical manifestations, ranging from an acute infection to a chronic, persistent infection. There are five main types of hepatitis viruses, named Hepatitis A, B, C, D, and E virus, each with distinct genetic material, modes of transmission, and disease severity.
1. Hepatitis A Virus (HAV): This is a single-stranded RNA virus that is primarily transmitted through the fecal-oral route, often via contaminated food or water. Infected individuals may experience symptoms such as jaundice, fatigue, abdominal pain, and loss of appetite. While most people recover completely within a few months, severe complications can occur in rare cases. A vaccine is available to prevent HAV infection.
2. Hepatitis B Virus (HBV): This is a double-stranded DNA virus that is primarily transmitted through contact with infected blood or bodily fluids, such as during sexual contact, sharing needles, or from mother to child during childbirth. HBV can cause both acute and chronic hepatitis, which may lead to severe liver complications like cirrhosis and liver cancer if left untreated. A vaccine is available to prevent HBV infection.
3. Hepatitis C Virus (HCV): This is a single-stranded RNA virus that is primarily transmitted through contact with infected blood, often through sharing needles or during medical procedures using contaminated equipment. Like HBV, HCV can cause both acute and chronic hepatitis, which may lead to severe liver complications if left untreated. No vaccine is currently available for HCV; however, antiviral treatments can cure the infection in many cases.
4. Hepatitis D Virus (HDV): This is a defective RNA virus that requires the presence of HBV to replicate and cause infection. HDV is primarily transmitted through contact with infected blood or bodily fluids, similar to HBV. Co-infection with both HBV and HDV can result in more severe liver disease compared to HBV infection alone. Antiviral treatments are available for HDV; however, a vaccine is not.
5. Hepatitis E Virus (HEV): This is a single-stranded RNA virus that primarily causes acute hepatitis and is usually transmitted through the fecal-oral route, often through contaminated food or water. In most cases, HEV infection resolves on its own without treatment. However, in pregnant women and individuals with weakened immune systems, HEV can cause severe liver complications. No vaccine is currently available for HEV in the United States; however, a vaccine has been approved in some countries.
Hepatitis E is a viral infection that specifically affects the liver, caused by the hepatitis E virus (HEV). The disease is primarily transmitted through the fecal-oral route, often through contaminated water or food. It can also be spread through blood transfusions and vertical transmission from mother to fetus.
The incubation period for hepatitis E ranges from 2 to 10 weeks. Symptoms of the disease are similar to other types of viral hepatitis and may include jaundice (yellowing of the skin and eyes), fatigue, loss of appetite, abdominal pain, nausea, vomiting, joint pain, and dark urine.
In most cases, hepatitis E is a self-limiting disease, meaning that it resolves on its own within a few weeks to months. However, in some individuals, particularly those with weakened immune systems, the infection can lead to severe complications such as acute liver failure and death. Pregnant women, especially those in the third trimester, are at higher risk of developing severe disease and have a mortality rate of up to 25%.
Prevention measures include maintaining good hygiene practices, practicing safe food handling and preparation, and ensuring access to clean water sources. Currently, there is no specific treatment for hepatitis E, but supportive care can help manage symptoms. Vaccines are available in some countries to prevent the disease.
Post-transcriptional RNA processing refers to the modifications and regulations that occur on RNA molecules after the transcription of DNA into RNA. This process includes several steps:
1. 5' capping: The addition of a cap structure, usually a methylated guanosine triphosphate (GTP), to the 5' end of the RNA molecule. This helps protect the RNA from degradation and plays a role in its transport, stability, and translation.
2. 3' polyadenylation: The addition of a string of adenosine residues (poly(A) tail) to the 3' end of the RNA molecule. This process is important for mRNA stability, export from the nucleus, and translation initiation.
3. Intron removal and exon ligation: Eukaryotic pre-messenger RNAs (pre-mRNAs) contain intronic sequences that do not code for proteins. These introns are removed by a process called splicing, where the flanking exons are joined together to form a continuous mRNA sequence. Alternative splicing can lead to different mature mRNAs from a single pre-mRNA, increasing transcriptomic and proteomic diversity.
4. RNA editing: Specific nucleotide changes in RNA molecules that alter the coding potential or regulatory functions of RNA. This process is catalyzed by enzymes like ADAR (Adenosine Deaminases Acting on RNA) and APOBEC (Apolipoprotein B mRNA Editing Catalytic Polypeptide-like).
5. Chemical modifications: Various chemical modifications can occur on RNA nucleotides, such as methylation, pseudouridination, and isomerization. These modifications can influence RNA stability, localization, and interaction with proteins or other RNAs.
6. Transport and localization: Mature mRNAs are transported from the nucleus to the cytoplasm for translation. In some cases, specific mRNAs are localized to particular cellular compartments to ensure local protein synthesis.
7. Degradation: RNA molecules have finite lifetimes and undergo degradation by various ribonucleases (RNases). The rate of degradation can be influenced by factors such as RNA structure, modifications, or interactions with proteins.
Hepatitis C antibodies are proteins produced by the immune system in response to an infection with the hepatitis C virus (HCV). Detection of these antibodies in the blood indicates a past or present HCV infection. However, it does not necessarily mean that the person is currently infected, as antibodies can persist for years even after the virus has been cleared from the body. Additional tests are usually needed to confirm whether the infection is still active and to guide treatment decisions.
RNA-binding proteins (RBPs) are a class of proteins that selectively interact with RNA molecules to form ribonucleoprotein complexes. These proteins play crucial roles in the post-transcriptional regulation of gene expression, including pre-mRNA processing, mRNA stability, transport, localization, and translation. RBPs recognize specific RNA sequences or structures through their modular RNA-binding domains, which can be highly degenerate and allow for the recognition of a wide range of RNA targets. The interaction between RBPs and RNA is often dynamic and can be regulated by various post-translational modifications of the proteins or by environmental stimuli, allowing for fine-tuning of gene expression in response to changing cellular needs. Dysregulation of RBP function has been implicated in various human diseases, including neurological disorders and cancer.
RNA Polymerase II is a type of enzyme responsible for transcribing DNA into RNA in eukaryotic cells. It plays a crucial role in the process of gene expression, where the information stored in DNA is used to create proteins. Specifically, RNA Polymerase II transcribes protein-coding genes to produce precursor messenger RNA (pre-mRNA), which is then processed into mature mRNA. This mature mRNA serves as a template for protein synthesis during translation.
RNA Polymerase II has a complex structure, consisting of multiple subunits, and it requires the assistance of various transcription factors and coactivators to initiate and regulate transcription. The enzyme recognizes specific promoter sequences in DNA, unwinds the double-stranded DNA, and synthesizes a complementary RNA strand using one of the unwound DNA strands as a template. This process results in the formation of a nascent RNA molecule that is further processed into mature mRNA for protein synthesis or other functional RNAs involved in gene regulation.
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Infection63
- Moreover, HBV/HDV co-infection leads to the most severe form of viral hepatitis with an accelerated progression to liver fibrosis, cirrhosis and hepatocellular carcinoma. (researchsquare.com)
- China is one of the countries with the highest number of hepatitis B virus infections in the world, however, no nationwide cohort study has been conducted to assess the prevalence of HDV infection. (researchsquare.com)
- Hepatitis D is a viral infection caused by the hepatitis D virus (previously called the Delta agent). (medlineplus.gov)
- It causes symptoms only in people who also have hepatitis B infection. (medlineplus.gov)
- Detect and treat hepatitis B infection as soon as possible to help prevent hepatitis D. (medlineplus.gov)
- Adults who are at high risk for hepatitis B infection and all children should get this vaccine. (medlineplus.gov)
- HDV coinfection is usually clinically indistinguishable from acute hepatitis B infection. (clinlabnavigator.com)
- HDV superinfection of a chronic HBsAg carrier more often presents as severe acute hepatitis in a previously unknown HBV carrier or as an exacerbation of preexisting chronic hepatitis B infection. (clinlabnavigator.com)
- Prevalence of hepatitis delta infection in the United States: National Health and Nutrition Examination Survey, 1999-2012. (clinlabnavigator.com)
- Newly acquired symptomatic hepatitis B virus (HBV) infection. (cdc.gov)
- Newly acquired symptomatic hepatitis C virus (HCV) infection. (cdc.gov)
- Chronic infection with viral hepatitis affects half a billion individuals worldwide and can lead to cirrhosis, cancer, and liver failure. (wjgnet.com)
- Acute infection may associate with acute liver failure, while persistent infection is mostly accompanied by chronic hepatitis with a severe, progressive course leading to cirrhosis and its end-stage complications, hepatic decompensation and hepatocellular carcinoma. (wustl.edu)
- While the molecular biology of the two viruses has been characterized in great detail, the absence of robust cell culture models for HBV and/or HDV infection has limited the investigation of virus-host interactions. (mdpi.com)
- The burden of hepatitis B infection is highest in the WHO Western Pacific Region and the WHO African Region, where 116 million and 81 million people, respectively, are chronically infected. (biomedcentral.com)
- The acute and chronic consequences of hepatitis B virus (HBV) infection are major health problems in the United States. (cdc.gov)
- Immunization with hepatitis B vaccine is the most effective means of preventing HBV infection and its consequences. (cdc.gov)
- Integrating hepatitis B vaccine into childhood vaccination schedules in populations with high rates of childhood infection (e.g. (cdc.gov)
- The risk of perinatal HBV infection among infants born to HBV-infected mothers ranges from 10% to 85%, depending on each mother's hepatitis B e antigen (HBeAg) status (3,7,8). (cdc.gov)
- Co-infection with hepatitis D virus (HDV) in persons with acute or chronic hepatitis B virus (HBV) infection can lead to fulminant hepatitis. (cdc.gov)
- Recommendations have also been developed for the prevention and control of hepatitis C virus (HCV) infection. (cdc.gov)
- Because of the high rate of asymptomatic infection with these viruses, information about the prevalence of these diseases is needed to monitor prevention efforts. (cdc.gov)
- NHANES testing for markers of infection with hepatitis viruses will be used to determine secular trends in infection rates across most age and racial/ethnic groups, and will provide a national picture of the epidemiologic determinants of these infections. (cdc.gov)
- 1. Hepatitis delta virus infection in Romania: Prevalence and risk factors. (hepb.org)
- Recent studies suggest that hepatitis Delta virus (HDV) infection of hepatitis B virus (HBV) carriers is responsible for the etiopathogenesis of Labrea Hepatitis 2,13 . (scielo.br)
- Morula-like cells" were more frequently found in HDV acute superinfection, as well as in HAV/HBV acute coinfection and acute HCV infection, and less often in other forms of viral hepatitis. (scielo.br)
- Infection with HDV in a patient who is already positive for the hepatitis B surface antigen (HBsAg) is known as superinfection and results in fulminant liver failure in 5% of patients. (medscape.com)
- Hepatitis D virus (HDV) infection is an acute and chronic inflammatory process involving the liver. (medscape.com)
- Widespread vaccination against hepatitis B in developed nations has helped to reduce the incidence of HDV infection. (medscape.com)
- [ 10 ] In the United States, hepatitis D virus (HDV) infection is observed more commonly among patients with a history of intravenous drug use and in persons from the Mediterranean basin. (medscape.com)
- Its lead product candidate is Lonafarnib, an orally bioavailable, small molecule, which is in Phase III clinical trials to treat hepatitis delta virus infection. (yahoo.com)
- Significance of delta agent infection in chronic hepatitis B virus infection: a study in British carriers. (bmj.com)
- Thus, the incidence of infection with these five viruses is generally lowest in industrialized and developed countries and highest in less-developed regions. (nationalacademies.org)
- Hepatitis D can cause significant liver damage and even death, so prevention of this dual infection is crucial. (everydayhealth.com)
- Hepatitis D can cause an acute or chronic infection, or both. (everydayhealth.com)
- If hepatitis D is suspected, the doctor will take a medical history to understand factors that may have led to the infection. (everydayhealth.com)
- If it's suspected that a person may have hepatitis D, a blood test that confirms the presence of the antibodies that are produced in response to the infection is required to confirm the diagnosis. (everydayhealth.com)
- About 10 percent of people infected with hepatitis D develop a chronic liver infection. (everydayhealth.com)
- Hepatitis D, also known as "delta hepatitis," is a liver infection caused by the hepatitis D virus (HDV). (researchandmarkets.com)
- Hepatitis D can be an acute, short-term infection or become a long-term, chronic infection. (researchandmarkets.com)
- There is no vaccine to prevent hepatitis D. However, prevention of hepatitis B with hepatitis B vaccine also protects against future hepatitis D infection. (researchandmarkets.com)
- Infection with adenovirus, a common childhood virus, is the leading hypothesis for recent cases of severe hepatitis of unknown origin in children that have led to at least six deaths, U.S. health officials said on May 20. (pharmalive.com)
- A chain of events possibly triggered by unrecognized infection with the SARS-CoV-2 coronavirus could be causing the mysterious cases of severe hepatitis reported in hundreds of young children around the world, researchers suggest. (pharmalive.com)
- Among the several viruses that can cause hepatitis, these three were selected for evaluation because of their potential to induce chronic liver infection. (who.int)
- The most extensive monograph evaluates the large body of data suggesting a link between infection with hepatitis B virus and hepatocellular carcinoma in humans. (who.int)
- The evaluation takes on particular importance in view of the high prevalence of chronic infection with this virus, particularly in developing countries. (who.int)
- A brief summary of the structure of the virus and methods for its detection and analysis is followed by a thorough assessment of human exposure data, including patterns of transmission and factors influencing the course and clinical manifestations of infection, studies of cancer in humans, and studies of cancer in primates, transgenic mice, woodchucks, ground squirrels, ducks and other species. (who.int)
- In view of the strong association between hepatocellular carcinoma and chronic infection with hepatitis B virus demonstrated in numerous studies, the monograph concludes that chronic infection with hepatitis B virus is carcinogenic to humans. (who.int)
- Following a similar format of evaluation, the monograph concludes that chronic infection with hepatitis C virus is carcinogenic to humans. (who.int)
- Chronic hepatitis B virus infection (48.2 %) and hepatitis C virus infection (38.2%) were the most frequently identified risk factors. (who.int)
- Special emphasis is placed on risk factors for coinfection, alcohol use, and family history of hepatitis B virus (HBV) infection and liver cancer. (medscape.com)
- Consider hepatitis D virus infection if a patient who is a carrier of chronic hepatitis B presents with recurrent acute hepatitis or sudden fulminant hepatitis. (medscape.com)
- Kane M. Global programme for control of hepatitis B infection. (medscape.com)
- Pathogenesis of hepatitis B virus infection. (medscape.com)
- Persons who have chronic hepatitis or persons identified as HBsAg positive or anti-HCV positive should not be reported as having acute viral hepatitis unless they have evidence of an acute illness compatible with viral hepatitis (with the exception of perinatal hepatitis B infection). (cdc.gov)
- and the third one went on to have chronic hepatitis B infection, which of course is very dangerous because it can progress to cirrhosis and liver cancer. (cdc.gov)
- When diagnostic tests for hepatitis A virus (HAV) and hepatitis B virus (HBV) infection were developed, HAV was found to be the major cause of infectious hepatitis and HBV was found to be the major cause of serum hepatitis. (cdc.gov)
- However, some patients with typical signs and symptoms of viral hepatitis did not have serologic markers of HAV, HBV or HDV infection and were categorized based on epidemiologic characteristics as having either parenterally transmitted non-A, non-B hepatitis or enterically transmitted non-A, non-B hepatitis. (cdc.gov)
- No products are available to prevent hepatitis C, and development of immunoprophylaxis for this disease is proving to be difficult because an effective protective antibody response has not been demonstrated following HCV infection. (cdc.gov)
- SLIDE 4] Acute Viral Hepatitis, by Type, United States, 1982-1993 Of acute hepatitis cases in the United States from 1982 through 1993, 47% were attributable to hepatitis A, 34% to hepatitis B, 16% to hepatitis C, and 3% were negative for serologic markers of HAV, HBV, and HCV infection. (cdc.gov)
- High rates of obesity, metabolic syndrome, and co-infection with hepatitis B and hepatitis D in Kiribati make treatment less effective. (who.int)
- Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study. (who.int)
- To map the epidemiology of HDV infection in the world, Professor Geretti and Dr Stockdale joined forces with the WHO Global Hepatitis Programme and IARC, alongside investigators in Germany, Malawi, and the United Kingdom. (who.int)
Viral29
- The hepatitis delta virus (HDV) ribozyme is a non-coding RNA found in the hepatitis delta virus that is necessary for viral replication and is the only known human virus that utilizes ribozyme activity to infect its host. (wikipedia.org)
- The HDV virions possess an outer layer containing hepatitis B surface antigens (HBsAg) and host lipid surrounding the inner nucleocapsid that consists of viral RNA. (researchsquare.com)
- Acute viral hepatitis. (medlineplus.gov)
- Its distinctiveness derives in the replication and framework from the viral RNA and in the dependence of HDV on coinfection with hepatitis buy MMAD B trojan (2), which gives the envelope proteins for buy MMAD HDV (3,C6) but will not play a primary function in HDV RNA replication (7). (gasyblog.com)
- Despite the undoubted progress achieved through the introduction of vaccination and successful antiviral therapy, the number of patients with chronic viral hepatitis B in Kazakhstan in 2021 was 4792 adults, with chronic viral hepatitis B with a delta agent 1239 people. (biomedcentral.com)
- Recommendations concerning the prevention of other types of viral hepatitis are found in MMWR 1990;39(No. RR-2): 1-8, 22-26. (cdc.gov)
- This pattern are different from those of massive and submassive necroses found in ordinary fulminant viral hepatitis. (scielo.br)
- HBV-HDV coinfection is the most aggressive form of viral hepatitis. (medscape.com)
- Leading a research group at Spain's global public health centre of excellence, the Barcelona Institute for Global Health (ISGlobal), that is working at the interface of health systems and communicable diseases - with a particular focus on viral hepatitis and HIV. (researchgate.net)
- Survey to evaluate the implementation of the recommendations on the comprehensive diagnosis of viral hepatitis in a single extraction: where are we? (researchgate.net)
- In the period spanning 1999 to 2016, approximately 561,000 confirmed cases of viral hepatitis were reported to health authorities in Brazil. (biomedcentral.com)
- Viral hepatitis is higher in the Northern areas where many Amerindians live, and even within this region prevalence varies between different areas. (biomedcentral.com)
- We are encouraged by today´s positive CHMP opinion reinforcing the potential to become the first approved therapy for this most severe form of viral hepatitis. (prnewswire.com)
- The replication process in these viruses produce long RNA carrying multiple units of the viral genome where each unit carries a small ribozymes like hammerhead. (jove.com)
- The Scholars of the Podcast reveal ribosomal proteins encoded in viral genomes, and a protein cell receptor for bat influenza viruses. (virology.ws)
- When I first entered the field of virology, in the 1970s, the definition of virus included the then-correct observation that no viral genome encoded any part of the translational apparatus. (virology.ws)
- Viral Hepatitis Topics. (medscape.com)
- Thus, other causes of acute hepatitis should be excluded for anti-HCV positive patients who have an acute illness compatible with viral hepatitis. (cdc.gov)
- Initial diagnosis of acute hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. (msdmanuals.com)
- No treatments attenuate acute viral hepatitis, including hepatitis D. Alcohol should be avoided because it can increase liver damage. (msdmanuals.com)
- Epidemiology and Prevention of Viral Hepatitis A to E: An Overview Hepatitis Branch Centers for Disease Control and Prevention [SLIDE 1] Title Slide [This slide set presents an overview of the clinical and epidemiologic features for viral hepatitis A, B, C, D, and E and prevention measures for these infections. (cdc.gov)
- SLIDE 2] Viral Hepatitis: Historical Perspective Before the discovery of hepatitis A virus (HAV) and hepatitis B virus (HBV) during the 1960s and 1970s, patients with viral hepatitis were classified based on epidemiologic studies as having either infectious (transmitted person to person by the fecal-oral route) or serum (transmitted by transfusion of blood products) hepatitis. (cdc.gov)
- In addition, some patients with typical signs and symptoms of acute viral hepatitis do not have serologic markers of any of these types of viral hepatitis and can be classified as having non-ABCDE hepatitis. (cdc.gov)
- Characterization of the epidemiology and clinical features of these and other possible agents of viral hepatitis will await the development of diagnostic assays. (cdc.gov)
- SLIDE 3] Viral Hepatitis: Overview For HAV and HEV, the primary source of virus is in feces and the fecal-oral route is the predominant mode of transmission. (cdc.gov)
- SLIDE 5] Estimates of Acute and Chronic Disease Burden for Viral Hepatitis, United States Viral hepatitis causes substantial morbidity and mortality in the United States. (cdc.gov)
- Global health sector strategy on viral hepatitis 2016-2021. (who.int)
- Towards ending viral hepatitis. (who.int)
- WHO Viral Hepatitis Situation and Response in Kiribati. (who.int)
Surface antigen5
- Hepatitis B surface antigen. (cdc.gov)
- Dr. Weisberg was a co-author on a study that looked back through electronic medical records (EMRs) for all hepatitis B surface antigen positive (HbSAg+) patients at his former health system to identify how common hepatitis delta virus (HDV) testing and prevalence were. (hepb.org)
- Testing to identify pregnant women who are hepatitis B surface antigen (HBsAg)-positive and providing their infants with immunoprophylaxis effec- tively prevents HBV transmission during the perinatal period (4,5). (cdc.gov)
- it can replicate independently within the hepatocyte, but it requires hepatitis B surface antigen (HBsAg) for propagation. (medscape.com)
- Infected hepatocytes contain delta particles coated with hepatitis B surface antigen (HBsAg). (msdmanuals.com)
Antigen4
- Antibody to hepatitis B core antigen. (cdc.gov)
- Hepatitis B e antigen. (cdc.gov)
- When he arrived at his former health system, they were only testing for hepatitis delta antigen rather than the hepatitis delta antibody (anti-HDV), which is the appropriate initial test to perform. (hepb.org)
- This involves the reaction of anti-HBc in the sample with hepatitis B core antigen (HBcAg) coated wells. (cdc.gov)
HBsAg2
- The current study was undertaken to assess HDV genotype distribution and determine clinical characteristics of hepatitis delta virus (HDV) among HBsAg positive individuals in Shanghai. (researchsquare.com)
- More than 90% of these infections can be prevented if HBsAg-positive mothers are identified so that their infants can receive hepatitis B vaccine and hepatitis B immune globulin (HBIG) soon after birth (4,5). (cdc.gov)
Vaccine10
- Despite the availability of an effective vaccine for hepatitis B, hundreds of millions of people worldwide are infected with the hepatitis B virus (HBV). (cshlpress.com)
- This prevention strategy includes making hepatitis B vaccine a part of routine vaccination schedules for all infants. (cdc.gov)
- The recommendations for implementing this strategy include making hepatitis B vaccine a part of routine vaccination schedules for infants. (cdc.gov)
- lack of hepatitis B vaccination recommendations for high risk groups, low implementation of hepatitis B screening during pregnancy, supply shortages and vaccine hesitancy, have created opportunities for hepatitis B and D transmission. (hepb.org)
- Exposure to infected blood or sexual fluids through blood transfusions or surgeries (before the 1990's), tattoos, piercings, injection drug use, or sexual contact with an infected person, can expose people already living with hepatitis B to hepatitis D, or expose those who have not received the full hepatitis B vaccine series to both viruses. (hepb.org)
- Bhimma R, Coovadia HM, Adhikari M, Connolly CA. The impact of the hepatitis B virus vaccine on the incidence of hepatitis B virus-associated membranous nephropathy. (medscape.com)
- Emergent Lineages of Mumps Virus Suggest the Need for a Polyvalent Vaccine. (cdc.gov)
- I was a fellow and then an assistant professor of medicine, and I gave grand rounds on the, you know, recently introduced hepatitis B vaccine, which was an enormous advance and very important for healthcare workers. (cdc.gov)
- Both immune globulin (IG) and hepatitis A vaccine are available for prevention of hepatitis A. Immune globulin can be used as either pre- or postexposure prophylaxis and hepatitis A vaccine can be used for preexposure prophylaxis. (cdc.gov)
- hepatitis B can be prevented using either preexposure prophylaxis with hepatitis B vaccine or postexposure prophylaxis with hepatitis B immune globulin (HBIG) and hepatitis B vaccine. (cdc.gov)
Epidemiology4
- In addition, NHANES provides the means to better define the epidemiology of other hepatitis viruses. (cdc.gov)
- Hepatitis delta: Epidemiology, diagnosis and management 36 Years after discovery. (hepb.org)
- Each belongs to an entirely different family of viruses, and they have very little in common except the target organ they affect, the liver, and a certain degree of shared epidemiology. (nationalacademies.org)
- Changes in human ecology and behavior have had discernable effects on the epidemiology of the hepatitis viruses in different ways and to different degrees. (nationalacademies.org)
Liver24
- This virus can cause serious liver damage and cancer in chronically infected patients. (cshlpress.com)
- HDV may make liver disease worse in people who have either recent (acute) or long-term (chronic) hepatitis B. It can even cause symptoms in people who carry hepatitis B virus but who never had symptoms. (medlineplus.gov)
- A liver transplant for end-stage chronic hepatitis B may be effective. (medlineplus.gov)
- About 1 in 10 of those who are infected may develop long-term (chronic) liver inflammation (hepatitis). (medlineplus.gov)
- Hepatitis D virus (HDV) is a defective virus requiring the hepatitis B virus (HBV) to complete its life cycle and cause liver damage in humans. (wustl.edu)
- HDV is responsible for rare acute and chronic liver diseases and is considered the most aggressive hepatitis virus. (wustl.edu)
- Launch Hepatitis delta trojan (HDV) is certainly a unique individual pathogen that triggers severe liver organ disease (1). (gasyblog.com)
- Chronic hepatitis B virus (HBV) and hepatitis D virus (HDV) infections are major causes of liver disease and hepatocellular carcinoma worldwide. (mdpi.com)
- HBV with delta agent remains the most common cause of liver transplantation in Kazakhstan. (biomedcentral.com)
- During the period from 2012 to 2021, among all 207 liver transplantations in A.Syzganov's National Scientific Center of Surgery (Almaty, Kazakhstan), 96 (39.1%) were due to HBV with delta agent. (biomedcentral.com)
- This document provides the rationale for a comprehensive strategy to eliminate transmission of HBV and ultimately reduce the incidence of hepatitis B and hepatitis B-associated chronic liver disease in the United States. (cdc.gov)
- Hepatitis Delta Connect seeks to provide information, resources and support for hepatitis B/D patients and their families through its website, social media, fact sheets, webinars and hepatitis D liver specialist directory . (hepb.org)
- The availability of histopathological liver specimens from cases of Labrea Hepatitis, showing a specific picture of microvesicular steatosis (morula-like cells) and eosinophilic necrosis, has been pointed out by Brazilian authors 9 . (scielo.br)
- A study presented at the International Liver Congress 2016 found that the current hepatitis delta treatment, interferon alpha (IFNa) based therapy, is effective in suppressing disease progression. (pharmacytimes.com)
- Rising number of Chronic Liver Diseases (CLD) and cirrhosis caused by Non-Alcoholic Fatty Liver Disease (NAFLD), Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and Alcohol Liver Disease (ALD) is rising demand for management of liver diseases as early diagnosis of Chronic liver disease and cirrhosis is essential for effective intervention and improving the prognosis. (emergenresearch.com)
- Hepatitis D, also known as "delta hepatitis," affects only those who have been exposed to the hepatitis B virus - if you contract both, the one-two punch can cause serious liver problems. (everydayhealth.com)
- Chronic hepatitis D leads to cirrhosis , or scarring of the liver, in about 70 to 80 percent of cases. (everydayhealth.com)
- 5 , 6 ) Once a person has cirrhosis, the disease may remain stable for as long as 10 years, although a high percentage of people with chronic hepatitis D and cirrhosis eventually die of acute liver failure or liver cancer unless they get a liver transplant. (everydayhealth.com)
- Hepatitis D can cause severe symptoms and serious illness that can lead to life-long liver damage and even death. (researchandmarkets.com)
- Lonafarnib inhibits the prenylation step of HDV replication inside liver cells and blocks the virus life cycle at the stage of assembly. (researchandmarkets.com)
- U.S. health officials on May 6 said they are investigating 109 cases of severe hepatitis of unknown origin in children, including five reported deaths, updating a nationwide alert issued in April for doctors to be on the lookout for such cases of the liver disease. (pharmalive.com)
- Health authorities around the world are investigating a mysterious increase in severe cases of hepatitis - inflammation of the liver - in young children. (pharmalive.com)
- Chronic hepatitis is symptomatic, and affected individuals have biochemical or serologic evidence of continuing or relapsing hepatic disease for longer than 6 months, with histologically documented liver inflammation. (medscape.com)
- Common causes include hepatitis B and C viruses, nonalcoholic steatohepatitis (NASH), alcohol-related liver disease, and autoimmune liver. (msdmanuals.com)
Fulminant2
- Figure 1 shows the presence of "morula-like" cells in hepatic tissue in the fulminant form of hepatitis A (HAV), B (HBV), C (HCV) and Delta (HDV). (scielo.br)
- Fulminant hepatitis and. (msdmanuals.com)
Diagnosis1
- Olivero A, Smedile A: Hepatitis delta virus diagnosis. (clinlabnavigator.com)
Clinical9
- The serological patterns of hepatitis D virus testing in different clinical settings are summarized in the following table. (clinlabnavigator.com)
- The geographical distribution of hepatitis B virus (HBV) and hepatitis D virus (HDV) genotypes is uneven and has its own clinical and organizational implications for health systems. (biomedcentral.com)
- have potential implications for public health policy and for further clinical research on chronic hepatitis in Kazakhstan. (biomedcentral.com)
- If you are a hepatitis delta patient, and wish to receive information about upcoming clinical trials, please enter your information here. (hepb.org)
- Similar clinical and histologic features of Labrea Hepatitis were found in northern Colombia 5 , western Venezuela 16 and Central African Republic 17 . (scielo.br)
- The assessment part of the report embraces, in depth Hepatitis D commercial assessment and clinical assessment of the pipeline products under development. (researchandmarkets.com)
- In the report, detailed description of the drug is given which includes mechanism of action of the drug, clinical studies, NDA approvals (if any), and product development activities comprising the technology, Hepatitis D collaborations, licensing, mergers and acquisition, funding, designations and other product related details. (researchandmarkets.com)
- This segment of the Hepatitis D report encloses its detailed analysis of various drugs in different stages of clinical development, including phase II, I, preclinical and Discovery. (researchandmarkets.com)
- Hepatitis D is also treated in the context of clinical trials. (msdmanuals.com)
Superinfection3
- If you already have chronic hepatitis B and are then exposed to the hepatitis D virus, it's called a superinfection. (everydayhealth.com)
- Doctors may suspect a person has hepatitis D when the symptoms of acute hepatitis B are unusually severe, chronic hepatitis B gets worse much faster than usual, or when chronic hepatitis B suddenly gets much worse, which would indicate a superinfection. (everydayhealth.com)
- It occurs uncommonly as a coinfection with acute hepatitis B or as a superinfection in chronic hepatitis B. (msdmanuals.com)
Ribozyme4
- The ribozyme acts to process the RNA transcripts to unit lengths in a self-cleavage reaction during replication of the hepatitis delta virus, which is thought to propagate by a double rolling circle mechanism. (wikipedia.org)
- In addition to the sense (genomic version), all HDV viruses also have an antigenomic version of the HDV ribozyme. (wikipedia.org)
- The grouping is probably a result of convergent evolution: Deltavirus found outside of humans also possess a DV ribozyme, and no horizontal gene transfer scenarios proposed can yet explain this. (wikipedia.org)
- 2002) pKa perturbation in genomic hepatitis delta virus ribozyme catalysis evidenced by nucleotide analogue interference mapping. (jenabioscience.com)
Vaccination3
- Despite the introduction of vaccination and successful antiviral therapy the prevalence of chronic hepatitis B (with or without delta agent) increased over the past 5 years. (biomedcentral.com)
- Since the 1990's most of Eastern Europe has seen a decline in the prevalence of hepatitis D, a dangerous coinfection of hepatitis B, attributed to successful vaccination programs and government prioritization. (hepb.org)
- More detailed information regarding the epidemiologic features and prevention measures for hepatitis B are presented in two previously published slide sets: 1) "Elimination of hepatitis B virus transmission in the United States: routine childhood vaccination," and 2) "Prevention of perinatal and early childhood hepatitis B virus infections in the United States," both of which are available from the National Technical Information Service (800-CDC-1824). (cdc.gov)
Immunization2
Cirrhosis2
- Patients coinfected with HBV and hepatitis D virus (HDV) have a greater risk of HCC and cirrhosis. (researchsquare.com)
- 70-80% of cirrhosis develops in 5-10 years with HBV with delta agent. (biomedcentral.com)
Replication1
- IMPORTANCE RNA-protein complexes (RNPs) produced with the hepatitis delta trojan RNAs and proteins, HDAg, perform vital roles in trojan replication. (gasyblog.com)
Infections6
- The reported incidence of acute hepatitis B increased by 37% from 1979 to 1989, and an estimated 200,000-300,000 new infections occurred annually during the period 1980- 1991. (cdc.gov)
- Hepatitis viruses constitute a major public health problem because of the morbidity and mortality associated with the acute and chronic consequences of these infections. (cdc.gov)
- Xiridou et al used a mathematical model for the transmission of both viruses and calculated the reproduction numbers of single HBV infections and dual HBV/HDV infections. (medscape.com)
- HEPCLUDEX ® is a first-in-class entry inhibitor for treatment of chronic hepatitis B and D infections. (prnewswire.com)
- MYR Pharmaceuticals is a German biotechnology company focused on drugs for the treatment of chronic hepatitis B and D virus infections. (prnewswire.com)
- JNJ 73763989 (formerly ARO HBV) is an RNA interference (RNAi) therapeutic, being developed by Arrowhead Pharmaceuticals for the treatment of patients with hepatitis B and hepatitis D infections. (researchandmarkets.com)
20161
- 2016. https://www.who.int/hepatitis/strategy2016-2021/ghss-hep/en/ . (who.int)
Prevent hepatitis1
- In the absence of immunoprohylaxis, the primary measure to prevent hepatitis E is to ensure the safety of drinking water. (cdc.gov)
Pathogen2
- Cunha C, Tavanez JP, Gudima S. Hepatitis delta virus: A fascinating and neglected pathogen. (wjgnet.com)
- These can be found in many RNA plant viruses, as well as the hepatitis delta virus, a human pathogen. (jove.com)
Antibody to hepatitis1
- Antibody to hepatitis C virus. (cdc.gov)
Treatment of chronic hepatitis1
- The only drug widely recommended for treatment of chronic hepatitis D is interferon-alfa, although pegylated interferon-alpha is likely equally effective. (msdmanuals.com)
Chronically infected2
- More than 240 million people throughout the world are chronically infected with hepatitis B virus (HBV), and approximately 15-25 million are co-infected with hepatitis D virus (HDV), a satellite virus which requires HBV envelope proteins for particle assembly and spread [1] . (researchsquare.com)
- Worldwide, approximately 257 million people are chronically infected with hepatitis B virus (HBV), 71 million with chronic hepatitis C virus (HCV) and 15 million with HBV and hepatitis D virus (HDV) [ 1 , 2 , 3 ]. (biomedcentral.com)
Ribonucleic acid2
Hepatotropic viruses1
- Evaluates the carcinogenic risk to humans posed by exposure to three hepatotropic viruses: hepatitis B virus, hepatitis C viruses, and hepatitis D virus, which exists as a satellite agent of hepatitis B virus. (who.int)
Transmission6
- Hepatitis B Virus: Strategy for Eliminating Transmission thru Vacc. (cdc.gov)
- This document provides the rationale for a comprehensive strategy to eliminate transmission of hepatitis B virus in the United States. (cdc.gov)
- Although it has been sought, arthropod-borne or other vector-mediated transmission of the blood-borne hepatitis viruses has not been found. (nationalacademies.org)
- Viremia occurs during the incubation period and the early acute phase of hepatitis A, and transmission by transfusion or recently by contaminated commercial factor VIII ( 3 ) has been reported, but such blood-borne transmissions are rare. (nationalacademies.org)
- The primary route of transmission for hepatitis D is contact with infected blood or other bodily fluids. (everydayhealth.com)
- There are no well-documented reports of HIV, hepatitis C virus, or hepatitis D virus transmission during sport. (lww.com)
Bloodborne Viruses1
- HBV, HCV, and HDV are bloodborne viruses and are primarily transmitted by percutaneous and mucosal exposures. (cdc.gov)
Patients with acute2
- A defective virus, containing particles of RNA nucleoprotein in virion-like form, present in patients with acute hepatitis B and chronic hepatitis. (bvsalud.org)
- Splenomegaly and cervical adenopathy are present in 10-20% of patients with acute hepatitis. (medscape.com)
Symptoms3
- Hepatitis D may make the symptoms of hepatitis B worse. (medlineplus.gov)
- Contact your health care provider if you have symptoms of hepatitis B. (medlineplus.gov)
- In contrast, the majority of people with chronic hepatitis D will have few symptoms until complications develop. (everydayhealth.com)
Eiger BioPharmaceuticals1
- 6+ key companies which are developing the therapies for Hepatitis D. The companies which have their Hepatitis D drug candidates in the most advanced stage, i.e. phase III include, Eiger Biopharmaceuticals. (researchandmarkets.com)
Characterization2
- His fields of research comprise RNA-mediated gene silencing processes with a focus on epigenetic phenomena, including studies on RNA-directed DNA methylation, the characterization of virus silencing suppressor proteins, the development of plant bioreactor platforms and viroid research. (degruyter.com)
- Full genomic characterization of California serogroup viruses, genus Orthobunyavirus, family Peribunyaviridae including phylogenetic relationships. (cdc.gov)
Presence of hepatitis1
- Hepatitis D is caused by a defective RNA virus (delta agent) that can replicate only in the presence of hepatitis B virus. (msdmanuals.com)
Control of hepatitis1
- Control of hepatitis B and D coinfection has also been hindered by the lack of a national registry and surveillance system thus preventing an understanding of the accurate prevalence and public health burden 1 . (hepb.org)
Cause hepatitis1
- Other viruses, principally from the families Arenaviridae, Bunyaviridae, Flaviviridae, Filoviridae, and Herpesviridae , also cause hepatitis as part of systemic diseases, but these are generally not grouped with the hepatitis viruses. (nationalacademies.org)
Treat hepatitis1
- Many of the medicines used to treat hepatitis B are not helpful for treating hepatitis D. (medlineplus.gov)
Defective2
- Hepatitis D is caused by a defective RNA virus, hepatitis delta virus (HDV). (clinlabnavigator.com)
- Hepatitis Delta virus (HDV), discovered in 1977, is a defective virus requiring the presence of HBV in order to replicate. (cdc.gov)
Occurs3
- It occurs in a small number of people who carry hepatitis B. (medlineplus.gov)
- Hepatitis delta only occurs in patients who already have hepatitis B. Currently, pegylated interferon is the only treatment for hepatitis delta. (pharmacytimes.com)
- Hepatitis D only occurs in people who are also infected with the hepatitis B virus. (researchandmarkets.com)
Serum hepatitis1
- The differentiation of hepatitis A, then called infectious hepatitis, from hepatitis B, then called serum hepatitis, came principally from studies in volunteers in Europe and the United States from the 1940s through the 1960s. (nationalacademies.org)
Antibodies3
- Anti-delta antibodies were found among Amerindians from Eastern Amazon suggesting a risk for this population. (biomedcentral.com)
- Pre-existing neutralising antibodies (NAbs) to adeno-associated viruses (AAVs) remain an impediment for systemically administered AAV-mediated gene therapy treatment in many patients, and various strategies are under investigation to overcome this limitation. (unav.edu)
- An Assay for Cirulating Antibodies to a Major Etiologic Virus of Human Non-A, Non-B Hepatitis. (cdc.gov)
Antiviral2
- There has been significant debate over whether there are long-term benefits to patients with Hepatitis delta receiving antiviral treatment,' said Anika Wranke, lead author of the study. (pharmacytimes.com)
- The potential antiviral activity of AdrAwas addressed in hepatitis B virus (HBV)-transgenic and adenovirus-associated virus (AAV)-HBV mouse models. (unav.edu)
Severe hepatitis1
- Our study demonstrates that the long-term outcomes for patients with severe Hepatitis delta, who have limited treatment options, could be improved with a widely available medication. (pharmacytimes.com)
Proteins1
- This dictum was shattered by the discovery of giant viruses which were found to encode tRNAs, aminoacyl tRNA syntheses, and many proteins involved in translation. (virology.ws)
Incidence2
- However, this strategy has not lowered the incidence of hepatitis B, primarily because vaccinating persons engaged in high-risk behaviors, life-styles, or occupations before they become infected generally has not been feasible. (cdc.gov)
- In general, the regional incidence rates for each virus are lowest in the Western Hemisphere and northern regions and highest in the Eastern Hemisphere and tropical regions. (nationalacademies.org)
Discovered in 19771
- Hepatitis D virus (HDV) is an RNA virus that was discovered in 1977 and is structurally unrelated to the hepatitis A (HAV), hepatitis B (HBV), and hepatitis C (HCV) viruses. (medscape.com)