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Transmission Of Hepadnaviruses
The transmission of hepadnaviruses between their natural hosts, humans, non-human primates, and birds, including intra-species host transmission and cross-species transmission, is a topic of study in virology. Hepadnaviruses are a family of viruses that can cause liver infections in humans and animals. They are Group VII viruses that possess double-stranded DNA genomes and replicate using reverse transcriptase. This unique replication strategy, combined with their extremely small genomes and a very narrow host and tissue tropism, has distinguished them enough to be classified in the family Hepadnaviridae. There are two recognized genera: * ''Orthohepadnavirus'', type species: ''hepatitis B virus'' (HBV) * ''Avihepadnavirus'', type species: '' duck hepatitis B virus'' (DHBV) Structure With the example of human HBV: the particular feature of the HBV structure is the presence of three different forms in the plasma of infected patients: * Dane particle (diameter ≈ 42 nm): th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission (medicine)
In medicine, public health, and biology, transmission is the passing of a pathogen causing communicable disease from an infected host individual or group to a particular individual or group, regardless of whether the other individual was previously infected. The term strictly refers to the transmission of microorganisms directly from one individual to another by one or more of the following means: * airborne transmission – very small dry and wet particles that stay in the air for long periods of time allowing airborne contamination even after the departure of the host. Particle size 5 μm. * direct physical contact – touching an infected individual, including sexual contact * indirect physical contact – usually by touching a contaminated surface, including soil (fomite) * fecal–oral transmission – usually from unwashed hands, contaminated food or water sources due to lack of sanitation and hygiene, an important transmission route in pediatrics, veterinary medicine and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B Virus V2
Hepatitis is inflammation of the liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), poor appetite, vomiting, tiredness, abdominal pain, and diarrhea. Hepatitis is ''acute'' if it resolves within six months, and '' chronic'' if it lasts longer than six months. Acute hepatitis can resolve on its own, progress to chronic hepatitis, or (rarely) result in acute liver failure. Chronic hepatitis may progress to scarring of the liver (cirrhosis), liver failure, and liver cancer. Hepatitis is most commonly caused by the virus ''hepatovirus A'', '' B'', '' C'', '' D'', and '' E''. Other viruses can also cause liver inflammation, including cytomegalovirus, Epstein–Barr virus, and yellow fever virus. Other common causes of hepatitis include heavy alcohol use, certain medications, toxins, other infections, autoimmune diseases, and non-alcoholic steatohepatitis (NASH). Hepatitis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hylobatidae
Gibbons () are apes in the family Hylobatidae (). The family historically contained one genus, but now is split into four extant genera and 20 species. Gibbons live in subtropical and tropical rainforest from eastern Bangladesh to Northeast India to southern China and Indonesia (including the islands of Sumatra, Borneo and Java). Also called the lesser apes, gibbons differ from great apes ( bonobos, chimpanzees, gorillas, orangutans and humans) in being smaller, exhibiting low sexual dimorphism, and not making nests. Like all apes, gibbons are tailless. Unlike most of the great apes, gibbons frequently form long-term pair bonds. Their primary mode of locomotion, brachiation, involves swinging from branch to branch for distances up to , at speeds as fast as . They can also make leaps up to , and walk bipedally with their arms raised for balance. They are the fastest of all tree-dwelling, nonflying mammals. Depending on the species and sex, gibbons' fur coloration varies from dar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pongidae
Pongidae , or the pongids is an obsolete primate taxon containing chimpanzees, gorillas and orangutans. By this definition pongids were also called "great apes". This taxon is not used today but is of historical significance. The great apes are currently classified as Hominidae. This entry addresses the old usage of pongid. The words "Pongidae" and "pongids" are sometimes used informally for the primate taxon containing orangutans and their extinct fossil relations. For this usage the currently most widely accepted name is Ponginae (or informally Asian hominids or pongines), the orangutan subfamily of the Hominidae or hominids. In current hominid taxonomy there is no “pongid” taxon. The orangutan taxon is now known to be paraphyletic to other (African) hominids. The orangutans are the only surviving species of the subfamily Ponginae, which genetically diverged from the other hominids (gorillas, chimpanzees and humans) between 19.3 and 15.7 million years ago. The subfamilies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatocellular Carcinoma
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide. It occurs in the setting of chronic liver inflammation, and is most closely linked to chronic viral hepatitis infection (hepatitis B or C) or exposure to toxins such as alcohol, aflatoxin, or pyrrolizidine alkaloids. Certain diseases, such as hemochromatosis and alpha 1-antitrypsin deficiency, markedly increase the risk of developing HCC. Metabolic syndrome and NASH are also increasingly recognized as risk factors for HCC. As with any cancer, the treatment and prognosis of HCC vary depending on the specifics of tumor histology, size, how far the cancer has spread, and overall health. The vast majority of HCC cases and the lowest survival rates after treatment occur in Asia and sub-Saharan Africa, in countries where hepatitis B infection is endem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woolly Monkey Hepatitis B Virus
The ''woolly monkey hepatitis B virus'' (WMHBV) is a viral species of the ''Orthohepadnavirus'' genus of the ''Hepadnaviridae'' family. Its natural host is the woolly monkey (''Lagothrix)'', an inhabitant of South America categorized as a New World primate. WMHBV, like other hepatitis viruses, infects the hepatocytes, or liver cells, of its host organism. It can cause hepatitis, liver necrosis, cirrhosis, and hepatocellular carcinoma (liver cancer). Because nearly all species of ''Lagothrix'' are threatened or endangered, researching and developing a vaccine and/or treatment for WMHBV is important for the protection of the whole woolly monkey genus. WMHBV is also of great interest to researchers because of its potential to teach us more about the human hepatitis B virus (HBV). WMHBV is a distant phylogenetic sister species to human HBV, although the evolutionary history of hepatitis B viruses is not well understood. Additionally, WMHBV was the first hepadnavirus other than huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepadnaviridae
''Hepadnaviridae'' is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas (chronic infections), and cirrhosis. It is the sole accepted family in the order ''Blubervirales''. Taxonomy The following genera are recognized: * ''Avihepadnavirus'' * ''Orthohepadnavirus'' * '' Herpetohepadnavirus'' * '' Metahepadnavirus'' * '' Parahepadnavirus'' History and discovery Although liver diseases transmissible among human populations were identified early in the history of medicine, the first known hepatitis with a viral etiological agent was Hepatitis A, in the picornaviridae family. Hepatitis B Virus (HBV) was identified as an infection distinct from Hepatitis A through its contamination of measles, mumps, and yellow fever vaccines in the 1930s and 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBV Replication , a former German trade union
{{disambiguation ...
HBV may refer to: * Buskerud and Vestfold University College (Norwegian: ') * Hamengkubuwono V, 19th-century ruler of Yogyakarta, Java * '' Handbuch der Vögel Mitteleuropas'' (''Handbook of the Birds of Central Europe'') * HBV hydrology model * Hepatitis B virus * Hepatitis B vaccine * Heterostructure barrier varactor * Trade, Banking and Insurance Union The Trade, Banking and Insurance Union (german: Gewerkschaft Handel, Banken und Versicherungen, HBV) was a trade union representing workers in commerce and finance in Germany. During 1947 and 1948, German trade unionists were regrouping and the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBV Genome , a former German trade union
{{disambiguation ...
HBV may refer to: * Buskerud and Vestfold University College (Norwegian: ') * Hamengkubuwono V, 19th-century ruler of Yogyakarta, Java * ''Handbuch der Vögel Mitteleuropas'' (''Handbook of the Birds of Central Europe'') * HBV hydrology model * Hepatitis B virus * Hepatitis B vaccine * Heterostructure barrier varactor * Trade, Banking and Insurance Union The Trade, Banking and Insurance Union (german: Gewerkschaft Handel, Banken und Versicherungen, HBV) was a trade union representing workers in commerce and finance in Germany. During 1947 and 1948, German trade unionists were regrouping and the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duck Hepatitis B Virus
''Duck hepatitis B virus'', abbreviated DHBV, is part of the genus ''Avihepadnavirus'' of the ''Hepadnaviridae'', and is the causal agent of duck hepatitis B. DHBV is a small DNA virus with a diameter of 40–45 nm. The viral envelope is made up from host cell lipid, with viral surface antigens (DHBsAg). The icosahedral nucleocapsid within, is composed of the virus core antigen (DHBcAg) and surrounds the DNA genome and viral polymerase. The viral genome is a circular double stranded DNA molecule about 3000 base pairs long. The genome has three overlapping open reading frames or ORFs: * C-ORF – encoding the core antigen and pre-core protein which are processed and secreted as DHBcAg * S-ORF – codes for the surface antigen DHBsAg * P-ORF – encoding the viral polymerase. On binding and entry of the virus to the host cell, the genome is transported to the nucleus to be transcribed. Novel viral RNA is then transferred to the cytoplasm for translation and subsequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepadnavirus
''Hepadnaviridae'' is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas (chronic infections), and cirrhosis. It is the sole accepted family in the order ''Blubervirales''. Taxonomy The following genera are recognized: * ''Avihepadnavirus'' * ''Orthohepadnavirus'' * '' Herpetohepadnavirus'' * '' Metahepadnavirus'' * '' Parahepadnavirus'' History and discovery Although liver diseases transmissible among human populations were identified early in the history of medicine, the first known hepatitis with a viral etiological agent was Hepatitis A, in the picornaviridae family. Hepatitis B Virus (HBV) was identified as an infection distinct from Hepatitis A through its contamination of measles, mumps, and yellow fever vaccines in the 1930s and 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avihepadnavirus
''Avihepadnavirus'' is a genus of viruses, in the family ''Hepadnaviridae''. Birds serve as natural hosts. There are three species in this genus. Diseases associated with this genus include: hepatitis, hepatocellular carcinomas (chronic infections), and cirrhosis. Taxonomy The genus contains the following species: * '' Duck hepatitis B virus'' * ''Heron hepatitis B virus'' * '' Parrot hepatitis B virus'' Structure Viruses in the genus ''Avihepadnavirus'' are enveloped, with spherical geometries, and T=4 symmetry. The diameter is around 42 nm. Genomes are circular, around 3.2kb in length. The genome codes for 7 proteins. Life cycle Viral replication is nucleo-cytoplasmic. Replication follows the dsDNA(RT) replication model. DNA-templated transcription, specifically dsDNA-RT transcription, with some alternative splicing mechanism is the method of transcription. Translation takes place by ribosomal shunting Ribosome shunting is a mechanism of translation initiation in which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
