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Astroviridae
''Astroviridae'' is a family of non-enveloped ssRNA viruses that cause infections in different animals. The family name is derived from the Greek word ''astron'' ("star") referring to the star-like appearance of spikes projecting from the surface of these small unenveloped viruses. Astroviruses were initially identified in humans but have since been isolated from other mammals and birds. This family of viruses consists of two genera, Avastrovirus (AAstV) and Mamastrovirus (MAstV). Astroviruses most frequently cause infection of the gastrointestinal tract but in some animals they may result in encephalitis (humans and cattle), hepatitis (avian) and nephritis (avian). Astroviruses were first identified in humans in 1975 from the stool of children with diarrhea. Human infections are usually self-limiting but may also spread systematically and infect immunocompromised individuals. Taxonomy The International Committee on Taxonomy of Viruses (ICTV) established ''Astroviridae'' as a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astroviridae
''Astroviridae'' is a family of non-enveloped ssRNA viruses that cause infections in different animals. The family name is derived from the Greek word ''astron'' ("star") referring to the star-like appearance of spikes projecting from the surface of these small unenveloped viruses. Astroviruses were initially identified in humans but have since been isolated from other mammals and birds. This family of viruses consists of two genera, Avastrovirus (AAstV) and Mamastrovirus (MAstV). Astroviruses most frequently cause infection of the gastrointestinal tract but in some animals they may result in encephalitis (humans and cattle), hepatitis (avian) and nephritis (avian). Astroviruses were first identified in humans in 1975 from the stool of children with diarrhea. Human infections are usually self-limiting but may also spread systematically and infect immunocompromised individuals. Taxonomy The International Committee on Taxonomy of Viruses (ICTV) established ''Astroviridae'' as a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avastrovirus
''Avastrovirus'' is a genus of viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's ..., in the family '' Astroviridae''. Birds serve as natural hosts. There are three species in this genus. Diseases associated with this genus include: gastroenteritis, liver or kidney damages. Taxonomy The genus contains the following species: * '' Avastrovirus 1'' * '' Avastrovirus 2'' * '' Avastrovirus 3'' Structure Viruses in ''Avastrovirus'' are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. The diameter is around 35 nm. Genomes are linear and non-segmented, around 6.8-7kb in length. Life cycle Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment to host receptors, which mediates endocytosis. Replication follows the positi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mamastrovirus
''Mamastrovirus'' is a genus of viruses, in the family ''Astroviridae ''Astroviridae'' is a family of non-enveloped ssRNA viruses that cause infections in different animals. The family name is derived from the Greek word ''astron'' ("star") referring to the star-like appearance of spikes projecting from the surface ...''. Human, mammals, and vertebrates serve as natural hosts. There are 19 species in this genus. Diseases associated with this genus include infantile gastroenteritis. Taxonomy The genus contains the following species: *'' Mamastrovirus 1'' *'' Mamastrovirus 2'' *'' Mamastrovirus 3'' *'' Mamastrovirus 4'' *'' Mamastrovirus 5'' *'' Mamastrovirus 6'' *'' Mamastrovirus 7'' *'' Mamastrovirus 8'' *'' Mamastrovirus 9'' *'' Mamastrovirus 10'' *'' Mamastrovirus 11'' *'' Mamastrovirus 12'' *'' Mamastrovirus 13'' *'' Mamastrovirus 14'' *'' Mamastrovirus 15'' *'' Mamastrovirus 16'' *'' Mamastrovirus 17'' *'' Mamastrovirus 18'' *'' Mamastrovirus 19'' Structure Viruses in ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avastrovirus
''Avastrovirus'' is a genus of viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's ..., in the family '' Astroviridae''. Birds serve as natural hosts. There are three species in this genus. Diseases associated with this genus include: gastroenteritis, liver or kidney damages. Taxonomy The genus contains the following species: * '' Avastrovirus 1'' * '' Avastrovirus 2'' * '' Avastrovirus 3'' Structure Viruses in ''Avastrovirus'' are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. The diameter is around 35 nm. Genomes are linear and non-segmented, around 6.8-7kb in length. Life cycle Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment to host receptors, which mediates endocytosis. Replication follows the positi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avian Nephritis Virus
''Avastrovirus 2'', also called avian nephritis virus, is an astrovirus which causes 'avian nephritis' in chickens. Causes: Infectious Stunting Syndrome — ISS — Baby Chick Nephritis — BCN. The virus has been reported in Japan, Europe, USA and New Zealand. The disease is mainly transmitted horizontally by the oro-faecal route, but rarely vertical transmission may occur. Clinical signs of the disease are normally only seen in chicks less than two weeks old, and these signs should be mild unless the chick is immunosuppressed. Clinical signs and diagnosis In mild cases diarrhea, stunted growth and skin lesions are the common clinical signs. Clinical signs are more severe in immunosuppressed, under-nourished or stressed chicks, with infection causing nephrosis, emaciation and even sudden death. On postmortem examination nephritis with accumulation of uric acid (gout) and enteritis are commonly present. A presumptive diagnosis may be based on clinical signs. For defin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Electron Microscopy
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device. Transmission electron microscopes are capable of imaging at a significantly higher resolution than light microscopes, owing to the smaller de Broglie wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands of times smaller than a resolvable object seen in a light microscope. Transmission electron microscopy is a major analytical method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foodborne Illnesses
Foodborne illness (also foodborne disease and food poisoning) is any illness resulting from the spoilage of contaminated food by pathogenic bacteria, viruses, or parasites that contaminate food, as well as prions (the agents of mad cow disease), and toxins such as aflatoxins in peanuts, poisonous mushrooms, and various species of beans that have not been boiled for at least 10 minutes. Symptoms vary depending on the cause but often include vomiting, fever, and aches, and may include diarrhea. Bouts of vomiting can be repeated with an extended delay in between, because even if infected food was eliminated from the stomach in the first bout, microbes, like bacteria (if applicable), can pass through the stomach into the intestine and begin to multiply. Some types of microbes stay in the intestine. For contaminants requiring an incubation period, symptoms may not manifest for hours to days, depending on the cause and on quantity of consumption. Longer incubation periods tend to ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastroenterology
Gastroenterology (from the Greek gastḗr- “belly”, -énteron “intestine”, and -logía "study of") is the branch of medicine focused on the digestive system and its disorders. The digestive system consists of the gastrointestinal tract, sometimes referred to as the ''GI tract,'' which includes the esophagus, stomach, small intestine and large intestine as well as the accessory organs of digestion which includes the pancreas, gallbladder, and liver. The digestive system functions to move material through the GI tract via peristalsis, break down that material via digestion, absorb nutrients for use throughout the body, and remove waste from the body via defecation. Physicians who specialize in the medical specialty of gastroenterology are called gastroenterologists or sometimes ''GI doctors''. Some of the most common conditions managed by gastroenterologists include gastroesophageal reflux disease, gastrointestinal bleeding, irritable bowel syndrome, irritable bow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Diseases
Viral means "relating to viruses" (small infectious agents). Viral may also refer to: Viral behavior, or virality Memetic behavior likened that of a virus, for example: * Viral marketing, the use of existing social networks to spread a marketing message * Viral phenomenon, relating to contagion theory or the "virality" of network culture, such as a meme * Viral video, a video that quickly attains a high popularity Titled works * ''Viral'' (2016 American film), a 2016 American science fiction horror drama * ''Viral'' (2016 Hindi film), an Indian Bollywood film based on social media * ''Viral'' (web series), a 2014 Brazilian comedy web series * '' V/H/S: Viral'', an American anthology horror film * '' Viral: The Search for the Origin of COVID-19'', a book by Alina Chand and Matt Ridley See also * '' Virals'', a novel series by Kathy Reichs * Virulence Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme ( RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and, utilising amino acids carried by transfer RNA (tRNA), the ribosome creates the protein. This process is known as translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleoside Triphosphate
A nucleoside triphosphate is a nucleoside containing a nitrogenous base bound to a 5-carbon sugar (either ribose or deoxyribose), with three phosphate groups bound to the sugar. They are the molecular precursors of both DNA and RNA, which are chains of nucleotides made through the processes of DNA replication and transcription. Nucleoside triphosphates also serve as a source of energy for cellular reactions and are involved in signalling pathways. Nucleoside triphosphates cannot be absorbed well, so they are typically synthesized within the cell. Synthesis pathways differ depending on the specific nucleoside triphosphate being made, but given the many important roles of nucleoside triphosphates, synthesis is tightly regulated in all cases. Nucleoside analogues may also be used to treat viral infections. For example, azidothymidine (AZT) is a nucleoside analogue used to prevent and treat HIV/AIDS. Naming The term nucleoside refers to a nitrogenous base linked to a 5-carbon su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA-dependent RNA Polymerase
RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to typical DNA-dependent RNA polymerases, which all organisms use to catalyze the transcription of RNA from a DNA template. RdRp is an essential protein encoded in the genomes of most RNA-containing viruses with no DNA stage including SARS-CoV-2. Some eukaryotes also contain RdRps, which are involved in RNA interference and differ structurally from viral RdRps. History Viral RdRps were discovered in the early 1960s from studies on mengovirus and polio virus when it was observed that these viruses were not sensitive to actinomycin D, a drug that inhibits cellular DNA-directed RNA synthesis. This lack of sensitivity suggested that there is a virus-specific enzyme that could copy RNA from an RNA template and not from a DNA template. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
