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Avian Paramyxovirus
''Avulavirinae'' is a subfamily of viruses in the family '' Paramyxoviridae''. Members of the subfamily are collectively known as avulaviruses. All members of the subfamily primarily infect birds. ''Avulavirinae'' was previously recognized as the genus ''Avulavirus'' before being elevated to a subfamily. The term ''avula'' comes from "avian rubula", distinguishing it from rubulaviruses of the subfamily '' Rubulavirinae'' due to avulaviruses only infecting birds and translating protein V from an edited RNA transcript. The most notable avulavirus is the Newcastle disease virus, a strain of ''Avian orthoavulavirus 1''. Characteristics Like all Paramyxoviruses, avulaviruses are enveloped negative-strand RNA viruses. Avulaviruses have a hemagglutinin-neuraminidase attachment protein and do not produce a non-structural protein C. Avulaviruses can be separated into distinct serotypes using hemagglutination assay and neuraminidase assay. All avulaviruses hemagglutinate chicken RBCs excep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avian Orthoavulavirus 1
Virulent Newcastle disease (VND), formerly exotic Newcastle disease, is a contagious viral avian disease affecting many domestic and wild bird species; it is transmissible to humans. Though it can infect humans, most cases are non-symptomatic; rarely it can cause a mild fever and influenza-like symptoms and/or conjunctivitis in humans. Its effects are most notable in domestic poultry due to their high susceptibility and the potential for severe impacts of an epizootic on the poultry industries. It is endemic to many countries. No treatment for VND is known, but the use of prophylactic vaccines and sanitary measures reduces the likelihood of outbreaks. The disease is caused by Newcastle disease virus (NDV), an avulavirus. Strains of Newcastle disease virus have been used to treat cancer in humans, since the virus appears to preferentially infect and kill cancerous cells. Strains of Newcastle disease virus have also been used to create viral vector vaccine candidates against Ebol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjunctiva
The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium and stratified cuboidal epithelium (depending on the zone). The conjunctiva is highly vascularised, with many microvessels easily accessible for imaging studies. Structure The conjunctiva is typically divided into three parts: Blood supply Blood to the bulbar conjunctiva is primarily derived from the ophthalmic artery. The blood supply to the palpebral conjunctiva (the eyelid) is derived from the external carotid artery. However, the circulations of the bulbar conjunctiva and palpebral conjunctiva are linked, so both bulbar conjunctival and palpebral conjunctival vessels are supplied by both the ophthalmic artery and the external carotid artery, to varying extents. Nerve supply Sensory innervation of the conjunctiva is divided into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
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 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paramyxoviridae
''Paramyxoviridae'' (from Ancient Greek, Greek ''para-'' “by the side of” and ''myxa'' “mucus”) is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Vertebrates serve as natural hosts. Diseases associated with this family include measles, mumps, and respiratory tract infections. The family has four subfamilies, 17 genera, and 78 species, three genera of which are unassigned to a subfamily. Structure Virions are enveloped and can be spherical or pleomorphic and capable of producing filamentous virions. The diameter is around 150 nm. Genomes are linear, around 15kb in length. Fusion proteins and attachment proteins appear as spikes on the virion surface. Matrix proteins inside the envelope stabilise virus structure. The nucleocapsid core is composed of the genomic RNA, nucleocapsid proteins, phosphoproteins and polymerase proteins. Genome The genome is nonsegmented, negative-sense RNA, 15–19 kilobases in length, and contains six to 10 gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubulavirinae
''Rubulavirinae'' is a subfamily of viruses in the family ''Paramyxoviridae''. Humans, apes, pigs, and dogs serve as natural hosts. There are currently 18 species in the two genera ''Orthorubulavirus'' and ''Pararubulavirus''. Diseases associated with this genus include mumps. Members of the subfamily are collectively called rubulaviruses. The subfamily was previously a genus named ''Rubulavirus'' but was elevated to subfamily in 2018. Viruses of this subfamily appear to be most closely related to members of ''Avulavirinae''. Taxonomy Subfamily: ''Rubulavirinae'' :Genus: ''Orthorubulavirus'' :Genus: ''Pararubulavirus'' Structure Rubulavirions are enveloped, with spherical geometries. The diameter is around 150 nm. Rubulavirus genomes are linear, around 15kb in length. The genome codes for 8 proteins. Life cycle Viral replication is cytoplasmic. Entry into the host cells is achieved after viral attachment to host cells. Replication follows the negative stranded RNA virus r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newcastle Disease
Virulent Newcastle disease (VND), formerly exotic Newcastle disease, is a contagious viral avian disease affecting many domestic and wild bird species; it is transmissible to humans. Though it can infect humans, most cases are non-symptomatic; rarely it can cause a mild fever and influenza-like symptoms and/or conjunctivitis in humans. Its effects are most notable in domestic poultry due to their high susceptibility and the potential for severe impacts of an epizootic on the poultry industries. It is endemic to many countries. No treatment for VND is known, but the use of prophylactic vaccines and sanitary measures reduces the likelihood of outbreaks. The disease is caused by Newcastle disease virus (NDV), an avulavirus. Strains of Newcastle disease virus have been used to treat cancer in humans, since the virus appears to preferentially infect and kill cancerous cells. Strains of Newcastle disease virus have also been used to create viral vector vaccine candidates against Ebo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enveloped Virus
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. Numerous human pathogenic viruses in circulation are encased in lipid bilayers, and they infect their target cells by causing the viral envelope and cell membrane to fuse. Although there are effective vaccines against some of these viruses, there is no preventative or curative medicine for the majority of them. In most cases, the known vaccines operate by inducing antibodies that prevent the pathogen from entering cells. This happens in the case of enveloped viruses when the antibodies bind to the viral envelope proteins. The membrane fusion event that triggers viral entrance is caused by the viral fusion protein. Many enveloped viruses only have one protein visible on the surface of the particle, which is required for both mediating adhesion to the cell surface and for the subsequent membrane fusi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative-strand RNA Virus
Negative-strand RNA viruses (−ssRNA viruses) are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid. They have genomes that act as complementary strands from which messenger RNA (mRNA) is synthesized by the viral enzyme RNA-dependent RNA polymerase (RdRp). During replication of the viral genome, RdRp synthesizes a positive-sense antigenome that it uses as a template to create genomic negative-sense RNA. Negative-strand RNA viruses also share a number of other characteristics: most contain a viral envelope that surrounds the capsid, which encases the viral genome, −ssRNA virus genomes are usually linear, and it is common for their genome to be segmented. Negative-strand RNA viruses constitute the phylum ''Negarnaviricota'', in the kingdom '' Orthornavirae'' and realm '' Riboviria''. They are descended from a common ancestor that was a double-stranded RNA (dsRNA) virus, and they are considered to be a sister clade of reovi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemagglutination Assay
The hemagglutination assay or haemagglutination assay (HA) and the hemagglutination inhibition assay (HI or HAI) were developed in 1941–42 by American virologist George Hirst as methods for quantifying the relative concentration of viruses, bacteria, or antibodies. HA and HI apply the process of hemagglutination, in which sialic acid receptors on the surface of red blood cells (RBCs) bind to the hemagglutinin glycoprotein found on the surface of influenza virus (and several other viruses) and create a network, or lattice structure, of interconnected RBCs and virus particles. The agglutinated lattice maintains the RBCs in a suspended distribution, typically viewed as a diffuse reddish solution. The formation of the lattice depends on the concentrations of the virus and RBCs, and when the relative virus concentration is too low, the RBCs are not constrained by the lattice and settle to the bottom of the well. Hemagglutination is observed in the presence of staphylococci, vibrios, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
