Orthomyxoviridae

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Or·tho·myx·o·vir·i·dae

(ōr'thō-mik'sō-vir'i-dē),
The family of viruses that contains the three genera of influenza viruses, types A and B, C, and Thogoto-like viruses. Virions are roughly spheric or filamentous, and the former (the more common form) are 80-120 mm in diameter and ether-sensitive; envelopes are studded with surface projections; nucleocapsids are of helical symmetry, 6-9 nm in diameter, and contain single-stranded, segmented RNA. The nucleoprotein antigen of each type of virus is common to all strains of the type but is distinct from those of the other types; the mosaic of surface antigens varies from strain to strain. Nucleocapsids seem to be formed in the nuclei of infected cells, hemagglutinin, and neuraminidase in the cytoplasm; virus maturation occurs during budding of the cell membrane. Influenza virus types A and B are subject to mutation resulting in epidemics. Influenza virus C differs from types A and B (for example, lacks neuraminidase) and belongs to a separate genus.
See also: Influenza virus.

Or·tho·myx·o·vir·i·dae

(ōr'thō-mik'sō-vir'i-dē)
The family of viruses that comprises the three groups of influenza viruses, types A, B, and C. The only recognized genus is Influenzavirus, which comprises the strains of virus types A and B, both of which are subject to mutation resulting in epidemics. Influenza virus type C differs from types A and B somewhat and probably belongs to a separate genus.
See also: Influenzavirus

Or·tho·myx·o·vir·i·dae

(ōr'thō-mik'sō-vir'i-dē)
The family of viruses that comprises the three groups of influenza viruses, types A, B, and C. The only recognized genus is Influenzavirus (q.v.), which comprises the strains of virus types A and B, both of which are subject to mutation resulting in epidemics.

Orthomyxoviridae

a family of viruses containing influenza viruses A, B and C of which only influenza A viruses cause disease in domestic animals. Virions are 100 nm diameter, enveloped and contain a single-stranded negative sense RNA genome in eight segments. The envelope carries two glycoprotein spikes, hemagglutination (H) and neuraminidase (N), each of which is coded for by a different genome segment and undergo continuous antigenic variation, either because of mutation (antigenic drift) or genetic recombination (antigenic shift).
References in periodicals archive ?
The orthokeratinized variant of the odontogenic keratocyst also called orthokeratinized odontogenic cyst (OOC) arises from the rests of the dental lamina.
The histopathology reports were categorised as para or orthokeratinized odontogenic keratocysts.
Odontogenic keratocysts are the most aggressive odontogenic cysts of the oral cavity and they have a high recurrence rate, these cysts are classified according to their histopathological behaviour and lining of the epithelium as parakeratinized, orthokeratinized and combination of the two.
Histologically the WHO (1992) classified the OKC into three variants parakeratinized, orthokeratinized and combination of the two.
Orthokeratinized odontogenic cyst had a male predominance with a male to female ratio of 2.
Histologic examination demonstrated several striking differences between the epithelial lining of orthokeratinized and parakeratinized cysts.
Orthokeratinized odontogenic cyst: a clinicopathological and immunocytochemical study of 15 cases.
Anatomic Location of Orthokeratinized Odontogenic Cysts (OOCs) and Comparison With Keratocystic Odontogenic Tumors (KCOTs) Reported Previously by Our Group Cases, Maxilla (%) Lesion No.
Histological diagnosis of orthokeratinized odontogenic cyst was excluded from study because of different biological behavior.
Incisional biopsy of the lesion was done and microscopic examination showed a cyst lined by orthokeratinized stratified squamous epithelium which was 6-10 layers thick with a distinct granular cell layer and a cuboidal basal layer which lacked any palisading.
Until recently orthokeratinized odontogenic cyst has been considered to be a type of odontogenic keratocyst.
Clinicopathological studies on odontogenic keratocysts have reported the orthokeratinized variant as ranging from 3.