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(vī′rōm″) [vir(us) + -ome] All of the viruses found in an organism or other environment.


(vī″rō-pĕk′sĭs) [″ + Gr. pexis, fixation] The fixation of a virus particle to a cell. This leads to the inclusion of the virus inside the cell.


(vī″rŏ-ther′ă-pē) [virus + therapy] 1. The use of viruses to infect and kill rapidly replicating cells, esp. cancer cells. Oncolytic viruses used in virotherapy include some adenoviruses, influenza virus, mumps virus, Newcastle virus, and poliovirus. 2. Treatment of cancer patients with cancer cell extracts (oncolysates) that have been obtained by breaking down the cancer cells with viruses to which they are susceptible.


A poisonous substance (usually a protein) released by a virus that destroys or alters the metabolic integrity of cells.


(vĭr′choo-ăl) [L. virtualis, (being) in essence or effect] 1. Having actual authority or real power without official acknowledgement or title. 2. In computer technology, made, conducted, or simulated by software on a computer, computer network, or online. virtuality (vĭr″choo-al′ĭt-ē), n. virtually (-ă-lē), adv.

virucide, viricide

(vī′rŭ-sīd″) [virus + -cide] An agent that destroys or inactivates a virus, esp. a chemical substance used on living tissue. virucidal (vī″rŭ-sīd′ăl), adj.


(vir′yŭ-lĕns) [L. virulentia, stench] 1. The relative power of an agent or a microorganism to cause harm or disease. Properties that influence the virulence of an organism include 1) the strength of its adhesion molecules, which link it to the target cell; 2) its ability to secrete enzymes or exotoxins that damage target cells, or endotoxins that interfere with the body’s normal regulatory systems; and 3) its ability to inhibit or evade the actions of the immune system and their chemical mediators. SEE: immunocompetence; immunocompromised. 2. Of a disease, the property of being virulent; venomousness. SEE: attenuation.


(vĭr′yŭū-lĕnt) [L. virulentus, poisonous] 1. Very poisonous. 2. Able to overcome the host’s defensive mechanism; infectious. SEE: malignant.


(vĭr-yŭ-lĭf′ér-ŭs) [virul(ence) + ″] Colonized or infected by a virus and able to transmit that virus to another organism.


(vīr-ūr′ē-ă) [″ + Gr. ouron, urine] The presence of viruses in the urine.


(vī′rŭs) [L. virus, poison] A pathogen that is composed of nucleic acid within a protein shell but can grow and reproduce only after infecting a host cell. More than 400 types of viruses are known. All of them can attach to cell membranes, enter the cytoplasm, take over cellular functions, reproduce ...

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