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15 Cards in this Set
- Front
- Back
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How is pathogenesis related to evolution?
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"Younger" viruses tend to be more pathogenic while "older" viruses are better adapted for symbiosis and thus are not as pathogenic.
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What is latency?
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Host cells have a viral persistance but not a productive infection - i.e. viral replication, and hence, viral pathogenesis is not occurring.
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What are the five most common host determinants of viral pathogenesis?
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1.Age
2.Nutritional status 3.Concurrent diseases 4.Gender 5.Immune status |
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Many viruses are adapted to a specific portal of entry, and this is taken advantage of during vaccine design. Name 2 viruses whose vaccines use a different portal of entry from the wild-type infection.
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1.Small Pox - natural portal of entry is through the oropharnxy, vaccine given through scarification
2.Adenovirus - natural portal of entry is through the oropharnxy, vaccine given enterically |
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Why do influenza and parainfluenza viruses require the presence of a specific protease released by host epithellium and some bacteria before they can enter the host cell?
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The host enzyme cleaves an "H" protein which then exposes the fusogenic protein.
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Does an epidermal infection usually spread systemically? Why or why not?
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These infections usually remain localized due to the absence of lymphatics, vasculature, or nerves.
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How do larger aerosolized droplets vs. smaller aerosolized droplets settle in the lungs?
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Larger droplets settle in the upper areas of the lungs while smaller droplets settle in the lower areas.
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What are three barriers the lungs present to viral infection via aerosolized droplets?
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1.Mucus and cilia
2.Secretory IgA 3.Phagocytic cells |
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How does the cellular site of maturation influence the dissemination of a virus?
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Viruses that mature at the basolateral membrane tend to penetrate deeper while those that mature at the apical membrane sre released back into the lumen.
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What is viremia?
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The presence of viral particles in the bloodstream
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How can viremia be diminished?
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Uptake of viral particles by cells of the RES and opsonization.
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What purpose does high titer viremia serve the virus?
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It allows penetration of multiple organ systems and increases the likelihood of transmission.
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What are four ways viruses are able to penetrate the blood-brain barrier?
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They can...
1.Cross cells in endocytic vesicles 2.Enter inside of monocytic cells 3.Cross the fenestrated epithelium of the choroid plexus 4.Travel retrograde up peripheral neurons |
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Name 2 things that influence viral tropism towards certain tissues.
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1.Presence of specific receptors
2.Mitotic state of the tissue 3.Specific transcription factors |
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Name three ways viruses can induce cell death.
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1.Inhibition of cellular metabolism
2.Induction of apoptotic pathways 3.Cell-mediated immune response 4.Fusion |
