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17 Cards in this Set
- Front
- Back
A Poxvirus mature virion (MV) is composed of? |
A bi-concave core, lateral bodies, and an envelope embedded with up to 100 proteins, all surrounding a tubular DNA structure |
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There are 2 forms of enveloped virions, both which are infectious what are their strengths? |
Enveloped Virus (EV): efficient for cell-to-cell spread required within a host Mature Virus (MV) extremely stable more responsible for person-to-person spread of virus |
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A unique aspect of Poxviruses genomes is that: |
They are linear but have no free ends |
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How are genes named? |
Individual genes are numbered sequentially within individual Hind III restriction fragments with the letters corresponding to the relative size of each fragment are designated with "L" or "R" to decipher which direction they are read from |
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Poxvirus entry occurs in 2 steps what are these steps? |
1. Uncoating I releases the core into the cytoplasm 2. Uncoating II releases the DNA |
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What's important to know regarding early genes |
Immediately following infection early genes are expressed within the core, then mRNAs are extruded from the core into the cytoplasm for translation |
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Poxvirus replication occurs solely in the? |
Cytoplasm |
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Virus gene transcription is tightly controlled by three sets of virus-encoded transcription factors what are these factors and what do they induce? |
Viral intermediate transcription factors (VITF): induce intermediate genes Viral late transcription factors (VLTF) induce late genes Viral early transcription factors (VETF) induce early genes upon entry |
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What is the accepted but not proven model for Poxvirus replication? |
Rolling hairpin replication |
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What is the primary disease caused by Poxviruses with an average fatality rate of 25%? |
Smallpox (variola virus) |
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Smallpox initial incubation period is? |
7-17 days (12-14 days typically) |
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After 2-3 days prodrome __________ rash develops over face and extremeties. Within a few days the rash transitions to ___________, and then to ___________. |
Papular (red bumps not painful/itchy) Vesicular (blistering) Pustular (painful lesions) |
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Variolation: |
Took advantage of the fact that infection with variola virus by an unnatural route resulted in disease of reduced severity and decreased mortality |
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insufflation: |
Chinese practitioners pulverized pock scabs from individuals undergoing mild infection then blew the powder through a tube into the nostrils of uninflected people. |
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Cutaneous Variolation: |
Indian practitioners seeded freshly scratched skin of a recipient with pus from an active smallpox infection |
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Edward Jenner invented vaccination after he observed cowpox marks on the hand of a milkmaid, and realized that the milkmaids were also: |
Resistant to variola virus |
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Smallpox vaccination is no longer used because? |
The virus was eradicated from the worlds population in 1979 |