Scheduled maintenance: Saturday, March 6 from 3–4 PM PST
Upgrade to remove ads
Only $2.99/month

Viral Pathogenesis and Diagnosis

Terms in this set (32)

Which of the following infectious inoculations is restricted to site of entry?
A. scratch/abrasion
B. insect bite
C. deep inoculation
A. scratch/abrasion
-the others can cause systemic infection
how do viruses escape our protective saliva defense?
tight binding
rapid penetration of cells
GI tract defenses
1. pH of stomach acid
2. proteases
3. bile salts
bile salts mainly damage what type of viruses?
enveloped
(enteroviruses are usu naked to avoid this mechanism)
T/F: viruses utilize the lymph nodes to facilitate invasion
true
T/F: bile salts remove the capsid of the virus
false- they remove the lipid envelope
T/F: temperature is only effective at killing bacteria, not viruses
false- temp is a defense against viruses
Outcome of exposure to a virus does not depend on:
A. pathogen
B. inoculum size
C. host immune system
D. all of the above
D. all of the above
How do people acquire viral genitourinary tract infections?
-tear or microabrasion
-viremia which filters into the kidneys and causes infection
initial infection that causes non-specific symptoms
prodrome
(innate immune response)
low level of viruses in blood
high levels of viruses in blood
primary viremia
secondary viremia
NK cells will kill cells that lack what?
MHC 1. When infected with a virus, the cell stops putting MHC 1 out, and the NK cell sees the lack of MHC 1 and kills the cell
monolayer of cells with little holes that shows where a single virus has infected the host
plaque assay
-add Ab and this decrease the amount of virus that is able to infect the host (these are neutralizing Ab)
Clinical Viral infection is caused by what 3 things?
1. direct tissue damage from virus
2. immune-mediated damage
3. activation of oncogenes
Clinical manifestation depends on what 3 things?
1. tissue tropism
2. effectiveness of the immune response
3. regulation of the immune response
Tissue tropism
infection is confined to a specific tissue
Place these events in the correct order:
-loss of contact inhibition of cell growth
-uncontrolled cell growth
-growth without senescence
-Accumulation of tumorigenic mutations
-increased rate of cell growth
1. uncontrolled cell growth
2. growth without senescence
3. increased rate of cell growth
4. loss of contact inhibition of cell growth
5. Accumulation of tumorigenic mutations
How can viruses induce tumor formation?
1. suppress tumor suppressor genes (blocking cell cycle check points)
2. activate oncogenes
Explain how viruses (HPV) bypass the check points of the cell cycle
Before the S phase, RB and E2F are bound and E2F needs to be released for gene transcription to occur.
-HPV uses E7 to bind to RB so that E2F is released for gene expression
1. Which of the following is NOT a way to look for viral infection
2. Which i the best way/most common?
-Ab
-ELISA
-oral HIV
-Southern
-Western Blot
-Viral Ag detection
-PCR (viral genome detection)
-Viral enzyme detection
-virion detection with EM
Southern Blot - no
best - PCR
What is a diagnostic feature of viruses when looking under microscope?
viral inclusion bodies
What are viral culture methods?
1. Tissue/cell culture
2. Plaque cultures
In viral serodiagnosis, what is the titer?
The highest Ab dilution that inhibits viral growth
Viral serodiagnosis:
-active response markers
-IgM --> first response
-rise or fall in IgG
Viral serodiagnosis:
1. what would indicate a first, active response to a virus
2. What would indicate a past infection?
1. IgM - active first response
2. single IgG titer - past infection
this is used as a way to monitor responses of host to vaccines
ELISA
What is the best way to detect
-antiviral Ab?
-virus Ag?
ELISA test
What test would you use to detect if someone was seroconverting to HIV?
Western Blot
The oral HIV test screens for what specifically?
Ab against HIV
assay that detects Ab or Ag
immunoflourescence
How does PCR amplify DNA?
Taq DNA polymerase
-H+ are released during base incorporation
-individual polymerases are attached to wells that rest on a pH meter
Ion torrent system
THIS SET IS OFTEN IN FOLDERS WITH...