Gastro-Adeno-Papilloma- Exam IV Flashcards
(113 cards)
1
Q
- inflammation of stomach or intestines
- important disease of infants and children
- leading cause of childhood death in developing countries
A
viral gastroenteritis
2
Q
The naming of viral gastroenteritis is named based on:
A
tissue tropism; not viral structure
3
Q
viral gastroenteritis is an important disease of ___ & ___
A
infants and children
4
Q
The leading cause of childhood death in developing countries:
A
viral gastroenteritis
5
Q
Etiological agents of viral gastroenteritis in humans include: (6)
A
- rotavirus (Groups A,B & C)
- Norovirus
- Sapovirus
- Enteric adenovirus
- Astrovirus
- Aichi virus
6
Q
Describe the genomic structure of groups A, B, and C rotaviruses:
A
segmented double stranded RNA
7
Q
Describe the genomic structures of Norovirus, Sapovirus, Astrovirus and Aichi virus:
A
positive sense single stranded RNA
8
Q
Describe the genomic structure of enteric adenovirus:
A
linear double stranded DNA
9
Q
Major cause of diarrhea in children 6-24 months:
A
Group A rotavirus
10
Q
Major cause of diarrhea outbreaks in children and adults:
A
Norovirus
11
Q
~50% of diarrhea cases still have:
A
unknown etiology (meaning we likely still have yet to discover many pathogens)
12
Q
first virus identified from stool samples by electron microscopic examination in 1972:
A
Norwalk
13
Q
What family of viruses does Rotaviruses belong too?
A
Reovirus family
14
Q
What does Reovirus stand for:
A
Respiratory Enteric Orphan virus
15
Q
Describe the characteristic structure of rotaviruses:
A
- nonenveloped
- inner and outer capsids
16
Q
How do rotaviruses enter host cells?
A
endocytosis
17
Q
What happens once rotaviruses have been endocytosed into the host cell?
A
exit the phagosome
18
Q
What allows for the ds-RNA genome of the rotavirus to be copied inside the host cell?
A
RNA dependent RNA polymerase
19
Q
What does the viral protein produced by the mRNA of rotavirus assemble into?
A
capsid structures
20
Q
Where does the viral replication of rotavirus complete?
A
inside capsid structures
21
Q
How rotavirus acquire an envelope? (recall it is originally unenveloped upon entering host cell)
A
by budding into ER
22
Q
Following acquiring the viral envelope via the ER, when does rotavirus shed the envelope?
A
Sheds envelope as the second capsid layer is build and the virus is released
23
Q
What does the release of the rotavirus envelope involve?
A
Lysis of infected cells
24
Q
What is responsible for the tissue damage associated with Rotaviruses?
A
lysis of infected cells
25
What is responsible for the fatality of infection rotaviruses?
dehydration
26
Discuss the transmission mode of rotavirus?
fecal-oral transmission
27
What is responsible for the acid stability seen in rotavirus?
double capsid structure
28
During an active infection of rotavirus, how many particles can be shed per ml of stool?
10^12 viral particles
29
How many viral particles are necessary to initiate infection of rotavirus?
as few as 10
30
What is the characteristic symptoms of infection with rotavirus?
watery-diarrhea
31
Rotavirus produces a ___.
enterotoxin
32
The enterotoxin produced by rotavirus binds ____, resulting in ___.
integrins, signaling that causes secretion of chloride and water
33
The enterotoxin produced by rotavirus ultimately results in:
secretion of chloride and water
34
During rotavirus infection, what happens to infected gut epithelial cells?
these cells are destroyed and replaced by immature epithelial cells
35
During a rotavirus infection, what is the significance of the infected gut epithelial cells being replaced with immature epithelial cells:
1. reduced uptake of ions
2. reduced water uptake
3. less absorption of food molecules (carbs)
36
What is the most common type of rotavirus in the U.S?
Group A
37
Is there a vaccine for rotavirus?
Yes- for infants and greater than 75% effective
38
Describe the genomic structure of Noroviruses:
- positive single stranded RNA genome
- ~7,500 bases in lengths
~ Naked Capside virions
39
Describe the virions produced by Noroviruses:
naked capside virions
40
The replication of Noroviruses are similar to ____ except for ____.
picornavirus (polioviruses); except for 2nd phase of translation
41
How does the 2nd phase of translation of Noroviruses differ from the replication of picornaviruses (poliovirus)?
The second phase of translation involves subgenomic RNAs
42
The second phase of translation of noroviruses involve subgenomic RNAs being produce. What other virus is this similar to?
coronaviruses
43
Similar to picornaviruses, Noroviruses have a ____ on the RNA.
5' VPg protein
44
Since the Noroviruses is a naked capsid virus, infection will result in:
tissue damage
45
Virus that is a characteristically a positive agent of infection in big group confined settings such as cruise ships:
Noroviruses
46
Describe the genomic structure of adenovirus:
- linear double stranded DNA genome
- nonenveloped
- icosahedral capsid
47
Discuss the location of viral replication characteristic of most DNA viruses (including adenovirus):
the nucleus is involved
48
Follow the endosome rupture during adenovirus replication, what occurs:
viral nucleoprotein complex enters the cell nucleus
49
DNA viruses have larger genomes and more genes and they end up having a cascade of gene expression and this typically involves three waves. What are waves of gene expression in the adenovirus?
pre-early, early, and late genes
50
Adenovirus displays ____, meaning replication occurs in waves.
temporal regulation
51
Adenovirus along with most DNA viruses produces ____ during viral gene expression
transcriptional regulators
52
Transcriptional regulators produced during one phase of gene expression/viral replication act to:
promote transcription of genes of subsequent phase
53
Describe the priming of DNA synthesis in adenovirus:
by pTP serine residue (pre-terminal protein)
54
Adenovirus DNA Replication:
1. Only ____ is copied at each replication fork
2. No ____ replication
3. Priming is by ___.
1. one of the two DNA strands
2. discontinuous
3. viral protein (pTP)
55
Adenovirus infections can be described as ____. Explain
widespread; 5-10% of all viral infections
56
Symptoms of adenovirus usually resemble:
common cold symptoms
57
Adenovirus are one of the causative agents for:
common cold
58
Is there an adenovirus vaccine? If so, describe:
vaccine, live virus, given to new military recruits for serotypes 4 & 7
59
What virus causes ARD (acute respiratory disease):
adenovirus serotypes 4 & 7
60
ARD:
acute respiratory disease
61
Discuss the mechanisms for evasion of host defenses used by Adenovirus:
1. block MHC class I mRNA production
2. block transport of MHC class I proteins to cell surface
62
How does adenovirus block transport of MHC class I proteins to cell surface in order to evade host defense?
viral E3gp19K protein does this and results in the block of killing by cytotoxic T cells
63
One thing we will encounter with most DNA viruses including adenovirus is their ability to drive host cell into:
cell division
64
Adenovirus drives the host cell into cell division which is necessary for:
adenovirus replication
65
What aspect of host cell division is necessary for adenovirus to replicate?
S phase factors
66
What aspects of adenovirus interfere with cell division controllers?
proteins E1a and E1b
67
What is the function of adenovirus proteins E1b and E1a?
both interfere with cell division controllers but specifically E1b sequesters p53 and E1a sequesters Rb (retinoblastoma protein)
68
Adenovirus protein E1b:
sequesters p53
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Adenovirus protein E1a:
sequesters Rb (retinoblastoma protein)
70
Because of the interference with cell division controllers, adenovirus infection can potentially:
drive a cell toward cancerous state
71
In typical cell cycle, ____ recognizes DNA damage and activates ____.
P53; P21
72
P53 recognizes DNA damage and activates P21 which will bind and inactivate the ____.
cyclin-CDK complex
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As DNA damage is repaired, what happens to P53 and P21?
P53 decreases; P21 no longer blocks cyclin CDK, cell-cycle progression
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Acts as a checkpoint controller to stop cell-cycle progression:
P53
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Inactivation of p53 by adenovirus E1b protein prevents:
activation of p21 (and Bax)
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Adenovirus E1a protein binds to:
Rb complex
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When adenovirus E1a protein binds to Rb complex, this:
prevents Rb from negatively regulating E2F
78
What is E2F responsible for in the cell cycle:
transcribing a number of different genes for DNA synthesis
79
Describe HPV genome and viral structure:
- double stranded circular DNA molecule
- nonenveloped viral particles
80
How many types of HPV are there and what are the broad categories?
at least 100 different types; cutaneous HPV or mucosal HPV
81
The infection process of HPV usually takes:
3-4 months
82
HPV accesses ____ through breaks in skin
basal layer
83
In HPV infection, viral early genes stimulate ____ which facilitates ___.
cell growth; viral replication
84
HPV reproduction is coordinated with:
development of keratinocytes
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non dividing, physical barrier; anuclear:
keratinocytes
86
In HPV infection, as cells move through skin layers:
HPV gene expression and DNA replication begins
87
For HPV gene expression and DNA replication, ___ is used
cellular DNA polymerase
88
In HPV infection, ____ are only made in differentiated layers
late proteins (capsid proteins)
89
In HPV infection, assembly occurs in ___ during ___ development
nucleus; keratinocyte
90
In HPV infection, as the nucleus breaks down you end up with nuclear remnants with ____ shed at ___.
viral particles; skin surface
91
HPVs are not considered:
lytic
92
HPVs are not considered lytic, as they simply rely on ___ to create a viral release event
the natural production of keratinocytes
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enlarged keratinocytes with clear halos around enlarged nuclei; characteristic of an HPV infection
koilocytes
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HPV spread is by _____ contact especially:
skin-to-skin; breaks in skin, mucous membranes, during birth
95
HPV may cause warts of the ____ which is a dental concern of HPV.
warts of the oropharynx
96
HPV-6 and HPV-11 are responsible for:
laryngeal papillomas
97
Laryngeal papillomas caused by HPV-6 and HPV-11 may lead to ____.
respiratory papillomatosis
98
Caused by HPV-6 and HPV-11, occurs in young children leading to respiratory distress; hoarseness is a usual symptom which signifies the obstructing HPV lesions; and secondary bacterial pneumonia can result.
respiratory papillomatosis
99
The most benign epithelial tumors of the oral cavity caused by HPV:
single oral papillomas
100
condylomata acuminata is commonly referred to as:
anogenital warts
101
90% of ___ are caused by HPV-6 and HPV-11:
anogenital warts (condylomata acuminata)
102
HPV is present in ___% of cervical cancers
99.7%
103
Greater than 85% of cervical carcinomas contain:
integrated HPV DNA
104
What are the high risk types of HPV that are associated with cervical papillomas?
16 & 18 (and 31& 45)
105
Cells are scraped from the crevice and examined under a microscope to check for disease and other problems:
pap smear
106
What cells determine if a Pap smear is abnormal?
koilocytic cells
107
Are there vaccinations for HPV? If so explain:
yes; vaccination protects against HPV-16 and HPV-18 (leading strains for cervical cancer)
108
The HPV proteins ____ & ____ are important for cancer development
E6 & E7
109
What are the only two HPV proteins that are ALWAYS expressed in cervical cancer cells?
E6 & E7
110
How does HPV E6 protein work to induce cancer?
inactivation of p53 (E6 signals the binding of ubiquination factors to bind to p53 and target its destruction)
111
How does HPV E7 protein work to induce cancer?
prevents Rb from controlling cell division (E7 binds to Rb complex and prevents Rb from negatively regulating E2f)
112
HPV E7 protein acts like the ____ protein which promotes disassembly of ____.
SV40 virus LT protein; Rb-E2f complex
113
SV40LT (similar to HPV E7 protein) promotes the disassembly of Rb-E2f complex which allows Ef2 to:
be free & activate transcription of cellular DNA synthesis genes
