Gastro-Adeno-Papilloma Flashcards
–Inflammation of stomach or intestines
–important disease of infants and children
–leading cause of childhood death in developing countries
- Mostly caused by rotaviruses
Viral Gastroenteritis (Chapter 37)
_____ is a segmented dsRNA virus that is the main cause of diarrhea in children 6-24 month
Group A rotavirus
_____ is (+) ssRNA and is the major cause of outbreaks in children and adults
Norovirus
_____ virus= 1st virus identified from stool samples by electron microscopic examination (1972)
Norwalk virus
Rotaviruses are members of the _____ family:
- Nonenveloped
- Inner and outer capsids
- 11 segments of dsRNA = genome
- lysis of infected cells
Reovirus family
_____ causes: -potentially fatal dehydration; fecal-oral transmission; watery-diarrhea
Rotaviruses
acid stability of rotaviruses is conferred by ______
double capsid structure
rotavirus produces an _____ that binds integrins; signaling results secretion of chloride and water-infected gut epithelial cells destroyed & replaced by immature epithelial cells (reduced uptake of ions, water; less absorption of foods molecules (carbs))
enterotoxin
\_\_\_\_\_: positive strand RNA genome ~7,500 bases in length Naked capsidvirions -Replication similar to picornaviruses (poliovirus) except 2nd phase of translation involves subgenomicRNAs (like coronaviruses). -Has a 5VPgprotein on RNA
Noroviruses
______ virus:
linear double-stranded DNA genome
non-enveloped
icosahedral capsid
Adenovirus
Adenoviral _______ enters cell nucleus
nucleoprotein complex
T/F: Adenovirus gene expression temporal regulation pre-early, early, late genes
Tru
_________ are produced during one phase act to promote transcription of genes of subsequent phase (adenovirus)
transcriptional regulators
____ DNA replication only one of the 2 DNA strands is copied at each replication fork; no discontinuous replication (lagging strand replication)priming is by a viral protein, pTP (preterminal protein)
Adenovirus
What is the primer of adenovirus DNA replication?
Viral protein pTP
______ infections:
- widespread: 5-10% of all viral infections
- usual symptoms resemble common cold
- Vaccine (live virus) given to new military recruits targets serotypes 4 and 7
Adenovirus
acute respiratory disease (ARD) is caused by what serotypes of adenovirus?
4, 7
block MHC class I mRNA production block transport of MHC class I proteins to the cell surface viral E3gp19K protein does this (see next slide) results in block of killing by cytotoxic T cells
Adenovirus
_____ drives the host cell into cell division
necessary for the virus to replicate (needs cellular S phase factors)
E1a and E1b proteins interfere with cell division controllers
E1b sequesters p53
E1a sequesters Rb (retinoblastoma protein)
Viral infection can potentially drive a cell toward a cancerous state
Adenovirus
Which Adenovirus protein sequesters p53?
E1B
Which adenovirus protein sequesters Rb?
E1a
P53 recognizes DNA damage and activates _____
P21
_____ binds and inactivates the cyclin-CDK complex which has already begun to be produced in response to different signals
P21
_____ viruses:
- genome is ds circular molecule
- Nonenveloped
- at least 100 different types
- cutaneous or mucosal
HPVs
______-enlarged keratinocytes with clear halos around enlarged nuclei -characteristic of HPV infection
Koilocytes
_____accesses basal layer through breaks in skinViral early genes stimulate cell growth (which facilitates viral replication)
- reproduction coordinated with development of keratinocytes
HPV
As cells move through skin layers the gene expression and DNA replication begins (uses cellular DNA polymerase)
Late proteins (capsid proteins) only made in differentiated layers
Assembly occurs in nucleus during keratinocyte development
Nuclear remnant with viral particles shed at skin surface. They are not lytic.
HPV
_______ are spread via:
breaks in skin for example, scratching
mucous membranes more susceptible
sexual contact During birth
HPV
The following are found in _____: Warts of oropharynx laryngeal papillomas (-6 and -11)
respiratory papillomatosis hoarseness is usual symptom (signify obstructing HPV lesions)respiratory distress and secondary bacterial pneumonia in children
HPV
________ are the most benign epithelial tumors of the oral cavity
Single oral papillomas
What are the 2 types of HPV seen in cervical cancer?
16 and 18
-___ is common in anogenital warts (condylomata acuminata) and cervical cancer
HPV
____: cells are scraped from the cervix and examined under a microscope to check for disease or other problems; used to find HPV
Pap smear
What 2 types of HPV are treated via vaccination?
16 and 18
The HPV ___ and ______ proteins are important for cancer development. They are the only 2 HPV proteins always expressed in cervical cancer cells.
E6 and E7 proteins
___ HPV protein inactivates p53 via ubiquitination promotion
E6
___ HPV protein inactivates Rb; acts like SV40 virus
E7
