Exam 1 continued Flashcards
What type of viral infection has a rapid clearance from the host immune response ?
Acute infection
What type of viral infection develops late, sometimes has no clinical signs, and is continuously shed ?
Persistent infection
What type of viral infection is a form persistent of infection and requires reactivation ?
Latent infection: can be maintained restriction of protein expression, or viral and host DNA integrated
What type of viral infections is a form of persistent infection is established if the acute infection is not cleared ?
Chronic infection
What type of viral infection is a form of persistent infection with a long incubation period, and progressively becomes a lethal disease ?
Slow infection
What is cytopahic/cytopathogenic effect ? (CPE)
Morphological damage to cells due to viral infection
Tell me what pyknosis is…
cell nucleus degeneration that has the appearance of clumped chromosomes, hyperchromatin, and shrinking of the nucleus
What type of destruction of cells is only the detachment of some, but not all cells ?
Subtotal destruction
What are 8 key characteristics of CPE ?
cell lysis, cell rounding, cell detachment, vacuoles in cytoplasm, inclusion bodies, syncytium formation, antigenic changes in cell membrane, swelling and clumping
Enveloped viruses are good at trigging this type of cell response that results in 4+ cells coming together to produce a large cell that is prone to premature death…
Syncytium (Cell fusion)
What are found in host cells during viral infections that have unique staining properties and what do they include ?
Inclusion bodies. Accumulation of viral components: negri bodies= ribnonuculear proteins from rabies Degenerative changes in cells: owl’s eye from herepesvirus Cyrstalline aggregates of virions: adenovirus infections
What are the 5 mechanisms of virus-induced cell injury and death?
inhibition of host-cell nucleic acid synthesis, inhibition of host cell RNA transcription, inhibition of host cell protein synthesis, interference with cell membrane function, apoptosis
What do non-cytocidal viruses do to cells ?
Cause persistent infections, allow infected cells to still replicate, pathophysiologic changes, slow changes lead to death Seen with: pestivirus, arenavirus, retrovirus, paramyxovirus
What type of viral infection stimulates a host immune response, allows for viral spread, but clinical signs are not present ?
Inapparent infections
What term is used to describe the changing of a normal cell into a cancerous cell ?
Cell transformation
Neoplasia…define it!
Leads to neoplasm, can be localized or dissmeinated
What is the change of a normal cell into a cancerous cell called ?
Cell transformation
Leads to neoplasm, and is a descriptive term used to denote abnormal tissue that is either local or disseminated.
Neoplasia
You better know what this means: Oncology…
study of neoplasia/neoplasms
What type of neoplasm stays localized and does not invade other tissues?
Benign
This jerk of a cancer likes to invade other areas locally and systemically…what is it ?
Malignant neoplasm aka cancer
This process is called metastasis
Metastasis is defined as…
spread of cancer cells from origin to other parts of the body.
Travel in bloodstream and lymphatics
T/F- oncogenic viruses cause tumors
TRUE
When a progenitor cell is genetically altered and has dysregulated growth…what develops ?
What gene encodes proteins that allow for normal cellular growth and differentiation?
Proto-oncogene
Mutation of this can INCREASE growth
This gene keeps cell division in check, and if a mutation arises there may be no inhibition of growth. What gene am I ?
Tumor suppressor gene
What 4 things do proto-onco genes code for?
Growth factor proteins/receptors, transcription factors, intracellular signalling proteins, signal transducers
What are oncogenes?
Mutated forms of proto-oncogenes
Tumor suppressor genes hold cell cycle at what phase?
G1 (yay general biology…again!)
What 3 proteins do tumor suppresor proteins code for, and what are their functions ?
Rb-retinblastoma protein
p53-activate DNA repair system, stops cell at G1
p16-blocks cycline dependent kinase –> Rb binds to E2F –> no cell division
T/F- tumor suppressor genes are responsible for repair of damaged DNA (apoptosis if failure occurs)
TRUE
adhesion proteins, metastasis are produced to prevent spread of cancer cells
What happens to your cells if Rb decides it wants to be different and change its genes ?!
Tumor cell production
(regulated cell division)
What is an important oncogenic virus ? (4)
Papillomavirus, polyomavirus, herpesvirus
retrovirus
What is the difference between productive infection in a permissive cell and non productive infection in a non permissive cell ?
Productive infection: cell lysis releasing its progeny
Non productive infection: viral genome is integrated into cellular DNA
What family do ALL oncogenic RNA viruses belong in?
Retroviridae
Acutely transforming retrovirus is…
directly oncogenic. carry an additional v-onc
insert c-onc into viral genome
Slow/chronic transforming retrovirus is..
Integration into the hosts’ chromosome
does NOT have v-onc
causes malignant tumors
Do you wanna do a bunch of cards on Innate immunity ?!
No ?… I didn’t either. Go review Immuno.
What are 8 ways the virus can evade the hosts’ immune system ?
1) Antigenic plasticity-rapid changes to viral antigen
2) Antigenic multiplicty
3) Negative cytokine regulation: virokines are homologs to cytokines and viroceptors are homologts to cytokine receptors
4) Inhibition of complement activation
5) Evasion of neutralizing antibodies
6) Latency
7) Cell-to-cell spread
8) Inhibtion of apoptosis
What definition is used to describe the number of deaths among the clinically ill animals ?
Case fatality rate
What is mortality rate ?
Number of animals in a population that die from a specific disease over a period of time
What term is used to describe the number of animals that develop clinical signs specific to a virus during a defined period of time?
Morbidity rate
What is incidence rate/attack rate?
number of new cases that occur in a population over a specified period of time
What are the number of occurrences of disease, infection, etc. in a population called ?
Enzootic vs. Epizootic ?
Enzootic: constant presence in a geographic location
Epizootic: peak in disease above normal range
