Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BS127: Agents Of Infectious Disease > Lecture 21. Consequences of Viral Infection > Flashcards

Lecture 21. Consequences of Viral Infection Flashcards

1
Q

What is pathogenesis?

A

The ability/capability of the virus to cause disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is virulence?

A

Quantitive or relative measure of the pathogenesis of the infecting virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does avirulent mean?

A

Attenuated virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How can virulence be quantitated?

A

Virus titre
Mean time to death
Mean time to appearance of disease
Measurement of fever, weight loss
Measurement of pathological lesions (poliovirus)
Reduction in CD4 T cell (HIV)
Case fatality ratio/hospitalisation rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mechanism of viral injury and disease?

A

Direct cytotoxicity of the virus
Virus-induced immunopathogenesis
Virus-induced immune suppression
Virus-induced transformation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does poliovirus kill?

A

Neurons: paralysis of muscles innervated by those neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does ebola virus damage?

A

Vascular endothelial cells cause haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is direct virus killing (cytotoxic diseases)?

A

Damage to the host may be a consequence of viral replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is virus-induced immunopathogenesis?

A

Tissue injury may reflect host defence mechanisms that include apoptosis or immune responses that target virus-infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is virus-induced immune suppression?

A

Some viruses can specifically target and infect cells of the immune system causing immunodeficiency.
The most prominent of these is HIV infection, which is known to cause AIDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What causes cancers associated with some viral infections?

A

Indirect effects of immunosuppresion associated with HIV infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is associated with HBV or HPC infection?

A

Chronic inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What family of viruses does HIV belong to?

A

Retroviruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the two human pathogens that cause HIV?

A

HumanImmunodeficiencyVirus(HIV)
HumanT‐LymphotropicVirus(HTLV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is HIV enveloped by?

A

Two surface glycoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does HIV replicate?

A

Interaction between the viral attachment proteins which is known as gp120 and the cellular receptor CD4
Entry of the virus into the host cells
The viral nucleic acid is released from the capsid
Synthesis of viral proteins
Replication of nucleic acid
Assembly

17
Q

What is the acute phase of HIV infection?

A

IscharacterisedbyinfectionofactivatedCD4+Tcellsin mucosallymphoidtissuesandthedeathofmanyinfected cells.
AtthisstageamodestreductioninCD4+Tcellcounts,butthenumberofbloodCD4+TcellsoftenreturnstonormalastheindividualmaycontinuetomakenewCD4+Tcells,andthereforethesecellscanbereplacedalmostasquicklyastheyaredestroyed.

18
Q

What is the chronic phase of HIV infection?

A

VirusspreadsthroughoutthebodytoinfecthelperTcells,macrophages,anddendriticcellsinperipherallymphoidtissues.
Thischronicphasemaylastformanyyears.
Duringthistime,thevirusiscontainedwithinlymphoidtissues,andthelossofCD4+Tcellsisreplenishedfromprogenitors
Patientsareasymptomaticorsuffer fromminorinfections.

19
Q

What is the AIDS phase of HIV infection?

A

Lymphnodesandthespleenaresitesof continuousHIVreplication
CelldestructionandthenumberofcirculatingbloodCD4+Tcellssteadily declines
NumberofcirculatingCD4+Tcellsthatare infectedatanyonetimemaybelessthan0.1%ofthetotalCD4+Tcellsinanindividual.
Eventually,thecontinuouscycleofvirusinfection,Tcelldeath,andnewinfectionleadstolossofCD4+Tcells: AIDSstage=CD4+Tcell<200cells/mm3

20
Q

What are the clinical features of Acute HIV disease?

A

Fever, headaches, sore throat with pharyngitis, generalised lymphadenopathy, rashes

21
Q

What are the clinical features during the clinical latency period of HIV?

A

Declining blood CD4+T cell count

22
Q

What increases the membrane permeability?

A

Theproductionofviralproteinsincludinggb41,andgp120intheplasmamembraneandbuddingofviralparticles

23
Q

What does a lethal influx of calcium cause?

A

Apoptosis

24
Q

What causes osmotic lysis of the cell?

A

Influx of water

25
Q

What targets infected CD4 cells?

A

Specific cytotoxic T cells

26
Q

What are viral virulence genes?

A

Gene/genesproductsthataffectviralreplication
Geneencodingtoxins
Genesencodingmodulatorsoftheimmuneresponse
Gene/gensproductsthatenablethevirustospreadin thehost

27
Q

What host gene protects against HIV infection?

A

CCR5:delta32mutation

28
Q

How does being very young influence virulence?

A

Immatureimmuneresponses

29
Q

How does being old influence virulence?

A

Lesselasticalveoli
Weakerrespiratorymuscles
Diminishedcoughreflex
Reducedrateofproductionofnewimmunecells

BS127: Agents Of Infectious Disease (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions