Brainscape's Knowledge GenomeTM

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


See full index

Block 6 Week 4 > AuCoin 2: Viral Pathogenesis > Flashcards

AuCoin 2: Viral Pathogenesis Flashcards

1
Q

What are these?

Nuclear or cytoplasmic aggregates of stainable substances, usually viral proteins

A

inclusion bodies

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

What are four possible cellular responses to infection?

A
  1. no effect
  2. cytopathology
  3. hyperplasia
  4. cancer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do many viral infections present?

A

subclinically - produce no overt sign of infection

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

Can a variety of different viruses produce the same disease? Can the same virus produce a variety of diseases? Does the disease produced bear a relationship to viral morphology?

A

yes; yes; no

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

So what determines the pathology caused by a virus?

A

both viral and host factors

also depends on the genetics of the patient

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

the study of the origin and development of disease

A

pathogenesis

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

events during infection that result in disease manifestation in the host

A

disease pathogenesis

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

A virus that can infect a host and cause signs of disease is considered (blank)

A

pathogenic

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

List the steps in viral pathogenesis

A 
viral entry into host
viral replication
viral spread
leads to cell injury
causes a host immune response
virus is cleared or infection persists
viral is shed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In what ways do viruses attach and enter cells?

A

can enter through skin, respiratory tract, GI, GU, eye

can enter by needles, transfusions, insect vectors (arboviruses)

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

Do viruses always spread to distant sites after initial infection?

A

no; some viruses, like influenza, produce disease at the site of initial infection and do not spread to distant sites

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

So after a virus enters a host, it is likely to spread. What is the most common route of spread?

A

through the blood or lymphatics

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

What is the presence of virus in the blood called?

A

viremia

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

Are viruses free in the blood or associated with a specific cell type?

A

either/or

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

What is called when viruses exhibit organ and cell specificity?

A

tropism

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

How does tissue and cell tropism occur?

A

there are cell surface receptors on these specific organs and tissues that the viral VAPs can bind to and initiate entry - the receptors have affinity for specific VAPs on viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A virus may enter a cell, but viral proteins may not be efficiently produced if there is a lack of (blank)

A

cellular transcription factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does the outcome of viral infections depend on?

A

the interplay between viral and host factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What cytokine is produced in viral infections? What cell types respond to viral infections?

A

interferons; mononuclear cells and lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Virally infected cells may be lysed by (blank) resulting from recognition of viral polypeptides on the cell surface on the infected cells

A

cytotoxic T lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

(blank) directed against capsid or glycoproteins blocks the viral infection of cells

A

neutralizing antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

(blank) protects against infection by viruses through the respiratory or gastrointestinal tracts (mucosal immunity)

A

secretory IgA antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How soon after viral infection are cytokines, like IFNs, produced? What IFN is critical for immunity against viral, bacterial, and protozoal infections? What IFN is an important activator of macrophages and induces MHC molecule expression?

A

within hours of the viral infection; IFNgamma; IFNgamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What secretes more IFN, dendritic cells or fibroblasts?

A

dendritic cells times 1000!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How is the synthesis of IFNs induced in cells?

A

infection with a virus induces production of IFNs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which is a stronger inducer of IFN, RNA viruses or DNA viruses?

A

RNA viruses

**also induced by double stranded RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

(blank) play a primary role in the NONSPECIFIC defense of the host against viral infections

A

IFNs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When do antibodies appear in response to viral infections?

A

DAYS after the infection

**so virus introduced, then IFNs produced within hours, then antibodies produced within days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Are IFNs actually antiviral? So how to they help in the immune response against viruses?

A

no; IFN induces the synthesis of other proteins that inhibit viral replication - IFN binds its receptor which activates trx factors that translocate to the nucleus and activate IFN-inducible genes

30
Q

What are two enzymes that IFN induces production of?

A

protein kinase R

RnaseL

31
Q

a dsRNA-dependent protein kinase which phosphorylates and inactivates cellular initiation factor eIF-2 preventing cellular and viral proteins synthesis

A

protein kinase R

32
Q

an interferon-induced ribonuclease which, upon activation, destroys all RNA in the cell (both cellular and viral)

A

RnaseL

33
Q

Some viruses infect and damage cells of the immune system. Name one such virus which infects T lymphocytes and makes them nonfunctional

A

HIV

34
Q

How do adenoviruses and the herpesviruses evade the immune response?

A

they inhibit MHC function essentially

35
Q

How do viruses like poxvirus and the measles virus evade the immune response?

A

they inhibit cytokine activity

36
Q

How do viruses like influenza and HIV evade the immune response?

A

they mutate and change antigenic sites of virion proteins

37
Q

What kind of infection is this?

when a virus first infects a host, most are self-limiting

A

acute viral infection

38
Q

What kind of infection is this?

replicating virus can continually be detected at low levels

A

chronic viral infection

39
Q

What kind of infection is this?

virus persists in a hidden form, and no new virus is produced; intermittent flare-ups of clinical disease where the virus can be detected - usu in immunocompromised patients

A

latent viral infection

40
Q

Viruses, such as poxviruses, papillomaviruses, and herpes simplex virus, enter the skin through (blank)

A

abrasions

41
Q

Arboviruses are introduced via (blank)

A

insect bites

42
Q

Hep B and HIV are injected during (blank)

A

blood transfusions or use of contaminated needles

43
Q

Why do generalized skin rashes occur after viral infection?

A

the virus spreads to the skin via the bloodstream after it replicates at the site of invasion

44
Q

How does poliovirus enter? Where does poliovirus multiply? Then what does it do? How can you prevent its spread to the CNS?

A

enters through the alimentary tract and multiplies in these tissues at the PRIMARY infection site; then, it spreads systemically; to keep it from spreading to the CNS, vaccination creates antibodies against it

45
Q

In what ways may viruses gain access to the brain?

A

bloodstream

peripheral nerve fibers (neuronal spread)

46
Q

How would a virus gain access to the brain from the blood?

A

may replicate in the endothelial cells of cerebral vessels

47
Q

Virions can also be taken up at (blank) and travel in axons to the dorsal root ganglia neurons - ex: herpesviruses

pathologic reaction may include CNS cell necrosis, inflammation, and phagocytosis by (blank) cells

A

sensory nerve endings; glial

48
Q

many viruses that infect the CNS can cause (blank) or (blank)

A

encephalitis; meningitis

49
Q

What is the most common viral route of infection?

A

via the respiratory tract in aerosolized droplets or saliva

**infection can occur despite innate host defenses

50
Q

Many infections that enter via the respiratory tract stay in the lung, but some can spread and develop characteristic symptoms. Name a few.

A

chickenpox, measles, rubella

51
Q

How do viruses enter the GI tract? What are they exposed to once in the GI tract?

A

poorly cooked contaminated food

fecal-oral route; harsh elements such as acid, bile salts, etc

52
Q

is short term disease ranging from mild, watery diarrhea to sever febrile illness (vomiting, diarrhea, and prostration)

A

acute gastroenteritis

53
Q

What are two viruses that are a major cause of gastroenteritis?

A

rotaviruses

Norwalk viruses

54
Q

What are the two organisms primarily responsible for congenital defects in newborn - these viruses cross the placenta and harm the fetus

A

rubella

cytomegalovirus

55
Q

This causes deafness, eye abnormalities, and congenital heart disease

A

Congenital rubella syndrome

56
Q

This is the leading infectious cause of deafness, learning disabilities, and mental retardation in children

A

Congenital human cytomegalovirus (HCMV)

57
Q

Because viruses are obligate INTRACELLULAR parasites, what must antiviral agents be capable of?

A

they must inhibit viral function, but NOT normal cellular function

58
Q

When are antivirals needed most?

A

for viruses where vaccines are not available

59
Q

inhibit viral polymerases by incorporating a terminal nucleoside

A

nucleoside analog

60
Q

binds to reverse transcriptase to disrupt enzymes catalytic site

A

reverse transcriptase inhibitor

61
Q

inhibits the viral protease that is required at the late stage of the HIV replicative cycle

A

protease inhibitor

62
Q

blocks viral and cellular membrane fusion step involved in entry of HIV into cells

A

fusion inhibitor

63
Q

What is the most cost effective method of prevention of serious viral infections?

A

vaccination

64
Q

What are some common targets for vaccines against viruses?

A

viral glycoproteins

65
Q

(blank) is important in resistance to infection by viruses that replicate in mucosal membranes (influenza)
viruses that have a viremic mode of spread (polio, hepatitis A and B, varicella) need to be controlled with (blank)

A 
mucosal immunity (IgA); 
serum antibodies (IgG)
66
Q

What are two challenging characteristics of a virus that may make vaccination difficult?

A

multiple viral serotypes (ex: rhinoviruses)

rapidly mutating viruses (ex: HIV)

67
Q

In addition to antibodies, (blank) is involved against systemic infections (herpesviruses) – control latent state

A

cell mediated immunity

68
Q

In viral vaccines, is the virus alive or dead? What do viral vaccines stimulate development of? What usually needs to be administered?

A

DEAD - must ensure there is no live virus in the vaccine; generally stimulate devo of circulating antibodies against viral membrane proteins; booster shot

69
Q

Will injected vaccines work well to protect against viruses of the respiratory and GI tract?

A

no bc IgG and IgM will be produced instead of IgA

70
Q

How can you get cell mediated immunity to a virus, in addition to an antibody response?

A

give a live attenuated vaccine by utilizing virus mutants that overlap with wild-type virus

71
Q

In what ways is a live vaccine better than a killed vaccine?

A

live vaccines only require one dose, no need for an adjuvant to cause an immune response and immunological memory, longer duration of immunity, greater protection, cell mediated immunity, mucosal immunity

72
Q

T/F: live virus vaccines to multiple viruses can be given in combination WITHOUT reduction in immunity

A

true

**antibody response to each component of these vaccines is comparable with antibody response to the individual vaccines administered separately

Block 6 Week 4 (10 decks)

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