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Flashcards in EXAM #1: REVIEW Deck (47):
1

What are the three major components of the innate immune system that defend against viral infection??

1) Type I IFN (alpha and beta IFN)
2) NK Cells
3) Macrophages

2

What is the general mechanism by which NK cells kill virally infected cells?

Perforin and granzyme, which induce apoptosis

3

What are the two ways that NK cells are induced to kill virally infected cells?

1) PAMPs and/or absence of MHC Class I
2) ADCC
- IgG is bound to virally infected cell
- CD16 of NK cells binds Fc portion of antibody

*Perforin and granzyme are released, triggering apoptosis

4

What cytokines/ cellular product mediate the anti-viral effects of macrophages?

1) TNFa
2) NO

5

List five functions of antibodies in an anti-viral response.

1) Prevention of viral binding to target cell
2) Opsonization
3) Complement activation
4) NK cell activation/ ADCC
5) Downregulation of viral gene expression

6

What innate immunity cells predominate in the response against intracellular bacteria?

1) Marcophages
2) NK cells

7

Outline how macrophages and NK cells are activated to produced an anti-bacterial (intracellular) response?

1) Macrphages activated to release IL-12
2) IL-12 activates NK cells
3) NK cells release IFN-gamma (Type II IFN)
4) IFN-gamma further activates macrophages
5) Macrophages release NO, which is a potent antibacterial measure

8

What is the adaptive immune response to intracellular bacteria?

T-cells are activated to produce IFN-gamma, which activates macrophages

9

List the major complications of acute otitis media.

1) TM rupture
2) Tympanosclerosis
3) Cholesteatoma
4) Mastoiditis
5) Lateral sinus thrombosis
6) Meningitis/ brain abscess

10

How acute bacterial sinusitis treated?

1) Amoxicillin
2) Nasal decongestants
3) Mucolytics

11

What are the major complications of acute bacterial sinusitis?

1) Meningitis
2) Cavernous sinus thrombosis
3) Boney invasion of the orbit

12

What is the hemolysis pattern of S. pyogenes?

Beta

13

What complement pathway is specifically inhibited by polysaccharide capsules?

Alternative pathway

14

How does S. pyogenes evade the immune system?

- Produces M protein
- M protein prevents complement activation

15

How does S. pneumoniae evade the immune system?

C3 protease

16

What is the major mechanism of immunity against spirochetes?

Adaptive immunity

17

What is the major role of cell-mediated immunity (Th1) in spirochete infections?

Clearing the infection

*Vs. Th2 that prevents reinfection

18

What cell type mediates the innate immune response against fungal infections?

Neutrophils

*Partly why neutropenic patients are so susceptible to C. albicans

19

What is the major adaptive immune mechanism against fungal infections?

Cell mediated immunity (Th1)

20

What is the major immune mechanism against Plasmodium? What stage of infection is being targeted?

Th1 vs. the intrahepatic stage

21

List four ways that parasites evade the immune system.

1) Conceal in gut lumen
2) Coat with host proteins
3) Produce enzymes that cleave bound antibodies
4) Inhibition of complement activation*

22

List the four major organisms that cause infectious diarrhea.

1) E. coli
2) Salmonella
3) Shigella
4) C. diff

23

How is H. pylori treated?

1) PPI + amoxicillin
2) PPI + clarithromycin + tinidazole

24

What is quadruple therapy for h. pylori?

1) Bismuth subsalicylate
2) TCN
3) Metronidazole
4) Omeprazole

25

Why is duration of diarrhea an important historical feature to ask about?

Less than 2 weeks= infectious

More than 2 weeks= not infectious

26

What are the two major non-inflammatory diarrheas?

1) V. cholerae
2) ETEC

27

What is the empiric treatment for chlamydia?

1) Ceftriaxone
2) Azithromycin

28

What are the non-infectious etiologies of a presentation similar to a CNS infection?

1) Neoplasia
2) Collagen vascular disorder
3) Medications

29

What are the expected CSF findings in bacterial meningitis?

- WBC: 1,000 - 5,000 (highest)
- Protein: 100- 500
- Neutrophils*
- Glucose less than 40

30

What are the expected CSF findings in tuberculous meningitis?

- WBC: 50-300
- Protein: 50-300
- Mononuclear
- Glucose less than 45

31

What are the expected CSF findings in viral meningitis?

- WBC: 50 - 1,000
- Protein: less than 200
- Mononuclear
- Glucose greater than 45

32

What are the expected CSF findings in cryptococcal meningitis?

- WBC: 20 - 500
- Protein: greater than 45
- Mononuclear
- Glucose less than 40

*Also, high opening pressure

33

If a CSF sample shows neutrophils, what is the etiology?

Bacterial

34

If a CSF sample has a glucose higher than 45, what is the etiology?

Viral

35

What are the two most common causes of viral meningitis?

1) Enterovirus
2) Herpes

36

What three pathogens are associated with subacute/ chronic meningitis?

1) MTB
2) T. pallidum (syphillis)
3) B. burgdorferi (lyme)

37

In a patient that has undergone neurosurgery, what bacterial pathogens are you concerned about causing meningitis?

1) Coagulase negative staphylococci
2) P. aeruginosa

38

What drug is used to cover coagulase negative staphylococci?

Vancomycin

39

What drug is used to cover P. aeruginosa?

4th generation cephalosporin e.g. Ceftazidime

40

What is the appropriate initial therapy for cryptococcal meningitis?

1) Amphotericin B or fluconazole
2) Measures to reduce ICP

41

What is a "fever" in a neutropenic patient?

1) Core temp greater than 38.0 or 100.4 F for an hour
2) Oral temp greater than 38.3 C/ 101.0 F

42

In a child between 3 and 36 months, what what lead you to suspect occult bactermia as a source of fever?

1) WBC count greater than 15K
2) Temp greater than 39 C

43

When are parenteral antibiotics indicated in a 3-36 month old with a fever without a source?

1) Ill appearing/ toxic appearance
2) Unstable
3) Abnormal lab findings
4) Unimmunized child

44

If you are going to start parenteral antibiotics indicated in a 3-36 month old with a fever without a source, what antibiotic should you use? What organisms are you targeting?

Ceftriaxone to target:
- S. pneumoniae
- S. aureus
- N. meningitidis
- H. influenza

45

What are the two most common causes of a "classic" fever of unknown origin in an adult?

Infection vs. malignancy

46

What criteria define severe sepsis?

1) Hypotension-- SBP less than 90 mmHg or MAP less than 70 mmHg
2) Tissue hypoperfusion--elevated lactate
3) Urine Output less than 0.5mL/kg/hr
4) Acute Lung Injury-- PaO2/FiO2 less than 250
5) Bilirubin greater than 4.0
6) Creatinine greater than 2.0
7) Platelets less than 100,000

47

What is the sequelae of pathologic events that occurs in sepsis?

1) Distributive shock
2) Myocardial depression
3) Bone marrow suppression
4) Activation of the clotting cascade
5) Organ dysfunction