9/7/12 Flashcards Preview

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Flashcards in 9/7/12 Deck (28):
1

Mycoplasma require a medium enriched in ______ to grow in culture.

cholesterol

2

S. pneumoniae can be differentiated from S. viridans by its sensitivity to which Abx used in bacterial culture?

optochin

3

What type of hemolysis do S. penumoniae and S. viridans display?

alpha (partial hemolysis)

4

Which pneumonia-causing oganism requires a medium enriched in L-cysteine?

Legionella

5

What is the mechnism of the diplopia that is often the presenting symptom of multiple sclerosis?

MLF syndrome (internuclear ophthalmoplegia) - loss of myelination of the MLF, which coordinates lateral conjugate gaze.

6

How is the definitive Dx of MS made?

Visualization of sclerotic plaques on MRI.

7

Briefly summarize the 5 steps of MS pathogenesis.

1. axon demyelination
2. destruction of oligodendrocytes
3. lipid-laden MΦs
4. fibrillary astrocytosis
5. infiltration by lymphocytes and monocytes

8

What is the function of gp120?

binding to CD4 receptor

9

What is the function of gp41?

fusion w/target cell

10

What are the 3 structural genes of HIV? Which one becomes gp160?

gag, pol, and env
env

11

The HIV structural gene gag codes for the protein _______, which makes up the _______.

p24; viral capsid

12

What kind of kidney damage may be caused by bacterial endocarditis? What is the mediator of the is damage?

acute diffuse proliferative glomerulonephritis

13

What mediates the acute diffuse proliferative glomerulonephritis caused in some cases of bacterial endocarditis?

circulating immune complexes that deposit in the subepithelium or mesangium

14

Why are glomeruli in PSGN referred to as "hypercellular"?

endothelial and mesangial proliferation & NΦ infiltrate

15

Where do the immune complexes of PSGN deposit?

subepithelial

16

Where do the immune complexes of SLE deposit?

subendothelial (too large to pass GBM)

17

What are the top 3 causes of crescentic glomerulonephritis?

1. Goodpasture syndrome
2. Wegener's granulomatosis
3. Microscopic polyangiitis

18

What is the most common Ag in Wegener's granulomatosis?

c-ANCA

19

What is the Ag seen in microscopic polyangiitis?

p-ANCA

20

What is the Tx for Wegener's granulomatosis?

cyclophosphamide

21

What is seen on electron microscopy in IgA nephropathy?

mesangial immune complexes

22

How does Alport Syndrome manifest in EM of the glomeruli?

Split basement membrane

23

What is the etiology of Alport syndrome?

mutation in type IV collagen

24

What are the clinical manifestations of Alport syndrome?

glomerulonephritis, nerve disorders, ocular disorders, deafness

25

How is Alport syndrome inherited?

X-linked

26

What is the primary reason for thiamine deficiency in alcoholics?

liver dysfunction

27

What drug frequently used in A-fib will increase the circulating dose of warfarin?

amiodarone

28

What is the main mechanism of amiodarone?

class III anti-arrhythmic (blocks K+ channels)