9/7/12 Flashcards
Mycoplasma require a medium enriched in ______ to grow in culture.
cholesterol
S. pneumoniae can be differentiated from S. viridans by its sensitivity to which Abx used in bacterial culture?
optochin
What type of hemolysis do S. penumoniae and S. viridans display?
alpha (partial hemolysis)
Which pneumonia-causing oganism requires a medium enriched in L-cysteine?
Legionella
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.
How is the definitive Dx of MS made?
Visualization of sclerotic plaques on MRI.
Briefly summarize the 5 steps of MS pathogenesis.
- axon demyelination
- destruction of oligodendrocytes
- lipid-laden MΦs
- fibrillary astrocytosis
- infiltration by lymphocytes and monocytes
What is the function of gp120?
binding to CD4 receptor
What is the function of gp41?
fusion w/target cell
What are the 3 structural genes of HIV? Which one becomes gp160?
gag, pol, and env
env
The HIV structural gene gag codes for the protein _______, which makes up the _______.
p24; viral capsid
What kind of kidney damage may be caused by bacterial endocarditis? What is the mediator of the is damage?
acute diffuse proliferative glomerulonephritis
What mediates the acute diffuse proliferative glomerulonephritis caused in some cases of bacterial endocarditis?
circulating immune complexes that deposit in the subepithelium or mesangium
Why are glomeruli in PSGN referred to as “hypercellular”?
endothelial and mesangial proliferation & NΦ infiltrate
Where do the immune complexes of PSGN deposit?
subepithelial
Where do the immune complexes of SLE deposit?
subendothelial (too large to pass GBM)
What are the top 3 causes of crescentic glomerulonephritis?
- Goodpasture syndrome
- Wegener’s granulomatosis
- Microscopic polyangiitis
What is the most common Ag in Wegener’s granulomatosis?
c-ANCA
What is the Ag seen in microscopic polyangiitis?
p-ANCA
What is the Tx for Wegener’s granulomatosis?
cyclophosphamide
What is seen on electron microscopy in IgA nephropathy?
mesangial immune complexes
How does Alport Syndrome manifest in EM of the glomeruli?
Split basement membrane
What is the etiology of Alport syndrome?
mutation in type IV collagen
What are the clinical manifestations of Alport syndrome?
glomerulonephritis, nerve disorders, ocular disorders, deafness
How is Alport syndrome inherited?
X-linked
What is the primary reason for thiamine deficiency in alcoholics?
liver dysfunction
What drug frequently used in A-fib will increase the circulating dose of warfarin?
amiodarone
What is the main mechanism of amiodarone?
class III anti-arrhythmic (blocks K+ channels)
