4/2 micro Flashcards
Give HIV + mother what drug to prevent vertical transmission?
Zidovudine.
Where is pH the lowest in the nephron?
DCT & collecting duct
Hypertrphic cardiomyopathy
- what type of murmur?
- heard best where?
- Systolic due to LVOT obstruction.
- left sternal border.
Aortic regurg murmur
-heard best where?
left sternal border.
Aortic stenosis
-heard best where?
Aortic area
-right sternal border, 2nd intercostal space.
Uremia: -PTT? -PT? -BT? whats the problem here?
- qualitative platelet problem.
- BT increased, everything else is normal.
Pt. w/ESRD, dialysis catheter placed into IJ, and bleeding occurs around catheter site.
- whats the problem?
- abnormal test values?
ESRD => uremia => qualitative platelet problem.
- inc. BT.
- everything else is normal.
Ehlers Danlos
-defect is in which protein?
Type 3 collagen defect.
HMP shunt
-where does it occur?
cytoplasm
HMP shunt
-primary enzymes involved in non-oxidative steps?
transaldolase & transketolase.
*transketolase req. thiamine as cofactor.
All cells can synthesize ribose from which glycolysis intermediates w/help of transketolase & transaldolase?
F-6-P, G-3-P.
-they can do this even if oxidative reactions in HMP shunt not active in these cells.
Where is collagen triple helix formed?
ER
Which steps of collagen synth happen outside the cell?
Terminal propeptide removal, covalent cross links via lysyl oxidase.
*after propeptide removal, its called tropocollagen.
Lysyl oxidase
- what does it do?
- what cofactor does it need?
Cross links collagen molecules in extracellular space.
-copper.
Osteogenesis imperfecta
- which step of collagen synth is faulty?
- where does this step occur?
- formation of the triple helix.
- ER.
Which quadrant of your ass should you not give injections so you dont damage sup. gluteal nerve?
superomedial.
Which quadrants of your ass should you not inject so you dont damage sciatic n?
supermedial, inferomedial, inferolatera.
-basically everywhere except superolateral.
Rash + post-auricular lymphadenopathy:
Rubella
Congenital rubella
-Sxs:
PDA, cataracts, sensoneural deafness
Paramyxoviruses
-why do you see multinucleated cells?
-All contain surface F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells.
Palivizumab
- whats it do?
- whats it treat?
Palivizumab = mab against F protein.
- prevents pneumonia caused by RSV infection in premature infants.
- dont forget all paramyxoviridae have surface F-protein which causes resp. epithelial cells to fuse & form multinucleated cells.
Measles
-is it blanchable?
yes
measles
-do koplik spots occur before or after the rash?
Before
Measles pts
-which vitamin will you give them?
vitamin A.
Measles
- Sxs before the rash?
- mnemonic?
3 Cs
- cough, coryza, conjuncitivits
- & koplik spots.
Pregnant mother w/measles
-what can happen to baby?
No birth defects but can cause fetal death in 20% of cases.
Measles rash vs Rubella rash
-which includes the limbs?
Measles
Mumps
- Sxs?
- mnemonic?
- what other Sx?
Mumps makes your parotid glands and testes as
big as POM-poms.
-Parotitis, Orchitis, & aseptic Meningitis. Can cause
sterility (especially after puberty).
*pancreatitis.
Mumps
-one or both parotid glands affected?
-one or both.
Mumps pt. w/elevated serum lipase.
-whats the problem?
Mumps can cause pancreatitis.
- serum amylase & lipase will be inc.
- parotids & pancreas both contribute to elevated amylase.
Negri body
- which disease
- what is it?
- where are they commonly found? which tissue?
Rabies
- site of viral assembly.
- Purkinje cells of cerebellum and in hippocampal neurons (both areas that are susceptible to ischemia).
Rabies
-post-exposure Tx:
Wound cleansing and vaccination ± rabies immune globulin.
How does rabies virus get to CNS?
- where does it initially enter neurons?
- where does it reside?
Initially binds to nicotinic receptors at NMJ.
- travels retrograde up axon to neuron cell body.
- resides in salivary glands.
Common food associated w/HAV?
Shellfish.
HBV
-what type of replicative intermediate does it have?
ssRNA
- starts w/partial, circular dsDNA.
- repaired in nucleus.
- (+) sense RNA made in nucleus, sent to cytoplasm.
- in cytoplasm, capsid made, and in capsid, the RNA => circular, partial dsDNA via its reverse transcriptase.
HBV
-incubation period?
45-180 days.
After active viral replication has stopped, is there still inc. risk of HCC?
- in HBV:
- in HCV:
- yes in HBV - integrates into host genome.
- no in HCV. - chronic inflammation led to inc. risk of HCC, so once infection contained, no more chronic inflam.
Most common outcome of HBV infection in adults (95%) =
-acute hepatitis w/mild or subclinical Sxs that eventually completely resolves.
HBV
-what causes the hepatocyte damage?
Damage is caused by the CD8 Tcell response to the viral Ags on the cell surface.
post transfusion hepatitis
-which one?
HCV
Which one usually goes chronic?
- hepB
- hepC
hepC goes chronic 80% of the time.
hepB
-what will hepatocyte look like in histology?
Hepatocyte cytoplasm becomes full of HBsAg,
will look like “ground glass”.
anti-HCV IgG
-is it protective?
NO
*getting a “C” in school wont protect you from getting your ass beat. A “B” will though.
IV drug abusers w/acute viral hepatitis = which hep?
Most likely HCV.
which hep can cause cryoglobulin formation?
hepC.
HepD
- what is a superinfection?
- what is a co-infection?
- which one is more severe?
- Superinfection (HDV after HBV)—short
- Co-infection (HDV with HBV)—long
- superinfection = more severe.
HBV
-whats special about the enzyme it carries with it?
The DNA pol. has both DNA and RNA-dependent activities. Upon entry into the nucleus, the polymerase completes the partial dsDNA. The host RNA polymerase transcribes mRNA from viral DNA to make viral proteins. The DNA polymerase then reverse transcribes viral RNA to DNA, which helps form new viral particles.
Anti-HAV (IgG)
-is it protective?
yes
HIV
-genome?
Diploid genome (2 molecules of RNA).
The 3 structural genes of HIV:
-name them
gag, env, pol.
HIV: env gene (envelope)
- what proteins does it code for?
- what do these proteins do?
-env => gp120 and gp41 (envelope proteins).
- remember, envelope = most outer layer of virus. The part that interacts w/target cell.
- Formed from cleavage of gp160.
- gp120—attachment to host CD4+ T cell.
- gp41—fusion and entry.
HIV: gp120
- what gene codes for it?
- whats its protein product?
- env (envelope).
- attachment to host CD4+ T cell.
HIV: gag gene
- what proteins does it code for?
- what do these proteins do?
-p24—capsid protein
HIV: gp41
- what gene codes for it?
- whats its protein product?
- drugs that bind it are what type of drugs?
- env (envelope)
- fusion and entry.
- drugs that bind gp41 = fusion inhibitors ie. enfuvirtide.
*Forty one = Fusion.
Env gene mutations: allow what?
Enable escape from host neutralizing Abs.
HIV: pol gene
- what proteins does it code for?
- what do these proteins do?
-reverse transcriptase, aspartate protease, integrase.
HIV
- binds what receptors on CD4 cells?
- binds what receptors on macros?
- CD4 + CCR5 (early) or CXCR4 (late) on T cells.
- CCR5 and CD4 on macrophages.
Homogenous mutation in which gene provides immunity against HIV?
Homozygous CCR5 mutation = immunity.
HIV:Dx
- whats the sensitive screening test?
- whats this test typically looking for?
- ELISA
- the “rule out” test.
- ELISA is typically looking for Abs to p24 (capsid protein whos Abs show up early).
HIV:Dx
-after a positive screen, whats the specific test?
- Western blot.
* the “rule in” test.
Criteria for AIDS Dx:
- ≤ 200 CD4+ cells/mm3.
- HIV-positive with AIDS-defining condition.
- CD4 percentage < 14%.
Normal ratio of CD4:CD8?
normal ratio of CD4:CD8 = 2:1
ELISA/Western blot
- what do they look for?
- when are they usually not reliable? which periods?
- Both look for Abs to viral proteins
- These tests often are falsely negative in the first 1–2 months of HIV infection and falsely positive initially in babies born to infected mothers (anti-gp120 crosses placenta).
Relationship btwn CD4 count & HIV RNA conc. in plasma:
The CD4 count and HIV RNA count are directly inversely proportional.
CD4+ < 100 cells/mm3
- fevers, cough, hepatosplenomegaly, tongue ulcer.
- which bug?
Histoplasma capsulatum
Candida
- oral thrush @ what CD4 count?
- Esophageal candida @ what CD4 count?
- oral if CD4+ < 400 cells/mm3
- esophageal if CD4+ < 100 cells/mm3
*200 & less Sxs = AIDS defining.
Is oral thrush an AIDS defining lesion?
No
- happens when CD4+ < 400 cells/mm3.
- need sub 200 for AIDS defining lesion.