High-Yield Facts from UWorld Flashcards
What does Vitamin E deficiency cause?
hemolytic anemia, stress on neurons (spinocerebellar tracts and dorsal columns)
-can look like B12 deficiency but no macrocytic anemia
Why is it possible for cystic fibrosis patients to be deficient in Vitamins A, D, E, K?
pancreatic insufficiency –> no lipase –> fat malabsorption –> also can’t absorb fat-soluble vitamins
What is the difference between condyloma lata vs. condyloma acuminata?
condyloma lata - warty lesion in secondary syphilis
condyloma acuminata - genital warts caused by HPV 6, 11
How can you eliminate a reflex brady- or tachycardia after you administer an autonomic drug?
- Ganglion blocker
- a selective M2 antagonist will block reflex bradycardia elicited by alpha1, and a beta1 blocker will cancel reflex tachycardia from beta 2 stimulation
Which transporter takes up glucose in the liver?
GLUT2
it has a high Km, allowing it to act as a glucose sensor, taking up glucose when the concentration is high
What are the positive regulators of PFK-1 in glycolysis? Negative regulators?
Positive: AMP and F26BP (insulin)
Negative: ATP and citrate
What cofactors do you need for Pyruvate dehydrogenase complex to function?
- Pyrophosphate (B1, thiamine, TPP)
- FAD (B2, riboflavin)
- NAD (B3, niacin)
- CoA (B5, pantothenate)
- Lipoic acid
How do you differentiate between the two most common hereditary causes of hemolytic anemia?
- Glucose 6 phosphate dehydrogenase deficiency is #1 cause (can’t generate NADPH for reducing power). Has Heinz bodies (oxidized hemoglobin)
- Pyruvate kinase deficiency is #2. Can’t complete glycolysis and make energy –> increased tissue O2 unloading. It is characterized by hemolytic anemia, increased BPG, but no Heinz bodies.
Why does sorbitol accumulate in the lens of diabetic patients?
In the eye, aldose reductase makes glucose into sorbitol to keep the lens viscous. But diabetics will accumulate too much of this because of hyperglycemia. In galactosemias, aldose reductase converts galactose into galactitol, which also gets trapped in the lens and causes swelling and cataracts.
Which microorganisms exhibit antigenic variation?
Bacteria - Salmonella (2 flagellar variants), Borrelia (relapsing fever), Neisseria gonorrhoea (pilus protein)
Virus: influenza
Parasites: trypanosomes (programmed rearrangement)
After what kinds of exposures are patients given preformed antibodies?
Tetanus toxin
Botulinum toxin
HBV
Rabies virus
Which vaccines would you never want to give to someone who is immunocompromised?
Live attenuated vaccines:
- MMR
- Polio (Sabin)
- Influenza (intranasal)
- Varicella
- Yellow Fever
Pantothenic acid affects which step in the TCA cycle?
Oxaloacetate to citrate
What antibiotic should you give an alcoholic patient with a lung abscess?
Clindamycin
Aspiration pneumonia –> lung abscess
Need to cover anaerobes
What types of molecules are lost in highly selective proteinuria?
Small molecules like albumin and transferrin, which are small enough to fit through slit membranes and hence filtration is provided by the negative charge of the glomerular basement membrane.
Occurs in minimal change disease.
