4/24 - UWorld

Question 1

Mechanism of action and major side effects of each drug in RIPE therapy

Answer 1

Rifampin - inhibits bacterial DNA-dependent RNA; causes red-orange body fluids

Isoniazid - inhibits mycolic acid synthesis; causes hepatotoxicity and neurotoxicity (give vitamin B6)

Pyrazinamide - unknown MOA; causes hepatotoxicity and hyperuricemia

Ethambutol - inhibits arabinosyl transferase (carbohydrate synthesis in cell wall); causes optic neuropathy (color blindness, central scotoma, decreased visual acuity)

Question 2

Describe how PAH relates to GFR

Answer 2

PAH is freely filtered and secreted but not reabsorbed

Will slightly overestimate GFR

Question 3

Describe how inulin relates to GFR

Answer 3

Inulin is filtered but not secreted or reabsorbed

Can be used to estimate GFR

Question 4

Describe how creatinine relates to GFR

Answer 4

Creatinine is filtered and slightly secreted (but not secreted as much as PAH

Question 5

Describe how urea is handled in the kidney

Answer 5

It is freely filtered and poorly reaborbed

But not as much net excretion as PAH and inulin

Question 6

Describe how bicarbonate is handled in the kidney

Answer 6

It is actively reaborbed in the proximal tubule

Question 7

What substances have almost 100% reabsorption in the proximal tubule?

Answer 7

Glucose and amino acids

Question 8

What is a Barr body

Answer 8

Inactivated X chromosome

One of two X chromosomes in females is inactivated by being condensed into heterochromatin with heavily methylated DNA and deacetylated histones

Question 9

What test is often used instead of bacitracin?

Answer 9

Pyrrolidonyl arylamidase (PYR) test

Strep Pyogenes is PYR-positive aka Bacitracin sensitive

Question 10

What are the effects of a VIPoma?

Answer 10

WDHA

Watery diarrhea, hypokalemia, achlorhydria

Question 11

What is Wilson disease?

Answer 11

Autosomal recessive defect in ATP-mediated hepatocyte copper transport

Results in lack of copper transport into bila and lack of copper incorporation into ceruloplasmisn (copper transport protein)

Copper accumulates especially in liver, brain, cornea, and kidneys

Presentation: liver disease, neurologic disease, Kayser-Fleisher rings (deposits in cornea)

Treatment: Penicillamine (chelates copper)

Question 12

Describe the process of atrial sepation

Answer 12

Question 13

What is Hartnup disease (defect, presentation, treatment)

Answer 13

Autosomal recessive deficiency of neutral amino acid transporters

Leads to decreased absorption of tryptophan, which is the source of niacin (B3)

Can lead to pellagra-like symptoms

Treat with high-protein diet and nicotinic acid

Question 14

What type of HSR is atopic dermatitis?

Answer 14

Type I HSR

Question 15

What type of HSR is contact dermatitis?

Answer 15

Type IV HSR

Question 16

Describe the common presentation of L-sided vs. R-sided colon cancer

Answer 16

R-sided are more likely to bleed, leading to iron deficiency anemia

L-sided often infiltrate the colon wall, narrowing the lumen and leading to obstruction (altered bowel habits, constipation, abd distension, nausea, vomiting)

Question 17

What terms from the 2x2 table can be used to help calculate ARR

Answer 17

ARR = NPV - PPV

Question 18

Common presentation of Giant cell arteritis

Answer 18

Unilateral headache, jaw claudication, polymyalgia rheumatic (joint and muscle pain), blindness

Question 19

Presentation of Takayasy arteritis

Answer 19

Usually Asian females < 40 y/o

Involves aortic arch at branch points

“Pulseless disease”, visual and neuro symptoms

Question 20

What is depersonalization/derealization disorder?

Answer 20

Peristent of recurrent experiences of 1 or both:

• Feelings of detachment of being an outside observer of one’s self
• Experiencing surroundings as unreal

Question 21

What is dissociative amnesia

Answer 21

Inability to recall personal information

Usually subsequent to severe trauma or stress

Question 22

What is dissociative identity disorder

Answer 22

Aka multiple personality disorder

Question 23

Sequence of events under light microscopy in acute MI

Answer 23

Time after myocardial infarction - Predominant light microscopic changes

0-4 hrs - minimal change

4-12 hrs - early coagulation necrosis, edema, hemorrhage, wavy fibers

12-24 hrs - coagulation necrosis and marginal contraction band necrosis

1 to 5 days - coagulation necrosis and neutrophilic infiltrate

5 to 10 days - macrophage phagocytosis of dead cells

10 to 14 days - granulation tissue and neovascularization

2 weeks to 2 months - collagen deposition / scar formation

Question 24

Describe Wernicke vs. Korsakoff syndrome

Answer 24

Both cause by Thiamine (B1) deficiency

Wernicke encephalopathy is the acute effects - ataxia, confusion, ophthalmoplegia; atrophy of mamillary bodies

Korsakoff syndrome is the chronic effects - memory loss, confabulation, personality change

Question 25

What is Mallory Weiss syndrome

Answer 25

Tear of the gastroesophageal junction caused by excessive/forceful vomiting

Question 26

Hypagogic vs. Hypopompic hallucination

Answer 26

Hypnagogic - occur while going to sleep

Hypnopompic - occur while waking from sleep

Question 27

What are the symptoms of neuroleptic malignant syndrome (NMS)

Answer 27

Rigidity, myoglobinuria, autonomic instability, hyperpyrexia

Question 28

What is the treatment for neuroleptic malignant syndrome

Answer 28

Dantrolene (muscle relaxant)

Bromocriptine (D2 agonist)