UWorld_3.31

Question 1

Reason for methodone use

Answer 1

• used to help patients recover from heroin addiction
• very long half-life opioid agonist w/good oral bioavailablity
• prevents withdrawal sx while weaning off heroin

Question 2

Gastroenteritis that can transfer between domestic animals and humans

Answer 2

• campylobacter
• acquired from domestic animals (cattle, chicken, dogs) or contaminated food
• ==> inflammatory diarrhea + ab pain + tenesmus

Question 3

hidgut derivatives + blood supply

Answer 3

• transverse colon
• descending colon
• sigmoid colon
• rectum
• bs = inferior mesenteric artery

Question 4

Major complication in subarachanoid hemorrhage + tx

Answer 4

• vasospasm can occur 4-12 days after ==> new onset sx
• Nimodipine = selective ca channel blocker usually prescribed to prevent

Question 5

Shizoaffective disorder

Answer 5

• multiple psychotic episodes with concurrent major depressive/manic sx
• >2 weeks of psychosis (delusions, hallucinations) w/out mood sx
• mood sx present over majority of illness

Question 6

Characteristics of Jervell and Lange-Nielson syndrome

Answer 6

• AR
• QT prolongation
• congenital neurosensory deafness

Question 7

Consequence of Afib in LVH/aortic stenosis pt.

Answer 7

• afib ==> ineffective atrial contraction
  
  • atrial contraction is important in ventricular filling of a noncompliant chamber
• innefective atrial contraction ==> sig. decreased preload ==> decreased CO

Question 8

Common causes of myopathy with elevated CK

Answer 8

• inflammatory myopathy
  
  • skin rash and inflammatory arthritis may also be present
• statin-induced
• hypothyroidism
  
  • hypothyroid sx present
  • myoedema = mounding of m. after percussion <== slow reabsorption of Ca from sarc. reticulum

Question 9

Characteristics of germinomas

Answer 9

• most common tumor of pineal gland ==>
• B-hCG ==> prec. puberty in males
• obstructive hydrocephalus
• parinaud syndrome = paralysis of upward gaze

Question 10

Common complication of bronchial asthma

Answer 10

• aspergillosis ==> transient recurrent pulm infiltrates ==> proximal bronchiectasis

Question 11

PrP definition & consequences

Answer 11

• PrP = prion protein = alpha helix ==> beta pleated sheet = resistant to proteases ==> accumulation ==> spongiform transformation of gray matter

Question 12

Ipratropium: MOA, use

Answer 12

• Muscarinic antagonist @ bronchial smooth m.
  
  • less effective than B2 agonists
  • enhance B2 agonists
• use in asthma

Question 13

Theophylline: MOA, use

Answer 13

• MOA: inhibit phosphodiesterase ==> increased cAMP ==> bronchial sm. m. dilation
• use: asthma

Question 14

Presentation of age-related macular degeneration (AMD) + Tx

Answer 14

• progressive ==> acute vision loss (usually)
• dry = subretinal drusden deposit or pigment changes
• wet = abnormal vessels, gray subretina, neovascularization
• dry ==> wet
• dry tx = antioxidant vitamins + zinc
• wet = anti-VEGF, laser therapy, phototherapy

Question 15

Nicotinic receptors

Answer 15

• ligand-gated ion channels
• ACh binding ==> immediate influx of Ca2+ and Na+ and efflux of K+

Question 16

Progressive dementia + cortical atropy ==> dx + tx

Answer 16

• dx = Alzheimer’s
• Tx
  
  • Donepezil = cholinesterase inhibitor
  • Vitamin E (antioxidant)
  • Memantine = NMDA antagonist

Question 17

Characteristics of cachexia

Answer 17

• lung mass that releases TNF-alpha ==> cachexia syndrome
• weight loss
• anemia
• anorexia
• wasting

Question 18

H. pylori location?

Answer 18

prepyloric area of gastric antrum = greatest concentrations

Question 19

Glucokinase fxn + deficiency consequences

Answer 19

• glucokinase = glucose sensor in pancreatic B-cells
• inactivation of glucokinase ==> mild hyperglycemia exacerbated by pregnancy

Question 20

Acitinic keratosis presentation

Answer 20

• erythematous papules + white central scale
• rough, sandpaper like texture

Question 21

Granulosa-theca cell tumors secrete…

Answer 21

estrogen

Question 22

Biotin role in metabolism

Answer 22

• CO2 carrier on carboxylase enzymes
  
  • pyruvate carboxylase
  • ACoA carboyxlase
  • propionyl carboxylase
  • beta-methylacrotonyl carboxylase
  • **all involved in carb and lipid metabolism
• in tissues that perform gluconeo gen, PC: pyruvate ==> OAA
  
  • no gluconeogen ==> pyruvate ==> LA ==> metabolic acidosis

Question 23

Clozapine: MOA, use, SE

Answer 23

• MOA: blocks D4 receptors
• use: refractory psychosis/schizophrenia
• SE
  
  • agranulocytosis <== must monitor WBC count
  • seizures

Question 24

Total flow (w/in tube) =

Answer 24

Flow = cross sectional area x velocity = constant

Question 25

Insulin types

Answer 25

• Basal/long-acting
  
  • Glargine; Determir = once daily
  • NPH = twice daily
• Short-acting/post-prandial
  
  • Regular = best for IV
  • Lispro, Aspart, Glulisine = peak @ 45 min - hour
    
    • best for post-prand hyperglycemia

Question 26

Common disinfectant mechanisms:

alcohols

chlorhexadine

hydrogen peroxide

iodine

Answer 26

• alcohols
  
  • disruption of cell membranes
  • denaturation of proteins
• chlorhexadine
  
  • disruption of cell membranes
  • coagulation of cytoplasm
• hydrogen peroxide
  
  • free radicals
  • sporocidal
• iodine
  
  • halogenation of proteins & nucleic acids
  • sporocidal

Question 27

Consequences of placental aromatase deficiency

Answer 27

• inability to produce estrogens in placenta ==> excess androgens
• XX w/ambigous genitalia
• virilization of mother during preg.

Question 28

Common sites of injury of ulnar nerve

Answer 28

• medial epicondyle of humerus
• near hook of hamate and pisiform bones of wrist