UWorld_2.27

Question 1

Fabry disease: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 1

• X-linked
• alpha-galactosidase
• ceramide trihexoside
• sx
  
  • angiokeratomas
  • cardiac and renal involvement
  • painful neuropathy

Question 2

Gaucher disease: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 2

• AR
• B-glucocerebrosidase
• glucocerebroside
• sx
  
  • gaucher cells = “tissue paper” macs
  • hepatosplenomegaly
  • developmental delay

Question 3

Hurler syndrome: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 3

• AR
• a-L-iduronidase
• dermatan & heparan sulfate
• Sx
  
  • gargoylism
  • corneal clouding
  • hepatosplenomegaly
  • devolpmental delay

Question 4

Hunter syndrome: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 4

• X-linked recessive
• iduronidate sulfatase
• dermatan & heparan sulfate
• Sx
  
  • milder hurler syndrome
  • gargoylism
  • NO corneal clouding
  • hepatosplenomegaly
  • devolpmental delay

Question 5

Niemann-Pick Disease: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 5

• AR
• sphingomyelinase
• sphingomyelin
• sx
  
  • hepatosplenomegaly
  • cherry-red macula spot
  • foam cells (lipid-laden macs)
  • progressive neurodegeneration

Question 6

Tay-Sachs Disease: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 6

• AR
• B-hexosaminidase A
• GM2 ganglioside
• sx
  
  • NO hepatosplenomegaly
  • cherry-red macula spot
  • progressive neurodegeneration

Question 7

Krabbe Disease: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 7

• AR
• galactocerebrosidase
• galactosylsphingosine & galactocerebroside
• Sx
  
  • progressive neurodegeneration
  • optic atrophy

Question 8

Metachromic leukodystrophy: inheritance, deficient enzyme, accumulated metabolite, presentation

Answer 8

• AR
• arylsulfatase A
• cerebroside sulfate
• sx
  
  • muscle wasting
  • dementia
  • ataxia

Question 9

Pathways ==> lysosomal storage disease

Answer 9

Question 10

Characteristics of mucormycosis

Answer 10

• opportunistic infection caused by Rhizopus, Mucor, and Absidia species
• ==> paranasl sinus involvement in a diabetic or immunosuppressed patient
  
  • facial or periorbital pain
  • H/A
  • purulent nasal discharge
  • black eschar (necrotic tissue) may be seen @ palate or nasal turbinates
• fungi form broad, nonseptate hyphae that branch at right angles

Question 11

Candida albicans presentation

Answer 11

• ==> variety of sx in immunosuppressed patients
• ==> R-sided endocarditis, renal abscesses, pneumonia, esophagitis
• budding yeasts and pseudohyphae

Question 12

Characteristics of aspergillosis

Answer 12

• can involve paranasal sinuses, lungs, etc.
• light microscopy ==> septate hyphae that branch @ 45 degree angle

Question 13

Dobutamine impact on pressure-volume loop

Answer 13

• ==> increased contractility
• ==> higher pressures during ventricular ejection phase + greater volume expelled
• ==> widening of P-V loop

Question 14

Gastric secretions

Answer 14

• epithelial layer ==> mucous for protection
• upper glandular layer = parietal cells @ body & fundus ==> gastric acid + intrinsic factor
• deep gastric glands = chief cells ==> pepsinogen

Question 15

Characteristics of MG

Answer 15

• autoimmune type II, antibody-mediated, hypersensitivy rxn against skeletal myocyte surface acetylcholine receptors
• improves with edrophonium (tensilon) injection = anti-cholinesterase agent

Question 16

Immune sensitivity types:

• Hypersensitivity pneumonitis
• Goodpasture
• Sarcoidosis
• PSGN
• Contact dermatitis
• Atopic dermatitis

Answer 16

• HP = type III
• Goodpasture = type II
• Sarcoidosis = type IV
• PSGN = type III
• Contact derm = type IV
• atopic = eczema = can involve type I

Question 17

Conus medullaris syndrome presentation

Answer 17

• lesions @ L2
• ==> flaccid paralysis of bladder and rectum
  
  • impotence
• ==> saddle (S3-S5 roots) anesthesia
• ==> mild weakness of leg m. if adjecent cord/nerves spared
• common causes
  
  • disk herniation
  • tumors
  • spinal fractures

Question 18

Cauda equina syndrome presentation

Answer 18

• massive rupture of intervertebral disk ==> compression of 2+/18 nerve root w/in cauda equina
• sx
  
  • low back pain radiating to legs
  • saddle anesthesia
  • loss of anocutaneous reflex
  • bowel/bladder dysfxn (S3-S5)
  • loss of ankle-jerk + plantar flexion weakness

Question 19

Emphysema consequences on PFTs

Answer 19

• destruction of interalveolar walls + decreased elastic recoil ==>
• FVC = normal to low
• Forced expiratory = low
• FEV1/FVC = low
• Total lung capacity = increased
• Fxnl residual capacity = increased ++
• pulm. compliance = increased
• bronchodilator response = none
• D_LCO = low

Question 20

Chronic bronchitis consequences on PFTs

Answer 20

• destruction of interalveolar walls + decreased elastic recoil ==>
• FVC = normal to low
• Forced expiratory = low
• FEV1/FVC = low
• Total lung capacity = normal
• Fxnl residual capacity = increased +
• pulm. compliance = normal
• bronchodilator response = partial response
• D_LCO = normal