Rx_Random Set #8

Question 1

Classic exam findings in osteoarthritis

Answer 1

• heberden’s nodes = swelling @ distal interphalangeal joints
• bouchard’s nodes = swelling @ proximal interphalangeal joints

Question 2

Flucytosine: MOA + use

Answer 2

• antifungal agent used to treat systemic fungal infections
• MOA = pyrimidine antimetabolite: inhibits DNA syntehsis by conversion to fluorouracil which competes w/uracil
  
  • selective for fungal cells bc enzymes required for entry and activation are found in low levels in mammalian cells

Question 3

Cause of heriditary spherocytosis

Answer 3

• lack/mlfxn of RBC proteins spectrin or ankyrin

Question 4

Mechanism/presentation of heriditary spherocytosis

Answer 4

• malfxn of spectrin/ankyrin ==> round sperocytes ==> prone to hemolysis, esp. @ spleen
• sx/signs
  
  • jaundiced after viral illness
• FHx
  
  • splenectomies
• Dx
  
  • spherocytes on peripheral smear
  • osmotic fragility test

Question 5

Common histologic finding in squamous cell carcinoma of bladder

Answer 5

keratin pearls

Question 6

Most common cause of squamous cell carcinoma of bladder (in world)

Answer 6

• helminth infection
• schistosoma haematobium ==> eggs @ bladder wall ==> chronic irritation ==> cancer

Question 7

Final enzyme in purine salvage pathway

Answer 7

• xanthine oxidase
  
  • converts xanthine ==> uric acid
  • inhibited by allopurinol (medication used to prevent gout attacks)

Question 8

Presentation/mechanism of alkaptonuria

Answer 8

• AR disorder of homogentisic acid oxidase
  
  • enzyme that helps degrade tyrosine
• ==> accumulation of homogetisic acid ==>
  
  • cartilage (joint) damage + dark color
  • heart valve damage
  • formation of kidney stones
  • excretion in urine ==> black urine

Question 9

Brain abnormality associated with Patau syndrome

Answer 9

• holoprosencephaly
• commonly: midline forebrain structures affected
  
  • optic tracts/bulbs
  • corpus callosum
  • pituitary
  • hypothalamus

Question 10

MOA of vasopressin @ V2 receptors

Answer 10

• V2 receptors located @ kidney collecting duct
• ADH/vasopressin ==> V2 ==> activation of adenylyl cyclase via G_s subunit ==> increased cAMP ==> insertion of aquaporin proteins @ apical membrane ==> increased urine concentration

Question 11

Methotrexate: MOA, uses

Answer 11

• methotrexate = folic acid analog antimetabolite ==> inhibition of dihydrofolate reductase
  
  • DHFR involved in synthesis of purines and some amino acids
• uses
  
  • inflammatory conditions
    
    • rheumatoid arthritis
    • IBD
  • chemotherapy
    
    • breast carcinoma
    • lung carcinoma
    • ALL
    • non-hodgkin’s lymphoma
    • etc.

Question 12

Cyclophosphamide: MOA, uses

Answer 12

• MOA: alkylating agent ==> adds alkyl group to DNA ==> interferes w/DNA synthesis
• Uses
  
  • immunosuppressant
    
    • SLE
    • MS
    • autoimmune hemolytic anemia
    • **restricted use due to severe side effects
  • chemotherapy
    
    • breast carcinoma
    • non-Hodgkin lymphoma
    • ovarian carcinoma

Question 13

Hep A: viral type, transmission, presenation, tx

Answer 13

• ssRNA
• fecal-oral transmission
  
  • esp. endemic areas w/contaminated water supply
• sx: jaundice, N/V, fever, abdominal pain, hepatomegaly
• tx: supportive care

Question 14

Heart murmur in patient w/SLE ==> ?

Answer 14

• most-likely indicates Libman-Sacks endocarditis
• LSE = small vegetation of fibrin + inflammatory cells, often on both sides of valve leaflets
  
  • rarely cause valvular complications or embolize

Question 15

Common pathologic feature in lungs of smokers

Answer 15

• metaplasia of pseudostratified ==> stratified squamous eptihelium

Question 16

Which of following types of epithelium not normally present in the lung, lines the bronchu shown in this image (hx: smoking)

A. pseudostratified columnar

B. simple squamous

C. stratified columnar

D. stratified squamous

E. transitional

Answer 16

D. stratified squamous

Question 17

Treatment for depression w/safe cardiac profile

Answer 17

• Monoamine oxidase inhibitors
  
  • e.g. phenelizine

Question 18

Characteristics of WAGR syndrome

Answer 18

• presents in childhood
• Wilm’s tumor (kidney tumor)
• Aniridia (partial or complete lack of iris)
• genital anomolies
• mental disability

Question 19

Presentation/mechanism of polyarteritis nodosa

Answer 19

• vasculitis of the small-medium arteries
  
  • necrotizing immune complex formation
• non-specific sx from end-organ damage related to blood flow
  
  • MSK, cutaneous, GI, cardiac, renal, neuro
  • lung’s are spared
• often associated with Hepatitis B

Question 20

Acarbose: MOA, use, SE

Answer 20

• MOA: alpha-glucosidase inhibitor ==> decrease hydrolysis and absorption of di/polysaccharides @ intestinal brush border
  
  • ==> decreased postprandial hyperglycemia
• Use
  
  • management of T2DM
• SE
  
  • GI: abdominal cramps, diarrhea, flatulence
  • contraindicated in poor liver fxn

Question 21

Presentation of herniation of L5-S1 disc

Answer 21

• radiculopathy of S1 nerve root ==>
• decreased sensation @ post. leg + lateral foot
• diminished ankle jerk reflex
• weak plantarflexion of foot
• back pain radiating to leg
• positive straight leg test

Question 22

Presentation of Vit D deficiency

Answer 22

• hypocalcemia
• secondary hyperparathyroidism
• hypophosphatemia

Question 23

Peripheral smear and lab results in DIC

Answer 23

• Labs
  
  • elevated prothrombin
  • elevated partial thromboplastin time
  • elevated D-dimer (=fibrin degradation products)
• Peripheral smear
  
  • shicstocytes (“helmet” cells)

Question 24

Presentation of indirect inguinal hernia

Answer 24

• most often = newborn male infants
  
  • peritoneum passes through internal inguinal ring and enters scrotum
  • ==> enlarged scrotum + pain
• covered by all three layers of fascia

Question 25

Possible late presentation of spina bifida occulta

Answer 25

* low back pain * intact patellar deep tendon reflex * x-ray shows incomplete fusion of S1 vertebra

Question 26

Causes of spina bifida occulta

Answer 26

* sbo = neural tube defect (incomplete closure of neural tube) * occurs during first month of gestations * associated w/maternal factors: * folate deficiency * anticonvulsant medication * e.g. Valproic acid * diabetes