Rx_01.19 Flashcards Preview

USMLE Step 1 > Rx_01.19 > Flashcards

Flashcards in Rx_01.19 Deck (19)
1

Rotavirus: virus type

  • double-stranded
  • linear-segmented
  • RNA virus
  • no envelope
  • **most prevalent cause of viral gastroenteritis in children

2

Rabies: virus type

  • Rabies = rhabdovirus
  • single-stranded
  • enveloped
  • helical
  • RNA virus

3

Tx of Karposi sarcoma

alpha-interferon

4

Interferons: MOA

  • interferons = cytotoxic proteins that interfere w/viral protein expression and DNA synthesis
  • types:
    • alpha-interferon
    • beta-interferon
    • gamma-interferon

5

Interferons: uses

  • alpha-interferon used for leukocytic effects in:
    • HepB, HepC
    • Karposi's Sarcoma
    • leukemias
    • malignant melanoma
  • B-interferon
    • MS
  • y-interferon:
    • CGD

6

Dx/identification/tx of Karposi-sarcoma-like lesions

  • Bartonella ==> bacillary angiomatosis ==> cutaneous lesions ~= Karposi sarcoma
  • Dx w/biopsy + Warthin-Starry silver stain
  • Tx = erythromycin or doxycycline

7

Presentation of leptospirosis

  • post-freshwater ingestion
  • high fever
  • renal impairment
  • mild hepatitis

8

Organism + syndromes?

  • Cryptocuccus neoformans
    • stained w/India Ink Stain
  • most commonly: fungal meningitis in immunocompromised patients
  • 2nd most common: cryptococcal pneumonia
    • initial site of innoculation = lung

9

EBV: virus type

  • **causes mononucleosis 
  • linear
  • double-stranded
  • enveloped
    • HSVs are only viruses that obtain envelope via budding from nuclear membrane
  • DNA virus

10

Agent that causes pneumonia + increased risk for liver cancer

aspergillus fumigatus (mold/fungus)

11

Presentation/characteristics of Aspergillus infection

  • Aspergillus ==> pneumonia/pulmonary disease ==> apergillomas ("fungus balls")
    • fever, malaise, brownish sputum
  • Produces aflatoxin ==> increased risk of liver cancer
  • Appearance
    • mold w/septate hyphae that branch at a V-shaped 45-degree angle

12

Dairy product consumption + spiking fever ==> dx?/characteristics

  • Brucella melitensis
    • intracellular 
    • ==> fever, weakness, weight loss
    • gram-negative coccobacilli
    • stain w/modified acid-fast stain

13

Common meningitis cause in unimmunized children

  • H. influenzae = gram-negative coccobacilli

14

E. coli O157:H7 presentation

  • undercooked hamburger meat ==> bloody diarrhea
  • EHEC (enterohemorrhagic E. Coli) = strain that has acquired Shiga toxin ==> bloody diarrhea, ab pain, mild feer
  • complication = hemolytic-uremic syndrome
    • low-platelet
    • anemia
    • renal failure/uremia

15

Shigella presentation/characteristics

  • Shigella = 
    • gram-negative
    • non-lactose
    • oxidase negative
    • does not produce hydrogen sulfide (vs. Salmonella does produce Hsulfide)
  • ==> bloody diarrhea + fever
  • shiga toxin ==> hemolytic uremic syndrome

16

Hanta virus characteristics 

  • bunyavirus ==> hantavirus pulmonary syndrome
  • contracted through exposure to deer-mouse dropping

17

Flaviviruses characteristics

  • Flavivirus ==>
    • Dengue fever
    • Yellow fever
  • West Nile virus = Flavivurs
  • Utilizes Aedes mosquito as vector

18

Most common cause of atypical pneumonia (+Dx)

  • mycoplasma pneumonia
    • cannot be cultured
  • Dx via cold agglutin test
    • cold agglutin = IgM antibodies ==> agglutination of RBCs @ cold temps
    • X-ray = patchy interstitial pattern

19

Tx of mot common atypical pneumo

  • most commone = M. pneumonoiae
  • tx = macrolide (usually azithromycin) for 5 days

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