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USMLE1

  1. Describe the esophagitis caused by Candida albicans.
    • White plaques on endoscopy.
    • Yeasts and pseudohyphae on biopsy
  2. Describe the esophagitis caused by CMV.
    • Linear ulcers on endoscopy.
    • Intranuclear (owl eye)  and cytoplasmic inclusions
  3. Describe the esophagitis caused by HSV-1.
    • Vesicles evolve into "punched out lesions"
    • Eosinophilic intranuclear inclusions (Cowdry type A)
  4. Endoscopic findings reveal "punched out" ulcers. Which organism is most likely responsible?
    • HSV-1 
    • Eosinophilic intranuclear inclusions (Cowdry type A)
  5. Endoscopic findings reveal linear ulcerations. Which organism is most likely responsible?
    CMV
  6. Describe the disease Babesiosis. What transmits the organism?
    • Fever and hemolytic anemia. 
    • Hepatosplenomegaly.
    • Often affects asplenic patients. 
    • Transmitted by Ixodes tick
  7. How do we treat Babesia?
    Atovaquone and Azithromycin
  8. This disease is characteristic of a maltese cross seen on blood smear.
    • Babesia
    • Blood smear: ring form, maltese cross
  9. What is the importance of the HMP shunt (pentose phosphate pathway) in RBCs?
    • The HMP shunt provides the reducing agent NADPH (from G6P by G6P dehydrogenase) to prevent oxidant damage.
    • In RBCs hydrogen peroxide (H2O2) is detoxified by reduced glutathione.
    • The regeneration of reduced glutathione is carried out by Glutathione reductase, using NADPH as an electron donor.
  10. What pathologic RBC forms are found in Glucose-6-phosphate dehydrogenase deficiency?
    • Heinz bodies- denatured hemoglobin
    • Bite cells-phagocytic removal of heinz bodies
  11. Image Upload 2
    • Acute poststreptococcal glomerulonephritis
    • IF—(“starry sky”) granular appearance (“lumpybumpy”) due to IgG, IgM, and C3 deposition along GBM and mesangium.
  12. Glomeruli enlarged and hypercellular is characteristic of which glomerular disease?
    • Acute poststreptococcal glomerulonephritis.
    • LM—Glomeruli enlarged and hypercellular.
    • IF—(“starry sky”) granular appearance (“lumpybumpy”) due to IgG, IgM, and C3 deposition along GBM and mesangium.
    • EM—Subepithelial immune complex (IC) humps
  13. Subepithelial immune complex humps are characteristic of which glomerular disease?
    • Acute poststreptococcal glomerulonephritis.
    • LM—Glomeruli enlarged and hypercellular.
    • IF—(“starry sky”) granular appearance (“lumpybumpy”) due to IgG, IgM, and C3 deposition along GBM and mesangium.
    • EM—Subepithelial immune complex (IC) humps
  14. Describe the findings in Acute poststreptococcal glomerulonephritis.
    • LM—Glomeruli enlarged and hypercellular.
    • IF—(“starry sky”) granular appearance (“lumpybumpy”) due to IgG, IgM, and C3 deposition along GBM and mesangium.
    • EM—Subepithelial immune complex (IC) humps
  15. What type of hypersensitivity reaction is Acute poststreptococcal glomerulonephritis?
    Type III hypersensitivity- Immune complex
  16. Child presents with peripheral and periorbital edema, dark urine (cola-colored), and hypertension.
    Acute poststreptococcal glomerulonephritis.
  17. Describe the presentation of Acute poststreptococcal glomerulonephritis.
    Presents with peripheral and periorbital edema, dark urine (cola-colored), and hypertension.
  18. In this glomerular disease, there are increased levels of anti-DNase B titers.
    Acute poststreptococcal glomerulonephritis.
  19. Which organisms secrete IgA protease and what is its function?
    • S.pneumoniae
    • H.influenzae type B
    • Neisseria
    • To colonize respiratory mucosa
  20. What is the function of Protein A?
    • Binds Fc region of IgG.
    • Prevents opsonization and phagocytosis. Expressed by S. aureus
  21. Why is S.pyogenes able to cause  acute rheumatic fever?
    Shares epitopes similar to human proteins (molecular mimicry) 
  22. What is the function of M protein?
    • Helps prevent phagocytosis.
    • Expressed by group A streptococci (S.pyogenes)
  23. These organisms inhibit phagosome-lysosome fusion.
    • Mycobacterium tuberculosis
    • Mycobacterium leprae
    • Legionella
    • Ehrlichia
  24. Describe the presentation of Atrial fibrillation.
    Patient experiences palpitations- awareness of one's heart beating fast and irregularly (irregularly irregular tachyarrythmia)
  25. What are the ECG findings in Atrial fibrillation?
    • Chaotic and erratic baseline
    • No discrete P waves
    • Irregularly spaced QRS complexes
    • Variable R-R interval
  26. What conditions are associated with Atrial Fibrillation?
    • Hypertension
    • Coronary Artery Disease
    • Rheumatic heart disease
    • Binge drinking (alcohol) ("holiday heart")
    • Heart Failure
    • Valvular disease
    • HYPERTHYROIDISM
  27. What risks are associated with Atrial fibrillation?
    Atrial stasis and can lead to cardioembolic events
  28. ST elevation is seen with?
    Transmural infarction
  29. What does a high QRS voltage indicate? What causes it?
    • Ventricular hypertrophy.
    • Commonly results from prolonged, untreated hypertension.
  30. What does a QRS interval prolongation indicate? What causes it?
    • Slowed intraventricular impulse conduction.
    • Common cause- Bundle Branch Block
  31. Decreased estriol levels are idicative of?
    • Placental insufficiency.
    • Intrauterine growth retardation
    • The placenta secretes estriol.
  32. What is the MCC of elevated fetal AFP levels?
    • Dating error (underestimation of gestational age)
    • Confirm by fetal USG
  33. Differentiate between the findings in Chronic HBV with high infectivity vs Chronic HBV with low infectivity
    • High infectivity: HBsAg + HBeAg  + Anti-HBc IgG
    • Low infectivity: HBsAg + Anti-HBe  + Anti-HBc IgG
  34. Which serologic markers are found in hepatitis B immunization?
    Anti-HBs (Antibody to HBsAg)
  35. Which serologic markers are found in recovery of HBV infection?
    • Anti-HBs
    • Anti-HBe
    • Anti-HBc IgG    *Note: IgG=prior exposure/ chronic infection
  36. Which serologic markers are found in Acute HBV?
    • HBsAg
    • HBeAg
    • Anti-HBc IgM   *Note: IgM= acute/recent infection
  37. What serological markers are present in the window period of HBV?
    • Anti-HBe
    • Anti-HBc IgM
  38. What does Anti-HBc IgM indicate?
    • HBcAg- antigen associated with core of HBV
    • IgM- acute/recent infection
  39. What does Anti-HBc IgG indicate?
    • HBcAg- antigen associated with core of HBV
    • IgG- prior exposure/ chronic infection
  40. Image Upload 4
    Acute poststreptococcal glomerulonephritis
  41. Decreased serum C3 levels are diagnostic of which glomerular disease?
    Acute poststreptococcal glomerulonephritis
  42. This is characteristic of which disease?

    Image Upload 6
    • Goodpasture syndrome
    • Crescent formation
  43. PR3-Antineutrophil cytoplasmic antibody (PR3-ANCA) is diagnostic of?
    • Granulomatosis with polyangiitis (Wegener)
    • c-ANCA, PR3-ANCA
  44. Cytoplasmic antineutrophil cytoplasmic antibody is diagnostic of?
    • c-ANCA, PR3-ANCA
    • Granulomatosis with polyangiitis (Wegener)
  45. Perinuclear antineutrophil cytoplasmic antibody is diagnostic of?
    • p-ANCA, MPO-ANCA
    • Microscopic polyangitis
  46. Myeloperoxidase antineutrophil cytoplasmic antibody is diagnostic of?
    • p-ANCA, MPO-ANCA
    • Microscopic polyangitis
  47. High circulating eosinophils are characteristic of which glomerular disease?
    • Interstitial nephritis
    • Fever, rash, hematuria, costovertebral angle tenderness
  48. What is a beta (type II) error?
    • Stating that there is not an effect or difference when one exists (null hypothesis is not rejected when it it in fact false).
    • Also known as a False negative error.
    • Image Upload 8
  49. What is an alpha (type I) error?
    • Stating that there is not an effect or difference when one exists (null hypothesis incorrectly rejected in favor of alternative hypothesis).
    • Also known as a false positive.

    Image Upload 10
  50. What are the causes of Homosyctinuria (high levels of homocysteine)?
    • 1. Cystathionine synthase deficiency
    • 2. Decreased affinity for cystathionine synthase for pyridoxal phosphate (B6) and Serine
    • 3. Homocysteine methyltransferase (methionine synthase) deficiency
    • 4. B12 deficiency
  51. What role does B6 play in the metabolism of  homocysteine?
    Acts as a cofactor for the enzyme cystathionine synthase  in the conversion of Homocysteine to Cystathionine 
  52. What role does B12 play in the metabolism of  homocysteine?
    Acts as a cofactor for the enzyme homocysteine methyltransferase in the conversion of Homocysteine to Methionine
  53. Which amino acid is used in the metabolism of  homocysteine? What role does it play?
    Serine and Homocysteine is converted to Cystathionine by Cystathionine synthase
  54. What role does homocysteine methyltransferase play in the metabolism of  homocysteine?
    • Homocysteine methyltransferase is used in the conversion of Homocysteine to Methionine
    • B12 acts as a cofactor to this enzyme.
  55. What role does methionine synthase play in the metabolism of  homocysteine?
    Methionine synthase/ Homocysteine methyltransferase converts Homocysteine to Methionine
  56. What role does cystathionine synthase play in the metabolism of  homocysteine?
    • Cystathionine synthase converts Homocysteine to Cystathionine.
    • B6 and Serine acts as cofactor.
  57. What are the findings in Homocystinuria?
    • Increased homocysteine in urine
    • Intellectual disability
    • Osteoporosis
    • Tall stature
    • Kyphosis
    • Lens subluxation (downward and inward)
    • Thrombosis
    • Atherosclerosis (stroke and MI).
  58. Lens subluxation (downward and inward) is found in which disease?
    • Homocystinuria
    • Image Upload 12
  59. Lens subluxation (upward and temporally) is found in which disease?
    • Marfan syndrome
    • Image Upload 14
  60. Describe the lens subluxation in Homocystinuria.
    • Lens subluxation (downward and inward)
    • Image Upload 16
  61. Describe the lens subluxation in Marfan syndrome.
    • Lens subluxation (upward and temporally).
    • Image Upload 18
  62. Descibe the metabolism of methionine to homocysteine.
    Image Upload 20
  63. How does homocysteine go back to form methionine?
    • Homocysteine can be converted to methionine by combining with N-5-methyl-tetrahydrofolate in a reaction requiring B12 (cobalamin).
    • In this reaction, a methyl group is transferred from a methylated THF to homocysteine, forming methionine and THF.
    • Image Upload 22
  64. What do monozygotic twins arise from?
    • 1 fertilized egg (1 egg + 1 sperm) that splits into 2 zygotes in early pregnancy
    • Same sex, genetically identical, similar in appearance.
  65. What do dizygotic twins arise from?
    • 2 eggs that are separately fertilized by 2 different sperm
    • Different sex, genetically different
  66. What type of  placentation is found in dizygotic twinning?
    Dichorionic diamniotic
  67. Where is hypocretin (orexin) produced and what is its function?
    • Lateral hypothalamus
    • Promote wakefullness and inhibit REM sleep
    • Decreased in narcolepsy
  68. Describe the presentation of Narcolepsy
    • Excessive daytime sleepiness.
    • ƒHypnagogic (just before sleep) or hypnopompic (just before awakening) hallucinations.ƒ
    • Nocturnal and narcoleptic sleep episodes that start off with REM sleep.ƒ
    • Cataplexy (loss of all muscle tone following a strong emotional stimulus, such as laughter) in some patients.
  69. What are hypnagoic hallucinations?
    • Hallucinations which occur just before sleep.
    • Hypnagoic- going to sleep
  70. What are hypnopompic hallucinations?
    Hallucinations which occur just before awakening.
  71. What does 5-HIAA mean? Where is it found?
    • 5-HIAA -5-hydroxyindoleacetic acid
    • Found in Carcinoid syndrome
    • Breakdown of serotonin
  72. Elevated amounts of 14-3-3 proteins are helpful in diagnosing?
    Creutzfeldt-Jakob disease
  73. Describe the protrusion of a femoral hernia.
    • Protrudes below inguinal ligament through femoral canal  *Note: direct and indirect inguinal hernias are above.
    • Lateral to pubic tubercule.
    • Medial to femoral vein and artery.
    • Image Upload 24
  74. What complications can arise from femoral hernias?
    • If a segment of bowel is present in the hernia sac, incaceration  can cause bowel obstruction (nausea, vomiting, abdominal pain)
    • Impaired blood flow to contents causes strangulation. 
    • Ischemia and necrosis occur (fever).
  75. This type of hernia protrudes below inguinal ligament.
    Femoral hernia
  76. Liver mass plus increased levels of AFP is suggestive of?
    Hepatocellular carcinoma
  77. How does HBV trigger neoplastic changes in hepatocellular carcinoma?
    Integrates viral DNA into cellular genome of host.
  78. Serum marker for hepatocellular carcincoma?
    Increased Alpha-fetoprotein.
  79. What does a promoter mutation results in?
    Decreased level of gene TRANSCRIPTION
  80. What occurs at the promoter region?
    RNA polymerase II and multiple other transcription factors bind to DNA upstream from locus (TATA and CAAT boxes)
  81. What is the function of small nuclear ribonucleoproteins?
    Remove introns from hnRNA/ pre-MRNA
Author
rere_girl4ever
ID
292891
Card Set
USMLE1
Description
USMLE1
Updated

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