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2012-10-18 15:42:24

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  1. Cause of ARDS
    Cause of emphysema
    Endothelial damage lining pulmonary capillaries

    Alveolar wall destruction
  2. Pathway of AP potential through the heart
    • Starts at the SA node (0.3)
    • Slowest at the AV node (0.05) to allow ventricles to fill durng diastole
    • Impulses travel the fastest through the Purkinje system (2.20)
    • Atrial muscle conduction is greater than ventricle conduction
  3. Paget's disease associated with what cancer
    Osteosarcoma: destruction of normal bone pattern, mixed radiodense and radioluscent areas, periostal new bone formation
  4. Osteopetrosis
    • Osteoclasts fail to reabsorb bone, imparing bone remodelling
    • Osteosclerosis and fractures
  5. Globus hystericus
    • Sensation of a lump in the throat
    • No evidence on physical exam, radio exam or all else
  6. Pseudobulbar paresis
    • Caused by MS
    • Sx: dysathria, dysphagia, dysphonia, impaired movement of tongue and facial muscles
  7. Presence of endometrial glands in the fallopian tube
    • Endometriosis 
    • (can be in any place other than the uterus)
  8. Where does vitamin A accumulate?
    Stellate cells of the liver (all fat soluble vitamins as cannot be excreted in the urine)
  9. DNA electrophoresis reveals fragmentation in multiples of 180 bases
    • DNA laddering: feature of apoptosis
    • distinguishing feature from necrosis
  10. Confusion, blurred vision, dry mucus membranes, intense thirst - associated with what drug toxicity?
    • Atropine
    • (n.b. methylphenidate causes mydriasis but can give confusion and dry mucus membranes)
  11. Germline mosaicism
    • Oocytes and spermatocytes are affected
    • Offspring are affected but not the adults
    • Boths siblings can be affected

    (n.b. somatic mutations cannot be passed onto offspring - both siblings wont be affected)
  12. What cytokine is stimulated only by T cells?
  13. Cytokine stimulated by macrophages
    TNF-a, GM-CSF, IFN-a (other cells produce these too, except TNF-a)
  14. Hemidesmosomes bind on basement membrane with help from?
    Integrins and fibronectin (ECM glycoprotein that binds to integrins)
  15. Cadherins
    transmembrane proteins binding to IM filaments (keratin) and microfilaments (actin) to form adherent junctions and desmosomes
  16. Anterior and posterior dislocations of the knee damage what structure?
    • Tibial a. 
    • Fixed rigidly to proximal and distal to the knee joint by adductor magnus and soleus
  17. Endometritis
    • Infection of the uterus
    • Follows pregnancy - complicatd with use of devices or rupture of the membranes
    • Foul smelling discharge
    • Anaerobic bacteria: Bacteriodes fragilis 
  18. Atopic dermatitis
    • Infants and young children
    • family history of atopy
    • Eruptions on their face or diaper area
    • Older children: on flexural surfaces
  19. Man recalls childhood abuse and becomes angry but takes it out in intense sports
  20. Resident takes out his anger on his medical student when being yelled by his attending
  21. Doctor says "Tell me how your drinking has increased". Use of what technique
  22. Doctor says "So you're saying the excessive drinking is related to recent stresses in your life." Use of what technique.
  23. Order of schizophrenia disorders based on time duration
    • <1 month: acute pyschosis
    • 1-6 months: schizophreniform
    • > 6 months: schiozphrenia

    n.b. schizotypal personality disorder: don't have auditory hallucinations
  24. If FP ratio is 0.1, and the prevalence of a disease is 10,000/100,000, how many people test FP?
    • 90,000 are free of the disease
    • Hence, 0.1 x 90,000 = 9000 FP
  25. Number needed to treat

    where ARR = placebo - treatment
  26. Acute intermittent porphyria
    • Accumulation of porphobilinogen
    • Urine darkens upon standing with sunlight
    • Skin manifestations are absent
  27. Porphyria cutanea tarda
    • Accumulation of uroporphyriogen III
    • Cutaneous blistering photsensitivity
  28. Features of pleural effusion caused by CHF
    Transudates: low protein content, low LDH content, low WBC count

    High WBC count indicative of empyema
  29. Splenectomy for hereditary spherocytosis
    • Increases Hb
    • Decreases hemolysis
    • Decreases jaundice
    • Decreases gallstones
  30. Sensory stroke
    Numbness of the face, arm, and leg on one side of the body without an accompanying motor deficit
  31. Retinoblastoma along with osteosarcoma
    Biochemical defect?
    • Loss of heterogeneity
    • Both copies of the tumor suppressor gene must be lost for cancer to occur
  32. Defective DNA repair
    Xeroderma pigmentosum
  33. Arnold Chiari Malformation: herniation of cerbellar tonsils into the posterior canal
  34. Dandy walker: shrunken cerebellar vermis replaced by a large, midline cyst representing an expanded 4th ventricle
  35. Male genotype with female phenotype and external female genitalia with a vagina ending in a blind pouch
    Complete androgen insensitivity
  36. Aspirin-induced asthma: increased production of what products?
    Leukotrienes C4, D4, and E4 are mediators of asthmatic bronchocontriction
  37. Polypeptide that increases protein hydrophobicity by anchoring carboxyl tails of the receptors to the plasma membrane
    • Palmitoylation
    • (e.g. V2 protein)
  38. Electrolyte differences in sweat and bronchial secretions in cystic fibrosis - cause?
    Difference in tissue-specific functioning of CFTR
  39. Albright hereditary osteodystrophy (pseudohypoparathyroidism)
    • Short stature, short thumbs
    • End-organ resistance to PTH, LH/FSH, TSH
    • (e.g. low Ca+2, high PTH)
  40. Exons in DNA find complementary binding to mature mRNA and introns form loops of unbound DNA - mechanism?
    RNA splicing
  41. mRNA produced fully complements the DNA sequence transcribed, without any loops
    DNA rearrangement during antibody and T cell receptor maturation
  42. Cirrhosis causes portal hypertension - consequence?
    Splenic vein hypertension and splenomegaly secondary to venous accumulation
  43. ELISA test components
    • A known antigen
    • Patient serum (to detect presence of antibodies against Ag)
    • Anti-human immunoglobulin antibodies binding to a substrate-modifying enzyme
    • substrate or chromogen modifying enzyme to cause a colour change
  44. Abnormal gene coding for a cytoplasmic tyrosine kinase activated in CD19+ cells by Ag exposure
    Also causes recurrent infections
    Abnormal gene?
    Bruton's agammaglobulinemia (X-linked)
  45. Male with secondary sexual characteristics and normal blood testosterone levels
    Testosterone [] in the seminiferous tubules and epidydmis are low
    Dysfunctional cells?
    • Sertoli cells
    • Tubules must contain high [testosterone] compared to circulation for spermatogenesis and sperm maturation to occur.
    • Localized testosterone is maintained by androgen-binding protein (ADP)
    • ADP secreted by Sertoli cells

    note: Leydig cells secrete testosterone in the circulation, not tubules
  46. Glucagon stimulates what receptors
    Gs increasing cAMP
  47. Patient presents with excessive sweating. Destruction of what structure will prevent this.
    • Cholinergic postganglionic fibres of the SNS
    • innervates ecrine and apocrine glands
    • Ecrine gland is responsible for hyperhydrosis
    • Surgery targetting the T2 sympathetic ganglion

    n.b. cervical SNS ganglion destruction is for Horner's syndrome
  48. Pathway of round ligament?
    From the uterus through the inguinal canal into the labia majora
  49. Pheochromocytoma increases synthesis of catecholamines by?
    • Increases urinary metanephrine and urine VMA (VMA = end product of NE and Epi metabolism)
    • Methylation needed from NE to Epi via SAM/PNMT and from Epi to VMA via monoamine oxidase
  50. Pulmonary embolism causes what acid: base status?
    Respiratory alkalosis
  51. What causes platelet aggregation?
    • Thromboxane
    • IP3 mediated release of Ca+2 (use of platelet-activating factor)
  52. NF-1 has what biochemical features and if present only in siblings and not adults is what feature?
    • AD, 100% penetrance, and variable expressivity
    • If only found in siblings, germline mosaicism
  53. Rapid infusion of vancomycin causes what chemical release? Prevention?
    • Massive release of histamine causing red man syndrome
    • Not an IgE-mediated allergic reaction
    • Prevention: slower rate of infusion
  54. Woman with heavy bleeding and passes clots sometimes. Palpable mass felt in the lower abdomen and anemic.

    • n.b ovarian cysts don't cause meonorrhagia
    • endometriosis is asymptomatic
  55. Low ketone bodies and severe hypoglycemia after prolonged fasting
    B-oxidation defect: deficiency in acyl coA dehydrogenase

    n.b. acyl coA carboxylase catalyses the 1st step in F.A. synthesis
  56. Bile salts have strong antimicrobial properties. How?
    Micelles: can bind to the lipid membranes and disrupt bacterial outer membranes 

    Common bile duct ligation will cause cholestasis - prevents bile salts from entering the SI
  57. Gram (-) prokaryotes features
    • Haploid genome
    • Inner and outer membrane, and sandwiched in between is the cell wall
    • Sensitivity to some penicillin
  58. Chlamydia features
    • Small, OIC bacteria
    • Double membranes and periplasmic spaces
    • Cysteine-rich outer membrane proteins with S-S bridges
    • Lack PDG cell walls hence, resistant to penicillins
  59. Bone deposition in osteomalacia?
    • Osteoid
    • Vitamin D deficiency = low Ca+2 = 2nd PTH 
    • Decreased bone mineralization and deposition of osteoid matrix in normal trabeculae
    • New bone formed is weak and prone to fracture
  60. Sx of peripheral artery disease
    • Thinned skin
    • Calf claudication (serious pain)
    • Foot ulcers
    • Hair loss and nail changes
    • Prolonged venous filling time
  61. One allele deletion in a tumor suppressor gene 
    Two allele deletion in a tumor suppressor gene 
    Inherited inactivating mutation (e.g. patient with a family history of Li Fraumeni syndrome)

    Malignant mutation (cancerous)
  62. Structures located near the aortic arch
    • Right and left laryngeal nerves
    • Right subclavian artery
  63. Lymphocytic infiltrate of the thyroid gland
    Hashimoto's thyroiditis
  64. Myelinated nerve fibres
    • Motor nerve to skeletal muscle
    • Sensory nerves
    • Autonomic preganglionic nerve
    • Efferent nerves
  65. Unmyelinated nerve fibres
    • Autonomic postganglionic nerves
    • First order bipolar (AFFERENT) sensory neurons of olfaction, heat, and slow pain (burning, visceral)
  66. Type of delusions in delusional disorder
    • Non-bizarre: unlikely, but possible (e.g. poisoned, cheated)
    • Time frame: 1 month
  67. MCC of aseptic meningitis
    Enteroviruses (Picorna family)
  68. Function of invariant chain in MHC class II processing
    • Brings a and B chains of MHC together to form a stable complex in the RER
    • Leaves RER and goes to Golgi and then is proteolytically degraded and an external protein is inserted between the a and B chains

  69. Marfan's and homocystinuria both present with marfanoid habitus. Reason?
    Genetic heterogeniety
  70. MoA of azoles
    Inhibits ergosterol synthesis by inhibiting P450 enzyme that converts lanastrol to ergosterol.
  71. Patient prescribed an azole for white patches seen on vagina and on labia majora, but didn't work. Dx and associated sx.
    • Lichen sclerosus
    • Vaginal pain, pruritis, pain during sex, defecation, and peeing
    • Can progress to SCC
  72. Leukoplakia occurs where?
    • white thickening of mucosal surfaces such as the mouth or genitals
    • Labia majora is not mucosal
  73. Ischemic ATN shows tubular atrophy on histo. Location in kidney?
    Medullary ischemia
    • Interstitial nephritis
    • Inflammatory cells in the interstitium and edema due to NSAIDs
    • Possible tubular damage
  74. How does cardiac hypertrophy occur?
    • Increased rate of myosin mRNA synthesis (protein synthesis)
    • (mitotic activity increase associated with hyperplasia)
  75. Where is the stratum corneum the thickest?
    • Soles of feet and hands. 
    • Callus formation = excessive proliferation of stratum corneum
  76. Polycystic ovarian syndrome hormone levels
    • Theca cells proliferate - LH is high causing androgen formation
    • Granulosa cells decrease (FSH decreases) - cannot aromatize androgens to estrogens
  77. Differentiation of cells occur via what regulatory protein
    Transcription factor
  78. Pernicious anemia causes an increase in what GI hormone?
    Gastrin and decreased HCl
  79. Varicocele pathogenesis
    • Dilations of the spermatic vein pamphinform plexus
    • Occurs because left renal vein is compressed between aorta and SMA
    • Increase pressure in the left gonadal vein and blood cannot return (i.e. pooling of blood backwards in the testes when standing) and also decreased venous return when standing

    Supine position: blood is distributed evenly to the heart, increased venous return. Varicoceles disappear
  80. Pulsatile and continuous mechanism of leuprolide
    • Pulsatile: acts as an GnRH agonist (increases LH and FSH)
    • Use: infertility

    • Continuous: acts as a GnRH antagonist (decreases LH and FSH)
    • Use: prostate cancer
  81. Which genetic material exchange process will be inhibited when DNAse is added to a plate?
    • Transformation
    • (DNAse will degrade naked DNA in the culture medium)
  82. In the cooling step of PCR, when DNA strands are separate, what occurs next?
    RNA primers bind to the ssDNA
  83. Lesions beyond the optic chiasm can cause what eye deficit
    U/L homonymous hemianopsia
  84. Increasing contraction velocity is due to an increase or decrease in preload/afterload
    Increase in preload (= passive tension) upto a certain point until actin/myosin cannot overlap anymore; muscle stretches to accumulate more volume

    Decrease in afterload (decreased the amount of pressure or work needed and decrease O2 consumption) to pump a heart. 
  85. Hematopoeitic precursor cells escape bone marrow and infiltrate the liver and spleen causing enlarged organs
    Extramedullary hematopoeisis
  86. Splenomegaly due to portal hypertension causes what else in the spleen
    • Portal hypertension --> congestive hypersplenism = expansion of red pulp of the spleen
    • Filled with blood-filled sinuses and cords lined by reticulo-endothelial cells