Nbme+ Flashcards
46 XY fetus, female external genitalia (mild clitoral enlargement), male genital ducts. Deficiency in ?
5alpha-reductase def
Bilateral weakness, decreased deep tendon reflexes, ataxic gait, numbness and tingling in legs and arms. No megaloblastic anemia. Deficiency?
Vit E (can present similarly to def in B12, cobalamin).
Cellulitis causes and differentiation
Staph aureus (clusters of cocci + purulent), Strep pyo (chains of cocci + non-purulent)
Cause of increased cerebral blood flow
increased CO2 in blood (hypercapnia= cerebral vasodilation) ex: decreased respiratory rate/ decreased tidal volume
AIDS patient with watery diarrhea, abd pain, intraluminal oocytes
Cryptosporidium parvum (stains acid fast) Tx: nitazoxanide
Metformin side effect
lactic acidosis
Respiratory alkalosis
hyperventilation (anxiety), anemia, hypoxemia (altitude), PE, pregnancy, hypotension, ILD, early salicylates
Respiratory acidosis
respiratory depression
Metabolic alkalosis
vomiting, loop/thiazide diuretics, antacids
(check urine Cl-)
Atrophic cerebella vermis Sx
gait ataxia (proximal muscles, truncal)
Spacial neglect cause
damage of non-dominant parietal lobe (usually right MCA)
1yo with coarse facial features, corneal clouding, hepatosplenomegaly, joint contractures, intellectual disability, hirsutism, and developmental delay.
Hurler syndrome AR : alpha-L-iduronidase def.
Deposition of heparan sulfate and dermatan sulfate.
Dx: urinary gylocosaminogylcan
coarse facial features, aggressive behavior and pearly papular skin lesions
Hunter syndrome XR: iduronate-2-sulfatase
Dx: urinary gylocosaminogylcan
skeletal abnormalities, clouded corneas, heart disease, no intellectual disability.
beta-galactosidase def
neurological decline, a cherry-red spot on the macula, blindness, deafness, and developmental delay.
Tay-sachs (beta-hexosaminidase A def)
myoclonus, gait abnormalities, cherry-red macules, coarse facial features, skeletal malformations and mild intellectual disability.
Neuroaminidase def
Steroid sulfatase def (XR)
ichthyosis, or hyperkeratosis of the skin with scaling, corneal opacification, ADHD, and cryptorchidism
Reason for neonatal hyperoxygenation (in premature infants)
ROP (protection of retina)
Fluoroquinolone example and mechanism of action
Ciprofloxacin, inhibition of DNA gyrase =topoisomerase
Rifampin mechanism of action
Inhibits RNA polymerase (mRNA synthesis)
Metronidazole mechanism of action
Inhibition of DNA integrity (free radicals)
TMP-SMX mechanism of action
Inhibition of DNA methylation
Side effects of beta2-adrenergic agonists
essential tremor, hyperglycemia, tachycardia, hypertension, headache, hypokalemia
Neonatal conjunctivitis prophylaxis
silver nitrate or erythromycin (inhibits 50s ribosomal subunit, protein synthesis)
Lack of CD18
leukocyte adhesion def: no migration
Baby with a 3day fever then a rash
HHV-6: roseola
Pruritus worst at night and erythematous papules with burrows + Tx
scabies. Tx:permethrin cream, oral ivermectin
PCA occlusion
ipsilat. occipital lobe- contralateral visual field deficit with macular sparing
PICA lesion
Sx: horsness, dysphagia, ipsilat horner syn., decreased gag reflex, nystagmus.
called wallenberg/ lat medullary syndrome
anti-GpIIb/IIIa antibody
Immune thrombocytopenic purpura
NNT
NNT=1/ARR= 1/ (risk control - risk tx)
acyclovir, valacyclovir, and famcyclovir mechanism of action
inhibit viral DNA polymerase, classically by guanosine analogs (must be phosphorylated by thymidine kinase)
Pulmonary embolism ECG changes
Sinus tachy, “S1T3Q3”, right axis deviation (if right heart strain)
peroxisome role
oxidation of VLCFA and of branched-chain fatty acid
if deficient: increased phytanic acid (shortened 4th toe)
necrotizing vasculitis, granulomas, and eosinophilic necrosis.
Churg-Strauss syndrome or eosinophilic granulomatosis with polyangiitis: a small-vessel vasculitis
Aripiprazole
D2 partial agonist (2nd gen antipsych)
Other 2nd gen antipsych are reversible antagonists.
XR
glucose-6-phosphate dehydrogenase deficiency. Duchenne and Becker muscular dystrophy, and hemophilia A and B. Fabry. Hunter
XD
Fragile X syndrome, Alport syndrome, incontinentia pigmenti, hypophosphatemic rickets, and Rett syndrome.
Mitochondrial inheritance
Leber hereditary optic neuropathy, maternally inherited diabetes and deafness, myoclonic epilepsy with ragged red fibers, and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) syndrome.
AD
10
Huntington disease, myotonic dystrophy, tuberous sclerosis, marfan, MEN, NF1, NF2, Li-fraumeni, VHL, achondroplasia
Cilostazol: use and mechanism of action
used for peripheral artery disease. It inhibits PDE3 (decreases platelet activation) and induces vasodilation.
VHL (ch3)
(AD), Hemangioblastomas (retina/CNS), tumors of pancreas and renal clear cell carcinoma, pheochromocytoma
non caseating granuloma, bilat hilar adenopathy, increased Ca2+, increased ACE,
Sarcoidosis (Type IV hypersensitivity)
Non polar amino acids
Gly, Ala, Val, Leu, Ile, Methionine, Phe, Pro, Tryptophan
Hydrophobic (transmembrane domain)
Basic amino acids +
Lys, Arg, His
Acidic amino acids -
Asp, Glu
Class IA antiarrythmics (moderate Na channel antag)
Quinidine, procainamide, disopyramide
Class IB antiarrythmics (weak Na channel blockage)
Lidocaine, phenytoin, mexiletine.
Class IC antiarrythmics (strong Na channel blockage)
Flecainide, propafenone.
AR
9
PKU, cystic fibrosis, sickle cell, wilson, hemochromatosis, glycogen storage, thalassemia, freidreich ataxia, kartagener (primary ciliary diskinesia),
Biceps brachii actions
Flexion of the elbow, supination of the forarm
Diverticula most common location
sigmoid colon (smaller diameter, increased pressure during peristalsis)
Split s2
Wide: pulmo stenosis, pulmo HTN, RBBB, VSD, ASD (fixed throughout resp)
Narrow: aortic stenosis, HTN, LBBB, Hypertrophic cardiomyopathy
Argininosuccinate
In urea cycle (citrulline + Asp = Argininosuccinate = Arginine + Fumarate)
Deficiency in Argininosuccinate Lyase (AR), results in argininosuccinic aciduria.
Malabsorption (diarrhea), muscle weakness, retinitis pigmentosa, spinocerebellar degeneration, blindness, mental retardation, acanthocytes (RBC).
Abetalipoproteinemia AR (mutation in MTP gene = microsomal transfer protein)
(spinocerebellar degeneration due to Vit E def. )
Histo: lipid-laden enterocytes.
Tx: vit E + restrict LCFA
Pituitary adenoma Tx
Dopamine agonists (bromocriptine, cabergoline) , transsphenoidal resection
Succinate dehydrogenase
=complex II
succinate to fumarate (TCA cycle), yields FADH2
Cyanide/ CO poisoning
MOA, Sx for each
Inhibit complex IV of the electron transport chain (cytochrome c oxidase).
Cyanide sx: almond odor, elevated lactate, anion gap met acid, cherry red skin. Can be caused by sodium nitroprusside due to NO releasing cyanide.
CO (competitive binding to heme) sx: left shift of ODC, cherry red skin with bullous skin lesions.
Deficit in pain and temperature sensation and LMN dysfunction in the bilateral upper extremities
Syringomyelia : cystic, fluid-filled, gliosis-lined cavity within spinal cord.
Associated with Chiari I
LMN lesion
weakness, fasciculation, flaccid paralysis, hypotonia, mm atrophy, absent reflexes
UMN lesion
spastic paralysis, clasp-knife rigidity, hyperreflexia, positive babinski
ex: internal capsule stroke
Cataracts, early balding in males, Gonadal atrophy, muscle wasting, difficulty releasing from handshake
Myotonic dystrophy AD. CTG trinucleotide repeat in DMPK gene.
Dysfunctional DNA mismatch repair.
Trinucleotide repeat susceptible for anticipation.
Angioedema, low C2 and C4 levels, no urticaria, increased bradykinin
hereditary angioedema AD (C1 esterase inhibitor def)
ACE inhibitors contraindicated (-pril)
Isoniazid:
- MOA
- CYP450
- Coenzyme needed
- Overdose Sx
- Used for TB, inhibit mycolic acid synthesis
- CYP450 inhibitor
- Different half-lives for slow and fast acetylators
- Uses B6 (pyridoxime) leading to a def of Vit B6
- Drug induced lupus risk
- Overdose= seizure
Epididymitis
Sx: fever, pain that alleviates with elevation of the hemiscrotum, purulent discharge
Cause: N. gonorrhoea or Chlamydia
Tx: ceftriaxone and doxycycline (for coinfection of chlamydia)
MODY/ gestational diabetes
-Enzyme def?
Glucokinase deficiency
MODY AD
In gestational diabetes (also hPL creates insulin resistance)
Bosentan
Use: Pulmo HTN
MOA: inhibit endothelin-1 receptor
Cabergolin
Dopamine agonist (for pituitary adenomas)
Leuprolide
GnRH analog
Octreotide
Somatostatin analog (used for secretory diarrheas in VIPoma and carcinoid syndrome) and to reduce portal HTN
Bupropion
inhibits NE - D reuptake
Side effect: seizure (no sex disfunction)
used as non-benzo anxiolytic, atypical antidepressant,
antagonist of nAchR: used for smoking cessation
Radiolucent osteolytic lesion
Metastasis from:
- multiple myeloma
- non-hodgkin
- non-SCLC
- RCC
- Melanoma
Radio-opaque osteoblastic lesion
Metastasis from:
- Prostate
- SCLC
- Hodgkin
Tx of drug-induced parkisonism
Anticholinergic: benztropine
Orotic aciduria
AR- UMP synthase def
Sx: increased urinary orotic acid, megaloblastic anemia
Severe combined immunodeficiency
- IL-2 receptor mutation
- adenosine deaminase def (tx: retroviral gene therapy, stem cell transplant)
Thymic hypoplasia or aplasia.
Gingival hyperplasia (caused by)
cyclosporins, Ca channel blockers (-dipines and diltiazem, verapamil) , phenytoin
Fulminant hepatitis in pregnant women
Hep E (naked ssRNA), fecal-oral transmission and acute illness (like HepA), high mortality in pregnant women
alpha1 blocker
doxazosin, prazosin, terazosin, (tamsulozin- uroselective)
NK cell activated by
NK cells target
INF + IL-12 + IL-2 or CD16 binding of IgG
Cells with no (or decreased) MHC I expression. Ex: virus infected/ tumor cells.
Vimentin
Mesenchymal tissue (ex: fibroblasts, endothelial cells, macrophages)
IL-1
osteoclast activating factor
Burton tyrosine kinase (BTK)
X-linked agammaglobulinemia
Acbiximab
Ab against platelet IIb/IIIa receptor
Rapid overcorrection of hyponatremia
Osmotic demyelination syndrome: pons are affected. “locked-in syndrome”
Can also occur with rapid glucose correction
Hemiballismus
Lacunar stroke of contralateral subthalamic nuclei -> controls the basal ggl -> no inhibition of thalamus ->
Dry skin, photosensitivity (prolonged severe sunburn), skin cancer
Xeroderma pigmentosum - DNA nucleotide excision repair defective (inability to repair DNA pyrimidine dimers)
Lynch (HNPCC) mechanism
Mismatch repair leading to instability of microsatellite regions of the genome
Metencephalon
Gives rise to cerebellum and pons
Dandy walker syndrome
Varenicline
partial agonist of nAchR.
Used for smoking cessation
Neuropathic pain Tx
TCA, SNRI
γ-glutamyl transpeptidase (GGT)
Increased in liver and bile diseases but NOT in bone disease
(determining factor when alkaline phosphatase high, can from cholestasis/bone)
Allergic Rhinitis Tx
Alpha1 agonist (phenylephrine)
Oligodendrocytes
Myelinate CNS neurons as well as CN II (optic) and CN I (olfactory). Stains GFAP.
It does not regenerate.
Destroyed in progressive multifocal leukoencephalopathy (reactivation of JC virus)
Clopidogrel, ticagrelor
Block ADP (P2Y12) receptor (decrease GpIIb/IIIa expression -> decreased platelet aggregation)
PKU
def in phenylalanine hydroxylase (cofactor tetrabiopterin BH4) which normally converts phenylalanine to tyrosine
MAO inhibitors
(Ex, MOA, Uses, side effects)
Tranylcypromine, phenelzine, isocarboxazid, selegiline.
increase presynaptic concentration of NE, E, 5-HT, dopamine by inhibiting their degradation.
Used in anxiety disorder and atypical depression.
Side effects: Hypertensive crises with tyramine ingestion (cheese, wine).
CCR5 inhibitor (HIV)
maraviroc
Fusion inhibitor (HIV)
enfuviritide
Protease inhibitor (HIV)
-navir (protein processing)
NRTI (HIV)
-vudine
ADPKD (AD polycystic kidney disease)
Polycystin mutation (PKD)
Desmin
Muscles (intermediate filaments)
Vaginal atrophy
decreased estrogen (negative feedback of prolactin on GnRH in breastfeeding women)
Melanoma in african americans
acral lentiginous- distal extremities, not related to UV radiation: finger, palms, soles, and toes.
Small cell lung cancer
Central location, Neuroendocrine tumor (neuron-specific enolase marker and Chromogranin/ synaptophysin stain).
associated with SIADH, Cushing syndrome (ACTH), Lambert-Eaton, encephalitis
GLUT 5
Found in GI tract and spermatocytes, absorb fructose (insulin-independent).
Tyrosine hydroxylase def
Normally, tyrosine -> L-DOPA
When deficient: decreased homovanillic acid in CSF, progressive dystonia (due to def of dopamine) and cognitive impairment (due to def in catecholamines)
Alpha-synuclein
Parkinson (Cells called Lewy bodies: circular eosinophilic inclusion) in substantia nigra
Type III hypersensitivity reaction
(immune complex-mediated 3; circulating Ag-Ab-complement that deposit in tissues)
ex: SLE, drug-induced serum sickness, RA, IgA vasculitis, PSGN,
Type II hypersensitivity reaction
(Ab bind to cell-surface Ag)
ex: Acute rheumatic fever (Step pyogenes), MG, Graves, autoimmune hemolytic anemia…
Type IV hypersensitivity reaction
(Cell mediated with Ag specific CD8+ and CD4+ T cells)
ex: Graft-vs-host disease, PPD test, allergic contact dermatitis
NO Ab needed
Tamoxifen
Selective estrogen receptor modulator
VACTERL
Association (mesodermal defects):
Vertebral, Anorectal atresia, Cardiac, Tracheoesophageal fistula, Esphageal, Renal/ Radial, Limb
epithelial Na+ channel inhibitors (collecting tubules)
Amiloride, Triamterene
(K-sparing)
Dermatomyosis
Paraneoplastic syndrome of adenoma or alone
Hypogastric artery (other name)
Internal iliac a
Polyarteritis nodosa
“beads on a string”, predisposing factor HepB and HepC.
Turner Syndrome
meiotic nondisjunction during gametogenesis
Micrognathia, low set ears, clenched fists (overlapping fingers), congenital heart, prominent occiput, rocker-bottom feet
Trisomy 18, Edwards
Dextrocardia
Kartagener, AR (dynein arm defect)
Akathesia
restlessness
Nitrates MOA
Venodilators: increased NO -> increased cGMP -> smooth muscle relax
Bilateral feet/hand edema, bilateral conjunctivitis, rash, mucositis, cervical lymphadenopathy, fever >5days
Kawasaki
More prominent in Asians
Risk for coronary aneurysm
anti-smooth muscle Ab
Autoimmune hepatitis
cystathionine synthase deficiency
Homocystinuria (AR): lens dislocation (down and in), intellectual disabilities, marfan. Risk for thrombosis.
Cofactor B6 (pyridoxine)
Teriparatide
Recombinant PTH analog (increase osteoblast proliferation)
Receptor tyrosine kinase
MAP pathway
IGF-1, FGF, EGF, PDGF, Insulin
Non-receptor tyrosine kinase
JAK-STAT pathway
GH, Prolactin, G-CSF, Erythropoietin, Thrombopoietin, Immunomodulators (ex: cytokines IL-2, IL-6, IFN) .
Positive heterophiles Ab production
EBV
Ab can be sheep/horse and will react/agglutinate with the patient’s RBC
Cause of Lithium toxicity
NSAIDs, Thiazides diuretics, ACEi, Metronidazole, Tetracycline
(decreased kidney clearance of lithium)
resistant to degradation by protein C
Factor V leiden mutation
Achondroplasia
AD, no carrier status (as homozygous is lethal).
Connexin
Gap Junction
