Step1_qbank_random2 Flashcards
How is Galactosemia inherited? Which enzyme is defective?
AR; galactose-1-phosphate uridyltransferase
What effect does the hypothalamus have on prolactin secretion?
Inhibitory via dopamine production
Effect modification
when the effect of an exposure on an outcome is modified by another variable
What is the triad for babies that experienced in-utero Toxo
(1) hydrocephalus (2) choreoretinitis (3) intracranial calcifications
Anti inflammatory cytokines
TGF-B and IL-10
Treatment for severe allergic asthma
Omalizumab; [anti-IgE antibodies]
What is Omalizumab? How does it work?
recombinant humanized IgG1 monoclonal antibody; binds with IgE to inhibit the action of IgE –> decrease allergic response
Which organism grows well at 41C
Mycobacterium avium complex
What is the ppx for mycobacterium avium complex?
Azithromycin
What metabolizes pro-carcinogens? Where is it located?
cytochrome P-450 monooxygenase; in hepatic microsomes and ER
What is the function of cytochrome P-450 monooxygenase?
metabolize steroids, alcohol, toxins, and other foreign substances
What is the draw back to cytochrome P-450 monooxygenase?
Also converts pro-carcinogens into carcinogens –> mutations in human DNA
How long after fertilization during ovulation does it take for Beta-HCG to be positive?
8-11days
How is Isoniazid metabolized?
Acetylation
What dictates the speed one acetylates?
Whether they are fast or slow acetylates
Most common comorbidity for imperforate anus?
Urogenital tract anomalies
What is Etanercept function
Soluble decoy protein
[suffix of biological agents] (mab)
monoclonal AB
[suffix of biological agents] (cept)
receptor molecule
[suffix of biological agents] (nib)
kinase inhibitor
Which region of the kidney is impermeable to water
Thick and thin ascending limbs of Henle’s loop
What is the most potent cerebral vasodilator?
pCO2
What is the effect of decreased cerebral vascular resistance on cerebral perfusion and ICP?
Increase; Increase
[MoA] C. diptheriae - Diphteria toxin
Inactivates EF-2 via ribosylation, thus inhibiting host cell protein synthesis
[MoA] P. aeruginosa - Exotoxin A
Inactivates EF-2 via ribosylation, thus inhibiting host cell protein synthesis
[MoA] S. aureus - Enterotoxin
Superantigen that acts locally in the GI tract causing vomiting
[MoA] S. aureus - TSS toxin
Superantigen that stimulates T-cells leading to widespread cytokine release and shock
[MoA] - C. difficile - Cytotoxin B
Induces actin depolymerization leading to mucosal cell death, necrosis of colonic mucosal surfaces, and pseudomembrane formation
[MoA] - C. botulinum - Botulinum toxin
Blocks the presynaptic release of acetylcholine at the neuromuscular junction resulting in flaccid paralysis
[MoA] - B. pertussis - Pertussis toxin
Disinhibits adenylate cyclase via Gi ADP ribosylation, increasing cAMP production in the host cell; causes increased histamine sensitivity and phagocyte dysfunction
[MoA] - V. cholera - Cholera toxin
Activates adenylate cyclase via Gs ADP ribosylation, increasing cAMP production in the host cell; causes secretory diarrhea, dehydration, and electrolyte imbalances
Which med class would you use to dilate the pupil? Why?
alpha-adrenergic agonist; dilator muscle of the pupil has alpha 1 receptors
Which med class would you use to relax the uterus?
beta 2 agonists
How is lithium excreted?
Kidneys
Signs of lithium toxicity (6)
Neuromuscular excitability, irregular course tremors, fascicular twitching, agitation, ataxia, delirium
Drugs that increase lithium levels? (3)
Thiazide diuretic;, ACE inhibitors; NSAIDs
Effect of Pramipexole [Parkinsons]?
Stimulates dopamine receptors
Sputum shows many neutrophils no organisms
Legionella
[features of immunodeficiency disorders] Ataxia -telangiectasia
Ataxia; telangiectasia; sinopulmonary infections
[features of immundeficiency disorders] Chediak-Higashi Syndrome
Oculocutaneous albinism; pyogenic infection; progressive neurologic dysfunction
[features of immundeficiency disorders] Chronic Granulomatous disease
Severe bacterial and fungal infections; granuloma formation
[features of immundeficiency disorders] DiGeorge Syndrome
Congenital heart disease; dysmorphic facies; hypocalcemia
[features of immundeficiency disorders] Severe Combined Immundeficiency
Severe bacterial and viral infections in infancy; Chronic diarrhea; Mucocutaneous CANDIDIASIS
[features of immundeficiency disorders] C5-C9 deficiency
recurrent NEISSERIA infection
[features of immundeficiency disorders] Wiskott-Aldrich
Recurrent infections that worsen with age; easy bleeding; eczema
Sputum findings: esosinophils and Charcot-leyden crystals
Extrinsic allergic asthma
Clinical findings extrinsic allergic asthma?
Paroxymal breathlessness, wheezing
[Epi] Latent Period
Time elapsed from initial exposure;
[Epi] Lead time bias
Time between the initial detection of disease and a specific outcome (ie detecting diseases at earlier stages)
Dyspnea, cough, swelling of the face, neck, and upper extremities, dilated collateral veins in upper trunk
Superior vena cava syndrome
mutation in TATA box affects which cell function?
Transcription initiation
What is a TATA box? What does it bind (2)?
Promoter region; binds transcription factors and RNA polymerase II
Where is the TATA box located?
25 bases upstream from the beginning of the coding region
Which centers regulate Micturition reflex (urination)? (3)
Sacral micturition center (S2-S4) - bladder contraction; Pontine micturition center (pontine reticular formation); Cerebral cortex - inhibits sacral micturition center
Describe the function of the Sacral micturition center. Location/ Fibers involved
S2-S4; Parasympathetic fibers travel from S2-S4 ventral white matter within pelvic nerves and stimulate cholinergic receptors in the bladder wall —> BLADDER CONTRACTION
Describe the function of the Pontine micturition center.
Coordinates relaxation of external urethral sphincter w/ bladder contraction during voiding
Generally which fibers regulate bladder control
Descending cortical fibers
Which histones help pack DNA into nucleosome
H1 histone
Impaired balance, difficulty speaking, elevated serum transaminases; What do you suspect; What is the next test?
Wilson’s disease; slit lamp
Polycythemia vera (PV) define.
Clonal myeloproliferative disease of pluripotent hematopoietic stem cells
Polycythemia vera (PV) characteristics.
Increased RBC mass, increased plasma volume, and low EPO levels
Mutation associated with Polycythemia vera? Effect
JAK2 V617F; hematopoietic stem cells become more sensitive to growth factors
What drug class is effective in preventing Chemo-induced vomiting?
5-HT3 receptor antagonists
Name some 5-HT3 receptor antagonists.
Onansetron; granisetron; dolasetron
Which neuropeptidesare deficient in the CSF of a Narcoleptic patient? Where are they produced
Hypocretin-1 (orexin-A) and Hypocretin-2 (orexin-B); lateral hypothalamus
1st arrhythmia associated with myocardial ischemia.
V Fib
Pyrrolidonyl arylamidase (PYR)-positive, beta-hemolytic, gram-positive coccie in chains
S. Pyogenes
S. agalactia is also known as___. Is Coag____. And catalase____. Gram ____ ____ in ____.
GBS; Negative; Negative; Gram positive cocci in chain
S. aureus is a gram _____ _____ that grows in ____. Catalase____. Coag____. PYR___.
gram positive coccus that grows in chains. Catalase positive. Coag positive. PYR negative.
C perferingen characteristics?
large spore forming; anarobic; gram positive ROD; catalase-neg; coag-neg
Whar does C perferingen produce on blood agar?
Double zone of beta hemolysis
A. Hydrophila characteristics? Likely exposure
oxidase-positive, non-fermenting, gram-negative ROD;; contaminated water
Genus of organism that lack cell wall? Which Abx are not effective with them?
Mycoplasma genus; Penicillins
Treatment for mycoplasma infections
tetracyclins; erythromycin
Common cause of UTI (not E. Coli)? Whast is it resistant to?
Staph Saprophyticus; Novobiocin
What is responsible for the toxic effects observed in meningitis and meningococcemia?
Lipooligosaccharide (LOS) -Outer membrane
How does Lipooligosaccaride (LOS) differ from Lipopolysaccharide (LPS) of enteric gram neg rods?
Lacks the repeating O-antigen of LPS
Hypopigmented or hyperpigmentedt skin patches or papules are characteristic of ___.
Pityriasis versicolor (aka tinea versicolor)
Name the fungus that causes Pityriasis versicolor (aka tinea versicolor).
Malassezia furfur
Where does the infection of Pityriasis versicolor (aka tinea versicolor) localize to? [which skin layer]
Stratum corneum
Superficial inguinal lymph nodes drain cutaneous lymph from where?
umbilicus to feet [exclude posterior calf]
Palpable firm superficial inguinal lymph nodes assoc with cancer where
external genitalia and anus
Toxic side effect of Loop Diuretics and Aminoglycosides/salicylates/cisplatin
Ototoxicity
Name some ototoxic agents
Aminoglycosides/salicylates/cisplatin
Genome imprinting is produced by what?
DNA methylation (ie methyl group from S-adenocyl-methionine to a cyosine residue in a DNA molecule)
Renal tubular ischemia affects which cells preferentially?
proximal tubules AND thick ascending limb of Henle’s loop
What is Cytochrome c? [What does it activate? What does it bring about? Through which pathway?]
mitochondrial enzyme that activates caspsaes and indirectly brings cell death through intrinsic pathway apoptosis
What are the regions of LPS; which is responsible for toxic shock?
O antigen, core polysaccaride, Lipid A; Lipid A responsible for toxic shock
What are the Golgi tendon organs (GTOs)?
sensory receptors located at the junction of the muscle and tendon – innervated by group Ib sensory axons –contract when muscle extends against too much force
What are A-delta fibers?
thin, myelinated nerve fibers; free nerve endings detect TEMP and PAIN
Which sensory axons innervate muscle spindles (intrafusal fibers)?
Group Ia and group II
What are muscle spindles (intrafusal fibers) sensitive to? What do they mediate?
changes in muscle length; stretch reflex
Drug class that reduces prostate volume; Examples
5-Alpha reductase inhibitors; finasteride/dutasteride
[stages of lobar pneumonia] Congestion - time/ presentation
(first 24hr) affected lobe is read heavy and boggy; vasc dilation/alveolar exudate (bacteria)
[stages of lobar pneumonia] Red hepatiation - time/ presentation
(days 2-3) Red, firm lobe “liver like”; Alverolar exudate (erythrocytes, neutrophils, fibrin)
[stages of lobar pneumonia] Gray hepatiation - time/ presentation
(days 4-6) Gray-brown firm lobe; RBCs disintergrate/ Averolar exudate (neutrophils and fibrin)
[stages of lobar pneumonia] Resolution - time/ presentation
restoration of normal architecture; Enzymatic digestion of the exudate
Gram positive organism causing cervicofacial manifestations after oral trauma
Actinomyces israelii
Sulfur granules
Actinomyces israelii
High fever, cough confusion, diarrhea - Causative organism? Lab findings?
HYPOnatremia; sputum gram stain showing many neutrophils but few/no organisms
Amyloid precursor protein (APP) is involved in what process? Name an abnormal fragment.
Synaptic formation and repair; A-Beta-amyloid
On which chromosome is Amyloid precursor protein (APP) located? Associated with which disease?
Chr 21; Down Syndrome
Which bug likes alkaline selective media (thiosulfate-citrate-bile sats sucrose)
V. Cholera
Which drug simulates an ideal environment in the body for V. Cholera?
Omeprazole
Tinnitus, Vertigo, Hearing loss (sensorineural)
Meniere’s disease
Disorder of inner ear characterised by increased volume of endolymph
Meniere’s disease
How to estimate the risk of metastasis in Melanoma?
Vertical growth (depth) [Breslow thickness)
What mediates paraneoplastic cachexia?
TNF-alpha
Consider _____ deficiency with sudden death after blood transfusion.
Select immunoglobulin (IgA) deficiency
Islets in Type 1 DM?
Leukocytic infiltration
Islets in Type 2 DM?
Amyloid deposition
Renal biopsy: ballooning and vacuolar degeneration of prox. Tubules AND multiple oxalate crystals
Toxic renal injury
How does ethylene glycol lead to acute renal failure
Precipitation of calcium oxalate crystals in renal tubules
Metabolic acidosis, increased osmolar gap, calcium oxalate crystals in urine, suggest WHICH INGESTION?
Ethylene glycol
Organism that causes transient pulmonary infiltrates in asthmatic or CF
Aspergillus Fumigatus
[Week 1 of illness] raising fever Bacteremia, relative bradycardia; [Week 2] abdominal pain; [Week 3] Hepatosplenomegaly, intestinal bleeding and perforation
Salmonella Typhi
Delayed umbilical cord falling off - diagnosis
Leukocyte adhesion deficiency
Cause of Leukocyte adhesion deficiency
Absence of CD18 antigen, which is needed to form INTERGRINS
Long term complication of Hydrocephalus? Why?
Hypertonicity/Hyperreflexia; UMN damage
What do lesions to the glossopharyngeal nerve result in?
Loss of the gag reflex (afferent limb); loss of sensation in the upper pharynx, posterior tongue, tonsils, and middle ear cavity, loss of sensation in the posterior 1/3 of the tongue
Fever and HA; CSF: bean-shaped gram negative cocci in pairs
N. Meningitides
Route of N. Meningitides infection? (4)
Pharynx –> blood –> choroid plexus –> meninges
Which deficiency(s) predispose patients to warfarin induced skin necrosis? Treatment?
Protein C or S; FFP
What causes acute appendicitis?
Obstruction of the appendicular lumen
Notable biochemical abnormality in Alzheimer disease?
decreased acetylcholine level (2/2 decreased choline acetyltransferase activity in nucleus basalis)
Where is the biochemical abnormality of Alzheimer disease seen (2)? What is that area responsible for?
[decrease acetylcholine level] basal nucleus of meynert and hippocampus; memory and cognition and formation of new memories
What do ergot alkaloids (ergonovine) do?
constrict vascular smooth muscle by stimulating both alpha-Adrenergic and Serotonergic receptors
Ergots alkaloids + Hypercontractile coronary artery segments (Prinzmetal’s angina) leads to what?
Coronary artery spasm, chest pain, and ST-segment elevation
Biopsy of a non-tender cervical lymphnode that fluctuates in size is likely to show what?
Follicular small cleaved cell lymphoma
Cell line Follicular small cleaved cell lymphoma is derived from? Cytogenetic change?
B cells (non-Hodgkin lymphoma); t(14;18) – over expression of bcl-2
Flushing, watery diarrhea, bronchospasm - associated with what?
Carcinoid syndrome (malignant carcinoid tumor)
What is elevated in urinary excretion in a person with carcinoid syndrome?
5-HIAA
Treatment for carcinoid syndrome?
Octreotide and surgery for mets
Insidious-onset exertional dyspnea, restrictive PFTs, paraseptal and subpleural cystic airspace enlarge (honeycomb lung)
Idiopathic pulmonary fibrosis
Gradual worsening of dyspnea and productive cough, bilateral patchy pulmonary opacification (2/2 intraalveolar accumulation of amorphous protein and phospholipid material–surfactant)
Pulmonary alveolar proteinosis (PAP)
Crohn’s disease associated with increase activity of which cells? And also produce and activate what (3)?
TH-1 helper cells; IL-2 and interferon-y and activate macorphages –> synthesize TNF
Cochlear part of CN VIII mediates what? Compression leads to what?
Hearing; Sensorineural hearing loss and tinnitus
Vestibular part of CN VIII mediates what? Compression leads to what?
Balance; vertigo, dysequilibrium, and nystagmus
Loss of taste in the anterior 2/3 of the tongue suggest problem with which CN?
CN VII
Compression of CN V results in what? (3)
Loss of sensation around the mouth and nose, loss of corneal reflex, and paralysis of the muscles of mastication
Low hemoglobin, thrombocytopenia, absent hematopoietic cells in the bone marrow
Aplastic anemia
Aplastic anemia is associated with a compensatory increase in what?
EPO
Demylenation of axons results in what?
Impaired saltatory conduction down the axon
1 test to demonstrate cystic duct obstruction. What would you see if obstructed?
HIDA scan; failed gallbladder visualization on radionucleotide biliary scan
Findings of DIC. (5)
(1) prolonged PT and PTT; (2) thrombocytopenia and microangiopathic hemolytic anemia; (3) low fibrinogen; (4) elevated fibrin spil products (D-dimer); (5) Low factor V and VIII levels
Abdominal discomfort, greasy stools, weight-loss; Biopsy: PAS-positive granules in lamina propria
Tropheryma whippelii
Hamartoma on histology
“popcorn calcification” - disorganized cartilage, fibrous and adipose
Gold standard diagnosis for Malignant mesothelioma
Electron microcopy
tumor cells with numerous long, slender microvilli and abundant tonofilaments
Malignant mesothelioma
