Cards from USMLE Practice Tests Flashcards
When deciding which tumor antigen will produce the highest antibody titer, what must you consider?
Whether the immune system will recognize and mount a response to the antigen (i.e. recognize it as “other”).
What signaling molecule is most directly associated with in an increase in lytic bone lesions?
Interleukin-1
What disease process is mostl likely occuring in a recently-hospitalized patient who presents with oliguria and uricemia?
Acute tubular necrosis
Which part of the kidney are necrotic cells most likely to be found in acute tubular necrosis?
The lumen of the proximal tubule
Which cells are infected by EBV? Which cells will be abnormal on blood smear?
B cells are infected via CD21
T cells present with reactive cytotoxic abnormality
Which drug is a monoclonal antibody against platelet IIb/IIIa receptor? How does it work?
Abciximab. Binds platelet fibrinogen receptor (Gp Iib/IIIa) on activated platelet preventing aggradation.
What is the effect of gemfibrozil on cytochrome P450?
It inhibits cytochrome P450.
What is pannus? Which disease process is associated with it?
Pannus is proliferative granulation tissue and is found in the setting of rheumatoid arthritis.
Where is the thyroid hormone receptor located?
In the nucleus
What features would be suggestive of myasthenia gravis in a patient presenting short of breath?
Difficulty taking a long deep breath, decreased tidal volume and vital capacity, symptoms become worse as the day goes on.
A new onset nonbacterial endocarditis in a patient with chronic diarrhea raises suspicion for which neoplasms?
Adenocarcinoma of the small intestine
What metabolite is responsible for the formation of diabetic cataract?
Sorbitol
What is the inheritance pattern of Tay-Sachs disease?
Autosomal recessive
What is the embryological origin of the mobile cystic mass on the lateral side of the neck which does not move with swallowing?
A pharyngeal cleft cyst, derived from a persistent cervical sinus. It will open anterior to the sternocleidomastoid muscle.
What drug could you use to treat someone who was exposed to paint thinner and is experiencing blurred vision, vomiting, fusion, and difficulty walking?
Fomepizole, an alcohol dehydrogenase inhibitor
What is heteroplasmy?
Presence of normal and mutated mitochondrial DNA; variable expression of mitochondrial inherited disease.
Where in the kidney does acetazolamide act?
Proximal tubule.
What is the mechanism of action of micafungin?
Inhibition of fungal cell wall synthesis (block synthesis of beta-glucan)
What is the most common inherited cause of susceptibility to mycobacteria?
IL-12 deficiency (leading to low interferon gamma)
Where is the neurovascular bundle located on the rib? What is the relevance for thoracentesis?
The neurovascular bundles located below so the needle has to go above the rib to avoid damage.
In a Whipple procedure, which nerve structures can be cut to reduce stomach acid output?
The vagal trunks
Which uterine ligament attaches to the cervical region and extends posteriorly?
The uterosacral ligament
Which apolipoprotein would mediate a deficiency in absorption of fat-soluble vitamins?
apoB - responsible for packaging of lipids into chylomicrons.
What are Bence Jones protein on urinalysis?
Ig light chains, characteristic of multiple myeloma.
What is the bronchial circulation?
The systemic vascular supply to the lung
Contrast apoptosis and necrosis cell findings.
Apoptosis: eosinophilic cytoplasm, basal ability clears, pyknosis and karyorrhexis.
Necrosis: produces a local inflammatory reaction, not as eosinophilic, nuclei disappear.
A deficiency of myeloperoxidase would present with the inability to produce which substance?
Bleach/hypochlorite (hydroxy-halide radical)
What is the primary driver behind muscle atrophy in cases of immobilization?
Increase protein degradation
What is the mechanism of action and indication of Praziquantel?
Increases calcium permeability and actualization to kill Hellminths.
What are the drugs used to treat helminth infections?
Pyrantel pamoate, ivermectin, mebendazole, praziquantel, diethylcarbamazine.
What is the indication and mechanism of action of niclosamide?
It is used to treat tapeworm infection by inhibiting glucose uptake, oxphos and anaerobic metabolism.
What causes the proteinuria in nephrotic syndrome?
Podocyte damage leading to loss of the negative glomerular charge barrier.
What is the mechanism of pindolol and acebutolol?
Partial beta agonist.
What is the mechanism of action of aminoglycosides in gentamicin and streptomycin? What you need to watch out for?
Irreversibly inhibit initiation to the 30S subunit and stop translocation thereby blocking bacterial protein synthesis. Requires oxygen for uptake.
Nephrotoxicity, neuromuscular blockade and ototoxicity can occur. Teratogenic.
What is the mechanism by which acetaminophen causes hepatotoxicity?
Cytochrome P 450 metabolism produces NAPQI -> depletion of glutathione stores.
Describe how P450 activity changes with alcoholism
Acute alcohol abuse = decreased P450
chronic alcohol abuse = induction of P450.
Describe the function of the bulbourethral glands and seminal vesicles.
Bulbourethral glands = lubrication added
Seminal vesicles = produce majority of seminal fluid.
Differentiate between caseating, coagulation and fat necrosis?
Caseous -> granuloma e.g. TB and systemic fungi
Fat -> lipase breaks down triglyceride, saponification (blue on H&E)
Coagulative -> preserved cell arch, red/pink on H&E)
Differentiate the effects of atrial natriuretic peptide and B type natriuretic peptide.
ANP -> atrial myocytes
BNP -> ventricular myocytes, longer half-life.
Both are secreted in response to tension’s an act via cGMP to cause vasodilation, decreased sodium resorption at the collecting tubule, dilation of the afferent arteriole and constriction of the efferent arteriole to promote diuresis.
Describe the course of the internal thoracic artery.
Branches off the subclavian artery and descends vertically to supply the anterior chest wall and breast. Commonly used as a coronary artery bypass graft.
What is the most important prognostic factor for breast neoplasm?
Degree of lymph node spread.
What is the mechanism of acion of fluoroquinolones? What are the important contraindications?
Inhibits topoisomerase II and IV (DNA gyrase).
Can cause cartilage damage, so not used in pregnancy or children
Can cause tendonitis and tendon rupture in older adults.
Describe the symptoms and inheritance of acute intermittent porphyria.
Due to a mutation autosomal dominant in porphobilinogen deaminase.
Precipitated by drugs, alcohol and starvation
Painful abdo
Port-wine colored pee
Polyneuropathy
Psychological disturbances.
Treat with hemin and glucose
What are the mechanism of action of oseltamivir and zanamivir?
Inhibition of influenza neuraminidase resulting in decreased release of progeny virus.
What does thromboxane A2 do?
It is produced by activated platelets and activates thromboxane receptor, which results in shape change and degranulation of platelets, recruitment of additional activated platelets and stabilization of the clot.
A harsh systolic murmur over the tricuspid area in a young child is most likely due to what?
A ventricular septal defect
A patient with diabetic ketoacidosis presents with the following black eschars on their face. What is the causative organism?
Mucormycosis (caused by mucor and rhizopus fungi, irregular broad nonseptate hyphae with WIDE angles)
What is Gilbert syndrome?
Mild unconjugated bilirubinemia usually co-occurring with stress or illness. A common, benign and autosomal recessive condition.
This electron micrograph shows a neuromuscular junction. Autoantibodies against the areas shown in arrows would be present in what disorder?
Lambert-eaton myasthenic syndrome (the arrows indicate presynaptic membranes with Ca2+ channels)
Orthostatic hypotension in a patient who is taking acetazolamide for altitude sickness is most probably caused by?
Hypovolemia.
Describe the cluster A personality disorders
Characterized by behavior which impairs meaningful social relationships:
Paranoid = Accusatory
Schizoid = Aloof (social withdrawal)
Schizotypal = Awkward (odd beliefs, eccentric)
NO association with schizophrenia.
Differentiate between pulmonary embolism and pulmonary edema.
An embolism would present with VQ mismatch, sudden onset dyspnea, pleuritic chest pain, tachypnea, and tachycardia.
Edema = findings of consolidation, crackles, wheezes and ronchi.
What is a myxoid tumor?
Most common cardiac tumor in adults presenting with a ball-valve obstruction. Myxoma cells immersed in glycosaminoglycans on histology
How would ischemic colitis present?
At watershed areas including the splenic flexure and the rectosigmoid junction; may have bloody stools.
What is the most likely diagnosis based on his bone marrow aspirate?
Multiple myeloma: lots of small round dysplastic cells. Clinically, look out for sudden-onset worsening back pain and B symptoms.
A tumor is positive on immunohistochemistry or synaptophysin, chromogranin and neuron specific enolase. It is located next to the bifurcation of the carotid artery. What is the most likely tumor?
A paraganglioma (benign, but can become malignant). This particular tumor is neuroendocrine.
What is the brain pathology shown here? What is the clinical presentation?
Normal pressure hydrocephalus, idiopathic, normally affects the elderly
Wet = urinary incontinence
Wobbly = gait adraxia
Wacky = cognitive dysfunction.
What disorder is associated with this picture? What is the etiology? How is it treated?
Dermatitis herpetiformis.
Caused by IgA deposits at tips of dermal papillae and associated with celiac disease.
Treatment: dapsone, gluten-free diet.
A microcytic anemia with spoon nails, glossitis, and cheilosis is most likely caused by?
Iron deficiency
Absent HGPRT presents as what?
Lesch-Nyhan syndrome
Hyperuricemia
Gout
Pissed off (aggression and self-mutilation)
Retardation
DysTonia
treat with allopurinol.
What diet would be most helpful to reduce diabetes risk in an overweight patient with no other lab abnormalities?
Low-caloric
How should you counsel a 15yo male who presents with unilateral breast enlargement with a palpable bud who is otherwise developing normally?
This is normal and should eventually go away with time.
What is the leading cause of death in women?
Cardiovascular disease
What is the best way to reduce the spread of Klebsiella pneumoniae in hospital.
Hand hygiene
What is the mechanism of the diphtheria exotoxin?
ADP ribosylation and inhibition of elongation factor 2.
What is the preferred way to rapidly reverse warfarin?
Fresh frozen plasma
How do you treat pulmonary hypertension in a newborn?
In an adult?
Neonate = Nitric oxide
PDE-5 inhibitors such as sildenafil
endothelin receptor antagonist including bosentan
Protacyclin analogs (epoprostenol, iloprost)
What maintains the ATP concentration in skeletal muscle, cardiac muscle and brain?
Creatine phosphate.
Why is Plasmodium vivax treated with both primaquine and chloroquine?
Primaquine kills hypnozoites (dormant form associated with relapse)
What is lung elastic recoil?
The tendency for the lungs to collapse inward and for the chest wall to spring outward.
Deficiencies of which micronutrients can cause delayed wound healing?
Delayed proliferative stage: vitamin C and copper
delayed remodelling: zinc
How does the carotid sinus sense blood pressure?
A drop in arterial pressure leads to decrease stretch which in turn causes baroreceptor firing and increased sympathetic and decreased parasympathetic function
Describe the derivatives of the four pharyngeal pouches
- ear
- tonsils
- dorsal wings to the inferior parathyroids, ventral wings to the thymus.
- dorsal wings to Superior parathyroids, ventral wings to ultimopharyngeal body and para-follicular cells of thyroid
What is the finding in this barium swallow?
Protrusion of the fundus into the chest above the level of T10
Describe how RANKL regulates osteoclasts.
RANKL is expressed on the surface of osteoblasts and stimulates osteoclasts
Which enzymes are affected by lead poisoning?
Ferrochelatase and aminolevulinic acid dehydratase
What is the storage and active form of vitamin D?
Storage: 25 – OH D3 in liver
Active: 1, 25-(OH)2 S3 (calcitriol) converted in kidney
Describe the classification and clinical relevance of GAS (Streptococcus pyogenes)
Gram-positive cocci in chains which are beta-hemolytic and bactracin sensitive.
Causes pharyngitis, cellulitis, impetigo, erysipelas, scarlet fever, toxic shock like syndrome, necrotizing fasciitis, rheumatic fever, and glomerulonephritis
Describe Pierre Robin sequence. Which pharyngeal arches are defective?
The sequence is micrognathia, glossoptosis, cleft palate, airway obstruction.
First pharyngeal arch (responsible for the maxillary and mandibular processes as well as the muscles of mastication)
second pharyngeal arch (responsible for cartilage of the stapes, styloid processes, lesser horn of the hyoid, stylohyoid ligament and the muscles of facial expression)
Which properties of anaesthetics are responsible for rapid induction and recovery as well as potency?
Rapid induction: decreased solubility in blood
increased potency: increase solubility in lipid.
What causes the closure of the foramen ovale and ductus arteriosus after birth?
With the first breath, pulmonary resistance drops leading to an increase in left atrial pressure, shutting foramen ovale.
As O2 increases and prostaglandins (from placental separation) decrease, the ductus arteriosus closes. Note that cyclooxygenase (resp. for prostaglandin synthesis) inhibition can also play a role.
Where is vitamin B12 absorbed?
The terminal ileum: it requires intrinsic factor.
Compare tetanus and botulism toxin.
Both proteases Cleves snare and stop neurotransmitter release. Tetanus results from inhibited release of inhibitory neurotransmitters whereas botulism results from inhibition of stimulatory neurotransmitters.
Describe the role of IkB in regulating NF-kB singnalling
IkB is phosphorylated by IKK, leading to release of NF-kB
What are the irreversible enzymes of gluconeogenesis?
Pyruvate carboxylase
Phosphoenolpyruvate carboxylase
Fructose 1,6 bisphosphatase
Glucose 6 phosphatase
What is the Haldane effect?
Deoxygenated blood has a higher affinity for carbon dioxide than oxygenated blood. This is due to deoxyhemoglobin acting as a buffer for to pull H2CO3 -> HCO3- + H+
A defect in which protein is associated with dextrocardia?
Dynein (Kartagener syndrome).
What disturbance in serum pH is caused by loop diuretics and thiazides?
Metabolic alkylosis
What is the neoplasm?
Medullary thyroid carcinoma, originating from parafollicular C cells (makes calcitonin).
Key characteristic is sheets of polygonal cells in amyloid stoma
What is the effect of antibiotics on fecal excretion for salmonella and Shigella?
Salmonella treatment results in longer excretion
Shigella treatment results in shorter excretion
Which coronary artery supplies the posterior left ventricle?
The right coronary artery
What does the diphtheria vaccine contain?
Purified inactivated diphtheria toxin
Which germ cell layer does the esophagus come from?
The endoderm
Describe the first four weeks of fetal development
- Blastocyst implantation at day six, hCG secretion from embryo begins.
- Bilaminar disk (2 layers)
- Gastrulation (3 layers), formation of neural plate
- Neurlation, limb buds (4 limbs), heart begins to beat.
Name some distinguishing characteristics for Streptococcus and Staphylococcus.
Gram +ve (both)
Streptococcus is in chains, Staphylococcus is in clusters
Streptococcus is alpha or beta-hemolytic, Staphylococcus is catalase positive
What are the characteristics and members of viridans group streptococci?
Gram-positive, alpha hemolytic cocci which are opthrochin resistant and bile insoluble.
S mutans and S mitis -> dental carries
S sanguinis bind fibrin-platlet aggregates on damaged heart valves.
Name some examples of the 4 major classes of HIV therapeutics.
- (non)Nucleotide reverse-transcriptase inhibitors: abacavir, didanosine, emtricitabine, lamivudine, stavudine, tenofovir, zidovudine | delavirdine, efavirenz, nevirapine
- Integrase inhibitors: bitegravir, dulotegravir, elvitegravir, raltegravir
- Protease inhibitors: Atazanavir, Darunavir, fosamprenavir, indinavir, lopinavir, ritonavir, saquinavir
- Entry inhibitors: Enfuvirtide (inhibits fusion) and Maraviroc (inhibits docking).
Name the four classes of obligate anaerobes
Clostridium, Bacteroides, Fusobacterium, Actinomyces
(can’t breathe fresh air)
Is Bacillus subtilis pathogenic?
no
What is the lymphatic drainage from the cervix?
Internal iliac
What is the blood supply to the AV node and diaphragmatic surface of the heart?
the posterior interventricular artery, a branch of the circumflex artery.
What are the enzymes involved in acute intermittent porphyria and porphyria cutanea tarda?
porphobilinogen deaminase and uroporphyrinogen decarboxylase
Staphylococcal toxic shock syndrome: how do they hint it, what will you find on labs?
Hints: nasal packing or tampon use,
Increased AST, ALT and bilirubin, fever, rash & desquamation
shock & end-organ failure.
What is the innervation of the gut?
Vagus nerve from pharynx to 2/3 transverse colon
Pelvic nerve from distal 1/3 colon to upper anal canal.
What are the classic findings for pheochromocytoma?
increased catecholamines and metanephrines (homovanillic acid, vanillylmandelic acid) in urine and plasma.
What pathologic process resulted in this kidney?
Hydronephrosis (notice widening fo the calices)
What would be the cause of elevated parathyroid hormone in the setting of low calcium levels?
Rickets or osteomalacia (also high ALP and low PO4)
How do you distinguish between primary and secondary hyperparathyroidism?
Primary = HIGH Ca2+, low phosphate
secondary (often compensatory for CKD = low vitamin D) = low CA2+ and high PO4
What is the acronym for findings in systemic lupus erythematosus?
RASH OR PAIN
Rash (malar, discoid)
Arthritis
Serotitis (pleuritis, pericarditis)
Hematologic disorder (cytopenias)
Oral or nasopharyngeal ulcers
Photosensitivity
Antinuclear antibodies
Immunologic disorder (anti dsDNA, anti-sm, antiphospholipid)
Neurologic disorder (seizure, psychosis)
What is gardner syndrome?
Familial adenomatous polyposis + osseous and soft tissue tumors + congenital hypertrophy of retinal pigment epi + impacted or supernumerary teeth.
What is conversion disorder?
Functional neurologic symptom disorder: acute motor or sensory LOF following a stressor, typically patient is aware but may not be bothered by the symptoms.
What is the most effective way to screen fresh frozen tissue and paraffin-embedded specimens for presence of a particular protein?
immunohistochemistry
Differentiate between cluster B personality disorders
Bad (antisocial = sociopath)
Borderline (unstable personal and interpersonal relationships, emotional emptiness, splitting)
flambuoyant (histrionic = attention-seeking, dramatic, shallow, labile emotions)
Best (narcissitic = gradiosity and sense of entitlement, lack of empathy)
What are the symptoms of croup? What is the causative virus?
Croup aka acute laryngotracheobronchitis. Barking cough and inspiratory stridor.
Caused by parainfluenza virus.
Individuals with sickle cell disease are more susceptible to bacteremia caused by which organism?
Salmonella: can present with osteomyelitis, liver/spleen abcess, sepsis.
Which population is at increased risk for sarcoidosis?
African-american (females)
What disease is associated with this finding on biopsy? What are the other associated symptoms on CXR and PE?
Noncaseating granuloma = sarcoidosis
Presents with bilateral adenopathy and coarse reticular opacities.
Other associated symptoms: bell’s palsy, uveitis, lupus pernio (lupus-like skin lesions), interstitial fibrosis, erythema nodosum, RA-like arthropathy, hypercalcemia.
Treat with steroids.
What is a Tc-99 scan used for?
Uptake indicates active thyroid (Tc-99 is similar to the iodide ion). Tc-99 is not turned into thyroid hormone so better for dosimetry / children.
Compare tissue from complete vs partial hydratiform mole.
Complete = hydropic villi, circumferential / diffuse trophoblast
Partial = fetal parts, some villi are hydropic + focal trophoblastic proliferation.
What cranial nerve is affected by a posterior communicating artery aneurysm?
CN III (ipsilateral)
How does serum insulin change in type II diabetes?
Initially increased, then decreases in advanced disease.
Describe the causes and findings of the 4 types of shock
Hypovolemic (cold, clammy) due to hemorrhage, severe dehydration, burns) very low preload, increased systemic resistance)
Cardiogenic or obstrcutive (cold, clammy) due to MI, HF, valve dysfunction, arrythmia, tamponade, PE, or tension pneumo, very low cardiac output, increased systemic resistance)
Distributive shock due to sepsis or anaphylaxis (warm, increased CO, very low SR) or CNS injury (dry, low CO, very low SR).
Distinguish between schizoid and schizotypal personality disorder.
Schizoid = voluntary social withdrawal, content with isolation
Schizotypal = odd beliefs or magical thinking, eccentric, interpersonal awkwardness.
What medication would you give to someone who develops post-op urinary retention? What is its mechanism of action?
Bethanechol (can also be used for bowel ileus). A cholinomimetic, it increases phosphoinositide turnover in muscle cells of the bladder fundus.
Distinguish between the MoA of tetracyclines and macrolides.
Tetracycline, doxycycline and minocystine bind the 30S subunit of bacterial ribosomes and prevent tRNA attachment.
Azithromycin, clarithromycin, erythromycin, binds 23S rRNA of the 50S ribosomal subunit blocking translocation.
What is the most appropriate treatment for trichomonas vaginitis?
Oral metronidazole
What is neostigmine used for?
it is an acetylcholinesterase inhibitor which does not penetrate the CNS (postop and neuorgenic ileus, urinary retention, myasthenia gravis and reversal of NMJ blockade post-op).
A man presents with dyspnea and a chemical exposure and smells of almonds. What is the treatment?
Cyanide poisoning
- Give nitrites to make cyanomethemoglobin (less toxic)
- Give sodium thiosulfate to increase conversion to thiocyanate and renal excretion.
When treating organophosphate poisoning, which drugs treats muscarinic vs nicotinic effects?
Atropine for DUMBBELSS symptoms (muscarinic)
Pralidoxime for neuromuscular blockade. (nicotinic)
How do you calculate specificity?
True negative rate = TN/(all N) = TN/(TN + FP)
How do you calculate sensitivity?
TP rate = TP / aii P = TP / TP + FN
Distinguish between type I and type II errors in hypothesis testing.
Type I = falsely rejecting the null hypothesis, calculated by alpha or significance level
Type II = failing to reject the null = beta (power = 1-beta)
Why is it important to pay attention to when a stem tells you a patient has had a condition “since birth”.
It implies a hereditary condition which is less likely to have an environmental component, e.g. for anemia, it suggests something like hereditary elliptocytosis or pyruvate kinase deficiency as opposed to sickle cell anemia or G6PD
What is the immediate precursor and enzyme which produces norepinephrine?
precursor is dopamine
enzyme is dopamine hydroxylase
Stick out your tongue and say “aaah” to test which cranial nerve?
Uvula elevation; cranial nerve X (vagus)
Which conditions result in schistocytes on blood smear?
microangiopathic hemolytic anemias: DIC, TTP/HUS, HELLP syndrome
Which cytokines mediate sepsis?
IL-1, IL-6, and TNF-alpha
What is the mechanism of action of cyclosporine? What is the dose-limiting toxicity?
It is a calcineurin inhibitor which blocks T-cell activation by preventing transcription of IL-2. Nephrotoxic, neurotoxic, gingival hyperplasia, hirsutism
Distinguish between causes of autoimmune hemolytic anemia.
Warm AIHA due to IgG, associated with SLE, CLL, alpha-methyldopa
Cold AIHA due to IgM, causes agglutination when exposed to cold, associated with Mycoplasma pneumoniae, infectious mononucleosis, CLL
Besides the liver, which other organ is capable of sufficient gluconeogenesis to release glucose into circulation?
the kidney
Describe the embryonal origin of the pituitary gland.
Anterior pituitary from oral ectoderm (rathke pouch)
Posterior pituitary from neurectoderm
Which cytokine is involved in recruiting neutrophils to the site of an infection?
IL-8
Clean-up on aisle 8
What is the significance of the kappa:lambda ratio?
Kappa:lambda higher than 3 is indicative of monoclonal lymphoma (or other lymphoproliferative disease)
What are the lung findings characteristic of idiopathic pulmonary fibrosis?
Increased collagen deposition, honeycomb appearance on CT, traction bronchiectasis (higher FEV1 than expected)
Which pathway is affected by warfarin? What is the first factor to be depleted?
The extrinsic pathway (measured by PT), Factor VII
How would you describe the lesion? What is it called? What is the causative organism?
umbilicated papulees ; molluscum contagiosum
poxvirus
What is the autoimmune target in myasthenia gravis? Which cancer is associated with it?
Post-synaptic ACh receptors at the neuromuscular junction; thymoma
What is the course of the inferior alveolar nerve?
It is a branch of the mandibular nerve which runs through the mandibular canal to supply sensation to the lower teeth. It exits at the mental foramen
What mutations cause familial hypercholesterolemia?
Absence of the LDL receptor on hepatocytes.
What is the mechanism of action of capsofungin? What are the other drugs in it sclass
Inhibits synthesis of beta-glucan, blocks cell wall synthesis. Useful for Candida and aspergillosis
Also micafungin and anidulafungin
What do lesions of the subthalamic nucleus produce?
Contralateral hemibalismus
What is the mechanism of action of reperfusion injury in cardiac ischemia?
Generation of mitochondrial free radicals and membrane lipid peroxidation
What does this X-ray indicate
Congential diaphragmatic hernia (note the placement of the NG tube, the absence of bowel gas and the right-shift of the mediastinum)
What are the classic signs/symptoms associated with inhalant abuse (e.g. sniffing glue).
Peaks around 8th grade. Headaches, N/V, belligerence, drowsiness, lethargy, poor school performance.
Long-term effects include ataxia, brain damage possible.
Label the nerves
A- CN III oculomotor
B - CN IV trochlear
C - CN VI abducent
D - CN V1 trigeminal/opthalmic
E - CN V2 trigeminal/maxillary
Which pituitary hormone is responsible for stimulating testosterone production?
LH
What mediates the inflammation seen in crohn’s disease?
T-lymphocytes
Acute kidney injury in an endurance athlete should raise suspicion for what condition? What is the protein that builds up?
Rhabdomyolysis - myoglobin
Nosocomial infection by gram-positive, catalase-negative cocci in pairs/chains is most likely which organism?
enterococcus faecalis (think VRE).
What protein structure produces characteristic birefringent pattern when stained with congo red?
Amyloid beta pleated sheets.
What is the arterial supply for the uterus?
The internal iliac artery
In a patient with sarcoidosis, what serum concentrations will be elevated?
1,25-dihydroxycholecalciferol (activation in macrophages) leading to elevated calcium levels
What does normal/low BP in the context of an elevated JVP indicate?
Right-sided heart failure (hence, increased cap hydrostatic pressure)
Describe this cardiac lesion
Myxoma
What vaive pathology results in concentric LV hypertrophy?
Aortic stenosis
What disease is caused by Trypanosoma brucei?
African sleeping sickness (enlarged lymph nodes, recurrent fever, somnolence, coma) spread by the Tsetse fly.
What immune deficiency would lead to susceptibility to Neisseria bacteremia?
Terminal complement deficiency (C5-C9)
To confirm hyperthyroidism, what should you measure?
Free T3 and/or T4 (bound T3/T4 is inactive, so total T3 is not useful)
What is the trousseau sign? What condition is associated with it?
Hypoparathyroidism -> occlusion of brachial artery with BP cuff leads to carpal spasm
How do you distinguish between eosinophilic granulomatosis with polyangiitis (Churg-Strauss) and granulomatosis with polyangiitis (Wegener)?
Churg-Strauss: asthma, sinusitis, skin nodules, peripheral neuropathy which may have heart/GI and kidney involvement; key marker is perinuclear(MPO)-ANCA
Wegener: resp necrotizing granulomas in nasal septum, sinusitis, otitis media, mastoiditis, hemoptysis cough and dyspnea with necrotizing glomerulonephritis and focal necrotizing vasculitis. Key marker is serum antineutrophil cytoplasmic antibody (c-ANCA or PR3-ANCA)
How are burns classified (degrees)
- Superficial (epidermis only, sunburn
- All epidermis + some dermis; blisters
- Full thickness of dermis, white waxy and leathry, does not blanch, painless
- Through to deeper tissue eg muscle and bone, no feeling in area, nerve endings destroyed.
What is the mechanism of action of ezetimibe?
Prevents cholesterol absorption in small intestine (brush border)
Which diuretic is good for hepatic ascities and HF?
Spironolactone
What causes gynecomastia in men?
Increases in sex hormone binding globulin (either due to estrogen or chronic liver disease, or drugs) reduces circulating levels of free testosterone.
What is the first-line pharmacotherapy for OCD?
SSRI or SNRI
What are the second-generation histamine-1 blockers? What’s their advantage over the first gen?
Loratadine, fexofenadine, desloratadine, cetirizine. Less sedation due to lower CNS entry
What are the drugs which can induce long-QT and put patients at risk of Torsades de pointes? What are other risk factors? How do you treat?
Antiarrhythmics (specifically IA and III)
Antibiotics (macrolides)
Anti”C“ychotics (haoperidol)
Antidepressants (TCAs)
Antiemetics (odansetron)
Hypo K+, Ca++ or Mg++
Treatment is magnesium sulfate.
What is sulfsalazine used for?
Combo sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory) for UC and Crohn disease (colitis).
Which vaccines will stimulate both cellular and humoral responses?
(Attention, Teachers! Please Vaccinate Small Beautiful Young Infants with MMR Regularly)
Adenovirus (nonattenuated), Typhoid, Polio, Varicella, BCG, Yellow fever, Influenza (intranasal), MMR, Rotavirus.
Distinguish between the aminoglycosides and the macrolides
Aminoglycosides (Gentamicin, Neo, Amikacin, Tobra, Strepto) bind 30S subunit, require O2 for uptake. Bactericidal and used for gram -ve rod infections
Macrolides bind 50S subunit (23S rRNA), used for atypical pneumonis, gram +ve cocci infections and B pertussis.
How do you calculate odds ratio for an exposure?
(Odds of exposure in those with disease) / (odds of exposure with no disease)
i.e. [(E+ D+) / (E- D+)] / [(E+ D-) / (E- D-)]
What are the nonselective alpha and beta antagonists?
Labetalol and carvedilol
What is the mechanism of action of hydralazine? What is it used for?
It increases cGMP and results in vasodilation of arterioles > veins, reducing afterload.
How does SIADH affect electrolyte concentrations?
Euvolemic hyponatremia (due to continued excretion of Na+)
What is renal papillary necrosis? What are its causes?
Gross hematuria and proteinuria due to sloughing off of necrotic renal papillae. Associated with sickle-cell disease or trait, acute pyelonephritis, analgesics (NSAIDs), diabetes mellitus. (SAAD papa)
What characteristic causes E. coli to stain gram-negative?
it has a thin peptidoglycan layer and an outer membrane.
What causes a horseshoe kidney? Why would a horseshoe kidney complicate abdominal surgery?
Horseshoe kidneys occur when the interior poles of both kidneys fuse and get trapped under the IMA. As a result, although the course of the ureters remains normal, the blood supply for the kidneys is abnormal.
What immune response causes induration at the site of a bee sting?
Macrophages which produce IL-1, IL-6, and TNF alpha.
What alternative testing methodolgy for TB produces fewer false positives from BCG vaccination?
The interferon-gamma release assay (whole blood is incubated with synthetic peptides).
What cellular mechanism may help explain muscle atrophy?
Polyubiquitination and degradation of proteins
If you were to do BAL on an aspiration pneumonia what bacteria might you expect to find?
Normal oral flora
Distinguish between the three protozoa which cause gastrointestinal infections.
Giardia is associated with multi-nucleated trophozoites and foul-smelling fatty diarrhea.
Entamoeba histolytica is associated with bloody diarrhea, liver abscess and trophozoites which consume RBCs.
Cryptosporidium is associated with severe diarrhea and aids or mild disease immunocompetent hosts (watery diarrhea).
What is leukoplakia?
White patches or spots on the inside of the mouth. Associated with chewing tobacco, heavy smoking, and alcohol use and may progress to squamous cell carcinoma.
Oral Harry leukoplakia occurs in immunocompromised to do EBV where the patches have folds.
What is a leukemoid reaction?
Increase in WBCs which mimic leukemia due to infection / another disease, which returns to normal following resolution of the condition.
Differentiate between precontemplation and contemplation.
Precontemplation involves denial of the problem whereas contemplation acknowledges the problem but is unwilling to change.
How would you characterize the pulmonary zone which is occluded due to a large embolism?
Dead space
What is the embryological origin of the aorticopulmonary septum?
Neural crest cells
What structures or cells originate from the neural crest cells?
MOETL PASSES
Melanocytes, Odontoblasts, Tracheal cartilage, Enterochromaffin cells, Leptomininges (arachnoid + pia), PNS ganglia, Adrenal medulla, Schwann cells, Spiral (aorticopulmonary) membrane, Endocaridal cushions (partial), Skull bones.
What types of inhibitor binding cannot be overcome by simply increasing the concentration of agonist?
Either noncompetitive antagonism or partial agonism.
What reaction does an ACE inhibitor target?
The conversion of angiotensin I to angiotensin II.
What organism causes these lesions? What is the pattern of spread? What exposures are more likely to result in this disease?
Sporotrichosis (Sporothrix schenckii) a cigar shaped yeast which lives on vegetation (“rose gardner’s disease”) and causes ascending lymphangeitis.
What are the characteristics of Pseudomonas aeruginosa?
It is a gram-negative rod that is aerobic, catalase and oxidase -positive and non-lactose fermenting. Colonies produce green colour and grape-like odour.
Name the numbered parts of the spinal cord
- Skin
- Fascia/fat
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Epidural space
- Dura mater
- Arachnoid mater
- Subarachnoid space
What are the functions of the 5’ cap on mRNA?
- Nuclear export (cap binding complex)
- preventing degradation
- promoting translation (recognized by eIF4F)
- 5’ proximal intron excision
Describe the foramina through which the divisions of the trigeminal nerve pass?
V1 Superior orbital fissure
V2 foramen rotundum
V3 Foramen ovale
What is heteroplasmy?
both normal and mutated mtDNA present, variable expression of mitochondrially inherited disease.
Describe the signs and symptoms of vitamin E deficiency
Hemolytic anemia, acanthocytosis (spur cells), muscle weakness, demyelination of posterior columns (loss of position and vibration sense) and spinocerebellar tract (ataxia)
3 hormones of appetite regulation? What are they, what do they do?
Ghrelin is the hunger hormone
Leptin is the satiety hormone
Endocannabinoids increase appetite (munchies)
How does smoking affect the lung?
Increases mucus production and secretion, decreases activity of airway cillia and alveolar macrophages.
Which parts of the kidney will experience ischemic injury first?
The straight segment of the proximal tubule and the thick ascending limb
Describe the pathophysiology of albinism
Normal melanocyte numbers but unable to produce melanin or decreased melanin production due to defects in tyrosine transport or tyrosinase.
When trying to find the primary site for a metastasis, what should you consider?
Make sure you are able to explain all of this physiologic symptoms based on the primary site of the tumor.
What is the defective protein in Marfan syndrome.
FBN1 gene mutation results in defective fibrillar which normally forms a sheath around elastin.
What is pseudofolliculitis barbae?
Most commonly occurs as razor bumps on African-American males which are hyper pigmented papules and pustules that are painful and pruritic on the cheeks, jawline and neck.
What is the presentation of SMA stenosis?
Severe postprandial abdominal pain (due to ischemia) and weight loss, typically with atherosclerotic disease elsewhere.
How does niacin lower cholesterol levels?
It decreases VLDL and raises HDL by inhibiting lipolysis and reducing hepatic VLDL synthesis
What is the mechanism of resistance in VRE?
Substitution of lactate for alanine in D-ala-D-ala cell wall precursors.
What complications of MI can occur acutely within the first week and result in murmurs?
Papillary muscle rupture leading to severe mitral regurgitation (apex holosystolic murmur)
interventricular septal defect (VSD—LLSB holosystolic murmur)
What is Fanconi syndrome?
Generalized reabsorption defect of the proximal convoluted tubule often associated with hereditary defects, ischemia, multiple myeloma, or nephrotoxins.
What malaria-causing protozoans require primaquine to prevent relapse?
P. vivax & P. ovale (due to hypnozoite)
What does endothelin-1 do in the lung? What drugs target it?
Increases pulmonary vascular resistance
Bosentran (antagonizes endothelin-1 receptors)
How is kallikrein related to the clotting cascade?
It is activated by factor XII and increases the conversion of plasminogen into plasmin.
How does a fatty-acid chain acyl-CoA dehydrogenase deficiency present?
hypoketotic hypoglycemia (can cause sudden death in infants/children)
Where is the lateral corticospinal tract? Where do neurons from here synapse?
E/F
first synapses on the anterior horn from which the LMN’s the spinal cord.
Describe the pathophysiology of asthma. What histological features are associated?
Cox inhibition leads to leukotriene overproduction and airway constriction, chronic sinusitis.
Smooth muscle hypertrophy and hyperplasia, Curschmann spirals and Charcot-leyden crystals.
What is the relationship of Enkephalin and substance P to pain?
Enkephalin activates Delta opioid and mu opioid receptors.
Substance P is important for transduction of pain to the CNS.
Calretinin and cytokeratin 5/6 are found in what type of neoplasm?
Mesothelioma
What are the five Ps that are associated with acute interstitial nephritis?
Pee (diuretics)
Pain-free (NSAIDs)
Penicillins / cephalosporins
PPI
Rifampin
Sulfa drugs
What is the classic presentation of kidney stones? What complications can be associated?
Unilateral flanked tenderness with sharp colicky pain radiating to groin and hematuria.
Complications include hydronephrosis pyelonephritis and AKI.
What are the risk factors for gout?
Hyperuricemia (#1), male, HTN, obesity, DM, dyslipidemia, alcohol use
What characteristics distinguish a hairy cell leukemia?
Stains tartarate resistant acid-phosphatase, LM shows hair-like projections on mature B cells. Pts typically have splenomegaly and pancytopenia. BRAF mutations
What aneurysm is associated with an ipsilateral CN III palsy?
A posterior communicating artery aneurysm
Which H2 blocker has the most drug interactionsD? What is the mechanism?
Cimetidine is a potent cytochrome P450 inhibitor.
What is this organism? What symptoms does it cause? What is the appropriate treatment?
Schistosoma mansoni causes liver/spleen enlargement, fibrosis, inflammation & portal hypertension.
Treat with praziquantel
When are PDE-5 inhibitors contraindicated?
When someone is taking nitrates / nitroglycerin due to risk of severe hypotension
When you’re asked why a medication is contraindicated, what do you need to think about?
Patient factors and also drug-drug interacitons
When calculating incidence from the population, what is the denominator?
new cases in given period / number of people that do not have the disease
When is buproprion contraindicated?
Contraindicated in pts with electrolyte disturbances (e.g. anorexia nervosa) due to increased risk of seizures
When is haloperidol contraindicated?
In patients which are obtunded or patients with Parkinson’s
What is the mechanism of action of lactulose for hepatic encephalopathy?
Lactulose is digested by bacteria to lactic acid + acetic acid. This protonates NH3 -> NH4+ which then causes the ammonium to stay in the colon.
Describe the pathway through which the fat soluble vitamins are absorbed.
Lacteals drain to thoracic duct into L subclavian (into systemic circulation)
What signs are suggestive of specific IgA deficiency?
Frequent pneumonia (more than 2x in 1 yr), anaphylactic reaction to blood transfusion.
Which organisms are more people with selective IgA deficiency more susceptible to?
Giardiasis (and other GI infections),
What is rabbit antithymocyte globulin used for? What side effects can occur?
Used to prevent transplant rejection or aplastic anemia.
Can cause cytokine syndrome (type III hypersensitivitY)
What does CD28 do? Which cells express it?
Binds MHCII / B7 for antigen presenting cells. Found on T cells.
What does CD80/CD86 do? Which cell type is it found on?
It is another name for MHC II, B7 (antigen presentation) by macrophages.
What is an open-label trial?
No blinding of researchers or participants. Does not preclude control or randomization.
What characterizes a sertoli-leydig cell tumor?
Ovarian benign tumor which resembles testicular histology and may produce androgens
What is a granulosa cell tumor?
Malignant sex cord stromal tumor which consists of call-exner bodies and often produces estrogen/progesterone. Presents with postmenopausal bleeding, endometrial hyperplasia, precocity (adolecents) and breast tenderness.
What is the diagnosis? What is the most likely causative organism?
Folliculitis, may be pseudomonas aeruginosa.
What is the mechanism by which H. pylori contributes to ulcer formation?
Elaboration of proteases and urease + local tissue destruction
What genuses of bacteria are spirochetes?
Spirocheta, Treponema, Borrelia, Leptospira
Differentiate between pemphigus vulgaris and bullous pemphigoid
Both type II hypersensitivity
Pemphigus vulgaris - possibly fatal, due to autoantibodies against desmoglein-1 (desmosomes -> connect keratinocytes in stratum spinosum). Presents with flaccid blisters, +ve nikolsky
Bullous pemphigoid - less severe, due to autoantibodies against hemidesmosomes (basement membrane). Presents with tense blisters, -ve nikolsky
What happens to pneumocytes in interstitial pneumonitis?
Type 1 decreases, type II increases
What is the most specific sign on physical exam of pulmonary arterial hypertension?
P2 (the S2 sound made by closure of the pulmonic valve) lounder than A2.(sound of aortic valves closing)
Does a polymorphism need to cause a change in protein sequence to have clinical importance?
No; in fact any change in an allele’s DNA sequence qualifies.
What is the best thing to say to someone who is frustrated by long wait time?
Apologize, thank them for waiting, offer to help.
How do the baroreceptors, systemic/pulmonary vascular resistance and capillary fluid transfer change in an acute bleed?
Baroreceptor firing decreases, systemic & pulmonary resistance increases, and capillaries absorb fluid from the interstial space.
Differentiate between anterior and posterior urethral injury
Anterior due to a straddle injury affecting spongy urethra, blood accumulates in scrotum, Buck fascia tear leads to blood in urethral space.
Posterior due to pelvic fracture affecting membranous urethra with urine leaking into retropubic space, high riding “boggy” prostate.
Suspect if blood at urethral meatus.
What is the function of C3b?
opsonization
Which complement factors are elevated in anaphylaxis?
C3a, C4a and C5a
Which complement causes neutrophil chemotaxis?
C5a
What is C5b-9?
The membrane attack complex (MAC) which defends against gram -ve bacteria, formed by activation of C5b under influence of C6-C9
What are the common inducers of cyt-P450?
Modafinil, chronic alcohol use, St john wort, Phenytoin, Phenobarbital, Nevirapine, Rifampin, Griseofulvin, Carbamazepine
(most chronic alcoholics steal phen-phen and never refuse greasy carbs)
What is the lymphatic drainage above and below the pectinate line?
Above: internal iliac
Below: superficial inguinal
What cranial nerve may be disrupted by an orbital floor fracture?
The maxillary nerve (CN V)
What is the effect of ACE inhibitors in pregnancy?
oligohydramnios, renal failure and hypocalvaria.
Describe the histology from this specimen of colon. What is the diagnosis?
Noncaseating granuloima; crohn disease
Brown blood and cyanosis is pathognomonic for what condition?
Methemoglobinemia; oxidized form of Hb (Fe3+). Caused by nitrites and benzocaine poisoning.
How would you differentiate between a GBS and a GAS infection?
GAS is bacitracin sensitive, GBS is bacitracin resistant.
GBS is for babies! (pneumonia, meningitis, sepsis)
GAS causes pyogenic infections (strep throat, cellulitis, impetigo, erysipelas), toxigenic (scarlet fever, toxic shock, necrotizing fasciitis), immunologic (rheumatic fever, PSGN) infections.
What is the mechanism of action of bisphosphonates?
Binds hydroxyapatite, inhibits osteoclasts.
What is the virulence factor common to all paramyxoviruses?
Fusion protein (F) which causes fusion of respiratory epithelial cells
Which tumor suppressors block the G1-S transition?
p16 (CDKN2A), Rb (via inhibition of E2F), and p53 (via p21)
The following biopsy is taken from a child’s jaw lesion. What is the diagnosis? What is the process is occuring in the regions marked by arrows?
Burkitt lymphoma (starry sky with tingible body macrophages).
What is the lymphatic drainage from the tongue?
Submental
Differentiate between type I and type II errors in hypothesis testing?
Type I - false positive finding
Type II - false negative finding
What is the presentation of tularensis? What is the treatment?
Varies; ulceroglandular is most common with lymphadenopathy + ulcer.
streptomycin or gentamicin
What are the symptoms of Cushing syndrome?
CUSHINGS
High cholesterol
High urine cortisol
Skin changes (thin, striae)
Hypertension
Immunosuppression,
Neoplasms (can cause it)
Growth retardation (children)
High sugar
also amenorrhea and moon facies
How does radon enter a home? What living situation may increase risk of radon exposure?
Via basement through drains, pipes, cracks and windows.
Which enzyme is responsible for causing autodigestion of the pancreas?
Trypsin (pepsin is stomach)
What innervation do the corticospinal tracts provide
Voluntary motor to ipsilateral alpha motor neuron
What innervation do the spinothalamic tracts provide?
pain / temperature to the contralateral side of the body (cell bodies in dorsal root ganglion, 1st synapse is ipsilateral dorsal horn, which then cross over and ascend to VPL nucleus)
What type of hypersensitivity reaction is eczema?
Type I (increased entry of antigens & microrganisms trigger immediate response)
What are the GLP-1 analogs? What is their mechanism of action & side effect?
Liraglutide and exenatide (lower glucagon, increase glucose-dependent insulin release). N/V and pancreatitis, causes weight loss.
What is the mechanism of action of canagliflozin / dapagliflozin or empagliflozin? What are the side-effects?
Blockade of SGLT2 leading to glucosuria / dehydration. UTI, candidiasis, dehydration, hyperK+, weight loss.
What drugs work similarly to the GLP1 analogs?
DPP4 inhibitors (inhibits the enzyme that deactivates GLP1)
Linagliptin, saxagliptin, sitagliptin.
Name the nerves A->E
A) axillary
B) median
C) ulnar
D) radial
E) suprascapular
When a question suggests a particular nerve deficit to address via physical therapy, which muscles need to be strengthened?
Those which the nerve innervates.
What is the presentation of ACA stroke?
Contralateral paralysis and sensory loss of the lower limb.
Urinary incontinence
Which nerve is responsible for adducting the leg? What muscles are innervated?
Obdurator nerve innervates obdurator externus, adductor longus, adductor brevis, gracilis, pectineus and adductor magnus.
What is the pathogenesis of Niemann-Pick disease?
Either mutations of lysozomal enzyme acid sphingomyelinase (type A or B) or mutations in NPC1 or 2 which result in defective lipid transport.
Which cells are responsible for dividing to turn over intestinal epithelium?
Crypt cells
What is a mechanism of action that differentiates tumor suppressor genes from oncogenes?
inhibition of cell cycle regulation
Identify the area of the brain
Broca’s area
What is 7-dehydrocholesterol?
It is converted via sun exposure to previtamin D
What is the gene which makes dynein? What does dynein do?
Microtubule-associated ATPase (MAP-1C)
Retrograde transport.
What change in the muscle microenvironment is indicative of muscle fatigue?
Lower pH
What is the difference between a catabolite activator and an allosteric activator?
The catabolite activator protein binds cAMP and activates transcription of the lac operon.
Allosteric activator binds protein not at active site.
What drugs are used for muscle paralysis in surgery or mechanical ventilation?
Succinylcholine (causes depolarization)
or Atracurium, cisatracurium, pancuronium, rocuronium, tubocurarine, vecuronium (competitive ACh antagonism)
What structures does the 3rd pharyngeal pouch contribute to?
Thymus, left and right inferior parathyroids
Identify the labeled structures
A - Deep dorsal vein
B - deep fascia
C - urethra
D - cavernous artery.
How does parathyroid hormone increase calcium concentration?
Acts to increase 1,25-OH2-cholecalciferol synthesis, which then activates osteoclasts via paracrine stimulation of osteoblasts and increases Ca2+ and PO3 absorption in intestines.
Where is the frontal lobe?
B
What is the likelihood that 2 siblings have identical HLA type?
25% or 1/4
Overflow incontinence is associated with what nerve damage?
Pelvic nerve (parasympathetic input to bladder)
Differentiate between the clinical course of hep A/B/C/D/E
A - acute and self limiting in adults, asymptomatic in children
B - initial serum sickness progressive to carcinoma
C - slow progression to cirrhossis and carcinoma
D - like HBV
HEV - fulminant hepitatis is pregnant people.
What is cardiac dominance?
Whether the posterior descending artery is supplied by the right coronary (85%) or left coronary (10%) or equally by both (5%)
What is the mechanism of action of ACE inhibitors?
Decrease GFR by reducing angiotensin II, which normally acts to constrict efferent arterioles.
Prevents inactivation of bradykinin, which contributes to vasodilation
Slimy stools and RUQ pain with large areas of destruction of intestinal epithelium is suspiscious for…
Amebiasis (caused by Entamoeba histolytica)
Urethritis without cistitis and pyelonephritis and pyuria without other symptoms in urine suggests infection by what organism?
Chlamydia trachomatis.
What is this lesion associated with?
Erythema multiforme, associated with M. pneumoniae, HSF, some drugs (sulfa, beta-lactams, phenytoin), with multiple types of lesions. Target lesion shown with epithelial disruption
Stevens johnson syndrome fever, bullae formation and sloughing of skin.
What does the achilles tendon reflex test?
S1
What is the key characteristic of membranous nephropathy
Thickening of glomerular basement membrane; granular deposits of IgG and C3
What is the difference between basophilic strippling and ringed sideroblasts
Both present in sideroblastic anemia (lead poisoning, myelodysplastic syndromes, alcoholism), but can only see ringed sideroblasts under prussian blue stain.
What is budd-chiari syndrome?
Thrombosis/compression of hepatic veins -> centrilobular congestion and necrosis; can cause “nutmeg liver”
Which HIV therapeutics are associated with hyperglyciemia, GI intolerance and lipodystrophy?
Protease inhibitors (ends in navir)
Which HIV therapeutics are associated with bone marrow suppression?
NRTIs
What are the toxicities common to all non-nucleotide reverse transcriptase inhibitors?
Rash, hepatotoxicity.
What are the causes of acute pericarditis?
Idiopathic / presumed viral
Cocksackie B
Neoplasia
Autoimmune (SLE; RA)
Uremia
Cardiovascular (acute STEMI, dressler syndorme)
Radiation
Osteoblastic mets in bone is characteristic of what disease? Where are they most likely to be found?
Late-stage prostatic adenocarcinoma; likely found in spine (presents with back pain)
What is the most reliable serum hormone marker to see that ovulation has occured?
Increase in progesterone
What are key findings in Paget disease of bone? What is the treatment?
Isolated increase in ALP with local bone remodelling with thickening of cortex e.g. “picture frame vertebrae”, chalk-stick fractures of long bone, hearing loss (due to auditory foramen narrowing).
Treat with bisphosphonates
What is meconium ileus? What is it associated with?
Obstruction of intestine due to meconium plug; associated with CF
High retics + jaundice suggests what condition?
A hemolytic anemia
Obliterative endarteritis is associated with what disease?
Syphilis
What are the physiologic effects of the nonselective beta blockers? What are some examples?
Decreased CO (due to B1 blockade), Vasoconstriction (due to B2 blockade)
Nadolol, pindolol, propranolol, timolol
In the treatment of prostate cancer, why is flutamide used alongside leuprolide?
Leuprolide = GnRH agonist, results in androgen increase initially. Flutamide is a competitive antagonist, blocks initial androgen surge.
Which antibiotics are associated with photosensitivity?
Tetracycline, doxycycline and minocycline
How do you differentiate carbon monoxide poisoning from cyanide poisoning? How does the therapy differ?
Carbon monoxide poisoining is typically associated with fires, car exhaust or gas heaters; cyanide with synthetic combustion or apricot seeds or cyanide ingestion.
Headache and dizziness, multiple family members involved, bilateral globus pallidus lesion
Treat with hyperbaric oxygen for CO, hydroxocobalamin followed by nitrites and sodium thioslulfate for CN.
What defects lead to severe combined immunodeficiency? What are their mechanisms of inheritance?
Defective IL-2R gamma chain (X-linked recessive)
Adenosine deaminase deficiency (AR)
RAG mutation (VDJ recombination defect)
How do you differentiate between obstructive and restrictive lung disease on PFTs?
Obstructive has increased lung volumes with decreased FEV1/FVC
Restrictive has decreased lung volumes and increased FEV1/FVC
What is the difference between in situ cervical carcinoma and invasive cervical carcinoma?
The former stays above the basement membrane.
How would you differentiate between postnasal drip and nocturnal asthma?
Wheezing and chest tightness is typically associated with asthma; allergy symptoms will more often present with PND
What is the treatment for nocturnal asthma?
Inhaled corticosteroids
With celiac disease, what is the expected change in phosphorus and calcitriol?
Secondary hyperparathyroidism resulting in hypocalcemia, hypophasphatemia and low vitamin D.
How do you differentiate adhesive capsulitis vs subacromial bursitis?
Adhesive capsulitis = frozen shoulder
Subacromial bursitis specifically leading to impingement syndrome with painful arc 60-120deg or positive neer’s
A virus which is destroyed by heating to 60deg has what characteristic?
Enveloped
What markers characterize regulatory T cells?
CD3, CD4, CD5 and FOXP3
What is the cause and presentation of IPEX?
Cause: genetic deficiency of FOXP3 leading to autoimmunity:
Immune dysregulation
Polyendocrinopathy
Enteropathy
X-linked + diabetes in male infants
Where is the receptor for the signal recognition particle located?
the rough ER
What substances are associated with swelling as a result of inflammation?
Leukotrienes (C/D/E-4) and histamine, serotonin
What is the function of IgE? What does it bind?
Crosslinked when exposed to antigen and activates immendiate hypersensitivity >>histamine
Binds mast cells and basophils
Activates eosinophils with parasite infection
Which electrolytes are lost due to stimulant laxative abuse?
Will cause hypokalemia
Can cause changes in chloride, bicarb, pH or sodium in either direction.
What is the arterial supply to the pancreas?
Tail - splenic artery
head - gastroduodenal artery + inferior pancreaticduodenal artery (from SMA)
What is the function of thromboxane A2?
Increases platealet activation and vascular tone
What are the functions of the prostaglandins?
PGE1 = lower vascular tone (alprostadil)
PGE2 (dinoprostone) and PDF2a (carboprost) increase uterine tone.
What is the most common side effect for niacin therapy? How do you prevent it?
Flushing due to prostaglandins
add aspirin.
What therapy can be used for SIADH?
ADH antagonists: conivaptan, tolvaptan, demeclocycline
What is indomethacin? what is it used for?
NSAID - used to close a PDA, in addition to fever / pain / stiffness from inflammation
An intension tremor results from what localization of lesion?
Ipselateral cerebellar hemisphere
How do you calculate the likelihood of having a child with an AR disorder that occurs 1 in x amount of individuals?
First figure out what the carrier frequency is i.e. 2pq.
remember that for AR it’s a 1 in 4 chance 2 carriers produce a child with the disease.(2pq)^2 x 1/4 = d
Identify the locations of CN5 through 12 on this image
A – CN5
B - CN7
C - CN8
D - CN9
E CN10
below E is CN11
CN12 is midline
What cell types are acted on by cGMP with PDE-5 inhibitors?
smooth muscle cells (relaxation)
What treatment is useful for male pattern baldness?
Finasteride - blocks conversion of T to DHT.
What animals are associated with Coxiella burnetii
Q fever - cattle or sheep amniotic fluid
What mechanism prevents peripheral tissue edema with increased diastolic BP?
Precapillary resistance
Describe what happens histologically with Hashimoto’s?
replacement of thyroid parenchyma by lymphoid cells
How does prostatic adenocarcinoma spread?
via Batson / vertebral venous plexus.
What BUN:creatinine values are consistent with prerenal azotemia?
>20
Which neurotransmitter is associated with the locus ceruleus? How does it change in anxiety and depression?
Norepinephrine, up in anxiety, down in depression.
Which neurotransmitter is associated with the raphe nuclei? Where are they located?
Serotonin
Located in the medulla and pons
Which vaccines use killed or inactivated virus? What is the immune response to this type of vaccination?
A TRIP could Kill you
Hep A
Typhoid
Rabies
Influenza
Polio (salK)
humoral response.
What are the nitrosoureas? what are they used for?
carmustine & lomustine
Cross BBB & x-link DNA, used for brain tumors
What is cytosine arabinoside? what is it used for?
Cytarabine used for DNA chain termination in the treatment of AML & lymphomas
What are the attachments of the rotator cuff muscles?
A - teres minor
B - infraspinatus
C- supraspinatus
D - subscapularis
What drugs are used for acute treatment of gout? Chronic treatment?
Acute gout: NSAIDs, steroids or colchicine
Chronic gout: probenecid, allopurinol, pegloticase or febuxostat
How would you differentiate fibromuscular dysplasia from polyarteritis nodosa
Both present with “string of pearls” on renal angiogram, but polyarteritis nodosa is microaneurysms and spasms assoc with hepatitis B (30% of cases) and middle-aged men
Fibromuscular dysplasia looks like a series of beads on the renal artery and often found in young women.
label the tracts A through D. Which ones ascend ipsilaterally vs contralaterally?
Dorsal columns: pressure, vibration, fine touch and proprioception. A fasciculus gracilis (lower body); B fasciculus cuneatus (upper body). Ascends ipsilaterally in cord
Lateral cortcospinal tract: voluntary motor C descends ipsilaterally
Spinothalamic tract: antreior is crude touch/pressure, lateral is pain/temp. D ascends contralaterally as it decussates in spinal cord at anterior comissure.
What are the drugs that are ADP receptor inhibitors? What is their mechanism? What are they used for?
Clopidogrel, prasugrel, ticagrelor, ticlopidine
Block platelet aggregation due to prevention of glycoprotein IIb/IIIa on cell surface
Used for acute coronary syndrome, post-stenting
Which adrenergic & cholinergic receptors are associated with sphincter contraction, bladder contraction, and bladder relaxation?
alpha-1 = sphincter contraction
M3 = bladder contraction
beta-3 = bladder relaxation
If your exact calculation results in an answer that isn’t one of the answer choices, what do you do?
Go for the closest answer choice; sometimes they round the numbers that they use in their own calculation.
What neoplasms are associated with hypercalcemia?
SCC of lung, head and neck, renal, bladder, breast and ovarian cancers can produce PTHrP
Lymphoma can produce increased calcitriol
What are the tick-born illnesses?
Rickettsia ricketsii (rocky mountain spotted fever)
Typhus (R. typhi)
Ehrlichosis (monocytes with morulae), anaplasmosis (granulocytes with morulae)
What diseases are transmitted by the Ixodes deer tick
Lyme disease (Borrelia burgdorferi), Anaplasma and Babesia
What pattern on PFT is associated with asbestosis? What findings on CXR?
Normal FEV1/FVC, decreased FVC and decreased DLCO
CXR: diffuse parenchimal opacities with reticular pattern and bilateral pleural plaques
What are the allergic and acute hemolytic transfusion reactions?
Allergic = type I reaction against plasma proteins with degranulation of mast cells (urticaia, pruritis, anaphylaxis)
Acute hemolytic = type II reaction due to preformed anti-A or anti-B IgG or IgM antibodies
What is the mechanism through which HER2/neu causes cancer?
Overexpression due to amplification
When does loss of heterozygosity lead to cancer?
When it involves a tumor suppressor gene.
How do you handle sharing bad news when the patient’s family or friends are also present.
Ask to speak with the patient first and or their partner before disclosing to family based on their wishes.
What is the testicular tumor? what are the key features?
Seminoma
painless germ cell tumor; large cells in lobules with watery cytoplasm and “fried egg” appearance
What complement is involved in SLE?
C1q, C4 and C2 (early complement deficiency)
Where in the nephron is phosphate primarily reabsorbed?
The proximal convoluted tubule
How would you differentiate between ARDS and atelectasis?
ARDS = alveolar insult leading to intra=alveolar transudates and formation of hyaline membranes. Bilateral lung opacification.
Atelectasis is alveolar colapse due to contraction/scarring, compressive lesion or airway obstruction (NRDS in babies)
How would you differentiate between hypertension associated with pheochromocytoma vs hyperaldosteronism
Pheo comes in spells - would be associated with catecholamines and metanephrines
Hyperaldosteronism is HTN all the time, suspect if renal bruit (secondary)
What pathogen is this? What complications can result?
Malaria; falciparum can cause lactic acidosis and hypoglycemia, occlusion of capillaries in brain, kidneys and lungs.
What is the mechanism of action for acetazolamide? How does it reduce intracranial pressure?
Acetazolamide inhibits carbonic anhydrase. It alkalinizes urine. Decreases CSF production by choroid plexus, potentially by reducing Na/K ATPase activitity.
Which nematodes infect hosts via ingestion?
EATTT
Enteriobius (tape test, anal itching), Ascaris (giant roundworm), Toxocara (visceral larva migrans), Trichinella (encyst in muscles), Trichuris (asymptomatic, loose stools, anemia, rectal prolapse in children)
Which nematodes infect hosts directly through skin?
Strongloides (GI / pulmonary / cutaneous), Ancylostoma & Necator (microcytic anemia) (SANd)
Which nematodes infect via bites?
Loa loa (worm in conjunctiva, skin swelling), Onchocera volvulus (river blindness), Wucheria bancrofti (elephantiasis) (lay LOW)
When someone who is “anxious” is experiencing sinus tachycardia, what happens to their ABGs?
Hyperventilation -> PCO2 drops
How would you explain a disappearance of howell-jolly bodies after splenectomy?
An accessory spleen
What is wide splitting of S2 associated with?
Exaggeration of physiologic split due to delay in RV emptying e.g. pulmonic stenosis, RBBB
What is fixed splitting of S2 associated with?
Atrial septal defect delays pulmonic valve closure regardless of respiration
What is paradoxical splitting of S2 associated with?
P2 before A2 due to delayed closure e.g. aortic stenosis or LBBB. Opposite of physiological split.
Weakness to external rotation of the shoulder = what muscle?
Weakness to internal rotation of the shoulder = what muscle?
External rotation = infraspinatus
Internal rotation = subscapularis
What serum findings are consistent with adrenal insufficiency?
Hyponatremia + hypotension
Hyperkalemia
Metabolic acidosis
What is the cause of postnatal hypoglycemia in infants of diabetic mothers?
Hyperinsulinemia impairs gluconeogenesis.
How would you diffrentiate between gastroschisis and omphalocele?
Gastroschisis is not covered by peritoneum, abdominal contents come out through gap in abdominal folds (R of umbilicus).
Omphalocele is associtaed with congenital abnormality eg T13/18; contents surrounded by peritoneum coming out through persistent midline herniation of contents into cord.
How does failure of vitelline duct obliteration present? what about a patent urachus?
Vitelline fistula -> meconium coming out of umbilicus; meckel diverticulum is partial closure
Patent urachus is urine coming out of umbilicus, or urachal cyst / diverticulum
How would you differentiate between paget disease and prostatic adenocarcinoma bone mets
Paget disease = osteocsclerotic or osteolytic areas
Prostatic mets = high PSA, osteoblastic lesions
superficial peronial nerve ensury is most likely occur due to pressure at which site?
Neck of the fibula
What causes inherited HOCM?
Autosomal dominant due to genes encoding myosin binding protein C and beta-myosin.
How does serum ACTH and the dexamethasone suppression test help with the differential for cushing syndrome?
Low ACTH -> ACTH independent likely exogenous glucocorticoids or adrenal tumor
Elevated ACTH -> either pituitary adenoma (suppressed by dexamethasone) or ectopic ACTH (no suppression)
How will intracellular and extracellular volume and osmolality change in response to hypertonic IV saline?
Intracellular decreased volume and increased osmolality
Extracellular increased volume, increased osmolality
What is the mechanism of action for azoles?
Inhibit fungal ergosterol synthesis via cytochrome P450 inhibition.
what are the spinocerebellar tracts?
Convey proprioceptive information and located on the outer edges of the cord.
What congenital abnormailty is caused by failed closure of the caudal neuropore? What about the rostral neuropore?
Failure of caudal neuropore needs to spina bifida
Failure of rostral neuropore (anterior) is anencephaly
Which viral infections are more common with low T cells?
CMV, EBV, JC and VZV or chronic resp/GI infections
What is the stellate ganglion?
The cervicothoracic ganglion is a sympathetic ganglion located at C6/7
Hypogonadism, hepatomegaly and diabetes mellitus would be associated with what serum abnormalities?
Hemochromatosis: high serum iron and ferritin; low transferrin/TIBC and high transferrin saturation
What do you do if a patient directly asks you about results you have been asked not to share?
Go ask resident / staff; don’t share the results.
What lung cancers present centrally? Peripherally?
Central: small cell carcinoma, squamous cell carcinoma
Peripheral: adenocarcinoma (only one common in non-smokers) or large cell carcinoma
Either: bronchial carcinoid
What is the diagnosis based on this liver? What is the most common liver mets?
Colon >> stomach > pancreas
Renal failure: how does it affect phosphate, calcium and PTH?
PTH up (secondary to renal failure), low C (secondary to low calcitriol), phosphate high.
What is the difference between borderline and dependent personality
Borderline: unstable mood & interperosnal relationships, fear of abandonment, suicidality, emptiness
Dependent: submissive and clingy, excessive need for support, low self-confidence.
What is the cause of endometrial hyperplasia?
Usually associated with excess estrogen binding
What is the treatment of cholera?
Rehydration (oral / IV)
What are the symptoms of a basilar artery stroke?
Loss of horizontal but not vertical eye movements, quadriplegia and loss of voluntary movements of face, mouth and tongue. “Locked-in” the basement.
How would you differentiate ketamine from methamphetamine abuse?
While both are sympathomimetics, ketamine would be typically associated with disociative symptoms & duration around 30mins-1hr. methamphetamine lasts 4-12 hours
What does the liver look like in hepatitis A, B and C
A - swollen hepatocytes with monocyte infiltration and councilman bodies
B - eosinophilic ground glass appearance
C - lymphoid aggregates with focal areas of macrovesicular steatosis
Why is tetracycline contraindicated in pregnancy and children?
Inhibits bone growth
Why is ritonavir given in combination with a second protease inhibitor?
It is a cyt P450 inhibitor so it increases concentrations of other protease inhibitors
What derivative of arachidonic acid is responsible for promoting bronchospasm? What enzime is responsible for making 5-HPETE?
5-hydroperoxyeicosatetraenoic acid (5-HPETE) makes leukotrienes (LTC/D/E-4 increases bronchial tone)
5-lipoxygenase (inhibited by zileuton)
What is the arterial supply to the testes?
Main via testicular artery (branch of aorta)
Collateral supply by branches of the cremasteric arteries (off inferior epigastric) and artery of the vas deferens (off inferior vesical artery)
Identify the lesion. What management is indicated?
Hemangioma - no intervention needed, most will fade by age 10
What is the primary effect of statins?
Blocks cholesterol synthesis in liver, increases LDL recycling (i.e. more LDL-R expression)
When asked about vitamin D levels, before answering, what must you clarify?
Whether it is asking about 25-OH-Vitamin D (inactive) or 1-25-OH-Vitamin D (active)
How would you distinguish polyneuropathy from syringomyelia?
Syringomyelia will present with loss of pain & temp sensation in a cape-like bilateral distribution
Polyneuropathy presents with symptoms in multiple nerve distributions & can be sensory and/or motor.
What is the location of a tumor that produces a vertigal gaze palsy and loss of near-vision accomodation? What is the name for this syndrome? What other symptoms may present? What is the histology?
Pinealoma; Parinaud syndrome
Causes obstructive hydrocephalus and precocious puberty in boys.
Similar to germ cell tumor
What is the presentation of a lesion in the paramedian pontine reticular formation?
Eyes that look away from the lesion (towards the hemiplegia)
What is the most likely cause of abdo pain that radiates to the scrotum without peritoneal signs or any scrotal masses?
A kidney stone
What is the classic presentation of testicular torsion?
Acute pain, loss of cremasteric reflex, boggy, high-riding testicle
How do changes in afferent and efferent arteriole diameter affect kidney RPF, GFR and FF?
Dilation of afferent = increased RPF and GFR, same FF
Constriction of efferent = decreased RPF, increased GFR, increased FF
What is the mechanism that maintains renal blood flow across a range of perfusion pressures?
The myogenic response of the afferent arterioles.
What is the most likely cause of postprandial pain with weight loss and food aversion in the presence of an ectatic abdominal aorta (AAA)?
Chronic mesenteric ischemia involving SMA &/or IMA
What channel is affected by tetrodotoxin (puffer fish) and ciguatoxin (reef fish, barracuda, snapper, moray eel)?
Tetrodotoxin blocks Na+ channels
Ciguatoxin opens Na+ channels
What is the vector and clinical presentation of Onchocerca volvulus infection? How do you treat it?
River blindness transmitted by female black fly
Black skin nodules, black sight, skin changes / loss of elastic fibres
Ivermectin
What enzyme synthesizes epinephrine from norepinephrine? How is it regulated?
phenylethanolamine-N-methyltransferase
Induced by cortisol
Distinguish between the 3 types of renal tubular acidosis.
Type 1: DCT unable to excrete H+ (amphotericin B toxicity, urinary tract obstruction, SLE), results in low K+ and increased risk of Ca/PO4 stones
Type 2: PCT due to inability to resorb HCO3- (Fanconi syndrome, MM, acetazolamide), also results in low K+
Type 4: Hyperkalemic due to hypoaldosteronism or resistance; high K+ reduces PCT NH3 synthesis and NH4+ excretion.
What is the most common side-effect of the beta-2 agonists (albuterol / terbutaline)
Uncontrollable shaking (tremor)
What is the vanilloid receptor?
AKA capsaicin receptor or TRPV1
Pain & temperature sensor, produces burning pain when activated.
What cells synapse in the dorsal root ganglion?
None - the dorsal root gangion holds the cell bodies of the pseudounipolar 1st order neurons.
When trying to decide between two answers which seem equally likely, what should you do?
Focus on seeing if you can prove one answer wrong or find something that makes it less likely to be correct.
What is the primary mechanism by which DKA causes altered level of consciousness?
Osmotic diuresis (due to glucose) leads to dehydration.
Where do flexor digtorum profundis and superficialis insert?
Deep flexor -> tendon inserts on the distal phalanges
Superficial -> tendon divides and inserts on the middle phalanges.
What is/are the name(s) of human lice? What diseases can be spread by them?
Pediculus humanus & Pthirus pubis
Rickettsia prowazekii (typhus), Borrelia recurrentis (relapsing fever) and Bartonella quintana (trench fever) spread by body lice
What is the difference between transfusion-related lung injury and anaphylaxis?
Both present rapidly within minutes to hours of starting transfusion
Anaphylaxis due to allergic reaction (type I) and presents with wheezing, hypotension, respiratory arrest, shock
Transfusion-related lung injury due to sensitized neutrophils releasing inflammatory cytokines causing pulmonary edema, resp distress.
What hormones are produced from pro-opiomelanocortin? How?
Post-translational cleavage of pro-opiomelanocortin produces beta-endorphins, ACTH and MSH (go pro with a BAM)
An immediate reaction of malignant hypertension would be caused by which agent?
Succinylcholine
(nb faster acting than rocuronium & more likely to cause rigidity)
What is bronchiolitis obliterans?
Chronic lung transplant rejection
What is the cause of a spina bifida?
Failure of the fusion of the sclerotomes
Under what situations would you expect pulmonary capillary wedge pressure to be elevated?
Left ventricle failure, mitral valve pathology, cardiac insufficiency, cardiac compression post hemorrhage
Where in the nephron does nephrotoxicity due to aminoglycosides occur?
Straight limb of proximal convoluted tubule
What is/are the most likely organisms in acute prostatitis?
Young men - Chlamydia trachomatis or Neisseria gonorrhoeae
Older men - E coli most common
For CF, if only one mutated allele is identified by the panel molecular analysis yet sweat test is positive, what is the most likely explanation?
The second mutation is not part of the panel.
What is the presentation of opioid withdrawal?
Sweating, dilated pupils, piloerection (cold turkey), rhinorrhea, lacrimation, yawning, nausea, stomach cramps, diarrhea (flu-like symptoms)
Do lesions of the corticospinal tract produce UMN or LMN sympotms? What would be the expected presntation?
UMN signs
Weakness, hyperreflexia, hypertonia, upgoing babinski, spactic paresis / clasp-knife.-
When in the cell cycle are mitotic cyclins synthesized?
G2 (they control the progression into mitosis)
What is the leading cause of melanoma in darker-skinned individuals? Where is it found
Acral lentiginous melanoma on the palms of hands or soles of feet or in the nail.
What viruses have negative-sense RNA for genetic material?
Always Bring Polymerase Or Fail Replication
Arenaviruses
Bunyavirus
Paramyxovirus
Orthomyxovirus
Filovirus
Rhabdovirus
What are the paramyxoviruses? What virulence factor do they all make?
Parainfluenza (croup)
Measles & Mumps
RSV
F protein causes resp epi to fuse and form multinucleated cells
Identify the type of tissue
Present 18 days post MI
Granulation tissue
What is the presentation of interstial i.e. restrictive lung diseases?
Low lung volumes (Low FVC, TLC, DLCO)
Increased Alveolar-arterial PO2 gradient
What are the 4 lung volumes
LITER
Inspiratory resrve volume
Tidal volume
Expiratory reserve volume
Residual volume
What are the 4 lung capacities?
Inspiratory capacity = IRV + TV
Functional residual capacity = RV + ERV
Vital capacity = maximum volume of gas expired after maximal inspiration (TV + IRV + ERV)
Total lung capacity = Volume of gas in lungs after maximal inspiration (TV + IRV + ERV + RV)
What is myositis ossificans?
Metaplasia of muscle -> bone after trauma.
How would you differentiate between the two main causes of renal artery stenosis?
Atherosclerosis if prox 1/3 of renal artery, usually older, male, smoker
Fibromuscular dysplasia if distal 2/3 of renal artery or segmental branches, young-to-middle-age females
Where does the breakdown of dipeptides and tripeptides to free AAs take place?
In the intestinal lumen
A schwannoma originates from what type of cells?
Neural crest cells or Schwann cell origin
What is the relevance of synaptobrevin?
One of 4 proteins in SNARE complex, bound by tetanospasmin and several botulinum toxin serotypes
What physiologic events will lead to swelling of parenchymal cells in a person with an MI?
Decrease in intracellular ATP concentrations subsequent to hypoxemia / hypoperfusion
What are the side effects of NRTIs?
Bone marrow suppression, peripheral neuropathy, lactic acidosis with nucleosides, anemia with zidovudine, pancreatitis with didanosine
Do not use abacavir in HLA B*5701
When a patient has a collapsed lung, what is the complication for which they are at highest risk?
Respiratory acidosis due to hypoventilation
What is the therapy for nematodes?
Intestinal - bendazoles, ivermectin for Strongyloides stercoralis
Tissue - Bendazole for toxocara, Ivermectin for river blindness, diethylcarbamazine for Loa loa and Wucheria bancrofti
What are the atypical lymphocytes in EBV/mononucleosis?
reactive cytotoxic (CD8+) T cells
What are the units of clearance? How would you calculate infusion rate to maintain a given steady state concentration C
Clearance is the volume of plasma cleared of drug per unit time i.e. mL/min
Cl x C = steady state infusion rate
What is the diagnosis? What would be seen on microsocopy?
Chronic pyelonephritis, often due to reflux (in children) or obstruction (not in children)
Interstitial inflammation
What is the microscopic presentation of kaposi sarcoma?
Slit-like vascular spaces due to spindled epithelial cells.
Kaposi = vascular neoplasm due to HHV8
What is the effect of acetazolamide on urinary pH and bicarbonate?
Blocks resorption of HCO3- leading to alkaline urine.
What are the diagnostic criteria of antiphospholipid syndrome? What are the lab findings?
Arterial or venous thrombosis or spontaneous abortion
Increased PTT, lupus anticoagulant, anticardiolipin (false positive VRDL), anti-B2 glycoprotein I antibodies
What are the consequences of renal failure?
MAD HUNGER
Metabolic Acidosis
Dyslipidemia
High K+
Uremia
Na+ & H2O retation
Growth retardation/ developmental delay
Erythropoetin deficiency
Renal osteodystrophy (Low D3, low Ca2+ high PO4 and high PTH)
What are the most common adverse effects of nitrates?
Reflex tachy, hypotension, flushing, headache, and monday disease (loss of tolerance to vasodilating action over weekend)
How is glucosamine synthesized in humans? What are the downstream products of this biosynthetic pathway
F-6P + glutamine -> glucosamine
via F-6P transaminase
What is entrapment neuropathy? What are common examples?
Nerve compression due to inflammation in a narrow space.
Carpal tunnal, cubital tunnel, guyon’s, radial compression, suprascapular compression and meralgia paraesthetica.
What is the nerve supply to the medial flexor digitorum profundus? What are the nerve roots?
Ulnar: C8/T1
How does the length of the mature heavy chain gene compare to the unrearranged gene?
Mature gene is shorter due to deletion of unwanted V, D, and J segments
What are the electrolyte changes that occur in early MI?
Increased Na +, decreased K+ due to low ATP and shutdown of Na/K+ pump
High Ca2+ due to reperfusion injury -> hypercontraction of myofibrils (wavy fibres)
Why would a patient with a 2week hystory of viral symptoms and positive plasma HIV viral load have a negative serum antibody test?
Window period = acute infection
What is the appropriate test to determine if the prevalence of hypertension is significantly different between 2 populations?
Chi-square test
What are the changes in insulin, testosterone and LH:FSH in PCOS?
High insulin causing increased LH:FSH ratio, increased testosterone & androgens
What is the enzyme that is inhibited by fluorouracil?
Thymidylate synthase (responsible for dTMP synthesis)
label A,C,D,E
A- thalamus
B - internal globus pallidus???
C - subthalamic nucleus
D - Substantia nigra
E - hippocampus
Differentiate between tuberous sclerois and neurofibromatosis-1
Tuberous sclerosis has lighter ash-leaf spots, seizures and kidney disease, wherease NF-1 has darker cafe-alu-lait spots, lisch nodules or bone lesions, axilary/inguinal freckling
What is the mechanism of action of dextromethorphan?
NMDA-glutamate antagonist / synthetic codeine analogue. No constipation
What are ipatropium and tiotropium used for?
COPD and asthma
What hepatic vascular injury is most likely to occur with blunt abdominal trauma?
Avulsion of the hepatic veins from the IVC
What are transference and countertransference?
Transference = patient projects feeling about important or formative persons onto doctor
Countertransference = doctor projects feelings about significant people onto the patient
What is the innervation of the scrotum?
Anteriorly - ilioinguinal and genitofemoral nerve
Posteriorly - perineal branches of pudendal nerves
How long will it take to remove all erythrocytes exposed to CO?
Basically, it’ll take as long as the longest remaining lifespan of the erythrocytes i.e. 120 days = 4 months
What is this organism? What disease and what symptoms are associated with it?
Trypanosoma cruzi
Chagas disease; acute unilateral periorbital swelling is characteristic, followed by megaesophagus, megacolon, dilated cardiomyopathy (edema, crackles)
What genetic mechanism helps staph aureus adapt to different environments in the body and evade the immune system?
Phase variation - “phase variable genes” have regions which can be quickly mutated to turn genes on or off.
What is the appropriate therapy in a bradycardic patient with 3rd degree heart block?
Insert a transvenous pacemaker
What are the characteristics of yersinia enterocolitica?
Gram -ve pleiormorphic coccobacillus often from pet feces, contaminated milk or pork. Causse bloody diarrhea and pseudoappendicitis and reactive arthritis
Can grow at 4C
What are the side effects of TCAs? What side effects tend to be problematic for compliance?
Sedation
alpha-block = postural hypotension
Anticholinergic = tachy, urinary retention, dry mouth
3Cs: Convulsions, coma and cardiotoxicity
Long QT
What process would be disrupted by a mutation to a gene’s TATA box?
Transcription by RNA polymerase
What are the key diagnostic criteria of peripartum cardiomyopathy?
HF within last month of pregnancy or <5 months post-delivery
Reduced ejection fraction
Diagnosis of exclusion (rule out other causes of heart failure)
What vascular changes occur in the setting of severe, uncontrolled HTN?
Hyperplastic or “onion skin” arteriosclerosis due to proliferation of smooth muscle cells
What is the ligament of Treitz? Why is it important
Suspensory fold of peritoneum at the duodenojejunal flexure - diagnostic of malrotation if located on the right of the abdomen. Involutes in adults
What is the embryonal origin of the pancreatic islets?
The pancreas is derived from foregut = endoderm
Muscle strength that improves with repetitive testing suggests which diagnosis?
Lambert-eaton myasthenic syndrome, as repeated stimulation increases ACh release (unlike MG where muscle weakness is worse with use)
What is the mechanism of adenosine deaminase deficiency?
ADA degrased adenosine and deoxyadenosine leading to increase in dATP and inhibition of ribonucleotide reductase -> lympotoxicity & SCID
What happens to the lysosomal enzymes in I-cell disease patients?
They are secreted from the cell due to lack of mannose-6-phosphate tag
How do you calculate lung compliance?
Tidal volume / (peak inspiratory pressure - positive end-expiratory pressure)
Where does niacin act to reduce LDL?
Inhibits lipolysis in adipose tissue and reduces hepatic VLDL synthesis
How does parvovirus B19 infection lead to anemia?
Results in interruption of erythrocyte production esp in sickle cell or immunocompromise
What is appropriate therapy for chlamydia in a pregnant woman?
Azithromycin
Do you need to adjust the loading dose given to a patient with renal compromise?
No; loading dose stayst the same.
Adults who are treated with previous chemotherapy or radiation are at increased risk of what cancer? What are the characteristic cells?
Acute myeloid / myelocytic leukemia.
Blasts
Salt wasting hyponatremia in a newborn with increased 17-hydroxyprogesterone is due to a deficiency in which enzyme?
21-hydroxylation.
What’s the easy to remember rule for the adrenal enzyme deficiencies?
If it starts with a 1, it causes hypertension if absent
If it ends with a 1, it causes virilization in females
With intrauterine transfusion, what is the appropriate blood type?
O, Rh-ve
Because Rh-ve blood will not trigger an Rh +ve reaction
A distal tibial fracture suggests what movement?
Eversion
In the setting of chronic heart failure, what causes hyponatremia?
Dilution of serum sodium due to ADH secretion
what is the presentation of a cervical rib?
Thoracic outlet syndrome - lower trunk and subclavian compression resulting ulnar neuropathy
What electrolyte abnormalities occur in laxative abuse?
Hypokalemia, hypochloremia, hypocalcemia and metabolic acidosis
name the major branches of the aortic order and their respective vertebral levels
T12 = celiac trunk
L1 = SMA
L1/L2 = Renal
L2 = Testicular/ovarian
L3 - IMA
L4 = bifurcation to common iliacs
What is the presentation of C1 esterase inhibitor deficiency? What is the treatment?
Hereditary angioediema due to elevated bradykinin, low C4 levels.
Treat with danazol and stanozolol.
What is the left hip pathology?
Avascular necrosis of femur
What is deficient in NRDS?
Dipalmitoyl lecithin
