Cards from USMLE-Rx (First Aid) Flashcards
What is the first step to manage increased ICP in a patient who has lost consciousness and has a suspected intracranial hemorrhage
Intubate and ventilate the patient to protect the airway.
How can a child inherit two copies of an allele from the same parent?
Uniparental disomy due to nondisjuction I/II error
What is the neuropathology shown on the image?
Lewy bodies, seen in Lewy Body dementia or secondary to Parkison’s
What autoantibodies could cause a macrocytic anemia?
Pernicious anemia due to autoantibodies to gastric parietal cells causing malabsorption of vitamin B12. Often co-occurs with Hashimoto’s
What types of cancer are associated with hereditary loss of function of the RB1 gene?
Retinoblastoma, osteosarcoma, melanoma, brain cancer.
What is the mechanism of action of Octreotide? What conditions does it treat?
It is a somatostatin analogue used to treat esophageal varices, acromegaly, carcinoid syndrome, VIPomas.
How do you distinguish between disseminated intravascular coagulation (DIC) and immune thrombocytopenic purpura on labs?
DIC will have thrombocytopenia AND elevated INR and elevated PTT, whereas the most commonly for ITP there will only be isolated thrombocytopenia (platelets <150,000/mm^3)
Where are the LMNs located in the spinal cord?
In the anterior horns.
What is the function of oxyphils and where are they located?
Oxyphils are present in the parathyroid gland and may contribute to PTH secretion (but classically PTH is secreted by parathyroid chief cells).
What changes to thyroid hormone occur in pregnancy? What is the mechanism of these changes?
Overall, pregnant persons remain euthyroid because even though estrogen stimulates liver synthesis of thyroxine-binding globulin, which in turn leads to more total T4, but the amount of free T4 remains the same.
What finding on urinalysis indicates kidney involvement (pyelonephritis)?
WBC casts
What is the most common cause of cancer mortality in the US?
Lung Cancer
What organism would cause characteristic “crackling” on palpation of a swollen, tender, red injured area?
Clostridium perfirindens; crackling comes from the subcutaneous gas production; the bacteria produces a phospholipase which cleaves lecthin in plasma membranes of cells.
A presentation of bilateral juvenile cateracts and bilateral hearing loss suggests which condition?
Neurofibromatosis type 2 (NF-2), due to a LoF mutation on chromosome 22, increasing the risk of multisystem cancer.
What is the location of the major blood supply to the uterus?
The uterine arteries and veins run along the cardinal ligament of the uterus attaching to the uterine walls above the level of the cervix.
How is gout and pseudogout differentiated on microscopy of arthrocenteis?
Gout = negatively birefringent needle-shaped crystals.
Psudogout = positively birefringent rhomboid crystals.
What glomerular abnormalities would be consistent with Henoch-Schonlein Purpura (HSP)?
Presence of mesangial IgA deposits.
What study type could be used to calculate relative risk for developing a given disease based on exposures?
Prospective cohort study.
Elevated levels of ketoacids in a newborn with neurologic symptoms is suggestive of what condition?
Maple Syrup Urine Disease—caused by deficiency in branched-chain alpha-ketoacid dehydrogenase leading to inability to metabolize isoleu, leu and val.
What is the mechanism of action of Flucytosine?
It is converted to 5-FU in fungal cells, thus interfering selectively with fungal DNA synthesis.
How do glucocorticoids block inflammation?
By inhibiting phospholipase A2, which stops the production of arachidonic acid, which acts downstream to cause prostacyclin and prostaglandin release.
Which bugs are the top causes of PID?
Chlamydia trachomatis and Neisseria gonorrhoeae
What class of GPCR receptors could contribute to postural hypotension? What is the mechanism of action?
alpha-1 (a1) receptor blockade, with resultant decrease in phospholipase C and decrease in calcium release. A1 vasoconstricts, B2 vasodilates.
What symptoms suggest giant cell arteritis? What is GCA often accompanied by?
Polymyalgia rheumatica (fatigue and stiffness esp with proximal muscle weakness in hip and shoulder) often accompanies GCA; GCA symptoms include unilateral headache and vision changes (classic patient is older female).
Name one way that cancer cells can escape immune detection.
MHC-I downregulation (note that MHC II downregulation does not play a role in immune evasion in cancer).
Which phospholipid is missing in neonatal respiratory distress syndrome?
phosphatidylcholine—the primary component of pulmonary surfactant?.
Pesticide exposure (organophosphates) would lead to what kind of symptoms? How would these be treated?
Symptoms: DUMBBELLS (diarrhea, urination, miosis, bronchospasm, bradycardia, excitation of skeletal muscle, lacrimation, sweating, salivation (cholinergic excess, is wet). Treated with atropine which blocks muscarinic receptors and pralidoxime in addition to binding and displacing the organophosphates from acetylcholinesterases.
What is a differential for a rash which begins initially on the soles and palms?
- Rocky Mountain spotted fever (caused by Rickettsia ricketsii, transmitted by ticks)
- Meningococcemia
- Secondary syphilis
What organism is associated with Guillain Barre Syndrome? What are its chacteristics?
Campylobacter jejuni: grows hot (42C), is a gram negative, S shaped, oxidase positive.
GBS -> rapidly progressive, ascending paralysis with muscle weakness originating in the distal lower extremities.
What is a hapten?
A hapten is a moleule which can only activate an immune response when it is bound by a protein (e.g. in penicillin induced autoimmune hemolytic anemia).
Which opioid receptors are responsible for the effects of heroin?
mu-receptors.
What is the characteristic rash in impetigo? Which organism(s) cause it?
Impetigo is either bullous (Staph aureus) or nonbullous (Group-A Strep OR staph aureus). The classic rash is erythematous with multiple vesicles which produce honey-coloured plaques on rupture.
Polyomavirus JC / JC virus presents in which population and with what symptoms?
JC virus can cause progressive multifocal leukoencephalopathy in patients which are immunosuppressed.
What changes on labs are expected in disseminated intravascular coagulation?
Decreased platelet count, higher bleeding time, prothrombin and partial thromboplastin (PT/PTT) time.
What are findings on urinalisys for post-strep glomerulonephritis? (or nephritic syndrome more generally)
hematuria (may have RBC casts), HTN, edema, moderate but not crazy (3.5g+) proteinuria.
What would explain a paradoxical high TSH and high T3 level in the context of low iodine uptake?
Exogenous levothyroxine (causing thyrotoxicosis factitia).
What are classic findings on light microscopy from a kidney biopsy in a patient with Goodpasture’s Syndrome?
Auto antibodies against collagen IV in glomerular basement membranes leading to glomerulonephritis (crescent formation + fibrosis). This is a nephritic
How would you clinically differentiate between spontaneous pneumo and tension pneumo?
Tension pneumo is typically associated with trauma to the chest wall which will develop tachycardia and tachypnea and eventually cardiac arrest. As well, the trachea should deviate away from the pneumo and there will be increased JVP.
What are the symptoms and associated organisms for reactive arthritis?
Typically occurs 2-3w post-infection with Shigella, yersinia, chlamydia, campylobacter, salmonella. Symptoms include asymmetric seronegative oligoarthritis, coupled with conjunctivitis and urethritis (can’t see, can’t pee, can’t bend my knee).
What is the impact of prostaglandin E2 on renal perfusion?
PgE2 causes afferent vasodilation.
What are some examples of anti-VEGF therapies? What diseases do they treat?
- Macular degeneration (ranibizumab, pegaptanib, aflibercept)
- colon, breast, non-small cell lung cancer (bevacizumab)
Which viruses contain hemagglutinin?
Influenza viruses and measles virus.
What is the mechanism of activity of digoxin?
Na+intracellular concentrations increase because digoxin inhibits Na/K pump. As Na+ increases, it inhibits Na/Ca++ pump activity, causing intracelullar concentrations of Ca++ to rise (increasing contractility).
What is the most common cause of hereditary thrombophilia?
factor V Leiden mutation, causing inability of protein C to inactivate factor V, leading to continuous activation of coag pathway.
What pituitary condition is associated with postpartum fatigue, weight loss, amenorrhea and failure to breastfeed?
Sheehan syndrome (postpartum hypopituitarism) -> global decrease in prolactin, GH, FSH/LH, TSH, ACTH
Necrotic inflammatory infiltrate and giant cells on a bone biopsy is characteristic of…?
Extrapulmonary tuberculosis of the spine (Pott disease).
For prolonged (10y+) alcohol use disorder, what signs are expected on brain imaging?
Cerebellar degeneration leading to ataxia
What are the indications and mechanism of action of macrolides?
Macrolides include azithromycin, clarithromycin and erythromycin. They work by inhibiting protein synthesis by binding 23S rRNA of the prok 50S ribosome, blocking the P site. Indications are atypical pneumonia, Chlamydia, Gram+ cocci for pts allergic to penicillin and pertussis.
What are the indications and side effects of ribavirin?
Ribavirin is used to treat RSV, hep C and some viral hemmhorragic fevers. It can cause a hemolytic anemia
What are the diagnostic criteria for rheumatic fever?
Migratory polyarthritis, pancarditis, subcutaneous nodules, erythema marginatum (pink rings on torso and inner surface of limbs), sydenham chorea., elevated ASO (anti-streptolysin O) titre..cardiac biopsy indicates insterstitial myocardial granulomas.
What extra heart sounds might be heard in a patient who had acute rheumatoid fever?
Mitral valve stenosis: an opening snap with a diastolic rumble best appreciated over the Mitral area.
What is the classic presentation and causative organism of karposi sarcoma?
KS is caused by human herpesvirus 8; it is an AIDS-defining illness with firm palpable purple maculopapular rashes.
How does liver cirrhosis lead to lowered platelet count?
Portal hypertension -> splenomegaly -> entrapment of platelets.
What is a classic presentation of prolactinoma?
Bitemporal hemianopia with diminished libido, worsening headache, gynecomastia and ED in men, decreases in muscle mass, body hair and osteopenia.
What is the mechanism of action of bleomycin?
Bleomycin causes DNA breakage leading to G2 arrest.
Which phase of the cell cycle is affected by vincristine and paclitaxel?
M phase—paclitaxel promotes microtubule stabilization, vincristine destabilizes micotubules.
What is leucovorin?
Leucovorin is folinic acid, the active metabolite of folic acid. It is used to counter myelosuppression (i.e. methotrexate).
What is the location of the lesions and the characteristic presentation of Korsakoff psychosis?
Korsakoff psychosis presents as anterograde amnesia, confabulation, personality changes. Lesions occur to the mammillary bodies (part of the limbic system). It is caused by thiamine deficiency (vitamin B1)
What is the natural reservoir and presentation of hantavirus?
Hantavirus infects the deer mouse; mouse dropping and urine are primary vectors for human infection. Presentation is fever, headache, myalgia, GI upset, dizziness and chills progressing to pulmonary edema, cough and respiratory distress.
What electrolyte changes are expected in a thiazide diuretic?
Thiazide diuretics cause hypokalemia, metabolic acidosis, hyperglycemia, hyperlipidemia, hyperuricemia and hypercalcemia due to the blockage of Na+/Cl- reabsorption in the early distal convoluted tubule.
What is the classification for C diff? Which toxins does it produce?
Gram-positive spore-forming anaerobe; produces toxin A (diarrhea causing) and toxin B (cytoxic)
The fusion of which embryonic structures creates the palate?
The palatine processes.
Which conditions lead to elevation of Anti-Jo-1 antibodies?
Anti-Jo-1 are specific myositis and are directed against histidyl-tRNA-synthetase.
What is the first line treatment for mild oral thrush?
Nystatin swish and swallow.
What are risk factors for hepatocellular carcinoma?
cirrhosis (alcohol abuse), hep B/C, FH, and aflatoxin (produced by Aspergillus flavus, a peanut and grain mold).
Which hormone can sometimes be elevated in small-cell lung cancer?
ADH
What is crigler-Najjar syndrome Type I?
Caused by mutations to UDP-glucuronosyltransferase, leading to inability to conjugate bilirubin. Eventually will proceed to kernicterus (bilirubin deposits in the brain leading to encephalopathy).
Type I is more severe, type II responds to phenobarbital.
Liver transplant = cure.
What is the classic presentation of BCC?
BCC presents as raised pearly borders surrounded by telangiectasias;
Which receptors are targeted by benzodiazepines? What drug would you give in an overdose? What is its mechanism of action?
GABA-A receptors; flumazenil, a competitive antagonist.
What is a risk factor for SCC of the bladder in sub-Saharan Africa?
Helminth infection due to chronic irritation from the eggs of Schistosoma haematobium.
What enzyme deficiency would explain weight loss, lethargy and disphoresis in an infant who has recently been introduced to fruit juices?
Aldolase B, the enzyme that converts fructose-1-phosphate to substrates for gluconeogenesis. A buildup of f1-p inhibits gluconeogenesis, leading to hypoglycaemia.
What is the most worrisome side effect of doxorubicin
Dilated cardiomyopathy
What are common symptoms of (mlld vs severe) hypocalcemia?
Mild: parasthesia, muscle cramps and perioral numbness.
Severe: carpopedal spasm, seizures, tetany.
How would you prevent hemorrhagic cystitis caused by cyclophosphamide?
Use of mesna (which provides a free thiol which binds and inactivates acrolein, an unwanted cytotoxic metabolyte respondsible for the hemorrhagic cystitis). May also be helped by increasing fluid intake.
Which GPCRs are targeted to treat asthma? What is the mechanism of action?
The Gs pathway is activated by a B2-agonist, such as albuterol; this leads to adenylyl cyclase activation, PKA activation and phosphorylation of myosin light chain kinase, which inactivates MLCK and causes smooth muscle relaxation (bronchodilation).
What are the long-term sequellae of untreated syphilis
Aortic insufficiency due to destruction of the vasa vasorum (blood vessel supply) of the ascending aorta.
What is the indication and mechanism of action of Zileuton?
Zileuton is used for chronic asthma and functions by inhibiting 5-lipoxygenase, which converts arachidonic acid into leukotrienes (potent bronchoconstrictors).
Which cranial nerves are affected by a vertebral artery or posterior inferior cerebellar artery dissection / thrombosis?
Lateral medullary syndrome: CN IX, X and XI (sparing XII since it is medial) leading to hoarseness or dysphagia. Also affects descending sympathetic fibres resulting in ipsilateral horner syndrome.
What symptomology should make you question a mania / bipolar I disorder diagnosis?
Normal sleeping (7+ hours), depression (not required to make a type I diagonsis), euthymic (not elated or expansive).
What is the cause and presentation of thrombotic thrombocytopenic purpura?
Cause is inhibition or congenital defect in ADAMTS13, an enzyme which breaks down large vWF multimers. Presentation is fever, Schistocytes (microangiopathic hemyolytic anemia), and thrombocytopenia, with normal PT and PTT, neurologic symptoms, acute kidney injury.
Elevated serum levels of amylase would suggest infection with which organism?
Something that causes parotitis, e.g. mumps.
What is the territory of the blood supply for the superior mesenteric artery?
Inferior pancreaticoduodenal artery -> head of pancreas and ascending and inferior duodenum
Branches to ileum and jejeunum,
Ileum, cecum and appendix (via ileocolic)
Right colic to ascending colon
Middle colic to transverse colon.
What is the indication and mechanism of action for montelukast?
Montelukast is a leukotriene receptor inhibitor (blocking bronchospasm without affecting leukotriene production).
How do you distinguish between epidural hematoma vs subdural hematoma?
Epidural hematoma occurs via rupture of the middle meningeal artery. Presents with a lucid interval followed by rapid deteroration and with a “lens-like” defect on CT, does not cross suture lines).
Subdural hematoma is due to rupture of bridging veins, gradual onset, crescent-shaped hemorrhage that crosses suture lines.
What enzyme defect would result in an infant with general weakness, a palpable liver and an enlarged cardiac silhouette on x-ray
lysosomal acid alpha-1,4-glucosidase; leading to accumulation of glycogen in the heart, liver and muscle.
What vitamin do hepatic satellite cells store?
Vitamin A
A t(14,18) translocation leads to overexpression of what gene?
BCL-2; prevention of apoptosis.
What is the pathogenesis of a syndrome involving blanching skin above the clavicle with erythema bilaterally in the upper limbs, face and neck?
SVC syndrome, could be a cancerous obstruction, venous thrombosis from indwelling catheter or hilar granuloma.
How are bronchiectasis and secondary TB differentiated on histology?
Bronchiectasis -> necrotizing inflammation with dilated bronchial tissue
secondary TB is caseating granulomas with central necrosis.
How would you differentiate between a CML and a lymphoma?
CML -> myeloid cells (neutrophils, macrophages); a lymphoma would present with lymphadenopathy, small round blue cells interspersed with nonmalignant macrophages on splenic biopsy.
cells with giant granules on blood smear could indicate a defect in which gene?
LYST (the lysosomal trafficking regulator gene) -> phagocyte dysfunction; Chediak-Higashi syndrome.
UV-based DNA damage requires which repair pathway?
Nucleotide excision repair
What is a classic presentation of sarcoidosis?
Resp symptoms + elevated ACE; CXR shows bilateral hilar lymphadenopathy and infiltrates. Erythema nodosum (bilateral tender red bumps on the shins). Treat with steroids.
How do you reverse heparin?
Proteamine sulfate (binds to negatively charged heparin)
What is the causative organism for a fishy-smelling vaginal odour with homogenous gray-white discharge without urethritis or cervicitis?
Gardnerella vaginalis; gram-variable pleomorphic rod.
What is the most common cause and characteristic presentation of B12 deficiency?
Pernicious anemia due to gastric parietal cell atrophy (lack of intrinsic factor). Presents as glossitis, and ascending motor and sensory loss in lower limbs, with macrocytic anemia.
NOT commonly dietary deficiency.
Does a decrease in cooperative oxygen binding cause a shift in the hemoglobin binding curve?
No.
What is the difference between direct inguinal hernia and indirect inguinal hernia? Which populations are they most common in?
Direct -> peritonium goes through the abdo wall into the inguinal triangle (common in older men).
Indirect -> peritoneum goes through the deep inguinal ring into the scrotum (common in male infants)
Which drugs and disease inhibit platelet aggregation via interference with GpIIIb/IIIa?
Abciximab, eptifibatide, tirofiban
Glanzmann thrombasthenia
What defense mechanism is associated with borderline personality disorder?
Splitting (ie. either/or classification of things as all good and all bad)
A glucose-6-phosphatase deficiency would present as…?
von Gierke disease, hepatomegaly, hypoglycemia, seizures, lactic acidosis, hypertriglyceridemia and hyperuricemia.
What is the mechanism of action of sildenafil?
They inhibit PDE-5, which causes enhanced smooth muscle relaxation due to the nitric oxide. They do not increase NO levels.
What is the pathogenesis of the following lesion?
Staphylococcal scalded skin syndrome; Staph aureus releases an exotoxin which binds desmoglein-1 and interferes with desmosomes.
What is libman-sacks endocarditis?
SLE -> nonbacterial thrombotic endocarditis, generally does not cause valve dysfunction or fever, emboli are composed of neutrophils, lymphocytes, fibrin and histiocytes.
A congenital pancytopenia with bony abnormalities is suggestive of….?
Fanconi anemia
Which nerve innervates the scrotum and medial thigh?
Ilioinguinal nerve (runs into the inguinal canal via the top of the spermatic cord).
What is the mechanism of action of beta-blockers for HTN?
Decrease in renin production by blocking beta-adrenergic receptors (which normally release renin in response to sympathetic stimulation).
What changes on PFT are expected in COPD?
Decrease in FEV
Decrease in forced Vital Capacity (FVC)
Decreased FEV1:FVC ratio
Increased Total Lung Capacity (TLC)
What is the mechanism of action of benzodiazepines?
Increased Cl- channel opening frequency in response to GABA.
What is the pectinate line?
The junction of endoderm and ectoderm just under the anal valves.
What receptor type mediates glucagon’s actions?
A GPCR (adenylyl cyclase -> cAMP); think fasted state (so “low energy”).
What is the mechanism of action of cyclophosphamide?
Cross-links DNA at guanine (alkylates)
What is the classic presentation and pathogenesis of Kartagener syndrome?
Bronchiectasis (with associated resp infections), inability to auscultate S1 and S2, situs inversus.
Kartagener syndrome is caused by a dynein arm defect that results in immotile cilia -> infertility.
When should you suspect multiple endocrine neoplasia type I?
Pituitary parathyroid and pancreatic (endocrine) tumors.
What kind of tumor would present as WHDA syndrome?
Watery Diarrhea
Hypokalemia
Achlorhydria
a VIPoma (vasoactive intestinal polypeptide) originating from the pancreas.
How does a meckel diverticulum appear most commonly on a technetium-99 scan?
Periumbilical area.
What is DHEA short for?
Dehydroepiandosterone.
What is the tumor marker most commonly found in hepatocellular carcinoma?
Alpha-fetoprotein.
(also found in yolk sac germ cell tumors)
Describe the order of the “zones” of the adrenal gland and associated hormone from the outside in.
Capsule
Zona glomerulosa - aldosterone
Zona fasciculata - cortisol and some sex hormones
Zona reticularis - sex hormones
Medulla - Catecholamines
What serum abnormalities would be found in post-strep glomerulonephritis?
Elevated creatinine, decreased C3 levels (due to complement activation).
What is the most common causative organism for otitis externa (swimmer’s ear)
Pseudomonas aeruginosa (gram-neg, rod-shaped)
What is the mechanism of action of cocaine?
It is an indirect sympathomimetic, functions by inhibiting reuptake of dopamine, norepinephrine and serotonin specifically targeting the nucleus accumbens.
How does cardiac tamponade present clinically? On ECG?
Beck triad: hypotension, distended neck veins, distant heart sounds, tachycardia with pulsus paradoxus.
ECG would show low-voltage QRS with different amplitudes.
What would explain a presentation of bone pain, headache, tinnitus, vertigo and hearing loss? What would you expect on labs?
Paget disease (abnormal bone remodelling with incraesed osteoclastic followed by osteoblastic activity). Increased alkaline phosphatase on lab.
Why would esmolol be preferred over metoprolol in acute arrhythmia?
Esmolol has a much shorter half life (9 minutes!) so it is good to trial if beta-blocker would be tolerated esp in a pt with cardiac conditions.
What is the drug class of choice for treating hypertriglyceridemia?
Fibrates e.g. gemfibrozil (the lowering in triglycerides is accompanied with small reduction in LDL and small increase in HDL).
What channels are blocked by amiodarone?
K+ channels
Describe the causative organism and progression of symptoms in syphilis.
Painless chancre (usually on the penis in men) but may also be in the vagina or rectum in women
Maculopapular rash, condyloma lata (genital warts), lymphadenopathy hair loss, muscle aches, sore throat
Subcutaneous granulomas, neurosyphilis (dementia, personality changes), tabes dorsalis (leading to loss of proprioception and vibratory sensation).
What would the bone marrow of someone with multiple myeloma look like?
Bone marrow plasma cells -> overproduction of monoclonal IgG and destructive bone lesions -> hypercalcemia.
What are the signs of a disseminated Neisseria meningitidis infection?
Hypotension, tachycardia, rapidly enlarging purpuring rash, DIC, coma.
What is the treatment for Wilson disease?
D-penicillamine (a chelating agent)
What metabolic defect would be associated with a child with long, thin extremities, generalized low muscle tone, developmental delay, a downward dislocation of the lens and thromboembolic events?
Homocystinuria caused by either cystathionine synthase or methionine synthase mutations.
How would you recognize a serratus anterior injury? What is the innervation of this muscle?
Winging of the scapula; the serratus anterior is innervated by C5,6 and 7 via the long thoracic nerve.
What is the biggest risk factor for placenta previa?
prior C-section
What form of thalassemia is incompatible with life and presents with hydrops fetalis and spontaneous abortion?
Alpha-thalassemia with deletions of all 4 alpha-globin genes: Hb Barts.
What symptoms are suggestive of turner syndrome? What congenital anomaly may be present?
Short stature, webbed neck and dactylitis (“sausage fingers”); may have coarctation of the aorta.
What findings would be seen on light microscopy in diabetic glomerulonephropathy?
Thickening of the the glomerular basement membrane and glomerulosclerosis (kimmelstiel-Wilson nodules)
What is the first-line treatment for seizure prophylaxis in patients with pre-eclampsia? What signs would indicate overdose for this drug?
Magnesium sulfate; loss of deep tendon reflexes (hyporeflexia) and CNS depression (drowsiness)˙.
What is the potter sequence? What is its cause?
Pulmonary hypoplasia
Oligohydramnios (cause)
Twisted face (retrognathia, flattened nose, low-set ears)
Twisted skin
Extremity defects
Renal failure (in utero)
What is the presentation on CXR of the most worrisome side-effect of bleomycin?
Ground glass opacities (pulmonary fibrosis).
What are the risk factors for nasopharyngeal carcinoma?
Male, asian (especial with epstein-barr virus infection), diet of salt-cured meats and fish.
Dislodged pieces of cartilage and subchondral bone would be found in what kind of arthritis?
Osteoarthritis
What disease process is indicated by the circled cells?
They are smudge cells (destroyed lymphocytes) suggestive of chronic lymphocytic leukemia or small lymphocytic leukemia (CLL/SLL) which originate from B lymphocytes.
What nerve root would be associated with decreased sensation around the inguinal ligament?
L1
What ovarian pathology would be present in a patient with Turner syndrome?
Follicular dysgenesis; theca and granulosa cells are replaced with fibrous tissue, resulting in “streak ovaries”
What is the clinical presentation and histology of the most common benign breast mass?
A fibroadenoma typically presents as a small, firm and mobile mass, nontender and changes with menstruation, with no skin changes, nipple discharge or lypmadenopathy.
On histology, fibrotic interlobular stroma are found around normal structure.
What breast pathology matches the picture?
Branching fibrovascular core exending into dilated duct: intraductal papilloma
What disease matches the histology?
Large cells with clear cells -> Paget disease of the breast
What disease process matches the histology?
Parallel arrays of small, monomorphic cells infiltrating in lines: lobular carcinoma (in situ or infiltrative)
What disease matches the histology?
Pleomorphic sheets of cells invading adjacent fibroadipose tissue; invasive ductal carcinoma (the most common breast mass in older women.
What are psammoma bodies? What diseases are associated with them?
They are laminated concentric calcific spherules.
Associated with Papilary thoyroid carcinoma, Serous ovary, Meningioma and Mesothelioma.
What is the classification and typical clinical presentation for Pasteurella multocida?
It is a gram-neg coccobacillus, found commonly in cat/dog mouth.
Rapid and aggressive infection, skin abcess with pus.
Cat scratches in young children may be infected by this gram-negative rod.
Bartonella henselae.
Brucella canis, commonly found in dogs, can cause what kind of illness in humans? What are risk factors for infection?
B. canis is a gram-negative coccobacillus, can cause fever, malaise and hepatosplenomegaly but typically only immunocompromised & blood exposure would be at high risk for infection.
What is the mecahism of action by which trimethoprim leads to megaloblastic anemia?
TMP inhibits tetrahydrofolic acid formation -> can also cause leukopenia and granulocytopenia.
What is the cause and presentation of DiGeorge Syndrome?
DiGeroge = thymus agenesis due to deletion in 22q11.2 (CATCH-22)
Cardiac defects
Abnormal facies
Thymic hypoplasia (opportunistic infections, think Candida and Pnumocystis)
Cleft palate
Hypocalcemia
What is the cause of absent tonsils and low B-cell concentrations?
X-linked agammaglobulinemia, caused by a recessive primary B-cell deficiency due to a mutation in Bruton’s tyrosine kinase (impairing the maturation of B cells).
Which spinal tract controls voluntary movement?
Lateral cortitcospinal tract.
How would you differentiate multiple myeloma from Waldenstrom macroglobulinemia?
Multiple myeloma leads to high levels of IgG or IgA, Neoplastic proliferation of plasma cells (characteristic clock face). CRAB (hyperCalcemia, Renal insufficiency, Anemia, lytic Bone lesions).
Waldenstrom macroglobulinemia is characterized by excessive IgM. Proliferation of plasmacytoid lymphocytes, proteinurea, hyperviscocity syndrome, Bence Jones proteins (no lytic bone lesions).
What are the characteristics of the infective organism most likely associated with a tricuspid diastolic murmur in a person with IV drug use history?
Staphylococcus aureus is a catalase positive, coagulative positive cocci.
What are the characteristic findings on cardiac biopsy for a patient with rheumatoid fever?
Ashoff bodies with activated macrophages called Anitschkow cells.
Describe the characteristic cell in the lung biopsy. What is the diagnosis?
Reed-Sternberg cell; giant tumors cells mirror images. “owl eyes”). Hodgkin lymphoma.
What should be done prior to splenectomy in a setting of malignant invasion?
Vaccination against encapsulated organisms e.g. pneumococcus and Haemophilus influenzae.
Identify the organism
Plasmodium, because of malaria.
What is the classic presentation of leishmaniasis
Ulcers of the skin, mouth, and nose, fever, lymphadenopathy splenomegaly confirmed using biopsy and transmitted by infected sand flies.
What is the mechanism of action of isoniazid?
Inhibits the synthesis of mycolic acid to build the cell wall in mycobacteria
What is a common side effect of vincristine?
Peripheral neuropathy, areflexia
Identify the ovarian lesion.
Struma ovarii; teratoma containing thyroid tissue.
What is an early sign and cause of myotonic dystrophy?
Early signs: proximal muscle weakness. Cause: it is a nucleotide repeat expansion. Muscle biopsy shows atrophy of fibers.
What is the characterization of herpes viruses?
Double-stranded linear DNA
What drugs follow zero order elimination kinetics?
Phenytoin, ethanol, high dose aspirin
Which organs drain to the para aortic lymph nodes?
Testes, ovaries, kidneys, uterine fundus
How would you differentiate a gastric and a duodenal ulcer?
Gastric = worse with eating and associated with NSAID use. Must biopsy margins to r/o malignancy.
duodenal =Relief with eating. Associated with Zollinger-ellison syndrome. On histology, hyperplasia of Brunner glands.
Both strongly associated with H. pylori
What are the four mature defence mechanisms?
Sublimation, altruism, suppression, humour
How would you distinguish between a lesion of the upper trunk and lower trunk of the brachial plexus?
Upper trunk results in a waiters tip position due to deltoid, infraspinatus and biceps deficit (C5-C6)
lower trunk presents as a clawed hand or deficit hand muscles (C8-T1)
What is the pathogenesis of a complete classic mole?
An enucleated egg is fertilized by a single sperm, which then duplicates.
What disease process would explain symptoms of anemia with cola coloured urine in the morning?
Paroxysmal nocturnal hemoglobinuria. Caused by loss of PIGA gene required for GPI anchors for CD55 and CD59. Loss of CD55 and CD59 leads to complement-mediated hemolysis
Identify the pathology from the bone marrow aspirate. What are the defining features?
Hamophagocytic lymphohistiocytosis; macrophages are overactive leading to fever, pancytopenia, hepatosplenomegaly….macrophages are shown phagocytosing marrow cells.
How would you distinguish between cholecystitis, large bowel seeding and PID seeding of a liver abcess
Cholecystitis tends to present with fever N/V.
Large bowel ascending infection will often be accompanied by bloody diarrhea
PID will show lower abdo pain and adhesions of the peritoneum to the liver (“violin string”)
What is the mechanism of action of ethosuximide
Ethosuximide is used for absence seizures and it blocks T-type calcium channels.
What hormone is secreted by dilated ventricles in heart failure? What are its physiologic effects (3)?
Brain Natriuretic Peptide (BNP), this acts on the collecting tubule to decrease Na+ reabsorption
Increases GFR by dilatation of afferent arteriole
Reduces the osmotic gradient by vasodilating the vasa recta.
Hyperintense lesions on FLAIR MRI may indicate what diagnosis?
MS
This kidney stone suggests infection with which microorganisms?
“staghorn stone” is made of ammonium magnesium phosphate, caused by infection by urease-producing bugs, eg. Proteus, Staph, Ureaplasma and Kliebsiella.
Which markers are Reed-Sternberg cells classically positive for?
CD15 and CD30
Describe the typical induction treatment for acute lymphoblastic leukemia
vincristine, L-asparaginase, prednisone
What chromosomal abnormality is associated with an increased risk of acute lymphoblastic leukemia?
Trisomy 21
Which organism causes a water diarrhea, hyponatremia and pneumonia with occasional CNS symptoms?
Legionella pneumophila
What is the mechanism of lead poisoning toxicity?
Inhibition of aminolevulinic acid dehydratase and ferrochelatase leading to issues in the heme synthesis pathway (hence, microcytic anemia).
What is the mechanism of action of steoroid suppression of inflammation?
Steroids inhibit NF-kB a transcription factor for TNF-alpha and other inflammatory agents.
An individual on albuterol which is experiencing persistent/chronic asthma should have what added to their treatment regiment?
An inhaled corticosteroid (fluticasone, budesonide).
How would you differentiate between injury to the common peroneal, the deep peroneal and the superficial peroneal nerve?
Deep peroneal: inability to dorsiflex foot, foot drop
Superficial peroneal, inability to evert foot and sensory loss over lateral leg and dorsal surface of foot.
Common peroneal = both.
Is furosemide a good choice for treatment of hypertension
No. It addresses volume overload, but generally has no effect on blood pressure.
What is the first line of treatment for diabetic nephropathy?
An ACE inhibitor – it’s renoprotective!
What is the presentation and cause of Prader-Willi syndrome?
Hyperphagia, obesity, intellectual disability, hypotonia and hypogonadism.
Occurs due to deletion or mutation of paternal copy of the gene on chromosome 15
What kind of antibody is rheumatoid factor? What is its epitope?
IgM; Fc portion of igG
Which receptors does ADH act on? What are their functions?
V1 increases blood pressure (vasoconstriction).
V2 lowers serum osmolarity (increases water reabsorption in collecting duct).
Suppose a patient is refusing a procedure and is capable of consent. What must you do before you grant the request?
Ensure they understand the risks and benefits of the procedures so their content is informed.
This patient presents with right flank pain. What is the diagnosis? What is the first line treatment?
Urolithiasis (kidney stones).
If hypercalciuric, then treat with hydrochlorothiazide
If gouty allopurinol would be ok.
What is procainamide’s effect on the heart?
Procainamide blocks sodium and potassium channels, acting to slow depolarization in ventricular muscle fibres.
What is adenosine’s effect on the heart?
Adenosine inhibits the SA AV and His-purkinje cell activity, decreasing conduction velocity by inhibiting L-type calcium channels.
What is the effect of verapamil in the heart?
Verapamil is a calcium channel blocker, lowers heart muscle contractility, highest specificity for heart.
How does HMG – CoA reductase activity affect cholesterol synthesis?
It is the rate limiting enzyme of cholesterol synthesis. Increases in activity result in higher cholesterol level
What is the mechanism of action of fibrates?
Activation of peroxisome proliferator activated receptor (PPAR) which increase HDL levels by increasing synthesis of the lipoprotein A1 and A2, as well as increasing lipoprotein lipase-mediate lipolysis.
What is the clinical presentation of Wilson disease?
Before age 40
Liver disease (hepatitis, liver failure, cirrhosis)
neurologic findings similar to Parkinson’s
decreased serum ceruloplasmin
Kayser-Fleischer rings (brown discoloration of the cornea)
What is the most common cause of acute appendicitis in children?
Lymphoid hyperplasia, often subsequent to a viral infection or vaccination.
Which area of the brain has the highest concentration of dopamine receptors?
:Putamen
What would a nitroblue tetrazolium dye reduction test be helpful for diagnosing?
Chronic granulomatous disease (caused by lack of NADPH oxidase activity).
How does infection with clostridium tetani lead to muscle spasms?
The tetanospasmin is a exotoxin which cleaves SNARE proteins for inhibitory neurotransmitters including GABA and glycine which results in a net increase in muscle tone.
Which is the most common ligament torn in and ankle sprain due to overinversion or supination of the foot?
The anterior talofibular ligaments
What class of antidepressants can lead to a hypertensive crisis?
Monoamine oxidase inhibitors -> tyramine injestion -> norepinephrine release (but can’t get degraded) ^^^BP
What type of skewness is this?
Negative skew
What type of skew is this?
Positive skew
A patient has a severe flush after starting IV antibiotic treatment. Which antibiotic was administered? How would you avoid this adverse effect?
Vancomycin. Do a slower infusion and/or add antihistamines.
What is the antibiotic most associated with aplastic anemia?
Chloramphenicol
What is the classification of the causative organism for lyme disease?
Borrelia burgdorferi; a corkscrew-shaped spirochete
What are the major acute regulators of inflammation (late phase response)?
IL-1, IL-6 and TNF-alpha
How do you differentiate between pre-renal vs intrinsic causes of kidney failure?
Pre-renal, Fractional sodium excretion <= 1%; BUN:Cr >= 20
Intrinsic; Fractional sodium excretion > 2%; BUN:Cr < 15
How do you calculate relative risk of developing a disease based on an exposure in a cohort study?
(odds of disease | exposure) / (odds of disease | not exposed)
What is the deficient enzyme that would result in elevated orotic acid? What is the inheritance pattern?
Ornithine transcarbamoylase; X-linked recessive.
A patient presents with hemibalismus on the right. Where is the lesion? What is the causative mechanism?
Left subthalamic nucleus (contralateral), often due to a lacunar stroke. The STN -> globus pallidus, which fires inhibitory GABA neurons to the thalamus.
What changes to LH, FSH and estrogen in menopause?
LH and FSH go up, estrogen goes down.
Where do T cells develop in the lymph nodes?
The paracortex.
This patient presents with a history of joint and abdo pain as well as loose, greasy stools. Given the biopsy of the lamina propria below, what is the causative organism? What is the stain used on the micrograph?
Tropheryma whipplei (whipple dissease).
Per-iodic Schiff stain showing intracellular gram +ve bacteria.
Also can get cardiac and neurologic symptoms.
What is the treatment of carbon monoxide poisoning?
Intubate if require protected airway; otherwise hyperbaric oxygen.
What antidote can be given for cyanide poisoning?
Hydroxocobalamin
Why must alcohol be avoided in patients taking metronidazole?
Metronidazole inhibits acetaldehyde dehydrogenase, consumption of alcohol leads to buildup acetaldehyde which will produce nausea, vomiting, headache, palpitations, and flushing.
Differentiate cluster headaches from migraines.
Cluster headaches: periorbital, sharp pain non-pulsatile at the same time each day. Last up to two hours and presents with autonomic symptoms including nasal congestion, lacrimation, conjunctival injection, flushing, sweating. Treat with high flow oxygen, a triptan, verapamil.
Migraine headaches: unilateral location with throbbing and pulsatile pain lasting up to 72 hours. Often accompanied by auras, nausea and vomiting, photophobia and photophobia. Maybe in improved with NSAIDs, and ergotamine, selective serotonin agonists including sumatriptan.
Differentiate between familial adenomatous polyposis and Lynch syndrome (non-polyposis colorectal cancer).
FAP presents with thousands of polyps on colonoscopy and is due to mutations in the APC gene. Lynch syndrome is due to problems in mismatch repair leading to microsatellite instability. 70% of people develop colorectal cancer and there is a high risk of endometrial, ovarian, urinary tract, small intestinal, stomach, and biliary cancer.
A fracture to the femoral head could disrupt blood flow to which artery?
The medial femoral circumflex artery
What pathology is present on this image? which disease is associated with it?
Auer rods appearing in acute promyelocytic leukemia (a type of AML)
What pathology is present on the image?
Call-exner bodies or pseudo-rosettes are spaces which appear among the granulosa cells found in granulosa cell.(Ovarian) tumors.
What pathology is present on this image?
Cowdry A inclusion bodies - intranuclear eosinophilic inclusions with a clear halo found in VZV infections.
What vitamin deficiency is related to this image?
Keratomalacia associated with vitamin A deficiency may also present with edamatous and thickened cornea.
What is the classification of Helicobacter pylori?
A gram-negative, flagellated, curved bacteria
Which immunosuppressant is associated with renal toxicity?
Cyclophosphamide
What is the characteristic presentation of endometriosis
Endometrial tissue found outside of canal. Often in the ovaries, pelvis, or peritoneum during the menstrual phase, this tissue has outlet end will begin to accumulate for example with chocolate sis filled with reddish-brown blood in the ovaries. It is associated with cyclic and progressively worsening pelvic pain, bleeding, dysparenuia, dyschezia, and infertility
What is the typical presentation of juvenile idiopathic arthritis?
Relapsing spiking fevers accompanied by poly articular joints, swelling, and macular salmon pink rash present anywhere in the body. Sometimes generalized lymphadenopathy and hepatosplenomegaly.
Treatment is nSAIDs, steroids, methotrexate IVIG and biologics.
Stage of the cell cycle sites oocytes are suspended in from birth to ovulation?
Prophase I
Which human leukocyte antigens and for greater susceptibility to type I diabetes?
HLA DR4 and DR3
What are the characteristics of glioblastoma multiforme?
Most common brain cancer in adults, presents in the hemispheres with areas of necrosis and localized edema surrounded by pseudo palisading cells. Headaches, focal neurologic findings, nausea and vomiting are common.
What is the classic presentation for a posterior urethral injury?
Boggy, high riding prostate, blood at the urethral meatus, inability to insert a foley
What is the genetic cause of ocularcutaneous albinism?
A defect in tyrosinase which impairs the ability to convert tyrosine to melanin.
What is Waterhouse-Friderichsen Syndrome?
Primary adrenal failure due to Neisseria gonorrheae-caused adrenal hemorrhage. Presents with septicaemia, DIC and endotoxic shock
What is the common trigger for hemolytic uremic syndrome?
Enterohemorrhagic E. coli infection. It’s also accompanied by diarrhea.
Which mutations are associated with autosomal dominant polycystic kidney disease? At what age does it typically present?
Polycystin 1 (Chromosome 16), less commonly polycystin 2 (chromosome 4)
Typical presentation is 20-30y
What are the classic symptoms of congenital rubella infection?
Sensorineural hearing loss, cataracts, cardiac disease (patent ductus arteriosus).
Which HLA antigen is associated with rheumatoid arthritis?
HLA – DR4
Which HLA antigen is associated with pernicious anemia and Hashimoto’s thyroiditis?
HLA – DR5
Which diseases are associated with HLA – B27?
Ankylosing spondylitis, other seronegative arthropathy including psoriatic arthritis and reactive arthritis as well as inflammatory bowel disease and anterior uveitis.
What medication would you use to treat an exogenous ACTH-secreting tumor?
Ketoconazole or mitotane
What symptoms would you expect to see in goodpasture syndrome?
Hemoptysis and Hematuria
Thiamine (B1 deficiency) can result in what electrolyte imbalance?
Lactic acidosis
What metabolic disturbances would be expected in a patient being treated with furosemide?
Hypocalcemia, hypokalemia, hyponatremia, hypomagnesemia, metabolic alkalosis
How would you treat an acetylsalicylic acid overdose?
Stabilize ABCd, add sodium bicarbonate infusion.
What is the causitive organism for slapped cheek disease?
Parvovirus B19
What is the difference between brief psychotic disorder, schizophreniform disorder and schizophrenia?
Brief psychotic disorder < 1mo
Schizophreniform disorder 1mo to 6 mo
Schizophrenia >6mo
What organelle is prominent in plasma cells?
Rough ER
What type of cells are these? What condition are they typically found it?
Heart failure cells (these are hemosiderin-laden macrophages
What is mittelschmerz?
Unilateral ovarian pain on ovulation.
What are the risk factors for cervical cancer?
Early sexual activity, multiple partners, smoking, low SES
How would you treat hyperthyroid in the setting of pregnancy (or when radiation is contraindicated)
Propylthiouracil
Which enzyme is deficient in galactosemia?
Galactose-1-phosphate uridyltransferase
What is the reason why patients with SLE may have recurrent thrombosis?
Antiphospholipid antibody syndrome: antiphospholipid antibodies -> bind and expose platelet phospholipids to clotting factors. Antibodies will cause a paradoxical increase in PTT (exogenous pathway).
What drugs can cause torsades de pointes?
Antiarrhythmics: Quinidine (IA, III antiarrhy9thmics)
Antibiotics
Anti”C”ychotics
Antidepressents
Antiemetics (ondansetron)
Predisposition in long QT
A patient undergoing treatment for cancer presents with new onset hyperglycemia. What is the most likely cause?
Prednisone
What type of murmur is heard in an Atrial Septal Defect?
ASD presents with a pulmonic systolic heart murmur with a wide fixed split S2
What type of murmur is heard in a patent ductus arteriosus?
PDA presents with a machinelike continuous murmur in the left infraclavicular lesion, often with tachy, dyspnea, poor growth.
What amino acid deficiency can lead to pellagra?
Tryptophan (hartnup disease)
What is globus sensation?
A psychological disorder in which a patient feels a lump in their throat; often follows a significant life stressor
Which medications are used to treat late-stage prostate cancer?
Leupromide — a GNRH analog (suppresses LH)
Flutamide — a nonsteroidal antiandrogen
Adjuvant radiotherapy in high-risk and metastatic disease.
How would you differentiate between asbestosis and coal workers’ pneumoconiosis?
Coal miner’s disease -> look for “black, sooty lung”
What does this lung image show? Which disease is associated with it?
Ferruginous bodies (dumbbell like, rusty red), a sign of asbestosis
What anatastomosis is associated with esophageal varices?
Left gastric vein into the esophageal vein
How do you distinguish between someone who has been vaccinated vs someone who has been exposed to HepB
(+)anti-HBc indicates prior infection.
Hepatitis A and E are what kind of viruses?
Single-stranded, linear RNA viruses.
What is the cause that you would suspect in a child with Gower sign and calf pseudohypertrophy?
Duchenne Muscular Dystrophy (Gower = using arm to pull oneself up).
Often caused by frameshift mutation leading to deletion of one or more exons of the DMD gene.
How do you differentiate between HUS and DIC?
HUS = hemolytic anemia, acute kidney failure, thrombocytopenia but no change to PT/INR or PTT.
What type of medium is used to culture Bordatella pertussis?
Bordet-gengou or Regan-Lowe
What type of medium is used to culture Corynebacterium diptheriae
Lôffler medium
What grows on Thayer-Martin medium?
Neisseria gonorrhoeae
How would you culture Haemophilus influenzae?
Chocolate agar with factor V and X
What is the cause of medication-induced hemolytic anemia?
G6PD deficiency leading to sensitivity to oxidant drugs (e.g. antimalarials) or infections.
Which hair cells in the organ of corti are associated with higher pitched sounds?
Those at the proximal end (closest to the oval window)
What are the findings on EM / IF in poststreptococcal glomerulonephritis?
Dense humps on epithelial side of glomerular basement membrane (EM)
Granular pattern “lumpy bumpy” on IF
Which translocation is associated with burkitt lymphoma?
T(8;14) involving c-myc into immunoglobin heavy chain locus, leading to constitutive c-myc expression.
What effect on volumes does mannitol have?
Mannitol can be used to pull fluid into the intravascular space; it is used to treat increased ICP
What is the effect of triamterene?
It is a potassium-sparing diuretic used when spironolactone is not tolerated
What kidney pathology is shown in the image? What are the causes?
membranous nephropathy
Thickening of capillaries glomerular basement membrane on LF, spike and dome on EM.
Primary disease can be due to antibodies to phospholipase A2 (poor prognosis)
Secondary occurs with drugs, infections, SLE, solid tumors.
What kidney pathology is shown on the image?
Membranoproliferative glomerulonephritis
Mesangial proliferation, thickening of the basement membrane
May present with mixed nephritic / nephrotic signs.
Has low C3
What is the normal function of retinoblastoma protein?
prevents cell from progressing through G1/S checkpoint.
Where are melanocytes found?
In the basal layer of the epidermis.
What conditions involve defective Type IV collagen?
Goodpasture syndrome and Alport syndrome
What immune cells are found in the crypts of Lieberkuhn?
Paneth cells
What is the function of Chief cells?
Pepsinogen secretion.
What is the function of I cells?
Cholecystokinin release (stimulates secretion of pancreatic enzymes and HCO3)
What is the function of S cells?
Secretin (increases pancreatic and biliary HCO3 secretion)
What is the cause of megacolon and failure to pass meconium with bilious vomiting in a neonate?
Hirschsprung disease (failure of neural crest cell migration leading to missing Auerbach and Meissner plexuses)
What hormone is responsible for the development of male external genetalia in utero?
Dihydrotestosterone
Hexagonal crystals forming kidney stones are most indicative of what pathology?
Cystine reabsorption problem causing cystinuria.
Radiolucent stones with rhomboid crystals are indicative of what source?
Uric acid
What are the 3 types of radiopaque stones?
Calcium oxalate (dumbbell), Calcium phosphate (wedge-shaped). Think low-sodium diet and thiazides.
Ammonium magnesium phosphate (struvite, coffin-lid, think bugs).
A lactose fermentation test (MacConkey agar) would be most helpful for differentiating which bacteria?
Enterobacteriaceae:
Escherchia and Klebsiella ferment lactose
Salmonella and Shigella do not.
What are common causes of secondary hypertensive crises?
Anything that causes renal artery stenosis: atherosclerosis, fibromuscular dysplasia, CKD, hyperaldosteronism.
What congenital abnormality can occur in babies whose moms are undergoing lithium treatment?
Ebstein anomaly (tricuspid valve is lower into the RV, big RA, small RV).
What is the common presentation of leptospirosis & Weil disease?
Leptospira interrogans (from contaminated water) leads to flu-like symptoms, calf myalgia, jaundice and conjunctivial suffusion. Weil disease is the more severe form with renal failure and hepatitis.
How do you differentiate hemophilia A / B from hemophilia C?
Hemophilia A (factor VIII) and B (factor IX) may present with bleeding into deep soft tissues and hemarthrosis. Hemophilia C has less spontaneous bleeding (factor XI) and it is more common in Ashkenazi Jews, but still very rare. All show abnormal PTT but normal PT.
How does the botulinum toxin get into cells?
Retrograde transport along axonal microtubules via dynein.
What is orlistat used for?
Orlistat is used for weight loss in patients BMI >30 (27 with comorbid conditions). It inhibits lipase -> fat loss.
What is the abnormality? What causes it?
Horseshoe kidney due to fusion at the bases of the two kidneys. The inferior mesenteric artery stops the kidneys from rising to their normal level.
Describe the effects of angiotensin II on the afferent and efferent arterioles.
It vasoconstricts both, but the efferent arteriole more, so under low dosage they will increase GFR. At high doses, it decreases GFR by constricting both afferent and efferent arterioles the same.
How does total peripheral resistance change in a traumatic bleed?
TPR is increased as the body responds to a fall in blood pressure by vasoconstriction.
Differentiate coagulative from liquefactive necrosis
Coagulative (*most organs*) cell outlines present but absent nuclei
Liquefactive (lung, brain) release of enzymes degrades tissue producing a glob.
Which diseases are associated with Schistosoma?
S. haematobium -> chronic inflammation of bladder
S. mansoni -> intestinal schistosomiasis
Are cerebellar infarcts ipsilateral or contralateral to the lesion?
Ipsilateral defecit (double-crossover, once above the red nucleus and again below the red nucleus)
What is covered by medicare part A?
Hospital insurance, home hospice care + nursing homes
What is covered by medicare part B?
Basic medical bills (doctors offices, diagnostic testing)
What is covered by medicare part C?
Combo: A + B delivered by private companies
What is covered by medicare part D?
prescription Drugs
Fetal screening with an elevated level of alpha-fetoprotein is concerning for what congenital malformation?
Open neural tube defect (meningocele, myelomeningocele, encephalocele or anencephaly).
What changes on fetal screening raise suspicion of trisomy 18?
decreased alpha-fetoprotein, estriol AND beta-hCG
What changes on fetal screening are suspicious for trisomy 21?
Decreased alpha-fetoprotein and estriol
Increased inhibin A and beta-hCG
What diabetes medication can result in lactic acidosis?
Metformin.
What characteristics would you expect of the skin lesion with the following biopsy?
Fleshy-coloured pearly papules with central telangiectasia - a Basal Cell Carcinoma
Identify the organism on this gram stain.
Candida albicans
What symptoms can accompany Candida vulvovaginitis in immunocompromised patients?
Esophagitis
How would you clinically differentiate between gonorrhea and candidiasis in a patient presenting with white discharge in the vaginal canal?
Gonorrhea presents with urethritis and PID.
Name the 3 branches of the aortic arch, in order from the heart.
- R brachiocephalic trunk (branching to R common carotid, R subclav and thyroid ima)
- L common carotid
- L subclavian
What is lambert-eaton syndrome?
A paraneoplastic syndrome in which antibodies are generated against presynaptic calcium channels at the neuromuscular junction.
Symptoms include proximal muscle weakness, decreased reflexes, sometimes diplopia
What changes do you expect to serum calcium, phosphorus and alkaline phosphatase in the setting of a patient with osteoporosis?
All will be normal.
What percentage of RB mutations are spontaneous?
55% of cases involve two spontaneous mutations
In the other 40%, kids inherit one allele which is mutated and develop a spontaneous mutation.
An individual reports a growing mass exuding a yellow discharge one month post oral surgery. What is the causative organism based on this acid-fast stain?
Actinomyces israeli, a branching rod-like gram-positive obligate anaerobe.
Characteristic sulfur granules, negative on acid-fast stain.
Treat with penicillin G
What is the mechanism of action of sulfonamides?
Block bacterial nucleotide synthesis
What is the mechanism of action of penicillin G (IV/IM) or V (oral)?
Inhibits transpeptidase cross-linking and prevents cell wall synthesis.
What is the mecahism of action of amphotericin B?
Binds ergosterol, forms pores in the membrane
What is the mechanism of action of azoles?
Inhibits ergosterol synthesis (fungal infections!).
What markers are found on T helper cells?
CD4, CD40L, CXCR4/CCR5 (co-receptors for HIV)
CD5 is found on what cells?
most T cells (and also CLL cells)
What markers do NK cells have?
CD16 and CD56
What marker is found on cytotoxic T cells?
CD8
What markers are found on B cells?
CD19, CD20 and CD21
CD40
MHC II
Ig (binds antigen)
What are these findings suggestive of in the context of fever and new heart murmur? What is the most common causative organism?
These are roth spots, osler nodes janeway lesions and nail-bed hemorrhage, suggestive of bacterial endocarditis.
Acute onset tends to be Staph aureus
Subacute is viridans streptococci (tends to be associated with dental work)
What is the classification of vvridans streptococci?
Gram-positive Cocci
Catalase-negative
alpha-hemolytic
opthrocin resistant
identify the brain tumor
oligodendroglioma: Fried egg with interspersed “chicken-wire” capillaries
A sudden swollen, warm exquisitely tender big toe is a classic presentation of…
gout
What is the presentation of neuroleptic malignant syndrome? What is the best management?
Fever, muscle rigidity, myoglobinuria, altered mental status.
Start benzodiazepines, then dantrolene (skeletal muscle relaxant) or bromocriptine
If the hip drops to the left (Tredelenburg), which side is weak?
The right gluteals; could be due to damage to the superior gluteal nerve (nerve roots L4-S1)
What is this finding on RBC smear called? Which disease process does it suggest?
Rouleaux formation, Multiple myeloma
What is the mechanism of action for the antibiotic commonly used to treat C. diff and MRSA?
Vancomycin is used for gram-positive infections; it binds D-ala-D-ala and prevents cell wall synthesis.
The following lesion appears on a patient with HIV. What is the cause of the lesion and the most common accompanying symptoms?
Kaposi sarcoma (a malignant proliferation of epithelial cells caused by HHV-8 infection).
Can be accompanied by mucosal bleeding leading to hematochezia, hematemesis or melena.
What conditions are associated with von Hippel-Lindau syndrome? Which chromosome is it located on?
chromosome 3p25
hemangioblastoma of the cerebellum, retinal capillary and spinal cord, polycythemia, renal cell carcinoma and pheochromocytoma.
In a fetus at risk of pre-term birth, what are steroids used for?
To increase fetal lung compliance (promotes synsthesis of surfactant by maturation of type II pneumocytes)
What is the presentation of 21-hydroxylase deficiency?
Congenital adrenal hyperplasia, salt-wasting hypotension (no aldosterone and cortisol) with shunting towards sex hormones.
What is the cause of the following tumor? In which ages does it present?
This is a Wilms tumor, common in young children between 2-4 years old. They arise from neoplastic embryonic renal cells -> abnormal proliferation of metanephric blastema (nephrogenic rests).
Can be associated with WAGR syndrome with WT1 mutation on chromosome 11.
What is WAGR syndrome?
Wilms tumor
Aniridia
Genitourinary abnormalities
mental Retardation
What is the indication and mechanism of action of prochlorperazine?
It is used as an antipsychotic agent and also potent antiemetic as an adjunct to chemo.
Acts by blocking D2 receptors in the chemotrigger receptor zone, located in the area postrema in the medulla.
How do you calculate sensitivity?
TP / (TP + FN)
How do you calculate specificity?
TN / (TN + FP)
What is the virulence factor that contributes to sepsis in Neisseria meningitidis?
Lipooligosaccharide (stimulates inflammatory cytokines similarly to LPS)
HIV encephalopathy occurs due to infection of what cells in the brain?
macrophages and microglia.
What is the critical period of fetal development for teratogen exposure?
weeks 3-8
What are common manifestations of uncal herniations?
Ipsilateral CN III compression (fixed dilated pupil, “down and out” eyeball, ptosis)
Contralateral hemiplagia (or ipsilateral if compression hits the structures on the other side of the brain)
Impaired consciousness.
Identify the thyroid carcinoma. What are the key characteristics?
Papillary thyroid carcinoma. Commonly presents with asymptomatic cold nodule after previous radiation exposure.
Large overlapping nuclei with finely dispersed chromatin; often optically clear.
What cells are characteristic of anaplastic thyroid cancer?
Large osteoclast-like multinucleated giant cells and biphasic spindle cells amongst sheets of undifferentiated pleomorphic cells.
What is panacinar emphysema?
Alpha-1 antitrypsin deficiency leads to chronic and progressive dyspnia and liver failure
How does CF affect the gut?
accumulation of pancreatic enzymes in the pancreas -> pancreatitis
Nutrient malabsorption due to dessication -> weight loss, potential obstruction
Biliary secretions are impaired -> biliary cirrhosis.
Describe the effects of tamoxifen
It is a selective estrogen receptor modulator
estrogen antagonist in breast
estrogen agonist in bone (inhibits osteoclasts) and uterus (increases risk of endometrial carcinoma)
What is an important side effect of heparin?
heparin induced thrombocytopenia (a type II reaction) due to antibodies against heparin/platelet factor 4 complex.
Occurs with a drop of 50%+ platelets in 3-10 days following treatment. More common with previous exposure to heparin.
Which symptoms make a diagnosis of henoch-schônlein purpura more likely vs granulomatosis with polyangiitis?
HSP -> arthralgia and abdo pain
GPA -> upper and lower resp findings, nephritic syndrome
What is the mechanism of action of metronidazole?
Forms free-radical metabolites that damage bacterial or protozoan DNA
Galactorrhea, abdo pain relieved by eating and hypercalcemia raises suspicion for which syndrome?
Multiple endocrine neoplasia type 1 (pituitary prolactinoma, zollinger-ellison syndrome caused by gastrinoma, parathyroid neoplasm).
A beta antagonist would have what effect on cAMP?
Decreased cAMP (because normally beta receptors are Gs -> increased cAMP).
How would you distinguish between hypercalcemia caused by parathyroid neoplasm and a lytic bone disease (e.g. multiple myeloma)
Alkaline phosphatase levels should be elevated in PTH neoplasm
Multiple myeloma is often accompanied by proteinuria (due to excessive antibody production).
What is the clinical presentation of invasive ductal carcinoma?
Mass with sharp margins with dimpling on the skin. Biopsy shows small glandular cells with a stellate appearance.
What is the clinical presentation of Paget’s disease.
Eczematous patches on nipple.
What chromosomal abnormality is associated with Hirschsprung disease?
Down syndrome
What is the motor and sensory distribution of the musculocutaneous nerve? Which nerve roots does it originate from?
Motor: coracobrachialis, biceps, brachialis
Sensory: lateral part of the forearm
Roots: C5-C7
Which cells are involved in acute graph rejection?
Activation of cytotoxic T-cells (CD8)
How do you treat achalasia?
Use calcium channel blockers e.g. nifedipine or nitroglycerin to have smooth muscle relaxation.
Botulinum toxin can be used as well.
Surgery is another option.
What are the 2 possible diagnoses for the abnormality on blood smear?
What finding would you see on labs?
These are spherocytes
Hereditary spherocytosis or autoimmune hemolytic anemia.
Increased mean cell hemoglobin concentration (MCHC)
What is trichotillomania?
Compulsive hair-pulling resulting in hair loss. Often precipitated by tension.
What are these bodies called? What is the diagnosis?
Hentz bodies, G6PD deficiency
What is the fracture? Which nerve is most likely impacted?
Supracondylar fracture of the humerus -> median nerve.
What does this ECG show?
Wolf-Parkinson-White syndrome.
Key findings are short PR, long/wide QRS, upsloping early QRS, commonly presenting with AVRT.
Due to an accessory tract bypassing the AV node
This individual has a creatininne of 1 mg/dL. What is the most likely diagnosis?
increased PTH
What is the anatomic location of a direct inguinal hernia?
Medial to the inferior epigastric vessels, lateral to the rectus abdominis and superior to the inguinal ligament
What is the anatomical location of an indirect inguinal hernia
Lateral to the inferior epigastric artery and superior to the inguinal ligament
What are the structures labeled A-E? What is their relevance for parkinson disease?
A = globus pallidus. Surgical ablation of the internal segment reduces inhibitory tone to the thalamus, improving bradykinesia
B = Putamen
C = Internal capsule (transmission of motor signals from cortex to body)
D = Caudate nucleus
E = Corpus callosum
What are the saliient features of this liver biopsy? What is the diagnosis?
Hypercellularity, hygh nuclear-to-cytoplasm ratio, pleomorphism. May be accompanied by bruit
Hepatocellular carcinoma.
Name the brain tumor. What are the characteristic findings?
Medulloblastoma: small blue cells around a neuropil (homer-wright rosette). They are the most common cerebellar midline tumor in children and can cause hydrocephalus and present with truncal ataxia and gait disturbances.
What does this x-ray show? What additional findings are associated with this condition?
Congenital diaphragmatic hernia.
Typical findings on exam include scaphoid abdomen and barrel chest
Also presents with pulmonary hypoplasia and pulmonary hypertension (pulmonary artery pressure >22mmHg)
Identify the atria and ventricles on this echo
A -> RV
B -> LV
C -> LA
D -> RA
E-> cardiac apex
What is the diagnosis in this pre-term neonate with dyspnea and cyanosis? How would you differentiate between the common syndromes which lead to neonatal respiratory distress?
Atelectasis with air bronchograms and low lung volumes = NRDS
TTN would present with pulmonary edema with increased lung volumes and pleural effusion.
What is the formula to calculate clearance of a drug?
What is the diagnosis? What is the cause of this disease? What other findings would you expect?
Niemann-Pick
This cherry-red spot would be accompanied by hepatosplenomegaly, neurodegeneration and foamy macrophages with lots of lipid.
This is caused by a sphingomyelinase deficiency (problem converting sphingomyelin to ceramide)
What is the cause of this image?
Pyruvate kinase deficiency (AR), resulting in splenomegaly and anemia
What is the diagnosis based on CT? What findings do you expect on CBC?
Pulmonary fibrosis (idiopathic), a restrictive lung disease.
Expect to see elevated hemoglobin and hematocrit due to compensation.
What is the cause of these lesions?
Warfarin-induced skin necrosis, especially in patients with a protein C or S deficiency. Thrombosis of the skin results when warfarin depletes C and S first, leading to hypercoagulation.
What is the diagnosis? What are the relevant features?
Bronchial asthma: obstruction of the lumen with mucoid exudate, goblet cell metaplasia and smooth muscle hypertrophy.
What do you see on this blood smear?
Microcytic, hypochromic anemia (most likely iron deficiency).
What do you see in this blood smear?
Cold agglutinin disease with clumping of RBCs
Associated with blue fingers and toes (painful), previous infection of Mycoplasma pneumoniae or EBV.
What is the most likely diagnosis based on this picture of a 64yo F
Osteoarthritis
A boy presents with fever, rash, bone swelling and the following skin biopsy.
What is the diagonsis? What would you see on EM?
Langerhans cell histiocytosis caused by infiltration of myeloid-progenitor derived cells, more common in boys.
EM shows birbeck granules (striated, rod-like outpouchings)
Name the organism on this acid fast stain
What is the appropriate antibiotic?
Nocardia (gram positve, weakly acid-fast, long branching filaments). Opportunistic (think immunocompromised)
Sulfonamides (TMP-SMX) preferred.
What is the pathology on this ECG?
What are the inherited causes of this pathology?
Long QT interval (>2 large boxes on ECG)
Jervell and Lange-Nielsen syndrome (autosomal recessive KCNQ1 or KCNE1 mutation): bilateral sensorineural hearing loss + defective voltage-gated K+ channels.
Romano-Ward (autosomal dominant K+ and Na+ channel defect) does not have hearing loss.
What is the arrow pointing to? What disease process could result in this slide?
Mallory bodies: eosinophilic inclusions in cytoplasm of necrotic hepatocyteso commonly found in alcoholic hepatitis.
What are councilman bodies?
Eosinophilic globules due to apoptosis of individual hepatocytes, can occur with yellow fever.
What is shown on this ECG? What drug can cause this effect?
Mobitz II heart block (dropped beats with no PR lengthening)
Can be caused by bupivicaine
This person presents with low-voltage QRS complexes, an ejection fraction of 55%, crackles at lung bases and lower-extremity edema. Based on these symptoms and cardiac biopsy below, what is the diaglosis? What is the etiology?
Amyloidosis
Primary due to Ig light-chain deposition from bone marrow antibody production or secondary due to chronic inflamation.
Produces restrictive cardiomyopathy (normal ejection fraction)
What pathologic finding would lead to this liver biopsy?
This is a cirrhotic liver with micronodular cirrhosis (pink nodules surrounded by cirrhotic tissue) which is associated with persistent activation of stellate cells.
Infants of diabetic mothers are at greater risk of being born with this condition which causes early cyanosis.
Transposition of the great vessels.
Name this tumor found in an eight year old boy. What are the key characteristics?
Well-circumscribed tumor with a large cystic component and a brightly enhancing mural nodule. Typically found in the posterior fossa, this is a (benign) pilocytic astrocytoma, the most common primary brain tumor in children
What are the characteristic findings of the disease associated with this intestinal biopsy? What is the classic presentation and findings on investigation?
Associated with northern European descent, steatorrhea, iron deficiency anemia (refractory to treatment).
Also associated with dermatitis herpetiformis which is characterized by clusters of pruritic, papular or bullous lesions on the trunk and extensor surfaces.
Intestinal biopsy will show villus blunting with crypt hyperplasia and lymphocytic infiltration into the lamb you propria.
Investigations positive for antiendomysial or anti-TTG antibodies.
What is the diagnosis based on this intestinal biopsy from a patient with a history of abdo pain and bloody diarrhea, as well as tender, erythematous bumps on the shins.
This shows a noncaseating granuloma consistent with Crohn’s disease.
What is the etiology and diagnosis in this young boy who presents with multiple hamartomatous polyps in the small intestine?
Peutz-Jehgers syndrome, caused by mutations in STK1. Hyperpigmented macules can also present in/on lips, mouth, hands and genitalia
What is growing on this culture? What is the virulence mechanism?
Pseudomonas aeruginosa; makes exotoxin A which ADP ribosylates + inhibits EF2, stopping protein synthesis.
What is the diagnosis? What would you see on utrasound bfore birth?
Tracheoesophageal fistula; 2/3 of cases present with polyhydramnios.
What fungal infection is characterized by a small intracellular yeast? Where is it typically found? What’s the transmission vector? What would you see on pathology?
Histoplasmosis, found in the Mississipi and Ohio river valleys and commonly tranmitted by bird and bat droppings. Lung granulomas with calcifications.
What is this fungus? What are the key characteristics?
Aspergillus fumigatus
Mold with septate hyphae that branch in a V-shaped 45-degree angle
Name this fungus. What are its special characteristics? Where is it found? What are the symptoms?
Blastomyces: it’s a dimorphic fungus (mold in the cold, yeaste in the heat). Found in soil in wooded areas east of the Mississippi River.
Symptoms of pneumonia: cough, fever, shortness of breath, sometimes hemoptysis.
What is the cause of these lesions in this HIV+ve individual? What other symptoms may occur? What is the treatment?
These lesions are characteristic of Kaposi sarcoma (HHV-8). Other symptoms include lymphedema or spread to oral mucosa, GI or respiratory tract.
Therapy is continued HAART, but can inject vinblastine or provide interferon-alpha or systemic chemo if severe.
What is abnormal about this ECG? What is the cause?
Peaked T waves, characteristic of hyperkalemia
What symptoms would you expect from someone with this jejunal biopsy?
Migratory arthritis, abdo pain, steatorrhea, weight loss
Caused by whipple disease (Tropheryma whipplei)
What CNS tumor is associated with this histology?
Meningioma (benign tumor from arachnoid cells). Note the psammona bodies.
This patient presents with thrombocytopenia. What is the etiology?
Thrombotic thrombocytopenic purpura, due to antibodies against ADAMTS13 metalloproteinase
What is the differential for this blood smear?
Megaloblastic anemia (note hypersegmented neutrophyl) due to folate deficiency or B12 deficiency.
What is the diagnosis? What immunodeficiency worsens the disease?
Leprosy (M. leprae), with interferon-gamma deficiency.
What is the pathogen which is most likely to cause this infection? What is it called?
HPV 6 / 11
condyloma acuminata
What is the diagnosis based on this blood smear? What symptoms and labs would you expect?
AML (note auer rods).
Symptoms hematuria, diffuse petichiae, chest pain and SOB
Labs low platelets, high D-dimer, low fibrinogen (DIC)
What is this finding? What condition is it found in?
Lisch nodules, found in neurofibromatosis type 1
Identify the cells from this micrograph of cerebellum. What neurotransmitter do they secrete?
Purkinje cells
Inhibitory – secrete GABA
What is the infectious organism that is responsible for this rash? What is the risk factor for transmission?
N. meningitidis causing meningococcemia.
Often transmitted in close quarters.
What does this bowel CT scan show? What other symptoms would you expect?
Bowel thickening with pericolic fat staining, suggestive of diverticulitis due to microperforation of a diverticulum.
Other symptoms include a tender mass int he LLQ, worsening cramping pain, fever, nausea, constipation.
What is the differential for these inclusions?
These are lewy bodies, found in Lewy body dementia and Parkinson disease.
What virus causes this common childhood lesion? What family does it belong to?
This is molluscum contagiosum, a poxvirus
What is the causative organism on this slide? What symptoms are expected?
Histoplasmosis caused by histoplasma capsulatum; common presentation is productive cough with green sputum, fever, headache, general malaise in someone who has exposure to contaminated soil with bird/bat droppings (ohio/mississippi valleys)
What is this finding from kidney biopsy stained with PAS? What other symptoms would you expect?
Crescentic glomerulonephritis, seen in Goodpasture syndrome. Cross-reactivity with resp. membranes leads to hemoptysis, anemia, and hematuria
What is the organism on this silver-stained mucous membrane biopsy? What is the treatment?
Mucor (wide-branching nonseptate hyphae), treat with amphotericin B
Describe the lesion. What is it most commonly associated with?
Punched-out soltary lesions with underlying tissues replaced by chronic inflammatory cells; characteristic of H. Pylori.
Describe how the JVP corresponds to the cardiac cycle (see image)
a - atrial contraction
c - RV contraction
x - displacement of tricuspid down during ventricular ejection
v - filling of RA against closed tricuspid valve
y - RA emptying into RV
What is the diagnosis?
Paget disease of breast
Name the class of drugs associated with letters B, C, and D
B - cholestyramine
C - HMG-CoA inhibitors
D - Fibrates e.g. gemfibrozil
Identify the pathogen. How is it transmitted?
Leishmania donovi transmitted by the sandfly
What are the key changes relative to point C that would produce A, B, D, or E?
A - Increased venous return (lower resistance) AND increased inotropy
B - Increased inotropy w/o change in venous return (e.g. digoxin, catecholamines (beta-1 agonist))
D - Negative inotropy due to narcotic overdose, beta-blockers, CCBs, dilated cardiomyopathy
E - increased total peripheral resistance (phenylephrine
What is the most likely etiology for someone presenting with back pain and this CXR?
Note cavitary lesion at lung apex -> TB
so Pott disease of spine
What is the diagnosis based on this kidney biopsy of a patient with SLE?
Membranous nephropathy
What asthma therapy interacts with these cells?
Mast cells - cromolyn sodium prevents degranulation.
