COMLEX/What You Missed From Truelearn

These are mostly concepts/wordings/tip-offs/distinguishing details that I learned from my mistakes on Truelearn and other resources while preparing for COMLEX.

“Prolonged time to release grip” which condition?

Myotonic dystrophy

Selegiline mechanism of action

Monoamine oxidase B inhibitor → serotonin syndrome risk.

Entacapone + Parkinson disease + mechanism = ?

COMT inhibition → decreases levodopa breakdown

Dantrolene →

Inhibits calcium release from the sarcoplasmic reticulum

Osteoporosis + oral antiresorptive medication + painful swallowing/retrosternal burning = drug, mechanism, adverse effect?

Alendronate (bisphosphonate) → inhibits osteoclasts; causes esophagitis. Take with water and remain upright ≥30 minutes.

Ischemia + ATP depletion + cellular swelling + intact plasma membrane = ?

Reversible cell injury due to decreased sodium-potassium ATPase activity → sodium and water accumulate intracellularly

Contralateral pelvic drop when standing on one leg + trunk lean toward affected side → injured nerve and muscles?

Superior gluteal nerve → gluteus medius and minimus weakness → Trendelenburg gait.

Rheumatoid arthritis + acute hot, swollen joint + fever + neutrophilic synovial fluid + negative Gram stain → most likely organism?

Staphylococcus aureus → septic arthritis. Negative Gram stain does not exclude infection.

Adolescent + metaphyseal bone tumor + Codman triangle/sunburst appearance → diagnosis and histology?

Osteosarcoma → malignant osteoblasts producing osteoid (woven bone). Associated with retinoblastoma and Paget disease.

Alpha-1-antitrypsin deficiency — lung injury mechanism?

Unopposed neutrophil elastase.

How to treat Paget disease

Biphosphates (big side effect is osteonecrosis of the jaw)

____a gram negative rod that stains poorly

Legionella (use charcoal yeast)

Klebsiella pneumoniae morphology

Gram negative, short, large polysaccharide (common in aspiration pneumonia)

“Gram positive diplococci that are lancet shaped”

Streptococcus pneumoniae

What about staph aureus release to make the skin peal

Exfoliative toxin which degrades desmoglein-1 in the epidermis

“Lethal factor induction of epithelial cell death” is in

anthrax

Superantigen activity caused by pyrogenic exotoxins is involved in

Bulbous impetigo, cellulitis, necrotizing fasciitis etc.

“Nodular proliyof cells extending from the stratum basisalis”

Basal cell carcinoma

The nucleus accumbens makes

GABA

The basal nucleus of meynert makes

ACH

Dopamine is made in the

Ventral tegmental and substantial nigra

Maple syrup urine disease results from

A deficiency in alpha ketoacid dehydrogenase

Can’t process methionine?

Homocysteinuria

“Can’t break down tyrosine; deficiency of homogentisate oxidase”

Alkaptonuria

“Deficiency of phenylalanine hydroxylase”

Phenylketonuria

Treatment for Osgood-Schlatter Disease

NSAIDS and rest

“Platelets lack glycoprotein 1b and can’t bind to Von Willebrand factor + thrombocytopenia + extended bleeding time + huge platelets”

Bernard-soulier syndrome

“Defect in the synthesis of platelet alpha IIb beta 3 integrin + congenital disorder”

Glanzmann thrombasthenia

Lewy bodies in the substantia nigra=

Parkinson’s Plus

Hydryoxeura huge side effect

Bone marrow suppression

Can mouth ulcers happen with methotrexate

Yes

Warfarin huge side effect

Skin necrosis

Nitro blue tetrazolium test is unreactive?

NADPH oxidase isn’t forming

“Spongiform changes”

Prion disease

“Intracellular eosinophilia inclusions composed of alpha synuclein”

Aka Lewy bodies; in Parkinson’s and Lewy body dementia

“Infant, muscle weakness; cherry red spot on macula; clonus; muscle weakness”

Gay sachs; deficiency of hexoaminindase A and GM2 gangliosides accumulates

“Erythematous crusted rash on one breast and histological findings of epithelial cells with a lot of cytoplasm (intraepithelial adenocarcinoma cells) “

Paget disease of the breast

Most common cause of middle ear infection in kids

H influenza

S. Pyogenese produces an enzyme that dissolves

Fibrin clots

Strep pyrogenes can cause

Superantigen activity to form a rash in scarlet fever

Cold agglutination disease involves

C3b

Antibodies to glycoproteins IIb-IIIa, and Ib-IX are found in

Idiopathic thrombocytopenic purpura

A splenectomy is mainly indicated for patients with sickle cell if

They have had a splenic crisis more than 1 time

Vaso-occlusive crisis typically happen in sickle cell when

The person gets sick

Flaps hands+falls a lot of work+brown pigmentation in iris+ATP7B

Wilson disease— decreased serum ceruloplasmin levels

Ceruplasmin is the protein carrier of ___ in the blood

Copper

Patients with ___ are at an increased risk for Alzheimer’s

Down syndrome

“Traumatic head injury; bones intact; sub epidural hemorrhage; worsening state; primitive reflexes appear (like sucking on anything that touches their face”

Subfalcine herniation

Medial aspect of the frontal lobe, cingulate gyrus herniates across the midline u def the free edge of the anterior falx

Subfalcine herniation

The two choices to treat acute gout

Non-aspirin NSAIDs, glucocorticoids or colchicine

“Large intracytoplasmic vacuoles”

Creutzfeldt Jakob

Huntington onset

20-50 years (if outside of that, it’s probably CJD)

Medication to detox from iron

Deferoxamine

Fomepizole uses

Treats overdose of alcohol, antifreeze and mentanol

____is characterized by acute low back pain, incontinence, and saddle anesthesia with lower motor neuron findings.

Cauda equina syndrome

What is used to diagnose peripheral nerve and muscles disorders

Electromyogram

Which method is used to diagnose cauda equina syndrome

Emergent MRI of lumbar spine

Serum creatinine measures

Muscle damage

Orthostatic hypertension, what’s not being stimulated

Alpha 1 receptors

Charcot-Marie-tooth underlying cause

Defective proteins found in myelin

“Demyelination secondary to enzymatic deficiency”

Cause of metachromatic leukodystrophy

Barrett esophagus is linked to

GERD

Cardiomyopathy+megacolon+achakasia+from South America

Chagas’ disease

“Liver issues, dizziness, numbness, being treated for TB”

Ionizid

Dopamine and norepinephrine are derived from

Tyrosine

Donepezil MOA

Prevents breakdown of Ach

____is a phosphodiesterase inhibitor used for intermittent claudication.

Cilostazol

Rotenone mechanism

Inhibits mitochondrial complex 1 which causes symptoms similar to Parkinson’s

Antimycin A mechanism

Inhibits complex 3 by binding to Qi site of cytochrome c reductase

“Farmer+ found in fish poison+ respiratory depression+pulmonary edema and shock”

Antimycin A

Arsenic exposure leads to the inhibition of

Pyruvate kinase

The hypothalamus is located next to the inferior aspect of the

3rd ventricle

Ataxia is seen in a lesion involving the

Cerebellum

Lesion in the hippocampus could lead to

Anterograde amnesia

The characteristic histopathology of psoriasis includes

hyperkeratosis, parakeratosis, thickening of the spiny layer, elongation of the rete ridges, small accumulations of neutrophils in the epidermis, and increased mitotic activity in the epidermis. The dermal papillae are elongated and hypervascular.

NSAIDs inhibit cyclooxygenase, thus preventing the synthesis of

prostaglandins and thromboxanes.

Priapism can be a complication of

Sickle cell disease

Treatment for vaso-occlusive crisis

Hydroxyurea

Fresh frozen plasma contains

Clotting factors

Serotonin is derived from

Tryptophan

woman has a stroke. Afterward, she cannot perform simple calculations, cannot write, cannot distinguish right from left, and cannot identify individual fingers.

Which structure is most likely damaged?

Angular gyrus.

Brief positional vertigo + positive Dix-Hallpike maneuver → mechanism?

Otoliths in the posterior semicircular canal.
Buzzwords: positional vertigo, posterior canal, Dix-Hallpike, Epley maneuver.

Viral illness + vertigo + tinnitus + hearing loss → diagnosis?

Labyrinthitis.
Buzzwords: vertigo, hearing loss, tinnitus, viral illness.

Clindamycin — mechanism + classic toxicity?

Binds 50S and inhibits translocation; anaerobic/oral infections and aspiration pneumonia; C. difficile pseudomembranous colitis.

Caloric testing: warm water in one ear produces no nystagmus → lesion where?

Ipsilateral vestibular apparatus.
Buzzwords: caloric reflex, warm water, absent nystagmus, vestibular apparatus.

Giardia lamblia — board buzzwords

Untreated stream water; campers; foul-smelling greasy diarrhea; bloating; steatorrhea; trophozoites attach but do not invade; metronidazole.

Pilocarpine — board buzzwords

Muscarinic agonist; increases salivation; Sjögren dry mouth; miosis; contracts ciliary muscle; increases aqueous humor outflow.

A patient develops bloody diarrhea followed several weeks later by a liver abscess. Which organism is most likely responsible?

Entamoeba histolytica

Recurrent Neisseria infections → immune defect?

Terminal complement deficiency → impaired membrane attack complex formation.
Buzzwords: Neisseria, terminal complement, membrane attack complex.

Dapsone — classic toxicity?

Used for leprosy; oxidative hemolysis in glucose-6-phosphate dehydrogenase deficiency → Heinz bodies + bite cells.

Intracellular viral antigen presented to cytotoxic T lymphocytes → processing step?

Proteasomal degradation before major histocompatibility complex class I presentation.
Buzzwords: intracellular antigen, proteasome, major histocompatibility complex class I, cytotoxic T lymphocyte.

Beta-2 microglobulin deficiency → which immune function is impaired?

Cytotoxic T-lymphocyte activation via major histocompatibility complex class I.
Buzzwords: beta-2 microglobulin, major histocompatibility complex class I, cytotoxic T lymphocytes.

Tetracycline — toxicity of expired drug?

Expired tetracycline → Fanconi syndrome (proximal renal tubular dysfunction)

A patient from South America develops chronic pulmonary symptoms, cervical lymphadenopathy, and painful oral mucosal ulcers. Microscopy shows yeast with multiple buds radiating from a central cell.

Which organism is most likely responsible?

Paracoccidioides brasiliensis

Pyridostigmine — board buzzwords

Myasthenia gravis long-term treatment; acetylcholinesterase inhibitor; increases acetylcholine at the neuromuscular junction; quaternary amine.

Macrolides — classic adverse effects?

50S inhibitors; increased gastrointestinal motility, cholestatic jaundice, QT prolongation; cytochrome P450 inhibition.

Rifabutin — key board associations?

Used for Mycobacterium avium complex; rifamycin; induces cytochrome P450.

Leishmania donovani — board buzzwords

Sand fly; amastigotes in macrophages; visceral leishmaniasis; hepatosplenomegaly + pancytopenia; “black fever.”

Infant with severe infections of all types + absent thymic shadow + absent lymphoid tissue → most likely defect?

Common gamma-chain mutation causing severe combined immunodeficiency.
Buzzwords: severe combined immunodeficiency, absent thymus, absent tonsils, combined T- and B-cell dysfunction.