Set 4 Flashcards
What is the cause of hypertrophic cardiomyopathy (HCM)?
Genetic mutation in gene segments which encode sarcomeric proteins
- B-myosin heavy chain
- Cardiac troponin T
- alpha-tropomyosin
- Myosin-binding protein C
60-70% are familial, AD (B-myosin heavy chain mutation)
Rarely can be associated with Friedreich ataxia
What are the Jones criteria for the diagnosis of acute rheumatic fever?
Joints - polyarthritis O Pancarditis (all three layers) Nodules (subq) Erythema marginatum (ring-like rash) Sydenham chorea
During fetal development what structure traps the inferior poles of the kidney resulting in a horseshoe kidney? Do patients with horseshoe kidneys have abnormal renal function?
Inferior mesenteric artery
Kidney functions normally but increased risk for uretopelvic junction obstruction, hydronephrosis, renal stones and rarely renal cancer (Wilms tumor)
What is the mechanism of action of the following cholinergic agents? Pralidoxime Neostigmine Bethanechol Hexamethonium Atropine Carbachol
Pralidoxime - regenerates cholinesterase (combat poisoning by cholinesterase inhibitors like organophosphates)
Neostigmine - cholinesterase inhibitor (increases endogenous ACh - not broken down, no CNS penetration)
Bethanechol - direct cholinergic agonist (bowel and bladder activation)
Hexamethonium - nicotinic ACh receptor antagonist (non-depolarizing ganglionic blocker)
Atropine - muscarinic antagonist
Carbachol - carbon copy of acetylcholine (agonist)
A 25-year-old man is evaluated in the clinic for red, swollen, and painful right wrist and left knee joint. During the exam, the patient brags about his sexual conquests. What sexually-transmitted organism can cause osteomyelitis as well as this patient’s septic arthritis?
Neisseria gonorrhoeae
An adult trauma patient begins to experience shortness of breath on day 3 of his hospital stay. The patient had an open reduction internal fixation of a right femur fracture. You are concerned the patient’s shortness of breath might be attributed to an embolus. What type of embolus is this patient at risk of getting? What are the different types of emboli?
Traditional thromboemboli - stasis
Fat - associated with long bone fractures and lipsuction (fat in bone marrow and disruption of fat tissue); classic triad of hypoxemia, neurologic abnormalities and petechial rash
Fat, Air, Thrombus, Bacteria, Amiontic fluid, Tumor (FAT BAT)
How can a skull fracture at the base of the brain lead to pulsating exophthalmos (protrusion of the eye)?
Skull fracture -> torn ICA in cavernous sinus -> increased blood pressure in sinus -> blood fills ophthalmic vein and orbital tissue -> exophthalmos (pulses)
What is the site of action of each of the following diuretics? Thiazide Loop Carbonic anhydrase Osmotic K+ sparing
Thiazide - DCT Loop - thick ascending loop Carbonic anhydrase - PCT Osmotic - PCT, and some in thin descending K+ sparing - collecting tubule
In patients with a prolactinoma, what pharmacologic agent can be used to inhibit the release of prolactin? In normal physiology, how is prolactin secretion regulated?
Bromocriptine (D2 agonist) inhibits prolactin secretion and can be used in the treatment of prolactinoma
Prolactin secretion from the anterior pituitary is tonically inhibited by dopamine from hypothalamus. Prolactin in turn inhibits its own secretion by increasing dopamine synthesis and secretion from the hypothalamus. TRH increases prolactin secretion.
Prolactin inhibits GnRH thus inhibiting spermatogenesis and ovulation. It increases milk production.
Cause of Gilbert syndrome? Type of bilirubin elevated?
Mildly decreased UDP-glucoronosyltransferase conjugation activity -> decreased bilirubin uptake by hepatocytes. Asymptomatic or mild jaundice. Elevated unconjugted bilirubin without overt hemolysis. Bilirubin increases with fasting and stress.
Cause of Crigler-Najjar syndrome, type I? Type of bilirubin elevated?
Absent UDP-glucoronosyltransferase. Presents early in life; patients die within a few years. Findings: jaundice, kernicterus (bilirubin deposition in the brain), increased unconjugated bilirubin. Treatment: plasmapheresis and phototherapy
Cause of Dubin-Johnson syndrome? Type of bilirubin elevated?
Conjugated hyperbilirubinemia due to defective liver excretion (hepatocytes can’t secrete conjugated bilirubin). Grossly black liver. Benign. (Rotor syndrome is similar but even milder and does not cause black liver)
