USLME world 1 Flashcards
(113 cards)
Collagen synthesis
RER: -Rough ribo: synthesizes Pre-Po-Alpha-chains -Signal Sequence cleaved: pro-alpha-chains -Hydroxylation: Proline & Lysine VITAMIN C DEPEnDENT -Glycosylation: of Galactose and Glucose -Assembly of pro-alpha chains into procollagen TRIPLE HELIX (transfered to Golgi and secreted) EXTRACELLULAR: -N and C terminals cleaved by peptidases: Tropcollagen -Spontaneous assembly: collagen fibrils -Covalent cross links made by Lysyl oxidase
Inulin PAH
Inulin=GFR, filtered PAH=filtered + secreted, renal plasma flow (better than creatinine for measuring bc creatinine not secreted as much)
Odds ration
ad/bc odds that the group with the disease was exposed to the risk factor (a/c) divided by the odds that the group without the disease was exposed (d/b) disease risk factor + - + a b - c d
Beck’s triad: -Jugular venous distension -hypotension -tachycardia -distant/muffled heart sounds -pulsus paradoxus
Cardiac tamponade -Elevated central venous pressure in superior vena cava–> JVD -low QRS and electrical alternans. -lung sounds nrml
Pleuritic chest pain + pericardial friction rub
Acute fibrinous pericarditis follows URI
Pulsus paradoxus
decreased amplitude of systolic blood pressure by > 10mmHg during inspiration. (Cardiac tamponade, astham, obstructive sleep apnea, pericarditis, croup)
6th aortic arch
pulmonary arteries & ductus arteriosus
1st aortic arch
maxillary artery
2nd aortic arch
stapedial artery and hyoid artery
3rd aortic arch
common carotid artery and proximal part of internal carotid artery
4th aortic arch
Left: aortic arch Right: proximal part of right subclavian artery
metalloproteinases
Zinc containing enzymes that degrade extracellular matrix (collagen, laminin, fibronectin). Metalloproteinases are essential for proper tissue remodeling during wound healing
FOscarnet
viral DNA polymerase inhibitor that binds pyrophosphate-binding site of the enzyme. DOES not require viral kinase activation. use: CMV retinitis if ganciclovir fails or in acyclovir-resistant HSV SE” Nephrotox Resistance: mutated DNA polymerase
Acute goutry arthritis tx, drug’s moa
NSAIDS-first line 2nd line: Colchicine: prevent MT formation by binding tubulin SE: diarrhea, nausea, vomiting, abdominal pain bc also disrupts MT in GI mucosa cells
drugs that act on MT
Mebendazole ( anti-helminthic) Griseofulvin (anti-fungal) Colchicine (anti-gout) Vincristine/Vinblastine (anti-cancer) Paclitaxel (anti-cancer)
Gingival hyperplasia SE drugs
Phenytoin, verapamil, cyclosporine, nifedipine
SLE like syndrome SE drugs
SHIPPE: Sulfa, Hydralazine (Vasodilation arteries>veins, increase cGMP-> smooth muscle relaxation. use: CHF, HTN in pregnancy) , INH, Procainamide (Class IA), Phenytoin, Etanercept (TNF receptor fusion protein)
Alveolar-arterial gradient (A-a)
Palveoli (O2)-Parterial (O2)=10-15mmHg=nrml If nrml-> no V/Q mismatch, no diffusino impairment If nrml and patient hypoxemic: alveolar hypoventilation or inspriing low P(O2)
4 major causes of hypoxemia
alveolar hypoventilation, ventilation perfusion mismatch,diffusion impairment, right-left shunting. The first one has nrml (A-a) gradient
Rifampin
Inhibits DNA dependent RNA polymerase Use: TB (NOT ALONE), with dapsone for leprosy to delay resistance, PROPHYLAXIS for meningococcal and chemoprophylaxis for H.influenza type B. Tox: Minor hepatotox, orange body fluids, Ramps UP CYP 450 (But Rifabutin doesnt!)
Young Caucasian, Recurrent Sinusitis
Cystic fibrosis: -Auto recessive, chrm.7-CFTR gene defect: deletion of Phe508 CFTR: ATP-gated Cl channel secrete Cl in lungs & GI and reabsord Cl in sweat glands (sweat test). Mutation: misfolded, stays in RER. Increased intracellular CL leads to Increased Na reabsorption via epithelial Na channel therefore to H2O reabsorption-> abnml think mucus in lungs and GI. Increased Na reabsorption also means negative transepithelial potentia difference
Lecithin/Spingomyelin <1.5
Neonatal Distress Syndrome if below 2 by 35 gestational weeks Surfactant starts being secreted in 3rd trimester by penumocytes II Lecithin: phosphatidylcholine
Hemoptysis, hematuria, Histo: focal necrosis of alvelolar wall and intra-alveolar hemorrhage, Kidney nep
Goodpasture HLA DR2 associated Type II hypersensitivity reaction, antibodies to GBM and alveolar basement membrane, linear IF, glomerulonephritis with crescent of fibrin and plasma proteins, macrophages…
Subcutaneous nodules on knee, dorsum of hand, achilles tendon xanthomas. Elevated total cholesterol, elevated LDL cholesterol.
Familiarl hypercholesterolemia: auto dominant Defective or absent LDL receptors. Excessive LDL deposits in arteries as atheromas and in tendons and skin as xanthomas xanthomas=hyper TG and cholesterol