May 11 Flashcards
A deletion or addition of a number of bases not divisible by 3 in the coding region of a gene will cause what type of mutation?
Frameshift mutation
What is a frameshift mutation?
deletion or addition of a number of bases not divisible by 3 in the coding region of a gene
What does heme oxygenase do?
Converts heme to biliverdin, a pigment that causes greenish color to develop in bruises several days after an injury
What enzyme is responsible for causing the greenish color of bruises?
Heme oxygenase
Why is skeletal muscle resistant to calcium channel blockers?
Calcium release by the SR (and therefore contraction) is triggered by a mechanical interaction between L-type and RyR calcium channels; little dependence on extracellular calcium influx
Patients with prolonged neutropenia are at increased risk for what infections?
Viral and fungal (most commonly Aspergillus and Candida)
What is the MOA of fenoldopam?
Selective dopamine 1 receptor agonist; causes arteriolar dilation, increases renal perfusion, and promotes diuresis and natriuresis
What is the most common cause of septic arthritis with prosthetic joints?
S epidermidis
Is staph epidermidis resistant or susceptible to novobiocin?
Susceptible
What is the mechanism for gingival hyperplasia seen with phenytoin?
Phenytoin increases the expression of PDGF, causing macrophages to promote proliferation of gingival cells and alveolar bone
What are the symptoms of phenytoin toxicity?
Ataxia and nystagmus
The left ventricular lead of a pacemaker courses through what structure?
The coronary sinus, which resides in the atrioventricular groove on the posterior aspect of the heart
What veins drain into the brachiocephalic vein? What does the brachiocephalic vein drain into?
Jugular and and subclavian drain into; the brachiocephalic drains into SVC
What is the difference in symptoms between compression of the SVC and brachiocephalic?
SVC has symptoms bilaterally; brachiocephalic ipsilaterally
What pigment accumulates with age and “wear and tear”?
Lipofuscin
What are Kupffer cells?
Hepatic macrophages that line the walls of sinusoids and breakdown RBC
Patient with eosinophilic granulomatosis with polyangiitis presents with mononeuritis; what is the mechanism of the peripheral nerve involvement?
Vasculitis Involvement of the epineural vessels of peripheral nerves, causing mononeuritis multiplex (eg wrist drop due to radial nerve involvement)
What are organophosphates?
Cholinesterase inhibitors; inhibit breakdown of Ach
The most common mutation seen in CF is what?
3-bp deletion of phenylalanine at aa position 508
The delta F508 mutation in CF causes what effect on DNA, RNA, Protein processing?
Causes impaired post-translational processing, which is detected in the ER, and the abnormal protein is targeted for proteasomal degradation.
What hormone is responsible for increasing serum insulin levels due to oral glucose administration vs IV glucose?
Incretins - glucagon-like peptide-1 (and gastric inhibitory peptide)
At what histological region do alveolar macrophages appear in the bronchopulomary tree?
Respiratory brochioles
Ciliated mucosal epithelium lines what part of the pulmonary airways?
From the trachea to the proximal portions of the respiratory bronchioles
What structures are incised when performing a cricothyrotomy?
Superficial cervical fascia –> pretracheal fascia –> cricothyroid membrane
Decerebrate (extensor) posturing occurs when there is a damage to what region?
Brainstem at or below the red nucleus (in the midbrain tegmentum, pons)
Decorticate (flexor) posturing occurs with damage to what?
Damage to neural structures above the red nucleus (eg cerebral hemispheres, internal capsule)
What is decorticate posture?
Flexor posturing
What is decerebrate posturing?
Extensor posturing
How is heparin-induced thrombocytopenia treated?
With direct thrombin inhibitors
What is the MOA of argatroban?
Direct thrombin inhibitor
Niemann-Pick disease is a deficiency in what enzyme?
Sphingomyelinase
What are the levels of C3 and C4 in PSGN?
Decreased C3; normal C4
