Posted by: Johnson Francis on: 10 Jun, 2010
All of the following are true of “smoker’s paradox” except:
A. It is a beneficial effect of smoking
B. Better outcome following reperfusion strategies
C. Likely to undergo reperfusion strategies at a younger age
D. Lower co-morbidity
Answer: A. It is a beneficial effect of smoking
Braunwald’s heart diseases, 8th Edition, Chapter 39, Page 1004.
Posted by: Johnson Francis on: 10 Jun, 2010
Endothelial nitric oxide synthase is:
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: C. Type III
Endothelial nitric oxide synthase (eNOS) is Type III. The other types are brain or neuronal NOS (b or nNOS, type I) and inducible NOS (iNOS, type II). All NOS isoforms contain domains for binding calmodulin, nicotinamide adenine dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), and flavin mononucleotide (FMN). NOS catalyzes the oxidation of L-arginine to produce L-citrulline and nitric oxide (NO).
Posted by: Johnson Francis on: 10 Jun, 2010
Pathways involved in myocardial postconditioning include all of the following except:
A. Reperfusion injury salvage kinase (RISK) pathway
B. MEK1/2-ERK pathway
C. PI3K-Akt pathway
D. GMP Shunt pathway
Answer: D. GMP Shunt pathway
Ischemic postconditioning, was initially described as a 44% reduction in infarct size with three cycles of 30 second occlusion – re-occlusion during reperfusion after a 60 minute occlusion of left anterior descending coronary artery in a dog model. The mechanism proposed is the upregulation of prosurvival kinases termed the reperfusion injury salvage kinase (RISK) pathway. PI3K-Akt and MEK 1/2-p42/44 kinases are important components of this cell survival pathway. These have anti-apoptotic effects.
Tsang A et al,Myocardial postconditioning: reperfusion injury revisited. Am J Physiol Heart Circ Physiol 289: H2-H7, 2005
Posted by: Johnson Francis on: 10 Jun, 2010
Maternal intake of lithium during pregnancy is associated with:
A. Tricupsid valve disease
B. Mitral valve disease
C. Aortic valve disease
D. Pulmonary valve disease
Answer: A. Tricupsid valve disease
Maternal intake of lithium during pregnancy has been associated with Ebstein’s anomaly of tricuspid valve.
Posted by: Johnson Francis on: 10 Jun, 2010
Vasoconstriction by endothelin is mediated by:
A. Activation of protein kinase C in vascular smooth muscle
B. Prostacyclin activation in vascular smooth muscle
C. Synthesis of EDHF in vascular endothelium
D. Acetyl choline mediated vasoconstriction
Answer: A. Activation of protein kinase C in vascular smooth muscle
Endothelins (ET-1, ET-2 and ET-3) are peptide endothelium dependent constricting factors. ET-1 is a potent vasoconstrictor and is formed from the precursor pre-pro-endothelin by endothelin converting enzyme. ET-A and ET-B receptors are present,of which ET-A receptor mediates vasoconstiction by activation of protein kinase C in vascular smooth muscle. ET-B mediated vasoconstriction is partially offset by ET-B mediated eNOS activity.
