Prospective Comparing the Efficacy of CT Colonography and Colonoscopy for Detecting Colorectal Adenomatous Polyp in Asymptomatic Adults / 대한소화기내시경학회지

BACKGROUND/AIMS: The purpose of this study is to evaluate the efficacy of CT colonography (CTC) in comparison with colonoscopy for the detection of colorectal adenomatous polyp in asymptomatic adults. METHODS: A total 208 asymptomatic adults underwent successive CTC and colonoscopy, on the same day. RESULTS: On the analysis of adenomatous polyps per subject, the sensitivity of CTC was 90% (9/10) in case of polyps > or =10 mm in size, and 67.7% (21/31) in case of polyps > or =6 mm in size. Those values of colonoscopy were 100% and 93.5%, respectively. The per-patient specificity of CTC was 98.0% (194/198) in case of polyps > or =10 mm in size and 88.1% (156/177) in case of polyps > or =6 mm in size. CTC missed 4 (3 flat adenomas and, 1 sessile adenoma) out of 17 adenomatous polyps > or =10 mm in size in 2 subjects. CONCLUSIONS: In asymptomatic adults, the sensitivity of CTC for detecting adenomatous polyps was lower than that of colonoscopy, particularly for the small lesions below 10 mm in size, and also for the flat adenomas > or = 10 mm in size. However, CTC showed a high sensitivity and specificity for detecting the subjects with clinically important colorectal adenomatous polyps > or = 10 mm in size. These results suggest that CTC has potential as a screening method for colorectal neoplasm.

Tyrosine phosphorylation of paxillin may be involved in vascular smooth muscle contraction

Paxillin is a regulatory component of the complex of cytoskeletal proteins that link the actin cytoskeleton to the plasma membrane. However, the role of paxillin during smooth muscle contraction is unclear. We investigated a possible role for the membrane-associated dense plaque protein paxillin in the regulation of contraction in rat aortic vascular smooth muscle. The tyrosine phosphorylation of paxillin, which was increased by norepinephrine, reached a peak level after 1 min stimulation and then decreased with time. However, norepinephrine induced a sustained contraction that reached a steady state 30 min after application. Pretreatment with tyrphostin, an inhibitor of tyrosine kinase, inhibited the tyrosine phosphorylation of paxillin and also the contraction stimulated by norepinephrine. Both inhibitions were concentration-dependent, and the degree of correlation between them was high. These results show that, in rat aortic smooth muscle, tyrosine kinase(s) activated by norepinephrine may phosphorylate the tyrosine residues of paxillin, thereby providing a source of regulation during vascular smooth muscle contraction.