Rho-Associated Kinase 2 Polymorphism in Patients With Vasospastic Angina

BACKGROUND AND OBJECTIVES: Recent studies indicate that in response to vasoconstrictor stimuli, the small GTPase RhoA and its down-stream effector, Rho-associated kinase 2 (ROCK)/Rho-kinase, are associated with hypercontraction of the vascular smooth muscle of coronary arteries through augmentation of myosin light chain phosphorylation and Ca2+ sensitization. Expression of ROCK/Rho-kinase mRNA was significantly increased and up-regulated in the spastic coronary artery in a porcine model, and a specific inhibitor of ROCK/Rho-kinase inhibited coronary artery spasm in humans. We therefore explored the role of ROCK2 polymorphisms in the pathogenesis of vasospastic angina (VA). SUBJECTS AND METHODS: We studied 106 patients with VA who exhibited spontaneous or provoked coronary spasm during coronary angiography and compared the prevalence of ROCK2 polymorphisms between this group of patients with VA and controls whose angiograms were normal, and in whom the ergonovine test did not cause spasm (n=107). Five single nucleotide polymorphisms (SNPs) of the ROCK2 gene were selected. SNPs were genotyped by high-resolution melting. Linkage disequilibrium and haplotype analyses were performed using the SHEsis program. RESULTS: The prevalence of genotypes of the 5 interesting SNPs in patients with VA was not different from that in the control group. In haplotype analysis, the haplotype G-T-C-T-G (in order of rs978906, rs2271621, rs2230774, rs1515210, and rs3771106) was significantly associated with a decreased risk of VA (p=0.007). CONCLUSION: The haplotype G-T-C-T-G in the ROCK2 gene had a protective effect against VA, suggesting the involvement of ROCK2 in VA pathogenesis.

Epidemiologic Trends of Rotavirus Infection in the Republic of Korea, July 1999 through June 2002 / 대한진단검사의학회지

BACKGROUND: Rotavirus is the most common cause of childhood diarrhea worldwide. Although rotavirus is also the leading cause of infant and childhood diarrhea in Korea, much remains unknown about the trends of rotavirus infection by month and geographic region in Korea. To monitor epidemiologic trends of rotavirus infection, a laboratory-based rotavirus surveillance network was established in 2002. This is the first nationwide, multicenter evaluation of rotavirus epidemiology in Korea. METHODS: The rotavirus test results were collected retrospectively from eight network laboratories, from July 1999 to June 2002. Four laboratories used latex agglutination, three used immunochromatography, and one used enzyme-linked fluorescent assay for the detection of rotavirus antigen. RESULTS: Of 10, 441 stool specimens, 2, 496 (23.9%) were positive for rotavirus. During the 3-year period, the rotavirus season began in December-January, and ended in April-May. The rotaviruspositive percentage of summer, autumn, winter, and spring was 11.5%, 10.0%, 32.8%, and 30.0%, respectively. A few hospitals revealed summer epidemics. The rotavirus positive rate in each hospital varied from 15.3% to 44.2%. A common feature of the three hospitals showing the lowest rotavirus-positive percentage (i.e. 800 beds). The secondary care hospitals showed a higher positive proportion (27.5%) compared with tertiary care hospitals (21.1%). CONCLUSIONS: Overall, the rotavirus-positive percentage among all diarrheal specimens was similar to that of other developed countries. The results of this study showed that the autumn epidemic of the rotavirus has declined or disappeared and the peak season for rotavirus has shifted to late winter/early spring in Korea.