Isolation and characterization of novel microsatellite loci in the wrinkled frog.

The wrinkled frog, Rana rugosa, is a species complex that inhabits plains and mountains near freshwater bodies throughout East Asia, encompassing China, Korea, Japan, and the Russian Primorye region. Although extensive efforts are required to estimate cryptic diversity in the R. rugosa complex, no specifically designed microsatellite loci are available. Here, novel and polymorphic microsatellites were isolated based on the construction of a microsatellite-enriched library and characterized using R. rugosa specimens collected on the Korean Peninsula. A total of 72 primer sets were designed from approximately 400 positive clones, and 22 were validated as being reliably amplified and polymorphic. Overall, high genetic variability was observed (mean number of alleles per locus = 22.23; mean observed and expected heterozygosities = 0.770 and 0.816, respectively) from a total of 60 individuals sampled from two geographically isolated localities. In the two sites analyzed, an extremely low level of relatedness was inferred from the estimation of pairwise relatedness, and no evidence of a genetic bottleneck was detected. The two sites showed a high level of genetic differentiation, suggesting a clear signature of isolation following colonization. With high statistical power in parentage and sibship exclusion, these microsatellite loci will be suitable for the identification of cryptic diversity and population structure as well as the recognition of individuals in social interaction and captive breeding practice.

Genetic variants of AICDA/CASP14 associated with childhood brain tumor.

We conducted a hospital-based case-control study in Korea to investigate whether apoptosis- and cell cycle control-related genes are associated with childhood brain tumor. Incident brain tumor cases (N = 70) and non-cancer controls (N = 140), frequency-matched by age and gender, were selected from 3 teaching hospitals in Seoul between 2003 and 2006. Tag single nucleotide polymorphisms (SNPs) (N = 297) in 30 genes related to apoptosis and cell cycle control were selected using a pairwise linkage-disequilibrium-based algorithm. Five tag SNPs in 2 genes (AICDA and CASP14) remained significant after adjusted multiple tests. The most significant association with childhood brain tumor risk was for IVS1-401G>C in the AICDA gene [odds ratio (OR) = 2.8; 95% confidence interval (95%CI) = 1.25-6.46]; the polymorphism *9276A>C of CASP14 was associated with decreased brain tumor risk (OR = 0.4; 95%CI = 0.19-0.95). We concluded that genetic polymorphisms in AICDA and CASP14 are associated with risk for brain tumor in Korean children.

Routine radiographic screening of the chest in pregnant women: is it indicated?

Experience with routine antepartum chest radiographic screening from July 1, 1976, through June 30, 1977, in a city-county hospital which serves a predominantly black indigent population was reviewed. The 5422 routine screening chest radiographs produced an extremely low yield of pathology (11 cases), and only 3 of the 11 cases were not suspected from the history or physical examination. Only 2 cases of active pulmonary tuberculosis were discovered, and both patients were recent immigrants from countries with a much higher incidence of tuberculosis. This low case finding probably reflects the general decline in incidence of pulmonary tuberculosis in the United States and suggests that routine screening chest radiographs (done primarily to exclude tuberculosis) are no longer indicated in our pregnant population.