Proportion of treatment effect mediated by surrogate endpoints.

One of the central aims in randomized clinical trials is to find well-validated surrogate endpoints to reduce the sample size and/or duration of trials. Clinical researchers and practitioners have proposed various surrogacy measures for assessing candidate surrogate endpoints. However, most existing surrogacy measures have the following shortcomings: (i) they often fall outside the range [0,1], (ii) they are imprecisely estimated, and (iii) they ignore the interaction associations between a treatment and candidate surrogate endpoints in the evaluation of the surrogacy level.

Genome-wide association study using the ethnicity-specific Japonica array: identification of new susceptibility loci for cold medicine-related Stevens-Johnson syndrome with severe ocular complications.

A genome-wide association study (GWAS) for cold medicine-related Stevens-Johnson syndrome (CM-SJS) with severe ocular complications (SOC) was performed in a Japanese population. A recently developed ethnicity-specific array with genome-wide imputation that was based on the whole-genome sequences of 1070 unrelated Japanese individuals was used. Validation analysis with additional samples from Japanese individuals and replication analysis using samples from Korean individuals identified two new susceptibility loci on chromosomes 15 and 16.

A proposal for improvement of genotyping performance for ethnically homogeneous population using DNA microarray.

DNA microarray is used to determine the genotypes of several hundred thousand to several million SNPs (Single Nucleotide Polymorphisms) on multiple samples at a time. In the conventional method of genotyping using DNA microarray, it is assumed that each SNP has three types of genotypes: two homozygous and one heterozygous genotypes. However, in an ethnically homogeneous population, there are cases when all the samples of a SNP belong to one homozygous genotype, and there are some other cases, especially in the SNPs of low MAFs (Minor Allele Frequencies), each sample belongs to either of the two genotypes: one homozygous and one heterozygous genotypes.

Terrestrial gamma radiation dose rate in Ryukyu Islands, subtropical region of Japan.

In order to explain the distribution of natural radiation level in the Asia, in situ measurements of dose rate in air due to terrestrial gamma radiation have been conducted in a total of 21 islands that belong to Ryukyu Islands (Ryukyu Archipelago), subtropical rejoin of southwest Japan. Car-borne surveys have also been carried out in Okinawa-jima, the biggest island of the archipelago. Based on the results for these measurements, arithmetic mean, the maximum and the minimum of the dose rates at 1 m in height from the unpaved soil ground in the archipelago were estimated to be 47, 165 and 8 nGy h(-1), respectively.

Mitigation of the effective dose of radon decay products through the use of an air cleaner in a dwelling in Okinawa, Japan.

Field measurements were conducted to assess the effects of an air cleaner on radon mitigation in a dwelling with a high radon concentration in Okinawa, Japan. The measurements included indoor radon concentration, individual radon progeny concentration, equilibrium equivalent concentration of radon (EECRn), unattached fraction, and size distribution of aerosol-attached radon progeny. These measurements were conducted in a 74 m(3) room with/without the use of an air cleaner.