With advances in computer performance, the use of high-resolution voxel models of the entire human body has become more frequent in numerical dosimetries of electromagnetic waves. Using magnetic resonance imaging, we have developed realistic high-resolution whole-body voxel models for Japanese adult males and females of average height and weight. The developed models consist of cubic voxels of 2 mm on each side; the models are segmented into 51 anatomic regions. The adult female model is the first of its kind in the world and both are the first Asian voxel models (representing average Japanese) that enable numerical evaluation of electromagnetic dosimetry at high frequencies of up to 3 GHz. In this paper, we will also describe the basic SAR characteristics of the developed models for the VHF/UHF bands, calculated using the finite-difference time-domain method.

mPer1, a mouse gene, is a homolog of the Drosophila clock gene period and has been shown to be closely associated with the light-induced resetting of a mammalian circadian clock. To investigate whether the rapid induction of mPer1 after light exposure is necessary for light-induced phase shifting, we injected an antisense phosphotioate oligonucleotide (ODN) to mPer1 mRNA into the cerebral ventricle. Light-induced phase delay of locomotor activity at CT16 was significantly inhibited when the mice were pretreated with mPer1 antisense ODN 1 hr before light exposure. mPer1 sense ODN or random ODN treatment had little effect on phase delay induced by light pulses. In addition, glutamate-induced phase delay of suprachiasmatic nucleus (SCN) firing rhythm was attenuated by pretreatment with mPer1 antisense ODN, but not by random ODN. The present results demonstrate that induction of mPer1 mRNA is required for light- or glutamate-induced phase shifting, suggesting that the acute induction of mPer1 mRNA in the SCN after light exposure is involved in light-induced phase shifting of the overt rhythm.

Because mitochondria play pivotal roles in both insulin secretion from the pancreatic beta cells and insulin resistance of skeletal muscles, we performed a large-scale association study to identify mitochondrial haplogroups that may confer resistance against or susceptibility to type 2 diabetes mellitus (T2DM). The study population comprised 2,906 unrelated Japanese individuals, including 1,289 patients with T2DM and 1,617 controls, and 1,365 unrelated Korean individuals, including 732 patients with T2DM and 633 controls. The genotypes for 25 polymorphisms in the coding region of the mitochondrial genome were determined, and the haplotypes were classified into 10 major haplogroups (i.e., F, B, A, N9a, M7a, M7b, G, D4a, D4b, and D5). Multivariate logistic-regression analysis with adjustment for age and sex revealed that the mitochondrial haplogroup N9a was significantly associated with resistance against T2DM (P=.0002) with an odds ratio of 0.55 (95% confidence interval 0.40-0.75). Even in the modern environment, which is often characterized by satiety and physical inactivity, this haplogroup might confer resistance against T2DM.

Although it has long been established that estrogen alters circadian rhythms in behavior, physiology, and reproductive functions in mammals, the molecular mechanism for these effects remains unknown. To explore the possibility that estrogen affects circadian rhythms by changing the expression of clock-related genes, we investigated the effects of chronic treatment with 17beta-estradiol (E2) on the expression of Per1 and Per2 genes in the brain (suprachiasmatic nucleus and cerebral cortex) and periphery (liver, kidney, and uterus) of ovariectomized rats by means of in situ hybridization and northern blotting. In the brain, E2 treatment advanced the peak of Per2 mRNA expression in the SCN; however, it failed to affect the rhythm of Per2 mRNA expression in the CX and Per1 mRNA expression in both the SCN and the CX. In nonreproductive peripheral tissues (liver and kidney), E2 delayed the phase and increased the amplitude of Per1 mRNA expression. In the reproductive tissues (uterus), biphasic rhythms in Per1 and Per2 mRNA were observed after E2 treatment. These findings suggest that the effects of estrogen are different between central and peripheral clock in the brain, and between reproductive and nonreproductive tissues in the periphery.

Reduced LA active EF (booster pump function) assessed by speckle tracking echocardiography independently predicts the risk of new-onset AF, suggesting a stronger association between LA functional remodelling and AF than between LA size and AF.