👤 K Shimokata

The apolipoprotein E ε4 (APOE ε4) allele, a major genetic risk factor for Alzheimer's disease, is associated with early atrophy in the precuneus and posterior cingulate cortex. Whether physical activity can mitigate this atrophy in high-risk APOE ε4 carriers remains unclear. This study aimed to determine whether physical activity can reduce such neurodegenerative changes in older adults carrying this allele. This 10-year longitudinal study included 295 community-dwelling older adults (154 men and 141 women; age ≥65 years). Baseline physical activity was measured using accelerometers and analyzed according to activity intensity. Participants were categorized as APOE ε4 carriers or non-carriers. Volumes of the precuneus and posterior cingulate cortex were assessed using longitudinal magnetic resonance imaging. Sex-stratified linear mixed models examined the interaction between physical activity and APOE ε4 status on brain volume changes, adjusting for relevant covariates. The moderate-to-vigorous physical activity (MVPA) × APOE ε4 × year effect in women's left precuneus was significant unadjusted but not after false discovery rate (FDR; 16 models) and exploratory. Left precuneus volume declined significantly over 10 years regardless of MVPA level or APOE ε4 genotype (each p < 0.0001). However, among APOE ε4 carriers, greater time spent in MVPA slowed the rate of volume decline. No similar effect was observed in men. Higher habitual MVPA may be associated with slower left precuneus decline in APOE ε4-positive women. As this exploratory three‑way effect was FDR‑nonsignificant, targeted replication is needed to clarify the role of everyday activity in genetically vulnerable groups. Show less

Hypertension is a complex multifactorial disorder that is thought to result from the interaction between genetic background and environmental factors. Although various loci and genes have been implicated in the predisposition to hypertension by genetic linkage analyses and candidate gene association studies, the genes that confer susceptibility to this condition remain to be identified definitively. We have now examined the relation of five candidate gene polymorphisms to blood pressure (BP) and the prevalence of hypertension in an 8-year population-based longitudinal cohort study. The 2267 subjects (1128 women, 1139 men) were aged 40-79 years and were randomly recruited to a population-based prospective cohort study of aging and age-related diseases in Japan. BP was measured after subjects had rested in a sitting position for at least 15 min. Genotypes for the -765G↷C polymorphism of PTGS2 and the 67G↷A (Ala23Thr) polymorphism of CCL11 were determined using a fluorescence-based allele-specific DNA primer assay system, and those of the 1444T↷C (3'-UTR) polymorphism of CRP, the -1131T↷C polymorphism of APOA5 and the 1425G↷A (Val374Ile) polymorphism of PRKCH using melting curve analysis. Longitudinal analysis of the relation between systolic or diastolic BP and the five polymorphisms with a mixed-effect model revealed that the polymorphism of CRP was significantly related to systolic BP in all subjects, that of APOA5 to systolic BP in men, and that of PRKCH to diastolic BP in women. Longitudinal analysis of the relation between the prevalence of hypertension and the five polymorphisms with a generalized estimating equation revealed that the CRP, APOA5 and CCL11 polymorphisms were significantly related to the prevalence of hypertension in men, the PTGS2 polymorphism to its prevalence in all subjects, and the PRKCH polymorphism to its prevalence in all subjects and in women. The APOA5 and PRKCH polymorphisms were thus associated with both BP and the prevalence of hypertension in men and women, respectively. These results suggest that the APOA5 and PRKCH polymorphisms are determinants of BP and the development of hypertension in Japanese men and women, respectively. Show less

We report a Japanese boy who died at Day 28 of life because of severe carbamoyl phosphate synthetase I (CPS1) deficiency that was proven by enzyme assay. By analysis of cDNA and genomic DNA, he was shown to be a compound heterozygote with two point mutations of the CPS1 gene, 840G>C leading to an aberrant splicing and 1123C>T (predicting Q375X). The 840G>C was a mutation described in another Japanese family. Since his parents carried each mutation heterozygously, we performed prenatal diagnosis at 16 weeks of his mother's next gestation by multiplex PCR and melting curve analysis in a single capillary containing two-color fluorescent (LC-Red 640 and LC-Red 705) probes on LightCycler. We analyzed genomic DNA extracted from amniotic cells and found that the fetus was homozygous for the wild-type alleles. At term a healthy girl was born without hyperammonemia. Show less