Association of heart rate variability with regional difference in senility death ratio: ALLSTAR big data analysis.

OBJECTIVES: Senility death is defined as natural death in the elderly who do not have a cause of death to be described otherwise and, if human life is finite, it may be one of the ultimate goals of medicine and healthcare. A recent survey in Japan reports that municipalities with a high senility death ratio have lower healthcare costs per late-elderly person. However, the causes of regional differences in senility death ratio and their biomedical determinants were unknown. In this study, we examined the relationships of the regional difference in senility death ratio with the regional differences in heart rate variability and physical activity. METHODS: We compared the age-adjusted senility death ratio of all Japanese prefectures with the regional averages of heart rate variability and actigraphic physical activity obtained from a physiological big data of Allostatic State Mapping by Ambulatory ECG Repository (ALLSTAR). RESULTS: The age-adjusted senility death ratio of 47 Japanese prefectures in 2015 ranged from 1.2% to 3.6% in men and from 3.5% to 7.8% in women. We compared these ratios with the age-adjusted indices of heart rate variability in 108,865 men and 136,536 women and of physical activity level in 16,661 men and 21,961 women. Heart rate variability indices and physical activity levels that are known to be associated with low mortality risk were higher in prefectures with higher senility death ratio. CONCLUSION: The regional senility death ratio in Japan may be associated with regional health status as reflected in heart rate variability and physical activity levels.

Prolactin and upstream migration of the amphidromous teleost, ayu Plecoglossus altivelis.

Changes in mRNA levels of prolactin (PRL) during the upstream migration were examined in fry of the amphidromous fish, ayu Plecoglossus altivelis. Quantification of mRNA has been done with real-time PCR and expressed as whole body or pituitary contents depending the body size of fry. PRL mRNA levels of ayu caught in seawater of the coastal area remained low during early spring. Prior to the start of the upstream migration, the fish caught in the coastal area in mid spring showed increased levels of PRL mRNA. There were further increases in PRL levels in the fish caught in the river. Analysis of proportions revealed that there were significant differences among PRL mRNA in the fish caught in different environmental salinities. Body weight showed a positive relation with PRL mRNA in ayu caught in seawater. A landlocked population of ayu, which migrates from lake to river, showed no significant change in PRL mRNA levels before and after upstream migration. Results in this study indicate the importance of up-regulation of PRL gene expression of ayu during the upstream migration from seawater to fresh water. There is a possible relationship between body size and PRL in the early developmental stage of ayu in seawater, but not in the fish in fresh water.

Changes in prolactin mRNA levels during downstream migration of the amphidromous teleost, ayu Plecoglossus altivelis.

Changes in mRNA levels of prolactin (PRL) during seaward migration and after experimental transfer from fresh water (FW) to seawater (SW) were examined in larvae of the amphidromous fish, ayu Plecoglossus altivelis. In the field study, ayu larvae caught in the surf zone showed lower levels of PRL mRNA than those in the river, while growth hormone (GH) levels showed no significant change. Decrease in PRL gene transcription was also observed 24h after direct transfer from FW to SW, whereas there was no significant influence of water temperature. On the other hand, there was no significant change in GH mRNA levels in relation to SW transfer or environmental temperature. In a raceway with a vertical salinity gradient, PRL mRNA levels of ayu larvae showed a significant reduction during spontaneous migration from FW to SW, which mimicked the results from the field observation and the transfer experiment, and then a gradual increase during the course of development. Whole body water and sodium contents of larvae in a salinity gradient were stable during migration to SW. Results in this study indicated the importance of regulation of PRL gene expression in the downstream migration and acclimation to SW during the early development of ayu.

Extracellular acidic environments induce phosphorylation of ZAP-70 in Jurkat T cells.

In solid tumor and inflammation loci, low pH conditions have been observed as a consequence of either a lack of sufficient vascularization or excess activity of tumor cells, and T cells have been reported to infiltrate tumors and inflammation sites. However, it remains unclear how extracellular acidic environments affect immune cell function. A previous report proposed that a different signal transduction cascade might occur under low pH conditions in Jurkat T cells (Fukamachi T, Saito H, Kakegawa T, Kobayashi H. Different proteins are phosphorylated under acidic environments in Jurkat cells. Immunol Lett 2002;82:155-8). In this study, we investigated the protein phosphotyrosine level in Jurkat and Jurkat mutant cells under different pH conditions. The ZAP-70 phosphorylation level increased under acidic environments. P38 MAPK was more activated at acidic pH. The level of active p38 was low in mutant P116 deficient in ZAP-70, and interestingly the level remained consistently low at all pH values tested. The activation of ERK was not stimulated at low pH. These results suggest that extracellular low pH stimulates or enhances TCR signaling via ZAP-70 and p38.