[Background]

Previous studies have presupposed the requirement of whole - body bathing after exercise; however, the physiological response when choosing different bathing conditions after exercise is unknown. The purpose of this study was to perform full - body bathing and shower after intense exercise and to examine how differences in bathing conditions affect the quality of subsequent sleep.

[Methods]

Subjects were 20 students who exercised for 3 hours a week for 2 hours or more. After intense exercise, they took a full immersion bath at 38℃ for 15 minutes (full bath condition) and a shower bath at 38℃ for 15 minutes (shower condition). Then, the subjects were allowed to go to bed for 7 hours from 00:00.

[Results]

For 30 minutes before going to bed, the parasympathetic nervous system was superior in the shower bath condition than in the full bath condition. Along with the autonomic nervous activity, we found that sleep, N2, and N3 latencies tended to be shorter in the full bath condition than in the shower condition.

[Conclusion]

This study clarified that the implementation of full body bath after intense exercise calms the excitation of the autonomic nervous system over time and may lead to smooth sleep onset. However, no statistical difference was found, and advanced further research with a larger sample size is necessary in the future.

[Background]

Sudden death in the bathroom (bath-related death) occurs quite frequently in Japan, and has been recognized as a critical social problem. However, the accurate process to the death has remained unclear. In this study, we investigated the gene expression of the lung varying in the process of hot water drowning by comprehensive DNA microarray analyses.

[Methods]

Agilent Array analysis (TaKaRa bio) was performed using the total RNA extracted from lung of hot water drowning mice (38 or 41℃). Ratio of target gene expression in study group to that in control group (sacrificed by cervical dislocation) is over 1.5 or under 0.66 as a statistically significant difference.

[Results and Discussion]

There were 793 or 743 genes whose pulmonary expression was varied significantly in 38 or 41℃ water drowning mice, respectively. Those varied genes in both temperature conditions were divided into 3 groups: (A) Aquaporins/Osmoreceptors including aqp (aquaporin) 2, aqp4, aqp11, trpm1(transient receptor potential cation channel, subfamily M, member1), (B) Heat shock proteins including kbp5(FK506 binding protein 5), hsp90ab1, hspa1l, hspb1, hspb8, and (C) Hypoxia-inducible proteins including hif1an(hypoxia-inducible factor1, alpha subunit inhibitor), egln3(egl-9 family hif3). There were numerous candidate genes whose expression has not been investigated by quantitative real-time PCR analysis. In future, I would like to establish a molecular biological diagnosis of hot water drowning based on those various gene expression profiles.

[Background]

Some basic and clinical studies revealed that the activity of autonomic nerves do not change to the same direction under the alteration of internal and external environments, indicating the importance of investigating the activity in several organs and tissues simultaneously. Recently, several clinical studies reported the efficacy of pupil light reflex (PLR) and heart rate variability (HRV) to evaluate stressor-induced autonomic function alteration. Up to now, some studies reported increased parasympathetic activity of HRV by foot bath, but no studies reporting the efficacy using PLR test. The aim of our current study is to investigate efficacies of foot bath on autonomic function using PLR and HRV tests.

[Methods]

To investigate the efficacy of foot bath on autonomic function, healthy 40 men enrolled in our current study. In PLR, we prepared four different stimulus intensities. We performed PLR and HRV tests before and during foot bath to all subjects. Repeated measures two-way ANOVA and paired t-test were performed in PLR and HRV analysis, respectively.

[Results]

Foot bath affected autonomic activity of PLR, but not of HRV. PLR showed increased parasympathetic activity by foot bath. In addition, minimum pupil diameter (peak of constriction), absolute constriction amplitude and averaged dilation velocity showed significant interactions (intervention×stimulus intensity of PLR), indicating that different stimulus intensities of PLR can be effective for investigating the efficacy of foot bath on the autonomic activity.

[Conclusion]

This study showed that HRV and PLR tests can be useful to reveal efficacies of foot bath on autonomic function.

[Background]

Depression is one of major causes of functional decline among older people. In this prospective longitudinal study, we aimed to investigate the association between tub-bathing frequency and the incidence of depressive symptoms among older people in Japan.

[Methods]

We recruited 4,466 participants (2,159 men and 2,307 women), who completed both 2010 and 2013 questionnaires of the Japan Gerontological Evaluation Study, be independent in activities of daily living, and not depressed in 2010, which was defined as Geriatric Depression Scale (GDS) <5. We classed tub-bathing frequency in 2010 as 0-6 times/week and 7 or more times/week in summer and winter, respectively. Participants were observed the incidence of depressive symptoms (GDS >=5) in 2013. We estimated the incidence rate ratios of depressive symptoms according to the tub-bathing frequency separately in summer and winter by using the Poisson regression analysis adjusting for 7 potential confounders: age, sex, marital status, employment status, equivalized income, years of education, and treatment for any disease.

[Results]

After adjustment for potential confounders, the incidence rate ratios (95% confidence interval) of the participants bathing 7 or more times/week compared with those bathing 0-6 times/week were 0.84 (0.71-1.00) for summer, and 0.77 (0.65-0.91) for winter.

[Discussion]

Our main finding was that participants who took baths more frequently were less likely to be depressed after 3 years. Therefore, tub-bathing might be beneficial for older people’s mental health.

[Background]

We have conducted the climatotherapy study in the mountain region of Fukui, based on the method developed by the research team of University of Munich. The aim of this study was to compare the core temperature, and physical strength between before and after the two months’ climatotherapy programme in the seaside region.

[Methods]

The subjects of this study were local residents with complaint of sensitive to cold living in Amami Oshima Island. Medical interview by the balneotherapy and industrial physician, Health check, physical fitness tests, and questionnaires about exercise habit, QOL, and occupation were conducted before and after climatotherapy programme. This programme consisted of climatic terrain cure with slightly cool condition and hot and cold stimuli using steamed towel on scapular region and lower back.

[Results]

Three healthy female workers, 40-53 yrs., were participated in this programme. An axillary temperature rose 0.3 degree under dairy steamed towel using. All participants’ records of one leg standing test and time up-and-go test were improved. Pulse rates in all of exercise bike load were descended by two 4 km climatic terrain cure sessions a week.

[Conclusion]

This study results suggest that the elevation of core temperature by daily hot and cold stimuli using steamed towel, and the improvement of balance ability of legs and endurance capacity by climatic terrain cure in Amami Oshima Island.

[Background]

Radiation dose is necessary as an exposure amount to evaluate effects of radon spa therapy. To discuss the distribution of its progeny (Pb-214) in the body that were generated by inhaled radon (Rn-222), we focused here on the progeny (Pb-212) of thoron (Rn-220) that is an isotope of radon and then exposed mice to thoron.

[Methods]

Thoron-rich air generated with its source of mantle was introduced to a mouse cage. Blood, liver, kidney and muscle, feces and urine were taken following the thoron exposure to mice. The activity concentrations of them were measured with gamma-ray spectrometry

[Results]

The activity concentrations of Pb-212 in blood, liver, kidney and urine were generally in the same order of magnitude. That in feces was higher by anther order.

[Conclusion]

It was found that the present exposure condition allows us to significantly detect Pb-212 in organs of mice exposed. To make the accuracy of data better, it was also found that the attachment of Pb-212, generated by the decay of thoron in air space of a mouse cage, onto the surface of feces should be examined.

[Background]

The Ministry of the Environment in Japan disclosed Research Project for the “ONSEN stay” Effects (hereafter referred to as “the project”). In this study, we performed a pilot study of the project at hot spring areas in Mie Prefecture as standard area. Because, Mie Prefecture have about 200 hot springs and this number is moderate in Japan. This study aimed to validate the adequacy of the project and flesh out its benefits and drawbacks. Furthermore, this study used the gathered data to statistically analyze subjective changes in the participant’ health conditions.

[Methods]

Participants in this study were adult users of 14 hot spring facilities from July to December 2018. This investigation uses the unified survey form of the stated project, which includes 11 items pertaining to subjective health conditions before and after staying in the hot spring areas. A total of 537 responses were gathered. We compared the data in each facility with a control group (Total of the whole of the hot spring facilities in Mie Prefecture excluding the facilities targeted this time) using a chi-squared test.

[Results]

Significantly high scores were observed in nine (e.g., “get healthy,” “become less stressed”) of 11 items in a public hot spring facility in the Sakakibara hot spring area.

[Conclusion]

There were significant differences in some of the investigated items, with a variety of factors involved, including hot spring quality and the condition of the hot spring facilities. The results in this study indicate the possibility that contributes to find the study seeds relevant to effects with staying hot spring area.

[Background]

Atopic dermatitis is a chronic, relapsing, intensely pruritic inflammatory skin disorder and it is difficult to completely cure. Recently, the therapeutic effect on atopic dermatitis by Toyotomi hot spring bathing has been reported. Therefore, the current study aimed to elucidate a mechanism of the effect.

[Methods]

In this study, a mouse model of atopic dermatitis was used. The therapeutic effect on atopic dermatitis of Toyotomi hot spring bathing and/or applying the oil that derived from Toyotomi hot spring was evaluated by comparing of severity scoring of atopic dermatitis (SCORAD).

[Results]

The value of SCORAD was tended to decrease in oil applying group as compared with the control group.

[Consideration]

The results in this study suggested some compound that has the therapeutic effect on atopic dermatitis is included in the oil derived from Toyotomi hot spring.