Objective: In the present study, we investigated the effects of enveloping-airflow air conditioner on health maintenance and fatigue in healthy volunteers. The enveloping airflow is that of gently holding the whole room space along the ceiling, wall, and floor.
Design: In a randomized placebo-controlled crossover trial, 10 healthy women who had feeling cold, stiff shoulder and knee pain very often under air conditioner working, participated in the study. They performed fatigue-inducing desk work for 2 hours, and rested for 30 minutes in the air conditioned room controlled by enveloping airflow or direct airflow.
Methods: We evaluated subjective sensation by Visual Analogue Scale (VAS), peripheral blood flow by laser-Doppler flowmetry, and body temperature.
Result: The enveloping airflow prevented hypothermia, increased blood flow, moreover attenuated feeling of cold, knee pain and fatigue, increased sensation of comfort as compared with the direct air flow.
Conclusion: Enveloping-airflow air conditioner is effective in maintaining health and attenuating fatigue.

Objective According to a survey conducted by the Japanese Ministry of Health, Labor and Welfare in 2002, 72% of workers feel fatigued, clearly indicating the degree to which the Japanese populace is affected by this problem. However, few scientifically proven anti-fatigue devices have been developed for the benefit of the Japanese society. An automated air massage chair provides soft stimulation with air bags, not spot stimulation with knead balls, over the muscle surface with movements that push the muscles upward. In the present study, using established methods to evaluate fatigue, we investigated the effect of this automated air massage chair on fatigue in healthy volunteers.
Method Ten healthy subjects participated in a randomized two-way crossover trial. As fatigue-inducing desk work, subjects performed 8 sets of a 30-min Uchida-Kraepelin psychodiagnostic test and 30-min advanced trail making test (ATMT) during the test day. Subjects rested 15 min on the air massage chair or control chair 4 times: immediately before and at 4, 6 and 8 hours after the start of the workload. We evaluated the subjective feeling of fatigue by visual analogue scale, work performance by ATMT, and analyzed underlying mechanisms by biochemical parameters in saliva and urine.
Result Stimulation by air massage chair alleviated the subjective sensation of fatigue and suppressed the decline in work performance. Furthermore, increase in salivary amylase activity and decrease in urine homovanillic acid/creatinine ratio was suppressed.
Conclusion Automated air massage chair attenuated fatigue induced by desk work, most likely by correcting the imbalance in the autonomic nervous system. The air massage chair is thus recommended for relieving fatigue induced by work and daily activities.

Objective Enveloping airflow, as opposed to direct airflow, warms the room by gently circulating the airflow along the floor, wall, and ceiling, thereby uniformly warming the entire room. The objective of our study was to determine the effects of air-conditioned heating by enveloping-airflow on sense of fatigue and comfort in healthy volunteers.
Design Eight healthy women, who often felt discomfort in an air-conditioned heating environment, participated in a randomized placebo-controlled crossover trial. Subjects rested for 30 minutes in a room air-conditioned either by enveloping airflow or by direct airflow, and then performed fatigue-inducing tasks for 2 hours.
Methods We evaluated the sense of fatigue by visual analogue scale (VAS), peripheral blood flow by laser-Doppler flowmetry, and sympathetic nerve activity by urinary vanillylmandelic acid level.
Result Air conditioning by enveloping-airflow, as compared to direct airflow, enhanced peripheral blood flow and attenuated sympathetic nerve hyperactivity caused by performing fatigue-inducing tasks. Moreover, it helped to maintain subjective levels of motivation and comfort, as well as to alleviate sense of fatigue and cold.
Conclusion Air-conditioned heating by enveloping-airflow is effective for attenuating sense of fatigue and discomfort as well as health maintenance.

Metabolic acidosis is one of the most common complications of chronic kidney disease (CKD). It is associated with the progression of CKD, and many other functional impairments. Until recently, only serum bicarbonate levels have been used to evaluate acid-base changes in patients with reduced kidney function. However, recent emerging evidence suggests that nephrologists should reevaluate the clinical approach for diagnosing metabolic acidosis in patients with CKD based on two perspectives; pH and anion gap. Biochemistry and physiology textbooks clearly indicate that blood pH is the most important acid-base parameter for cellular function. Therefore, it is important to determine if the prognostic impact of hypobicarbonatemia varies according to pH level. A recent cohort study of CKD patients showed that venous pH modified the association between a low bicarbonate level and the progression of CKD. Furthermore, acidosis with a high anion gap has recently been recognized as an important prognostic factor, because veverimer, a nonabsorbable hydrochloride-binding polymer, has been shown to improve kidney function and decrease the anion gap. Acidosis with high anion gap frequently develops in later stages of CKD. Therefore, the anion gap is a time-varying factor and renal function (estimated glomerular filtration rate) is a time-dependent confounder for the anion gap and renal outcomes. Recent analyses using marginal structural models showed that acidosis with a high anion gap was associated with a high risk of CKD. Based on these observations, reconsideration of the clinical approach to diagnosing and treating metabolic acidosis in CKD may be warranted.