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To examine the effects of micro mist sauna bathing, produced by water crushing method, we exposed ten male subjects to five cases of micro mist sauna, namely (1) room temperature (RT) 38 °C with 100 % (actually 91 %) relative humidity (RH), (2) RT 41.5 °C with 80 % (actually 81 %) RH, (3) RT 41.5 °C with 100 % (actually 96 %) RH, (4) RT 45.0 °C with 64 % (actually 61 %) RH, and (5) RT 45.0 °C with 100 % (actually 86 %) RH, and measured tympanic temperature, mean skin temperature, heart rate (HR), and cheek moisture content, as well as ratings of thermal and sweating sensation tympanic temperatures at RT 45 °C were significantly higher at 86 % RH than those at 61 % RH; however, those at RT 45 °C with 61 % RH were higher than those with 86 % RH during recovery. There were no significant differences at RT 41.5 °C between with 81 % RH and with 96 % RH. Mean skin temperature was the highest at RT 45 °C 86 % RH case, followed by at RT 41.5 °C 96 % RH, RT 45 °C 61 % RH, RT 41.5 °C 81 % RH, and finally at RT 38 °C 91 % RH. HR change showed the same order as for mean skin temperature. A significant difference in cheek moisture content was observed between RT 41.5 °C with 81 % RH and RT 45 °C with 86 % RH 10 min after the micro mist bathing. There were no significant differences between ratings of thermal sensation at RT 41.5 °C with 81 % RH and at RT 45 °C with 61 % RH and RT 45 °C with 61 % RH and RT 45 °C with 86 % RH. Between RT 45 °C with 86 % RH and RT 41.5 °C with 81 % RH, there was a tendency for interaction (0.05 < p < 0.1). Other cases showed significant higher ratings of thermal sensation at higher room temperature or higher relative humidity. The ratings of sweating sensation 10 min after the mist sauna bathing were significantly higher at higher RT and RH except between RT 41.5 °C 96 % RH and RT 45 °C 86 % RH which exhibited no significant difference. We concluded that the micro mist sauna produced by water crushing method induced more moderate and effective thermal effect during micro mist sauna bathing than the conventional mist sauna bathing. In addition, micro mist sauna is as effective for heating the human subjects as bathtub bathing as well as more moderate thermal and sweating sensations.

Objective Arousal stimuli evoke bursts of skin sympathetic nerve activity (SSNA). SSNA usually contains sudomotor and vasoconstrictor neural spikes. The aim of this study was to elucidate which components of event-related potentials (ERPs) are related to sudomotor and vasoconstrictor responses comprising arousal SSNA bursts. Methods We recorded SSNA from the tibial nerve by microneurography, with corresponding sympathetic skin response (SSR), sympathetic flow response (SFR), and ERPs in 10 healthy subjects. Electrical stimulation of the median nerve was used to induce arousal responses. ERPs were classified by the occurrence of SSR and SFR. Results SSNA bursts followed by SSR were associated with larger P300 than SSNA bursts followed by no SSR. For N140, no difference in the amplitude was found between SSNA bursts with and without SSR. SSNA bursts followed by SFR were associated with larger N140 than SSNA bursts followed by no SFR. However, there were no differences in the amplitude of P300 between SSNA bursts with and without SFR. Conclusions Sudomotor and skin vasoconstrictor responses to arousal stimuli were differently associated with distinct ERP components. Significance The possibility that sudomotor and skin vasoconstrictor activities comprising arousal SSNA reflect different stages of the cognitive process is suggested.

High tolerance to postural changes was examined in nurses. Twelve female nurses and 12 healthy controls underwent a 70° head-up tilt (HUT) test for 10 min. Blood pressure (BP), heart rate (HR), pulse pressure, and hormone levels were measured. Baroreceptor sensitivity (BRS) was calculated using a sequence technique. HR increased during HUT in both subject groups, with no difference between groups. Systolic BP was rapidly increased by HUT in both subject groups, and was higher in the nurse group than in the control group during the first 2 min of HUT. Pulse pressure decreased during 1–2.5 min of HUT in the control group, but there was no decrease in the nurse group. BRS was decreased by HUT in the nurse group, while it tended to be decreased in the control group. Both during baseline and HUT, BRS was lower in the nurse group than in the control group. Plasma noradrenaline increased with HUT, and the increase was greater in the nurse group than in the control group. Although nurse subjects had a lower BRS during HUT than control subjects, they were able to effectively maintain BP during HUT, suggesting that nurse subjects had higher orthostatic tolerance. The better maintenance of BP in nurse subjects appeared to be associated with a compensatory mechanism other than the arterial baroreflex and/or a hemodynamic mechanism.

The risk of developing metabolic syndrome, hypertension, type 2 diabetes, and hyperlipidemia increases with obesity, and an elevated visceral fat content has been associated with a higher incidence of metabolic risk factors. We investigated differences in IL-6 (Interleukin-6), TNF-α (tumor necrosis factor-α), adiponectin and FFA (free fatty acid) levels in obese and non-obese Japanese men. Five obese men (BMI: 32.4±4.9 kg/m) and five non-obese men (BMI: 23.2±2.9 kg/m 2 ) participated in this study.IL-6 levels were significantly higher in obese than in non-obese subjects, whereas no significant differences were observed in TNF-α, adiponectin, or FFA levels. These results suggested that IL-6 levels may be affected more by obesity in Japanese men than TNF-α and adiponectin levels, which may, in turn, influence the pathophysiology of obesity in Japanese individuals. Short Communication Sato et al.; BJMMR, 7(2): 131-137, 2015; Article no.BJMMR.2015.316 132

Skin sympathetic nerve activity (SSNA) is microneurographically recorded from the skin nerve fascicle in the peripheral nerves with properties of an irregular, pulse asynchronous burst with respiratory variation, followed by sweating and/or vasoconstriction, elicited by mental stress and arousal stimuli. It comprises sudomotor and vasoconstrictor nerve activities as well as vasodilator ones. SSNA function in thermoregulation in humans, however, is also elicited by mental stress or cognition. SSNA is lowest at thermoneutral temperature and enhanced in the presence of ambient warm and cool air. Burst amplitude is well correlated to sweat rate change or skin blood flow reduction rate. The clinical application of SSNA comprises the following: (1) clarification of sweating events, (2) clarification and diagnosis of anhidrosis or hyperhidrosis, (3) clarification of thermoregulatory function and diagnosis of thermoregulatory disorder, (4) clarification of pathophysiology and diagnosis of vascular disorders, (5) clarification of the relationship between cognitive function and SSNA, and (6) determination of pharmacological effects attributable to change in neuroeffector responses. Lastly, SSNA’s significance as a feedforward thermoregulatory tool is discussed since SSNA contributes more to rapid thermoregulatory response than thermoregulation using convectional thermotransmission. Especially feedforward thermoregulatory sweating response is estimated to be highly phylogenetic than vasoconstrictive response.

During the past several decades, obesity has been increasing globally. In Japan, obesity is defined by a BMI of 25 kg/m² or over; 28.6 % of men and 20.6 % of women are obese. Obese people have an increased incidence of developing cardiovascular, renal, and hormonal diseases and sleep disorders. Obese people also have shortened sleep durations. We investigated seasonal differences in melatonin concentrations, heart rates, and heart rate variability during sleep in obese subjects in Japan. Five obese (BMI, 32.0 ± 4.9 kg/m²) and five non-obese (BMI, 23.2 ± 2.9 kg/m²) men participated in this study in the summer and winter. Electrocardiograms were measured continuously overnight in a climatic chamber at 26 °C with a relative humidity of 50 %. Saliva samples for melatonin were collected at 2300 hours, 0200 hours, and 0600 hours. We found that melatonin concentrations during sleep in obese subjects were significantly lower than those in non-obese subjects in the winter. Heart rate during sleep in winter was significantly higher than that in summer in both obese and non-obese subjects. Heart rate variability was not significantly different in the summer and winter in both obese and non-obese subjects. Our results show that decreased nocturnal melatonin concentrations during winter in obese men may be related to higher heart rates, and this may suggest that obese men are at an increased risk of a cardiovascular incident during sleep, especially in the winter.

Obese subjects may be more vulnerable to injury from heat stress, and appear to be less efficient at thermoregulation. Sweat rate, tympanic temperature and osmolality in obese subjects were investigated in Japan during two seasons. The purpose of this study was to examine the relationship between obesity, thermoregulatory response and season. Five obese (BMI, 32.0 ± 4.9 kg/m²) and five non-obese (BMI, 23.2 ± 2.9 kg/m²) men participated in this experiment at latitude 35°10' N and longitude 136°57.9'E. The average atmospheric temperature was 29.1 ± 1.0 °C in summer and 3.3 ± 1.4 °C in winter. Tympanic temperature and sweat rate were measured during leg water immersion at 42 °C for 30 min. Blood samples were analyzed for plasma osmolality. The relationship between tympanic temperature and sweat rate decreased significantly in obese compared to in non-obese subjects in both seasons, there being a lowered sweat rate for any core temperature in obese subjects. Plasma osmolality was significantly higher in obese than in non-obese subjects in both seasons. Thermal sensation increased significantly in non-obese than in obese in winter but not in summer. Our data show that thermoregulatory responses are attenuated in obese subjects compared with controls, suggesting that obese people are at increased risk of heat-related illnesses.

Heat acclimation results in whole body-adaptations that increase heat tolerance, and might also result in changed immune responses. We hypothesized that, after heat acclimation, tumor necrosis factor alpha, interleukin 6 and the lymphocyte count would be altered. Heat acclimation was induced in 6 healthy men by 100 min of heat exposure for 9 days. Heat exposure consisted of (1) 10 min of immersion up to chest-level in water at 42°C and (2) 90 min of passive heating by a warm blanket to maintain tympanic temperature at 37.5°C. The climatic chamber was maintained at 40°C and a relative humidity of 50%. Blood samples were analyzed before and after heat acclimation for natural killer (NK) cell activity, counts of lymphocytes B and T, before and after heat acclimation for peripheral blood morphology, interleukin 6, tumor necrosis factor alpha, and cortisol. A Japanese version of the profile of mood states questionnaire was also administered before and after acclimation. The concentrations of white blood cells, lymphocytes B and T, cortisol, interleukin 6, tumor necrosis factor alpha and NK cell activity showed no significant differences between pre- and post-acclimation, but there was a significantly lower platelet count after acclimation and, with the profile of mood states questionnaire, there was a significant rise in anger after acclimation. It is concluded that heat acclimation by passive heating does not induce alterations in immune or endocrine responses.

Physiological functions are impaired in various organs in aged people, as manifest by, e.g., renal and cardiac dysfunction and muscle atrophy. The elderly are also at increased risk of both hypothermia and hyperthermia in extreme temperatures. The majority of those over 65 years old have elevated serum osmolality. Our hypothesis is that the elderly have suppressed osmolality control in different seasons compared to the young. Eight healthy young men and six healthy older men participated in this study. The experiments were performed during spring, summer, autumn and winter in Japan, with average atmospheric temperatures of 15-20°C in spring, 25-30°C in summer, 15-23°C in autumn and 5-10°C in winter. Each subject immersed his lower legs in warm water at 40°C for 30 min. Core (tympanic) temperature and sweat rate at chest were recorded continuously. Blood was taken pre-immersion to measure the concentrations of antidiuretic hormone, serum osmolality, plasma renin activity, angiotensin II, aldosterone, leptin, thyroid stimulating hormone, fT(3) and fT(4). The results suggested that the elderly have suppressed osmolality control compared to the young; osmolality was especially elevated in winter compared to the summer in elderly subjects. Therefore, particularly in the elderly, balancing fluid by drinking water should be encouraged to maintain euhydration status in winter.

INTRODUCTION The aim of this study was to investigate the consequences of 20 d of physical inactivity using head-down bed rest (HDBR) at -6 degrees on leptin, ghrelin, and counter-regulatory hormone responses. METHODS Eight male volunteers were subjected to HDBR for 20 d. Variables measured before, during, and after HDBR included plasma cortisol, insulin, glucose, leptin, ghrelin, thyroid stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3). RESULTS No changes in ghrelin and leptin concentrations were observed during HDBR. Glucose concentration decreased significantly on the 20th day of HDBR compared to the pre-value (day 0) of HDBR (87.6 +/- 2.0 vs. 93 +/- 1.6 mg x dl(-1)). Significant correlation was observed between glucose and leptin concentrations. DISCUSSION The results provide the first evidence that 20 d of HDBR is not associated with an alteration in ghrelin concentration. Leptin, insulin, and cortisol concentrations did not differ during 20 d of HDBR.

We investigated seasonal changes in blood concentrations of interleukin-6 (IL-6), adrenocorticotrophic hormone (ACTH), metabolites of catecholamine (VMA, HVA, and 5-HIAA) and cortisol in humans. Eight volunteers were investigated at four times during the year (February, May, August and October) at latitude 35 degrees N. The mean ambient temperature at the collection periods was higher in the order of summerautumn approximately springwinter. Changes in mood were also monitored by a profile of mood states (POMS) questionnaire. The concentration of IL-6 was significantly higher in winter and summer than in spring and autumn. The concentrations of ACTH, HVA and VMA were significantly higher in summer. No seasonal variation was detected in cortisol. There were significant differences among the seasons in subscale tension and anger in the POMS questionnaire; the tension subscale showed significant differences between spring and autumn, with a higher score in spring. The results demonstrate that Il-6, ACTH, HVA and VMA exhibit statistically significant seasonal rhythms, which might have important diagnostic and therapeutic implications.

We tested the hypothesis that encouraged water drinking according to urine output for 20 days could ameliorate impaired thermoregulatory function under microgravity conditions. Twelve healthy men, aged 24 +/- 1.5 years (mean +/- SE), underwent -6 degrees head-down bed rest (HDBR) for 20 days. During bed rest, subjects were encouraged to drink the same amount of water as the 24-h urine output volume of the previous day. A heat exposure test consisting of water immersion up to the knees at 42 degrees C for 45 min after a 10 min rest (baseline) in the sitting position was performed 2 days before the 20-day HDBR (PRE), and 2 days after the 20-day HDBR (POST). Core temperature (tympanic), skin temperature, skin blood flow and sweat rate were recorded continuously. We found that the -6 degrees HDBR did not increase the threshold temperature for onset of sweating under the encouraged water drinking regime. We conclude that encouraged water drinking could prevent impaired thermoregulatory responses after HDBR.

INTRODUCTION Head-down bed rest (HDBR) at -6 degrees is used as a model for studying physiological changes during microgravity in spaceflight. The aim of the present study was to investigate whether exposure to such an environment is associated with alterations in the synthesis of some acute-phase proteins and cytokines, and whether countermeasures would prevent these changes. METHODS There were 12 male volunteers who were subjected to HDBR for 20 d; 6 formed the countermeasure (CMS) group and exercised on a short-arm centrifuge for 30 min/d, while the other 6 served as controls (CTL). Variables measured before and after HDBR included plasma noradrenaline, adrenaline, dopamine, leukocyte count, interleukin 6, total serum protein, C-reactive protein, and alpha-1 antichimotrypsin. RESULTS Adrenaline and noradrenaline concentrations increased significantly in both groups, while the concentration of C-reactive protein decreased. The concentration of C-reactive protein was significantly higher (CTL: 0.028 +/- 0.005 mg x dl(-1); CMS: 0.025 +/-0.003 mg x dl(-1)), and that of adrenaline was significantly lower in CTL compared to CMS (CTL: 46.8 +/- 7.5 pg x ml(-1); CMS: 71 +/- 22.5 pg x ml(-1)). DISCUSSION The results indicate that several neuroendocrine and immunological parameters are modulated by prolonged HDBR and these changes may be counteracted at least in part by artificial gravity with exercise.

There are many reports of corneal complications caused by argon laser peripheral iridotomy. In this study, we investigated whether cooling the anterior ocular segment during laser iridotomy prevented corneal damage. A space for cooling the anterior ocular segment by perfusion with ice-cold water was made between the cornea and a contact lens. Dutch pigmented rabbits were excessively irradiated by an argon green laser, aiming at the peripheral iris. We used a contact lens without a cooling system as a control. Temperature in the anterior chamber and intraocular pressure were also monitored throughout the experiment. During laser treatment, the temperature without the cooling system rose to a maximum of 44.5°C in the anterior chamber, whereas use of the cooling system consistently kept this temperature at 11.1°–16.1°C. Although most eyes treated without cooling showed corneal damage, damage was seen in only a few or in no eyes cooled during laser treatment. Argon laser treatment using contact lenses with a cooling system drastically reduced the corneal damage induced by argon laser peripheral iridotomy. This technique may be acceptable for clinical use, considering its technical simplicity and low incidence of treatment-related complications. Jpn J Ophthalmol 2007;51:317–324 © Japanese Ophthalmological Society 2007

To estimate the effects of changes in body posture on sudomotor function, sweat rates on the forearm, chest and thigh, tympanic temperature ( T ty ), and skin temperatures were recorded in an upright sitting and a supine position under a hot environment of 40 °C T a and 40% relative humidity for 60 min. Sweat expulsions were identified on sweat rate curves and their rates ( F sw ) were calculated. T ty was higher, and its initial fall was greater, in the supine position than in the sitting position. On the forearm and the chest, the regression line relating sweat rate to mean body temperature ( T mb ) had a gentler slope in the supine position, whereas on the thigh, it showed a steeper slope. The regression line relating F sw to T mb had a steeper slope in the supine position than in the sitting position, suggesting that the gain in the mechanisms for central integration and rhythm-generation was enhanced in the supine position. The parameter of sweat rate divided by F sw was lower on the forearm and the chest, whereas it was higher on the thigh in the supine position than in the sitting position, suggesting that sudomotor outflow was modified at the spinal cord in association with skin pressure. It was concluded that body posture affects sudomotor functions through both brain and spinal mechanisms.

The effects of CO2 (100 ppm) bathing were investigated. It was found that the chest blood flow, chest sweat rate and tympanic temperature were significantly greater during the immersion in CO2 bathing than in freshwater bathing ( P 0.05 ). Thus, CO2 bathing at 100 ppm could produce cutaneous vasodilatation in the immersed skin, affecting thermoregulation.

The effects of skin pressure applied to one side of the waist on sudomotor and vasoconstrictor nerve activity were compared with the effects on sweating and cutaneous blood flow in humans. The sweat rate and cutaneous blood flow were measured on left and right dorsal feet. Skin sympathetic nerve activity (SSNA) was recorded by microneurography from a microelectrode inserted in left and right peroneal nerves. Skin pressure was applied in a supine position to the area over the left or right anterior superior iliac spine under warm ( T a : 30–36 °C) and cool ( T a : 19–23 °C) conditions. Sudomotor and vasoconstrictor bursts were identified for quantitative analysis. The skin pressure increased the contralateral/ipsilateral ratio of the sweat rate. It also increased the contralateral/ipsilateral ratio of the cutaneous blood flow and the contralateral/ipsilateral ratio of the sudomotor burst amplitude. However, skin pressure did not induce any significant changes in the contralateral/ipsilateral ratio of the vasoconstrictor burst amplitude. The results indicate that an asymmetrical reflex effect of skin pressure on vasoconstrictor nerve activity was absent, suggesting that, whereas the ipsilateral suppression of sweating elicited by skin pressure was mediated by the sudomotor nerve system, the ipsilateral suppression of cutaneous blood flow was not mediated by the vasoconstrictor nerve system. Thus, the occurrence of the spinal reflex due to skin pressure is not uniform between the sudomotor and the vasoconstrictor nerve systems, which represent different organizations at the level of spinal cord.

Background/purpose By performing experiments in air-conditioned chamber, we previously demonstrated that the presence of water nanodroplets (mist) improved facial skin moisture levels without reducing water loss from the facial skin surface or inducing excessive humidity. Some previous studies have demonstrated that the epidermis is a less effective barrier to water in winter because the corneocytes that comprise facial skin become smaller in winter as skin turnover increases in cold environments. We hypothesized that it would be easier for mist to penetrate into the facial stratum corneum (SC) in winter than in summer. In the present study, we investigated the ability of mist to improve facial skin moisture levels in winter and summer. Methods We examined transepidermal water loss (TEWL) as an index of barrier function and skin conductance as an index of SC hydration at the forehead, lateral canthus, and cheeks in eight healthy Japanese females (mean ± SD: 45.5 ± 3.2 years) in the presence or absence of mist in February–March and July. Results In the absence of mist, skin conductance at the forehead and lateral canthus was significantly higher in summer than in winter, but these seasonal differences were diminished in the presence of mist. In the presence of mist, skin conductance was increased in winter and decreased in summer at the lateral canthus; however, these changes were not significant. Thus, our findings suggest that mist penetrates into the SC and improves skin moisture levels in winter. Conclusion We demonstrated that it is easier for mist to penetrate into the SC at the lateral canthus during winter than in summer. Thus, mist is expected to improve facial moisture levels in winter by penetrating into and remaining in the SC. Hence, mist could be used to help prevent facial skin from becoming dry in air-conditioned rooms during winter.

1 Skin sympathetic nerve activity (SSNA) was recorded in seven male subjects from the peroneal nerve by microneurography, and the temporal correspondence of spontaneously occurring SSNA bursts with vasodilatation and sweating responses on the dorsal foot was studied during a mild body heating at rest. 2 Some SSNA bursts were followed by a sweat expulsion with a latency of 2.4 ± 0.4 s, and some bursts by a transient vasodilatation with a latency of 2.2 ± 0.4 s (means ± s.d.). SSNA bursts followed both by a sweat expulsion and by a vasodilatation response (Type 1), those followed only by a sweat expulsion (Type 2) and those followed only by a vasodilatation response (Type 3) were 70 %, 10 % and 1 % of the total bursts examined, respectively. 3 For Type 1 bursts, there was a significant, but weak linear relationship among the burst amplitude, the amplitude of the corresponding vasodilatation and the amplitude of the corresponding sweat expulsion. 4 It was concluded that SSNA contains vasodilatory activity which is synchronous with sudomotor nerve activity. The results suggest that such vasodilatory activity contributes to sustaining the sweat gland function by supplying sufficient blood.

Sweating is an important mechanism for ensuring constant thermoregulation, but hyperhidrosis may be disturbing. We present five cases of hemifacial hyperhidrosis as a compensatory response to an/hypohidrosis caused by cervical disc herniation. All the patients complained of hemifacial hyperhidrosis, without anisocoria or blepharoptosis. Sweat function testing and thermography confirmed hyperhidrosis of hemifacial and adjacent areas. Neck MRI showed cervical disc herniation. Three of the patients had lateral compression with well-demarcated hypohidrosis below the hyperhidrosis on the same side as the cervical lesion. The rest had paramedian compression with poorly demarcated hyperhidrosis and hypohidrosis on the contralateral side. Although MRI showed no intraspinal pathological signal intensity, lateral dural compression might influence the circulation to the sudomotor pathway, and paramedian compression might influence the ipsilateral sulcal artery, which perfuses the sympathetic descending pathway and the intermediolateral nucleus. Sweat function testing and thermography should be performed to determine the focus of the hemifacial hyperhidrosis, and the myelopathy should be investigated on both sides.

Skin sympathetic nerve activities (SSNAs) were recorded simultaneously from the tibial and peroneal nerves by microneurography at an ambient temperature of 25 degrees C in five subjects with primary palmoplantar hyperhidrosis. The resting of the tibial SSNA innervating the sole (glabrous skin) increased moderately (36.5 +/- 1.5 bursts/min), while mental arithmetic provoked marked responses (1,003.3 +/- 457.4% compared with the resting level) in the hyperhidrosis group compared with the control normohidrosis group (n = 5, 25.3 +/ 4.2 bursts/min and 142.2 +/- 58.4%, respectively). Differentiation of the tibial SSNA into sudomotor (innervating sweat glands) and vasoconstrictor (innervating presphincter of skin vessels) revealed that this SSNA enhancement was attributable to not only sudomotor but also vasoconstrictor components during mental arithmetic. In contrast, the responses in the peroneal SSNA (innervating the dorsum pedis, hairy skin) of the hyperhidrosis group were only slightly changed, exhibiting no significant difference from those in the normohidrosis group. Reflex bursts elicited by sound and electric stimulation were normal in amplitude and latency. When the ambient temperature was elevated to 30 degrees C, the tibial SSNAs became more enhanced than did the peroneal SSNAs. The tibial SSNA was markedly enhanced in the hyperhidrosis group (290.0 +/- 78.5%) compared with the normohidrosis group (78.3 +/- 25.4%). We conclude that the excessive responses in SSNA to the plantar glabrous skin to both mental and thermal stimuli may be responsible for the profuse sweating in subjects with primary palmoplantar hyperhidrosis.

Loss of sweating is a characteristic feature of multiple system atrophy (MSA) with autonomic failure, and widespread anhidrosis may lead to hyperthermia and collapse in a hot environment. Calcitonin gene-related peptide (CGRP) is present in the periglandular nerves around sweat glands and is a strong stimulant of methacholine (MCH)-mediated cholinergic sweating. The present study evaluated CGRP-related regulation of cholinergic sweating in patients with MSA. CGRP-induced potentiation of MCH-mediated cholinergic sweating was significantly reduced in MSA patients as compared with normal age-matched controls. These results suggest that regulation of sweating is extensively affected in MSA as a consequence of peptidergic dysfunction.

We performed a quantitative sudomotor function test using thermal stimulation (40°C) and thyrotropin-releasing hormone (TRH) in 14 patients with multiple system atrophy (MSA), 10 patients with Parkinson's disease (PD), 11 patients with amyotrophic lateral sclerosis (ALS) and in 11 age-matched control subjects. There was thermal sudomotor dysfunction in the lower extremities of the MSA patients. The PD patients failed to increase their local sweating and frequency of sweat expulsions with TRH infusion, in spite of the fact that they still had normal thermal sweating. ALS patients had mild thermoregulatory sweat dysfunction in their lower extremities. These results suggest that in MSA the lesion most responsible for sudomotor dysfunction is the intermediolateral column cells of the spinal cord and postganglionic sympathetic neurons. There may be an impairment of TRH-induced sympathetic responses in PD, and there is a mild postganglionic sympathetic lesion in the lower extremities of ALS patients.

Background/purpose In air-conditioned rooms, dry air exacerbates some skin diseases, for example, senile xerosis, atopic dermatitis, and surface roughness. Humidifiers are used to improve air dryness, which often induces excess humidity and thermal discomfort. To address this issue, we investigated the effects of water nanodroplets (mist) on skin hydration, which may increase skin hydration by penetrating into the interstitial spaces between corneocytes of the stratum corneum (SC) without increasing air humidity. Methods We examined biophysical parameters, including skin conductance and transepidermal water loss (TEWL), and biomechanical parameters of skin distension/retraction before and after suction at the forehead, lateral canthus, and cheek, with or without mist, in a testing environment (24°C, 35% relative humidity) for 120 min. Results In the group without mist, TEWL values significantly decreased at all the sites after 1 h compared with the initial values. However, in the presence of mist, TEWL values were maintained at the initial values through the test, yielding significant differences vs. the group without mist. There were no significant differences between mist and mist-free groups in terms of skin conductance. Skin distension was significantly increased in the group with mist compared with that in the group without mist at the forehead and cheek, suggesting a softening effect of mist. Conclusion Skin deformation of the face was improved by mist, suggesting hydration of the SC by mist. The change in TEWL was influenced by mist, suggesting supply of water to the skin, particularly the SC, by mist. These data indicated that a mist of water nanodroplets played an important role in softening skin in an air-conditioned room without increasing excess humidity.

To clarify the effects of isometric and isotonic exercise during mist sauna bathing on the cardiovascular function, thermoregulatory function, and metabolism, six healthy young men (22 ± 1 years old, height 173 ± 4 cm, weight 65.0 ± 5.0 kg) were exposed to a mist sauna for 10 min at a temperature of 40 °C, and relative humidity of 100 % while performing or not performing ∼30 W of isometric or isotonic exercise. The effect of the exercise was assessed by measuring tympanic temperature, heart rate, systolic and diastolic blood pressure, chest sweat rate, chest skin blood flow, and plasma catecholamine and cortisol, glucose, lactate, and free fatty acid levels. Repeated measures ANOVA showed no significant differences in blood pressure, skin blood flow, sweat rate, and total amount of sweating. Tympanic temperature increased more during isotonic exercise, and heart rate increase was more marked during isotonic exercise. The changes in lactate indicated that fatigue was not very great during isometric exercise. The glucose level indicated greater energy expenditure during isometric exercise. The free fatty acid and catecholamine levels indicated that isometric exercise did not result in very great energy expenditure and stress, respectively. The results for isotonic exercise of a decrease in lactate level and an increase in plasma free fatty acid level indicated that fatigue and energy expenditure were rather large while the perceived stress was comparatively low. We concluded that isotonic exercise may be a more desirable form of exercise during mist sauna bathing given the changes in glucose and free fatty acid levels.

Both spectral power within the low-frequency component, i.e., 0.04 to 0.15 Hz, of systolic pressure and muscle sympathetic nerve activity are increased during head-up tilt. The nerve activity during tilt is altered after space flight and exposure to simulated microgravity. In the present study, correlations of the low-frequency component and the nerve activity were analyzed before and after 20 days of -6° of head-down bed rest. Measurements were performed at -6° head-down bed rest, 0° (flat), and 30° and 60° head-up tilt (HUT). Mean arterial pressure during HUT was not different between pre- and post-bed rest, but muscle sympathetic nerve activity in post-bed rest significantly increased at tilt angles of -6°, 0°, 30°, and 60° compared with those during pre-bed rest. The low-frequency component of systolic pressure also significantly increased during post-bed rest compared with pre-bed rest at tilts of 0°, 30°, and 60°. The nerve activity and the frequency component were linearly correlated for individual (r(2) = 0.51-0.88) and averaged (r(2) = 0.60) values when the values included both pre- and post-bed rest. Thus, the low-frequency component of systolic pressure could be an index of the muscle sympathetic nerve activity during tilt during pre- and post-bed rest.

The effects of environmental temperature on blood pressure and hormones in obese subjects in Japan were compared in two seasons: summer vs winter. Five obese (BMI, 32 ± 5 kg/m(2)) and five non-obese (BMI, 23 ±3 kg/m(2)) men participated in this experiment at latitude 35°10' N and longitude 136°57.9' E. The average environmental temperature was 29 ± 1 °C in summer and 3 ± 1 °C in winter. Blood samples were analyzed for leptin, ghrelin, catecholamines, thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), total cholesterol, triglycerides, insulin and glucose. Blood pressure was measured over the course of 24 h in summer and winter. A Japanese version of the Profile of Mood States (POMS) questionnaire was also administered each season. Systolic and diastolic blood pressures in obese men were significantly higher in winter (lower environmental temperatures) than in summer (higher environmental temperatures). Noradrenaline and dopamine concentrations were also significantly higher at lower environmental temperatures in obese subjects, but ghrelin, TSH, fT3, fT4, insulin and glucose were not significantly different in summer and winter between obese and non-obese subjects. Leptin, total cholesterol and triglyceride concentrations were significantly higher in winter in obese than non-obese men. Results from the POMS questionnaire showed a significant rise in Confusion at lower environmental temperatures (winter) in obese subjects. In this pilot study, increased blood pressure may have been due to increased secretion of noradrenaline in obese men in winter, and the results suggest that blood pressure control in obese men is particularly important in winter.

Objectives: Constipation affects as many as 26% of elderly men and 34% of elderly women and is a problem that has been related to a diminished quality of life. The aim of this study was to investigate the influence of aging on electrogastrograms (EGGs). On the basis of the EGGs of elderly individuals, the effect of hot stupe application on the epigastrium was also evaluated. Methods: The first group included 14 healthy, young participants (age, 20–25 years) and the second group comprised 14 healthy, elderly participants (age, 65–76 years). EGGs were obtained for the first 30 min in a sitting position and for the next period (> 150 min) in a supine position. A hot stupe was placed on the epigastrium of each elderly patient 90 min after the postural change. We evaluated EGGs by spectral analysis and nonlinear analysis. Results: On comparing the gastrointestinal electrical activity of the elderly group with that of the young group, the activity in the former revealed an overall decrease. With hot stupe application, translation error in the elderly individuals was significantly larger than that without hot stupe application (p < 0.01). We also observed a gender-specific characteristic, wherein the gastrointestinal motility of the young women was likely only influenced by postural change. Moreover, the translation error in the EGGs of the elderly individuals increased during hot stupe heating. Conclusions: This increase in the translation error suggests that the electrical synergy between the stomach and intestine could be enhanced by the application of a hot stupe. Our findings also indicated that hot stupe application on the epigastrium was effective for improving gastrointestinal motility in elderly individuals.

1. 1. Thermoregulatory respones to gradual rise and fall in the ambient temperature ( T a ) were compared between 8 old (68–78 years) and 8 younger (20–25 years) male subjects. 2. 2. Starting at T a of 31.5°C (r.h. 40%), T a was raised to 39.5°C, then lowered to 21.5°C, and raised back to 31.5°C at a constant rate of 0.3°C/min. 3. 3. Noticeable differences in responses between the age groups were as follows: decline of sweating rate and reduction of acral blood flow during room cooling were retarded in the aged group, with wider variations among individuals, compared with those in the younger group; the tympanic and oesophageal temperatures fell considerably during cooling in the elderly group, failing to return to the level at start during the rewarming of the room, in contrast to the younger group. 4. 4. Such sluggish responses may be attributed largely to reduced cutaneous thermal perception with advancing age.

We have examined the nonparallel changes in tympanic membrane temperatures (Tty) from the two ears in response to various changes in body and head positions. Upon assuming a lateral recumbent position, the Tty on the lower side increased while that on the upper side decreased. Pressure application over a wide area of the lateral chest only caused inconsistent and obscure asymmetric changes in Tty. A lateral flexion of the head with the subject sitting upright and a rotation of the head to the side in a supine position induced an increase in the Tty on the lower side compared to that on the upper side. The temperature and blood flow of the forehead often decreased on the lower side and increased on the upper side, although such responses were not always concomitant with the asymmetric changes in Tty. A dorsal flexion of the head with the subject in a reclining position caused a slight increase in the Tty, whereas raising the head upright induced a slight decrease in them. Two additional experiments were carried out with single photon emission computed tomography using 99mTc-hexamethylpropyleneamine oxime as tracer, and a slight, relative decrease in counts was noted in the right hemisphere during rotation of the head to the right. These results would strongly suggest that unilateral increases and decreases in Tty could have been caused by one-sided decreases and increases, respectively, in blood flow to the brain and/or the tympanic membrane, induced by a vasomotor reflex involving vestibular stimulation.

To investigate the effects of age on thermal sensitivity, preferred ambient temperature (Tpref) was compared between old (71-76 years) and young (21-30 years) groups, each consisting of six male subjects in summer and winter. The air temperature (Ta) was set at either 20 degrees C or 40 degrees C at commencement. The subject was directed to adjust the Ta for 45 min by manipulating a remote control switch to the level at which he felt most comfortable. In the older group, the Tpref was significantly lower in trails starting at 20 degrees C than that starting at 40 degrees C in summer. The fluctuation of Tpref (temperature difference between maximum and minimum Ta during the last 10 min) was significantly wider in the older group in both summer and winter. Repetition of the same experiment on each subject showed a poorer reproducibility of Tpref in the older group than in the younger group in summer. Tympanic and esophageal temperatures of the older group kept falling throughout the trial starting at 20 degrees C in summer. These results suggest that thermal sensitivity is decreased with advancing age and that thermal perception in the elderly, especially to cold, is less sensitive in summer.

In summer and winter, young, sedentary male (N = 5) and female (N = 7) subjects were exposed to heat in a climate chamber in which ambient temperature (Ta) was raised continuously from 30 to 42°C at a rate of 0.1°C min−1 at a relative humidity of 40%. Sweat rates (SR) were measured continuously on forearm, chest and forehead together with tympanic temperature (Tty), mean skin temperature $$ \left( {\overline {\hbox{T}} {\hbox{s}}} \right) $$ and mean body temperature $$ \left( {\overline {\hbox{T}} {\hbox{b}}} \right) $$ . The rate of sweat expulsions (Fsw) was obtained as an indicator of central sudomotor activity. Tty and $$ \left( {\overline {\hbox{T}} {\hbox{b}}} \right) $$ were significantly lower during summer compared with winter in males; SR was not significantly different between summer and winter in males, but was significantly higher during summer in females; SR during winter was higher in males compared with females. The regression line relating Fsw to $$ \left( {\overline {\hbox{T}} {\hbox{b}}} \right) $$ shifted significantly from winter to summer in males and females, but the magnitude of the shift was not significantly different between the two subject groups. The regression line relating SR to Fsw was steepened significantly from winter to summer in males and females, and the change in the slope was significantly greater in females than in males. Females showed a lower slope in winter and a similar slope in summer compared to males. It was concluded that sweating function was improved during summer mediated by central sudomotor and sweat gland mechanisms in males and females, and, although the change of sweat gland function from winter to summer was greater in females as compared with males, the level of increased sweat gland function during summer was similar between the two subject groups.

Various treatments are currently available for palmoplantar hyperhidrosis. We have treated palmoplantar hyperhidrosis patients effectively with the use of alternating current (AC) iontophoresis. However, much remains unknown about the physiological changes that occur with AC iontophoresis, and its mechanism of action. We measured the changes in Na(+), K(+) concentration in perspiration and perspiration volume with AC iontophoresis in palmoplantar hyperhidrosis patients. We found that hyperhidrosis patients have significantly higher perspiration volume and Na(+) concentration in perspiration than healthy controls. Looking at the temporal changes with AC iontophoresis, we found a significant decrease in perspiration volume and Na(+) concentration in perspiration after six iontophoresis treatments. This result is further evidence that Na(+) concentration in perspiration is closely involved with perspiration volume. However, looking at the changes in perspiration volume and Na(+) concentration in perspiration before and after a single AC iontophoresis treatment, we found that while perspiration volume did not decrease in hyperhidrosis patients after a single treatment, there was a significant decrease in Na(+) concentration. In healthy controls as well, Na(+) concentration in perspiration decreased significantly after a single treatment. These findings suggest that the effect of AC iontophoresis may be due to a complex mechanism involving changes in reabsorption of ductal Na(+).

We investigated the effect of change in intrathoracic pressure by total body negative pressure (TBNP) or positive pressure (TBPP) on thermoregulatory responses during -6 degree head-down bed rest (HDBR). Eight healthy male subjects participated to three of the following interventions in a randomised sequence: 1) HDBR, 2) HDBR with TBNP of -15 cmH2O, 3) HDBR with TBPP of +15 cmH2O. A rapid decrease of cutaneous blood flow occurred after the start of TBNP. In contrast, cutaneous blood flow increased slightly at TBPP. Sweat rate decreased immediately after the start of TBNP. Immediately after the TBPP was started, tympanic temperature greatly decreased. It is concluded that combination of HDBR and intrathoracic pressure changes thermoregulatory responses through the cardiopulmonary baroreceptor to reduce the wall stretch.