Effect of carbon dioxide bath on cardiovascular functions and peripheral circulation were studied using a new system of carbon dioxide bath. The subjects consisted of 13 males and 17 females, ranging from 50 to 84 years old, 67.4±8.3 in average, having the complaints resulting mainly from arteriosclerosis such as coldness on extremities or exertional pains of lower extremities. Each subject took a bath in plain water (PW) on the first experimental day and then a bath in carbon dioxide (CO₂) at the same time on the second experimental day. Both baths were done for 10min. at 39°C of water temperature. The results obtained were as follows.
1) Mean blood pressure (MBP) was elevating during bath and lowered below prebath level immediately after bath in both PW and CO₂ groups. However, MBP in CO₂ group was lower significantly (p<0.05) than in PW group 20 and 30min after bath.
2) Both body and skin temperatures were similarly elevated at all points to be measured directly after bath, and then lowerd gradually thereafter. There was no significance in changes between both groups.
4) An increase in cutaneous blood flow was observed at the same grade in both groups during and after bath, though no showing significant difference between both groups.
5) PO₂ in venous blood increased after bath, while PCO₂ decreased. However, no significant difference in these changes was observed between both groups.
6) Tendency to increase in CV R-R was observed during and after bath, though no significant difference was showed between both groups.
7) Relating to the feeling to bath, all subjects had the feeling of “warmness” at the beginning of bath and also of comfortableness during and after bath in both PW and CO₂ groups. However, there was no difference in the intensity of these feelings between both groups.
8) No side reaction due to an inhalation of carbon dioxide during bath was observed in all subjects.
From these results, it is expected that a new carbon dioxide bath results in benefit for patients with disturbance of peripheral circulation.

We have investigated change in platelets and the blood coagulation and fibrinolytic systems as a mechanism of the onset of thrombotic diseases during and after hot-spring bathing. In this study, We examined effect of 10min 42°C and 37°C hot-spring bathing on protein C, protein S and antithrombin III in seven healthy male subjects. The mean values of protein C antigen, protein C activity, total and fee protein S antigens, protein S activity and antithrombin III activity were slightly increased by both methods, while these changes were not statistically significant. Taken together with our previous reports, 10min 42°C hot-spring bathing gives no effect on the blood coagulation system.

From March 1990 to September 2001, 24 patients with psoriasis (16 males and 8 females, 54±18 years) were admitted to our hospital to receive balneotherapy using Kusatsu hot-spring water. The psoriasis had been refractory to various treatments including steroid ointment therapy over a long period of time. The patients took a 10-minute 40-42°C hot-spring bath followed by application of vitamine D3 ointment 1-2 times daily for 37±19 days. The main components of the hot-spring water are aluminium, sulphates and chlorides, and its pH is 2.0. The skin symptoms of 20 of 24 cases (83%) were improved through the balneotherapy, while those of the remaining 4 cases were not changed. No side effects were observed. The serum levels of uric acid, GOT and GPT which are reported to be increased slightly did not correlate with the skin symptoms. The serum LDH level which is associated with the skin manifestastions in patients with atopic dermatitis also gave no useful information in the treatment of psoriasis. Although the mechanism of the improvement of skin manifestations is not clarified, balneotherapy at Kusatsu can be useful for the treatment of refractory cases of psoriasis as alternative and complementary medicine

A patient with atopic dermatitis who presented muscular weakness of lower extrimities and tetany due to severe hypokalemia, hypocalcemia and hypomagnemia was described. The hypokalemia and hypomagnemia were caused by pseudo-Bartter's syndrome due to persistent dehydration, and the hypocalcemia was caused by pseudohypoparathyroidism due to hypomagnemia. The persistent dehydration was considered to be resulted from long-term and long-time bathing. Thus, adequate supply of water and electrolytes may be necessary in long-term balneotherapy.

From June 1990 to October 1998, 100 patients with adult-type atopic dermatitis (59 males and 41 females, 25±8 years) were admitted to our hospital to receive balneotherapy using Kusatsu hot-spring water. The atopic dermatitis in all but 9 cases occurred while the patients were still under 20 and had been refractory to various treatments including steroid ointment therapy over a long period of time. The patients took a 10-minute 40-42°C hot-spring bath followed by immediate application of white petrolatum 1-2 times daily for 75±46 days. The main components of the hot-spring water are aluminium, sulphates and chlorides, and its pH is 2.0. The skin symptoms of 79 of 100 cases (79%) were improved through the balneotherapy and furthermore pruritus was improved in 55 of the 79 cases (70%). The improvement of skin manifestations was supported by a significant decrease in serum LDH levels. In contrast, pruritus was not improved in the remaining 21 cases who showed no changes in skin symptoms and serum LDH levels. Moreover, changes in the number of Staphylococcus aureus on the skin surface were examined before and after balneotherapy. In the 69 cases examined whose skin symptoms were improved, many Staphylococci aureus were detected in 52 of the cases but not in the other 17 cases before starting balneotherapy. They disappeared in 24 cases and decreased in 18 cases of the 52 cases, but were not changed in the remaining 10 cases through the balneotherapy. On the other hand, the number of Staphylococcus aureus on the skin surface was not changed in 11 of the 14 cases examined whose skin symptoms were not improved. Our previous study reported that bactericidal activity against Staphylococcus aureus is expressed by the co-existence of manganese and iodide ions contained in the hot-spring water under an acidic (pH 2.0-3.0) condition. Thus, the mechanisms of the improvement of skin manifestations through the balneotherapy may be explained by considering bactericidal activity of Kusatsu hot-spring water against Staphylococcus aureus inducing acute flares of skin manifestations. Therefore, balneotherapy at Kusatsu can be useful for the treatment of refractory cases of adult-type atopic dermatitis as a suitable method of skin care.

The circumferences of chest, abdomen, thigh and calf during head-out water immersion up to chin level were measured in 8 healthy male subjects (age 35.4±1.6years old, body mass index 23.7±1.6kg/m²) in standing and sitting positions. The circumferences of chest, abdomen, thigh and calf decreased significantly during immersion in standing position. The circumferences of chest, abdmen and thigh decreased significantly in sitting position. The circumference of chest decreased from 90.6±3.4 to 90.1±3.1cm, that of abdomen decreased from 81.4±2.8 to 80.6±2.5cm, that of thigh decreased from 47.1±1.6 to 46.6±1.8cm, and that of calf decreased from 37.7±1.8 to 37.2±1.8cm during immersion in standing position. As the body surface area is about 1.6m², the decrease in the volume of human body is considered to be 730cm³ or less when the body shape change during immersion is not taken into considerarion.

This study investigated the existence of platelet activation before the onset of cerebral infarction, and analyzed the association between the platelet activation and the degree of atherosclerosis. Furthermore, prediction of the risk of cerebral infarction by assessing platelet activation was attempted. Thirteen patients with cerebral infarction, 7 patients with atherosclerosis and 8 healthy subjects were enrolled in this study. Ultrastructural shape change, peroxidase reaction, and fibrinogen content in the platelets were observed and plasma levels of thrombin antithrombin complex, α₂-plasmin inhibitor plasmin complex, β-thromboglobulin and platelet factor-4 were measured in patients with atherosclerosis and cerebral infarction at the acute, subacute and chronic phases. The ultrastructural shape change, peroxidase reaction, and fibrinogen content did not differ among acute, subacute and chronic phases of cerebral infarction. The frequency of platelet shape changes were also increased in patients with atherosclerosis, compared with healthy subjects. Plasma levels of β-thromboglobulin, platelet factor-4, and thrombin antithrombin complex increased only during the acute phase of cerebral infarction. It is suggested that platelet activation occurs before the onset of cerebral infarction and that platelet shape change is associated with the degree of atherosclerosis, or plaque stability. Platelet activation would be derived not from thrombotic event itself but from endothelial damage or pre-existing atherosclerosis. Platelet shape change, therefore, could predict the risk of cerebral infarction. Taken together with our previous reports demonstrating increased blood viscosity, noctural hypotension, increased human atrial natriuretic peptide, decreased fibrinolytic activity, and platelet shape change were observed after very hot hot-spring bathing, cerebral infarction in spa-resort could be caused partly by very hot hot-spring bathing after traveling on a tight schedule and alcohol drinking by elderly patients with atherosclerosis.

Sodium sulfate·sodium bicarbonate bathing is known to exert stimulatory effect upon an increase in cutaneous circulation after bathing due to its skin-coating and vasodilating action. In the study, authors investigate the change in cutaneous blood flow after artificial sodium sulfate·sodium bicarbonate bathing in the healthy man, and clarify its antihypertensive effect upon diurnal variations in blood pressure in patients with essential hypertension.
The results obtained are as follows.
1) Changes in cutaneous blood flow after bathing were studied in five healthy volunteers. Sodium sulfate·sodium bicarbonate bathing (40°C, 10 min) resulted in a significant increase in cutaneous blood flow 30 min after the beginning of bathing, comparing with plain water bathing. Thermographic study on body surface revealed the findings corresponding to the change in cutaneous blood flow.
2) Diurnal changes in blood pressure after bathing were studied in ten patients with essential hypertension, who had been treated with hypotensive drugs. No significant difference of hyperbaric indici in systolic, diastolic and mean blood pressure (MBP) was observed between sodium sulfate and plain water as a whole. However, six cases out of ten showed the significant decrease in MBP after sodim sulfate·sodium bicarbonate bathing, comparing with the plain water bathing.
From these findings it is expected that artificial sodium sulfate·sodium bicarbonate bathing is available as a supportive therapy for refractory hypertension to medicaments.