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This study evaluated the performance of a new O3 /H2 O2 mixed gas sterilization instrument for killing microorganisms and inactivating bacterial endotoxin at low temperatures. Sterility assurance level was achieved by an over 6-log reduction of Geobacillus stearothermophilus ATCC 12980, and the decimal reduction value was 0.77 min in sterilization mode. A reduction of over 3 logs in Limulus amebocyte lysate coagulation activity of purified endotoxin from Escherichia coli was observed after treatment in endotoxin-inactivation mode. The same inactivation ability was observed when treating dried bacterial cells. Biomaterials made of polymer or metal did not exhibit cytotoxicity after gas exposure at O3 concentrations below 200 ppm. As the results of human cell-based pyrogen testing, significant amounts of endotoxin that were over the limit for medical devices contacting cerebrospinal fluid (2.15 EU/device) were detected on scissors washed with a washer-disinfector and sterilized with ethylene oxide or autoclaving. In contrast, endotoxin decreased to 0.29 ± 0.05 EU/device after O3 /H2 O2 mixed gas sterilization in endotoxin-inactivation mode. Compared to conventional gas sterilization methods, O3 /H2 O2 mixed gas has high sterilization ability and a strong capacity to inactivate endotoxin. It is expected that this sterilization technology will improve the safety of reusable medical devices and utensils for regenerative medicine.

Prions are infectious agents causing prion diseases, which include Creutzfeldt-Jacob disease (CJD) in humans. Several cases have been reported to be transmitted through medical instruments that were used for preclinical CJD patients, raising public health concerns on iatrogenic transmissions of the disease. Since preclinical CJD patients are currently difficult to identify, medical instruments need to be adequately sterilized not to transmit the disease. In this study, we investigated the sterilizing activity of two oxidizing gases, ozone gas and hydrogen peroxide gas, against prions fixed on stainless steel wires using a mouse bioassay. Mice intracerebrally implanted with prion-contaminated stainless steel wires treated with ozone gas or hydrogen peroxide gas developed prion disease later than those implanted with control prion-contaminated stainless steel wires, indicating that ozone gas and hydrogen peroxide gas could reduce prion infectivity on wires. Incubation times were further elongated in mice implanted with prion-contaminated stainless steel wires treated with ozone and hydrogen peroxide-mixed gas, indicating that ozone-mixed hydrogen peroxide gas inactivates prions on these wires more potently than ozone gas or hydrogen peroxide gas. Taken together, these results suggest that ozone-mixed hydrogen peroxide gas may be useful for prion sterilization of medical instruments.

研究, 玉村和彦教授 定年退職記念号

The Republic of Korea achieved high economic growth in the latter of 1970's and entered upon a mass tourism stage in the 1980's. The ratio that the people participated in a sightseeing trips was just 19% in a day trip as well as in a lodging trip in 1976. However, the ratio shows the former for 54%, the latter for 65% in 1984, a remarkable increase was observed. The author aimed to make clear the process of tourism development, the actual condition of tourist, tourist industry, and the changes of life for regional residents in Bugok hot spring resort.Bugok hot spring resort is located in the southeastern part of Korea and it runs about 50Km from Taegu or Pusan. A developer named Mr. Sin was from Seoul succeeded in gushing out the powerful sulfur hot spring of 72°C in the paddy field between a mountain area in January 1973. After that he constructed a public bath and an inn. Furthermore a Korean who lives in Japan opened a tourist hotel and invited capitalists from every place of Korea, thus tourist inns, restaurants and other shops were opened in that same place. Bugok Hawaii which has a large leisure center, was opened in 1982, has the increasing number of tourist which shows 510, 0000 guests in 1979 to 2, 570, 000 in 1984, becaue a highway between Taegu and Masan was opened in 1977 and direct bus revolved from Seoul. Changnynung County Office made a city plan at once and a land adjustment was completed in 1978. The size of minimum land division was about 600 tsubo, thus a tourist investment was stagnated. After it was changed to about 200 tsubo in 1983, inns and stores increased rapidly. Total investment for the development of Bugok hot spring is 3, 100 million won in public working, 60, 600 million won in private enterprise till 1984, and 23, 800 million won are planned from now on.The day tripper occupies about 60-70% on account of the opening of Bugok Hawaii. On the other hand, many lodging facilities gathered a lot of tourist. A tourist like merchants, company employees and farmers visit Bugok in winter season generally for recuperation, recreation, dutifulness to parents and meeting etc.. They hire tourist buses and sometimes reguler highway buses.On the other hand, farmers sell their paddy fields nearby farm village adjacent the tourist development, and sometimes manages inn and could help people make extra money. Aside from this many farmers offer their vacant rooms to employees of tourist industry. Besides this tourist industry, agriculture flourished thus making the people life easy.A hot spring was dug freely in Bugok and there are the sources of 95 in 1985. 65 of them were developed since 1980. The water level and the volume of hot spring had decreased just recetly. However protection and proper application of hot spring had been labored. For this reason the environment protection of hot spring tourist resort had been enhanced. The problem is to maintain the hot spring, pavement, green park and harmonious landscape in Bugok, and an action must be taken immediately.

The suburban agriculture around big cities generally shows a declining tendency because of rapid urbanization, and many studies of its actual situation are presented in the field such as geography, sociology and economics. However, about the detailed development process of tourist farms as suburban agriculture around cities, it is not sufficiently explained.In this paper, taking the right shore of the River Tama as an example, we have mainly investigated the actual condition of what developmental process the tourist orchards of Tamagawa Pear, which have long history, have gone through, and how they have corresponded to and been transformed by the surge of rapid urbanization of Kawasaki after the middle of 1950s. The results of this paper are as follows;At the right shore of the Tama in northern Kawasaki City, though the urbanization has been proceeded rapidly, tourist pear orchards in pluck-for-oneself system are widely distributed now, being crowded briskly in Autumn. Those pear orchards have co-existed with residences, apartment houses, shops and carparks scattered among them, where urbanized use of land is prevailing, showing a conspicuous sight.The tourist orchards have developed since the combined activity of local farms with the Odakyu Electric Railway Co. Ltd. in 1928, when the Electric Railway opened. During ten years since 1956, owing to the dull market price of pear, many farms had changed their character to tourist farm and become profitable. At present, they have come to sell 46% of annual production by tourist pear orchards in pluck-for-oneself system, and 52% by direct sales along the road system. At the same time, they generally operate their farms with the aid of another jobs depending on real property such as rental housing, apartment houses, and carparks.In the northern part of Kawasaki City, urbanization accompanied by residential development was already past its peak, but the development is still progressing steadily and tourist pear orchards are decreasing gradually. The prospect of those orchards are beclouded owing to the deterioration of farming environments and the difficulty of keeping their successors.Under these circumstnces, there comes up a new corresponding plan. It is the tourist farm policy of Kawasaki City authorities including establishment of citizenry orchards, fruit parks and citizenry farms. It is worthy of note that this shows the integration of such viewpoints as promoting urban farming, preserving green belt, and citizenry recreation.

Modern tourism in Japan is characterized by the mass, various and widespread tourist movement. As a phenomenon, mass tourist movement appears particularly in relation to the remarkable growth of metropolitan areas, and most resorts surrounding metropolitan areas have developed greatly. First, the resorts with over 100, 000 visitors each year were identified. Then, according to the tourist market the resorts were classified into three main types, (i) metropolitan type, (ii) intermediate type and (iii) local type. Finally, the area of the metropolitan area and the intermediate type resorts serving the Tokyo tourist market was designated as the Tokyo tourist region and an attempt was made to explain the regional differentiation of the development stages by considering only the external factors affecting these resorts. The indices for the regional differentiation are based on changes in the number of bathing tourists (in 1939 and 1965), the accommodation capacity (in 1933 and 1963) and the worker rate from service industry (in 1950 and 1965). The results of this analysis are as follows: (1) In 1939, before the Second World War, the number of bathing tourists at each hot-spring resort in the Hakone-Izu area is nearly similar to the Kitakanto area, mainly Tochigi and Gunma Prefecture. Hakone-Izu Area……Hakone (510, 000), Atami (470, 000), Ito (360, 000), Yugawara (300, 000), Izunagaoka (250, 000). Kitakanto Area……Nikkoyumoto (460, 000), Kusatsu (320, 000), Ikaho (240, 000), Shiobara (210, 000). The above each hot-spring resort is more than 200, 000 bathing tourist. Also, the accommondation capacities in 1933 were similar. (2) By 1965, both bathing tourists and accommodation capacities were centralized remarkably in the hot-spring resorts in the Hakone-Izu area ; on the other hand, the wellknown hot-spring resorts (the traditional hot-spring resort) before the Second World War in the Kitakanto area were characterized by stagnation. However, Kinugawa and Minakami, non-traditional resorts established since the beginning of the Showa period, in Kitakanto have rapidly developed, and now Kinugawa is the largest hot-spring resort in Kitakanto area. The number of bathing tourists at each hot-spring resorts in 1965 is as follows : Hakone-Izu Area……Atami (5, 330, 000), Hakone (2, 550, 000), Ito (2, 050, 000), Yugawara (1, 390, 000), Izunagaoka (1, 140, 000), Shuzenji (620, 000), Shimoda (510, 000), Atagawa (500, 000). Kitakanto Area……Kinugawa (1, 320, 000), Ikaho (810, 000), Shiobara (740, 000), Minakami (730, 000), Kusatsu (690, 000), Nasu (680, 000). The above each hot-spring resort is more than 500, 000 bathing tourist. (3) The differentiation of the worker rate from service industry corresponds to the number of bathing tourists and the accommodation capacity. Hakone hot-spring resort indicated 60.6 % and Atami of 51.8% in 1965. (4) In addition, the next five development stages of the hot-spring resorts made cleared by the synthetic analysis of (1), (2) and (3). I. health-spa stage, II. recreation resort stage, III. recreation and tourist resort stage, IV, tourist resort stage, and V. tourist city stage. (5) The external factor which has resulted in the regional differentiation of the development stages of the hot-spring resorts is accessibility, through train and road traffic convenience between the hot-spring resorts and the Tokyo metropolitan area. The accessibility indices(=arrival time (minute)×traveling expenses (yen)/1, 000) of the Hakone and Atami spas are low, respectively 34 and 35. In comparison, traffic conditions in the Kitakanto area are unfavorable (Kinugawa-70, Ikaho-85, Shiobara-121 and Kusatsu-149).

In a study on hot spring resorts in Japan, part II, the author refered to the development and economic function of hot spring resort settlements at Ikaho and Kinugawa spas in northern Kanto. This part III is a report on factors in the formation of hot spring resort settlements from a view point of the socio-economic structure at Ikaho and Kinugawa spas. Especially, he analyzed the internal structure of settlements concerning the hot spring right and landownership and the active attitude of local autonomy and other functional groups. (1) The hot spring of Ikaho has a special hot spring utilization system, namely, it springs up at Yumoto, 550 m apart from the settlement and is conducted down to the settlement through an Oseki (hot spring conductor) to be divided among hot spring creditors (Fig.l). Through the Edo era, 14 Oyas were monopolisticly possessed of the hot spring divided from Komaguchi (hot spring entrance) being installed at both sides (Tab. 1). And the cooperative hot spring utilization system was consecutively kept unchanged until the early years of the Meiji era. However, owing to introduction of a modern private property system and external influence, the old custom of the hot spring utilization system was collapsed. Consequently, 3 Oyas out of 14 narrowly retained their position, occupying only 11. 5% of Ikaho hot spring, while newly-risen local financial capitals gained 13.9% and central capitals 62.7% (Tab. 2). Yoshimasa Ono, vice-president of Japan Railway Company, one of the central capitalists, purchased 1/3 of the right of Ikaho hot spring and attempted to remove the hot spring entrance in order to freely conduct the hot spring with the intention of constructing a new hot spring settlement adjacent to the old one. Against the central capitalist's purpose, the local power group centering around the old Oyas developed an opposition movement on the strength of a time honored hot spring utilization agreement to protect their own hot spring. On account of the opposition movement the Ono's plan failed. In 1922, the rate of hot spring occupied by 4 old Oyas recovered up to 50.0%, and that of central capital fell to 11.4%. Here it was made clear that the exclusivism of local capitalists against the central capital was strong. After the World War II, medium and small-sized hotels, having no hot spring rights, were united to get open access to the hot spring which had been under monopolistic possession of a few influential hotels. In consequence, a new hot spring boring was carried out and a new system of hot spring division (Tab. 3) was established, but the hot spring in possession of 21 Kadoyas, the opposition movement leaders, reached only 19.4% of the whole of Ikaho, whereas 4 Oyas continuing from the Edo era retained 38.0%. However, that plan of hot spring division was cancelled because of decrease in quantity of the hot spring. Thus, the monopolistic hot spring utilization system maintained by a few powerful hotels has been continued until today, which resulted in retarding development of the tourist industry. Besides, the 4 Oyas still hold vast area of land (Tab. 4), with complete control of the old hot spring settlement (Fig. 4). Ikaho Tourist Association, an actually ruling organization at Ikaho hot spring settlement, has practiced various kinds of tourist developments, but its ropeway and skate enterprises were placed under the supervision of Ikaho Town Office in 1967. Since then, the Town authority has positively coped with the development. Moreover, the local government opened the munincipal land to the small hotelowners at the old settlement and constructed the second Ikaho hot spring settlement (Fig. 2).