Twelve healthy male nonathletic university students were selected as subjects. Anthropometric measurement and a work capacity test using a bicycle ergometer in a climatic chamber of 30°C and 60% R. H. were carried out in summer and winter. Observations of the physiological responses of the subjects were made while pedalling a bicycle ergometer at a constant work load of 50% Vo₂max and at a cycling rate of 50 rpm for 30 min in a climatic chamber of 30°C and 60% R.H., in summer. The subjects took the same exercise for 13 successive days except the day after training, for 6 days in a climatic chamber of 30°C and 60% R.H., after the work capacity test was tested in winter. Body weight and skinfold thickness showed a tendency to decrease in summer. Vo₂max per body weight was considerably greater in summer than in winter though this difference was statistically not significant. Na concentration in sweat and the increase in heart rate during exercise were significantly lesser in summer than in winter. Sweat volume induced by exercise increased and rise in rectal temperature during exercise showed a tendency to decrease in summer. Increase in heart rate during exercise was decreased significantly by physical training. Sweat volume during exercise tended to increase and rise in rectal temperature during exercise tended to decrease progressively during physical training. Decrease in heart rate during exercise induced by physical training was greater than that induced by climatic heat acclimatiztion, while decrease in Na concentration of sweat due to climatic heat acclimatization was greater than that observed during physical training. Indices representing the magnitude of strain including relative increase in heart rate, relative rise in core temperature and relative water loss are proposed for the assessment of work capacity in heat.

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We made a comparative study on serum biochemical values of mature Mongolian gerbils between the wild-colored (agouti) and the coat color mutants of both sexes by autoanalyzers. The coat colors of the mutants were white spotted-agouti, albino, black and white spotted-black. All of serum biochemical values we measured of different coat color gerbils were not significantly different each other. We did not find any lipemic sera and any hyperglycemia in all coat color gerbils. Compare to the other common laboratory rodents, patterns and values of serum protein fractions of the gerbils were different. Namely, A/G ratios and rates of y-globulin fraction of gerbils were much higher than those of mice and rats and were the same as those of human beings.

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A seroepidemiological study of the prevalence of malaria, employing the frequency distribution curve of ELISA titers, was conducted. Comparison of the shape of the curves obtained in the two villages in the Sudan before and after the flood of the Blue Nile in 1988, clearly demonstrated the existence of certain malarial foci which might pose a potential risk for development of malaria epidemics in the area, although these malarial foci could not be detected by either slidepositivity rate or seropositivity rate. Thus, application of this method is of considerable value in identifying latent malarial foci where control measures should be strengthened.

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The Indian colony under study is located in relatively inaccessible part of the Amazonian jungle, restricting frequent visits. Malaria survey in such a community requires methods which would yield reliable results even from a single visit. Malaria was regarded as a minor disease by the inhabitants who appeared to be free from malaria. The reported incidence was very low, and in fact, no parasitemia was detected in the blood smears of a group of inhabitants obtained through our short visit. But on the contrary, an avidin biotin peroxidase complexed enzyme-linked immunosorbent assay (ABC-ELISA) revealed a 100% prevalence of malaria antibodies in the population. Therefore, serological studies which can obtain the period prevalence are useful for the assessment of malaria situation in the highly endemic community which is not readily accessible, or whose populations seem to have acquired a certain degree of immunity depressing parasitemia to submicroscopic levels.

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Chagas' disease, a chronic parasitic disease caused by the protozoan Trypanosoma cruzi, is one of the endemic diseases in Central and South America. In Bolivia its seroprevalence is very high and the most common digestive manifestation of chronic Chagas' disease is megacolon.
A new protocol for the surgical treatment of Chagasic megacolon has been started in Santa Cruz General Hospital. It consists of a peri-operative management, a choice of operative technique and a long term follow-up.
From July 1989 to August 1992, among 46 Chagasic seropositive megacolons, 37 definitive operations of colorectal resection and anastomosis were perfomed. Although five cases developed early postoperative complications, there were no deaths in the group which had definitive operations.
The purpose of this study is to establish a standard surgical management for Chagasic megacolon in Bolivia.

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In the summer of 1993, an epidemic of aseptic meningitis had broken out in Okinawa island, the southernmost area of Japan. It started in June (or probably in May), reached a peak early in July and subsided in August. A total of 216 specimens (cerebrospinal fluids, throat swabs and sera) was collected from the patients with aseptic meningitis and viruses were recovered from 83 specimens (38.4%). Five isolates randomly selected were examined for the identification of the virus. The virus was identified as echovirus type 30 (echo-30) by plaque reduction neutralization test using enterovirus antiserum pools and monospecific antiserum. Large-plaque and small-plaque phenotypes of echo-30 were isolated. The two were neutralized by anti-echo-30 sera. For the plaque assay of echo-30 in RD-18S cells, the use of tragacanth gum for the overlay medium could reduce the incubation period to 25-30 hr.

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The positive rate of Dirofilaria immitis infection was studied in the eastern, western, southern and northern parts of Nagasaki City 3 times between 1968 and 1983. Chronological changes in the positive rate of dogs for microfilariae in these 4 parts and the roles of epidemic factors in the changes of the positive rate were evaluated. The positive rate decreased in the northern part, where houses and buildings increased annually, whereas the number of dog owners and the density of dogs decreased. Improvements in the drainage such as side ditches, which are primary breeding sites of vector mosquitoes (Culex p. pallens), are assumed to have led to a decrease in the mosquito density, resulting in a decrease in the positive rate of dogs. However, the positive rate increased in the eastern, western, and southern parts. The density of dogs decreased also in these parts, but it remained higher than in the northern part as the number of houses was smaller, and more people kept dogs. Also, as the sewage system did not seem to be so well developed as in the northern part, more mosquitoes might be present. The high positive rates in these parts may be ascribed to these conditions.

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An ultrastructural study of African endemic Kaposi's sarcoma (KS) of the skin and lymph nodes revealed an irregularity of blood vascular tissues and prominent diapiresis of erythrocytes in the early stage of the disease. In the advanced stage, incomplete blood capillary structures covered with primitive mesenchymal cells were observed. Erythrophagia was frequently seen. These results suggest that KS cells are derived from primitive mesenchymal cells which may differentiate to immature endothelial cells.

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Halofantrine, a phenanthrene derivative, has been used for the treatment of human malaria since 1984, and reported to be effective against all parasite species without any major side effects. The chemical structure of the drug is unique and not closely related to any other antimalarials, therefore, it is particularly effective for the treatment of the wide-spread drug resistant malaria. Four cases of imported falciparum malaria, including chloroquine and pyrimethamine resistant malaria, were treated with halofantrine and reported in this paper. Halofantrine cleared parasites and fever of all the cases rapidly and produced salutary symptomatic improvement of the patients. No adverse reactions were recognized after the administration of the drug, nor was there recrudescence. Fansidar is the only antimalarial drug commercially available in Japan, and imported drug resistant malaria not only against chloroquine but also Fansidar has been on the increase. The general use of halofantrine is thus expected in Japan.

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Sexual mosaics were found in eight adult Japanese blackflies, i.e., two Simulium arakawae Matsumura, 1921, four S. bidentatum (Shiraki, 1935), all collected from cattle sheds while biting, and two S. aokii (Takahasi, 1941) which emerged from pupae. They were distinguished into three types, i.e., bilateral, antero-posterior and other types of gynandromorph.

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