Collections of adult chironomids were carried out in Mongolia, Central Asia, located about midway between Europe and Japan, in August 1995 and also in August 1996. The specimens were preserved in 70% ethylalcohol, and individually mounted on slides in gum-chloral medium after digested in 10% hot KOH solution and dissected under stereomicroscope. A total of 345 male specimens were studied for species identification. As the results, a total of 42 species belonging to 23 genera were identified, among which 12 species are considered as belonging to the same one as those already recorded from Europe, and 11 species among them are also in common with those from Japan, and the rest 29 species are described here as new species. Three new genara were created in order to accept 4 new species among them.

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Metamorphosis of Trypanosoma rangeli during the migration in the insect host, Rhodonius prolixius, was first documented by scanning electron microscopy (SEM). After infection, the parasites reach the insect alimentally tract and then they penetrate into the mid-gut and eventually emerge in the hemolymph of the abdominal cavity. From the abdominal cavity, both the parasites and the hemolymph are propelled to the thorax by the dorsal vessel (aorta pump), the end of which is terminated very near the salivary glands. Thus, once these parasites invade the abdominal cavity, they finally appear in the salivary-glands via the transport by the dorsal vessel. The parasites gradually change themselves in shape during the migration. In the present study, we focused on the morphological characteristics of T. rangeli at individual stage in the vector by SEM and revealed some new findings in morphology and confirmed a migration route of this species. These results suggest that Guatemalan T. rangeli is mainly transmitted through the salivary gland.

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All structural protein genes as well as one of the nonstructual protein NS1 gene of four dengue virus serotype 4 (DEN 4) strains recently isolated from patients admitted to the Children's Hospital in Bangkok, Thailand in 1993, were sequenced and analyzed. Isolates from a dengue fever (DF) case, CT93-77, dengue hemorrhagic fever (DHF) grade I cases, CT93-129 and CT93-158 as well as DHF grade II case, CT93-74 were selected in this study. It was found that the DHF grade II isolate had the highest percentage sequence divergence in the PrM and M regions from the published prototype strain (Caribbean, 814669). In all four Thai isolates, the C region had the lowest divergence, while the PrM region had the highest divergence both in nucleotide and amino acid sequence. In the whole analyzed regions, the percentage divergence ranges from 8.02-8.33% (nucleotide) and 3.97-4.90% (amino acid) respectively. Three amino acid replacements were found to be specific to the DF strain : at position 136, phenylalanine (F) instead of leucine (L); at position 914, phenylalanine (F) instead of serine (S) and at position 1, 042, glutamine (Q) instead of histidine (H). The mean hydrophobicity and isoelectric point value did not show significant differences in the sequenced region for all analyzed isolates. When compare to other strains from different geographical locations, four amino acid replacements were found unique to the Thai isolates. These were at position 269, isoleucine (I) instead of valine (V); at position 374, methionine (M) instead of valine (V); at position 482, threonine (T) instead of lysine (K) and position 608, threonine (T) instead of alanine (A). Phylogenetic analysis using the M/E junction showed that DEN 4 from different geographical areas can be classsified into three genotypic groups, and the Thai isolates were divided into two genotypes.

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In vitro effects of extracts from the 5 species of Chinese herbal medicine against Trichomonas vaginalis, one of the most important protozoal diseases in China, were investigated. It was demonstrated that the extracts from Artemisia annua, Phellodendron amurense and Pulsatilla chinensis were highly effective against the protozoa at 1 to 5 hr after the start of the exposure to the drugs. The extract from Cnidium monnieri was much less effective and that from Sophora flavescens showed no activity even afterthe exposure for 5 hr. After this screening for excluding non-effective drugs, the parasites were exposed to all of the drugs except the extract from S. flavescens, the negative one in the above test, for 5 days at the drug concentrations lower than those above. The extracts from A. annua and P. chinensis were highly effective, immobilizing the parasites completely 2 or 3 days after the start of the exposure and afterwards. Contrarily, those from C. monnieri and P. amurense were not so effective. The results obtained in the present studies were in favour of the prospect that further studies including those on side effects, would be worthy of being carried out for the establishment of the chemotherapy of T. vaginalis infection with the crude drugs from medicinal plants in China.

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Stool and urine examinations revealed eggs of Schistosoma haematobium in a 31-year-old asymptomatic Japanese female returned from Africa. She was treated with praziquantel, and good therapeutic result was obtained. However, as S. haematobium is not indigeneous to Japan, most Japanese doctors and medical technologists are unfamiliar with this parasitic disease, they need to be reminded of its existence when they encounter persons who have visited or resided in endemic areas, and of the necessity of urine and stool examinations of such persons.

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